ISSN 0289-842X

RIKEN
Accelerator
Progress Report
vol.

30

理化学研究所

The Institute of Physical and Chemical Research (RIKEN)RIKEN Accelerator Progress Report iI(Q)(Q)L.

January-December

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The Institute of Physical and Chemical Research (RIKEN)
Wako-shi, Saitama, 351-01 JAPANEditors
A. GotoT.Ichihara

T. Kambara

T. Kobayashi

Y. Kobayashi

T. Okada

I. Shimamura

M. Takami

S. Yamaji

F. Yatagai

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
I.

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

II.

OPERATION OF ACCELERATORSRRC and AVF Cyclotron Operations

3

RILAC Operation ..................................................................

5

The Tandem Operation

7

III.

RESEARCH ACTIVITIES

1.

Nuclear Physics

Distribution of the Gamow-Teller Strength in 11 Li

9Stochastic Variational Method with Non-Central Potentials. . . . .. . . . . . . . . . .. .. . . . . . . .

10

Occupation Probability of Harmonic-Oscillator Quanta for Microscopic
Cluster-Model Wave Functions..... .. ...... .. ... ... . .. .. ... ........... ..... ...... ...

11

Reaction Cross Sections and Radii of A = 17 and A = 20 Isobars

12

New SU(3) Symmetry in Superdeformation, Hyperdeformation,and Highly-Deformed Shape ........................................................

13

Origin of tlI = 2 Staggering in Superdeformed States ................................

14

Role of the Xo Factor of Skyrme Force in the Interaction Radius of Extremely
Neutron-Rich Nucleus ...............................................................

15

A Modified Second Order Glauber Model Calculation of the Interaction Cross
Sections of Extremely Neutron Rich Nuclei... ............. ...... .. ... ...... .. ... ....

16

Electric Dipole Transitions in Neutron Capture and Coulomb
Dissoeiation Processes ... . . ....... .... ................ ........................ ..... .

17

Quantum Monte Carlo Diagonalization Method for Nuclear Many Body Problem ....

18

Spreading of Gamow-Teller Resonance in 90Nb and 208Bi ............................

19

Two-Dimensional GCM Calculation of TAR States..................................

20

Variation of Transport Coefficients for Average Fission Dynamics with
Temperature and Shape .............................................................

21

The Continuity Equation of the Nuclear Four-Current ...............................

22

Unstable Nuclei and the Equation of State of Asymmetric Nuclear Matter

23

Effect of Relativistic Equation of State on Vortex Pinning to the Nuclei in
Neutron Star Crusts ................................................................

24

Baryon Properties Based on the Chiral Quark Soliton Model ........................

25

QCD Corrections to the Structure Function g2 ......... .......... ......... ..........

26

Next-to-Leading-Order Q2 Evolution Program for Spin-Dependent
Structure Functions .................................................................

27

Q2-Evolution of the Chiral-Odd Twist-3 Parton Distributions hL(X, Q2) ande(x, Q2) in the Large Nc Limit ......................................................

28

Q2-Evolution of Chiral-Odd Twist-3 Structure Function and Fragmentation
Function: e(x, Q2) and e(z, Q2) .....................................................

29

Quark Helicity Distributions Using QCD Sum Rule Approach .......................

30

Quark Helicity in Proton by Semi-Inclusive Asymmetries of Kaons ................. ...

31

Test of flg in Spin Correlations between Target Protons and Produced A~
at COMPASS Experiment..........................................................

32

RHIC Spin Project .................................................................

33

Spin Physics with PHENIX Detector System at RHIC ...............................

34

Study of Polarized Parton Distribution Functions in the Nucleon ....................

35

R&D of Iarocci Tube for RHIC Spin Project ........................................

36

Measurement of Neutrons from Muon Catalyzed dt Fusion Reaction
at RIKEN-RAL Muon Facility ......................................................

37

Muon Thansfer in Excited States of Muonic Hydrogen Atoms Observedwith X-ray Measurement........................................... .................

38

Measurement of X-rays from a-Sticking in Muon Catalyzed dt Fusion Reaction
at RIKEN-RAL Muon Facility ......................................................

39

Experimental Study of CSB Force in N-d Scatterings at 12 MeV. . .. ... .. . .. ........ .

40

Cross Sections ofaxn Channels in the 40 Ar + 209Bi Reaction .........................

41

High-Spin States in 146Eu ...........................................................

42

Study of High-Lying States in 147Eu ................................. . . . . . . . . . . . . . . . .

43High Spin Isomer Beam Line.... ........................ ........ ...... ..............

44

Measurement of Deuteron Spin-Flip Probability in the 12C(J: J ') Reactionat Ed=270 MeV....................................................................

45

Measurement of Polarization Correlation Coefficient forthe 3He( d, p )4He Reaction ...........................................................

46

Spin-Flip Dipole State of 90y Studied by the 90Z r (d , 2He) Reactionat Ed=270 MeV....................................................................

47

Production Cross Sections of Projectile-like Fragments in the 4BCa + 64Ni and
4BCa + 1B 1Ta Reactions at 70A MeV. ... ... ... .. ... ... .. . .. ... ... .. ... .. . ... .. ......

48

New Neutron-Rich Isotopes 3BMg, 40 AI, and 41 Al Produced by Fragmentationof a 70A MeV 4BCa Beam............................................. . .............

49

Isomer Production in Fragmentation Reactions Induced by
a 70A MeV 4BCa Beam.............................................................

50

Angular Distribution of the BB Dissociation and E2 Components ....................

51

Charge Exchange Reactions of Neutron-Rich Nuclei .................................

52

Quasifree Nucleon-Knockout Reactions from 6He and 11 Li ...........................

53

Reaction Cross Sections Measured for BB to Obtain Its Density Distribution .........

54

Momentum Distribution of 7Be Produced through BB Fragmentation ................

55

Electromagnetic Dissociation of 8B at 2A Ge V ......................................

56

Nuclear Radii of N a and Mg Isotopes ...............................................

57

Beta Decay of 11 Li .................................................................. ' 58

2.

,B-Delayed Neutron Decay of Spin Polarized 17B .....................................

59

Measurement of ,B-decay Branching Ratio of 17Ne into the First
Excited State of 17F ................................................................

60

Magnetic Moments of 17N and 17B ..................................................

61

Quadrupole Moment of 23Mg ........................................................

62

Asymmetry Parameter of 23Mg Beta Decay .........................................

63

Development of Polarized 129Xe Solid for Polarizing Unstable Nuclei

64

Production of a Low Energy 12B Beam and Observation of
its Nuclear Polarization .............................................................

65

Atomic and Solid-State Physics
Inelastic Processes in Collisions of H+ Ions with C, N, and 0 Atoms below 1 keY

67Electron Capture Rates in Collisions of H+ Ions with Si Atoms: Captureby the ground and excited state .....................................................

68

Charge Transfer in Collisions H+ Ions with Ground State Mg Atom at
Low ke V Collision Energies .........................................................

69

Triple-Center Expansion Study of Ionization Processes ..............................

70

Elastic and Inelastic Processes in H+ + C 2H 2 Collisions below 1.5 keV Regime .. . . . . .

71

Double Electron Detachment from Negative Hydrogen Ions under High Energy,
Highly Charged Ion Impact .........................................................

72

Theoretical Study for Absorption and Emission Spectra of Alkali Atom andLiquid-He Composite System .......................................................

73

Photodetachment Cross-Sections of the Positronium Negative Ion...... .. ... .. . ... ...

74

Recoil-Ion Momentum Spectroscopy of 0.25 MeV/nucleon Ar-He Collisions ..........

75

Recoil-Ion Momentum Analyses of Single-Electron Capture of He by B 4 +,5+
at 0.5-1 MeV/nucleon ..............................................................

76

Beam Foil Spectra of Highly Charged Argon Ion in Visible Region ...................

77

Beam Foil Spectra of Highly Charged Neon Ion in Visible Region ....................

78

Intercombination Line Oscillator Strengths for High-Z Mg- and AI-like Ions. . . . . . . . . .

79

Lifetimes for the Be- and B-like Fe Intercombination Lines ..... . . . . . . . . . . . . . . . . . . . . . .

80

Oscillator Strengths for Resonance Transitions in Na-like Kr .........................

81

Wavelengths for AI- and Si-like Intercombination Lines ..............................

82

Charge Transfer Cross Sections of Low-Energy Highly Charged Ions with N2 .........

83

Diode-Laser Spectroscopy of Atomic Beams .........................................

84

Laser Spectroscopy of AgHe2 Exciplex in Liquid Helium... ..... ... ... .. ... ..........

85

3.

Temperature Dependence of AI-LVV Auger Electron Spectra (I) .....................

86

Temperature Dependence of AI-LVV Auger Electron Spectra (II) ....................

87

Mossbauer Spectroscopy using 57Mn Beam from RIPS.......... ........ .............

88

Hyperfine Interactions of 61 Ni in Distorted Spinel Chromites .........................

89

Magnetic Properties of YSr2Cu3-xFex07+8 and Effects of Hot Isostatic Pressing .....

90

57Fe Mossbauer Spectroscopy of CU1-xFexGe03 .....................................

91

61 Ni Mossbauer Spectroscopy of LiNi0 2 and NaNi02 ................................

92

Effect of 4s Electrons on the Electronic State of Ni 3+ Ions in LiNi02 and NaNi02 ....

93

Channeling Study on H in Nb-Mo Alloys ............................................

94

j.L+SR Study of Polaron Motion in Polyaniline .......................................

95

Magnetic State of TIBa2 Y 1-xCaxCuOy Studied by IL+SR ............................

96

Evidence for Muonium Passivation in n-Doped Ge ........ . ...................... ....

97

j.LSR Study on the Two-Leg Ladder Compound, La1-xSrxCu02.5 .....................

98

Bose-Glass Transition of the Heavy-Ion Irradiated La1.85Sro.15Cu04
Single Crystal ......................................................................

99

Heavy-Ion Irradiation Effects on the Super-Conducting Material, La1.85Sro.15Cu04 ...

100

Studies of Columnar Defects in Bi2Sr2CaCu20x by TEM and STS ...................

101

An Evaluation of Single Event Upset on Memories.... .. ...... ..... ... ..... ...... ....

102

Radiochemistry and Nuclear Chemistry
In-Beam Mossbauer Study on Jump Processes of Self-Interstitial in Pure Iron
after 56Fe(d, p) 57 Fe Reaction ........................................................

103

In-Beam Mossbauer Spectroscopy on 57Fe in Solid Ar and Solid Xe after
Coulomb-Excitation and Recoil-Implantation... ..... ...... .. ... ... ........ ... .. .....

104

Simultaneous Determination of Biobehavior of Sc, Mn, Fe, Co, Zn, Se, Rb, Y, andZr in Mice Bred under Different O 2 Gas Percentage Circumstance ...................

105

Uptake Behavior of Multitracers in LEC Rats before Jaundice Development (II)106

In vivo Behavior of Various Elements in Hepatopathic Animals (I)Metabolic study of trace elements in acute alcoholic mice ............................

107

In vivo Behavior of Various Elements in Hepatopathic Animals (II)Metabolic study of trace elements in liver-cancer bearing rat. . . . . . . . . . . . . . . . . . . . . . . . .

108

Accumulation of Inorganic Elements in the ddY Mice Implanted with
Ehr lich Sarcoma ....................................................................

109

Metabolic Study of Trace Elements in Se-deficient Rats ............ . .................

110

Metabolic Study on Ca-deficient Rats Using a Multitracer ...........................

111

In vitro Binding Assay of the Trace Elements in Bovine Serum Proteins ..............

112

Binding Activity of Various Metallic Elements to Blood Components ................

113

4.

5.

Beneficial Effect of Rare Earth Elements on the Growth of Dryopteris erythrosora .. . .

114

Influence of Aluminum on the Uptake of Various Cations from a Solution
into Carrots ........................................................................

115

Translocation and Re-distribution of Radionuclides from the Leaf Surface
in Plants ...........................................................................

116

Studies on Some Parameters that May Influence the Uptake of Radioisotopes
by Plants from the Soil .............................................................

117

Uptake Rate of Trace Elements by Soybean Plant ...................................

118

Multitracer Studies on the Extraction of Noble Metals with N,N-Dialkyl
Aliphatic Amides from Nitric Acid Solutions ........................................

119

Separation of a Multitracer from the Gold Target Irradiated with High-Energy
Heavy Ions by Means of a Supported Liquid Membrane................ ..............

120

Multitracer Study for the Effect of Humate Formation on the Adsorption Behaviorof Metal Ions on Kaolinite and Silica Gel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .

121

Model Study of Acid Rain Effect on Adsorption of Trace Elements on Soils (I) .......

122

Model Study of Acid Rain Effect on Adsorption of Trace Elements on Soils (II) ......

123

Linear Momentum Transfer in the Heavy-Ion Reactions at Intermediate Energies

124

Preparation of Positron Emitter Sources for Slow Positron Generation by
the Bombardment of a Liquid or Gas Target ........................................

125

Measurement of Spin Polarization of Positron Beam

126

Radiation Chemistry and Radiation Biology
An Effective Mutation Method for Plants Using Heavy-Ion Beams

127

Physical Characteristics of Irradiation Field for Proton Radiotherapy ................

128

Decay Enhancement of Self-Trapped Excitons at High Excitation-Density and
Low Temperature in an Ion-Irradiated BaF 2 Single Crystal ..........................

129

Effects of Ne Ion Beams on Survival of Arabidopsis thaliana .........................

130

Response of Radio-Sensitive Mutant Cell Line against Heavy-Ion Beams .............

131

LET Dependence of Interphase Cell Death Induction for CHO Cells Exposed to
Accelerated Heavy-Ions .............................................................

132

Analysis of the Mutations in Human HPRT Gene Induced by
Heavy-ion Irradiations (III) .........................................................

133

Mutation of Human Cancer Cell-Line Caused by Heavy-Ions and X-Rays

134

Instrumentation
A Rotating Target System for High-Intensity Heavy Ion Beams

135

Windowless Gas Target for High-Spin Isomer Beam Production...... ... .. ... ... ... ..

136

Ge Telescope for "(-Ray Doppler Correction ..........................................

137

Development of a Polarized 3He Target System. ...... .. ... ........ ... ... .. ...... ... .

139

Performance Study of a Phoswich Detector in the Mixed Field of Neutrons andCharged Particles ...................................................................

141

6.

7.

IV.

Proton-Knockout (p,2p) Reactions from 12C with Normal and Inverse Kinematics. .. .

142

Development of a MUSIC (MUlti-Sampling Ionization Chamber)-type Detector for
Identification of Low Energy Nuclear Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

143

Toroidal Spectrometer for Measurernent of Emitted Electron Spectra Arising from
Collisions between Highly Charged Ions and Neutral Atoms ......... . ...............

145

Mounting of a CCD Detector on the Rowland Circle of a Grazing-Incidence
Spectrometer for Use in Beam-Foil Spectroscopy. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .

146

Proton Beam Test of Cosmic Ray Telescope for the First Brazilian
Scientific Satellite ................................... . ...............................

147

Development of a Liquid Argon Ionization Chamber with Excellent Energy
Resolution for High Energy Heavy Ions . ... .. .... .. . .. .. ... ... .. ... ... .. . .. ... ... ... .

148

Collinear Laser Spectroscopy of Li-like 11 B Beam. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

149

Development of an On-Line Laser Ion Source .......... , .. . ... ... ..... . .. ... . . ... .. . .

150

Completion of Tritium Gas Handling System for Muon Catalyzed Fusion
Experiment at RIKEN-RAL Muon Facility......... . ...................... .. ...... ..

151

Compact CAMAC Data Acquisition System with ACC K3976 and PC-Linux . .......

152

Evaluation of UNIX DAQ System (UNIDAQ) on VME ................. . ....... . ....

154

Computing Environment around the Accelerator Research Facility... .. .... .. .. ... ...

155

Fabrication of the Muon Magnet for the RHIC Spin Project

156

Material Analysis
Development of an In-Air High-Resolution PIXE Syst em

159

Positron/Positronium Annihilation in Nanocrystalline Si ............. . ...............

161

Development of a TOF-ERDA System for Wide Mass Range

162

MiscellaneousStrong X-Ray Emission due to a Charge- Up Effect163

Residual Radioactivity Produced by 2.9 MeV/nucleon a-Particles. ..... . .. . .. ... . . . ..

164

NUCLEAR DATA

Status Report of the Nuclear Data GroupV.

165

DEVELOPMENT OF ACCELERATOR FACILITIES

Production of 48 Ca Ions in 10 GHz ECRIS ..... . ................. . ..................

167

Present Status of RIKEN 14.5 GHz Caprice ........................... . .... . ........

168

RIKEN Duoplasmatron Ion Source: The performance characterization andbackground physics .................................................................

169

Recent Progress in ECRIS Physics Study: Radial distribution of negative potential,
hot ring , and instability .............................................................

171

Beam Optics Study of Superconducting Solenoid Focusing in RI Beam
Production Beamline ................................................... . ..... . .....

173

A Liquid He-Free Solenoid for RI Beam Production .......... .. ......... . ...........

175

Study of Spin Dynamics for RHIC Spin Project .....................................

176

Optimization Method Using 2D Analysis in Helical Dipole Magnets for RHIC

178

High Current Design of Superconducting Helical Dipole Magnets for
RHIC Spin Project .................................................................

180

Field Analysis of a Helical Dipole Magnet ...........................................

182

Analytical Field Calculation of Helical Coils for RHIC Spin Project183

Observation of Slow Transient Effect of Magnetic Field Gradient in
RIKEN Ring Cyclotron Magnet .....................................................

185

Commissioning Run of a New Injector System for RILAC ...........................

186

Development of RIKEN 18 GHz ECRIS .............................................

188

Performance Tests of a Variable-Frequency RFQ Linac for RILAC ...................

189

Beam Matching Section in the New Injector for RILAC ..............................

191

Maximum Beam Current in a Low-Energy Transport Line.......................... .

193

Progress of RIKEN RI Beam Factory Project .......................................

195

The Superconducting Ring Cyclotrons for RIKEN RI Beam Factory.. ... .. ... ... .. ..

196

Design Study of Sector Magnets for RIKEN Superc~nducting Ring Cyclotron (I) .....

197

Design Study of Sector Magnets for RIKEN Superconducting Ring Cyclotron (II) ....

199

Design of a Model Sector Magnet for RIKEN Super conducting Ring Cyclotron.. ... ..

201

Design Study of Injection System for RIKEN Superconducting Ring Cyclotron (I) ...

203

Design Study of Injection System for RIKEN Superconducting Ring Cyclotron (II) ...

205

Design Study of Injection System for RIKEN Superconducting Ring Cyclotron (III)Analysis of the injected beam trajectories ...........................................

207

Optimization of Trim Coils in a Superconducting Ring Cyclotron ....................

209

Design Study of the Accumulator Cooler Ring for MUSES.. ... ..... ... .. . ........ ...

211

Design Study of Electron Cooling for ACR in MUSES ...............................

213

Design of the Booster Synchrotron for MUSES ......................................

215

Design of the Double Storage Rings for MUSES .....................................

217

Expected Luminosity at MUSES ....................................................

219

One-Dimensional Compensation Scheme for Beam-Beam Effects .....................

221

Hamiltonian Treatment of Nonlinear Beam-Beam Resonances.. .. . ... . .. .. ... ... .. . ..

223

Beam-Beam Instability due to Noise in Opposing Beam Size. .... ... .. ... . .. ........ .

225

Beam Emittance Growth in Storage Ring due to the Ground Noise ..................

227

Simulation of Beam Bunching by Electron Cooling for DSR in MUSES ..............

229

An RF System for the Electron Beam at DSR .......................................

231

An Undulator for Elliptically Polarized X-ray Beam Line at DSR ....................

233

Calculations of Radiation Shield for RIKEN RI Beam Factory .......................
VI.

235

RADIATION MONITORING

Leakage Radiation Measurements in the Ring Cyclotron Facility.. ........ ... ..... ...

237

Dose Rates due to Residual Activities in the Ring Cyclotron Facility. . . . . . .. . . . . . . . . .

239

VII.

LIST OF PUBLICATIONS ............................................................ 241

VIII.

LIST OF PREPRINTS ................................................................ 249

IX.

PAPERS PRESENTED AT MEETINGS ........................................... .... 251

X.

LIST OF SYMPOSIA ................................................................. 263

XI.

LIST OF SEMINARS ................................................................. 264

XII.

LIST OF PERSONNEL ........... . ................................................... 267

AUTHOR INDEX

I. PREFACE

This issue reports the research activities of the
RIKEN Accelerator Research Facility (RARF) during
the calendar year of 1996. The research programs havebeen coordinated in the framework of the project entitled by Multidisciplinary Researches on Heavy Ion
Science. The project involves a variety of fields such
as; nuclear physics, atomic physics, nuclear chemistry,
radiation biology, condensed matter physics in terms ofaccelerator or radiation , basic studies on energy production, basic studies on accelerator cancer therapy,
material characterization, application to space science,accelerator physics and engineering, laser technology,
and computational technology. The whole project involved 12 laboratories in RIKEN and more than 400
researchers including outside users.
Major research activities of RARF are based ona heavy-ion accelerator complex consisting of theK = 540 RIKEN Ring Cyclotron (RRC) and its subordinate accelerators, i.e., the energy-variable heavy
ion linear accelerator (RILAC) and the K = 70 Azimuthally Variable Fi~ld (AVF) cyclotron, which has
altogether delivered a beam time (on the target) of
more than 8000 hours through the year. Besides, theRARF carries out two international collaboration programs based on oversea accelerator facilities; one is
the muon science collaboration with the RutherfordAppleton Laboratory (RAL) and another is the spin
physics program in collaboration with the Brookhaven
National Laboratory (BNL) .
The year of 1996 should be marked as the 10th
anniversary since the completion of RRC. A memorial symposium was performed in November-96 anda booklet summarizing the 10-years' achievement wasissued. Taking this opportunity a brief summery isgiven below of the characteristic features and important achievement in our research programs spanned forthe 10 years followed by t he perspectives for the future.
The three accelerat ors currently available provide
heavy ion beams in a broad range of elements with energies covering from a few A Me V to 135A Me V. They
have been used in different configurations. Studies on
nuclear physics primarily utilized the RRC to exploit
the high-energy beams, while studies on other domains
often utilized the RILAC and AVF in their stand-alone
mode of operation. Nuclear physics composes nearly
half of the whole activities, while the other disciplines
combined compose another half.
In the domain of nuclear physics the primary emphasis has been placed on the studies of unstable nuclei by
exploiting powerful capabilities of radioactive beams.
Uniquely, three different types of radioactive beams,
namely; projectile-fragment (PF) radioactive beam;

spin-polarized radioactive beam; and high-spin isomerbeam, have been developed to facilitate broad typesof experiments. Major subjects pursued are: 1) exotic nuclear structure and new dynamics of extremely
neutron-rich nuclei (such as with neutron halo or skin) ,2) nuclear astrophysics involving unstable-nucleus reactions, 3) synthesis of new unstable isotopes far fromthe valley of stability, 4) extensive measurement of nuclear moments, and 5) challenge to high spin physics
by means of isomer beams. A variety of experimental methods have been cultivated, and many new findings have been revealed. These studies constitute animportant portion of the frontier of radioactive-beamexperiments, which is a world-widely emerging field in
the contemporary nuclear physics.
Studies on nuclear physics have been also performed
utilizing the primary beams, where the RRC's characteristic beam energies around 100A Me V was mostappreciated to pursue spectroscopy with direct reactions. In particular, a polarized ion source of deutrons
has been developed, and spin-isospin responses of different modes were studied by means of (d,2He) and(d,d(O+)) reactions. Similarly, heavy-ion exchange reactions have been proved to be a useful means for investigation of spin-isospin response.
The RARF has offered a rich capability for atomic
physics research with beams of an extremely wide
range of highly charged ions as provided by the combination of the ECR ion source, RILAC: and RRC. Spectroscopy of multiply-excited atomic states and study
on collision dynamics of highly charged ions have been
extensively pursued in various aspects. As for recent
developments, a high precision recoil-ion momentum
spectroscopy has been developed to open up a new
possibility of final-substate-resolved differential analysis of high-energy reactions. An extensive program ofbeam-foil spectroscopy for highly-charged heavy ions isin progress. Irradiation effect of energetic heavy ionson materials is another subject of current interest, andphysics of columnar defects is studied in relation topinning phenomena of high-T c superconductors.
The research of nuclear chemistry and condensedmatter physics has involved two main domains: One
is the microscopic analysis or characterization of condensed matter using accelerated beams and radioactive sources, and another is the application of radio
isotopes as a tracer. In the first category, the condensed matter study by means of channeling effect has
been a unique program consistently pursued. Studiesof Moessbauer spectroscopy and of perturbed angularcorrelations have also been promoted with a current
emphasis on in-beam Moessbauer methods with 57Fe
1

and 57Mn sources. In the latter category, a remarkable development has been accomplished on a novel
methodology of multi-tracer. The method utilizes auseful feature of high-energy reactions which allows
easy production of mixed sources of different radioactive elements to trace the circulation of a variety ofelements in the same time. Application of the multitracer method is now developing over the broad fieldsof bio-inorganic chemistry, dietetics, toxicology, pharmacology, environmental issues, and medical fields ingeneral.
Irradiation effects of high-energy heavy-ion beams
are studied in several aspects. The most important has
been the research on radiation biology. Effects of highLET are studied for biological samples. Basic studies
for the heavy-ion-beam cancer therapy were conductedin collaboration with National Institute of Radiological
Science to offer basis for practical medical operation.
As a remarkable recent finding, a striking mutagenic
effect has been observed on the embryo of a tabacco
plant shot by heavy ions. This presents a new possibility in the mutation research featuring an efficientand well-controlled method in terms of heavy-ion irradiation. Another important research concerns thespace technology. High-energy heavy ions from RRC
served as a good simulator of cosmic rays in space. In
particular, studies of radiation effect on electronic devices are made in collaboration with National Space
Development Agency of Japan.
Naturally, the whole research activities and the qualities of outcomes have strongly depended on capabilities of the accelerator facilities. Continuous efforts of
upgrading the capabilities have been pursued. Most
recently, a set of a 18 GHz ECR ion source and afrequency-variable RFQ linac has been completed andreplaced the upstream end of RILAC system, which
drastically improved beam intensities of the accelerator. Besides, beam of 48Ca has been initiated and acceleration of other rare isotopes including uranium is inpreparation. Also, emittance of the PF beam has been
improved significantly by installing a super-conducting
solenoid along the beam line.
The accelerators at the RARF focus on heavy ionsby emphasizing the aspect of intermediate-energy andintense beams. Beyond this capability the RARF tries
to coordinate international research programs for utilizing oversea facilities. Two such programs are ongoing. The muon science program at RAL is based on
the muon beam facility constructed at the site of the
proton synchrotron (ISIS). The operation has started
since 1995 to carry out versatile research programs using powerful pulsed muon beams. Problems of themuon-catalyzed fusion have been studied among others. Another international project is on relativisticenergy spin physics which is to be carried out at BNL
by facilitating spin-polarized proton beams at RHIC.
The program aims at investigation of quark-gluon spin
structure functions and related properties of nucleons.
The project was initiated in 1995 and construction of
apparatuses is in progress.
To conclude shortly, we believe, the RARF has beensuccessful in promoting productive activities over a variety of research fields , which have contributed considerably to open up and advance new frontiers of heavyion science. In particular we are proud of our contribution to the development of the science to use radioactive ion beams (RIB). With this belief we haveproposed a new project so called RIKEN Radioactive
Ion Beam Factory, which will promote global development of the next generation RIB science. After two
years of R&D research, construction of a superconducting cyclotron system with K-number around 1600
has been approved this year to start in FY 1997. The
new accelerator system will serve as an energy booster
for the existing RRC to achieve sufficiently high energy
beams of heavier elements, and thereby to produce PFradioactive beams over an extended range of unstable nuclei. The RARF has been determined further tostrengthen the international collaboration programs.
In this context , installation of a new RIKEN researchbranch called RIKEN BNL Research Center has been
approved to start in FY 1997 to intensively promote
the program on spin physics and RHIC physics. With
the approval of these new projects we can foresee enhanced development of our activities and thus an enlarged contribution to the world enterprise of heavy
ion science in coming years.

M. Ishihara
Director
RIKEN Accelerator Research Facility

2

II.

OPERATION OF ACCELERATORSRIKEN Accel. Prog. Rep. 30 (1997)

RRC and AVF Cyclotron Operations
M. Kase, A. Goto, T. Kageyama, 1. Yokoyama, M. Nagase, S. Kohara, T. Nakagawa, N. Inabe,
K. Ikegami, O. Kamigaito, J. Fujita, H. Isshiki,* H. Akagi,* R. Ichikawa,* N. Tsukiori,*
R. Abe,* K. Takahashi,* T. Maie,* T. Homma,* and Y. Yano

It has passed 10 years since the first beam of 21
Me V lu 40 Ar was extracted from the RIKEN Ring Cyclot ron (RRC) successfully. Figure 1 shows the statistics of the RRC operation during these 10 years. A
total of the operation time is gradually increasing after
the RIKEN Accelerator Research Facility (RARF) was
fully completed in 1990 and recently reaching to 6500
hrs in a year , which is a practical upper limit if holidays

and maintenance times are taken into account.
All the beams accelerated in these ten years arelisted in Table 1, together with their acceleration conditions and beam intensities. There appear more than
90 kinds of combinations of ion and energy. Theirmasses as well as their energies cover almost fully theavailable regions with the two injectors, AVF cyclotron
and RILAC.

Table 1. RRC Beams (1987-1996).
ION

q

p

H2
d
pol.d

Energy(MeV/u)RF(MHz)

Injector

150-21070-13570-13434- 39AVF

25 - 33
25 - 33
33
29133

AVF
AVF

1000
1000
300

AVF
AVF

280
50

Rll..AC

190
200

135
21

24
25
35
25-33
35
25-29
25-35
25-33
20-35
25-31
26-33
35
25-29
33
33
28

70-110

25-30

AVF

150

100

29

AVF

50

100
135
7.5

29
33
19

AVF

5
6
1000

7.5
9-40

19
19-34

80195

26/28
28
25
19
26
28
20

134
1001135

a

2

liB

2

15

5
6
6

70
42
70-135
42

12 C
\3C
14N

416

IS N

Iii 0

18 0
20 Ne

9

10
22 Ne
24 Mg
27 Al
28 Si

9/10
12
13
14

36 Ar
40 Ar

40 Ca
48 Ca
48 Ti
SO Ti
56 Fe
58 Ni

11-15
16117
14
18
20
24
9

70-10021-42
70-135
11-42
70-11580-1354270-100
37

26
70
7.6
80
90
10

59 Co

25
24

64Zn

20

95
80
21

6S CU

8118

7/17

84Kr

13 - 15
22
22
21

11-36
7.5
7.5

21 - 3122

7.5-26140Ce
166Er
170 Er181 Ta

32
24
37

16

130 Te119 Xe132 Xe136 Xe

21

28
26

AVF

Intensity(pnA)

Rll..AC

40

AVF

500
10
160
100
230
20

Rll..AC
AVF
Rll..AC
AVF
RILAC
AVF
AVF
Rll..AC
AVF
Rll..AC
AVF

30
300
70
380
17
70

Rll..AC

AVF
Rll..AC
Rll..AC
Rll..AC
AVF
Rll..AC
AVF
Rll..AC500
140-13
10130
0.7
4
18

AVF
AVF
Rll..AC
AVF
AVF

30
4
4

25
18125
20-33
19
19
18
19-28

Rll..AC

0.5

Rll..AC

3/0.5
6-0.8

18

RILAC

22
18
25

RILAC

Rll..AC
Rll..AC
Rll..AC
Rll..AC
Rll..AC

RILAC
Rll..AC

2-10

1.5
0.1

Sumijyu Accelerator Service, Ltd.

3

Construction Time

(Hours)Holidaysor Maintenance
Unscheduled
Shutdown
MachineTunning
Non-Nuclear
Physics Research

Nuclear Physics
Research

o
1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

(Year)

Fig. 1. Statistics of RRC operation from 1987 to 1996.

In 1996, a total of the beam service time was 5000
hrs. Most of the beam time (85%) was devoted tonuclear physics experiments and the rest (15%) to experiments in the other fields, such as medical science,
radio-chemistry, health physics, material science, biology, and atomic physics. The number of users forbiologic researches is increasing in recent years.
The AVF-RRC operation was performed for 150
days (80%) and the RILAC-RRC operation for 38.5
days (20%). The stand-alone use of the AVF cyclotron
was limited in this year, partly because the RILAC had
been shutdown since July 1996 due to the installationof its new pre-injector. A total of the AVF stand aloneamounted 500 hrs, being half of that in 1995.
As shown in Fig. 1, a total of the unscheduled shutdowns, which occurred frequently for a few years justafter the competition, minimized in 1992, and afterthat increased a little bit and in recent years reacheda constant around 300 hrs. There were a variety ofreasons for them until 1992, including serious vacuum
leaks of cooling water into a vacuum chamber of RRC.
On the other hand, in these four years , most of thetroubles have been concentrating on parts of the AVF
cyclotron (i.e. deflector, magnetic channel, and rf cavity).
In June of this year, a serious vacuum leak occurred inside a plasma chamber of the 10 GHz ECR ion
source. It was found that the coolant inside a coolingjacket of the sextupole magnet leaked into the chamber through a small hole on the surface of the jacket,
which had been produced probably due to some kindof spark. In a course of its repair, some sets of the
sextupole magnet bars, which had been composed ofmany small magnet-blocks (SmCo), were partly broken into pieces. After a temporary repair, due to the4imperfection of the sextupole magnet, the obtainable
beam intensity decreased down to half of the full performance in case of heavy ions. The sextupole magnet
was replaced with a new one in December 1996.
In May, a beam of 48Ca was successfully producedwith the 10 GHz ECR ion source. The same method
was used as that for 50Ti tried in 1995 in order tosave the quantity of enriched material. A beam of 70
MeV lu 48Ca was accelerated with the intensity of 4
pnA for ten days. As a result , new isotopes of 3 8Mg,
40 AI, and 41Al were found using the RIPS under theinternational collaboration with JINR (Dubna).
After the installation of a new pre-injector system
of RILAC (an 18 GHz ECR ion source and a variablefrequency RFQ linac) , a beam test , in the RILACRRC operation, began in December 1996. A beam of
7.6 MeV lu 36 Ar has been already upgraded as for theintensity on target up to 1 pp.,A , reaching the present
official limit. It is the first-step improvement of theaccelerators in aim of the new project , the RI beamfactory.
In this winter, a new focusing element (a superconducting solenoid, 6.8 Tm) will be installed in just frontof a production target of RIPS in place of the beamswinger. With the new device, a beam size on the target will be expected to be as small as 0.4 mm in adiameter, being 25% of the present value. In advanceof its installation, in the last summer , a table of theswinger system, which consists of two sets of dipole
magnets, was replaced with a movable one on threefloor rails. When the new solenoid is used, the swinger
system will move away from the beam line of the RIPS,
and give the space to the solenoid. The switch between
the new solenoid and the beam swinger will be easily
done.

RIKEN Accel. Prog. Rep. 30 (1997)

RILAC Operation
E. Ikezawa, M. Hemmi, T. Chiba, S. Kohara, T. Aihara,* T. Ohki ,* H. Hasebe,*
H. Yamauchi ,* and Y. Miyazawa
RILAC has been in a steady operation, and has supplied various kinds of ion beams for the experiments.
Table 1 gives the statistics of operation from January
through July 5, 1996. Table 2 summarizes the numb er of days allotted to individual research groups. The
percentage of the beam time used by RIKEN Ring Cyclotron (RRC) was about 34% of the total; the ions of
11 B 2 + , 14N3+, 40 Ar 5+ , 48T?+, 58Ni8+, 84Kr11+, and136Xe 15 + from RILAC were injected to RRC. Table 3
gives the statistics of ions used in this year. Total 19
kinds of ion beams were used for the experiments andbeam acceleration tests. The percentage of the beamtime to use metallic ions amounted to about 38% of
the total. Among them, a 103Rh16+ beam at the acceleration frequency of 35 MHz is new.
Table 1. Statistics of the RILAC operation from Jan. 1
through July 5, 1996.
Days

%

105

56.1

Frequency change

7

3.7

Overhaul and improvement

7

3.7

Periodic inspection and repair

13

7.0

Machine trouble00.0

Scheduled shut down

55

29.4

187

100

Beam time

Total

Table 2. Beam time allocated for individual researchgroups.
Days%

Atomic physics

37

35.2

Nuclear physics

14

13.3

Nuclear chemistry

4

3.8

Radiation chemistry

12

11.4

Accelerator research

2

1.9

Beam transportation to RRC

36

34.3

105

100

Total

Table 3. List of ions used in this year.
Ion
He
B
C
N
Ne
Ar
Ti
Fe
Ni
Kr
Y
Rh

Xe

Mass

Charge state

4
11
12
14
20
40
48
56
58
84
89
103
136

1,2
1,2,3
4
3
3
5, 6, 87
11
811, 13

14
16
15

Days
10

22
8
2
3
21
4
6
2
8
2
4
13

We had following machine troubles: (1) In the resonator No.6 , the thin copper sheets (each had 10 cm
wide, 7 cm long, and 0.3 mm thick) used for electriccontact were melted due to the too-high rf currents
with parasitic oscillation. This trouble rarely occurredat the acceleration frequency of 32 MHz or above andat the acceleration voltage of 200 kV or above. (2) A
sliding transformer was worn out in the filament power
supply dedicated for the final vacuum tube (No.1); replaced by a new one. (3) A high voltage power supply
for the final vacuum tubes had troubles; overhauled inthis summer. (4) The computer system controlling RILAC had troubles; the CPU card, memory cards, andthe DC power supplies were replaced by spare parts.
For the 8 GHz ECR ion source we have tested to
produce metallic ions employing so-called MIVOCmethod (metal ions from volatile compounds) .l) We
obtained the unstable beam currents of 500 enA for
Ni 6+ and 350 enA for Ru 10 + from volatile compounds
such as Ni(C5H5h and Ru(C5H5h. Also, we obtained
7 eJ-LA of the Fe6 + beam by use of the Fe(C5H5hvolatile compound.
The RILAC operation was temporarily discontinued by July 5, and an installation work of a new
pre-injector system consisting of a variable frequency
RFQ linac and a 18 GHz ECR ion source for the
RIKEN RI beam factory project started in July 8.
The existing beam transport line between the 450 k V
Cockcroft-Walton injector (equipped with 8 GHz ECRion source) and the rf resonator No.1 was modified,
and the new pre-injector was installed in parallel tothe existing injector. Figure 1 shows the layout of the
new pre-injector system for RILAC together with the

Sumijyu Accelerator Service, Ltd .

5injector

SL
PM
PM : Profile monitor
SL: Slit
Fe : Faraday cup
EM : Emittance monitor

o

1m

~

____________-L~3E~~~~~~W

Fig. 1. Layout of the new pre-injector system for RILAC together with the beamtransport line from the existing injector.

beam transport line from the existing injector. The
details of the new pre-injector system are reported inthis issue. 2- 4 ) The beam acceleration tests used the existing injector which started in the middle of October.
The beam service for user will be reopened in the middle of January 1997. A beam acceleration test with thenew pre-injector system was started in this November
for the gaseous ions.

6

References
1) J. Arje et al.: 12th Int. Workshop on ECR Ion Sources,
RIKEN , p. 136 (1995).
2) A. Goto et al.: RIKEN Accel. Prog. Rep. 30, 186 (1997).
3) O. Kamigaito et al.: RIKEN Accel. Prog. Rep. 30, 189(1997).
4) T. Nakagawa et al.: RIKEN Accel. Prog. Rep. 30, 188(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

The Tandem Operation
E. Vagi, K. Ogiwara, and T. Urai
The tandem accelerator was operated for 96 days except for the machine inspection, beam test , and so on
during the period from Nov. 1, 1995 to Oct. 31 , 1996.
The construction of beam lines for the PIXE, RBS, andchanneling experiments was completed. Here , PIXEand RBS stand for Particle-Induced X-ray Emission
and Rutherford Backscattering Spectroscopy, respectively.
Experimental studies on the following subjects are
made in progress.
(1) Rutherford Backscattering Spectroscopy (RBS)(a) Behavior of Xe atoms implanted into iron (Muon
Science Lab).
(b) RBS analysis of the polystyrene surfaces modified by ion implantation (Surface Characterization
Center) .
(c) Characterization of the oxide films grown on
SrTi0 3 (Surface Chemistry Lab).

(d) RBS study of multilayer films, welded steel, andoxides (Linear Accelerator Lab).
(2) Nuclear Reaction Analysis (NRA)(a) Lattice location of hydrogen in niobium alloys
by a channelling method (Muon Science Lab).
(3) Particle-Induced X-ray Emission (PIXE)(a) Application of PIXE to the biomedical and material sciences: Trace element analysis using energydispersive X-ray spectrometry, and chemical state
analysis using wave-dispersive X-ray spectrometry (Inorganic Chemical Physics Lab).
(b) Development of an X-ray detector (CyclotronLab).
(c) Development of an in-air high-resolution PIXE
system for chemical state analysis (Inorganic Chemical
Physics Lab).
(d) Channeling analysis of dopants in II-VI compound semiconductors (Muon Science Lab).

7

III.

RESEARCH ACTIVITIES1. Nuclear Physics

RIKEN Accel. Prog. Rep. 30 (1997)

Distribution of the Gamow-Teller Strength in llLi
T. 8uzuki and T. Otsuka[Neutron halo, GT f3 decay]
The distribution of the Gamow-Teller (GT) strengthin 11 Li is investigated. We study: 1) where we can find
GT strengths of the transitions 11Li (3/2 g .s . -) ----+ 11Be
(1/2-, 3/2-, 5/2-) and 2) quenching effects due to the~-h contribution. Connection with GT sum rule andeffects of the halo structure of 11 Li on the strength are
discussed. The shell gap between p-shell and sd-shell
is found to modify the structure of the distribution ofstrengths.
We, first , give the result of reinvestigation of thestructure of two-neutron halo in 11 Li 1) obtained fromthe recent two new measurements at RIKEN 2) and180LDE,3) which indicates more retardation of thetransition 11 Li ----+ 11 Be (1/2-, 0.32 MeV) than before:
log it = 5.67 ± 0.04 2) and 5.73 ± 0.03,3) respectively.
We change the probability of VP1/2 2 configuration, P(P1/2 2), by lowering the single-particle energy of 1S 1/ 2
orbit and study the variation of the calculated log it
values. We find that P (P1/22) for the two recent measurements is around 50% (45% 55%).
The GT sum rule 4 ) suggests 8,6- - 8,6+ =3 (N - Z) = 15,
where8,6± = 2:fl < flot± li > 12.
Within the p-shell, 8,6- = 15 and 8,6+ = o. Whenthe two P1/2 neutrons are excited into the 1S 1/ 2 shellwith probability 1-0' , then 8,6- = 15 0'+49/3 (1 - a)and 8,6+ = 4/3 (1 - a) . The sum rule remains valid.
The halo reduces the overlaps: (rrplvP1/2) = 0.85 and< 7r1S1/2Iv1s1 / 2 > = 0.625. When these halo effects
are taken into account , 8,6- (halo) = 13.7050'+ 12.677(1- a) and 8,6+ (halo) = 0.963 (1 - a). For 0'=50%,
8,6- (halo) = 13.191 and 8,6+ (halo) = 0.482. The sum
rule is not satisfied any more in the p-sd shell model
space. For neutron-rich nuclei, we can expect to observe in experiment mostly the 8,6 - .
We show in Fig. 1 calculated results of the GT
strength 8,6- for 11Li (3/2 g .s . -) ----+ l1Be (1/2 -, 3/2-,
5/2-) obtained in the p-sd shell model configuration
space with Millener-Kurath interaction [P8DMK2 5)].
Here, the single-particle energy of 1S 1 / 2 orbit is lowered
to increase the probability of the admixture of p5(sd)2
configurations to P (P1 / 22) = 55%. The 8,6- summed
up to the IA8 state in 11 Be is 10.58 (11.41) for thecase with (without) the ~33 contributions. Quenchingof the strength by 0.83 due to the coupling to the ~-hconfiguration is seen. The effect of the halo is to reduce the summed strength by 0.81. The strengths fromOp ----+ Op and sd ----+ sd contributions are mixed, resulting in the remaining of the strengths at higher energy.
Without the change of single-particle energies of the
sd-shell, the structure of the strength is much simpler
and there is little mixing between the two contribu-~ s (b) J<oL>J z"" • =nohaJowith ... "-"IithhaJo., '--'--..I.---'-----'------'-----'---'--~

o

5

10

15

20

15

30

3S

. , 0'--'--'---'----'----'-----'-2'---'-30-',,---1.
0

40

Ex{ MeV)Ex( MeV)

6.-~~~~~~~~;::::'-'(c) J <OL>J
'

z

t

5

2

.. ":d~:dl'-' ,
~

3

--- 0

T Mi.

,

2

0 1--

r--..J

Fig.
1.
(a) Calculated GT strength St3- for llLi
(3/2 g . s .-) --+ llBe (1/2-, 3/2 - , 5/2-) as a functionsof the excitation energy (Ex) of l1Be. The sum of
the strength within Ex = N - 0.5 rv N + 0.5 MeV (N= integer) is plotted. Black (White) histograms are
obtained with (without) the ~33 contributions. Here,the single-particle energy of 1s 1 / 2-shell is lowered to increase the probability of the admixture of p5(sd)2 configurations: P (p 7) = 55% (b) Effects of the halo on
S{3-. The black histograms obtained with the halo issame as in Fig. 1a. The white ones are obtained without the halo effects. (c) Same as in Fig. 1a for separate
contributions from Op --+ Op, and Is --+ Is and Od --+ Odtransitions.

tions. There is little contribution from the sd ----+ sdtransitions below Ex = EIAS. The narrowing of theshell-gap between the p- and sd-shells, thus, leads to a
spreading of the GT distribution.
In summary, we conclude that about 2/3 of the sum
rule value can be observed below Ex = E IAS . There isa preliminary report 2,3) describing that a substantial
GT strength was found around Ex = 18.5 MeV.
References
1) T . Suzuki and T. Otsuka: Phys. Rev. C 50, R555 (1994).
2) N. Aoi: preprint (RIKEN-AF-NP-240,241).
3) M. J. G . Borge et al.: submitted to Phys. Rev. C.
4) K. Ikeda, S. Fujii, and J. 1. Fujita: Phys. Lett. 3 , 271(1963) .
5) W.-T. Chou, E. K. Warburton, and B. A. Brown: Phys.
Rev. C 47, 163 (1993).
9

RIKEN Accel. Prog. Rep. 30 (1997)

Stochastic Variational Method with Non-Central Potentials
Y. Ohbayasi ,* K. Varga, and Y. Suzuki[Few-body systems, Stochastic variational method, Realistic potentials]
In a recent paper1 ) we have shown that the stochastic variational method (SVM) with correlated Gaussian basis provides an accurate solution for various fewbody systems. Applications of the SVM were, however, limited to central interactions so far. The real
challenge in nuclear few-body problems is the solution
with a realistic nucleon-nucleon interaction including
spin-orbit, tensor, etc. The application of SVM for realistic interactions is , therefore, a stringent test of theusefulness of the method.
We applied SVM calculations to the 3H and 4He
nuclei with the interactions V6 (1 , a· a , T' T , a· aT' T ,S, ST . T) and V8 (1 , a . a , T . T , a . aT . T , S, ST . T ,L . S, L · ST' T). For the triton, we used all partial wave
channels with (h , l2)L , (ll + l2 ::; 4) , and L = 0,1,2.
For the alpha particle, all partial waves ((h, l2)l12' l3)Lsatisfying h + l2 + l3 ::; 4, III - l21 2:: h2 ::; h + l2 'and L = 0, 1,2 have been tried. There are 3 spin and 2
isospin channels for the triton , and 6 spin and 2 isospin
channels for the alpha particle.
Basis setup for the SVM can be briefly described asfollows: Let us assume that the dimension of the basis
is K - 1.
(1) Generate N random candidates to find the Kthbasis function.
(la) Pick up a spin, isospin, and partial wave channelrandomly.
(1 b) Select the nonlinear parameters randomly froma "physically" important interval.
(2) Calculate the ground state energy on the K basis
states.
(3) Select the basis state which gave the lowest energy among the randomly generated trial functions,and add it to the basis.
(4) Increase the dimension to K + 1.
Table 1 shows the results for triton and alpha with
the Reid V8 potential. 2) We obtain the energy of triton (alpha) within 100(400) basis. Results given by
Green Function Monte Carlo (GFMC) and that by
Faddeev Method (FY) are compared. The low dimen-

Graduate School of Science andUniversity

10

Technology,

Niigata

Table 1. Energies (in MeV) and radii (in fm) of the triton
and alpha by different methods with Reid V8 potential.
The probability P L is given in %.

RV8 triton

RV8 alpha

GFMC 3 )
SVM
52.2
(T)
54.0(0.20)- 59.8-62.0(0.20)
(V )
1.0
(VLS)
(r2 ) ~
1.75
1.68(0.07)
90.3
Ps
Pp
0.1
9.7
PD
- 7.59-7.54(0.10)E
111.7
109.2(0.20)(T )- 138.3 - 137.5(0.20)
(V6 )
2.1
2.45(0.23)(VLS )
0.71(0.02)(Vcou l )(1'2 ) ~1.53(0.02)
1.51
84.1
Ps
Pp
0.4
15.5
15.5(0.20)
PDE- 24.49 -24.55(0.13)

Fy3 )
52.2
-59 .8
1.76-7.59

sion of the bases required to solve the A = 3- 4 problems confirms that it is possible to treat heavier nuclei
with realistic forces by the SVM.
In summary, we have presented a stochastic variational solution for the triton and alpha particles withrealistic nuclear forces. The fact that the results arein good agreement with those of the best calculationsin the literature encourages the applications of themethod to the other cases, such as A = 6 and 7 nuclei.
References
1) K. Varga and Y. Suzuki: Phys. Rev . C 52 , 2885 (1995) .
2) R. B . Wiringa and V. R. Pandharipande: Nucl. Phys.
A 317, 1 (1979).
3) J . Carlson: Phys. Rev. C 38 , 1879 (1988).

RIKEN Accel. Prog. Rep. 30 {1997}

Occupation Probability of Harmonic-Oscillator Quanta for
Microscopic Cluster-Model Wave Functions
Y. Suzuki, K. Arai,* Y. Ogawa, and K. Varga[Microscopic cluster model]
The microscopic cluster model (MCM) is a manynucleon theory which provides a unified pictureof bound-state properties of nuclei and nuclear
reactions. 1) Though the MCM is capable of describing a variety of structures, its application has been
limited mostly to two- or three-cluster systems. The
stochastic variational method,2) on the other hand, enabled one to treat systems containing more than threeclusters, thereby giving a detailed description of lightnuclei including halo nuclei. 3)
The utility, understanding, and appreciation of
MCM would considerably increase, if its wave function
and model space are easily related to the other nuclear
models and calculations. The MCM has a relationshipwith the widely used nuclear shell model. However,
it is hard to analyse a general MCM wave function interms of shell-model configurations. We show that it iseasy to calculate the fraction of various HO excitations
contained in the MCM wave function. The present paper introduces a useful and efficient way to compare
MCM wave functions with shell model wave functions,and opens a possibility of comparing different MCM
wave functions as well.
The occupation probability PQ of a definite number of total HO quanta Q for the A-nucleon system
is obtained by calculating the expectation value of theoperator 0 given by
0= -

1

27l'

1211" dB exp(iB ( LPA
3
[HHO(i) - -] - Q)).
i

0

i=1

2

Here, HHO(i) is the 3-dimensional HO Hamiltonian divided by nw = 2,!2, and Pi projects out either protons
or neutrons. It is set by the unit operator when one calculates the number of total quanta occupied by bothprotons and neutrons. Calculational method of the
expectation value of the operator 0 can be found in
Ref. 4.
Table 1 lists the PQ values in percentage for nucleon. The wave functions used were obtained in ourrecent MCM calculations using the Minnesota potential. " one input-parameter of HO, is set to be 0.17
fm- 2 (hw = 14.4 MeV); which is a standard value used
in a shell-model calculation for p-shell nuclei. The PQ
values are given as a function of Qexc = Q - Qrnin,
where Qrnin is the minimum number of HO quanta for

Graduate School of Science andUniversity

the lowest Pauli-allowed configuration. The lowest Ohw
component is around 50-60% for most cases. Admixtures of the higher components than Qexc = 4 are significant in the ground states of 6Li and 9Be, and also in
the ground state of 6He corresponding to its extended
halo structure. The probability distribution spreads
out to a very large number of HO quanta in 8Be andthestate of 12C, well-known cluster states. It isnoted that no component is dominant in thestateof 12C. Of course, it would be possible to maximize
the probability with lower Q by choosing an appropriate value of ,. However, the probability distribution
would then spread to higher HO quanta in the groundstate of 12C.

ot

ot

Occupation probability of the number ofTable 1.
harmonic-oscillator quanta for microscopic multicluster-model wave functions. The probabilities are given
in %. Asterisk indicates the probability of less than 1%.
Nuclei6He(0+)
6Li(1+)
7Li(3/2-)
BLi(2+)
BBe(O+)
9Li(3/2- )9Be(3/2-)
12C(Ot)12C(Ot)

Qexc

0
60
62
63
61
36
66
54
54

2
14
16
20
18
18
17
21
30

4
12
10
9

*

11

12

11

12
11

12
11

6
5
5
4
4
7
4
5
3
12

8
3
3
2
2
5
2
3

*

10

10
2
2

*

1
4

*2
*

8

< Qexc >
2.2
1.9
1.4
1.7
7.6
1.3
2.1
1.4
16.1

We have presented a new and simple method of calculating the occupation probability of the number of
harmonic-oscillator quanta. The analysis is found to be
useful for comparing various wave functions by quantifying the amount of excitations across the major shell.
References
1) K. Wildermuth and Y. C. Tang: in A Unified Theory of
Nucleus, (Vieweg, Braunschweig, 1977); K. Langanke:Adv. Nucl. Phys. 21, 85 (1994).
2) K. Varga et al.: Nucl. Phys. A 311, 447 (1994).
3) Y. Suzuki et al.: Nucl. Phys. A 588, 15c (1995).
4) Y. Suzuki et al.: Phys. Rev. C 54, 2073 (1996).

Technology, Niigata

11

RIKEN Accel. Prog. Rep. 30 (1997)

Reaction Cross Sections and Radii
of A = 1 7 and A - 20 Isobars
H. Kitagawa, N. Tajima, and H. Sagawa[Glauber model, Hartree-Fock]
Measurements of the reaction cross sections of A =17 isobars (17Ne, 17F, 17N, 17B) at LBL (incident energy at around 700 MeV/nucleon) revealed an anomaly
in 17Ne and 17B;1) the measured cross sections of thetwo nuclei on carbon targets are substantially larger
than those of the other isobars. As far as the separation energies are concerned, 17Ne is similar to 11 Li. It
might be interesting to study whether 17Ne has characteristic features of "proton halo" in the reaction crosssections since the small separation energy is responsible to induce the halo phenomena together with the
low centrifugal barrier. Recently, the reaction crosssections of A = 20 isobars are reported showing a large
enhancement of the reaction cross sections of 20Mg and
2oNe.2) These data provide the information of deformation and "skin" in A = 20 isobars. It is interesting how
the deformation and skin are predicted by HartreeFock (HF) calculations and how it compares with theempirical information.
Data of mirror nuclei provide an opportunity to discuss the isospin symmetry which plays an importantrole in nuclear physics. It is interesting to see whether
the isospin symmetry is preserved or violated in thereaction cross sections of mirror nuclei, because of thesmall separation energies and Coulomb interaction.
We use the Glauber model taking into account theeffects of Coulomb interaction and Pauli blocking. We
study the reactions of 17Ne, 17F, 170, and 17N nuclei
with three targets 9Be, 12C, and 27 AI. For A = 20
isobars, the reaction cross sections of 9 isobars which
are stable for HF calculations are calculated on carbon
target.
We calculate the densities of A = 17 and 20 isobars
using spherical and deformed HF approximation with
Skyrme interactions. In the spherical calculations for
17B, 17 C, 17N, and 17Ne, we take into account the effect of small separation energies on radii by adjusting
the central part of the potential in order to reproduce
the empirical separation energies. The deformed HF
calculations are performed on a Cartesian mesh which
can describe low-density tails correctly.
Although the calculated cross sections are somewhat
overshooting the experimental ones of A = 17 nuclei,
the isospin dependence is obtained in a reasonable way
by the calculations with Id s / 2 valence configuration in
the cases of Be and Al targets. On the other hand,the experimental data show a substantial increase of
the cross sections of 17Ne on C targets in comparison
with those of 17F and 17N. This tendency is consistent

12

with the calculated results which include the proton
halo effect of 2S1/ 2 configuration. These comparisonssuggest that the evidence of proton halo in 17Ne is still
not conclusive.
We performed the deformed HF calculations of A =17 nuclei and found large prolate deformations in 17C,
17B, and 17Na around 8 = 0.3, while the deformationof 17N and 17Ne are somewhat smaller than the former
ones. The effect of deformation on the reaction crosssections is only a few percent at most and much smaller
than the halo effect.
The densities of A = 20 isobars were also calculated by the spherical and deformed HF models andcompared with experimental data. The calculated deformations of A = 20 isobars are larger than those of
A = 17 isobars. We found that the calculated resultsin Fig. 1 show a similar irregular pattern of the empirical mass radii as a function of the z-component of theisospin, T z while the missing correlations in the HF
approximation might further enhance this irregularity.

N........
~I\

co

N

N

,-E

v

lD
N

- 4- 3 - 2- 1 0

1

2

3

4

Fig. 1. The rms mass radii of A = 20 isobars. The
dashed and solid lines are by the spherical and deformed HF calculations with SGn force , respectively;
while the dotted lines correspond to the deformed HF
results with SIll interaction. The experimental values
are taken from Ref. 2.

References
1) A. Ozawa et al.: Phys. Lett. B 334, 18 (1994) .
2) L. Chulkov et al.: GSl preprint (November, 1995).

RIKEN Accel. Prog. Rep. 30 (1997)

New SU(3) Symmetry in Superdeformation, Hyperdeformation,and Highly-Deformed ShapeK. Sugawara-Tanabe and A. Arima[SU(3) symmetry, Superdeformation, Hyperdeformation]
We have previously shown that the L - S coupling
scheme is restored around the superdeformation, instead of the j - j coupling scheme , because of the large
quadrupole field. I } Thus, we can extend our discussion
using an axi-symmetrically deformed harmonic oscillator Hamiltonian without the residual Is and 12 interactions. For the case of superdeformation (sd), weconstruct new boson operators d and d t as a biproductct.

of the harmonic oscillator bosons, Ci and
Becauseof the degeneracy of the vacuum of d, we have twokinds of bosons:(1)

We obtain the new set of group operators, Q and l. In
contrast to Elliott 's case 2 } where ±2/iwQ excitations are
excluded, our group operators exclude ±2/iws d excitations. Now we extend our formalism to the many-bodyproblem. Let us put ntotal particles into the superdeformed oscillator shell from 0 to N sd (= 2nl.. + n z ) , andwe assume that n particles out of ntotal are in the final
Nsd shell. The eigenstate of the ntotal particle system
is denoted by /\lI > >. The particles which occupy theshells up to Nsd - 1 do not contribute to the expectation value of « \lI/Qo/\lI » nor of« \lI/Lz/\lI ».
Thus, only the n particles in the outer-most shell, Nsd ,contribute to these expectation values. In the representation of (A, J-L) developed by Elliott, the expectation
value of the many-body Casimir operator becomes

Similar to the case of sd, we can construct new boson
operators which form SU(3) group at hyperdeformation (hd), where parity is not mixed in the Nsh as
Nsh = 3nl.. + n z . In this case we obtain three kindsof solutions which satisfy the boson commutation relation, [g, 9 t] = 1. Here, the SU(3) is not doublet but
triplet. We can obtain 8 generators for hd in the same
way as obtained for sd, i.e. , we replace d t and d by gt
and g, respectively. The Casimir operator is similarly
obtained by replacing nd by ng = 9 t g. For the case of
superdeformation at A '" 130 or for highly-deformed
shape, where Wl.. / Wz is given by 3/2, different parity
levels are mixed in the Nsh(= 3nl.. +2n z ), corresponding to odd n z . We introduce two kinds of bosons, i.e. ,d bosons for .-i-axis and 9 boson for z-axis. Bosons forx - y plane , d and d t are defined in the same equation
as in (1), but with

cl and c±. The other bosons for

z-axis are defined by 9 and gt. Now, the SU(3) here isdouble in nd and triple in n g • The sixfold degeneracy
is for Nsh = 6m , 6m + 2, 6m + 3, 6m + 4, 6m + 5, and6m + 7. The 8 generators for 3/2 deformation is givenby the same equation as given for sd, but dt and dare
replaced by 9 t and g , andt and d±.
d±ci and c± are replaced by

References
1) K. Sugawara-Tanabe and A. Arima: Phys. Lett. B
317, 1 (1993); K . Sugawara-Tanabe, A. Arima, and N.
Yoshida: Phys. Rev. C 51 , 1809 (1995); Phys. Rev. C
53, 195 (1996).
2) J. P. Elliott: Proc. Roy. Soc. A 245, 128 and 562 (1958).

13

RIKEN Accel. Prog. Rep. 30 (1997)

Origin of ~I = 2 Staggering in Superdeformed States
K. Tanabe and K. Sugawara-Tanabe[Cm / n symmetry, fl.I=2 staggering, Superdeformation]
Recent observations of the fl.I = 2 staggerings inseveral superdeformed bands have shed a light on theinternal nuclear structure. We propose a dynamicalmechanism, in which the staggering originates fromthe symmetry of the intrinsic wave function which describes nucleons moving in the field induced by theprecession of the angular frequency vector w(t) aroundthe I-axis in the body-fixed frame (B). The vector w(t)is decomposed into a component with the constant rotational frequency Wo pointing in the direction of therotation axis 1, and a component fl.w(t) which corresponds to the precessional motion caused by the small
asymmetry. An important remark is that .6.w(t) oscillates with the precessional angular frequency wp whichis related to Wo by
Wowp= Tp = A(mod 1).

(1)TO

Thus, especially when these two periods are commensurable so that the ratio is expressed as A = min « 1)
in terms of two irreducible positive integers m and n ,the nuclear system comes back to its original positionand direction after the time-duration nTp.
We start from the generic microscopic Hamiltonian
H defined in the laboratory frame (L). We assume a rotational motion with the rotational frequency of w(t).
Next, we transform the laboratory frame to the bodyfixed frame (B) by employing unitary operators. Then,the corresponding Schrodinger equation at the frame(B) becomes,

14

An important remark here is that Eq. (2) has the periodicity of Tp and is invariant under the transformationof T = exp(ivTPit) (v: integer). Manifestly invariant solution describing the doubly periodic system canbe constructed by summing up a finite series of interfering terms with different hysteresies. Now , we identify the state 1'11(0) >L with lIMa >L , and 1'11(0) >Bwith lIMa >B , where a corresponds to 13 = K forthe case of axially symmetric deformation (uniform rotation). Hence , the stationary wave function of the
Cm/n-type, '11r;lt:(q , n), is constructed from this periodic solution, which reduces to the axially symmetricsolution in the limit .6.w(t) ~ O. Expectation value ofthe asymmetric part of the rotor Hamiltonian with respect to '11~~Q(q , n) reproduces the experimental dataquite well. Similar numerical analysis was performed
also for the C 1 / 3 -type symmetry, and the result predicts the .6.1 = 6 trifurcation as a new possibility.
From the relationship of Eq. (1) , we can show that
there exists a domain of allowance for the stability ofthe state of Cm/ n-type against the change of the ratio wo/wp in such a way that lo(wo/wp)1 < 1/n 2 . The
E2 transition rate calculated from the wave functionof Eq. (2) yields the B(E2) value which deviates fromthe ordinary result for the axially symmetric rotor onlyin the second order of energy shift.

RIKEN Accel. Prog. Rep. 30 (1997)

Role of the Xo Factor of Skyrme Force in the Interaction
Radius of Extremely Neutron-Rich Nucleus
H. Sato[N uclear interaction radii]
We study the isotone dependence of the interaction
cross sections and interaction radii of the p shell nuclei at neutron magic numbers N = 6 and N = 8 scattering off on a carbon target. We have used the
Glauber model including terms up to the second order of nucleon-nucleon profile function which was evaluated with the nuclear density distributions given by
the density dependent Hartree Fock type variational
calculation with shell corrections. 1) First, we study aninteraction radius dependence on the force parameters
to , t 1 , t 2, t3 , Xo, and W o of Skyrme (SK) forces. And
we find that an increase of the Xo factor can reproduce
the experimental trend of the isotone dependence on
the interaction radius. Also we find that , if a parabolic
type of isotonic dependence on the interaction radii(RI = aZ 2 + bZ + c) is assumed, the coefficients ofthe parabolic curve obtained are a smooth linear function of the Xo factor employed in each force parameter set. Then, by readjusting the force parameters
so as to reproduce the single neutron energy of the
IPI/2 state of 11 Li (0.15 MeV), we obtained the valuesof -1128.75 MeVfm3, 330 MeVfm5 , -120 MeVfm5 ,16400 MeVfm6 , 0.618, and 125 MeVfm 5 , respectively
for the to, tI, t2, t3, Xo, and W o of the SKIll force. 2)
With this parameter set, we calculate the interaction
cross sections, and summarize them in Table 1 withthose by SKIll force. We find that the second order Glauber model calculation of the interaction crosssection can reproduce the experimental feature of theisotone dependent interaction cross sections, and canreproduce about a half of the difference between theoretical and experimental values observed in the original

Table 1. The interaction cross sections for scattering of the p shell nuclei of N = 6 and 8
on a carbon target· at 0.79 GeV /nucleon calculated with the SKIll and modified SKIll
forces.
Nucleus
8He
9Li
lOBe
llLi
12Be
13B

(SKIll) mb
2nd order
793
781
796
926
899
903

<Tint

(Modified SKIll) mb<Texp
1st order
2nd order
mb
914
825
817 ± 6857
790
796 ± 6801866
825 ± 101088
9781056 ± 14993
916
927 ± 18914985
883 ± 14

<Tint

Glauber model calculation of 11 Li. We also find thatthe first order Glauber model calculation now gives alarger interaction cross section of 11 Li than the experimental one due to loosely bound neutrons in the 1Pl/ 2
state.

References
1) H. Sato and Y. Okuhara: Phys. Rev. C 34,2171 (1986).
2) M. Beiner, H. Flocard, N . Van Giai, and P . Quentin:
Nucl. Phys. A 238, 29 (1975).

15

RIKEN Accel. Prog. Rep. 30 (1997)

A Modified Second Order Glauber Model Calculation of theInteraction Cross Sections of Extremely Neutron Rich Nuclei
H. Sato[N uclear interaction radii]
Some extremely neutron-rich nuclei, like 11 Li, havea halo type neutron distribution due to the existenceof extremely loosely bound neutrons. 1) To study theeffect of extremely loosely bound neutrons in the interaction cross section, we re-investigate the second order
Glauber model calculation.
The optical phase-shift function is given by the evaluation of the powers of the nucleon-nucleon (NN) profile function f. 2) While the loosely bound neutrons do
not affect the optical phase-shift function due to thefirst order NN profile function , they may cause an overestimation in the second order Glauber model calculation through the second order NN profile function:
AB

22: 2:

Af cw f /3b +

B

2:2:
a

/3>ab>aA

f aa f ab +B

2: 2: f faa

/3 a .

b>a

Here, r aa are the NN profile functions between nu-

cleons a and a , respectively, in the projectile and target. For example, in the second term of the above
expression, the nucleons in the projectile are assumed
to bear double collisions with nucleons in the target.
However , extremely loosely bound nucleons may beeasily kicked out from the projectile by the first collision against the target nucleons. Therefore, the contribution from the loosely bound nucleon should be takenout from the sum of the second term in the above expression. With such a modification of the second order
Glauber model we evaluate the interaction cross sections for the scattering of 6He and 11 Li on a carbon
target at 0.79 GeV jnucleon, and compare the resultswith ordinary second order Glauber model calculationsin Table 1. Here we have employed the Skyrme (SK) III
and modified SKIII3) forces. We find that the modified
second order Glauber model calculation reproduces theexperimental interaction cross sections of 6He and 11 Li

Table 1. The interaction cross sections for the nucleus-carbon scattering at 0.79 GeV /nucleon
calculated with the second and modified second order Glauber model.
Nucleus

Separationenergy (Me V)

2nd

6He

0.97 (2n)l1Li

0.247 (2n)

O"int

675

731

683

742

722±6

926

972

978

1046

1056 ± 14very nicely, particularly with the modified SKIll force.
From these analyses, we can conclude that, as far as theinteraction cross sections are concerned, the groundstates of 6He and 11 Li can be expressed by a Slater determinant of a simple configuration of the 1S 1 / 2, 1P3/ 2,
and 1Pl/ 2 states (no 2s1d shell).

16(Modified SKIll) mb
Modified 2nd(SKIll) mb
Modified 2nd

O"int

2nd

O"ex pmb

References
1) 1. Tanihata: to be published in J. Phys. G: Nucl. Part.
Phys. as a Topical Review.
2) V. France and G. Varma: Phys. Rev. C 15, 1375 (1977);
Phys. Rev. C 18, 349 (1978).
3) H . Sato: the previous paper.

RIKEN Accel. Prog. Rep. 30 (1997)

Electric Dipole Transitions in Neutron Capture andCoulomb Dissociation Processes
A. Mengoni, T. Otsuka, T. Nakamura, and M. Ishihara[Neutron capture, Coulomb break-up, Neutron-rich nuclei, Neutron halo]
Electric dipole (El) radiation emitted (or absorbed)
by light neutron-rich nuclei carries important information on the structure of the nuclear states involved in
the gamma decay transition. For example, a neutron
capture process in which El radiation is emitted in thetransition from a given state We, describing the incident neutron in the continuum, to a bound state <I>b isessentially determined by the matrix elements(E1) =< 'll IT E1 1'll b > ·Qbc
c

If a reliable description of the two-body continuum isavailable,l ) the matrix elements Qi~l] may be used
to track down the structure of the bound state <I>b.
The matrix elements Qi~l] may be obtained from theneutron capture, (n, 1'), as well as Coulomb dissociation experiments. In the latter case , the El strength
distribution following the dissociation of neutron-richradioactive nuclei can be measured and the result be
used to derive information on exotic structures such as
halo and skin states of nuclei far from the beta stabilityline.
We have recently developed a technique in which the
B(El) strength distribution of a Coulomb break-up
experiment can be used to derive the structure of halostates. 2 ) In fact , the strength distribution is related to
the El matrix elements byHere, the subscripts 0 and 1 refer to the l = 0 and 1
components of the neutron-core relative motion. By a
suitable inversion of the last equation it is possible toobtain the radial component of loosely bound s-orbits(halo states).
An example of the reconstruction of the radial partof a halo-state wave function (for the 11 Be groundstate) is shown in the Fig. 1. The B(El) strength
distribution used to derive uo(r) is what was measured in RIKEN.3) Further developments and results
obtainable by the use of this technique can be expected
because new data from planned Coulomb dissociation
experiments will be available in the near future.

" B • ground-.tat. radial wave function
2., ... orbit (8 n -0.505 MeV)

0 .2

0 .0 11t----------=::::::~;;;;;;;;;;;;;--_t

~

-0 .2

-0 . 4-0 .6-0.80'-::.0~....c...",'="5.-:0 ----:'-=0.-=-0-

Here Ex is the excitation energy (defined as the sumof the neutron-residual nucleus relative energy plus theneutron binding energy) , k is the wave number of theneutron relative motion in the continuum (and v its
velocity) , e the El effective charge, J b the total angular momentum of the bound state, and J c the spinof the residual nucleus in the continuum. Under suitable assumptions concerning the description of the relative motion of the neutron in the continuum, it canbe shown that the radial part of the bound state wave
function is related to the radial part of the El matrix
elements, IOl (k), by the Fourier-Bessel integral:Jex:)

IOl(k) = 2i~uo(r)r 2 j1(kr)dr.

----=-'=-5.-:0-~20:'-:.O~-2-=-=5~.O~-........,3::-:'O.O

r [tm]

Fig. 1. Reconstruction of the radial wave function of theground-state of 11 Be. The single particle wave function
calculated from a Woods-Saxon potential is also shownfor comparison.

References
1) A. Mengoni, T . Otsuka, and M. Ishihara: Phys. Rev.
52 , R2334 (1995).
2) A. Mengoni, T. Otsuka, T. Nakamura, and M. Ishihara:
Proc. Int. Symp. Capture Gamma-ray Spectroscopy,
Budapest, 1996-10, edited by G. Molnar (SpringerVerlag) in press.
3) T. Nakamura et al.: Phys. Lett. B 331, 296 (1994).

o17

RIKEN Accel. Prog. Rep. 30 (1997)

Quantum Monte Carlo Diagonalization Method
for Nuclear Many Body Problem
T. Otsuka, T. Mizusaki, and M. Honma[Monte Carlo method, Nuclear structure]
The nuclear shell model has been successful in thedescription of various aspects of nuclear structure,
partly because the model is based on a minimum number of natural assumptions. Although the direct diagonalization of the Hamiltonian matrix in the fullvalence-nucleon Hilbert space is desired, the dimension of such a space is too large in many cases, thereby
preventing us from performing the full calculations.
Recently, active developments have been made in thestochastic approaches to overcome this difficulty. For
an instance, the Shell Model Monte Carlo (SMMC)l )method has been developed by the Caltech group,
which was successful in clarifying the zero temperatureand thermal properties of the ground state for hugesystems. However, its application also suffers fromthe so-called minus-sign problem. Furthermore, thestructure of excited states can be seen only throughthe response functions. For spectroscopic investigations of the nuclear structure physics , it is a crucial
step to remove or relax such restrictions. Thus we proposed a new stochastic approach for solving the nuclear
shell model, whose formulation is shown in Ref. 2. By
this method, we can study the spectroscopic properties based on the nuclear shell model. The feasibilityof this method was well-tested by comparing the exact
sd or pf shell calculations with realistic forces. 2 ) As thismethod is based on the Quantum Monte Carlo method
and Diagonalization method , we refer it as the Quantum Monte Carlo Diagonalization (QMCD) method. 2 )Here, we report a recent application of this method
on 64Ge, which is considered to show the I"-soft nature.
If we take the pf shell as its model space, its shell model
dimension is over two billion. In Fig. 1, calculated
low-lying spectra by the QMCD method are comparedwith experimental data. It is remarkable that the calculated levels show a rather good agreement with experimental ones without any adjustment. The I"-soft
nature is evident also in the calculation. The calculated ratio of the excitation energies of 2~· tois 1. 9and that oftois 2.6. Experimentally, these ratios are 1.75 and 2.27, respectively. The relative magnitudes of B(E2) values are shown in Fig. 1. With
ep = 1.33e and en == 0.64e, B(E2;27 ---+ 07) = 5 X 10 2

47

18

27

27

>

_ _ _ _ 4+

(\)

6

2

~
....(\)
c

UJ

c

.g
z:!

'u><

UJ

0

_ _ _ _ 0+~~-----o+

Exp.

QMCD

Fig. 1. Experimental and calculated energy levels of 64Ge.
The arrows designate E2 transitions with B(E2) values
indicated by their widths.

(e 2 fm4) is obtained, which corresponds to /32 rv 0.28.
The B(E2) values of the---+ 2t and---+transitions are about 1.3 times larger than that ofB(E2;2i ---+ Oi) , suggesting I"-softness. We obtain
B(E2;2t ---+ Oi)/B(E2 ;2t ---+ 2i) rv 2x lO- 3 , whichis quite small similarly to the experimental value, suggesting l' rv 30° in triaxial deformation models. Calculated quadrupole moments appear to be small (typically, I Q I < 10 efm 2 ) , consistently with I"-softness.
Thus, the present QMCD method can radically widen
the scope of the shell model calculation.

47

2t

27

References
1) C. W. Johnson , S. E. Koonin, G. H. Lang , and W. E .
Ormand: Phys. Rev. Lett. 69 , 3157 (1992); W. E. Ormand , D. J. Dean, C. W. Johnson , G. H. Lang, and S.
E. Koonin: Phys. Rev. C 49 , 1422 (1994); S. E. Koonin,
D. J. Dean, and K. Langanke: to be published in Phys.
Repts. (1996).
2) M. Honma, T. Mizusaki, and T. Otsuka: Phys. Rev.
Lett. 75 , 1284 (1995); T. Mizusaki , M. Honma, and T.
Otsuka: Phys. Rev. C 53, 2786 (1996); M. Honma, T.
Mizusaki , and T. Otsuka: Phys. Rev. Lett. 77, 3315
(1996); T. Otsuka, M. Honma, and T. Mizusaki: Proc.
Workshop on Comtemporary Nuclear Shell Model,
1996-4, Drexel Univ. , U.S.A., to be published in Lecture Notes in Physics (Springer-Verlag).

RIKEN Accel. Prog. Rep. 30 (1997)

Spreading of Gamow-Teller Resonance in 90Nb and 208Bi
N. Dinh Dang, A. Arima, T. Suzuki, and S. Yamaji[Gamow-Teller resonance, 2p2h configuration mixing)
The giant Gamow-Teller resonance (GTR) was predicted in 1963 1) to explain the hindrance of allowed
unfavored (3 decays. It was experimentally observed
first in 1975 in the 90Zr(p , n) reaction. 2) A measure of
the total observed transition strength for the GTR isprovided by the model-independent Ikeda sum rule,1)
which should be nearly exhausted by the transition
strength summed over all GT states in the daughter(Z + 1, N - 1) nucleus. However, during the last 20
years experimental systematics over a wide range ofthe periodic table found only around 60% of this sum
rule value. The ~(1232) isobar-hole admixtures in the
nuclear wave function 3 ) were first proposed as a mechanism for the GTR quenching. Theoretical studies haveshown that this effect seems to be small. 4- 6) The 2p2hconfiguration mixing must be taken into account. If
this mechanism plays an important role, t he missing
GT strength should be spread over the physical background below and beyond the G TR. 6 , 7) Several models, including Ref. 8, have been proposed to calculate
the spreading of G TR due to a mixing with 2p2h configurations. Even though all of them recover the Ikeda
sum rule in the energy interval below 50
60 Me V ,the amount of strength in the GTR region as well as
the shape of the strength function varies noticeably
depending on models . Recently, high-resolution measurements of GTR in the 208Pbe H e , t)20BBi reaction 9)
and in the 90Zr(p , n) 90Nb reaction lO ) were carried out
in RCNP (Osaka). In particular, the authors of Ref.
10 were able to extract , for the first time, the L = 0
cross section in t he continuum, resulting in a longtail of G TR extending up to around 60 Me V , which
seems to recover the missing part of the GTR strength.
These new experimental results9,10) have motivatedthe present work.
We propose an approach to the damping of GTR,
where the GTR is generated by proton particle - neutron hole phonons (Prr - hv phonons) within the rE)llormalized random phase approximation (RPA). The
renormalization is due to the ground-state correlations beyond RPA. The second-order configuration
mixing beyond RPA was realized by constructing twophonon configurations , in which one of two intermediate phonon states was a P7r - hv phonon. The numerical calculations were performed in the parent nuclei
90Zr and 208Pb making use of the nucleon-nucleon effective M3Y interaction l l ) and of the single-particle
wave functions obtained in the standard harmonic oscillator potential. The single-particle energies aroundthe Fermi surface were substituted with the empirical values or those given by a Woods-Saxon potential.

Results obtained have provided a reasonable accountfor recent experimental findings of the spreading andquenching of GTR in these nuclei (Fig. 1). An extension of the present approach to highly-excited (hot)nuclei was also performed. We found that the GTR isstable against increasing temperature up to
6 MeV.
f'V

10

beyond t e scale

90

Nb

8

>
Q)

6

~

(j)

~

4
2

o

f'V

10

20

30
40
11, MeV50

60

Fig. 1. Strength function of GTR in 90Nb. Energies aremeasured wit h respect to the ground state of 90Zr. The
experimental distribution from Ref. 10 is shown by thehistogram. Impulses show the RPA results. Dotted andsolid curves refer to the results of Ref. 8 and our results,
respectively.

References
1) K . Ikeda, S . Fujii, and J. I. Fujita: Phys. Rev. Lett. 3 ,271 (1963) .
2) R. R. Doering et al.: Phys. Rev . Lett. 35 , 1961 (1975).
3) M. Rho: Nucl. Phys. A 231, 493 (1974) ; E. Oset andM. Rho: Phys. Rev. Lett. 42 , 47 (1979).
4) K . Shimizu, M. Ichimura, and A . Arima: Nucl. Phys. A
226, 282 (1974); A. Arima and H. Hyuga: in Meson in
nuclei (North-Holland, Amsterdam, 1979) , p. 683.
5) L. S. Towner and F . C. Khanna: Phys . Rev. Lett. 42 ,
51 (1979).
6) F. Osterfeld: Rev . Mod. Phys. 64, 491 (1992) .
7) C. Gaarde et al.: Nucl. Phys. A 369, 258 (1981).
8) S. Drozdz et al. : Phys. Lett. B 166, 18 (1986).
9) H. Akimune et al.: Phys. Rev . C 52, 604 (1995).
10) T. Wakasa et al.: Proc. Int. Symp. on Non-Nucl. Degrees of Freedom detected in Nucleus , Osaka, 1996-9, tobe published .
11) G. F. Bertsch and I. Hamamoto: Phys. Rev . C 26,
1323 (1982).

19

RIKEN Accel. Prog. Rep. 30 (1997)

Two-Dimensional GCM Calculation of TAR States
T. Horibata, M. Oi, and N. Onishi[Tilted rotation, Generator coordinate method, Signature splitting]
We have been carrying out a systematic calculation
based on a self-consistent three-dimensional cranked
HFB method in A rv 180 region and have founda solution which represents a Tilted Axis Rotating(TAR) state using an appropriately chosen set offorce parameters. 1 ,2) This fact means that the intrinsic
states become more stable through mixing of the odd
angular momentum members in the wave functions.
Taking notice of this feature we tried to explain theexperimental fact that the energies of odd angular momentum members are very low; these states were considered to be the same members of the yrast band. A
three-band mixing analysis with g-band, t-band ands- band gives, however, a different interpretation for an
observed signature splitting and also for the yrast band
structure. That is, the yrast is mainly composed of thes-band, and the signature splitting t-band (odd andeven) locates just above the yrast. 3 )Previously, we tried to describe the signature splitting in terms of the Generator Coordinate Method(GCM),4) in which the north-latitude along the prime
meridian is employed as a generator coo~dinate. The
method is quite general and an interesting approach indescribing the excited band as well as the yrast band
where the quantum tunneling between two wells located symmetrically with respect to an equator is expected.
Since the one-dimensional GCM calculation could
not give any stable plateau against the increase of number of states in the s-band, we extended the calculation into the two-dimensional(2D) space. We took 837
points of grid in the plane for the numerical integration. In the one-dimensional(ID) case only 31 points
were considered. The norm kernel is first diagonalized.
In this step we found the existence of negative solutions
whose absolute values are not negligibly small. We will
discuss the characteristic feature of these solutions in a
separate report. The discretized hamiltonian matrices
are diagonalized by utilizing only the positive eigenvalues of the norm kernel to obtain energy eigenvalues.
The energy eigenvalues of the five lowest states for
J = 1611, (s-band) are depicted in Fig. 1 as a functionof the number of states employed. We found a stable plateau in the result in contrast with the previous(ID) case. The employed number of states in the calculation are, however, restricted only to less than 200
solutions for the diagonalization of the norm kernel.
Many solutions which give very small eigen values inthe diagonalization of the norm kernel are left behind

20

030

J = 16,.
~

~

~-40
~

()

='

~-45

5

co
iil.6()

~

()

I:

Ul~

~

so

100

ISO

Number of States

Fig. 1. The energy spectra for J = 161i in g-band as afunction of the number of states employed in diagonalization. The energy is the absolute value.

in the calculation.
Moreover, we could not obtain the stable plateau
for J = 1411, and J = 1811, states. The reason may be
attributed to the fact that we lost many informations
about high-frequency part of the wave functions which
are contained in the states with small eigen values of
the norm kernel. These informations can mostly betaken into account through angular momentum projection of Hartree-Fock-Bogoliubov states. 5 ) Calculation
along this line is in progress.
In the meanwhile, we are again to make the calculation for the ID GCM with more carefully adjusted
force parameters and with much finer mesh points,
since the rate of occurrence for the zero eigen value
solutions in the diagonalization of the norm kernel are
relatively small compared to the 2D case. Angular momentum projection will play less important roles in ID
GeM.
References
1) T. Horibata and N. Onishi: Phys. Lett. B 325 , 283(1994).
2) T. Horibata and N. Onishi: Nucl. Phys. A 596, 251(1996).
3) P. M. Walker: Proc. Int. Conf. on the Future of Nuclear
Spectroscopy, Crete, p. 134 (1993).
4) T. Horibata, M . Oi, and N. Onishi: Phys. Lett. B 355,
433 (1995).
5) M. Oi, N. Onishi, and T. Horibata: RIKEN Accel. Prog.
Rep. 29, 29 (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Variation of Transport Coefficients for Average Fission Dynamics
with Temperature and ShapeS. Yamaji, F. A. Ivanyuk,* and H. Hofmann**[Thermal fission, Linear response theory]
We study a slow collective motion at finite thermal
excitations on the basis of linear response theory applied to the locally harmonic approximation. 1) The response functions have been calculated within a realistic
two-center shell model. Effects of collisions have beenaccounted for by using self-energies having both realand imaginary parts. The latter is allowed to depend
not only on temperature but on frequency as well; inthis way memory effects of the collision term can be
simulated. Locally collective motion is treated selfconsistently, in the sense that the structure of the associated response resembles the one known from the
RPA motion. The corresponding friction " inertia
M, and the local stiffness G are computed along a
fission path of 224Th within a quasi-static picture. Fora damped oscillator the quantity TJ = ,/2'; MIGI indicates whether the motion is underdamped (TJ < 1) oroverdamped (TJ > 1). Therefore, it is a good measurefor the effective degree of damping. Furthermore, it isexactly this quantity, if calculated at the saddle point,
which according to Kramers ' famous formula(1)
determines the deviation of the fission decay rate R K
from the RBW of the Bohr-Wheeler formula. The TJ
has been calculated as a function of T before,2) but
only for the case of quadrupole vibrations around thespherical minimum of lead. In the light of Eq. (1) it
may suffice first to study it around the barrier. Indeed,this formula applies if, from the full dynamics acrossthe barrier, it is only the motion around the stationary
points which matters. The latter situation can be seen
to be given if the height B of the barrier is much larger
than the temperature: 3) B /T » 1 . Unfortunately,
often Eq. (1) is applied even in cases that this basic
condition on T and B is violated.
To study these questions for our example we havecalculated all relevant quantities by performing averages both around the potential minimum as well asaround the barrier. The results are put together in thefollowing Table 1.
Several inferences can be drawn immediately:a) One of the most striking features is the weak dependence of TJ on the shape parameter. The temperature dependence of this quantity is similar to the one
Institute for Nuclear Research of the Ukrainian Academy of
Sciences, Ukraine** Physik-Department der Technischen Universitat Miinchen,
Germany

Table 1. The quantities ;"ID = ;,,/(ICII M) and TJ at theminimum and saddle points and the barrier height B
as a function of T.
T

1i 'W""

MeV

MeV

1
2
3
4
5

0.82
0.94
0.93
0.87
0.79

'TI""

1.1
2.2
2.5
2.7
2.9

B

1i 'W s

MeV

MeV

7.20
5.95
4.31
2.59
1.18

0.50
0.59
0.59
0.60
0.67

'TIs

1.2
2.7
3.2
3.3
3.0

reported previously2) for vibrations of 208Pb: it increases with T, to eventually reach some saturation
around T :::::: 4 Me V. This behavior is in agreementwith findings,4) at least qualitatively. Our damping
rate is somewhat smaller, and its variation with theshape is weaker than that in the analysis4) of the ,ray multiplicity encountered in fission of 224Th. However, it must be said that we have not yet striven for
quantitative agreements. For instance, there is a room
for a more appropriate choice of the two parameters ofcollisional damping. Furthermore, one should mention
the influence of pairing, which still might be important at the smaller T value of 1 MeV. Moreover, theinfluence of angular momentum ought to be taken into
account. 5)b) The basic condition on the validity of Eq. (1) issatisfied for temperatures up to 3 MeV at best. It isinteresting to note that nws increases with T, albeit
only slightly. A closer inspection shows the quantity
27fT / (n r:v s) to be of the order of 7f and thus definitely
larger than unity. This implies that collective quantum
effects do not contribute to fission dynamics for the examples chosen here. It should be said that in simplifiedstudies Kramers' picture is often applied, even in cases
where the barrier is too low to guaranty that the flux
across the barrier can be described by Kramers' solution of the Fokker-Planck equation. This problem canonly be cured by performing dynamical studies along
the lines. 6- 8)
References
1) S. Yamaji et al.: to be published in Nucl. Phys.
2) H. Hofmann et al.: Nuel. Phys. A 598, 187 (1996).
3) H. Hofmann et al.: Phys. Lett. B 317, 489 (1993).
4) P. Paul and M. Thoennessen: Ann. Rev. Part. Nuel.
Sci. 44, 65 (1994).
5) K. Pomorski and H. Hofmann: Phys. Lett. B 263, 164(1991).
6) E. Strumberger et al.: Nucl. Phys. A 529, 522 (1991).
7) P. Frobrich et al.: Nuel. Phys. A 563, 326 (1993).
8) T. Wada et al.: Phys. Rev. Lett. 70, 3538 (1993).

21

RIKEN Accel. Prog. Rep. 30 (1997)

The Continuity Equation of the Nuclear Four-Current
H. Kurasawa* and T. Suzuki[Four-current, Continuity equation]
The nuclear four-current should satisfy the continuity equation,(5)

where the effective mass M* is defined by

ap + V'. J = o.

at~. ~ ~ { 1+" 2~;FHere, the density operator is
exp(iq . ri)(1 - T~)/2,

i=l

and the current density is given by[H, p] = iV' . J,

for H standing for the nuclear hamiltonian. Using the
eigenstate of H, the continuity equation is expressedas(En - Eo)(nlpIO) = (n liV' . JIO) (Hln) = En In»).

(1)

Usually, however, we can not solve the Schrodinger
equation exactly. As a result, Eq. (1) is not satisfied.
It is shown below that the Hartree-Fock approximationis one of the examples in which the continuity equation
is violated.
Let us assume the nuclear hamiltonian to bei=l2v'(r)jr(PFr)r dr },v*(r) = vo(r) + 3x Tv T (r) + 3xava(r) + 3XaTVaT(r).

A

Lp(q) =J

Iw n ) = O~ I O) ,o~ = L(Y~iatnai - Z~iaJa171)'171i

and the RPA ground state defined by OnIO) = o. We
can show that the RPA equation of motion for theforward and backward amplitudes , Y~i and Z~i' gives

i,j

i=l

The right hand side of Eq. (5) is different from thatof Eq. (3) expressed by the free mass. Thus, in the
Hartree-Fock approximation the continuity equation isviolated. The reason of the violation is clear. We haveobtained Eq. (3), since the nuclear interaction satisfies[V(l, 2), pS(l) + pS(2)] = 0 as in Eq. (2). Equation (4),however, takes into account only a part of the above
commutator.
We can prove that in the random phase approximation (RPA) based on the Hartree-Fock approximation,
the continuity equation is satisfied approximately. In
RPA I ) the particle-hole states are described aswhere the nuclear interaction generally has a form:
V(i,j) = vo(r) + xTvT(r)Ti· Tj + XaVa(r)O"i .O"j1+-XaTVaT(r)Ti . TjO"i .O"j,3(6)(r = Iri - rjl).

For this hamiltonian, the isoscalar part of the fourcurrent satisfies[H,pS] = [T,pS] = iV'. P ,(2)being the excitation energy of the state Iw n ). As
for the isoscalar density p\ the relationship of Eq. (2)gives the one-body current. Therefore, Eq. (6) can be
written as,

Wn

and the single-particle current at q ---t 0 should be
iV'.jS(q-tO)=q.~.

(7)

(3)

M

Now, the Hartree-Fock equation 1 ) provides us withthe matrix element for a particle(m)-hole(i) state;(10171 -Ei)(mi-1Ips l ) = (ml[t , pS]li)

L (mjlV(1, 2)pS(l) - pS
-L2)pS(2) - pS(1)V(1,+(l)V(l, 2)lij)j(mjlV(l,2)lji),(4)

w here I ) denotes the Hartree-Fock ground state of
the nucleus, and pS (i) the isoscalar part of the singleparticle density. In a nuclear matter approximation,
we have for P = PF,
Faculty of Science, Chiba University

22

which is the same as the continuity equation given by
Eq. (1).
For the isovector current, the Hartree-Fock approximation yields the same equation as Eq. (5) for theisoscalar current. In RPA, the isovector four-current
satisfies an equation different from Eq. (7). Since wehave [V, pV] i= 0 for the isovector density, the isovector current is given by two-body operators. Hence, we
can not write the continuity equation of the isovector
four-current in the form of Eq. (7).
References
1) D. J. Rowe: in Nuclear Collective Motion (Methuen Co.
Ltd., London , 1970).

RIKEN Accel. Prog. Rep. 30 (1997)

Unstable Nuclei and the Equation of Stateof Asymmetric Nuclear Matter
K.Oyamatsu[Unstable nuclei, Equation of state, Atomic masses, Nuclear radii]
We aim to extract the equation of state (EOS) of
asymmetric nuclear matter from the masses and radiiof unstable nuclei, which are closely related to thesaturation energies and densities of asymmetric nuclear matter whose proton fraction (Yp) is Yp < 0.5.
Figure 1 shows the Yp values of various matters. We
see that the unstable nuclei bridge a gap between stable
nuclei and supernova matter as well as the one between
stable nuclei and nuclei in inner crusts of neutron stars.
As the first step of our study, we neglect surface effects
and attempt to relate the EOS of asymmetric nuclear
matter with the bulk properties of neutron rich nuclei.

and

Pno(
) Kno-Kso(S()
n :::::: S 0 + 2 n - no +2n - no )2 . (3)no18 noHere, Wo and So are the saturation energy of symmetric nuclear matter and the symmetry energy atn = no , respectively. Equations (2) and (3) includedensity derivatives of w(n, Yp). They are the pressureof pure neutron matter, Pno , and the compressibility
modulus of symmetric nuclear matter (pure neutron
matter) , Kso (Kno).
In the above approximation, the saturation density,
nl , and the energy per nucleon, WI , of asymmetricnuclear matter are given , respectively, byO.S
Stable Nuclei
0.4
Unstablc:asupernova matter

0 .3

and

'4J

u

~

c:

(5)

0.2

B
a
C. 0.1
0.0
0.0

0.2

0.4

0 .6

0.8

3

local nucleon density (fm' )Fig. 1. Proton fractions and nucleon densities of asymmetric nuclear matter and at the centers of nuclei. The abbreviations oya4 and RBHF indicate the Thomas Fermi
calculations in Refs. 1 (model IV) and 2, respectively.

For simplicity, we assume the following form for theenergy per nucleon of uniform nuclear matter, whose
nucleon density is n , as(1)
where ws(n) and S(n) are the energy per nucleon ofsymmetric (Yp = 0.5) nuclear matter and the symmetry energy, respectively. When the density n is close
to the saturation density of symmetric nuclear matter,
no , we can write()2
ws (n) :::::: Wo + -Kso
- 2 n - no
18no

In deriving Eqs. (4) and (5) , we have neglected thehigher order terms than (1 - 2Yp)4. The second termin the square bracket in Eq. (4) is expected to be quite
small.
From Eqs. (4) and (5) , we see that the pressure ofpure neutron matter primarily determines the saturation densities of asymmetric matter, while the symmetry energy at n = no dominates their energies. We note
further that the compressibility of symmetric matteralso affects the saturation densities. Therefore, what
we can obtain from the radii and masses of neutronrich nuclei are the energy, pressure, and possibly compressibility of pure neutron matter. However, further
studies, especially on nuclear surfaces, are still necessary to determine the EOS of asymmetric matter quantitatively from the nuclear masses and radii.
References
1) K. Oyamatsu: Nucl. Phys. A 561 , 431 (1993).
2) K. Sumiyoshi et al.: Nucl. Phys. A 595, 327 (1995) .

(2)

23

RIKEN Accel. Prog. Rep. 30 (1997)

Effect of Relativistic Equation of State on Vortex Pinningto the Nuclei in Neutron Star Crusts
Y. S. Mochizuki[Neutron stars]
The inner c~ust of a neutron star consists of a bodycentered cubic (bce) lattice of neutron rich nuclei, relativistic degenerate electrons, and a neutron superfluid.
Since the star is rotating, there are a number of quantized vortices in the superfluid. The vortex lines are
expected to be nearly parallel to the axis of rotation.
Each vortex line possesses a normal fluid core overa distance ~, the coherence length of the superfluid.
We take a view that the BeS pairing is prohibitedcompletely inside the vortex core. The pairing energy
is ,rather large. In the superfluid, the pairing energy
per neutron is given by cp = (3/8) ~2 / E F , where ~is the superfluid energy gap and EF the Fermi energyof superfluid neutrons. For simplicity we assume thatthe superfluidity does not exist in the nuclei. Thenthe pairing energy can be gained by increasing overlapof the vortex core line with nuclei. This is simply theorigin of the vortex pinning.
The pinning energy (the energy gain when a vortex line pins to nuclear materials) is given by Ep =cp n~ut V, where V is the overlap volume of the vortex core and the nuclear materials, and n~ut is thesuperfluid neutron number density outside the nuclei.
Hence, the pinning energy depends on the ~ and also
on the size of the nuclei. The pinning energy is a key
physical quantity to explain frequency of neutron starglitches (sudden spinups in pulsars).
So far, the nuclear size dependence on Ep has notbeen considered except by Takatsuka (1984).1) Usually,
the following parametric form 2 )Ep = 0.87 kF~ 2(1)

is used to estimate Ep. Here, kF = (37r2n~ut)1/3 is the
Fermi wave number. It should be noted that in Eq. (1)the radius of nuclei is fixed as RN = 7 fm.
Recently, Sumiyoshi, Oyamatsu, and Toki (1995)3)
calculated a nuclear lattice structure in the inner crust,adopting the equation of state based on the relativistic Brueckner-Hartree-Fock theory. It has been known,from the analysis of laboratory nuclei, that calculations in the relativistic framework produce larger radiiof neutron distributions in the nuclei than conventional
calculations as the neutron richness increases. In fact,
the nuclear size obtained in Ref. 3 is quite large inthe region of average baryon density, p/ po.:G 0.2, ascompared with those reported so far. Here Po == 0.17
fm- 3 denotes the normal nuclear density.
It is the purpose of present paper to examine thissize effect which stems from the relativistic equation of
24

state on the pinning energy, using the results obtainedin Ref. 3. Not ' only usual spherical nuclear shape,
here we consider also nonspherical (cylindrical) shapesof nuclei. In particular, we consider the pinninginduced nuclear rods (PINRs) proposed by Mochizuki
and Izuyama4 ) (For details, see Refs. 4 and 5).
Figure l(a) shows the result of Ep as a function of
P/ Po· In this figure , ~ is adopted from Ref. 1. Epthat was reported in Ref. 1, in which only the spherical nuclear shape was taken into account , is also shownfor comparison. We found a remarkable difference between the two' calculations in the high density region,p/ Po.:G 0.25. We note that Eq. (1) gives almost thesame behavior as the Ep obtained in Ref. 1. It is thus
concluded that, contrary to the conventional picture,
Ep is strong enough in the deep inside of the innercrust.

,. (a)>Q)

Jcylinder(b)

IPINRI

10' 2

8

::;E
~c. 6

cylindero __- - - - ' -0 .0-J..:..:..L---'-------''-----:-'--- - ' - - - - ' 1 0' 0

p/ Po

O. 2

10"

OPt PoFig. 1. (a) Pinning energy per nearest neighbor distancein the bee lattice. (b) Pinning energy per unit length (1cm) of a vortex line.

In Fig. 1 (b), we show the result of Ep including thatof PINR. Here, ~ is adopted from Ref. 6. From thefigure we confirm the assertion in Ref. 4 which mentioned that PINRs give singularly stronger pinning.
Formation of PINRs will thus be a crucial mechanism
to explain neutron star glitches as discussed in Refs. 4
and 5.
References
1) T. Takatsuka: Prog. Theor. Phys. 71, 6, 1432 (1984).
2) M. A. Alpar et al.: Astrophys. J. 346, 823 (1989).
3) K. Sumiyoshi et al.: Nucl. Phys. A 595 , 327 (1995).
4) Y. Mochizuki and T. Izuyama: Astrophys. J. 440, 263(1995).
5) Y. S. Mochizuki et al.: submitted to Astrophys. J.
6) T. L. Ainsworth et al.: Phys. Lett. B 222, 173 (1989).

RIKEN Accel. Prog. Rep. 30 (1997)

Baryon Properties Based on
the Chiral Quark Soliton Model t
M. Wakamatsu[Nucleon spin structure, Effective theory of QCD)
The chiral quark soliton model (CQSM) is one of
the simplest models of baryons, which takes accountof the most important properties of low energy QCD:
i.e., the spontaneous breakdown of chiral symmetry
and the associated appearance of Nambu-Goldstonebosons. 1 ,2 ) The basic theoretical framework of CQSM
consists of mean field theory and subsequent quantization of the collective rotational motion based on the
cranking method; which are both familiar techniquesin the theory of deformed nuclei. With this framework, the bound state problem for a baryon can besolved nonperturbatively under a full inclusion of thenegative-energy Dirac-sea quark degrees of freedom in
addition to the three valence quarks. A unique featureof this model is that it predicts a quite small fractionof quark spin to the nucleon spin. 2 ) It means that inthis model a sizable part of the total nucleon spin iscarried by the orbital angular momentum of quarks.
Undoubtedly, this is a natural consequence of the basic dynamical assumption of the model: i.e. , a physicalbaryon as a rotating hedgehog object.
By extending the model further to the case of flavor
SU(3) , we can study the properties of strange baryons
like the A and L: , and can also study the strangeness
contents of nonstrange baryons like the nucleon. 3 ,4) Table 1 shows the prediction of the flavor SU(3) CQSM
as for the flavor decomposition of quark spin fractions
to the nucleon spin.

Table 1. The flavor decomposition of quark spin fractions.
0(0 0 )
D.u
D.d
D.s
D.E

0.34
-0.26
-0.08
0

0(0

0

+ 0 1 ) + D.ms
0.87
-0.35
-0.03
0.49

experiment
0.83- 0.43-0.10
0.31

Here, the column represented by 0(0°) shows themean field predictions, or equivalently, the contributions of the zeroth order term in the collective angularvelocity, O. On the other hand, the column represented by 0 (0° + 0 1 ) + ~ m s gives the final predictionsof the SU(3) CQSM, which takes account of the firstorder rotational correction in 0 as well as the flaverSU(3) breaking effects caused by the mass difference
between the strange and nonstrange quarks. One cansee from this table that one of the characteristic predictions of the SU(3) CQSM is the negative polarizationof the strange quark sea with respect to the directionof the nucleon spin. This feature is also interpreted as
an evidence of the formation of the symmetry breaking hedgehog mean field. As the terminology "hedgehog mean field" indicates, the model (CQSM) naturally has close connections with the Skyrme model. In
fact, the correspondence between these two models become almost exact in the fictitious limit of Nc ---+ 00.
However, we have recently found that this correspondence seriously breaks down at the next leading orderin N c .5 ,6) This observation resolves the long-standinggA problem of the Skyrme model, thereby confirming
the superiority of the CQSM to the Skyrme model asa realistic low energy model of baryons.
References
1) D. I. Diakonov, V . Yu. Petrov, and P. V. Pobylitsa:
Nucl. Phys. B 306, 809 (1988).
2) M. Wakamatsu: Nucl. Phys. A 524, 561 (1991).
3) H. Weigel, R. Alkofer, and H. Reinhardt: Nucl. Phys.
B 378, 638 (1992).
4) A. Blotz, D. I. Diakonov, K. Goeke, N. W. Park, V. Yu.
Petrov, and P. V. Pobylitsa: Nuc!. Phys. A 555, 765(1993).
5) M. Wakamatsu and T. Watabe: Phys. Lett. B 325, 467(1994).
6) M. Wakamatsu: Prog. Theor. Phys. 95, 143 (1996).

Invited talk at the XIII International Seminar on High Energy Physics Problem, Dubna, 2- 7 September, 1996.

25

RIKEN Accel. Prog. Rep. 30 (1997)

QCD Corrections to the Structure Function g2
J. Kodaira[Deeply inelastic scattering, Spin structure]
Recently there has been much interest in the nucleon
spin structure function, 92' In the framework of theoperator product expansion, not only the twist-2 but
also the twist-3 (higher-twist) operators contribute to
g2 in the leading order of 1/Q2. The general featurescharacteristic to the higher-twist operators are; (1) the
occurrence of the operators which are proportional tothe equation of motion (EOM operators) and several
operators are related through the EOM operators;1)(2) some gauge non-invariant EOM operators will mix
under the procedure of the renormalization. 2 ) These
facts bring about some complication for the highertwist operators through the course of renormalization.
The anomalous dimensions of the composite operators, which are obtained from the renormalization
constant, control the Q2 dependence of the structure
functions. We examine what happens to the renormalization if there are several operators which are related through the EOM operators. We illustrate thepoints with the scalar field theory. Assume that wehave two composite operators R1 and R2 which are
related through the equation of motion:(1)
where E is an EOM operator. Since we have threecomposite operators with a constraint of Eq. (1), we
can choose any two operators among three as an independent basis.
First we choose R 1 and R 2 • Then renormalization
takes the following form:( ~~)R (~~: ~~~)( ~~ )B(2)

Here, the suffix R (B) denotes the renormalized (bare)operator. Next, we change the operator basis to Ri(i = 1 or 2) and E. Then, the renormalization matrix
should become triangular, 3)(3)since the counterterm to the E operator should vanishby the equation of motion. From Eqs. (2) and (3), we
can derive the following relations among the renormalization constants, Z's:

26

zfi

Zll

ZEE

Z22 - Z12 = Zll -+ Z12 = Z21 + Z22 = Z~,
Z21 ,

(4)
Equation (4) is a consistency condition for the renormalization of the operators satisfying Eq. (1).
We note that the arbitrariness in the choice of theoperator basis does not enter into the physical quantities. This fact can be explicitly confirmed by notingthat the physical matrix element of the E operator
vanishes: 1,3) (PIElp') = O. Taking the physical matrix
element of Eq. (3), we conclude that the renormaliza,tion constant of z.ff is only relevant. We reach thesame conclusion also from Eq. (2).
The anomalous dimensions of twist-3 operators in
QCD at the one-loop level have been studied in Ref. 4.
However it is not clear how the EOM operators aredealt with and their results do not coincide each other.
We have reanalyzed the operator mixing problems bykeeping the EOM operators. We have clarified the roleof the EOM operators and given a correct answer forthe anomalous dimensions by calculating the off-shell
Green's functions. 2 )Finally let us make a comment on the BurkhardtCottingham sum rule. The operator product expansion naively suggests:

We have shown that this sum rule does not receive any
corrections in QCD. S )We expect that future measurements on 92 will clarify the effect of twist-3 operators which share somecommon feature with more general higher-twist effects
in QeD.
References
1) H. D. Politzer: Nucl. Phys. B 172, 349 (1980) .
2) J. Kodaira, T. Uematsu, and Y. Yasui: Phys. Lett. B
344, 348 (1995); J. Kodaira, K. Tanaka, T. Uematsu,
and Y. Yasui: Phys. Lett. in press.
3) J. C. Collins: in Renormalization (Cambridge Univ.
Press, 1984); and references therein.
4) E. V. Shuryak and A. 1. Vainshtein: Nucl. Phys. B 199,
951 (1982); A. P. Bukhvostov, E. A. Kuraev, and 1. N.
Lipatov; JETP Lett. 37, 483 (1984); X. Ji and C. Chou:
Phys. Rev. D 42 , 3637 (1990).
5) J. Kodaira, S. Matsuda, K. Sasaki, and T. Uematsu:
Phys. Lett. B 345, 527 (1995).

RIKEN Accel. Prog. Rep. 30 (1997)

Next-to-Leading-Order Q2 Evolution Programfor Spin-Dependent Structure Functions
M. Hirai ,* S. Kumano, and M. Miyama*[Q2 evolution, Structure function]
Spin-dependent structure functions are measured in
the polarized lepton-nucleon scattering. They dependon two kinematical variables, x and Q2. The Q2
dependence is calculated within perturbative QeD,
and it is described by integrodifferential equations
so called DGLAP equations. Next-to-Ieading-order(NLO) splitting functions for spin-dependent parton distributions are evaluated recently. I) Therefore,
we can study numerical solution of the NLO spindependent Q2 evolution equations. 2)
Although we used a Laguerre-polynomial method 3 )for solving the equations of unpolarized case, a bruteforce method can be employed as an alternative one.
This method was already investigated for solving thespin-independent evolution equations with or without parton-recombination effects.4) The same method
is applied to the spin-dependent case. We divide
variables into small steps (Nx steps in the Bjorken
variable In x, and Nt steps in the variable t ==-(2/f3o) In[O:s(Q2)/O:s(Q6)]) and calculate the differentiation and integration in the evolution equations after
rewriting them by df(x)/dx = [f(xm+d- f(xm)JI ~xm
and J dxf(x) = L~:I ~xrnf(xm)' In this way, theintegrodifferential equations are solved step by step if
the initial parton distributions are provided.
We use the Gehrmann-Stirling set-A 5) as the input
distributions given at Q2 = 4 Ge y2. We study evolution of nonsinglet , singlet , and gluon distributions
from Q2 = 4 Gey2 to Q2 = 200 Gey2 with N f = 4
and A MS = 231 MeY. Numerical results depend on
the step numbers, Nt and N x . First, Nt is varied from
20 to 1000 steps with a fixed N x = 1000. We findthat the evolved distributions are almost the same. Itmeans that merely Nt = 50 steps are enough for obtaining accurate evolution. This conclusion is expected
because the scaling violation is a small logarithmic effect. Next , N x is varied from 100 to 4000 steps with afixed Nt = 200. The result is shown in Fig. 1. From
this figure, we find that several hundred of x steps
are necessary for obtaining good accuracy. Namely, if
we choose the parameters Nt = 200 and N x = 1000,

0.25- - - Nx=1oo
0.2
0.15

g

0.1

Ul

C"

<l
X

0.05
0
-0.05
-0.1
0.0001

0.001

0.01

0.1

X

Fig. 1. N x dependence in the xbt.qs evolution.

the evolution results are good enough. We also analyzed evolution of the nonsinglet and gluon distributions. The obtained results show the similar accuracy.
Our numerical analysis is still in progress, particularly in comparison with scaling violation data of gl.
However, the results indicate that an accurate solution can be obtained in the region 10- 4 < x < 0.8 bytaking more than two-hundred t steps and more than
one-thousand x steps.
References
1) W. Vogelsang: Phys. Rev. D 54, 2023 (1996), RAL-TR96-020; R. Mertig and W. L. van Neerven: Z. Phys. C
70 , 637 (1996).
2) M. Hirai , S. Kumano , and M. Miyama: research inprogress.
3) R. Kobayashi , M. Konuma, and S. Kumano: Comput.
Phys. Commun. 86 , 264 (1995) .
4) M . Miyama and S. Kumano: Comput. Phys. Commun.
94, 185 (1996).
5) T. Gehrmann and W. J. Stirling: Phys. Rev. D 53, 6100
(1996) .

Department of Physics, Saga University

27

RIKEN Accel. Prog. Rep. 30 (1997)

Q2-Evolution of the Chiral-Odd Twist-3 Parton Distributionsh L (x,Q2) and e(x,Q 2) in the Large Nc Limit
1. 1. Balitsky,* V. M. Braun,** Y. Koike, and K. Tanaka[N ucleon structure functions, Chiral-odd, Twist-3, Large Ne QCD]
The nucleon has three independent twist-3 parton distributions: g2(X, Q2), hL(x, Q2), and e(x, Q2)1)
which are the functions of the Bjorken variable x andlarge momentum squared Q2 characterizing relevant
hard processes. Here, g2 is chiral-even while hL ande are chiral-odd. The increasing experimental precision requires understanding of these higher twist effects induced by correlations of partons. In particular,
g2 and h L play a distinguished role in spin physics,
since they can be measured as leading effects for certain asymmetries. I)
Q2-evolution of the twist-3 distribution is generally quite sophisticated due to mixing with quarkantiquark-gluon operators, the number of which increases with spin (moment of the distribution). For
the flavor-nonsinglet part of g2, a crucial simplification
has been pointed out in the large Ne limit of SU(Ne)color to neglect O(l/N;) corrections: 2) g2(X, Q2) obeys
a simple Gribov-Lipatov-Altarelli-Parisi (GLAP) evolution equation and the corresponding anomalous dimension is known in analytic form.
In this work3 ) we have proved that the same pattern is obeyed by chiral-odd distributions hL(x, Q2)
and e(x, Q2) and that the simplification at large Ne
is of universal nature. We have obtained the renormalization group (RG) equation in the leading logarithmic approximation for the twist-3 nonlocal operators i/;(uz)aJ.Lt;,AgGvt;,(tz)zJ.Lzv'IjJ(vz) with A = 1 and
iTS; which are relevant respectively for e and hL' andexpress quark-gluon correlations. Here, 1j; denotes thequark field, Gvt;, the gluon field strength tensor, zJ.L thelight-like vector (z2 = 0). We have found analytic solutions of the RG equation in the limit Ne ----+ 00, andobtained the Q2-evolu tion for the moments:

Mn[e(Q2)] = DY~ /b M n [e(t-£2)](1)

Mn[h L (Q2)] = L';: /b M n [h L (t-£2)],(2)

where the anomalous dimensions equal respectively"V± = 2NIne

{S - ~4 - _1_(- ~ ± 1) } .
n +1
2
n

Center for Theoretical Physics, MIT, U.S.A.
NORDITA, Denmark

28

(3)

Here, Mn[e(Q2)] == J~1 dxx n e(x,Q 2), b = (lINe 2Nf )/3 with Nf the number of flavors, Sn = 2:,7=11/j,
and L = a s (Q2)/a s (t-£2) with a s (Q2) the running coupling constant of QCD. The results (1)-(3) show thathL and e both obey simple GLAP evolution equations
with the corresponding anomalous dimensions given in
analytic form and with no complicated operator mixing. Our results are valid to O(1/N;) accuracy.
One can check the above results (1)-(3) directly byusing the anomalous dimension matrix which are obtained in Refs. 4 and 5 by renormalization of the twist3 local operators. In particular, by comparing our solution of (3) with the spectrum of anomalous dimensions
which is obtained by the numerical diagonalization of
the mixing matrix in Refs. 4 and 5, we conclude that
our solutions always correspond to operators with thelowest anomalous dimension in the spectrum (for moredetail, see Refs. 3 and 5).
corrections are small, our solutions
Since the 1/
solve the problem of the Q2-evolution of twist-3 nonsinglet parton distributions for all practical purposes,
providing a powerful framework both in confronting
with experimental data and in model-building. Froma general point of view, our solutions are interesting as
providing an example of an interacting three-particle
system in which one can find an exact energy of thelowest state. For phenomenology, the main lesson isthat inclusive measurements of twist-3 distributions
are complete (to our accuracy) in the sense that knowledge of the distribution at one value of Q6 is enoughto predict it at arbitrary Q2, in the spirit of GLAP
evolution equation.

N;

References
1) R. L. Jaffe and X. Ji: Nucl. Phys. B 315, 527 (1992).
2) A. Ali, V. M. Braun, and G. Hiller: Phys. Lett. B 266,
117 (1991).
3) 1. 1. Balitsky, V. M. Braun, Y. Koike, and K. Tanaka:
Phys. Rev. Lett. 11, 3078 (1996).
4) Y. Koike and K. Tanaka: Phys. Rev. D 51, 6125 (1995).
5) Y. Koike and N. Nishiyama: hep-ph/9609207; RIKEN
Accel. Prog. Rep. 30, 29 (1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Q2-Evolution of Chiral-Odd Twist-3 Structure Function andFragmentation Function: e(x, Q2) and e(z, Q2)
Y. Koike and N . Nishiyama*[Structure function, Twist-3, Chiral-odd, Large-Nc ]The nucleon has three independent twist-3 quark
distributions; g2(X , Q2), hL(x, Q2), and e(x, Q2).1) The
Q2-evolu tion of these twist-3 distributions is generally very complicated due to the mixing among quarkantiquark-gluon operators, the number of which increases with spin (the moment of the distributions).
So far , the anomalous dimension matrices for g2 (x, Q2)
and hL (x , Q2) have been calculated in the one-loop
level. In our recent work,2) we have completed the calculation of the one-loop anomalous dimension matrix
for e(x , Q2). Our method follows closely the one in 3 )which discussed the Q2 dependence of hL(x , Q2). In
the large-Nc limit, we have confirmed that the Q2 evolution is solely governed by the lowest eigenvalues of
the anomalous dimension matrix, as was found in 4 ) bya different method. Taking the n-th moment of e, theQ2 dependence at Nc ~ 00 becomesMn[e(Q2)] = LI'~/b M n [e(JL2)]
with

I~ = 2Nc (Sn - ~4 - 2 (1)), (1)n+ 1where Mn[e(Q2)]J~l dx xne(x, Q2), L
Qs(Q2)/Qs(JL2) , b = (11/3)Nc - (2/3)Nj and Sn
L7=1 1/j. This shows that e(x, Q2) evolves slightly

Graduate School of Science andUniversity

Technology,

slower than the other two twist-3 distributions.
For phenomenological applications, the twist-3 fragmentation function e(z, Q2) is more interesting, since
it appears as a leading contribution to the pion production cross section in the transversely-polarized deep
inelastic scattering from the nucleon5 ): e(z, Q2) of
the pion appears with the transversity distribution,h 1 (x , Q2) , of the nucleon. Our present study is expected to supply useful information about the Q2
evolution of e(z, Q2). In particular, if the so-called
Gribov-Lipatov reciprocity relation 6 ) holds true evenfor the twist-3 distribution and fragmentation functions, the problem of Q2 dependence of e(z, Q2) has
virtually been solved.
References
1) R. L. Jaffe and X. Ji: Nuel. Phys. B 375, 527 (1992).
2) Y. Koike and N. Nishiyama: hep-ph/9609207, Phys.
Rev. D, in press.
3) Y. Koike and K. Tanaka: Phys. Rev. D 51, 6125 (1995).
4) I. I. Balitsky, V. M. Braun, Y. Koike, and K. Tanaka:
Phys. Rev. Lett. 77, 3078 (1996).
5) R. L. Jaffe and X. Ji: Phys. Rev. Lett. 71, 2547 (1993).
6) V. N. Gribov and L. N. Lipatov: Sov. J. Nuel. Phys.
15 , 675 (1972).

Niigata29

RIKEN Accel. Prog. Rep. 30 (1997)

Quark Helicity Distributions Using QeD Sum Rule Approach
H. Kitagawa and T. Hatsuda[Quark helicity, QCD sum rule]"Spin Crisis", raised in the 1980's from the data ofgl (x) for the proton (in the polarized lepton-proton in-clusive experiment), is a problem that the quarks do
not carryall of the spins of the proton. This problem has not been solved yet. Experimentally, one of
the main purposes of the RHIC-SPIN project (by thepolarized proton-proton collider) is to investigate thehelicity of quarks and gluons in the proton. Theoretically, the spin contents of quarks are being discussed
qualitatively using "effective" models of QCD. In order to compare the data, however, it is necessary toevaluate them quantitatively.
QCD sum rule is a useful tool to evaluate physical quantities. It was applied to the (spin-averaged)
quark distribution functions by Kolesnichenko 1) andBelyaev and Blok. 2) They evaluated the second moments of quark distributions:

MJq) =

which contains spp)..S~~1. (where sp is the spin of thenucleon). After the Borel transformation, we obtain(in the leading order):x E3(so/M2)em~/M2

(1)

2
M8
5(27r)4 AJvmJv
x E3(so/M2)e m't IM2.

(2)

Results of calculations are shown in Fig. 1. The left
hand sides (1.h.s.) of the above Eqs. (1) and (2) areapproximated by the straight line at M2 = 1.5 GeV 2 .
Extrapolation of this line into the point M2 = 0 gives~MJu) = 0.3 and ~MJd) = -0.24.

Jx q(x) dx.

QSR O-th order : pol. 2nd mom .

0 .75

We have followed the method of Ref. 2 for the quark
helicity distribution.
The second moment of quark appears in the responseof constant external field, which is introduced by thelagrangian term, ~Cq = -i~D"/)'v'ljJSIJ,V, where 'IjJ represents quark and S/.-LV is a tensor external field. This
form is determined by the operator product expansion(OPE). In the spin-polarized case, by OPE we can derive lagrangian term, ~C~ol. = -i~D/.-L'Y5'Yv'ljJS~~I.'
For the spin-averaged quark distributions, the second moment Mi can be obtained, by comparing coeffients of ppp)..p/.-L'Y/.-LSP).. in both theoretical and phenomenological sides. After the Borel transformation,
we obtain (in the leading order):M(d)+ C(d) M2 =3
M6 E (s /M2)e m't/M2
20(27r)4 AJv
2 0+ C(u) M2 =7
M6 E (s /M2)e m't IM2
20(27r)4 AJv
2 0

2

M(u)
2

Here M and m N are the Borel mass and the nucleon
mass respectively, and(OI'TlIN) = AN v
V (>9 V =p/.-L'Y/.-L + mN
n

En(x) = 1 - e- x

L
k=O

:!

k

for 'Tl being an interpolating field of the nucleon and So
being the threshold of the continuum.
For the quark helicity distributions , the second moment ~MJq) can be obtained, by picking up terms
30

g
~

0.50

~

ro

.........

.....

0.25

00

C"

~

0.00

.....
0

[I)

-0.25

..d
......

-0.50

o

0.5

1.5
(Borel mass)22

2.5

Fig. 1. The Borel mass , M, dependence of the left handsides of Eqs. (1) and (2) denoted by u and d , respectively. The dashed lines are the extrapolation to thepoint M2 = O.

The first moment of quarks corresponds to the valueof the spin of the nucleon, which are calculated by Balitsky and Ji 3 ) using QCD sum rule technique. On theother hand, these second moments are not measured
by the inclusive reaction. They can be measured by
exclusive reactions, such as RHIC-SPIN.
Further calculation including gluon corrections are
now in progress.
References
1) A. V. Kolesnichenko: Sov. J. Nucl. Phys. 39, 968 (1984).
2) V. M. Belyaev and B. Yu. Blok: Z. Phys. C 30, 279(1986).
3) X. Ji: MIT-CTP-2517 Hep-ph/9603249, Mar. 1996.

RIKEN Accel. Prog. Rep. 30 (1997)

Quark Helicity in Proton by Semi-Inclusive Asymmetries of Kaons
H. Kitagawa and Y. Sakemi[Quark helicity, Semi-inclusive]
High-energy inclusive lepton-hadron reactions havemade clear the contents of the hadrons, i.e. , much ofknowledge on quark distributions in the proton andneutron was gained owing to perturbative QCD techniques as well as high precision data. However, as forthe distributions of gluons and sea quarks, which cannot be observed directly by the inclusive processes, wehave not obtained a unified view. This is the problemof the moment.
A semi-inclusive reaction, in which the scattered lepton and a produced hadron are detected simultaneously, provides many kinds of information on the target depending on the tagged hadron, and is expected
to solve the above problem. The HERMES collaboration at Deutsches Elektronen-SYnchrotron (DESY)
is measuring the quark and gluon distributions by thesemi-inclusive reaction with polarized positron beamand polarized gas targets tagging the pion and neutralkaon. Data with pions are now under analysis, anddata with kaons will appear in 1997. Here we formulate relationships between the quark distributions andthe observed spin asymmetries.
We follow the formulation by Giillenstern 1 ) andFrankfurt 2 ) who investigated the pion-tagged case. We
use the quark-parton model to assume factorization.
Fragmentat ion function , D] (z), is assumed to be spinindependent , isospin-symmetric , and different between
strange quarks and light quarks.
Negatively charged pion, 11'- , is composed of d andu quarks. For the proton target, we use a favored fragmentation function , D( z), for d and u, and an unfavored fragmentation function , D( z ), for u , d, s , and s
quarks. These fragmentation functions were obtainedby fitting the e+ -e- scattering data. Combining thedata with 11' - and with 11'+ , we obtain the spin asymmetry :(1)z D( z )dz
Jtl in _I:Z'" = Z

JZl'nin l+ z D(z )dz

I'"V

(2)

0.34

with Z m i n = 0.2. The distributions, s and ~s , can bederived from the above equation.
On the other hand, neutral kaon,
contains squark Kg = (ds + sd) / J2. Fragmentation functionof s-quark is assumed to be factorized as Ds(z) =D( z )/>. , where>. 0.3. Spin asymmetry for this case

K5,

I'"V

IS

p

+ "'1~d + "'2~S
8u + "'ld + "'2S'

8~u

A KOs -

- - -_ _ _ __-(3)

where "'1
3.05 and "'2
7.84. Note that we can extract the distributions, s and ~s, with less ambiguity,
since their coefficients are large.
Next , we estimate the spin asymmetries which will
be measured by the HERMES collaboration. We uset he existing parametrization for the quark distributions: CTEQ3L for the unpolarized quark distribution
and Gehrmann-Stirling A(LO) for the polarized quark
distribution. Results of the calculations are shown in
Fig. 1. In the case of kaon tagging, we can see a significant difference from zero at x ~ 0.1 (x is the Bjorken
scaling variable.) which corresponds to the s-quark
contribu tion.
I'"V

I'"V

0.6

- - A 1f++1fP

0.4

- -

A 1f++1f-_ g P/F P
P

1

1

0.2
rn

Q)

'i::
..,

..

0.0

Q)

8
8
>.

0 .6

rn

- - A KOs
P

<

0.4

- -

A ~8_g PIF P
P

1

1

0.2
0.0
0.01

0.05 0.1

0.5

1

x

Fig. 1. Estimated spin asymmetries for the cases of pion
tagging (upper figure) and kaon tagging (lower figure) .
The existing parametrizations for the quark distributions are used.

We can obtain much information on the hadrons
from semi-inclusive reactions. This reaction contains
the fragmentation processes, which have not been studied so much as the quark distributions. It is necessary
to study the fragmentation functions experimentallyand theoretically, in order to remove ambiguity in thesemi-inclusive process.
References
1) St. Giillenstern et al.: Phys. Lett. B 312, 166 (1993).
2) L. L. Frankfurt et al.: Phys. Lett. B 230, 141 (1989).

31

RIKEN Accel. Prog. Rep. 30 (1997)

Test of ~g in Spin Correlations between Target Protons andProduced A+
at COMPASS ExperimentcT. Yamanishi and T. Morii *[Gluon, Polarized gluon, Spin structure, Charmed baryon]
Recent measurement of the spin- dependent proton
structure function implies that little (only 15%) of the
proton spin is carried by quarks. 1) The result is far
from the prediction by the naive quark/parton model.
On the other hand, a spin sum rule,(1)
suggests that in addition to quarks, the gluons andorbital angular momenta of quarks and gluons contribute to the proton spin. In Eq. (1), ~I: and ~g are
the amount of the proton spin carried by quarks andgluons, respectively; and (L z )q+g denotes the orbital
angular momentum of quarks and gluons. In order tounderstand the proton spin structure, it is very important to measure the density and behavior of spindependent gluon distribution in a proton for various
reactions.
Here, we study a semi-inclusive production of polarized At baryons from a longitudinally polarized proton, /!.p ~ .e' At x, in order to deduce ~g in a proton.
The correlation between the spin of the At (producedin the target fragmentation region, x F < 0) and thatof the target proton is expected to be significantly affected by the polarized gluon contents, because theprocess can occur only via photon-gluon fusion mechanism in the lowest order as shown in Fig. 1. Sincea charm is created by a gluon and has its spin parallel to the gluon spin, the direction of At spin, whichmust preserve the charm quark spin, depends on thatof gluon spin. Therefore, the spin correlation between
the produced At and target proton gives a good information on gluon polarizations in a proton.
In order to estimate the sensitivity of this process for~g, we calculate a spin correlation asymmetry, ALL
defined as

Faculty of Human Development and Graduate School of Science and Technology, Kobe University

32

Fig. 1. The lowest order QeD diagram for the inelastic At
leptoproduction in unpolarized lepton-polarized proton
scatterings.

where dO' +_, for an instance, denotes that the spin of
the target proton is positive while that of the produced
At is negative. Calculating the ALL with various examples of ~g , we have found that the ALL strongly
depends on the density and behavior of ~g. It is concluded that the process considered here, /!.p ~ l At X,
can give a quite useful information on the behavior ofgluon polarizations.
References
1) J . Ashman et al.: Phys. Lett. B 206 , 364 (1 988); Nucl.
Phys. B 328, 1 (1989); B. Adeva et al.: Phys. Lett.
B 302 , 533 (1993); Phys. Lett. B 320, 400 (1994); P.
L. Anthony et al.: Phys. Rev. Lett. 71 , 959 (1993); D.
Adeva et al.: Phys. Lett. B 329 , 399 (1994); K. Abe etal.: Phys. Rev. Lett. 14, 346 (1995).

RIKEN Accel. Prog. Rep. 30 (1997)

RHIC Spin Project
H. En'yo, Y. Goto, K. Hatanaka, N. Hayashi, T. Ichihara, K. Imai, M. Ishihara, T. Katayama,
A. Luccio, Y. Mao, A. Masaike, Y. Nakada, M. Okamura, N. Saito, Y. Sakemi, H. Sato,T. Shibata, Z. Sun, Y. Watanabe, H. Wu, and M. Yosoi[pp interaction, Structure function, Spin, Asymmetry, Polarized beam]

We are promoting the RHIC spin project. 1 ) The
main physics goals of the project are to elucidate
the spin structure of proton , and to test the standard model mainly via the parity violating process,in collaboration with Brookhaven National Laboratory(BNL). The Relativistic Heavy Ion Collider (RHIC)
and the PHENIX detector at BNL will provide us
an opportunity of experiments taking advantages ofhigh energy (up to 250 GeV), high luminosity (rv 10 32
cm - 2 S -1) , and high polarization (rv 70% ) of protonbeam. The project includes not only the physics research but also the development and construction ofaccelerators and detectors.
The present article summarizes all the progress madefor the project in this year. Detailed description ofeach subject is carried out in this issue separately. The
preparation for physics experiments is one of the main
subject of the project. First of all, it should be mentioned specifically that construction of the PHENIX
detector was started during this year (Fig. 1). The
photo of Fig. 1 shows the Muon arm section which
RIKEN contributes much effort for its construction.
The remaining Muon Magnet South (MMS) has been
fabricated by Mitsubishi Electric Co. and RIKEN with

Fig. 1. A photo of the PHENIX construction at present,
showing the Central Magnet, an arm of the Muon Magnet (Muon Magnet North) , and a pair of iron walls for
Muon Identifier (MuID).

technical supports of Lawrence Livermore National
Lab. (LLNL).
The investigation of Limited Streamer Thbe (LST)
is proceeded, which forms the MuID with iron walls.
We are testing the LSTs with the high energy ( rv 2
GeV) muon and pion beams at National Lab for HighEnergy Phys. (KEK), and also with cosmic ray andradioactive sources. Fabrication of the LSTs will startin the next year according to the results of this test
experiment at KEK.
Simulation studies are underway to establish theanalysis methods as well as on-line trigger scheme.
Sensitivity of the measurements of polarized parton
distributions is evaluated using the results of resolution and acceptance studies. For these studies we havethree coherent activities with collaboration of theorists: (1) summarize both unpolarized and polarizedcross sections for various reactions expected in RHIC j 2)(2) evaluate the yields and statistical uncertainties; (3)develop polarized parton distributions based on thecurrently available experimental data. Details of thesimulation studies and studies of polarized parton distributions are described in separate papers.
We, responsible for accelerator field, concentrate on
accelerating polarized proton, by using the RHIC accelerator, up to 250 Ge V without a depolarization.
The main effort is R&D of the special superconductive magnet (so called Siberian Snake magnet) to flip
the spin of the proton, which is the main component tokeep the polarization of protons in the RHIC accelerator. The magnetic field calculation in three dimensions
is well established, which is an indispensable technique
to design the Siberian Snake magnet in an optimized
form. The "Spin Tracking" is also well established,which calculates the behavior of the proton spin in the
RHIC accelerator. Furthermore, a model magnet of
the Siberian Snake was made, whose maximum current reached 470 A (planned maximum 420 A) whichcorresponds 4 T of magnetic field at the central region.
As we described above, the project is proceeding
very well. We will put further effort in the coming
year toward the first beam scheduled in 1999.
References
1) H. En'yo et al.: RIKEN Accel. Prog. Rep. 29, 80 (1996).
2) R. L. Jaffe and N. Saito: Phys. Lett. B 382, 165 (1996).

33

RIKEN Accel. Prog. Rep. 30 (1997)

Spin Physics with PHENIX Detector System at RHIC
H. En'yo, Y. Goto, N. Hayashi, T. Ichihara, K. Imai, Y. Mao, A. Masaike, Y. Nakada,N. Saito, Y. Sakemi, T. Shibata, Y. Watanabe, M. Yosoi, and M. Ishihara[ pp interaction, Structure function, Spin, Asymmetry, Polarized beam]
We are studying the spin physics possible with the
PHENIX detector system at Relativistic Heavy Ion
Collider (RHIC) in Brookhaven National Laboratory. I)
Here we report the results of our recent studies onprospective measurements of the gluon helicity distribution !::.C and of the anti-quark helicity distribution!::.q. Measurements of these two distributions are crucial for understanding the spin structure of nucleon.
One of the promising methods to determine !::.C
is to measure the asymmetry for the production ofa prompt photon (,) with the high transverse momentum PT. In proton-proton (pp) collisions at theenergy of RHIC, about 90% of the photon production comes from the quark-gluon Compton scattering process (q + 9 ---+ q + ,), and the rest originatesfrom the quark annihilation process (q + q ---+ 9 + ,).
We define a double longitudinal-spin asymmetry ashhh
A LL = 0"(++)-0"(+-)
0"(++ )+O"( +_)' were C7 represents t e p oton
production cross section and the signs indicate the helicity states of two colliding protons. Since the quarkgluon Compton process dominates in the production ofa high PT photon, the asymmetry is dominantly governed by that process. The asymmetry for the Compton process is given by ALL = ~q . .6.c? aLL , where aLL
is an asymmetry in partonic level and is calculable; q
and C are the unpolarized quark and gluon distribution functions , respectively; ~is fixed by other exq
periments; and C is determined from an unpolarizedcross section of the photon production. Thus, one canextract !::.G by measuring ALL. We have estimated theyield of prompt photons by using a QCD event generator named PYTHIA 2) in a wide PT range assuming
the integrated luminosities 320 and 800 pb- 1 for thecolliding energy VB = 200 and 500 Ge V , respectively.
From this study we have confirmed a correlation between probed Bjorken's x of gluon and PT of photon,
which allows us to study the x dependence of !::.C. Expected errors on .6.f were calculated from the photon
yield and ALL formula, which are indicated by error
bars in Fig. 1 together with the preliminary results of
the J /7./J production process. It is shown clearly that avery precise measurement can be made around x rv 0.1
where a recent theoretical model depicts a maximum
in the magnitude of .6.c?
!::.q can be determined from the single longitudinalspin asymmetry AL = ~~! ~~~~:::: ~ for production of a
weak boson, W±. Here C7( +) stands for the cross section for a W production in collision of the unpolarized
proton and the proton with positive helicity, and a( -)denotes the same as C7( +) but with negative helicity.
Since the W+ is produced dominantly by ud ---+ W+,
the asymmetry for its production AL(W+) is sensitive to both !::.U and !::.d. Similarly, AL(W-) is sensitive to !::.d and !::.u. As in the case of !::.C , we haveevaluated the statistical error of our measurements of
34~

1r---------------~~ 0.8

g ~~~ ~:~

0_6•

ct 200 G~V•

tt500GeV•

Jlj1 200 C.V
Jlj1500C.V

-0.6
-0.8
-110 .3

Fig. 1. Prospective measurements of the ~GG calculated
from prompt photon and J /'1/; (e e, J-LJ-L) yield.

.6. -

.6.
r!

the ~ and
which were calculated from the bosonyield estimated by PYTHIA. The results are plotted inFig. 2. Curves in the figure show theoretical predictions performed separately on ~ij
and .6.q
for differentqqflavors of two independent groups. The filled and open
circles show the points to be determined from productions of W+ and W-, respectively. Obviously, we canselect one of the models from our measurements.

Q2 =

M/

• AL(wt)-;. 05o AdW-)

<1

cd

~

.:i

,?>
<1 -0.5

GS9SLO(A)~ BS

Fig. 2. Flavor decomposition of the quark and anti-quark
polarizations for a W production.

In summary, we have estimated the yields for PP
reactions, from which we could determine the helicity
distributions of gluon and of anti-quark in the proton.
The statistical error on the measurement of .6.f will
be in between 0.01 to 0.1 at 0.05 < x < 0.20. ~canq
be determined with the statistical error of 0.02 to 0.05
at 0.05 < x < 0.10.
References
1) H. En'yo et al.: RIKEN Accel. Prog. Rep. 29, 80 (1996).
2) T. Sjostrand: Comput. Phys. Commun. 82, 74 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Study of Polarized Parton Distribution
Functions in the Nucleon
Y. Goto, N. Hayashi, M. Hirai, S. Kumano, M. Miyama, T. Morii,
N. Saito, T. Shibata, and T. Yamanishi[Polarization, Structure functions, Spin structure, Nucleon]
In 1995, RIKEN started the RHIC-spin project incollaboration with Brookhaven National Laboratory(BNL). The main goal of the project is to elucidate thespin structure of the nucleon. The Relativistic Heavy
Ion Collider (RHIC) , which is designed to give a luminosity of 2x 1032 cm- 2sec- 1 , an energy of y's = 50500 GeV, and a proton beam polarization of about
70% for polarized pp collisions, is under construction
at BNL. To meet the goal of planned experiments andto propose crucial measurements to constrain the spin
structure of the nucleon, a working group on the polarized parton distribution functions (pol-pdf's) was
formed.
The spin structure of the nucleon has been studiedin polarized lepton scattering off the polarized nucleon
target (pol-DIS). As revealed in the "proton spin crisis ", our understanding of the spin structure is not
sufficient yet. In particular, the gluon polarization,
sea-quark polarization, and flavor decomposition are
not tightly constrained by the pol-DIS experiments.
On the other hand, the experiments on the spin
structure are entering to new stages:• further precision measurement in inclusive polDIS ,• Q2- evolution group,
to develop computer programs on the pol-pdf up
to any Q2 with the splitting functions to include
next- to-Ieading-order as corrections.
The first stage of the program is in progress.
As the second stage, we would like to suggest crucial measurements for pol-pdf. Based on the results
obtained from these subgroups, we will study the processes sensitive to the polarized strange quarks and gluons, and predict the physics for di-muon productionsin the final state, prompt photon productions, heavy
flavor productions, weak boson productions, etc. at the
RHIC energies.
We are opening the home page on WWW for virtual
conference at the address,
http://www.rarf.riken.go.jp/rarf/rhic/theory / .
We are grateful to Prof. T. Hatsuda, Dr. H.
Kitagawa, Dr. K. Tanaka, Dr. S. Ohta, and Prof. Y.
Koike for useful discussions.

Working Group on Polarized Parton
Distribution Functions (Pol-PDF)

1st stage• semi-inclusive pol-DIS , and• polarized proton-proton collision.
The goals of these experiments are to determine:• gluon polarization,• sea-quark polarization, and• Parametrization Group
Modeling polarized quarks andgluon distribution functions• Data Analysis Group
Fitting - error analysis• Q2 _ evolution GroupQ2 _ evolution• flavor decomposition.
The working group is composed of three subgroups
with respective subject:

2nd stage• data analysis group,
to summarize the current experimental and theoretical knowledges on the spin structure• parametrization group,
to develop the best polarized parton distributionfunctions (pol-pdf) which fit well to all available
experimental data including new one

Suggesting crucial
measurements for
Pol-PDF

Fig. 1. Flow chart of the program of our working group.
The first stage is in progress.

35

RIKEN Accel. Prog. Rep. 30 (1997)

R&D of Iarocci Tube for RHIC Spin Project
Y. Mao, Y. Nakada, H. En'yo, K. Imai, N. Saito, N. Hayashi,
Y. Watanabe, Y. Goto, T. Ichihara, and M. Ishihara[Iarocci tube, Working mode, Time spread]A clean identification of muon is a key issue for
RHIC spin project. The production of weak bosons
W which is sensitive to the anti-quark contents of thepr~ton, can be identified by the detection of high transverse momentum muons. The production of heavy
quark system, which is sensitive to the gluon contentsof the proton, can be tagged with the detection of
dimuon in the proper mass range.
To meet the goal of the experiments, the muonIDin PHENIX detector system should have the following
characteristics: (i) time resolution ~100 ns, (ii) stability in detection efficiency, and (iii) low cost to cover awide area. Iarocci tube!) has been selected as a candidate for such detector. As a part of PHENIX' muonID
R&D, we have investigated the Iarocci tube's plateau
range and time response in different conditions to specify its operation mode and operation gas. In addition,
we have compared performance of the tubes from Italy
and from China; both of them are candidates for mass
production in future.
Figure 1 shows a cross-sectional view of two Iarocci
tubes which mainly comprise three parts: a 8-cell comb
extrusion with the inner wall painted by graphite, anouter jacket and a set of silver-plated Cu-Be wires of
100 J-Lm diameter. Iarocci tubes can be operated ineither streamer mode or proportional mode. It is oneof urgent issues to select one mode out of two. By
using a mixture of Ar:C 4H lO = 1:3 (Ar-C 4H lO , hereafter) as the working gas, we measured the pulse heightspectra of cosmic ray and 90Sr radioactive source under the HV from 3.9 to 5.0 kV. The transition fromthe proportional to streamer modes has been clearlyobserved at about 4.5 kV. An comparison of streamer
mode with proportional mode has been made as described below. Although the plateau range, detection
efficiency and time spread of the proportional mode aresimilar to those of the streamer mode, the pulse heightis quite different in two modes. Since the average pulse
height of streamer mode is over 10 times larger thanthat of proportional mode, we may be able to use a
low-gain pre-amplifier to reduce the cost. In addition,a larger signal output allows a higher discriminationlevel. Consequently, a higher noise level is acceptable.
In operation, a streamer occurs when electrons drift
close to the anode wire after the primary ionization.
The drift time depends on the position where the primary ionization occurred in a cell. Therefore, there
exists a time uncertainty or time spread. We investigated the time spread with cosmic ray and 90Sr source
by a triple coincidence setup which consisted of two
36

jacketI

WIre

comb extrusion

j 11/ I I rJ I

IIIIIIII!

Fig. 1. . The cross-section of two Iarocci tubes.

scintillation detectors one above and another below the
tube. The FWHM of time spread was about 75 ns for
Ar-C 4H lO , and was 40 ns for CF 4:C4HlO = 1:l.
Using the same method, we also measured the time
spread for two tubes shifted each other by half-cell (asshown in Fig. 1). The result confirmed that the time
spread decreased to about 40 ns for Ar-C 4H lO , which ishalf of that for a single layer tube. Namely, when two
tubes are layered and shifted by half-cell, one can meetthe requirement ( < 100 ns) of PHENIX trigger system.
To compare Chinese tubes with Italian ones, we firstmade a quality index (Table 1) to define a better tube.
We started the evaluation work from comparing Italian
tubes and Chinese assembled ones. The result showedthat Chinese tubes are as stable as Italian ones after
we examined all items listed above. 2 ) We are going toreceive 80 of genuine Chinese made tubes for further
comparison.
Table 1. Quality index of Iarocci tube.
Pressure drop
Current leakage
HV tolerance
Plateau range< 1 mbar after 10 min. at
30 mbar over-pressure.
< 1 J-LA without a source> 5.0 kV with Ar-C4HlO> 400 V beyond about 4.5 kV

Based on our R&D work, we suggest that Iarocci
tubes are to be operated in the streamer mode for
PHENIX muonID for a better noise tolerance andthere is no need to use CF 4 since the time spread already met the requirement when two tubes were layered and shifted by half-cell. In order to evaluate themuon identifier system as a whole, especially in muon
detection efficiency and pion rejection rate, we are going to perform test experiment at KEK.
References
1) E. Iarocci: Nucl. Instrum. Methods Phys. Res. A 217,
30 (1983).
2) Y. Nakada and Y. Mao: Report of MuonID Chamber
R&D at Kyoto, PHENIX-muon-96-11, Aug. 1996.

RIKEN Accel. Prog. Rep. 30 (1997)

Measurement of Neutrons from Muon Catalyzed
dt Fusion Reaction at RIKEN-RAL Muon Facility
N. Kawamura, S. N. Nakamura, K. Nagamine, T. Matsuzaki, K. Ishida, S. Sakamoto, M. Tanase,
M. Kato, K. Kurosawa, K. Kudo,* N. Takeda,* and G. H. Eaton**[Muon catalyzed fusion , Fusion produced neutron]
In this article , we report on the muon catalyzed fusion (J1CF) produced neutron detection system at the
RIKEN-RAL Muon Facility. For each dt-J1CF cycle,
one 14.1 MeV neutron is created via the following reactions:dtJ1-----tn + a + J1 + 17.6 MeV-----tn+aJ1+17.6MeV.

(> 99%),(1)(2)

The muon cycle rate (Ac) and the muon loss probability per cycle (W), which is mainly caused by the reaction (2) , were deduced from the neutron yield (Y n)and the decreasing time constant of neutron yield (An).
These values are associated each other as follows:(3)(4)
where Ao = 0.455 X 106 S-l is the muon free decay rate,and ¢ is the DT-target density.
In our setup two neutron counters , that have beencalibrated by the standard neutron source at the ETLTsukuba, were placed 82 cm away from the DT-target
along the J1 - beam axis (Fig. 1). The neutron events
via J1CF cycle were separated from ')'-ray events andfrom pile-up events by signal processing. We determine
An and the total neutron number due to p,CF , whichis the product of Y n and the J1- stopping number inthe target , from the neutron spectra.
Preliminary analysis on 28% tritium (T) concentrated pure DT -system shows:
1.262(6) X 10 6S-l

Liquid (20K) , (5)6s-lSolid (15K).

1.414(6) X 10

(6)

According to Eq. (3) , the above-obtained difference ofAn between the liquid and solid targets comes from the~"I "-------~"''''''' '''~J.!- beam fOCUSing~~ e- confinement ~~ .... '!Iag.n.et . . . . ~Fig. 1. The cross-sectional view of the neutron detection
system along the beam axis. The jJ,- beam injectedfrom the left is focused on the DT-target under 2.4 T
magnetic field. Two neutron counters were placed 82
cm down-stream from the DT-target. In front of theneutron counters, 5 cm thick lead blocks were placed,
so that jJ,-e decay electrons do not enter the neutron
counters.

difference in the target density (¢solid/¢liquid = 1.14),
and Ac and W do not depend on the DT-system phases.
However , only in the solid phase target we observed
the increases of An as a function of the time after thesolidification. This was not possible to observe in theliquid phase target. We consider that this effect is dueto the accumulation of the 3He decayed from tritium,
which can not diffuse nor go out from the solid DTsystem. If once a J1 - transfers from dJ1 or tJ1 to thisresidual 3He, 'in which binding energy of J1- is aboutfour times deeper than those of the hydrogen isotopes,
such a J1- can not contribute to the J1CF cycle, and as
a result An increases.

Electrotechnical Laboratory
Rutherford-Appleton Laboratory, U.K.

37

RIKEN Accel. Prog. Rep. 30 {1997}

Muon Transfer in Excited States of Muonic Hydrogen Atoms
Observed with X-ray Measurement
S. Sakamoto, K. Nagamine, and K. Ishida[Exotic atom, Muonic hydrogen X ray, Muon transfer]
The muon transfer between hydrogen isotopes [ e.g.,(pJ-L) + d ~ (dJ-L) + p] is one of the vital processes in
the muon catalyzed fusion (J-LCF). Muons may transfer from the excited states of muonic hydrogen atoms.
The population of the muonic hydrogen atoms in the
ground state is, therefore, different from the composition of the hydrogen isotopes. The parameter qls,l) defined by the probability of a muonic atom with lighter
nucleus to reach its ground state after its initial formation, has been introduced to express this muon transfer rate relative to the atomic cascade rate. Although
theoretical studies 2 ) predicted low qls, the first indirect measurements 3 ) for a d-t mixture have reported
rather high qis values.
The fraction of the non-radiative transition to theground state is negligibly smaU 4 ) in gaseous hydrogen.
The number of muonic hydrogen atoms that reach theground state can be estimated by observing Lyman
X-rays from muonic hydrogen atoms (1.9 f".J 2.7 keY).
The most crucial point is to detect and resolve X-rays
from different muonic hydrogen isotopes, whose energy
separation is only f".JO.l keY. A lithium-drifted silicondetector (Si(Li)) adopted for our experiment was managed to achieve the energy resolution of 112 eV at theenergy around 2 ke V.
The experiment has been initiated at the Port-3 of
RIKEN's Pulsed Muon Facility at the Rutherford Appleton Laboratory (RAL). A gas target chamber of 1.5
liter capacity was filled with protium gas, deuterium
gas, or their mixture. The gas density 1> was 0.01 of
liquid hydrogen density (LHD) when the chamber wascooled down to 1'"V80 K. The first experimental run was
successfully carried out in September, 1996. Figure 1
shows X-ray energy spectra in a prompt time interval.
Peaks of the Ka:, K,e, and K-y X-rays originated frommuonic hydrogen atoms are clearly seen in pure protium and pure deuterium spectra. By referring these
spectra for the exact energies and widths of peaks, thepeaks of X-rays from different muonic hydrogen isotopes are easily resolvable in the spectra of the mixtures of protium and deuterium.
Our previous result,S) along with a similar
experiment 6 ) at Paul Scherrer Institute (PSI), has suggested a high qls when the deuteron concentration
Cd::; 0.5. There are some theoretical and experimentalsuggestions that muonic hydrogen atoms may have arather high kinetic energy (f".J 1 e V) during their atomic
cascade process, which might explain this discrepancy

38

Preliminary
120

a) H2

PIt ~
/

/p,1l

~

IP't K,

80
40
0
120

>tU
V)

-

80

C'i

40

t il

0

M

>.
tIS

c) H 2+D 2(Cd-O.3)

7

160
><
.......
0

0

Z

120
80

40
0
240

d) ~+D2(Cd...(). 7)

160
80

o

l...-.~-L---'-----L.---'----..Jl...-...L..-....l....-....J

1.0

1.5

2.0

2.5

3.0

x -ray energy (ke V)
Fig. 1. Energy spectra of prompt X-rays (¢ = 0.01 LHD).
The events detected within 100 nsec of each muon beampulse were selected.

between measured and predicted qls ' S. The analysis
is now in progress and the second run is scheduled in
February, 1997 for more systematic measurements.
References
1) C. Petijean: Nuc!. Phys. A 543, 79 (1992).
2) A. V. Kravtsov: Phys. Lett. A 132, 124 (1988).
3) S. E. Jones et al.: Phys. Rev. Lett. 56, 588 (1986).
4) E. C. Aschenauer and V. E. Markushin: to be publishedin Hyperfine Interact.
5) S. Sakamoto and K. Nagamine: to be published in Hyperfine Interact.
6) B. Lauss et al.: Phys. Rev. Lett. 76, 4693 (1996) .

RIKEN Accel. Prog. Rep. 30 (1997)

Measurement of X-rays from a-Sticking in Muon Catalyzed
dt Fusion Reaction at RIKEN-RAL Muon Facility
K. Ishida, K. Nagamine, T. Matsuzaki, S. N. Nakamura, N. Kawamura, S. Sakamoto, M. Tanase,
M. Kato, K. Kurosawa, and G. H. Eaton*[Muon catalyzed fusion, Muonic X-ray]
Direct knowledge of the muon to alpha sticking probability (ws) in the Muon-Catalyzed Fusion (MCF) is
one of the most important observable in all the MCF
studies, since the Ws draws a stringent upper limit on
the energy-production capability from the MCF reaction. The Ws can be determined directly by measuring the characteristic muonic X-ray from the recoiling(MQ)+ ions. The 8.2 keY Ka X-ray with a Doppler
broadening of around 0.5 keY is expected to be observed. A serious difficulty in this X-ray measurement
in a high density and high tritium fraction D-T mixture is a huge radiation background of bremsstrahlung
up to 17 ke V from the tritium decay in a D-T mixture.
With a strong pulsed muon beam, the X-ray detection
system needs to be operational only during the presence of muon pulse, so that the signal to noise ratio
is drastically increased. This type of MCF experiment
was initiated at the Meson Science Laboratory, U niversity of Tokyo, located at the National Laboratoryfor High Energy Physics (UTMSL/KEK).l)At the RIKEN-RAL Muon Facility recently
completed,2) an advanced experiment was performed
with the strongest pulsed muon beam and using thetritium handling system which can remove the 3He
impurity produced from tritium decay. 3) A backward
negative muon with a double pulsed structure (each70 ns in duration with a 320 ns separation and 50 Hz
repetition frequency) was introduced into the liquid
DO.72To.28 target.
The typical energy spectrum is shown in Fig. 1,
which was measured by a Si(Li) detector placed 12.4
cm away from the target. A clear Doppler broadened
Ka peak is seen at 8.2 keY. The disappearance rateof the Ka peak was found to be consistent with thatof neutrons. 4 ) Also, the K,e /Ka ratio was preliminary
obtained to be 0.076 ± 0.027. Further measurements
are planned to determine this ratio more precisely.
Through calibration works of the X-ray detection

Liquid DT (80-2080 ns)

7000
6000
5000
{I)

=: 4000

=
Q

U

3000
2000
1000
0

4

6

8

10

12

14

Energy (keV)

Fig. 1. Energy Spectrum of the observed delayed partof the X-ray from muon catalyzed fusion in liquid
DO.72To.28. The time range is from 80 ns to 2080 ns
after the second muon beam pulse.

system, the number of occurrence X-ray emission was
obtained to be around 0.32 ± 0.03 per muon stopped in
the target. A detailed analysis of fusion neutron data
is now under progress to deduce the value of sticking
probability.
References
1) K. Nagamine, T. Matsuzaki, K. Ishida et al.: Muon
Catalyzed Fusion 5, 1239 (1990); Hyperfine Interact.
82, 343 (1993).
2) K. Nagamine, T. Matsuzaki, K. Ishida, 1. Watanabe etal.: Hyperfine Interact. 85, 1091 (1994).
3) T. Matsuzaki et al.: RIKEN Accel. Prog. Rep. 30, 151(1997).
4) N. Kawamura et al.: RIKEN Accel. Prog. Rep. 30, 37(1997).

Rutherford Appleton Laboratory, Chilton, DIDCOT, Oxon,
U.K.

39

RIKEN Accel. Prog. Rep. 30 (1997)

Experimental Study of CSB Force in N-d Scatterings at 12 MeV
N. Nishimori, K. Sagara, T. Fujita, H. Akiyoshi, F. Wakamatsu, K. Maeda, H. Nakamura, and T. Nakashima*[NUCLEAR REACTION: D(n,n)D , Polarized-neutron beam, En = 12 MeV; Charge symmetry breaking]Angular distribution of analyzing power Ay(8) ofD(n,n) scattering at En = 12 MeV was measured in
the CM angular range from 59.8° to 146.5° to study
the charge symmetry breaking (CSB) in the P-state
nucleon-nucleon (NN) interaction. The experimental
method and the preliminary result have been described
elsewhere.!) The statistical accuracy of the Ay(8) was
about 1.5% around the Ay maximum. The systematic
uncertainty of the Ay (8) is the sum of the uncertaintyof the n-beam polarization plus the other systematic
uncertainty in the D(n,n) experiment. To determine
the n-beam polarization uncertainty, we made a separate experiment on the polarization transfer coefficient K~' (0°) of the D(J:n) reaction by which a polarized neutron (n) beam was produced. The systematic
uncertainty of the present Ay (8) was estimated to be
1.0%, and the most accurate n-d data of Ay (8) was
obtained.
We compared our data with Triangle University National Laboratory (TUNL) data. 2 ) Though the global
structure of the angular distribution was nearly thesame, a small difference was found around the peak of
A y . The difference was 1.9±3.6% at the Ay peak. The
difference was mainly attributed to the difference of
3.9±1.0% between the adopted values for the K~' (0°)
of the D(J:n) reaction. The(0°) value adopted in
the TUNL experiment 3 ) was obtained using one setof the n-4He phase shifts, whereas the value adopted
in the present experiment was determined absolutely
without using the phase shifts.
In Fig. 1 we compared the present n-d data of Ay (8)with the ~d data of Ay(8) measured at the sameenergy.4) A distinct difference was found in the angular distribution. The n-d Ay (8) is smaller than the

p..d Ay(8) in the CM angular range from 60° to 110°,
and is larger in the CM angular range above 110°. If
the incident proton energy in the rrd scattering is assumed to decrease by 0.64 MeV due to the Coulomb
barrier, the angular dependence of 6.A Nd (8) is considerably well explained. At present we can not extract
any quantitative conclusion from the energy shift.
We extracted the difference in the Ay maxima between n-d and p..d scatterings (6.ANd) to study CSB of
N-N interaction, because it was considered that the Ay
has a large value of about 0.19 at the peak and seems
to be sensitive to a possible small change in N-N forces
such as caused by CSB. We obtained 6.ANd value of
0.0083±0.0028 at 12 MeV, which was slightly smaller
than that derived from the TUNL data as shown in
Fig. 2. This small value of 6.ANd is still higher thanthat by the approximate Coulomb calculation. 5)

Pr

..,

present.!of

n+d .....--.

~d ~

~

0.15

:t 0 .1
0.05•••.•••. •..•••. lr'l! .·( . ; ''' T

20

40

60

80

100

120

140

160

180

CM Angle. 8(deg.)

Fig. 1. Ay(O) ofN-d scattering at 12 MeV. The squares are
the present n-d data. The crosses are ji-d data obtainedat Kyushu University Tandem Laboratory (KUTL).
Department of Physics, Kyushu University

40

0,015

.1

0.01
0.005
0
0

II

I //
10

15

20

En(MeV)

Fig. 2. Energy dependence of Ay (0) difference between n-d
and ji-d scatterings at their peaks. The experimental
TUNL data are marked by + symbols. The square is thepresent data. The diamond shows an exact Coulomb
calculation. 6 ) The dotted line indicates an approximate
Coulomb calculation.

It is necessary to evaluate the contribution of
Coulomb force on 6.ANd in order to draw a conclusion on CSB of N-N interaction from the present experiment. If the energy shift by Coulomb force can be
explained by an exact Coulomb calculation at 12 Me V ,some conclusion may be possible to be drawn.
Referenceso ~~~--~~--~~~--~~

o

0 .02

IR

.t

•

Approx Coulomb -

te-

.t

tdata .......-..

Coulomb

0.025

Kt

0.2

f--

0.03

1) N. Nishimori et al.: RIKEN Accel. Prog. Rep. 29, 58(1996).
2) C. R. Howell et al.: Few Body Systems 2, 19 (1987).
3) P. W. Lisowski et al.: Nucl. Phys. A 242, 298 (1975).
4) K. Sagara et al.: Phys. Rev. C 50, 576 (1994).
5) T. Takemiya: Prog. Theor. Phys. 86, 975 (1991).
6) G. H. Berthold et al.: Phys. Rev. C 41, 1365 (1990).

RIKEN Accel. Prog. Rep. 30 (1997)

Cross Sections ofaxn Channels in the 40 Ar + 209Bi Reaction
Y. Pu, K. Morita, T. Nomura, Y. Tagaya, T. Uchibori, T. Minemura, M. Kurokawa,T. Motobayashi, M. G. Hies, T. Ariga, A. Yoshida, and K. Sueki[Nuclear reaction, a-decay, 209Bi (40 Ar, axn) 245- x Es, Elab = 207 MeV]
In an effort to search for a more effective method forthe synthesis of super heavy elements, an experiment
was performed to measure the cross sections ofaxn
channels in the reaction of 40 Ar + 209Bi. Even thougha similar measurement was carried out by Nomura etal. a few years ago,1) the present experiment was donewith an improved focal-plane detector, where a 2D position sensitive detector (PSD) was used to measureboth the single a-decays as well as the possible correlations of subsequent decays. From this experiment,a more decisive conclusion is expected regarding theprospect of using axn channels as an alternative tool
for the production of super-heavy elements throughheavy ion reactions.
A pulsed 40 Ar beam with energy of 7.6 MeV jnucleon
from the RIKEN Ring Cyclotron was passed througha thin aluminum-foil energy degrader to bombard a
0.8 mgjcm 2 209Bi target. The bombarding energy at
the center of the target was adjusted to be 207 MeV
to optimize the production of a2n channels. The key
point is to compare the production cross section ofaxn
channels with that of xn channels. The evaporation
residues were separated from the beam and the otherreaction products by using the gas-filled isotope separator (GARIS)2) at the cyclotron lab. The primarybeam was pulsed typically with a sequence of 1 sec onand 2 sec off mode in order to achieve a good separation
between the long-lived evaporation residues of interestand some short-lived transfer products when their adecay energies are close. The average beam current on
the target was around 30 pnA during a period of 4.5
days.
The result of the beam-off alpha spectrum obtainedin the present experiment is shown in Fig. 1 (a), and thesame beam-off alpha spectrum but measured 0.9 sec after the beam was switched off is in Fig. 1 (b) over thesame alpha decay energy region. In Fig. 1 (a), about
21 counts of alpha decays which are assigned to betransfer product of 212m At are clearly seen, while inFig. 1 (b), only a few events located around 7855- 7895
ke V survived. Due to the short life time of 212m At, only
an average of 0.1 events of 212m At decay could remainin the delayed spectrum. Because the energies of these
events are very close to the Ea of 242Es or 243Es, the4 events in Fig. 1 (b) are most likely originated fromthe alpha decay of 242Es or 243Es isotopes produced
through the 209Bi(40 Ar,a2n) or 209Bi(40 Ar,a3n) reactions. From a preliminary correlation analysis of thepresent data, we obtained a cross section of approximately 200 pb for the xn channels and obtained an
approximate cross section of 10 nb for the axn channels. The former value is consistent with the 4 n crosssection in the same reaction reported in Ref. 3 and thelater values confirmed the previous result reported by
Nomura et al. in Ref. 1. A more complete analysis of
the data is under way.

10
(a)
7.5

5

-

2.5

::s

10

U

8

C"J'}

s:=

0

(b)

6
4

2

0

7600

8000

8400

8800

Ea(keV)
Fig. 1. The a-decay energy spectrum measured in thereaction 40 Ar + 209Bi, at Elab = 207 MeV (a) during
the beam-off period and (b) 0.9 sec after switch-off ofthe beam.

References
1) T. Nomura et al.: RIKEN Accel. Prog. Rep. 24, 25(1990).
2) K. Morita et al.: Nuel. Instrum. Methods Phys. Res. B
70, 220 (1992).
3) S. Hofmann: Proc. Tours Symp. on Nuel. Phys. II, Aug.
3D-Sept. 2, p. 362 (1994).

41

RIKEN Accel. Prog. Rep. 30 (1997)

High-Spin States in 146Eu
E. Ideguchi, Y. Gono, S. Mitarai, T. Morikawa, A. Odahara, M. Kidera, M. Shibata, H. Tsuchida,
T. Kishida, X. Zhou, M. Oshima, Y. Hatsukawa, S. Hamada,* H. Iimura,*
T. Ishii, * and M. Ishihara
NUCLEAR REACTION: 140CeeOB,4n)146Eu,E(lOB) = 50 MeV;
[ 139Lae3C,5n)146Eu,Ee3C) = 98 MeV; ,-, coincidence measurement
In the N = 83 isotones high-spin isomers have beenfound systematically, i.e., 144Pm,1) 145Sm,2) 146Eu,3)
147Gd4) and 148Tb.5) Among them the half-life of thehigh-spin isomer in 146Eu is much shorter than those of
the adjacent isotones, 145Sm and 147 Gd, although theexcitation energies of these three isomers are similar,!"V8.5 MeV. This large deviation of half-life from thesystematics suggests a different origin in the isomerism
or an abrupt change of the level structure at high-spinstates in 146Eu.
On the other hand, isomers with the spin of 27/2 arealso found in the N = 83 odd isotones systematically.
The excitation energies of the states decrease gradually with increase of the mass number. The parities ofthese states, however, change suddenly from positive tonegative between 145S m 6) and 147Gd.4) This trend also
appears in the spin 10 states of N = 82 doubly-evenisotones between 144Sm7) and 146Gd.8) Since 146Eu islocated in the middle of 145Sm and 147 Gd, it is meaningful to study the level structure of 146Eu in order tounderstand the reason why the change of parity in 27/2
state happened. The spins and parties of corresponding states in 146Eu are estimated to be 16- or 15+ bycoupling 1 proton hole to the 27/2- state in 147 Gd or
1 proton to the 27/2+ state in 145Sm, respectively.
Although the level scheme of 146Eu was reported
previously9) up to the excitation energy of 3.5 MeV,
the 15+ state was only tentatively assigned and the
16- state was not found yet. The existence of 10 ns
isomer at !"V 8.5 MeV was also reported,3) but the decay
scheme from the high-spin isomer was not establishedwell.
In order to clarify the low lying states in 146Eu,
an in-beam ,-ray measnrement was made by using
140CeeOB,4n)146Eu reaction at the tandem laboratoryof Kyushu University. The lOB beam with energy of
50 MeV was bombarded on a natural Ce target withthickness of 1.6 mg/cm 2. The level scheme of excitedstates below 5 Me V was made based on this ,-, coincidence data.
For the purpose of constructing the level scheme
up to high-spin states, !"V8.5 MeV, another ,-, coincidence measurement was carried out by using
139Lae 3C,6n) 146 Eu reaction. The 13C beam of 98
MeV was provided by the J AERI tandem accelerator.
In order to obtain the time information of ,-rays thepulsed beam was used in the experiment. The duraJapan Atomic Energy Research Institute42

1tion and the repetition of the pulsed beam were 40
ns and 4 MHz, respectively. A self-supporting 139La
foil target with the thickness of 11 mg/ cm 2 was used.
Gamma-rays were detected by using six HPGe detectors with BGO Anti-Compton shields. These detectors
were placed at four different angles with respect to thebeam axis, so that the information of the angular distribution could be obtained. Fifty new ,-rays wereidentified to originate from 146Eu by setting gates on
the previously reported ,-rays.9) Figure 1 shows thelevel scheme so far constructed. Spins above 14+ state
were tentatively assigned based on the angular distribution of , -rays. The data analysis is still in progress.

.. ·· 14171',

4·....

(16) 1 ~)r (15)f~)
3715,--.....

>Q)

I 3782

J T

6

>-

(Jl
L

~

2

W

c

o

:.;;
....,o

'0
x

W

6-

o

Fig. 1. Proposed level scheme of 146Eu.

References
1) T. Murakami et al.: Z. Phys. A 345, 123 (1993).
2) A. Ferragut et al.: J. Phys. Soc. Jpn. 62, 3343 (1993).
3) E. Ideguchi et al.: Bull. Phys. Soc. Jpn. , p. 108 (1993).
4) M. W. Drigert et al.: Nucl. Phys. A 515 , 466 (1990);
and references therein.
5) R. Broda et al.: Proc. Symp. on High-Spin Phenomena
in Nuclei , Argonne, p. 397 (1979).
6) A. Odahara et al.: Z. Phys. A 350, 185 (1994).
7) E. Ott et al.: Z. Phys. A 348 , 57 (1994).
8) H . Wolters et al.: Z. Phys. A 333, 413 (1989).
9) A . Ercan et al.: Z. Phys. A 329, 63 (1988) .

RIKEN Accel. Prog. Rep. 30 (1997)

Study of High-Lying States in 147Eu
X. H. Zhou, E. Ideguchi, Y. Gono, T. Kishida, S. Mitarai, T. Morikawa, H. Tsuchida,
M. Shibata, H. Watanabe, M. Miyake, M. Oshima, Y. Hatsukawa, S. Hamada,*
H. Iimura,* M. Shibata,* T. Ishii ,* and M. Ishihara[NUCLEAR REACTION: 13C + 139La at E Zab = 98 MeV; "(-"( coin. measurement; Level scheme]
Extensive "(-ray spectroscopies of odd-mass nuclei
in the neighborhood of the doubly-magic 146Gd nucleus have resulted in a well -developed understanding of the coupling between a valence nucleon and an
even-even spherical core nucleus. 1-5) The weak coupling model was suggested to interpret the observed
yrast level (the yrast level is the lowest level in energy
at a given angular moment) structures in odd-A europium isotopes 3) which exhibit a level structure withthe spin sequence and energy spacing very similar to
the yrast level scheme of the adjacent even-even nuclei.
Prior to the present work the level structure in 147Eu
had been studied mainly via fusion- evaporation reactions with rather light projectiles. 3,6) Therefore, theprevious investigations have only provided information
on states with excitation energies less than 4.2 MeV.
In this paper we present the preliminary results for thehigher-lying states in 147Eu.
The excited states in 147Eu were populated by thereaction of 139La(13C, 5n) at the 13C beam energy ofEZab = 98 MeV provided by the Tandem Accelerator
at J AERI. A "(-"( coincidence measurement was performed with six HPGe detectors with anti-Compton
shields. Based on the coincidences with the known "(rays in 147Eu, sixteen new "( rays were identified tobelong to 147Eu. Therefore, the previously reported
level scheme for 147Eu was extended from 4174 keY to7064 keVin the excitation energy. The level schemefor 147Eu proposed from the present work is shown in
Fig. 1, The spin and parity assignments were adopted
from the previous work for low-lying states. 3)
In the weak coupling framework, it could be expected that states in 147Eu arise from the stretchedcoupling of d~/~ and g-;A proton holes to 148Gd7)
and of h 11 / 2 protons to 146Sm.8) Previous experiments
identified that t he d~/2 and g-;/~ proton hole states arelocated at 0 and 229 keY , respectively, and that theh11 /2 proton state occurs at 625 keY. With the zeroorder approximation , the energy of a state in 147Eu
is calculated to be the sum of the energy of the correct particle or hole state and the energy of the corresponding state of the even-even core. The predictionsof the weak coupling calculation are compared withthe experimental results in Fig. 1. The weak coupling
calculation indicates that the low-lying yrast states in
147Eu can be formed by the coupling of h 11 / 2 proton'"'""'-r"513

6l.l4!:()4\l~ ~_33/t--31/Z+

29/Z+

~~~

_ _ 21/'l'--23/r- - "SfT--17It

-'OIT

k
iJ
~~~1:

=:--41/Z+_ _ 35/z+-- rl/ t

1204

\

--31/t_ _ 271Z+ --29/'l'--29/T _ _ 25/z+--271r-~-- \~20565\ ~\n1 ~/~ f

1342

~

2994 =23/"zt

\

2898

fJJ7 ~/r j7--21/T

23/r- JJ21~2347 --fliT
9/r-

T

_i22

'OIT

t

23fr-

==~~~

--9/Z+ --fl/r---fl/'zt

1925--fl/'zt1345

720--n/r---45/T--45/T--43/T--33jz.+SIll-- - 4 I j l---13/T --13/'l'--~/r---~/Z+~/r-162t
625 '71z+ 229

5/~--9/'l'--71Z+--5/'l'Fig. 1. Comparison of experimentally observed levels in
147Eu with the zero-order weak coupling calculations
shown on the left for the hll / 2 proton state and on theright for the d~/2 and g-:;/2 proton hole states, respectively.

t o 146Sm, but the d~/2 and g-;/2 proton holes shouldplay an important role in the high-lying yrast states.
We are planning an experiment to assign the spin andparity values to the newly established levels in 147Eu.
References
1) S. M. Aziz et al.: Phys. Rev. C 41 , 1268 (1990).
2) T. Glasmacher et al.: Phys. Rev. C 47, 2586 (1993) .
3) J . G. Fleissner et al.: Phys. Rev. C 16, 227 (1977).
4) A. Odahara et al.: Z. Phys. A 350, 185 (1994).
5) E. Ideguchi et al.: Z. Phys. A 352, 363 (1995).
6) G. L. Bianco et al.: J. Phys. 7, 219 (1981).
7) S. Lunardi et al.: Phys. Rev. Lett. 53, 1531 (1984).
8) J. Kownachi et al. : Nucl. Phys. A 337, 464 (1980).

Japan Atomic Energy Research Institute

43

RIKEN Accel. Prog. Rep. 30 (1997)

High Spin Isomer Beam LineT. Kishida, Y. Gono, E. Ideguchi, T. Morikawa, M. Kidera, M. Shibata, H. Tsuchida, K. Miyazaki,
H. Watanabe, H. Wu, A. Tanokura, S. S. Yamamoto, A. Yoshida, S. Mitarai, A. Odahara, T. Murakami,
M. Oshima, H. Kusakari, M. Sugawara, M. Kubo, T. Murata, M. Shimura, H. Kumagai, and M. Ishihara
NUCLEAR REACTIONS: 12Ce40Ce,5n), 24Mge36Xe,a9n),[ Ep = 7-10 MeV lu; Recoil separator; High-spin isomer beams
The high spin isomer beam line of RIKEN Accelerator Facility is a unique apparatus in the world which
provides a high spin isomer as a secondary beam. In
general, the intensity of a secondary beam is muchsmaller than its primary beam. It is, therefore, very
important to study characteristics of high spin isomerbeam and to develop a beam line with a high transport efficiency. In this report , discussions are madeon some general requirements for the construction of ahigh spin isomer beam line.
First, Requirement for the Primary Beam. The
mechanism of inverse kinematics should be used, whichmeans that a heavy ion is the incident and a light atomis the target . For this case, the reaction products recoilin the forward direction, maintaining the kinetic energies high enough to induce the secondary reactions.
In general, the energy range required for the primarybeam is 6- 10 MeV/nucleon for the mass region of 140.
N ext, Requirement for the Reaction Mode. There
are many reaction modes for the production of highspin isomer states. In general, when the production target is heavier, the separation between the primary beam and the reaction products by their magnetic rigidity becomes better, and the angular divergence of the reaction products becomes larger; and viceversa. To see this more quantitatively, some calculations were made for 147 Gd produced by the reactionsof 12Ce40Ce,5n) and 24Mge36Xe ,a9n). From the results of the angular distributions of 147 Gd calculated
for these two cases, it is concluded that the angular
acceptance of ± 40 mr is large enough to transport Gd
efficiently even when the production target is heavy.
Calculations were also made for the charge state distributions of 147 Gd and of the primary beam as a function of the magnetic rigidity. The yield of 140Ce is 103
times as large as that of 147 Gd at the magnetic rigidity
with which the charge state distribution of 147 Gd becomes maximum, while the yield of 147 Gd is 105 times
as large as that of 136Xe in the latter reaction. And in
our energy region, it is concluded that a high spin isomer beam line must cover the range magnetic rigidity
0.8- 1.3 Tm.
There are some other requirements for high spin isomer beams: 1) The optics should be dispersive at thefirst focal plane. 2) The optics should have small dispersion after the first focal plane. 3) Double stage

44

1

spectrometer system is desirable. 4) The path lengthof the beam line should be as short as possible.
RIKEN Accelerator Facility has two beam lines
which have been used as a high spin isomer beam line:
E1C and RIPS.
E1C was a gas filled beam line in the first stage. A
gas filled system makes it possible to transport several
different charge states efficiently to the experimental
area. But the problem of this system was its beam
size. The diameter of the beam spot was more than
40 mm. It does not fit for the secondary reactions. By
evacuating the beam line, the diameter of the beam
spot became much less than 10 mm. E1C has an angular acceptance of ± 7 mr.
In order to improve the transmission efficiency, alarge acceptance beam line, RIPS , was recently used asa high spin isomer beam line. Though the RIPS is wellknown as a high energy RI beam line using a projectile
fragmentation method, it can be used also successfully
as a low energy isomeric beam line by using a fusionevaporation method. RIPS has an angular acceptanceof ± 40 mr.
By considering all the requirements described above,it is concluded that RIPS is more suitable for a highspin isomer beam line than E1C. RIPS has an advantage in every characteristics except the path length between the production target and the final focal plane.
RIPS has a long path length which corresponds to thetime of flight of about 860 ns , while E1C has that ofabout 220 ns.
For a quantitative comparison, some considerations
are made here for the case of 12Ce40Ce ,5n). When themagnetic rigidity is set at the value corresponding to
the charge state 48+ of 147 Gd, the acceptance for eachcharge state is calculated as (47+ : 5.1%, 48+ : 29%,
49+ : 5.1 %) for E1C , and (46+ , 47+ , 48+ , 49+ ,50+
: 100%) for RIPS. Then, by taking into account of thecharge state distribution, the total acceptance of E1C
becomes 9.4%, and that of RIPS 89%, which is almost
10 times larger than E1C. But, due to the flight decayof the isomer 47m Gd; t 1/ 2 = 0.55 J-ls), the resulting
transmissions are 6.4% and 19% for RIPS and E1C,
respectively. Then the ratio of transmission between
RIPS and E1C is calculated to be 3. The experimental
ratio was 4, which agrees with the calculation.

eRIKEN Accel. Prog. Rep. 30 (1997)

Measurement of Deuteron Spin-Flip Probability in the
12C(d, d ') Reaction at Ed == 270 MeV
Y. Satou, H. Sakai, H. Okamura, S. Ishida, N. Sakamoto, H. Otsu, T. Uesaka, T. Wakasa, T. Oonishi,
T. Nonaka, G. Yokoyama, H. Ohnuma, T. Niizeki, T. Ichihara, and K. Hatanaka[ NUCLEAR REACTION: 12C(d~ if) at Ed = 270 MeV; Isoscalar spin excitation]
Inelastic scattering of polarized deuterons is oneof the promising processes to study isoscalar spindependent excitation modes in nuclei, such as coherent particle-hole states and isoscalar spin strength in
the continuum. To perform the (<1,reaction, we
have developed a focal plane Deuteron POLarimeter (named DPOL)l) which utilizes the 12C(d, d) and1H(d,pp) reactions to cope with the simultaneous determination of all the vector and tensor polarizationsof the scattered deuterons. Effective analyzing powers and double scattering efficiencies of these reactions
have been measured by a calibration experiment andhave already been reported. 2)
Here we present new data obtained by the measurement of 12C(<1, d') reaction using DPOL. Eight spin
observables in the reaction (Ay ,A yy , Py' ,pY'Y' , K~' ,K~' Y' ,K~~ , K~~Y') and differential cross sections ((J")
were measured over an angular range from 2° to 8°
and an excitation energy range from 2 to 25 MeV.
A 270 MeV polarized deuteron beam from the
RIKEN Ring Cyclotron was used to bombard a 87.2
mg/cm 2-thick 12C t arget. Typical beam intensity was
10 nA. Details of the polarized deuteron beam are described elsewhere. 3 ) The scattered deuterons were momentum analyzed by a magnetic spectrometer SMART
and their positions were determined by a multiwire
drift chamber (MWDC) located at the second focal
plane. Plastic trigger counters accompanied with a
2.5 cm-thick polyethylene plate were used as the secondary targets. The 12 C (d, d) and 1 H (d, pp) reactions
took place in the targets were identified by a plastic
counter hodoscope (2 m x 2 m x 6.5 cm) which wasplaced 4 m downstream from the secondary targets.
Polarizations of the scattered deuterons were deduced
from the scattering asymmetry of these reactions.
Figure 1(a.) shows the excitation energy spectrum of
12C. The unnatural parity 1+ (12. 7 MeV) and 2- (18.3
Me V) states are clearly excited as well as the naturalparity 2+ (4.44 MeV), 0+ (7.65 MeV) , and 3- (9.64
MeV) states. All these are isoscalar states. Figure 1 (b)shows the spin-flip probability 8 1 (~8z = 1) plotted
every 500 ke V bins. 8 1 is derived from the tensor spin
observables by using the relationship:

a')

1
, ,
8 1 = -9 (4 - A YY - Py Y - 2KYYYY ) .
J

J

(1)

The result is based on the analysis of 60% of the total
data collected. The errors given are statistical ones

'0
Q.l

>=

260

0
0 .•

-

rn

0.2

0.0
0

5

10

15

20

excitation energy (MeV)
Fig. 1. Experimental results of the deuteron polarizationtransfer measurement on 12C. (a) Measured excitationenergy spectrum. (b) Spin-flip probability 51.

only. It is to be noted that this is the first case inwhich 8 1 is presented as a spectrum. The spin-flip 1+
state at 12.7 MeV is strongly enhanced compared tothe other natural parity transitions. This shows that
8 1 is a good signature of the isoscalar spin transfer
strength.
From the recent analysis of the 12C(d~ d') experiment
performed at SATURNE, Johnson et a1. have reported
a previously unknown isoscalar state of a 1+ nature
at 20.5 MeV. 4 ) They have measured a vector polarization of the scattered deuterons to extract a signature
8~ .5 ) It would be of interest to see that our data shown
here seem to suggest as well an existence of some spinflip structure at the corresponding excitation energy
region.
Further analysis to estimate the systematic errors
as well as to extract the double spin-flip probability
8 2 (~8z = 2) is now in progress.
References
1) S. Ishida et al.: AlP ConL Proc. 343, 182 (1995).
2) S. Ishida et al.: RIKEN Accel. Prog. Rep. 29, 179(1996).
3) H. Okamura et al.: AlP Conf. Proc. 343, 182 (1995).
4) B. N. Johnson et al.: Phys. Rev. C 51, 1726 (1995).
5) M. Morlet et al.: Phys. Lett. B 247, 228 (1990).

45

RIKEN Accel. Prog. Rep. 30 (1997)

Measurement of Polarization Correlation Coefficient forthe 3He(d,p)4He Reaction
T. Uesaka, H. Okamura, T. Oonishi , Y. Satou, S. Ishida, N. Sakamoto, H. Otsu, T. Wakasa,
T. Nonaka, G. Yokoyama, K. Itoh, T. Wakui, and H. Sakai
NUCLEAR REACTIONS 3He(d,p)4He, E = 270 MeV; Measured
polarization correlation coefficient, Polarized beam, Polarized target
A structure of deuteron is still an important subject in nuclear physics. In particular, the D-state wave
function in the high p - n relative momentum region
is not well studied.
Recently, we have proposed a new approach to study
the D-state wave function, by measuring the polarization correlation coefficient, Gil, for the 3He( d, p )4He
reaction. Here, Gil is defined as a ratio of the differential cross section at forward angle when d- and 3Hespins are parallel each other to that when spins are
unpolarized,

breakup bump

1500

I

Qi

s::
s::

(d,p) from\ glaSS , air, ...

1l 1000

3He (d,p)4 He

\

(.J

....
';;;-

I::::IoU

500o ~~~~~~~~~~-~~~~~b=~~

400

- dan
GII - - - - .

600

600

1000

1200

1400

Proton energy loss [Channel](1)

daunpol

Fig. 1. Proton energy loss spectrum in N aI.

Assuming that s-wave is dominant in the neutron
capture process by 3He, the Gil is expressed underplain wave Born approximation by

0.00-005 ~

29w (k)Gil = 4 u 2 (k) + w 2 (k)'-0 15 ~

where k, u(k) and w(k) are the p - n relative momentum, the S-state deuteron wave function, and the
D-state one, respectively. It is important to point out
that Gil is directly proportional to the D-state density
at k.
The present experiment was performed at E3-roomof RIKEN Accelerator Research Facility. This is thefirst experiment to use the polarized 3He gas target
developed at RIKEN. 1 ) The polarized 3He gas with athickness of about 10 mg/cm 2 was bombarded by a polarized deuteron beam of 270 Me V. Protons at 4 0 weredetected by NaI(TI) detectors with 2/1 ¢ x 3/1 in size,
which were placed at a distance of 2.6 m downstream
from the target. Figure 1 shows a measured energy
spectrum. A peak corresponding to the 3He(d, p)4He
reaction, which has a large positive Q-value , is isolated from a large bump which is most probably due
to deuteron breakup events.
The coefficient Gil is a linear combination of thetensor analyzing powers, Axx and A yy , and the vector
polarization correlation coefficients, Cx,x and Gy ,y:Figure 2 shows a preliminary result of the measured
asymmetry. This asymmetry corresponds to
1

3T

4 Pyy (Axx + Ayy) + 4PxPy (Gx ,x + Gy ,y),46-010 ~(2)(4)

Beam with pure t ensor mode

(a)

o

,

o-Tl +0 . +

-020~
>,

•

~ -025~~~rl ~~~-+~~~-+~~~~~____~~<(b)

Beam with pure vector mode

0.1-

.

• +.

+

0

0

•

+

+
• + ••

-

:

"'9
y

0

0

y

-:

• +' :.t----------¢ ,..

0.0 -- - - -.,-- - - - - - - - - - - - .,...- - - - - - - ~G - - - - - - 0
'-'
0 r-.

0

¥

- 0.1 -

50

60

70

RUN #

60

.3

He Cp
03 He Do wn

Fig. 2. A preliminary result of the measured asymmetry.
Error bars included statistical errors only, Each run
took approximately for 2-hours.

pJ

where Pyy , Py , andare the beam tensor, the vector polarization, and the target vector polarization, respectively. Figure 2(a) is the asymmetry for the beamwith the pure tensor mode (Pyy rv -0.9 , Py rv 0). It
does not depend on the 3He polarization. On the other
hand , Fig. 2(b) shows the asymmetry by the beam withthe pure vector mode (Py rv - 0.45 , Pyy rv 0) , whichchanges its sign depending on the 3He polarizations"U p" or "Down" .
Further analysis to obtain Gil is in progress.
References
1) T, Uesaka et al.: RIKEN Accel. Prog. Rep. 30, 139(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Spin-Flip Dipole State of 90y Studied by the 90Z r (d,2He)
Reaction at Ed = 270 Me V
H. Okamura, T. Uesaka, T. Wakasa, Y. Satou, T. Oonishi, T. Nonaka, H. Sakai,
S. Ishida, N. Sakamoto, T. Ichihara, T. Niizeki, and H. Ohnuma
NUCLEAR REACTION: 90Zr(polarized d, 2He); Ed=270 MeV;
[ Measured (J, A y , A yy , and Axx; Multipole decomposition analysis
In spite of the extensive study made by using thecharge exchange reactions at intermediate energies,
the understanding of the spin- and isospin-flip statesother than the Gamow-Teller state (L=O) is still rather
limited. The (d,2He) reaction is considered to be a
promising tool for the study of higher multipolarities,
because (a) it exclusively excites the spin-flip state,(b) the background Gamow-Teller transition is Pauliblocked for heavy nuclei, and (c) the tensor analyzing
powers, Ayy and A xx , are useful in identifying J7r of
the final state. The last feature (c), which was theoretically pointed out first,1) has experimentally been
established by the previous study of the 12C(d, 2He)12B
reaction. 2)
The aim of the present experiment is a study of thespin-dipole state (8=1, L=l) of 90y, making the mostof the feature (b). The angular distributions of thedifferential cross section, A y , A yy , and Axx for the
90Zr (d,2He) reaction at 270 MeV have been obtainedin the range of 6L =00-15°. The typical spectra of thedifferential cross section and Axx are shown in Fig. 1.
It should be noted that a fine structure of low-lying levels observable in Fig. l(a) was smeared out in the (n,p)
spectra obtained at TRIUMF because of the lack of energy resolution. 3 ) The (n,p) spectra also suffered fromthe large amount of hydrogen contamination caused by
the complicated target system.
Since the simple one-step distorted-wave Born approximation (DWBA) was proved to be successful inthe analysis of the 12C(d, 2He)12B reaction,!) the multipole decomposition of the spectra has been performed
based on the DWBA prediction for various L-transfers.
The result is shown in Fig. 1(b). The dipole component is dominant up to the excitation energy of about
20 Me V. This allows us to discuss the analyzing powers with small ambiguities.
Concerning the spin-dipole states, the DWBA prediction is summarized as following: Axx
2 for0-, Axx rv + 1 for 1 - , and Axx rv 0 for 2 - . The
observed Axx shows, however, a structure-less distribution with a positive but small value in the whole
region measured. It suggests that there exists no concentrated distribution of the 0- or 1- state and thatthe dipole component mainly consists of the 2- state.
This is consistent with the recent result of the (p, n)measurement. 4 ) Further analysis is in progress.
f'V

-

0.4

90 Zr (

d,2He )90 y

Ed,=270MeV(a)
Oem = 1.9°

0.3>' 0.2
Q)

~

!-.

rn

0.1

~

.!:J

S
(b)

kl

"tj

c

"tj
~
N

b

0 .2

"tj

0.1

0.4
0.2
0.0
-0.2

~~ 0.4em = 6°-10°

0.2

-~:~
-5

0
gOy

5

10

15

20

25

Excitation Energy (MeV)

Fig. 1. (a) Spectrum of the differential cross section at
the mean center-of-mass angle of 1.9°. The contributionof the hydrogen contamination is shown by the shaded
area. (b) Multipole decomposition of the spectrum at
2° - 4°. The contributions of each L-transfer component
are indicated by the shaded regions. The total spectrum
reconstructed is in good agreement with the data shownby the closed circle. (c) Spectra of the tensor analyzing
power Axx at 2°_6° and 6° - 10°.

References
1) D. V. Bugg and C. Wilkin: Nucl. Phys. A 467, 575(1987).
2) H. Okamura et al.: Phys. Lett. B 345, 1 (1995).
3) K. J. Raywood et al.: Phys. Rev. C 41, 2836 (1990).
4) T. Wakasa et al.: Nucl. Phys. A 599, 217c (1996).

47

RIKEN Accel. Prog. Rep. 30 (1997)

Production Cross Sections of Projectile-like Fragmentsin the 48Ca
64Ni and 48Ca
181Ta Reactions at 70A MeV++

M. Notani, N. Aoi, D. Beaumel, N. Fukuda, M. Hirai, E. Ideguchi, M. Ishihara, H. Iwasaki, T. Kishida,
T. Kubo, H. Kumagai, S. M. Lukyanov, T. Nakamura, Y. T. Oganessian, Y. E. Penionzhkevich,
H. Sakurai, T. Teranishi, Y. Watanabe, Y. Watanabe, K. Yoneda, and A. Yoshida
NUCLEAR REACTIONS: 64Ni,181Ta(48Ca,X), E(48Ca) = 70A MeV;
[ Production cross sections of projectile-like fragments.
The particle stability of extremely neutron-rich nuclei close to the drip-line can be used for testing
various mass predictions. For the efficient production of extremely neutron-rich nuclei, we have investigated the target dependence on production rates ofthe projectile-like fragments1) with a 70A MeV 48Ca
beam. In addition, we made an attempt to estimatecross sections and yields for 33Ne, 34Ne, and 36Na, andto argue their particle stabilities. We expect the target
dependence to give a clue of elucidating the production
mechanism of projectile-like fragments at intermediate
energies (10 100 A MeV).2)
To investigate the target dependence on production
cross sections, we used two energy-loss-equivalent production targets, 64Ni and 181Ta, with thickness of 244
and 400 mg/ cm 2, respectively. The experimental setup
is described in Ref. 3. Table 1 shows the ratio of
the yield for 18 1Ta target to that for 64Ni target with
Bp = 3.68 Tm setting of the RIPS spectrometer. We
found that the 181Ta target provides lager yields than
64Ni for the fragments with A = 3Z + 2. Thus, weemployed the 18 1Ta target for the next new isotope
search experiment. By using the transmission calculated with the INTENSITY code,4,5) we deduced the
production cross sections from the production rates ofprojectile-like fragments for 19- 23 N, 21- 24 0, 23- 29 F,
24-3 2Ne, 29- 35 Na, 34- 38 Mg, and 35-41 Al as shown in
Fig. 1.

1

10 0'i> 10- 3

..s
c

j

10- 6

"'2

u

10 - 9I".J

Table 1. Ratios of the yields for 181Ta to 64Ni targets inneutron-rich fragments production in the F-Na region.
A
3Z - 13Z
3Z + 1F
0.42 ± 0.03 0.62 ± 0.04 (unstable)
Ne 0.21 ± 0.07 0.36 ± 0.05 0.84 ± 0.03
Na 0.26 ± 0.16 0.29 ± 0.08 0.44 ± 0.22

3Z + 2
1.6 ± 0.3
2.0 ± 0.5
1.5 ± 0.7

At the new isotope search experiment with the 181Ta
target, we found no events associated with 33Ne, 34Ne,
and 36Na. No observed events of these isotopes insists on either their particle instabilities or insufficient
statistics due to low cross sections. Thus, we have estimated the cross sections and total yields with all of ourdata sets for the new isotope search. In this estimation,
we assumed that isotope and isotone dependencies on

48

20

30
Mass Numb e r , A

40

Fig. 1. Production cross sections of projectile-like fragments for the 64Ni and 181Ta targets, compared withthose calculated by the INTENSITY code. 4)

the cross sections are described in an exponential form
with consideration of even-odd effects. The estimatedcross sections and total yields are tabulated in Table 2.
At present, due to low statistics or large uncertainties
of the cross sections, we could not conclude their particle instabilities.
Table 2. Estimated production cross sections and yields
under present experimental conditions with the 181Ta
target for three nuclei, 33Ne, 34Ne, and 36Na.
Nuclei

Cross section [pb]1 - 6
0.6 - 3
0.4 - 1

Yield [counts]
1.5-8.7
0.8 - 4.0
0.6 - 1.6

References
1) M. Notani et al.: RIKEN Accel. Prog. Rep. 29, 50(1996).
2) D. Guerreau: Nucl. Phys. A 447, 37c (1985).
3) H. Sakurai et al.: RIKEN Accel. Prog. Rep. 30, 49(1997).
4) J. A. Winger, B. M. Sherrill, and D. J . Morrissey: Nucl.
Instrum. Methods Phys. Res. B 70, 380 (1992).
5) Y. Doki: JAERI-M 94-028, p. 70; Master thesis, Univ.
Tokyo (1994) .

RIKEN Accel. Prog. Rep. 30 (1997)

New Neutron-Rich Isotopes 38Mg, 40 AI, and 41 Al Produced
by Fragmentation of a 70A MeV 48Ca Beam
H. Sakurai, N. Aoi , D. Beaumel, N. Fukuda, M. Hirai, E. Ideguchi; M. Ishihara, H. Iwasaki, T. Kishida,
T. Kubo , H. Kumagai, S. M. Lukyanov, T. Nakamura, M. Notani, Y. Ts. Oganessian, Y. E. Penionzhkevich,
T. Teranishi, Y. Watanabe, Y. Watanabe, K. Yoneda, and A. Yoshida[NUCLEAR REACTIONS: 181Ta(48Ca,X), E(48Ca)=70A MeV; Evidence for 38Mg, 40 AI, 41 AI]
The results of an experiment by the RIKEN- JINR
collaboration on search for the new N e, N a , Mg and Al
isotopes close to the neutron drip-line are presented.
We found , for the first time, three new neutron-richnuclei: 38Mg and 40,41 AI.
These nuclei were produced by the projectile fragmentation of a 70A MeV 48Ca beam. The 64% enriched 48Ca oxide powder was used to produce the
48Ca ions at the ECR source of the AVF cyclotron.
The 48Ca beam reacted with a 181Ta target of 400
mg/cm 2 thickness. The reaction fragments were collected and analyzed with the RIPS spectrometer 1) operated in the achromatic mode. Taking into accountthe energy loss in the target for both the beam andfragments with A/ Z
3.2 , the magnetic rigidity of
the RIPS was set to be 3.438 Tm. Particle identification was performed event-by-event by measuring themagnetic rigidity (Bp) , time-of-flight (TOF) , energy
loss (!:lE) , and total kinetic energy (TKE).2)
The positions of fragments at the momentumdispersi ve focal plane were measured using a parallel
plate avalanche counter (PPAC) in order to determine
the Bp value. The PPAC with the sensitive area of
15 cm(W) x 10 cm(H) was larger than the one used
at a previous experiment: 2) it covered the full rigidity
acceptance of RIPS (6%). All of the other detectors
were located at the final focal point (F3) , involving a
0.5 mm thick plastic scintillation counter (PL), a fourelement silicon-detector telescope, and an 1 mm thickplastic scintillation veto counter. The TOF of eachfragment over the 27.5 m flight-path between the target and F3 was determined from the PL timing andRF signal of the cyclotron. The silicon telescope consisted of two 0.5 mm thick surface-barrier-type silicondetectors , and 3 mm and 4.2 mm thick lithium-drift
silicon detectors. This configuration provided two or
three independent !:lE measurements and all the silicon detectors combined provided a TKE measurement.
The veto counter was used for rejecting such events as
piled up due to light fragments. The measured valuesof Bp , TOF , !:lE , and TKE were combined to give redundant particle identifications for obtaining the proton number (Z), charge (Q) , and mass number (A) of

the fragment, as described in Ref. 2.
Figure 1 shows a two-dimensional plot of events,
A/Z versus Z . The result was obtained from the data
accumulated for one day with an average beam intensity of "-'2 pnA. Significant numbers of events were observed for new isotopes, 38Mg (18 events), 40 Al (34events) , and 41 Al (4 events). We observed no events associated with 33Ne. We took also the data with different Bp settings, e.g., for A/Z 3.3 and 3.4, and witha higher beam intensity up to 4 pnA, where no 33Ne
events were observed, either. These data were evaluated to estimate the expected yields of 33Ne, which
may lead to arguments on particle instability of 33Ne.
The related discussion is found in Ref. 3.
t'.J

t'.J

z
14

13

.

12 "

. .

"

~..j~;. . ~,
.\

;/

",-.

~ ';Ij: ~i(:.2.8

2.9

3.1

3.2

3.3

3.4

AIZ
Fig. 1. Two-dimensional A/Z versus Z plot. Three 38Mg,
40 AI, and 41 Al isotopes are clearly visible. See text for
further details.

References
1) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
2) H. Sakurai et al.: Phys. Rev . C. 54, R2802 (1996).
3) M. Notani et al.: RIKEN Accel. Prog. Rep. 30, 48(1997).

49

RIKEN Accel. Prog. Rep. 30 (1997)

Isomer Production in Fragmentation Reactions
Induced by a 70A MeV 48Ca Beam
H. Iwasaki, N. Aoi, D. Beaumel, N. Fukuda, M. Hirai, E. Ideguchi, M. Ishihara,
T. Kishida, T. Kubo, H. Kumagai, S. M. Lukyanov, T. Nakamura, M. Notani, Y. Ts. Oganessian,Y. E. Penionzhkevich, H. Sakurai, T. Teranishi, Ya. Watanabe, Yu. Watanabe,
K. Yoneda, and A. Yoshida
NUCLEAR REACTION: 64Ni,181Ta(48Ca,X),E(48Ca) = 70AMeV; Measured (fragment) gamma-coin;
Reviewed small T 1/ 2 isomer production for 26'mNa and 32'm AI.
Recently the projectile-like fragmentation has beenused as a method for production of long-lived isomers1)
as well as radio-active beams. The study on isomericstates of the reaction fragments is important for understanding the reaction mechanism of projectile-likefragmentation. We have made an attempt to search
for new isomers in neutron-rich nuclei in the 7::; Z ::; 18
region, and have deduced isomer ratios of the known
isomers, 26'mNa and 32'm AI, with two different targets.
The neutron-rich nuclei were produced by using the
projectile fragmentation of a 70A MeV 48Ca beam. We
used two targets, 181Ta and 64Ni, with thickness of
400 mg/cm2 and 244 mg/cm 2, respectively. The reaction fragments were collected and analyzed by RIKEN
projectile-fragment separator (RIPS).2) The magnetic
rigidity of RIPS was set to be 2.78 Tm to optimize
for A/Z 2.6 nuclei, while the momentum acceptance
was restricted to 0.2%. The reaction fragments were
implanted into a 2 mm thick Al stopper, which was located between the first and second silicon detectors at
the final focal plane (F3), as described in Ref. 3. The
particle identification was performed event by event bymeasuring the ~E and TOF. The "I rays from the implanted ions were measured by using a Clover-type Ge
detector4) placed 20 em apart from the stopper. The
Ge detector was calibrated with standard 15 2Eu and
133Ba "I-ray sources. The summed photo-peak efficiency of the Ge detector was obtained about 0.2%
at 1 MeV. The detector covered the energy range from
20 ke V to 3 Me V. The timing spectra of "I rays wereobtained using a unit called TDC (Lecroy 4208) whosegate opened for 30 JiS after the arrival of a fragment at
the stopper.
Implanted fragments were 17- 19 N, 18- 21 0, 20- 23 F,
23-26Ne, 25- 28 Na, 28-31 Mg, 31-34 AI, 34- 36 Si, 37-39p,
39- 42 S, 42- 45 CI, and 46-47 Ar. These fragments wereaccumulated from 50,000 to 800,000 events withthe 181Ta target. The statistics obtained with the
Ta target was about seven times lager than thatwith the 64Ni target. Among them, we could findno characteristic peaks indicating the new isomers.
t"V50

On the other hand, we have observed known "Irays from 26'mNa (E-y=82.5 keY) and 32m Al (E-y =221.6,
734.1 keV).1) The sensitivity of this experiment for new
isomer search was limited. For instance, more than
10% of isomer ratio is necessary for detecting the associates of 200 ke V "I rays.
We deduced a half-life of 32'm Al to be 185 ± 15 ns byanalyzing a timing spectrum gated by the "I ray at energies of 221.6 keY and 734.1 keY. This half-life is consistent with that previously reported, 200 ±20 ns.1)
Taking account of the "I-ray detection efficiency andthe isomer decay in its flight, we have deduced theisomer ratios of 26m N a and 32'm Al for each target.
In this evaluation, the half-lives used for 26mNa and
32m Al were, 9.2 JiS and 185 ± 15 ns, respectively. Table 1 shows the measured isomer ratios for 26'mNa
and 32m AI , compared with the results measured at
GANIL.1) High isomer production is evident in thesystems of 48Ca + 181Ta and 48Ca + 64Ni as high asthat in the 40 Ar + 9Be system obtained at GANIL.
Table 1. Isomer ratios (F) obtained for 26mNa and 32m Alwith two different targets, compared with the resultsfor 32m Al measured at GANIL.

Isomer26mNa
32'm Al
32m All)

Beam
48Ca
48Ca
48Ca
48Ca
36S
40Ar

Target
181Ta
64Ni
181Ta
64Ni
9Be
9Be

E/A(MeV)
70
70
70
70
75
61

F (%)
16 (1)
13 (3)
78 (7)
68 (13)32 (3)
93 +7-12

References
1) M. Robinson et al.: Phys. Rev. C 53, 1465 (1996).

2) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70 , 309 (1992).
3) H. Sakurai et al.: RIKEN Accel. Prog. Rep. 30, 49(1997).
4) Catalog of Eurisys Mesures (France, 1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Angular Distribution of the 8B Dissociation and E2 Components t
T. Motobayashi, T. Kikuchi, N. Iwasa,*l Y. Ando, M. Kurokawa, S. Moriya,
H. Murakami, T. Nishio, J.-Z. Ruan, S. Shirato, S. Shimoura, T. Uchibori, Y. Yanagisawa, T. Kubo,
H. Sakurai, T. Teranishi, Y. Watanabe, M. Ishihara, M. Hirai , T. Nakamura, S. Kubono, M. Gai,*2
R. H. France III,*3 K. Inskik Hahn, T. Delbar, P. Lipnik, and C. Michotte[208Pb(8B,7Be p)208Pb, Coulomb dissociation, E2 component , Angular distribution]
Breakup of 8B in the Coulomb field of 208Pb was
performed for the first time at RIKEN. 1 ) The results
demonstrated that this Coulomb dissociation provides
an alternative method for studying the 7Be(p,,)8B reaction at low energies. This reaction is important for
estimating the high-energy neutrino flux relevant to
the "solar neutrino puzzle", defined as the discrepancy
between the measured and predicted neutrino yields
from the sun.
A question remains for possible contribution ofE2 transitions to the Coulomb dissociation results,
whereas astrophysical 8 17 -factors were extracted by assuming pure E1 transitions in the analysis reported inRef. 1. In the 7Be(p,,)8B reaction, the E2 amplitudes
are very small, but they are enhanced in the Coulomb
dissociation process. It is known that the differential
cross section (dO'l dB) near the grazing angle is sensitive to the E2 component. The nuclear excitation,
which introduces an uncertainty in the analysis, is important also for the angular momentum transfer R = 2
in addition to the E2 Coulomb excitation.
We performed new measurements of the dissociation of 8B in order to elucidate E2 contributions. 2)
The RIPS separator provided radioactive 8B beamsof 2 x 104 particles per second, which bombarded a
50 mgl cm 2 208Pb target. The averaged incident energy was 51.9 MeV l u. The breakup fragments , 7Be
and proton , were detected in coincidence after traveling through the 3.1 m flight-path filled with heliumgas. In order to increase the sensitivity of the measurement to the E2 amplitude, the detector system covereda larger angular range up to B8 ~ 10° compared withthat in the the first experiment where the efficiency
was essentially zero in the vicinity of B8 = 6° .
Figure 1 shows the experimental yields as a functionof the scattering angle B8 for two relative energy bins.
The yield labelled as E • dO'l dB is related to the original cross section dO'l dB via the response function thattakes into account the detection efficiency and all sortsof experimental resolution. The response function was
obtained by a Monte-Carlo simulation and used also in
calculating the theoretical Eland R = 2 curves. N uclear contribution for f = 2 transitions was evaluated
*1

*2
*3

Condensed from an article in Phys. Lett. B , in print.
GSI, Germany
Department of Physics, University of Connecticut, U.S.A.
Institut de Physique Nucleaire , Universite Catholique deLouvain, Belgium

10 0..--..
"0
~

~

10- 1

""'-

e 10 - 2CI::>"0""'b 10 - 1
"0
~

10- 2
10- 3
0

2

6

4

8

10

88
Fig. 1. Observed cross sections, Edcr / d8 , defined by the
product of the detection efficiency and differential
cross section, as a function of the scattering angle 88
for two relative energy bins of 500- 750 keY (a) and
1250- 1500 keY (b). The theoretical best fits (solid
curves) are in favour of the pure E1 transitions. Dashedand dotted curves correspond to the results calculatedwith R. = 1 [E1] and R. = 2 [E2 and nuclear] components
predicted by two different theoretical models, respectively.

by a quantum mechanical calculation with a collective
form factor , where the deformation length was set tobe the same as the Coulomb one.
The curves for the pure E1 transition fit to the dataof Fig. 1, thereby suggesting very small R = 2 amplitudes at low relative energies. In fact, the best fits arein favour of essentially no mixture of R = 2 amplitudes
below 1. 75 MeV. The curves calculated with a mixtureof the R = 2 amplitudes (: obtained by applying two
different theoretical models 3,4) on 8B) are also shownin the figure for comparison. The small R = 2 component verified here may support our previous analysis
with pure E1 transition in deducing the 817 factors
from the Coulomb dissociation data. 1 )References
1) T. Motobayashi et al.: Phys. Rev. Lett. 73, 2680 (1994);
N. Iwasa et al.: J. Phys. Soc. Jpn. 65, 1256 (1996).
2) T. Kikuchi et al.: RIKEN Accel. Prog. Rep. 29, 73(1996).
3) B. T. Kim , M. H. Park, and K. H. Kim: Phys. Rev. C
35 , 363 (1987) .
4) S. Typel and G. Baur: Phys. Rev. C 50, 2104 (1994).

51

RIKEN Accel. Prog. Rep. 30 (1997)

Charge Exchange Reactions of Neutron-Rich Nuclei
S. Shimoura, T. Teranishi, Y. Ando, M. Hirai, N. Iwasa, T. Kikuchi, S. Moriya, T. Motobayashi,
H. Murakami, T. Nakamura, T. Nishio, H. Sakurai, T. Uchibori, Y. Watanabe,
Y. Yanagisawa, and M. Ishihara
NUCLEAR REACTIONS: 1,2H(l1Li,l1Be*), 1,2 H(9Li,9Be*), 63 A MeV;
[ Charge exchange reaction; Isobaric analog state; Neutron halo.
Charge exchange reactions of (p,n) and (d,2n) havebeen measured for the 11 Li and 9Li nuclei employing
the inverse kinematics and invariant mass methods at
63 A MeV.
The experiments have been performed at the RIKEN
secondary beam line called RIPS. The detector setup
is described in elsewhere. I)
We have observed the isobaric analog state (lAS)of 11 Li nucleus in the relative energy spectrum of the
9Li+p+n system produced by the 1H(l1 Li,l1 Be* ~9Li+p+n) reaction. The lAS has been identified by
the comparison between the relative energy spectra forthe 1Hand 2H targets 1) and the angular distribution(Fig. 1) of the 9Li+p+n center-of-mass system.

s-wave resonance.
The excitation energy and width of the lAS of 11 Li
nucleus are deduced to be Ex = 21.14 ± O. 03 MeV andr = 0.25~g:i MeV, respectively, by an R-matrix analysis (Fig. 2). The Coulomb displacement energy estimated from the above Ex is smaller than that for the
9Li nucleus, which is attributed to the extend natureof the wave function of halo nucleons. The magnitudeof width of the lAS indicates an importance of the swave component of the halo nucleon in the lAS, whichis consistent with the result of the angular correlation
analysis.
200

>Q)

::::s

~+p+n
150

'-.....
..0

3

-c:l

100

t:.:I
~

'-.....
b

~

50

UJ

0

0

2

3

4

5

Ed (MeV)Fig. 2. Relative energy spectrum of the 9Li+p+n system
for the Fermi transition. Solid line denotes a predictionof an R-matrix analysis

o

2

3

4

5

8 lab (deg)Fig. 1. Angular distribution of the observed differential
cross-section in the laboratory system for the 9Li+p+ncenter-of-mass system. Solid line denotes a Gaussianfit.

The decay mode of lAS is analyzed from relative
energy spectra of the two-body systems 9Li+n andp+n. The angular correlation of p and n is also analyzed for the angular momentum of the decay process. It is found that the lAS mainly decays, throughan s-wave proton emission, to s-wave scattering statesof the 9Li+n system; which may be identified as an

52

In order to study the optical potentials and effective interactions for the neutron-rich nuclei, analyses
on the absolute magnitudes of the cross sections are
now in progress for the 1,2H(9Li,9Be*(GTS,IAS)) reactions followed by the 2a+n channels, observed in.6-decay.2) The angular correlation of the three-bodysystem is also being analyzed for the study of intermediate channels and their angular momenta.
References
1) T. Teranishi et al.: RIKEN Accel. Prog. Rep. 29, 72(1996)
2) G. Nyman et al.: Nucl. Phys. A 510, 189 (1990).

RIKEN Accel. Prog. Rep. 30 (1997)

Quasifree Nucleon-Knockout Reactions from 6He and llLi
T. Kobayashi , A. Ozawa, K. Yoshida, A. Korsheninnikov, 1. Tanihata,
E. Y. Nikolski, and T. Nakamura*
NUCLEAR REACTIONS p(6He,pn)5He, p(l1 Li,pn)lOLi,[ p(6He,pp)5H , p(l1Li,pp)lOHe; E/A=83 MeV
The quasifree nucleon-knockout reactions, (p,2p)
and (e,e' p), by proton or electron beams have beenused to study the single-particle properties, such as
the binding energy or the momentum distribution, ofbound nucleons inside the nucleus.!} We have applied
this method to the neutron-knockout reactions (p,pn)
and proton-knockout reactions (p,2p) from neutronrich nuclei on a proton target with inverse kinematics.
The former reaction was used for studying the singleparticle properties of valence neutrons in 6He and 11 Li,
and the latter for producing neutron-rich resonances
beyond the neutron drip line.
The measurement was performed using secondary
beams of p , d, 6He, and 11 Li at 83 A MeV. Targets
used were a CH 2 plate as a proton target , and a C
plate for background subtraction. Two nucleons (pn orpp) from the quasifree p-N scattering were detected at
Blab = ±45 ° using plastic-scintillator telescopes with
MWPC's. Forward fragments , from the decay of the(A-I) system produced in the nucleon-knockout process, were detected at 0° by a magnetic spectrometer.
Detection of the forward fragments provides information on the decay properties of the (A-I) system.
Separation-energy spectra are shown in Fig. 1, when
the forward fragment was detected in coincidence. The
separation-energy resolution, evaluated by the p( d,pN)
and p(p,2p) reactions , was 1.1 MeV and 1.5 MeV forthe (p,pn) and (p,2p) processes, respectively. Known
resonances, 5He and lOHe, were clearly observed. Twostates in lOLi were observed. From the characteristicsof the (p,pn) reaction, two states at Sn = 0.42 MeV
and 5.2 MeV were assigned as (VPl /2 )- 1 and (VP3/2)-1
hole states, respectively. A peak for the p(6He,pp 3H)process was assigned as the 5H resonance.
By gating on the separation-energy distribution, themomentum distribution of the valence neutron in a
specific orbit was obtained (Fig. 2). The momentum resolution evaluated by the p(p ,2p) reaction was 8
MeV Ic (rms) in one direction. It was noticed that the
momentum distribution was isotropic in the projectile
rest frame. The momentum distribution obtained by
the present method is roughly free from the final-stateinteraction, which was turned out to be the dominant
process in the projectile fragmentation processes. 2) By
comparing the width of the neutron momentum distribution and that of the core fragment in the projec-

1

tile fragmentation processes , the momentum correlation (Pl. P2) between two valence neutrons in 6He and
11 Li was turned out to be negative, indicating that thetwo valence neutrons are moving in the opposite direction.

1000

o ~----~~~~----~~~~~~~~~~-4

'" r

t

-"P-t,P(ULi ,pn)'Li.

-'P'I'".ff"..: . .. .,. - L-.! . ~/ ++.\"., I,": L .

J

10

-- 10

20 - 10

..

0

10

20

30

Separation Energy [MeV]Fig. l. Separation-energy spectra for the (p,pn) and (p,2p)
processes from 6He and 11 Li. Contribution from 12C in
a CH 2 target is shown by a solid histogram.

p(d .pp)pe 1U,pn)Br.i-115 1/ 2

+
200

-e

~
><

.go

1000

' b-

1000

"t:l

500

o

~~

- 150

__

- 100

k--L~~~~

- 50

0

50

100

____

-iC8l

- 100

~

__

-50

~~~~~

0

50

100

150

Momentum Px of Removed Nucleon [MeV/ c]

Fig. 2. Momentum distributions of valence neutron.
Gaussian fittings are shown by solid lines.

References
1) G. Jacob and T. Maris: Rev. Mod. Phys. 38, 121 (1966).
2) M. Zinser et al.: Phys. Rev. Lett. 75, 1719 (1980).

Department of Physics, University of Tokyo

53

RIKEN Accel. Prog. Rep. 30 {1997}

Reaction Cross Sections Measured for 8B to
Obtain Its Density Distribution
M. Fukuda, M. Mihara, T. Fukao,* M. Tanigaki, T. Onishi, K. Matsuta, Y. Nojiri, T. Minamisono,
T. Ohtsubo, S. Fukuda, S. Ito, T. Kobayashi, S. Momota, A. Ozawa, T. Suzuki,
1. Tanihata, K. Yoshida, M. Ishihara, and T. Nakamura
NUCLEAR REACTION Be(12c,8B) ; E = 135 MeV/nucleon; Measured 8B[ reaction cross sections; Deduced 8B density distribution.
In order to investigate the density distribution of
8B, we measured the reaction cross sections for 8B
on Be, C , and Al targets at the beam energies of 40
and 60 MeV/nucleon using the transmission method.
The unstable nuclear beam of 8B was produced by
the projectile fragmentation of the 135 MeV/nucleon
12C primary beam provided from the RIKEN Ring
Cyclotron; the nuclide selection was made throughthe RIPS (Rlken Projectile fragment Separator). The
beam energy of 40 Me V / nucleon was chosen to gain
the large nucleon-nucleon total cross sections that areabout three times of the ones at the LBL energy of
790 Me V / nucleon. 1) At 60 Me V / nucleon the cross section is about in the middle of the values at these twoenergies. The 8B secondary-beam energy was roughly
adjusted by a combination of the thickness of production target and that of wedge degrader at the first focus
point of the RIPS. The fine tuning of the beam energy
was done by adj usting the magnetic field of the second
dipole of the RIPS.
The particle counting and identification before thereaction target was done by a thin Si counter for .6.E
measurement and three parallel plate avalanche counters (PPACs) that provide the time and position infor··mation. Downstream of the reaction target , the identification was made from .6.E taken by Si counters andfrom time-of-flight (TOF) taken in between the PPACand plastic counters. The thickness of the reaction targets were chosen so that the energy loss in the target
was about 20 MeV/nucleon for both energies.
In order to connect the experimental O"R to the density distribution of 8B, we employed the Glauber-type
calculation 2 ) with an enhancement factor at the intermediate energy range. This factor was deduced fromthe O"R data for other stabler nuclides such as 6Li , 7Be,
and 12C , whose densities can well reproduce the interaction cross sections at high energies. 1) We assumed ashape of the density distribution of 8B and fitted it to
the O"R data including the high-energy data through the
Glauber-type calculation. The assumed shape for protons in 8B was a Gaussian at the core and a Yukawasquare tail at the outer region, while that for neutrons
was a Gaussian with the same width as proton core.
In the X2-fitting procedure unrealistic tail slopes corresponding to negative binding energies were rejected.
Present address: Mitsubishi Electric Inc .

54

The preliminary result is shown by the shaded regionin Fig. 1, where the error is indicated as the width of
the region. The density calculated by Kitagawa andSagawa3 ) (KS) is also shown in the same figure by thesolid line. The present density deduced from the experimental O"R is in agreement with the theoretical calculation though it seems to have a little bit smaller
amplitude at the tail part.
In addition to the reaction cross sections , the fragmentation cross sections O"F(8B ~ 7Be) were observed
and found to be quite large as abou.t 15% of the reaction cross sections. If the tail shown in Fig. 1 consistsof proton and O"F(8B ~ 7Be) is governed by the probability of the removal of the tail proton, O"F(8B ~ 7Be)
becomes nearly equal to O"R(8B) - O"RCBe). Using theexperimental values of O"R(8B) and O"R(7Be) , the fragmentation cross sections, O"F(8B ~ 7 Be) , were found tobe almost equal to O"R(8B) - O"R(7Be). This fact supports the existence of the proton tail in the 8B density
distribution as shown in Fig. 1

10°
10. 1
10-2
C?

:§.. 10.3~·iii 10-4
c:
G.I

C

10-5
10-6
10.7

0

2

4

6

8

10

12

r (fm)

Fig. 1. Density distribution of 8B deduced by a fitting to
the O'"R data (shaded region) and by the calculation in
Ref. 3 (solid line denoted as KS).

References
1) I. Tanihata et al.: Phys . Lett. B 206, 592 (1988).
2) P . J. Karol: Phys. Rev. e l l , 1203 (1975) .
3) H. Kitagawa and H. Sagawa: Phys. Lett. B 2 99 , 1(1993).

RIKEN Accel. Prog. Rep. 30 (1997)

Momentum Distribution of 7Be Produced
through 8B Fragmentation
M. Mihara, M. Fukuda, T. Fukao, M. Tanigaki, T. Onishi, K. Matsuta, Y. Nojiri, T. Minamisono,
T. Ohtsubo, M. Ishihara, T. Nakamura, S. Fukuda, S. Ito, T. Kobayashi, S. Momota,
A. Ozawa, T. Suzuki, 1. Tanihata, K. Yoshida, and Y. Ogawa
NUCLEAR REACTION Be( 12 C, 8B); E = 135 MeV/nucleon, Be, C, Al(8B, 7Be); ]E = 38 and 60 MeV/nucleon, Si(8B, 7Be) and Be, C, Al(1Be, 6Li);[ E = 50 MeV/nucleon, Measured momentum distributions.
The momentum distribution of 7Be produced
through fragmentation of the 8B which is a proton-halo
candidate was measured. The momentum distribution
is sensitive to the spatial wave function of a removed
proton near the nuclear surface as well as the reaction
cross sections of 8B at several tens of MeV/nucleon,
which have shown a large enhancement. 1- 3 )We measured both the longitudinal and transverse
momentum distributions of 7Be on a thin Si target
at 50 MeV/nucleon. The transverse distributions were
measured also for thick Be, C , and Al targets at 38 and
60 MeV/nucleon. The 8B beam was produced throughthe 12C + 9Be collision with a 135 MeV/nucleon 12C
beam provided by the RIKEN ring cyclotron, and wasseparated by RIPS. A schematic view of the experimental setup is shown in Fig. 1. The 7Be nuclei
were identified by a combination of t heir energy loss inthin Si detectors and a large plastic scintillator, withthe time of flight (TOF) between the parallel-plateavalanc-he counters (PPACs) and the plastic scintillator. The Si detect ors D1 and D2 were used as targets when a reaction t arget was removed, and then thenext detectors (D2 and/or D3) were used for particle
identification. The longitudinal momentum of 7Be wasobtained from TOF and the transverse one was fromthe horizontal positions of PPACs and from the plastic scintillator which gives light outputs with both left
and right sides.

get by Negoita et a1. 3 ) is about 20% larger than thepresent result. The widths for the transverse momentum distributions are about 110 MeV /c independent
on the energy and targets within the uncertainties of
10%, which are about 40% larger than that for thelongitudinal one. The present values are, however,much smaller than the value expected from Goldharber theory 5) (",,210 MeV/c) that accounts for the momentum distribution of stable nuclei. The transverse
momentum spectra of 6Li after the break up of 7Be
on Be, C, and Al targets at 50 MeV/nucleon were alsomeasured. A typical result of 6Li for Be target is inserted in Fig. 2. The width 217 ± 20 MeV /c from a
Gaussian fitting is in good agreement with the Goldharber theory.
The experimental momentum spectra of 7Be werecompared with the calculation within the Glauber theory. In the calculation, the proton radial wave function
with a long tail obtained from the nucleon density distribution of 8B, which was in turn deduced from thereaction cross section data,2) was used. The result is
consistent with the experiment as shown by solid line
in Fig. 2. This supports the existence of a proton halo
in 8B.

Plastic Counter
Si Detectors(60 x 60cm x 3 mm t)
20

10

--'

88 beam·200
7

Pil I Be] (MoVie)

Vacuum Chamber

10--- -2 .05 m~

Fig. 1. Schematic view of the experimental setup.

Typical momentum spectra of 7Be are shown in
Fig. 2. A Lorentzian function was fitted to each spectrum. The width obtained for the longitudinal distribution is preliminarily 75 ± 8 MeV / c, which is inagreement with the previous data measured at 1471
MeV /nucleon with C, Al and Pb targets by Schwab
et a1. 4 ) The result at 38 MeV/nucleon with Si tar-

0200

pJ 'Be] (MoVie)

Fig. 2. a) Longitudinal and b) transverse momentum
distributions of 7Be at 50 MeV /nudeon on a Si target.
The solid line shows the Glauber calculation. The insert
shows the transverse momentum distribution of BLi.

References
1) R. E. Warner et al.: Phys. Rev. C 52, R1166 (1995).
2) M. Fukuda et al.: OULNS Annual Report 1995, p. 47(1995) .
3) F. Negoita et al.: Phys. Rev. C 54, 1787 (1996).
4) W. Schwab et al.: Z. Phys. A 350, 283 (1995).
5) A. S. Goldharber: Phys. Lett. B 53, 306 (1974).

55

RIKEN Accel. Prog. Rep. 30 (1997)

Electromagnetic Dissociation of 8B at 2A Ge V
T. Kobayashi, A. Ozawa, K. Yoshida, I. Tanihata, K. Matsuta, D. 01son,* and H. Wieman*[NUCLEAR REACTIONS 8B,9C, 13 0+C,Cu,Pb; EjA=2 GeV; Electromagnetic dissociation.]Interaction of high-energy nuclear beams with ahigh-Z target is characterized by the interaction ofvirtual photons from the target with the projectile.
This process, called the electromagnetic dissociation(EMD), provides the information concerning the Giantdipole resonance in the projectile. In order to study the
GDR in {3-unstable proton-rich nuclei, we have studied
the EMD of proton-rich projectiles. Experiments were
performed at LBL, using secondary nuclear beams of
8B, 9C, and 13 0 at 2 A GeV. Targets used were C, Cu,
and Pb. Particles in the final state were measured,
inclusively or exclusively, by the HISS spectrometercomposed of drift chambers and plastic-scintillator hodoscopes.
Firstly, one-prot on-removal cross sections (a_ p )from the projectile were measured inclusively by detecting each of the leading fragments 7Be, 8B, 'and
12N, produced from the breakup of 8B,9C, and 13 0
projectiles, respectively. Target-mass dependences areshown in Fig. 1. The cross section caused by the nuclear interaction (a nucl ) was estimated by scaling thecross sections into He isotopes, as shown by solid lines
in Fig. 1. The EMD cross sections (a EMD ) were obtained by a subtraction: a EMD = a _p_a nucl .
500
9

'13
-;;
.§.
.::

~

{/)

100

<I> U _ p

13

C

t u_.

/~

50

...0
U

I

c
10

50

100

. ~ u_ p

~ .-

III
III

10

0

10

I

I

Cu

Pb

50 100

I
10.0
5 .0

I
-

t:CD'13

';:;

9

E.

cp C

'"N
;;-.'"

1.0

b'

0 .5

13

r-

<P

i:I 0.

0.1

'"Off

0

--:

CD 180t:-

10 - 1

,I

.1

10 0

10 1

-

Sp [MeV]Fig. 2. Normalized (1EMD on a Pb target as a function ofSp.

4He + d + 2p) were measured on C and Pb targets.
The Q-value dependence is shown in Fig. 3. Firstly,
one-prot on-removal cross section (8B ---+ 7Be + p) on
a C target is reduced by about a factor of 3 compared with the incl usi ve cross section, due to thelarge contribution from the pion production. Secondly, it is noted that the Q-value dependence ischaracterized by an inverse slope of 4 Me V, except
for the process into 7Be + p on a Pb target. The
nuclear part of the cross section was estimated using the average ratio of a_p(Pb)ja_p(C). The EMD
cross section a EMD (8B + Pb ---+ 7Be + p) obtainedby this method is 120 mb , which agrees well witha EMD (8B + Pb ---+ 7Be + X) of 127 mb from the inclusive measurement.

~ .10

50

100

Target Mass [amu]Fig. 1. Target-mass dependence of (1 _ p'

The EMD cross sections on a Pb target , normalized
by the square of the projectile charge ZB, are shownin Fig. 2 as a function of the proton-separation energy(Sp), together with those of 12C, 16 0, and 18 0 measured at the same energy. 1) In contrast to the EMD
cross sections of neutron-rich nuclei, dependence on theseparation energy is small. The large enhancement by
the low-energy continuum were not observed, presumably due to the Coulomb and centrifugal barriers.
Secondly, the breakup of 8B into multi-particle final states CBe + p,
6Li + 2p,
4He + 3He + p,
Nuclear Science Division, Lawrence Berkeley Laboratory,

U.S.A.

56-"Li+2p'(])..-[]]o-m'He+d+2p

246

8

10

-Q Value [MeV]Fig. 3. Q-value dependence of breakup cross sections.

References
1) D. L. Olson et al.: Phys. Rev. C 28, 1602 (1983).

RIKEN Accel. Prog. Rep. 30 (1997)

Nuclear Radii of N a and Mg Isotopes
T. Suzuki, H. Geissel,* O. Bochkarev,** L, Chulkov,** N. Fukunishi, M. S. Golovkov,**
D. Hirata, H. Irnich,* Z. Janas,* H. Keller,* T. Kobayashi, G. Kraus,* G. Miinzenberg,*
S. Neumaier,* F. Nickel,* A. Ozawa, A. Piechaczeck,* E. Rockl,*
W. Schwab,* K. Siimmerer,* K. Yoshida, and 1. Tanihata[Heavy-ion collision, Radioactive beam, rms radii]
The effective root-mean-square matter radii (rm ==(rm 2 )1/2) of ANa (A = 20-23, 25- 32) and AMg (A =20, 22 , 23 , 27, 29- 32) were deduced from the measured interaction cross sections (a I) . The experiment
was performed at the projectile fragment separator
facility at GS1. We related a[ to rm by a Glaubermodel employing the Fermi-type distribution: p(r) =Po/[l + exp((r-roA l / 3 )/a)].
We did not assume the existence of a neutron skinin the present analysis. The manner of the analysis isslightly different from the previous report , where weobserved a growth of a neutron skin as a function of
the Fermi-energy difference, Sp- Sn.1) We calculated
the loci for constant rm and for constant a I in thea vs. r a plane. Thus-determined rm of N a isotopes
agreed with those calculated from neutron-skin data
by: Arm 2 = Z r p 2 + N r n 2 within error bars.2) Therefore, measurements of rm themselves are not sufficient
to discuss a neutron skin. However, the Tm of Mg isotopes do not contradict from what we observed in Na
isotopes as seen in Fig. 1.
In Fig. 1, the spherical nuclear radii normalized
by A 1/3 are plotted against Sp- Sn. The spherical radii can be written as: 3 ) (rm 2 ) == (r m S2 )[1 +(511" /4) «(32 2) ]. This assumes that the nuclear shapes
can be parametrized as rotational ellipsoids with thedeformation being limited to the quadrupole contribution. The deformation parameter «(32) of the nuclei under consideration were taken from relativistic
mean field (RMF) calculation. The common tendency of decreasing spherical radii as the function of
ISp- Snl is seen for both Na and Mg isotopes. This
fact can be explained by a model where the valence
nucleons are responsible for the changes in nuclear
radii. 4 ) The spherical part of the nucleus decreases
when neutrons are added in the d 5 / 2 subshell and increases when 81/2 subshell is filled. The fact that therm S A - 1/3 takes minimum around Sp- Sn ~ 0 veri-

g
S

~

1.1

1.0

""E

l'

f

, hi
1

0.9

I

-20

Fig. 1. Dependence of Tm S A -1/3 on the difference between
the minimal energies necessary to remove one protonor neutron from a nucleus of N a (closed circles) or Mg(open circles) isotopes.

fies that no neutron/proton skin is formed in stable
nuclei. The deviation of Sp- Sn from zero may be explained by the difference of Coulomb displacement energy, !:lEe = 6Ze2/(5rm). Note that the tendency did
not change essentially except for the steepness of theradius of curvature when we took another deformation
parameter by Moller et a1. 5 )The present data thus support the idea of growth ofneutron skin not only in N a but also in Mg isotopes.
A thick proton skin of 0.4 fm in 2°Mg is reported. 4 )References
1) T . Suzuki et al.: Phys. Rev. Lett. 75, 3241 (1995).
2) T . Suzuki et al.: in preparation.
3) G. Fricke et al.: Phys. Rev. C 45, 80 (1982).
4) L. Chulkov et al.: Nucl. Phys. A 603, 219 (1996).
5) P. Moller et al.: At. Data Nucl. Data Tables 59, 185(1995).

GSI, Darmstadt, Germany
Kurchatov Institute, Moscow, Russia

57

RIKEN Accel. Prog. Rep. 30 (1997)

Beta Decay of 11 Li
K. Yoneda, N. Aoi, H. Miyatake, H. Ogawa, Y. Yamamoto, E. Ideguchi, T. Kishida, T. Nakamura, M. Notani ,H. Sakurai, T. Teranishi, H.-Y. Wu, S. Yamamoto, Y. Watanabe, A. Yoshida, and M. Ishihara[RADIOACTIVITY 11Li(;3-), measured ;3-delayed neutron, deduced log it, and deduced Ex in 11Be.]
We have investigated ;3 decay of the neutron dripline nucleus 11 Li. For determination of the decay
scheme of 11 Li, detection of the delayed neutrons aswell as , rays is critical because the ;3-delayed neutron
emission probability of 11 Li is large (P1n = 85%) reflecting its large Q,e-value (20.68 MeV) and small neutron separation energy of the daughter nucleus 11 Be(0.504 MeV). We have performed for the first time a;3-n-, triple coincidence measurement and have determined the decay scheme associated with a single neutron and/or ,-ray emission.
11 Li beam was produced by the projectile-fragment
separator RIPS and was implanted into the stoppermaterial (1 mm-thick Si detector). The emitted ;3 rays
were detected by L1E-E plastic-scintillator telescopes
placed above and below the stopper. Delayed , rays
were detected by a Ge detector and two N aI(TI) scintillators. For delayed neutron detection , two sets ofplastic scintillators were used to cover wide range ofneutron energies: one for high-energy neutrons above
about 1 MeV, the other for low-energy neutrons below 1 MeV. 1 ) Neutron energy was determined fromits time-of-flight (TOF) , which was deduced from thedifference between the detection times of ;3 ray andneutron.
The main panel of Fig. 1 shows the neutron TOF
spectrum obtained by the high-energy neutron detectors and the inset by the low-energy neutron detectors. Eight neutron groups labeled by the number 1
to 8 were observed. In the , -ray spectrum obtained incoincidence with the ;3 ray, five peaks associated withthe decay of 11 Li were identified.

From the ;3-n-, triple coincidence analysis, we determined the decay scheme as shown in Fig. 2. The
branch leading to the state of 11 Be (Ex = 8.03 ±0.05 MeV) is newly identified. From the obtained
log it values indicated in Fig. 2, all the observed transi tions are classified as the Gamow-Teller (G T) transitions. The spin and parity of the final states of 11 Be areconfined to 1/ 2-, 3/2- or 5/2- from the selection ruleof the GT transitions. Among the observed five statesof 11 Be, the three states (Ex = 2.69, 3.96, 8.03 MeV)
have significant neutron emission components leading
to the 0+ ground state of lOBe. Since the neutron emissions connect different parity states, it is most probable that these neutron emissions are due to p-wave
neutrons. We can thus assign the spin and parity ofthese neutron emitting states to be 1/2- or 3/ 2- .

8.82

logft=
13(3)%

4.43(8) (1/2 ,3/2f

8.1(16)%5.05 (8 5/2-

21(4)%

4.81 (826(5)%

4.87(87.6(8)%

5/2+

1.78

5.67(4) lIZ

0.32

1/2+

Neutron Energy [MeV]
765 4

3

2

0 .8 0 .4

10

118e

1
0. 2

0 .1

8

.:::

6

:::J
0

CJ
C")

4

0

,...;

2

o

40

60

80
100
TOF [ns]

120

1~e+n

140

Fig. 1. TOF spectra of the neutron emitted in the f3 decayof 11 Li (see text in detail).
58

0

The log it value of the GT transition to the firstexcited state of 11 Be (J7r = 1/2- , Ex = 0.32 MeV) is
sensitive to the wave function of the two halo neutronsof 11 Li. 2) The wave function of the halo neutrons canbe described as QI(2S1 /2)~ > + ;3 1(lpV2)~ >. Fromthe present log it value , 5.67 ± 0.04 , 1;31 is deduced to
be 51 ± 6%.

0

"!l

0+

Fig. 2. Deduced llLi decay scheme. Excita tion energies
are indicated in Me V.

(JJ

c

If)

33.3%

References
1) K. Yoneda et al.: RIKEN Accel. Prog. Rep. 29 , 182(1996) .
2) T. Suzuki and T. Otsuka: Phys. Rev. C 50 , 555 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

j3-Delayed Neutron Decay of Spin Polarized 17B
H. Miyatake, Y. Yamamoto, T. Shimoda, S. Tanimoto, S. Mitsuoka, H. Veno, H. Izumi,
H. Ogawa, K. Asahi, N. Aoi, Y. Mizoi, M. Notani, K. Yoneda, M. Ishihara,
E. Ideguchi, A. Ozawa, T. Kubo, and T. Kishida[RADIOACTIVITY spin polarized 17B(,B-), Measured ,B-delayed neutrons, I-rays]
The nucleus 17B is known as one of halo nuclei on
the neutron drip-line and its valence proton occupies
a p-shell, different from the valence neutrons in a sdshell. The final states of allowed ,B-transitions are nonnormal parity states in 17 C. Hence, we can obtain systematic information about the strengths of cross-shellinteractions by the decay study of 17B together withthe magnetic moment experiment. 1) In the previous
measurement,2) the decay scheme was constructed assuming the ground state in 16C as a final state of delayed neutron transitions. This assumption should be
confirmed experimentally. In our measurement, therefore, all possible transitions to the excited states in
16C were studied by detecting the subsequent I-rays.
Moreover, J7r of excited states in 17 C were studied todetermine the decay scheme clearly. A new experimental method of J7r assignment, which was deduced fromdetection of the asYIIl:metric ,B-rays coincident with respective delayed particles using the polarized parent
nucleus,3) was applied. The polarized 17B obtained in
the same manner of Ref. 1 was implanted into the Ptfoil. The polarization ,of individual ,B-transition wasmeasured by applying the ,B-NMR method. The energies of neutrons were measured by means of the time offlight method with two different sets of plastic scintillators; one set had 1.5 m flight path for the measurementof high-energy neutrons and another set had 0.5 m forthe low-energy neutron measurement, respectively, as
shown in Fig. 1. A clover Ge detector (4 x 470 cc)
and NaI(Tl) scintillators (4 x 960 cc) were placed 5 cm
from the Pt-foil to observe the I-rays with a high detection efficiency. Figure 2 shows the energy spectrumof I-rays, measured by the Ge detector. The I-ray
peak of 1.77 MeV, which corresponds to the excitationenergy of the first 2+ state in 16C, was clearly found.
From the lifetime analysis, the half life of this transition was 5.5(6) ms, which agrees with the half life of
17B [T 1 / 2 = 4.9(2) ms].2) Therefore, it indicates thatthe 2+ state in 16C is fed by some delayed neutrons.
The more detailed analysis for polarization of the individual ,B-transition as well as neutron TOF spectrum
is in progress. A revised decay scheme will be constructed including these results.

Neutron Counter (>lMeV)~, .

NeutronCounter«lMeV)

NaI

Direction of Beam

Fig. 1. A schematic drawing of the detector set-up aroundthe Pt-foil (not shown). The clover Ge detector and
NaI(Tl) scintillators are located inside the Helmholtz
magnet.

1.77MeV

Energy(keV)

Fig. 2. The ,-ray spectrum coincident with the {3-ray andneutron signals.

References
1) H. Deno et al.: Phys. Rev. C 53, 2142 (1996).
2) G. Raimann et al.: Phys. Rev. C 53, 453 (1996).
3) H . Miyatake et al.: RIKEN Accel. Prog. Rep. 29, 64(1996).

59

RIKEN Accel. Prog. Rep. 30 (1997)

Measurement of ,a-decay Branching Ratio of 17Ne
into the First Excited State of 17F
A. Ozawa, M. Fujimaki, S. Fukuda, S. Ito, H. Kitagawa, T. Kobayashi, G. Kraus, S. Momota,
G. Miinzenberg, T. Suzuki, I. Tanihata, and K. Yoshida[RADIOACTIVITY 17Ne(jJ+ ')'); Measured ,6-decayed ,)" Deduced branching ratios]
The jJ-decay branching ratio of 17Ne into the firstexcited state of 17F has been measured by a direct
method. In the previous report,1) the motivation andexperimental setup for the present experiment were described in detail; so that only the experimental results
and discussions are described here.
The branching ratio with E-y = 495 ke V (denoted byBr( 495)) was deduced by the following equation:N-y(495) x €time_bin =€ [2(495) x Br(495) x Nbeame 7 Ne),
where N-y(495) is the peak intensity of the E-y = 495
keY, €time_bin is the correction for the time used forthe measurement since we observed ')'-rays only in the
beam-off period, € [2(495) is the 495 keY ')'-ray detection efficiency, and Nbeam(17Ne) is the number of 17Ne
implanted in the stopper. The €time_bin can be calculated using the known T 1 / 2 of 17Ne and the beam-on
and -off cycle. Since no excited state feeds to the firstexcited state in 17F, the deduced Br( 495) corresponds
to the ,6-decay branching ratio of 17Ne into the first excited state of 17F. The € [2(495) was deduced from theon-line detection efficiency, which was measured using
lOC beam. For the deduction, energy dependence on
efficiency determined by point ')'-ray sources was used.
Since the branching ratios obtained by using two Ge
detectors were consistent each other within the error
bars, we determined a branching ratio of 1.44 ± 0.16%
by averaging the two values.
The present value of branching ratio determined
above is consistent with the previous one (1.65 ±
0.16%)2) within their error bars. From the branching ratio, we have deduced the ,6-decay ft value to obtain logft = 6.43 ± 0.07. The ,6-decay branching ratio
for the corresponding state of 17N, the mirror nucleiof 17Ne, is well known. Thus, we have deduced theft value for 17N in the same way. Using the ft values
for 17Ne and 17N, we obtained the asymmetry given by
the 8-value defined by 8 = (ft)+ /(ft)- -1, where (ft) +and (ft)- are the ft values for positron and electron decays, respectively. The 8-value obtained in the present
study is -0.57 ± 0.10. This value shows a large deviation from zero, thus suggesting an anomalous nuclear
structure for the pair.
In order to understand the large anomaly, we
performed theoretical calculations for the jJ-decay
strength, as follows. The 8 is given by the overlapping of the valence nucleon in the initial nuclei and acore part in the final nuclei. In our calculations, the60valence nucleon of the initial nuclei can be describedby only the configuration of the 281/2 and 1ds / 2 orbits. Thus, the observed 8 is sensitive to the fractionof the 281/2 component in the valence nucleon and to
the radial part of the component. The wave functions
obtained by the spherical Skyrme Hartree-Fock equations with the SGn interaction are used, except for thevalence nucleons. The wave functions of the valence
nucleons are obtained in the Woods-Saxon potential,
whose depth is adjusted in order to reproduce the empirical separation energies: for example, 0.48 MeV (ahalf of the empirical S2p) for 17Ne, and 4.19 MeV (ahalf of the empirical S2n) for 17N. We performed thisprocedure for both the 281/2 and 1ds/ 2 orbits. Thus,in our calculations 8 can be given by fractions of the281/2 component in 17Ne and 17N. The results of calculation are shown in Fig. 1. In the figure, the calculated
8 is shown as a function of the fraction of 281/2 component for the valence nucleons in 17Ne and 17N. The
8 observed in the present experiment is indicated by
the hatched area on the figure. The area is located at
the region where the fraction of 281/2 component in
17Ne is higher than that in 17N by a factor of six. This
supports the occurrence of an 8-d inversion in the 17Ne
and 17N mirror pair, as described in Ref. 3.

.--- 100

~

'-

+1.5

80
Z 60

~

.S
r::I

0

40

'.::;j

~

20

-

0

<l::

~

~

0

20

40

60

80

100

sII2 fraction in I7N (%)

Fig. 1. Calculated 0 as a function of the fraction of 281/2
component in 17Ne and in 17N.

References
1) A. Ozawa et al.: RIKEN Accel. Prog. Rep. 29, 66(1996).
2) M. J. G. Borge et al.: Phys. Lett. B 317, 25 (1993).
3) A. Ozawa et al.: Phys. Lett. B 334, 18 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Magnetic Moments of 17N and 17Bt
H. Ueno, K. Asahi, H. Izumi, K. Nagata, H. Ogawa, A. Yoshimi, H. Sato, M. Adachi, Y. Hori, K. Mochinaga,
H. Okuno, N. Aoi, M. Ishihara, A. Yoshida, G. Liu, T. Kubo, N. Fukunishi, T. Shimoda, H. Miyatake,
M. Sasaki, T. Shirakura, N. Takahashi, S. Mitsuoka, and W.-D. Schmidt-Ott[NUCLEAR STRUCTURE: Magnetic moments, Ground state 17N and 17B]
The magnetic moments of 17N and 17B were measured by using spin-polarized radioactive nuclear
beams which were obtained from the projectile fragmentation reaction. The result for the 17N magnetic
moment, Me 7N) = (-0.352 ± 0.002) MN , where MN
is the nuclear magnet on , shows an outward deviationfrom the Schmidt value. Hereafter, the experimental
M(17N) will be assigned a negative sign taken from the
Schmidt value. By virtue of a simplifying feature of
nuclear structure inherent in a P1/Tvalence nucleus,
the deviation is reliably attributed to admixing of theconfigurations in which two neutrons in the sd shell arecoupled to J7r = 2+. This interpretation is confirmedin standard shell-model calculations. In Fig. 1 the experimental Me 7N) value is compared with the resultsof shell-model calculations. The shell-model calculations were made with two different sets of effective interactions, "PSDMK;" 1,2) and "PSDWBT" .1,3) These
calculations reproduce fairly well the experimentallyinferred amount of 2+ admixture, as well as the experimental magnetic moment itself.

single particle value, and the shell-model calculations
indicate that the quenching of J.l largely stems from
J7r = 2+ configurations of the sd neutrons. The experimentally observed amount of quenching is, however, larger than the shell-model predictions, suggesting an enhanced contribution of the 2+ neutron configurations. This result is explainable if the pairing
energy (VOl) for neutrons in the sd shell of a neutronrich nucleus is assumed to diminish by about 30%, asindicated by the curve of dotted line in Fig. 2. We
also found that the use of the reduced pairing energy
improves agreements in not only the magnetic moment
but low-lying level energies of 17N as well.
3.4

::!

3.2

C
Q)

3.0

E

2.8

0

::2
u

2.6

c

2.4

co
::2

2.2

~
0)

2.0

exp

11

13

15

17

19

Mass Number
PSDMK -~.......... • ..

PSDWBT t- .... q .;..... . .. ...................................................... j............................... -I

-0.35

-0.30

-0.25

Magnetic Moment {JIN}
Fig. 1. Comparison of the experimental J.L value (denotedby exp) for l7N with the theoretical predictions. For
the abbreviations denoting the theories, see text.

The magnetic moment for 17B was determined to be
Me 7B) = (2.545 ± 0.020) J.lN. Hereafter, the experimental Me 7B) will be assigned a positive sign takenfrom the Schmidt value. The experimental value andshell-model calculations of M for 17B are plotted inFig. 2, together with those for odd-mass B isotopes.
The result is substantially smaller than the ~P1/2

Fig. 2. The experimental and theoretical values of J.L for
the odd-mass B isotopes. exp: the experimental values.
PSDWBT: the shell model calculations with the PSDWBT interaction. PSDWBT (0.7Vo~TD): the PSDWBT
calculations with IVoll values reduced by 30% (i.e.,
the three matrix elements, ((d5/2)2IVI(d5/2)2)r=o+,((Sl /2 )2IVI(Sl/2)2)r=o+, and((d3/2)2IVI(d3/2)2)r=o+,
are multiplied by a common factor 0.7). PSDMK: theshell model calculations with the PSDMK interaction.

References
1) B. A. Brown, A. Etchegoyen, and W. D. M. Rae:OXBASH, MSU Cyclotron Laboratory Report No. 524(1986).
2) D. J. Millener and D. Kurath: Nucl. Phys. A 255, 315(1975).
3) E. K. Warburton and B. A. Brown: Phys. Rev. C 46,
923 (1992).

Condensed from the article in Phys. Rev. C 53, 2142 (1996)

61

RIKEN Accel. Prog. Rep. 30 (1997)

Quadrupole Moment of 23Mg
K. Matsuta, T. Onishi, M. Fukuda, M. Mihara, M. Sasaki, T. Yamaguchi, T. Miyake,
K. Sato, K. Minamisono, Y. Nojiri, T. Minamisono, T. Ohtsubo, A. Ozawa, S. Fukuda, S. Momota,
K. Yoshida, T. Suzuki, T. Kobayashi, 1. Tanihata, G. F. Krebs,*
J. R. Alonso,* and T. J. M. Symons*
NUCLEAR STRUCTURE: Nuclear magnetic resonance,[ Measured quadrupole moment of 23Mg ground state.
The quadrupole(Q) moment is an important nuclear
property for the study of the nuclear structure, especially for the halo structure of proton-rich nuclei. I) As
a step toward the systematic studies, the Q momentof 23Mg(J7r = 3/2+, T 1 / 2 = 11.3 s) has been measured
for the first time using combined technique of the polarized nuclear beams and (3- NMR at RIKEN.
Experimental procedure was similar to the previous
works.I ,2) A 100 A MeV 24Mg beam extracted fromthe RIKEN ring cyclotron was used to bombard a 1mm thick Be target. Considering energy loss in thetarget, the average beam energy was 91 A MeV. The
polarized 23Mg fragments emerging from the target at
1.5° ±0.6° were separated and momentum analyzed by
the RIPS (RIken Projectile fragment Separator). Momentum window was set at ~p/p = (1.5 ± 0.5)% relative to the beam velocity. The separated 23Mg nuclei
were then implanted in a 500-J..Lm-thick MgF 2 catcher
placed in a magnetic field Ho of 6.5 kOe. The c axis or
the (110) axis of the MgF 2 (tetragonal) catcher was set
parallel to lio. The polarization of 23Mg was detected
through the {3-ray counting asymmetry.
For the efficient NMR measurement , NNQR (New
Nuclear Quadrupole Resonance) method l ) combinedwith the Adiabatic Fast Passage (AFP) method wasused, where a set of 6 rf fields (a sequence of the 3
frequencies split by the eqQ interaction) was applied
to invert the polarization. Split frequencies for given
eqQ were programmed based on the known q and fl.
The programmed ~f , a half of the full split, is very
close to ~f = 1(1 + fl)eqQ/4hl or 1(1- fl)eqQ/4hl for
Ho //c(V yy ) or Ho //(110)(V xx ,) respectively. Here,
Larmor frequency VL = 1.7691 MHz, leqQ(2sMg)/hl =(3.450 ± 0.015) MHz, fl = 0.28 ± 0.04 and Q(2sMg) =(201 ± 3) mb are given from the literature.
Two eqQ spectra were obtained as shown in Fig. 1
for two different crystal orientations. From the spectra, the eqQ coupling frequencies and the Q momentof 23Mg were determined as shown in Table 1. The
last column Vxx + Vyy (= 1V zz I) in Table 1, is the mostaccurate because it is insensitive to the ambiguity of fl.
The obtained Q moment IQ(23Mg) 1 = (114.2 ± 2.2)

LBL, Berkeley, CA94720 , U.S.A.

62

0.2
0.0

~
~

OJ)
~

ro

..c

U

-0.4
-0.6

S -0.8cllHo~§>. -1.0
VJ« -1.223 Mg in MgF2
Ho= 6.5kOe

-1.4
0.0

1.0

0.5

1.5

2.5

2.0

eVjjQIh (MHz)Fig. 1. eqQ spectra of 23Mg in MgF 2.
Table 1. The eqQ couplings and the Q moment of 21 F.
orientation
FG
leViiQ/hl
Q 23 Mg/Q 25 Mg

Q( 23 Mg) (mb)
Theory (mb)Cluster
Shell(Kuo)
Shell(PW)c/ /Ho(110)/ / Ho

Vyy

Vxx

1.282(17)0.678(12)0.581(20)0.546(32)
W.M.0.571(17)114.8(3.8)

Vzz

1.960(21)0.568(7)114.2(2.2)
118
122
112

mb is compared with the theoretical calculations asshown in Table 1. The Q moment values predictedfrom the cluster model 3) and from the shell model 4 )with Kuo and PW interactions are in good agreementwith the present experimental Q moment.
References
1) T. Minamisono et al.: Phys. Rev. Lett. 69, 2058 (1992).
2) K . Matsuta et al.: Nucl. Phys. A 588 , 153e (1995) ;Nucl. Phys. A 377, 361 (1982).
3) A. Kabir and B. Buek: Nucl. Phys. A 518, 449 (1990).
4) B. J. Cole, A. Watt, and R. R. Whitehead: J. Phys. G:
Nuel. Phys. 1 , 303 (1975).

RIKEN Accel. Prog. Rep. 30 (1997)

Asymmetry Parameter of 23Mg Beta Decay
K. Matsuta, T. Onishi, M. Fukuda, M. Mihara, T. Yamaguchi, T. Miyake, M. Sasaki, Y. Nojiri,
T. Minamisono, T. Izumikawa, M. Tanigaki, M. Nakazato, A. Harada, T. Ohtsubo, S. Fukuda, S. Momota,
K. Yoshida, A. Ozawa, T. Suzuki, T. Kobayashi, 1. Tanihata, J. R. Alonso,·
G. F. Krebs,· and T. J. M. Symons·
NUCLEAR STRUCTURE: Nuclear magnetic resonance, Measured[ asymmetry parameter of 23Mg ground state transition.
Study of the weak vector coupling constant G v with
mixed transitions provides a sharp test for cve (conserved vector current) theory. The G v is determined
for mixed transitions from the asymmetry parameter
A and the half life. In the early measurement, the A of
35 Ar showed apparent violation of CVC,l) i.e., the deduced G v differed significantly (by 3%) from the one
precisely determined for the pure Fermi transitions. 2)
Although this long standing problem seems to havebeen solved by the recent data from the LBL groupand from the Wisconsin group, the A's of neutron and
19Ne still show significant discrepancy. This may suggest incompleteness of our knowledge on the nuclear
structure dependent correction, if it is not really a eve
violation. In order to clarify this interesting problem
from the mass number dependence, the A of the 23Mg
(I7r = 3/2+, T 1 / 2 = 11.32 sec) ,8-decay has been measured in the present experiment.
Spin polarized beta-emitting 23Mg fragment was
produced through the projectile fragmentation processwith the 91-AMeV 24Mg beam on Be target. The 23Mg
fragments emerging from the target at 1.5 0 ± 0.6 0 wereselected by a slit and separated it out from the othervarious fragments using the RIPS (RIKEN Projectile
Fragment Separator). The 23Mg nuclei were then implanted into a thin Pt catcher (15-50 p,m thick). The
catcher was placed in a strong magnetic field Hoof
2.15 kOe and was cooled down to 14 K to maintain thepolarization produced in the projectile fragmentation
process. The ,8-ray asymmetry AP (P: polarization)
was measured by means of asymmetric ,8-ray emission
for both ground state transition and the decay branch
to the first excited state, which was tagged by the ,8delayed , rays (E-y = 440 ke V) .
The ,8-ray asymmetries obtained from ,8-ray singles(APo ) and the ,8-, coincidence (APex) with several different conditions are shown in Fig. 1a. Although theabsolute AP values are different for different conditions, the ratio APex / APo consistently stays constant
as shown in Fig. lb. The average value of the ratio is1

0.838 ± 0.009. Correcting the ,8-, angular correlation,(3-ray scattering effect, and ,-ray background, the true
ratio Aex/Ao = 0.990 ± 0.012 was obtained. Since thetransition to the excited state is pure Gamow-Teller,
Aex is precisely predicted to be -3/5. Thus the preliminary result for the asymmetry parameter was obtainedas Ao = -0.606 ± 0.007.

a)

20

~

u
co

• Beta-ray singles
P-Y coincidence

o

10
-4

~ -6
€
e -8
~

.li.....M

<I)

< -10
-12
1.1

b)

1.0
0.9

)
C:;..

0.8

<u

0.7
0.6
0.5
0

10

20

30

40

50

60 W.M.

Runs

Fig. 1. Asymmetries for the {3-ray single and (3-, coincidence events.

References
1) F. P. Calaprice, E. D. Commins, and D. A. Dobson:
Phys. Rev. 137, 1453 (1965).
2) J. C. Hardy and I. S. Towner: Nucl. Phys. A 254, 221(1975).

LBL , Berkeley, CA94720, U.S.A.

63

RIKEN Accel. Prog. Rep. 30 (1997)

Development of Polarized 129Xe Solid for
Polarizing Unstable Nuclei
H. Sato, M. Tsuda, A. Yoshimi, H. Izumi, H. Ogawa, N. Kurokawa, K. Sakai, M. Adachi, K. Asahi,
H. Okuno, T. Kubo, S. Fukuda, A. Yoshida, M. Ishihara, K. Yoneda, and M. Notani[Nuclear magnetic moment, 129Xe solid stopper]
Measurements of nuclear moments provide useful information in the study of microscopic structure of thenuclei far from stability.1-4) In such experiments, producing a spin polarization in the objective nuclei plays
a key role. We have proposed a new method to produce
the spin polarization, which comprises an implantationof unstable nuclei into a highly polarized stopper andsubsequent transfer of the host nuclear polarization to
unstable nuclei through dipole-dipole interaction. To
use for the host material, we are developing a polarized
129Xe solid stopper for which a large spin polarization
as well as a long relaxation time can be attained. 5 ) In
order to obtain a large nuclear polarization, the 129Xe
gas atom is polarized by spin exchange with an optically polarized Rb atom. After the 129Xe polarization (PXe ) reaches its equilibrium, the gas cell is cooled
down in contact with liquid nitrogen to obtain a polarized 129Xe solid. PXe is determined by measuring an
NMR signal.
Previously, we reported on the development of a polarized Xe cell. 6) A cylindrical glass cell, 4 cm long and
2 cm in diameter, was filled with a natural Xe gas of apartial pressure PXe, a N 2 gas of 100 Torr, and a small
amount of Rb vapor. The cell was illuminated by thecircularly polarized light from a Ti-Sapphire laser (f'V 1
W in laser power). As a result, a polarization as large
as PXe = 59% was obtained at PXe = 10 Torr. At ahigh pressure PXe = 800 Torr, which corresponded to
5 x 5 x 1 mm 3 volume of solid Xe, the polarization attained was P Xe = 1%. The wall relaxation time (Tw),which represents the effect of relaxation due to collisions of Xe atoms against the cell wall, was 5 min in
average. 6)
As a matter of fact, the above achieved Xe polarization and pressurE;!, PXe = 1% at PXe = 800 Torr, arenot satisfactory for realization of a practical volume
nor for polarization as a practical 129Xe solid stopper. In order to obtain a larger PXe and a higher
PXe, we have developed a new 129Xe cell system. We

64employed an optical pumping scheme with two diodelasers (f'V 15 W each) which are suitable to polarization
in a high pressure cell. In order to suppress the wall
relaxation, an inner surface of the glass cell was coatedwith SurfaSil. 7) We made several coated as well as uncoated cells, and measured Twin them. Although Tw's
were found to differ from cell to cell, Tw > 20 min wasachieved within some of the coated ones. As a result,
we obtained PXe = 11% at 800 Torr and P Xe = 5.6%
at 2300 Torr of an enriched (79.2%) 129 Xe gas.
In the new system, the glass cell has a rectangularpart (8 x 20 x 2 mm 3 ) at the bottom. After polarizing
the 129Xe gas in a dewar, the 129Xe solid was made in
the rectangular part within 5 minutes by directly immersing it into the liquid nitrogen. We also made anexperiment to test the performance of apparatus withthe beam of unstable nuclei 11 Be which was provided
from Riken Ring Cyclotron and separated by the projectile fragment separator (RIPS) at Riken. Almost
100% of 11 Be particles incident on the system could be
implanted into a solid 129Xe stopper of 1.5 x 8 x 1.5mm3 in size, and {3-rays thus detected were identified
as those from 11 Be atoms properly stopped inside the
129Xe stopper. Because of a trouble occurred in thepolarizing laser system during the last beam time, so
far we have not yet succeeded in observing 11 Be polarization. Repairs have been done, and we are now
developing an apparatus for the measurement of themagnetic moment of 11 Be.
References
1) H. Okuno et al. : Phys. Lett. B 354, 41 (1995) .
2) H. Izumi et al.: Phys. Lett. B 336, 51 (1995).
3) H. Veno et al. : Phys. Rev. C 53, 2142 (1996).
4) K. Asahi et al.: Nucl. Phys. A 588 , 135c (1995).
5) M. Gatzke et al.: Phys. Rev. Lett. 70, 690 (1993).
6) H . Sato et al.: RIKEN Accel. Prog. Rep. 29, 181 (1996).
7) X. Zeng et al.: Phys. Lett. A 96, 191 (1983).

RIKEN Accel. Prog. Rep. 30 (1997)

Production of a Low Energy 12B Beam and Observationof its Nuclear Polarization
A. Ozawa, M. Fujimaki, S. Fukuda, G. Kalnins, S. Momota, T. Suzuki, I. Tanihata, and H. Yamazaki[RADIOACTIVITY 12B(b-), Measured {3- rays, Deduced nuclear polarization]
A low-energy secondary beam (E / A < few Me V) is
indispensable for studying the nuclear reactions relevant to astrophysical interests and to {3, 'Y spectroscopy
for unstable nuclei. For such studies, recoil mass spectrometers have been constructed combined with heavyion accelerators, such as the Tandem Van de Graff. On
the other hand, a polarized secondary beam is indispensable for measuring the nuclear moments for unstable nuclei and studying the hyperfine interactions
in material.
In RIKEN, a heavy-ion linear accelerator (RILAC)
has mainly been used for injecting the beam into
the RING Cyclotron, and for experiments using lowenergy primary beams. The RILAC is also suitable for
producing low-energy secondary beams, since it can accelerate various primary beams (He to Bi) with variable energies (for example, E/A = 0.6- 3.0 MeV for
11 B) and high intensities (for example, a few 100 nA
for 11 B). Thus, based on the above motivations, westarted to construct the secondary beam line in RILAC from 1994.
The beam line comprises a set of QQDQQ magnets, as shown in Fig. 1. The line has two focusing
points. The angular and momentum acceptances are
2.6 msr and ±1.0%, respectively. The momentum dispersion is 1.4 cm/% at the intermediate focus. A small
dipole magnet is located upstream of the target chamber, which is used to deflect the primary beam. The
primary beams can be bent on the target by two magnets, thus providing a deflection angle of up to 5°. Between the first Q-doublet and the intermediate dipole
magnet thin foils can be placed so as to create the nuclear polarization (PN ) by beam-foil interactions. A
magnetic field of up to 600 G can be applied to thefoils. At the first focus, devices for the {3-NMR andmomentum slits are located. The scattering chamber,

located at the second focus, can be used for reaction
experiments using a secondary beam.
We obtained a 12B (T1/2 = 20 ms) beam with
E / A ~ 1.8 Me V; the typical production rate was about
50 cps/nA. The 12B beam was produced by the reaction d(l1B, 12B)p with a E/A = 2.5 MeV 11B beam
accelerated by RILAC and a 1.5 mg/cm2 thick CD 2
target. The production of 12B was confirmed by its(3-decay time spectrum. The spectrum was composedof an exponential curve of signal plus a constant background. Also, we finally obtained T 1 / 2 = 19.6±0.3 ms,
which is consistent with that in the literature. 1) The
intensity of the 12B beam was estimated based on the{3-ray intensity. We can also obtain a good separation
for different charge states of the secondary beam.
We measured PN of the 12B5+ produced by the reaction process under the above conditions. In this case,the primary beam was deflected by magnets. The 12B
beam was collected at a scattering angle of 4° with
±1 ° of acceptance, which corresponds to 10° scattering in the inverted reaction: 11B(d,p)12B. PN was measured as a function of the momentum of the 12B beamby the (3-NMR method. We observed a decisive PN
at the high-energy side of the 12B beam, as shown in
Fig. 2. Here, the sign of PN is defined to be positive
for the direction parallel to Pi x
where Pi andare the momentum vectors of incoming and outgoingparticles. The P N integrated in the total momentum
distribution is about 1.5%; consistent with that observed in the inverted reaction in Ref. 2.

pr,

pr

40
----+---

;;
~

30

"0

t

20

:>.

e 10

cO.

---

----+---

-+-

~ 5
c

.52
<;i

.~

Beam_

'"

deflecto~~

Primary
targetchamber

1

0

-6.45

-+- .....
0.46

0.47

0.48

0.49

Bp (T*m)/Fig. 2. Momentum dependence of the polarization of a
12B beam.

Foil chamber
NMRmagnet(l'st focus)

Fig. 1. Layout of the secondary beam line in RILAC.

References
1) F. Ajzenberg-Selove: Nucl. Phys. A 506, 1 (1990).
2) M. Tanaka et al.: Nucl. Phys. A 263, 1 (1976) .

65

2. Atomic and 'Solid-State Physics

RIKEN Accel. Prog. Rep. 30 (1997)

Inelastic Processes in Collisions of H+ Ions with
C, N, and 0 Atoms below 1 keY
M. Kimura, J.-P. Gu,* G. Hirsch,* R. J. Buenker,* and I. Shimamura
Electron capture reactions resulting from collisionsof protons with carbon, nitrogen and oxygen atoms
are known to play an important role in earth's
atmosphere, 1) interstellar space,2) and astrophysicalplasmas,3) and are fundamental for other relevant applied fields. 4) Yet, accurate rates of these collision processes are rarely known except some crude and limited
attempts for evaluation. Rate coefficients for the [H++ N] and [H+ + 0] collision processes were theoretically evaluated by Steigman et a1. 5 ) and Field andSteigman,6) respectively, based on an orbiting approximation with corresponding values of 2.5 x 10- 14 cm 3/s
and 7.4 x 10- 10 cm 3/s at 10,000 K , respectively. Chambaud et al. 7) carried out a more rigorous study onelectron capture in the [H+ + 0] collisions using amolecular orbital method with the spin-orbit coupling
as a driving force and determined the rate coefficientas 4.8 x 10- 10 cm 3/s at 10,000 K. There is no largescale theoretical study on the [H+ + C] and [H+ + N]
collision systems except for an exploratory calculation
by Butler and Dalgarno8 ) for the [N+ + H) system.
In this paper, we attempt to investigate collision
dynamics, and to evaluate electron capture cross sections and corresponding rate coefficients for the three(C, N, 0) target atoms rigorously based on a molecular representation within a semiclassical framework for
HC+ , HN+, and HO+. The processes studied are as
follows , with corresponding asymptotic energy defects
given between the closest states:
H+ + Cep) -----+ H + C+(2p)+ 2.33 eV(la)

H+ + N(4S) -----+ H + N+ep)- 0.95 eV(lb)

H+ + Oep) -----+ H + 0+(4S)- 0.02 eV(lc)

The multireference single- and double-excitation(MRD-CI) configuration interaction method was
employed. 9) A semiclassical MO expansion methodwith a straight-line trajectory of the incident ion was
employed to study the collision dynamics. 10) Substituting the total wave function into the time-dependent
Schrodinger equation, we obtain a set of first-ordercoupled equations. By solving the coupled equations
numerically, we obtain the scattering probabilities fortransitions, and integration of this probability over the
impact parameter gives the cross section. In adiabatic potentials obtained, for the CH+ system, theground [H+ + Cep) ] channel lies above the dominant electron capture [H + C+ep)] channel, whereas
all the target-excitation [H+ + Ce D, IS)] channels lie
slightly above the ground state. For the NH+ system,
Theoretische Chemie, Universitaet Wuppertal, Wuppertal,
Germany

the [H+ + N(4S)] channel is the ground state withthe electron capture [H + N+ep)] channel nearby.
Above this electron capture channel, a series of target excitation channels follows. For OH+ system, the"[H+ + Oep)] channel is the lowest level similarly for
the NH+ system and then, the electron capture [H+ 0+(4S)] channel and the target excitation [H+ +0* (1 D)] channel follow. Because of a small asymptotic energy defect (near-resonant processes) between
the initial and closest electron capture channels for almost all systems, the electron capture cross sections
from the ground-state atoms are very large: approximately 10- 16 _10- 15 cm 2 for all systems at above
100 eV. The rate coefficients for electron capture fromthe ground-state Cep), N(4S), and Oep), and some
representative values are givend in Table 1. The rates
increase with temperature (T) from less than 10- 14
cm 3/s to 2 X 10- 11 cm 3/s for CH+, 3.5 X 10- 11 cm 3/s
to 2 X 10- 9 cm 3/s for NH+ and 6.1 x 10- 11 cm3 /s to
7 X 10- 9 cm 3/s for OH+, when T is raised from 10,000
K to 100,000 K, respectively.
Table 1. Representative rate coefficients for electron capture at temperatures above 10,000 K resulting from ~ol­lisions of H+ ions with C, N, and 0 target atoms.
Targets

N(4S)

Temp. (K )10, 000
50 ,000
100 ,000
20 0,000

2.6 1 X 10 - 122.34 X 10- 1 1
2. 08 X 10 - 10

3.5 1 X 10 - 11
4.8 0 X 10- 10
2.03 X 10- 9
6. 73 X 10- 9(')5. 3 x 10

10

O(3p)
6.10 x 10 11(6) 9.1 x 10
2.91 X 10-'9
7 .02 X 101.39 X 10- 8

10References
1) R. F. Stebbings, A. C. H. Smith, and H. Ehrhardt: J.
Geophys. Res. 69, 2349 (1964).
2) J. H. Black and A. Dalgarno: Astrophys. J. 206 , 132(1976).
3) G. E. Geisler: J. Geophys. Res. 72 , 81 (1967).
4) R. A. Phaneuf, F. W. Meyer, and R. H. McKnight:
Phys. Rev. A 17, 534 (1974).
5) G. L. Steigman, M. W. Werner, and F. M. Geldon: Astrophys. J. 168, 373 (1971).
6) G. B. Field and G. Steigman: Astrophys. J. 166, 59(1971).
7) G. Chambaud et al. : J. Phys. B 13, 4205 (1980).
8) S. E. Butler and A. Dalgarno: Astrophys. J. 234, 765(1979).
9) R. J. Buenker and S. D . Peyerimhoff: Theo. Chim.
Acta 35, 33 (1974); R. J. Buenker: Intern. J. Quantum Chern. 29, 435 (1986).
10) M. Kimura and N. F. Lane: in Advanced Atomic Molecular Optical Physics Vol. 26, edited by D. R. Bates and
B. Bederson (Academic Press, NY, 1989) p. 76.

67

RIKEN Accel. Prog. Rep. 30 (1997)

Electron Capture Rates in Collisions of H+ Ions with Si Atoms:
Capture by the ground and excited state
M. Kimura, A. B. Sannigrahi,* J.P. Gu,* G. Hirsch,* R. J. Buenker,* and 1. Shimamura
Baliunas and Butler l ) examined the effect of chargetransfer in conjunction with the silicon spectral lines,
and estimated the value of the rate coefficient as 10- 11
cm3/s for the charge transfer process in collisions of
H+ ions with Siep) ground state atoms. From this,they suggested a possible importance of the ionization
process of silicon atoms. Apart from this case study,
to the best of our knowledge, there is no theoreticalor experimental determination of the charge transfer
cross section.
We have carried out a theoretical investigation forcharge transfer in collisions of H+ ions with neutral
Si atoms both in the ground and metastable states atcollision energies from 10- 3 eV to 10 keY. The processes we have studied are as follows , with corresponding asymptotic energy defects:i) Ground state Si ions:
H+ + Si(3p) ----+ H + Si+ (4p) + 1112 cm - 1(la)+ Si+ep) + 43936 cm- ,I(lb)

H+ + SieD) ----+ H + Si+eD) - 5069 cm- I .

(2)----+ Handii) Metastable Si ions:
The metastable I D state in Eq. (2), which lies at50235 cm- I higher in energy than the [Si+ ep) + H)
state, is considered to compete with the ground stateas the collision energy increases to ke V regime. Hence,
it is important to understand the electron capture
mechanism of the both ground and metastable states.
The adiabatic potential curves of SiH+ are obtainedby employing the ab initio multireference single- anddouble-excitation configuration interaction (MRD-CI)
method. 2) From the bottom of adiabatic potentials,
they correspond asymptotically to the atomic states[H + Si+ep): 13II 13~+], [H + Si+(4P): 23II , 13~ - ]and [H+ + Siep): 33II, 23~-) for triplet manifold,and [H+ + Si(1D: 21II, 21~+] and [H + Si+e D): 3 1II,
3 1~+] for singlet manifold. A semiclassical molecularorbital expansion method with a straight-line trajectory of the incident ion was employed to study thecollision dynamics. 3) By solving the coupled equations
numerically, we obtain the scattering probability fortransitions, and integration of this probability over the
impact parameter gives the cross section. The molecular states included are the two sets of states: separating
to [H+ + Siep)] (23~ -, 33II) , [H + Si+(4p)] (13~-,23II), [H + Si+ ep)] (13~+, 13II) for the charge transfer from the initial ground state, and [H+ + Sie D)]
Theoretische Chemie, Universitiit Wuppertal, Wuppertal,
Germany68(21~+, 2 1II) , [H

+ Si+eD)] (31~+,31II) for the electron capture from the initial metastable state. A fully
quantum mechanical representation of the MO expansion method was employed for collision energies below
30 e V. The coupled equations are solved numerically toobtain the scattering matrix. The molecular states included are two sets of channels: (i) [Si+ (4p) + H) (3 3II)and [Siep) + H+] (23II) and (ii) [Si+(2D) + H) (3 1II)
and [Si(1 D) + H+] (2 1II). The cross sections obtained
are shown in Fig. 1. Because of a small asymptotic
energy defect between the initial and closest electron
capture channels, and because of the exothermicity innature for the transition, the electron capture processfrom the ground state Siep) atoms is extremely efficient. Therefore, the present cross section for the
Si+ (4p) formation are found to have a broad peak witha value of 1 x 10- 14 cm 2 between 10 eV and 10 keY. It
gradually decreases as the collision energy decreases,
but it still has a value of 10 - 15 cm 2 even at 1 eV. The
present cross section for the Si+ ep) formation is comparable with those of the Si+ (4p) formation above 1
keY, but it sharply decreases below 0.5 keY becauseof a larger energy defect from the initial state. The
Si + e D) formation in the singlet-state collision is also
large with the charge transfer cross section of 3 x 10- 15
cm 2 above 1 eV.

. . .....: .......•....--

Cbarge transfer in H' + Si collisions

10. 14. 00 rna 00•• • • O ••

•

•

_. ~~

0

o

"~

"'"

00

10·"

•

~

U

o

10·"

o

51'<'P) formation•

51'<'D) (ormatioD

0

10·"
100

0.01

10'

E (eV/u)Fig. 1. Charge transfer cross sections below 10 keV. Filled
circles: Si+(4p) formation ; open circles; Si+ep) formation; filled squares: Si+eD) formation.

References
1) S. L. Baliunas and S. E. Butler: Astrophys. J. 235, L45(1980).
2) A. B . Sannigrahi, R. J. Buenker, G. Hirsch, and J. P.
Gu: Chern. Phys. Lett . 231, 204 (1995).
3) M. Kimura and N. F. Lane: in Advanced Atomic Molecular Optical Physics Vol. 26, edited by D. R. Bates and
B. Bederson (Academic Press, NY, 1989) p. 76.

RIKEN Accel. Prog. Rep. 30 (1997)

Charge Transfer in Collisions H+ Ions with Ground State
Mg Atom at Low ke V Collision Energies
C. M. Dutta,* P. Nordlander,* and M. Kimura
Charge transfer cross sections of the process
Mg + H+ ---+ Mg+ + H were measured for the range of1- 2 ke V collision energies. 1-3) Most of the theoreticalwork were performed by using either classical approximations or semi-empirical approaches. 4 ,5) The only
quantum mechanical ab-initio calculation at ke V energies was performed by Olson and Liu. 6 ) They calculated charge transfer cross sections by using a molecular orbital (MO) expansion method within a semiclassical framework and by employing straight-line trajectories. They obtained a good agreement with experiments around the maximum of the cross section at 1"'0..18
keY, but at the lower energies their calculated values
appear to overestimate the electron capture. Therefore , it seems appropriate at this time to carry out an
ab-initio calculation of charge transfer cross sections
by taking couplings to more MO states than previous
calculations into account.
We have employed the semi-classical impact parameter method based on a MO expansion. Thisapproach was explained in detail elsewhere. 7) The(MgH) + molecule is treated as a quasi two-electron
system by representing the Mg++ (ls 2 2s 2 2p 6) ion coreby a Gaussian-type pseudopotential. The configuration interaction (CI) method with linear combinations of Slater determinants consisting of Slater-type
orbitals is used to obtain Born-Oppenheimer MO'sand eigenenergies of the system. Substituting the total wavefunction into the time-dependent Schroedinger
equation, we obtain a set of first-order coupled equations in time. By solving the coupled equations numerically, we obtain the scattering amplitudes for transitions, and integration of the probability over the impact parameter gives the cross section for the processconcerned.
Figure 1 shows the adiabatic potential energies ofthe lowest fourteen states of the (MgH) + system as afunction of the internuclear separation, R. Figure 2
shows the total single-charge transfer cross sections
calculated by inclusion of the lowest fourteen MO's,
together with some other theoretical results and experimental data. Our calculated charge transfer crosssections (depicted by a solid-line curve in the figure)are in fairly good agreement above E 1"'0..1 3 ke V withmost of experimental data. At lower collision energies,
however, the calculated cross sections become larger
by 30% than measurements, although ours are smaller
than the values (dashed-line curve in the figure) by
Olson and Liu. At lower energies, these measurements
were carried out by using D+ or He+ ions instead of* Department of Physics, Rice University, Houston, TX, U.S.A.

H+ ions. Therefore, if the claim that when H+ ions
are used, the cross sections obtained become uniformly
larger than those by D+ and He+ at low energies stillholds and is taken into account, then we would expectthat the discrepancy between the calculated cross sections and measurements should be somewhat reduced.
More experimental efforts are desirable in this energy
region (E < 3 ke V) in order to verify the theoreticalresults.

H + M +(3d).

H + Ma+(4s)H+ + MI(3s 1 )H + M.·CJp)·1 ~H + M t ( JS}. 1.2 ~~_~--'--'-~~"""""""~......l.-~...........J'--'--'---.......J
o
10
IS
20
25
30
IDternuciear separatioD (a.u.)

Fig. 1. Adiabatic potentials for the MgH+.
It + Mg Collis ioDs'-------;.:--~

.:-

g
-

~

10

r

~
-

-

-

-

-

..... -

-

~

.....

.. "

0;0 ~

•

06

~

e

u

I L-------------------------~

0.1

10

100

E Ck .. )Fig. 2. Charge transfer cross sections in collisionsof H+ ions with Mg atoms. Solid-line: the present,
dashed-line: Olson and Liu. All symbols are the experimental results (Ref. 1- 3).

References
1) R. D . DuBois and L. H. Toburen: Phys. Rev. A 31,
3603 (1985).
2) R. D. DuBois: Phys. Rev. A 34, 2738 (1986).
3) J. Eriksen: Phys. Rev. A 19, 2185 (1979).
4) D. R. Bates and R. A. Mapleton: Proc. Phys. Soc. (London), 87, 657 (1966).
5) R. A. Mapleton and N. Crossbaard: Phys. Rev. 188,228 (1969).
6) R . E. Olson and B. Liu: Phys. Rev. A 20, 1366 (1979).
7) M. Kimura and N. F. Lane: in Advanced Atomic Molecular Optical Physics Vol. 26, edited by D. Bates and B.
Bederson (Academic Press, NY, 1989) p. 76.
69

RIKEN Accel. Prog. Rep. 30 (1997)

Triple-Center Expansion Study of Ionization Processes
N. Toshima
The triple-center expansion method was first applied
to ion-atom collisions by Anderson et al. 1) in order toincorporate the united atom wave functions explicitly
into the basis funct,ions used for the coupled-channel
method. The method was studied further by Lin etal. 2) and Winter and Lin. 3 ) Under the recognition thatthe united atom wave functions have sizable overlap
with the continuum states of the target and projectile
atoms, Winter and Lin 4 ) and Winter 5 ) applied it to
the calculations of ionization cross sections. In thisreport we extend the two-center Gaussian-type-orbitalbasis (GTO) coupled-channel method to a triple-center
description in order to study ionization processes.
We adopt the impact parameter method; the relative motion of the heavy particles is described classically by a rectilinear trajectory wi th a constant velocity v in the impact-parameter representation. We solve
the time-dependent Schrodinger equation of a singleelectron system,[H - i %t 1w(r, t) = a(1)

by introducing an expansion:NT\lI(r , t) =L ai(t)'l/J'[ (rT' t)

(2)

i= l

L

ai(t)'l/Jr (rp , t)i=NT +lN+L

in terms of the target wave functions:(3)'l/J'[ (rT' t) = ¢r (rT) exp( -iE'[ t) ,the projectile wave functions:(4)'l/Jr(rp,t) = ¢f(rp)x exp(-iE['t + iv· rT - ~v2t) ,and wave functions of a virtual atom on the third center C:(5)'l/Jf(rc,t) = ¢?(rc)

,c.
~22)
X exp ( -~Ei t + ~pv . rT - 2 v t .
PHere, ¢r,and ¢f are the hydrogenic eigenfunctions
with eigenvalues E[, Ef and Ef of the Hamiltoniansof the target T , projectile P and virtual atom C , respectively; and rT, rp, rc and r are the electron coordinates measured from the three centers T , P , C , and70

ZC = ZT+Zp.

(7)

Here, P is the ratio of the distances between T and C
and between T and P, while ZT , Zp and Zc stand forthe charges on T , P and C, respectively. The eigenfunctions of each center are further expanded in termsof the Gaussian-type basis functions as
""

'Pnlm

(r)

=~
6 CvnP. e

-0

v

r2

( ~)
r P.v
I em r ,(8)v

where the nonlinear parameters Q v are generated as amodified geometrical progression. The coefficients C~P.
are determined so as to diagonalize the atomic Hamiltonians of the target, projectile and virtual atom. Substitution ofEq. (2) into Eq. (1) gives coupled equations
in a matrix form:dais dt = Va,

Sij = < 'l/Ji I'l/Jj >,Vij = < 'l/Ji I H - ia / at I 'l/J j > .

ai(t)'l/Jf (rc, t),i=NT+Np+l¢r(6)

P = VZT+.jZp '(9)where a is the column vector of the expansion coefficients, while S and V are the overlap and interaction
matrices defined as

NT+N p+from the coordinate origin , respectively. The third center C and its nuclear charge are arbitrary in principle.
We choose C as the equiforce saddle point between thetwo nuclei, and the charge as that of the united atom,
i.e.,

(10)
(11)

All the matrix elements of S and V are calculated analytically in the same way as stated for the two-center
expansion. 6 ) This high analyticity is a great advantageof the G TO expansion method since three-center matrix elements appearing in Vij are very complicatedto handle and since the calculation in the representation of the Slater-type-orbital (STO) expansion istime-consuming.
References
1) D. G. M. Anderson , M. J. Antal, and M. B. McElroy:
J. Phys. B 7 , L118 (1974).
2) C. D. Lin , T. G. Winter, and W. Fritsch: Phys. Rev. A
25 , 2395 (1982) .
3) T. G. Winter and C. D. Lin: Phys. Rev. A 29 , 567(1984).
4) T. G. Winter and C. D. Lin: Phys. Rev. A 29, 3071
(1984).
5) T. G. Winter: Phys. Rev. A 37, 4656 (1988).
6) N. Toshima and J. Eichler: Phys. Rev. A 46, 2564
(1992).

RIKEN Accel. Prog. Rep . 30 (1997)

Elastic and Inelastic Processes in H+ + C 2 H 2Collisions below 1.5 keY Regime
M. Kimura, Y. Li, * G. Hirsch, * and R. J. Buenker*
In the present note, we report the results for electron capture and direct elastic scattering in collisionsof H+ ions with C 2H 2 molecules for energies below 1.5
keY. Contribution from electron-capture accompaniedwith simultaneous target excitation is also examined.
Hence, the processes studied are:H+ + C 2H 2 ----t H + C 2H 2+(electron capture) (la)----t H + C 2H 2+*(electron-capture
with simultaneous target excitation) (1 b)

H+ + C 2H 2* (target excitation) (lc)----t

Two molecular configurations are specifically considered to study the effects of molecular orientations on
collision dynamics: (i) a proton approaches an H atomalong the molecular axis of the C-C bond and (ii) it approaches perpendicularly toward the midpoint of the
C-C bond in C 2H 2. The interference arising from different molecular orientations is investigated. The adiabatic pot ential energy curves are calculated by meansof the multireference single- and double-excitation configuration interaction (MRD-CI) method. 1 ,2) A fully
quantum mechanical representation of the MO expansion method was employed; that is , dynamical transitions were driven by nonadiabatic couplings. 3 ) The

coupled equations are solved numerically to obtain the
scattering Sl matrix for each partial wave l. 3) The differential cross section is then obtained from the standard formula. In the present calculation, we have employed two- and three-state close-coupling treatmentswith molecular orbitals (MOs) corresponding to theinitial [H+ + C 2H 2] and electron capture [H + C 2H 2+]channels. Adiabatic potential curves are displayed in
Figs. la and 1b. The differential cross sections obtained are shown in Figs. 2a and 2b both for C 2v andCoov symmetries, respectively, for scattering angles 0180 0 at 1.5 keY. Collision dynamics for C 2v and Coovsymmetries were found to be effective in nearly thesame small scattering-angle regions. Hence, the interference arising from these two molecular configurations
occurs rather strongly at narrow regions of scattering
angle, and unambiguous structures in differential crosssections arising from the interference are observed.
1o ~

!
r

10'

,) !

H' + C, H,i

E = l .S k. V

i

C,.
-

El astic

10'

-

S!

1

100

~
0 .0 1.76. 5\10" 0i-76.72 1.. .

\'

t·

~ .

~

\

.f

.::, . 76 .9' f

~

.

10'

.

""

t

- 100

I

·L . . ._o- ' - - - - - ' - - - - ' - -_ _9~_---'--'-~.L...-_

~

6

1

R ( a .n .)-7 6 .5 ~ . . -,.---~----.,.......,-------76 .7~~-7 6 . 8

~

c••.

10'

rr

.76.6

b,

H' + C, H,
E = 1. 5 k. V

10'-77. 18 ~

_7U

45

'.

r

.ur¥'
lO · ~

4S

b)

90

135

180

9 (d'g. )rt

Fig. 2. a) Differential cross sections for elastic and electron
capture processes for C2v symmetry at 1.5 keV. b) Differential cross sections for elastic and electron capture
processes for CODy symmetry at 1.5 ke V.

-7 6.9-77 .0·77. 110

12

14

R ( a.n .)Fig. 1. a) Adiabatic potentials for C2y symmetry in the[H + C2H2]+ system. b) Adiabatic potentials for COOY
symmetry in the [H + C 2H2]+ system.
Theoretische Chemie, Universitaet Wuppertal , Germany

References
1) M. Kimura, Y. Li, G. Hirsch, and R. J. Buenker: Phys.
Rev. A 52 , 1196 (1995).
2) R. J. Buenker and S. D. Peyerimhoff: Theoret. Chim.
Acta 35, 33 (1974); 39, 217 (1975); R. J. Buenker: Int.
J. Quantum Chern. 29, 435 (1986).
3) M. Kimura and N. F. Lane: Adv. At. Mol. Phys. Vol.
26, Eds. D. R. Bates and B. Bederson (Academic Press,
NY, 1989) p. 79.
71

RIKEN Accel. Prog. Rep . 30 (1997)

Double Electron Detachment from Negative Hydrogen Ions
under High Energy, Highly Charged Ion Impact
H. Tawara, L. P. Presnyakov,* and D. B. Uskov*
Phenomena of the electron detachment from negative hydrogen ions in collisions with highly charged
ions (HeI) are not only interesting in basic collision
aspects but also important in applications such as fusion plasma heating technology.
So far, the single electron detachment from H- ions
resulting in the production of neutral hydrogen beam,
HO, has been studied at HCI collisions, but only under relatively low energy. 1) Namely, there are no such
experimental studies under a high energy (MeV /amu)
HCI collision. We have thus started to investigate theelectron detachment from H- ions under such collisions at Me V / amu region and to measure their crosssections. 2) It should be noted that no investigationon the double electron detachment from H- ions has
been reported yet, except for that under the electron
impact. 3)
In the present work, we describe some results of ourcalculations of the cross sections for the double electron
detachment from H- ions under the MeV /amu HCI
ion impact. The present approach in calculating the
double electron detachment from H- ions is based ona modified version of our method previously applied tothe double electron removal from a neutral He atom. 4)
Assuming that two electrons (Is, Is') in a H- ion
are independent, the one-electron continuum wavefunctions in the final channel have different forms forthe "outer" (Is') and "inner" (Is) electrons. The function for the "outer" electron is in the Volkov-Keldysh
state, given asiii, = ilik, (t) = (27r}-3/2 exp [ip,(t}r, -~l' dTp~(T)],
(1)

where

Pi = k i - A(t}, A(t} = ql'dTR(T}j[R(t)]'.

(2)Here, k i is the momentum of the i-th electron at the
distance rj from nucleus, R(t) = b + vt is the internuclear distance depending on the impact parameterb and the relative velocity v, and q is the projectile
charge.
On the other hand, the wavefunction for the "inner"electron describes the electron motion in the Coulomb
field of proton and the dipole field of projectile ion,
given as:(3)
'11 2 = Wk)t)G,where
G = exp(7rv/2)r(1 + iv)F( -iv, 1, i(P2r2 + P2r2)),
v = 1/P2'
Lebedev Physics Institute, Moscow, Russia

72

(4)

Here, rand F are the gamma function and the confluent hypergeometric function, respectively.
Using these functions, the second-order perturbation
theory, similar to the independent-event model,S) results in the following cross sections for the double electron detachment from a H- ion:(5)
where O"s is the single electron detachment cross section, Rso the shake-off constant which represents theratio of the cross sections for double-to-single-electron
detachment at asymptotic collision energies , and O"TSthe cross section of a two-step process in terms of oneelectron event. Rso can be estimated, from the experimental data available under electron impact ,3) to be(2.3 - 4.0) x 10- 3 .
0" s has been calculated in the previous study l) to be22o"s = 51.6(q/v)2 In{2.03v /(1 + 0.139v )1 / 2 + l.01}[10- 16 cm 2 ](6)where q is the charge of a HeI and v the H- ion velocity in atomic units. Equation (2) agrees with the abinitio Bethe-Born calculation at asymptotic region. 6 )On the other hand, using a similar treatment of Refs.
4 and 7, the present analysis for the two-step process
results in the following analytical expression for O"TS
given to be
O"TS =

2.9(q/v)4 exp( -0.41Q/v

2-

l.l/v)[10- 16 cm 2 ].

(7)

It should be noted that the single-electron detachment
cross section scales as (ql v) 2, whereas that for the double electron detachment does as (q/v)4.
The contribution from the interference term between
two wavefunctions has been estimated and found to beless than the cross sections given by Eq. (5).
References
1) F. Melchert, M. Benner, S. Kriidener, R. Schultze, S.
Meuser, S. Petri, S. Pfaff, E. Salzborn, D. B. Uskov,
and L. P. Presnyakov: Phys. Rev. Lett. 74, 888 (1995).
2) H. Tawara, T. Tonuma, H. Kumagai, and T. Matsuo:
RIKEN Accel. Prog. Rep. 29, 91 (1996).
3) D. J. Yu, S. Rachafi , J. Jureta, and P. Defrance: J.
Phys. B 25, 4593 (1992).
4) L. P. Presnyakov, H. Tawara, I. Yu. Tolstikhina, and D.
B. Uskov: J. Phys. B 28, 85 (1995).
5) N. C. Deb and D. S. F. Crothers: J. Phys. B 23, L799
(1990).
6) Y. K. Kim and M. Inokuti: Phys. Rev. A 33,665 (1971).
7) L. P. Presnyakov and D. B. Uskov: SOy. J.- JETP 59,
515 (1984).

RIKEN Accel. Prog. Rep. 30 (1997)

Theoretical Study for Absorption and Emission Spectra of
Alkali Atom and Liquid-He Composite System
J. Z. Tang,* M. Kimura, and 1. Shimamura
Spectroscopic studies of atoms and molecules in the
superfiuid He have provided a new and exciting research subject not only in the atomic and molecularphysics, but also in the condensed-matter physics.1- 5 )Because the electron-He interaction is uniformly repulsive in nature, atomic electrons of the impurity atom
push the surrounding He away, forming a nearly spherical vacuum space, or so-called a "bubble" around theimpurity atom. A general size of the bubble is as large
as 10- 30 a.u. The atomic state and dynamics inside
the bubble are expected to be significantly different
from those of a free atom, and this type of study (given
below) should provide an important knowledge for fundamental physics. Experimental attempts to explore
these physics have been very active recently, and have
deepened our level of understandings for the bubble.
There were several problems formerly for understanding what were observed , but very recently some theoretical works have been performed to shed much lighton them. 6 - 8 )Earlier, we presented the result of a comparative
study of absorption and emission spectra from Mg
through Be and showed a good agreement with measurements in general. 5) In present report , we extend
the calculation to alkali atoms in the liquid-He , explain our results of each absorption and emission spectra resulted from transitions between the ground stateand optically-allowed first excited state, and discusscharacteristics of spectrum shift and half-width seen
in each spectrum.
The system of an impurity atom in the liquid-He is
a complicated many-body problem if all particles involved are treated fully quantum mechanically. Since
we are interested in studying a perturbation of theliquid-He on the optical transitions of the impurity
atom, we employ here a simple bubble model of theliquid-He as fully documented earlier. 5 ) Atomic units
are used throughout.
Density distribution: The density distribution of
atoms in liquid-He around the impurity atom may bedescribed by a bubble model. 6 ) The shape of the bubble depends on the electronic distribution of the impurity atom. For the study of absorption spectra, thebubble may be assumed to be spherically symmetric if
the atom is initially in an s state. For studying emission, however, the bubble is considered to be of a nonsymmetric shape because of the unsymmetric natureof an excited 7r state.
Total energy and the breathing bubble oscillation: An impurity atom is introduced into theliquid-He of the temperature below 3K. For simplicity,
we assume the spherical symmetric structure for the
bubble here.
Department of Physics, University of Tennessee, Knoxville,
TN , U.S.A .

The total energy of this composite system of the
impurity atom and liquid-He is given as
E tot = E atm + Esurf + Epv + E int ,where E atm is the free-atom energy; Esurf represents
the surface tension energy of the bubble; Epv describes
the pressure-volume work at the surface of the bubble;
and E int is the interaction between the impurity andsurrounding He atoms.
Adiabatic line-broadening theory: The spectral
intensity for an optical transition of atoms may be obtained by the Fourier transformation of the transition
dipole correlation function.
Absorption and emission spectra: The conventional procedure to evaluate absorption and emission
spectra is based on the line-broadening theory.1-5,9)This theory is based on the collisional broadening of
the spectrum through the interaction with liquid-He.
In the present study, we modify the standard line
broadening theory by including the effect of the bubble
oscillation. Then , the spectrum can be described as

I(w) = / dR o Ia(w, flo) Ix (~) 12,
where Ia and X are the line-broadening based on the
adiabatic theory and distribution of the bubble size(i.e. , bubble nuclear wavefunction) , respectively.
Diatomic molecular states: Molecular states ofa two-body adiabatic system are obtained by using
the configuration-interaction (CI) method. We believethat the present precision is considered to be reasonably sufficient for ab initio calculations of spectra, inwhich experimental shifts were found to be in a rangeof 200 cm- l to 700 cm- l .
Based the theory above, a theoretical study of theatomic absorption and emission spectra of alkaline
atoms (Li, Na, K , Rb and Cs) in the superfiuid He(a bubble) was carried out , and their shifts and halfwidths were also examined to be compared with measured spectra. The results for the absorption and emission spectra agree very well with measurements formost cases in spectral shapes and give rationales tosome of unexpected observations.
References
1) Special issue of Zeit. fuer Physik B, 98 (1995).
2) A. FUjisaki et al.: Phys. Rev. Lett. 71 , 1039 (1993).
3) Y. Takahashi et al.: Phys. Rev. Lett. 71 , 1035 (1993).
4) T. Kinoshita, Y. Takahashi, and T. Yabusaki: Phys.
Rev. B 49 , 3648 (1994).
5) J. H. M. Beijersbergen, Q. Hui, and M. Takami: Phys.
Lett. A 181, 393 (1993).
6) J. Dupont-Roc: Z. Phys. B 98, 383 (1995).
7) J. 1. Persson et al.: Phys. Rev. Lett. 76, 1501 (1996).
8) T. Kinoshita, K. Fukuda, and T. Yabusaki: Phys. Rev.
B 54, 6600 (1996).
9) J. Z. Tang, M. Kimura, and I. Shimamura: Chern. Phys.
Lett. 256, 327 (1996).
73

RIKEN Accel. Prog. Rep. 30 (1997)

Photodetachment Cross-Sections of
the Positronium Negative Ion
A. Igarashi
The positronium negative ion, Ps-(e-e-e+), is the
special system in which three particles with same mass
are interacting through Coulomb potentials. The Pssystem has only one bound state of the symmetry 1 Se .
Its existence has been confirmed and the decay rate
has been measured to be 2.09±0.09 ns- 1 , 1) which isin good agreement with theories. As for Ps- photodetachment, there is no experimental measurement
and there are little theoretical works enough to discuss
their reliability of cross-sections.
Thus in present report , we calculated photodetachment cross-sections of Ps - in the process:

N

E

u
r--.

b

20

c
o

'n
Q)

(f)

en
en

10

o

o

(1)

up to just above the n=2 threshold by use of thehyperspherical-coupled-channel (HCe) method. The
Hee method is a powerful tool to describe the strong
electron-electron correlations in a two-electron system,
such as He and H- , and was successfully applied tothe calculation of photoionization cross-sections. 2 ) The
photodetachment cross-section can be written as(2)Here, 7/Ji is the initial bound state of 1 Se symmetry and7/J f the continuum state of 1 po symmetry, and D the
dipole operator in either the velocity or length form. 3 )The initial and final wave functions are calculated
in the HCC method with an expansion in terms of thechannel functions which converge to atomic states ofPs(n=14) at the asymptotic region. Our binding
energy for the initial state is 0.011997 a.u. , which is
sufficiently accurate for our purpose compared withthe best variational value of 0.012005 a.u. 4 ) The results
obtained in the velocity and length forms agree within
less than about 1%, and only results calculated withthe length form are shown in figure.
Present photodetachment cross-sections for the process (1) are shown in Fig. 1 in the energy region near
the Ps(n = 2) threshold. Two prominent spikes, justbelow e- + Ps(n=2) threshold, are the first two of theinfinite series of Feshbach resonance. These resonances
are attributed to an attractive potential between eand Ps, which decays as 1/ R2 owing to the Stark effect for the degenerate Ps(n=2) states. Another peakabove the Ps(n=2) threshold is the shape resonance of
1 po symmetry predicted by Botero et a1. 5 )It is interesting to compare the photodetachment
spectrum of Ps- with those of H- (for example,
Fig. 4(a) in Ref. 2). A close qualitative resemblance
f",.J

74

Photon Energy (eV)Fig. 1. Photodetachment cross-sections by nw + Ps - ---t
Ps(n) + e- near the energy of the Ps(n = 2) threshold.
Ps(l) production: solid curve; Ps(2) production: dottedcurve.

can be seen. A qualitative discussion based on the hyperspherical adiabatic potential curves has been madein Ref. 5.
The resonance energies and widths around Ps(n=2)
threshold of 1 po symmetry are tabulated in Table 1.
The lowest resonance position by the complexcoordinate calculation of Bhatia et al. 6) is in good
agreement with the present value. The results of adiabatic treatment in the hyperspherical coordinates 5 ) arereasonable, since it is a simple, single channel calculation.
Table 1. Resonance energies Er and widths r (in a . u.) of
Ps - of Ipo symmetry, where 9.8[-7J == 9.8 x 10- 7 .
Botero et al. 5)

Present

-Er

r

-Er

r

Bhatia et a1. 6 )-Err

0.063156 1.0[ -6J
1. 0.063156 9.8[-7J 0.062587
2. 0.062543 2.8[-7J 0.062506
3. 0.062137 5.4[-4J 0.0621
4.[-4]

References
1) A. P. Mills Jr.: Phys. Rev. Lett. 46 , 717 (1981).
2) J .-Z. Tang et al.: Phys . Rev. A 49 , 1021 (1994).
3) A. K. Bhatia et al.: Phys. Rev. A 32 3745 (1985).
4) Y . K . Ho : J. Phys. B 16, 1503 (1983).
5) J. Botero et al.: Phys. Rev. Lett. 56, 1366 (1986).
6) A. K. Bhatia et al.: Phys. Rev. A 42, 1119 (1990).

RIKEN Accel. Prog. Rep. 30 (1997)

Recoil-Ion Momentum Spectroscopy of
0.25 MeV/nucleon Ar-He Collisions
T. Kambara, Y. Awaya, Y. Kanai, T. M. Kojima, Y. Nakai, R. Dorner, V. Mergel,
H. W. Schmidt-Bocking, M. Jager, and B. D. DePaola
Final-state distribution of single-electron capture by
0.25 MeV Inucleon Ar 8 + ions from He atom,
Ar 8 + + He ~ Ar7 + + He+,(1)

have been measured with COLd Target Recoil Ion
Momentum Spectroscopy (COLTRIMS).1-3) In singleelectron capture processes without an emission of freeelectrons, the binding energy of the captured electron
to a nl-orbital of the projectile is related to the longitudinal component (parallel to the beam direction) of
the recoil ion momentum PIIR by the relationship:

tured to the orbitals with n ~ 3. The figure also shows
the final electron orbitals and the excitation energies
relative to the ground 38 state of the Ar 7+ ion. The
present resolution of the final state binding energy isenough to separate the capture to the n = 3 states fromthose to the n ~ 4 states. The capture to the n = 4
states also appears as a shoulder of the peak due tothe capture to the n = 5 states. The n = 5 states are
dominantly populated by single-electron capture in thepresent collision system and this result agrees with aclassical overbarrier model. 4)(2)where me is the electron mass, v is the projectile velocity, E is the electron binding energy of He atom, and
Enl is the binding energy of captured electron in the nl
orbit. In this and next articles, the recoil-ion momentum is expressed by atomic unit (au) which correspondto 300 mls for a He ion.
The experiments were performed at RILAC witha setup which was almost same as that described
previously,2) but was improved in the resolution of
the recoil-ion momentum measurement. The slow recoil ions produced in the intersection region were analyzed by an elect rostatic spectrometer,3) where thethree components of the recoil-ion momentum vector
were determined by the recoil-ion trajectory and its
time-of-flight (TOF) in coincidence with the projectile. In the present measurements, a non-uniform electric field was used to achieve a position focusing effect of the same momenta from the whole collision volume (lens effect). The lens effect has improved theresolution of the longitudinal momentum component
to about ±0.2 au (atomic unit) from the resolution of±0.5 au without it. In the present collision system,
this momentum resolution corresponds to about ±17
eV of resolution for the binding energy of the captured
electron. The overall resolution of the transverse component P..LR was about ±0.2 au.
Figure 1 shows a PIIR distribution by Ar 8 + ions,where the yield is integrated over P ..LR :::; 4 au. Since
the projectile of Ar8 + ion is a neon-like system where
the orbitals with n :::; 2 are closed, the electron is cap-

n=5(1 01 - 10geV)~1 14d(86.5eV)
4p(78 .0eV)

I n= CXl

Q3

c
c
m

(143 .5eV)

2.I:::.

()

---C
C/)

::J

o

()

3d(41 .3eV)
3 P(17 '5ev)\
3S(OeVlj\

0 ~~---~
4--~~--~-~2--~~--~~0Longitudinal Momentum (au)Fig. 1. The longitudinal momentum distribution ofrecoil ions for one-electron capture from He by 0.25
MeV /nucleon Ar 8 + ions. The electronic states of thecaptured electron and respective excitation energies arealso indicated.

References
1) K. Ullmann et al.: Proc. 4th US/Mexico Symp. on
Atomic and Molecular Phys. , San Juan del Rio, Mexico,1994, World Scientific, 1995, p. 269.
2) T. Kambara et al.: J. Phys. B 28 , 4593 (1995).
3) V. Mergel et al.: Phys. Rev. Lett. 74, 2200 (1995).
4) H. Ryufuku , K. Sasaki , and T. Watanabe: Phys. Rev.
A 21 , 745 (1980).

75

RIKEN Accel. Prog. Rep. 30 (1997)

Recoil-Ion Momentum Analyses of Single-Electron Capture of He
by B 4 +,5+ at 0.5-1 MeV/nucleon
T. Kambara, A. Igarashi, N. Watanabe, Y. Nakai, T. M. Kojima, and Y. Awaya
We have made state-selective measurements of differential cross sections of one-electron capture processes from helium atoms by fast boron ions (Z = 5),
Bq+ + He ~ B(q-l)+(n) + He+,(1)

where n is the principal quantum number of the captured electron. The projectiles were fully-stripped
B5+ ions at energies of 0.75 and 1 MeV/nucleon andwere hydrogen-like B 4 + ions at 0.567, 0.75, and 1
Me V /nucleon.
We have measured all the momentum components of
the recoil He+ ions applying COLd Target Recoil Ion
Momentum Spectroscopy (COLTRIMS)1 ,2) in coincidence with the projectiles which captured one electron.
From the longitudinal component of the recoil-ion momentum, we have deduced the binding energy of the
final states of the captured electron. The differential
cross sections for these final states have been obtained
as functions of the transverse component.
The experimental setup was almost same as that ofthe previous study. 2) A collimated boron beam fromRILAC intersected a target of He gas jet. Before theformation of the gas jet, the target He gas was precooled to 35-40 K at a pressure of 500 mbar.
The projectile ions which captured one electron in
the target gas were selected by a deflecting magnet andwere detected with a position-sensitive parallel-plateavalanche counter. The recoil ions were analyzed bya electrostatic spectrometer with a uniform extraction
field and the charge state and three components of the
momentum vector were determined in coincidence withthe detected projectile ions.
Figure 1 shows the measured longitudinal momentum distribution of the recoil He+ ions. The final
states of the captured electron were separated to theground state (n = 1) and to the excited states (n > 1)
as shown in the figure. A peak around 0 au wasproduced by chance coincidences between projectile
charge change and target ionization. The electron capture predominantly occurs into the excited states, but

c

.Q

1)

3l

o

U

c
(!)

&
is
Transverse Recoil Momentum (a.u.)

Fig. 2. Differential cross section of one-electron capture
to the ground (lower figure) and excited (upper figure)states by 1 MeV/nucleon B 5 + ions. Dots are experimental results and solid lines are the calculation results.

o

The experimental results of the differential cross sections were compared with calculations of the eikonal
approximation. 3) The results are shown in Fig. 2 bycurves of solid lines. The theoretical predictions forthe capture to the excited states agree well the experimental results at all the projectile velocities and charge
states. The theory can well reproduce the hump structure in the differential cross section for the capture
to the ground state. The agreement is better for thehigher velocity and charge state of the projectile. The
details of this work are reported elsewhere. 4 )Sl

References

n>l

Qi

1 MeV/u 85+

2 100

..c.

§ 50
o
u

Longitudinal Recoil Momentum (a.u.)

Fig. 1. Longitudinal recoil-momentum distribution of He+
by 1 MeV /nudeon B 5 + projectiles.

76

the relative intensity of the capture into the groundstate increases rapidly with the collision energy.
Figure 2 shows the differential cross section of singleelectron capture by 1 MeV/nucleon B 5+ projectiles.
The results are normalized to the theoretical total crosssections of an eikonal approximation. 3 ) The capture
cross sections to the excited states have an almost samedependence on the transverse momentum regardless ofthe charge state and energy of the projectile; with apeak around 1 au and a monotonous decrease at thehigher transverse momentum and a slower decrease
above 3 au. The capture cross section to the groundstate, on the other hand, has a different feature: It depicts a peak at about 1.5 au and a broad tailor a humpat the higher transverse momentum. The shape of thehump depends on the collision velocity and projectile
charge.

1) K. Ullmann et al.: Proc. 4th US/Mexico Symp. on
Atomic and Molecular Phys., San Juan del Rio, Mexico,1994, World Scientific, 1995, p. 269.
2) T. Kambara et al.: J. Phys. B 28, 4593 (1995).
3) K. Kobayashi, N. Toshima, and T. Ishihara: Phys. Rev.
A 32, 1363 (1985).
4) T. Kambara et al.: J. Phys. B in press.

RIKEN Accel. Prog. Rep. 30 (1997)

Beam Foil Spectra of Highly Charged Argon Ion
in Visible Region
K. Ishii, T. Nishida,* Y. Kimura, M. Fujiwara, T. Nakano,S. Kawae , K. Ando, and Y. Awaya
Beam-foil spectra of highly charged Ar ion at theenergy of 1.0 and 2.0 MeV /amu were recorded in theregion between 200 and 700 nm. Photons emitted fromthe Ar ion after its passage through a thin carbon foil
were dispersed by a monochromator and detected bya liquid nitrogen cooled CCD camera (Princeton Instruments, Inc.). The CCD detectors cover the wavelength range of about 80 nm. The recording of thespectra for each range were successively repeated atleast twice while keeping the conditions unchanged,
e.g. , the beam current and the exposure time. The
spectra thus recorded contain several spurious spikes ,whose height is often as large as the intense spectral
lines. Most of them originate from the cosmic rays
and the others from X-rays from the beam transport.
The spikes due to the X-rays were reduced by covering
the detector with lead sheets . Still some were left andtherefore the exposure time for each run was limited
to less than three minutes. The remaining spikes were
eliminated in the data processing by comaring the two
successively recorded spectra.
U sing the hydrogenic term energies, the wavelengths
and the transition probabilities for the Rydberg transitions were calculated. 1 ,2) Most of the intense lines arethus classified as transitions of high n , l levels in Ar X
to Ar XVII.
In Fig. 1 the observed argon spectra in the range
210- 250 nm at 1.0 MeV /amu beam energy are displayed. It is noted that a satellite line on the longer
wavelength side of the n = 9- 10 transition in Ar XIII
apears only at the observation in the close vicinity of
the foil and moves to the longer wavelength side as thefoil was translated upstream relative to the observation
line.
The short-lived and broad feature of the satellite line
suggests that this line is due to the multiply excited
Rydberg transition. We have tentatively attributed
this to the Ar XII 1s22s22p9ln"l"-ls22s22p10l' n"l"transition, where l = 8, l' = 9, and n" is larger than 10.
As a first approximation, we have calculated the level
energies of [core]9 8 n"l" and the [core]10 g n"l" using themodified Rydberg formula. 3) We have also calculated
them by use of the atomic structure calculation code. 4 )

I

~

><:

0

M

d-.

~

X
2>

A

67.8

E 67 .6 E

.A

J...A
.A
f'oft...

';;' 67.4~

o:~ 67.2o~ 67.0l~~ 66.8
66.6
66.4
66.2

N

-2>

c

-'"
d-.

N

~

>
><:

'0

2>
.A

"

"

1\

JL

.JI.

A~-

.JL

lA.

A

v... . . . .

A

'-".

A

V'-

JL

66.0
65.8
65.6
210

I

220
230
Wavelength (nm)

I

240

250

Fig. 1. A portion of Ar ion spectra at 1.0 MeV / amu energy
at a sequence of successive foil position. The prompt
spectrum is at the bottom and the delayed ones areshown upwards.

The calculated wavelength varies from 230.7 to 236.7
nm when n" was changed from 22 down to 12. The
further study both in experiment and in calculation is
now in progress.
References
1) H. A. Bethe and E. E. Salpeter: in Quantum Theory ofOne- and Two-Electron Atoms (Springer-Verlag, Berlin,1957), p. 262.
2) B. EdlEm: in Handbuch der Physik, edited by S. Fliigge,(Springer-Verlag, Berlin, 1964) Vol. XXVII , p. 80.
3) F. H . Read: J . Phys. BID, 449 (1977).
4) R. D . Cowan: in The Theory of Atomic Strcture andSpectra, University of California Press, Berkley (1981).

Department of Engineering Science, Kyoto University

77

RIKEN Accel. Prog. Rep. 30 {1997}

Beam Foil Spectra of Highly Charged Neon Ion
in Visible Region
K. Ishii, T. Nishida,* Y. Kimura,* M. Fujiwara,* S. Kawae,*
T. Nakano,* K. Ando, and T. Kambara
Beam-foil spectra of highly charged Ne ion at thebeam energy of 0.5 and 1.0 MeV /amu were recorded in
the region between 200 and 700 nm. Photons emitted
from the Ne ion after a passage through a thin carbon foil were dispersed by a monochromator and detected by a photomultiplier (PMT). In the early Summer of 1996, the PMT was replaced by a liquid nitrogen cooled CCD detector (Princeton Instruments,Inc.). The data acquisition time was largely reduced.
In the previous years, it took 24 hours to scan the spectral range from 200 to 450 nm by use of a single channel
photomultiplier. Now, the efficiency was improved bya factor of almost one hundred.
In the spectra thus far recorded, most of the lines
are classified as transitions of high n , .e levels in Ne V
to Ne X, where n ranges from 5 to 11. The lines
due to transition of 2s7.e-2s8.e' in Be-like Ne VII were
found split into .e-components by the perturbation of
the nearby lying doubly excited 2p5.e configuration to
2s8.e. The energy levels, the transition wavelengths,
and the transition probabilities were computed by useof the atomic structure code. I) In the calculation, relevant configurations were included as many as possible. In addition to the main configurations of 2s7.e and2s8.e, the pertubing 2p3.e, 2p4.e, 2p5.e, 2p6.e, 2p7.e and2s6.e were included with all the possible.e. In Fig. 1
the observed neon spectrum in the range 360- 400 nm
at 0.5 Me V / amu beam energy is compared with thecalculated spectrum. Note that the agreement is good
not only in the line positions, but also in the relative
intensities. The identification was confirmed by the
decay measurements of individual lines.
The use of the CCD detector made it possible torecord the spectra at the different foil positions. The
integrated beam current collected in the Faraday cup
and also the non-dispersed photons counted by a photomultiplier at the fixed position close to the foil
through an optical fiber were used to normalize thespectra. The CCD camera covers the spectral range ofabout 80 nm. The recording of spectra for each range
was repeated successively at least twice under the same
conditions in order to eliminate the spurious spikes
caused by cosmic rays. A broad satellite line at 390
nm on the longer wavelength side of Ne VII 2s7i-2s8ktransition was found to decay as soon as the observation position goes downstream from the foil. Strikingly, it moves towards the longer wavelength side.

Department of Engineering Science, Kyoto University

78

1000

(A)
800

!/)

600

C

(U

::::I

.::t.

0
(.)

400

I

dJ

~
200

370

365

375

360

390

385

395

Wavelength (nm)

(8)

i:i5
VI

C\I

1:.
r--.

(/)

C\I

365

I

I

I

I

I

I

370

375

380

385

390

395

Wavelength (nm)Fig. 1. Comparison of observed and calculated spectra in
the range of 360- 400 nm. (A) Observed at the beamenergy of 0.5 MeV /amu. (B) Calculated lines are dueto the transition of Ne VII Is 2 2s7f-1s 2 2s8.e'.

The broad and short-lived features suggest that thisline originates from the multiply excited transitions.
This line is tentatively assigned as the transition of
Ne VI Is 2 2s7.en.e' -ls 2 2s8.en.e' , where n ranges from 12
to 18 with highest .e'. This is not a special case. NIost of
the Rydberg transitions with 6n = 1 are accompanied
by a short-lived, broad line on the longer wavelength
side. They show the same feature as described for the
Ne VI n = 7- 8 transition.
References
1) R. D. Cowan: in The Theory of Atomic Strcture andSpectra, University of California Press, Berkley (1981).

RIKEN Accel. Prog. Rep. 30 (1997)

Intercombination Line Oscillator Strengths forHigh-Z Mg- and AI-like Ions
R. Hutton, L. Engstrom, S. Huldt, I. Kink, B. Nystrom, Y. Zou,
I. Martinson, P. Bengtsson, K. Ando, T. Kambara, Y. Kanai,
T. M. Kojima, Y. Nakai, and Y. Awaya
Intercombination line transition rates have been investigated for various ions belonging to the Mg- andAI-like sequences. The investigation has been performed using the ion beams from RILAC and thetechniques of beam-foil spectroscopy.
The procedure for doing these measurements has been described
elsewhere. 1) The results of the measurements show aconsistent deviation from the generally accepted theoretical trend. This is summarized in Figs. 1 and 2. In
Fig. 1 the (scaled) 3s 2 1 So - 3s3p 3 PI transition oscillator strength (f) in Mg-like ions is shown for ions up
to Mg-like Au as a function of the effective charge ( =q + 1 of the ion, where q is the charge state. The experimental results are compared to theoretical values.

The points represented by filled circles are the data obtained at RIKEN. A clear discrepancy between theory
and experiment is observed. A similar plot but for the
3s 23p 2 P3 / 2 - 3s3p2 4 P5 / 2 transition in AI-like ionsis presented in Fig. 2, where the open circles represent
data obtained at RIKEN. The origin of this discrepancy is not understood at present; there are no known
experimental problems which could result in such deviations.
25

.s

20

t

T

01)
~

I

(\)

b
:

15

0

~

SO

"<3
45

¥

40

I

35

!

C5 10
"0
(\)

"@

! t

~

0

£""' 30

's

15

!

,
t
20

25

30

effective charge
25

N

'-.J>
4-

Fig.
2.
A similar picture to Fig. 1 but for the
3s 23p 2 P3 / 2 - 3s3p2 4 P S / 2 transition in AI-like ions.
The points measured at RIKEN are represented by open
circles. The theoretical data denoted by x are from Ref.
4. References to the data represented by filled circles
can be found in Ref. 5.

20

15
10

Fe XV

o

o

10

15

Kr XXV

20

25

30

Rh XXXIV

35

40

45

SO

effective charge, (Fig. 1. Scaled oscillator strength for the Mg-like intercombination line as a function of the effective charge.
The darkened points were measured at RIKEN. The
full curve represents theoretical values. 2 ) References tothe data represented by open circles and to other theoretical works can be found in Ref. 3.

References
1) R. Hutton: Proc. 8th Int. Conf. on the Physics of Highly
Charged Ions, Sept. 1996, Omiya, Japan, to be published in Physica Scripta.
2) L. J. Curtis: Physica Scripta 43, 137 (1991).
3) E. Trabert et al.: Z. Phys. D 32, 295 (1995).
4) K.-N. Huang: At . Data Nucl. Data Tables 34, 1 (1986).
5) E. Trabert: Phys. Rev. A 47, 3805 (1993).

79

RIKEN Accel. Prog. Rep. 30 (1997)

Lifetimes for the Be- and B-like Fe Intercombination Lines
R. Hutton, B. Nystrom, I. Martinson, K. Ishii, M. Jager,
K. Ando, P. Bengtsson, T. Kambara, and Y. Awaya
The 2S2 I So - 2s2p 3 PI intercombination line in Belike ions is of considerable interest. This is reflected in
the amount of work, both theoretical and experimental, done on the intercombination rate for ions in thissequence. The main reason for the interest is due tothe fact that the intercombination lines in C III and 0
V are used in the diagnostics of astrophysical plasmas.
Given the amount of theoretical data available for the
decay rate of the 2s2p 3 PI level, there is surprisingly
little amount of experimental data for the ions of thissequence. The 2s2p 3 PI lifetime has been measured
for only four ions in the sequence, namely C III, Fe
XXIII, Kr XXXIII, and Xe LI. The measurement for
Fe- XXIII I ) was not in agreement with the currently
recommended theoretical result. 2 ) However, the previous Fe XXIII beam-foil measurement suffered fromrather large error estimates. With this in mind a remeasurement of the 2s2p 3 PI lifetime was initiated for
Fe XXIII. The measurement was made using a beamof 2.5 MeV/nucleon Fe ions provided by the RILAC.
The measurement procedure has been described in a
number of previous articles (e.g. , Ref. 3) and will not
be discussed here. The experimentally determined lifetime was found to be 17.5±1.5 ns which is in reasonableagreement with the recommended theoretical value of
19.6±O.8 ns. 2 ) The scaled 2s2p 3 PI lifetime is shown in
Fig. 1 for a number of ions in the Be I sequence. Moredetails of this figure can be found in Ref. 4. Using
the same ion beam a measurement was made for the2s2p2 4 P5 / 2 lifetime in B-like Fe. No measurements of
the B-like intercombination line transition rates havebeen previously reported for high-Z ions. The experimentally determined value for the 4 P5 / 2 lifetime is14.8 ± 1 ns which is in good agreement with the mostrecent theoretical result of 13.4 ns. 5 )80

Be-like 1s22s21S0 - 1s22S2p3 P 1

10 12 ,

-T

I

Z

en

x

~

E..

Theory• This Exp .

"-

0

N

Prevo Exp.

+

IV'

X
Q)

E

~

f

::i

10 11

I

Gill
SiXI

1

Fe XXIIIKr XXXIIIMoXXXIX

Fig. 1. A comparison between theoretical and experimental values for the 2s2p 3 PI lifetime in Be-like ions.
( = q + 1 is the effective charge where q is the charge
state of the ion. The new Fe 22 + data point (filled circle) was measured at RIKEN ; see Ref. 4 for details.
The remaining experimental data are taken: C 2 + from
Ref. 6, Fe 22 + from Ref. 1, and Kr 32 + from Ref. 7. The
theoretical data are from Ref. 8.

References
1) D. Deitrich et al.: Phys. Rev. A 18, 208 (1978).
2) T. Brage, J. Flemming, and R . Hutton: manuscript in
preparation for Mon. Not. R. Astron. Soc.
3) R. Hutton et al.: Phys. Rev. A 51, 143 (1995).
4) R. Hutton et al.: accepted for publication in Physica
Scripta.
5) G. Merkelis et al.: Physica Scripta 51, 233 (1995).
6) V. H. S. Kwong et al.: Astrophys. J. 411 , 431 (1993).
7) D. Deitrich et al.: Phys. Rev. A 22, 1109 (1980).
8) A. Ynnerman and C. Froese-Fischer: Phys. Rev. A 51,
2020 (1995).

RIKEN Accel. Prog. Rep. 30 (1997)

Oscillator Strengths for ResonanceTransitions in Na-like Kr
1. Kink, R. Hutton, B. Nystrom, 1. Martinson, K. Ishii, K. Ando,
T. Kambara, Y. Nakai, T. M. Kojima, and Y. Awaya
We have measured the lifetime of the 3p 2 P 3 / 2
level in Na-like Kr 25 +, using beam-foil excitationand cascade corrected analysis. The Kr beam at
2 MeV/nucleon was provided by RILAC. Our result,
T = 45 ± 2 ps, has half the uncertainty as compared tothe previous experimental data taken for highly ionizedNa-like ions, and permits an important test of theoretical methods. Recently, Hutton et al. l ) pointed out aseemingly systematic one standard deviation (10'8) difference between theoretical and experimental i-valuesof the 38 2 SI/2 - 3p 2 P3 / 2 transitions for Na-likeions with the charge state Z > 20. More precise resultof ours indicates that these small differences (I"V 10'8)
are coincidental and insignificant , confirming the reliability of theoretical calculations for this N a-like system. A review of the scaled line strength for the
38 2 SI/2 - 3p 2 P3 / 2 transition is shown in a graphicalform in Fig. 1. Here , the quantity Z 2 S/C is plottedagainst l/(Z - 10) , where S is the line strength ina. u. and C is a relativistic correction. The measured
point for Kr 25 + is shown by a filled black square andindicates that there is no remaining discrepancy between theory and experiment. References to the otherexperimental points can be found in Ref. 1. The theoretical data were produced using the Coulomb approximation Hartree-Slater method; cf., Ref. 2. Moredetails can be found in a recent publication by Kink
et al. 3 )'= ---------------------------------------900 -Na sequence
3s 2 S,/2-3p 2 p1l2. 3/2

1/2·3/2' 00 -

0 .05

0.'

0.'5

0.2

0.25

0.3

1/(2·'0)

Fig. 1. The quantity Z 2 SjC as a function of l/(Z - 10)
for Na-like ions: Dots show the experimental results
and lines show the theoretical results.

References
1) R. Hutton, S. Huldt, B. Nystrom, I. Martinson, K.
Ando , T. Kambara, Y. Kanai, Y. Nakai, and Y. Awaya:
Phys. Rev. A 51, 143 (1995).
2) 1. J. Curtis, D. G. Ellis, and I. Martinson: Phys. Rev.
A 51 , 251 (1995).
3) I. Kink, R. Hutton, B. Nystrom , I. Martinson, K. Ando ,T. Kambara, Y. Nakai, T. M. Kojima, and Y. Awaya:
accepted for publication in Phys. Rev. A , Nov. 1996.

81

RIKEN Accel. Prog. Rep. 30 (1997)

Wavelengths for AI- and Si-like Intercombination Lines
R. Hutton, P. Bengtsson, K. Ando, T. Kambara, and Y. Awaya
In a number of previous articles, intercombination
rates for the Mg-like lines have been discussed forions ranging from Ni to Nb. l ) Those previous works
have concentrated on lifetime measurements as the intercombination line wavelengths were already known.
However, although the Mg-like 3s 2 1 So - 3s3p 3 PI
transition wavelength is well known for ions up to
Z = 54 the situation for AI- and Si-like ions is not
so well documented. By using the beam-foil spectroscopy and in particular the techniques of delayedspectroscopy, the wavelengths for AI-like and Si-likeintercombination lines in ions up to Nb (Z = 41)
have been determined. Some deviations from calculated wavelengths and from previous experimental
data were noticed. An example of such a deviation
can be seen in Fig. 1, where (Eobs - Ecaz)/(Z - 13) isplotted as a function of (Z -13). Here Eobs is observed
transition energy and Ecal is calculated transition energy. When all relevant effects are included for Ecal
this difference is expected to converge to a constantvalue. The method used to find the AI- and Si-likeintercombination lines is based on the fact that the3s 2 1 So - 3s3p 3 PI wavelength is already known up
to Xe (Z = 54).3) Then, a simple isoelectronic plotof wavelength differences allows easy extrapolation for

the AI- and Si-like lines (See, Fig. 2). In Fig. 2 thedifference between AI-like and Mg-like intercombination line wavelengths are plotted. The identifications
were confirmed by choosing different beam energies tovary the charge state fractions after the exciter foil.
The results of this work are discussed in more detail in
Ref. 2.

7

6

~

""
""

,

o
Si-like 3 p _ \12-1 ~~--~~--~~--~~--~--~~

35

900
700

n
'I
::::::
N

500
300

U

100

~

-100

I

QJ

Ll

E
:J

c

QJ

>

0

3:

- - - --~~ -~ ~ I-----------I-

x- - - -- -

37

38

39

40

41

42

43

44

45

20

30
40
(Z-13)-300

Fig. 2. Wavelength differences for Mg- and AI-like intercombination lines are plotted against the atomic number. The AI- and Si-like wavelengths were determined
at RIKEN and the Mg-like intercombination line wavelength is known for ions up to Xe. 3 )

-500
-700
-900
-1100

References

o

10

50

60

70

Fig. 1. The difference between the (scaled) observed andcalculated transition energies for one of the Si-like intercombination lines. The data for Y , Zr, and Nb wereobtained at RIKEN.

82

36

atomic numberI1) R. Hutton: Proc. 8th Int. Conf. on the Physics of Highly
Charged Ions , Sept. 1996, Omiya, Japan , to be published in Physica Scripta, see references therein.
2) P. Bengtsson et al.: Proc. 8th Int. Conf. on the Physics
of Highly Charged Ions, Sept. 1996, Omiya, Japan, tobe published in Physica Scripta.
3) J. F. Seely et al.: J. Opt. Soc. Am. B 5 , 602 (1988).

RIKEN Accel. Prog. Rep. 30 (1997)

Charge Transfer Cross Sections of Low-Energy Highly
Charged Ions with N 2
Y. Kanai, Y. Nakai, M. Kitajima, T. Kambara, and Y. Awaya
To study the charge transfer processes of the lowenergy highly charged ion and atom (or molecule) collisions, we started to measure the charge transfer crosssections of highly charged ions. Low-energy highly
charged ions from the 14.5 GHz Caprice l ) ion source
were energy-analyzed and focused on the gas cell. The
cell length was 5 cm. The entrance and exit aperturesof the gas cell were 1 and 2 mm, respectively. Afterthe collisions, the ion charge states were analyzed byan electrostatic analyzer and a position sensitive detector (MCP + wedge and stripe anode).
Here, we report the total single electron capture
cross section 0"1 of highly charged ions in the collisions
with N 2 molecules. Present results are shown in Fig.
1. We used the Ar 3,7+ , 0 3,6+ and N3+ ions in theenergy range of 2- 10,000 eV lu. In this energy range,
the energy dependence of the 0"1 is small. This typeof energy dependence can be explained by a simple
model called absorbing sphere model. 2) In this model,
when the highly charged ions come to a critical distance from the target , all the ions capture the target
electrons. To compare our experimental results withthis model, we show the broken and solid lines in Fig.
1: the values calculated with this model divided bysome factors (2.8 and 1.6). The energy dependence ofour results, except for the N 3+ ions, is in good agreement with this model made for the single electron capture processes. In the case of collisions of the highly
charged ions with targets, an ion can capture multiple
electrons (> 2) inside the critical distance. Therefore,
for the absolute values of the capture cross sections, wehave to compare the values calculated by the absorbing sphere model with the total capture cross section
7
O"tot = ~i O" j . For Ar + collisions, we measured the total
capture cross section and found O"tot = 1. 7 x 0"1 . These
values are almost same as those calculated by the absor bing sphere model. For the collisions of high charge(q = 6,7) ions, we can obtain the total cross sections by
this model. For the low charge (q = 3) ions, however,absolute values of our results are not in agreement withthis model. For the low charge ion collisions, we need

--

('IE

~

10-14 ~_ _. -_ _-,--_
I--.-_ _....,.-_ _-.-.
I

I
Ill-

.2

10-15 1-

- - - I-O-l-t-Oi- - - -00- Lb- - 0- --

~

x

x

-- -- -x _x0U
~ 10 _16 ,::- - -Absorb i ng sphere Model-:-2. 8c..

~Absorbing~usphere Model -:-1. 6

a.>

en

.:::

I

~
~
-.~~

c:

]

_

I

10-17 '--_ _-'-' _

v:,

100

10 1

_

-'--_ _-L...._

102

10 3

_

• Ar 7+o Ar 3+
[J

06+

_

o

03+

-

. X

N3+

-1I_ _ _U
I

10 4

105

Colliding Ion Energy (eV/u)
Fig. 1. Single electron capture cross sections of highly
charged ions with N 2. Solid and broken lines show thevalues calculated by the absorbing sphere model divided
by 1.6 and 2.8, respectively.

more experimental results to discuss about the applicability of this model.
For the lower energy region « 10 eV lu), our results contain a couple of experimental uncertainties
due to (A) the beam energy spread of the low-energy
ion beams and (B) the limitation of the scattering angle of scattered ions by the exit aperture of gas cell.
To solve these problems, we are planning the following
new experiments: (a) to set the energy selector before
the collisions region, (b) to use the gas jet as target,and (c) to measure the angular dependence of chargetransfer cross sections to obtain the total cross sections. After these new experiments, we may be able todiscuss more detail of the charge transfer processes ofhighly charged ions.
References
1) Y. Kanai et al.: RIKEN Accel. Prog. Rep. 30, 168(1997).
2) R . E. Olson and A. Salop: Phys. Rev. A 14, 579 (1976).

83

RIKEN Accel. Prog. Rep. 30 (1997)

Diode-Laser Spectroscopy of Atomic Beams
T. Wakui, W.-G. Jin, T. Minowa, H. Katsuragawa, H. Uematsu,* and M. Wakasugi
Measurements of the isotope shift and hyperfine
structure in atomic transitions by means of laser spectroscopy give us information about atomic structuresand nuclear properties. Using RIKEN accelerator facility, we are performing laser spectroscopy of atoms withunstable nuclei. Therefore, test experiments with stable isotopes using a new laser spectroscopic techniqueare necessary, and development of such a techniqueusing a diode-laser instead of the conventional complicated and expensive ring-dye laser is particularly desirable for nuclear laser spectroscopy. This paper reports
measurements of the isotope shift and hyperfine structure obtained by means of a high-resolution diode-laser
spectroscopy.
As a light source, we used single-mode diode lasers
with power of 15- 50 m W in the wavelength region of
670-800 nm. Both the temperature and current of thediode-laser were controlled by a controller. Frequency
scanning of laser was made by modulation of the current. An atomic beam was ejected from a molybdenum
oven with a small hole of 1 mm in diameter. The ovenwas heated to 600°C for Ba beam with a tungsten filament. The atomic beam then passed through anothercollimation oriffice of 2 mm in diameter. The laser
beam was crossed with the atomic beam orthogonallyso that the Doppler broadening is reduced. The resonant fluorescence from the atomic beam was focused bya spherical mirror onto a cooled photomultiplier to bemeasured. A Fabry-Perot interferometer (FPI) with afree spectral range of 300 MHz was used for the calibration of the relative frequency. The fluorescence andthe transmitted signal of the FPI were simultaneously
recorded with a multichannel scaler.
Figures 1 and 2 show laser-induced fluorescence
spectra of the 791.1-nm transition in Ba I and the680.3-nm transition in Sm I, respectively. In Fig.
1, small peaks indicated by a, b, and care hyperfine transitions in 135Ba while Q , {3, and , arethose in 13 7Ba.
The peaks of both 130Ba and
132Ba isotopes are overlapped with 138Ba. In Fig.
2, the peaks indicated by * are hyperfine transitions in 147 Sm and 149Sm. The FWHM of peaks
is about 50 MHz for Ba and about 70 MHz forTokyo Gakugei University

84

o

0.5

1.0

1.5

2.0

2.5

Relative Frequency (GHz)
Fig. 1. Observed spectrum of the 791.1-nm transition in
Ba I.

152Sm

150Sm

o

1234567

8

Relative Frequency (GHz)
Fig. 2. Observed spectrum of the 680.3-nm transition in
8m I.

Sm. This shows that the resolution of our experimental setup is enough for the measurements of hyperfine
structure and isotope shift. From the observed hyperfine spectra, the hyperfine structure constants for the3P 1 state of 135Ba and 137Ba were determined. The
isotope shifts in Ba I and Sm I were also obtained, andthe electron density at the nucleus was derived.

RIKEN Accel. Prog. Rep. 30 (1997)

Laser Spectroscopy of AgHe2 Exciplex in Liquid Helium
Q. Hui,* J. L. Persson,** Z. J. Jakubek,** M.-P. Coquard,** M. Nakamura, and M. Takami
We are currently studying the physical properties of neutral atoms in liquid helium by laser
spectroscopy. 1,2) One of the aims of this work is to
explore the feasibility of using liquid helium for theon-line spectroscopic study of the unstable nuclei produced by Riken ring cyclotron (RRC). For this purpose, it is crucial to understand the behavior of stableneutral and ionic atoms trapped in liquid helium andtheir interaction with the surrounding liquid. A neutral atom is known to be trapped in a bubble-like cavity due to a strong repulsive force between the impurity and the surrounding helium atoms. 3 ) The couplingof the cavity with the trapped atom induces a large
shift and broadening of the atomic absorption spectra,
while the shift and broadening are relatively small inthe emission stage. In our recent study of Ag in liquid helium, we found a new feature as described here
in the observed spectra,4,5) which should be important
for the study of atomic ions with unstable nuclei.
Figure 1 shows the observed emission spectrum of
Ag in liquid helium. The excitation laser wavelength
was 322.5 nm, which corresponds to the peak of thebroad and blue-shifted D2 absorption line of Ag. Only
the Dl emission line was observed close to the positionof the free atomic line. In addition, an extra broad
emission band was observed around 382 nm with a01

35 nm (FWHM) band-width. The excitation spectra
measured by monitoring the Dl line and the broadband emission showed a significant difference between
the two: the Dl emission was observed by exciting theDl and D2 absorption lines, while the broad emission
was observed only when the D2 line was excited. Theseobsevations indicate that the Ag atoms excited to theP3/2 fine structure component relax to the P 1 / 2 state
and also to an unknown state from which the broad
emission occurs.
The absence of D2 emission in liquid helium has beenreported for Rb and Cs.6) Dupont-Roc 7 ) has proposedthat in the P3 / 2 states of these alkali atoms, two helium
atoms may attach to the atom along the nodal line ofthe doughnut-like P3 / 2 electron distribution, thereby
forming an exciplex, by the attractive force from their
exposed ion cores. He predicted a red-shifted, boundfree emission band from the exciplex, but observationof the emission has not been reported till today. We
assigned the observed broad emission from Ag to thecounterpart of the red-shifted emission expected forthe alkali atoms. To confirm this assignment, we havemade an extensive ab initio calculation on the AgHe2
potential energy curves and have simulated the emission spectrum. The simulated emission band is drawn
in Fig. 1 with a solid curve over the observed band. An
excellent agreement between the calculation and observation has confirmed that the Dupont-Roc's model iscorrect.
This discovery is of particular importance for the
study of charged atoms in liquid helium, because they
are expected to have stronger attractive interaction
with helium atoms, and because any atomic ion with
one valence electron should show exactly the same behavior. Extension of the present work to atomic ionsis in progress.
References

325

345

365

385

405

425 nmFig. 1. Emission spectrum from Ag in liquid helium.
In addition to the D1 emission line, a weak and broad
emission band is observed on the red side of the D1 line.
A simulated emission band is drawn by a solid line.

1) Q. Hui et al.: Z. Phys. B 98, 353 (1995).
2) J. L. Persson et al.: Phys. Rev. A 52, 2011 (1995).
3) H . Bauer et al.: Phys. Lett. A 146, 134 (1990).
4) J. L. Persson et al.: Phys. Rev. Lett. 76 , 1501 (1996).
5) M. Nakamura et al.: RIKEN Accel. Prog. Rep. 28, 77(1995); RIKEN Accel. Prog. Rep. 29, 124 (1996).
6) Y. Takahashi et al.: Phys. Rev. Lett. 71, 1035 (1993).
7) J. Dupont-Roc: Z. Phys. B 98, 383 (1995).

Inorganic Chemical Physics Laboratory; Saitama University, Graduate School of Science and Engineering.
Inorganic Chemical Physics Laboratory; STA Fellow.

85

RIKEN Accel. Prog. Rep. 30 (1997)

Temperature Dependence of AI-LVV
Auger Electron Spectra (I)A. Koyama, A. Yoneda, K. Ogiwara, and M. Uda*
AI-L 23 VV Auger electron spectra induced by fast
Ar 12+-ions (1 MeV jamu) were measured at the target
temperatures of 40 and 300°C. Figure 1 shows thedifference between the AI-LVV Auger spectrum at 300°C and that at 40°C for an incident angle of 25° withrespect to the surface of the target. The spectrum at
300 ° C is also shown as reference. At energies high andlow sides of the peak energy, Em , the difference is negative, and at energies where the spectrum is steepest
it is almost zero; indicating only a slight narrowing of
the spectrum, but no decrease of Em at 300°C compared to that at 40°C. Figure 2 shows the difference ofspectra for a grazing incident angle of 4 0. At energies
higher than Em, the difference is negative, and at lower
energies it is positive. At energies where the spectra is

g
~

UJ

0.04

VI

'0

~
~

'0 -0.01~ -0.02 ~=-

c:

Q)

-

~

;

~ -0.03 =------~--------------~~

0o -0.04 ~r_ _----L~.

60

64

68
72
76
80
Electron Energy(ev)

84

Fig.

2. Difference between the energy spectra at 300°C and 40°C, Y 30o (E)-Y40(E), for the grazing incident
angle of 4° . The dotted curve is the Auger specrumat 300°C. Scattering of data is ±0.005 as indicated bya segment in the figure. The difference is negative at
the high energy part of the peak and positive at thelow energy one, which means the decrease of the peakenergy for 300°C compared to that for 40°C. Theenergy decrease is deduced to be about 0.2 eV from thecomparison of the spectra.

0.03
0.02

'8
>= 0.01
I/)

~

- 1.0

0 ~~~+--+~------.~----------~~'0 -0.01

B -0.02c:~£ -0.03~--------------------------~~

0

1:5 -0.04
60

64

68

Electron

72

76

80

Energy(ev)84Fig. 1. Difference between the energy spectrum of Al-LVV
Auger electrons at the target temperature of 300°C
and that at 40°C, Y30o(E)-Y40(E), for the impact of
Ar 12 + -ions (1 MeV/amu) at the incident angle of 25°
with respect to the surface. Scattering of data is ±0.005
as indicated by a segment in the figure. The energy
spectrum for 300°C is shown by the dotted curve. The
difference is negative at energies arround Em, whichmeans the narrowing of the peak at 300°C comparedto that at 40°C, but no energy shift.

Department of Materials Science and Engineering, Waseda
University
86

steepest, the negative difference is most pronounced;
indicating that Em for 300 ° C is lower than that for 40°C. The magnitude is about 0.2 eV.
This temperaure dependence strongly supports themultiple-hole (MH) transportation model. The model
states that; the energy decrease of Em is caused by
the increase of binding energy of the valence electrons(VE), which is induced by the Coulomb potential due
to MH. The MH are created by the emission of VE fromthe surface due to an impact of a projectile. Diffusing
out of the MH is delayed at high target temperature
because transportation of valence electrons is slow athigh temperature compared to low. That is, loweringof the energy of Auger electrons continues for a longtime at high temperature compared to the case of low
temperature.

RIKEN Accel. Prog. Rep. 30 {1997}

Temperature Dependence of AI-LVV
Auger Electron Spectra (II)A. Koyama, A. Yoneda, K. Ogiwara, and M. Uda*
Multiple electron-holes (MH) created in the valenceband composed of s- or p-like electrons are annihilated promptly, and their effect on Auger electron
spectra was scarcely observed for the impact of various projectiles incident at large angles with respect tothe surface of a target. However, we observed clear
projectile-dependence of AI- and Si-LVV Auger electron spectra for small incident angles near 4°. We also
observed temperature-dependence on AI-LVV Auger
electron spectra induced by the impact of Ar 12+ ions (1MeV / amu) incident at 4°; decrease of the most probable energy of 0.2 eV at 300°C compared to 40°C. Suchtemperature-dependence as well as those projectileand incident angle-dependences can be explained byusing a model of transportation of MH in the valenceband.
Binding energies of valence electrons are considered
to increase with existence of those holes via Coulomb
potential and kinetic energy of Auger electrons, Em,
decreases; it is because of the relationship approximately given by Em = BL-Bv-Bvl. That is, the energy decrease is given by(1)

When a projectile excites a L-shell electron of an Al
atom located the top-most layer of the surface, valence
electrons are also excited, emitted from the surface,and MH are left behind. Density of them is proportional to the projectile's stopping power. It is the causeof the projectile-dependence. For grazing angle incidence, they are created in a semicylindrical region on
the surface with its radius a and its length infinitive.
For normal incidence, they are created in a cylindricalregion on the surface with its radius a and its depth
d. Values of a and d should be nearly equal to the
dynamic screening distance of 6A. The area is muchlarger for grazing angle incidence than for normal incidence, and it takes long time for the holes to diffuse
out in the case of grazing angle incidence compared
to normal incidence, which gives rise to the incident
angle-dependence.
MH will begin to diffuse from the created region,
and after t sec the density of them at the excited Al
location will be approximetely given by

Pg(t) = Po{l - exp( _a 2/4Dt)},

for grazing angle incidence. For the normal incidence,on the other hand,

Pn(t) = 2Po/(47rDt)3/21d exp(-Z2/4Dt)dx
x

1"

27rrdrexp( _r2 14Dt).

(3)

The diffusion constant D of MH is nearly equal tothat of valence electrons and is approximately given by(4)

D "" Av/3,

where A is the mean free path of valence electrons,
and v is their velocity. A is dependent on target
temperature, which is the origin of the temperaturedependence, and can be estimated from the electrical resistivity. Then we can calculate the value of
D as D = 2.41 X 10 17 A2 /sec at 40°C, and D =1.6 X 10 17 A2 /sec at 300°C.
The energy decrease of Auger electrons averaged
over the time is given byJ~Ev = 2 nA~Bv(t)dt/

J

nAdt,

(5)

where v is meant n or g, and nA = exp( -t/TA) is thenumber of Auger electrons emitted in the time intervalfrom t to t+dt. ~BI/ is approximately given by Qe 2 /r,
where r is the screening distance of the Coulomb potential due to MH, and Q is the total number of MH
in the hemispherical region with the radius r arroundthe excited Al atom, and Q = (27r/3)r3 p (t) with thehole density p( t).
By substituting Eqs. (1), (2), (3), and (4) into
Eq. (5), we can estimate the energy decrease to be~Eg = 1.3 eV (300°C) and ~Eg = 1.0 eV (40°C) for
those values of a = 9A, r = 6A, and d = 6A. That is~Eg(300 DC) - ~Eg(40 DC) = 0.3 eV, which is almost
equal to the experimental value of 0.2 eV. The value ofr is put to be equal to that of the dynamic screening
distance, and ~En(40 DC) = 0.2 eV, which is also thesame with the previously obtained experimental value.
Thus, we can reproduce the projectile-, incident angle-,
and temperature-dependences of AI-LVV Auger electrons, by using the multiple hole transportation model.

(2)

Department of Materials Science and Engineering, Waseda
University-

87

RIKEN Accel. Prog. Rep. 30 (1997)

Mossbauer Spectroscopy using 57Mn Beam from RIPS
Y. Kobayashi, Y. Yoshida, J. Nakamura, K. Yukihira,* K. Hayakawa,* A. Yoshida, Y. Watanabe,
N. Aoi, N. Inabe, M. Kase, A. Goto , Y. Yano, M. Ishihara, and F. Ambe
Radioisotope beams (RI-beams) are becoming recently very attractive in the field of materials science.
So far , radioisotopes have been used as nuclear probes
to obtain the atomistic information by the implantation technique. In addition to that, the RI-beams are
expected to change physical and chemical propertiesof materials and even to synthesize new materials ina limited part of samples due to their very high energies. In this year (1996) , new in-beam Mossbauer
experimental apparatus has been constructed at theE6 hall at RIKEN Ring Cyclotron Facility to use the57Mn beam provided by the projectile fragmentation
reaction in RIPS. Besides the 57 Co used for conventional Mossbauer experiments, 57Mn is long known tobe another source nuclide of 57Fe with a short half-lifeof 1.45 m.
Among the applications of RI-beams to materials science, the in-beam Mossbauer spectroscopy has
been one of the most powerful method to study isolated 57Fe atoms and their dynamics in metals andsemiconductors.!) We report here a preliminary result from the in-beam Mossbauer experiment on 57Fe(~57Mn) in a single crystal of Si. Since we implant
57Mn as highly charged ions with high energy into theSi crystal, the 57Fe atoms decayed from 57Mn in thesample may be expected at exotic valence states.
A 57Mn beam was produced by the projectile fragmentation reaction of 59 Co (E = 80 Me V / nucleon)
with a Be target. After the 57Mn beam was slowed
down through a degrader with an appropriate thickness, its final implantation energy and intensity were
estimated to be several tens MeV/nucleon and about
105 particles/s, respectively. The beam irradiated theSi sample through a lead collimater with a hole of 4>30
mm. The Si wafer with thickness of 0.5 mm was placed
45° against the beam direction in the vacuum chamber. In order to confirm the 57Mn nuclei stopping inthe sample, two solid-state-detectors were placed before and behind the sample, and the , -rays of 14.4 and122 ke V were monitored by a CdZnTe detector througha Mylar window of the chamber. The energy spectrumof ,-rays is shown in Pig. 1. The background level was
considerably low, so that the ,-peaks of 14.4 and 122
keY originating from the excited states of 57Fe could
be clearly seen in the spectrum.
The Mossbauer spectrum of 57Pe (~57Mn) in Si atroom temperature is shown in Fig. 2. The ,-rays fromthe 14.4 keY Mossbauer level of 57Fe atoms were detected by a parallel-plate avalanche counter (PPAC)

Shizuoka Institute of Science and Technology

88with a 57Fe enriched stainless steel as an absorber.
The fast-timing signals from the PPAC were used for
the Mossbauer measurements. Although the quality of the spectrum was still rather low due to extremely low counting rate (/"VO .06 cps), broad lines canbe seen around zero Doppler velocity and at high velocity range. The peaks near zero correspond to theMossbauer spectrum observed at 300 K after Coulombexcitation and recoil-implantation. 2 ) The satellite lines
around ±3 mm/s and ±11 mm/s are entirely different
from other components of 57Fe in Si. If they are real
ones, the present result might suggest the existence ofan exotic ionic state and/or the appearance of novel
physical property of 57Fe having decayed from 57Mn.

1000

(I)

e

::::J

0

0

I

I

I

I

I

800 1-14.4 keV-

600 l--

400 I--

200
0

122 keV~ ........t

0

-

.....

400

200

1000

800

600

ChannelFig. 1. The ')'-ray spectrum of the Si wafer during
Mossbauer measurement.

140

- 12

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

Velocity (mm/s)

Fig.

2.

The in-beam Mossbauer spectrum of 57Fe(~57Mn) in Si using the RIPS at room temperature.

References
1) R. Sielemann and Y. Yoshida: Hyperfine Interact. 68,
119 (1991).
2) P. Schwalbach et al.: Phys. Rev. Lett. 64, 1274 (1990).

RIKEN Accel. Prog. Rep. 30 (1997)

Hyperfine Interactions of 61 Ni in Distorted
Spinel Chromites
J. Nakamura, T. Okada, Y. Noro,* Y. Kobayashi, H. Kitazawa,** and F. Ambe
A huge value of hyp erfine magnetic field (Hhf)of 61 Ni 2+ on the spinel A-sites (tetrahedral sites)in NiCr204 was first reported by Sekizawa etal. 1) Recently, Okada et a1. 2) have applied a 61 Ni
Mossbauer spectroscopy to various spinel chromite including Mo.gNio.1 Cr204 (M = Mn, Co, or Zn) andCU1 -x NixCr204, in which much larger Hhf have observed. The largest value of IHhf l observed was about
800 kOe in the tetragonally distorted spinel chromite
CUo.gNio.1 Cr204 (when cia = 0.92). Furthermore,they have found a linear dependence between IHhfl
and bulk distortion given by c/ a. Namely, the hugevalue of IH hf I decreased linearly with increase of c/ aaround c/ a = 1.0.
Freeman and Watson calculated the Fermi contact
term in Hhf to be about -200 "" -300 kOe for Ni 2+
ion. The huge value observed in these spinel compounds was not possible to be interpreted by only the
Fermi term. Love and Obenshain have applied the
61 Ni Mossbauer spectroscopy on several spinel compounds, and have reported that degenerated Ni 2+ electronic state should produce a finite orbital angularmomentum. 3 ) They proposed that the unquenched orbital angular momentum originates H hf. In thesechromites, this orbital term will be the major one, andis written as

parameter e2 qQg was derived under the assumption ofe, the angle between a principal axis of EFG and the
direction of spin, being fixed to 0° and 90° for c/ a <1 and c/ a > 1, respectively. The theoretical value of
EFG using an orbital angular momentum was reported
by Okiji and Kanamori for Fe 2+ in some oxides. 5 ) We
extended their theory to the Ni 2+ case, and derived
the uniaxial EFG , eqz , as;Then, we calculated eqz with <r- 3 >av of 6.1 a.u.,
and the derived relation between Hhf and e2 qQg isshown wit h solid lines in Fig. 1.

1.0
~
~

~
~

~
~

,.-..
r/l

E

~
~

0.5

~

~

5

O/l

~
('l

.. .. ..

~

~

(::)l

~

0.0

~

-0.5

----_

-200

Here, < Lz >av is the mean value of unquenched orbital angular momenta for degenerated Ni 2+ electronic
states and is calculable from ligand theory. The hugevalue of H hf was able to be interpreted using calculated <L z > av .2 ) However, there is still a controversy,
because Giit lich et a1. 4) have reported a negative signof H hf , which denies the H o rb origin mentioned above.
The purpose of this study is to obtain an interpretation of both the huge H hf and electric field gradient (EFG) , using <Lz> av . The CU1 - xNixCr204 system has at tracted our attention because it exhibits
the largest at Hhf compound (at x = 0.1) and has
a wide solubility range corresponding to a variety of
c/ a. We prepared the samples with several compositions (x = 0.5 , 0.8 and 0.9) and measured the 61 Ni
Mossbauer spectra at 4 K. The detailed experimental
procedure is described in Ref. 2.
The present spectra indicate the same relationshipbetween IHhfl and c/aobserved previously.2) The EFG

..

....

--spin /I c-axisoFig. 1. Correlation between H hf and e 2 qQ 9 for several
chromite spinels. The Fermi term was assumed to be-200 kOe.

In the figure, the experimentally observed values arealso plotted, which are found to be on the theoreticalsolid line. The present result indicates that the unquenched orbital angular momentum gives an accountof the huge Hhf and EFG.
References
1) H. Sekizawa et al.: J. de Physique 32, C1- 326 (1971).
2) T. Okada et al.: Phys. Lett. A 209, 241 (1995).
3) J. C. Love and F. E. Obenshain: AlP Conf. Proc. 18,513 (1973) .
4) P. Giitlich et al.: J. de Physique 41, C1-185 (1980).
5) A. Okiji and J. Kanamori: J. Phys. Soc. Jpn. 19, 908(1964).

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National Institute for Metals

89

RIKEN Accel. Prog. Rep. 30 (1997)

Magnetic Properties of YSr2Cu3-xFex07+6 andEffects of Hot Isostatic Pressing
T. Fuwa,* N. Ikeda,** J. Nakmura, T. Okada, K. Kohn,** and N. Yamada*
We have studied the effect of heat-treatment on themagnetic properties of Fe-doped YSr2 CU3 0 7+8,1) especially for x = 0.4 and x = 1.0, by the magnetic
susceptibility measurements and 57Fe Mossbauer spectroscopy. The room temperature Mossbauer spectra
are shown in Fig. l(a)- (d). Doublet A originates fromthe Fe-ions substituting Cu(II) sites. Other doublets
B, B' and C are attributed to the Fe-ions substituting
Cu(I) sites.

Table 1.
Mossbauer
YSr2Cu3-xFex07+6.
x

A
0.4

0.4 HIP1.0100(a) x=O.4

90

site

1.0HIP

B
C
A
B
C
A
B
B'
C
A
B

parameters

measuredforIS[mm/s] Q.S.[mm/s] Area[%]15
0.578+0.25440
0.848-0.04245
1.761+0.1250.584
17+0.29278-0.018
0.893
5
1.711
+0.17032
0.610+0.2560.725
36-0.0560.914
13+0.0471.646
19+0.1690.574
38+0.28762
0.733-0.036

80
70
~

100
(b) x=O.4
HIP

c::
.~

·s
<f.l

90

<f.l

c::

ro

'""
E-<

100

Q)

.~

(c) x=l.O

ro

~

0::::

90
~

80

L.!!..........J B,

~cl

100
(d) x=l.O

95

HIP

90
85

~

80

o...!L..--.J

-3

-2

-1

0

Velocity

2

3

mmls

Fig. 1. The room-temperature Mossbauer spectra of
YSr2Cu3-x Fe x 0 7+6.

The measured Mossbauer parameters are listed inTable 1.
(1) YSr2.6Fe0.407+8 : The sample synthesized in 1
atm oxygen environment (NON-HIP sample) was not asuperconductor, while the Hot Isostatic Pressing (HIP)
sample prepared under oxygen partial pressure of 40
MPa 2) was found to be a superconductor with Tc = 37
K. At low temperature (T < 14 K) , the hyperfine mag**

90

Dept. Appl. Phys. and Chern., Univ. of Electro-Cornrn.
Dept. Phys. , Waseda University

netic fields larger than 280 kOe were observed. Thismeans that for the HIP sample the superconductivity and the magnetic ordering can coexist in that low
temperature region.
(2) YSr2Cu2Fel.o07+8 : From the susceptibility
measurement , it was observed that the sample prepared under 1 atm oxygen environment is antiferromagnetically ordered near 70 K. By the HIP process, the magnetic ordering temperature of the same
sample went down to about 55 K , but unlike thecase of YSr2Cu2.6Feo.407+8 this sample did not show
any sign of superconductivity. The room temperature Mossbauer spectra show that the spectrum of the
NON-HIP sample is composed of four doublets (SeeFig. 1 (c)) and that the spectrum of the HIP sample
changed two doublets (See Fig. l(d)). The magnetic
ordering temperature obtained by the Mossbauer spectroscopy was different from that by the susceptibility
measurements. Namely, the magnetic ordering temperature of the NON-HIP sample was about 240 K
and that of the HIP sample was ordered below about
77 K.
In summary, we can consider two possibilities on theeffect of HIP process. One is that more oxygen was introduced into the sample. Another is that the redistribution of Fe-ions between Cu(I) and Cu(II) sites took
place. The latter is supposed to be a more important
effect in the HIP process. But in order to discuss the
HIP effects in detail, it is necessary to do more experiments with a series of YSr2Cu3-xFex07+8 samples at
x ::; 1.0 prepared by the HIP process.
References
1) M. Pissas, G. Kallias , E. Moraitakis, D. Niarchos, and
A. Simopouls: Physica C 234, 127 (1994).
2) B. Okai: Jpn. Appl. Phys. 29, L2180 (1990).

RIKEN Accel. Prog, Rep, 30 (1997)

57Fe Mossbauer Spectroscopy of CUl - xFexGeOg
T, Okada, H. Kitazawa,* J . Nakamura, Y. Kobayashi, and F. Ambe
A spin-Peierls (SP) transition in inorganic compounds was first found in CuGe03 by Hase et al.l)
The oxide, CuGe03, is a quasi-one-dimensional antiferromagnet (AF) with S = 1/2 for the linear structureof this compound. As the temperature is lowered below the SP transition temperature (Tsp), the magnetic
susceptibility decreases rapidly. This SP transition canbe described as a progressive dimerization of S = 1/2
AF chains. It is quite attractive that the dimerizationof AF chains can be controlled by replacement of theother ions. 2,3) From this point of view we doped Fe
ions in CuGe03'
Polycrystalline specimens were obtained by heating
the mixture of CuO, Ge02 and o:-Fe203 for 10 days inair. The 5 7 Fe Mossbauer effect and magnetic measurements of CUl-xFexGe03 (x = 0.005 , 0.01 and 0.03)
with the SP transition around 14 K were made atvarious temperatures. The isomer shift (IS) refers to
the one of metallic irons. The Mossbauer spectra of
CUo.ggFeO.Ol Ge03 measured at various temperaturesare shown in Fig. 1. The spectrum at 297 K consists of three doublets due to the quadrupole splitting (QS). The first doublet (A) (17% in population)
has QS = 2.08 mmls and IS = +0.95 mm/s. The
second doublet (B) (45%) has QS = 1.38 mmls andIS = +0.25 mm/s. The third doublet (C) (38%) has
QS = 0.61 mmls and IS = +0.27 mm/s. The valuesof IS indicate that Fe ions in (A) site are in the divalent state and those in (B) and (C) sites are in thetrivalent state. Lowering temperature below 30 K , thecomponent of (B) site becomes broad and shows thebroad sextet at least at 2 K as for a magnetic splitting.
The spectra of (A) and (C) sites remain quadrupole
doublets even at 2 K. The Fe ions of (A) and (C) sites
are paramagnetic at the whole temperature range measured. However, no Mossbauer parameters change appreciably near Tsp. In the Fe rich composition (e.g.,x = 0.03), although not shown here, one part of Fe
ions do not dissolve into the CuGe03. Thus the solubility range of Fe ions in CuGe03 is found very narrow.
The curves of temperature dependence of the magnetization are shown in Fig. 2. The values of Tsp for 0.005,
0.01 and 0.03 are obtained as 14.5, 14.0 and 13.0 K,
respectively. Theses compounds are in the SP state.
The values of Tsp decrease more gradually by replacing Fe ions than by non magnetic ions. The increaseof the magnetization at very low temperature is due toparamagnetic Fe ions (C).
The Fe ions replaced in CuGe03 are both in trivalent (83%) and divalent (17%) states. One part of Fe 3+
ions orders magnetically at low temperature. It means
National Research Institute for Metals

101
100
99

%

g Q

98

8

297K

\q,Q

~l

97

e

100

rJ.
c

!1(

0

'enC/)

'E

98
100

C/)

c

jg

s

99

~

ri

40K

"".

15K

~"

Ql

>

70K

~.

99

dJ

98

~

Q.) 100

a:

\•

99

§ d>

~aI ~

·0

i

98
100

, ~f
e !

99

2K

~

-10

-5

0

5

10

Velocity (mm/s)

Fig.!. Mossbauer spectra of CUo.ggFeo .ol Ge03 (x = 0.01)
measured at various temperatures.

0 . 0 4 . - - - - - - - -- - - - - ,B=0.1 To CUO.97Feo.03Ge03• CUO.99Feo.Q1Ge03

O +------.----~

o

50

100

Temperature (K)Fig. 2. Temperature dependence of the magnetization of
CUl- x Fe x Ge03 (x = 0.005, 0.01 and 0.03) under anexternal field strength B = 0.1 T.

that the SP state and the long-range antiferromagnetic
order can coexist in this system.
References
1) M. Hase et al.: Phys. Rev. Lett. 70, 3651 (1993) .
2) S, B . Oseroff et al.: Phys. Rev. Lett. 74, 1450 (1995).
3) M. Rase et al.: Phys. Rev. 54, R3722 (1996) .

91

RIKEN Accel. Prog. Rep. 30 (1997)

61Ni Mossbauer Spectroscopy of LiNi0 2 and NaNi0 2
T. Okada, Y. Noro,* J. Nakamura, Y. Kobayashi, and F. Ambe
61 Ni Mossbauer measurements are made to elucidate
the magnetic properties of LiNi02 and NaNi0 2 with a
two-dimensional (2-D) magnetic layer.
The 2-D triangular lattice anti ferromagnet with S =1/2 is much interested in the relation of the new magnetic ordering model 1) (RVB model) which assumes
that the antiferromagnetic spin pairs move in the 2D magnetic layer. Hirakawa2) proposed LiNi0 2 as amaterial adapted to the RVB model. However, it is
not yet testified, though many studies are made byvarious methods. On the other hand, a transition to
the antiferromagnetic state in N aNi0 2 was observed
at TN = 20 K by Bongers and Enz.3) A two sublattice model with an ordinary antiferromagnetic order
between the ferromagnetic layers of Ni 3+ ions was proposed by them. The Ni ions in LiNi0 2 and NaNi0 2 arein the trivalent and in the low spin 2E state, t2g 6eg 1,
with S = 1/2 based on the magnetic susceptibilities
observed at high temperature range.
The crystal structures of LiNi0 2 and NaNi0 2 are anordered rock salt type (R3m) and a slightly distortedone (C2/m), respectively. The Ni ions are occupied in
the octahedral sites.
The single line source of 61Cu (--+ 61 Ni) for the
Mossbauer spectroscopy was produced by the RIKEN
AVF cyclotron. Experimental procedure was reported
in detail in previous papers. 4 )Mossbauer spectra of LiNi0 2 and NaNi0 2 taken at
5 K are shown in Fig. 1. Each spectrum consists of abroadened line caused by the hyperfine magnetic fields(H hJ ). Values of HhJ amount approximately 80 and
66 kOe for LiNi0 2 and NaNi0 2 , respectively. Valuesof the isomer shift (IS) are -0.18 and -0.17 mmls for
LiNi0 2 and NaNi0 2 , respectively, relative to the oneof metallic Ni. This is the first report on IS of Ni ions----in the trivalent state.
The magnitude of Fermi term in HhJ is roughly proportional to the number of the polarized electrons. 5 )The g-value observed from ESR measurements on
LiNi0 2 indicates that the orbital angular momentum
is completely quenched. The observed values of H hJ of
61 Ni 3+ ions in LiNi0 2 and NaNi02 are almost same as

Hitachi Multimedia Systems R&D Division

92

c:

o

'00
en

'E 98

LiNi02enc:

jg 1OOt·.. ~;;:....::.~
o....
o

Q)

>
~
<i5
a:

98

96,L-____ ____ ______ ____
-10
-5
0
5
10
~

~

~

~

Velocity (mm/s)
Fig. 1. 6INi Mossbauer spectra of LiNi0 2 and NaNi0 2 at
5 K.

100 kOe expected in the low spin state. We discuss indetail the values of these HhJ in the following paper. 6)
In the RVB model the antiferromagnetic spin pairs
move quite rapidly in the 2-D magnetic layer. Then,the broadened line caused by HhJ is expected sharp
due to the motional narrowing. However, experimental
results of the nearly same HhJ in LiNi0 2 and NaNi0 2
indicate the existence of an ordinary magnetic order inboth oxides at least at 5 K. It suggests that the RVB
model is not adapted to the LiNi0 2 .

References
1) P. W. Anderson: Mater. Res. Bull. A 8 , 153 (1973).
2) K. Hirakawa et al.: J. Phys. Soc. Jpn. 54, 3526 (1985).
3) P. E. Bongers and U. Enz.: Solid State Comm. 4 , 153(1966).
4) T. Okada et al.: Phys. Lett. 209 , 241 (1995).
5) R. E. Watson and A. J. Freeman: Phys. Rev. 123, 2027
(1961).
6) T. Okada et al.: RIKEN Accel. Prog. Rep. 30 , 93(1997) .

RIKEN Accel. Prog. Rep. 30 (1997)

Effect of 4s Electrons on the Electronic State of Ni 3 + Ionsin LiNi0 2 and NaNi0 2
T. Okada, Y. Noro,* J. Nakamura, Y. Kobayashi, and F. Ambe
The hyperfine magnetic fields (H hf) and isomer
shifts (IS) of Ni 3 + ions in LiNi0 2 and N aNi0 2 withtwo dimensional (2-D) magnetic layer structure were
measured by 61 Ni Mossbauer spectroscopy. The effectof 4s electron on H hf is discussed relating to the measured large IS. They indicate a significant role of 4s
electron in the electronic state of Ni 3 + ions in LiNi0 2
and NaNi02.
The 2-D magnetic layer made with Ni 3 + ions in theoctahedral ligands is interesting because 1) it may support a new magnetic ordering model 1) (RVB model)
and 2) it must have a strong relation with high Tc superconductor made of Cu 2+ ion layers. There is only
a little report on the electronic state of Ni 3 + ions andno report on Mossbauer measurements on it.
Mossbauer spectra of LiNi0 2 and N aNi0 2 measured
at liquid-helium temperature show a broadened line
caused by the hyperfine magnetic fields. 2) The valuesof them amount around 80 and 66 kOe for LiNi0 2
and NaNi0 2 , respectively. The values of IS are -0.18
and -0.17 mmls for LiNi0 2 and NaNi0 2, respectively,
relative to metallic Ni.
The 4s-electron dependence on IS for three different electron configurations of 61 Ni calculated by Travis
and Spijkerman 3 ) is shown in Fig. 1, where our data areshown by the circles. The observed values of IS of Ni 3 +ions in LiNi0 2 and NaNi0 2 are on the line of 3d 7 -4s
electron configuration. This is the first report on IS ofNi 3 + ions. The measured values of IS are much larger
than that for NiO. They indicate presence of a large
fraction of 4s electrons in the electronic state of Ni 3 +ions. The horizontal axis of Fig. 1 shows the 4s electron
contribution to each state. They are about 15% in NiO

14-0.6.2='12

'00

~

.sE

ai 10

-0.4

e

-0.2 en

<1>

E

-c
c 8

and 28% in LiNi0 2 and NaNi0 2, respectively. The
typical value of 4s electron contribution for Fe 3 + ionsis less than 5%. So, the contribution for LiNi0 2 and
NaNi0 2 have 20% larger than that for Fe 3 +. Thislarge fraction of 4s electrons in Ni 3 + ions must playa
significant role in the magnetic properties of LiNi0 2
and NaNi0 2.
The Hhf is induced mainly from Fermi contact (corepolarization) and the orbital angular momentum. 4)
The electronic state of Ni 3 + ions in the octahedral sites
is t2g 6eg 1 with one unpaired electron. It is similar toNi 2+ in the octahedral sites as seen below;
ValenceNi 3 +

Electronic statet2g 6eg 1

Spin
1/2

Hhf (kOe)+ or - 66/80

t 2g 6 eg2

1

-100.

As a first approximation, HhJ coming from the corepolarization and the orbital angular momentum is proportional to the number of unpaired electrons. The
value of H hf of Ni 3 + ions can be estimated as - 50
kOe from -100 kOe of Ni 2+ ions in NiFe204' Next,
we consider the effect of covalency on H hf. Fractionof covalent 4s electrons is known to induce the positive
H hf in the case of Fe 3 + ions. Evans concluded thata difference of 0.10 mmls in the isomer shifts corresponds to a difference of 30 kOe in Hhf.5) A differencein IS can be transfer to a difference in 4s electron contribution by using Walker chart;6) 2.8% of 4s electron
contribution corresponding to 0.10 mmls of IS. Assuming that the relation between the 4s contribution andthe correction for Hhf can maintain in 61 Ni, we deduceabout + 140 kOe for a difference of 13% of fraction of
4s electron between NiO and LiNi0 2 . As a result, we
obtain about +90 kOe for 61 Ni 3 + ions in LiNi02. Experimental results of 80 kOe and 66 kOe in LiNi0 2 and
NaNi0 2 show fairly good agreement with them. So weconclude that contrary to ordinary transition ions, thedominant mechanism for Hhf of Ni 3 + ions is Fermi
contact term induced from the 4s electron.

~

:E

t5 6

CD

CD

0 .0 ~
2

0.2

OL-~~~--~--~--~

o

20

40

60

80

100

45 electron contribution (%)

Fig. 1. The 4s-electron dependence on the isomer shift of
61 Ni, calculated for three electron configurations, withtypical examples and our data (the circles).
Hitachi Multimedia Systems R&D Division

References
1) P. W. Anderson: Mater. Res. Bull. A 8 , 153 (1973).
2) T. Okada et al.: RIKEN Accel. Prog. Rep. 30, 92(1997).
3) J. C. Travis and J. J. Spijkerman: in Mossbaer EffectMethodology Vol. 3, edited by I. J. Gruverman (Plenum
press, 1968) p. 237.
4) A. Okiji and J. Kanamori: J. Phys. Soc. Jpn. 21, 2732
(1966).
5) B. J. Evans and S. Hafner: J. Appl. Phys. 38, 694(1968).
6) L. R. Walker et al.: Phys. Rev. Lett. 6, 98 (1961).

93

RIKEN Accel. Prog. Rep. 30 (1997)

Channeling Study on H in Nb-Mo Alloys
E. Yagi and S. Koike*In previous studies we investigated the lattice location of H in Nb-3(at%)Mo-2(at%)H, Nb-3(at%)Mo5(at%)H, and Nb-10(at%)M0-6(at%)H alloys bymeans of a channeling method using a nuclear reaction
IH(llB , a)2a with a llB beam of the energy about 2
MeV. 1 ,2) In this method, hydrogen is detected by measuring the emitted a-particles.
In Nb-3(at%)Mo alloys, when the H concentration
is lower than that of Mo, H atoms are located at room
temperature at the sites displaced from tetrahedral
sites (T sites) by about 0.6 A towards one of theirnearest neighbor lattice points, while they become located at T sites at 373 K.1) The result demonstrates
the trapping of hydrogen by an undersized Mo atom.
We concluded that, at this low Mo concentration, thetrapping of H by Mo is very effective as a mechanism
for the enhancement of the terminal solubility of H in
Nb on alloying with the undersized Mo atoms. 3 ,4) In
this alloy one Mo atom traps approximately 0.7- 1.0 H
atoms, i.e., the trapping efficiency is 70- 100%. However, in an Nb-10(at%)Mo alloy the efficiency decreases
to 20-30%, suggesting a change in the lattice locationof H in the more concentrated Nb-Mo alloys.2) Therefore, in the present study the lattice location of hydrogen in Nb-20(at%)Mo alloys has been investigated.
Figure l(a) shows channeling angular profiles obtained at room temperature for the Nb-20(at%)Mo2.6(at%)H alloy. The profiles of a-particles exhibit acentral peak superimposed on a shallow dip for the(100) channel, a broad peak consisting of three subpeaks superimposed on a shallow dip for the (110)channel, and a small central peak superimposed on ashallow dip for the {100} channel. The angular positions of peaks expected for the T-site occupancy are
indicated by arrows in the figure. They coincide withthe observed peak positions. The overall features are
similar to those for the T -site occupancy, indicatingthat a large portion of H atoms are located at T sites.
The point to be noted as a difference from the profiles for the T-site occupancy is that a shallow dip
is observed for the (100) and (110) channels. This

Department of Physics II, Faculty of Science, Science University of Tokyo

94

result suggests that a portion of H atoms are located at
the sites which are shadowed by both (100) and (110)atomic rows. They are octahedral sites (0 sites). By
fitting the calculated angular profiles of a-particles forvarious distributions of H atoms between T and 0 sites
to the observed ones, it is concluded that 20- 30 percentof H atoms become located at 0 sites and remains areat T sites. The occupancy at the trapped sites, which
was observed in Nb-3(at%)Mo alloys (Fig. l(b)), is no
more observed.

(a)

(100)

( 110)

flOo)

.

III

I

(b)
(110)

iv tf I V~
j \. V
V
,II

1.5

~

~

• H

• Nb

• Nb

V'
,</

.1>:

'0 C

~

III

• H

0.5 r-

o -4

-2

0

2

4

-4

-2

0

2

4

-1

0

1

-4

-2

0

2

ANGLE(deg)Fig. 1. Channelling angular profiles of a-particle yields( .) and yields of 11 B ions backscattered by host metal
atoms (0) obtained at room temperature for ( a) the Nb20(at%)Mo-2.6(at%)H alloy, and (b) the Nb-3(at%)Mo2 (at % ) H alloy. The full curves and the dashed curves
have been drawn to guide the eye.

References
1) E. Vagi, S. Nakamura, F. Kano, T. Kobayashi, K.
Watanabe, Y. Fukai, and T. Matsumoto: Phys. Rev.
B 39, 57 (1989).
2) E. Vagi, T. Kobayashi, K. Watanabe, Y. Fukai, and T.
Matsumoto: Proc. Jpn. Acad. B 65, 38 (1989).
3) T . Matsumoto, Y. Sasaki, and M. Hihara: J. Phys.
Chern. Solids 36, 215 (1975).
4) J. F. Miller and D. G. Westlake: Trans. Jpn. lnst. Metals 21 , suppl., 153 (1980).

RIKEN Accel. Prog. Rep. 30 (1997)

JL+SR Study of Polaron Motion in Polyaniline t
F. L. Pratt, K. Ishida, and K. Nagamine
Fundamental to the understanding of conducting
polymer systems are the nature and properties of theircharge and spin excitations which are strongly coupled
to the underlying molecular structure of the polymer.
The muon is a particularly sensitive probe of such soliton and polaron excitations, as the muon implantation
process itself can generate an excitation whose dynamical properties can be studied via the evolution of themuon spin polarization. This was first demonstrated inpolyacetylene 1 ) and subsequent studies were reported
for a range of conducting polymers.2) In earlier studies
the muon spin relaxation was fitted to an exponential
decay function which does not describe the relaxation
so well over a wide time range. Risch and Kehr recently
derived a relaxation function that more properly describes the 1D diffusion of the spin defect. 3 ) Their longitudinal muon spin relaxation function in finite fieldstrengths has the form: G (t) = ¢(rt) for AT > > 1
with ¢(x) = exp(x) erfc(fi) , where erfc signifies thecomplementary error function , A the electron spin flip
rate, T the experimental timescale and r a relaxation
parameter. This relaxation function goes as t- 1 / 2 atlong times rather than decaying exponentially. Whenthe intrachain diffusion rate D II is large compared to
w5/J2weA (wo is the muon-electron hyperfine coupling
and We is the electronic Larmor frequency) , the relaxation parameter follows the l/B field dependencer = W6/2weDU ' which is independent of the spin flip
rate A and depends sensitively on Dr . At low fieldstrengths there will be a cutoff to the l/B field dependence at B e which may be due to crossover to a
3D diffusion regime when We becomes smaller than theinterchain diffusion rate D...L.
We have carried out muon spin relaxation measurements on samples of undoped polyaniline (PANI:EB)
at the RIKEN-RAL muon facility in order to study
the motion of the polarons in this system. We havefound that the measured relaxation is well describedby the Risch-Kehr function over a wide range of experimental conditions. The data are fitted with only two
parameters; the initial amplitude and the relaxation
parameter r. Some results for PANI:EB are shown in
Fig. l.
It can be seen in Fig. 1 that at 6 K the onedimensional l/B regime holds down to below 10 G,
whereas at 300 K the l/B regime only holds down
to 300 G or so. This suggests that D...L increases byaround two orders of magnitude between 6 K and 300
K , where it reaches a value of rv 5 X 10 9 rad/s. Since at
500 G and above the l/B field dependence is obeyedover a wide range of temperature, a field of 1 kG waschosen for a more detailed study of the temperaturedependence of the relaxation. This is shown in Fig. 2.
From Fig. 2 it can be seen that there is a rapid increase in the relaxation above 150 K. This is believed
to be associated with the excitation of phenyl ring librations which are known to couple strongly to theelectronic excitations. 4 ) Using the value for the hyperCondensed from an article to appear in Synthetic Metals.

100

o

•

0. 1
10

100
Magnetic Field (G)Fig. 1. Relaxation parameter r versus magnetic field B for
PANI:EB at 6 K and 300 K. The lines show the regions
where r obeys the liB law.

-/~.. \IT
1!

••

i'

'0

10

·

30
'00
lOa
Tompe<olu," (K)

.30

..

...
100

.300

Temperature (K)Fig. 2. Temperature dependence of the relaxation parameter r for PANI:EB at 1 kG. The inset shows the polaron
intrachain diffusion rate D II derived from the 1 kG relaxation using the value Wo = 27r x 150 MHz.
fine frequency Wo = 27f x 150 MHz estimated fromthe longitudinal decoupling field of the initial muon
asymmetry, the diffusion rate Drr was calculated fromr and is shown in the inset to Fig. 2. The diffusion
rate shows a weak metallic temperature coefficient at
low temperatures which becomes rather stronger above
150 K. Between 150 K and 200 K the diffusion rate isinversely proportional to temperature, which is suggestive of phonon limited metallic transport. In contrast
to Drr, the interchain diffusion D...L increases sharply
above 150 K, suggesting that ring rotation assists interchain transport but hinders intrachain motion. The
values for D II at 300 K and for the temperature dependence of D...L are quite similar here to an earlier
ESR study of spin dynamics in metallic polyaniline, 5 )but the fully metallic temperature dependence of Drr
seen here is in marked contrast to the semiconducting
behaviour reported below 150 K in the doped case. 5 )References
1) K. Nagamine et al.: Phys. Rev. Lett. 53, 1763 (1984);
K. Ishida et al.: Phys. Rev. Lett. 55 , 2009 (1985).
2) F. L. Pratt et al.: Synth. Met. 55, 677 (1993); F. L.
Pratt et al.: Synth. Met. 69, 231 (1995); F. L. Pratt etal.: Hyperfine Interactions (1996, to be published).
3) R. Risch and K. W. Kehr: Phys. Rev. B 46, 5246 (1992).
4) J. M. Ginder and A. J. Epstein: Phys. Rev. B 41 , 10674(1990); A. J. Milton and A. P. Monkman: J. Phys. D:
Appl. Phys. 26 , 1468 (1993).
5) K. Mizoguchi and K. Kume: Sol. St. Comm. 89, 971(1994).
95

RIKEN Accel. Prog. Rep. 30 (1997)

Magnetic State of T1Ba2 Y l-xCaxCuOy Studied by J.L+SR
1. Watanabe, S. Nakajima,* S. Ohira,** K. Nishiyama, and K. Nagamine

TIBa2 Y l-xCaxCuOy (TI-1212) is one of the highT c superconducting (SC) oxides and shows the highest transition temperature, Tc = 106 K at x = 0.6.1)
In previous studies, we reported that an antiferromagnetically (AF) ordered state of Cu-spins with thetransition temperature of about 400 K can exist foro .::; x .::; 0.5 2- 5 ) and that an abrupt transition from the
AF st~te to the SC state occured at around x = 0.5.
In a present paper, the results of detailed analysis of
the zero-field muon spin resonance (ZF-p,+SR) experiments including low temperature measurements down
to 30 mK are reported. The ZF-p,+SR experiments
down to 1.5 K were carried out at RIKEN-RAL Muon
Facility in Rutherford-Appleton Laboratory, UK and
the ZF-p,+SR ones down to 30 mK was carried out at
UTMSL in KEK by using a top loading type dilution
refrigerator. A pulsed muon beam with the momentumof 27 MeV Ic was used.
As described in previous reports,2,3) the ZF-p,+SR
time spectrum observed in the AF ordered state consists of three asymmetry components. Because an implanted muon prefers to stop near by an oxygen atom,
three muon sites are expected in the TI-1212 crystal:a CuO-plane oxygen site (Api), an apical oxygen site(Aap), and TIO-plane oxygen site (A T1 ).3)
Saturated internal field of 23 and 170 Oe which were
due to the AF ordering of the eu-spins were observedat Aap- and Api-sites, respectively. An asymmetry amplitude of the Aap-component is about four times larger
than that of Api-component. The asymmetry amplitudes of both A pl - and Aap- components decrease linearly with increasing x and vanish in the SC state,indicating that the fraction of the AF spin alignment
decreases with x.
A randomly distributed static field was observedat the A TI-site. 2,3) It was confirmed from thelongitudinal-field experiment that the distributed field
is also induced by the AF ordering. The asymmetry amplitude of the ATI-component increases withincreasing x up to x = 0.5 and vanishes in the SC
state. Figure 1 shows the x-dependence of the depolarization rate of the muon spin of the ATI-component
obtained at 5 and 300 K. The depolarization rates decrease rapidly with increasing x. Since the muon spinat the AT1-site is depolarized by the distributed staticinternal field, the width of the field distribution canroughly be estimated from the depolarization rate to
be about 70 Oe at x = 0 and 7 Oe for x ~ 0.3. The
reduction of internal field at the muon site which originates from randomization of spin directions may beenhanced with increasing x.
Vol ume fraction of the SC state was estimated fromthe transverse-field p,+SR measurements to be approximately zero, up to x = 0.5. It increased suddenly to beFac. Sci., Tohoku University
Meson Science Laboratory (UTMSL) , Department of
Physics, Faculty of Science, University of Tokyo

96

1.5

:ru

I

I

Exponential

•

II>

o

~ 1.0 I- 0

300K

-

• SK

II>

15
a::
c
0

'2 0.5 l-

-

.;::

.2
0
a.

Q

II>

£:)

o I- I
0

~

• • •

0

0

0

-

I

0.2

0.4

1.0

0.8

0.6
X

Fig. 1. Ca-Concentration of the depolarization rate of themuon spin at the ATI-site, obtained at 5 and 300 K.

50% at x = 0.6 and showed more than 80% at x = 1.0.
These results give us an aspect that the AF spinalignment is partially destroyed by the hole-doping.
When the randomly distributed region overwhelms the
AF ordered region, the system changes to the SC state.
1.5
x=l.O
?;>

~

I.8K

1.0

~

< 0.5

]

-5eo:
12
t

16

20

(llsec)Fig. 2. Zero-field J.L+SR time-spectrum at x = 1.0 and
T = 277 K, 1.8 K, and 30 mK . No sign of a magnetic
ordering was observed.

Figure 2 shows the ZF-p,+SR time-spectra obtained
when for x = 1.0 (T c = 86 K) and T = 277, 1.8 K and
30 mK. The spectra are well described by the dynamical Kubo-Toyabe function , indicating that the muon
spin is depolarized only by randomly-distributed nuclear dipolar fields at the muon sites. The motional
narrowing effect which was due to the diffusion ofmuons through the crystal was observed with increasing temperature. Any sign of the magnetically orderedstate was not observed down to 30 mK. Thus, the coexistence between the SC state and the magneticallyordered state is unlikely for x = 1.0 in the TI-1212
system.
References
1) S. Nakajima et al.: Physica C 182 , 89 (1991).
2) I. Watanabe et al.: RIKEN Accel. Prog. Rep. 29 , 113(1996).
3) I. Watanabe et al.: to be published in Hyperfine Interactions (1996).
4) I. Watanabe et al.: Czech. J. Phys. 46, 2673 (1996).
5) I. Watanabe et al.: to be published in J. Low Temp.
Phys. (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Evidence for Muonium Passivation in n-Doped Ge
R. Kadono, R. M. Macrae, K. Nishiyama, and K. Nagamine
The current state of knowledge about the dynamical
properties of atomic defects under thermal/electronic
excitations (including defect metastability and associated site change) in semiconductors is still rather
limited compared with the situation regarding theirequilibrium structure. In this regard, hydrogen isotopes are no exception despite their apparent simplicity; the accumulated knowledge largely relates to theelectronic structure of isolated (paramagnetic) muonium centers, for which high-resolution /1SR (Muon
Spin Rotation, Relaxation, and Resonance)l) spectroscopic techniques analogous to EPR (electron paramagnetic resonance) and ENDO R (electron-nuclear double resonance) are available. The situation is moredifficult where the study of diamagnetic muon states(Mu±, i.e. , /1+ or Mu-) is concerned, as such highresolution spectroscopy is not possible due to the absence of the electron-muon hyperfine interaction.
Recently, we have shown that charge/spin exchangeinteraction between implanted muons and excess carriers may serve as a probe of the electronic state of diamagnetic muons in semiconductors. 2 ) We found that a
Mu± state formed slowly at lower temperatures in nGe does not interact with photo-induced excess carriers, suggesting that the electronic level associated with
the Mu± state is not in the band gap. Since the Mu±
state seems to be Mu- formed by a process Mu~ +dO -+ MuTd+ (where Mu~ is the muonium at the
tetrahedral interstitial site), the result is strong evidence that the observations correspond to the passivation of donor levels by Mu~ centers, a phenomenon of
crucial importance in determining the electronic transport properties of semiconductors. 3 )The experiment was conducted primarily at the
RIKEN-RAL Muon Facility in the Rutherford Appleton Laboratory which provides a pulsed beam of nearly
100% spin-polarized muons. A part of the measurement was performed at the Meson Science Laboratory, University of Tokyo (UTMSL, located at KEK).
The single crystal Ge specimen described in Ref. 4)(subsequently discovered to be n-doped with Sb, with
[Sbl'" 10 14 cm- 3 estimated from p '" 15 Ocm) was usedagain in the current experiment. The observed timedependent muon polarization at 12 K in Fig. 1 indicates that there is a fraction of implanted muons which
exhibits moderate depolarization only weakly affectedby illumination. Moreover, the spectra in Fig. 1 consistof a relaxing and a non-relaxing component with relative amplitudes dependent on the applied longitudinal
field, a feature characteristic of slow irreversible conversion from a state undergoing spin/charge exchangeinteraction to the final non-relaxing state. The detailed analysis of the field dependence indicates that

almost 50% of the non-relaxing component is a Mu±
state (the rest is attributed to a stationary Mu~
state) . Taking into account that M u~ is known to
be a very fast diffuser in this temperature range, sucha "delayed" Mu± state strongly suggests the formation of a Mu-donor complex (which is akin to Mu±)by diffusion-controlled reaction between M u and donor
atoms. More importantly, the absence of charge exchange interaction between the final M u ± centers andexcess carriers under illumination (as inferred by theabsence of spin relaxation) supports the presumptionthat there is no electronic level in the band gap associated with this complex state, i.e., passivation of thedonor level by muonium.

0)

0.2

00

0

s

9

0.175

>cr::
f-

w

b)

0 .15

off
I

On

:2
:2 0.125

>-

If)

«

c)

0.1

off

......
ono.05'-------'._--'-_--1-_ _- - ' - - _ - - ' -----'

o

2

4

6

8

10

12

TIME (jJ-s)
Fig. 1. Time spectra of decay positron asymmetry in Ge
at 12 K with ("on") and without ("off") illumination
when a) Longitudinal Field=0.34 T , b) 0.1 T, and c)
0.01 T .

References
1) For recent reviews , see for example, B. D . Patterson:
Rev. Mod. Phys. 60, 69 (1988); R. F. Kieft and T. L.
Estle: in Hydrogen in Semiconductors, Academic Press,
San Diego, p. 547 (1991).
2) R. Kadono et al.: Phys. Rev. B 55, 4035 (1997).
3) For recent reviews, see for example, S. J. Pearton, J.
W. Corbett, and M. Stavola: Hydrogen in Crystalline
Semiconductors, Springer, Berlin (1992); J. I. Pankove
and N. M. Johnson eds.: Hydrogen in Semiconductors,
Academic Press, San Diego (1991).
4) R. Kadono et al.: Phys. Rev. Lett. 73, 2724 (1994).

97

RIKEN Accel. Prog. Rep. 30 (1997)

J.1,SR Study on the Two-Leg Ladder Compound, Lal-xSrxCu02.5
J. Akimitsu, A. Yamashita, K. Ishii, K. Ohishi, R. Kadono, N. Kobayashi,*Z. Hiroi,* M. Takano,* and K. Nagamine
LaCu02.5 is a new two-leg ladder compound recently
discovered by Hiroi and Takano 1 ) under a high pressure. The temperature dependence of the susceptibility suggests that the ground state of this compound is
the spin liquid state with a finite spin gap. However,
the recent NMR2) and j.LSR3) measurements clearly indicate the antiferromagnetic long-range order of thissystem, contrary to the previous suggestion.
Recently, we have performed the muon spin relaxation(Ji'sR)
measurementsonhole-doped
Lal-xSrxCu02.5 for x=0.025, 0.05, 0.10, 0.15, and0.20, to confirm whether the superconducting correlation is suppressed by weak but non-negligible interladder interactions. In zero external field, a rapid decrease of the initial asymmetry was observed, indicating that Cu spins are antiferromagnetically ordered at
Neel temperature (TN ~ 150 K). And surprisingly,
there appears no change of TN for the different Sr
concentrations, x, as shown in Figs. 1 and 2. Figure
3 shows the concentration dependence of the internal
magnetic fields at muon sites measured by applying anaxial magnetic field. They are almost constant at B
800 G in the insulating phase (x = 00.10), andgrad ually decrease to B
300 G in the metallic phase(x = 0.20). However, time spectra is different between
x = 0.20 (metallic phase) and the other concentrations (insulating phase) ; a fast relaxation function was
clearly observed in the former samples, although it was
not observable in the latter ones.
Our preliminary conclusion is that magnetic order
I"'-.J. L a•. % S~ CnOl . S·0·Sr1 Cn0 1 (C0 3 )1.z (B03 )z

250
~ 200

'-"

50

o Go

~~~~~~~~~~~

0.00 0.05

I"'-.J

I"'-.J.E:

n 1.000.80 00~ 0.40• 0.20La1.xSrxCu0 2 • S

~

800

"C
~

600

-;
cI-

400

c

200

~

•

S

'c

ii i • ~0.10 0.15 0.20
xFig. 2. The phase diagram of the two-leg ladder system Lal- xSr x Cu02.5 and oxycarbonate superconductor Sr2CU02(C03h - x(B03)x.4) In contrast a rapid decrease of TN for the oxycarbonate superconductor , it isalmost constant for the ladder compound.

1000

00 6
,. •
C:) (:)~ 0.60

QJ•.......

~.OO
50

100

150

200

250

Temperature (K)Fig. 1. Temperature dependence of the initial asymmetry
for two different Sr concentrations x , indicating thatthe magnetic transition temperature (TN rv 150 K) did
not change.
Department of Physics Aoyama Gakuin University;
Institute for Chemical Research, Kyoto University

98

can not be destroyed by the increase of hole concentration, contrary to our initial expectation.

0.05

0.10

0.15

0.20

x

Fig. 3. Internal magnetic field at the muon site vs. Srconcentration, x.

References
1) Z. Hiroi and M. Takano: Nature 377, 41 (1995).
2) S. Matsumoto et al.: Phys. Rev. B 53, 11942 (1996).
3) R. Kadono et al.: Phys. Rev. B 54, 9628 (1996).
4) H . Nakata et al.: Physica C 263 , 344 (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Bose-Glass Transition of the Heavy-Ion IrradiatedLal.85SrO.15Cu04 Single Crystal t
G. Tatara, M. Matsuda, K. Katsumata, T. Kambara, Y. Awaya, T. Mitamura,
M. Terasawa, Y. Endoh, K. Yamada, and S. Hosoya
Recently the vortex system in high-Te superconductors has been attracting much attention because of its
rich phase structure.!) We report on the study of phasestructure of a vortex system in the heavy-ion irradiated La1.85SrO.!5 CU04 single crystal. The ions createdtracks work as columnar pinning centers, resulting in
a new Bose-glass phase. 2 )Unirradiated (or pre-irradiation) sample, grown by
the traveling solvent floating zone (TSFZ) method, hasa sharp superconducting transition at 37.5 K. One ofsuch samples was irradiated parallel to the c-axis by
the 3.4 GeV Xe ions produced from the RIKEN Ring
Cyclotron. The density of irradiation for this sample
was 2.7x 10 10 cm- 2 , which corresponds to the vortex
density at the field of Bcp = 0.5 T.
Figure 1 shows the hysteresis curve of the samples
with Bcp = 0 (i.e., unirradiated) and Bcp = 0.5 T at
15 K. It is notable that the absolute value of the magnetization of the sample with Bcp = 0.5 T is enhanced
by a factor of about 2.8 compared to the unirradiated(open circles) one.

of the unirradiated sample shows a peak at a temperature below the critical temperature Te. The behaviorof X" of the Bcp = 0.5 T sample below a crossover fieldof Bcr rv 0.5 T is similar to that of the unirradiatedsample, although the peak temperature is shifted tothe higher field side (Fig. 2). Above B cr ) X" of the irradiated sample becomes asymmetric and has anothersmall broad peak at a lower temperature.

10000
8000

..-

Q.
CO

6000
4000
2000

o
30
200

34

36

38

T(K)
Fig. 2. The irreversibility line determined from the position of the peak of X" for the samples with Bcp = 0(open circles) and 0.5 T (open squares). Solid lines are
the fits of the low field region (B ~ 0.5 T) with a function of B ex: (Tc - Ttl'. with 0: = 1.8. Dotted line is a
guide to the eye.

~ -100-200-10000

32

-5000

0

5000

10000

H (Oe)
Fig. 1. Hysteresis curve of the unirradiated (Bcp = 0)
and irradiated (Bcp = 0.5 T) samples at 15 K. Closed
circles: Irradiated by the intensity 2.7 x 1Q10(cm- 2 ).
Open circles: Unirradiated sample.

The imaginary part, X" (T), of the AC susceptibility

The origin of the two peaks for B > Bcr of Bcp
0.5 T sample may be due to the co-existence of columnar defects and intrinsic point defects.
References
1) G. Blatter et al.: Rev. Mod. Phys. 66, 1125 (1994).
2) D. R. Nelson and V. M. Vinokur: Phys. Rev. B 48
13060 (1993); A. I. Larkin and V. M. Vinokur: Phys.
Rev. Lett. 75 4666 (1995).

Condensed from the article in Czech. J. Phys., 46, 1555
(1996).

99

RIKEN Accel. Prog. Rep. 30 (1997)

Heavy-Ion Irradiation Effects on the Super-Conducting
Material, La1.85SrO.15Cu04
T. Mitamura, M. Terasawa, X.-J. Fan, T. Kohara, K. Ueda, T. Kambara, Y. Awaya,
M. Matsuda, G. Tatara, N. Takezawa,* and K. Fukushima*
Practical application of the high-temperature superconductor is strongly dependent on the efforts toachieve a high critical current density under high magnetic fields, because, by a free motion of vortices,
the critical current density tends to decrease rapidly
when the temperature approaches the critical temperature. The introduction of columnar defects bya swift irradiation of heavy-ions is one of the mostpromising approaches to create effective defects which
pin the magnetic fluxes. Enhancement of the pinningstrength in high-T c cuprates introducing parallel or
multi-direction columnar defects of high-energy heavyions has been reported. 1- 5) In the present study, the effect of columnar defects on the critical current densityof a polycrystalline high-T e cuprate is investigated.
The polycrystalline La1.85SrO.15Cu04 bulk material
was produced by an usual sintering method. The critical temperature, T e , was measured to be 38 K. Specimens with the size of about 2 mm x 10 mm and thickness of 0.1 mm were irradiated at room temperature
in a high vacuum by the 3.5 GeV, 136Xe31 + ions whichwere obtained from RIKEN Ring Cyclotron. Ion irradiations were carried out by two ways: a single direction irradiation perpendicularly to the surface of specimen (parallel irradiation), and a multi-direction irradiation (splay irradiation) at angles of 0, ±5 and ±10 degrees with respect to the normal vector to the surface.
Considering ion range and electronic stopping powerof the target material to this ion , defects with cylindrical structure can be assumed to have formed along
the ion trajectories. By a high-resolution transmission
microscopy, columnar defects were found almost amorphous phase and its damaged region was about 5 nm
in mean diameter. 6) The measurements of magnetization hysteresis were performed using a SQUID magnetometer of Quantum Design, and irreversibility line
was deduced in the temperature-magnetization plane,
which corresponds to the boundary dividing the pinning region of the magnetic flux lines (vortices) fromcomplete depinning one.
As shown in Fig. 1, the irreversibility lines for theB¢ = 6.0 T specimens are improved to a higher magnetic field. In the figure , B¢ is the field-equivalent
irradiation dose. The irradiation dose of 1.0 x 1011
Xejcm 2 corresponds to the vortex density at thefield of B¢ = 2.0 T. Especially, the splay-irradiatedspecimen shows more improvement than the parallelirradiated one, indicating that the splay configurationof columnar defects is more effective to pin the vortex.
A sudden collapse of the irreversibility line observablenear T e , i.e., at T = 37.5 K , for only the irradiatedspecimens may be the evidence of the existence of another type of vortex pinning mechanism which is enhanced under the irradiation. Krusin-Elbaum et a1. 7 )found a similar behavior of the irreversibility line forToshiba Research and Development Center

100

3.5 GeV Xe 31 +~ LSCOH II zB, = 6.0T----<>-- parallel

32

33

34
35
T (K)

36

37

38

Fig. 1. Change of irreversibility line before and after the
3.5 GeV, Xe ion irradiation.
YBCO in their ac susceptibility observation, and proposed that this change is an evidence of the thermaly
softening boundary, which is theoretically predicted by
Feigel'man and Vinokur. 8) At the moment , we have nodecisive explanation about this.
From the crystal orientation point of view, there
should be no difference between the parallel and splay
irradiations to the polycrystalline materials, because
the crystal axes of various grains are randomly distributed with respect to the direction of a columnar
defect. Hence, it is natural to mention that the direction of ion beam does not play an important role.
In the present study, however, it was found that the
splay irradiation is more effective to introduce defects
for vortex pinning than the parallel irradiation, suggesting that entangled states of vortices, which result
from random exchanges of vortices between columnar
defects, are more easily attained in the configuration of
randomly oriented columnar defects. As a result, evenin the polycrystalline high-T e cuprates, the vortex pinning strength may be more enhanced in the case of the
splay irradiation.
References
1) V. Hardy et a1.: Nucl. lnstrum. Methods Phys. Res. B
54, 472 (1991).
2) Th. Becker et a1.: Physica C 245 , 273 (1995).
3) M. Terasawa et a1.: Physica C 235- 240, 2805 (1994).

4) T. Hwa, P. Le Doussal, D. R. Nelson, and V. M.
Vinokur: Phys. Rev. Lett. 71 , 3545 (1993).
5) Th. Schuster et a1.: Phys. Rev. B 51, 16358 (1995).
6) M. Terasawa et a1.: Trans. Mat. Res. Soc. Jpn. 17, 383(1994).

7) L. Krusin-Elbaum et a1.: in Progress in High Temperature Superconductivity, Vol. 30 (World Scientific, 1992)
p.62.
8) M. V. Feigel'man and V. M. Vinokur: Phys. Rev. B 41,
8986 (1990).

RIKEN Accel. Prog. Rep. 30 (1997)

Studies of Columnar Defects in Bi2Sr2CaCu20x by TEM and STS
N. Nishida, S. Kaneko, Y. Ono, H. Sakata, K. Satoh,T. Kambara, and Y. Awaya
High-energy heavy ions are known to produce columnar defects (3-10 nm in diameter) in high-T c oxide
superconductors along their tracks. I) As the diameteris the order of the superconducting coherence length,
columnar defects can act as pinning centers in highT c superconductors. It is interesting and important tostudy the microscopic electronic states at and aroundcolumnar defects. We have generated columnar defects in Bi2Sr2CaCu20x at a (E5a) beam line by impacting 3.4 GeV 136Xe31+ ions from RIKEN ring cyclotron, and studied them by applying transmission
electron microscope (TEM) and scanning tunnelingmicroscope (STM). In STM experiment a clean surfaceof Bi2Sr2CaCu20x was prepared by cleaving the single
crystal of Bi2Sr2CaCu20x at 4.2 K in vacuum. Scanning tunneling spectroscopic (STS) method has also
been successfully applied to study columnar defects.
In Fig. 1, a high resolution TEM photograph isshown, where we can see that a columnar defect has
an amorphous structure and has a sharp boundary
in atomic scale. In Figs. 2 one of our STM observations of columnar defects on Bi2Sr2CaCu20x is
shown. Figure 2(a) exhibits a constant-current STM
image of a columnar defect. The image corresponds tothe vertical movement of a STM needle probe against
Bi2Sr2CaCu20x surface in order to keep a tunnelingcurrent constant at a constant applied voltage between
the needle and the sample. In Fig. 2(b) the movementof the needle is plotted across the columnar defect; it
can be seen that a STM needle comes closer to the surface abruptly at the region of columnar defect. Thismeans that the columnar defect is an insulator. This is

the first experimental evidence shown microscopicallyof the insulating electronic state of columnar defects
in high-temperature oxide superconductors. Recent
theories 2) have discussed that boundary effects in dwave superconductors depend on kinds of the surface,such as (1,1,0) or (1,0,0) surface boundary of CU02
plane, and are quite different from those in s-wave supercond uctors. In order to study the boundary effects,
the local density of states around a columnar defect in
Bi2Sr2CaCu20x has been measured by using our LTSTS at 2.2 K. The analysis is now in progress and expected to give us back valuable information about thesymmetry of Cooper-pairing in high-T c copper-oxide
supercond uctors.
We acknowledge JEOL for kindly taking a highresolution TEM photograph.

(a)E.s 0.2Na..

oFig. 2. (a): A constant-current STM image of a columnar defect in BbSr2CaCu20x at a bias voltage of 1
Volt. (b): The columnar defect revealed by moving
STM-needle across it.

-

2 .5nmFig. 1. Columnar defects in BbSr 2CaCu 20x observed bya high-resolution TEM.

References
1) M. Toulemonde, S. Bufford, and F. Studer: Nucl. Instrum. Methods Phys. Res. B 91, 108 (1994).
2) M. Matsumoto and H. Shiba: J. Phys. Soc. Jpn. 64,
1703 (1995).

101

RIKEN Accel. Prog. Rep. 30 (1997)

An Evaluation of Single Event Upset on Memories
S. Matsuda, T. Akutsu, S. Shugyo, M. Nakamura, K. Sugimoto, T. Hirose, H. Ohira,Y. Nagai, T. Kohno, N. Inabe, M. Kase, A. Goto, and Y. Yano
Semiconductor devices, which are essential in artificial satellites and spacecrafts, degrade by radiation in
space. The radiation environment around the earth includes the electrons and protons trapped by the earth's
magnetosphere, solar protons , and heavy ions in galactic cosmic rays. It is well known that the impingement of high energy heavy ions on semiconductor devices causes so-called single event phenomenon (SEP)
like singe event upset (SEU) on memory devices, single event latch-up (SEL) on CMOS and LSI etc., andsingle event burnout (SEB) by the heavy ion going
through the active area of POWER MOSFET. The
author's affiliation NASDA (National Space Development Agency of Japan) previously studied SEB andSingle Event Gate Rapture (SEGR) on POWER MOSFET by using the heavy ions from the RIKEN Ring
Cyclotron.
During this reporting period , we performed irradiation test on two types of memory chips (256kSRAM
and 16MDRAM) with a beam of 40 Ar at 90 MeV j u(3600 MeV). The LET of the ion in the material(Si) is
2.02 MeV j(mgjcm 2 ) and its range is 4330 f.Lm(Si). We
have performed several irradiation tests on 256kSRAM
in use of TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) and measured the crosssection of SEU as a function of LET. In this irradiation test at RIKEN , we acquired a new set of data on
the cross section. The results are plotted in Figs. 1(write data = '0000 ') and 2 (write data = '1111'). At
TIARA , we had to open the lid of the devices since therange of the ions was not long enough. In this test at
RIKEN, we irradiated the devices both with lid andwithout lid. This result gives an evidence that the ion
beam with the same LET evokes SEU with the samecross section even at different energies of the ion beam.
Therefore, we could acquire the correlation data of the
SEU on 256kSRAM by the beam with different LETs.
Recently, memory devices are getting smaller andlighter, and special type of package structure such as
LOC (Lead on Chip structure) is used to shrink the delE~6}--- ....................... -.... -- .. .... ~-Ie), l E~8.. --- -- -- -- -- --: -- -- .. - •.• --~ ---. - - -. -. - -~ -- -- - - - - - - --1E- 128~ IE-I I.

..... .x ...... __ .............. _____ . __.~~_~a RIKEN(no lid)•••• _ _ _ _ _ _ _ _ _ _ ___________________ _ _ . .. RIKEN(lI d)
_

lE-12

lE-13 L-_o_~_ _-L~_~: X~
TI=AR=A(n=o=li d)::J
10

20

30

40

LET [MeV/(mi/cm 2)]

Fig. 1. Test result of 256kSRAM (Write data = '0000').
102

'

x

x :

-t-----. ------r ----. -----.. :---..-.. --. -.
:- -i --,; -----:' -- --. ------: -- ---- --- ---: -- ---- ---- --

l

:,. x
:
:
I ~ ::~:no lid)
- - x. - -- - - - --~ ... - .. - -. - - ' : ' - - - - -. - - -- ~~~ lid)[-lE- 13

.

o

10

-

20

30

40

LET [MeV/ (mi/cm 2)]

Fig. 2. Test result of 256kSRAM (write data = ' 1111') .
vice. For this type of package, the chip surface is partly
covered with its lead-flame. The heavy ion beam does
not reach the chip surface in usual way of its irradiation. But by the use of a long-range ion beam andby irradiating from backside of chip, the observationof SEU is possible.
We has performed a few irradiation t ests on
16MDRAM (assembled inside an ordinary package andopened the lid) in TIARA to measure the cross section as a function of LET. In this irradiation test at
RIKEN, we used a LOC structure 16MDRAM and irradiated from backside of the chip to obtain a new dataof SEU cross section as a function of LET , as plottedin Fig. 3. There is a disagreement between the Ar3600 MeV data at RIKEN and the Ne-260 MeV data
at TIARA. In the case of irradiating from the backsideof chip, LET changes because of the energy loss of ions
before the ions reach the sensitive area. But , in this
irradiation test , the beam range was long enough, sothat the change of LET does not effect the test result.
Moreover, the data at TIARA were on 8bit 16MDRAM
and the data at RIKEN is on 4bit 16MDRAM. From
our experience, the memory-bit composition of devices
does not effect the SEU test result. We are under discussion on the discrepancy of test result and have aplan to continue the irradiation test from backside of
the chip for storing more data.

lE-D6 r - - - - - - - - - - - ----,
1E-D7-- -- -- .... -- . . .. -- -- .. - .. - - ...... -- -- -- .....q . -' --~i3 1E-D8... - - - . - .. - ..m__ . _.......... __ ..... _. _.....K~.5.2 ~~•••.~

Jl lE-l 0- - - - - -- - - -.

)C

~ ::~: ~ :I::~:::::t::::::::::: I:::::::::: .:-. ..-------:-;~ lE~9,)( : )(

lE~8

u

..

x

r---~--------~.~ lE~9r------------~

lE~7

lE~6

1E~7

_+_ _

lE-D9

At .330M.. - .... -- .. ---- .• - ------ ...... -.- .. -------.

~

Jl l E-lO.. g. ............... ... .. -.............. -- ..

~ IE-II~ ------ .......... - ............ - ........ .. ..

-- .... -1E-1 2
1E-13

o

10

20

30

LET [MeV/(mi/cm 2)]

Fig. 3. Test result of 16MDRAM.

40

3. Radiochemistry and Nuclear Chemistry

RIKEN Accel. Prog. Rep. 30 (1997)

In-Beam Mossbauer Study on Jump Processes of Self-Interstitialin Pure Iron after 56Fe(d, p) 57 Fe Reaction
Y. Yoshida, Y. Kobayashi, J. Nakamura, F. Ambe, E. Yagi, R. Sielemann,* H. HaBlein,*
A. Feinauer,** T. Grund,** and A. Seeger**In order to elucidate the dynamical effects due tojump processes of the interstitial 57Fe atoms producedby the 56Fe( d,p) 57 Fe reaction, we measured the angulardependence of Mossbauer spectrum at different crystal
orientations. 1 ,2) The iron single crystal (5 x 10 mm 2with 1 mm thick) was oriented so that the surface was(001) and the long axis of the rectangle was [001]. The
deuteron beam (E = 8 MeV) was introduced into thespecimen with an angle of 45° to the surface from thedirection of [110] and stopped about 100 f-Lm of depth
inside the sample. This means that both the deuterons
and the radiation damage were accumulated during themeasurement. To reduce any effects caused by thisaccumulation, we used a low intensity of 50 nA (onefourth of the full current) and the sample was annealed
above 350 K after every measurement. The spectra
were measured between the pulsed beams to avoid theprompt peaks because the time-structure of the beams
was not suitable for our measurement.
The emission direction of the Mossbauer ,),-radiation
can be varied from parallel to [100] to [110] by changing the position of the detector. Figure 1 shows theMossbauer spectra of single crystal iron along [100] direction between 60 and 420 K. It is clearly seen that thepeak intensities of the 2nd and 5th lines decrease as thetemperature decreases. This means that the directionof the magnetization changed, roughly speaking, fromparallel to perpendicular to the surface shallower than

the region where the deuterons were stopped. The total area intensity of the spectrum at 60 K is muchsmaller than those of the other spectra at higher temperatures. It suggests the existence of a broad component. The origin of such effects are not clear at thisexperiment, but one possible explanation may be due
to an internal stress which would arise from the accumulation of deuterons and defects and would become
stronger in lower temperatures.
The angular dependence of the Mossbauer spectra at
370 K and 160 K is shown in Fig. 2(a) and (b), respectively. The angles of -11 and +34 degrees correspondto the directions of [110] and [100]' respectively. The
hyperfine splitting of the spectrum at [110] is considerably higher than those at another angle both at 370
K and 160 K, indicating the existence of the defectlines in addition to the substitutional line. The ,),-rays
emitting from the 57Fe atoms which are stopping on
the substitutional sites will be strongly self-absorbedby the 57Fe atoms existing with a natural abundance of
2% in the sample. This is why the intensity of the substitutionalline depends on the detection angle. On theother hand, the ,),-rays emitting from the 57Fe atoms
ending up on a defect site, for instance, on the interstitial sites, will not be resonantly absorbed inside thesample. Accordingly, the intensity of the defect lines
will not depend so much on the angles.
_lId"l!

::f~l

~
(a)

ISO

100

3~OK.

'.

.: - ,,' .~::l JJJJJLJL.j!::l J0lNJuL I

l00~'•• '.'"+3~'~" ',' - • • • •: .. ~

j,•.•...

11°O~)Isor'~'~! ::l JWJuJL 1

100

::t~l

100

Y

~ u U\.!\..! V

~
.deg.

150

-10

•

-s

160K

0

S

10

Velocity (mmls)

10

-10

Velocity (mm/s)

Fig. 1. In-beam Mossbauer spectra of 57Fe in single crystal
Fe along [100] after 56Fe(d,p)57Fe reaction. The spectra
were measured between 60 and 420 K.
Hahn-Meitner-Institut Berlin, Germany
Max-Planck-Institut fur Metalforschung & Max-PlanckInstitut fur Physik, Stuttgart, Germany

Fig. 2. Angular dependence of Mossbauer spectra at 370
and 160 K.

References
1) Y. Yoshida et al.: RIKEN Accel. Prog. Rep. 29, 111(1996).
2) A. Feinauer et al.: HMI-Berlin Ann. Rep. B 540, 111(1995).

103

RIKEN Accel. Prog. Rep. 30 (1997)

In-Beam Mossbauer Spectroscopy on 57Fe in Solid Ar and Solid Xe
after Coulomb-Excitation and Recoil-Implantation
Y. Yoshida, Y. Kobayashi, K. Hayakawa,* K. Yukihira,* H. HaBlein,*
J. Nakamura, S. Nasu, E. Yagi, and F. Ambe
The inert gas solid has been often used for a matrix
to study isolated ions using Mossbauer spectroscopy
at a low temperature.
This technique is usuallycalled "matrix isolation", and often combined with acoevapolation 1 ) or with an implantation technique at alow energy of several 10 keV 2 ) to introduce Mossbauer
probes into the inert gas solids.
In the present study, we implanted 57Fe into solid Ar
and solid Xe immediately after the Coulomb-excitation
via a pulsed Ar ion beam with energy of 120 MeV
from the AVF-cyclotron at RIKEN, and simultaneously measured Mossbauer spectra of 57Fe in the solid
Ar and Xe samples. This in-beam Mossbauer technique is supposed to be more appropriate to study isolated 57Fe atoms on different lattice sites and their dynamic behavior in the inert gas solids. This is because
the high recoil implantation energy of several MeV,
the low 57Fe concentration of 1010 necessary for one
measurement, and the short measuring time of several
hundreds nano seconds make us possible to study thecompletely isolated 57Fe-states even at elevated temperatures. The same technique has been developed
and applied to the studies of atomic jump processes
in metals and semiconductors3) at the Hahn-MeitnerInstitute in Berlin. A preliminary result was reported
in the last year. 4 )The solid samples were prepared by condensation of
Ar and Xe gases on a copper substrate in 40 x 30 mm
rectangular shape, which was cooled by a continuousHe-flow cryostat down to 50 and 90 K, respectively,
in a small chamber directly connected to the measuring chamber. Mossbauer spectrum was measured by
two Parallel-Plate-Avalanche Counters (PPAC), whichwere mounted on the Mossbauer driving units. The
beam intensity of 40 Ar was only 3 pnA, yielding the,-ray count rate of about 0.3 S-l per each detector.
This rather low intensity was mainly due to a poor
condition of the ion source, which will be improved in
the next experiment.
Figures 1 (a) and (b) show the 57Fe Mossbauer spectra in the solid Ar and Xe samples, respectively, incomparison with the 57Fe spectrum in the bare Cu substrate (Fig. l(c)). Each spectrum was measured at 10
K for 18, 20, and 6 hours, respectively. Although theaccumulation time for the spectrum of 57Fe in Cu was
the shortest, the spectrum can be seen most clearlyand be analyzed by a sharp single Lorentzian. The
center shift is -0.37(3) mm/s, which corresponds tothe isomer shift of 0.26(3) mm/s at the room temperaShizuoka. Institute of Science and Technology

104ture. This component can, therefore, be assigned as Fe
atoms on the substitutional site in Cu. On the other
hand, the quality of the spectra for solid Ar and solid
Xe is rather poor, which is supposed to be mainly due
to the small Debye-Waller factors in both systems, due
to the low beam intensity of Ar (about 3 pnA) , anddue to a short repetition time of beam pulses of 160
ns. In both spectra, there seems to be at least two
different components: in the spectrum of solid Ar, ataround 1.0(2) and -0.48(8) mm/s, and in the spectrum of solid Xe, at around 0.5(1) and -1.3(2) mm/s.
The component at the right hand side of each spectrum appears to be due to the "Feo monomer state(configuration 3d6 4s 2 ) ", which was reported and assigned as "substitutional" in the experiments 1 ,2) after
the coevaporation of 57Fe and 57 Co and implantationof 57 Co. When we compare the isomer shifts of thesecomponents with the values obtained from the in-beam
Mossbauer measurements on metals,3) however, it may
be more plausible to assign them as the interstitial sites
in solid Ar and solid Xe.
40 ,.............-,--.-.-,---..-.--o--r~..,....-.-.--.--,.--.-.--,

30

(0)

S7 Fe in solid AI at 10 K

20:.·M::.··:.:..:. ·:. ·. : :."':

10..:::.,-::..'; ..... :·..

70

(b)

60

'" 50

~ ig

S7Fe in solid Xe at 10 K.:...:.:,;. ..: .

... .:.:. .:". .,. . .:y~:

10

o

50

S7 Fe in Cu al 10 K

f: '""oL.

,'" . ......... . ',... :

·10

·5

10

Velocity (mm/s)

Fig. 1. Mossbauer spectra of 57Fe in (a) solid Ar,(b) solid Xe, and (c) bare Cu-substrate after the
Coulomb-excitation and its recoil-implantation at 10 K.

References
1) P. H. Barrett and T. K. McNab: Phys. Rev. Lett. 25,
1601 (1970); H. Micklitz and P. H. Barrett: Phys. Rev.
Lett. 28, 1547 (1972).
2) M. Van Rossum et al.: Phys. Lett. A 75, 241 (1980).
3) Y. Yoshida et al.: Phys. Rev. Lett. 61 , 195 (1988); Y.
Yoshida: Hyperfine Int. 47, 95 (1989); R. Sielemann
and Y. Yoshida: Hyperfine Int. 68, 119 (1991); B. Keck,
R. Sielemann, and Y. Yoshida: Phys. Rev. Lett. 71,
4178 (1993).
4) Y. Yoshida et al.: RIKEN Accel. Prog. Rep. 29, 111(1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Simultaneous Determination of Biobehavior ofSc, Mn, Fe, Co, Zn, Se, Rb, Y, and Zr in Mice Bred underDifferent O 2 Gas Percentage CircumstanceR. Amano, S. Oishi,* S. Seto,* N. Fukumoto,* S. Enomoto, and F. Ambe
Radioactive multitracer has been utilized and proved
its versatility for simultaneous tracing of many elements in various biological systemsJ) We have also
been applying the multitracer technique to study thetissue and subcellular behavior of many trace elements
in mice. We have described that the multitracer solution, which was prepared from an Ag target irradiatedwith heavy ion beams in RIKEN Ring Cyclotron, is
effective for simultaneous tracing of biotrace elements
such as Mn, Co, Zn, Se, and Rb over the experimental
period up to 2 months. 2 ,3) The present work aimed to
examine the simultaneous evaluation of biobehavior ofSc, Mn, Fe, Co, Zn, Se, Rb, Y, and Zr in mice bred indifferent O 2 gas percentage circumstance.
A no-carrier-added multitracer solution was obtained from an Ag (purity: more than 99.99%) target irradiated by heavy-ion beam in RIKEN Ring Cyclotron. The multitracer solution was prepared according to the method of S. Ambe4-6) in Radioisotope
Center, Kanazawa University. This animal experimentstarted one month after cyclotron bombardment andthereby produced 10 radioisotopes (46 SC , 54Mn, 59Fe,
57 Co , 58CO , 65Zn , 75Se , 83Rb , 88y , and 88Z r ) of 9 elements were utilized as the tracers. Male Crj: CDI(ICR) mice weighing 20-22 g (4 weeks old) were used.
Physiological saline solutions (O.OOIN HCI, pH 2-3)
containing the radioactive multitracer were intraperitoneally injected (0.2 ml/mouse). The injected mice
were housed in the steel net cages, which were placed
into the box with a constant gas flow (2 l/min) froma cylinder. In this way, the mice were bred under 4different O 2 gas percentage circumstances.
At 48 hrs after injection of the multitracer, the mice
were sacrificed under ether anesthesia and approximately 0.2 ml of blood was collected. After this, brain,
cardiac muscle; lung, liver, spleen, pancreas, kidney,skeletal muscle, and bone were excised. The 9 tissues
and blood were weighed and freeze-dried. The driedsamples were subjected to ,-ray spectrometry using a
Ge detector in reference to an appropriate standard inorder to obtain the tissue uptake rate of each tracer,
which was expressed as the radioactivity percentage ofthe injected dose per gram of tissue (% dose/g).
The tracers of Mn, Zn, Se, Rb, Y, and Zr were simultaneously detected in all liver samples at 48 hrs
after the intraperitoneal injection under 4 different O 2
gas percentage circumstances (10, 20, 80, and 100%).
Each liver uptake rate is expressed as the mean value
with its standard deviation from five mice bred under same circumstance. Figure 1 compares the liver
uptake rates of the 6 tracers. Although all the liver
School of Health Sciences, Faculty of Medicine, Kanazawa
University

uptake rates except those of Rb were observed to beequal within the standard deviations under the 4 different circumstances, the uptake rate of Rb tracer under
10% O 2 circumstance is higher than those under theother circumstances (20, 80, and 100%). The tracersof Se and Rb were observed in all blood and soft tissue
samples except in bone. The uptake rates of Se andRb tracers in all tissues and blood can be compared
under 4 different circumstances. Figure 2 shows theuptake rates of Se and Rb tracers in blood and brain.
It was found that the Rb uptake rates of all soft tissues
and blood under 10% O 2 circumstance is only higher
than those under the other 3 circumstances (20, 80,
and 100%).
15-.----------------,
IJ & 0 Rb m MIl
Liver.7r[)z..mv

T

T

1

1

10%

100%

Oxygen gas percentage (%)

Fig. 1. Liver uptake rates of Mn, Zn, Se, Rb, Y, and Zr inmice at 48 hrs after injection under 4 different 02 gas
percentage circumstances.
6.0 - . - - - - - - - - - , 4.0

Blood

0&

Brain

o Rb

0&

0

Rb

3.0

2.0

T
1

T

1 .
T

1.0

0.0
10%

20%

80%

100%

Oxygen gas percentage (%)

10%

20%

80%

100%

Oxygen gas percentage (%)

Fig. 2. Uptake rates of Se and Rb tracers at 48 hrs
after injection in blood and brain of mice bred under 4different O 2 gas percentage circumstances.

References
1) In RIKEN Review No. 13 (1996).
2) R. Amano et al.: J. Trace Elements Med. BioI. 10, 145(1996).
3) R. Amano et al.: Ann. Clio Lab. Sci. 26, 531 (1996).
4) S. Ambe et al.: Chern. Lett. 1991, 149.
5) S. Ambe et aI.: Anal. Sci. 7, Suppl., 317 (1991).
6) S. Ambe et al.: J. Radioanal. Nucl. Chern., Articles 195,
297 (1995).

105

RIKEN Accel. Prog. Rep. 30 (1997)

Uptake Behavior of Multitracers in LEe Rats before
Jaundice Development (II)S. Oishi,* R. Amano, A. Ando,* T. Takada,* R. Takafuji,* S. Enomoto, and F. Ambe
Unusual Cu accumulation in LEC (Long Evans Cinnamon) rats has been known to be involved in the development of jaundice, hepatic injury, and hepatocellular carcinoma. Previously, we examined the distribution of multitracers in tissue of LEC rats, and described the age-dependence on increased uptake of Zn
by liver and kidneys before jaundice development. 1) In
present work, we have mainly studied the subcellular
fractionation and gel-filtration pattern of the Zn and
Se trace elements in the supernatant fraction in liversof the LEC and Wistar rats having the same 7 weeks
of age.
A no-carrier-added radioactive multitracer was obtained from an Ag target irradiated with the 135
MeV /nucleon N-14 beam which was accelerated by
RIKEN Ring Cyclotron. The preparation for a multitracer solution was carried out in the Radioisotope
Center, Kanazawa University, following to the methodof Ambe et al. 2-4) This animal experiment started
2 months after the cyclotron-produced ion bombardment , and therefore four radioisotopes of 54Mn, 65Zn,
75Se and 83Rb were mainly served as tracers.
One fifth of ml of the final radioactive multitracer
solution (pH 2- 3, physiological saline solution) was
intraperitoneally (i. p.) injected in to LEC and Wistar rats. At 12 hr after the i.p. injection containing the radioactive multitracer solution , these rats
were sacrificed after ether anesthesia.
Then, theliver was excised and treated by subcellular distribution method followed by Sephadex G-75 gel filtration
method. The excised liver were homogenized in acold (5°C) 0.25 M sucrose solution containing 0.01
M Tris (hydroxymethyl) aminomethane-HCI buffer ofpH7.6 (10% weight per volume) by a Potter-Elvehjem
type homogenizer, following to a modificated methodof Hogeboom and Schneider. Separation of the supernatant solution was performed on Sephadex G-75
gel-filtration column (25 mme/> x 500 mm length) using a 0.001 M This-HCI buffer (pH 8.6) solution and aflow rate of 0.6 ml min- I. The 5.5 ml aliquot obtained
from the filtration was freeze-dried and its radioactivity (gamma-ray spectrometry) was measured by using
pure Ge semi-conductor detectors.
From the results of subcellular distribution as shownin Fig. 1, there were no significant age-dependentchanges for both Se and Zn uptake cellular distributions in the liver of LEC rats. It shows high percentages of Zn and Se in the supernatant fraction. Figure 2
compares the elution curves of Se and Zn tracers in the
School of Health Sciences, Faculty of Medicine, Kanazawa
University

106

supernatant by use of Sephadex G-75 gel filtration. We
find that Se behaves in a similar manner in both LEC
and Wistar rats, but Zn behaves different way. The
amount of Zn tracer in LEC rat was higher than thatof Wistar rat, especially for fraction numbers 18- 26 asshown in Fig. 2. Moreover, we think that the high accumulation of Zn in the liver of LEC rat is involved
in metallothionein, because the solutions of the 18- 26
fraction numbers were estimated to contain proteins of
7000-10000 molecular weights, which are almost equal
to the molecular weight of metallothionein.
Further study is required to discuss the relationshipbetween metallothionein and high uptake of Zn in theliver and kidneys.
(%)

(%)

Zn

Se

11

11

Weeks of Age

Wee ks of Age_

IrA ~i~~i~i~:~aly~~s~~~)supernatant fraction

c=J microsomal fraction_

nuclear fract ion

Fig. 1. Subcellular distribution of Se and Zn in the liverof LEC rat.

'~,::I::::;:~"' 1

Se

0OOI~~~i~~~~~i~~~~~i~~~~~i~

10

20

30

10

20

30

Fraction Number

Fraction Number

40

40

Fig. 2. Elution curves of Se and Zn for the supernatantfraction in the liver of the LEC and Wistar rats on
Sephadex G-75 gel-filtration.

References
1) S. Oishi et al.: RIKEN Accel. Prog. Rep. 29, 155 (1996).
2) S. Arnbe et al.: Chern. Lett. 1991 , 149.
3) S. Arnbe et al.: Anal. Sci. 1, Suppl. , 317 (1991).
4) S. Arnbe et al.: J . Radioanal. Nucl. Chern., Articls 195,
297 (1995).

RIKEN Accel. Prog. Rep. 30 (1997)

In vivo Behavior of Various Elements in Hepatopathic Animals (I)Metabolic study of trace elements in acute alcoholic mice
S. Enomoto, R. G. Weginwar, S. Ambe, and F. Ambe
Recently, the research of adult diseases such as cancer, diabetes mellitus, and hypertension is widely carried out. The hepatopathy is focused as a chronic disease in the present so called age of satiation, and theresearch from various phases to liver cancer and livercirrhosis has been done. Alcoholic hepatopathy has
various types such as fatty liver, acute alcoholic hepatitis, liver cirrhosis, and the ZIEVE syndrome. In thecurrent idea, the reason why the fatty liver develops
to the liver cirrhosis is doubtful, and it is dominant to
the idea of inducing by the overlap of acute alcoholic
hepatitis. In the present paper, we discuss the dysbolism of trace elements by the hepatopathy using amodel mouse which induced the acute alcoholism.
The acute alcoholic hepatopathy model and normal
mice used ddY strain in 7 weeks of ages. Three ddY
mice were treated intraperitoneally with alcohol for 3
hrs before, and for 3, 11 , 19, 27, 35, 43, 51 , 59, 67 and71 hrs after injection of the multitracer solution described below. Each mouse received 0.025 ml/g bodyweight of 25 (V IV) % alcohol each time. The injection schedule and experimental procedure are shown
in Ref. l.
Figure 1 shows the comparison of biodistribution on
the acute alcoholic hepatopathy and normal mouse livers at 24 hrs after the multitracer administration. In
the liver of the acute alcoholic hepatopathy mouse, theuptake of Be, Sc, Mn, Se, Rb, Y, and Zr increased further than the normal one. The uptake of Be, Cr, andY in the acute alcoholic hepatopathy mouse increased
about 3 times of the normal one. This tendency wasseen even in 72 hrs after the multitracer administration, and especially, Be and Y were increased after 72
hrs by about 8.5 times than the normal mouse. In vivo,
Be exists as Be 2 +, and it seems to be similar to AI 3 +,and Sc, Cr, Mn, Y, and Zr exist in vivo at 3 valences.
The alcohol seemed to give some effects on there because of an increase for the uptake of these elements of
3 valences. On the other hand, Be and Yare the boneseeking elements, and these elements are easy to accumulate in the liver which induced the hepatopathy.

We observed many fat granulations and fiberization in
the diabetes mellitus model mouse, and it was reported
that the bone seeking elements are stored in the partof fiberization. It was estimated that such a change
had been generated by the crisis of the hepatopathy
in the alcoholism model mouse, and the uptake of Be
and Y was suggested to increase by this reason. In
the liver of the alcoholism model mouse, the uptakeof As decreased remarkably. In the alcoholism model
mouse, the hemoglobin concentration was 9.23 ± 0.23
g/dl, and that in the normal mouse was 13.21 ± 0.56
g/ dl. The anaemia seemed to have been caused in thealcoholism model mouse. In general, the As incorporated in the internal mainly shifts in the erythrocyte.
By the anaemia, a decrease in number of erythrocyte
was induced, and the As uptake quantity seemed to decrease in the liver, since the number of the erythrocyte
which transports to the liver decreases.

...
hliver (24hr)

ScVo lICUle eIcoIIca mice

Cr
Mn
In

C

ddYmice

Zn

t>

G.

iii

s.

~

•

Co

M

Rb
Sr

Y
Zr

Au
Ah
0

10

20

30

40

50

Uptake("'-)

Fig. 1. Uptake (%) of various elements in the acute alcoholic and normal mice.

References
1) S. Enomoto et al.: RIKEN Accel. Prog. Rep. 29, 145(1996).

107

RIKEN Accel. Prog. Rep. 30 (1997)

In vivo Behavior of Various Elements in Hepatopathic Animals (II)Metabolic study of trace elements inliver-cancer bearing rat
S. Enomoto, N. Hayakawa, K. Endo, S. Ambe, and F. Ambe
The Long Evans Cinnamon (LEC) rat geneticallycontracts the jaundice at 4 rv 5 months which causes
acute hepatitis, and approximately the half dies. Survived rat passes through chronic hepatitis, liver cirrhosis, and it contracts the liver cancer. Critical causesof the hepatitis were examined in detail, and it was
found that the copper abnormally accumulates in theliver and that the copper concentration reaches about
50 times of the sound rat. It became clear that concentration of the ceruloplasmin in the blood remarkably
lowered and that it is very similar to human's Wilson
disease. The LEC rat seems to be able to become not
only model animal of the Wilson disease but also thatof the human liver disease. In this paper, we discussdysbolism and accumulation of the trace element using
LEC rats as a model animal of liver cancer that derives
from Wilson disease.
The liver-cancer bearing rat used a LEC strain in 80
weeks old and normal rat used a Wistar strain in 12
weeks old. The 0.1 ml of multitracer solution was dissolved in the physiological saline, and was injected toeach rat intravenously. After 24 hrs from the administration, we sacrificed and liver, kidney, spleen, andbrain were collected. The gamma ray was measured
by a Ge semiconductor detector.
In the liver, the uptake of Sc, V , Mn, Zn, Rb, As,
and Zr on LEC rat increased compared with normal
one as shown in Fig. 1. The uptake of Sc, V, Zn, andAs by LEC rat increased by two times while that ofMn was increased by 1.5 times, that of Ga by 3 times,
and that of Zr by 4 times. On the other hand, the uptake of Se and Y decreased. In the kidney, the uptakeof Sc, Ga, As, and Zr increased compared with normal
rat. The uptake of As and Zr increased by 3 times.
The uptake of Mn, Zn, Se, Rb, Ru, and Rh decreased.
There was no change for V, Cr, and Co. The liverof LEC rat cancerated, and liver tissue grew a large
number of false bile ducts in the leaflet marginal zone,
and hepatic duct fibrous disease surrounded in the fibroblast was recognized frequently. Because Ga has atumor seeking property, the uptake of Ga by LEC rat
increased. In the liver, As is methylated by S-adenosyl
methionine, and becomes monomethyl arsonic acid anddimethylarsinic acid, and it is excreted from the kidney. LEC rat caused various enzymatic abnormalities
by the Cu dysbolism; especially, in our result, there
were remarkable decrease with the ceruloplasmin andincrease in copper and metallothionein. In LEC rat,
the lowering of the concentration of glutathione peroxidase and cytochrome P-450 is reported . It is consid108

ered that As may increase in liver and kidney; becauseof an enzymopathy and a dysbolism, the methylation
does not work completely. In the liver of LEC rat,
the uptake of the essential elements such as Mn, Co,
and Zn increased, since the essential element is closely
related to the enzyme. In the organs such as kidney,spleen, and brain, there was also a change on the uptake of Mn, Co , and Zn. In these organs, this tendency
seems to originate the enzymatic abnormalities as wellas to result in the liver cancer. The uptake of essential elements is remarkably different from the liver dataof acute alcoholic hepatopathy mouse l ) and LEC rat.
On mouse which contracted an acute alcoholic hepatopathy, the initial state of the hepatic disorder, theabnormalities of enzymatic system and other proteins
are not directly connected with the dysbolism of theessential elements. However, in the LEC rat of the laststage of cancer, our result suggested that the uptake ofthe essential elements was increased , since the homeostasis maintenance mechanism of the trace elementsin the internal is collapsed by a remarkable liver injury.
Uptake of the bone seeking elements such as Sc and Zr
increased. These results and previous papers l - 2 ) suggested that the hepatopathy and the storage of boneseeker in the liver have a close relation through thefiberization of the liver.

...

Be

Uv.,(24hr)~~~===::J~
V

Se

C
t>

Ct
lin
Co
Zn
G.

iIi

s.

."

~

o Long EV8n<» C , • •(l10 . . . . old)•

WI. . r•• (1 2 week. old)

A.
Rb
Sr

Y
ZI
Ru
Rh

0

10

20

30

40

50

Uptake (,.)

Fig. 1. Uptake (%) of various elements in the LEC andWistar rats liver.

References
1) S. Enomoto et al.: RIKEN Accel. Prog. Rep. 30, 107(1997).
2) S. Enomoto et al.: RIKEN Rev. No. 13, p. 31 (1996) .

RIKEN Accel. Prog. Rep. 30 (1997)

Accumulation of Inorganic Elements in the ddY Mice
Implanted with Ehrlich Sarcoma
S. Enomoto, B. Liu, S. Ambe, R. Amano, and F. Ambe
Investigation of the metabolism of inorganic compounds in tumor will help develop anti-tumor drugs
and tumor diagnosis agents. We have investigated theshort-term metabolism of 16 radioactive elements inthe mice implanted with Ehrlich sarcoma. A discussionof the transportation, accumulation, and metabolismof radioactive elements and their relation with muscle
and tumor is given.
The experimental ddY mice underwent implantationof Ehrlich sarcoma in the thigh. After one week when
the tumor diameter grew about 1-2 cm, a multitracer
solution in physiological saline was administered intraperitoneally to the tumor-bearing mice. At 3, 24,
and 48 hrs after injection, three mice were sacrificed
and samples of blood, liver, muscle and tumor were
excised. These tissues and the blood were weighed
and applied for radioactivity measurements.
In this study, the radioisotopes of following elements
were used as multitracers: Be 2+ , Sc 3+, Zn 2+ , Rb+ ,y 3+ , Zr 4 +, Te032-, Ba 2+ , Hf4 +, 1r6+ , Pt 6+ , Ce 3+ ,Eu 3+, Gd 3+ , Yb 3+ , Tm3+ , and Lu 3+. In saline, Zr,
Hf, Pt , and Ir exists as a mixture of chloro-complexes,
while other metal ions are kept as simple free ions.
In order to elucidate a selective tumor accumulation, the tumor/muscle ratios were calculated. The
radioactivity of 16 elements in muscle and tumor wascompared in Fig. 1. At 3 hrs after the administration, only Be, Y , Ba, Eu, Gd, Vb, and Lu showed athe tumor/muscle ratio higher than 1. At 24 hrs after the injection of tracers, only Rb, Te, and Hf gave
a tumor/muscle ratio less than 1. At 48 hrs, Rb, Zr,
and Hf still showed the tumor/muscle ratio less than 1,
while the rare-earth element (REE) revealed a higher
tumor /muscle ratio than other elements showed. Generally speaking, among the 16 elements used in thisstudy, alkaline metals Rb and bivalent cations Be,
Ba, and Zn showed relatively low tumor/muscle ratio.
Trivalent cations REE revealed a high tumor/muscle
ratio. On the other hand, Zr and Hf, Pt and Ir also
showed low tumor/muscle ratio.
Most elements showed a lower uptakes in tumor andhigher uptakes in liver. It demonstrated that the compounds injected in vivo accumulated more quickly intoliver than those into tumor. During the whole timestudied, a low tumor/liver ratio was observed for mostof elements studied. However, we may noticed that 24
and 48 hrs after injection, the accumulation difference
between liver and tumor becomes smaller gradually.
Comparing the distribution in blood and tumor, a highradioactivity in blood did not result in a high uptake
in tumor tissue. On the contrary, REE that have a

Lu
Yb
Gel

I

Eu
Ce
Pt
Ir

o T1M3.n~

TIM14.n•

TIM4U,n

Hf
B8

Te
Zr
y
Rb

Zn
Sc
Be
0

5

10

IS

20

TIM

Fig. 1. Time dependence of the ratio of the uptake intumor to that in muscle (TIM) for each element.

fast or metabolism in blood show a high uptake bytumor. From this experiment, it seems that the REE
were transported to the tumor location in around 24
hrs and accumulated there.
It is thought that the transportation process has aclosed relation with the tumor uptake. It is surely truethat blood or serum played an important role in the
distribution of the trace elements in the living body.
The two proteins of major importance for transport ofmetal ions are albumin and transferrin. It has been
well discussed that trivalent REE has been found to
displace Fe3+ in transferrin.
In general, tumor cells exhibit a high amount oftransferrin receptors. As a result of pathological stain
on a tumor tissue slice which were used by fluorescencelabeled anti-transferrin receptor polyclonal antibody,
we observed that Ehrlich sarcoma solid tumor cell had
a lot of transferrin receptor. It is presumed that thetrivalent REE interacts with transferrin and is thencarried to the tumor transferrin receptor.
On the other hand, alkali metal and alkaline earth
metal did not accumulate in tumor . This maybe fromthe two reasons: first, it may interact with the serum
albumin that is responsible for transport of Ca, Co,
and Zn and for metabolism in the liver. Second, they
can not replace Fe 3+ on the transferrin.
As for Pt, Ir, Zr, and Hf, their lower tumor/muscle
ratio maybe due to that, first, they form a complicated chemical form or complex and second, they
have a strong affinity with some substance before
they reached the tumor and this substance metabolism
point is not high in tumor cells.

109

RIKEN Accel. Prog. Rep. 30 (1997)

Metabolic Study of Trace Elements in Se-deficient Rats
R. Hirunuma, N. Sotogaku, K. Endo, S. Enomoto, S. Ambe, and F. Ambe
Yeast Co., LTD.) since their 14th day of pregnancy until the weanling period of their baby rats. The weanlingrats were separated from their mothers, and were fed
with Se-deficient diet until the age of 12 weeks. As areference, 12-week-old normal rats were used. A tenth
ml of saline containing the multitracer was injected byintravenously in the tail vein of all the rats. The Sedeficient and normal rats were sacrificed at 3, 12, 24
and 72 hours after injection, and the radioactivities of
their organs and body fluids were determined by ,-ray
spectrometry. The observed , -rays were assigned on
the basis of their energies and half-lives. The behaviorof Be, N a, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Ga, As, Se,
Rb, Sr, Y , Zr, Tc, Ru, and Rh was examined. There
were little individual differences in each group of rats.
Figure 1 shows the uptake of various elements inthe kidney, liver, and spleen of Se-deficient and normal
rats, as typical examples. At 24 hours after injection,
the uptake of Se was larger in the brain, intestine, kidney, spleen , and ovary of the Se-deficient rats than inthose of the normal ones.

A number of studies on the role of Se in biochemistry are found in literatures. 1- 3 ) Selenium is one of theessential trace elements and is known as the central ion
in glutathione peroxidase. It is also reported that Se isin a competitive or synergetic relationship with several
metals such as Mn, Fe, Co, Zn, and As. Therefore, it
is very important to clarify the distribution of trace elements in various organs of Se-deficient rats. However,no systematic study has been reported on the behaviorof trace elements in Se-deficient rats.
In the present study, the uptake and distribution of
trace elements in Se-deficient rats were examined by amultitracer technique, which can be used to evaluate
the behavior of many elements under a same experimental condition.
A multitracer solution containing 20 different radioisotopes was prepared from a silver target irradiated by a heavy ion beam of 135 Me V jnucleon fromRIKEN Ring Cyclotron. After chemical separation,
this multitracer was dissolved in saline. Mother rats
were fed with Se-deficient diet (produced by Oriental

Be
Sc

Uver

Be

Sc

V

V

V

Cr

Cr

Cr

Mn
Fe

Mn
Fe

Mn
Fe

Co

Co

Co

Zn

Zn

Zn

Ga
As

Ga
As

Ga
As

Se
Rb

Se
Rb

Se
Rb

Y
Zr

Y
Zr

Y
Zr

Ru
Rh

Ru
Rh

Ru
Rh

0

5

10

15

0

5

Uptake (%)

10

15

20

Spleen

Be

Sc

::r-l

25

Uptake (%)

0

1

2

3

4

5

Uptake (%)

Fig. 1. Tissue uptake of various elements in normal and Se-deficient rats at 24 hours
after the elements injection.

In the kidney, the uptake of Be, Mn, and Y of the
Se-deficient rats was larger than that of the normal
ones. In case of the liver, there was little differencein the uptake of the elements except Co between the
Se-deficient and normal rats. In the spleen, the uptakeof Fe and As of the Se-deficient rats was smaller thanthat of the normal ones.
The elements, Se, Fe, and As, are closely related
to hemoglobin. Arsenic is bound to a globin part ofhemoglobin in erythrocytes, and Fe is a constituentof hemoglobin. Glutathione peroxidase has a greateraffinity for hemoglobin. The observed decrease of the110

uptake of Fe and As by the spleen in Se-deficiency suggests that the deficiency causes hemopoietic hypofunction of this organ.
References
1) J. N. Thompson and M. L. Scott: J. Nutr. 97, 335(1969).
2) H. G. Seiler, A. Sigel, and H. Sigel: in Handbook on metaLs in clinicaL and anaLyticaL chemistry (Marcel Dekker,
New York, 1994), p. 55l.
3) E. Glattre et al.: BioI. Trace. Elem. Res. 49, 177 (1995).

RIKEN Accel. Prog. Rep. 30 (1997)

Metabolic Study on Ca-deficient Rats Using a Multitracer
R. Hirunuma, K. Endo, S. Enomoto, S. Ambe, and F. Ambe
Calcium is the fifth most abundant element in theliving body.l) The most important Ca compound ishydroxyapatite in vivo, which constitutes the mechanical strength of bone and teeth. Calcium homeostasis
is maintained by hormonal regulation of the intestinal absorption and renal reabsorption. Calcium is absorbed in the whole small intestine, preferentially fromduodenum and the upper part of jejunum. The intestinal absorption is regulated by hormones and vitamin
D. The excretion in the kidneys is influenced by local
factors like the glomerulus and tubulus functions andby the amount of filterable Ca2 + as well as by otherfactors such as cortisol, parathyroid hormone, vitaminD, and calcitonin. Vitamin D is necessary for normal
absorption of Ca and phosphate from both the intestine and the skeleton. In the present study, the uptake
and distribution of trace elements in various organsof Ca-deficient rats were examined by a multitracer
technique, by which one can determine the behavior ofvarious elements under a given experimental condition.
A multi tracer solution was prepared from a gold
target irradiated with a heavy-ion beam of 135
MeV /nucleon from RIKEN Ring Cyclotron.
Cadeficient rats were fed with Ca- and vitamin Ddeficient diet (produced by Oriental Yeast Co., LTD.)for three weeks. The purpose of this vitamin Ddeficiency in the diet was to inhibit Ca absorption

from the small intestine. Three male Ca-deficient rats
weighing 105 g on average were used, while three sixweek-old male normal ones weighing 190 g on average
were used as a reference. A tenth ml of a saline containing the multitracer was injected intravenously inthe tail vein of each rat. The Ca-deficient and normal rats were sacrificed at 24 hours after the injection,and the radioactivities of organs and body fluids were
determined by '"'(-ray spectrometry.
In order to examine the physiological condition of
the rats fed with Ca-deficient food, the contents of Ca
in their plasma were measured. The Ca contents were
found to be 10.8±0.2 mg/dl and 3.4±0.2 mg/dl, respectively, for the normal and the Ca-deficient rats;
proving that the latter were really deficient in Ca.
The behavior of Be, Ca, V, Mn, Zn, As, Se, Rb,
Sr, and Ba was examined using the multitracer. The
results on Rb, V, and Mn are shown in Fig. 1. The
tracer of Ca was found predominantly in bones of both
Ca-deficient and normal rats. However, its uptake bybones of the Ca-deficient rats was only slightly higher
than that of the normal rats. This observation is interpreted that Ca was acutely required and taken up
not only by the bone but also by the other organs andbody fluids of the rats, because Ca concentration inthem was much lower than that expected by the homeostasis.

v

Rb

Mn

I

o

5

10
15
Uptake(%)

20

0

1
2
3
4
Uptake (%)

5

o

10
20
30
Uptake (%)

40

Fig. 1. Tissue uptake of Rb, V, and Mn in Ca-deficient and normal rats.

There was little difference in the uptake of Zn, As,
Se, and Rb between the Ca-deficient and normal rats.
The uptake of V was larger by the intestine and boneof the Ca-deficient rats than by those of the normal
ones, while the uptake by the kidneys of the former
was smaller than by those of the latter. Manganese
was found mainly in the liver of both the Ca-deficientand normal rats, and the uptake of the former rats
was smaller than that of the latter. Manganese accumulates in the liver and excretes to bile. It is known
that Mn controls catalysis of the enzyme (for example,
pyrvate carboxylase 2 »), to which it is combined andthat Mn 2 + is antagonistic to Ca2 + (for example, Ca

contained in calumodulin 3 »). The decrease of Mn inthe liver of Ca-deficient rats suggests that an enzyme
such as pyrvate carboxylase must be influenced by Ca
deficiency.
References
1) H. G. Seiler, A. Sigel, and H. Sigel: in Handbook on metals in clinical and analytical chemistry (Marcel Dekker,
New York, 1994), p. 299.
2) M. C. Scrutton and A. S. Mildvan: Biochemistry 7 ,1490 (1968) .
3) D. J. Wolff et al.: J. BioI. Chern. 252, 4108 (1977).

111

RIKEN Accel. Prog. Rep. 30 (1997)

In vitro Binding Assay of the Trace Elements
in Bovine Serum Proteins
N. Sotogaku, R. Hirunuma, K. Endo, S. Enomoto, S. Ambe, and F. Ambe
Since Pribram l ) studied the interaction of Ca 2 +ions with plasma proteins, a number of works havebeen done on the affinity of biotrace elements to various proteins. 2 ,3) The elements investigated are however limited. Once absorbed, metal ions enter into
the blood and are mostly bound to blood cells and/or
to plasma proteins; for example, Fe and Cu bind totransferrin and ceruloplasmin, respectively. Metals
are widely distributed in the body via bloodstream.
Although metal ions in vivo are known to play important roles for various enzyme reactions, the information of affinity of respective metal ions to various
proteins of living body is required in order to understand the mechanisms of transfer of energy and/or
electrons in the system. In the present work, we
examined the pH-dependence of binding affinity ofvarious elements with serum proteins using a multitracer technique. Their dependence in the range ofpH 6.4- 8.5 was examined by ethanol sedimentation
method. The serum proteins used were albumin , {3globulin, ,-globulin, apotransferrin, and holotransferrin, which means iron-free and monoferric- or diferrictransferrin, respectively. These purified bovine serum
proteins were purchased from Wako Pure Chern. Ind. ,Ltd. and were used without further purification. Asa sample buffer, N-[2-hydroxyethyl]piperazine-N'-[2ethanesulfonic acid] (HEPES) was used, and the eachprotein (1.0 mg) was dissolved in 50 mM-HEPES solution. The pH value of protein solution was adjusted tobe 6.4, 6.8, 7.4, 8.0, and 8.5 by adding a diluted NaOH
solution. Then, each protein solution was mixed with
50 J.1f. of a buffer solution containing the multitracer,
and the final mixed solution was mildly incubated at
37 0 C for 20 min. After the incubation, excess ethanol
was added and then centrifuged at 3,000 rpm for 10
min. The ,-ray radioactivities of the sediment were
measured by a pure Ge detector, and compared withthose of the standard multitracer solution. From theanalysis of the I-ray energy spectra, the affinities of
Be, Cr, Mn, Co, Zn, Rb, Sr, Ba, Ir, and Pt were determined.
Figure 1 shows the effect of pH on the binding percentage of Be, Mn, Co, Zn, and Sr to each serum pro-112

tein. Among them, high binding percentages (morethan 70%) of Be and Sr to albumin were observed in
the pH range investigated. Carboxyl and imidazole
groups of albumin play an important role to bind these
metals, because these groups are both ionized in thispH range. Alkaline-earth metal ions are bound to thecarboxyl groups, since alkaline-earth metal ions havelittle affinity for imidazole groups. I ) Binding of Co and
Zn to both types of transferrin increased with an increase of the pH values above 6.8. Transferrin is known
to possess two metal-binding sites, and therefore highly
specific structural changes occur as the pH values rise .
On the basis of our results, the structural changes ofprotein was confirmed to affect its affinity of metals.

Be
100""T4I~____r-.-,

Mn

Co

100....-------, 100-I ~ j.
~ ~

j _ t

~ 75
0:;,
.: 50

.: • i. .

•

..,

-! !

=

t

=:i 2575

50

50

I I- ,. ,I
~ ..

25

o+-r--r--r--r--r--1

0+-=;"-=""""::"---,---,---1

6 6.5 7 7.5 8 8.5 9pH

6 6.5 7 7.5 8 8.5 9
pH, it ,- i tf
I'

Zn
100

~ 75
0:;,

~ 50
c

iii 25

75

25

o

i-~

,!,

!
~ X
Ii ~ Ii.1 i ! .

6 6.5 7 7.5 8 8.5 9
pH

Sr

100

,

~ *~
~ i

8
~,
!

X
...

0

75

.1
50

¥~ !

25

!

!

0
6 6.5 7 7.5 8 8.5 9pH

6 6.5 7 7.5 8 8.5 9pH•

apotransferrinXtransferrin*

albuminT

lI'globulin•y·globullo

Fig. 1. Effect of pH on the binding of various elements tobovine serum proteins.

References
1) L. I. Iron and D. J. Perkins: Biochem. J. 84, 152 (1962).
2) D. C. Ross , T . J . Egan, and L. R. Purves: J. Biol. Chern.
21, 12404 (1995).
3) K. Ichimura, H. Kihara, T. Yamamura, and K. Satake:
Biochem. J. 106, 50 (1989).

RIKEN Accel. Prog. Rep. 30 (1997)

Binding Activity of Various Metallic Elements
to Blood Components
N. Sotogaku, R. Hirunuma, K. Endo, S. Enomoto, S. Ambe, and F. Ambe
Metallic ions which are absorbed into body from digestive organs are passed into blood and are transported to organs. The blood is composed of plasmaand corpuscles, both of which affect transportationof metal ions. The transport and chemical state ofmetallic ions are of basic importance in bio-inorganic
chemistry, but they have not yet been understood completely. In this work, we have studied binding activitiesof blood components for various metallic ions using themultitracer technique.
A multitracer was prepared by employing an established procedure. Fifty ml of blood was drawn fromrats and was mixed with 50 ml of a buffer solution(4.2 mM-Citrate, 8.5 mM-Sodium Citrate, 12.2 mMglucose; pH 7.4). The procedure for separation ofblood components was essentially the same as that described by Kasahara et al. l ) but was modified for asmall scale experiment. In this study, blood components used were plasma, corpuscles, and erythrocyte
ghost. One ml of the buffer solution containing themultitracer was mixed with a buffer solution (1 ml)
containing a component of blood. These samples wereincubated for 20 min at 37 °C in an incubator andwere centrifuged at 3,000rpm for 10 min. The radioactivities of sediments were determined by the ')'-rayspectrometry.
The results are given in percentage compared to a
standard. In this experiment, Be, N a, V, Mn, Fe, Co,
Zn, Ga, As , Se, Rb , Sr, Ru, Rh, and rare earth elements (REEs) were analyzed. However , the other possible elements N a, Fe , Co, Ga, As , Rb, Ru, and Rh
were not analyzed and will not be discussed in thispaper. Figure 1 shows the binding percentage of Be,
V, Mn, Zn , Se, Sr, and REEs for each component of
the blood. It is seen from Fig. 1a that the binding activity of Be, Mn, Zn , and Sr are high for the plasmacomponent. The binding assay for serum proteins invitro shows that Mn, Zn, and Sr are bound to albumin,,B-globulin, and ,),-globulin. 2 )These observations suggest that Mn (II) is bound to
the proteins in plasma. Bery lli urn is known to be a
toxic element, and its high binding affinity to serum

(b)

(a)
Be~ii···i···i· ···f·····~· ....~-·-·-~
···z
·· z
.·.·=
·.··~
...m····livi. ... ·!Iii.... .·· .
~

Ce

·~
· ··......i l···.....·.. ~

~

.

Eu

............................ -...... :':':':':':':'-i

Mn~

Gd

:.=-:~~~I
Sr~

o

25

50

75

Tm

Yb
Lu

100

o

o plasma

25

50

75

100

Binding(%)

Binding(%)•

corpsucles~

erythrocyte ghost

Fig. 1. Binding (%) of various elements to blood components. (a) Typical elements other than (b) rare earth
elements, REE.

proteins was found. 2 ) The results on Zn and Sr agreewith those reported in the literature. 3 ) On the other
hand , Se and V are highly bound to the componentof corpuscles, and the former to that of erythrocyte
ghost too. As a component of glutathione peroxidase, Se is known to reduce lipid peroxides in living
body. This element undergoes reductive metabolism
in the erythrocyte. We presume that the bindingsi te of Se to the erythrocyte ghost is the phospholipid, because the element is highly concerned withthe lipid of bio-membrane. The constitution of erythrocyte ghost is water-19.5%, protein-39.6%, glucide5.8%, and lipid-35.1 %, while the lipid consists of phospholipid and cholesterol. The REEs were mainly foundin the plasma, and binding percentages are similar to
one another (Fig. 1b).
References
1) M. Kasahara and P. C. Hinkei: Proc. Nat. Acad. Sci.
73 , 396 (1976).
2) N. Sotogaku et al.: RIKEN Accel.Prog. Rep. 30, 112(1997).
3) H. Sigel, A. Sigel, and H . G. Seiler: in Handbook on metals in clinical and analytical chemistry, (Marcel Dekker,
New York, 1994), p . 577; p. 667.

113

RIKEN Accel. Prog. Rep. 30 (1997)

Beneficial Effect of Rare Earth Elements on
the Growth of Dryopteris erythrosora
T. Ozaki , S. Enomoto, Y. Minai, S. Ambe, F. Ambe, and T. Tominaga
For a long time, most biochemists have considered
the rare earth elements (REE) to be harmful, interrupting physiological functions involving Ca antagonistically. This is mainly because of the similarities in theionic radii of Ca and REE.l) Many works to determine
the amount of REE in plants were performed recently
by chemists. 2 ) Some of them reported very high concentration of REE in plants, but they seldom pursued
their research up to biological roles of the elements. In
the present paper, we describe determination of REE
in a fern, Dryopteris erythrosora, by the instrumental
neutron activation analysis (INAA) and describe theeffect of La on the growth of Dryopteris erythrosora.
For the growth rate experiment , small sporophytes
about 2 cm high above the ground were chosen. Those
sporophytes originated from the same fern and grewnaturally on the same soil without receiving any artificial treatment. After washing with distilled water ,sterilization was conducted by immersing them in 70%(v / v) ethanol for 30 seconds followed by three rinses
in ultra-purified water. The Murashige-Skoog (MS)basal medium3 ) was used throughout this study. The
culture medium was dissolved in ultra-purified waterand the pH was adjusted to be 5.7 with 0.5-N NaOH or
0.5-N HCI. After adding 1.0% (w Iv) agar to the above
solution, we dissolved it by autoclaving for 15 min at
121°C and each 30 ml of the agar was poured into
100 ml plastic wares. A La-containing medium (hereafter referred to as a LA-medium) was prepared byadding 10 mM LaCl3 to the MS basal medium before
the pH adjustment. A Ca-containing medium (CAmedium) and a Na-containing medium (NA-medium)
were prepared in the same way. Growth condition wasmaintained as 12hr light / 12hr dark photoperiod , at alight intensity of about 10,000 lux and 25 ± 2°C. After
2 months of cultivating, the fresh weight of the samples was measured to obtain the growth rate defined
as follows: Growth rate
= Fresh weight after 2 months of cultivation/Fresh weight at the start of cultivation
Here, we define the concentration ratio as follows:
Concentration ratio= Concentration in plant/Concentration in soil
in order to make it easier to grasp the image howhighly the ferns absorb REE from the soil. Ferns in a
LA-medium for the growth experiment showed a highconcentration of La (more than 2 ppm) at the end of
the growth period. On the other hand, the concentrations of La were under detection limit (less than 10ppb) for the case of ferns in a control (MS), NA-, andCA-media. Growth rate was drastically accelerated by
114

the addition of La (Fig. 1). This strongly suggests a
beneficial effect of La on the growth of Dryopteris erythrosora. The effect is neither the same nor alternative
one of Ca because the average of growth rates of ferns
in a LA-medium exceeded the one in a CA-medium.
..c.~ 1500~..c~. ,. *•· ,

1000

c

••

~ 500
~
..c

0

~

A

2

0

B

C

D

Treatment

Fig.
1.
Growth of Dryopteris erythrosora affectedby Na(A) , Ca(B) , La(C), and control (D) , Treat. A:
MS+Na, Treat. B: MS+Ca, Treat. C: MS + La, Treat.
D: MS(control) , x Average of each treatment .

The concentrations of Ca and La measured for eachfern were plotted in Fig. 2. No correlation can beseen between the concentrations of La and Ca, suggesting different responses of the fern to REE and to Ca.
Furthermore, the concentration ratio of lighter rareearth elements sometimes exceeded 1 which was larger
than that of Ca, although Ca is an essential elements
and has many functions in plants. This also indicatesthat the sample ferns required REE for some biological
functions and absorbed REE quite aggressively.
E0..

.e

j
'0
c:

.s

i

5

U

25.0

•

20.0
15.0

••

.. •

10.0

••

5.0

~

•

•

0.0
0.00 0.25 0.50 0.75 1.00 1.25
Concenlration of Ca (%)

Fig. 2. Concentration of La vs. Ca.

A multitracer from an Au target irradiated in
RIKEN Ring Cyclotron contains many kinds of radioisotopes of REE. Application of the multitracer
technique should be useful for elucidation of the uptake mechanisms of REE and their roles in the growthof ferns.
References
1) R. J. P. Williams: Biochem. Soc. Trans. 7 , 481 (1970).
2) M. Koyama et al.: J. Radioanal. Nuel. Chern. 112, 789(1987) .
3) T. Murashige et al. : Physiol. Plant. 15, 473 (1962).

RIKEN Accel. Prog. Rep. 30 (1997)

Influence of Aluminum on the Uptake of Various Cations
from a Solution into Carrots
T. Ozaki, S. Enomoto, Y. Minai, S. Ambe, F. Ambe, and Y. Makide*
In these days, increased acidification of rain has become a serious problem, particularly for agriculture.
The dominant harmful effect caused by acidificationis thought to be exerted due to H+ ions , or otherwise A13+ ions produced more as lowering pH of thesoil. Incidentally, one of the strikingly conspicuous features of salt absorption by plant roots is the stimulatory effect of polyvalent cations, which was first reported by Viets 1 } for barley roots. This is indicativethat the A1 3+ may do harm plants not only by existence of itself but via the other ions affected by AI 3+.
. Many researchers have been trying to reveal the riddleof this effect; their interests have been in the interactions among essential or beneficial elements. This
must be caused from the background of this discovery; that is , Ca, one of the most important elementsfor plant cells, was first reported to have this scenario.
Since then, many researchers have paid their attention
only to essential or beneficial elements and not to toxic
ones. However, kinds of elements existing in the soil
are abundant , and there must be some influence of Al
on the uptake of other elements from soils into plants.
For producing multitracers, plates of gold, silver, and titanium were irradiated with the 135
MeV /nucleon 12C beam from the RIKEN Ring Cyclotron. Procedures for the preparation of multitracer
solutions from Au and Ag targets are described in Ref.
2 and 3. For Ti also will be reported elsewhere theprocedures of separation of a multitracer solution containing valuable nuclides as 28Mg or 47 Ca. The influence of Al on the uptake of Be, Na, Mg, K , Sc, Ti , V ,Mn, Fe, Co, Ni, Zn, Rb, Sr, Y , Zr, Ce, Eu, Cd, Vb, Lu,
and Hf was examined. A standard solution of AICh(O.OOlN) for atomic absorption analysis was purchasedfrom Wako-Junyaku.
Carrots (harumakigosun) were germinated andgrown at 25 ± 2 0 C on soil for 20 days. Light wasprovided by fluorescent lamps of 10000 lux with a photoperiod of 12h. The carrots which became 7 em longfrom root to top were transplanted, after washing withultra-purified water, into the aerated ultra-purified water. They were kept there before absorption of themultitracer for 3 days in order to remove the soil on
the root surfaces as much as possible. The water was

renewed every several hours. For the uptake experiments, the multitracer solution was once evaporated todryness, and the tracers were dissolved into the ultrapurified water with pH adjusted to 4.5±0.1 using O.OlN
HClonly.
.
Figure 1 shows the uptake of Be into intact roots andleaves grown in the multitracer solutions with various
concentrations of AICh. A maximum was found at theconcentration of 0.002 ppm of Al for the uptake of Be
by the root. This phenomenon may be explained as
Viets' effect. The similar effect was observed even forrare earth elements (REE). Both of these lead us to theidea that the Viets' effect is sometimes not favorable
for plants because Be and REE are toxic for plants.
Increase of the uptake into leaves was not observed for
all the elements including essential or beneficial ones,
presumably because this experiment was conducted fora short period. This suggests that the influences of Al
on the toxic element uptake may appear at different
times between roots and leaves: the former because of
the increase in harmful elements and the latter, due tothe decrease of beneficial ones.
100

---.
Ol}

--

75

~

'"-"
(L)

~

....0..

8000

Leaves

50

I

T

6000

4000

T

~

~

25

Roots

T

2000
T

0

o

§o 8 $ ~
.

0

0

0
N

o

§o § ~ ~N

0

Al Concentration (ppm)Fig. 1. Uptake of Be into roots and leaves

References
1) F. G. Viets, Jr. et al.: Plant Physiol. 19, 466 (1944).
2) S. Arnbe et al.: Anal. Sci. 7, 317 (1991).
3) S. Arnbe et al.: Chern. Lett. 1991, 149.

University of Tokyo, School of Science, Radioisotope Center

115

RIKEN Accel. Prog. Rep. 30 (1997)

Translocation and Re-distribution of Radionuclides
from the Leaf Surface in Plants
T. Watanabe, K. Matsumoto, S. Ambe, and 1. Yamaguchi
and mung bean (Phaseolus mungo L.) at the 5th leaf
stage. In order to determine their selection mechanism,a radioactive multitracer technique was used.
Ten micro liter (5 micro liter x 2) of the multitracer
selection was applied onto the central region of uppersurface of the 2nd leaf of a plant. The translocation ofradionuclides was periodically assayed by determining
the radioactivity of five fractions; the surface residueof applied site, the cuticuler layer beneath the appliedsite, the residual area outside the applied site on the
2nd leaf, the other aerial parts except the 2nd leaf, andthe roots.
The results revealed that the translocation is a sitesequential process and that a stable state distribution is reached 14 days after application, as shown in
Table 1.

The cuticle that covers the outermost surfaces of
the aerial parts of growing plants is thought to play
an important role to protect the plants against invasion by microbes and against penetration of foreign substances. Our previous study on translocationof radionuclides, performed using the multitracer,1 ,2)
showed in a couple of plants a possibility that the cuticle possesses a selection mechanism in foliar-uptakeof radionuclides and that the translocation pattern inplants can relate to an intrinsic nature of each radionuclides.
This study deals with the transcuticular translocation and re-distribution of the multitracer from leaf
surfaces in a wide range of plants like red clover (Triforium pratense L.), orchard grass (Dactylis glomerata L.), Japanese radish (Raphanus sativus L.) ,Table 1. Uptake and translocation of radionuclides 14 days after application in red clover, orchard grass,mung bean, and Japanese radish.
Accumulation in the

E ......nt~~

ResId ... OIIleafAlr1ace

P....tnion into cuticle

IlUted "'fouuid.of

non·t....ted ......

(")

(")

tilt Ipplied .ik(cr.)

Ind ".m(cr.)~. I~ _. . 76 .}CICI
Be

V
Ce
Pm

Gd

Vb
Lu

0.
Ir

72
73
64
80
75
37
81
31
33

._~ .. __... ~:2.
Mn

Sr
Sa

Hr
Sc

Zn
Co
Se

Eu
Rb

28
37
74
9
13
69

98
95
97

96
97
100
100

0
37
44
81

~

~

I

0

0

51 _._ ......1_0.0. ... .. ~ ._n..~
32
44
28
68
68
85
26
60
84
36
10
84
20
71
68
25
6S
86
62
74
9S
19
72
70
69
36
11
67

49
68
32
40

0
55
15
16
16
32
14

28
58
41

...

0

.t.s. .- . . ~ .. ~CICI

48

14
26
47

82 . .... ~~
67
44
49
72
52
39
77
72
77
69
27

12
55
10
18
61
73
10

82
3
98
22
72
19
63 . _. I~ _.
\3
6
2
32
12
48
11

~

29
35
26
28
64
72
42
58
51
42
41
28

32

30

89

o

... . ~_.. _.. ~

38
61
49
••

•

•

~ .n
35

48

19
31
32

19
11
5

0
0
54

0
-

--- ~

12
7
2

14

The radionucleides of Be*, Ca*, Y*, Te*, Ba*, Ce* ,Pm*, Gd*, Yb*, Lu*, Hf*, Os*, Ir*, and Pt* havetented to remain on the cuticle or to move within anarea close to the application site, but Sc* , Zn*, Co*,
Se*, Eu*, Rb*, and probably Cs* have easily migrated
to accumulate into various parts of the plant including roots. Mn * and Sr* were slightly ambiguous andintermediate in behavior, but possibly they are moremobile over a longer period.
The selection mechanisms at both the transcuticular uptake stage and the metabolic migration stage(apoplast-symplast transport) inside the plant tissues

116

Root(%)

33
0
0
10

0

0
42
\3
0
4
4 ... .. -. ~ ... . _.
10
45
5
31
21
8
11
56
_

0 _....

.

41
22
15
51

38

0
0
16
20
28

21

7
48
17
12
21

38
15
13
15

16

\3
29
44
17
12
56

can work in the overall process of uptake and translocation of radionuclides from the air into the plant tissues.
References
1) T. Watanabe, K. Matsumoto, S. Ambe, and I.
Yamaguchi: Proc. 32th Ann. Meeting on Radionuclides
in the Physical Science and Industry, Tokyo, July, p.
129 (1995).
2) K. Matsumoto, T. Watanabe, S. Ambe, and I.
Yamaguchi: Proc. of Nuclear Cross-Over Research International Workshop, Tokyo, 1996-2, p. 274 (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Studies on Some Parameters that May Influence the Uptakeof Radioisotopes by Plants from the Soil
S. Gouthu, T. Arie, and 1. Yamaguchi
Much research has been extended towards decreasing the radiation burden of soil using plants during
the past decade. 1 ,2) Uptake by plants or transfer coefficients of all radioisotopes are widely varying due todifferences in plant species and soil types, and manyother reasons. Also the reported uptake percentagesof many isotopes by plants are too low for the effective and fast removal of isotopes from soil. So, we attempted to test several plant species for their relative
uptake capabilities of radioisotopes under uniform laboratory conditions. Our objective is to identify whichplant species shows a general high uptake ability overothers and to explore the possibility of improving itby:A) soil amendments like varying pH conditions, nutrient mineral content, organic matter content, etc. B)
the introduction of some soilborne non-pathogenic fungal and bacterial species. This is attempted since somemicroorganisms, associated with roots of plants, are

known to absorb nutrients from the soil and supply
them to the host plants and also alter soil conditions,which in turn may augment the uptake capability ofplants.
As the first step of this project, we are now testing several plants for their relative uptake capabilities
using multitracer as the source of radioisotopes. Useof multi tracer enables us to test uptake percentagesof several isotopes at the same time under the same
conditions.
To the multitracer solution an appropriate amountof 137 Cs was added and diluted to the desired concentration with distilled water. This solution was supplied
to the soil in which seeds are sown. After thirty days ofgrowing period, the aerial plant part was taken and theuptake of radioactive isotopes of interest were detectedusing a Ge detector. So far, we have tested thirty-fiveplants and the screening is still under way. The data of
the first set of five tested plants is presented in Table 1.

Table 1. Uptake percentage of the multitracer elements and cesium from the soil by some plants.
22Na
Thrnipl)Chinese cabbage 2)
Soybean 3)
Black mungbean 4 )Maize 5)

Uptake percentage (per gram dry weight of plant)
58CO
83Rb
85Sr

6.08 ± 0.80
5.09 ± 1.08
8.76 ± 0.91
11.80 ± 1.31
0.00

0.37 ± 0.17
0.33 ± 0.22
0.01 ± 0.01
0.09 ± 0.02
0.03 ± 0.01

8.76 ± 0.91
10.14 ± 3.55
1.80 ± 0.27
3.45 ± 1.20
7.51 ± 4.63

0.66 ± 0.20
0.58 ± 0.22
0.15 ± 0.01
0.15 ± 0.13
0.13 ± 0.00

137CS
0.19 ± 0.18
0.07 ± 0.08
0.05 ± 0.01
0.04 ± 0.04
0.20 ± 0.08

Multitracer A2 (0.40 kbq) and cesium (0.93 kbq) were given to a pot containing 160 g of soil and a seed ofplant was sown.
Uptake was calculated as percentage of total amount given to each pot. The values are shown along withthe standard deviations.
1) Brassica campestris L. (capitata group) cv. Rinona (Average dry weight was 0.98 ± 0.16 g/plant)2) B. campestris L. (pekinensis group) cv. Oosaka-shirona (Average dry weight was 1.46 ± 0.36 g/plant)
3) Glycine max Merr. (Average dry weight was 3.40 ± 0.26 g/plant)
4) Vigna radiata R. Wilcz. (Average dry weight was 1.77 ± 0.05 g/plant)
5) Zea maize L (Average dry weight was 1.99 ± 0.48 g/plant)

After screening, we plan to select some plants withhigher uptake rates and proceed to the second part ofthe experiment by manipulating several soil parameters including microorganisms to further increase theuptake.

References
1) W. Kuhn, J. Handl, and P. Schuller: Health Phys. 46,
1083 (1984).
2) D. C. Lauria, I. A. Sachett, J. C. Pereira, and R. Zenaro:
J. Radioanal. Nucl. Chern., Articles 182, 91 (1994).

117

RIKEN Accel. Prog. Rep. 30 (1997)

Uptake Rate of Trace Elements by Soybean Plant
T. Shinonaga, S. Ambe, and 1. Yamaguchi
Toxic radionuclides released into atmosphere aretrapped and eventually deposited on the soil and leavesof plants. They are absorbed through roots from thesoil and directly through leaves, and are translocatedalso into the edible part of plants. Such problems ofpollution have been aggravated in these years. Concerning these problems, there are many studies not
only on the uptake of toxic elements but also on theinfluence of co-existent elements on it. In the previous
multitracer study, we demonstrated that the trace elements in the atmosphere are absorbed by the leavesof soybean plants and are translocated into the edible
parts. 1- 3 )In the present study, the uptake rate, translocation,and distribution of Sc, Mn, Co, Zn, As, Se, Rb, Sr,
Y, Tc, and Re by the soybean (Glycine max L. Merrill
cv. Okuharawase) root have been investigated using
the multitracer technique. The soybean plants were
cultivated in soil for 39 d at 26°C under exposure to17000-lux of light from fluorescent lamps for 12 h a
day in a growth chamber. After that , the multitracer
solution was added to the soil near to each soybean
plants which were further cultivated under the diurnal
condition (8000 lux, 25°C in a draft chamber). They
were harvested after 2, 6, 10, 16, 26, 42, 68 , 120, 190,
and 247-h culture. Leaves, stems and beans originatingfrom the same node were collected together.
The ,-ray measurement was performed for theroots, leaves, stems, and beans with HP-Ge detectors.
Among the elements, Rb and Tc were found to bequickly translocated into each part of a soybean plant.

118

The ,-ray intensity of 95mTc in the first leaf is shown
as a function of time in Fig. 1. The other data are
currently being analyzed.

60

~

•

40

~

~
~

a-

•

20

•

0
0

f
50

100

150

200

250

Time (h)Fig. 1. Uptake of 95mTc by the first leaf of soybean plants
during 2 to 247 h .

,References
1) T. Shinonaga and S. Ambe: \\Tater , Air, and Soil Poll. ,in press.
2) T. Shinonaga, S. Ambe , S. Enomoto, H. Maeda, M.
Iwamoto, T. Watanabe , and 1. Yamaguchi: J. Radioanal. Nucl. Chern., Lett. 212 , 163 (1996).
3) T. Shinonaga, S. Arnbe , T. Watanabe , and 1. Yamaguchi: RIKEN Rev. No. 13, p. 19 (1996) .

RIKEN Accel. Prog. Rep. 30 (1997)

Multitracer Studies on the Extraction of Noble Metals with
N,N-Dialkyl Aliphatic Amides from Nitric Acid Solutions
N. Ito, Y. Saito, K. Kimura, H. Narita,* T. Yaita,**
S. Tachimori,** S. Ambe, and F. Ambe
Distribution ratios of noble metals with N ,N-dialkyl
aliphatic amides from nitric acid solutions were determined by using a fraction of multitracer solutions.
Multitracer solutions were prepared from an irradiatedsilver or gold target l - 3 ) by removing the target metal.
A platinum group and oxoacid-forming metal fraction
separated from other cation elements by cation exchange column (Dowex 50W-X8 100- 200 mesh) wasused for the extraction studies.
N ,N-dialkyl aliphatic amides are known to be good
extractants of some actinides such as U, Pu, and Th.4)
Moreover, their stability is better than that of Tri-nbutyl phosphate (TBP) , and their degradation products do not interfere unlike those of TBP. Therefore,
amides were expected as alternative extract ants to
TBP in the reprocessing of nuclear fuels. Our investigation was carried out with 5 ami des of different alkyl
and aliphatic substituents focusing of fission produced
noble metals such as Ru and Rh.
The amides of different structures used are:N,N-n-dioctyl butyramide (DNOBA) , N ,N-n-dioctyl
hexanamide (DNOHA) , N,N-n-dioctyl octanamide(DNOOA), N,N-dihexyl octanamide (DROA), andN,N-dibutyl octanamide (DBOA). Concentration ofamides was chosen 1 mol·dm- 3 in a diluent of dodecane close to the molarity of 30% TBP.
Extraction was carried out at certain acidities of nitric acid, 1, 1.5, 2, 3, 4, 5, 6, 7 mol·dm- 3 . These acidsolutions containing the multitracer were shaken withthe same volume of the solvent solution for 10 minutes
by using a mixer. After centrifugation, the distribution ratio was determined by ,-ray spectrometry forboth organic and aqueous phases.
The distribution ratios with TBP has decreased withincreasing acidity of nitric acid, whereas those withamides showed relatively flat acid dependence, but increased with decreasing in carbon numbers of alkyl
group substituent.
A slope analysis of DNOOA and TBP solvent con-centration dependent distribution ratio was carried out
to obtain the solvation number and to compare it eachother. Figure 1 shows the distributionratios of the noble metals in 3 mol·dm- 3 HN0 3 as a function of the
DNOOA concentration. The slopes are 1- 2 for theplatinum group metals such as Ru, Rh, Ir, and Pt, and2- 3 for the Tc and Re. These results were quite similar to those of TBP, suggesting very similar extraction
mechanisms each other.

10

1.9 10°~ lO'l

E

I

r

0

r
::; 10'2

0

=
.9

r

.D

"5
rJl

i:5

lO,3

r

10-1 ~

lO'l

0
0

B

;

[II)

~

Ii

A

•
B

0

o·
•

•

66
111111

Q

~~

0

Ii

..,

Slope:

..,
0
III
0

Tc-96
- 2.9
. ..... 1.3
Ru-97
Rh-lOlm .. ..... I.S...····l.S•• Ir-18S.... I.S
Pt-188

Re-183

Ii

6···· 2.7

.

.,

.,

I

10°

10 1

Concentration of DNOOA (mol.dm,3)Fig. 1. Distribution as a function of DNOOA concentration.

References
1) S. Ambe, S. Y. Chen, Y. Ohkubo, Y. Kobayashi, M.
Iwamoto, M. Yanokura, and F. Ambe: Anal. Sci. 7,
Suppl. , 317 (1991).
2) S. Ambe, S. Y. Chen, Y. Ohkubo, Y. Kobayashi, M.
Iwamoto, M. Yanokura, and F. Ambe: Chern. Lett.
1991, 149.

3) S. Ambe, S. Y. Chen, Y. Ohkubo, Y. Kobayashi, H.
Maeda, M. Iwamoto, M. Yanokura, N. Takematsu, and
F . Ambe: J. Radioanal. Nucl. Chern., Articles 195, 297(1995) .
4) G. M. Gasparini and G. Grossi: Sep. Sci. Technol. 15,825 (1980).

Faculty of Science, Ibaraki University
Japan Atomic Energy Research Institute (JAERI)

119

RIKEN Accel. Prog. Rep. 30 (1997)

Separation of a Multitracer from the Gold Target Irradiatedwith High-Energy Heavy Ions by Means ofa Supported Liquid Membrane t
S. Ambe, M. Iwamoto, H. Maeda, and F. Ambe
The transport of Au(III) and other ions througha tributyl phosphate (TBP)/decalin membrane supported on a microporous polytetrafluoroethylene sheet
was studied in order to establish a procedure for removing Au (III) ions from acid solutions of a gold target
irradiated by high-energy heavy ions, leaving a multitracer solution in a carrier- and salt-free state.
. Permeation was carried out under various conditions
by changing the kind of the stripping solution, the concentrations of Hel and HN0 3 in feed solutions, andthe concentration of TBP in the membrane. Figure 1
shows the transport of Au(III) ions from feed solutionsof various concentrations of HeI. A feed solution of 3
mol dm -3 Hel gave the highest transport rate, though
the difference in the initial transport rates was small
among the Hel feed solutions in the 1- 6 mol dm- 3
concentration range. More than 90% of the Au(III)ions were transported to the stripping solution within
100 min. The permeability coefficient was 3 x 10- 3
cm s-1 for Au (III) in the 6 mol dm- 3 HeI. On theother hand, the initial transport rates of Au(III) fromfeed solutions of 0.1 and 8 mol dm- 3 Hel were smaller
than those described above, though the transport fromthese two feed solutions was observed to increase with
time.
100

:A~~!8~DSll~

:O~D

~80
'0

• ABc

~60
a.

A

<II

CD

::J

•

c

• • •

•

:e •

II)

c

e

~40
A
0

c(

8

••

•

20

lie
Vi)

50

100

150

200

l00~----------------~

"0

200

400
600
Time/min800

Fig. 2. Transport of Au(III) ions from the feed solutions of
0.2 (0), 1 (.6), and 2 (0) mol dm - 3 HN0 3 to distilledwater through a membrane with a TBP /decalin ratioof 0.27.
efficient of Au (III) ions from the solutions was determined to be 7 x 10- 4 cm S-l.
As described above, Au (III) ions can be transported
from both HCI and HN0 3 feed solutions. Therefore,
permeation from an aqua-regia solution was examinedas the final practical procedure. In this case, 4.8 gof Au target was dissolved in 20 cm 3 of aqua regia.
This solution was used for permeation after its dilution with distilled water to 100 cm 3 . In order to avoid
saturation, permeation was carried out with a continuous supply of fresh distilled water to the strippingsolution compartment at a rate of 2 cm 3 min -1. Figure 3 shows the decrease of Au (III) in the feed solution
with the permeation time. About 99% of the Au (III)ions were removed from the feed solution within 70 h.
Only the peaks due to radioactive Au were detected in
the stripping solution, showing selective permeation of
the Au (III) ions.

250

Time/minFig. 1. The transport of Au (III) ions from the feed solutionsof 0.1 (*), 1 (0),3 (+), 5 (0),6 (.6), and 8 (e) mol
dm -3 HCI to the distilled water through a membranewith a TBP /decalin ratio of 0.27.
oFigure 2 shows the transport of Au (III) ions fromfeed solutions of 0.2, 1, and 2 mol dm- 3 HN0 3 . It was
found that the acid concentration of the feed solutions
only slightly influenced the initial rates of the transport of Au (III) ions. However, the transport reachedsaturation after 70, 80, and 90% of Au (III) ions had
been transported from feed solutions of 2, 1, and 0.2
mol dm- 3 HN0 3 , respectively. The permeability coCondensed from the article in Anal. Sci. 12, 219 (1996)

120ooL-~~~~_o~~~~~
o

20

40
Time (h)6080Fig. 3. Transport of Au(III) ions (4.8 g) from the feedsolution of 1.8 mol dm -3 in Hel and 0.7 mol dm -3 in
HN0 3 to the distilled water through a membrane witha TBP / decalin ratio of 1.

RIKEN Accel. Prog. Rep. 30 (1997)

Multitracer Study for the Effect of Humate Formation on the
Adsorption Behavior of Metal Ions on Kaolinite and Silica Gelt
Y. Takahashi, Y. Minai, T. Ozaki, S. Ambe, M. Iwamoto,
H. Maeda, F. Ambe, and T. Tominaga
Environmental behavior of the trace elements inlithosphere and hydrosphere is affected by various
physicochemical processes. In particular, hydrolysis
and adsorption on minerals are of primary importancein understanding their environmental behavior. 1) In
addition, humic substance may also be important, because it can form stable complexes with metal ions.2 )It is likely that the adsorption, hydrolysis, and humate
formation compete for the metal ion behavior in theenvironment. In present work, we report applicationof the multitracer technique to the study of adsorption
behavior of 16 trace elements on kaolinite and silica gel.
Distribution of the humic acid between the aqueous and solid phases at various pH values is shown in
Fig. 1 by solid line. Photopeaks in the l'-ray spectra
were assigned for 16 elements based on the analysis ofl'-ray energy and its half-life. In Fig. 1 also shows thefractions of Ce, Re, Ba, Pt , and Hf remaining in thesolution in contact with kaolinite. The adsorption behavior of Ce, Re, Ba, and Pt on silica gel was similar
to their adsorption behavior on kaolinite. Based on
the plot of dissolved fractions of humic acid and eachtrace element, the 16 elements can be classified into
four groups by their distribution behavior, as follows.
(1) The distributions of Ce [Fig. l(a) ] between the(b) Re

1

3

5

7

pH

o

o
0
O<l>

o·

o

aqueous and solid phases were identical to that of humic acid at 3 < pH < 10. Similar results were also obtained for other rare earth elements such as Y, Eu, Gd,
Tb , Yb, and Lu. This implies that most of those elements distributed in the solution and on the surface ofkaolinite or silica gel are present as humate complexes.
Larger amount of rare earth elements was dissolvedin contact with silica gel than with kaolinite due tothe higher affinity of kaolinite than silica gel with thehumic acid. The distribution behavior of humic acidmay be a decisive factor controlling the distribution of
those elements between mineral surface and water inthe environment.
(2) The dissolved fractions of Rb, As, and Re[Fig. 1 (b) 1 were not influenced by the addition of thehumic acid. This indicates that humate formation of
those elements did not affect the adsorption behavior. These elements were adsorbed neither on kaolinite
nor on silica gel in the absence of the humic acid. It
is likely that free Rb ion and oxo-anions of As and Re
were the dissolved species in the aqueous phase. Abundances of Rb, As, and Re in seawater, 3) compared withthose of the elements classified into the other groups
in this work, were reported to be higher than thosein the earth's crust. 4 ) It suggests that those elements
are not scavenged onto the surface of minerals which isin contact with seawater. The experimental results inthis work agree with the adsorption behavior of thoseelements estimated from their geochemistry.
(3) The fractions of dissolved Ba, Sr, Co [Fig. 1 (c)],and Pt [Fig. l(d)] increased with the addition of the humic acid in the neutral pH region. However, dissolved
fractions of these elements were not identical to that of
the humic acid. This implies that both the other complex formation (hydrolysis and carbonate formation)and humate formation affect the adsorption behavior of these elements. Distribution pattern of alkaline
earth elements (Sr and Ba) was identical to each other.
For summary, the humate formation affects, to somedegree, their adsorption behavior in the environment.

·t ••••
5

7

pIf

I

11

13

1

3

5

7

9

11

13

pIf

Fig. 1. Dissolved fraction of the tracer [(a )Ce, (b )Re,(c)Ba, and (d)Pt] or the humic acid when the aqueous phase (5 ml) was in contact with kaolinite (10 mg).
Open circles: the tracer with humic acid, closed triangles: the tracer without humic acid, solid line: thehumic acid whose initial concentration was 30 mg/l.
Condensed from the article in J. Radioanal. Nucl. Chern.
205, 255 (1996).

References
1) M. Whitfield et al.: Nature 278, 132 (1979).
2) F. J. Stevenson: in Humus Chemistry (John Wiley andSons, New York, 1982).
3) J. P . Riley et aI.: in Chemical Oceanography, 2nd edit.
(Academic, London, 1975).
4) S. R. Tayler: Geochim. Cosmochim. Acta 28, 1273
(1964).
5) C. F. Baes, Jr. et al.: in The Hydrolysis of Cations(Wiley, New York, 1976).

121

RIKEN Accel. Prog. Rep. 30 (1997)

Model Study of Acid Rain Effect on Adsorption ofTrace Elements on Soils (I)
H. Wang, S. Ambe, N. Takematsu, and F. Ambe
As a worldwide problem, acid rainfall (pH < 5.6) has
drawn much attention of society and researchers. 1) One
serious effect caused by the acid rain is a disturbanceof the adsorption equilibrium of elements in the soil,
because the mobility and bioavailability of elements inthe soil play an important role in the process of element
uptake by plant. Therefore, it is essential to improve
our knowledge of this process. Using a multitracer
technique, effect of model acid rains on the adsorptionof 11 trace elements on kaolin and soil was investigated.
Kaolin (the mineral composition is ca. 100% kaolinite [AhSi 2 0 5 (OH) 4]) and Kureha soil (the particle
size is < 2 mm) were used as the adsorbents. Distilled water and rain water collected in RIKEN wereacidified with H 2 S0 4 and used as simulated acid rains(pH 1.8-5.6). A multitracer (Be, Sc, Mn, Fe, Co,
Zn, Se, Rb, Sr, Y, and Zr) was produced by the
RIKEN Ring Cyclotron. It was stored as a 10- 3 M
H 2 S0 4 solution. Triplicate samples of the adsorbent
with the model acid rain water containing the multitracer solution were shaken at room temperature. The
solid/liquid ratio was 30 mg/ml. The pH value wasadjusted with H 2 S0 4 or NaOH whenever necessary.
After equilibrium, the mixture was separated by centrifugation. The supernatants were analyzed for pH
value by a pH-meter and an aliquot of the supernatantsolution was subjected to the ,),-ray spectrum measurement by a HPGe detector. Subsequently, the adsorption percentage of each trace element was calculated bycomparing the ,),-ray intensities at a given energy before and after the adsorption, with correction for the
decay.
Based on kinetic results, the equilibration period waschosen to be 3 days for kaolin/H 2 S0 4 solution system,
4 days for a kaolin/rain water system, and 6 days fora Kureha soil/H 2 S0 4 solution system.
Figure 1 shows the adsorption percentages of sometrace elements on kaolin from two kinds of model acidrain water. Adsorption increases continuously with pH
values, except for the anionic Se which shows uniqueadsorption behavior. Adsorption of Be, Mn, Co, Zn,
and Sr increases sharply in the pH range 3.0-4.0. At
pH < 3.0, their adsorption is low. And at pH > 5.0,
their adsorption percentages are almost 100%, except
for Mn (ca. 90%). Adsorption of Y increases graduallywith pH value, and reaches 100% at pH 4.0. The elements Fe, Sc, and Zr give high adsorption yields evenin the acidic pH range, amounting to almost 100% at

122

rJ-U

100

Be

~

75

s:1

Se
75

R

0

'a

e0

50

50

"'0
~

25

25

r.f)

0

0
1
100

~
Q

2

75

~

50

"'0
~

25

r.f)

I

4

5

~

q

o

0

1

2

3

4

~
A

50

g

25

0

pH

4

5

6

1

2

6

..

..

0

.

0
3

5

o gj

Rb
75

g

2

0
(

100

~

1

0

~

0

6

.,-'

y

0

'a

~
3

...... ..

100

~

3

4

5

6

pH

Fig. 1. pH effect of the model acid rains on the adsorption of trace elements on kaolin. Open circles: H 2 S0 4
solution; and triangles: rain water.

pH 4.0. Adsorption percentage of Se in the H 2 S0 4
solution is roughly constant over the pH range studied,while the adsorption percentage in the rain water ismuch higher at pH > 3.0.
There is no significant difference in the cationic ion
adsorption between the two kinds of acid rain water.
However, a large difference in the adsorption behaviorof Se was found between the two model acid rains.
Except for Rb and Se, the adsorption behavior of
the metal ions from the H 2 S0 4 solution on Kureha
soil is similar to that on kaolin. For Rb, the increaseof adsorption on the soil with respect to pH is smaller
than that on kaolin. A large difference between the soil
and kaolin appears in the adsorption of Se. Adsorption
percentage is about 90% below pH 5.0, and decreases
slowly above pH 5.0.
We are able to conclude that the adsorption
percentage-pH relationship depends strongly on thenatures of the element and of the adsorbent. Acid rain
reduces the retention of various cationic elements inthe soil. This results in a loss of trace elements in thesoil and an enrichment of trace elements in the groundwater.
References
1) A. R. Bowers et aL: Water, Air and Soil Pollution 32,
129 (1987).

RIKEN Accel. Prog. Rep. 30 (1997)

Model Study of Acid Rain Effect on Adsorption ofTrace Elements on Soils (II)H. Wang, S. Ambe, N. Takematsu, and F. Ambe
As presented in the preceding paper, acid rain has
significant effect on the adsorption of various elements
on kaolin and soil. The adsorption behavior of traceelements can influence the availability of ions to plants.
The soil is a very complicated system, which is mainlycomposed of aluminosiliceous materials , oxides, andhumic substances. The nature of soil and the chemical
properties of elements decide the adsorption behavior of various elements. Therefore, it is very important to know the adsorption process in detail. Usinga radioactive multitracer technique, batch experiments
have been performed to study the acid rain effect onelement adsorption by soils and by the soils without
organic matters or oxides.
A radioactive multitracer (Be, Sc, Mn, Fe, Co, Zn,
As, Se, Rb , Sr, Y , Zr, Tc, Ru, Rh, and Re) was
dissolved in solutions of different HCI concentration(pH 1.9- 5.6) selected as the model acid rain. Sevensoils (Kureha soil, Black soil, :Forest soil, Kureha soil
without oxides, Forest soil without oxides, Kureha
soil without organic matters, and Black soil without
organic matters) were employed as the adsorbents.
These soil samples were air-dried and sieved to obtain the aggregates smaller than 0.15 mm in diameter.
Three hundred mg of soil was suspended in 10 ml of
the model acid rain containing the multitracer. Triplicate samples were equilibrated for 96 hours at room
temperature. Suspension pH value was adjusted whennecessary with HCI or NaOH solutions. The further
experimental procedure is similar to that described in
the preceding paper.
The pH effect of model acid rain on the adsorptionof some trace elements on K ureha soils is shown in
Fig. 1. The adsorption of almost all elements studied
here are strongly dependent on the pH value. The adsorption trends of each element on different soils are
similar. The experimental results indicate that the oxides of K ureha soil do not affect the adsorption of Be,
As, Co, Zn, Zr, Tc, and Re over the pH range studied. If oxide components were removed, the adsorption
percentages of Rb , Sr and Sc are higher and those of
Fe and Se are lower than those on the original soil inthe whole pH range. On Kureha soil and that without organic matters, the adsorption of Be, As, Se, Zr,
Ru, and Rh is similar. However, the removal of or-

~

100

c

75

e.

50

.2
0
rn

"0

«

~
c
0

';:l

e?;;

o

.~

25

•

6

i:
•

~

25

25

5 6

50

0

As
1 2 3 4

100

e.

o

25

«

0

5 6

o

0

6

6••

u v

6

~.

0
rn

6

•

Rb
1

1

2 3

1

4 5 6

75

0..
I-.

50

?;;

25

«

0

0

Se

1000
I

0

75

4 5 6

o.

6

•

25
0

2 3

1

Y
1

4 5 6

2 3

a~

75 Ru
100

25
.

5 6

0

0

•

0

6

50
S

4

~Ja M6oa50~ l°°Dc
.2
"0

1 2 3

50

50

c

0

75

75

"0

Fe

lOOD
1 2 3 4

75

c

,2

8 0

50

100

0

0

75

25

"0

«

lOOD
6

Mn

o
6

Ai

0
123 456

O~~~~~~~

pHpH

123 456

Fig. 1. The pH effect of model acid rain on the adsorptionof trace elements on Kureha soils. Triangles: Kureha
soil; Circles: Kureha soil without oxides; filled rhombuses: Kureha soil without organic matters.

ganic matters from K ureha soil made the adsorption
percentage of the other elements much lower than thatin the original soil. The removal of oxides from Forest soil made the adsorption percentage of Mn and Fe
higher. However, there is no difference on adsorptionof the other elements. The adsorption of elements on
Black soils was similar to that on Kureha soils.
The adsorption of each trace element on different
soils has similar trend, but the adsorption percentage
on different soils is various, because the mineral andchemical properties of these soils are different.

123

RIKEN Accel. Prog. Rep. 30 (1997)

Linear Momentum Transfer in the Heavy-Ion Reactionsat Intermediate Energies
A. Yokoyama, K. Mukai, S. Morimoto, T. Saito, H. Baba, Y. Ohkubo,
A. Shinohara, T. Muroyama, S. Kojima, and M. Furukawa
Fusion reaction has been of much interest for many
years because it is predominant in the low-energy
heavy-ion reaction, and it accompanies a drastic rearrangement of nucleons in a nucleus especially for theheavy ion reaction. As the incident energy increases,
the completeness of fusion reaction decreases and theincomplete fusion reaction becomes more important.
The systematics of linear momentum transfer vs. incident energy1) has been proposed for the incomplete
fusion. But the mechanism and the factors controllingincompleteness are still an open question. Therefore,
we like to investigate how an incomplete fusion develops according to the increase of incident energy andwhat kind of factor contributes to the mechanism.
The nuclear systems studied are 14N+ 165 Ho and
40 Ar+141 Pr at intermediate energies. We measured recoil momenta of the nuclides identified in experiments
by using not only a thick-target-thick-catcher technique but also an angular distribution measurement.
We obtained the momenta from the recoil ranges determined in the former experiment and from a fit to the
angular distribution by using Monte Carlo calculations
with the recoil velocity as a free parameter.
Examples of the obtained recoil velocities and the recoil momenta are listed in Tables 1 and 2. The resultsfrom the thick-target-thick-catcher method are shownin Table 1, while those from the angular distribution
measurement are shown in Table 2. Both results exhibit a similar tendency that the momentum decreases
as the product mass increases or as the incident energy
increases in each combination of target and projectile.
However, the absolute values obtained from the two
methods are rather different from each other. Because
complete fusion or nearly complete fusion are expected
to show a forward peaking distribution, the component from such mechanism is lost to some extent for
Table 1. Recoil velocities and recoil momenta obtained
from the thick-target-thick-catcher method.
System(Projectile energy)
14N+165Ho

Nuclideproduced,811

16OHoTn(35 MeV jnucleon)

106AgTn

0.006
0.018

PII
(GeV jc)
0.98
1.9

14N+165Ho

16OHoTn(70 MeV jnucleon)

106 AgTn

0.0037
0.015

0.60
1.6

40 Ar+141Pr

139NdTn
1111n9

0.011
0.019

1.4
1.9

(25 MeV jnucleon)

124

the measurement of angular distribution. But we canassume that the incomplete fusion process is predominant as a whole as the energy increases, because we
obtained a similar tendency from either one of the two
experiments.
Table 2. Recoil velocities and recoil momenta obtained
from the angular distribution measurement.
System(Projectile energy)
14N+165Ho(35 MeV jnucleon)

Nuclideproduced
160Er
1111n90.00220.0072PII(GeV jc)
0.33
0.74

14N+165Ho(70 MeV jnucleon)

160Er
11°1nTn

0.00150.00620.23
0.63

40 Ar+141Pr(25 MeV jnucleon)

138PrTn
1111n90.00260.0052

0.34
0.54

,811

In Table 3, we compare the ratios of average momenta to Pen , the momenta for the case of full momentum transfer, with the calculated values by a sum
rule mode1. 2 ) The model applies well to the incomplete
fusion process and takes into consideration the characteristics of projectile such as Q values of the reaction
and the difference of Coulomb energies at the entrance
and exit channels. The calculated value reproduces thetrend of the observed data in relation to the productmass. This means that the projectile dependence is important in the incomplete fusion reaction, that is, thecharacteristics of projectile should be taken into consideration as an important factor in the systematics of
the incompleteness.
Table 3. Comparison of averaged recoil momenta withmodel calculation.
System(Projectile energy)
14N+165Ho< P II >jPcn
Measured
0.49±0.06

Modelcalculation
0.16

0.19±0.02

0.086(35 MeV jnucleon)
40 Ar+141Pr(25 MeV jnucleon)

References
1) S. Leray: J. Phys. Colloq. 47, C4-275 (1986).
2) J. Wilczynski et al.: Nucl. Phys. A 373, 109 (1982).

RIKEN Accel. Prog. Rep. 30 (1997)

Preparation of Positron Emitter Sources for Slow Positron
Generation by the Bombardment of a Liquid or Gas Target
T. Nozaki, Y. Itoh, P. Zi-Lin, Y. Ito, N. Nakanishi, H. Yoshida, * and A. Goto
Slow positron beams are becoming more useful. It
is highly desirable that the available intensities be increased. The two approaches for achieving higher intensities of slow positrons are: (1) to increase moderator efficiencies, and (2) to generate higher intensities
of fast positrons. For the latter approach, the activation of gas and liquid targets appears to have several
advantages over that of solid targets. We thus intend
to develop an automated system for handling gas andliquid targets. The gas or liquid target will be activated, and the product positron emitter collected on asmall spot.
The technology for handling the isotopes commonlyused in positron emission tomography (PET) has been
well developed. The most common nuclides in use for
PET are l1C (t 1/ 2 = 24.4 m), ISO (t1/2 = 122 s),
and 1BF(t1/ 2 = 110 m). All are pure f3+ emitters,
and are produced routinely in hospitals by compact cyclotrons, using automated RI handling methods. 1) Nitrogen gas target is bombarded by proton or deuteronto give either l1e by the 14N(p,a)l1e reaction or ISO
by the 14N(d,n)lSO reaction. The activated products
are transferred together with the target gas to theplace where they are used. On the other hand, the1BO(p,n)lBF reaction using an lBO-enriched water target is presently the best method for 1BF production.
The yield is about 6 GBq/mA (thick target saturation activity for 15 MeV protons), which is higher thanmost other reactions easily accessible. The H 2 1B O containing 1BF is forced to pass through a fine tube andtransported into another room, where the 1BF is separated from the H 2 1B O which is then returned to thetarget chamber.
In the synthesis of l1C-Iabeled organic compounds,
the 11 CO 2 which is formed spontaneously by the reaction of the l1e with impurity oxygen is often preconcentrated by its adsorption on molecular sieves oron liquid nitrogen-cooled substrates. For 1BF, either
the distillation of H 2 1B O or the trapping of 18F on ananion exchange membrane filter is used for its separation from the H 218 0. For our purposes it will benecessary to modify these methods slightly.
We have designed an automated apparatus for
preparing the 1BF positron ((3+) source, which is shownin Fig. 1.

Proton beame+ beam~~~~:..-=solenoid coil

Ion Exchanger
Glass filter

Filtration assembly

CD Filtrationoo

180 deg Rotation
Push up and fix to the 18F source

Fig. l. Automated apparatus for preparing the 18F
positron (13+) source.

References
1) H. N. Wagne: in Principles of Nuclear Medicine, 2ndedit. , (W. B. Sanders, Philadelphia, 1995) p. 135 (chapters 10 and 11).

The Japan Steel Works, Ltd.

125

RIKEN Accel. Prog. Rep. 30 (1997)

Measurement of Spin Polarization of Positron BeamT. Shimosaka, Y. Itoh, S. Mori, N. Nakanishi, A. Goto, M. Kase, and Y. Ito
From the viewpoint of analytical methods, the polarized slow positron beam can be expected to becomea new probe for the surface characterization of materials such as surface magnetism,l) Fermi level of themagnetic material, etc. We have been developing slow
positron beams from the various radioisotopes produced by RIKEN AVF cyclotron. We are now planning
to measure the spin polarization.
The positron beam emitted from a {3+ decay process
is polarized toward the direction of emission becauseof the parity non-conservation. The polarization, P,
depends on the velocity of positron, v:

Accelaratore+~~, ~~,'~IIIIIIIIIIIQ~~~~~~Start~~l ~ ~/~~'------~l'-------'

tim e{ ns l

P = (lvi/c) cos 0,,

where 0 is the angle between the vector v and thequantization axis of polarity.
The measurement is based on the mixing, in themagnetic field, of m = 0 states of para and ortho
positroniums, whose spin direction is anti-parallel (singlet: 'lI s) and parallel (triplet: 'lit) for the electrons and positrons, respectively. The mixing resultschanges in their lifetime and intensity.2,3) The experimental setup is shown in Fig. 1. When polarized slow
positrons hit the micro channel plate (MCP) , they arethermalized in it, and the MCP gives a start signal to
the time-to-amplitude converter (TAC). The thermalized positrons form the para and ortho positroniums.
Under the magnetic field , 'lis and 'lit are perturbed toform two mixed states,
w~ = {yWs + w t (O)}/(l + y2)1 / 2
w~ = {ws - yW t (O)}/(l + y2)1/2 ,~I ~__ _~~I---+

o

35.75

z(cm)

Fig. 1. Outline of the equipments for positron polarization
measurement. Positrons come from the left hand side,
hit the MCP, and make positroniums . The z-axis iscommon with Fig. 2.

approximately 5% for the positron beam whose polarization is unity at incidence. This amount is negligible.
Therefore, we shall be able to obt ain the polarizationfrom the annihilat ion measurement.

1.1

~
!II

c:

0 1.15 ~

~

'iii

0
Il.

....

where

0 1

c:

y = x/{l + (1 + x2)1/2},0;;x = O.0276B (where B in kGauss).

-.::: 0.95 ~
CIS

CIS

N

'0

The lifetime distribution of these perturbed states aredescribed as,

Il.

(

0.9 t
0

where A is the annihilation rate of non-perturbed
triplet states, A' is that of the perturbed state w~ , anda is the angle between the magnetic field and the quantization axis. Positron polarization (P) is obtained
from the intensity of TAC or the lifetime of A' , which
will be measured by the equipment shown in Fig. 1.
We checked a decrease of the polarization inside theequipment by a simulator POEM made by Kumita et
a1. 3) Its result is presented in Fig. 2. The decrease was

126

5

10

15

20

25

30

35

40

Z(cm)

dN(t)/dt = N/4[2Aexp(-At)+ (1 - cP cos a)\' exp( -A't)],iI

Fig. 2. Result of the simulation for positron beam polarization along z-axis inside the magnetic channel.

References
1) D. Gidley, A. R. Koymen , and T. W. Capehart : Phys.
Rev. Lett. 49, 1779 (1982).
2) P . W. Zitzewitz, J. C . Van House, A. Rich , and D. W.
Gidley: Phys. Rev. Lett. 43 , 1281 (1979).
3) T. Kumita et al.: Appl. Sur. Sci. in press.

4. Radiation Chemistry and Radiation Biology

RIKEN Aced. Prog. Rep. 30 (1997) .

An Effective Mutation Method for Plants Using Heavy-Ion Beams
T. Abe, C.-H. Bae, and S. YoshidaIn the previous paper,l) we have reported that thefertilization cycle of plants is very sensitive to the irradiation of heavy-ion beams. In the present paper, tobacco embryos were irradiated with heavy-ion beams
immediately after the pollination to obtain a high frequency mutation. And this new technique subjectedto screening of salt-tolerant mutants.
Tobacco plants were grown for this experiment in agreen house under 18-hours photoperiod at 25 to 30°C
for 3 to 4 months in the flowering period. After 24 to
108 hors of pollination, intact embryos in the flowers
were irradiated with 10 to 200 [gray] of dose by heavyion beams 4 N or 2oNe: 135 MeV /u). LET of the N
and Ne ion corresponded to 28.5 and 63.0 KeV / J-Lm ,respectively. One month after the irradiation, seedsof M1 generation were harvested. The treated plants
were cultivated in a green house and the resulting M1
seeds were harvested one month after the treatment.
The Ml seeds were germinated in the 1/2 MS medium
at 25°C under continuous light. Two weeks later,morphologically abnormal plants were planted in plastic trays containing soil, and were placed in a growthcabinet under 12-hours photoperiod at 25 °C . After
two weeks, the shapes of Ml abnormal plants were observed. M1 seeds of Xanthi (3,098) and BY-4 (7,257)
were placed on the 1/2 MS medium containing 2.5%
and 2.0% of NaCI, respectively, and were incubatedfor 4 weeks. Putatively salt-tolerant seedlings germinated under saline condition were selected and planted
in soil.
High irradiation dose caused a decrease in the germination percentage (Fig. 1). The highest rate of abnormal plants at 24 to 48 hours of treatment stage after
pollination was 8.3% with Ne ion and 18.1% with Neion in Xanthi, respectively (Fig. 2). However, there isno peak in the mutation rate for BY-4. A total of 17
putatively salt-tolerant plants were selected from BY4, whereas no salt tolerant progeny was obtained from
. Xanthi (Table 1). Shapes of the filament and pollen
grain of salt-tolerant plants were abnormal comparedwith the control, and both the seed weight and fertility
rate obviously decreased. One cell line induced fromthe three salt-tolerant seedlings indicated a salt tolerance. The cell growth and chlorophyll content werehigher than those of control (wild type) in the medium
containing NaCI. Above work shows that the sensitivity of plant embryos to this irradiation technique mayvary by species or even by cultivars.
2~--------------------~

24-48

48-72

72-96

96-108Treatment stage (bour)

Fig. 2. Effects of embryo treatment with ion beams at
different developmental stages on frequency of morphologically abnormal plants. eN ion for Xanthij oNe ion
for Xanthi j .N ion for BY-4; oNe ion for BY-4.

Table 1. Effect of heavy ion beams on the seed germinationof tobacco embryos under salt conditions .

• •Cultivar
Xanlhi

Ion
N

~
c:

Stage (hr)control
36 - 48
60 -7284 - 96
tOlal

Seed no.
413
277
30
367
674

Survival no.
0
0
0
0
0

Survival (%)
0
0
0
0
0

48-60
72-84
total
conlrol
24 - 60
60 - 72
84-96
total

1151
104
2424
723
855
246
1664
2765

0
0
0
0
9
5
3
17

0
0
0
0
1.05
2.03
0.18
0.6 I

3158

0
0
0

0
0
0

···Ne··········-36-:4S·················ii·iii·········· ·········-0-···············-0-····

.S!
~

c:

's...

Q,I

BY-4

~

N

25
0

I

···Ne······· ····j6-~-4-8-· ······ ·· ····· ··ii8i····· ··········· ··· ·- 0-····· ··· ·· ·· ··· ·0-·····

0

0

0

50

48 - 60

100

ISO

200

72-~

250

total

I~

4492

Dose (gray)Fig. 1. Effects of embryo treatment with ion beams at
different developmental stages on seed germination. eN
ion for Xanthi; oNe ion for Xanthi ; .N ion for BY-4;
oNe ion for BY-4.

References
1) T. Abe et al.: in Modification of Gene Expression andNon-mendelian Inheritance, ed. by K. Gono and F.
Takaiwa (NIAR, Japan , 1995) p. 469.
127

RIKEN Accel. Prog. Rep. 30 (1997)

Physical Characteristics of Irradiation Field for Proton Radiotherapy
A. Higashi, T. Kanai, H. Tomura, Y. Futami, N. Matsufuji, and F. Yatagai
We have studied physical characteristics of irradiation field using the proton beam produced at RIKEN
Ring Cyclotron (RRC) facility. Proton therapy, amethod of radiotherapy, has already started at several facilities. Their proton beam gantries have about
one third of the source axis distance (SAD, distance
between scatterer and isocenter) of the fixed port intheir facilities. Therefore, data of physical characteristics obtainable with such fixed port are insufficient for
designing the proton gantries. Problems are as follows:when passing through both the irradiation system andhuman tissue, the proton beam has a scattering angle
larger than the case of heavy ions because of its lighter
mass. Further, a gantry with a short SAD causes alarge scattering angle. For this case, if parametersof devices in proton gantry are slightly changed, bothflatness of irradiation field and depth-dose distribution
will become worse than the case of carbon beam. One
purpose of our experiment is, therefore, to obtain thedata for designing an irradiation system, a gantry inparticular, using proton beam. The other purpose is
to compare the present proton data with the carbon
data l ,2) obtained both from previous RRC experimentand from NIRS (National Institute of Radiological Sciences) with the HIMAC (Heavy Ion Medical Accelerator in Chiba)3) for carbon therapy.
We used 160 and 210 MeV proton beams in the
RRC-E5 area. Our setup consisted of wobbler magnets, a scatterer, a ridge filter, and a range shifter.
The total length was about 4 m, which corresponds tothe size of a proposed gantry.
Concerning the flat irradiation field, optimal combinations of the scatterer thickness and the wobbler radius were searched. Polyethylene plates simulating ahuman tissue were placed just upstream of the isocenter. A parallel plate ionization chamber was locatedat the isocenter. For each thickness of polyethylene, alateral dose distribution was measured. We found thatthe method of the optimization developed for the carbon case at HIMAC I ) can be applied for designing a
proton gantry. Thickness of the scatterer and the wobbIer radius, however, had to be adjusted more finely foreach beam energy, irradiation-field radius, and thickness of the range shifter than the case of RIMAC. I )Penumbra size of the irradiation field was measured
by using X-ray films located perpendicularly to thebeam axis at the isocenter. A collimator was placed
15 or 30 cm upstream from the isocenter. Polyethylene
plates were also placed just upstream of the isocenter. The penumbra size is defined as the distance between lateral position of 80% dose and that of 20%
dose compared with the dose of the isocenter, which isdenoted by P 80- 20 . We found that the scattering effect128

in polyethylene plate dominates if the thickness ex~eeds 20 cm caused by the irradiation system (Fig. 1),

m contrast to the carbon case. 2 )87! g4 *---~ 3 ~ RS = 5.1 em
RS = 0 em
1= 15 em

c...g 2

o

'

o

50

100

!

I

150

200

250

300

Polyethylene Depth (mm)Fig. 1. Penumbra size (P 80-20) of 210 MeV proton beam.
Lc and RS denote the distance between collimator andisocenter and the range shifter thickness, respectively.

Lateral dose distribution may be affected by the edgeof the collimator. Since a beam passes through theirradiation system and since its radius is large, beam
will be scattered by the edge of the collimator. The
angle of the collimator to the plane perpendicular tothe beam axis was set at 0, 2, 4, and 6 degrees. An
X-ray film was placed at the isocenter to measure thelateral dose distribution. We found that the edge effectis negligible when the angle is smaller than 2 degrees.
Depth-dose distribution in water was measured witha parallel plate ionization chamber, by scanning thewater column around the isocenter. Pristine Bragg
peak and spread-out Bragg peak were measured byusing a ridge filter for both 160 and 210 MeV proton
beams. Results of calculation for a ridge filter developed at NIRS I ) were compared with the experimental
data. Analysis is now under way.
The ridge filter is composed of many bars and placedin parallel and 5 mm apart each other. At a downstream from the ridge filter , lateral dose distribution
would show irregular stripes caused by differences ofscattering beam by each bar and each gap. Whenthe beam passes through the irradiation system andis scattered sufficiently, flatness of the irradiation field
is satisfactory. We placed X-ray films at eight different positions downstream of the ridge filter toward theisocenter. Stripes corresponding to each gap were observable in X-ray films placed at the distances of lessthan 85 cm from the ridge filter, but were impossible
in those placed at the distance of 135 cm.
References
1) T. Kanai et al.: HIMAC Report HIMAC-004 (NIRS,
1993), p. 1.
2) H. Tomura et al.: submitted to Med. Phys. (1996).
3) Y. Hirao et al.: HIMAC Report HIMAC-001 (NIRS,
1992), p. 1.

RIKEN Accel. Prog, Rep, 30 (1997)

Decay Enhancement of Self-Trapped Excitons at High
Excitation-Density and Low Temperature in an
Ion-Irradiated BaF 2 Single Crystal
K. Kimura, T. Kohama, D. Kawakami, and W. Hong
Luminescence decay of the self-trapped exciton(STE) in an ion-irradiated BaF 2 single crystal wasstudied using a single-ion hitting and single-photon
counting (SISP)l) with resolution of 100 ps developedby us. Another important luminescence band, theAuger-electron free luminescence, was also studied but
we have reported it elsewhere. 2 ) The decay curve measured by ion irradiation was found quite different fromthat by photo- or electron-irradiation. The decay curveby photo- or electron-irradiation are characterized by adelayed peak i.e. , a delayed growth of STE. In contrast,
the decay by ion irradiation had no delayed rise, andfurthermore was much more rapid at the initial stage.
We could explain the peaking in the decay curves byphoto- and electron- irradiation as a competing process
between spontaneous luminescence-decay of STE's anda delayed regeneration of STE 's by the recombinationof F - and H-centers: the experimental curves were simulated by solving the rate equation. Before the explanation for the decay enhancement by ion irradiation,
let us show the effect of decreasing temperature. Figures la through d show the decay curves measured
with He, N , Ar , and Kr ions at two different temperatures in a narrow range of 20 ns in order to observe
the initial stage precisely. Figure 1a shows that withdecreasing temperature from 298 K to 35 K, the half
lifetime was reduced from 1200 to 150 ps. This temperature effect is contrary to the known fact that STE'sin photo- or electron-irradiated alkali-halides increases
in the decay time with decreasing temperature. Thisphenomenon was explained as follows. It is noted that
F and H centers and STE's are generated too close inion irradiated BaF 2 to form a delayed peak of STE's
appeared in case of photo-irradiation, At about 30 K ,these centers and STE's are frozen so that the recombination does not occur and hence the decay of STE is
independent of the F-H recombination. Nevertheless,the decay constant, 150 ps, is too fast to be ascribedto the spontaneous decay (cf. 600 ns in case of electron
irradiation). By supposing that nonradiative decay byac

He ion

Arion

1.0

298K

0 ,5

0.5

25K.

o L......--...-:=..::~~~QSZa L~"""""';'''':'':':::':':~~~~

o

2

3

4 0

2

3

4

Time/os

Fig, 1. Temperature-dependent decay of luminescenceat 310 nm in He (a), N (b) , Ar (c), and Kr (d) ions
irradiated BaF 2 . Solid lines are simulation curves basedon the equation in the text.

STE-STE exchange interaction plays a role, we could
solve the rate equations and simulate the experimental
decay as shown by solid lines in Fig. 1. A solution of
the rate equation is given bys=

1(a + 50 -1) exp(k 1 t) - a'where 5 is the quantity proportional to the concentration of STE, the subscript 0 means time 0, k1 is therate constant of the spontaneous luminescence, and athe constant.
References
1) K. Kimura: Nucl. Instrum. Methods Phys. Res. B 90,
100 (1994),
2) K. Kimura and J. Wada: Phys. Rev. B 48,15535 (1993);
Phys, Rev. B 116, 57 (1996).
3) K. Kimura: submitted to Phys. Rev. B.

129

RIKEN Accel. Prog. Rep. 30 (1997)

Effects of Ne Ion Beams on Survival of Arabidopsis thaliana
N. Shikazono, A. Tanaka, Y. Yokota, * H. Watanabe, ** S. Tano, **T. Kanai, and S. Ki tayama
The biological effects of heavy ions, estimated fromthe relative biological effectiveness (RBE) on lethality
as a function of the linear energy transfer (LET), havebeen extensively studied with bacteria, yeast, and cultured mammalian cells. However, the effects of heavy
ions on lethality of the multicellular organisms are notyet fully understood. Arabidopsis thaliana (L.) Heynh.
is a multicellular organism particularly suitable forstudying the effects of heavy ions and radiations. It
is because the seed and plant are small, a large number of seeds are produced, and the life cycle is short. I)
We previously investigated the effects of heavy ionson the survival of A rabidopsis using several different
kinds of ions with LETs of 17 rv 549 ke V / /-lm, andfound that the highest RBE is given by Ar ions at LET
252 ke V / /-lm. 2) To further elucidate the dependenceof RBE on LET, we used only the Ne ions but withseveral different LETs for present study.
For the particle irradiation, the dry seeds of A rabidopsis thaliana ecotype Columbia were carefully
sandwiched between kapton films (7.5 /-lm thickness)
as a single layer. Seeds were exposed to the Ne ionsaccelerated by RIKEN Ring Cyclotron or by J AERI
(Takasaki) AVF Cyclotron. The LET of N e ions at
RIKEN Ring Cyclotron was varied by placing an absorber in front of the irradiation site. The mean LETs
were calculated by ELOSS code (a modified OSCARcode). After the irradiation, the plants were grown
at 23°C under a continuous light (40 /-lE/m 2 /s). One
month after sowing, those plants with expanded rosetteleaves were scored as survivors.
The survival curves for the Ne ions with LET 156,
275, 352, 525, and 549 keY / /-lm are shown in Fig. l.
The Ne ions with LET of 156 keY / /-lm had the largest
shoulder, while those with LET of 352 ke V / /-lm had
the smallest. The RBE on lethality was calculated byusing the dose for 37% survival (D37) for electrons as
a standard and was found to give a peak at the LET
around 350 keY / /-lm (Fig. 2).
In the unicellular systems, a peak was observed at
the LET around 100 keY / /-lm, and heavy ions withgreater LETs usually reduced the RBE value. 3 ) The
difference of LET for the RBE peak between the unicellular system and Arabidopsis may be explained by

Beam Operation Co.
Advanced Science Research Center, JAERI130__ 100~""--'.~""~'-'

50 100 150 200 250 300

Dose (Gy)Fig. 1. Effect of the Ne ion beams with different LETs on
survival. 0: LET 156 keY / J-Lm, 0: LET 275 keY / J-Lm,.... : LET 352 keV/J-Lm, 0: LET 525 keV/J-Lm, .: LET
549 keY / J-Lm.

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

100

1000
LET(KeV/ I-lm)

Fig. 2. RBE on lethality as a function of LET of Ne ions.

Ambidopsis' repair mechanism specific to the multicellular organisms.
Further investigations using the other heavy ionswith LETs of around 300 rv 400 ke V / /-lm seem tobe important in order to conclude the relationship between RBE and LET in A rabidopsis.
References
1) U. Bork et al.: Adv. Space Res. 9(10), 117 (1989).
2) A. Tanaka et al.: submitted to Int. J. Radiat. BioI.
3) G. Kraft: Nucl. Sci. Appl. 3, 1 (1987).

RIKEN Accel. Prog. Rep. 30 {1997}

Response of Radio-Sensitive Mutant Cell Lineagainst Heavy-Ion Beams
K. Eguchi-Kasai, H. Itsukaichi, M. Murakami, T. Kanai, F. Yatagai, and K. 8ato*
It can be noted that the high LET radiations are
more effective to kill cells because of a more inductionof non-repairable dsb than the low LET radiations.
Here, we compare the effects of charged particles oncell killing in a pair of mouse cell lines which are normal(LTA) or defective in the repair of DNA dsb (8L3-147).
Charged-particle beams were C ion of 135 MeV lu,
Ar ion of 83 or 90 MeV lu, and Fe ion of 90 MeV lu.
Inactivation cross sections were calculated from 37%
survival dose of the survival curves fitted by a linear
regression analysis to the linear quadratic model.
In the dsb repair deficient cells, relative biologicaleffectiveness (RBE) values were close to unity for cellkilling induced by charged particles with the linear
energy transfer (LET) up to 200 ke V I /-lm, and wereeven smaller than unity at the LET region larger than
300 keV I /-lm. The inactivation cross section (IC8) increased with LET for both cell lines (Fig. 1). The ICS
of dsb repair deficient mutants is always larger thanthat of their parents for the all LET ranges. With
increasing LET, the difference of ICS between the mutant and its parent became smaller. This suggests that
repairable dsb decrease, and that the ratio of nonrepairable dsb to the total dsb induced increases with

-

.!

a;

U

N

'E
.!:!..

increasing LET. However, there still remained a small
difference in ICS at the LET of about 300 ke V I /-lm.
This phenomenon may show that dsb repair still takes
place at these high LET regions in the normal cell line,
even its efficiency is low.
There is also other possibilities. It has been argued
that the DNA content!) and geometrical cross section2 )of nuclei play important roles in cell inactivation byhigh LET radiations. Karyotypes of the both cell lines
were near diploid. Chromosome number widely varies
in 8L3-147 cells. The average chromosome number isslightly higher in 8L3-147 cells than LTA. The averagenuclear area of dsb repair deficient cells is also bigger
than that of their parent cell line (Fig. 2). On the other
hand, R1 cells which were triploid showed similar ICS
to LTA and L5178Y although they are triploid. These
results suggest that DNA contents are not importantfor cell inactivation at high LET regions. It is notclear yet which is more important, dsb repair or nuclear
area. Further study is necessary.

~LTA/C. e· . SL3-147JC-a--- LTAlAr-tT-LTA/Fe• . SL3-147JAr. . • . - SL3-147/Fe

40

0

~

CII

.Q

E
::l

Z

20

50

100

Area

(Arbitrary

150

200

250

unit)

Fig. 2. Distributions of the nuclear area of dsb repair
deficient cell line and its parent cell line.

Fig. 1. Inactivation cross section of heavy ion beams.
Closed symbols represent dsb repair deficient cells(SL3-147) and open symbols represent wild type cells(LTA).

References
1) \""1. Sontag et al.: Int. J. Radiat. BioI. 57, 1183 (1990).
2) W. Kraft-Weyrather et aI.: GSI Report GSI-91-29, C6(1991).

National Institute of Radiological Sciences

131

RIKEN Accel. Prog. Rep. 30 (1997)

LET Dependence of Interphase Cell Death Induction for
CHO Cells Exposed to Accelerated Heavy-Ions
H. Sasaki, F. Yatagai, T. Kanai, Y. Furusawa, and F. Hanaoka
Radiobiological studies using ionizing radiations
with various LETs (Linear Energy Transfers) haveshown that kill-the-cell effect of radiation depends on
the ionization density (LET) and that its relative biological effectiveness (RBE) reaches a maximum around100-200 keY / J.Lm. Since a high LET radiation deposits
considerable energy along the primary tracks, it induces multiply damaged sites locally within a target
molecule like DNA.1) Therefore, the predisposition todeath before dividing (interphase death) may be higher
for the high-LET than low-LET radiations. In orderto verify this possibility, we have examined the LET
dependence of the induction of interphase cell deathusing accelerated heavy-ions such as C, Ne, Ar, andFe.
Exponentially growing asynchronous CHO-K1 (Chinese hamster ovary) cells were exposed to monoenergetic beams of heavy-ions. The dose averaged LET was
selected by inserting sheets of absorber of appropriate
thickness. 2 ) X-rays (200 kVp) were also used as a standard radiation source. The fraction of cells that underwent interphase cell death after irradiation was determined by observing individual cells with time-lapse
photography (direct method) as well as counting theinterphase death-initiated cells which were induced bycaffeine (indirect method). This fraction increased linearly after exposure to X-rays with dose larger thanabout 10 Gy (threshold), whereas it increased at ahigher rate without a threshold after exposure to highLET heavy-ions such as 230 keY / J.Lm Neon (Fig. 1).

keY / J.Lm followed by a decay with further increase in
LET (Fig. 2a). The range of LET values corresponding
to the maximum RBE was narrower for the interphase
death (around 230 keY / J.Lm) than for the reproductive
death (120- 230 keY / J.Lm) as assayed using the loss ofcolony-forming ability as a criterion (Fig. 2b). Thissuggests that targets should be more severely damaged
for induction of the interphase cell death than thatof reproductive cell death. On the· other hand, theinactivation cross-section for interphase cell death ((J =1/F37) reached a plateau at 5- 10 J.Lm2.

aInterphase Deathb•

Reproductive Death

r~

1\...

.j
1
10

l 00 ~----------------------~

r.

-;

100

1000

10000

LET(keV/JJm)

eoFig. 2. RBE vs. LET relationship for the induction of (a)interphase or (b) reproductive cell deaths. (0): C-ion,(e): Ne-ion, (0): Ar-ion, (6): Fe-ion.

40

The present results are consistent with our previous
time-lapse observations of the HeLa cells exposed to
a-rays 41 Am) ,3) indicating a predisposition to interphase cell death against heavy-ions irradiation. Further studies are needed to elucidate the mechanisms
of interphase cell death induction by high-LET heavyions.

GI

Q

CD

en

III

r.

eCD

E
;!.

e

20

20

50

Dose(Gy)

Fig. 1. Induction of interphase cell death after an exposure
to X-rays or Ne ions (230 ke V / Jlm). The fraction of cells
that underwent interphase cell death was determined bya time-lapse method.
The RBE values of heavy-ions relative to X-rays,
as determined at 50% induction level, increased with
LET and reached a maximum at the LET around 230
132

References
1) D. J. Brenner and J. F. Ward: Int . J. Radiat. BioI. 61,
737 (1992).
2) T. Kanai, T . Kohno, S. Minohara, M. Sudou, E. Takada,

F. Soga, K. Kawachi, and A. Fukumura: Radiat. Res.
135, 293 (1993).
3) H. Sasaki: Radiat. Res. 99, 311 (1984).

RIKEN Accel. Prog. Rep. 30 (1997)

Analysis of the Mutations in Human HPRT Gene Induced
by Heavy-ion Irradiations (III)F. Yatagai , Y. Kagawa, N. Fukunishi, M. Hirano,* T. Shimazu,* N. Inabe, K. Eguchi-Kasai,
Y. Furusawa, M. Suzuki, M. Watanabe, T. Kato,** and F. Hanaoka
To gain insight of the characteristics of the mutations induced by heavy-ion irradiation, we have analyzed the hypoxanthine phosphoribosyltransferase hprt
mutations in human cultured cells. Both WI-L2-NS
and TK6 are the human lymphoblastoid cell lines, derived from the same human spleen. The WI-L2-NS
cell has a mutation in codon 237 of p53. For irradiation on these cells, the energies of C- and Ne-ions were
adjusted so to irradiate the cells with three different
LETs; one at the initial energy or so, one at the peakof Relative Biological Effectiveness (RBE) , and one at
the level just before the stop of the ions. Only the 13
keY / /-tm C-ion beam was supplied by HIMAC, and others were by RIKEN Ring Cyclotron. It is interesting
to determine whether the difference in X-ray sensitivity between these two cell lines can still be seen evenafter irradiation of such heavy ions. A difference of thetype and level of the p53 protein between these two celllines has been reported to account for the differences intheir X-ray sensitivities. I) Another interest is whether
the analysis of eDNA for the heavy-ion induced hprt
mutant clones would provide a frequent recovery ofexon skipping, because we often observed such type of
hprt mutations in the human embryo (HE) cells irradiated by 230 keY / /-tm C-ions. 2 ) Some knowledges on
the former question were obtained as described below,
but not yet for the latter.
The survival curves for both C- and N e-ions areshown in Fig. 1. Using the DlO dose for X-ray irradiation as a standard, the values of RBE were calculated and the result is shown in Fig. 2. The expected
LET effect on cell killing was observed with both celllines. The hprt mutation frequencies at a certain survival level were also compared and the tendency of
RBE for mutation seems to be similar to that for cellkilling (data not shown). Isolation of genomic DNA
and mRNA from the mutant clones induced by HIMAC
C-ions (13 keY / /-tm) were performed to identify the
hprt mutation at the DNA sequence level. Althoughanalysis is not yet complete, we have observed relatively fewer exon skipping. This result seems to be notcontradicting with our previous results 3 ) for HE cells,
but more detailed analysis is in need to judge the difference in induced mutational events between the twocell lines. We are planning to expand this line of analysis to the mutant clones obtained by the high-LET
ion irradiations as mentioned above.
Toray Research Center
School of Medicine, Osaka University

(a) 1

0 .1
~ 13 k~VI,..,.. TK·6-..!Io- 13

keVlJIM WH2 -NS- 9- ~, 20 keY/ pm TK-6

- .... · lZ0 keVI"", Wl-L2-NS-e- ZZO keV/"", 'lJ(·6--ZZO keVlpm W~L2-NS

0.01 OC:====:;:===~Z--~-~
Dose (Gy)(b) , --..",=:::--::::::::_

Ne-ion~-----:::::::::::;<!
5 0.1

.~

~

Dose (Gy)Fig. 1. LET dependence of killing effect by heavy ions(a) C-ion, (b) Ne-ion.

C-ion

~.

~
so

100

150

LET (keV/"",)

Ne-iono L-~-~~-~-~~-~

o

SO

100

150
ZOO
LET (keVl)olTl)

Z50

300

350

Fig. 2. RBE for a killing effect.

References
1) W. Zhen, C. M. Denault, K. Loviscek, S. Walter, L.
Geng, and A. T. M. Vaughan: Mutat. Res. 346, 85(1995).
2) Y. Kagawa, F. Yatagai, M. Suzuki, Y. Kase, A.
Kobayashi, M. Hirano, T. Kato, M. Watanabe, and F.
Hanaoka: J. Radiat. Res. 36, 185 (1995).
3) M. Suzuki, M. Watanabe, M. Kanai, Y. Kase, F. Yatagai, T. Kato, and S. Matsubara: Adv. Space Res. 18,
127 (1995).
133

RIKEN Accel. Prog. Rep. 30 (1997)

Mutation of Human Cancer Cell-Line Caused
by Heavy-Ions and X-Rays
T. Kawada,* N. Shigematsu,* H. Ito, S. Yamashita, T. Nakayama,*
K. Toya,* A. T. Yida-Sakate,* A. Kubo,* and T. Kanai
In our previous study, we reported that the mutation
frequencies of V79 cells irradiated by a heavy-ion beamand X-rays increased in proportion to the irradiateddose. 1) The results are shown in Fig. 1.

• Neon(80keV)z'" Carbon(SOke V)

6 10"• Carbon(20keV)

0g• X-ray(l50kVp)

0

z

;;
;;

~

2500
- - - + - X-ray(l50kVp)

10'- - • - - Carbon(20keV)
10-'Carbon(80ke V)

i

//.-

..

Fig. 2. Survival curves against X-rays and heavy-ions (20and 80 keV//-Lm carbon and 80 keV//-Lm neon).

-:_!;~-:I/~-> ;'.---

450
10

~ 350

400

12

DOSE(Gy)

The purpose of this study is to evaluate the mutation frequency of human-cell line caused by heavyions and X-rays. The human-cell line we used was
RMG 1 which was derived from human- ovarian cancer. RMG 1 cells were irradiated by the heavy-ion beamfrom RIKEN Ring Cyclotron or by X-rays from MBR1520R (Hitachi made) and cell survivals were calculated by colony assay. After one or two weeks of expression periods, the mutation frequencies at the hprt locus
were calculated from the numbers of colonies formed inmedia supplemented with 6-thioguanine (10 I1g/ml).
Survival curves of RMG 1 against the dose of heavyions and X-rays are shown in Fig. 2. The Do value
for 150 kVp X-rays, 80 keY 111m carbon beam and80 keY 111m neon beam were 1.6 Gy, 0.78 Gy, and 0.65
Gy, respectively. With the increase of linear energy
transfer (LET) of a carbon beam, survival curve of
RMG 1 moved leftward. High LET carbon beam has
more powerful kill-the-cell (KTC) effects than low LET
beam. When the carbon and neon beams were used at
the same LET level, they showed nearly equal KTC
effects.
Mutation frequencies caused by carbon beam, neon
beam and X-rays are shown in Fig. 3. In comparison
with X-rays, heavy-ions result much higher mutation
frequencies. As the irradiation dose of carbon beamincreased, the rate of mutation frequencies further increased above a certain dose. A neon beam caused lessmutation than a carbon beam under the same LETof Radiology,

Keio

I

>:"
u

Fig. 1. Mutation frequencies of V79 per 10 6 cells irradiated by X-rays and heavy-ions (20 and 80 keY / /-Lm
car bon and 80 ke V / /-Lm neon).

134

12

DOSE(Gy)-:..';".-~

Department
Medicine

100- - - Neon(80ke V)

University

SchoolofI
I~C1 250
300

~

I

i

. .
I

J

I
I

100

- - • - - Carbon(20ke V)

--- .

J

150

§ 50

- - - + - X -ray(l50kVp)

I

~ 200
Z
0

"

~

.->.

I

.;/

- - Carbon(SOke V)- - - Neon(80keV)

~

~

I

~./:.;:!."

5

10

DOSE(Gy)

Fig. 3_ Mutation frequencies against X-rays , carbon beam
(20 and 80 keY / /-Lm), and neon beam (80 keY / /-Lm) irradiation.

leveL These results were very similar to those of V79.
In cOIiclusion with the use of the human cancer cellline (RMGl) , we have evaluated the mutation caused
by carbon beam, neon beam and X-rays. The results
were as follows.
1) The mutation frequency was higher for RMGl cells
when irradiated by a heavy-ion beam than by Xrays.
2) Carbon beam and neon beam with the same LETlevel showed nearly equal KTC effects.
3) The mutation frequency increased when the LET ofa carbon beam increased.
4) The mutation frequency was less for a neon thancarbon beam, which suggests that neon is more favorable than carbon when a high dose therapy isneeded.
5) As to the mutation frequencies caused by heavyions and X-rays, RMGl showed the similar trend
as V79.
References
1) N. Shigematsu et al.: RIKEN Accel. Prog. Rep. 28, 117(1995).
2) K. Toya: Nippon Acta Radiologica 56, 736 (1996).

5. Instrumentation

RIKEN Accel. Prog. Rep. 30 (1997)

A Rotating Target System for High-Intensity
Heavy Ion Beams
Y. Tagaya, T. Nomura, K. Morita, Y. Pu, M. Kurokawa, and T. Motobayashi
To produce the rare nuclei whose formation crosssection is extremely low, a high-intensity heavy ion beamis required. Correspondingly, the RIKEN Ring Cyclotron facility plans to increase its accerelator's beam
intensity. Then a new target system that can withstand the intense beam becomes necessary. One solution to the problem is to use multiple targets arranged
on a rotating disk in such a way that one target is irradiated in a short period of time, but is cooled down
during the other targets are irradiated.
We are now testing the new rotating target system
and its schematic view is shown in Fig. 1. The system consists of two disks, disk-l and disk-2. Energy
degraders are mounted on the disk-l while targets areon the disk-2. The two disks are driven by individual stepping motors and are controlled by a personal
computer so as to move synchronously with pulsed ion
beam. The absolute rotating angle of each disk is readby an optical encoder and is fedback to the control system for adjusting the precise position-setting. To stepup the speed of disks, we adopt 1 to 5 gear ratio.

in enhanced cooling effect, but targets need to be madelarge to increase the time for irradiation. In an intermittent rotation mode, on the other hand, disks are rotated and stopped intermittently and therefore small
targets can be used. When 10 targets are mounted
on a disk in this operating mode, we can set the next
target to the beam position in 50ms minimum.
We made a simple calculation of the temperature
distribution of the U 3 0 S target. It was assumed thatthe system is operated synchronously with 50ms-on
50ms-off pulsed Ti ion beam in an intermittent rotation mode with 10 targets on a disk. This means thateach target is irradiated 50ms-on and 950ms-off. The
beam intensity of IPILA (momentary value) was also assumed, which is expected to be available at the RIKEN
Ring Cyclotron facility. Calculated temperature at thetarget center (Fig. 2) is lower than U 3 0 S sublimating
temperature and thus the system is expected to work
effectually at the time of the beam experiment.

1500 ~--------------------~
1""""""1.• ·,· · · · ·( Y~~~~~ .¢4~~~·.·:

E~ergyQegtader

U
o

1250

-- --------------- ~Ts

1000
750
500
250

o

o

5

10

15

20

Time[s]Fig. 1. Schematic view of the rotating target system.
Only the two disks are inside the vacuum chamber andall the other components are outside.

Two operating modes are now prepared, one is acontinual rotation mode and another is an intermittent
rotation mode. In a continual rotation mode, disks arerotated at a constand speed and beam pulsing is determined by the target size. In this operating mode, fast
rotation (a few hundred rpm) is possible which results

Fig. 2. Temperature at the center of U 3 0 S target. To simplify the calculation, a cubic shape target (2x2x2 cm3 )and 1 cm thick U 3 Os and Al degrader thickness wereassumed. Boundary temperature is 20 ° C. Energy deposited per volume is calculated for Ti ion beam (1pJ.tA,
247 MeV) on the 1 mg/cm 2 U 3 0 S target and 10 J.tm Al
combination. 24 7 MeV is roughly estimated to be theoptimum energy to produce 2so112 nuclei in a2n deexcitation channel. Ts (1300 DC) is the U 30s sublimating
temperature.

135

RIKEN Accel. Prog. Rep. 30 (1997)

Windowless Gas Target for High-Spin Isomer Beam Production
M. Shibata, Y. Cono, T. Kishida, E. Ideguchi, and M. Ishihara
Presently an upgrade of the beam intensity is underdevelopment for the heavy ion injector lineae, RILAC,
and RIKEN Ring Cyclotron (RRC). Anticipated increase of their beam intensities is 10- 100 times depending on the mass of ions. These high intensity beams
are quite profitable for the secondary beam production, such as for the high-spin isomer beam (HSIB)
production.!) However it is required to use metal foils
with a high heat conductivity, such as (Be, AI, and Mg)
in order to produce HSIB. Therefore it will be highly
required in the future to use an windowless gas target, since any foil to separate a vessel of the gas target
from the beam line vacuum would not stand against
such high intensity heavy ion beams of relatively low
energy.
Recently a new type windowless gas target has beendeveloped by Sagara et a1. 2) By using a blow-in stylerather than traditional blow-out one, they succeededto achieve more than 70 Torr of the N 2 gas pressure in
the almost entire target region.
The same type of gas target has been designed for
HSIB production as shown in Fig. 1. This has 10 emof gas target region and ",,0.6 mg/cm 2 of thickness at
70 Torr of gas pressure for gasses of N 2, O 2 and N e.
The reactions which will be used to produce HSIB 'sof 144Pm, 145Sm and 147Cd are: 14N(136Xe,6n) 144Pm,
160(136Xe,7n)145Sm, and 20Nee36Xe,9n) 147 Cd. 1) The
cross sections of these reactions are 100 "" 300 mb.
Since the 136Xe beam of 100 "" 200 pnA can be expected after the upgrade of the RRC , the above mentioned thickness of gas target is enough to produce
HSIB's of 105 "" 106 particles/sec. The gas target has

136

Sagara Gas Target Top View

nM.B.P + R.P.

M.B.P
+ R.P

Gas inlet

Gas inlet

I
II

I

I

!

I
10 em

Fig. 1. A blow-in type gas target.

been designed to be placed at the entrance of the RIPS.
References
1) Y. Gono et al.: Nucl. Phys. A 588, 241c (1995).
2) K. Sagara et al.: Nucl. Instrum. Methods Phys. Res. A
378 , 392 (1996) .

RIKEN Accel. Prog. Rep. 30 (1997)

Ge Telescope for ,-Ray Doppler Correction
Y. Gono, T. Morikawa, H. Tsuchida, E. Ideguchi, T. Kishida, and M. Ishihara
A germanium (Ge) counter telescope was developed
for the in-beam ,-ray spectroscopy utilizing high-spin
isomer beams (HSIB). The system consists of a segmented Ge (Segge) as a ~E counter and a large volume Ge as an E counter. They were placed as shownin Fig. 1. Segge is divided into 10 x 10 mm squares
with a 20 mm thickness. A Compton scattered , -rayby Segge was detected by the large volume Ge detector
which was a clover type Ge (CIge) in case of Fig. 1.

The energy dependences of ,-ray efficiencies of various
detection modes are shown in Fig. 3.

i·•. ·.•·.• ·.·. J'/(. /:jIt~jie:s.~:,~p·i c!' j:T·· . . . .. . .

.. .

iI . . . . . . . . . . . . . .;. . . . . . . . . . . . . . . .;. . . .

····· H. .; " ... . . . . . . .. . . . . . :. . . ,.::::: ..... :E: :~ =:l:H: ~ : :~:~U

Ge Telescopefor Position Sensitive y-Ray Detection. ............

j ....... ,1:, V. . . . . . . . . . . . .+ ..................;............,......... ...... ·i ··+ .. i · ' ..·....·..· ..··············....··H;... j .•.

j··························· ..

... ; .... ..

100

Fig. 1. A Ge telescope system.

Gamma-ray spectra of 152Eu taken by this system
are shown in Fig. 2. These spectra were taken byusing a 50% Ge as an E counter. A telescopic spectrum shows relatively constant energy dependence ofthe detection efficiency comparing with those taken ina singles mode. This is reproduced by a simulation calculation made by using a computer code GEANT-IV.

This system was developed for Doppler correctionof the ,-rays emitted from rapidly flying sources. Thisis the case of secondary fusion reactions by HSIB. In
these reactions recoiled nuclei are anticipated to fly
with a velocity of about 10% of the light velocity (f3 rv0.10). A small size of each segment in Segge allows
to place it near a target, e.g. 5 rv 10 cm, to obtain aproper energy resolution even in case of f3 rv 0.10.
Gamma-ray spectra with and without Doppler corrections are shown in Figs. 4 and 5. In Fig. 4, thespectra of ,-rays emitted from the reaction productsof 27 Al bombarded by 32 S at E = 90 MeV are displayed. This experiment was made in Kyushu University Tandem Laboratory. The recoil velocities of the,----------------------------------::;::y-Ray spectra of Eu taken in three modes \

tt-

lS2

~ l ~~~~L~~l~Hg

~

~

1000

Fig. 3. ,-ray detection efficiencies of a Ge telescope in fivedifferent modes of detection.

Clover Ge)··-··lAL. j,~~~-~ 1 J~~/ ., .L\ .L~~ Telescopic mode,N.~(

Energy (ke V)

32S (90 MeV) + 27Al
y-Ray singles spectra
taken at 90°

V)

I

I

. L..-,---~-l.~t..",.

00
..",.

t-

N

~oo

N~~ Doppler corrected

\C)

..",.

~

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

with fJ=0.02

2,"1. , : ' " : ' " modo of 50% Go~(-..............'l...A.....-..

~::;::~-------.,J..~. I.. ~' ........,..N__

3. Singles mode of segmented Ge

Fig. 2. ,-ray spectra taken by a Ge telescope in threedifferent modes.

Fig. 4. ,-ray spectra taken by a Ge telescope with andwithout a Doppler correction for a recoil velocity of
j3 rv 0.02.
137reaction products were (3 0.02. Though the Doppler
correction is suffered by the effects of the emitted parf",.,), , , ,, , ,,iii

i j f i ) :'-'-~-'-'--',-l~ ~ ~ ~ : :i ' , -i-Ray singles spectra: : : •! O!f 1; 2~e;O~e; 4!n)~48G~ ~ea!ct~o~ _i ;,,,:' ,,,:::! ' I
10000
;>
o

~
i:i;:loU0oEnergy (keY)

Fig. 5. ,-ray spectra taken by a Ge telescope with andwithout a Doppler correction for a recoil velocity of(3 '" 0.10.

138

tides, e.i. protons and neutrons, the energy resolutionof less than 10 keVin FWHM could be obtained forthe 1.7 MeV ')'-ray. The ,),-ray spectra shown in Fig. 5
were taken by Segge only. The ')'-rays are from the
12C + 140Ce reaction under the l40Ce beam energy of
7 Me V / u. In this case the velocity of the reaction products was (3 0.10. Peaks of 785 (2 ---7 0),632 (4 ---7 2),
and 395 ke V (6 ---7 4) of 148 Gd in the corrected spectrum correspond to bumps in the un-corrected spectrum as corresponded by arrows.
Since the singles spectra of each segment as well as atelescopic spectrum gives position information to makethe Doppler corrections, the efficiency of this system
is comparable to a 23% single crystal Ge detector as
can be seen in Fig. 3. This means that 25 Ge's of 23%
efficiency are necessary to achieve the same detection
efficiencies as the present system when one needs thesame quality of the Doppler correction. A comparisonof the costs for these two systems results in a factor
3- 4 better cost performance for the present system.
Further improvements in a spectrum quality can beattained by using an anti-Compton shield.
f",.,)

RIKEN Accel. Prog. Rep. 30 (1997)

Development of a Polarized 3He Target System
T. Uesaka, T. Wakui, T . Oonishi, M. Wakasugi, H. Sakai, and Y. Yano
A newly constructed polarized 3He target system
has been applied to a nuclear physics experiment at
RIKEN Accelerator Research Facility. Figure 1 shows
the photograph of the system.

In order to use this target system for theexperiment,!) we made a few preparations. At first,
for reduction of the background events due to the entrance and exit windows of the cell, we employed thinwindows as thin as 100 J.1m (Fig. 3). The shape of thewindow was hemispherical in order to endure a highinner pressure of more than 8 atm. Among the cellsof this type, the longest relaxation time was 6.8 hours.
This value is smaller than one obtained before the modification by about one order. The reason for the reduct ion is under investigation.

Fig. 1. Photograph of the polarized 3He target system.
We started a performance test of the system with a
few glass cells in the cigar shape of 30 mm¢ x 100 mm.
A glass cell is filled with 3He gas and N2 gas of thepressure 3.3 atm and about 0.13 atm at the room temperature, respectively. The cell is also filled with Rbvapor of the density l.Ox 10 15 atoms/cm 3 at 200 °C.
Polarization of the 3He is attained by means of a spin
exchange process between a 3He nuclei and an optically
pumped Rb atom. The relaxation time, which is a determining factor of the maximum polarization whena laser pumping power is sufficient, was measured foreach cell. Figure 2 shows an example of a relaxation
time measurement. The deduced relaxation time was65.3 ± 6.8 hours for this case of test bench. This value
is large enough to polarize the 3He gas more than 50%.

100
138

Fig. 3. The cell used in the experiment. Thickness of theent rance and exit windows is 100 /-Lm .
Secondly, an absolute vaiue of the polarization wascalibrated by a proton NMR measurement. Namely,
P3He =VNMR [m V . atm]
228 [m V] x p[atm] ,(1)

where P3He is the polarization of 3He, VNrvIR the NMR
signal for 3He, p the 3He density in the unit of atm at

9
10

8

...'2
~

7

..ci...

~

.:

6

:3

. : 3 He

N

·c
<0

0

spin UP

0: 3 He spin DOWN<0

T 1 = 65.3 ± 6 .8 hours

5

0..
20

4

40

60

80

Time [hours]
0

5

10
15
time [hours]

20

Fig. 2. Typical result of relaxation time measurement.
The solid line corresponds to Tl =65.3 hours.

Fig. 4. The result of polarization measurement throughthe experiments. Open and closed circles represent the"UP" and "DOWN" states of 3He polarization, respectively.
139273 K.
Lastly, a spin-flip system was introduced. In orderto reduce the systematic errors included in measured
polarization observables, the direction of 3He polarization should be reversed within a proper interval. The
spin-flip system makes use of so-called Adiabatic-FastPassage NMR method.
Figure 4 shows a result of the polarization measurement through the experiment performed in N ovember, 1996. This experiment was performed at the E3room of RIKEN Accelerator Research Facility. The
poiarized 3He gas target at the density of 10 mgjcm2

140

was bombarded by a polarized deuteron beam of
270 MeV. I ) Open and closed circles are for the spin"UP" and "DOWN" states, respectively. The spin-flip
system worked well. A problem of the small difference between "UP" and "DOWN" is, however, still
remained. We are now conducting an off-line measurement to correct this difference.
References
1) T. Uesaka et al.: RIKEN Accel. Prog. Rep. 30, 46(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Performance Study of a Phoswich Detector in the Mixed Fieldof Neutrons and Charged Particles
T. Nakamura, M. Takada, S. Taniguchi, N. Nakao, T. Shibata, Y. Uwamino, and N. Nakanishi
The contribution of neutrons to the radiation exposure of astronauts still remains vague, because theneutron detection in the spacecraft is difficult due tothe intense charged particle field in the space.
In order to measure an accurate neutron spectrum
in the mixed field of neutrons and charged particles,
we have developed a phoswich detector composing of
a 50.8 mm diameter and 50.8 mm long NE2l3 organic
liquid scintillator contacted with a 5 mm thick NEl15
plastic scintillator via an optical glass, as shown in
Fig. 1. If a charged particle enters into the detector, fast and slow pulses come out from NE2l3 andNEl15, respectively. If neutron or ')'-ray enters into
the detector, only the fast pulse from NE2l3 comesout. Light flashes in both scintillators are registeredby one-photomultiplier. Using a technique of pulseshape discrimination based on the decay time differences of the light flash (the decay times of NE2l3 andNEl15 are a few nsec and a few hundred nsec, respectively) , this detector is able to discriminate neutron
events from charged particle events.

NEIlS (Smmtarget at an angle of 30 degrees relative to the proton
beam direction in the E4 beam line of RIKEN Ring
Cyclotron.
A two-dimensional plot of slow- versus totalcomponent pulses detected with this phoswich detector
in a mixed field of neutrons and protons is shown in
Fig. 2. Five areas labelled from 'A' to 'E' can be seenin Fig. 2. The area 'A' refers to ')' rays, while the area'B' refers to the neutrons which did not interact with
NEl15 but with NE213. The area 'C' indicates the
protons which stopped inside the NEl15 scintillator or
the glass, whereas the area 'D' indicates the protons
interacted with both NEl15 and NE2l3 scintillators.
The area 'E' shows electrical noise events caused by a
too high voltage supplied to the photomultiplier.

(SO.8mm dia xSO.8mm length)

o

25

50

75

100

125

150

slow component

optimum window (pyrex glass)light guide (pyrex glass)

o

25

50

75

100

125

photomultiplier (H1949)+---t-t-+o 1020 30 mm

Fig. 1. The phoswich detector consisting of a NE115 plastic scintillator optically coupled with a NE213 liquid
scintillator.

We produced a mixed field of neutrons and protons
by bombarding 135 Me V protons on a 10 mm thick Li

Fig. 2. Two-dimensional map [total component, slow component] obtained with the phoswich detector in a mixed
field of neutrons and protons. The area 'A' is due to, rays, 'B' is due to neutrons, 'C' and 'D' are due toprotons, and 'E' is due to electrical noises.

This phoswich detector can clearly discriminate neutron events from proton events, and is useful to measure neutrons in the mixed field with protons.

141

RIKEN Accel. Prog. Rep. 30 (1997)

Proton-Knockout (p,2p) Reactions from 12C
with Normal and Inverse Kinematics
T. Kobayashi, S. Ito, A. Ozawa, K. Yoshida, K. Miki, and E. Takada*
Quasifree (p,2p) proton-knockout reaction by proton
beams has been used to study the single-particle properties, such as the binding energy or the momentum
distribution, of bound protons in the nucleus. 1) Using
inverse kinematics, i.e., a heavy-ion beam on a proton
target, this method can be applied to any ,B-unstable
nuclei. For the experiments using secondary nuclear
beams, we have studied a feasibility of the (p,2p) reaction with inverse kinematics, comparing the same process by two kinds of kinematics: (1) 12C(p,2p) reaction
with a proton beam on a 12C target at 210 MeV, and(2) pe 2C,2p) reaction with a 12C beam on a proton
target at 230 A MeV.
A two-arm detector system is shown in Fig. 1. It
is composed of drift chambers, a thin plastic scintillator, and a NaI (6" diam. by 5" thick) which can stop
protons up to 210 MeV.

e (p.p)230MeV/ A

l2

~

250

500

500

500

100
500

40

60

20

5 1/2

(e) p(" C,2p)B

200

<l>a>

a>
_",cDiIl

cD

ill

cD

cD
cD
cD""

(B)

'2e (p,2p)<p<P<p.pa>a>-200 -100P3/'_~a>cD~<I> ~~<l>a><I>

~~

ffHH

+~

20

~cjl~<P'a>.

+~~ ~+~+~ +~~

P3/2

+

<I>

~

a>
cD
cDcD

0

SI/2

(D) p("C,2p)Li+Be<M><P<P<p

<I>

~CD

Measurements using proton beams were performed
at RIKEN. The detector was calibrated using thep(p,2p) reaction. The energy resolution for a 100 MeV
proton was 0.6 MeV (rins) evaluated by the 12C(p,p)
reaction. The missing-energy resolution for two protons was 1.0 MeV (rms) evaluated by the p(p,2p) reaction.
The 12C(p,2p) reaction using proton beams on a 0.1
g/cm 2-thick CH 2 was studied at 135 and 210 MeV.
The separation energy spectra are shown in Fig. 2. A
sharp peak at 16 MeV (7I"P3/2 knockout) and a broad
peak around 35 Me V (7I"SI/2 knockout) were clearlyobserved, with a resolution of 1.2 MeV (rms). Momentum distributions of 7I"SI/2 and 7I"P3/2 protons areshown in Fig. 3. The momentum resolution, evaluatedby the p(p,2p) reaction, is 3.511eV/c (rms) shown by
the solid histogram. Characteristic shapes for L = 0+<1><1>

ill

Fig. 1. Two-arm detector system.

8040<P.p<p.p.p

so60

Fig. 2. Separation-energy spectra.

(A) 12e(p,2p)

Scal.e[..m)40

Separation Energy [MeV)~

100 200 -200 - 100
Momentum Px [:.leV/c)~.p<l>~CD.'P<P<P
a

100

200

Fig. 3. Momentum distributions of knockout protons.

and L = 1 can be seen.
The proton-knockout reaction with inverse kinematics , pC 2C,2p), was performed using a 230 A MeV 12C
beam from HIMAC on a CH 2 target at NIRS. A plastic scintillator was placed at 0° in order to detect particles from the decay of the (A-I) system formed inthe (p,2p) process. As shown in Fig. 2, 7I"P3/2 - and7I"sl / 2-knockout peaks were associated with fragmentswith Z = 5 and Z = 3,4, respectively. The separationenergy resolution was 1.9 MeV (rms), which was dominated by the target thickness of 0.2 g/cm 2. As shownin Fig. 3, momentum distributions of knockout protons
in the projectile-rest frame were similar to those of the
12 C (p,2p) reaction.
In summary, it was proved that the (p,2p) protonknockout reaction can be studied using inverse kinematics with a reasonable separation-energy resolution
by a simple scintillator-based two-arm telescope.
References

National Institute of Radiological Sciences

1421) G. Jacob and T. Maris: Rev. Mod. Phys. 38 121 (1966).

RI KEN Accel. Prog. Rep. 30 (1997)

Development of a MUSIC (MUlti-Sampling Ionization
Chamber)-type Detector for Identification of. Low Energy Nuclear Reactions
Y. Mizoi, T. Miyachi, Y. Matsuyama, T. Fukuda, H. Miyatake, N. Aoi, K. Yoneda, Y. Watanabe,
M. Notani, N. Fukuda, H. Sakurai, A. Yoshida, Y. Watanabe, and M. Ishihara
We have developed a MUSIC-type detector systemand tested its performance by using beams from the
RILAC and AVF cyclotron at RIKEN. We also performed an experiment to measure the 8Li(a,n)11 B* reaction at energies of astrophysical interest l ) with RIPS
at the RIKEN Ring Cyclotron. Analysis of the data is
now in progress.
This detector is based on MUSIC (MUlti-Sampling
Ionization Chamber)-type detectors,2) which can measure the energy loss along the particle trajectory. A
main advantage of the present MUSIC-type detector
is the capability of a time-projection chamber (TPC)
employing a flash ADC to identify multi-track events.
The vertical position is determined by the drift time ofthe electrons, and the horizontal position is determinedby employing a backgammon-type cathode (PADs).3)
The other feature is that the gas in the chamber works
as both a detection medium and a gas target , resulting
in a high detection efficiency. Owing to these featuresof the MUSIC-type detector, we can measure reactions
induced by RI beams with low intensities.
Figure 1 shows a cross-sectional view of the MUSICtype detector, which consists of a field cage and 64
backgammon-type cathode PAD cells. The field cage
has a 70 cm long, 15 cm high, and 20 cm wide active area, and the field wires are wound doubly to obtain a better uniformity of the drift field. To preventcross talk between adjacent anode wires, three planesof cathode PADs surround the anode wire. Each cathode PAD cell is 1 cm long, 1 cm high, and 20 cm wide.

_ Cross sectional view of lhis plane

Figure 2 shows a three-dimensional plot of the averaged energy loss in each PAD for the 8Li beams withvarious energies. The x-axis represents the time-offlight of incident 8Li beams. The TOF at 200 nsec
equals about 3 MeV/nucleon, and the shorter TOF
corresponds to the higher incident energy. The y-axis
represents the PAD numbers, which are aligned along
the beam direction from upstream to downstream. The
width of one PAD is 1.1 cm. The gas ingredients are

.c.

~' BO
;)160
"0140
120
100
80
60
40
20

45

40

35

,0"'0

'Vo

30 25
20

15
10

5

160 170 180o

ToF vs PAD No

Fig. 2. Bragg curve of BLi.

~140
~120

Grid &

100}---==--_-----.l80~_e .. Beam Direction

60
40
20

200

Drift Tirne( Ch)

Fig. 1. Cross-sectional view of the MUSIC-type detector.
The field wires are wound doubly with a 5 mm pitch.

100

8Multi-Track

Fig. 3. Typical multi-track event: a candidate for anelastic scattering.

143

4He(90%) and iso-butane(lO%), and gas pressure isabout 400 torr. While this plot clearly shows Bragg
curves for various incident energies, higher energy particles go through the detector. A contour plot (Fig. 2)
shows an energy-range curve. To select the reaction
events, we can use these Bragg curves as a reference.
We show two examples of the reaction events whichwere selected by this method. Figure 3 shows the raw
data of flash ADCs of a typical multi-track event. The
y-axis represents the drift time of electrons ionized bycharged particles under electric field. The drift velocity of the electrons equals about 1 cm/ J,Lsec, and theunit of the y-axis equals 25 nsec/channel. This event
is a candidate for an elastic event, 8Li(a,a)8Li. The
right track may be an a particle, because of its longrange and lower dE/dX. The left track may be a 8Li.
Figure 4 shows a typical fusion-like event. The
dotted-line histogram is a reference Bragg curve relevant to the beam energy of this event, and the solidline histogram is a reaction event. This is a candidate for the 8Li(a,n)1l B reaction because of a suddenchange in dE/dX and the very short range. We canguess from kinematics calculations that a 11 B may run
forward and a neutron may run backward. We havemeasured not only charged particles but also a neutron in this experiment. We can thus derive further
information about the 8Li(a,n)1l B* reaction; for example, the branching ratio of the excited states(ll B*)
as well as the ground state of 11 B, by performing fur-

144

I:-

v

~225

~

200

175

150

125

100

75

50

25

Fusion Like Event60
PAD No.

Fig.
4.
Typical fusion-like event: a candidate forBLi(a,n)llB reaction. Dotted line is a Bragg curve forreference and solid line is a reaction event.

ther analyses.
References
1) X. Gu et al.: Phys. Lett. B 343, 31 (1995).
2) K. Kimura et al.: Nucl. Instrum. Methods Phys. Res. A
297, 190 (1990).
3) R. Allemand et al.: Nucl. Instrum. Methods 137, 141(1976).

RIKEN Accel. Prog. Rep. 30 (1997)

Toroidal Spectrometer for Measurement of Emitted Electron
Spectra Arising from Collisions between Highly Charged
Ions and Neutral Atoms
Y. Tamagawa, D. Chiba, T. Takayanagi, K. Wakiya, Y. Kanai,
T. Kambara, and Y. Awaya
We have constructed a toroidal-mirror-type electronenergy analyzer l ) which can measure electron spectra
arising from the collisions between highly-charged ionsand neutral atoms. An eminent character of this analyzer is the capability to measure the angular distribution of emitted electrons without a moving part.
Figure 1 shows a sketch of the apparatus. The wall
radius and the toroidal (axis) radius of the analyzer are
104 mm and 136.8 mm, respectively. The ion (or electron) beam passes through the target region perpendicular to this figure. Electrons ejected from the target
region are energy-analyzed by the toroidal prism andfocused on the position-sensitive detector indicated as
MCP. A TOF recoil ion analyzer is set inside to study
their charge states.

e+Ar 100eV
101~'~'~'~1~'~'~'~
1 ~'~' ~'I~I~I~I~I~
I ~
I ~
I ~I~
I I~I~I~I~I"I

Ref. 1

-

v;
v;

o

o

U

-

o •

o

o

10.

3

o

I"

I I ' , I I"

20 40

I " , I,f'

II I ' I I I ,60 80 100 120 140

MCP

Guiding Lens '.f7/"-r--,.,

Electron Trajectory

Fig. 1. A sketch of the toroidal analyzer. Distance fromthe center axis of toroid to the entrance slit is 32.8 mm.
Spacing between the inner and outer electrodes of theanalyzer is 40 mm.

As a test of the apparatus , we have measured elastic
e-Ar scattering at an electron energy of 100 eV in anangular range of 20-120 degrees (See, Fig. 2). At thisstage, we used the channel electron multiplier (CEM)
instead of the position-sensitive MCP detector, andhave not set the recoil ion analyzer yet. In present
setup , the angular distribution of the scattered electrons was measured by rotating the CEM. In Fig. 2,
our result is compared with that of Srivastava et al. 2)
We have measured only a relative distribution of elas-

Scattering Angle (deg.)
Fig. 2. The double differential cross section for the elastic scattering of 100 e V electrons by Ar. Open circles:
present results, closed circles: Ref. 1.

tic scattering and normalized our data to the referreddata at 90 degrees. Our result agrees well with that ofSrivastava et al. except below 30 degrees. This demonstrates that our analyzer can measure the angular distribution of the emitted electrons from ion-atom collisions for a wide angular range (30- 140 degrees withrespect to the beam direction).
In March of 1996, we set our analyzer at the beamline of RIKEN 14.5 GHz ECR ion source (Caprice),and have tried to measure the Auger electrons fromthe N 4 + (ls 2 3l 3l') produced by the collisions of 50
ke V N 5 + on Ar. At that time, we could not get aclear spectrum of those Auger electrons, because of alarge background noise. The background signals are
considered as the low energy electrons produced near
the collision region. To reduce the background noise,
we are currently trying to improve our analyzer andbeam transport systems.
References
1) H. A. Engelhardt, W. Back, and D. Menzel: Rev. Sci.
rnstrum. 52, 835 (1981).
2) S . K. Srivastava, H. Tanaka, A. Chutjian, and S. Trajmar: Phys. Rev. A 23, 2156 (1981).

145

RIKEN Accel. Prog. Rep . 30 (1997), Mounting of a CCD Detector on the Rowland Circle ofa Grazing-Incidence Spectrometer for Use
in Beam-Foil Spectroscopy
R. Hutton, -S. Huldt, 1. Martinson, Y. Zou, K. Ando, T. Kambara, and Y. Awaya
A back illuminated CCD detector has been tested
on a 2.2 meter McPherson/Nikon grazing incidence
spectrometer. This spectrometer is used in beam-foil
spectroscopy experiments at RIKEN. The geometryof the grazing-incidence mounting would require the
CCD chip to be positioned with a high angle of incidence with respect to the incoming analyzed photons. However, this would present 2 practical problems; (a) the CCD chip would reflect a high percentage of the incoming photons and (b) the chip deadlayer would be effectively enlarged at such high angle
Q by 1/ cos( Q). For these reasons the CCD chip was
positioned normal to the incoming photons. This alleviates the 2 above problems , but introduces imaging
problems either side of the CCD chip center. These
imaging problems were investigated using geometricalarguments and also by imaging light from a vacuum
spark source. The grazing-incident geometry is shownin Fig. 1.

Entrance slit
Detector positions(a )Fig. 1. Schematic diagram of the grazing-incidence geometry.

The results of the spark spectra are summarized in
Figs. 2a, b , and c. Two strong lines are seen fromthe spark. These are Ne-like Al lines, namely the
2p 6 - 2p5 3s resonance and intercombination lines at
160.07 and 161.69 A, respectively. Figure 2b shows146(c) 20 inches
16
I

.~
cQ)

12

.5
Q)

(b) 18 inches

.:::

~
~

c:::

~\

4

d~
0
150

200

250

l

300

(a) 16 inches
350

400

450

500

550

Wavelength (A)Fig. 2. Spectra recorded at various positions around the
Rowland circle of a 2.2 meter grazing incidence spectrometer (i.e. 16, 18, and 20 inches). The 2 strong lines
seen at the center of the CCD chip recorded at the
18 inch position are separated by 1.6 A. The imaging
is seen to degenerate as the lines move away from thecenter of the chip.

data recorded with the CCD center placed at 18 inches
along the Rowland circle. Here) the 2 lines are almost
centered on the CCD chip and the resolution is seen
to be good. The other 2 images are taken at 16 and20 inches (2a and 2c respectively) around the Rowland circle. Here, the imaging is acceptable for lower
resolution beam-foil work.

RIKEN Accel. Prog. Rep. 30 (1997)

Proton Beam Test of Cosmic Ray Telescope for
the First Brazilian Scientific ,S atellite
T. Kohno, H. Kato, and K. Nagata
We are promoting a joint collaboration program!) ofcosmic ray observation with USA group and Braziliangroup, aboarding instrumentation on the first Brazilian scientific microsatellite. Our main objective of thisobservation is heavy ions of the solar and anomalous
cosmic rays. For this purpose, we designed a telescopewith a large geometric factor (2.5 cm 2 . sr) since the fluxof these heavy ions is very low in comparison with protons and electrons in space. The heavy ion beam test of
this telescope named MAIN by RIKEN Ring Cyclotron
was performed in 1995. 2 ) The protons and electrons
have been widely observed so far. But, their fluxes
at the district near Brazil are not yet measured correctly due to its extraordinary high intensity. This phenomenon arises from the anomalously weak geomagnetic field of that area called South Atlantic Anomaly(SAA). The above described MAIN telescope is notfavorable for the observation of protons and electrons
at SAA since the counting rate would rapidly saturate
due to its large geometric factor and the very high intensity. Therefore, we have designed a dedicated small
telescope (we call it PRE) with very small geometricfactor (5 x 10- 3 cm 2 . sr) for the purpose to observe
protons, electrons, and alphas in the SAA region. The
basic design of this PRE telescope is shown in Fig. 1.

ORCAS/ PRE

1

T

IOmm CO-----~- - ---~-----~ ~ ------ - ~ . ----:-- --10'
Particle Energy (MeY)10'

Fig. 2. Response curves of the telescope for protons.
Vertical incidence is assumed. The nominal thicknessof each detector is 400 micron, but it contains a deadlayer having 40 micron thickness.

left hand side in Fig. 1 and we took pulseheight analysis
data for each detector. In order to take data for various
input energies, we used Al absorbers in front of Dl withvarious thicknesses as an energy degrader. We plotted
the observed peak energy and calculated energy deposition in the detector vs. Al absorber thickness (Fig. 3).

Zmm BrassT zmm At5m m At

~

I,

O.4mm

PRE Response Curve wftII dead layer

:,

10·

I
D1

o 0

I

D2 D3

D4

10

20

Aluminium thickness (mm)Fig. 1. Cross sectional view of the telescope. Each detector
consists of two PIN diodes with thickness of 200 micron.

In order to observe a wide energy region , we usedaluminum absorbers in between D2 and D3 , D3, andD4. The response curves of this telescope for protons
is shown in Fig. 2. Using many discriminators having
various levels we can obtain counting rates of fixed energy ranges with four channels for electrons, five channels for protons , and four channels for alphas. As seenfrom Fig. 2, the observable energy range is from 3 MeV
to 60 MeV for protons. However, we used 70 Me V proton beam, which is the lowest energy available at Riken
Ring Cyclotron, for the first calibration experiment of
the telescope.
The main purpose of this first calibration experiment
was to check the response of each detector to the beam
at various energy levels. The beam was injected from

Fig. 3. Experimentally observed peak energies and calculated energies deposited in D3 vs. thicknesses of the Al
absorber.

Agreement of the two values is good for the thinabsorbers, but discrepancy increases at thick absorberregion. Specially, at the very point where the rangeof proton beam is nearly same as the physical lengthof absorber, a slight error in the detector or absorber
thicknesses can produce some amount of residual energy after the absorber. But this is not a so serious
problem for the real observation because its probability is rather low.
References
1) T. Kohnoet al.: RIKEN Accel. Prog. Rep. 28,132 (1995).
2) T. Kohnoet al.: RIKEN Accel. Prog. Rep. 29, 189 (1996).

147

RIKEN Accel. Prog. Rep. 30 (1997)

Development of a Liquid Argon Ionization Chamber with Excellent
Energy Resolution for High Energy Heavy Ions
A. Yunoki, T. Doke, M. Kase, T. Kato, J. Kikuchi, K. Masuda,
M. Niimura, Y. Piao, E. Shibamura, and I. Tanihata
An experiment was carried out for estimation of
the energy resolution of the detector which was constructed for measuring the precise energy of heavy
ion particles at the beam energy (E b ) around 100
MeV j nucleon.
The detector medium was liquid argon doped with80 ppm allene (C 3 H4). Allene is a photosensitive
molecule, which can be photoionized by absorbing a
VUV photon emitted from argon. A high-energy particle passing through the liquid argon produces manyelectron-ion pairs and excitons along the particle track.
Electrons cah be collected to the anode by applying anelectric field (E). Excitons and neutralized ions become
self-trapped molecules to emit VUV photons. The
VUV photons are absorbed by the allene molecules
to be photoionized, and the resultant electrons arealso collected to the same anode. Consequently, morenumbers of electrons can be collected and a better energy resolution can be obtained in the allene-doped
liquid argon than in the pure liquid argon. 1) Hitachi
et al. 2 ) measured the energy resolution (FWHM) in
the allene-doped liquid argon to obtain 0.37% for 33.5
MeV jnucleon 18 0 and 0.57% for 31.9 MeV jnucleon
36Ar.
Recently, it is required to measure the precise energy of heavy ions at around 100 MeV jnucleon. So,
we have developed a gridded ionization chamber suitable for this requirement. Figure 1 shows the chamber
and its cryostat. The beam window of the chamber
is made of 48 mm x 48 mm Havar foil with thickness of 130 mgjcm 2 , which works at the same time
as a cathode electrode. A screen grid consists of 10
J.lm¢ tungsten wires soldered to the flame with 150 J.lm
pitch. An anode electrode is a stainless steel plate connected to hermetic feedthroughs, which are connected
to a high-voltage (HV) module and to a preamplifier
through a coupling capacitor. A distance from thecathode to grid is 40 mm, longer than the range ofthe high-energy ions to be measured. Shielding inefficiency of the screen grid is <1%, which is negligible inmeasuring the energy resolution but might cause a little disturbance in the linearity of pulse heights against
the particle energies.
The gridded ionization chamber is fixed inside of astainless-steel vacuum vessel for the thermal insulation. The outside of the chamber is surrounded byabout four layers of superinsulators. To keep the chamber at a low temperature, liquid argon at the upper

148

part of the stainless-steel vessel is utilized as a coolant.
Argon and allene gas were purified through preconditioned molecular sieves at liquid oxygen temperature.
They were condensed into the chamber. The measurement started over 30 hours after the liquefaction.
The charge signal from the anode was fed into a linear amplifier (ORTEC 450) through a charge-sensitive
preamplifier. The shaping time constant of the linear
amplifier is 10 J.ls to ensure the entire charge collection.
Figure 2 shows the energy spectrum for 94
MeV jnucleon 40Ca experimentally observed. The energy resolution was obtained by subtracting in quadrature the width of test pulses from that of the charge
signal. At E = 2.5 kV jcm, the energy resolution was
0.6% (FWHM). The fraction of collected charge was
27% of the total charge produced.

512.------"T"E-=-2f)-k;-V.-km-,~ 94 MeVlnucleoo• 0.6 % (l'WHM)

1024

Fig. 1. Cross sectional viewof experimental apparatus.

2048
chanuel3072

Fig. 2. Experimental
energy spectrum obtained with detectorof Fig. 1.

Contribution of the fluctuation of energy loss into
the windows to the energy resolution was estimated tobe 0.26% (FWHM). The experimental result was worse
than this estimation by a factor of 2. Further study
is needed to understand and improve the limitation of
the energy resolution.
References
1) S. Suzuki: Ph. D. thesis, Waseda University, 1986.
2) A. Hitachi et al.: Nucl. Instrum. Methods Phys. Res. A
340, 546 (1994).
3) K. Masuda et al.: Nucl. Instrum. Methods Phys. Res. A
279, 560 (1989).

RIKEN Accel. Prog. Rep. 30 (1997)

Collinear Laser Spectroscopy of Li-like lIB BeamS. Ozawa, M. Hies, N. Inabe, T. Katayama, T. Kubo, H. Okuno, 1. Tanihata,
M. Wakasugi, Y. Watanabe, Y. Yano, and A. Yoshida
A new on-line laser spectroscopy system for thehighly-charged and high-energy ion beam is now in development to study systematically the nuclear charge
radii of unstable isotopes. In order to test the system,
we measured D1 transition of Li-like 11 B 2 + ion (primary beam) with the beam energy of 15 MeV/nucleon.
Figure 1 shows the experimental setup. The laser
pulse having the repetition rate of 100Hz is synchronized with the ion beam to collide each other at theinteraction region. The RF signal of the cyclotron isused as a trigger of the laser. The 11 B 2 + ions are excited by the laser from the ground state 2S I / 2 to the excited state 2P I / 2 . The D1 transition energy is 48358.5
cm -1 (A = 207 nm) ,1 ) and the laser wavelength is required to be 247 nm because of the Doppler shift. The
laser beam is provided with a pulsed dye laser excitedby an excimer laser and a second harmonic generator.
After the interaction, the excited ions are separated
from the laser beam line using a bending magnet. A
fluorescence photon detector, which consists of twelve
photomultipliers (PM) and two cylindrical mirrors, isput on the ion beam line behind the magnet to suppress a huge noise from the laser. The time of flightfrom the interaction region to the detector is about 40
ns. Before measurement , the spatial overlapping between the laser and the ion beam is checked using twoviewers made of ZnS , and the time overlapping is also
checked with a plastic scintillator (PL1).

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247.35 247.4 247.45 247.5 247.55 247.6 247.65
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curve shows the fitted line shape including hyperfine
components.

ity, the measurement should be made using two lasers
propagating parallel and anti parallel to the ion beam.
Then, the accuracy of the result should be .sufficientfor the isotope shift measuring.
Since PMs are put along the beam line, the decay
curve of the 2P I / 2 state is measured as shown in Fig. 3.
The life time is estimated to be 9(2) ns. The error isestimated without the systematic error.

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Fig. 3. Decay curve of the 2Pl / 2 state.

The fluorescence photon counts normalized by theion beam intensity are plotted in Fig. 2. Resonancepeaks are clearly observed. By making a least square
fitting to the data with Lorentz function, the center ofgravity of the spectrum line is derived to be 247.489(8)nm. Using the velocity of the ion (3 = 0.1779(8) measured with dipole magnets of RIPS, the transition energy is obtained to be 48365(24) cm- I . This is inagreement with NBS value. 1) Because of an ambiguityof the (3 value, the present accuracy is not enough tomeasure the isotope shift. To suppress the ambigu-

The detection efficiency of the present system is
8.1(8) x 10- 8 . The improvement of the 2P 1 / 2 stateat the detector is the easiest way to get a higher detection efficiency. Thus, we are now constructing a new
detection system that is put just after the interaction
region.
References
1) C. E. Moor: in Atomic Energy Levels (NBS, Washington
D.C. 1949), p. 19.

149

RIKEN Accel. Prog. Rep. 30 (1997)

Development of an On-Line Laser Ion Source
T. Ariga, M. G. Hies, T. T. Inamura, T . Ishizuka, W.-G. Jin,
K. Morita, T. Murayama, Y. Pu, and M. Wakasugi
An on-line laser ion source to employ a resonanceionization scheme has been developed at RIKENGARIS/IGISOL facility to investigate the nuclear
charge radii and electromagnetic moments of unstable
nuclei in the refractory element region. 1 ,2)The ion source was tested for the short lived isotopes
161- 157 Hf produced with the natsn (48 Ti, xn) reaction
using a 7.6-MeV /nucleon 48Ti beam from RIKEN Ring
Cyclotron. 3 ) These Hf isotopes are a-emitters. A target of natural Sn was used and the target thickness
was 1.0 mg/cm 2 . This target was put at the entranceof the gas-filled recoil isotope separator (GARIS). To
estimate the number of produced Hf isotopes, the 48Ti
ions elastically scattered from the Sn target were monitored. The Hf isotopes were collected at the ion guideisotope separation on-line (IGISOL) gas cell with the
GARIS. The Hf isotopes are thermalized and neutralized in the gas cell filled with a buffer gas of He and
Ar. The typical gas pressures were 150 Torr for He
and 120 Torr for Ar.
The Hf atoms are selectively ionized by a two-stepionization process using two-color lasers as shown in
Fig. 1, and are extracted together with the gas flow.
The wavelengths of lasers are 368.195 nm for the firststep (laser 1), and 357.408 nm for the second step (laser
2). The wavelength of the laser 2 is fixed , while that of
the laser 1 is scanned to find out the resonance wavelength of unstable Hf isotopes.

Fig. 2. If the wavelength of laser 1 is on resonance,
the intensities of the a-peaks of Hf at detector 2 areenhanced. The measurement of the a-spectrum is repeated by changing the laser wavelength. In Fig. 3, thecount rate of a-particles emitted from ionized Hf isotopes, which is measured with the detector 2, is shown
as a function of the laser wavelength. The count rate
are normalized with the monitor counts of elastic scattering of 48Ti beam. The deviation.of the resonancewavelength for the unstable Hf isotopes from that forthe stable isotopes is expected to be around -0.007
nm. A small enhancement is observable near -0.005
nm, but not clear because of the poor count rate.
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trap

0.001

.{l.OIS~~:p ,~e368 .1_95_nm_-ia.. ~:~\~,tateFig. 1. Experimental setup and the resonance ionization
scheme of Hf isotopes.

To prevent chemical reactions caused by the impurities in the buffer gas , highly purified gas (over99.9999%) was used, and a liquid nitrogen trap wasused to remove water in the gas line. To measure thea-decay of Hf isotopes, two photodiodes (10 x 10 mm 2 )were put in front of the nozzle of the gas cell (Fig. 1).
The detector 1 was put on the beam axis, whereas thedetector 2 was put off axis, and a negative voltage ( -40
V) was applied in order to catch only the ionized Hf
isotopes.
A measured a-spectrum in the gas cell is shown in
150

8] 0.00].{l.OI.{l.OOSWavelength [+368.195 nm 1

Fig. 3. The resonance ionization spectrum for 1 6 1- 157 Hf
isotopes.

In the present experiment , the enhancement of theyield of the a-decay of Hf isotopes due to laser resonance ionization is much smaller than that in the casesof off-line test experiment. 1) It seems that the purification of the buffer gas was insufficient; a small amountof O 2 may still be contained in the buffer gas. In the
future, the gas purifier system shall be improved inorder to increase the yield.
References
1) M. Hies et al.: RIKEN Accel. Prog. Rep. 29 , 177 (1996).
2) M. Hies et al.: RIKEN Accel. Prog. Rep. 29, 198 (1996).
3) M. Hies et al.: RIKEN Accel. Prog. Rep. 29, 46 (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Completion of Tritium Gas Handling System for Muon Catalyzed
Fusion Experiment at RIKEN-RAL Muon Facility
T. Matsuzaki, K. Nagamine, K. Ishida, S. N. Nakamura, 1. Watanabe, M. Kato,
K. Kurosawa, M. Hashimoto, and M. Tanase
We have completed a tritium gas handling system(TGHS) for the muon catalyzed fusion (fLCF) experiment at RIKEN Muon Facility of Rutherford Appleton
Laboratory (RAL) in U.K. This system enables us, atthe experimental site, to purify the target gas by removing 3He component, to change the D IT mixing
ratio, and to measure hydrogen isotope components,
in the target gas.
Detailed description of the system was given in Refs.
1 and 2.
The RAL staffs were called to Japan during the factory test to confirm the safe operation of TGHS before
its transportation to U.K. The TGHS installation including various tests and inspections, a tertiary house
construction as the third container of the target gas,
and the interlock system assembly were completed at
RAL in December 1995.
The tritium gas for the fLCF experiment has been
produced, enriched, and filled in gas cylinders at
JAER1. Two cylinders, containing 700 Ci (26 TBq)
tritium gas in each, were transported and installed in
the TGHS at RAL in January 1996.
Gas operation procedure of the TGHS was simulated
by using deuterium gas. Then, a small quantity of tritium gas (14 Ci or 0.5 TBq) was introduced to repeat
all the operations including the gas analysis procedure
to assure the safety. After some modification of thesystem together with a titanium-getter's performance
test at RAL, a tritium gas of 100 Ci (3.7 TBq) was
introduced further to the system to prove the safety
during the gas operation in May 1996. Finally, tritium gas was added up to 700 Ci (26 TBq) to confirm
the safety operation again, and then the fLCF experiment with 28% tritium concentration was commenced
in June 1996, where the total D/T gas quantity was
about 950 ml.
The schematic diagram of TGHS displayed on screenof the control computer is shown in Fig. 1. The D IT
target-gas purification was performed in every five days
approximately during the experiment according to thefollowing procedure, where the D IT gas was liquefied
in the target.
1. Target warm-up and the D IT gas vaporization tobuffer tank.

Fig. 1. Schematic diagram of the TGHS.

2. The D IT gas collection to an uranium getter atroom temperature.
3. Recovery of residual gas in the system to cryopump.
4. System evacuation by. turbo molecular pump andscroll pump.
5. The D/T gas release to constant volume from theuranium getter by heating.
6. Gas purification by passing the D IT gas throughPd-filter to cryotrap.
7. The D IT gas liquefaction in the target by cooling.
The gas quantity was calculated by PVT method,where P, V, and T are pressure, volume, and temperature, respectively. The tritium-release to stack during the system evacuation was monitored by an ionchamber (AI01) in the exhaust line.
The fLCF experiment with 28% tritium concentration has been conducted and some results are reported
in present volume.
References
1) T. Matsuzaki et al.: RIKEN Accel. Prog. Rep. 28, 134(1995).
2) T. Matsuzaki et al.: RIKEN Accel. Prog. Rep. 29, 194(1996).

151

RIKEN Accel. Prog. Rep. 30 (1997)

Compact CAMAC Data Acquisition System with
ACC K3976 and PC-LinuxS. N. Nakamura and M. Iwasaki*
We have developed a CAMAC data acquisition system (EXP95) with ACC K3976 and workstation (DEC
AXP200-4/166) at RIKEN-RAL Muon Facility. I) Thisdata acquisition system (DAQ system) had following
characteristics:• Data acquisition and on-line analysis are performed by two computers (ACC and a host computer),and heavy duty of on-line analysis on the host computer will not disturb data acquisition.
• It is especially suitable for pulsed beam facility,
because the data transfer from ACC to the host computer can be carried out during the spill off cycle.

• Acquired data quality can be monitored from aremote station via network.
• Off-line analysis can be performed by the same
software which is used for the on-line analysis.
• Commands to DAQ system can be given from auser-friendly graphical interface.
The EXP95 DAQ system is compact and highly flexible but the workstation is still too expensive (a few
million yen) to use for just test or very simple experiments. Recently, performance of the personal computers (PCs) increased rapidly and multi-user, multi-task
operating systems (e.g., PC-UNIX) became available.
Practically, there is no large difference in performances
between workstations (WSs) and PCs, even though PC
is one order less expensive than WS. Therefore, we de-signed a compact CAMAC DAQ system (EXP96) for
PC with all advantages of EXP95. We chose Linux
as the operating system (OS) of PC. Linux is a freely
distributable implementation of UNIX for Intel 80X86
machines (Recently, Linux project supports other platforms as DEC-Alpha and SUN-sparc). It is very stable
OS, and X window system is also available (XFree86
and Accelerated X). Most of CERN Library including
PAW ++ has been already ported to Linux and furthermore software developing environment is also well
prepared.
1) Hardware Configuration
Hardware configuration is exactly the same as EXP95,
except that WS was replaced by PC. The system
consists of two computers: One is a CAMAC Auxiliary Crate Controller (ACC: Kinetics K3976) with
MC68030 40MHz CPU and 1MB memory (upgradable to 4MB). The ACC concentrates on data collection from CAMAC modules, and the acquired data aretransferred to PC via CAMAC-SCSI interface (Kinetics K3929). CAMAC DAQ part was not changed from
EXP95 and its ability is the same. Typically, one CAMAC word data acquisition takes 1.6 J-lsec.
In present paper, PC means so-called AT clone
which is supported by Linux. Detail of the required
PC specifications can be found in Ref. 2. There aremany options of hardware for AT clone, but the selections of SCSI interface board and video card are
crucial. Table 1 shows hardware specifications of ourPC on which EXP96 has been developed.

Table 1. Hardware configuration of the PCs used for development.

CPU
MemoryHard DiskSCSI Interface
Video Card

PC 1Intel Pentium 100MHz
32 MB
EIDE 1GB, SCSI 1GB
BT-946C
Number Nine Motion 771

CPU power and DAQ performance have no direct
relation since the ACC collects data from CAMAC
modules. Even 80486 CPU can be used for EXP96,
however, more powerful CPU is desirable for quick response in on-line analysis. Memory should be more
important than CPU power. In order to use X window system, 16MB RAM is prerequisite. As a DAQ
host computer, 32MB or more is preferable. We used
Meson Science Laboratory, Faculty of Science, University of
Tokyo

152

PC 2
Pentium-Pro 200MHz
32 MB
EIDE 2GB, SCSI 2GB
AHA-2940
Matrox Millennium

an EID E harddisk as well as a SCSI hard disk during
development, because a bug of the software related
to the SCSI device driver disabled us to access SCSI
harddisk. We believe that there is no more serious
bug and one SCSI harddisk should be enough for now.
Any SCSI interface card on the Linux supporting list
is usable. However, it should be noted that the performance of SCSI interface has direct relation to datatransfer rate from ACC to PC. The EXP96 requires X
window system and the video card should be supported

by XFree86 (free port of MIT X Window System for
80X86) or by Accelerated X (commercial X Window
System for 80X86).

~CAMAC Commands

~

I

I

CAMAC Modules

Data2) Software Configuration (See, Fig. 1)
On ACC K3976, the program which manages CAMAC functions is running. This program is written
by M C68030 assembly language. Cross 68030 assembler was written by Fortran and compiled with f2c+gcc
on PC. A user can easily write CAMAC commands
sequence using macro library without any knowledge
on MC68030 CPU. This ACC machine code has 100%
compatibility between EXP96 and EXP95.
On the host PC , several processes are running on
Linux to receive data from ACC. Main programs of
EXP96 are written from scratch by C, not using thecode from EXP95 written in Fortran. The CAMAC
function driver uses a generic SCSI device driver (apart of Linux kernel) and it does not depend on a particular hardware. Therefore, any SCSI interface board
can be used if it is supported by Linux kernel. It should
be noted that even PCMCIA SCSI interface card canbe used for EXP96 and thus even laptop PC can serveas the host computer.
On-line and off-line analysis were performed by
PAW++ software developed at CERN. 3 ) Stored data
can be analyzed after the experiment with the same
software used for the on-line analysis. The off-line
analysis can be performed on PC as well as WS.
The graphical user interface was constructed on XWindow system with Tcl/Tk and the same look-andfeel was realized between EXP95 and EXP96.
3) Performance Test
ACC can acquire one CAMAC word data per 1.6 f.Lsec

ComputerDEC AXP200-4/166MHz
Pentium 100MHz
Pentium-Pro 200MHzOS
OVMS 6.1H2
Linux 2.0.0
Linux 2.0.0

ACC K3976

PC + Linux
Fig. 1. Three processes (expdriver, analysis and command)run on the host PC communicating with each other by
expmail process which uses UNIX message. Acquired
data by the ACC are transferred to PC via generic SCSI
device driver and stored on a hard disk by expdriver.
These data are shared with analysis using UNIX sharedmemory function and some of them are analyzed andpassed to it PAW++.

and it does not depend on the host computer. Contrarily, SCSI data transfer rate depends on the hardware. Three different computers, DEC AXP200-4/166(WS) , Pentium 100MHz (PC), and Pentium-Pro 200
MHz (PC) were tested.

SCSI Interface
Originally equipped
BT-946C (ISA)
AHA-2940 (PCI)

As seen in the table, PC performance is better than
WS against our expectation. Linux is much smaller
and lighter OS than Open VMS, and thus it might
have better performance for low-level I/O accesses. In
addition, a new SCSI card (e.g. , AHA-2940) with better performance will be supported quickly by Linuxbecause it is improved constantly.
We developed a compact CAMAC DAQ system with
ACC and PC + Linux. This DAQ system inherits alladvantages of the workstation version, and shows better performance even though PC is one order less expensive than workstation. PC will be useful as a part

Block Transfer Rate (kB / sec)
750
790
912

of DAQ system for the medium and small experimentswith the best cost performance.
References
1) S. N. Nakamura and M. Iwasaki: RIKEN Accel. Prog.
Rep. 29, 192 (1996); Nucl. Instrum. Methods Phys. Res.
in press.
2) FRiC: Linux Hardware Compatibility HOWTO,
http://sunsite.unc.edu/mdw.
3) CERN Application Software Group: CERN Program
Library Q121, (1995).

153

RIKEN Accel. Prog. Rep. 30 (1997)

Evaluation of UNIX DAQ System (UNIDAQ) on VME
Y. Watanabe, H. Kobinata, * Y. Mizoi, Y. Watanabe, A. Yoshida,
T. Miyachi, T. Fukuda, M. Notani, and M. Ishihara
We are now developing a MUSIC-type detector 1) inorder to research fusion reactions with unstable nuclei. The UNIX DAQ (Data Acquisition) system on
a VME (Versa Module Europa) board computer was
introduced to deal with a large amount of data at ahigh-speed, and its ability was evaluated.
Our MUSIC-type detector 2 ) measures the drift time
and the energy loss of incident charged particles. This
makes it possible to locate the particles in the three
dimensional space so that their plural tracks can bedetected at the same time.
For that purpose, we employ Flash-ADC TKO(TRISTAN/KEK Online system) modules which readout pulse signals from the cathode pads as a time series data. A single Flash-ADC module contains eightFlash-ADC channels and each one will sample thepulse shape every 25 ns during 25.6 J.LS. The dynamic
range of the Flash-ADC is 8 bits. We use 128 FlashADC channels and the TKO crate controller, SCH, extends 8 bits data to 32 bits data, so the total data sizeof all Flash-ADC's is 512 kbytes per event. Although
SCH has the ability to suppress the data beneath a certain threshold and hence to reduce the total size of data
(threshold suppression), the total data size was yet toolarge. We have thus introduced TKO-VME DAQ system to deal with these enormous data swiftly. The
TKO interface of VME, SMP, has two buffers. The
data from TKO is stored on one buffer; another bufferis accessed through the VME dataway. They are able
to be swapped. Thus, simultaneous two data transfers
make the data acquisition rate enhance. The SMP
is controlled by the UNIX DAQ system, UNIDAQ ,3)which runs on the HP743rt/HP-RT v2.02 board computer placed in a VME module. Figure 1 illustrates aschematic of the UNIX DAQ system. The workstation,
HP-UX v9.05, controls the DAQ system and analyzes
data.

The UNIDAQ contains three computer processes:
collector, recorder, and analyzer. The collector process and the recorder process run on the HP -RT board
computer. The analyzer process runs on the HP-UX
workstation. The collector process fetches data fromthe CAMAC and TKO modules; the recorder process writes down the data on the DAT (Digital Audio
Tape); and the analyzer process analyzes them.
We evaluated the data acquisition rate using only
four units of Flash-ADC modules with random pulse
triggers. 4 ) The only half size of the data (12.8 J.Ls) was
read from each Flash-ADC for the evaluation. Figure 2
shows the time required by each stage of the data acquisition. From Fig. 2 we can expect the data acquisition rate without (with) the DAT to be 90 cps (17cps). The measured data acquisition rates are shownin Table 1, and they were only slightly smaller than the
expectation values. In the present circumstances, thethreshold value of the threshold suppression was zeroand the total data size was about 24 kbytes. So, thedata transfer rate without the DAT is 1.8 Mbytes/sec.
Adjustment of the threshold value and the adoptionof a high-speed data storage device may improve thedata acquisition rate.
Trigger

FADe -SMP

SMP - > HP· RT

Hp·RT -

OAT

U

--g

--US
------,C 48ms -~Fig. 2. Time required by each stage ofthe data acquisition.
Table 1. Data acquisition rate by four units of Flash-ADC
modules. Only half size of the data was read from eachFlash-ADC for the evaluation. The data size of one
event was compressed from 64 kbytes into about 24
kbytes by the threshold suppression.
Expectation
Measurement

w/o DATwi DAT

90 cps75 cps17 cps15.5 cps(1.8 Mbytes/sec) (0.4 Mbytes/sec)

References

Fig. 1. A schematic illustrating the UNIX DAQ system .
Micro-Fabrication P rocess Dev. Lab. , ULSI Device Development Laboratories, NEC Corporation

1541) K. Kimura et al.: Nucl. lnstrum. Methods Phys. Res. A
2 9 7, 190 (1990).
2) Y. Mizoi et al. : RIKEN Accel. Prog. Rep . 30, 143 (1997).
3) Unidaq Documentation Set , SDC-93-478, Superconducting Super Collider Laboratory (1993).
4) H . Kobinata: Master's thesis, University of Tokyo, 1996.

RIKEN Accel. Prog. Rep. 30 (1997)

Computing Environment around the Accelerator Research Facility
T. Ichihara, Y. Watanabe, and A. YoshidaIn this report, we describe the recent update and improvement of the computing environment around the
RIKEN Accelerator Research Facility (RARF). The
updates of the computers in this year are indicated by
the underline. General description of the data acquisition system at the RARF can be found elsewhere. 1)(1) On-line data acquisition system
Currently, seven VAX's are used for CAMAC-based
on-line experiments at the RARF. The node names
and locations are as follows:
GALlS::GALISF::
SMART::
SMARTF::RIPSVX::RIKMVI::RIKMV2::RIKMV3::RIKMV4::Alpha station (B2F EI)
VAX 4000/106A(B2F El)
Alpha Station (B2F E4)
VAX 4000/106A(B2F E4 )VAX 4000 (B2F RIPS)
Micro VAX II (IF)Micro VAX II (B2F E3)
Micro VAX II (Linac )Micro VAX II (B2F E6)

Two new VAX 4000/106A computers (GALISF:: ,SMARTF::) were installed for data acquisitions , andtwo new Alpha stations (GALlS , SMART) were installed for on-line data analysis and display. Independent measurements and detector tests can be performed without interference. The current version of
the data-acquisition system supports a CAMAC multicrate parallel-readout using multi-Jll 's (starbursts).
Digital audio tapes (DAT) of 2 GB capacity are used
for the standard on-line data recording media.
(2) Off-line data processing system -1
The following Alpha/VMS and VAX/VMS workstations are available for the off-line data analysis and for
RIKAXP::
RIKAXl::RIKAX2::RIKAX3::RIKAX4::RIKAX5::RIKAX6::RIKAX7::
RIKEN::RIKVAX::RIKVSO::RIKVS2::RIKVS3::
RIK835::RIKLVl::RIKLV2::Alpha server 5/250 (Ring IF) 4 CPU
Alpha Station 255/233 (Ring IF)
Alpha Station 255/233 (Ring IF)
Alpha Station 255/233 (Ring IF)
DEC 3000-300 (Linac Lab.)DEC 3000-300 (Atomic Lab.)DEC 3000-300 (Ring, nuclear theory)
DEC 3000-300 (Radiation Lab.)(virtual node name of the VAX cluster)VAX-4000/106A(Ring IF)
DEC 3000-400 (Ring IF)
VAX Station 4000-60 (Ring 2F)
VAX Station 4000-60 (Ring IF)
DEC 3000-400 (Radiation Lab.)VAX Station 3100 M76 (Linac Lab.)DEC 3000-400 (Linac Lab.)

general purpose calculations.
Two CPU modules were added in the Alpha server
5/250. As a result, the server equips four CPU's and
512 MB memory. This is utilized as a home machinefor the experimental users and also a boot server for
AXP workstations. File servers for the experimental
data of RIKAXI-3 were replaced from DEC 3000-400
by Alpha Station 255/233. In total eleven alpha workstations and three VAX workstations are used for thedata analysis etc. These computers are connected by
LAVC (Local Area VAX Clusters) via the FDDI or ethernet. They are also connected to the HEPnet (DECnet) and STA/IM Internet (IP /DECnet) and reachable
from all over the world.
(3) Off-line data processing system -2
Following FACOM VPP 500 Massive Parallel computers and DEC OSF /1 server and workstation groups
have been also used for the off-line data analysis, simulations, and theoretical calculation:
FACOM VPP 500
DEC 7000 (OSF /1)(RIKEN computing center)(RIKEN computing center)(4) Wide area computer network connectivities
The TISN (Todai Inter~ational Science Network)
was terminated in May 1996. RIKEN is now connectedto the STA/IMnet at the speed of 1.5Mbps. This will
be increased to 6Mbps in 1997. Also the RIKEN accelerator research facility is connected to the world-wide
network of HEPnet (High Energy Physics NETwork)/ SPAN (Space Physics Analysis Network) as Area 40,
which is a part of the DECnet Internet. In order tosupport these wide area network connections, following
three leased lines are used:
1.5 Mbps
64 kbps
9.6 kbps

to STA/IMnet (IP, Decnet)
to KEK , Tsukuba (DECnet)
to Tokyo Institute of Technology (DECnet)(5) Address of the electric-mailThe address of the electric-mail for a general userof the RIKEN accelerator research facility is describedas follows, where the userid should be replaced by aproper name.
(Internet)
userid@rikaxp. riken. go .jp(HEPnet /D ECnet)
rikaxp::USERID (or 41823::userid)

References
1) T. Ichihara et al.: IEEE Transaction on Nuclear Science
35-6, 1628 (1989).

155

RIKEN Accel. Prog. Rep. 30 (1997)

Fabrication of the Muon Magnet for the RHIC Spin Project
T. Ichihara, H. Enyo, Y. Goto, N. Hayashi, K. Imai, A. Masaike, N. Saito,
T. Shibata, Y. Watanabe, and M. Ishihara
Relativistic Heavy Ion Collider (RHIC) will be completed in 1999 at the Brookheaven National Laboratory (BNL). The Siberian snakes and spin rotator magnets will be installed in the RHIC main ring, according
to the RIKEN-BNL spin physics collaboration.!) These
make it possible to accelerate the polarized protons up
to 250 Ge V for collision to investigate the origin of thenucleon spin.
Muon magnet (MM) is one of the detector magnets
to be installed in the PHENIX detector in order to analyze the momenta of muon and muon-pair with highresolution. It is about 8 m tall and weighs approximately 200 metric tons. RIKEN is taking a role of fabricating it. Basic design 2 ) of the magnet has been carried out in collaboration with Lawrence Livermore National Laboratory (LLNL). The results has been presented by means of 3D CAD (Pro/ENGINEER) data.
The contract between RIKEN and Mitsubishi Elec-

Fig. 1. M lion magnet on the track system.

tric Cooperation (Meleo) was concluded in March 1996
for the fabrication of the magnet. After the completion, the whole magnet will be transported to the BNLin April 1997. A part of the magnet (coil) was alreadyshipped to the BNL in August 1996.
As shown in Fig. 1, the muon magnet consists ofbasic part and attachments. The whole magnet is put
on a track system and can be moved by a Hilman roller
and hydraulic cylinder system for the installation andmaintenance of the tracking detector.
The basic part of the muon magnet consists of steel
and coils. Its main components are shown in Fig. 2.
The piston core is mounted on the backplate. The
counter weight is made of lead bricks, which is necessary to keep the center of the gravity low and to makesure of the stability in traveling.
A cross section of the magnet is shown in Fig. 3.
Two coils, the front and rear coils, will be installed on

Fig. 2. Basic component of the muon magnet.
(j

1000

1000 Nilf---'---'-----'
SCAlf

-N

Fig. 3. Front view and cross section of the muon magnet.

156

Table 1. Specifications of the coil.
Item
AT
Current
N umber of Turns
Inner Diameter
Outer Diameter
Coil Length
Conductor cross section
Conductor Material
Resistance (at 20° C)
Voltage
Joule Loss
No. of Water Cir.
Water Flow Rate
Water Temp. Rise
Flow Velocity

Front Coil
131 , 100AT
2 , 300A
57turn/coil¢1413.0mm¢1499 .4mm
586mm

Rear Coil
262 , 200AT
2,300A
114turn/coil¢1617.0mm¢1787.4mm
606/567mm

18.5 x 18.5mm 2¢ 11 .5OFC
19.0mf2
44.4V
102 .1kW
8179l/min
8.1 ° C
3.6m/sec

18.5 x 18.5mm 2
¢11.5
OFC
44 .4mf2
104.1 V239 .5kW
16
331l/min10.2°C
3.3m/sec

the piston core of the magnet. Insulation of the coils
will be done by pre-pregnant method. The windingsof each coil will be connected electrically in series.
The specification of the MM coils are as shown in
Table 1.
The muon magnet is presently under construction
at Melco Kobe Works and will be completed in March
1997. The news on current status of the magnet fabrication can be obtained by the WWW server at the
URL ofhttp://www.rar.f.riken.go.jp/rar f /rhic/mmsj.
References
1) See the WWW server oj
http://www.rarf.riken.go.jp/rarJ/rhicj.
2) PHENIX Muon Magnet South-Preliminary Design Review, LLNL-PHENIX-96-002, May 11996, unpublished.

157

6. Material Analysis

RI KEN Accel. Prog. Rep. 30 (1997)

Development of an In-Air High-Resolution PIXE System
K. Maeda, K. Ogiwara, H. Hamanaka,* and K. Hasegawa*
We have constructed a compact, wavelengthdispersive spectrometer system for the high-resolution
PIXE (particle induced X-ray emission) analysis in the
air of atmospheric pressure.
An experimental setup for the PIXE system isschematically shown in Fig. 1. 1 ) A proton beam (rv2.5
Me V) generated by a tandem accelerator is taken outof the vacuum line to the air through a 7 J.lm-thickAI-foil, which collides against a sample target placedin the air. The distance between the exit AI-foil andthe target surface is 15 mm. Passing through the airand AI-foil reduces the proton energy by 0.3 MeV. Xrays emitted from the target are analyzed with a flat
single crystal and detected by a position-sensitive proportional counter (PSPC).
ion

vacuum beam line
crystal~~~~a3~~polyethylenebagFig. 1. A compact, in-air , high-resolution PIXE system:
Sd , the divergence slit ; G e and G a , the guide frames for
X-ray path; and </>, the X-ray take-off angle.

The analyzing crystal and PSPC are both mounted
on a B-2B goniometer. A guiding frame (entrance guideG e ) for the path of X-rays is placed between the source
and crystal, and another frame (acceptance guide G a )is placed between the crystal and PSPC. The top of theentrance guide is covered with a thin (1.5 J.lm-thick)Mylar window. The whole path of X-rays from theentrance guide to the PSPC window via the crystal isenveloped with a commercial polyethylene bag. The
total path length of the X-rays is fixed by 35 cm. Helium gas is introduced through a small hole made on
the bag. It requires a few minutes to fully replace theair in the bag by He gas. No serious loss of He gas wasobserved during the B-2B rotation of the crystal and
PSPC. The top part of the entrance guide is so smallthat the entrance window can be placed very close to
the X-ray source, as close as 3 mm of distance.
The PSPC used here is a home-made, single resistive anode type. It employs a carbon fiber of 7 J.lmdiameter as the anode. The cathode is the window andCollege of Engineering, Hosei University

walls of the counter tube. We have also constructed acharge-division type multichannel analyzer. The output pulses of the PSPC are converted into position signals by a digital divider and accumulated in the memory of the analyzer. 2,3) The system control and dataprocessing are carried out with a personal computer.
The size of the PSPC is very small, i.e., 10 cm x 3.5
cm x 4 cm. Its sensitive window is 30 mm in widthand 8 mm in height , and its spatial resolution is 0.3
mm with a 1 bar of P-I0 counter gas. For the present
geometry, the simultaneously detectable angular range(~e) is 5°, and 1 channel in the PSPC corresponds to0.094 mm in position and 0.0157° in the angle B. An
aluminized 4 or 1.5 J.lm-thick Mylar sheet is used for
the PSPC window.
Considering the absorption factors of X-rays by thespectrometer window, PSPC window, helium gas, andair, the lower limit of X-ray energy detectable with thissystem is estimated to be around 1 keV. Until now, wehave measured Ka and K{3 spectra of AI, Si, P, S, andCI in several compounds. It took only a few minutes
to one hour to obtain one spectrum which was inducedby 100 nA of 2.2 MeV protons. For examples, theobserved intensity of Si Ka from a crystalline Si wafer
was 5000 counts/ J.lC and that of P Ka from pressed
powders of boron phosphide (BP) was 3500 counts/ J.lC,
using an InSb (111) analyzing crystal.
As representative spectra measured with this system, Si Ka and K{3 of a fused quartz (Si0 2 ) and acrystalline silicon (c-Si) are shown in Figs. 2 and 3, respectively. These spectra were induced by a 2.2 MeV

10000

100

~

·iii
c:

~

10000

/\

CI3

i 100) \'-.J\ oS;~~'": ...

-.",.. ,.:- ..

.,....~.!:

I

1740

1750

1760

1770

X-ray energy (eV)Fig. 2. Si Ka. spectra of Si02 and c-Si. Accumulated
beam charge = 50 j.LC.
159

I

600 I-

I

I

Sil¢,

I

I

-

SiC,

-

..

-

.~

~

~ 600 -

!

I--i

c-Si

20channels-.EO~ 4001-

X

Q:l00 ...C

-

2001-

X-ray energy (eV)Fig. 3. Si K{3 spectra of Si0 2 and c-Si, where Q is theaccumulated beam charge.
proton beam of 3 mm-diameter and analyzed with an
InSb (111) crystal of interplaner spacing of d=0.374
nm. The X-ray take-off angle was 10°. The angle 2Bat the center of the PSPC was set at 141° for the Si
Ka and 129° for the Si K(3.
The line (al ,2) of Ka emitted from a singly ionizedstate, KLo, and the Ka satellites emitted from multiply
ionized states, KLl and KL2, were well resolved asshown in Fig. 2. Moreover, fine structures in the KLI
satellite (a3 and a4) were clearly distinguished.
FWHM (full width at half maximum) for the Si
Kal ,2 of c-Si estimated from Fig. 2 was 1.8 eV. Thisvalue is reasonable considering the following factors:(1) natural width of each component of the Si Kal ,2doublet is 0.49 eV and splitting of the doublet is 0.60
eV, and (2) line broadening due to the angular resolution (dB) of the spectrometer is 0.9 eV. The dB isdetermined mainly by the X-ray source width, the spatial resolution of the PSPC, and by the path lengthof X-rays from the source to PSPC. The dB was estimated to be 0.094° for the experimental condition of

160

Figs. 2 and 3, corresponding to 0.9 eV and 1.4 eV in
the energy ranges of Si Ka (1.74 keY) and Si K(3 (1.84
ke V), respectively.
The K(3 spectra reflect the nature of the chemicalbonding more prominently than the Ka spectra, as
can be seen from Fig. 3. A satellite line denoted byK(3' appears on the low-energy side of the main line
K(31 in the spectrum of Si0 2 . The K(3' line is notobserved in the spectrum of the c-Si. The energy difference between the K(3' and K(31 lines is 14 eV. Thisvalue approximately equals to the energy difference between 0 2s and 0 2p orbitals. While the K(31 main line
is due to the molecular-orbitals composed of both Si
3p and 0 2p, the K(3' satellite is originated from themolecular-orbital composed mainly of 0 2s. Thus , finestructures of K(3 spectra can represent well the chemical environments of atoms in compounds.
PIXE measurements in non-vacuum , especially inthe atmospheric air, are quite useful for biological, environmental, and archeological substances because thein-air PIXE has many advantages such as: 1) the sample handling is simple, 2) there is no limit of sample size, 3) the vaporization of a volatile component
is suppressed. We have made a compact , in-air highresolution PIXE system in reality. Using this system,
in-situ chemical state analysis of delicate samples is
now possible. Since the PIXE system requires only asmall amount of samples (::; 1 mg and/or::; 10 mm 2 )and a short data acquisition time (::; 1 h for a spectrum), a two-dimensional mapping of chemical states
for an example is promising.
References
1) K. Maeda, H. Hamanaka, and K. Hasegawa: Int. J.
PIXE in press.
2) H. Hamanaka, K. Hasegawa, and Y. Yamamoto: Int. J.
PIXE 1 , 141 (1990) .
3) M. Koike and K. Hasegawa: Nucl. lnstrum. Methods
Phys. Res. A 272, 840 (1988).

RIKEN Accel. Prog. Rep. 30 (1997)

Positron/Positronium Annihilation in Nanocrystalline Si
X. Zhao* and Y. Itoh
Positron and positronium annihilation investigations
were applied to nanocrystalline silicon (nc-Si) thinfilms , for the first time. The nc-Si thin films with average crystallite diameters of 3- 5 nm show intense blue
luminescence at room temperature. The nanometersized Si crystallites formed in amorphous Si (a-Si) matrix give rise to this luminescence caused by a quantum
size effect. 1) Because of the nc-Si layer is formed by acrystallization of a-Si and is a mixture of a-Si and nc-Si
phases combined by a grain boundary, it is interesting
to observe the positron (Ps) annihilation effect in suchnew materials, especially to observe the phase transition from amorphous to crystalline in nanometer scale.
S-parameter-positron energy curves were measured
for the samples crystallized for 10 s to 1 h as well as forthe as-grown a-Si, as shown in Fig. 1. Very Large Sparameters up to 0.62 were observed in the as-grown aSi thin film , and then, the S-parameters dropped suddenly to 0.53 by crystallization of the thin film at 800°C for 10 s, which was almost the same to the value
observed in the c-Si (100) substrate. Further crystallization from 60 s to 1 hour showed smaller change in
the S-parameters than that from the a-Si to 10 s, as
shown in the figure. The large S value for the as-grown
a-Si sample indicates that a great number of para-Ps

0.64 r--,-----,-~-r=====~
nc-Si thin film 500nm :o Virgin a-Si
Crystallized at 800c .
•
lOs
0.62
o 60s
0 .6 ~ ..................,.................

6.

600s

o

..

3600s

20

25

o

............... , ................ 00.56 f- .......... .... ....... .... ....... ,

0.54

0.52
0.5

0.48 05

10

15(p-Ps) annihilates in the structural defects, such as
nanometer-sized voids. The a-Si layer was depositedon Si substrate at room temperature, which introduces
a high strain field if there is a structural defect. The
defect seems to disappear by a relaxation of the strain
during annealing at 800°C, no matter how short theannealing time is. The relaxation of the strain, on theother hand, induces a nucleus generation in the straininduced crystallization process. Thus, the vanishing of
the Ps formation indicates the growth of the nanocrystallites in the a-Si matrix. This suggests that positronis a sensitive probe for structural investigations of thenc-Si materials.
In order to obtain additional information on the nature of Ps formed in a-Si, positron lifetime measurements were carried out by using an accelerator-based
pulsed positron beam at Electrotechnical Laboratory,
Japan. It is interesting that there is no long-lived
ortho-Ps component (> ns) in the as-grown a-Si layer.
The average lifetime of the Ps is estimated from thespectra to be 520 ps, which is close to the spin-averaged
lifetime of the Ps. The absence of the long-lived component might be attributed to a fast spin conversion
effect of o-Ps to p-Ps. Because no H was involved in
the deposition process,l ) there may be a lot of dangling bonds in the as-grown a-Si layer. It is proposedthat upon the collision with the unpaired electron of
the dangling bond 0- Ps undergoes the spin conversion
and annihilates with the short lifetime of about 520
ps. The lifetime for the sample annealed for 10 s wasdetermined to be 310 ps which is close to the valueof positron annihilating in a divacancy defect in c-Si 2 )indicating an annealing out effect of the larger size defects. The sample annealed for 1 h showed a longer lifetime component besides the 310 ps one. This should
be due to the growth of the crystallites from the nuclei
which introduces additional structural defects in thegrain boundaries.
We would like to thank K. Hirata and Y. Kobayashi
of National Institute of Materials and Chemical Research and T. 0 hdaira, R. Suzuki, and T. Mikado ofElectrotechnical Laboratory for the collaboration.

30

POSITRON ENERGY (KeV)
Fig. 1. S-parameters of a-Si and nc-Si thin films as functions of the positron energy. S-values at energies higher
than 25 ke V are close to that measured from the c-Si
substrate.

References
1) X. Zhao, O. Schoenfeld, S. Komuro, Y. Aoyagi, and T.
Sugano: Phys. Rev. B 50, 18654 (1994).
2) M. Kwete, D. Segers, M. Dorikens, L. DorikensVanpraet, and P. Clauws: Phys. Status Solidi A 122,
129 (1990).

Laboratory for Nanoelectronics Materials, Frontier Research
Program161

RIKEN Accel. Prog. Rep. 30 (1997)

Development of a TOF-ERDA System for Wide Mass Range
W. Hong, S. Hayakawa,* K. Maeda, S. Fukuda, M. Yanokura, M. Aratani,
K. Kimura, Y. Gohshi,* and I. Tanihata
Elastic recoil detection analysis (ERDA) is one of
the most promising methods for determination of lightand medium elements in a heavy matrix, such as tracehydrogen analysis. Though a conventional ERDA employing a stopper foil in front of the detector has been
performed at RIKEN,1 ,2) a new ERDA system using
time of flight (TOF) detection was set up to realizeboth higher mass resolution and lower detection limit.
The experimental arrangement is shown in Fig. 1.
40 Ar ions accelerated to 41.5 MeV by the RILAC wereused as a probe. Incident angle of the beam was 55°.
A tantalum collimator having 3 mm¢hole was used. A
time detector composed of two MCPs and 10 J-Lgjcm 2
carbon foil 3 ) was assembled and installed between thesample and the SSB detector. The time resolution of
the detector was better than 100 ps. Detector angle
was 55° and the physical length of flight was 314 mm.
A CAMAC system was used to control counting system
by KODAQ code 4 ) on a personal computer. Figure 2
shows the spectra of a Si wafer. High channel of thetime axis represents short time because the start andstop signals are reversed to each other. Oxygen is fromnatural oxide layer of the Si wafer surface. Carbon appears because of low vacuum (3 x 10- 7 torr) of thetarget chamber. The energy and time resolutions were
530 keV at 13.2 MeV and 0.9 ns at 33.0 ns respectively.
The mass resolution was calculated to be 1.9 at mass
28. The energy and time resolutions may be overestimated because of the car bon and silicon oxide layers
at surface.

35 deg.
Collimator I

L-..

Sample........ ~.

Beam~ .

I).

.

Time ~ 55 deg.
detector

0

SSB
detector

Fig. 1. Setup of the TOF-ERDA spectrometer.

After the measurement, the spectra are reconstructed with the region of interest determined by an
input gate defined anew on the scatter plot , Fig. 2(a).
The gate established on the scatter plot affects theother windows, Fig. 2 (b), (c) so that the only data
corresponding to the selected data of the scatter plot
appear in the energy and time spectra. With thisDepartment of Applied Chemistry, University of Tokyo

162

1000 r - - - - - - - - - - - - ,

_800

c

0

200

300

(a)

.c

~600
G)

~ 400
200
100

400

500

energy (ch)
600

(b)
400

E::J
0

u
200

100

200

300

400

500

energy (ch)
600

(c)
400

E

::J

0

u
200

200

400

600

800

1000

time (ch)Fig. 2. Raw spectra for a Si wafer. (a) TOF-Energy
scatter plot, (b) energy spectrum, (c) time spectrum.
Counting time: 20 min.

method, a peak can be separated from the other peaks
and background in the energy and time spectra.
By using the TOF system the mass resolution of
ERDA was improved remarkably. The main results
are: (1) Hydrogen, carbon, nitrogen and oxygen weredetected simultaneously. (2) The mass resolution of
the system was 1.9 for silicon of the mass 28. (3)Carbon, nitrogen and oxygen peaks were separated in
TOF -E scatter plot, and energy spectra of individual
elements were obtained with use of KODAQ code. Resultant low-background spectra are promising for detecting trace elements whose peaks are difficult to be
detected by conventional ERDA.
References
1) H. Nagai, S. Hayashi, M. Aratani, T. Nozaki, M.
Yanokura, I. Kohno, O. Kuboi, and Y. Yatsurugi: Nucl.
Instrum. Methods B 28, 5'9 (1987).
2) K. Kanazawa, M. Yanokura, M. Aratani, and H.
Akiyama: Vacuum 44, 7 (1993).
3) K. Kimura and J. Wada: Phys. Rev. B 48 , 15535 (1993).
4) K. Ornata, Y. Fujita, N. Yoshikawa, M. Sekiguchi, andY. Yoshida: IEEE Trans. Nucl. 39, 143 (1992).

7. Miscellaneous

RIKEN Accel. Prog. Rep. 30 (1997)

Strong X-Ray Emission due to a Charge-Up EffectJ. Kawai, N. Inada, and K. Maeda
We have found that strong x-rays are emitted fromcharged-up targets when MeV ion is bombardingJ-3)
The electrified insulator target was ionized by electron
beam as well as ion beam. X-ray emission cross sectionof the electron excitation is much higher than that of
the ion excitation for such an experimental condition.
This charge-up X-ray emission effect was first discovered by Terasawa4 ) almost 30 years ago.
To clarify the mechanism of the charge-up effect,
we applied DC 3 k V between a copper pin and copper
plate in a 10- 5 Torr vacuum (see Fig. 1). The distance
between the pin and the plate was 8 mm. The plate
was coated by fluorescent powder. A tungsten filament
to supply thermionic electrons was set in the vacuum
chamber. Once the filament was switched on, electrons
were supplied from the filament to the vacuum chamber, and X-rays began to generate after one strong
spark between the pin and the plate. The X-rays weredetected by a Si(Li) solid state detector. Just after
the spark, we switched off the filament, but the X-rays
were still emitting. The X-rays continued for several
minutes or say thirty minutes, and stopped by anotherstrong spark. There observed a few bright spots on the
fluorescent powder coated on the copper plate during
this X-ray emission. Thus, the X-rays emitted after
the filament had been switched off was a field emission
from the sample. The details of the mechanism of theFig. 1. Schematic illustration of the experimental setup.
1. Copper pin, 2. Copper plate coated by fluorescentpowder, 3. Vacuum chamber, and 4. Thngsten filament.

strong X-ray emission from a charged-up insulator has
not yet been clarified, but it has been demonstrated
that the 3 k V DC field emission can generate strong
X-rays.
References
1) J. Kawai, K. Maeda, N. Sakauchi, and I. Konishi: Spectrochim. Acta B 50, L1 (1995).
2) K. Maeda and H. Hamanaka: Spectrochim. Acta B 51,
343 (1996).
3) J. Kawai, K. Maeda, N. Sakauchi, and I. Konishi: Nucl.
lnstrum. Methods Phys. Res. B 109/110, 206 (1996).
4) M. Terasawa: J. Phys. Soc. Jpn. 25, 1199 (1968).

163

RIKEN Accel. Prog. Rep. 30 (1997)

Residual Radioactivity Produced by
2.9 MeV/nucleon a-Particles
Y. Uwamino, S. Kagaya, S. Shinohara, K. Harasawa, and T. Kambara
The maximum energy of RILAC is above 2.5
Me V / nucleon, but any experiment should be performed with the energy below or equal to 2.5
MeV /nucleon at present because of the radiation
safety. The main purpose of this experiment is toget an accurate information on radiation safety for theabolishment of the above energy adjustment.
Residual radioactivity produced by 2.864 MeV /nucleon alpha (a) particles was measured with thick targets of graphite, aluminum, copper, lead, and stainless steel. The targets were separately irradiated foran hour with about 1 Ji-A of beam current , and the
gamma rays were measured by a Ge detector.
We observed very weak 511 keY gamma rays only
from the graphite target. Induced radioactivity in lead
was not detected at all.
Gamma-ray emission from the aluminum target was164

also weak, and only the radioactivity found was what
were produced by the impurities: that is, 72 As and
5 7 Ni.
66Ga and 67 Ga were intensely produced in the copper target via the 63Cu(a , n) and 63Cu(a, ,) reactions. The Q values of these reactions are -7.5 Me V
and 3. 7 MeV, and the reaction rates were estimated tobe 6 x 10 13 and 8 x 1011 [coulomb- I], respectively.
The induced radioactivity was strong in the copper
target , and a slight contamination was observed withthe wipe test which was performed immediately after
the irradiation.
In the stainless steel target , 58Co and 57Ni wereobserved , and the latter seems to be produced by
the 54Fe(a , n) reaction. The secondary neutron andgamma rays were also measured by an NE213 scintillator, and the data are presently under analysis.

IV. NUCLEAR DATARIKEN Accel. Prog. Rep. 30 (1997)

Status Report of the Nuclear Data Group
Y. Tendow, A. Yoshida, A. Hashizume, and K. Kitao
The Nuclear Data Group has been continuing thedata related activities described below since the previous year. 1)(1) Nuclear reaction cross-section data (EXFOR)Compilation of the charged particle nuclear reaction
cross sections has been continued. The reaction crosssections to produce 20 radioisotopes of medical use:
llC, 13N, 150 , 18F , 28Mg, 52Fe, 67Ga, 68Ge, 74As, 77Br,
82Br, 77Kr, 81Rb, 82 m Rb, 111 In, 123Xe, 127Xe, 123 1,
124 1, and 125 1 as well as related old data which have notbeen included in the EXFOR master file up to now andnew data appeared in recent journals are continued tobe collected and compiled into EXFOR files. This year,
we have transmitted two so-called 'TRANS ' files to theInternational Atomic Energy Agency (IAEA) Nuclear
Data Section (NDS). One is named 'TRANS R010 'containing t he revised 'R0038 ' entry which had beencombined into the EXFOR master previously. The
other is 'TRANS ROll ' containing three new entries
with a total of 86 subentries (excitation curves), thatis the entry ' R0051 ' with 50 curves for (0:, x) reactions
on several natural targets , the entry 'R0052' with 9
curves for (0: , xn) and (0: , pxn) reactions on lanthanide
targets, and the entry 'R0053' with 27 curves for (0:,xn) and (3He, x) reactions on Ta and Bi targets.
(2) Evaluated Nuclear Structure Data File (ENSDF)
We have been participating in the ENSDF compilation network coordinated by the Brookhaven N ational Nuclear Data Center (NNDC). The evaluationand compilation of A = 129 mass chain and updated
evaluation of A = 127 have been completed and published in the Nuclear Data Sheets this year. 2,3) Masschain A = 120 evaluation has also been completed andthe draft is now under the review at the NNDC. The
ENSDF, as well as the other databases, is supposed tobe listed more and more by the on-line service throughthe network like WWW, and can be updated more frequently hereafter. We are expecting to update A = 129
mass chain partially whenever new data come out after
this day.
(3) Nuclear Science References (NSR)
We are engaged in collecting and compiling secondary references (annual reports, conference proceedings, etc.) appeared in Japan since the previous year
into the Nuclear Science References (NSR) file andsending it to NNDC.
The Nuclear Science References (previously Nuclear
Structure References) Coding Manual was revised thisyear with small modifications and improvements fromthe old version. 4)

The compilation of 1995 annual reports has been
completed and sent to the NNDC. Japanese secondary
sources surveyed this year are as follows (in code namein NSR):
RIKEN (RIKEN Accel. Prog. Rep.),
JAERI-TV (JAERI Tandem & V.D.G.),
JAER1-TIARA (JAERI Takasaki Ion Ace. Advanced Rad. Appl.) ,INS (INS Univ. Tokyo),
UTTAC (Univ. Tsukuba Tandem Accel. Center),
RCNP (Res. Center Nucl. Phys. Osaka Univ.) ,OULNS (Osaka Univ. Lab. Nucl. Study),
CYRIC (Cyclo. Radioisot. Center, Tohoku Univ.).
(4) Others
The biennial IAEA Advisory Group Meeting on the
Coordination of the Nuclear Reaction Data Centers(NRDC) was held at the Brookhaven National Laboratory, National Nuclear Data Center (NNDC) on
3- 7 of June 1996. Participants were the heads andobservers from 11 nuclear data centers: IAEA NDS,NEA Data Bank, CJD (Nuclear Data Center, Obninsk) , CAJaD (Kurchatov Inst.), CDFE (Photonuclear Data Center, Moscow), RIKEN, JAER1, JCPRG(Sapporo) , CNDC (China Nuclear Data Center, Beijing) , ATOMKI (Hungary) and NNDC (Brookhaven)
who served the host of the meeting. In addition to
the authorized members mentioned above, two centersattended the meeting for the first time this year: N1IEF Nuclear Data Group (Sarov, previously Arzamas16, Russia) and Institute for Nuclear Research (Kiev,
Ukraine). A major topic discussed at the meeting was
the challenge from the rapid advance of computer network technologies and its impact on the data dissemination methods by the centers. Both NNDC and NDS
agreed to take actions for expanding their on-line services under the WWW technology. Because the online information can be updated frequently, new problems on the archiving of database and accurate referencing of data extracted from on-line services will
be expected. It was agreed to establish new citation
guidelines.
References
1) Y. Tendow, A. Yoshida, A. Hashizume, and K. Kitao:
RIKEN Accel. Prog. Rep. 29, 205 (1996).
2) Y. Tendow: Nuclear Data Sheets 77, 631 (1996).
3) K. Kitao and M. Oshima: Nuclear Data Sheets 77, 1(1996).
4) S. Ramavataram and C. L. Dunford: BNL-NCS-51800,
Rev. 08/96 (1996).

165

V.

DEVELOPMENT OF ACCELERATOR FACILITIESRI KEN Accel. Prog. Rep. 30 (1997)

Production of 48Ca Ions in 10 GHz ECRIS
T. Nakagawa, T. Kageyama, J. Fujita, M. Kase, A. Goto, and Y. Yano
For an experiment to search new isotopes, an intense
beam of 48Ca was strongly demanded. To produce
such beams, it is effective to use its enriched materials, because its natural abundance is very low. As theenriched 48Ca are normally sold as oxides, the method
to produce highly charged ions from oxide materials as
described in Ref. 1 is one of the best ways. However, it
is not advantageous to make a rod of oxide materials of
the enriched isotopes in view of the cost. From thesereasons, we put the oxide powder into an Al 2 0 3 tube
(2 mm inside diameter, 4 mm outside diameter) andinserted it directly into the plasma as shown in Fig. 1.

The support gas was oxygen. The vacuums of thefirst, second, and extraction stages were 6.0 x 10- 6 ,6 X 10- 7 , and 7 x 10- 8 Torr, respectively. The microwave power supplied into the second stage was 600
W. Figure 2 shows the charge state distribution as afunction of the analyzing magnet current. The ECRIS
was tuned for producing 48Call+ ions. The 48Ca ionswere accelerated by the AVF - Ring Cyclotron complex
up to 70 MeV /u. The maximum beam intensity was
40 eJ-lA for a short time. The average beam intensity of
15 eJ.LA( 48 Ca l l +) was produced from the ECRIS and
100 enA was on the target for the experiment. The
powder consumption rate was 0.3 mg/h.

The Second Stage

-'c

CaO

.c

RF power -600 W~

Support gas ~i

E

Supporting rod

...~
~

o

E
cu
cP

m
Analyzing Magnet Current (arb. unit)

Fig. 2. Charge state distributions as a function of analyzing magnet current. The source was tuned for producing the 48Cal1+ ions.

CaO powder ("'Ca 60 %)AI.03 tube

100 m!Tl
50 mm----71

Fig. 1. Cross sectional view of the RIKEN 10 GHz ECRIS.

References
1) T. Nakagawa, T. Kageyama, A. Goto, M. Kase, and Y.
Yano: Jpn. J. Appl. Phys. 32, 2463 (1995).

167

RIKEN Accel. Prog. Rep. 30 (1997)

Present Status of RIKEN 14.5 GHz CapriceY. Kanai, Y. Nakai, T. M. Kojima, T. Kambara, and Y. Awaya
In order to study the low energy highly-charged ion
and atom collision processes, and to study the excited states of highly-charged ions, we installed a 14.5
GHz ECRIS (Caprice) and constructed the beam lines
in 1995. 1 ) This year (1996), we have made some improvements of the ion source itself and beam transport system: (1) we placed an aluminum tube inside
the plasma chamber, and (2) we ransported the low
energy highly-charged ion beams to the experimental
chamber.
Hitz 2 ,3) and Nakagawa4 ) reported that by using an
aluminum chamber, or using an aluminum tube inside the plasma chamber, they have improved the efficiency of the ECRIS. We used an almost same aluminum tube (1 mm thickness) as Nakagawa used for
RIKEN 18 GHz ECRIS, and obtained some improvement in the efficiency. In Fig. 1, we show the Ar ion
current extracted from the Caprice and measured after
the analyzing magnet. We obtained higher currents at
higher charge states with the aluminum tube in side
the plasma chamber. This tendency is same as re-

103

:?
(J)

102

.. .,

C 10 1

t

::l

U
c::

.2

-o-with Al tube

10°-. --without Al tube

•

10-1

ported by Nakagawa et al. They reported that they
did not need the support gas to acieve the high performance with the aluminum tube. For our case, however,to obtain the best result, we needed the support gas(oxygen gas).
To obtain the low energy highly-charged ion beams,
we have designed and made the whole beam lines
of Caprice isolated from the ground. I) From January
1996, we have tried to transport the low energy highlycharged ion beams to the experimental chamber. We
used the Ar 7+ ion beams for this test. We could transport the 140 e V Ar 7 + ion beams to the experimental
chamber. The Ar 7 + ions were extracted by the voltage
difference Vg between the plasma chamber Vp and thebeam line Vb (e.g., Vg = 1020 V when Vp = 20 V and
Vb = -1000 V), transported, and were decelerated to
the ground potential just before the chamber. Afterthe deceleration lens, we used the einzel lens to focus
the beam at the experimental chamber. The beam
spot size on the target position was 1 mm in diameter. Typical current of the 140 eV Ar 7 + ions was 0.1
enA . Higher energy (>4 keY) Ar 7 + ions could be transported to the experimental chamber without the deceleration method: Vg = Vp and Vb = 0 V. Lower energy(<4 ke V) Ar 7+ ions could not be transported to thechamber without the deceleration method. For lower
energy beams, the energy spread due to the plasma
potential is compatible to the final beam energy. We
are preparing an electrostatic energy analyzer to place
after the deceleration lens, which will determine theprecise beam energy of lower energy ions.

Extraction voltage=20 kY '.
10-2

5

10
15
Charge State

20

Fig. 1. Charge state distribution of Ar ions form RIKEN
14.5 GRz Caprice. Open circles: with aluminum tube,
closed circle: without aluminum tube.

168

References
1) Y. Kanai et al.: RIKEN Accel. Prog. Rep. 29, 208(1995).
2) D. Ritz et al.: Proc. 12th Int. Workshop on ECR Ion
Sources, p. 126 (1995).
3) D. Ritz et al. : Rev. Sci. Instrum. 67, 883 (1996).
4) T. Nakagawa et al.: Jpn. J. Appl. Phys. 35, 4077 (1996) .

RIKEN Accel. Prog. Rep. 30 (1997)

RIKEN Duoplasmatron Ion Source: The performance
characterization and background physics
M. Niimura, T. Kageyama, K. Ikegami, A. Goto, and Y. Yano
As an injector for accelerators, the ECR ion source(ECRIS) has established its popularity in a way that
it is always used so heavily to leave no time for its own
experimental research. In order to give a break for suchan ECRIS, an alternative ion source called duoplasmatron (DP) is under preparation at the RIKEN Accelerator Research Facility. A large ion beam current of
433 J-LA/cm 2 has been successfully extracted from it.
If the DP ion source (DPIS) could take over some of
the ECRIS work-load, ECRIS may be able to evolve
towards the RI Beam Factory project , for instances , asa highly-charged ion source on line (HC-ISOL) and as
an efficient stable ion source which can overcome theplasma instability limiting RF power absorption. This
report introduces a DPIS device with its experimental
results, predicts its background physics , and discusses
how to improve it for a long-term stable operation.
Unlike ECRIS, the DPIS (invented by Ardenne 1 ))is unable to produce highly charged ions (HCI) at thepresent form due to the lack of an ion trapping negative potential-well. However, this device is one of thebest for production of intense light ions such as p+,
d+ and Q+ (plus their negatives) thanks to the highplasma density of DPIS much higher than ECRIS byapproximately two orders of magnitude. As the name"duo-" implies, the DPIS consists of "dual-" or two
plasmas in series; one is cathodic plasma located between a filamentary hot cathode (K) and intermediate
electrode (IE), and another is anodic plasma between
IE and anode (A). [Refer, Fig. 1] They are basically avacuum arc plasma, and their conductions (heatings)
are sustained mostly by the primary electron beam. A
dc-current driven DPIS has no cutoff density as encountered with an RF-wave driven ECRIS.
Figure 1 shows the present construction of Riken
DPIS together with its hook-up circuit. These precise magnitudes of the relative dimensions and circuit
elements were found quite critical for the best performance of system, or more precisely, for initiation ofthe "dual" arcs one after another, and for successfulformation of the "dual" (geometric and magnetic) constrictions at the entrance of IE's canal and at the positive column near anode. The geometric constriction
is necessary for formation of the double layer to focus
the primary electron beam generated in K-IE region,
while the magnetic constriction is important to reducethe diameter D of anode plasma column. The cathodic
and anodic plasmas therefore work similarly to the 1ststage (electron beam generation and transport) and2nd stage (ionization and confinement) of an ECRIS,
respectively; but without a well-defined electron gun

Fig. 1. Riken Duoplasmatron Construction and Circuit.

nor a magnetic bottle. The key roles are played by theIE (whose chamber to canal diameters is 44/5 = 8.8,
and whose canal length to ' its diameter is 7/5 = 1.4);
specifically by the bias (VIE) which is controllable inprinciple by the series resistor R IE . Without the conical IE, a mere diode-type arc plasma (or a cathodic
plasma only) results. Typical experimental data arepresented next together with the physics behind.
Figure 2 shows the extracted ion beam current(Ibeam) as a function of the extraction voltage (Vex).
The maximum intensity of 340 J-LA (which is 433
J-LA/cm 2 in terms of the current density) is evident at
Vex = 20 kV under the working gas of argon. A Faraday cup (¢ = 10 mm entrance surface) was located 324
mm down-stream from the nose of the extraction electrode (whose opening is 2 mm¢). For small Vex, the' 1.-2A°O~~~S~~~'~
O ~--~1S~~~
Ext.-.c:tlon VoIt.v-.

v_ [kVI

Fig. 2. Extraction voltage (Vex) dependent I beam .

169

Ibeam was found to be scaled by Vex2.5 as shown by dotted curves, regardless of discharge conditions. Such a
sharp rise to exceed the scaling (Vex 1.5) of space-charge
limited current, followed by a saturation, can be explained due to a sharp convergence of the beam divergence (caused by the expansion cup) as Vex is raised,thus reducing beam loss to the extraction electrode.
Figure 3 indicates that the optimum working gas
pressure (p) to maximize Ibeam is around 7 x 10- 4
Torr-Ar independent of Vex. The Paschen 's minimumpressure at which the arc start voltage (V s) is minimum was Pmin = 5 X 10- 3 [Torr] for the working gasof hydrogen. When the filament current If ~ 18A, theV s was found to decrease drastically than the voltage
predicted by Paschen's law:Vs[V] = 165

P/Pmin(1)
1 + In(p/Pmin)
No arc initiated at p ~ 5 X 10- 3 [Torr] with anode potential V a ~ 250V. Throughout the paper , the pressure is the one measured near Faraday cup, whichis 2
3 orders lower than the pressure at theanodic (IE- K) plasma region. The arc resistance
was Rare 20n when Va was at Paschen's minimum(165V) at p = 5 X 10- 3 Torr. Interestingly, Ibeam depicts its maximum at this Va = 165V.

o.2

Vb-SkY, V_",·600V, p_Sal0";-orr-At•

V.... l 0kV.V_• ••V.kV.p.8J110·srOff."r•Vot,o-S kV, V_'" OV. p_4.81l10'So.r orr-Ar

so... .. ... ... ........
~

~

1.5

Z

2.5

Discharge Current. Id [AJ

Fig. 4. Discharge current (Id) dep endent h eam.

a stability condition given by je = ji(M/m)1 / 2. Therefore , j+ = ji = je(m/M)1 / 2 without loss. However, if
ji = ,),j+ due to a loss, where ,), ( ~ 1) is a parameter describing the loss into IE, we have j + = (je/ ,),)(m/M)1 / 2.
Obviously, 1+ j+d 2 (d: anode orifice diameter) and
Id jeD2 (D: anode column diameter), thenr-...;

r-...;

1+ == Ibeam = Id(m/M)1 / 2 (d/D)2 ,),-1(3)r-...;

r-...;

110

~

100

~

t

~
t

j. f
90

~ 80 f
~

CD

70

o
~

::

60

~

10'·

10')

Gass Pressure, p (Torr)- Ar

Fig. 3. Pressure dependent Ibeam at various V ex and I d .

This 1+ can explain the scaling of Eq. (2) :Ibeam Id. Our case, (d/D)2 = (0 .8/5)2 = 2.6 X 10- 2and (m/M)1 / 2 = 3.7 x 10- 3 for argon so that Eq. (3)gives ')' 1 since Ibeam/ld = 55.7 X 10- 6 from Eq. (2).
This means that we have still a room to achieve thehigher Ibeam by decreasing the ')' to IE.
A decay is observable for large Id ( ~ Ido) in Fig.
4. This can be a transition from a normal arc mode
to a so-called "arc-starvation" mode where D and ')'increase suddenly, thereby decreasing Ibeam via Eq.
(3). We have observed, however, a linear increase of
the dark current (I dark ) in to the extraction electrode,which started exactly at Id = Ido. This phenomenon istherefore attributable as an increase of new D and ')' definable for the beam in between anode and extraction
electrode. Increase of D can be suppressed increasing
the axial field B since D B- 1/ 2. Indeed , we have observed Ibeam
B. This and our another observation
Ibeam p as seen by Fig. 4 support the sheath modelof Eq. (3). Also observed was the effect of suppressor
voltage (V sup), which decreases Idark , there by increasing the beam current: Ibeam
Vsup 1/2.
Data of the pre-arc phase demonstrates that the
production of Ibeam takes place only after lIE = 0, or
when IE is floating at around VIE = -50V. The Id ==la + lIE should not be too large for the sake of I beam .
Longevity of the filament (presently around 11 hrs
with W) is the most crucial factor for DPIS to evolve apractical source. Use of a tantalum (150 hrs) , composite (oxidized Ni-mesh), or LaB 6 (850 hrs max in highvacuum) cathode and pulsjng of the anode potential(Va) are in progress.
r-...;

r-...;

r-...;

r-...;

Figure 4 shows a linear growth of Ibeam with respect
to Id (== IK == la + lIE) independent of Vex. Namely,
for small Id, the next formula was found:Ibeam[A] = 55.7 X 10- 6 Id[A].

(2)

The scaling of Eq. (2) agrees with the sheath modelby Lejeune 2) based on the theory by Langmuir. 3 ) Electric potential of the anode column becomes positive inreference to the grounded (HV-GND) anode, when the
total ion generation exceeds 2.86 times of the numberof ions contributing the ion current density ji. With thepositive potential the ions can be extracted from theanode column even when Vex = 0 or without a penetration of the extraction electric field into the column. At the both sheath boundaries of anode column
ends, the ion flux should be given by the same j+ if
there were no loss . Now, the electron current density je permitted to pass the anode column depends
upon the ji arrived at the sheath boundary; which is
170r-...;

r-...;

References
1) M . von Ardenne: Atomkernernerg 1 , 2015 (1956).
2) L. L. Lejeune: Nucl. Instrum. Methods 116 , 417 (1974).
3) I. Langmuir: Phys. Rev. 33, 945 (1929).

RIKEN Accel. Prog. Rep. 30 (1997)

Recent Progress in ECRIS Physics Study: Radial distributionof negative potential, hot ring, and instability
M. Niimura, T. Nakagawa, A. Goto, and Y. Yano
Progress was made in understanding the physics ofelectron cyclotron resonance (ECR) ion source. Actual distribution of the electric potential inside an
ECR ion source (ECRIS) was derived based upon an
experimental!) data, with which distributions of thehighly charged ions (HCI) trapped electrostatically inside the ECR-zone were calculated. These profiles revealed a shell-like ring structure of hot electrons distributed right on the ECR-surface. It was evident fromthe localized area of less-space charge and less-trappedions than the vicinity. The ECR-zone which is a 'nucleus' of an ECRIS plasma is shown to possess an internal structure: hot electron ring (HER) distribution,
inside of which the warm electrons, responsible for theionization and/or trapping of HCI, occupy as core.
The extra-nucleus cold electrons also trap some ionsradially due to the negative potential. The purpose of
study is to discover better methods of ECR-heating(ECRH) to the right electron temperature (Te), of
HCI cooling to mitigate the driftwave instability, andof positive potential lowering to extract HCI out ofthe potential-well. In the present paper, we demonstrate that ECRIS potential profiles can be deduced
by a simple ion endloss current (or ion confinementtime) measurement, without employing costly heavyion beam techniques. The 'dia-magnetic' current (idm)
accounted for the HER heating is shown to help stabilize the instability, thereby allowing more absorptionof RF power across the ECR surface.
Before ECRH: The 'thermal' motion of the axiallymagnetized ions and electrons is a gyration motion
along the field line (Bz) going back and forth, because
the velocity (v / /) parallel to Bz remains same evenafter the perpendicular velocities (V..l) undergo gyrations around B z. Therefore, both ions and electrons
will be bounced back together toward the midplaneby the mirror magnetic field (MMF) whose maximum
field is B m, unless their pitch-angles at the midplaneo := sin- 1 V..l/v (where v 2 = v / / + v..l 2) were smaller
than the critical angle Om := sin- 1 (Rm -1/2). Therefore, the charge neutrality prevails inside the MMF: noaxial space charge before RF. Here: Rm := Bm/Bo ~ 1
is the mirror ratio and subscript "0" denotes midplane(Min-B z) quantities. This situation is consistent withthe experimental fact: a HCI trapping negative potential has never been evidenced before applying the RF
for ECRH.
After ECRH: Once RF is applied at the frequency
We = eBz/me, only the electrons of mass me can increase the V..l component. This ensures 0 » Om
and thus can start trapping more electrons than off-

resonant ions within MMF III the matter of nanoseconds. In practice, most of the ECR-heated electrons tend to be reflected at BEeR (~Bm) before
reaching the point of B m, as confirmed by a study of
Coulomb collisions in the RF-diffusion velocity space.!)This means that all the MMF confined electrons will
eventually achieve v / / = 0 at B = BEeR; i.e., there
the total kinetic energy W (:= W / / + W ..l) becomes
W..l := (1/2)mv..l 2. The W..l relaxes as the particle migrates along the field line toward the lower-B z region(core heating) following the invariance of the magnetic
moment J1e := W ..l /B z.
Axial Distribution of Negative Potential, ¢(z) < 0:This origin is the space charge of ECRH electrons, as
clear from the above discussion, accumulated inside thezone Bo ~ B ~ BEeR. Another experimental fact, thata negative potential-well deepened from 10 to 30V proportional to the RF input power, 2) can be accounted
for an increase of the electron space charge (not of theTe) by RF.
Axial Distribution of Positive Potential, ¢ / / A ~ 0:
Length of ECR-zone is necessarily shorter than orequal to that of l\fMF. The electrons outside the MMF
are what have fallen into the loss cone and thus left
cold. They drift along field lines to be lost on endwalls at a higher rate than the ions. In order to retard
the fast diffusion of electrons a positive ambipolar potential (¢ 1/ A ~ 0) is induced outside ECR-zone. The
positive ¢ I I A is a problem for the HCI extraction outof a negative potential-well.
Radial Distribution of Negative Potential, ¢..lA ~ 0:
If the radial diffusion (..1 to B z) is classical, the crossfield diffusion of ions is faster than that of electrons,
thereby establishing a negative ambipolar potential(¢..lA ~ 0) to retard ion diffusion. Therefore, ¢(r) < 0
prior to RF power application inside and outside of the
ECR-zone.
Semi-Experimental Derivation of the ¢(r) under RF:
We have tried to derive ¢(r) based from the ion endloss current-densities J I Ii (r) measured by a Faraday
cup and time-of-flight detector which was scanned radially outside the ECR-zone. 3 ) Let us discuss briefly
the ion endloss flux (r I Ii) because of the relationship JI/i(r):= Zierl/i(r). The r/ li is defined by the
number of ions escaping every second per unit areafrom two ends of an ECR cylinder with cross-section
Send and length Lp U/ to MMF). The volume ofcylinder is V:= LpSend being filled with the averaged ion density (ni). Namely, r / Ii = (1/2)(ni)(vi),where (Vi) is the arithmetically averaged ion velocity. Substitution of this r I Ii into the continuity equa171

1¢(r)1 = kTiln TI/i(r)v i .
Zie
Lp

(5)

Figures 2(a) and (b) show the distributions of ¢(r)and ni(r)/nw at the midplane derived from Eqs. (5)and (2), respectively. It is straight forward to derive
the space charge distribution ~ne(r) of the warm andhot electrons using Fig. 2(a).

Fig. 1. Parameters of an ECRIS, Constance-B. 1 )tion, 8(ni) / at + r I IdLp = 0, yields the ion confinement time TI Ii = Lp/Vi. Here, the ion escaping velocity Vi == (vi)/2 == J2kTi/7rM. If ni(O) == nio is known
to be the peak ion density, we can always write (ni) as(ni) == ~inio so that r I Ii = 6nio Vi, using a multiplication factor 6 ( ~ 1). Then TI/i == (ni)Lp/ (ni)vi can be
expressed:
nioLp _()
nioLp
T//i(r) = ~i(r)rl/i(r) = ~i r ZieJ//i(r)'kTil ni(r)ni(r)-Zie¢(r) (2).
¢ (r ) = - - n - - or - - = exp
niw
niw
kTi
Zie
Due to the potential barrier I¢( r) I, the trapped ionsare confined much longer than the parallel drift time
Lp/Vi by a factor of exp(Ziel¢(r)l/kTi); as much as(3)Equating this with Eq. (1), we have¢(r) = _ kT iln RJI/i(r)Zie
Zie~i(r)niovi(4)

Notice that 6(r)nio is the axially averaged ion density
at the radius r. Using Eq. (4), ~i(O), and measured
J / /i (0) we can obtain an accurate ¢(O) rv -15.5 eV.
However, since we can not know ~i(r) at arbitrary r,1¢(r)1 is best to be derived using Eq. (3) and measured
data of TI/i(r) by
172

j

W ·15

r

~

r

r

(b)

.

.-

i

-

~

9 -

~-

-

....

. . os.~\

~~

(1)

With
our
simple-minded
formula~i(O)= 0.5[1 + exp( -0.5Zi)] together with the experimental data of J//i(O), nio, and Lp = 20 cm, above Eq. (1)gives the T/ /i (0) in good agreement with measured one
as shown in Fig. 1.
Imagine now a radial distribution of ¢(r) ~ 0 at
the midplane of an ECR-zone, in which ions areelectrostatically trapped. Radial equation of motion
for the trapped ion mass density is, at the steadystate dVi/dt = 0, nothing but a balance equation between the two force densities of - kTiVr ni(r) and-ZieniVr¢(r). Within the present paper , we assume
the ion temperature (Ti) to be isotropic although it
may differ at different charge states, Zi (=1,2,3 ... wheni = 1,2,3 ... ). The integration under the conditions¢(wall) = 0 and ni(wall) = niw gives:

Lp(Ziel¢(r)l)
T/ /i(r) = ~ exp
kTi
.

E

j
o

.

.~

10

Radial Position. r (em]Fig. 2. Radial distributions of (a) electric potential and(b) trapped HCI, derived from an experimental data.1 )Discussions: Figure 2(a) shows that the radius of
the ECR-cylinder is ro = 6 cm. When this cylinder
is filled with an uniform excess-electron density ~ne,the negative potential maximum should be given by¢(O) == (~nee/4co)r02 = 4.52 x 10-9 ne (m- 3 )r02(m)2
in Volts , which calculates ~ne = 9.53 x 105 (cm- 3 ) forI¢(O)I = 15.5V. This parabolic potential is due to the
new inside the ECR core. A hole-burning visible atro = 6 cm in Fig. 2a indicates a shell-like HER with theexcess electron density ~neh less than ~new. Shell's
half width (~r) is close to 1 cm, giving the aspectratio (~r/ro) of 6. The ~neh modifies the otherwise
parabolic potential profile at around r = 6 cm. The
shell-like HER must be heated via the idm generated
by Vph x B z mechanism (Vph: radially outward phasevelocity of an electrostatic wave) that can accelerate
electrons up to a relativistic energy. The idm has astabilizing effect against the resistive driftwave instabilities because it can reduce the core magnetic pressure, similarly to gas mixing which can reduce the core
thermal pressure; thereby giving a room to increase theHC! particle density inside 'the core.
References
1) A. Girard et aL: Proc. ECR-12, INS-J-182, p. 164 (1995).
2) K. S. Golovanivsky: Rev. Sci. Instr. 63, 2886 (1992).
3) C, C. Petty et al.: J. Phy. Colloq. 50, Cl-783 (1989).

RIKEN Accel. Prog. Rep. 30 (1997)

Beam Optics Study of Superconducting Solenoid Focusing
in RI Beam Production Beamline
J.-W. Kim and T. Kubo
The use of a strong focusing element has been suggested to obtain a small beam spot on the RI-beamproduction target located at the entrance of the RIPS
(Riken Projectile-fragment Separator).l) The focused
spot size which can be obtained at present is around
2 mm, but some nuclear experiments require evensmaller spot size to realize a point-like source of RI
beams.
Two kinds of focusing elements were considered:quadrupole triplet and superconducting solenoid. After a series of comparison work we chose to use a supercond ucting solenoid partly because of its symmetric
optical properties.
A high field superconducting solenoid can produce
a strong focusing even for the heavy ions of relatively
high energy. The solenoid is intrinsically a weak focusing element, but the high magnetic field produced bya superconducting coil overcomes its weakness. The
focal length by the solenoidal magnetic field (B) is

f = q 2 j B 2 dz ,where p is the particle momentum and

2.
1.

o.

.0

-1-

-2.
-3.

D
2.
1-

o.

.0

- 1.

-2.
-3.

Fig. 1. Beam envelopes when the solenoid field on axis is
6.2 tesla. The beam spot size on target is 0.4 mm, andthe drift space from the edge of the solenoid coil to thetarget is 1.2 m.

p2

q is the charge state.
We chose a superconducting solenoid employing a
conduction cooling method since we wanted to avoid
difficulties of maintaining a cryogenic system utilizing
liquid helium. In order to provide a sufficient operation margin for such type, the field strength on axis
is decided to be 6.2 tesla. Considering the dimension of the RI-beam production target-chamber andthe strong stray fields of the solenoid, the distance between solenoid and target is chosen to be around 1
meter.
Beam optics calculations have been carried out using a first- and second- order matrix multiplication
program 'TRANSPORT' to optimize the solenoid location and to find out the magnetic parameters anddimensions. The design particle is l2C 6 + with a beamenergy of 135 MeV /u which is the most rigid beamfrom RRC. From these conditions the solenoid lengthis calculated to be 1.1 meter. The beam envelopes arecalculated with TRANSPORT when the beam emittance is 3.2 7r mm mrad., which is plotted in Fig. 1.
The diameter of the focused beam spot is 0.4 mm.
To examine the settings of optical elements for different beam spot sizes, optics calculations have been
carried out assuming 1 mm of spot size. Since the beam
parameters at the solenoid can be adjusted by the upstream beamline quadrupoles, a range of the present
solenoid fields can be actually used to produce a 1 mm
diameter spot. With a field of 5.6 T, a 1 mm beamspot can be comfortably achieved, where the beam envelopes look similar to those in Fig. 1. Even with 5.2

T it is possible to focus the beam down to 1 mm, but
at the cost of transmission efficiency.
The beam spot-size at the focal plane is calculated
assuming aberration free for optical elements. However, in focusing the beam to a small dimension, suchas in our application, the aberration effects could be ofappreciable concern. Especially, if even a smaller beam
is needed such as in microbeam applications, aberrations have to be carefully examined since they are thelimiting factors to the focusing. 2- 4 ) Lens errors limiting
the performance of a lens system are following: spherical, chromatic, and parasitic aberrations. Ray tracing
programs can be used for accurate calculations of theseerrors. In our case, however, only rough error estimations are made using simple analytic expressions foundin Ref. 2.
The spherical aberration is described as d s = C s a 3 ,where d s is the diffusion diameter of beam spot, C s
is the aberration coefficient, and a is the half angle ofconvergence in the image side. The C s is roughly 90
rad -3 m , and then d s is 0.3 mm when a is 15 mrad.
This apears to be rather large, but since our solenoid
is a thick lens, unlike the Glaser type field of Ref. 2,
the result may be overestimating.
The chromatic aberration depends on the energy
spread of beam. A description of the chromatic aberration is d e=C ea.6.E/E. The C e is 1.2 rad-lm, which
is roughly the focal length. Assuming .6.E/E is 0.1 %,de is 0.02 mm, which does not appear detrimental.
On the other hand, misalignment which is a main
source of parasitic error can be divided into two compo173

nents: lateral displacement and tilting about its center.
This error is known to be sensitive for microbeams 4 ,but expected to be less sensitive for a half-millimetersize of beam.
In conclusion, aberrations seem not to be a serious
limiting factor in our application, although we need anelaborate ray-tracing calculation for a more definite
conclusion.

174

References
1) J. Kim et al.: RIKEN Aeeel. Prog. Rep. 30, 175 (1997).
2) A. Stephan et al.: Nuel. Instrum. Methods Phys. Res.
B 89, 420 (1994).
3) C. J. Maggiore: Nuel. Instrum. Methods 191, 199(1981).
4) H. Koyama-Ito et al.: Nuel. Instrum. Methods 174, 331(1980).

RIKEN Accel. Prog. Rep. 30 (1997)

A Liquid He-Free Solenoid for RI Beam Production
J.-W. Kim, T. Kubo, and T. Kawaguchi
A superconducting solenoid has been designed andunder construction by Mitsubishi Electric Corporation
for use at the entrance of RIKEN projectile-fragment
separator (RIPS). The solenoid which utilizes a conduction cooling method will focus heavy ion beams ontarget for the production of radioactive isotope (RI)
beams. Advantages of the superconducting solenoid asa final focusing element, such as symmetric beam optical properties and easy operation, were the reason forour choice over usual multiplets typically quadrupole
magnets. The maximum magnetic field on axis is 6.2
tesla (T), and the coil length is 1.05 m. A GiffordMcMahon (GM) refrigerator is employed together withhigh-T c material current leads. Some detailed solenoid
parameters are listed in Table 1. A test coil has beenwound, its performance being tested. We expect thecomplete solenoid to be delivered in early 1997.

'50
LENGTH UNIT: m m

Fig. 1. A schematic view of the solenoid.
Table 1. Design parameters of the solenoid.
Bmax on axis

J B· dl
J ave
Amp·turnlopStored Energy
InductanceSuperconducting
Wire

6.2 T
6.8T·m
9,800 A/cm 2
5.5 MA·turn41 A
450 kJ
534 H
Cu/NbTi=1.3,
4> =0.60 mm

The solenoid is divided into three equal-length coils
as shown in Fig. 1. Its purposes are to limit the lengthof coil-winding and to distribute the stored energy.
When the solenoid quenches, the current of each coildecays individually through three diodes in a parallel connection with each coil. Since the coil is epoxy
impregnated and radially thin, a high voltage problem becomes negligible only by adopting the diodeprotection. According to calculations with the program QUENCH,l) the normal region reaches the radial boundary of the coil prior to the axial boundary
in usual quench situations, so that the inter-layer voltage is not of concern.
The refrigerator is a Gifford-McMahon type, and its

cold head is directly attached the central coil. To improve the conduction cooling efficiency, copper plates
are placed between the coil and the coil end flanges.
Since the cold mass of 300 kg is rather large for a G M
refrigerator of 1 W at 4.5 K, the cooling time is expected to be longer than one week. A low operatingcurrent (41 A) was chosen to reduce the heat load
through the high-T c material current leads, resulting
in a large coil inductance of 534 H. The current ramJr
ing time will be about 2 hours with a 3 volt power
supply. We have accepted this slow cooling and ramJr
ing times since the solenoid operation will usually not
require frequent adjustments of solenoid current.
The solenoid doesn't have a flux return yoke. The
stray field on the RI beam production target is around
140 gauss when the maximum field on the solenoid axis
is 6.2 T. Those instruments sensitive to the magnetic
fields such as turbo pump will have their own shields,
which seems to be the most effective shielding method
for our case.
References
1) M.

N.

Wilson:Rutherford

Laboratory

Report

RHEL/M-151 (1968).

175

RIKEN Accel. Prog. Rep. 30 (1997)

Study of Spin Dynamics for RHIC Spin Project
H.-Y. Wu, T. Katayama,* A.-U. Luccio,** K. Hatanaka,*** N. Saito, and M. Ishihara
The RHIC collider consists of two rings of superconducting magnets. Each ring consists of three inner arcs
and three outer arcs and six insertions joining the inner and outer arcs. Each arc is composed of 11 FODO
cells. These kinds of periodic structure will produce aperiodic structure on the beam orbit, which will cause
the depolarization resonance of polarized beam. During acceleration process, such a resonance occur when
the number of spin precession rotations per revolution
G, (G = 1.793 is the anomalous magnetic moment of
the proton, , is the relativistic factor) is equal to an
integer (imperfection resonance) or equal to kP ± Vy
(intrinsic resonance), where k is an integer, and P thesuperperiodicity of ring, and Vy the vertical betatrontune.
The motion of spin vector is described by BMT
equation, and the orbital motion of particle obeys theLorentz equation. The individual magnet will kick out
the spin direction at the place where § x jj is not zero,
where § is spin vector.l) The change of spin direction
can be recovered by a periodic magnet setup. But,
when the beam energy is at depolarization resonancearea, the polarization will be lost.
To avoid the depolarization resonance during the acceleration and colliding experiments, a pair of Siberiansnakes will be installed in each ring. One Siberiansnake consists of four helical magnets. The perfectly
working Siberian snake in one side of the ring rotates
spin 1800 and the Siberian snake in the other side of
the ring would restore the spin to the initial direction.
Because this process makes the spin tune value change
suddenly at depolarization resonance point, the lostpolarization can be recovered and depolarization resonance is easily crossed.
A search of the working points of Siberian snake wasmade by an analysis for the first order magnetic field
and by tracking in both the first and second order magnetic field. The results are given in Table 1, and ofcourse, we use the lowest value set.
The depolarization is mainly decided by vertical motion. The vertical displacement of the particle can be
decomposed into two parts: (1) the closed orbit distortion (COD) due to a misalignment of the magnet system and (2) the betatron amplitude of a particle. Intrinsic depolarization resonance is caused by betatronmotion, and imperfection depolarization resonance iscaused by closed orbit errors. For a perfectly aligned
machine, the vertical COD is zero and the strengthsof imperfection depolarization resonance are zero, although the energy dispersion produces the horizontal
INS, University of Tokyo** Brookheaven National Laboratory, U.S.A.
*** RCNP, Osaka University

176

Table 1. Field strengths of perfectly working Siberiansnakes. (B2=-B3, B 4 =-BI) at 25 GeV polarized proton.
U nits by Tesla.
1

2

3

4

First orderBl1.23193.22825.08925.3788analytic

B3

3.95805.53002.38618.8272First orderBl1.23363.22655.08655.3769numerical

B3

3.95705.52732.38368.8225

Second orderBl

1.07233.38725.13245.5050numerical

B3

3.93285.65872.2711

8.9256

COD, which is the second order effect of imperfection
depolarization.
We used the MAD program to search the closed orbit, and to deduce the transport matrix of the orbit
from the lattice output. The BMT equation is givenby the matrix formulation:
1 - (B2 + C 2)e

ABc - Cs

ABc - Cs
1 - (A2 + C 2 )eACe - Bs
BCe + As

ACe+ Bs

BCe - As

1- (A2 + B2)ewith{

e = 1 - cosw8s A -!:... B =s = sinw8s
'
- w'

w2 =

Py
w '

C= ~
w '

P; + P; + P; .

Here, the spin rotation strengths are P:

P x = dip) [(1 + G,)( _Xl Bs + Bx)+ (1 + G)XI(XI Bx + Bs + yl By)],+ G,)( _ Xl Bx + yl By)+ (1 + G)(XI Bx + Bs + yl By)],
Py = (;p) [(1 + G,)( _yl Bs + By)+ (1 + G)yl(X I Bx + Bs + yl By)].
Ps =(:p) [(1The matrices for each kind of magnet are given for the
first order and the second ~rder approximations. 3 ,4)For the arrangement of magnet system of the lattice of RHIC, a spin tracking of intrinsic depolarization
was made with both vertical and horizontal displacements in all elements (dipoles, quadrupoles, sextuples,
Siberian snakes, RF's, etc.). The result for the first

1.00

tt" ,

1

, 'r 1

,

Wi

or

0.75
0.50
0.25
0.00
1.00
0.75

,

r

"
(a)

'rr 1rh~b~'I""'" t

iipt

0.50

i

(;; 0.25
0.00
I

1.0
0.6

r

0.6

'f

....

¥

'1--'f

0 .4

'W

(c)

0 .2
0.0

Spin tracking of the second order is needed for highprecision result (Fig. l(b)) , in which the second order terms of spin rotation strength, higher orders ofmagnetic field in Siberian snake, and spin matrix for
slices of an element are involved. A more noise in the
background of depolarization spectrum and a larger
strength of depolarizing peaks are observed. Withlarger emittance than 7 7r mm - mrad, it is difficulty
to keep the polarization.
The imperfection depolarization (Fig. 1 (c)) was
studied by tracking a particle of zero normal emittance,with the COD at 5 mm rms 5 ) which is produced bya random misalignment of magnets (±0.1 mm rms inlength, ±0.1 mrad rms in angle).
When both the imperfection resonance and intrinsic
resonance are taken into account, the alignment error
was required to be less than ±0.01 mm rms in lengthand ±0.01 mrad rms in angle; which are too smallvalues to realize in the alignment of magnet system.
Although the alignment error can be improved to 0.1
mm rms, the COD correction system can improve the
COD as small as ±0.2 mm rms. Figure 2 shows thatthe polarization spectrum was stable at the vertical
COD of ±0.2 mm rms, but becomes unstable at the
COD of ±0.3 mm rms for the normalized emittance
20 7r mm - mrad.

..

100

200

G")' 300

400

500

Fig. 1. The intrinsic depolarization spectrum (a) for the
first order at 7 7r mm - mrad and (b) for the second
order spin tracking at 7 7r mm - mrad, compared with(c) the imperfection depolarization spectrum.

order is shown in Fig. l(a). Here, the first order spinrotation strengths P x , Ps , Py , second order magnetic
field in Siberian snake, and one spin transport matrix
for each element are used.
1.1
1.0
0.9
0.8
0.7
0.6

, l

=~:~

1

g:~
=~:~

i

1

ij

,

r

1

I

'f 1·

COOY," _ _ _r''t r • ·X~.-._5p1_ 'fpo, I' ,Tl"

CODYoG.-_XoG,1 7 _ . - . _ , I " , _ _

~:i
-0.9
-1.3

r '''r T

CODY,O.- ... X , O . 1 7 _ . - . _ , 5 p 1 _

-0.1
-0.5

Y

Co;YoG--_x~,-,-,,,-

CODYoG _ _ _ X,O,17_.-._,Opl__

0.7
0.3
-0.1
-0.5

, T •

I·,11

COOY," _ _ _ X~'-'_l"'_

0,

f·

IT

COOY'"_ _ _ X~'-'_'l!fi_

CODYoG_ _ _ XoG,1 7 _ . - . _ l ! f i _ _=U ~,~~ ..:l~D~ ~,~~,~_~~
-1.3

f

30

130

230

330

430

30

130

230

330

430

G(
Fig. 2. The intrinsic depolarization coupled with the imperfection depolarization.

References
1) H. Wu: AGS/RHIC/Spin Note, BNL, No. 23 (1996).
2) H. Wu et al.: AGS/RHIC/Spin Note, BNL, No. 25(1996).
3) H. Wu et al.: AGS/RHIC/Spin Note, BNL, No. 26(1996).

4) A. Luccio: AGS/RHIC/Spin Note, BNL, No. 13 (1996).
5) H. Wu et al.: AGS/RHIC/Spin Note, BNL, No. 36(1996).

177

RIKEN Accel. Prog. Rep. 30 {1997}

Optimization Method Using 2D Analysis in
Helical Dipole Magnets for RHIC
M. Okamura, T. Kawaguchi, T. To mi n aka , and T. Katayama
The Relativistic Heavy Ion Collider (RHIC) - Spin
Project, a joint project between Brookhaven National
Laboratory (BNL) and RIKEN, started in 1995. We
are collaborating with the BNL-accelerator group topromote research in the Siberian Snake which consistsof helical dipole magnets. In present report, a distortion of the dipole field caused by the spiral structureof helical coils is discussed.
In the helical dipole magnets, a large longitudinal
field can exist. Therefore we started to compute thelongitudinal as well as transverse fields in these magnets using three dimensional (3D) analysis numericalcode, OPERA-3d/TOSCA. The results of this work
can predict the fraction of longitudinal fields,1) and arebeing used successfully in the orbit-spin tracking. On
the other hand, to optimize the cross sectional dimensions, the two-dimensional (2D) analysis is more convenient than the 3D analysis which obviously requires
time consuming procedures and long computing times.
In fact, 2D magnetic field calculation at BNL has beenused to optimize the positions of conductors and yokes.
However, we need to investigate a difference between
the 2D and 3D analysis due to the helical structure.
In order to confirm the effect of helical structure, twotypes of coils were analyzed by OPERA-3d. Figure 1
shows the first-type which is a full-length Snake Magnet based on the half-length model now being fabricated at BNL. The second-type coil shown in Fig. 2
was drawn by untwisting the first coil. The calculationof this second coil corresponds to the 2D analysis. In
order to optimize the configuration of magnets for the
RHIC project, calculated azimuthal fields, Be, along a

circular arc have been expanded in terms of the multipole coefficients of Fourier series in the cylindrical coordinates. In this method, the multipole components
by OPERA for both the first and second coils are almost same. Yet, there must be an effect due to thelongitudinal fields in the helical magnet. We have analyzed this by using the vertical fields, By. The ratioof the sextupole component to the dipole component
in the first coil was predicted to be 0.'076% larger thanthat in the second coil.
In case of helical dipole magnets, the expressions of
the field are given ignoring skew components as follows.

Br = Bo

L fnI~+1 ((n + 1)kr)bn sin(n + 1)8(1)owhere,

2n+1(n + 1)! 1
k = 27r
fn = (n + 1)n+1 rokn'
). .

(4)

Here, I and ). are the modified Bessel function and helical pitch of helix, respectively. As mentioned above,
according to our 3D analysis, there is no obvious effect of helical structure on muttipole components inthe cylindrical coordinates. Then, the above series canbe converted into the Cartesian coordinates,
Bx = Bo

L fnbn[I~+1 ((n + 1)kr) sin(n + 1)8· cos 8oIn+1((n+1)kr)ll]
kr
cos (n + 1 )ll·
0 . sm 0
By = Bo

L fnbn[I~+1 ((n + 1)kr) sin(n + 1)8 . sin 8+
Fig. 1. Helical coil.

(5)oIn+1((n + 1)kr)
k

r

(

Il]

)ll

cos n + 1 0 . cos 0
.

.

(6)

Here, we assume that the helical dipole magnet can be
optimized only using Be components. Then bn = 0 forn > o. So, these expressions can be transformed into,(7)

Fig. 2. Untwisted helical coil.

178

(8)

These expressions show that the Bx component consists of a single sextupole term. Also, the By component is expressed as a sum of the dipole and sextupoleterms. Accordingly, when the magnet is optimized using Fourier expansion of only Be, it appears a sextupole component in the Cartesian coordinates. In ourmagnets, the ratio of the sextupole component to thedipole component is predicted to be 0.0771 % at r = 3.0
cm. This value, which is caused by the bo coefficient
explains the results of the 3D analysis. Of course, ina real magnet there are effects caused by higher ordercoefficients, n = 1, 2, 3, ... but these terms can beignored because the n = 0 or bo , term is dominant in
the Snake Magnet.

To optimize the configuration of helical dipole magnets by using 2D calculations, it will be effective to
set b2 so as to offset the helical effect due to boo As aresult, the azimuthal angle dependence () dependenceof magnetic fields will be eliminated, and the only remaining effect of being helical is the radial dependence
expressed by the first term in Eq. (8). We plan toachieve the ideal field uniformity limit of ±O.077% dueto this radial dependence in our helical magnet designs.
References
1) M. Okamura et al.: Proe. 5th Eur. Part. Accel. Conf.,
p. 2261 (1996).

179

RIKEN Accel. Prog. Rep. 30 (1997)

High Current Design of Superconducting Helical
Dipole Magnets for RHIC Spin Project
T. Kawaguchi, T. Tominaka, M. Okamura, K. Hatanaka, and T. Katayama
The RHIC spin project!) under RIKEN-BNL collaboration is planning to use 48 superconducting helical dipole magnets as Siberian Snakes and spin rotators. The construction of superconducting helical
dipole magnets is the first trial in the world. The magnets have its straight length of 2.4 m and helical angleof 360 degrees, which needs to generate the maximum
magnetic field of 4.0 T in the beam orbit area.
BNL has designed low-current helical dipole magnets
its operation current around 400 A. 2 ,3) The principal
idea of designing the low current magnet is to decrease
the cooling capacity for the power leads which connect
the current-carrying lines between the room temperature and 4.5 K regions. But this low current design
is risky to achieve such a high magnetic field, because
the low current coil requires fine-round wires and hence
more turn numbers, which is liable to cause wiremotions that may induce a coil quench. Thus, all of thesuperconducting dipole magnets (of straight type) existed in the world are operating at currents higher than
5000 A, and are using Rutherford type cables formed ina rectangular shape. From the above point of view, wehave decided to design the high-current helical dipole
magnets as one of the backups to the BNL low current
design.
In our design we selected the operation current to
be 3000 A which enables to use Rutherford type cable,
satisfactory in the cooling capacity. Table 1 shows acomparison of the basic design parameters among the
BNL standard dipole (straight type), the BNL helicalmodel, and the RIKEN helical model. The merits ofour high current design are as follows: (1) wire arrangement is accurate because of the small turn number and of the rectangular wire shape; (2) the firstpoint makes the coil tough against the quench becausewire motions can hardly occur; (3) the first point also
makes the magnetic field accurate due to the precise
wire arrangement ; (4) applying a pre-stress during thecoil winding is easy compared with the low current coil,and the pre-stress can give a further quench toughness;(5) the small turn number reduces the construction
cost and time. The demerits are as follows: (1) the
cooling capacity increases (although acceptable); (2)the power supplies and the bus bar system between
the power supplies and the magnets are much more
expensive than those in the low current design.
The basic design was made by RIKEN ,4) andthe technical design study was done by Hitachi
Ltd. Corp.5) and Mitsubishi Electric Corporation. 6 )Figure 1 shows the coil shape of model magnet , used
for three dimensional magnetic field calculation. Cross
section of designed coils is shown in Fig. 2. During
the design, we have studied the wire arrangements

Fig. 1. Helical coil structure (for 3D magnetic field calculation).

SUPPORr RING

AL IONHEHr KEY

Table 1. Comparison among RHIC dipole coil and twomodel snake coils by BNL & RIKEN designs.
Items

RHIC
dipole coil

Model snake coil
BNLdesign RII(EN design

Central field withyoke, BO(T)

3.5

4.0

4.0

Coil inner dia. (mm)

80

100

100

Yoke inner dia. (mm)

119.4

182.8

139.4

Length of straightsection (m)

9.266

1.1

2.0

Helical angle (degree)

0

180

360

Operation current (A)

5000

382

3000

Rutherford

round cable

Superconductiog cable

180

Rutherford(rectangular )(rectangular )dO.648 mm dO.33 mm
x7x30

dO.648mm
x 18

Fig. 2. Helical dipole coil cross section (unit: mm).

resulting in better magnetic field distributions, winding procedures, pre-stress application methods, electrical insulation systems for the coil, magnetic forces of
the coil, and so on. The pre-stress application method
for the helical dipoles is very different from that fornormal straight dipoles, and we need more elaborate
technical designs before the real construction of themodel magnet.
BNL had already constructed the first model coil in
1995 based on the low current design, when our design
work was initiated. After our design study, we decided to postpone the construction of our model magnet, because the second and third model magnets werebeing constructed at BNL. In November 1996, one of
the two model magnets reached 4 T after 12 quenches.
This magnet should be improved from the view pointsof the quench toughness and of the accurate magnetic
field, but it succeeded to achieve the required magnetic
field (of 4.0 T) which was thought risky. As describedabove, the BNL low current design allows to make economical systems. Though our design will be finishedas only a design work, we have studied many aspects
through this design work and we can give our comments to BNL for the next prototype magnet design
and for the real magnets to be constructed through the
RIKEN-BNL collaboration.
References
1) RHIC spin project: Proposal on spin physics using the
RHIC polarized collider, Sep. (1993).
2) R. Gupta et al.: Design and status of helical magnet at
BNL, BNL internal workshop, Sep. (1994).
3) R. Meinke: Helical dipole magnets using advanced
manufacturing technology, BNL internal report, Apr.
(1996).
4) T. Kawaguchi: Preliminary study for superconducting
snake coil, RIKEN internal workshop, Dec. (1995).
5) Hitachi Ltd. Corp.: Design study for Siberian snake coilin RHIC, RIKEN internal report, Mar. (1996).
6) Mitsubishi Electric Corp.: Design report of a superconducting helical coil (Siberian snake) for the relativistic
heavy ion collider (RHIC), RIKEN internal report, Mar.
(1996).

181

RIKEN Accel. Prog. Rep. 30 (1997)

Field Analysis of a Helical Dipole Magnet
K. Hatanaka, T. Katayama, T. Kawaguchi, M. Okamura, and T. Tominaka
Superconducting helical dipole magnets will be usedin RHIC as Siberian snakes and rotators. I ) Extensive investigations are performed on the orbit and spin
trackings to examine whether the spin polarization of
the proton will be conserved up to the highest energies
with the help of Siberian snakes. During the first stage,
the numerical tracking was performed using an analytical expression for the magnetic field in the snake.
It is now required to use a more realistic description
for the magnetic field in the snake. Beam trajectoryand spin motion can numerically be calculated, providethat the magnetic field map is given along the beampath. However, it is not practical to store the whole
field strengths along the helical magnets. Besides, themap has usually some errors. Calculated or measured
magnetic field maps may not always satisfy Maxwell'sequations. This causes errors in numerical calculationsof the orbit and spin matrices; orbit matrices should
be symplectic, and spin matrices be unitary. There arefollowing three methods to improve the situation. (1)An approximately symplectic matrix calculated froma field map is transformed into an exactly symplectic one, (2) Small modifications to the field values are
performed so as to bring the field satisfy Maxwell'sequation. (3) The field is made more Maxwellian byreading only one or two field components from the map
and deriving the other components by using appropriate expansion coefficients.
The method (3) is physically more sound2 ) andshould produce a more symplectic matrix.
Thisstrategy was applied to examine three dimensional(3D) magnetic field calculated by the computer code
TaSCA including the fringing field region. In the central region of a finite-length helical dipole magnet orin the whole region if the length was infinite, the magnetic field has a cylindrical symmetry, and a solutionof the Laplace equation Ll W = 0 is given by00
2n+ 1 (n + I)!
1
W = -Bo{~ (n + 1)n+2 r(jkn+I In+I ((n + l)kr)

x [an cos((n + 1)8) + bn sin((n + 1)8)]}.

e-Here In is the modified Bessel function and 8 =kz,
where k = 27r / >. and>' is the wave length of the helix.

182

In the analysis of the magnetic field , above expansion
was assumed to be applicable at the fringing field region as well as at the magnet center. The coefficientsan and bn were determined by fitting the radial field
Br and azimuthal field Be in the median plane (e = 0
or 1T), respectively. In the fitting procedure, the maximum value of n was taken to be 6, and odd n values
were included as well. The longitudinal field B z in
the median plane was derived from the obtained coefficients. Differences between the 3D calculated andfitted/derived fields are shown in Fig. 1. Off medianplane magnetic field distributions were derived withthe same coefficients and are also compared with the
3D calculations by TaSCA in Fig. 1. The magnetic
field in the median plane is seen from the figure tohave magnetic field well simulated by a simple function. For the off median plane magnetic field , however, the difference is quite large: contributions fromthe coils should be taken into account for the functionused. 3 )

(b)

(a)

.; ...
I'lI 0.....
III

~

<l

N

I

I

0

0

0

~

-1

.....

,.-..

,.-..

.; ...
I

~

~

III

~

<l

III

0

...
I

<l

~

0
'lI
III

N

I

~

0

2
0

-2

~

-2

10

,.-..

2
1

~

N

0

0
..... -1
~ -2
-3

I

0

-~

- 10
-15

0

25

0

2b

50

75

100

125

z (em)

Fig. 1. Differences between the 3D-calculated and fitted/derived fields normalized by Bo,(a): in the medianplane x = 3 em and y = 0 em, and (b): off medianplane x = 0 em and y = 3 em.

References
1) E. Courant et al. : AGSjRHIC/Spin Note, BNL, No. 40(1996).
2) A. Luccio et al.: AGSjRHICjSpin Note, BNL, No. 41(1996) .
3) K. Hatanaka et al.: AGSjRHIC/Spin Note , BNL, No.
37 (1996).

RIKEN Accel. Prog. Rep. 30 {1997}

Analytical Field Calculation of HelicalCoils for RHIC Spin Project
T. Tominaka, M. Okamura, T. Kawaguchi, K. Hatanaka, H. Sato, and T. Katayama
The purpose of this paper is to give the analyticalexpression of multi pole expansion for a single helicalcurrent conductor, and to give that for a helical dipole
magnet. These analytical expressions may be usefulfor not only design but also field analysis of a helical
dipole magnet.
The field in the current-free and iron-free regions ofa helical magnet can be obtained by using the scalarpotential w. The 3-dimensional (3D) Laplace's equation III circular cylindrical coordinates is expressed
as:
2

82 W

1 82 W

1 8w

82 W\7 W = 8r2 +;: 8r + r2 802 + 8z2 = o.

Since the winding is periodic in z-direction with apitch length L , the general solution of Laplace's equation is,l)00

n=l{a~ cos (n(O - kz)) + b~ sin (n(O - kz))} + e' z + f' O.

Here, k = 27r / L, In (nkr) is the modified Bessel function of the first kind of order n, and Kn(nkr) is themodified Bessel function of the second kind of ordern. The helical scalar potential can be determined fromthe requirement that the non-helical scalar potential
Wh is equal to the 2D scalar potential. As a result, theinterior (r < a) helical scalar potential and magnetic
field generated by a single helical conductor of radiusa, angle 7./J and current I are given by
J.L I ~(n-l)!
00
Wh in (r, 0, z) = _0_,
27r L....J
n=l

[

2 ]n
-kIn(nkr) Xna_ J.LoI~
I [ 2 ]n I~(nka)Wh ,ex (r,O,z) - 27r L....J(n-l). nka K~(nka)Kn(nkr) xn=l{-an (k) cos (n(O-k z)) + bn (k) sin (n(8-k z))} _ ~o: 8Br(r,O,z) = J.L:I k 2 a

fnI~(nka) K~(nkr)xn=lsin ( n (0 - 'ljJ - k z) )2:00

J.Lo I k a n n
I' (n k a ) Kn (n k r) x7rr
n=lJ.Lo I I
cos (n(O - 'ljJ - k z)) + - 27r r
2
Bz(r,O,z) = _J.L:I k a
Kn(nkr)x

B e (r, 0 , z ) --fnI~(nka)

n=lcos (n(O - 'ljJ - k z))

The above expressions for the magnetic field of a helical coil are the functions of rand (() - kz), and arehelically symmetric. However, the sum E to a finite
order of the above expressions of the interior and exterior magnetic fields do not approach the same value
at r = a. This discontinuity of the magnetic field at
r = a can be overcome with application of the Cesaro's
method of summation. 1)
For a single helical conductor with current I = 100
A, radius a = 0.33 mm, angle 7./J = 30°, and pitch
length L = 9.51 mm, a comparison between the analytical and numerical calculations was made. Since anagreement was confirmed between the analytical andnumerical calculations, the field was calculated for thewhole space except for the located point of a single
helical conductor, as shown in Fig. 1.

{-an(k) cos (n(O - k z)) + bn(k) sin (n(O - k z))} - J.Lo I k Z
27r
Br(r,O,z) = J.L:I k 2 afnK~(nka) I~(nkr)xn=lsin (n(O - 'ljJ - k z))

2: nKn nka )In(nkr) x
00

J.LoI
Be(r,O,z) = ka
7r

'(

n=l
cos (n(O - 'ljJ - k z))

Bz(r,O,z) = _J.L:I k 2 arBz

fnK~(nka) In(nkr)xn=lJ.Lo Icos (n(O - 'ljJ - k z)) + 27r k.

Similarly, the exterior (r > a) helical scalar potential
and magnetic field are:Fig. 1. 3D plot of the analytically calculated Bz at z = 0,
which is consistent with the numerical calculation with
Biot-Savart Law.
183

U sing the above expression for T < a, the interior magnetic field of helical dipole coil with an infinite length can easily be derived as the summation offour (4) helical line currents with dipole symmetry as
follows: 2)

B r (r,8 , z) = Bref(k)rofnn! [n:rJkI~(nkr)xn=l{ - an(k) cos (n(8 - k z)) + bn(k) sin (n(8 - k z )}~1 [B8(r, 8, z) = Bref(k) ro L- n.

2

n kro

of slotted type designed in BNL, the twist (or k) dependence of the reference field Bref (k) and of the helical sextupole coefficient b3 (k) are shown in Fig. 2,
while the dipole field distribution without iron yoke isshown in Fig. 3. In addition, it was confirmed that thisanalytical calculation is consistent with the numericalcalculation by the 3D magnetic field numerical code,
OPERA-3d/TOSCA. 2 ,3,5)]n In(nkr)
r
X

2.79

n=l

{an(k) sin (n(8 - k z)) + bn(k) cos (n(8 - k z ))}n
B z(r,8 , z) = Bref(k)ro f(-k)n! [n:rJ In(nkr)xn =l{an(k) sin (n(8 - k z)) + bn(k) cos (n(8 - k z ))} ,E!

mwhere TO is the reference radius.
The above expression can be obtained as the ext ension of the following interior magnetic field of 2D dipole
coil in the European definition,

2.78·. . .1-;- Br~f I. . . · T·

2.77··....I - -·-- -b3 ·, ............L................ ........................
,

2.76

2.75 ................i .................J;.~....... . L.................i.. ...
2.74_...•• _••~.~ ••• _Breflimk-+o [Be,h (r, 8, z)] = Be ,2d(r, 8) =00•• _________ i.. •••••••••••••• ~ •••••••••••••••-0.001935~-0.00194-0.001945

2.73 =-......J.....J.....l.....L...J-'-'-.J......L....L...L.L...L.L-L.J......I..-'---'-l......I.....L...J.....L..~ -0.00195
0.5
1.5
2
2.5
3
0
k(radlm)

L (~) (- an cos n8 + bn sin n8)
L (~)-0.00193

n- l

n= l

Bref

-0.001925/:...
·············,i···· ············i················ ..;...------.....-

limk-+O[Br,h(r, 8, z)] = B r ,2d (r, 8) =00.......

Fig. 2. Twist dependence of t he reference field Bref(k)and of the normal sextupole coefficient b3 (k).

n-l(bn cos n8 + an sin n8)

n=llimk-+O[Bz ,h(r, 8, z)] = B z ,2d(r, 8) = o.
Therefore, the normal and skew multipoles due tomany helical line currents with current Ii , radius ai,
angle 'l/Ji are
Bn(k) = Bref(k) bn(k) = - J1,o 2 (\)1
7r

n

n-

. ro

(n kro t x

L Ii (k ai Kn-l(n k ad + Kn(n k ad) cos mpi
An (;) = B",(k) an(k) = _,"0 2 (
7r

n

\)1

n-

. ro

By

(n k ro) n X

L Ii (k ai K n- (n k ai) + K n(n k ai )) sin m pi.
1

With the definition of b1 (k) = 1 (=constant) , naturally Bref(k) = Bl(k). Then, the asymptotic forms forthe reference field Bref (k) and for these helical multipole coefficients an (k) and bn (k) are given in the limit
k -+ 0 (or L -+ 00) by,l~mk-+o [Bref (k)] = Brefhmk-+o[an (k)] = an{limk-+o[bn (k)] = bn .

Therefore, the twisting from the 2D dipole to helical
dipole gives mathematically two changes. One is in
the character of the function describing the field , andanother is in the values of multipoles determined by
the current and position of the conductor.
This analytical method was used to obtain the contents of multi poles expected for both helicai dipoles ofslotted and direct-wind types. 3 ,4) For the helical dipole

184

Fig. 3. Dipole field dist ribution of the BNL helical dipole
magnet of slotted type without an iron yoke.

References
1) T. Tominaka:(1996).
2) T. Tominaka:(1996) .
3) T. Tominaka:(1996) .
4) T. Tominaka:(1996).
5) M. Okamura:(1996).

AGS/RHIC/Spin Note, BNL, No. 49
AGS/RHIC/Spin Note, BNL, No. 24
AGS /RHIC /Spin Note , BNL, No. 47
AGS/RHIC/Spin Note, BNL, No. 48
AGS/RHIC/Spin Note, BNL, No. 46

RIKEN Accel. Prog. Rep. 30 (1997)

Observation of Slow Transient Effect of Magnetic Field Gradientin RIKEN Ring Cyclotron Magnet
M. Kumada* and M. Kase
In a cyclotron, it is known that during the startup
a kind of sophisticated initialization of magnets is necessary. The way of initialization seems to vary from
Institute to Institute. Even with the best way acquired during the startup, it is common that operator
has to wait for a couple of hours until a circulating
beam stabilizes. This waiting period is much longer
than that of synchrotron. This long waiting time isusually ascribed to the magnetic after-effect, warm-up
effect of magnet iron, or a temperature effect of cooling water. These causes, however, can not explain the
difference between a cyclotron and a synchrotron, as
the causes affect similarly for both. The major difference between the cyclotron and synchrotron is in the
thickness of iron material. The cyclotron uses a block
solid magnet, whereas the synchrotron in many cases
uses laminated magnet. The adoption of a laminatedmagnet in a synchrotron is to avoid an eddy current
effect. Since a cyclotron magnet operates by DC, it isbelieved that the eddy current effect does not exist.
The time constant of the eddy current scales as
square of the thickness of the iron width. Thicknessof 0.5 mm lamination is common in synchrotron. The
width of a block of the cyclotron ranges upto a few
meter. Even in a DC magnet, one has to turn on its
current from zero to a finite value or has to change
the field strength in need for tuning. The questionis whether the time constant of a response of the DC
block magnet is negligible or not. The ratio of the time
constant between the laminated magnet and the typical cyclotron magnet is (3 x 10- 3 /3)2 = 10- 6 , whoselarge difference in magnitude makes us uneasy. It canbe shown that the time constant can be calculated analytically for a simple magnet of simple geometry andis an order of tens of minutes. The measurement wasdone in DC magnets of various sizes at NIRS.l) For
further detailed study of transient effect, we have measured the time response of the RIKEN sector magnet
during the summer shut down period. Analysis of theeddy current predicts a transient response of the field
distribution as well as strength. Therefore, we have set
three hall probes at different locations inside the gapof the sector magnet. The magnet excitation current
whose shape is trapezoidal was also measured at thesame time.
Figure 1 shows the time response of the ratio of themagnetic strengths at two locations, and the shape of
excitation current. It is apparent that the field distribution changes with time. Figure 2 shows the fieldstrength (Bin) and at the same time the ratio of thisNational Institute of Radiological Sciences

I-Bmid/Bin'I

I-I(ampere)rI en2038

1.04

1000

1.02

800

1:::::::::::~:t:::::::l;;;,;;,;;jjiiiIJ·t::t:::::::::::t::::::::::t::::::::::1 600
0 .98

..

L

0 .96 ....
0 .94••• • •••• •,~F..i....:·..··.·.:·•.·;i·.:·.l~ ..... '.~.~. ·····.···········r·········~400 ~.~_~:::::::::~r::::::t ::::::::::::::c~:::::t:~200

0 .92 1::::::::: ::: ~::::::::~::::::::::::1:::::~'!!!!!!!!!~~::::::::::j
0 .9
-200

0

200

400

-200
800 1000 1200

600

tlm_l·eel

Fig. 1. Time response of the Ratio of field.

I

I -Bin1.5

I

I -Bmid/Bin

rlken20S8

1.04·::IfII"''f-'·;·········j······-lr"''I 1.02

0 .98 ~
ii

0 .96

~

0 .94
~:

...._.....;......!!lc.:..;...... l~+........... --'I 0 .92

05 L..t....o.....................0...1....0...........~'-'-'-...................................... 0 .9
-200

200

400

Ilam".,.,

600

800

1000

Fig. 2. Hysteresis of the ratio of the field and the strengthof the field.
I -BinI

I-I(amperej

relken2036

I

15

1000

'.'V·/~'-.:--". . . . . . . . . . . + ."....,,.-...
"~~

j......... - .... -1

800

U""-' ''; ' '''''-'''''''''';''''~''''''''~' ''-'''''''''' '';-''''''' ''-''-1 600..

~··" .... ···j"·"·"·""··+ ""'~I\· ·+··"·· ·"· "·"·;-""""·""-140o!
tw "'''''' '' ''';''''''''''''+'' ''I' \'''\- ,;"-,,,,,,,,,,,,;-,,-,,,,,,,,,-1 200

05:~ · 200

l....L-.........I.....&............................................................~

200

400

600

(ma ,a_c )

800

1000

Fig. 3. Time response of the field strength.

field strengths (Bmid IB in ) as a function of the exciting current. It shows a large hysteresis: characteristics
never seen in the existing literature. Finally, Fig. 3
shows the time response of the field strength and excitation current. From this data, it can be shown thatthe decaying time constant is not composed from a single component, but at least from several component,
as predicted by the theory. They are 1.8, 6.25, 34.7
and 81.8 minutes respectively. Further study by computer calculation is currently underway by the code of
OPERA2D.
References
1) Kumada et al.: Pres. at 1996 Fall Meet. Phys. Soc. Jpn.,
to be also submitted to PAC97.

185

RIKEN Accel. Prog. Rep. 30 (1997)

Commissioning Run of a New Injector System for RILAC
A. Goto, Y. Miyazawa, M. Hemmi, o. Kamigaito, T. Nakagawa, M. Kase, T. Chiba, S. Kohara,
E. Ikezawa, T. Kageyama, S. Numata, Y. Batygin, and Y. Yano
Installation of a new injector system for RILAC onsite was made during the August and September '96
after its one-year test on the test bench. The commissioning run of the system then started in October,
1996.
Figure 1 shows a photograph of the new injector
system consisting of an 18 GHz ECR ion source1) anda variable-frequency folded-coaxial (FCRFQ) linac ,2)along with the beam transport line from the existing 450 kV Cockcroft-Walton terminal to a new beam
matching section 3) installed in between the FCRFQ
linac and RILAC.
During the commissioning runs, beam acceleration
tests through RILAC have been performed successfullyfor 14N2+,3+, 36 Ar 5+ , 40 Ar 2+ 4+ 5+ , 56Fe8+, 84Kr5+,
and 129Xe7+ ions at the frequencies of 18.8, 22.3, 28 ,32, 35, and 36 MHz. High beam intensity and highbeam transmission efficiency both better than ever before were obtained; the maximum efficiency of 51%
was attained for transmission from the ion source till
the end of. RILAC. An 36 Ar 5+ ion beam was further
delivered to and accelerated through RRC. We haveachieved for the first time the beam intensity of 1 pJ-lA
from RRC, which is the maximum intensity required
for the RI Beam Factory project. Results of beam acceleration tests are summarized in Table 1.

Fig. 1. Photograph of the new injector system along withthe beam transport line starting from the existing 450
kV Co ckcroft-Walton terminal.

Table 1. Results of the acceleration tests through RILAC using the new injector system.
Ion

Intensity

Transmission efficiency

EnergyBeam Power(MHz)(ef.L A)

(%)

(MeV)

(W)

after ECRIS

before Rll...ACafterRILAC

afterRTILACYafterECRIS

1"N 2+

28.0

88

51

22

25

22.0

296

1"N:4

32.0

96

66

37

39

28.6

352

1"N3+

35.0

120

84

40

33

34.3

457

1"N:4

36.0

68

45

30

44

36.4

364

18.8

28

16

11

38

16.5

35

36Ars+
4O

Ar2+

18.8

93

45

25

27

28.2

352

4O

5+

18.8

27

19

10

38

25.0

50

4+

Ar

22.3

40

22

14

34

40.0

135

~eS+

28.0

20

14

10

51

87.7

110

~r5+

18.8

22

10

6.3

29

59.3

75

18.8

10

3

2.2

22

91.2

28

4O

I29

186

Freguency

Ar

Xe

7+

Beam services using the new injector system areplanned to start from the Spring of 1997.
We have decided to raise the maximum extraction
voltage of the ECR ion source from 10 kV (the initial designed value) to 20 kV in order to obtain higher
beam intensities. Modifications of the devices for that
purpose such as bending magnet, solenoid magnet, andtheir power supplies have been completed, while refabrication of the vanes of FCRFQ linac is under way.
Fabrication of the new vanes is to be completed in theSummer of 1997. With this upgrade we can expect thebeam intensity much higher than the present one: e.g.,
by a factor of about 2 for Ar l1 + ions.
References
1) T. Nakagawa et al.: RIKEN Accel. Prog. Rep. 30, 188(1997).
2) O. Kamigaito et al.: RIKEN Accel. Prog. Rep. 30, 189(1997).
3) O. Kamigaito et al.: RIKEN Accel. Prog. Rep. 30, 191(1997).

187

RIKEN Accel. Prog. Rep. 30 (1997)

Development of RIKEN 18 GHz ECRIS
T. Nakagawa, J. Arje,* Y. Miyazawa, M. Hemmi, T. Chiba, N. Inabe, M. Kase,
T. Kageyama, O. Kamigaito, A. Goto, and Y. Yano
After the successful production of highly charged
ions from gass using RIKEN 18 GHz ECRIS, we
tried to produce the metallic ions using the socalled "MIVOC (Metal Ion by VOlatile Compounds)
method" 1,2) in collaboration with JyviiskyHi University.
Organic metallic compounds are in a high vapor
pressure (i.e., 10- 3 mbar) as the materiiliransforms
into its gaseous state at room temperature. As reported in Ref. 2, the main drawback of the MIVOC
method is the contamination of the plasma chamberby carbon. In order to minimize this drawback, theplasma chamber wall was covered with a thin aluminum tube (of the thickness 1 mm) which can beeasily changed upon contamination of its inner wall.
Furthermore, it emits several secondary electrons by
an electron impact, which helps to increase the densityof plasma. 3 ) The compound chamber is attached to thegas feeding line with a regulation valve to control its
floating rate. Figure 1 shows the beam intensities ofhighly cha:rged Fe, Ni and Ru ions produced respec-tively from Fe(CsHsh, Ni(CsHsh and Ru(CsHsh at
the extraction voltage (Vext ) of 10 kV. The typical gas
pressures of the plasma chamber and extraction stage
were 1.5 x 10- 6 and 5 x 10- 7 Torrs, respectively. The
RF power was in the range of 300 rv 500 W. The typicalbeam intensity of Fe 13+, Ni 13 +, and Ru 16 + were 80, 60,
and 30 ellA, respectively. Because the Ru has the very
high melting point of rv 2450 ec, it is quite difficult
to achieve such an intense beam of highly charged Ru
ions by other methods.
In order to produce highly charged Ta ions, we inserted a Ta-rod (of 2 mm diameter) directly to theplasma. Figure 2 shows the best results of Ta ions at
the extraction voltage of 14 kV. The beam intensity of
Ta20+ was 32 ellA.

:(
::l.

.!.
~

c;;
c

S
.E

10

Ta rod ~2mm

E

!

Fe

~100 -~\~:5~8

I

21

..!.

1:

i;

c

Ru

15

E

CD

Vext= 14 kV

q=10 12

15

20

25

Charge State

Fig. 2. Charge state distributions of Ta ions.

10 ~References
I

I

I

I

I

Charge State

Fig. 1. Charge state distributions of Ni, Fe, and Ru ions.

Accelerator Laboratory, University of JyvaskyHi, Finland

1881) H. Koivisto et al.: Nucl. lnstrum. Methods Phys. Res.
B 94, 291 (1994).
2) H. Waldmann et al.: Nucl. Instrum. Methods Phys. Res.
B 98, 532 (1995).
3) T. Nakagawa et al.: Jpn. J. Appl. Phys. 35, 4077 (1996) .

RIKEN Accel. Prog. Rep. 30 {1997}

Performance Tests of a Variable-Frequency RFQ Linac
for RILAC
O. Kamigaito, A. Goto, Y. Miyazawa, T. Chiba, M. Hemmi, M. Kase,s. Kohara, Y. Batygin, and Y. Yano
Performance tests of the variable-frequency RFQ
were successfully carried out and the commissioning
run has started in the RILAC beam line. The RFQ,
based on a folded-coaxial resonator with a movable
shorting plate, accelerates ions with mass-to-charge ratios of 6 to 26 up to 450 ke V per charge in the cw
mode.!) In the present paper we describe the results
obtained from the performance tests as well as the improvements made during in this year.
In the initial stage of the high power tests carriedout in the last year (1995), we encountered a problem
on the ceramic pillars. They broke by the heat due
to the dielectric loss around the metal screws fixing
the pillars to the conductor tube, when the intervane
voltage was above 25- 30 kV.2)
This problem was solved by adopting a new structure for the pillars as illustrated in Fig. 1. This pillar
consists of Ah03 and is welded its top and bottom
with copper-tungsten alloy. This kind of welding ispossible because both materials have the similar coeffi.cients of the linear thermal expansion. After this improvement, the RFQ is stably operating in the whole
range of the acceleration voltage acceptable by the RILAC. The vacuum stays in a range of 1 - 3 X 10- 7
Torr at the pump head. No significant temperaturerise has been detected from the RFQ resonator during
the operation.
conduct.o~rT=u!::be4~ve=rt=ic=al=vrlanehHorizontal
Vane

0

Copper-Tungsten Alloy

Water
Channel(Cross Section)

Fig. 1. Schematic drawing of the improved ceramic pillar.

Acceleration tests were performed using the ion
beams transported from the 18-GHz ECRIS.3) Figure 2 shows the schematic drawing of the beam line. 4 )The extracted beam from the ion source is focusedby an Einzel lens and is bent by a bending magnet.
The bending magnet also has a focusing function by
the slant pole edges. The beam is focused again by asolenoid before entering the RFQ.
There are two diagnostic chambers in the beam line.
One chamber is located between the bending magnet

18GHzECRIS

Faraday Cup(FC I)-+--+-+-_ Profile Monitor
Emittance Monitor
Slit....-f-+lll--- RFQo1m

Faraday Cup(FC2)
Profile Monitor
Emittance Monitor
Electrostatic Deflector

Fig. 2. Schematic drawing of the beam line for the acceleration tests.

and the solenoid, which contains a Faraday cup, two
profile-monitors, and two slits. The other chamber isplaced just after the RFQ, inside of which is equippedwith a profile-monitor, a Faraday cup, two slits, andan electrostatic deflector with a scanning wire probe.
The so far accelerated ions are 0 3,4,5+, Ne 4+,
Ar 2,3,6,8,9,11+, Kr 9 +, Xe 12 +, Ta7,16,17+ at the frequencies of 17.7, 19.5,26.1,29.5,32.8,34.4,36.8 and 39.2
MHz applying the intervane voltage in the range of 1735 k V. They are indicated by closed circles in Fig. 3.
The maximum transmission efficiency, defined by theratio of the beam current in the two Faraday cups (FC1and FC2 in Fig. 2), was 88% with the beam intensityof 120 eJ-lA.
The emittances of the input and output beams were
measured by the profile monitors, along with the slits.
The input beam emittance from the ion source was
15D-300 7r mm·mrad, which decreases as the extraction voltage of the ion source and/or the charge statesof ions increase. An example of the measured results
is shown in Fig. 4. On the other hand, the output
beam emittance is almost independent of the acceleration condition; in agreement with the PARMTEQ
189

simulation.
The energy distribution of the RFQ output beam
was measured by the electrostatic deflector (40 mm ingap and 200 mm in length), along with the scanningwire probe placed downstream of the RFQ. The beamenergy was deduced from the beam position measured
by the probe and the voltage applied to the deflector.
As shown in Fig. 5, the output energy decreases as theintervane voltage is reduced, which is well reproducedby the simulation. The energy spread of the output
beam was also measured by the same method. The
result is 2- 3% at FWHM and is consistent with the
PARMTEQ simulation.

tT

:>

~

,-...

:>
C 75
G)

bi)

;>..

e.o

u

s::

Ions

LLl

'5

5

G)

~

450

t:

B

..

/.

Vn=0.9, .... , ...... " ...........' ...................... - - ...... - - ~ ,.. ' ....... . .

300

~

150

0

15

20

25

30
35
Frequency (MHz).IO• • .'. __ : •• __Fig. 3. Specification of the RFQ linac. The abscissa
and the ordinate represent the resonant frequency andthe intervane voltage, respectively. The output energy,
proportional to the intervane voltage, is also indicated.
The hatched area shows the region where the RFQ hasever been operated in the cw mode. The accelerated
ions are indicated by closed circles. The solid curves
represent the acceleration condition of ions, each ofwhich is indicated by the m/q-value. The dashed curveshows the maximum attainable voltage with the present
power source (40 kW), which is estimated by the measured shunt impedance of the resonator.

68

Verticalx' (mrad)45

10- 15 . 1015.!.. -_____ ..... -.. -... __ .__ .

Vn=0.8

40

100

68

y' (mrad)45. 15 . 10

10

300
200
Energy (keV/q)

400

Fig. 5. Measured energy distribution (solid curves) and
the PARMTEQ simulation (dashed curves). This measurement was done at the frequency of 17.64 MHz using
Ar2+ beam. The corresponding output energy is 350
keY /q. The numbers represented by Vn indicate theratios of the intervane voltage to the standard value of
26.1 kV.
The new injector system was installed in the RILAC
beam line in August-1996 and the commissioning run
has started. Preliminary results show that the transmission efficiency from the ion source to the end of the
RILAC is 51%. Further improvements are expected
for the transmission efficiency.
We are planning to raise the extraction voltage ofthe ion source to 20 kV in the near future. New vanes
for the upgraded beams are under fabrication.

15

y(mm)

x(mro)

·45

·45

·68

·68

Fig. 4. Emittance of the input beam of Ar 8 + extracted
from the ECRIS at 8.5 kV. The measurement was doneat 1400 mm upstream of the RFQ. The transmission
efficiency was 87%. The ellipse indicates the emittanceassumed in the vane design (145 1T mm·mrad).

190

Vn=l.O

0600:>

Horizontal!"\. __

1-.-.••-..-.. .-...-.-.•-..-...-.••-••-.••-.•.•

.9::l

'0 50

References
1) O. Kamigaito et al.: Jpn. J. Appl. Phys. 33, L537 (1994)
and O. Kamigaito et al.: Jpn. J. Appl. Phys. 34, 5799
(1995).
2) O. Kamigaito et al.: RIKEN Accel. Prog. Rep. 29, 221(1996).
3) T . Nakagawa et al.: RIKEN Accel. Prog. Rep. 30, 188(1997).
4) N. Inabe et al.: RIKEN Accel. Prog. Rep. 28, 166(1995).

RIKEN Accel. Prog. Rep. 30 (1997)

Beam Matching Section in the New Injector for RILAC
O. Kamigaito, A. Goto, Y. Miyazawa, T. Chiba, M. Hemmi,
M. Kase, s. Kohara, and Y. Yano
The beam matching section between the RFQ linac
and the RILAC was designed and constructed. Figure 1 shows the schematic layout of the matching section. The transverse matching is achieved by twoquadrupole doublets, while the longitudinal one is done
by a rebuncher of the fundamental frequency. A dipole
magnet is introduced for the injection of the beam fromthe Cockcroft-Walton injector. All the components
have been working properly since their installations in
the RILAC beam line in August 1996.

the RILAC are the same as those of the acceptanceellipses.
The calculation of the magnetic field in thequadrupole magnets was made by use of the POISSON program. The four quadrupole magnets have thesame specification listed in Table 1. The maximum
field gradient of 1.6 kG / cm was found large enough forthe beam with the largest m/ q value.
The dipole magnet is of the H type whose parameters were optimized with the POISSON code. Slightsaturation of the magnetic filed is observed in the highest field region. The main parameters are also listed
in Table 1.
Table 1. Main parameters of the magnets.

from

RFQ

RebuncherFig. 1. Schematic layout of the beam matching sectionin the new injector for the RILAC. DQ and BM denote the quadrupole doublets and the bending magnet,
respectively.

We optimized the transverse beam matching by useof the TRANSPORT code. The emittance of the output beam from the RFQ was calculated to be 227r
mm·mrad with the PARMTEQ program. The acceptance of the RILAC was assumed to be 1207r mm·mrad,
taking the result in Ref. 1 into account. This value wasalso checked by the simulation code LINOR.2) The optimized result is shown in Fig. 2, where the Twiss parameters of the emittance ellipses at the entrance of
RFQ
Exit
4cm

DQ

(Rebuncher)

(BM)

DQ

RILAC
Entrance

3

2

o
I

50

100 cm!

!

- - - Horizontal- - - - - - - VerticalFig. 2. Transverse beam optics optimized with the
TRANSPORT code.

Quadupole
Effective length
Real length
Bore radiusMax. current
Max. field gradient
DipoleOrbit radius
Bending angle
Edge angle
Gap
Pole width
Max. current
Max. magnetic field

150 mm
115 mm
35mm
9152 AT/pole
1.6 kG/cm
400mm
60°
0°
60mm
170 mm
36000 AT/pole
13.5 kG

The longitudinal-matching condition was optimized
with a transfer matrix method so that the output beamfrom the RFQ is focused at the entrance of the RILA C.
According to the simulation using the PARMTEQ, thephase and the momentum spread at the end of the
RFQ channel are 38 degree and ±2%, respectively.
The total effective voltage of 16 kV in the rebuncher
is sufficient to realize this condition when it is placedin the downstream of the RFQ by 1.2 m.
The rebuncher resonator, having four gaps of 8 mm,
is a coaxial resonator of a quarter-wavelength with a
movable shorting plate, as shown in Fig. 3. All thegeometrical parameters were optimized by use of the
MAFIA code. The capacitance between the tall drift
tubes as well as the large tuners make the coaxial line
short. The bore diameter of the drift tube has to be
kept 40 mm because the vertical beam size is that value
at the entrance of the rebuncher, as shown in Fig. 2. Inorder to increase the transit time factor through theselarge holes, a thin mesh plate made of copper, whose
191

A-A

Tuner gap (mm)30 20 10 0
Shorting
Plate-

Measured

40
-

-

0- -

-

MAFIA

~ 35
;;.-.,

g 30
4)

::s

C1'

J: 25
.- - - -o

50mm

L---.J

L TunerB

Pumping
Hole

Beam

L

15 ~~--~~~~~--~~~~~
450
700
900
1100
Shorting plate position (mm)A

Fig. 3. Schematic drawing of the rebuncher resonator.
transmission efficiency is 95%, was put at every endof the drift tubes. A wide-band amplifier having theoutput power of 1 kW is used for the operation. The
resonator is evacuated with a turbo molecular pumpof 350 lis.
Figure 4 shows the measured resonant frequency of
the rebuncher resonator along with the calculated ones.
The measured values are in good agreement with the
MAFIA calculations. On the other hand , the measured Q-values are around 2500, being about one halfof the calculated ones. One of the possible reasons forthis deterioration is that the electric contacts are not
perfect, particularly around the shorting plate where
sliding contacts are used.
Two diagnostic boxes are installed in the matching
section. One is located just after the rebuncher and theother is in front of the RILAC. They are equipped with
two Faraday cups, two phase probes, two slits, andthree profile monitors. The former one is evacuatedwith a turbo molecular pump of 350 lis.
All the components have been assembled in the RILAC beam line and have worked proper ly. The vacuum
stays in the range of 2 - 4 X 10- 7 Torr during the oper-

192

20

Fig. 4. Resonant frequency of the rebuncher resonator.
The solid and the dashed lines represent the measured
and calculated ones, respectively. Above 24 MHz , theresonant frequency is changed with the shorting plate,while the gap between the tuner and the drift tube is
kept constant (30 mm). Below 24 MHz, it is changed
with the tuners, keeping the position of the shorting
plate to be the highest value of 1100 mm.
ation. The transmission efficiency including the RFQ
and the matching section was 40- 50% in the first stageof the test.
In a high beam-current operation, one of the meshplate of the rebuncher has melted due to the high beam
power. Therefore, we have removed all of them, andthe transmission efficiency has increased to 70%. The
gap voltage is still high enough for the matching condition even at the maximum output energy. Measurements of the effect of the mesh plate on the longitudinalemittance are in preparation.
References
1) M. Tonuma et al.: Rep. Inst. Phys. Chern. Res. (inJapanese) 51 , 53 (1975).
2) A. Goto et al.: Proc. Computing in Accelerator Design
and Operation, Europhys. Conf. , Berlin, W. Germany,
Sept. (1983).

RIKEN Accel. Prog. Rep. 30 (1997)

Maximum Beam Current in a Low-Energy Transport Line
Y. Batygin, A. Goto, and Y. Yano

A new RIKEN low energy beam transport line in
between 18 GHz ECR ion source and RFQ linac I ) consists of an einzellens, a bending magnet and a solenoid
coil (see Fig. 1). Parameters of the structure are listed
in Table 1. Intensity of the transported beam in thebeamline considered is limited by the einzel lens aperture, dipole gap, and solenoid aperture which have thesame value of Rmax (: max beam radius) = 3.5 cm. In
this paper we estimate the maximum value of currentof the beam, that can be transported without particle
losses.

2L

Equation (1)(dR/dz)o = 0:

has

an

approximate

solution

for

2

P )
RRo = 1 + 0.5 z2 (E2R4 + R2 .
0

(3)

0

From Eq. (3) it is easy to distinguish the threshold ofdifferent transport regimes, depending on which termin Eq. (3) is essential for beam spread. Space charge
dominated beam transport results if the following condition is valid:

P~min > 1.

(4)

On the contrary, if the above combination of parameters is less than unit, emittance dominated beam drift
is fulfilled:

SolenoidL

PRmin < 1.

(5)

E

From symmetry point of view, it is clear that beam
should have a minimum size Ro (waist) in the middle
point z = L = 110 em between dipole and solenoid.
Suppose the value of P is fixed, the differentiation
OE2 / oRo = 0 gives the following expression of optimal
relationship between Ro and Rmax:
Fig. 1. Layout of extraction beamline of 18 GHz ECR ion
source.

(6)

Table 1. Parameters of beam transport line.
Maximum ion magnetic rigidity
Extraction voltage
Einzellens voltage
Maximum magnetic field in dipole
Maximum magnetic field in solenoid

Substitution of Eq. (6) into Eq. (3) gives the maximum
beam emittance A under a fixed space charge parameter for the beam:

76 kG cm
8 rv 10 kV
10 kV
1.6 kG
6.3 kGA = Emax = ~ JR~ Rmax - R~ - 0.5(L Ro P)2. (7)Evolution of the beam radius R in the drift space
between focusing elements is described by KapchinskyVladimirsky (KV) equation 2 ) for beam of circularcross-section:
d2 R
E2
p2
(1)
d z2 - R3 - If = 0,
where E is the non-normalized beam emittance, P =J2I/(Io,83,3) the space charge parameter, ,8 the particle velocity, , the Lorentz factor, I the beam current,
and 10 = 47rco mc 3 /q the characteristic current. Equation (1) has a first integral:

+p

1n

(~r

50

.-

-ee

'0

= 40

:---

~,

30

u

~
'-'

<

20,

'" ",

~

JO
0.005

(!~r = (!~): + (~r (1- ~)2

In Fig. 2 a dependence of the maximum beam emittance against the space charge parameter is presented.

O.OJ

0.015

\

0.02

0.025

P

(2)

Fig. 2. The maximum beam emittance A as a function of
the space charge parameter of beam P = J21/(1 0 ,63,3).

193

As seen, the value of acceptance of the channel is 50
From Eqs. (6) and (7) it follows that the
maximum value of space charge parameter isTable 2. Maximum transported beam current, Imax.

7r cm mrad.

(8)

P max = 0.0215.

Combining the expressions not only for parameter P
but also for beam velocity {3 as a function of extraction
voltage Uext like

(9)

{3=

the maximum beam current transported in the channel
is found to be

Im= = V2

194

Ion
ArtoS
Art~
Art;

3 If (:~~x2t )3/2, (10)P~= ( 41ro ID:C )oUext [kV]
8.5
10
10

Imax [J.tkA]
247
318
251

where m p c2 Ie = 938.3 MV is a proton rest energy. In
Table 2 the values of maximum beam current for several ions are presented.
References
1) N. Inabe et al.: RIKEN Accel. Prog. Rep. 28, 166(1995).
2) 1. M. Kapchinsky: Theory of resonance linear accelerators, Harwood, Chur, 1985.

RIKEN Accel. Prog. Rep. 30 (1997)

Progress of RIKEN RI Beam Factory Project
Y. Yano, A. Goto, and T. Katayama
The project of "RI-Beam Factory", or "RIB-factory"
for short, was formally approved by the Government
in December, 1996.
An up-to-date layout of the RIB-factory is shownin Fig. 1. The K2500-MeV superconducting ring cyclotron (SRC) in the former design has been split into
two stages: a four-sector SRC (SRC-4) for the firststage and a six-sector SRC (SRC-6) for the second
one. This two-stage scheme has been adopted in orderto make the simultaneous utilization of SRC-4 beams
possible in the both existing experimental facility andyears; and the third phase to construct BSR for three
new facility, and to relieve the difficulties in fabricating
the SRC: such as huge cold masses, huge electromagnetic forces exerted on it, etc. Further details on thegeneral features of SRC's are given in Ref. 1, and thedesign studies of their main components appear in therespective papers in this progress report. Constructionof a full-scale model sector magnet of SRC-6 without
a yoke has been undertaken. With this model magnet,
which is scheduled to be completed late in 1997, we
will verify the mechanical design of magnet and thecryogenic design of the main and trim coils. 2)

Existing Facility

Fig. 1. Layout of the designed RIKEN RI Beam Factory.

The multi-use experimental storage rings (MUSES)
will be accommodated in a one-story building, although in the former design it was in a two-story one.
In the design work of MUSES, the circumferences ofthe both booster synchrotron ring (BSR) and double
storage rings (DSR) have been elongated to reservea more space for installation of the injection system.
Namely, circumference of BSR has become 168 m instead of 135 m, and that of DSR 264 m instead of 258
m. Intersecting angle of the two rings of DSR at thecolliding point has also been changed to be 10 mrad
(or 0.57 degrees) instead of 10 degrees. Design studies of their main components and of the accumulator
cooler ring (ACR) are given in separate papers in thisprogress report.
Construction of the RIB-factory is now scheduled inthree phases. The first phase is to construct SRC-4,
SRC-6, Big RIPS, and related experimental facilities
for five years after one-year of the investigation andfundamental design of building; the second phase toconstruct ACR, DSR, and an electron linac for four

years. The first beam from the SRC-6 is scheduled forthe year 2002.
In parallel to the above design work, a new injector
system for the existing heavy-ion linac (RILAC), which
had been essential to upgrade the beam intensity forthe factory, was installed on site, and its commissioning started in October, 1996. 3 ) Beam acceleration tests
showed the beam intensity and beam transmission efficiency much better than ever obtained. An 36 Ar 5 +ion beam whose intensity of 1 pf-LA was successfully
extracted from the RRC for the first time, which is
the maximum intensity required for the factory of ourinterest.
References
1) A. Goto et al.: RIKEN Accel. Prog. Rep. 30, 186 (1996).
2) T. Kubo et al.: RIKEN Accel. Prog. Rep. 30, 201(1996).
3) A. Goto et al.: RIKEN Accel. Prog. Rep. 30, 196 (1996).

195

RIKEN Accel. Prog. Rep. 30 (1997)

The Superconducting Ring Cyclotrons
for RIKEN RI Beam Factory
A. Goto, T. Kubo, H. Okuno, T. Kawaguchi, T. Mitsumoto, T. Tominaka, S. Fujishima, J.-W. Kim,
K. Ikegami, N. Sakamaoto, S. Yokouchi, T. Morikawa, Y. Tanaka, and Y. Yano
In a previous design,!) a very large single SRC (Superconducting Ring Cyclotron) had been studied as a
post-accelerator ofRRC. After a further study, we haverecently modified the design in such a way that SRC
is split into two stages: a 4-sector SRC (SRC-4) for
the first stage and a 6-sector SRC (SRC-6; K = 2500
Me V) for the second one. This two-stage scheme has
two big advantages. Firstly, the simultaneous utilization of SRC-4 beams is possible in both the existing experimental facility and the new facility, whena part of the beams is charge-stripped and is transferred back to the existing facility. For an example,
a 127 MeV/nucleon 16 0 7+ beam from SRC-4, while
the main part of which is injected into SRC-6, a partof which is charge-stripped to 0 8 + and delivered tothe existing facility (where the magnetic rigidity of the
0 8 + beam can be accepted). Secondly, the difficultyof fabrication due to huge length of the cold mass andhuge electromagnetic force on it is drastically eased
compared to the single-stage scheme.
The maximum beam energy of SRC-6 is set to be
400 MeV/nucleon for light heavy ions, which should beachieved at 38 MHz, the maximum rf frequency stably
operated in the injector heavy-ion linac (RILAC). Thismeans that the velocity of RRC output beam has to be
amplified by a factor of 2.26 by the two SRC's. Harmonic numbers of SRC-4 and SRC-6 are chosen to be
7 and 6, respectively, while that of the existing K540MeV ring cyclotron (RRC) is 9, considering the maximum magnetic field strengths and the injection andextraction radii. The mean injection radius of SRC-4
is then taken to be 7/9 times the mean extraction radius of RRC, and the velocity gain factor of SRC-4 to
be 1.50. (For 400 MeV/nucleon light heavy ions, theirbeam energy from SRC-4 becomes 127 MeV/nucleon,
which is almost same as the maximum beam energyof RRC.) From the above conditions, the mean injection and extraction radii of SRC-4 are 2.77 m and4.15 m, respectively, and those of SRC-6 are 3.56 m
and 5.36 m , respectively. The sector angles of SRC-4
and SRC-6 are 51 0 and 25 0 , respectively. The radiofrequency of SRC-4 and SRC-6 ranges from 18 MHz to
38 MHz, which is the same as that of RILAC and RRC.
The maximum magnetic fields required for SRC-4 andSRC-6 are to be 1.9 T and 4.2 T, respectively. Thiscascade of SRC's boosts energies of heavy ion beams
up to: e.g., 400 MeV/nucleon for light heavy ions likecarbon, 300 MeV/nucleon for krypton ions, and over
100 MeV/nucleon for uranium ions.
Geometries and characteristics of SRC-4 and SRC-

196

Rinj(m)Reld(m)Velocity gainh8(T)Weight (ton)

RRC

SRC-4

SRC-6

0.89

2.77
4.15
1.50
7
1.9
2,400

3.56

3.56

4.0
9
1.7
2,100

5.36

1.51
6
4.2
4,000

Fig. 1. Comparisons of the geometries and characteristics
of RRC , SRC-4, and SRC-6.

6 thus designed are shown in Fig. 1 along with thoseof RRC. The structure and size of SRC-4 are similar
to those of RRC. A warm-pole method is adopted for
SRC-4, while a cold-pole method is adopted for SRC6. 1 ) At present , our effort is concentrated on the designof SRC-6: optimization of the geometry of the sector
magnet by the calculation of tunes,2) optimization oftrim coil configuration,3) fixing of the specifications of
the main and trim COilS,4) structural design to support
the main coil vessel and the whole cold mass,4) designof the injection system,5-7) etc.
We have started to construct a full-scale model sector magnet of SRC-6 without a yoke to verify particularly the mechanical design of magnet and the cryogenic design of the main and trim coils. 8 ) We havealready placed orders with companies for the superconducting wires of the main and trim coils, and forthe fabrication of the main coil vessel and cold pole.
Test of the model magnet is scheduled to start in late
1997.
References
1) T. Mitsumoto et al.: Proc. 14th Int . Conf. on Cyclotrons
and their Applications, Cape Town, p. 237 (1995).
2) T. Mitsumoto et al.: RIKEN Accel. Prog. Rep. 30, 197(1997).
3) J.-W.Kimet al.: RIKEN Accel. Prog. Rep. 30, 209 (1997).
4) T. Kawaguchi et al.: RIKEN Accel. Prog. Rep. 30, 199(1997).
5) H. Okuno et al.: RIKEN Accel. Prog. Rep. 30, 203 (1997).
6) T. Tominaka et al.: RIKEN Accel. Prog. Rep. 30, 205(1997).
7) S. Fujishima et al.: RIKEN Accel. Prog. Rep. 30, 207(1997) .
8) T. Kuboetal.: RIKEN Accel. Prog. Rep. 30, 201 (1997) .

RIKEN Accel. Prog. Rep. 30 (1997)

Design Study of Sector Magnets for RIKENSuperconducting Ring Cyclotron (I)T. Mitsumoto, A. Goto, T. Kawaguchi, J.-W. Kim, Y. Tanaka, T. Kubo,
H. Okuno, T. Tominaka, S. Fujishima, and Y. Yano
An "RI beam factory" has been proposed as thenext facility-expansion project of the RIKEN Accelerator Research Facility (RARF).l) The "RI beam factory" aims at production and acceleration of radioactive isotope beams covering the whole mass region.
It requires the energy of ion beam to be higher than
100 MeV/nucleon. To accomplish this requirement,
the following two superconducting ring cyclotrons wereadopted as post-accelerators of the existing RIKEN
Ring Cyclotron (RRC): a 4-sector superconducting
ring cyclotron (SRC-4) for the first stage and a 6-sector
superconducting ring cyclotron (SRC-6) for the second stage. 2 ) The sector magnet of the SRC-6 has tobe flexible enough to generate isochronous fields in awide range of energies and for various q/ A values. In
this report we describe the feature of the sector magnet
together with the field calculation and orbit analysis.
The maximum acceleration energy of the SRC-6 wasdetermined by experimental requirements. The SRC6 is expected to boost the energy of ion beam up to
400 MeV/nucleon for light heavy ions like carbon ionsand 150 MeV/nucleon for very heavy ions like uranium
ions. Beam current is expected to be more than 100
pl-lA for light heavy ions and about 0.2 pl-lA for 150
MeV/nucleon uranium ions.
To accomplish this requirement, the total velocity
gain factor for the two new cyclotrons becomes 2.26.
The velocity gain factors of the SRC-4 and SRC-6 aretherefore selected to be 1.50 and 1.506, respectively.
Main parameters of the SRC-6 are listed in Table 1.

along beam orbits but just straight in the beam region. These coils are controlled by three independent
currents. Each coil is put in the same layer whose
thickness is 2 cm. Configuration will be optimized bydetailed analysis. Using three sets of superconducting
trim coils, it is possible to adjust various distributionsof isochronous fields within ±0.01 T. Further fine adjustment will be done with the trim coils of room temperature.
Figure 1 shows typical magnetic field strengths along
the center line of the sector magnet for typical ions.
Maximum magnetic field in the accelerating region is
4.3 tesla.
4.5

E

r__----r------.------,

4.0

-0

~

t.;::
.~

3.5

vc

00
CIS

::E

3.0

2.5

300

400

500

600

Radius along the center line (cm)Fig. 1. Magnetic field strengths along the center line of
the sector magnet for (1) 238U58+ 150 MeV/nucleon,(2) 84Kr30+ 300 MeV/nucleon and (3) 12C6+ 400
MeV /nucleon.

Table 1. Main parameters of the SRC-6.
Number of sectors

6

Harmonics

6

A verage radius:

Number of cavities
RF frequency

injection

3.56 mextraction

5.36 m3

18-38 MHz

Size of the superconducting main coil is 284 mm(width) x 310 mm (height). The maximum excitation
current is 6 MA for one sector magnet. The superconducting main coil is installed inside the stainless steel
Helium vessel which is fixed to the cold pole.
Superconducting trim coils are placed on the innersurface of the cold pole. The coils are not wound

Magnetic fields and related characteristics are calculated by a three-dimensional code TOSCA.3) Equilibrium orbits and betatron tunes were calculated by
the computer program that had been originally developed for the RRC. Results of the field distributions by
TOSCA were used in the orbit calculations.
In the case of high energy acceleration, verticaltune V z goes down toward 1.0 as the energy increases.
Preliminary estimation of v z = 1 resonance was simulated by the accelerating beam calculation. Figure 2
shows an example of the calculation for 12C6+ 400
MeV /nucleon in the case that the tune values crossv z =l resonance. In this calculation, magnetic field has
first order harmonics which come from the fact thatone sector magnet and another sector magnet of opposite side are vertically displaced 1 mm and -1 mm,
respectively. Amplitude of vertical oscillation increases
fatally when the beam crosses the resonance.
197

e

~

50

vz = 1 resonance

-5
c

.:-

.g0

II

e

•

1

•I

j 0

/

~l= 1 mm~

~l=-I mm

(;j

u

.€
u

;>

shapes for 12C6+ 400 MeV/nucleon. The radius of curvature of 8.0 m increases V z value by 0.12 to 1.01 at
the extraction radius compared with the straight pole.
Figure 4 shows typical tune values calculated for thesector magnet thus far designed. Figure 5 shows region of ions (grey area) which can be obtained fromthe SRC-6.
1.7"\/;1 Nt

-50

,

0

"1

100

1.6

200
Tum number

300

Vz

1.5
l-

1.4

Fig. 2. Influence of l/z=l resonance. The magnetic field
has first order harmonics which come from the fact one
sector magnet and another sector magnet of opposite
side are vertically displaced 1 mm and -1 mm, respectively.

N

;>

~)(l-

"~.j

1.3

1.2
1.1

vz = 1

1.0

The sector shape was selected so that vertical tune
values never across l/z = 1.0. Smaller sector angle
causes larger vertical focusing force. From the viewpoint of minimizing the maximum field, a large sector
angle is preferable. Therefore, edge of the pole has astraight line from the injection side to the middle ofthe sector with the wide angle of 25 deg. Then thepole shape has a curvature in order to increase verticaltune V z at the extraction side.
Figure 3 shows tune values of three different pole

= 1.5

0.9
1.0

1.1

1.2

1.3

1.4

1.5

1.7

1.6

1.8

Vr

Fig. 4. Thne values for typical ions for (1) 238U58+
150 MeV/nucleon, (2) 238U49+ 100 MeV/nucleon, (3)84Kr30+ 300 MeV/nucleon, (4) 12C6+ 300 MeV/nucleonand (5) 12C 6+ 400 MeV/nucleon.

100 ~----------~
1.3o~~~~~~~~~~~~~~~~~~~

o
1.2

>l.l
1.0~----';;-------~~~-~--I

0.1

0.2

0.3
q/A

0.4

0.5

Fig. 5. Performance of the SRC-6. Grey area shows theregion of the beam obtained. Typical ions are shownby white circles.

0.9
1.2

1.3

1.4
Vr

1.5

1.6

Fig. 3. 1\me values of three different pole shapes for 12C 6+400 MeV/nucleon are shown in the case of (1) straight
line, (2) 16 meters radius and (3) 8 meters radius.

198

References
1) Y. Yano et al.: 14th Int. Conf. on Cyclotrons and Their
Applications, Cape Town, South Africa, Oct. p. 590(1995).
2) A. Goto et al.: RIKEN Accel. Prog. Rep. 30,196 (1997).
3) Vector Fields Limited, Oxford, England.

RIKEN Accel. Prog. Rep. 30 (1997)

Design Study of Sector Magnets for RIKENSuperconducting Ring Cyclotron (II)T. Kawaguchi , T. Kubo, T. Mitsumoto, T. Tominaka, S. Fujishima, H. Okuno, Y. Tanaka,
J.-W. Kim, K. Ikegami, N. Sakamoto, S. Yokouchi, T. Morikawa, A. Goto, and Y. Yano
The RIKEN Superconducting Ring Cyclotrons,
SRC-4 and SRC-6, are one of the main accelerators
for the "RIKEN RI-Beam Factory" .1) Here, the design
study of the sector magnets for the SRC-6 is described.
Figure 1 and Table 1 show a cross sectional view andbasic parameters of the sector magnet for the SRC-

6, respectively. Main components of the magnetic
elements are superconducting and normal-conducting
coils, poles, and a yoke. We use two kinds of superconducting coils; a pair of main coils and a group oftrim coils. A group of normal-conducting trim coils
is also arranged in the upper and lower side of the

o

10m

I

I

FZ SUPPORTCOLD POLE

1RIMCOJL(super)

MAlNCOJL
TRIM COIL
MID(normal)PLANE

FXSUPPORT__ I__ ~ _­

S.4m

MIC

COIL LINKBEAMCHAMBER
80KSHIELDVACUUM
VESSEL

Fig. 1. Section view of the sector magnet.

Table 1. Parameters of the sector magnet.
3.56m,
Average radii of beam injection
extraction
5.36 m.
Sector angle of main coil
25 degree
Maximum magnetic fields
in beam orbital area
4.5 T,
in main coil
5.5 T,
in trim coil
5.0 T.
Main coil ampere turns per magnet 6.0 MA
Coil cooling method
LHe bath cooling
Magnetic stored energy for 6 magnets 450 MJ( 75 % in air, 17 % in cold poles, 8 % in yokes)
Maximum operation Currents
5000 A,for main CoilSOOA.
for trim CoilIron weight of 6 magnets
216 tons,
cold poles
3630 tons.
yokes

beam chamber. A special feature is the cold-pole arrangement. This arrangement gives a mechanical sup-port against the huge magnetic force of the main coils,
and gives the reductions of ampere-turns and of magnetic forces, compared with a warm-pole arrangement.
A vertical magnetic force (Fz) is supported with twocoil links which are attached the upper and lower cold
poles. We have been investigating two ways of supporting a magnetic shifting force (Fx) in the radial
direction. One way is to arrange a pair of cold rings
which connect the cold masses (coils and cold poles)of the six sector magnets in 4.5 K region. A problemof the cold ring support system is the central space forthe cyclotron. This space is limited for arranging thebeam injection elements. Another way is to use large
size thermal insulated supports made of high strength
material like as titanium alloy, in between the coldmass and the yoke using the outer space of the sector magnet. The problems of the thermal insulating
support system are its large heat leak, and its mechanical deflection which causes a position shift of themagnetic field. After optimization for decreasing theshifting force Fx, we have almost decided to use thethermal insulation support system as shown in Fig. 1.
199

Table 2 shows the calculated magnetic forces of themain coil and of the cold pole with an ampere turnsof 6 MA per magnet (or per two coils). The verticalforce Fz of 1154 tons will make a bending deflection of
2 mm in the normal direction to the cold pole of 465
mm thickness. The shifting force Fx of 104 tons will
make the coil position change by 1 mm in the radial direction. This force Fx is generated by the arrangementof six sector coils and the asymmetry configuration of
the coils and irons.
Table 2. Magnetic forces in a main coil and a c~ld pole.
unit: ton
For half coilFx
FyFz
No. 1 element
-87
0
-9
No.2
-166
132
-25
No.3
-185
940 -254
No.4
160 205
-84
No.5
310
21 -115Sum.
32 1298 -487
For a cold pole-12
0 -180For half cold mass52
o -1154( one main coil and one cold pole)
Fora magnet
104
00( one cold mass)

No.4

Yl
z

~NO.2~No.5

No.1

The main superconducting coil has triangle shapewith two long straight sections of about 3.5 m long.

200

The magnetic forces on the main coil are supported by
the coil vessel and the cold pole. We apply a cryogenic
stabilizing method for the main coil and trim coil toprevent coil quench. The average current density ofthem are 34 A/mm2 and 41 A/mm 2 , respectively. We
were considering two materials for the stabilizer of thesuperconducting wire. One was pure copper having
rough surface, and another was pure aluminum having flat surface. We have decided to use pure aluminum stabilizer considering the electrical and mechanical properties, the thermal contraction from room
temperature to 4.5 K, and the price. Main reason ofthis choice was the price.
Two refrigerators having a capacity of 500 W each at
4.5 K will be used for cooling of the six sector magnets
plus the beam injection/extraction magnets. The coldmass weight of the six sector magnets is 360 tons, andit will take one and a half months for cooling the coldmass from room temperature to 4.5 K. We expect thesuperconducting ring cyclotron to operate more than6000 hours a year. The cold mass should be kept in low
temperature as long as possible. When one refrigerator
breaks down, the magnets can be kept at 5 to 6 K withanother refrigerator. We will have one or two days ofpower off a year for the power system maintenance, andat that time a recovery compressor with an emergency
power source will recover the evaporated helium gas tothe buffer tank. We will have no liquid nitrogen in thiscryogenic system for simplicity of the cooling system.
Currently we are constructing a real-size model sector magnet 2 ) to verify our design.
References
1) A. Goto et al.: RIKEN Accel. Prog. Rep. 30,196 (1997).
2) T. Kubo et al.: RIKEN Accel. Prog. Rep. 30, 201(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Design of a Model Sector Magnet for RIKENSuperconducting Ring Cyclotron
T. Kubo, T. Kawaguchi, T. Mitsumoto, T. Tominaka, S. Fujishima, H. Okuno, J.-W. Kim, Y. Tanaka,
K. Ikegami, N. Sakamoto, S. Yokouchi, T. Morikawa, A. Goto, and Y. Yano
In the RI-beam factory project, it is planned to build
two superconducting ring cyclotrons (SRC) as post accelerators of RIKEN Ring Cyclotron. I) The SRC, previously designed as a single-stage device, has been determined to split into two stages. The first and second SRCs have been named SRC-4 and SRC-6, respectively. The details on the split are described in Ref. 1.
Here we report on the design of a model superconducting sector magnet for the SRC-6.
As reported elsewhere within this progress
report,2,3) the SRC-6 consists of six superconducting
sector magnets with a sector angle of 25 degrees. Its
mean injection and extraction radii are decided to be
3.56 m and 5.36 m, respectively, and the maximum
magnetic field of sector magnets is designed to be 4.3
T. These parameters are the same as those of thesingle-satge SRC except for the mean injection radiusthat was 2.37 m rather than 3.56 m of new design.
In the last progress report ,4) we reported a designof a full-scale model magnet for the single-stage SRC.
New design of a model magnet for the SRC-6 is essentially the same as that old design, except the size
reduced due to the split. Figure 1 shows a schematic
drawing of the model sector magnet. Length of themodel along the center line of sector has reduced in

6600mmFig. 1. Schematic drawing of the model sector magnet: aside view (upper figure); a top view (lower figure).

Fig. 2. Some details of the main coil and cold pole.

accordance with the increase of mean injection radius.
The same cold pole method is adopted as before to
support the huge electromagnetic force due to the large
magnetic field and coil current. 3) Figure 2 shows somedetails of the main coil and cold pole. As seen from
Figs. 1 and 2, the pole pieces are separated from theiron yoke and are cooled down together with the main
coils in the cryostat. Two 'coil vessels that accommodate the main coils are attached to the side of the UJr
per and lower pole pieces that are linked each other bypole links.
The pole gap is designed to be 380 mm, considering
sizes of the trim coils and of the magnets for injectionand extraction to be installed in the gap space. The
cold-mass weight is estimated to be about 50 tons. The
coil vessels are made of stainless steel. One of theimportant issues in the design is how to fix the coilvessel to the side of pole piece. At present we have
not yet finalized it. The detailed design study is inprogress, considering the stresses due to the thermal
contraction and electromagnetic force.
A cryogenically-stabilized superconductor was designed based on Maddock's criterion, and is used forthe main coil in order to prevent it from quenching.
The main coil has been designed to be stable up toa current of 6000 A when the applied magnetic fieldis 6 T and the cooling efficiency is assumed to be
50%. The conductor has a rectangular shape, consisting of a Rutherford-type NbTi cable located at thecenter of conductor and a stabilizer housing. The conductor's cross-sectional area is 8 mm x 15 mm. The
Rutherford-type cable is composed of ten NbTi superconducting wires of 1.25 mID diameter and 1.05 Cu/SC
ratio. The diameter and twisting pitch of the filaments
contained in each wire are 27 J-Lm and 18 mm, respec-201

tively. Critical currents of the wire at 4.3 K is greaterthan 14500 A at 5 T, 11500 A at 6 T, and 8500 A
at 7 T. The Rutherford-type cable has a rectangularcross-section of 2.35 mm x 6.35 mm and has a twisting pitch of 55 mm. The stabilizer material has beenchosen to be pure aluminum with a residual resistivity
ratio greater than 500. 3 ) The condition of the stabilizer
surface is flat. The AI:Cu:SC ratio of the conductor is
17 : 1.05 : 1. Fabrication of the conductor has beenordered from a conductor manufacturer.
Cross-sectional area of the main coil is 283.5 mm x309.5 mm, as shown in Fig. 2. The number of turns
is 600 for each coil. The main coil is wound by thesolenoid winding method in such a way that it has 30
layers in the horizontal direction and 20 turns in thevertical direction. The horizontal and vertical cooling gaps are taken to be 0.5 mm and 1.5 mm, respectively. These gap-widths are large enough to achieve
the designed heat flux. The spacers of FRP (Fiber
Reinforced Plastic) are placed in the gaps in such a
way that 50% of conductor surface is exposed to the202

liquid helium. We plan to excite the main coil withvarious currents lower than 5000 A, because deterioration of cooling and/or larger heating than expected
may happen in some parts of the coil. The current density at 5000 A is estimated to be about 34.2 A/mm 2 •The total ampere-turn is 6 MA at 5000 A , which islarge enough to generate the designed field strength of
the sector magnet.
Partial fabrications of the model magnet have beenplaced an order with manufacturers. The detailed design is going on in collaboration with the manufacturers.
References
1) A. Goto et al.: RIKEN Accel. Prog. Rep. 30,196 (1997).
2) T. Mitsumoto et al.: RIKEN Accel. Prog. Rep. 30, 197(1997).
3) T. Kawaguchi et al.: RIKEN Accel. Prog. Rep. 30, 199(1997).
4) T. Kubo et al.: RIKEN Accel. Prog. Rep. 29, 236(1996).

RIKEN Accel. Prog. Rep. 30 {1997}

Design Study of Injection System for RIKENSuperconducting Ring Cyclotron (I)H. Okuno, T. Tominaka, s. Fujishima, T. Kubo, T. Kawaguchi, T. Mitsumoto,
J.-W. Kim, K. Ikegami, N. Sakamoto, S. Yokouchi, T. Morikawa,Y. Tanaka, A. Goto, and Y. Yano
In the RI beam factory project,!) two Superconducting Ring Cyclotrons (SRC-4 and SRC-6)2) are designed
to boost the energy of the ion beams available fromthe existing RIKEN Ring Cyclotron (RRC). Consequently, the output energies designed to the SRC-6
are 400 MeV/nucleon for light ions such as carbon andare 150 MeV/nucleon for heavy ions such as uranium.
The injection energies (E inj ), required to obtain thedesigned output energies (Eexd, for three kinds of ion
beams, are shown in Table 1. In present report , we describe the recent status of design study of the injection
system for SRC-6.

Table 1. Energies of the injected and extracted beams at
the full-power operation of SRC-6.
Charge
16

0

84Kr
238U

8+
30+
59+

E inj
(MeV /nucleon)
127.0
102.5
57.9

Eext
(MeV /nucleon)
400
300
150

Figure 1 shows examples of the trajectories of injected beams in SRC-6. The beam is injected throughone of the magnetic valleys into the central region of
SRC-6, which is then radially guided to the first equilibrium orbit. The transport system consists of threebending magnets (BMl, BM2, BM3), three magnetic
inflection channels (MICl, MIC2, MIC3), and an electrostatic inflection channel (EIC). The MICs are inserted in the gap between the pair of poles of the sector
magnets to increase the bending power of sector field
locally. The EIC is placed in the position where thetrajectory of injected beams matches finally with thefirst equilibrium orbit. The radial-injection method
as shown in Fig. 1 is the most straightforward one
adopted in many ring cyclotrons. However, to apply
the same method on the SRC-6 is more difficult thanto do on the normal conducting ring cyclotron, because
a strong negative fringe field exists in the valley regionand so the beam trajectory strongly depends on theacceleration condition for the case of SRC-6.
In the original layout of the injection system shownin the last progress report,3) the injected beam crossed
the EIC as for the case of normal conducting ring cyclotrons. Usually, the injected beam goes through asmall hole in the EIC. In the SRC-6 case, however, thesize of a hole is required to be more than 10 cm in diameter not to disturb the electric field in the EIC. We
adopted a new layout where the injected beam dose
not cross the EIC, because we could not find a simple
mechanical structure for the EIC with small holes.
In order to accept the changes in the beam trajectory, the elements should be movable or have a large
bore. We adopted the latter method, except for the
EIC which is required to move 25 cm maximum in theradial direction, because the former method makes themechanical structure of elements and the beam tuning complicated. It is important to make the change

Table 2. Conditions of the injection elements and changes(~x) in the trajectories resulted from the numericalanalysis of injection orbits.
Radius[cm]

Fig. 1. A schematic layout of injection elements for the
SRC-6, and possible trajectories for the injected beam.

EIC
MICI
MIC2
MIC3
BMI
BM2
BM3

Angle
[deg]

-

-

110.0
110.0
94.0
154.0
162.0
498.0

42.5
47.5
53.0
40.0
124.0
7.0

B or E (max.)[T] or [kV /crn]
100
0.19
0.22
0.95
3.5
3.3
-1 .89

~x

[cm]
12.0
1.1
1.2
1.0
2.5
3.7
10.2

203

of the beam trajectories inside the elements as small
as possible. In the numerical analysis of the injection orbits,4) we concentrated our effort to minimize
them (~x). Obtained results from such an analysis
are shown in Table 2, together with their conditions.
Further optimizations for the number and position of
the injection elements are in progress.
The three bending magnets and the third inflection
channel (MIC3) are required to be superconducting
magnets in order to produce the required magnetic
fields. The strong fringe fields mentioned above makethese bending magnets difficult to be constructed, because we can not use the iron yoke for magnetic shielding. The total flux of the stray field is large enoughto saturate the iron in the central region. Thus, we
adopted the active shield type magnets for the BMs
although more magnetic motive force is needed thanthe case of iron shield type. The BM1 has the smallest
available space. In Table 3 the specifications of BM1
are listed. The BM1 has a space limit of ±20 cm in theradial direction. Magnetic field analyses 5 ) show thatsuperconducting coils can produce the required fieldwith the current less than 50% of the critical current,
and can be installed in the limited radial space. In
the coil end region within the space of 10 cm needs tocontain coil supports and cryostat walls. The designfor the coil end region is in progress.

204

Table 3. The main specifications of BM1 .
Item
Type
Maximum field
Homogenity
Beam Bore
RadiusAngle
Fringe Field
Space limit in theradial direction
Space for the coilend region

Value
Iron free
active shield
3.5 [T]1 x 10- 3 [fcm 2 ]40 (Horizontal) x
20 (Vertical) mm 21540 mm40 degLess than 100 G at thefirst equilibrium orbit±20 cm
10 cm

References
1) Y. Yano et al.: RIKEN Accel. Prog. Rep. 30, 195 (1997).
2) T. Mitsumoto et al.: RIKEN Accel. Prog. Rep. 30, 197(1997) .
3) H. Okuno et al.: RIKEN Accel. Prog. Rep. 29, 61 (1996).
4) S. Fujishima et al.: RIKEN Accel. Prog. Rep. 30 , 207(1997).
5) T. Tominaka et al.: RIKEN Accel. Prog. Rep. 30, 205(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Design Study of Injection System for RIKENSuperconducting Ring Cyclotron (II)T. Tominaka, H. Okuno, s. Fujishima, T. Kubo, T. Kawaguchi, T. Mitsumoto, Y. Tanaka, S. Yokouchi,
J.-W. Kim, K. Ikegami, N. Sakamoto, T . Morikawa, A. Goto, and Y. Yano
The injection elements for a superconducting ring
cyclotron (SRC) are designed. 1- 3 ) The injection system
for the 6-sector SRC (SRC-6) consists of four bending
magnets (BMl , BM2, BM3, BM4) , three magnetic inflection channels (MICl , MIC2 , MIC3) , and an electrostatic inflection channel (EIC).4,5) In this present
report , the design study of a bending magnet (BM1)
is described. Major parameters of BM1 are shown in
Table 1.

'~~.' ': '. ~
.''
..'~

...,

... '

....

f11~O

X100.0~-

Table 1. Major parameters of BM1.
Bending field

3.6 T

Bore size

40 (H) X 20 (V) mm 2

Homogeniety (excluding quadrupole)

1 X 10-3

Bending radius

1.54m

Effective magnetic angle (length)

40 · (1 .08 m)

Stray field< 100 G at 0.5 m

A stray field up to 0.6 T is anticipated in the area of
the BMI due to the saturation of iron yoke of the main
SRC's sector magnet, depending on the acceleratingions. Then, if the BMI have its iron yoke, the ironyoke saturates due to the stray field. Such a saturationof the iron yoke was confirmed by the field calculation,with 3D electromagnetic calculation code of TOSCA,
for the complete configuration of 6-sector magnets. As
a result, the iron yoke of BMI is ineffective to shield
the field of bending magnet, though it is required toreduce the magnetic disturbance into the level of 100
G over the acceleration region. Therefore, an activeshield type magnet which is equipped with shield coils
is adopted for the BMI of SRC-6.
A schematic view of the designed BMl, which consists of three main coils and two shield coils, is shownin Fig. 1. It is assumed that both coils are fabricatedfrom the superconducting wire having the cross sectionof 2 X 4 mm 2 which permits the operating current of
1.8 kA. Distribution of the BMI 's dipole field against
bending along the x axis (horizontally transversal direction for the beam axis) is shown in Fig. 2. It is seenthat the shield coil reduces the interior field of main
coils by about 20%, but can compensate the exterior
field of main coils. The dipole field in the midplaneis shown in Fig. 3. The quadrupole field is produced
due to the curved structure of BM1. The 2D multipole contents calculated from the field distribution
along the circle of r = 20 mm and along the x axis areshown in Table 2. Both contents are slightly different

'

It

..
~ .. ,..

'~
' .

'.f 1
l

,-

I

,-Z-40.0

Fig. 1. Schematic view of the bending magnet (BM1).

4
2

No F=~~~~----+---~--~~~

III

-2

-0.15 - 0.1-0.05

0x

0 _05 0_1 0.15 0_2(m)Fig. 2. Field distribution along the x axis (2D calculation).

3 . 58E-<~ 3.57N

III

3.SS~-_~1-S--_~1-0--_~S--~0~~---1~0---1~S~20
x(mm)

Fig. 3. Field distribution in the midplane (3D calculation).

each other due to the curved structure. The effective
length of the dipole field along the beam axis shown in
Fig. 4 is about 1.08 m.
205

Table 2. Contents of multi pole components of BM1, withthe reference radius of r = 20 mm.
n(Bref)
123456circle (r = 20 mm)
3.5695Pole

dipolel.
quadrupole 0.00326
sextupole - 0.00135
octupole
0.0000323
decapole
0.00126
dodecapole 5.82 10- 6

x axis
3.5695l.

0.00327-0.00141
0 .000065
0.001610.00031

are shown in Fig. 7. Supporting structure for the magnetic forces should be optimized. The mechanical andcryogenic design are currently under study. Since theinstallation space for the bending magnet (BMl) is solimited, a compromise between the compactness for thewhole structure and the easiness for the coil fabricationmust be made.

3

N

III

1
O~--~r-------~--------~----~-1~--0-.~7-5---0~.5~-0~.~2~5~0---0~.2~5~0~.~5~0~.7~5~1

Length along beam axis, s(m)xFig. 4. Field distribution along the beam axis (3D calculation).

For the case with vertical bias field of -0.6 T, thedistribution of field vectors is drawn, together with thecross sections of coils in Fig. 5. The inversely verticalbias field - Bbias increases the total field between themain coils and the shield coils, and changes the location of the maximum field and changes the magnetic
forces acting on each coil. The contour plot of IBI isshown in Fig. 6 The white region corresponds to themax strength value of IBI, while the black region corresponds to the minimum IBI. The maximum field ofcoils is 4.2 T. The magnetic forces exerting on coils

150 ~- ...... _s __~_~ .... _: "

,

"

,

•

•

,

,

,

,

•

•

•

•

.

t

,

,

,

,

,

(m)

Fig. 6. Contour plot of IBI with the vertical bias field (2D
calculation) .

r------ __ _FIx = -140 leN/m
Fly =- 170 leN/m

F4x = 78 leN/m
F4y 76 leN/m

F2x = 2.5 leN/ill
F2y =-250 kN/m

F5x = 9 1 leN/m
F5 y = 27 kN/m=

F3x = 170 leN/m
F3y · 110 kN/m=

I " .. '" " ..... "" . . ~ " .. .. ,:,.... ~ .... ~

"

" . ,

! " • .. ~ ,. ~ " " " ~,~ •
,
I

•

a

•••

"

"

"

.'4

"

I
.. .. ,. • .. .. .. , , ", 'I , # " .. .. .. .. .. , , , , . ' , , , ,100 ,...-----__"
I ' # ,.. ..........: . . . . . . . , , \ \ , • , '~, 'I , # " , - .... , ... " ... ~ " ,* '-' ,

! ' , , , - - ~,~ ... " \ \ ~I , , " -' - - _ ....'" " \ \I , I___ '" <,~ ~ \,y

I

...

,

30 degree
Shi e ld Coil" ''-x''\' \ ",50 ~-~--l f.... _ ~,'(\ \ \ \... , '
' ,.r-, '" '\. \'\ \\\ \\ \~ "\ "\ ~~ ''\\ ''I ff
f f I "-,fI f I I, , ' --." \ ~ \ \ \ \ " \ \,20 --kJ ,-,~''"." \ \" \ \ \ \ \ \ ~f )\1 f f ,. \h~ ~ l • • to ~:LLt_Lt_
T'rT-rT-rT-i ----+ r (mm)I , 1 I"

I
l

f\

20

150 (mm)
Main Coil 100

Fig. 5. Distribution of field vectors with vertical bias fieldof - 0.6 T (2D calculation).
206

Fig. 7. Magnetic forces exerting on coils under the verticalbias field (2D calculation).

References
1) A. Goto et al.: RIKEN Accel. Prog. Rep. 30, 196 (1997).
2) T. Mitsumoto et al.: RIKEN Accel. Prog. Rep. 30, 197(1997).
3) T. Kawaguchi et al.: RIKEN Accel. Prog. Rep. 30 , 199(1997).
4) H. Okuno et al.: RIKEN Accel. Prog. Rep. 30, 203(1997).
5) S. Fujishima et al.: RIKEN Accel. Prog. Rep. 30, 207(1997).

RIKEN Accel. Prog. Rep . 30 (1997)

Design Study of Injection System for RIKEN Superconducting
Ring Cyclotron (III): Analysis of the injected beam trajectories
S. Fujishima, H. Okuno, T. Tominaka, T. Kubo, T. Kawaguchi, T. Mitsumoto, J.-W. Kim, K. Ikegami,
N. Sakamoto, S. Yokouchi, T. Morikawa, Y. Tanaka, A. Goto, and Y. Yano
For the RI beam factory project , a design of
the Superconducting Ring Cyclotron-6 (SRC-6) is inprogress. 1) We report current status of analysis of theinjected beam trajectories.
To determine the layout of the injection elements,
we are analyzing the injected beam trajectories by numerical calculation. For the numerical calculation, we
use a code "INJECT" originally developed by Goto
et al. 2) to design the presently existing RIKEN Ring
Cyclotron. To calculate the injected beam trajectories, a Lorentz equation is solved with Runge-KuttaGill method. In the code "INJECT" an independent
variable is the time normalized by the beam velocity.
The beam trajectories are traced back from the injection points on the first equilibrium orbits against time.
The magnetic field of the sector magnets is calculatedwith a 3D-code "TOSCA" by Mitsumoto.
Figures 1, 2, and 3 show examples of the calculationof the injected beam trajectories in the SRC-6.
The beams from a pre-accelerator are guided to thecentral region of the SRC-6 and then injected into thefirst equilibrium orbits. The injection system consistsof two or three bending magnets (BM), three magnetic inflection channels (MIC), and an electric inflection channel (EIC) .3,4)
The SRC-6 has strong fringing field of the sector
magnets , and the fringing field strongly depend on thecondition of acceleration. Thus, the trajectories of various beams differ very much each other. This makes
the design of the injection system difficult. For an example, at the injection points on the first equilibrium
orbits in the valley, the maximum change in the radiusFig. 2. Schematic layout of the injection elements andtypical trajectories of the injected beams for Example 2.

Fig. 3. Schematic layout of the injection elements andtypical trajectories of the injected beams for Example 3.

/

/

/

Fig. 1. Schematic layout of the injection elements andtypical trajectories of the injected beams for Example 1.

of the orbits is about 12 cm. But the realizable gap
width of the EIC is 1 or 2 cm at most. Thus, the EIC
must be movable in the direction with radial range of
12 cm.
We have not yet determined the final layout of theinjection elements. We merely introduce here three examples of the layout. Figures 1, 2, and 3 correspondto Example 1, 2, and 3, respectively. Figures 1, 2, and3 schematically show the different layouts of the injection elements, and show typical trajectories of theinjected beams. Table 1 shows their energies and magnetic rigidities. Tables 2, 3, and 4 show characteristicsof the injection elements used for Example 1, 2, and 3,
respectively. The characteristics of EIC, MIC1 , MIC2,207

Table 1. Energies and magnetic rigidities of typical beams.
Energy[MeVInucleon]
injection
extraction

Bp[Tm]
injection

160 7 +

74.2

200

2.89

238U58+

58.0

150

4.57

Table 2. Characteristics of the injection elements for Example 1.

EIC
MICI
MIC2
MIC3
BMl
BM2
BM3

Radius
[cm]

Angle
[deg]

110.0
110.0
94.0
154.0
171.0
180.0

42.5
· 47.5
53.0
40.0
30.0
30.0

Length[em]

B or E (max.)[T] or [kV/em]

(100)

100
0.19
0.22
0.95
3.5
3.3
-1.89

(90)

MIC3, and BMI are common in all three Examples.
In the c~e of Example 1, the beams guided froma pre-accelerator cross the EIC, and the distance between the crossing points of both beams is about 25
cm. Therefore, the EIC must be divided into twopieces. The difference of the trajectories in the BM3
is about 8 cm, thus the BM3 must have a large boreof more than 8 cm.
In the case of Example 2, the beams don't cross theEIC, and the magnetic field required for the BM3 issmaller than that of Example 1. But, the length of theBM2 is four times longer.

208

Table 3. Characteristics of the injection elements for Example 2.

BM2
BM3

Radius
[em]

Angle
[deg]

Length[cm]

B (max.)
[T]

162.0
498.0

124.0
7.0

(351)
( 61)

3.23
-1.14

Table 4. Characteristics of the injection elements for Example 3.

BM2

Radius
[em]

Angle
[deg]

Length[em]

B (max.)[T]

1500.0

1.7

(45)

0.78

In the case of Example 3, the beams don 't cross the
EIC. And the BM3 is not necessary. The differenceof the trajectories at the BM2 is only 1.3 cm and themagnetic field for the BM2 is only 0.8 T. Moreover,the length of the BM2 is shorter than those of othertwo examples. However, since the beams pass throughthe tip of a sector magnet , the space for the sector coillink is restricted.
References
1) A. Goto et al.: RIKEN Accel. Prog. Rep. 30, 196 (1997).
2) A. Goto: Rep. Inst. Phys. Chern. Res. (in Japanese) 57,
203 (1981).
3) H. Okuno et al.: RIKEN Accel. Prog. Rep. 30, 203(1997).
4) T. Tominaka et al.: RIKEN Accel. Prog. Rep. 30, 205(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Optimization of Trim Coils in a Superconducting Ring Cyclotron
J.-W. Kim, S. Fujishima, A. Goto, K. Ikegami, T. Kawaguchi, T. Kubo, T. Mitsumoto,T. Morikawa, T. Ohkawa, H. Okuno, N. Sakamoto, S. Yokouchi, Y. Tanaka,
T. Tominaka, 1. Watanabe, and Y. Yano
In designing a superconducting ring cyclotron (SRC)
as a variable energy and multi-ion accelerator, it is oneof the main works to optimize a magnetic field trimming system for the field isochronization. Most of thering and compact superconducting cyclotrons in operation uses resistive (normal) trim coils for their field
trimming. On the other hand, it is not practical fora SRC to use resistive trim coils alone. Problems arethat the pole piece of superconducting sector magnet,
either cold or warm,1) is distant from the resistive trim
coil, and is saturated. Therefore, the field correction
by normal trim coils must rely on the magnetomotive
force without much contribution from iron parts. The
SRC-6 which is a booster cyclotron in the proposed
RIKEN RI beam factory employs both superconducting and normal trim coils. 2 } A major correction is madeby the superconducting trim coils, and the remnant error field is corrected by the normal trim coils, because
the power loss in the superconducting coils is independent of its tot al ampere-turns.
The isochronous and sector magnetic fields areshown in Fig. 1 for two test particles. The radial field
profile by the sector magnet matches with that of theisochronous field of low ql A ions like 238U58+ , and thehigh ql A ions like 16 0 7 + need a maximum correction
field from trim coils. The optimization of both trim
coils is now under way in terms of the number of independent coils, coil positions, and so on.
~

15000+-~--~~--~~--L-~--~~~~-Tenen

In the SRC-6, high-T c current leads will be used forits superconducting trim coils to reduce the heat conduction to liquid helium. (Furukawa electric company
will supply the superconducting wire with operation
current of 500 A.) The heat leak through the high-T ccurrent leads for the current of 500 A is about 0.2 W
at 4.3 K which roughly corresponds to 2 kW at 300
K. The normal trim coil operating at 500 A, on theother hand, dissipates 3- 4 kW. Two kinds of trim coils
look comparable in aspect of power loss. However, in
this calculation it is assumed that the normal trim coilhas only one turn on each sector, whereas the power
loss of the superconducting trim coils is independent of
the number of turns. The field distributions of the trim
coils are shown in Fig. 2. The field profile of the normal
trim coil is not so optimal as a correction coil, considering the cancelation effect on adjacent coils. Therefore,
it may be advantageous to use a large number of superconducting trim coils, but its usable number is limited
by available space for the outlets of the current leads.
Ul 10+-~--~~--~~--~~~~~~--~~

8~ :~~~~~~~~~~~SX2(>C~~rii~~~~:;;:I1~~~~~~~ii

~ -2

oE -4

E -6
'"--

-8

:£ 1000-1~.~3.0====================::::=::::::::=======:~ 800
is 600'.-. / 200
CJ'

400~----:J~o 14000~//":2 13000/"-j..:>.,,--_____

Z-200r~~~~~~~==:S;;~~~;;~1(/)-4003.30 350 .370 390 410 4.30 450470 490 510 5.30 550
Radius (em)+------,----r-----r--..-----r---.....--.----rr----.------r--~.~l.J.... 12000
()

+-'

~

01

o

11000

--- ---~ 10000 +----,----y----r- --r-----r--..-----r---.....--.----r,----T

330 350 370 390 410 430 450 470 490 510 530 550

Radius (cm)Fig. 1. Isochronous and sector magnetic fields for two test
particles shown by dashed and solid lines, respectively.
The magnetic field is the azimuthal average of the field
at a given radius.
The criterion of optimization is not well defined as
two different kinds of trim coils are involved. The condition of minimum power dissipation which is often
adopted for the resistive trim coil optimization is notequally applicable to the superconducting trim coil.

Fig. 2. Upper Graph: field distributions of twenty normal
trim coils at 500 A, and Lower Graph: field distributions of five superconducting trim coils when the sector
field at the center is 3.5 tesla.
First, we tried to make an isochronized field forin the energy range of 55-400 MeV lu. The
program used in this calculation utilizes a least square
fitting subroutine, which is the same as used for thedesign of previous RIKEN cyclotrons. 3 ) As a functionof the superconducting trim coil number, the leftovererror fields after fitting were examined. For the cases ofthree to five superconducting trim coils, the error fields
are shown in Fig. 3. With use of 5 sets of superconducting trim coils, the error field reduced within ±10
16 0 7 +

209

10

60
,,--..

,,--..

(f)
(f)

(f)
(f)

40

::l

::l

0

0
CJl

'--""
(f)

20

(J'l
'--""
(f)

0

32

(lJ

(lJ

'+-

-20

LL

32

5

0

o

o -5

W

W

I.-

~ -40

l.I....

-60+------,----- - . -- -- -,------.------+
300
350
400
450
500
550

-10+------,--- -- - . - - - - - , - - -- - - .------+
300
350
400
450
550
500

Radius (em)Fig. 3. The error fields remained after fitting with superconducting trim coils. The solid line shows the casefitted by three superconducting trim coils, the dashedline by four coils, and the dot-dashed line by five coils.
gauss, or ±1 % of the isochronous field. The case of
6 trim coils was also calculated, but it didn't improve
the fitting so much, although further investigation may
be necessary on the locations of trim coils.
Twenty sets of resistive coils were then tested withuniform spacing of 10 cm at radii between 365 cmand
555 cm, and fitting was carried out. Figure 4 shows
the leftover error fields after fitting with twenty normal trim coils for the two cases of four and five supercond ucting trim coils. The field error is less than±O.05% for the case of the five superconducting trim
coils, which meets our criterion of field isochronism.
For the case of four superconducting trim coils it issurely feasible to use additional resistive trim coils andreduce the error fields, but it may be less attractive be-

210

Radius (em)Fig. 4. The error fields leftover after fitting with twenty
normal trim coils against those shown in Fig. 3. The
solid line shows the final error field a.fter four superconducting trim coils are used, and the doted line showsthat after five coils are used.
cause of the higher electric power loss.
A combination of the normal and superconducting trim coils that satisfies our requirement has beenfound. Further optimization for different test ions in afull operating energy range is in progress.

References
1) T. Kawaguchi et al.: RIKEN Accel. Progr. Rep. 29, 232(1996).
2) T. Mitsumoto et al.: RIKEN Accel. Progr. Rep. 29, 230(1996).
3) H. Takebe et al.: RIKEN Accel. Progr. Rep. 15, 173(1981).

RIKEN Accel. Prog. Rep. 30 (1997)

Design Study of the Accumulator Cooler Ring for MUSES
K. Ohtomo, Y. J. Yuan, J. Xia, and T. Katayama
In the proposed RI beam factory project, Accumulator Cooler Ring (ACR) will be used for the accumulation and cooling of the radioactive isotope (RI)
beams which are produced by the beam from a Superconducting Ring Cyclotron (SRC) and pass through afragment separator. The momentum spreads of these
RI beams will be significantly reduced by the electron
cooling and stochastic cooling devices in the AeR. Devices for multi-turn injection and RF stacking are alsoneeded in order to build up the beam current. Latticeof the ACR shall be designed by taking the following
requirements of devices into account:1) Electron cooler requires a long straight free space(nearly 8.0 m) free from dispersion.
2) Stochastic cooling devices require a few pairs ofdispersion-free space for a pickup and a kicker, andthe phase advance of the betatron oscillation shouldbe nearly kIT /4 between them. 1)
3) Multi-turn injection requires the sections where
the phase advance of the betatron oscillation is nearly
7r, to arrange kickers and septum magnets.
4) RF stacking requires a dispersion in the multiturn injection section and a space for tunable RF
cavity.
5) Accumulation of high current beams requires a large acceptance in the horizontal plane(=1257r.mm.mrad) and a large momentum spread(~p/p rv ±2%).
Optimized design of the lattice is shown in Table 1
and Figs. 1 and 2.
Table 1. Lattice parameters of AeR.
Circumference
A verage RadiusMax. Magnetic Rigidity
Max. Beam Energy
Momentum Compaction
Transition Gamma
Betatron Tune Values
Natural Chromaticity
Max. ,B-Amplitude
Max. Dispersion

C = 168.4836 m

R = 26.815 m
Bp = 7.244 T.m
E = 500 MeV /u (Z/ A=1/2)
a = 0.0402042,= 4.987
Qx/Qy = 4.555/3.540
Q'x/Q'y = -5.058/-6.571,Bx/,By = 18.33 m/24.53 m
Dx/Dy = 4.518 m/O .O m-<~~~~~"o.
. _~ ___ ,' _L _~ __ .' .
. . ,~~~59.166m. "urge.

Fig. 1. The layout of AeR.

40

[
)(

0

-betax. ·betay_ . -Ox

30

! 20
~

~ 10

~
CD

0
-10
-20

0
Orbit length (m)Fig. 2. Distributions of f3 and Dx in arc section.

HCELL = -

Lr

Lk

Li

QD-QF-B-B-QD-QF-,

where QF and QD are the focusing and defocusing
quadrupoles, B bending magnets, and L long drift
space. Each CELL functions as a dispersion suppresser
and makes the free dispersion space at Lr, where RF
cavities or electron coolers are located. An injection
kicker and septums occupy one CELL.
The two long straight sections are given as follows:
Le

STRC = - QC--QD-QF-QF-QD-QC- ,The ACR lattice consists of two arc sections andtwo long straight sections, as shown in Fig. 1 and is
described as follows.
ACR = CELL-STRC-2CELL- STRC-·CELL,
where STRC denotes the long straight section and
CELL the half of the arc section. A CELL is symmetric and decomposed into two half elements, HCELL.
CELL = (HCELL,-HCELL)A HCELL is described as follows:

where Qc is a quadrupole for chromaticity correction.
Le is a long drift space of 8.0 m for beam extraction
devices or for an internal target.
Next, we evaluated the efficiency ofRF stacking withthe cooling devices. This process was simulated for
typical nuclear beam of 132Sn50+ , using the parameterslisted in Table 2.
The repetitive RF stacking procedure consists of thefollowing steps. Firstly, an RF bucket of the caJrture voltage is prepared. After 1/4 period of synchrotron oscillation the RF voltage is sharply reduced211

Table 2. Parameters of RF stacking.
132S n 50+

Typical beams
Kinetic energy
Harmonic number
RF frequency of injected beam
Momentum spread of injected beam
Phase spread of injected beams
Capture voltage
Accelerating voltage
Stacking period
Transverse emittance
Momentum difference at injection
Momentum difference at stack-top

41C)

210 MeV lu
3029.1 MHz
±0.5%
±10 0
600 kV
10 kV
30 ms
57r.mm.mrad
-1%
2.7%

!!I.
c:

...

41
~
41

.

11.

X' (mrad)PHASE (rad)PC (MeV/u)

PHASE (rad)

41
C)

•

"'
C
41 ...
~

41

to the accelerating voltage and the beam is kept in
the bucket. Then the RF voltage, frequency, andsynchronous phase are adiabatically changed and thebeam is moved to the top of the stacking orbit. Finally,
the RF voltage is switched off and the beam is releasedon the stacking orbit. During the whole procedure theelectron cooling and stochastic cooling are applied at
the stacking-top.
The following differential equations describe thephysical method of the RF stacking with electron cooling and stochastic cooling:d~peVRF .
.
- - (sm <I> - sm <I> s)

dt

27rRs

~P

30

(

2
)

-k(02 + ~ 2 )3/2 2LFH + (02 + ~ 2 )LMH
Prel

Prel

+ Stochastic cooling term
d<I>
dt

dO
dt

-

1

h'r/ws!:l.p

27r

Rs P s 27r Rs

k

2
0
(2L
0 - 2!:l.p;el L ~(02+!:l. 2 )3/2
FH+ (02+!:l. 2) MH .
Prel

Prel

Here, the stochastic cooling term was derived according to Ref. 2. L FHand L MH are constants, !:l.p( t) is
the momentum difference, <I>(t) is the phase of the particle, O(t) = (e X ,y//3x,y)1/2, ~Prel(t) = ~p(t)/(,ps),and k = 27rTeTnjeZ2 /e/34,5 A. These formula related
to electron cooling were derived from Ref. 3.
The typical parameters of electron cooling andstochastic cooling are listed in Tables 3 and 4, respecTable 3. Parameter of electron cooling.
Ratio of cooler length to circumferenceElectron current density
Diameter of electron flow

2.1%
0.5 A/cm 2
5cm

11.

20

0-

.I..

Fig. 3. Simulation of RF stacking for 132Sn50+ with electron cooling and stochastic cooling: Graph at lower
right shows the stacked beam on phase space. Histogram at lower left represents the distribution in momentum space, where a large peak at the right is stacked
beams, while the left small peak is spilt one.

tively. The simulated results are shown in Fig. 3.
The simulation results show that the stacking efficiency is 80% and that LJp/p reaches ±0.03%. The
efficiency are saturated when more than 100 periods of
RF stacking are done because the acceptance is filledwith the beams.
It should be noticed that the sharp decreasing pattern of the RF voltage is assumed in this simulationin order to compress the momentum spread of the injected beam when the beam captured. It is, however,difficult to realize this property in the proposed RF
cavity which has a high voltage of 600 kV. Anotherand more realistic way to achieve a small momentum
spread is to install debuncher cavities in the injection
beam line for the reduction of the spread prior to thecapture.
We have presented the ACR lattice design which fulfills the demand of the beam accumulation with RF
stacking, stochastic cooling, and electron cooling, as
well as the experimental equipments. It has many
free space sections left for various devices. The RF
stacking simulation results turn to be reasonable but
is supposing a high-efficiency debuncher in the beamline. The designs of a pre-debuncher system and of
the frequency-modulable RF devices for the RF stacking are in progress.

Table 4. Parameter of stochastic cooling.
Number of particles
Kicker efficiency
Total temperature
Midband I width frequency
Zp I Zc
Number of pickups
Output power

212

107
50%
400 K
0.75 GHz I 0.5 GHz
25 n I 50 n
10
lOkW

References
1) P. Krejcik et al.: Proc. Eur. Part. Accel. Conf., p. 788(1988).
2) D . A. Goldenberg et al.: LBL-24979 (1988).
3) I. N. Meshkov: Phys. Part. Nucl. 25, 631 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Design Study of Electron Cooling for ACR in MUSES
Y. Rao, K. Ohtomo, I. Watanabe, and T. Katayama
The Accumulator Cooler Ring (ACR) is one component of the Multi-USe Experimental Storage rings(MUSES) proposed for RIKEN RI beam factory. 1) The
use of electron cooling is planned for compression of
the phase space volume of multiturn-injected and RFstacked ion beams at the top of stack, which helps
increase the intensity of accumulated beam.
Heavy ion beams injected into ACR have energies
from 150 to 500 MeV lu. Corresponding electron beamenergies range from 82 to 274 keV. Therefore, voltage for the electron gun cathode is required to be adjustable within a range of 70- 300 kV.
Larger electron current might be required to achievea fast cooling during injection of hot ion beams. However, cooler operation with larger current may cause
the loss of stored highly charged ions due to the radiative electron capture process in the cooling section.
By compromise, a maximum electron current of 4.0 A
is chosen.
The multiturn-injected ion beam which has a maximum emittance of 120 1T mm·mrad horizontally andhas a beta function of (3h = 5 m in the cooling section should be totally immersed in the electron beam.
Therefore, the electron beam diameter in cooling section is determined as 50 mm.
Since ACR has a circumference of 168.48 m , thelength of cooling section 3.6 m corresponds the relative cooler length 1]ec = 0.021.
Because the electron beam with a low transverse
temperature is preferable for faster cooling, our ACR
electron cooler will utilize a magnetically expanded
electron beam. 2 ) Normally, a solenoid field strength of0.5- 1.2 kG is required for maintaining the magnetizedcooling regime. If we plan for an adiabatic expansion of
the magnetic field by a factor of 10, the corresponding

gun solenoid field becomes 0.5-1.2 Tesla.
This expansion scheme will lower the electron beamtransverse temperature by a factor of 10, because thetransverse energy of electron divided by the strength ofthe longitudinal magnetic field is an adiabatic invariant
under the changes of field strength. The 'area' of theelectron beam cross section times the magnetic fieldstrength is also an adiabatic invariant. Therefore, inorder to keep the electron beam diameter 50 mm in
the cooling solenoid, a flat cathode must be made witha diameter of 16 mm.
The electron gun consists of a flat cathode, a Pierce
electrode, an anode, and an acceleration column, being
somewhat similar to that of TARN-II.3) Fig. 1 shows
an example of the calculated electron trajectories.

Fig. 1. Computer generated plot of electron trajectories
in electron gun. Expanded electron beam trailored by
B(z) is observable.

Main parameters of the ACR electron cooling system
are summarized in Table 1.

Table 1. Parameters of ACR electron cooling system.
Energy range of the cooled ions
Energy range of electrons
Maximum electron current
Gun design
Cathode diameter
Electron beam diameter at cooling section
Maximum solenoid field at acceleration section
Maximum solenoid field at cooling section
Length of cooling section
B..l.. /B II in cooling section
Bending angle of toroids
Collector efficiency
Voltage stability of HVPS

150- 500 MeV /u70-300 keV
4.0 A
Pierce geometry + adiabatic focusing electrodes
16 mm
50mm
1.2 T
1.2 kG
3.6 m< 1.0 x 10- 4
90°>99.98%±1.0 x 10- 5213

By using this system, one can expect the coolingtime of the order of 10 s, depending on different ionsand their energies.
In the practical application of electron cooling at
ACR, the cooling time and its dependence on someparameters must be known. The simulation was donein order to investigate the bunched beam emittanceand relative momentum spread as a function of time,by using the analytical formulae of cooling force by I.
N. Meshkov,4) taking into account the betatron andsynchrotron oscillations of particles and the influenceof electron beam space charge in the cooling section.
The time evolution of transverse emittances (ch' cv)
and longitudinal momentum spread (t:::.p I p) resulted
from the simulation are shown in Fig. 2 for a beam of
210 MeV lu 132 S n 50+ with initial horizontal and vertical emittance of 120 and 5 7rmm·mrad, respectively,
and with initial momentum spread of ±2.5 x 10- 4 .

f =90%•

f =50%~r------------------------,

120

~ 110
ca lOO
~

- ,.
E 50
~

time (sec)

90

E 10
E :
40

~20
Co)
10

t~~==========~

Fig. 3. Simulated longitudinal cooling effects for threedifferent neutralization factors of electron beam spacecharge.

~5l!

5~r------------------------------------,

E ..

E3
E
.=.2
,ll

-J
I

f

4.5
4

02

~4

O~

traDIftne tempenture (eV)Fig. 2. Time evolutions of beam emittance and momentum spread.

In order to investigate the space charge effect due toelectron beam, the above simulation was repeated bychanging the neutralization factor fn . Figure 3 shows
the results of the longitudinal cooling for fn = 90%,
50%, and 0%, where the other parameters are kept thesame and no dispersion was assumed in cooling section.
It can be seen from the figure that the longitudinalcooling becomes much faster by neutralizing the spacecharge of electron beam.
Also, the transverse temperature kT t of electron
beam is one of the critical factors that influence thecooling speed. As a result of the simulation in Fig. 4,
the destination cooling time i.e., the time durationneeded to cool the ion beam from the initial horizontal emittance to a specified values of 30 7rmm·mrad,
214

Fig. 4. The transverse cooling time as a function of theelectron beam transverse temperature, when fn = 90%,
Dh = 0 m.

changes from 3.73 to 5.08 seconds with the increase ofkT t from 0.01 to 0.6 eV. Therefore, an electron beamwith low transverse temperature is expected to speed
up the cooling process.
In conclusion, neutralizing the space charge of electron beam with a very low transverse temperature ispreferable to finish cooling faster.
References
1) Y. Yano et a1.: RIKEN Acce1. Prog. Rep. 30 , 195 (1997).
2) D. Habs et a1.: Workshop on beam cooling and related
topics, Montreux, CERN 94-03, p. 188 (1994).
3) T. Tanabe et a1.: Nucl. Instrum. Methods Phys. Res. A
307, 7 (1991).
4) I. N. Meshkov: Phys. Part. Nuc1. 25, 631 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Design of the Booster Synchrotron for MUSES
T. Ohkawa and T. Katayama
The Booster Synchrotron Ring (BSR), a part ofMulti-Use experimental Storage Rings (MUSES), functions exclusively for the acceleration of ion and electron
beams. The maximum accelerating energy is, for example, to be 3 GeV for proton; 1.45 GeV /nucleon forlight ions of q/ A = 1/2; and 800 MeV/nucleon forheavy ions of q/ A = 1/3. In this paper some results oflattice study of the BSR are presented.
The lattice structure was designed to be as compact
as possible. Basically FODO structure was used, andwe adopted a racetrack type to accommodate two longstraight sections. The two long straight sections areused for fast and slow extractions of ion and electron
beams, and each of them contains four long drift space
where RF cavities and kicker magnets are inserted.
In this design, the total length of the structure was
fixed to be 168.484 m which is 5 times the SRC extraction radius, and the maximum magnetic rigidity wasdetermined to be 14.6 Tm corresponding to the energyof 800 MeV/nucleon for heavy ions with q/ A = 1/3.
Transition I was chosen to be higher than 4.77, a value
being still satisfactorily high for beam stability.
As shown in Fig. 1, the BSR consists of two arc
sections and two long straight sections. Each arc section is a mirror symmetrical system, and there are two
bending cells in it. Each bending cell is a dispersion
suppressor, and consists of four FODO cells because
this number of cells is pre-determined to raise ,t sufficiently large. The two long straight sections are also
mirror symmetry. The dispersion in the straight sections is zero. The length of a dipole magnet is 1.911 m,
which is determined by the circumference specification.
The maximum magnetic field of a dipole is then 1.5 T,

which is determined by required maximum rigidity ofparticles 14.6 Tm.
The lattice is specified for eight families ofquadrupoles: QF1, QD1, QF4 and QD4 in the arcs,
and QF2 , QD2, QF3 and QD3 in the long straightsections. The structure of one FODO cell and shortstraight section(str2) in the arc are given as follows:
cel = QF1~B~QD1~B~,
cel2 = QF1~B~QD1 ~ B~,andstr2 = QF4~QD4~QD4~QF4,
so the lattice of each arc section (60.365 m) is
arc = (cel, ceI2.ceI2, cel, str2, -cel, -ceI2, -ceI2, -cel).
In this structure, d1 (0.5 m) and d2 (0.511 m) between dipoles and quadrupoles are the drift spaces
in which the sextupole magnets for chromaticity correction and the correction magnets for COD correction are installed. The lattice of each straight section(23.876 m) is
strl = ~QF2~QD2.~QD3~QF3~QD3~QD2~QF2~,
where d s is a free space of 4.819 m long in which RF
cavities, injection kickers, and/or other devices are installed. Then, the whole lattice of the BSR is describedas follows:
BSR = (arc, str1, arc, str1).
Parameters of the lattice are summarized in Table 1.
The {3 and dispersion functions are shown in Fig. 2.
Transition I is 4.786 and the peak dispersion is 3.206
m. The peak {3 functions are 13.360 m in horizontal
direction and 19.508 m in vertical direction. These
calculations were performed using the MAD program.
Table 1. Lattice parameters of BSR.

Ion injection

o-Jnjection

Ion fast extraction

o-Extraction

Circumference
Average radiusMax. magnetic rigidity
Momentum compaction
Transition gamma
Betatron tune values
Natural chromaticity
Max. (3 amplitude
Max. dispersion

C = 168.4836 m
R = 26.815 m
Bp = 14.6 Tm
Q = 0.0437
I't = 4.786
Qx/Qy = 6.380/4.910
Q'x/Q'y = -7.355/-7.004(3x/ (3y = 13.360 m/19.508 m
Dx/Dy = 3.206 m/O.O m

Fig. 1. Layout of the BSR.
215

TWISS FUNCllONS OF BSR
~10

~

!

~ 10
~O~~~~~~~~
~ -10

5

0
~-5

~30

~ 20

GGG
Phase

15

I

~ -10

"~{~~;;"'I~. . JY'·

~

~5

216

10

;~:..'f
,,'

!

0
~
>--5

~

-75-1IG-25 0 25 &0 75

§0

space

"~:~~;"'1 ',.. )y--5-w-10 -6

x[nun]

5

>:

~

-~

0

5

10

-w-'76-IIG-26 0 26 &0 75

y[nun]

x[nun]a) Turn No. = 0:o::[I]:oI:[:J =E:]
~ 6

'v: 0

The dynamic aperture was seriously reduced whenchromaticity was corrected. The reason for this is thatstrong-field sextupoles are necessary to use because of
the low average value of dispersion in the ring aimed
at high ,to In this lattice, natural chromaticity values are -7.355 (horizontal) and -7.004 (vertical), andthey are corrected by two families of sextupoles (focusing SF and defocusing SD). Same family's sextupoles
in one bending cell are located 7r apart in phase in order not to excite the third order resonance. The normalized field strengths of sextupoles required to correct chromaticity are relatively large: 7.642 m- 3 for
the SF and -11.998 m- 3 for the SD. Multi-particle
tracking was performed in this lattice to study the
motion stability of particles with a large beam emittance. Results of the multi-particle tracking for theperfect lattice with chromaticity correction are shownin Fig. 3. At the initial state, 100 particles were distributed within an emittance of Ex = 1257r mm.mrad
and Ey = 57r mm.mrad, which are the designed maximum value for the beam from ACR (Accumulator
Cooler Ring). After 1000 turns, the motion of part i-

space

10

phase space

Fig. 2. Beta and dispersion functions along the lattice.

real

Phase

space

~-6

phase space~.,.'.;'.ft:~{.. " .

~-10

'v: 0

~6

.~

-'76-IIG-25 0 26 &0 76

x[nun]

elO

g0

.:~.

;>"'10-20~-~

real space-w-30-20-100 10 20 30 -~-75-6CHl60 26 &0 76
y[nun]

x[nun]b) Tum No. = 1000
Fig. 3. Results of multi-particle tracking at a) Thrn No.
= 0 and b) Turn No. = 1000. The number of particles
is 100.

cles was stable without any particle loss. In this study
the dynamic aperture was determined by multi-particle
tracking for a perfect machine with zero chromaticity
over 1000 turns. The above tracking results show thatthe dynamic aperture of BSR is larger than Ex = 1257r
mm.mrad and Ey = 57r mm.mrad. Further tracking has
to be performed to obtain information about the main
sources of dynamic aperture reduction and to estimate
the level of multipole content tolerable in the dipoles.
We have designed the lattice of the BSR satisfying
the fundamental requirements. Optimization of thelattice for the BSR is under way.

RIKEN Accel. Prog. Rep. 30 (1997)

Design of the Double Storage Rings for MUSES
N. Inabe and T. Katayama
A design of the Double Storage Rings (DSR), which
was reported in the last progress report,1) has been developed. The DSR is composed of two rings which are
to be constructed vertically each other. One shownin Fig. 1(a) is mainly used to store electron beams(electron ring). When a merging or colliding experiment between ions is performed, ion beams are stored
in the electron ring. Another ring in Fig. 1(b) is tostore ion beams only (ion ring). The both rings havemaximum rigidities of 14.6 Tm that corresponds toenergy of 1 GeV /u with A/Z = 3 and circumferenceof 260.123 m which is 47/6 times of circumference ofSuper-conducting Ring Cyclotron.

lnsersion

Electron ring(e . I)
Circwnferena:
Mu. Bp263.952 m
14.6 Tm

Merging point

Colliding pointround counter-clockwise direction from the insertion
point. The other long straight section is used for collision experiments between electron and RI beams. The
details of construction for the merging and collision
will be described later.
The ion ring is almost same as the electron ring. The
main difference is in the construction of the colliding
section. Other differences are a lack of devices needed
for the electron beams such as the cavity for electron
beam and undulator and two insertions. Because theion beam only is stored in this ring, it is operated with
the ion mode.
The (3 and dispersion functions at each section arecalculated for several modes. The functions of the unit
cell for the small emittance mode are shown in Fig. 2(a)and those of the arc for the large emittance mode arein Fig. 2(b). Figure 2(c) shows the ion mode. All
dispersion function is 0 outside of the arc.

Lon,

Lon,

• .su-a.ia ht

suaiabt

S' 2

<1
t:i

Unduwor

10m

(a)

III

~
~y

(a)

~x , --,The electron ring is consisting with 4 parts of arc,a short straight section, and two long straight sections. The arc is composed of 8 dipole magnets and
24 quadrupole magnets. To store the electron beams
with small emittance (rv 107r nm*rad; small emittancemode), the arc has 4 unit cells with lattice of Double
Bend Achromat (DBA). For electron beams with large
emittance (rv 17r mm *mrad; large emittance mode) the
lattice is so designed that the DBA system is not
adopted but that the center of the arc is a symmetry point of (3 and dispersion functions. The lattice
for the ion beams (ion mode) is similar to that for thelarge emittance mode. The short straight section has
cavities for the ion and electron beams, and has an electron cooler. The cavities are used to keep longitudinalemittance constant. The cavity for electron is usedalso to compensate energy of synchrotron radiation oflight. The electron cooler is used to reduce emittance
growth of ion beams originated from beam-beam effect during collisions. One of the long straight section
is used for such merging experiments and for collision
between X-rays and RI's. In this section, an undulator is located to produce X-ray. Insertion port is also
located in this section. The electron and ion beams go

~ S'

Q<
~ t:i 2Ie IIIe 8;g24
ORBIT LENGTH(M)

.100

Z

g-,

~=~~~:::;~
~
'I
10
20
30 C
ORBIT LENGTH(M)§~C:::;«~Qtrr:::: .
(c)Fig. 1. Schematic drawing of two rings in the DSR. Electron ring are shown in ( a) and ion ring, in (b).

g ~;g;::~I;::::::~~~g

Z

o

Vi

-....;;;..."II'::'--"""""i~.......

10
20
30 C
ORBIT LENGTH(M)

Fig. 2. {3 and dispersion functions in the arc. The small
emittance mode is shown in (a), large emittance modein (b), and the ion mode in (c).

The (3 functions of the ion mode for the shortstraight section are shown in Fig. 3. In this mode the(3 functions are required to be small and parallel for ahighly efficient electron cooling. The designed {3 functions are rv6 m. For the other modes, the (3 functions
are designed so as to connect their values between twoarcs.
A side view of the merging section is shown in Fig. 4.

_

!

0

~x

<
~

§

20

~

10

~

-

~
~
. ~

0 1--------------1

C

Fig. 3. f3 functions of the ion mode in the short straightsection.

217

Kicker

El~n ring~~~Merging section

Beam

Kicker===:::===:::::~:~/~~~~~/~,~:~:~-":::~:::..;::=:====
I~

Undulator

Fig. 4. Side view of the merging section.

The construction of two rings are same. In the figure
the arrows show directions of ion beams. Merging angle is determined to be 10° from requirement of experiments. Beta and dispersion functions are shown in
Fig. 5. Values of (3 at the merging point are 0.6 m forboth vertical and horizontal directions. Dispersion is

~

~

~ 75

z

<'

o

tu 50

en

a:
w

II)

0-

25

(/l

--nr--Ci

o

10

20
30
ORBIT LENGTH(M)40

50

Fig. 5. f3 and dispersion functions in the merging section.

=

_:!!:
•
12.5' Bendo m at the merging point.
A side view of the colliding section is shown is Fig. 6.
In the figure, black arrows show electron beams of
the large emittance mode while white ones show ion
beams. The ion ring crosses to the electron ring with
20 mrad. The values of {3 at the colliding point are
0.02 m for electron beams in both directions and 0.1
m for ion beams. The small crossing angle and {3 values
are required to obtain a large luminosity. Such small{3's can be achieved by locating two quadrupole doublets near the colliding point. The both beams passthrough the quadrupole doublets when the colliding
experiments are performed. For the other experiments
such magnets are not used. The (3 and dispersion functions for electron beams are shown in Fig. 7(a) andthose for ion beams in Fig. 7(b). The large maximum
values of {3 are due to the small values of {3 at the colliding section. Dispersion functions are 0 at the colliding

Electron beam";;'Bend

---+

11/

~_=-

-~.

IS

8.as' Bend

10.0'Bend=

10.0'eend
8.86 , Bend ........
_ _ _.....,AI beam4--

12.5'Bend

Colliding point(crossing angle 20 mrad)

12.5'Bend

Fig. 6. Side view of the colliding section.

oooi:r::;==;:t:it=f; ~~
Z
o

ena:

.. fu

~~----~~~-aw

2OdO~'IIIi!1'!.'10~2~O-3"'OUlliii40~""50. 15
ORBIT LENGTH(M)

Fig. 7. f3 and dispersion functions in the colliding section.
(a) is for the eiectron ring and (b), for the ion one.

point.
Ring parameters are summarized in Table 1 for several modes. In the table, electron 1 represents the large
emittance mode and electron 2 does the small emittance mode. Parameters of ion beams are separately
shown as ion 1 for ions colliding with electron, ion 2 forions colliding with X-ray, ion 3 for ions stored in the ion
ring for merging, and ion 4 for ions stored in the electron ring for merging. In particular, betatron tunes

Table 1. Ring parameters for several modes.
Betatron tune(Qx/Qy)
Chromaticity(Qx' /Qy')
Momentum Compaction
Transition gamma
Max . betatron amplitude{3xJTlax, {3YJTlax (m)Max . Dispersion
D XJTlax, Dy.max (m)Beta at crossing point
M e rging({3x ,{3y,m)Colliding({3x,{3y,m)electron 1
5 .080/8 .751
- 75 .5/-31. 6
0 .0407
4 .9 54e lectron 2
16.802/9 .186
-439/-334
0 .000 118
02 .15ion 2
5 .755/5 .788
-8.70/-10 .0
0 .0377
5 .1 51

ion 3
5 .711/5691-11.3/-11.8
0 .0377
5.151

ion 4
5 .791/5426-11.0/ - 11.5
0 .0372
5 .187487/11355 .0/66.7

828/336

57.1/51.9

102/76.4

102/76.4

3 .66/3 .05

0 .537/1.20

3 .98/0 .778

398/0 .835

3 .98/0 .778

3 .98/0.835

9 .76/1.02
0 .02/0 .02

1.11/22.8
3 .76/10.0

1.08/0 .888
0 .1/01

1.08/0 .888
13 .5 /1.75

0 .6 /0 .6
13.5 / 1.75

0 .6/0 .6
6.59/6 .68

and chromaticities are large for the small emittancemode, large emittance mode, and for ions to be used
for collision. The largeness for the small emittancemode is due to the DBA system of the arc and that for
the large emittance mode and ion for collision is due
to lattice structure of the colliding section.
218

ion 1
5 .532/6 .394
-50 .0/-31.4
0 .0378
5147

Dynamic appartures for several modes are studied
currently.
References
1) N. Inabe and T. Katayama: RIKEN Accel. Prog. Rep.
29, 248 (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Expected Luminosity at MUSEst
K. Yoshida and T. Katayama
Luminosity of e-RI collision is evaluated for the current design of the Multi- Use Experimental Storage ring
(MUSES). Luminosity L of the collision of two beams
with Gaussian distributions in space is calculated byHere ni (i = 1,2) is the number of particles in one
beam bunch in the Double Storage Ring (DSR), f31
the ratio of beam velocity to the speed of light c, Nc
the number of collisions per unit time, O"XI 'O"YI 'O"ZI thesizes of beam bunch in x, y, and z direction, and 7jJ thecollision angle. Subscripts i = 1,2 represents the electron and Radioactive Isotope (RI) beams, respectively.
In Eq. (1) E(f31,f32,7jJ) is called kinematical factor andgiven asE (f31 , f32, 7jJ) =separator named Big-RIPS to be 10 mrad in angle and
1% in momentum.
RI beams separated by the Big-RIPS will then be
stored and accumulated in the Accumulater-Cooler
Ring (ACR). In the ACR, the momentum coolingwill be continuously applied to the stacked beam during the RF stacking process. Both electron coolingand stochastic cooling were studied for the momentum
cooling of particles. As a result, it was found that thestochastic cooling is always much faster than the electron cooling for the present case. The electron cooler
with 3 m length and current density of 0.5 AI cm 2 gives
the cooling times of 380 s for 6He and 0.42 s for 232U,
whereas the stochastic cooling by a 10 kW feed backamplifier with a band width of 2 GHz gives 0.20 sand
5.0 ms, respectively. This is due to the following properties of the RI beam; the intensity is rather weak andthe momentum- and emittance-spread are large. In
Fig. 2, the cooling time achievable by the stochastic
cooling is shown for various nuclei.

Jf3r + f3~ + 2f31 f32 cos 7jJ - f3r f3~ sin2 7jJ.

80

(2)
As seen in Eq. (1), L depends on the number ofparticle in a beam bunch and on beam sizes. Therefore,
we need to evaluate these to obtain the luminosity.
Production rates of RI beams are estimated with thecode INTENSITY2. 1 ) In the code, the physical featureof the fragmentation process is treated in an empirical way. The primary beam and the thickness of the
Be production target are optimized so as to obtainthe maximum production rate. In the calculation, theintensity of the primary beam is assumed to be 100
particle /-lA. Figure 1 shows the result of the calculation with assumption of the acceptance of an RI-beam

80

60

60
N

40

20

20

40

60

80

100

120

140

N

Fig. 2. Stochastic cooling time with a feedback amplifierof 10 kW and of 2 GHz in band width.

Accumulation of the RI beam is performed by using
the RF stacking technique. The beam of unstable nuclei is injected into the ACR by means of a multi-turninjection with the time interval equal to the coolingtime. The supply rate is

R _ RpCinj
s-

N

(3)

,

Tcool
40

I it I

20

10 7
109
Production Rite (1/5)

10 5

where Rp is the production rate, Cinj the efficiency of
injection and Tcool cooling time. The Cinj is given as

I

h SRC L ACR

10 11

Cinj

= N rnult -1-- -L--'
SRC

20

40

60

80

100

120

(4)

SRC

140

N

Fig. 1. Production rate of RI beams.
Condensed from Proc. of 5th EPAC, Barcelona, June 1996.

where N rnult is the number of multi-turn injection,
hSRC, iSRC the harmonics number and RF frequencyof the SRC, and L ACR , LSCR the circumference of
ACR and that of the extraction orbit of SRC.
219

The beams accumulated in the ACR is decaying with
its own life time, T. The maximum number of thenuclei stored in the ACR is determined by the balanceof the supply rate and the decay rate,(5)

The space charge limit of the ACR is also consideredin the estimation of N stl of Eq. (5) . However, thespace charge limit is only important for nuclei withthe high production rate such as for stable nuclei andtheir neighbors.
The accumulated RI beam will be fast extracted
from the ACR and be injected into the Booster
Synchrotron Ring (BSR). In the BSR, the beams will
be accelerated to the energy required for the experiment within 1 sec, and then be injected into the one
ring of DSR to collide with the electrons stored in another ring of DSR. Since the RI beam is bunched by 46
pulses in the DSR, the maximum number of nuclei ina bunch is obtained by dividing the maximum stored
nuclei in the ACR by 46. Result is shown in Fig. 3.

beam size was studied by substituting Eq. (6) in to
Eq. (1) and calculating the overlap integral in numerical way. Bunch lengths (jZ l , 2 are determined by the RF
voltage of DSR and are 50 cm for RI beam and 2 cm forelectron beam. Fig. 4 shows the normalized luminosity
as a function of f3; ,y. As seen, the luminosity increases
with decreasing the beta function. Since 13* = 10 cm
is the technical limit for ions, the setting of 13* = 2 cm
for electrons gives the maximum luminosity.

20~\-----:-----1\

15
6 .0e+08

Eu 10

10

5

80

20

15

~Ion (em)Fig. 4. Contour plot of the normalized luminosity as afunction of the ion and electron betatron functions, 13* .

60
N

40

20

20

40

60

80

100

120

140

N

Fig. 3. The number of nuclei contained in a single bunchat DSR.

Electrons are accelerate up to 300 Me V in the electron linac and then injected to the BSR. The BSR
boost electron energy up to 2.5 GeV and supply electrons to the one of the two rings of the DSR. Expectedbeam current in the DSR is approximately 500 rnA.
In order to make a synchronous collision of electrons
and nuclei, the number of electron bunches will bevaried from 30 to 45 according to the beam energyof nuclei which is in the ring from 300 MeV lu to 3.5
GeV / u. The number of electrons in a single bunch isthen 9 x 10 10 and 6 x 10 10 , respectively.
Beam sizes of the electron and RI beams at the collision point also affect the Luminosity. Transverse beam
sizes near the collision point are given by

Luminosities at MUSES are now calculable by using
Eq. (1). In Fig. 5, Luminosity of e-RI head-on collision is plotted for various nuclei in an N-Z plane. In the
figure , plotted are only for the nuclei whose luminosity L ~ 10 27 cm 2 / s , the numerical value corresponds
to the minimum luminosity required to measure thecharge distribution from the e-RI elastic scattering experiment. Those nuclei should have their life-times
longer than about 1 min.

80

60
N

40

20

20

40

60

80

100

120

140

N

Fig. 5. Luminosity of e-RI collision for various nuclei.

(6)
where Cx,y is the beam emittance and f3;,y is the betatron function at the collision center. The effect of the220

References
1) J. A. Winger, B. M. Sherrill, and D. J. Morrissey: Nucl.
Instrum. Methods Phys. Res. B 70, 380 (1992).

RIKEN Accel. Prog. Rep. 30 (1997)

One-Dimensional Compensation Scheme for Beam-Beam Effects
Y. Batygin and T. Katayama
From the study of the noise beam-beamphenomena,1) it follows that the linear beam-beamkick preserves the beam emittance even in the case ofnoise. Therefore, linearization of the kick is expected
to be a way to improve particle stability. The trivial
way assumes that the opposite beam is uniformly populated, or at least, it's inner part is close to uniform.
Another way suggests utilization of high order multipoles. Suppose, particles receive the Gaussian kickevery turn:
A

_

up -

_

0.2
0./5

00

0./

::!.-

0.05

~

a.

<l

./

/

'

.

-0.2

-4

-3

-2

0

-1

(1)

/

2

3

4

3

4

3

4

b

0.25
0.2
0./5

~
-a.

<l

(_1)k-1 ( x 2 )k-1
k!

0
·0.05
-0./
-0./5
-0.25

where p = f3 (dx/dz), f3 is a f3 - function of a ring in theinteraction point, ~ a linear part of beam-beam tune
shift, and a a standard deviation in size of a counteracted beam. If we apply the opposite kick:

L

r;:;,

x/a

1 - exp( _x 2 /2a 2 ),47l"~x(x 2 /2a 2 )~Popposite = 47l"~x

a

0.25

0./

/

0.05

,,/

0

/'

-0.05
/

-0./
-0./5

/

-0.2
-0.25

2a2

-4

k=2

/

-3

-2

0

-1

/

2

x/a

(2)
c

0.25

then the total kick will be a linear function of coordinate (see Fig. 1). The opposite kick can be created by
the high order multipole lenses located in the interaction point. After passing through the multipole of theorder n+1 (n = 3 for octupole, n = 5 for duodecapole,etc.), the particle with rigidity Bp gets a kick:

0.2
0./5

r;:;,

0./

::!.-

0.05

~

a.
<l

n

Rg

Bp '

(4)
Let us note that in the presence of noise in beambeam kick, the total kick is not a perfect linear function of coordinate, but also is a subject of noise. It
is demonstrated in Fig. 1, where resulting kick for thenoise in parameter a is presented a(n) = a(o) (1 ± un).
In Fig. 2 the results of beam-beam dynamics without
and with nonlinear compensation are presented.

./
./

-0./

/

-0. /5-0.2(3)where Sn is a multipole strength, d n a multipole length,
Bo a pole tip field, and Ro a pole radius. Octupole(n = 3) can be used for compensation of the first nonlinear term in beam-beam kick x 3 , then duodecapole(n = 5) can be used to compensate second nonlinear
term in beam-beam kick x 5 , etc. Comparing the values of kicks obtained from beam-beam interaction andafter crossing multipole lens, the values of the multipole strengths for compensation are

V

0
-0.05

-0.25

S = (Bo) d n

v
V

-4

-3

-2

-/

0

1

2

x/a
Fig. 1. (a) Beam-beam kick, (b) compensation kick, and(c) the resulting kick.

1.2
1.15
0

w

1.1

--w 1.05
c

0.95
0.9

... ...--...... ij11

!..u6

....

II!"!

~

...........

...iMIfII..... J.IIiII

Li...oII!PI""

I .....

o 20 40 60 80 100 120 140 160 180 200
103 n

Fig. 2. Beam emittance growth in beam-beam interaction
without compensation (upper trace) and with compensation (lower trace). Parameters of the interaction are
as follow: Q = 3.168, ~ = 0.005, and noise in a is 5%.

2210.5 .-----,--,----,.-----,- -,----,.-------.--,----,.-----,
0.4 E---+--+--f-----+-_+_-f-----+-_+_- f-------1
0.3 E----+--+--f------+- -+--f------+-_+_-l--___1
0.2 E--.-+- -+--f----:-+-_f_-l___:-+-_f_- l___---1
0.1

o

W

o

__:>.

-0.1
-0.2 E---+--+--f----:-+~_+_-l___'-+-_f_-l___---1-0.3 E---+--+--I--:-+- _ + _ -l___:-+-_f_-l___---1-0.4 E---+--+--f-----+-_+_- I - -:-+-_+_-l___---1_0.5~'-'--'--'-'-'--'--'--'--'--'-'-l..L.L.'-'--'--'-'--'--'--'--'--'--'-'-l..L.L........L..'-'-'-'--'--'--...........1..L..L......J-1.25 -1 -0.75 -0.5 -0.25 0 0.25 0.5 0.75
1.25

-0.1
. '," " C.'; J"~'" ':';1f-0.2 E--+--+--+-----1f--+--i-0.3 ~+--+--+-If--+--i-0.4 E--+--+--+----1I---+---I-0.5 UL.uJ....L...u..L1..J...Lu...l..u LLLULLLUL..L.L.L.J-1.5 -1 -0.5 0 0.5 1 1.5

X

:>.
W

~..

><

0.5 ...-- r - - r - - - r_ _r---r--,
0.4 t--+--+--+-----1f--+--i
0.3 E--+--+--+----1I---+---I
0.2.
0.16;ru' .' . . . . ...'.. ': .

"-' ~.

0.5 1:----+--+--t---+--+
V~F"--+--+-+----1
Of----+-+---f--_+-~-I--_+-_+_-l--___1-0.5 f----+--+--/~+__+_--t-_+__-l-___l

I----.,.......

~-~~~.~~. ~. ~~. ~~~~--+-~~-1 t--1.5 w...............u...............~u....o..J~.....u...............~'_'__'_'~L..L..l.-'_'__'_w......'_'_'__L...................J-1 .25 -1 -0.75 -0.5 -0.25 0 0.25 0.5 0.75
1.25
X

Fig. 3. Particle distribution and space charge forces (Ex and E y) of a Gaussian beam
when the semi-axis ratio ax/ay = 10.

Utilization of the suggested scheme can be complicated due to the realistic 2-dimensional particle distribution of the opposite beam, which is usually approximated by Gaussian funct ion:p(x,y) = poexp (-- .

2:~ ::~)(5)

Space charge potential of the beam with an ellipticalcross section is given by the expression: 2 )100

U(x, y) = U
o

o

x2
y2}
{
exp - (2a~ + q) - (2a~ + q) dq.
J(2a~ + q)(2a~ + q)

References(6)
In the flat beam a x > > a y , space charge forces in x-

222

direction are a weak function of y-position (see Fig. 3)
and x - beam-beam kick is close to a single-valued function of x. The kick , obtained by the flat beam after
passing through the multipole is also a single-valued
function of coordinate. It allows to adjust the values ofcompensating mult ipoles according to Eq. (4). On thecontrary, space charge forces in y - direction strongly
depend on x-position, which results in a strong discrepancy of y-kicks. The value of compensating multipolesin y-direction cannot be adjusted for all the particles.
Therefore, the suggested scheme requires further study
to meet the realistic requirements.

1) Y . Batygin and T. Kat ayama: RIKEN Accel. Prog. Rep.
30, 225 (1997).
2) B. Montague: CERN 68-38 (1968).

RIKEN Accel. Prog. Rep. 30 (1997)

Hamiltonian Treatment of Nonlinear Beam-Beam Resonances
Y. Batygin and T. Katayama
Beam-beam instability is one of the main factors limiting achievable value of the collider luminosity. Beambeam interaction excites nonlinear resonances, which
are stable until different islands overlap each other 1)or until the noise factor become dominant. 2) Stableparticle motion in the phase space is governed by aninvariant of motion. Hamiltonian for beam-beam interaction is usually treated as an unperturbed integrable
system plus a small perturbation. 3- S ) In present paper
we derive the beam-beam Hamiltonian directly frommapping equations.
Let us consider linear matrix of particle motion incoordinates (x, p = (3 dx/dz) with nonlinear beambeam kick LlPn between lattice arc with the betatronangle ():
Xn+1 = Xn cos () + Pn sin () + Llpn sin (),Pn+1 = -Xn sin () + Pn cos () + ~Pn cos ().

(1)

(2)
where ~ is the linear part of beam-beam tune shift
and a is a standard deviation in opposite beam size.
Note that Jacobian of the transformation always equals
unity:

J=

(cos

8Xn+1
8pn
0Pn+1
°Pn

00

Llp =

(8)

1

k=l
( _1)k82k - 1 = 47r~ k! (2a2)k-1·(9)

The first Hamiltonian equation becomes as follows:
8K
.
~
k(
)2k-1
-a
= 2 smcp L../52k-l J cos cp
.

(10)

k=l

To obtain another Hamiltonian equation, let us utilize the second order difference equation,6) which isequivalent to the mapping transformation of Eq. (1):
Xn+1 - 2x n cos () + Xn-l = LlPn sin ().

(11)

If kick is absent or Llpn = 0, solution to the Eq. (11)is trivial Xn = a cosn(), i.e., angle advance per turn isequal to betatron tune <pn+1 - <Pn = (). In the presenceof beam-beam kick the angle increment is corrected ona value of betatron tune shift as <Pn+l - <Pn = () + Ll().
According to the method of harmonic balance, generalsolution to the nonlinear Eq. (11) can be expressed by
00

L: ak cos knll. 6) To find the tune
k=O

shift, one can use only the first term from series:
=1.

(3)

8Llpn
) (
)
.
( - sm () + oXn cos () cos ()It indicates that this process obeys Liouville's theorem, i.e., phase space area occupied by the beam isconserved. We introduce action-angle variables:

Xn = acos nll = VJ cos n( () + ~()).

(12)

Substituting the expected solution of Eq. (12) into thedifference equation (11) and including expression for
beam-beam kick (8) we have:
2VJ cos nll (cos 1I - cos ())
00

Xn =

= sin()(4)

In mapping equations, the turn number n is equivalent to time t, therefore time-increment dt has to be
substituted by turn-increment dn = fodt , where fo isa revolution frequency. Hamiltonian equations of motions for new Hamiltonian K = H/fo are defined as follows:
dJ
dJ
8K
(5)
d(fot) = dn = I n+ 1 - I n = - o<p'
dip
dip
oK
d(fot) = dn = <Pn+1 - <Pn = oJ·

L82k - J k- 1/ 2 (coscp)2k-1,

Fourier series, Xn =0+ 8!::.n sin 0) (sinO)

JJ: cos <Pn,
Pn = JJ: sin <Pn·

Let us express the Gaussian beam-beam kick by
power series of coordinate with coefficients 82k - 1:

<P

The beam-beam kick is usually approximated by Gaussian function:

OXn+1
8x n
OPn+1
oXn

Increment of action variable follows directly from thematrix equations:(6)

L 82k-1 Jk-l/2 (cosnll)2k-1.

(13)

k=l
U sing the power expression of trigonometric cosine
function for (cos nll) 2k-l and taking into account Taylor expansion cos 1I = cos () - Ll() sin (), one can obtain
the expected value of betatron tune shift:
A() = _~

[81 383 J
82k - 1 (2k)! J k- 1] (14)
2 + 8 + ... + 22k (k!)2.

An important feature of the betatron tune shift is it's
amplitude dependence, which provides particle stability in phase space. Second Hamiltonian equation is223

8K
8J =O+~O+X(J,<p),(15)

where the function X( J, <p) describes higher order terms
both in Fourier expansion of expected solution andin expansion of (cos nv )2k-l, which were neglected inusual calculations. Combining solutions of Eqs. (10)and (15), the Hamiltonian of beam-beam interactionis
81J _ 383J2 __ 82k - 1 (2k -1)!Jk
K = JLlu
216. . . 22k- 1 (k!)2+ ...

-0.3 lL.u..&..J..u...u...lJ..u...U.UJ..J...l..llJ...Ll..L..LL.L.I...I..JL..1.ll.iu..u..JI.U..Uu...L..U..l.J-5 -4 -3 -2 -1 0 1 2 3 4 5

8 J2+81J(coscp)2 + +(coscp)4 + ...

+k
82k _ 1J (

k

coscp

)2k

.

x/a
(16)

Particle motion, governed by the Hamiltonian (16),is stable due to amplitude dependence of the beambeam tune shift. Typical phase space trajectories
excited by beam-beam collisions are presented inFig. 1. If betatron tune is close to a rational value
O/(27r) = m/n and if particle is inside the resonance,
it's amplitude increases, which provides a detuningfrom resonance. Amplitude of particle decreases accordingly and particle again comes to resonance. This
process repeats steadily and provides a stable particle
motion.

224

Fig. 1. The 4th order nonlinear resona:nce excited by theGaussian kick, /27r = 3.26.

eReferences
1) B. Chirikov: Phys. Rep. 52 , 263 (1979).
2) Y. Batygin and T . Katayama: RIKEN Accel. Prog. Rep.
30, 225 (1997).
3) L. R. Evans: CERN 84-15, p. 319 (1984).
4) A. G. Ruggiero and L. Smith: PEP Summer Study,
1973.
5) E. Keil: CERN 95-06, p. 539 (1995) .
6) S. G. Peggs and R. M. Talman: Ann. Rev. Nucl. Sci.
36, 287 (1986).

RIKEN Accel. Prog. Rep . 30 (1997)

Beam-Beam Instability due to Noise in Opposing Beam Size
Y. Batygin and T. Katayama
One of the main problems in ion-ion circular colliders is a small value of achievable beam-beam tune shift~ = 0.005. Physical reason for beam-beam limitation
is usually attributed to the excitation of a set of nonlinear resonances due to a periodic nonlinear kick in linear
system. If beam-beam interaction is too strong, resonant islands from different nonlinear resonances overlap each other, creating zones of unstable (stochastic)
particle motion. Overlapping of nonlinear resonances
is an universal mechanism of stochastic particle instability in nonlinear systems. 1)
Another mechanism of unstable particle motion is adiffusion, created by a noise. 2 - 5 ) This noise can exist,
for example, due to mismatch of the beam with thechannel. In this paper we study the noise which appears in an incoherent beam-beam interaction. As it
is shown below, such a noise can induce beam-beam
instability in much more simple conditions than theoverlapping of nonlinear resonances. Due to the diffusion character, noisy beam-beam instability does nothave a threshold character and can exists under any
value of beam-beam tune shift.
Let us consider a I-dimensional model, which combines linear matrix of particle motion in coordinates(x, p = (3 dx/dz) with nonlinear beam-beam kick ~Pnbetween lattice arc with betatron angle = 27rQ:(a)1.15 t--l-+-+-+-+--+--t--t-+-----i°

1.1 t--l-+-+-+-+--+--t--t-+-----i'" 1.05 r--l-+-+-+-+-+--+--t-t-----l.

0.95·O.3'--'--'---'~-'--'-'--'-'-'-~'--'-'-'--'--'-'-'--'

·6

-4

·2

0.9 0

0

20 40 60 80 100 120140 160 180 200

Ht n

(e)

(d)
1.2 r--r---r--r---.--.--.--.--.--.---..

0.06

1.

r

0.04

I

0.02

r--l-+-+-+-+-+--+--t-t-----l
1---1f-t-+-+--+-+--+-+-+--1ww" 1.05 r--l-+-+-+-+-+-+--t-t-----l
1.15" ......

1.1

a.

<J ·0.02

I...... i"--·0.04

0.95 1---1-+-+-+--+-+--+-+-+--1

fJ

·0.06
-6

-4

·2

0.9 0

0

20 40 60 80 100 120 140 160 180 200
3

x/a

10 n

Fig. 1. Stable particle motion in the vicinity of the 6th order nonlinear resonance with the values of beam-beamtune shift ~ = 0.005 and betatron tune Q = 3.168:(a) phase space trajectories; (b) beam envelope; (c)beam-beam kick; (d) rms beam emittance.

(b)

(a)

(~:::) (~::e ~~~:) (

1.2

03

Pn :nt,Pn ). (1)

1.15

0.2
",0

0.1

Beam-beam kick ~p is expressed by a Gaussian function of coordinate x, beam-beam tune shift ~, and sizeof the opposite beam cr:

'""

·0.1

1.1
1.05

0.95

-0.2
-4

·2

(2)

103 n

x/a

(d)

(e)

Nonlinear kick (2) induces a set of nonlinear resonances, which are stable, until islands do not overlap
each other. In Fig. 1 an example of stable beam-beaminteraction in the vicinity of the 6th order resonance ispresented. In simulations, one beam was presented as acollection of 3000 particles. Simulations were done forthe value of beam-beam tune shift ~ = 0.005 and betatron tune Q = 3.168, close to the 6th order resonancevalue 3.16666 (or 6Q = 19). From the simulations it isclear that both the envelope and emittance are stable.
Another picture is observed if the parameter cr ofbeam-beam kick (2) is a subject of noise. In the calculations, presented in Fig. 2, parameters of the process
were chosen to be the same as those in Fig. 1, butstandard deviation cr was changed from turn to turnaccording to the expression:cr(n) = cr(o) (1 ± 0.025 un),

(3)

,.

r--l-+-+-+-+-+--+--t-t-----lx/ae

1 - - exp( _x 2 /2cr 2 )~p = -47r~ X(x 2 /2cr 2 )•(b)
1.2 .---r---r--r---.--.--.--.--.--.---..

1.2
0.06
0.04

I

"if 0.02

r~

::t..

1.15

' .......

wo: " 1.05

a.

<l ·0.02......

·0.04

·0.06

·6

'" f...I/-4·2,............. ....-

0.95

0

x/a

.
-.....

1.1

0.9 0

""

J.IIII• ""20 40 60 80 100 120 140 160 180 200

103 n

Fig. 2. Beam-beam instability under 5% noise in the parameter (j during particle interaction with
= 0.005
and Q = 3.168: (a) phase space trajectories; (b) beamenvelope instability; (c) beam-beam kick; (d) beamemittance growth.

ewhere Un is a random noise function within the interval (0, 1). It corresponds to the noise in the size of the
opposite beam, which can exist due to small beam mismatch with the channel. As shown in Fig. 2, this noise
destroys the stability. In contrast with Fig. 1, phase225

space trajectories of particles are not closed and boththe beam envelope and beam emittance expand withtime. Therefore, a weak noise in the opposite beam
size creates instability.
Important feature of noise regime is that this kindof instability can exist apart from the excitation of
nonlinear resonances. Noise beam-beam instability appears if two conditions are met:
- beam-beam kick is a nonlinear function of coordinate;- parameter of beam-beam kick (beam standard deviation 0-) is a subject of noise.
Let us provide analytical estimations of emittance
growth under noise beam-beam interaction. Transfer
matrix after n turns with arbitrary momentum kick at
every turn, ~Pi, is given by the expression: 6 )(7)Above derivations are approximate due to suggestionthat linear beam-beam kick is proportional to the unperturbed trajectory. Conservation of beam emittanceis explained by the fact that in case of linear kick abeam of particles experiences sequence of linear transformation, each of them conserves beam emittance.
Let us consider now the case when kick is a nonlinear
function of unperturbed trajectory:(8)
Calculation of rms beam emittance gives:

16

n-l

Xn

= a cos(nO + w) + L ~Pi sin(n - i) 0,
i= O
n-l

Pn = -a sin(nO + w) +6 n- l

L ~Pi cos(n - i) 0,(4)

where W is the initial phase of oscillations. Random
beam-beam kick (~pJ can be expressed as a function of unperturbed trajectory. It gives an approximate treatment of the problem, valid for small valuesof perturbation. Suppose that perturbation is a linear
function of coordinate:(5)
We study evolution of the root-mean-square (rms)beam emittance en = 4J(x~)(p~) - (xn Pn)2, wherebrackets mean averaging on initial phases of particles.
Calculation of beam emittance growth gives:16+: ~8;
2 n-l

]2

[

~

-

~ ~ Ii; sin(2nti - 2iO)
[

2 n-l

2n-l

]2

cos (2nti - 2iti)

4 n-l

i=O

2

-5; ~ 8?
- 3; ~- : ~ 8; cos(2nO - 2iO)

]2[8; cos(2nti - 2iti)

6 n-l+ 5; ~ Ii? sin(2nti - 2iti)

]2

(9)

In contrast with linear beam-beam kick the terms proportional to 8 2 in expression (9) do not vanish. Effective beam emittance growth is then as follows:(10)
In the case of nonlinear kick , the beam emittance
growth does not vanish in the first positive term 82 ,which indicates that nonlinearity is an essential point
for expansion of emittance growth under noise conditions.
Performed study shows importance of noise factor inbeam-beam interaction, which can be one of the reasonof small value of experimentally achievable beam- beamtune shift in existing colliders.
References

2 n-l

[

~ ~ Ii; cos(2nti - 2iti)

2n-l+ : ~ Ii? sin(2nti - 2iti)

]2

(6)

Analysis of the expression (6) shows that terms proportional to 8, 8 2 , 83 are vanished. Rms beam emittance is conserved until high order of perturbation,

2261) B. Chirikov: Phys. Rep. 52 , 263 (1979) .
2) K. Cornelis: Proc. 3rd Workshop on LEP Performance,
edited by J. Poole, CERN 8L/93-19 (1993).
3) J. K. Koga and T. Tajima: Phys. Rev. Lett. 72, 2025
(1994).
4) T. Sen and J. A. Ellison: Phys. Rev. Lett. 77, 1051
(1996).
5) Y. Batygin and T. Katayama: Proc. EPAC96,
p. 1173 (1996).
6) V. Lebedev et al.: Part. Accel. 44, 147 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Beam Emittance Growth in Storage Ring
due to the Ground Noise
Y. Batygin
Vibration of the ground is a serious concern for stability of beam dynamics in a storage ring. In Table 1
the typical amplitudes of cultural noise measured indifferent accelerator facilities are presented. Groundnoise has it's spectrum between 0.001- 100 Hz withtypical declined spectrum function with respect to thefrequencies. The amplitude of ground noise is in therange 0.01-10 microns.

N-l

PN+l = -A sin (NO + Wo ) -i=O

where amplitude A and phase Wo are defined by the
initial conditions only. Averaged square of the single
particle trajectory is:2)
1( XN+l = -

CERN
HERA

0.1 J-Lm
0.1- 2 J-Lm
0.015 J-Lm

sse

Noise
frequency>10 Hz0.01- 0.1 Hz
3 Hz

(3)

In calculations we used an assumption that kicks are
not correlated. Therefore
N-lboXk cos (N-k)O
boxm cos (N-m)O

Table 1. Ground noise in accelerator facilities.
Amplitude

j7r XN+l dwo·
-7r
2

27r

Accelerator

L boXi sin (N-i)O, (2)

Ref.

L

1)
2)
3)

m=O

k#m
k=m

(4)

After N turns the rms value of beam size is
Two aspects of the problem are essential to be investigated. The first is a motion of the equilibrium orbit
caused by a few Hz noise. One of the results of thisnoise is that two colliding beams miss each other in
the interaction point. This effect can be controlled bya feedback 4 ) to provide beam centering. If the beams
are off centered, the modulation signal of feedback system is created to center the beam.
The second case is a few hundred Hz noise, which isserious for large colliders (SSC, HERA, LHC). Due tothe average velocity of ground signal, V ground = 3-6
km/sec, the noise kicks become uncorrelated for noise
frequency fnoise = 100 Hz at the distance). = V ground = 30- 60 m.

(1)

fnoiseThis is a typical distance between two neighboring
quadrupole magnets in a large ring. This kind of uncorellation quickly transforms to the beam emittance
growth. 5 ) According to estimations in Ref. 5, the mostdangerous is a noise with frequency fnoise = fo bov,where fo is a revolution frequency and bov is a spread of
the betatron frequencies in a ring. For small rings withdiameter around 100 m, noise in this spectrum looks
not dangerous. Therefore, only the first case with afew Hz noise can be a subject of precaution.
Let us estimate the particle stability in a ring due tothe ground noise. Matrix of particle motion in coordinates (x, p == f3 dx/dz) after N turns, assuming thatparticle trajectory receives random kick box n once per
revolution, is given by:

1

2
2
A
(XN)
= 2

[1

boX) 2+ ( AN.

(5)

Using the relationship between beam size and beamemittance

X~ax

(6)

c=/3'

the phase space area available for a beam under thenoise fluctuation is~ = 1 + (boX) N.
CO

A

(7)

2

Equation (7) is a general expression for emittance
growth due to noise in linear oscillator system. In
Eq. (7), box is the amplitude of an arbitrary noise.
Ground noise has a frequency much smaller than revolution frequency. Therefore, instead of N in Eq. (7),
we have to use N (fnoise/fo), which indicates that one
ground kick appears every (fo/fnoise) turns:
C _
(boX)
2 Nfnoise
--1+
--.
Co

A

(8)

fo

For estimation, let us take the following parameters,
typical for MUSES ring:
Revolution frequency, fo
Noise frequency, fnoise
N umber of turns for 24 hoursof ring operation, N

106 Hz10 Hz
8.6.10 10

N-l

XN+l = Acos (NO + Wo ) +L boXi cos (N-i)O,
i=O

In order to prevent the doubling of beam emittance,
the distortion of beam orbit should be smaller than:
227

1
106
= 10- 3
8.6 10 10 10(9)In the colliding point the beam size is A = 0.6 mm.
Therefore, the amplitude of ground noise should not
be larger thanfu < 10- 3 A = 0.6 micron.

(10)

Performed estimations shows that long term beam sta-

228

bility requirements impose strong restrictions on amplitudes of the ground noise (less than 1 micron).
References
1) Juravlevet al.: Proc. EPAC94, p. 2573 (1994).
2) V. Shiltsev et al.: DESY HERA 95-06 (1995).
3) K. Y. Ng et al.: Proc. PAC93, p. 1645 (1993).
4) H. Jostlein: Fermilab TM-1253 (1984).
5) V. Lebedev et al.: Part. Accel. 44, 147 (1994).

RIKEN Accel. Prog. Rep. 30 (1997)

Simulation of Beam Bunching by Electron
Cooling for DSR in MUSES
M. Takanaka and T. Katayama
Collision experiments are planned with ion-ion orion-electron beams in Double Storage Rings (DSR).
Coasting or nearly-coasting ion beams are supplied
from the cooler storage ring (ACR) or the booster
synchrotron (BSR). The luminosity of the beams canbecome high by bunching them. The longitudinal
space charge force is dominant over the longitudinal
forces induced through the coupling impedances between beams and the vacuum chamber in the energy
region 100 MeV lu to 1.5 GeV lu of the ring. As
the currently-designed ion storage ring runs below thetransition energy, the space charge force makes thebunch long. On the other hand, electron cooling force
can make the bunch short under an RF-voltage application. The previous simulation of the beam bunching showed effectiveness of the cooling in the bunching, but whether the bunching process is stable or not
was left to be answered.!) The question will be answered here , and the longitudinal phase space distribution near the equilibrium state will be shown together
with the transverse one.
The tools of the bunching are RF voltage application and electron cooling. The former is just for rotating ions in the longitudinal phase space. The latter is for pushing ions towards the synchronous energy level where the velocity of ions is equal to thatof the electron beam. As a result, ions 'gradually get
together at the center of the RF separatrix. It would
be possible to realize a very small bunching factor if
there were no force but the two forces. However, themain longitudinal beam-self-induced force or the spacecharge force pushes ions outward from the bunch center. Roughly speaking, the bunch length settles at theequilibrium among the three forces. The bunching ispossible without an increase of the momentum spreadby applying both RF voltage and electron cooling, although bunching just with an RF voltage application
always increases the momentum spread.
The bunching procedure is as follows. If the beam
is not in the equilibrium state, or the cooling force
is stronger than the space charge force, the momentum spread decreases. On the other hand, the increaseof the RF voltage makes the RF bucket height large,
which is followed by the increase of the momentum
spread and by the decrease of the bunch length. One
tunes the RF voltage as a control parameter under
the constant electron current in the electron cooler, sothat the momentum spread of the ion beam is kept
around a given spread. The space charge force begins to compete with the cooling force as the bunch
length decreases. One can easily get the equilibriumby increasing the voltage, while paying attention not
to load over-voltage.
The simulation has been carried out with 104 particles, using Runge-Kutta method. The following forces
acting on ions have been taken into account: 1) the RFforce, 2) the longitudinal electron cooling force and thetransverse one,2) 3) the transverse linear force comingfrom the ring lattice, and 4) the longitudinal spacecharge force. The space charge force has been evaluated each one-twentieth revolution by Fourier series
expanding a bunch of beam line density up to lOath
series and by using the gradient.
Hereby presented are the results for a 150 MeV luu~;t beam with the 6xrms relative-momentum spread
10- 3 and 4.5 x 106 ions per bunch or the full-bunchedbeam current 3.3 rnA. One does not prefer the spread
smaller than 10- 3 , because the smaller the spread isthe lower the beam-current threshold of the microwave
instability becomes. The bunching process is seen to bestable, as seen in Fig. 1. The fluctuation of the relativemomentum spread is within ±2 x 10- 5 . The longitudinal equilibriu~ state seems to be realized at the end of
the simulation, although the transverse emittance stilldecreases. The distributions in the longitudinal phasespace and the horizontal one at the end are shown in
Figs. 2 and 3, respectively. The longitudinal bunch
structure is seen not to be Gaussian, nor to be centrally
parabolic. 3 ) The momentum distribution is characterized by both a non-cooled broad background and awell-cooled high peak. The transverse distribution is
like a starfish, whose shape is dependent on the beta-

6 r - - - , - - - - - , , - - - - - , - - - - - . - - - - . - - - . . - - - , 1. I 10- 3

2

4

Fig. 1. Beam bunching of a 150 MeV lu u~~t beam of
4.5 x 106 ions per bunch. During the bunching, RF
voltage is increased so that the momentum spread is
kept constant.

229

6 10-4

1.2 IO- ~'2. 4 10-4
"0..

8 10-4e

4 10-4

..

'. .'

"

:

~ 2 10-4

~

.:.

0 10°

CI)

:0
lOll
~ 0

§ -2 10-

4

~

->(

-4 10- 4

.. :
'.

.."
'.

-4 10-4-6 10-4
-3

-1

-2

0
I
RF phase [rad]2-1.2 IO-~-1 10-2

3_5

3
2.5
2
1.5
I
0.5

-8 10-4

3- - - Fourier
Data

~

400

~

300

CI)

~

Q..

.....0

o -I

-0.5
0
0.5
I
Longitudinal position from the bunch center [m]I

II-5 1O-~

0 lOll

5 IO - ~1 10- 2-5 IO-~

0 lOll x [m] 5 IO-~

1 10- 2

x[m]

500
c:

2000

_ ..... .

ci

Z

I

c:

~ 1500 f--~ 1000 -

-

200
100
0
-1 10-2

CI)

~

Q..

.....
0

Z

-

500 -

ci

0

I

-4 10-4

I

~...

I

-2 10-4 0 IOn
2 10-4
Momentum (dplp)

Fig. 3. Horizontal phase space distribution and position
profile at the cooling section and at the end of the simulation .

I

4 10-4

to appear less clearly when the transverse space charge
effects are taken into account.

Fig. 2. Longitudinal phase space distribution, bunch
structure, and momentum profile at the end of the simulation.

References

tron tune. The horizontal tune is just 7.4. The dense
distribution at the center and the starfish are expected

1) M. Takanaka and T. Katayama: Proc. of EPAC'96, p.
1991 (1996).
2) 1. N. Meshkov: Phys. Part. Nucl. 25 , 631 (1994).
3) S. S. Nagaitsev et al.: CERN 94-03, p. 405 (1994).

230

RIKEN Accel. Prog. Rep. 30 (1997)

An RF System for the Electron Beam at DSR
M. Wakasugi and T. Katayama
An RF system for the electron beam at the DSR,
which is a part of the MUSES project in the RI-Beam
Factory (RIBF) program,1) is designed. It consistsof four RF cavities with higher-order mode (HOM)
dumper, a klystron, an RF transport system, a control system, and a cooling system. This RF system
is needed to compensate the energy loss of t he electron beam due to synchrotron radiation, and essential
in order to store the beam for a long time inside the
DSR.
The energy of the electron beam in DSR is Ee =0.3- 2.5 GeV. The energy loss of the electron beam is
U = 9- 372 keY /turn due to the bending magnet. Theenergy loss due to the undulator is about 25 keY /turnat Ee = 2.5 GeV. 2 ) The total energy loss is therefore
U = 400 ke V /turn approximately at the maximum
beam energy of 2.5 GeV.
To ensure a long life for the stored electron beam, alarge RF bucket should be prepared. Figure 1 shows
the calculated Toushek lifetime versus the peak acceleration voltage V in the RF cavity. If the beam loading
into the DSR is scheduled twice a day, the peak acceleration voltage should be at least 2-MV. This is also
understandable in Fig. 2, which shows the relation between the energy acceptance of the RF bucket (dE/E)
and the over voltage fact or (V /U). The acceptance issaturated at around V /U = 5. This means that the
RF voltage of 2.0 MV is enough from t he energy acceptance point of view.
The RF cavity with the fundamental frequency of
about 500 MHz is well established as an RF cavity
for electron beam, and is chosen for our system. It is
partly because the circumference of the DSR is 263.952
m 3 ) and the harmonics is 440, then the fundamental resonance frequency should become 499.745 MHz.
Figure 3 shows a single cell cavity designed here atuCD.!!..10/

2.5 GeVCD

E-:; 104

::i
.lie:

~ 10

3

VI

~

o
~ 1 0 2 L - _ L - - - - l_o

0.5---l_-----'_-----'_

1 1.5 2 2.5
RF Voltage (MV)

a.
G)

()
()

ct 10-3
>C)
~

CD

c

W

-4

10 0~~2~--4~--~6~--8L---1~0---1~2

Overvoltage Factor V/U (N. D.)

Fig. 2. Relation between the energy acceptance and theovervoltage factor.

Fig. 3. Designed single cell cavity.

RIKEN. The main parameters relating to the RF cavity are listed in Table 1. The cavity has a coupler port,
two tuner ports, a monitor port, beam ports, and cooling water lines. The size of the beam port is relatively
large (4)140 mm) , so that the HOM excited in the cavity can immediately escape through the beam ports.
At the both sides of the cavity, a couple of the ceramic tubes made of SiC will be inserted to absorb the
HOM. It has been confirmed that this tube can dump
the HOM by -20 -30 dB.
Four of the single cell cavities are inserted in the
short straight sections at one ring of the double ringof the DSR. 3 ) The maximum acceleration voltage is
0.5 MV / cavity. In this case, the wall loss power is
expected to be 35 kW /cavity, and one cavity has tofeed the power of approximately 50 k W to the electron
beam because the averaged beam current is 0.5 A at
Ee = 2.5 GeV. The total input power is required to beabout 340 kW.
The RF power is provided by two klystrons; each
klystron has the output power of 180 kW. Since thepower gain is expected to be about 44 dB , the input
RF power to excite the klystron should be about 7-8"-J

l Ee =1.0 GeV
5

810-2
c
as

-----'_---'

3

3.5

Fig. 1. Toushek lifetime of the electron beam in the DSR.

231

Table 1. Parameters relating to the RF system for the 2.5
GeV electron beam in the DSR.
Circumference
Revolution frequency
Harmonic number
Beam energy
Beam current
Momentum compaction factor
Natural energy spread
Bunch length
Radiation loss in bending magnets
Radiation loss in insertion device
Radio frequency
Synchrotron frequency
Number of cavity
Q value of the cavity
Shunt impedance per cavity
Peak voltage
Over voltage factor
Wall loss per cavity
Number of klystron
Klystron power
Total klystron power

263.952 m
1.136 MHz440
0.3- 2.5 GeV
0.5 A
0.001
6.8 x 10- 4
0.5 cm372 keY
25 keY
499.745 MHz
11.1 kHz
4
44000
7.68 Mf2
2.0MV
5.038
35 kW
2
180 kW
338.5 kWW. Assuming the efficiency of the klystron of 55%, theelectric power source of about 400 k W will be needed
for the RF system of each krystron.
A block diagram of the RF system is shown in Fig. 4.
The RF signal is divided into the two klystrons throughthe phase and power control systems. The RF powerfrom each klystron is transported by the waveguides
into two cavities through a 180-kW circulator, a magicT, and phase controllers. The layout of the RF transport system is shown in Fig. 5. The klystron gallery
will be located close to the short straight section of the
DSR.
The water cooling system is necessary to cool theRF system; the water flow required here is estimatedas follows: 140 l/min for a cavity, 410 l/min for a
klystron, 170 1/ min for a circulator, and 330 1/ min forthe other electronics. In total water flow of 2380 l/min
is required.

232

I

iKlystron:Power Supply,-l--,~i Klystron .
:Klystron L------; RF Monitor >------<~'-.
' -.---.-_

Ie
CirCulator~- :y'-:t-y-,ie~ Circulator-~+I---~c-a_:~_,~d; "'~-H-y--Tf---1Ca---,tlFig. 4. Block diagram of the RF system.

Fig. 5. Layout of the RF transport system.

References
1) Y. Yano et al.: RIKEN Aceel. Prog. Rep. 29, 226 (1996).
2) M. Wakasugi et al.: RIKEN Aeeel. Prog. Rep. 29, 257(1996) .
3) N. Inabe et al.: RIKEN Aceel. Prog. Rep. 30, 217 (1997).

RIKEN Accel. Prog. Rep. 30 (1997)

An Undulator for Elliptically Polarized X-ray Beam Line at DSR
M. Wakasugi, N. Inabe, and T. Katayama
An X-ray beam line is planned to be constructed at
the merging section of the DSR. The beam line consistsof an undulator and an X-ray transport line including
an X-ray spectrometer. The undulator is a source ofhigh brilliance X ray and an X-ray spectrometer is employed to improve the X-ray energy resolution.
A linear undulator has been conceptually designedin the previous last report.!) Another type of undulator, which is the elliptical undulator, is consideredto achieve a higher photon flux and to obtain completely polarized photons. In this progress report, acomparison between the elliptical undulator and thelinear one is reported. Conceptual design of the X-ray
spectrometer and the performance calculation are alsopresented.
The value of the beta function has been changed
from 5 m to 2 m at the undulator section in the DSR,2)
because the size of the X ray at the source should be as
small as possible. Then, the quality of the X ray fromthe undulator has also changed. The parameters of thelinear undulator are the same with the previous one.!)The elliptical undulator was considered, because thephoton flux of it is expected to be larger than that of
the linear undulator. The controllability of the polarization is also an advantage of the elliptical undulator.
The higher-order harmonic radiation from the elliptical und ulator can be expected much weaker than thatfrom the linear one. The parameters of the ellipticalundulator is listed in Table 1.

Fig. 1. X-ray flux from the elliptical undulator (Kx = Ky
= 1.0) and the linear undulator (K = 1.0) at the electron beam energy of Ee = 1.0 GeV.

Table 1. Parameters of the elliptical undulator.

Fig. 2. Relative intensity of the third harmonic radiationfrom the elliptical (solid circles) and the linear (opencircles) undulators.

LengthN umber of periods
Kx/Ky
Gap width
Magnetic field

6 m
200
0.3- 2.0
1.1-2.9 cm
1.3 T at pole tip

Figure 1 shows the comparison of the calculated photon flux density (photons/sec mrad 2 O.l%b.w.) between the two types of undulators, where the electron
beam energy 1.0 GeV, the electron beam emittance
ex/ ey = 1.37/4.08 nmrad and the current 500 rnA wereassumed. In this calculation, the parameters Kx andK y , which are the bending factors in horizontal andvertical directions, respectively, are both unity, andthe K value for the linear undulator is also unity. As
seen in the figure, the photon flux from the ellipticalundulator is about twice larger than that from the linear one. The ratio of the strength of the third-orderharmonic radiation to that of the first-order harmonic
radiation was calculated as a function of the electron_ 1 10 18 , - -_ _- , -_ _----.-_ _ _,---_ _--,~.ci~~ 81017

Elliptical
Kx=Ky=1.0r

Ee = 1.0 GeV~oQ)NC" 610>etU

17-LinearK=1.0~Ec~41017
OCl)

0(;;
jfS210 17o.s:;.s 010~O~0~-~1~5~O~-~2~O~0~-=2~50~-~3~OO)i)
X Ray Energy (eV)

0
til

0

0

0

10. 1

0

0

~

•

~

~ 10.3
til
c:

•

CI)

0
)(

:::l

u:::

0

•

10.5

c:

•

•

0

0

•

.s::.

0..

(5

10-7

0

~
a::

10-9
10-12

•
10-11

10-10

10-9

1 O~

10-7

Electron Beam Emittance (mrad)

beam emittance (Fig. 2). The ratio for the linear undulator is independent of the electron beam emittanceand is nearly constant. It, however, strongly depends
on the emittance for the case of the elliptical undulator. The ratio for the elliptical undulator is three-ordersmaller than that for the linear one at Ee = 1.0 Ge V.
This is important to avoid the radiation damage of the
X-ray beam line due to higher energy X ray.
The polarization is required to be fully controllable.
Figure 3 shows the relation between the X-ray energy and the polarization obtainable with the elliptical undulator. The energy and the polarization can bechanged independently by tuning the Kx and Ky values. Shaded area shows the X ray produced with Kx
and Ky values of 0.3-2.0 at the electron beam energy of
1.0 GeV. The maximum K value was determined fromthe minimum gap width of 1.1 cm. The shaded area
can be moved by changing the electron beam energy
from 0.3 to 2.5 GeV, which is the designed value for
233

c

o

~
N

.~

~ 10- 1

Umitat
Ee=O.3 Ge

Fig. 3. Relation between the energy and the polarizationof the X-ray from the elliptical undulator. The photon
flux densities are shown by contour lines.

the DSR. Therefore, the elliptical undulator designed
here can provide the X ray having any polarization in
the energy range of 10- 1800 eV. Higher photon flux
density is obtainable with the circular polarization ofclose to unity.
The X ray extracted from the undulator is injected
into the X-ray beam line that consists of an X-ray spectrometer and an X-ray mirror system. Figure 4 shows
the layout of the X-ray beam line, which is inserted in
between the vertically bending magnets near the merging section of the DSR. A pre-mirror MO is used tomake a horizontal focusing for injection into the X-ray
spectrometer. The X-ray spectrometer has a movablemirror MM, a spherical grating G , and an entrance
and exit slits. After the spectrometer, two mirrors Ml
and M2 are used to re-inject the X-ray beam into theCenter of undulator

2.0m

8.0m
M2

----~~~17~5.~80~~:~7~3.9~4_0~ ~ir2__

X-ray spectrometer 7.111 m I 2.993 m I
Sl

MO

~

8.9m
Top View__________~-;;~--------

M1(3
Side View----~E£2J~~------====c=~----------------~~~~----~c==J~~----------MO : Pre-mirror (Horizontal focus), M1 : Vertical focusing mirror, M2: Plane mirror
MM : Movable plane mirror, G: Spherical grating
S 1 : Entrance slit, S2: Exit slit

Fig. 4. Layout of the X-ray beam line inserted in between the vertically bending magnets
at the merging section of the DSR.

other ring of the DSR, in which the RI beam is stored.
The total length from the MO to the M2 is about 21
m including the X-ray spectrometer of about 7.1-m
length.
In principal, the X-ray spectrometer is designed to
be of the Rowland circle type. Since the mirror MM
and the grating G are movable, the entrance and exit
beam axises are fixed even when the wavelength ischanged. The positions of SI ', G, and S2 are kept
on the Rowland circle as shown in Fig. 5. Since theincident angle of the X rayon the grating has to bechanged by changing the wavelength, the center ofthe Rowland circle is shifted. In our calculation, theenergy resolution of the X-ray spectrometer is about~ExjEx = 7600 at the wavelength of 40 nm, where
the grating has 800 grooresjmm and the radius of curvature is 57.3 m. The requirement on the energy resolution is ~ExjEx = 10000. We are now optimizing
the spectrometer and trying to make various ray-trace234

calculations.

Fig. 5. Conceptual design of the X-ray spectrometer.

References
1) M. Wakasugi et al.: RIKEN Accel. Prog. Rep . 29 , 257(1996).
2) N. Inabe et al.: RIKEN Accel. Prog. Rep. 30, 217(1997).

RIKEN Accel. Prog. Rep. 30 (1997)

Calculations of Radiation Shield for
RIKEN RI Beam Factory
N. Nakanishi, Y. Vwamino, S. Yamaji, H. Okuno, S. Fujita, and S. Nakajima
In the new project of RIKEN RI beam factory, allkinds of ions from protons to V's, and electrons are to
be accelerated. Two successive superconducting ring
cyclotrons (SRC) are designed to boost the energy ofion beams from the existing ring cyclotron up to 400
MeV /nucleon for light-heavy ions like Ar ions and 150
MeV /nucleon for very-heavy ions like V ions. Secondary beams produced by these primary heavy ionsfrom the SRC are cooled and accelerated up to 1.45
GeV /nucleon by an accumulator-cooler ring (ACR)
and by a booster synchrotron ring (BSR), respectively.
On the other hand, electrons are accelerated by a 300
MeV injector linac followed by a 2.5 GeV BSR.
We have calculated the dose rate in the shielding material for radiations caused by 400 MeV /nucleon and
1.5 GeV /nucleon heavy ion beams, and 300 MeV and
2.5 GeV electron beams.
For radiations induced by high-energy heavy ions,the neutron transport code ANISN 1) and nuclear data
DLC-87/HIL0 2 ) were adopted. Neutron spectra wereobtained for the reactions of carbon beams incident on
thick carbon and copper targets by calculations basedon the quantum molecular dynamics. 3 ) These elements
are typical materials used in accelerators and beamfocusing systems. Since the C + C reaction produces
more high-energy neutrons than the C + Cu reaction
does, we employed neutron spectra of the former reaction for both energies. Actually the shielding of theradiations produced by 400 MeV/nucleon ion-beams ismore serious in spite of the lower energy relative to thatof the 1.45 GeV /nucleon ion beams in the beam intensity point of view. The intensity of 400 MeV/nucleon
ion beams is expected to be 2-orders higher than thatof 1.45 GeV /nucleon ion beams. We have to use twolayer shields consisting of iron and concrete in order toreduce the total thickness of shielding materials. The
thickness dependence of the product of dose rates andthe distance between a radiation source and an observing point are shown in Fig. l(a) for a radiation source
by a 400 MeV/nucleon Ar + C reaction, where an additional iron wall of 2 m thickness is placed between
a radiation source and the concrete shield. Here, theneutron spectra by a Ar + C reaction were scaled fromthose of a C + C reaction by multiplying the mass-ratioof Ar to C nuclei, 40/12.
We used empirical formula for the shielding of radiations by electron beams. It is known that gamma rays,
neutrons, muons, and the gas bremsstrahlung contribute to the total dose rate. The gas bremsstrahlungis caused by the interaction of electron beams withresidual gases in beam ducts, and raises intensity of

>

C/)

o

(3

'E
Q)

iii
a:

...........

'"

Q)
CJ)

o

o

4

6

10

Thickness [ m 1

~

.~
a.
.s::.

10'7..-----t-----t- - - + - - _ - +_ _ _+_--.I,~-----1r__--_I_---t--- ( L---+- -.I1016 .....
'0 '5

2.5 GeV elec~ron + thick Cu _."101 • ..----~r--....r__--_I_---t--conclrete
'"
I

I'"

1013

N8

'0 '2

~

10"

........

I'"'~...." " ' ,'".. ....... "~10 10..--_ ..

().dog::: _-+----.1_'~--"'· k·'·-'!.···~-_I_-,,-----""'r_+---__t_-9CJ.dog-·""'". . . ·.. ;._:--1---..1" '~...... ...........
10 9 r----t---"'....
.,.=,.....--'•••"f. ...-;:---~,----I----+-_J
lOB
Q)
CJ)

o

o

r----t--....-~:.:_f.c....•• ::......::,.::.:::::""'••....,•••,-:•••-=t=......."'---=---I-~-=-==_~_J

107 r----+-----+-~-'~-'-..::.:+..

=::. .::~:~:...::c:::""". ...__...+'.-=-.~_~--J

106 r----t----t---+--~-'-"-:.+-.:-.:~.:.:"-.:. . . .,.:.: : : :... .:I___J
~~,

10

5

r-- - - t - - - - t- --+----I----I___J
2

3

Thickness [ m 1

Fig. 1. Attenuation of the product of dose rate anddistance L as a function of the hickness of specified shielding materials for radiations induced by (a)400 MeV/nucleon heavy ion and (b) 2.5 GeV electron
beams. The L denotes the distance between a radiation
source and an observing point in units of cm.

electron beams effectively. For dose rates due to neutrons and gamma rays, the Swanson expressions4 ) wereused in the 0 deg. direction, and the Jenkins ones 5 )in the directions between 30 and 130 degrees. The
Swanson4 ) and Rindi 6 ) expressions were used for thecontributions by muons and the gas bremsstrahlung,respectively. Typical examples shown in Fig. l(b) are
the attenuation behavior in the concrete shield of the235dose rate by 2.5 GeV electrons on a eu target. For the
direction of 0 deg., the dose rates by gamma rays andmuons are predominant. Since gamma rays attenuate
steeply with the thickness of the concrete shield, thedose rate by muons is conspicuous in the region of theconcrete of more than 3 m thickness. For the directionsof more than 30 degrees, the contribution by gamma
rays and neutrons is predominant in dose rates i.e., thedose rate by gamma rays is remarkable in the region ofless than 1.5 m, and that by the neutrons in the outerregion.

236

Further calculations will have to be made precisely
against the actual structure of accelerators and/or
beam lines from now on.
References
1) K. Koyama et al.: JAERI-M 6954 (1977) .
2) DLC-87, RSIC, ORNL (1981).
3) J . Aichelin et al.: Phys. Rev. C 37, 2451 (1988).
4) W. P. Swanson: Technical Report Series No. 188 (1979).
5) T. M. Jenkins: Nucl. Instrum. Methods 159, 265 (1979).
6) A. Rindi: Health Phys. 42 , 187 (1982).

VI.

RADIATION MONITORINGRIKEN Accel. Prog. Rep. 30 (1997)

Leakage Radiation Measurements in
the Ring Cyclotron Facility
S. Fujita, N. Nakanishi, H. Ohishi,* H. Uehara,* Y. Uwamino, and T. T. Inamura
Dose rates due to leakage radiation have been measured at various points around the beam distribution
corridor. The results of similar measurements havebeen reported annually since 1995. 1 ,2)In this year (1996), the measurements of leakage radiation were carried out with 113-MeV proton beams.
The beam intensities were between 100 and 200 pnA.
The beams were stopped at an iron target in the beam
distribution corridor. Leakage radiation of neutrons
from the corridor was measured with four neutron dose
rate meters, TPS-451S's (Aloka). The beam current at

(a)

X WR

x GC

~ WC

II

x WL

x GR

(b)

J

II
II

X GL

II

Table 1. Dose rates of neutron leakage radiation from atarget placed in the beam distribution corridor. [Forpositions, see Fig. 1-(a),(b),(c)]. The unit of energy is
MeV /nucleon. The unit of dose rate is (J.LSV /h)/(pJ.LA).
Measureddate
Accelerated
particle
EnergyPosition
1F a
1F c
1F b
ES a
ES c
ES b
E4 a
E4 c
E4 b
82 a
82 c
82 b
Out R
OutC
Out L
WR
WC
WL
GR
GC
GL

Jan 28, '96

Jun 27, '96

Proton113
Dose rate
3.70E-02
2.66E-02
2.26E-02
1.60E+Ol
1.14E+Ol
4.24E+01
4.26E+00
2.80E+00
8.S7E-Ol
1.06E+01
7.S7E+00
4.31 E+OO
5.4 1E+OO
6.48E+OO
S.18E+00
2.20E-Ol
2.89E-Ol
1.99E-Ol
1.40E-Ol
1.S9E-Ol
1.21 E-Ol. Proton
113
Dose rate
2.17E-02
1.S3E-02
2.00E-02
1.04E+Ol
S.37E+00
1.61 E+01
3.S1 E+OO
1.77E+OO
S.06E-Ol
8.38E+00
S.83£+00
3.74E+00
S.33E+OO
6.18E+OO
4.89E+00
2.03E-01
2.S4E-Ol
2.09E-01
l.S1E-Ol
1.44E-Ol
1.24E-01

C\tRx
C\tcx
o..tL xI

(c)Fig. 1. Partial layout of the RIKEN Ring Cyclotron
facility where the leakage radiation measurement was
made. (a) Part of the 1st floor; (b) Part of the 1st
basement floor; (c) Part of the 2nd basement floor.
The target point is denoted by a closed circle. Leakage-radiation-dose measuring points are denoted by x.
Faculty of Science and Technology, Chuo University

the target was read with a current integrator (ORTEC
439) and recorded with a personal computer. Figure 1(a), (b), and (c) show the target point and the positions
where the measurements were done. The positions ofE5c and E4c are just right and left from the target
point, respectively. Leakage of neutrons was detectedalso at the several points outside the building. The
position denoted by OutC is right behind the target
point. Results are summarized in Table 1. The dataof dose rates were normalized with respect to the beam
intensity of 1 pJ.LA.
The behavior of leakage neutrons around the beam
distribution corridor for several kinds of beams had
been measured in series of measurements. For examples, Figs. 2 and 3 show the neutron dose rates at E4a,E4c, and E4b, and the attenuation curves of neutron
dose rates measured along the points denoted in Fig.
l(b), respectively.
On the other hands, the automatic monitoring ofleakage radiation using a computer (MX-3000) was alsodone continuously during this year. From the accumulated data of leakage neutrons, the radiation level inthe controlled area was found to have been much less237

140.00-

1.00E+04.

- - - - - - - - - - - - - - - - - - - - --- --- - N-135• 0-135 ---::- Si-135
120.00~«100.000-100--/~.-

0-135

80.00

.....-

p-135

-.:0-

p- 113

-

::t

~
~
Ji

-

- - - p-110::t(, 0-100 .. p-135

<'::t

p-113

c.

~ 1.00E+02~~~~---------~--. "-

CI>

60.00

• Si- 135

1.00E+03

::t

~

"0

..!L..~ "

5:o

c:

~

~ 1.00E+01

e

CI>

z

;

~
en

~
~

= N-135- - - - ---11

+ -

-

40.00

20.00

_

"5CI>
z

- - - ---"-.,.......---"'c----- - - - -_.
1.00E+00-----------~:----___c,- -,

E4 a

E4 c

E4 b

Dose-rate measured position

1.00E· 01

Out C

oFig. 2. Neutron dose rates at E4a, E4c and E4b [See,Fig. 1 (b)]. The distances between E4c and E4a, andbetween E4c and E4b are 2 m, respectively.

than the safety limit (0.3 mSv /week). Leakage of neutrons has been recorded with a monitor in the groundfloor computer room just above a bending magnet thatguides the beams from Ring Cyclotron vault to the
distribution corridor. This radiation level is, however,much less than the safety limit (1 mSv /year) requiredat the boundary of the accelerator facility. No leakage
of , rays and neutrons was detected with environmental monitors outside the building during this reporting
period.

238

5

10

15

WC
20

GC
25

Distance from the target (m)Fig. 3. Attenuation curves of neutron dose rates at OutC,
WC, and GC [See, Fig. l(b)]. The distances at OutC,
WC, and GC are 6.4, 19.6, and 23.8 m from the target
point, respectively.

References
1) S. Fujita, N. Nakanishi, S. Nakajima, M. Watanabe, H.
Ohishi, K. Tanaka, Y. Uwamino , and T. T. Inamura:
RIKEN Accel. Prog. Rep. 28, 183 (1995).
2) S. Fujita, N. Nakanishi, S. Nakajima, M . Watanabe, H.
Ohishi , Y. Uwamino , and T. T. Inamura: RIKEN Accel.
Prog. Rep. 29 , 259 (1996).

RIKEN Accel. Prog. Rep. 30 (1997)

Dose Rates due to Residual Activities in
the Ring Cyclotron Facility
S. Fujita, H. Ohishi,* H. Uehara,* N. Nakanishi, Y. Uwamino, and T. T. Inamura
Dose rates due to residual radioactivities have routinely been measured at various points in the RIKEN
Ring Cyclotron (RRC) Facility every summer, and at
those along the beam lines after every experiment. The
results of measurements have been reported annually
since 1986.
Figure 1 shows the variation of the dose rates at the
deflectors of the RRC and AVF in the last ten years.
It is clearly seen that the dose rates have been about
ten thousand j.LSV /h since 1990, while they were lower
by two orders of magnitude until 1989. This is due tothe increase in the maximum energy of the beam fromthe RRC, which has changed from 75 MeV/nucleon to
135 MeV/nucleon.

was found to be 5000 j.LSV /h at the target chamber,denoted by the point V in Fig. 2.

105

104

.c

RINGI
I ~ AVF

103l-Fig. 2. Layout of the RIKEN Ring Cyclotron Facility in
1996. The positions where the residual activities were
measured along the beam lines are denoted by a-z.

e-

-;

l-

Cf)
~

-

i

102

Table 1. Summary of the dose rates measured along thebeam lines with ionization-chamber survey meters. The
points a-z correspond to the positions shown in Fig. 2.

I-

10 1

Detection Measured
Date
point
dose rate(tLSv/h)
160 Nov 13, '95
n1000 Nov 24, '95
60 Apr 25, '96
0
95 Oct 13, '95
62 Oct 13, '95
50 Nov 8, '95
P
11 0 Aug 13, '96q
60 lun 6, '96
54 Oct 13, '95r
270 Nov I~ , '95
11 0 Dec 20, '95
220 Nov 13, '95s
350 Nov 13, '95t
50 luI 2, '96
11 0 Nov 13, '95
U
60 Apr 25, '96
5000 Nov 13, '95V
300 luI 2, '96
220 Nov 27, '95w
180 Aug 13, '96
X
120 Aug 13, '96
3000 Mar 8, '96
120 Nov 24, '95
3000 Mar 8, '96
Yz
SO Jan 31, '96
550 Mar 6, '96

Detecti on Measured
point
dose rate(tL Sv/h)

10°

a
year

Fig. 1. Variation of the dose rates at the deflectors of the
RIKEN Ring Cyclotron and AVF injector cyclotron.

In the period from Oct. 1, 1995 to Sep. 30, 1996, dose
rates were measured along the beam lines. The points
a-z in Fig. 2 denote the places where the dose rates
exceeded 50 j..tSv /h. Table 1 summarizes the observed
dose rates together with the dates on which the measurements were performed. The maximum dose rate

b
c
d

e
f
g
h
j
k
I
m

Date

Faculty of Science and Technology, Chuo University

239

VII. LIST OF PUBLICATIONS
1.

Accelerator
physics

development

andaccelerator

A. Goto, Y. Miyazawa, M. Hemmi, O. Kamigaito,
T. Nakagawa, M. Kase, T. Chiba, N. Inabe, S.
Kohara, T. Kageyama, Y. Batygin, E. Ikezawa, andY. Yano: "Construction of a new pre-injector system
for the RILAC" , Proc. 14th Int. Conf. on Cyclotrons
and Their Applications, 1995-10, Cape Town, South
Africa, pp. 202- 205 (1995).
T. Mitsumoto, T. Kawaguchi, T. Kubo, H. Okuno,
T. Tominaka, Y. Tanaka, S. Fujishima, K. Ikegami,
A. Goto, and Y. Yano: "Design study of sector
magnets of Superconducting Ring Cyclotron for the
RIKEN RI Beam Factory", Proc. 14th Int. Conf. on
Cyclotrons and Their Applications, 1995-10, CapeTown, South Africa, pp. 237- 240 (1995).
M. Kase, N. Inabe, 1. Yokoyama, M. Hemmi, A. Goto,
and Y. Yano: "Applications of MCP phase monitor to operation of RIKEN heavy ion accelerators" ,Proc. 14th Int. Conf. on Cyclotrons and their Applications, 1995-10, Cape Town, South Africa, pp.
291- 294 (1995).
Y. Yano, A. Goto, Y. Miyazawa, M. Hemmi, T.
Chiba, T. Kageyama, K. Ikegami, M. Takan aka ,T. Kawaguchi, S. Kohara, M. Kase, T. Tominaka'
Y. Batygin, T. Kubo, T. Nakagawa, Y. Tanaka, E.
Ikezawa, M. Wakasugi, T. Mitsumoto, N. Inabe, O.
Kamigaito, H. Okuno, S. Fujishima, A. Ohtomo, andT.Ohkawa: "RIKEN RI Beam Factory project", (invited paper), Proc. 14th Int. Conf. on Cyclotrons
and their Applications, 1995-10, Cape Town, South
Africa, pp. 590- 597 (1995).
Y. Batygin: "On space charge dominated beam transport without emittance growth" , AlP Conf. Proc.
377, edited by S. Y. Lee, Woodbury, New York, pp.
290-306 (1996).
T. Nakagawa, Y. Miyazawa, M. Hemmi, T. Chiba, N.
Inabe, M. K~e, T. Kageyama, O. Kamigaito, A.
Goto, and Y. Yano: "Improvement of RIKEN 18
G Hz electron cyclotron resonance ion source usingaluminum tube", Jpn. J. Appl. Phys. 35 , 4077- 4078
(1996).
T. Nakagawa, Y. Miyazawa, M. Hemmi, T. Chiba, N.
Inabe, M. Kase, T. Kageyama, O. Kamigaito, A.
Goto, and Y. Yano: "Determination of ion confinement time in RIKEN 18 GHz electron cyclotron resonance ion source (ECRIS) under pulsed mode operation", Jpn. J. Appl. Phys. 35, L1124-L1126 (1996).
Y. Batygin: "Conservation of space-charge-dominatedbeam emittance in a strong nonlinear focusing field" ,Phys. Rev. E 53, 5358- 5365 (1996).
Y. Batygin: "Adiabatic matching of nonuniform intense charged - particle beam into the focusing channel", Phys. Rev. E 54, 5673- 5680 (1996).

N. Shimakura, S. Suzuki, Y. Mllrakami, and J. P. Gu:"Electron capture and target excitation in collisionsof Bq+ and Beq+ ions with H and He atoms at energies below 10 keY ju", Phys. Scr. T_62, 39-42 (1996).
Y. Yano and A. Goto: "Progress of RIKEN RI Beam
Factory project", Proc. 5th Eur. Part. Accel. Conf.
(EPAC '96), pp. 536-538 (1996).
T. Katayama, S. Watanabe, Y. Batygin, N. Inabe, K.
Ohtomo, T. Ohkawa, M. Takanaka, M. Wakasugi,
Y. Yana, K. Yoshida, J. Xia, Y. Rao, and Y. Than:"MUSES project at RI Beam Factory", Proc. 5thEur. Part. Accel. Conf. (EPAC '96), pp. 563- 565(1996) .
M. Wakasugi, N. Inabe, and T. Katayama: "Undulator
and photon spectrum at DSR", Proc. 5th Eur. Part.
Accel. Conf. (EPAC '96), pp. 611- 613 (1996).
O. Kamigaito, A. Goto, Y. Miyazawa, T. Chiba, M.
Hemmi, S. Kohara, M. Kase, Y. Batygin, and Y.
Yano: "Development of a variable-frequency RFQ
linac for the RILAC", Proc. 5th Eur. Part. Accel.
Conf. (EPAC '96), pp. 786-788 (1996).
K. Yoshida and T. Katayama: "Expected luminosity at MUSES", Proc. 5th Eur. Part. Accel. Conf.
(EPAC '96), pp. 870-872 (1996).
N. Inabe and T. Katayama: "Design of double storage
ring at MUSES", Proc. 5th Eur. Part. Accel. Conf.
(EPAC '96), pp. 926-928 (1996).
T. Ohkawa and T. Katayama: "Design of booster synchrotron for MUSES" , Proc. 5th Eur. Part. Accel.
Conf. (EPAC '96), pp. 929- 931 (1996).
J. W. Xia and T. Katayama: "Lattice for accumulator
cooler ring for MUSES", Proc. 5th Eur. Part. Accel.
Conf. (EPAC '96), pp. 932- 934 (1996).
Y. N. Rao and T. Katayama: "Intrabeam scatteringof heavy ion in DSR", Proc. 5th Eur. Part. Accel.
Conf. (EPAC '96), pp. 1024- 1026 (1996).
M. Takanaka and T. Katayama: "Beam current limitation due to single-beam collective effects in the ion
storage ring of RIKEN RI-beam factory project",
Proc. 5th Eur. Part. Accel. Conf. (EPAC '96), pp.
1138- 1140 (1996).
Y. Batygin and T. Katayama: "Beam-beam interaction of electrons and ions at RIKEN RI beam factory", Proc. 5th Eur. Part. Accel. Conf. (EPAC '96),
pp. 1170- 1172 (1996).
Y. Batygin and T. Katayama: "Merging beam-beamcollisions at RIKEN RI Beam Factory", Proc. 5thEur. Part. Accel. Conf. (EPAC '96), pp. 1173- 1175
(1996).
Y. N. Rao, K. Ohtomo, and T. Katayama: "Electron
cooler at ACR", Proc. 5th Eur. Part: Accel. Conf.
(EPAC '96), pp. 1182-1184 (1996).
Y. J. Yuan, K. Ohtomo, and T. Katayama: "Simulation of RF stacking combined with cooling effects",
Proc. 5th Eur. Part. Accel. Conf. (EPAC '96), pp.
1338-1340 (1996).
241

T. Nakagawa, J. Arje, Y. Miyazawa, M. Hemmi, M.
Kase, T. Kageyama, O. Kamigaito, T. Chiba, N.
Inabe, A. Goto, and Y. Yano: "Development of
RIKEN 18 GHz ECRIS", Proc. 5th Eur. Part. Accel.
Conf. (EPAC '96), pp. 1478-1480 (1996).
M. Takanaka and T. Katayama: "Design of beam
bunching system for the ion storage ring of RIKEN
RI-beam factory project", Proc. 5th Eur. Part. Accel. Conf. (EPAC '96), pp. 1991- 1993 (1996).
T. Kubo, T. Kawaguchi, T. Mitsumoto, H. Okuno, T.
Tominaka, J.-W. Kim, S. Fujishima, K. Ikegami, Y.
Tanaka, A. Goto, and Y. Yano: "Design of model
sector magnet for the RIKEN Superconducting Ring
Cyclotron", Proc. 5th Eur. Part. Accel. Conf. (EPAC'96), pp. 2279- 2280 (1996).
T. Mitsumoto, A. Goto, T. Kawaguchi, J.-W. Kim,
Y. Tanaka, T. Kubo, H. Okuno, T. Tominaka, W.
Fujishima, and Y. Yano: "Design study of sector magnet for the RIKEN Superconducting Ring
Cyclotron (I)", Proc. 5th Eur. Part. Accel. Conf.
(EPAC '96), pp. 2302- 2304 (1996).
T. Kawaguchi, T. Kubo, T. Mitsumoto, T. Tominaka,
S. Fujishima, H. Okuno, Y. Tanaka, J.-W. Kim, K.
Ikegami, A. Goto, and Y. Yano: "Design study of
sector magnet for the RIKEN Superconducting Ring
Cyclotron (II)", Proc. 5th Eur. Part. Accel. Conf.
(EPAC '96), pp. 2305- 2307 (1996).
S. Watanabe, T. Katayama, N. Inabe, T. Ohkawa, and
M. Takanaka: "Study of a magnet power supply for a
MUSES booster synchrotron", Proc. 5th Eur. Part.
Accel. Conf. (EPAC '96), pp. 2340-2342 (1996).
H. Okuno, T. Tominaka, T. Kubo, J.-W. Kim, T.
Mitsumoto, T. Kawaguchi, Y. Tanaka, S. Fujishima,
K. Ikegami, A. Goto, and Y. Yano: "Design study ofthe injection system of the RIKEN superconducting
Ring Cyclotron", Proc. 5th Eur. Part. Accel. Conf.
(EPAC '96), pp. 2397- 2399 (1996).
Y. Batygin, A. Goto, and Y. Yano: "Hollow beamprofile in the extraction system of ECR ion source",
Proc. Part. Accel. Conf. (PAC95), 1995-5, Dallas,
U.S.A., pp. 1001- 1003 (1996).
Y. Batygin: "Invariability of intense beam emittancein nonlinear focusing channel", Proc. Part. Accel.
Conf. (PAC95), 1995-5, Dallas, U.S.A., pp. 32513253 (1996).
D. L. Bruhwiler and Y. K. Batygin: "Beam transport for uniform irradiation: Nonlinear space charge
forces and the effect of boundary conditions", Proc.
Part. Accel. Conf. (PAC95), 1995-5, Dallas, U.S.A.,
pp. 3254-3256 (1996).
2.

Nuclear physics and nuclear instrumentation

A. Ryowa, N. Hasebe, M. Kobayashi, K. Kondo, Y.
Mishima, K. Nagata, T. Kohno, J. Kikuchi, and
T. Doke: "Global distributions of trapped particle
fluxes observed by OHZORA satellite during 19841987", Bulletin of General Education Fuculty of
242

Ehime Univ., p. 28 (1995).
Y. Mizoi, T. Miyachi, Y. Matsuyama, T. Fukuda, H.
Kobinata, Y. Watanabe, Y. Watanabe, A. Yoshida,
H. Sakurai, and K. Kimura: "Construction of the
New MUSIC detector system", INS Ann. Rep. pp.
38- 39 (1995).
N. Hasebe, K. Kondoh, M. Kobayashi, Y. Mishima,
T. Doke, J. Kikuchi, T. Hayashi, K. Itsumi, T.
Takashima, T, Yanagimachi, H. Murakami, A.
Nakamoto, K. Nagata, T. Kashiwagi, K. :tvlunakata,
C. Kato, T. Kohno, Y. Muraki, T. Koi, K. Maezawa,
S. Yanagita, T. Teras awa , A. Nishida, K. Fujiki, J.
Medina, J. Sequeiros, and B. Wilken: "Corotating
ion events associated with cosmic ray modulation",
J. Geomagn. Geoelectr. 47, 1333- 1338 (1995).
Y. Koike and K. Tanaka: "Q2 evolution of thenucleon's chiral-odd twist-three structure function:hL(X , Q2)" , Phys. Rev. D 51, 6125-6138 (1995).
A. A. Gusev, T. Kohno, 1. M. Martin, G. 1. Pugacheva,
A. Turtelli, A. Tylka, and K. Kudela: "Injection andfast radial diffusion of energetic electrons into theinner magnetosphere", Planet. Space Sci. 43 , 11311134 (1995).
S. Shimoura: "Spectroscopy of neutron-rich nuclei via
direct reactions using secondary nuclear beams atseveral tens of MeV per nucleon", Proc. Int. Conf.
on Exotic Nuclei and Atomic Masses, edited by M.
de Saint Simon and O. Sorlin, Editions Frontiers,
France, pp. 217- 225 (1995).
H. Kurasawa and T. Suzuki: "A sum rule constraint
on the soft dipole mode", Prog. Theor. Phys. 94,
931- 936 (1995).
K. Oyamatsu: "Symmetry energy at subnuclear densities", Genshikaku Kenkyu 41 , 39- 43 (1996).
H. Kurasawa and T. Suzuki: "Electron scattering in
relativistic and non-relativistic model", Genshikaku
Kenkyu 41, 103- 110 (1996).
G. I. Pugacheva, A. A. Gusev, I. M. Martin, W. N.
Spjeldvik, and T. Kohno: "The temporal evolutionof 3- 9 MeV jnucleon He flux trapped in the magnetosphere" , Geophys. Res. Lett. 23, 2793- 2796 (1996).
K. Matsuta, M. Fukuda, M. Tanigaki, T. Minamisono,
Y. Nojiri, H. Akai, T. Izumikawa, M. Nakazato, M.
Mihara, T. Yamaguchi, A. Harada, M. Sasaki, T.
Miyake, T. Ohnishi, K. Minamisono, T. Fukao, K.
Sato, Y. Matsumoto, T. Ohtsubo, S. Fukuda, K.
Yoshida, A. Ozawa, S. Momota, T. Kobayashi, I.
Tanihata, J. R. Alonso, G. F. Krebs, and T. J. M.
Symons: "Hyperfine interaction of 13 0 and 23Mg implanted in Pt", Hyperfine Interact. 97/98 , 501-508(1996).
H. Izumi, K. Asahi, H. Deno, H. Okuno, H. Sato, K.
Nagata, Y. Hori, M. Adachi, M. Aoi, A. Yoshida, G.
Liu, N. Fukunishi, and M. Ishihara: "Measurementof electric quadrupole moments of neutron-rich nuclei 14B and 15B", Hyperfine Interact. 97/98, 509517 (1996).
K. Matsuta, T. Minamisono, M. Tanigaki, M. Fukuda,

Y. Nojiri, M. Mihara, T. Onishi, T. Yamaguchi,
A. Harada, M. Sasaki, T. Miyake, K. Minamisono,
T. Fukao, K. Sato, Y. Matsumoto, T. Ohtsubo,
S. Fukuda, S. Momota, K. Yoshida, A. Ozawa, T.
Kobayashi, I. Tanihata, J. R. Alonso, G. F. Krebs,
and T. J. M. Symons: "Magnetic moments of proton drip-line nuclei 13 0 and gc", Hyperfine Interact.
97/98, 519- 526 (1996).
T. Matsuzaki, K. Ishida, S. Nakamura, I. Watanabe, N.
Kawamura, M. Tanase, K. Kurosawa, M. Koto, M.
Hashimoto, K. Nagamine: "Muon catalyzed fusion
experiment at RIKEN-RAL Muon Facility", JAERIConf 96-014 pp. 121- 128 (1996).
H. Kurasawa and T. Suzuki: "Does a soft dipole mode
exist?", JHP-Suppl. 20, 21-25 (1996).
H. Miyatake, M. Sasaki, H. Ueno, T. Shimoda, N. Aoi,
T. Shirakura, K. Asahi, H. Izumi, H. Ogawa, G.
Liu, and A. Yoshida: "Delayed neutron spectroscopy
with using spin-polarized neutron-rich nuclei beam",
JHP-Suppl. 20, 48-50 (1996).
K. Sumiyoshi, K. Oyamatsu, and H. Toki: "Neutronstars and unstable nuclei in relativistic many-bodyframework", JHP-Suppl. 20, 279 (1996).
A. A. Gusev, T. Kohno, W. N . Spijeldvik, I. M. Martin,
G. 1. Pugacheva, and A. Tutelli, Jr.: "Dynamics
of low-altitude energetic proton fluxes beneath themain terrestrial radiation belts", J. Geophys. Res.
101, 19659- 19663 (1996).
N. lwasa, T. Motobayashi, Y. A:qdo, M. Kurokawa,
H. Murakami, J. Ruan, S. Shimoura, S. Shirato,
N. lnabe, T. Kubo, Y. Watanabe, M. Gai, R. H.
France III, K. I. Hahn, Z. Zhao, T. Nakamura, T.
Teranishi, Y. Futami, K. Furutaka, Th. Delbar, and
M. Ishihara: "Study of the 7Be(p,I')8B reaction with
Coulomb dissociation method", J. Phys. Soc. Jpn.
65, 1256- 1263 (1996).
H. Miyatake, T. Shimoda, M. Sasaki, T. Shirakura,
N. Aoi, K. Asahi, H. Ueno, H. Izumi, H. Ogawa, A.
Yoshida, and G. Liu: "Delayed neutron spectroscopy
with using spin polarized RI Beam", KURRl-KR-3,
pp. 60- 64 (1996).
K. Kitao and M. Oshima: "Nuclear data sheets update
for A=127", Nuclear Data Sheets 77, 1- 298 (1996).
Y. Tendow: "Nuclear data sheets for A=129", Nuclear
Data Sheets 77, 631- 770 (1996).
H. Okada, T. Doke, K. Hasuike, J. Kikuchi, K.
Masuda, M. Shinoda, T. Takahashi, and K.
Terasawa: "Time stability of liquid xenon photoionization detectors", N ucl. lnstrum. Methods Phys.
Res. A 374, 188- 192 (1996).
M. Takada, T. Shibata, Y. Uwamino, and T.
Nakamura: "A perfoqnance study on a phoswich
detector consisting of an inner NE213 scintillator
and an outer CaF 2 (Eu) crystal wall" , N ucl. Instrum.
Methods Phys. Res. A 379, 293-306 (1996).
T. Horibata and N. Onishi: "Self-consistent threedimensional cranking calculation based on HFB",
Nucl. Phys. A 596, 251-284 (1996).

H. Kurasawa and T. Suzuki: "The mean energy,
strength and width of the double giant dipole states" ,Nucl. Phys. A 597, 374-386 (1996).
H. Hofmann, F. A. Ivanyuk, and S. Yamaji: "On thenature of nuclear dissipation, as a hallmark for collective dynamics at finite excitation", Nucl. Phys. A
598, 187- 234 (1996).
L. Chulkov, G. Kraus, O. Bochkarev, P. Egelhof,
H. Geissel, M. Golovkov, H. Irnich, Z. Janas, H.
Keller, T. Kobayashi, G. Miinzenberg, F. Nickel,
A. Ogloblin, A. Ozawa, S. Patra, A. Piechaczek,
E. Roeckl, W. Schwab, K. Siimmerer, T. Suzuki, I.
Tanihata, and K. Yoshida: "Interaction cross sections and matter radii of A = 20 isobars", Nucl.
Phys. A 603, 219-237 (1996).
Y. Futami, K. Yuasa-Nakagawa, T. Nakagawa, S. M.
Lee, K. Furutaka, K. Matsuda, K. Yoshida, S. C.
Jeong, H. Fujiwara, T. Mizota, Y. Honjo, S. Tomita,
B. Heusch, K. Ieki, J. Kasagi, W. Q. Shen, and T.
Matsuse: "Decay mechanism of a highly excited nucleus produced in the reaction 84Kr+ 27 Al at 10.6
MeV /nucleon", Nucl. Phys. A 607, 85- 104 (1996).
A. Ozawa, 1. Tanihata, T. Kobayashi, Y. Sugahara, O.
Yamakawa, K. Ornata, K. Sugimoto, D. Olson, W.
Christie, and H. Wieman: "Interaction cross sections
and radii of light nuclei", N ucl. Phys. A 608, 63-76(1996).
I. Tanihata and Y. A waya: "RI Beam Facilities for
21-century", (in Japanese), Parity 11, 39-41 (1996).
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).
P. Strasser, K. Ishida, S. Sakamoto, K. Shimomura,N. Kawamura, E. Torikai, M. Iwasaki, and K.
N agamine: "Muon catalyzed fusion experiments on
muonic deuterium atom deceleration in thin solid
deuterium films", Phys. Lett. B 368, 32-38 (1996).
R. L. Jaffe and N. Saito: "QCD selection rules in polarized hadron collisions", Phys. Lett. B 382, 165-172(1996).
T. Kikuchi, T. Motobayashi, N. Iwasa, Y. Ando, M.
Kurokawa, S. Moriya, H. Murakami, T. Nishio, J.
Ruan, S. Shimoura, S. Shirato, T. Uchibori, Y.
Yanagisawa, T. Kubo, H. Sakurai, T. Teranishi, Y.
Watanabe, M. Ishihara, M. Hirai, T. Nakamura, S.
Kubono, M. Gai, R. H. France III, K. 1. Hahn, Th.
Delbar, P. Lipnik, and C. Michotte: "Experimental
determination of the E2 component in the Coulomb
dissociation of 8B", Phys. Lett. B 391, 261-266(1996).
N. Dinh Dang: "On the width of giant dipole resonancein hot nuclei", Phys. Rep. 264, 123-135 (1996).
K. Sugawara-Tanabe, A. Arima, and N. Yoshida:"Magnetic dipole transitions in superdeformed nuclei", Phys. Rev. C 53, 195-200 (1996).
G. Rainmann, A. Ozawa, R. N. Boyd, F. R. Chloupek,243

M. Fujimaki, K. Kimura, T. Kobayashi, J. J. Kolata,
S. Kubono, I. Tanihata, Y. Watanabe, and K.
Yoshida: "Levels in 17C above the 16C+neutron
threshold", Phys. Rev. C 53,453-458 (1996).
K. Yuasa-Nakagawa, J. Kasagi, T. Nakagawa, K.
Yoshida, Y. Futami, S. M. Lee, K. Furutaka, K.
Matsuda, and W. Q. Shen: "Binary decay fragment
cross sections and prescission charge multiplicity in
84Kr+27 Al at 10.6 MeV/nucleon", Phys. Rev. C 53,
997-1000 (1996).
F. Kappeler, K. A. Toukan, M. Schumann, and A.
Mengoni: "Neutron capture cross sections of thecerium isotopes for the s- and p-process studies",
Phys. Rev. C 53,. 1397-1408 (1996).
H. Ueno, K. Asahi, ' H. Izumi, K. Nagata, H. Ogawa,A. Yoshimi, H. Ogawa, H. Sato, K. Adachi, Y.
Hori, K. Mochinaga, H. Okuno, N. Aoi, M. Ishihara,
A. Yoshida, G. Liu, T. Kubo, N. Fukunishi, T.
Shimoda, H. Miyatake, M. Sasaki, T. Shirakura,
N. Takahashi, S. Mitsuoka, and W.-D. Schmidt-Ott:"Magnetic moments of 17N and 17B", Phys. Rev. C
53, 2142-2151 (1996).
A. A. Korsheninnikov, E. Yu. Nikolskii, T. Kobay~hi,
A. Ozawa, S. Fukuda, E. A. Kuzmin, S. Momota,
B. G. Novatskii, A. A. Ogloblin, V. Pribora, 1.
Tanihata, and K. Yoshida: "Spectroscopy of the halo
nucleus 11 Li by an experimental study of 11 Li + P
collisions", Phys. Rev. C 53, R537- R540 (1996).
Y. Suzuki, K. Arai, Y. Ogawa, and K. Varga: "Occupation probability of harmonic-oscillator quanta
for microscopic cluster-model wave functions", Phys.
Rev. C 54, 2073-2080 (1996).
T. Nozawa, M. Hashimoto, K. Oyamatsu, and Y.
Eriguchi: "Structure of rotating neutron stars withmeson condensates", Phys. Rev. D 53, 1845- 1852
(1996).
M. Wakamatsu: "Can the SU(3) chiral quark soliton
model describe the nucleon properties better thanthe SU(2) model?", Phys. Rev. D 54, 2161- 2167
(1996).
I. I. Balitsky, V. M. Braun, Y. Koike, and K. Tanaka:"The Cf evolution of chiral-odd twist-3 distributions
hL(x, Q2) and e(x, Q2) in the large-Nc QCD", Phys.
Rev. Lett. 77, 3078-3081 (1996).
K. Matsuta, M. Tanigaki, M. Fukuda, T. Minamisono,
Y. Nojiri, M. Mihara, T. Onishi, T. Yamaguchi,
A. Harada, M. Sasaki, T. Miyake, K. Minamisono,
T. Fukao, K. Sato, Y. Matsumoto, T. Ohtsubo,
S. Fukuda, S. Momota, K. Yoshida, A. Ozawa, T.
Kobayashi, I. Tanihata, J. R. Alonso, G. F. Krebs,
and T. J. M. Symons: "Magnetic moments of proton
drip-line nuclei", Proc. Int. Conf. on Exotic Nuclei
and Atomic Masses, edited by M. de Saint Simon and
O. Sorlin, Editions Frontiers, Gif-sur-Yvette Cedex,
pp. 43-52 (1996).
M. Tanigaki, K. Matsuta, M. Fukuda, T. Minamisono,
Y. Noj iri , M. Mihara, K. Minamisono, T. Fukao,
K. Sato, Y. Matsumoto, T. Ohtsubo, S. Fukuda,
244

S. Momota, K. Yoshida, A. Ozawa, T. Kobayashi,
I. Tanihata, J. R. Alonso, G. F. Krebs, and T. J.
M. Symons: "Quadrupole moment of proton dripline
nucleus 130(F = 3/2-, T 1/2 = 8.6 ms)", Proc. 10th
Int. Conf. on Hyperfine Interactions, edited by M.
Rots, A. Vantomme, J. Dekoster, R. Coussement,
and G. Langouche, J. C. Baltzer AG, Basel, pp. 549552 (1996).
T. Nakamura et al.: "Instrumentation and dosimetryat accelerator facilities", Proc. 9th Int. Congr. on Radiation Protection, Vol. 1, 1996-4, Vienna, Austria,
pp. 123-130 (1996).
. A. A. Gusev, T. Kohno, I. M. Martin, G. I. Pugacheva,
A. Thrtelli, Jr., and A. J. Tylka: "Injection and fastradial diffusion of energetic electrons into the innermagnetosphere", Proc. 24th Int. Cosmic Ray Conf.,
Vol. 4, 1995-9, Rome, Italy, pp. 981-984 (1996).
A. Thrtelli, T. Kohno, U. B. J ayant hi , J. H. Adams
Jr., I. M. Martin, T. Villera, A. Neri, A. A. Gusev,
G. I. Pugacheva, H. Kato, K. Nagata, A. J. Tylka,
and P. R. Boberg: "Anomalous and solar cosmic rayobservations with the first Brazilian Scientific Microsatellite" , Proc. 24th Int. Cosmic Ray Conf., Vol.
4, 1995-9, Rome, Italy, pp. 1275- 1278 (1996).
N. Dinh Dang and F. Sakata: "Damping of hot giant dipole resonance as a linear irreversible process" ,Proc. 2nd Japan-Italy Joint Symp. on Perspectives
in Heavy Ion Physics, edited by M. Ishihara, T.
Fukuda, and C. Signorini, World Scientific, Singapore, pp. 257-268 (1996).
Y. Koike and K. Tanaka:"Perturbative QCD
study of the chiral-odd twist-3 structure function:hL(x, Q2)", Proc. RIKEN Symp. on Spin Structureof the Nucleon, edited by T.-A. Shibata, S. Ohta,
and N. Saito, World Scientific, Singapore, pp. 83-86(1996).
Y. Nishino and K. Tanaka: "Strange matrix elementsof the proton and instantons in QCD" , Proc. RIKEN
Symp. on Spin Structure of the Nucleon, edited by
T.-A. Shibata, S. Ohta, and N. Saito, World Scientific, Singapore, pp. 87-91 (1996).
H. Kurasawa and T. Suzuku: "Double giant dipole
states" , Proc. RIKEN Symp. on Structure of
Medium Nuclei, pp. 141- 150 (1996).
T. Nakamura et al.: "Activation cross-section measurements using quasi-monoenergetic neutron fieldfrom 20 to 150 MeV", Proc. 2nd Specialists' Meet.
on Shielding Aspects of Accelerators, Target and Irradiation Facilities, Nuclear Energy Agency, OECD,
pp. 215- 220 (1996).
S. Yamaji: "The temperature dependent of the friction in the fission", Proc. Specialists' Res. Meet. on
Frontier in Nuclear Fission Research Basic Scienceand Technology, Res. Reactor Inst., Kyoto Univ., pp.
53-62 (1996).
M. Takada, T. Nakamura, T. Shibata, and N. Nakao:"Development of a phoswich counter to detect neutrons and charged particles for space application",

Proc. 1996 Topical Meet. of Radiation Protectionand Shielding, Vol. 1, 1996-4, No. Falmouth, U.S.A.,
pp. 51- 58 (1996).
N. Nakanishi , S. Fujita, M. Watanabe, and S.
Nakajima: "Neutron activation cross sections for
12C, 27 AI, 56Fe, 59Co, 58Ni, and 197 Au for energies
up to 110 MeV", Proc. 1996 Topical Meet. Radiation Protection and Shielding, Vol. 1, 1996-4, No.
Falmouth, U.S.A., pp. 258-265 (1996).
Y. S. Mochizuki, K. Oyamatsu, and T. Izuyama: "Amicroscopic model for physical origin of neutron starglitches" , Proc. Workshop on Astrophysics with Linex- and , -Rays (IV) , pp. 144- 149 (1996).
M. Wakamatsu: "Tracing the origin of the gA problem
in the skyrme model", Prog. Theor. Phys. 95 , pp.
143-173 (1996).
M. Wakamatsu: "Magnetic moments of octet and decuplet baryons in the SU(3) chiral quark soliton
model" , Prog. Theor. Phys. 95 , pp. 767- 778 (1996).
Y. S. Mochizuki, K. Oyamatsu , Y. Izuyama, and I.
Tanihata: "Screened Coulomb potential for exotic
nuclear deformation in neutron star crusts" , RIKEN
Rev., No. 14, pp. 39- 40 (1996).

3.

Atomic and solid-state physics

M. Kimura, I. Shimamura, and M. Inokuti: "Double
and single ionization of He and H2 by slow protons
and antiprotons", Atomic and Molecular Physics,
edited by 1. Alvarez, C. Cisneros, and T. J. Morgan,
World Scientific, Singapore, pp. 243- 246 (1995).
Z. L. Peng and Y. Itoh: "Study of ionic transport inpolymer electrolyte using positron lifetime distribution method", Appl. Phys. A 63 , 267- 270 (1996).
Y. Itoh, H. Murakami, and A. Kinoshita: "Positronj
positronium annihilation in low dimensional siliconmaterials", Appl. Surf. Sci. 102, 423- 426 (1996).
M. Kimura, A. B. Sannigrahi, J. P. Gu, G. Hirsch, R.
J. Buenker, and I. Shimamura: "Charge transfer rate
in collisions of H+ ions with Si atoms" , Astrophys.
J. 473 , 1114-1117 (1996).
J. Z. Tang and I. Shimamura: "Hyperspherical closecoupling approach to single and double photoionization of two-electron systems", Atomic and Molecular Photoionization, edited by A. Yagishita and T.
Sasaki, Universal Academy Press, Tokyo, pp. 223232 (1996).
J. Z. Tang, M. Kimura, and I. Shimamura: "Absorption and emission spectra of alkaline-earth atoms inliquid helium: A theoretical study", Chern. Phys.
Lett. 256, 327- 333 (1996).
M. Takami:"Spectroscopic study of atoms andmolecules in liquid helium", Comments At. Mol.
Phys. 32 , 219- 231 (1996).
I. Watanabe, S. Nakajima, K. Nagase, T. Matsuzaki,
K. Ishida, and K. Nagamine: "J1+SR study on magnetic state of TIBa2 Y 1-xCaxCu20y", Czechoslovak
J. Phys. 46, 2673- 2674 (1996).

K. Matsuta, M. Fukuda, M. Tanigaki, T. Minamisono,
Y. Nojiri, H. Akai, T. Izumikawa, M. Nakazato, M.
Mihara, T. Yamaguchi, A. Harada, M. Sasaki, T.
Miyake, T. Onishi, K. Mina'misono, T. Fukao, K.
Sato, Y. Matsumoto, T. Ohtsubo, S. Fukuda, K.
Yoshida, A. Ozawa, S. Momota, T. Kobayashi, I.
Tanihata, J. R. Alonso, G. F. Krebs, and T. J. M.
Symons: "Hyperfine interaction of 13 0 and 23Mg implanted in Pt", Hyperfine Interact. 97/98 , 501- 508(1996).
T. Briere, R. Kadono, A. Matsushita, and K.
Nagamine: "Theoretical investigation of the structure and associated hyperfine properties of hydrogenic impurities in alkali halides", Hyperfine Interact. C 1 , 17- 20 (1996).
R. Kadono, R. M. Macrae, A. Matsushita, K.
Nishiyama, and K. Nagamine: "Bistability of muonium centers in crystalline Si and Ge probed byphoto-induced J1SR", Hyperfine Interact. C 1, 195198 (1996).
Y. Awaya: "Nuclear power and atomic physics", (inJapanese) , J. At. Energy Soc. Jpn. 38, 337 (1996).
J. Z. Tang and I. Shimamura: "Differential cross sections for photoionization of He", J. Electron. Spectrosc. Relat. Phenom. 79, 259- 261 (1996).
Y. Kobayashi, Y. Yoshida, J. Nakamura, K. Yukihira,K. Hayakawa, C. Yamamoto, A. Yoshida, N. Aoi,
Y. Watanabe, N. Inabe, M. Kase, A. Goto, Y. Yano,
M. Ishihara, and F. Ambe: "Mossbauer spectroscopyusing a 57Mn beam from the RIPS of RIKEN Ring
Cyclotron", JHP-Suppl. 20, 369- 371 (1996).
M. F. V. Lundsgaard, N. Toshima, and C. D. Lin: "Dependence of electron loss cross section on the alignment and orientation of elliptic Rydberg states", J.
Phys. B 29 , 1045- 1062 (1996).
B. D. DePaola, Y. Kanai, P. Richard, Y. Awaya, H.
Schone, J. M. Sanders, J. P. Giese, and T. J. M.
Zouros: "Stark beats from highly charged rydberg
ions created in high-energy beam-foil collisions" , J.
Phys. B: At. Mol. Opt. Phys. 29, 1247- 1262 (1996).
N. Nakamura, Y. Awaya, F. J. Currell, T. Kambara,
Y. Kanai, S. Kitazawa, M. Koide, S. Ohtani, U.
I. Safronova, H. Suzuki, T. Takayanagi , and K.
Wakiya: "Electron spectra from doublet and quartet
states ofN 4 +(ls3131') produced by 60 keV N 6 + + H 2,
O 2 collisions", J. Phys. B: At. Mol. Opt. Phys. 29,
1995- 2006 (1996).
X. Zhao, Y. Itoh, Y. Aoyagi, T. Sugano, K.
Hirata, Y. Kobayashi, T. Ohdaira, R. Suzuki, andT. Mikado: "Positronjpositronium annihilation in
nanocrystalline silicon", J. Radioanal. N ucl. Chern.
211, 31- 38 (1986).
Y. Itoh, Z. L. Peng, A. Goto, N. Nakanishi, M. Kase,K. H. Lee, and Y. Ito: "Production of short-lived
positron sources for spin-polarized positron beams
using a 35 MeV a-beam", Nucl. Instrurn. Methods
Phys. Res. A 383, 272- 276 (1996).
H. Kageyama, K. Kawatsura, R. Takahashi, T. Awata,245

T. Nakae, S. Arai, T. Kambara, M. Oura, T. Papp,
Y. Kanai, Y. Awaya, H. Takeshita, Y. Aoki, S.
Yamamoto, P. Goppelt-Langer, H. Naramoto, Y.
Horino, Y. Mokuno, and K. Fujii: "L X-ray spectra of Fe and Cu by 0.75 MeV ju H, He, Si and Ar
ion impacts", N ud. Instrum. Methods Phys. Res. B
107, 47- 50 (1996).
I. Tanihata and Y. A waya: "RI Beam Facilities for
21-century", (in Japanese), Parity 11 , 39- 41 (1996).
K. Kowari: "Electron degradation and thermalizationin H2 gas" , Phys. Rev. A 53, 853- 866 (1996).
M. Kimura, S. Suzuki, N. Shimakura, J. P. Gu, G.
Hirsch, R. J. Buenker, and I. Shimamura: "Chargetransfer in collisions of B2 +2p) and B 3+ (lS)ions with He atoms below 200 ke V", Phys. Rev. A
54, 3029-3035 (1996).
R. Kadono, R. F. Kieft, W. A. MacFarlane, and S. R .
Dunsiger: "Diffusion and localization of muonium in
Na-doped KCI", Phys. Rev. B 53, 3177- 3182 (1996) .
R. Kadono, H. Okajima, A. Yamashita, K. Ishii , T.
Yokoo, J. Akimitsu, N. Kobayashi , Z. Hiroi, M.
Takano, and K. Nagamine: "Long-range magnetic
ordering in the spin ladder compound LaCu02. 5
probed by muon-spin-relaxation", Phys. Rev. B 54,
R9628- R9630 (1996).
J. 1. Persson , Q. Hui, Z. J. Jakubek, M. Nakamura,and M. Takami: "Formation of AgHe2 exciplex in liquid helium", Phys. Rev. Lett. 76 , 1501- 1504 (1996) .
K. Ando, Y. Zou, T. Kambara, Y. Nakai, Y. Kanai, M.
Oura, Y. A waya, and T. Tonuma: "Lifetime measurements of some 2p 53p and 2p 53d levels in Ne-like
CrXV and FeXVII", Phys. Scr. 53 , 33- 36 (1996).
N. Shimakura, S. Suzuki, Y. Murakami , J. P. Gu,
G. Hirsch, R. J . Buenker, M. Kimura, and I.
Shimamura: "Electron capture and t arget excitationin collisions of Bq+ and Be q+ ions with H and He
atoms at energies below 20 keV ju", Phys. Scr. T 62 ,39- 42 (1996).
Y. D . Wang, N. Toshima, and C. D. Lin: "One- andTwo-electron processes in collisions of He with 105000 keY jamu Beq+ (q = 2 - 4) and Bq+ (q = 2 - 5)ions" , Phys. Scr. T 62 , 63- 68 (1996) .
Z. L. Peng, Y.ltoh, S. Q. Li, and S. J. Wang: "Positron
irradiation effects during positron annihilation lifetime measurement", Phys. Status Solidi A 155, 299303 (1996).
K. H. Lee, Y. Itoh, I. Kanazawa, N. Ohshima, T.
Nakajyo, and Y.lto: "Practical usage of a W moderator for slow positron beam production", Phys. Status Solidi A 157, 93- 98 (1996).
Y. C. Wu, Y. Itoh, and Y. Ito: "Positron annihilation
studies on the interaction between hydrogen and defects in nickel" , Phys. Status Solidi B 193, 307- 310(1996).
S. F. C. O'Rourke, I. Shimamura, and D. S. F.
Crothers: "CDW-EIS calculations for recoil ion
emission in proton-helium collisions", Proc. R. Soc.
London A 452, 175- 184 (1996).

eS,

246

4.

Radiochemistry, radiation chemistry, and radiation biology

S. Y. Chen, S. Ambe, N. Takematsu, and F. Ambe:"Multi tracer study on removal mechanisms of metalelements from seawater", Anal. Sci. 12, 1- 6 (1996).
S. Ambe, M. Iwamoto, H.lVlaeda, and F. Ambe: "Separation of a multitracer from an Au target irradiatedwith high-energy heavy ions by means of a supported
liquid membrane", Anal. Sci. 12, 219- 224 (1996).
R. Amano, S. Oishi, S. Enomoto, and F. Ambe:"Biodistribution of trace elements in normal , AIoverloaded and Cd-overloaded mice: An applicationof the radioactive multi tracer technique" , Ann. Clin.
Lab. Sci. 26 , 531- 541 (1996).
M. Yanaga, S. Enomoto, R. Hirunuma, R. Furuta,
K. Endo, A. Tanaka, S. Ambe, M. Tozawa, and F.
Ambe: "Multitracer study on uptake and excretionof trace elements in rats", Appl. Radiat . Isot. 47,
235- 240 (1996).
Y. Kobayashi , T . Okada, Y. Noro, H. Kitazawa, and
F. Ambe: "Giant magnetic hyperfine field of Ni 2+
ions in spinel chromites", Conf. Proc. ICAME-95,
edited by I. Ortalli, SIF, Bologna, Vol. 50, pp. 283286 (1996).
S. Ambe , T. Okada, and F. Ambe: "Emission
Mossbauer studies of 57Co 2+ and 119Sb5+ adsorbedon ,),-Fe203 and NiFe204 surfaces", II Nuovo Cimento D 18, 313- 317 (1996).
K. Nakagawa, M. Otoda, A. Kimura, D. Nurdiawati,
K . Tanaka, K. Kimura, and A. Ejiri: "A dustermodel to explain the ionization potent ial and energy
positions of photo-current structures of anthracene
doped in supercritical xenon as a function of xenon
density", J. Electron Spectrosc. Relat. Phenom. 78 ,415- 418 (1996).
K. Kimura: "Decay of core exciton and STE formed
at high density in BaF2 and CsCI single crystals",
J. Electron Spectrosc. Relat. Phenom. 79 , 43- 46(1996).
Y. Yoshida, Y. Kobayashi , K. Hayakawa, K. Yukihira,
H. Ha£lein, S. Nasu, J . Nakamura, E. Yagi, Y . Hsia,
and F. Ambe: "In-beam mossbauer study of 57 Fe in
solid Ar and Xe", JHP-Suppl. 20, 359- 362 (1996).
Y. Takahashi, Y. Minai, T. Ozaki, S. Ambe , M.
Iwamoto, H. Maeda, F. Ambe, and T. Tominaga:"Multitracer study on the effect of humate formationon the adsorption behavior of metal ions on kaolinite and silica gel", J . Radioanal. Nucl. Chern. 205,
255- 260 (1996).
S. Ambe, M. Iwamoto, H. Maeda, and F . Ambe: "Multitracer study on adsorption of metal ions on (YFe203", J. Radioanal. Nucl. Chern. 205 , 283- 289(1996).
S. Enomoto, NI. Yanaga, R. Hirunuma, K. Endo, S.
Ambe, and F. Ambe: "Multitracer study on distribution of carrier-free radioactive isotopes in organsof rats", J. Radioanal. Nucl. Chern. 205, 291- 298

(1996).
T. Shinonaga, S. Ambe, S. Enomoto, H. Maeda, M.
Iwamoto , T. Watanabe, and I. Yamaguchi: "Multitracer study on the behavior of various elements
in atmosphere plant-system", J . RadioanaI. NucI.
.Chem. Lett. 212 , 163- 172 (1996).
A. Yokoyama, K . Take sako, T. Saito, H. Baba, Y.
Ohkubo, A. Shinohara, and M. Furukawa: "Limiting
behavior of target fragmentation in the reaction oflanthanide nuclei induced by heavy projectiles", J.
Radioanal. NucI. Chern. Lett. 212,451-459 (1996).
R. Amano, S. Enomoto, M . Nobuta, M . Sakamoto, R.
Tsujioka, and F. Ambe: "Bone uptake of vanadiumin mice: Simultaneous tracing of V, Se, Sr, Y, Zr,
Ru, and Rh using a radioactive multitracer" , J. Trace
Elem. Med. BioI. 10, 145-148 (1996).
K . Kimura: "LET-, ionic species-, and temperaturedependence on Auger-free and self-trapped exciton
luminescence of ion-irradiated BaF 2 and CsCI single
crystals", Nucl. Instrum. Met hods Phys. Res. B 116,
57- 60 (1996).
S. Ambe, T. Shinonaga, T. Watanabe, and I.
Yamaguchi: "Multitracer study on absorption of radionuclides in atmosphere-plant system", Proc. Int .
Workshop on Improvement of Environmental Transfer Models and Parameters, edited by M. J. 'Frissel,
R. M. Brown, and S. Uchida, Tokyo, pp. 267- 273(1996).
K. Matsumoto, T. Watanabe, S. Ambe , and I.
Yamaguchi: "Transcuticular translocation of radionuclides on plant leaf surfaces", Proc. Nuclear
Cross-Over Res. Int. Workshop, Tokyo, pp. 274- 280(1996).
K . Kimura: "Time and depth resolved measurement ofion tracks in condensed matter" , Proc. 10th Workshop on Radiation Detectors and their uses, editedby M. Miyajima and S. Sasaki, KEK , Tsukuba, p.
84 (1996).
T. Abe and S. Yoshida: "Effect of heavy-ion beam on
the specific stages of fertilization cycle of plants",
Radiation & Industries 71 , 63- 66 (1996).
S. Ambe: "Preparation of multitracers", RIKEN Rev.
No. 13, pp. 3- 4 (1996).
S. Ambe, M. Iwamoto, H. Maeda, and F. Ambe: "Multitracer study on adsorption of metal ions on QFe203", RIKEN Rev. No. 13, pp. 9- 10 (1996).
H. Yasuda, S. Ambe, and S. Uchida: "Multitracer
study on sorption of platinum group metals onto
agricultural soils", RIKEN Rev. No. 13, pp. 13- 14(1996).
S. Y . Chen, S. Ambe, N. Takematsu, and F. Ambe:"Multit racer study on removal mechanisms of metalelements from seawater" , RIKEN Rev. No. 13, pp.
15- 16 (1996).
S. Ambe, Y. Ohkubo, Y. Kobayashi , M. Iwamoto,
H. Maeda, and F. Ambe: "Multitracer study ontransport of metal ions in rice and soybean plants",
RIKEN Rev. No. 13, pp. 17-18 (1996).

T. Shinonaga, S. Amba, T. Watanabe, and I.
Yamaguchi: "Multitracer study on behavior of various elements in atmosphere-I?lant system", RIKEN
Rev . No. 13, pp. 19- 20 (1996).
R. Hirunuma, K. Endo, M . Yanaga, S. Enomoto, B.
Liu, S. Ambe, and F. Ambe: "Studies on distribution of radioisotopes in rats using the multitracer
technique", RIKEN Rev. No. 13, pp. 21- 22 (1996).
M. Yanaga, R. Hirunuma, K. Endo, S. Enomoto, B.
Lui, S. Ambe, and F. Ambe: "Uptake and excretionof various elements in rats", RIKEN Rev. No. 13, pp.
23- 24 (1996).
R. Amano, S. Oishi, S. Enomoto, and F. Ambe: "Boneaccumulation of vanadium: Simultaneous tracing of
V , Se, Sr, Y , Zr, Ru, and Rh in mice", RIKEN Rev.
No. 13, pp. 25-26 (1996).
S. Enomoto, M. Yanaga, R. Hirunuma, K. Endo, S.
Ambe, and F. Ambe: "Metabolic and biochemical studies of trace elements in zinc-deficient rats:
Biochemical properties of platinum-group elements" ,RIKEN Rev. No. 13, pp. 27- 28 (1996).
R. Amano, S. Oishi, S. Enomoto, and F. Ambe:"Comparative uptake behavior of trace elements
in normal, AI-overloaded and Cd-overloaded mice",
RIKEN Rev. No. 13, pp. 29- 30 (1996).
S. Enomoto, B. Lui, R. Amano, S. Ambe, and F.
Ambe: "Metabolic and pathological studies on rareearth elements in non-insulin dependent diabetes .
mellitus model mice", RIKEN Rev. No. 13, pp. 3132 (1996).
S. Oishi, R. Amano, A. Ando, S. Enomoto, and F.
Ambe: "Comparative study on biodistribution ofmultitracers in LEC and wistar rats", RIKEN Rev.
No. 13, pp. 33-34 (1996).
B . Lui, S. Enomoto, S. Ambe, R. G. Weginwar, and F.
Ambe: "Study of labeling immunoglobulin G with amultitracer", RIKEN Rev. No. 13, pp. 35-36 (1996).
5.

Material analysis

N. Arai, N. Takai, W. Sakamoto, K. Yoshida, and K.
Maeda: "Fish otoliths analysis by PIXE: Application
to stock determination", Int. J. PIXE 5 , 153- 157(1995).
Y. Ikeda, N. Arai , W. Sakamoto, T. Murayama, K.
Maeda, and K . Yoshida: "Preliminary report on the
PIXE analysis of the squid statoliths" , Int. J. PIXE
5 , 159- 162 (1995).
H. Hamanaka, A. Itoh, Y. Kurosawa, K. Hasegawa,
and K. Maeda: "Influence of sample charging on
satellite spectra of characteristic X-rays from insulating materials" , Proc. 14th Symp. on Materials Science and Engineering Research Center of Ion BeamTechnology, Hosei University, edited by T. Inada, pp.
129- 134 (1995).
N. Arai, W . Sakamoto, and K. Maeda: "Correlation between ambient seawater temperature andstrontium-calcium concentration ratios in otoliths of247

red sea bream Pagrus major", Fisheries Sci. 62, 652653 (1996).
X. Zhao, Y. Itoh, Y. Aoyagi, T. Sugano, K. Hirata, Y.
Kobayashi, T. Ohdaira, R. Suzuki, and T. Mikado:"Positron/positronium annihilation in nanocrystalline silicon thin films", J. Radioanal. Nucl. Chern.
Article 211, 31-38 (1996).
H. Hamanaka, K. Hasegawa, and K. Maeda: "Study ofsample charging effects on satellite spectra of Ca Ka
by means of high-resolution PIXE", N ucl. Instrum.
Methods Phys. Res. B 109/110, 203- 205 (1996).

248

J. Kawai, K. Maeda, N. Sakauchi, and 1. Konishi:"Strong X-ray emission due to electrification", Nucl.
Instrum. Methods Phys. Res. B 109/110, 206- 208(1996).
N. Arai, W. Sakamoto, and K. Maeda: "An attempt toanalyze fish otoliths by in-air PIXE" , N ucl. Instrum.
Methods Phys. Res. B 109/110, 341- 344 (1996).
K. Maeda and H. Hamanaka: "Influence of sample
charging on satellite spectra during particle induced
X-ray emission analysis", Spectrochim. Acta B 51 ,
343- 348 (1996).

VIII. LIST OF PREPRINTS
1996

RIKEN-AF-NP
218 A. Ono and H. Horinouchi: "Antisymmetrized molecular dynamics of wave packets with stochastic incor-

poration of Vlasov equation"
219 I. Tanihata: "Recent studies with radioactive beams at RIKEN"
220 D. Hirata, K. Sumiyoshi, B. V. Carlson, H. Toki, and 1. Tanihata: "Triaxial deformation of unstable nuclei

in the relativistic mean field theory"
221

K. Arai, Y. Ogawa, Y. Suzuki, and K. Varga: "Structure of the mirror nuclei 9Be and 9B in a microscopic
cluster model"

222 N. Sakamoto: "A study of the d-p elastic scattering at Ed = 270 MeV"
223

R. L. Jaffe and N. Saito: "QCD selection rules in polarized hadron collisions"

224 S. Yamaji , F. A. Ivanyuk, and H. Hofmann: "Variation of transport coefficients for average fission dynamics

with temperature and shape"
225

M. Honma, T. Mizusaki, and T . Otsuka: "Nuclear shell model by the quantum Monte Carlo diagonalization
method"226 N. Saito: "Spin physics with PHENIX detector system at RHIC"
227 M. M. Obuti, T. Kobayashi , D. Hirata, Y. Ogawa, A. Ozawa, K. Sugimoto, I. Tanihata, D. Olson, W.

Christie, and H. Wieman: "Interaction cross section and radius of the 8B nucleus"
228

A. Ozawa, 1. Tanihata, T. Kobayahi , Y . Sugahara, O. Yamakawa, K. Ornata, K. Sugimoto, D. Olson, W.
Christie, and H. Wieman: "Interaction cross-section and radii of light nuclei"

229 I. Tanihata: "RI Beam Factory project"
230 F. A. Ivanyuk, H. Hofmann, V. V. Pashkevich, and S. Yamaji: "Collective motion at finite excitations interms of Cassini ovaloids"
231

D. Hirata, K. Sumiyoshi , I. Tanihata, Y. Sugahara, T. Tachibana, and H. Toki: "A systematic study ofeven-even nuclei up to the drip lines within the relativistic mean field framework"

232

A. A. Korsheninnikov, E. A. Kuzmin, E. Yu. Nikolskii, C. A. Bertulani, O. V. Bochkarev, S. Fukuda, T.
Kobayashi, S. Momota, B. G. Novatskii , A. A. Ogloblin, A. Ozawa, V. Privora, I. Tanihata, and K. Yoshida:"Elastic and inelastic scattering of exotic nuclei"

233 A. A. Korsheninnikov, E. Yu. Nikolskii , C. A. Bertulani, S. Fukuda, T. Kobayashi, E. A. Kuzmin, S.

Momota, B. G. Novatskii, A. A. Ogloblin, A. Ozawa, V . Pribora, I. Tanihata, and K. Yoshida: "Scatteringof radioactive nuclei 6He and 3H by proton. Effects of neutron skin and halo in 6He, 8He, and 11 Li"
234 S. Kim and S. Ohta: "Quenched KS light hadron mass at beta = 6.5 on a 64 x 48 3 lattice"
235 A. U. Luccio: "Field map generated matrices for spin tracking"236

A. Ozawa, M. Fujimaki, S. Fukuda, G. Kalnins, S. Momota, T. Suzuki, I. Tanihata, and H. Yamazaki:"Production of a low energy 12B beam and observation of its nuclear polarization"249

237 M. Petrascu, I. Tanihata, T. Kobayashi, A. Isbasescu, H. Petrascu, A. Korsheninnikov, E. Nikolski, S.

Fukuda, H. Kumagai, S. Momota, A. Ozawa, K. Yoshida, C. Bordeanu, I. Lazar, 1. Mihai, G. Vaman, and
M. Giurgiu: "Neutron pre-emission at the fusion of 11 Li halo nuclei with Si target"
238

A. Ozawa, M. Fujimaki, S. Hukuda, S. Ito, T. Kobayashi, S. Momota, T. Suzuki, 1. Tanihata, and K.
Yoshida: "Measurement of the beta-decay branching ratio of 17Ne into the first excited state of 17F"

239 N. D. Dang, A. Arima, T. Suzuki, and S. Yamaji: "Spreading of Gamow-Teller resonance in 90Nb and

208Bi"
240 N. Aoi, K. Yoneda, H. Miyatake, H. Ogawa, Y. Yamamoto, E. Ideguchi, T. Kishida, T. Nakamura, M.
Notani, H. Sakurai, T. Teranishi, H. Wu, S. S. Yamamoto, Y. Watanabe, A. Yoshida, and M. Ishihara:",B-delayed neutron decay of drip line nuclei 11 Li and 14Be"
241 N. Aoi, K. Yoneda, H. Miyatake, H. Ogawa, Y. Yamamoto, E. Ideguchi , T. Kishida, T. Nakamura, M.
Notani, H. Sakurai, T. Teranishi, H. Wu, S. S. Yamamoto, Y. Watanabe, A. Yoshida, and M. Ishihara:",B-spectroscopy of 11 Li and 14Be: With a ,B-n-",("
242 H. Sakurai, N. Aoi, A. Goto, M. Hirai, N. Inabe, M. Ishihara, H. Kobinata, T. Kubo, H. Kumagai, T.
Nakagawa, T. Nakamura, M. Notani, Y. Watanabe, Y. Watanabe, and A. Yoshida: "Production and identification of new neutron-rich nuclei, 31 N e and 37Mg, in the reaction 80 A MeV 50Ti + 181 Ta"
243 I. Tanihata: "Planned storage ring facilities in Japan and China"

244 M. Wakasugi, M. Hies, N. Inabe, T. Katayama, T. Kubo, H. Okuno, S. Ozawa, I. Tanihata, Y. Watanabe,
Y. Yano, and A. Yoshida: "Collinear laser spectroscopy of high-energy Li-like 11 B beam"
245 H. Sakurai, N. Aoi, D. Beaumel, N. Fukuda, M. Hirai, E. Ideguchi, M. Ishihara, H. Iwasaki, T. Kishida, T.

Kubo, H. Kumagai, S. M. Lukyanov, T. Nakamura, M. Notani, Yu. Ts. Oganessian, Yu. E. Penionzhkevich,
T. Teranishi, Y. Watanabe, Y. Watanabe , K. Yoneda, and A. Yoshida: "Search for new neutron-rich with
a 70A MeV 48Ca beam"
246 A. Yoshida, C. Signorini, T. Fukuda, Y. Watanabe, N. Aoi, M. Hirai, M. Ishihara, H. Kobinata, Y. Mizoi,
L. Mueller, Y. Nagashima, J. Nakano, T. Nomura, Y. H. Pu, and F. Scarlassara: "Fusion and breakup at
the barrier with 11 Be"
247 N. D. Dang, A. Arima, T. Suzuki, and S. Yamaji: "Description of Gamow-Teller resonance in heavy nuclei:

Examples with 90Nb and 208Bi''
248 T. Nakamura, T. Motobayashi, Y. Ando, A. Mengoni, T. Nishio, H. Sakurai, S. Shimoura, T. Teranishi, Y.
Yanagisawa, and M. Ishihara: "Coulomb excitation of 11 Be"

250

IX. PAPERS PRESENTED AT MEETINGS
1.

Accelerator 'physics

development

andaccelerator

Y. Yano, T. Katayama, and RARF Accelerator Group:"R1KEN R1 Beam Factory projector", Tamura
Symp. on Accelerator Physics, Austin, U.S.A., Nov.
(1995).
A. Goto: "On the RI Beam Factory project at
R1KEN", 1st Beam Phys. Meet. , Uji, Mar. (1996).
Y. Batygin, A. Goto, and Y. Yano: "Nonlinear beam
dynamics effects in heavy ion transport line", 5thEur. Part. Accel. Conf. (EPAC '96), Barcelona,
Spain, June (1996).
Y. Batygin, A. Goto, and Y. Yano: "Suppressionof space charge induced beam emittance growth intransport line," 5th Eur. Part. Accel. Conf. (EPAC'96), Barcelona, Spain, June (1996).
Y. Batygin, A. Goto, O. Kamigaito, and Y. Yano:"Beam transmission efficiency study at R1KEN RFQ
linac", 5th Eur. Part. Accel. Conf. (EPAC '96) ,Barcelona, Spain, June (1996).
Y. Batygin and T. Katayama: "Merging beam-beamcollisions at RIKEN RI Beam Factory", 5th Eur.
Part. Accel. Conf. (EPAC '96), Barcelona, Spain,
June (1996).
Y. Batygin and T. Katayama: "Beam-beam interaction of electrons and ions at RIKEN RI Beam
Factory", 5th Eur. Part. Accel. Conf. (EPAC '96),
Barcelona, Spain, June (1996).
A. Goto, Y. Yano, and T. Katayama: "R1KEN R1
Beam Factory project," 5th Eur. Part. Accel. Conf.
(EPAC '96) , Barcelona, Spain, June (1996).
O. Kamigaito, A. Goto, Y. Miyazawa, T. Chiba, M.
Hemmi, S. Kohara, M. Kase, Y. Batygin, and Y.
Yano: "Development of a variable-frequency RFQ
linac for the R1LAC," 5th Eur. Part. Accel. Conf.
(EPAC '96), Barcelona, Spain, June (1996).
T. Mitsumoto, A. Goto, T. Kawaguchi, J. W. Kim,
Y. Tanaka, T. Kubo, H. Okuno, T. Tominaka, S.
Fujishima, and Y. Yano: "Design study of sector
magnet for the R1KEN Superconducting Ring Cyclotron (I)", 5th Eur. Part. Accel. Conf. (EPAC '96),
Barcelona, Spain, June (1996).
T. Nakagawa, J. Arje, Y. Miyazawa, M. Hemmi , M.
Kase, T. Kageyama, O. Kamigaito, T. Chiba, N. Inabe, A. Goto, and Y. Yano: "Development of RIKEN
18 GHz ECRIS", 5th Eur. Part. Accel. Conf. (EPAC'96), Barcelona, Spain, June (1996).
M. Okamura, T. Kawaguchi, T. Tominaka, and T.
Katayama: "Three dimensional field analysis of helical snake magnets for RHIC", 5th Eur. Part. Accel.
Conf. (EPAC '96) , Barcelona, Spain, June (1996).
H. Okuno, T. To mi naka , T. Kubo, J.-W. Kim, T.
Mitsumoto, T. Kawaguchi, Y. Tanaka, S. Fujishima,
K. Ikegami, A. Goto, and Y. Yano: "Design study ofthe injection system of the RIKEN Superconducting

Ring Cyclotron", 5th Eur. Pa~t. Accel. Conf. (EPAC'96), Barcelona, June (1996).
Y. N. Rao and T. Katayama: "Intrabeam scatteringof heavy ion in DSR" , 5th Eur. Part. Accel. Conf.
(EPAC '96), Barcelona, Spain, June (1996).
Y. N. Rao, K. Ohtomo, and T. Katayama: "Electron
cooling at ACR" , 5th Eur. Part. Accel. Conf. (EPAC'96), Barcelona, Spain, June (1996).
K. Yoshida and T. Katayama: "Expected luminosity
at MUSES", 5th Eur. Part. Accel. Conf. (EPAC '96),
Barcelona, Spain, June (1996).
Y. J. Yuan, K. Ohtomo, and T. Katayama: "Simulation of rf stacking combined with cooling effects" ,5th Eur. Part. Accel. Conf. (EPAC '96), Barcelona,
Spain, June (1996).
J. W. Xia and T. Katayama: "Lattice for accumulator
cooler ring for MUSES", 5th Eur. Part. Accel. Conf.
(EPAC '96), Barcelona, Spain, June (1996).
O. Kamigaito, A. Goto, Y. Miyazawa, T. Chiba, M.
Hemmi, S. Kohara, M. Kase, Y. Batygin, and Y.
Yano: "Development of a folded-coaxial RFQ linac
for the RILAC", 18th Int. Linac Conf. (LINAC96),
Geneva, Switzerland, Aug. (1996).
A. Goto, Y. Miyazawa, M. Hemmi , O. Kamigaito, T.
Nakagawa, M. Kase, T. Chiba, N. Inabe, S. Kohara, T. Kageyama, Y. Batygin, and Y. Yano: "Newpre-injector system of the RILAC for the RIKEN
RI Beam Factory project", 6th China-Japan Joint
Symp. on Accelerator for Nuclear Science and Their
Applications, Chengtu, China, Oct. (1996).
A. Goto, Y. Yano, and T. Katayama: "RIKEN
RI Beam Factory project", 6th China-Japan Joint
Symp. on Accelerator for Nuclear Science and Their
Applications, Chengtu, China, Oct. (1996).
M. Kase, A. Goto, T. Kageyama, 1. Yokoyama, M.
Nagase, S. Kohara, T. Nakagawa, N. Inabe, K.
Ikegami, O. Kamigaito, J. Fujita, and Y. Yano: "Status report on RIKEN Ring Cyclotron", 6th ChinaJapan Joint Symp. on Accelerator for Nuclear Science and Their Applications, Chengtu, China, Oct.
(1996).
J. W. Kim, S. Fujishima, A. Goto, T. Kawaguchi,
T. Kubo, T. Mitsumoto, H. Okuno, T. Tominaka,
and Y. Yano: "Design study of sector magnet for
the RIKEN Superconducting Ring Cyclotron", Fall
Meet. Korean Phys. Soc., Seoul, Korea, Oct. (1996).
Y. Batygin, A. Goto, and Y. Yano: "Nonlinear
matcher for prevention of emittance growth in spacecharge dominated beams", 14th Int. Conf. on Application of Accelerators in Research and Industry,
Univ. North Texas, Denton, U.S.A. Nov. (1996).
2.

Nuclear physics and nuclear instrumentation

Y. S. Mochizuki: "Glitch problems: Superfluidity andnuclei inside neutron stars", Seminar at Dept. As251

tronomy, Univ. Tokyo, Tokyo, Nov. (1995).
Y. S. Mochizuki, K. Oyamatsu, and T. Izuyama:"Glitch problems: Superfiuidity and nuclei insideneutron stars", Workshop on Astrophysics with LineX- and ,-Rays (IV), Sagamihara, Nov.-Dec. (1995).
N. Saito: "Spin physics with PHENIX detector system
at RHIC", Adriatico Res. Conf. on Trends in Collider
Spin Physics, Trieste, Italy, Dec. (1995).
N. Saito: "Spin physics with PHENIX detector system
at RHIC", RIKEN Symp. on Spin Structure of the
Nucleon, Wako, Dec. (1995).
T. Kohno: "Experimental facility available at current
and future RIKEN", Workshop on high and ultrahigh energy neutrino astrophysics, Irkutsk, Russia,
Dec. (1995).
T. Kishida: "Production of high spin isomer beam",
Grant-in-Aid Symp. on Science of Short-lived Nuclear Beam, Tanashi, Jan . .(1996).
T. Motobayashi, N. Iwasa, T. Kikuchi, Y. Ando, M.
Kurokawa, S. Moriya, H. Murakami, T. Nishio, J.
Ruan (Gen), S. Shimoura, S. Shirato, T. Uchibori,Y. Yanagisawa, N. Inabe, M. Ishihara, T. Kubo, Y.
Watanabe, M. Hirai, T. Nakamura, H. Sakurai, T.
Teranishi, S. Kubono, M. Gai, R. H. France III,K. L Hahn, Z. Zhao, Y. Futami, K. Furutaka, Th.
Delbar, C. Michotte, and P. Lipnik: "Coulomb excitation measurement for 7Be(p,,) BB and missingsolar-neutrino problem", Int. Symp. on Origin of
Matter and Evolution of Galaxies in the Universe,
At ami , Jan. (1996).
S. Yamaji: "The temperature dependence of the friction in the fission", Specialists' Meet. on Frontier in
Nuclear Fission Research Basic Science and Technology, Kumatori, Jan. (1996).
H. Miyatake, T. Shimoda, M. Sasaki, T. Shirakura,
N. Aoi, K. Asahi, H. Ueno, H. Izumi, H. Ogawa, A.
Yoshida, and G. Liu: "Delayed neutron spectroscopy
with using spin polarized RI Beam", Specialists' Res.
Meet. on Scientific and Engineering Researches of
Unstable Nuclei and on Their Nuclear Methodology,
Res. Reactor Inst., Kyoto Univ., Kyoto, Jan. (1996).
H. Miyatake, M. Sasaki, H. Ueno, T. Shimoda, N. Aoi,
T. Shirakura, K. Asahi, H. Izumi, H. Ogawa, G.
Liu, and A. Yoshida: "Delayed neutron spectroscopy
with using spin-polarized neutron-rich nuclei beam",
Symp. on Science with Radioactive Nuclear Beams,
INS, Tokyo, Jan. (1996).
Y. Gono: "Recent development of gamma detector
for nuclear spectroscopy and multi-detectors", 15th
RCNP Osaka Int. Symp. on Nuclear Physics Frontiers with Electro-Weak Probes, Osaka, Mar. (1996).
T. Motobayashi: "Coulomb breakup of BB and Sfactor", 15th RCNP Osaka Int. Symp. on Nuclear
Physics Frontiers with Electro-Weak Probes, Osaka,Mar. (1996).
T. Kishida: "Summary", RIKEN Symp. on ,-ray
spectroscopy and exotic nuclear beams, Wako, Mar.
(1996).
252

E. Kim, T. Nakamura, A. Konno, M. Imamura, T.
Shibata, S. Shibata, N. Nakao, Y. Uwamino, N.
Nakanishi, and S. Tanaka: "Measurements of neutron spallation cross sections", 1996 Spring Meet. At.
Energy Soc. Jpn., Suita, Mar. (1996).
T. Matsuzaki, K. Ishida, S. Nakamura, L Watanabe,
N. Kawamura, M. Tanase, K. Kurosawa, M. Koto,
M. Hashimoto, and K. Nagamine: "Muon catalyzed
fusion experiment at RIKEN-RAL Muon Facility",
1st Workshop of Neutron Science Research Program,
Tokai, Mar. (1996).
K. Asahi: "Physics and applications of stopped radioactive nuclei", 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.- Apr. (1996).
T. Horibata, M. Oi, and N. Onishi: "·Two-dimensional
GCM calculation of TAR states", 51st Ann. Meet.
Phys. Soc. Jpn., Kanazawa, Mar.-Apr. (1996).
T. Kishida; "Study by using the merging beam facil- ity" , 51st Ann. Meet. Phys. Soc. Jpn., Kanazawa,
Mar.- Apr. (1996).
T. Kohno et al.: "International collabolation programof cosmic ray observation on board the first Brazilianscientific micro satellite" ,51st Ann. Meet. Phys. Soc.
Jpn., Kanazawa, Mar.-Apr. (1996).
M. Kurokawa, T. Motobayashi, H. Murakami, Y.
Iwata, T. Uchibori, T. Nomura, J. C. Jeong,
Y. Tagaya, M. Wada, N. Ikeda, S. Kubono, L
Katayama, K. Morita, Y. H. Pu, A. Yoshida,
Y. Nagai, H. Kudo, K. Sueki, H. Nakahara,
T. Shinozuka, M. Fujioka, H. Miyatake, Y. Fujita, T. Shimoda, and K. Tanikawa: "Alpha decay of the evaporation residues produced by the232
40 Ar+Th reaction", 51st Ann. Meet. Phys. Soc.
Jpn., Kanazawa, Mar.-Apr. (1996).
A. Mengoni: "Neutron capture reactions and the structure oflight nuclei", 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.- Apr. (1996).
M. Mihara, M. Fukuda, T. Fukao, M. Tanigaki, T.
Onishi, K. Matsuta, Y. Nojiri, T. Minamisono, T.
Ohtsubo, M. Ishihata, T. Nakamura, S. Fukuda, S.
Ito, T. Kobayashi, S. Momota, A. Ozawa, T. Suzuki,
L Tanihata, and K. Yoshida: "Reaction cross sectionof BB", 51st Ann. Meet. Phys. Soc. Jpn., Kanazawa,
Mar.- Apr. (1996).
Y. Mizoi, T. Fukuda, Y. Matsuyama, J. Nakano, T.
Miyachi, H. Kobinata, Y. Watanabe, Y. Watanabe,
A. Yoshida, H. Sakurai, and K. Kimura: "Development and research of the new MUSIC detector" ,51stAnn. Meet. Phys. Soc. Jpn., Kanazawa, Mar.- Apr.
(1996).
Y. S. Mochizuki, T. Izuyama, and K. Oyamatsu: "Nuclear fusion induced by superfiuid vortices in the neutron star crusts", 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.-Apr. (1996).
T. Motobayashi, T. Kikuchi, N. Iwasa, Y. Ando, M.
Kurokawa, S. Moriya, H. Murakami, T. Nishio, J.
Ruan (Gen), S. Shirato, S. Shimoura, T. Uchibori,Y. Yanagisawa, T. Kubo, H. Sakurai, T. Teranishi,

Y. Watanabe, M. Ishihara, M. Hirai, T. Nakamura,
S. Kubono, M. Gai, R. France III, K. I. Hahn, Th.
Delbar, P. Lipnik, and C. Michotte: "Coulomb dissociation of 8B (2)", 51st Ann. Meet. Phys. Soc. Jpn. ,Kanazawa, Mar.- Apr. (1996).
T. Motobayashi: "Nuclear astrophysics at the RI
Beam Factory", 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.-Apr. (1996).
N. Nishimori , K. Sagara, T. Fujita, F. Wakamatsu, H.
Akiyoshi , T. Bussaki, K. Tsuruta, H. Nakamura, K.
Maeda, and T. Nakashima: "Comparison b etween
Ay of n-d and p-d scatt erings at 12 MeV" , 51st Ann.
Meet. Phys. Soc. Jpn. , Kanazawa, Mar.- Apr. (1996).
M. Oi, N. Onishi , and T. Horibata: "Angular momentum projection of the tilted axis rotating states",
51st Ann. Meet. Phys. Soc. Jpn. , Kanazawa, Mar.Apr. (1996).
K. Oyamatsu and Y. S. Mochizuki: "The equation ofstate of nuclear matter and the moment of inertia of
the neutron star crust" , 51st Ann. Meet. Phys. Soc.
Jpn. , Kanazawa, Mar.-Apr. (1996).
A. Ozawa, S. Ito, T. Kobayashi, T. Suzuki, I. Tanihata,
S. Fukuda, M. Fujimaki, S. Momota, K. Yoshida,
G . Munzenberg, and G. Kraus: "Measurement of,B-decay branching rat io of 17Ne into the first excited state of 17F", 51st Ann. Meet. Phys . Soc. Jpn. ,Kanazawa, Mar.-Apr. (1996) .
Y. H. Pu, K. Morita, M. G. Hies, O. K. Lee, A.
Yoshida, T. Nomura, Y. Tagaya , T. Uchibori , T.
Motobayashi , Y . Minemura, T. Ariga, K. Sueki, and
A. Shin: "Synthesis of new isotope 196Rn by heavyion reactions", 51st Ann. Meet. Phys. Soc. Jpn. ,Kanazawa, Mar.- Apr. (1996).
T. Uesaka, T. Wakui, M. Wakasugi , and Y. Yano: "Development of polarized 3He target at RIKEN (II) ",51st Ann. Meet . Phys. Soc. Jpn. , Kanazawa, Mar.Apr. (1996) .
M. Wakasugi: "Measurement of nuclear charge radiiand electromagnetic moments at MUSES", 51stAnn. Meet. Phys. Soc. Jpn. , Kanazawa , Mar.- Apr.
(1996).
Y. Yanagisawa, T . Motobayashi, S. Shimoura, K. Ieki,
Y. Ando, H. Murakami, Y. Iwata, T. Kikuchi , T.
Nishio, S. Moriya, T. Nakamura, T. Teranishi, N.
Aoi, M. Notani , H. Ishihara, and J. Peter: "Coulomb
excitation of 56Ni" , 51st Ann. Meet. Phys. Soc. Jpn. ,Kanazawa, Mar.- Apr. (1996).
K. Yoneda, N. Aoi, H. Miyatake, H. Ogawa, Y.
Yamamoto, E . Ideguchi , T. Kishida, T. Nakamura, M. Not ani, H. Sakurai, T. Teranishi, S. S.
Yamamoto, Y. Watanabe, A. Yoshida, and M. Ishihara: "Beta decay of 11 Li", 51st Ann. Meet. Phys.
Soc. Jpn. , Kanazawa, Mar.- Apr. (1996).
A. Yunoki, T. Katoh, H. Okada, K. Teras awa, N.
Fukuda, T. Kozu, J. Kikuchi , T. Doke, K. Masuda,
E. Shibamura, I. Tanihata, and M. Kase: "Development of a LAr ionization chamber with excellent energy resolution for heavy ion energy measurement" ,51st Ann. Meet. Phys. Soc. Jpn., Kanazawa, Mar.Apr. (1996).
A. Mengoni, T. Otsuka, T. Nakamura, and M.
Ishihara: "Exotic properties ~f light nuclei and theirneutron capture cross sections", Int. Seminar on Interaction of Neutrons with Nuclei, Dubna, Russia,
Apr. (1996).
A. Mengoni: "Photon production and absorption inlight nuclei" , 2nd Res. Co-ordination Meet. on Measurement, Calculation and Evaluation of Proton Production Data, IAEA, Vienna, Austria, May (1996).
Y . S. Mochizuki: "Glitch problems: Superfiuidity andnuclei inside neutron stars" , Seminar at CoIl. Art
Sci. , Univ. Tokyo, Tokyo, May (1996).
A. Mengoni, T. Otsuka, T. Nakamura, and M.
Ishihara: "Exotic structure of light nuclei and theirneutron capture reaction rates", Int. Conf. Nuclei in
the Cosmos, Notre Dame, U.S.A., June (1996).
N. Aoi, K. :Yoneda, H. Miyatake, H. Ogawa, Y.
Yamamoto, E. Ideguchi, T. Kishida, T. Nakamura,
M. Notani, H. Sakurai, T. Teranishi, H. Wu, S.
S. Yamamoto, Y. Watanabe, A. Yoshida, and M.
Ishihara: ",B-spectroscopy of 11 Li and 14Be" , 4thInt. Conf. on Radioactive Nuclear Beams (RNB-4),
Omiya, June (1996).
Y. S. Mochizuki , K. Oyamatsu, and T. Izuyama: "Amicroscopic model for the origin of neutron starglitches", 4th Int. Conf. on Radioactive Nuclear
Beams (RNB-4) , Omiya, June (1996).
T. Motobayashi, T. Kikuchi, N. Iwasa, Y. Ando, M.
Kurokawa, S. Moriya, H. Murakami, T. Nishino, J.
Ruan (Gen) , S. Shirato, S. Shimoura, T. Uchibori,Y. Yanagisawa, T . Kubo, H. Sakurai, T. Teranishi,
Y. Watanabe, M. Ishihara, M. Hirai, T. Nakamura,
S. Kubono , M. Gai, R. France III, K. I. Hahn, Th.
Delbar, P. Lipnik, and C. Michotte: "New measurement of 8B Coulomb dissociation and E2 component" , 4th Int. Conf. on Radioactive Nuclear Beams(RNB-4) , Omiya, June (1996).
K. Oyamatsu and Y. S. Mochizuki: "Symmetry energy
at subnuclear densities and nuclei in neutron starcrusts", 4t h Int. Conf. on Radioactive Nuclear Beams(RNB-4) , Omiya, June (1996).
H. Sakurai et al.: "Search for new neutron-rich nuclei
with a 70 A MeV 48Ca beam", 4th Int. Conf. onRadioactive Nuclear Beams (RNB-4) , Omiya, June
(1996) .
S. Shimoura, T. Teranishi , Y. Ando, M. Hirai, N.
Iwasa, T. Kikuchi, S. Moriya, T. Motobayashi, T.
Murakami , T. Nakamura, T. Nishino, H. Sakurai,
T. Uchibori, Y. Watanabe, Y. Yanagisawa, and M.
Ishihara: "Charge exchange reaction of the neutronhalo nucleus 11 Li" , 4th Int. Conf. on Radioactive Nuclear Beams (RNB-4) , Omiya, June (1996).
T. Suzuki: "Nuclear radii of Na and Mg isotopes" . 4th
Int. Conf. on Radioactive Nuclear Beams (RNB--!).
Omiya, June (1996).
Y. S. Mochizuki: "Glitch problems: Superfluidity and253

nuclei inside neutron stars" , Seminar at Adv. Res.
Center for Sci. Eng. , Waseda Univ. , Tokyo , June
(1996).
T. Motobayashi: "Measurement of the E2-component
in the Coulomb dissociation of BB", 4th Int. Symp.
on Nuclear Astrophysics (NIC96) , Notre Dame,
U.S.A., June (1996).
Y. Gono, T. Morikawa, T. Kishida, E. Ideguchi , T.
Murakami, S. Mitarai , A. Odahara, M. Kidera, M.
Shibata, H. Tsuchida, H. Watanabe, M. Oshima, H.
Kusakari, M. Sugawara, H. Y. Wu, and M. Ishihara:"High-spin isomer beams at RIKEN" , Int. Workshop
on Isomeric Beams: Why and How? G ANIL, Caen,
France, June (1996).
T. Kishida, Y. Gono, E. Ideguchi, T. Morikawa, M.
Kidera, M. Shibata, H. Tsuchida, K. Miyazaki, H.
Watanabe, H.-Y. Wu, A. Tanokura, S. S. Yamamoto,
A. Yoshida, S. Mitarai, A. Odahara, T. Murakami,
M. Oshima, H. Kusakari, M. Sugawara, M. Kubo, T .
Murata, M. Shimura, H. Kumagai, and M. Ishihara:"High spin isomer beam line at RIKEN" , Conf. on
Nuclear Structure at the Limits, Argonne, U.S.A. ,July (1996).
N. Aoi, K. Yoneda, H. Miyatake, H. Ogawa, Y.
Yamamoto, E. Ideguchi, T. Kishida, T. Nakamura,
M. Notani, H. Sakurai, T. Teranishi, H. Wu, S.
S. Yamamoto, Y. Watanabe, A. Yoshida, and M.
Ishihara: ",6-delayed neutron decay of drip line nuclei 11 Li and 14Be", Int. Conf. on Nuclear Structurearound the Turn of the Century, Crete, Greece, July
(1996).
K. Tanaka and K. Sugawara-Tanabe: "Origin of the.6.1=2 staggering in superdeformed states", Int . Conf.
on Nuclear Structure around the Turn of the Century, Crete, Greece, July (1996) .
K. Sugawara-Tanabe: "Magnetic dipole transitions insuper deformed shape nuclei", Int. Conf. on Nuclear
Structure around the Turn of the Century, Crete,
Greece, July (1996).
Y. S. Mochizuki: "Glitch problems: Superfiuidity andnuclei inside neutron stars", Seminar at Cosmic Radiation Lab. , RIKEN, Wako, July (1996).
T. Kohno: "Radiation measurements with Japanesespacecraft", Seminar at Univ. Alabama Huntsville,
Huntsville, U.S.A. , July (1996).
A. Mengoni, T. Otsuka, T. Nakamura, and M.
Ishihara: "Halo structure of 11 Be from its Coulomb
dissociation", Gull Lake Conf. on Nuclear Physics
near the Drip Lines, Gull Lake, U.S.A. , Aug. (1996).
T. Suzuki: "Matter radii of N a and Mg isotopes" , Talk
Presented in Physics of Unstable Nuclear Beams, Sao
Paulo, Brazil, Aug. (1996).
E. Kim, T. Nakamura, M. Imamura, T . Shibata, S.
Shibata, N. Nakao, Y. Uwamino, S. Tanaka, and Y.
N akane: "Measurements of neutron spallation crosssections (2) " , 1996 Fall Meet. At. Energy Soc. Jpn. ,Sendai, Sept. (1996).
K. Yuasa-Nakagawa, T. Nakagawa, K. Yoshida, K.
254

Furutaka, K. Matsuda, Y. Futami, X. Liu, Y. Aoki,
S. M. Lee, J. Kasagi, D. X. Jiang, T. Suomijarvi,
W. Q. Shen, T. Wada, S. Yamaji , and Y. Abe: "Dynamical effect and angular momentum dependenceof fission phenomena in medium mass nuclei" , 3rdInt. Conf. on Dynamical Aspects of Nuclear Fission,
Casta-Papiernicka, Slovak Republic, Sept. (1996).
M. Wakasugi, M. Hies, N. Inabe~ T. Katayama,
T. Kubo, H. Okuno, S. Ozawa, I. Tanihata, Y.
Watanabe, Y. Yano, and A. Yoshida: "Collinear
laser spectroscopy of high-energy Li-like 11 B beam",
8th Int. Conf. on the Physics of Highly Charged Ions
(HCI-96) , Omiya, Sept. (1996).
M. Wakamatsu: "BARYON structure based on theSU(3) chiral quark soliton model", 13th Int . Seminaron High Energy Physics Problem, Dubna, Russia,
Sept. (1996).
I. I. Balitsky, V. M . Braun, Y. Koike, and K. Tanaka:"Q2 evolution of chiral-odd twist-3 distributionsh L (x,Q2) and e(x,Q2) in the large-Nc limit", 12th
Int. Symp. on High.. Energy Spin Physics, Amsterdam, The Net herlands, Sept. (1996).
H. En'yo: "Spin physics at RHIC" , 12th Int. Symp. on
High-Energy Spin Physics , Amsterdam, The Netherlands, Sept. (1996).
N. Hayashi , Y. Goto, and N. Saito: "Possible measurements of the gluon polarizat ion in the nucleon with
the PHENIX detector system", 12th Int. Symp. on
High-Energy Spin Physics , Amsterdam, The Netherlands, Sept. (1996).
M. Hirai, S. Kumano, and M. Miyama: "Numericalsolution of NLO Q2 evolutions equations for spindependent structure functions", 12th Int. Symp. on
High-Energy Spin Physics , Amsterdam, The Netherlands, Sept. (1996).
Y. Koike and N. Nishiyama: " Q2-evolution of chiralodd twist-3 structure function and fragmention function: e(x, Q2) and e(z, Q2)", 12th Int. Symp. on HighEnergy Spin Physics, Amsterdam, The Netherlands,
Sept. (1996).
N. Saito: "Measurements of anti-quark polarizations
with PHENIX detector system at RHIC" , 12th Int.
Symp. on High-Energy Spin Physics , Amsterdam,
The Netherlands, Sept. (1996) .
T. Yamanishi and T. Morii: "Test of .6.g in spin correlations between target protons and produced A+ c
at the COMPASS experiments", 12th Int. Symp. on
High-Energy Spin Physics , Amsterdam , The Netherlands, Sept. (1996).
A. Arima, N. Dinh Dang, T. Suzuki, and S. Yamaji:"Study of Gamow-Teller resonance in 20Bpb taking lplh-2p2h configuration mixing and ground-statecorrelations beyond RPA into account", Int. Symp.
on Non-Nucleonic Degrees of Freedom Detected in
Nucleus, Osaka, Sept. (1996).
A. Ozawa, M. Fujimaki, S. Fukuda, G. Kalnins, S.
Momota, T. Suzuki, I. Tanihata, and H. Yamazaki:"Production of a low energy 12B beam and observa-

tion of its nuclear polarization", Int. Symp. on Nonnucleonic Degree of Freedom Detected in Nucleus,
Osaka, Sept. (1996).
H. Kurasawa and T. Suzuki: "Nuclear response to electromagnetic field", Int. Symp. on Non-nucleonic Degrees of Freedom Detected in Nucleus, Osaka, Sept.
(1996).
M. Hirai, S. Kumano, and M. Miyama: "Numerical solution for Q2-evolution equations", RHIC-SPIN
Meet., Marseille, France, Sept. (1996).
S. Kumano: "Light antiquark flavor asymmetry u-d" ,RHIC-SPIN Meet., Marseille, France, Sept. (1996).
T. Kohno: "Scientific programs on Japanese experiment module" , Round Table of Int. Sch. Space Science, L'Aquila, Italy, Sept. (1996).
Y. Goto: "PHENIX studies on direct photons", RSC
Ann. Meet. , Marseille, France, Sept. (1996).
N. Hayashi: "Gluon spin via charmonium production
at PHENIX", RSC Ann. Meet. , Marseille, France,
Sept. (1996).
N. Saito: "Physics probes Wand Z: PHENIX studies",
RSC Ann. Meet. , Marseille, France, Sept. (1996).
N. Saito: "New theoretical ideas ATT/ALL ", RSC
Ann. Meet. , Marseille, France, Sept. (1996).
Y. Gono, T . Morikawa, T. Kishida, E. Ideguchi, T .
Murakami, S. Mitarai, A. Odahara, M. Kidera, M.
Shibata, H. Tsuchida, H. Watanabe, M. Oshima, H.
Kusakari , M. Sugawara, H. Y. Wu, and M. Ishihara:"A germanium counter telescope for studies of highspin states with HSIB" , 7th Franco-Japonais Colloq.
on Frontier and Perspective of Nuclear Science, Dogashima, Sept.- Oct. (1996).
N. Saito: "RHIC spin project" , Circum-Pan-PacificWorkshop on High Energy Spin Physics, Kobe, Oct.
(1996).
H. Okamura, T. Uesaka, T. Wakasa, Y. Satou,
T. Ohnishi, T. Nonaka, H. Sakai, S. Ishida, N.
Sakamoto, T. Ichihara, T. Niizeki, and H. Ohnuma:" 90Z r (d,2He) 90y reaction at 270 MeV", 1996 Fall
Meet. APS Division of Nuclear Physics, Cambridge,
U.S.A. , Oct. (1996).
Y. Satou: "Measurement of the 12C (d, d') reaction at
Ed = 270 MeV", 1996 Fall Meet. APS Division of
Nuclear Physics, Cambridge, U.S.A. , Oct. (1996).
Y. S. Mochizuki: "Vortex pinning to nuclei in neutronstar crusts" , Fall Meet. Astron. Soc. Jpn. , Mizusawa,Oct. (1996).
T. Ariga, M. G. Hies, M. Wakasugi, K. Morita, Y.
Pu, W. G. Jin, T. Murayama, T. Ishizuka, H.
Katsuragawa, and T. Inamura: "Development of an
on-line laser ion source using resonance ionization
at RIKEN GARIS/IGISOL", 1996 Fall Meet. Phys.
Soc. Jpn., Saga, Oct. (1996).
M. Fukuda, M. Mihara, T. Fukao, M. Tanigaki, T.
Onishi, K. Matsuta, Y. Nojiri, T. Minamisono,
T. Ohtsubo, S. Fukuda, S. Ito, T. Kobayashi, S.
Momota, A. Ozawa, T. Suzuki, I. Tanihata, K.
Yoshida, M. Ishihara, and T. Nakamura: "Reaction

cross sections for 8B and its density distribution",
1996 Fall Meet. Phys. Soc. Jpn., Saga, Oct. (1996).
T. Horibata, M. Oi, and N. Onishi: "Two-dimensional
GCM calculation of TAR states II", 1996 Fall Meet.
Phys. Soc. Jpn., Saga, Oct. (1996).
E. Ideguchi, Y. Gono, S. Mitarai, T. Morikawa, A.
Odahara, M. Kidera, M. Shibata, H. Tsuchida, T.
Kishida, M. Oshima, Y. Hatsukawa, S. Hamada, H.
Iimura, T . Ishii, and M. Ishihara: "High-spin statesin 146Eu" , 1996 Fall Meet. Phys. Soc. Jpn., Saga,
Oct. (1996).
T. Matsuzaki, K. Ishida, S. N. Nakamura, I. Watanabe,
K. Nagamine, N. Kawamura, M. Iwasaki, M. Tanase,
M. Kato, K. Kurosawa, G. H. Eaton, P. Wright, R.
Hall, D. Haynes, W. A. Morris, G. Thomas, and H.
J. Jones: "Muon catalyzed fusion experiment in D~T
mixture at RIKEN-RAL Muon Facility (1): Experimental facility" , 1996 Fall Meet. Phys. Soc. Jpn.,
Saga, Oct. (1996).
K. Ishida, T. Matsuzaki, S. N. Nakamura, K.
Nagamine, N. Kawamura, S. Sakamoto, M. Tanase,
M. Kato, K. Kurosawa, and G. H. Eaton: "Muoncatalyzed fusion experiment in D-T mixture at
RIKEN-RAL Muon Facility (2): X-ray measurementof a-sticking probability" , 1996 Fall Meet. Phys. Soc.
Jpn. , Saga, Oct. (1996).
N. Kawamura, T. Matsuzaki, K. Ishida, S. N.
Nakamura, K. Nagamine, S. Sakamoto, M. Tanase,
M. Kato, K. Kurosawa, K. Kudo, and G. H. Eaton:"Muon catalyzed fusion experiment in D-T mixture at RIKEN-RAL Muon Facility (3): Fusion neutron measurement" , 1996 Fall Meet. Phys. Soc. Jpn.,
Saga, Oct. (1996).
T. Kubota and M. Wakamatsu: "ISO SPIN asymmetryof qij sea in the nucleon based on the chiral quark soliton model" , 1996 Fall Meet. Phys. Soc. Jpn., Saga,
Oct. (1996).
T. Matsuzaki , K. Nagamine, K. Ishida, S. Nakamura,
I. Watanabe, N. Kawamura, M. Iwasaki, M. Tanase,
K. Kurosawa, M. Kato, M. Hashimoto, G. H. Eaton,
P. Wright , R . Hall, D. Haynes, W. A. Moriis, G.
Thomas, and H. J. Jones: "Experimental apparatus
for advanced DT muon catalyzed fusion research at
RIKEN-RAL Muon Facility", 1996 Fall Meet. Phys.
Soc. Jpn. , Saga, Oct. (1996).
M. Mihara, M. Fukuda, T. Fukao, M. Tanigaki, T.
Onishi, K. Matsuta, Y. Nojiri, T. Minamisono, T.
Ohtsubo, M. Ishihata, T. Nakamura, S. Fukuda, S.
Ito, T. Kobayashi , S. Momota, A. Ozawa, T. Suzuki,
I. Tanihata, K. Yoshida, and Y. Ogawa: "Momentum distribution of 7Be produced in 8B fragmentation" , 1996 Fall 1feet. Phys. Soc. Jpn., Saga, Oct.
(1996).
Y. S. Mochizuki, T. Izuyama, and I. Tanihata: "Amodel for nuclear fusion induced by superfluid vortices in neutron star crusts", 1996 Fall Meet. Phys.
Soc. Jpn., Saga, Oct. (1996).
M. Notani et al.: "Search for new neutron-rich nuclei
255

with a 70 A MeV 48Ca beam", 1996 Fall Meet. Phys.
Soc. Jpn., Saga, Oct. (1996).
M. Oi, N. Onishi, N. Tajima, and T. Horibata: "Riemann surface for the Euler angle space of overlap kernel of TAR state", 1996 Fall Meet. Phys. Soc. Jpn.,
Saga, Oct. (1996).
T. Onishi, K. Matsuta, M. Fukuda, M. Mihara, M.
Sasaki, T. Yamaguchi, T. Miyake, K. Sato, K.
Minamisono, Y. Nojiri, T. Minamisono, T. Otsubo,
A. Ozawa, S. Fukuda, S. Momota, K. Yoshida, T.
Suzuki, T. Kobayashi, I. Tanihata, G. F. Krebs, J. R.
Alonso, and T. J. M. Symons: "Electric quadrupole
moment of 23Mg", 1996 Fall Meet. Phys. Soc. Jpn.,
Saga, Oct. (1996).
K. Oyamatsu: "From masses and radii of unstable nuclei to the neutron star structure", 1996 Fall Meet.
Phys. Soc. Jpn., Saga, Oct. (1996).
S. Ozawa, T. Ariga, M. G. Hies, N. Inabe, T.
Katayama, T. Kubo, H. Okuno, I. Tanihata, M.
Wakasugi, Y. Watanabe, Y. Yano, and A. Yoshida:"Collinear laser spectroscopy of 11 B 2+" , 1996 Fall
Meet. Phys. Soc. Jpn., Saga, Oct. (1996).
H. Sato, M. Tsuda, A. Yoshimi, K. Sakai, M. Adachi,
K . Asahi, H. Izumi, H. Ogawa, N. Kurokawa,
H. Okuno, T . Kubo, S. Fukuda, A. Yoshida, M.
Ishihara, K. Yoneda, and M. Notani: "Polarizationof short-lived nuclei by means of polarized 129Xe
solid stopper", 1996 Fall Meet. Phys. Soc. Jpn., Saga,
Oct. (1996).
Y. Suzuki, K. Arai, Y. Ogawa, and K. Varga: "Occupation probability of harmonic-oscillator quanta for
microscopic cluster-model wave functions", 1996 Fall
Meet. Phys. Soc. Jpn., Saga, Oct. (1996).
M. Tsuda, H. Sato, A. Yoshimi, K. Sakai, M. Adachi,
and K. Asahi: "Polarization of 129Xe by means ofdiode-laser optical pumping", 1996 Fall Meet. Phys.
Soc. Jpn., Saga, Oct. (1996).
M. Wakamatsu: "EXTENDED Nambu-Jona-Lasiniomodel and hidden local symmetry of low energy
QCD" , 1996 Fall Meet. Phys. Soc. Jpn., Saga, Oct.
(1996).
A. Yunoki, T. Katoh, Y. Piau, K. Ozaki, H. Okada,K. Terasawa, J. Kikuchi, T. Doke, K. Masuda, E.
Shibamura, I. Tanihata, M. Kase, and M. Niimura:"Development of a LAr ionization chamber with excellent energy resolution for heavy ion energy measurement II" , 1996 Fall Meet. Phys. Soc. Jpn., Saga,
Oct. (1996).
K. Asahi: "Test of time-reversal violation with polarized 129Xe", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
T. Kohno: "Summary of scientific satellite OHZORA",
Int. Standard Org. 5th ISO/TC20/SC14/WG4Meet., Pasadena, U.S.A., Oct. (1996).
A. Mengoni, T. Otsuka, T. Nakamura, and M.
Ishihara: "Neutron capture and neutron halos", Int.
Symp. on Capture ,-Ray Spectroscopy and Related
Topics, Budapest, Hungary, Oct. (1996).
256

T. Nakagawa, K. Yuasa-Nakagawa, K. Yoshida, K.
Furutaka, K. Matsuda, Y. Futami, X. Liu, Y. Aoki,
S. M. Lee, J. Kasagi, D. X. Jiang, T. Suomijarvi, W.
Q. Shen, T. Wada, S. Yamaji, and Y. Abe: "Angularmomentum dependence of prescission time and mass
distribution for medium mass nuclei", Int. Symp.
on Large-scale Collective Motion of Atomic Nuclei,
Brolo, Italy, Oct. (1996).
K. Oyamatsu: "Nuclei in nuclear reactors and stars" ,Specialists' Meet. on Frontier in Nuclear Fission Research, Basic Science and Technology, Res. Reactor
Inst., Kyoto University, Kyoto, Oct. (1996).
T. Kohno: "Other scientific proposal for JEM" , Symp.
on Space Station Experiment JEM-EC for Cosmic
Nuclei, Tokyo, Oct. (1996).

3.

Atomic and solid-state physics

L. Engstrom, R. Hutton, S. Huldt" I. Kink, I.
Martinson, B. Nystrom, K. Ando, Y. Awaya, P.
Bengtsson, T. Kambara, Y. Kanai, T. M. Kojima,
and Y. Nakai: "The lifetime of the 3s3p 3P 1 levelof high Z Mg-like ions", Ann. Meet. Swedish Phys.
Soc. , Uppsala, Sweden, Nov. (1995).
K. Kimura: "Time- and depth-resolved measurementsof ion tracks in condensed matter", Symp. on Radiation Detectors and Their Uses, Tsukuba, Jan.
(1996).
Y. Kobayashi, Y. Yoshida, J. Nakamura, K. Yukihira,K . Hayakawa, S. Nasu, E. Vagi, Y. Watanabe, A.
Yoshida, N. Aoi, M. Ishihira, N. Inabe, M. Kase,
A. Goto, Y. Yano, and F. Ambe: "Mossbauer spectroscopy using a 57Mn beam from the RIPS of
RIKEN Ring Cyclotron", Symp. on Science with Radioactive Nuclear Beams, Tanashi, Jan. (1996).
Y. Yoshida, Y. Kobayashi, K. Hayakawa, K. Yukihira,K. HaBlein, S. Nasu, J. Nakamura, E. Vagi, Y. Hsia,
and F. Ambe: "In-beam Mossbauer Study of 57Fe in
Solid Ar and Xe" , Symp. on Science with Radioactive Nuclear Beams, Tanashi , Jan. (1996).
A. Igarashi: "Muon-transfer reaction between hydrogenic atoms in excited states t + dj..£ (n = 2) -+tj..£ (n = 2) + d", 4th RIKEN Symp. on the Theory ofAtomic and Molecular Processes, Wako, Jan. (1996).
M. Kimura: "What would cross sections for heavyparticle collisions behave below MeV regime?", 4th
RIKEN Symp. on the Theory of Atomic and Molecular Processes, Wako, Jan. (1996).
J. Z. Tang: "Dynamics of atoms in liquid helium" ,4th
RIKEN Symp. on the Theory of Atomic and Molecular Processes, Wako, Jan. (1996).
P. Bengtsson: "Spectroscopy of heavy-highly-charged
ions using beam-foil method", RIKEN Symp. on
Studies on Condensed Matter Physics, Atomic
Physics, Nuclear Chemistry, and Biology andMedicine Using RIKEN Accelerators, Wako, Feb.
(1996).

T. Kambara: "Comments on RIKEN accelerator
future projects from non-nuclear physics fields",
RIKEN Symp. on Studies on Condensed Matter
Physics, Atomic Physics , Nuclear Chemistry, andBiology and Medicine Using RIKEN Accelerators,
Wako, Feb. (1996).
Y. Kanai: "Experimental study of ion-atom collisions
by using low energy ions from ECRIS", RIKEN
Symp. on Studies on Condensed Matter Physics,
Atomic Physics, Nuclear Chemistry, and Biology andMedicine Using RIKEN Accelerators, Wako, Feb.
(1996).
M. Matsuda and T. Kambara: "Heavy-ion irradiation effects of high-temperature super conductors",
RIKEN Symp. on Studies on Condensed Matter
Physics, Atomic Physics, Nuclear Chemistry, andBiology and Medicine Using RIKEN Accelerators,
Wako , Feb. (1996).
Y. Kobayashi, Y. Yoshida, J . Nakamura, K. Yukihira,K. Hayakawa, S. Nasu, E. Vagi, Y. Watanabe, A.
Yoshida, N. Aoi, M. Ishihara, N. Inabe, M. Kase ,A. Goto, Y. Yano, R. Sielemann, H. HaBlein, A.
Feinauer, and F. Ambe: "In-beam Mossbauer spectroscopy in RIKEN accelerator research facility" ,RIKEN Symp. on Studies on Condensed Matter
Physics, At omic Physics, Nuclear Chemistry, andBiology Using RIKEN Ring Cyclotron, Wako, Feb.
(1996).
Y. Awaya and Y. Kanai: "Impact parameter dependence of double-electron capture processes in
low-energy highly-charge ion collisions", Symp. on
the Physics of Highly-Charged Ions, Niigata, Mar.
(1996) .
I. Watanabe, K. Kumagai, S. Nakajima, K. Nagase,
T. Matsuzaki , S. N. Nakamura, and K. Nagamine:"p,+SR st udy on the magnetic properties of TI- andLa-systems high-TC superconductor", Workshop on
the Neut ron Science Projects, JAERI, Mar. (1996).
P. Bengtsson , K . Ando , T. Kambara, Y. Kanai, T.
M. Kojima, Y. Nakai , Y. Awaya, L. Engstrom, R.
Hutton, I. Kink, I. Martinson, and B. Nystrom: "Int ercombinat ion lines in highly charged ions", 51stAnn. Meet. Phys. Soc. Jpn. , Kanazawa, Mar.- Apr.
(1996).
R. Hutt on, L. Engstrom, S. Huldt , B. Nystrom, I.
Mart inson, K . Ando,P. Bengtsson, T. Kambara, T .
M. Kojima, Y. Nakai, and Y. Awaya: "Observationof a systematic deviation between experimental andtheoretical lifet imes for the 3s3p 3P 1 level of highZ Mg-like ions", 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.- Apr. (1996).
A. Igarashi: "Theoretical study of positron scattering by atoms", 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.-Apr. (1996).
Y. Kanai, Y. Nakai, K. Soejima, T. M. Kojima, T.
Kambara, and Y. Awaya: "Present status of the
RIKEN 14.5 GH z ECRIS" , 51st Aim. Meet. Phys.
Soc. Jpn. , Kanazawa, Mar.- Apr. (1996).

S. Kaneko, H. Sawada, H. Sakata, N. Nishida, T.
Mochiku, K. Kadowaki, T. Kambara, and Y. Awaya:"Investigations of boundary effects in high-Tc superconductors using LT-STS", 51st Ann. Meet. Phys.
Soc. Jpn., Kanazawa, Mar.- Apr. (1996).
K. Kimura, T . Morita, Y. Yoshioka, W. Sekiguchi,
M. limura, and W. Hon: "Bragg curve of nearliquid rare gasses", 51th Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.-Apr. (1996).
T. M. Kojima, M. Bannister, X.-Q. Guo, and G.
Dunn: "Electron-impact dissociation of DCO+ into
CO+ fragment" , 51st Ann. Meet. Phys. Soc. Jpn.,
Kanazawa, Mar.- Apr. (1996).
J. Nakamura, I. Watanabe, K. Asai, H. Anbe, and K.
Nagamine: "Fel.lsSb studied by p,+SR", 51st Ann.
Meet. Phys. Soc. Jpn., Kanazawa, Mar.- Apr. (1996).
T. Okada, Y. Noro, Y. Kobayashi, H. Kitazawa, J.
Nakamura, and F. Ambe: "Relation between thehyperfine magnetic field of 61 Ni and crystal distortion II" , 51st Ann. Meet. Phys. Soc. Jpn., Kanazawa,
Mar.- Apr. (1996).
H. Takeuchi, H. Sato, J. Z. Tang, M. Kimura, and I.
Shimamura: "Potential-energy curves of the alkaliHe and alkaline-earth-He systems", 51st Ann. Meet.
Phys. Soc. Jpn., Kanazawa, Mar.- Apr. (1996).
Y. Tamagawa, M. Kagawa, D. Chiba, R. Yamamoto,
K . Wakiya, T. Takayanagi, Y. Kanai, and Y.
Awaya: "Study of multiply excited highly charged
ions formed by collisions with neutral atoms using
toroidal electron energy analyzer" , 51st Ann. Meet.
Phys. Soc. Jpn. , Kanazawa, Mar.-Apr. (1996).
J . Z. Tang, M. Kimura, and I. Shimamura: "Dynamics
of alkali atoms in liquid helium", 51st Ann. Meet.
Phys. Soc. Jpn. , Kanazawa, Mar.-Apr. (1996).
G. Tatara, M. Matsuda, K. Katsumata, T. Kambara,
Y. Awaya, T. Mitamura, M. Terasawa, Y. Endoh, K.
Yamada, and S. Hosoya: "Heavy-ion irradiation effect on mixed state of LA1.8SSrO.lSCu04 single crystal", 51st Ann. Meet. Phys. Soc. Jpn., Kanazawa,
Mar.- Apr. (1996).
K. Uematsu, H. Sato, M. Kimura, and I. Shimamura:"Computations of doubly excited electronic states ofthe H2 molecules" , 51st Ann. Meet. Phys. Soc. Jpn. ,Kanazawa, Mar.- Apr. (1996).
N. Wat anabe, T. Kambara, Y. Nakai , T. M. Kojima,
and Y. Awaya: "Recoil ion momentum spectroscopy
in 6 MeV B 4 + -He collisions", 51st Ann. Meet. Phys.
Soc. Jpn. , Kanazawa, Mar.-Apr. (1996).
I. Watanabe, S. Nakajima. K. Nagase, T. Matsuzaki,
S. N. Nakamura, and K. Nagamine: "p,SR on
TIBa2 Y l - xCaxCU20y in the magnetically orderedphase", 51st Ann. Meet. Phys. Soc. Jpn., Kanazawa,
Mar.- Apr. (1996).
I. Watanabe, S. Nakajima, K. Nagase, T. Matsuzaki,
S. N. Nakamura, and K. Nagamine: "p,SR on related materials to high-TC superconductors (2)" ,51st Ann. Meet. Phys. Soc. Jpn., Kanazawa, ~Iar. ­Apr. (1996).
257

E. Vagi and S. Koike: "State of hydrogen in Nb-Mo
alloys", 51st Ann. Meet. Phys. Soc. Jpn., Kanazawa,
Mar.- Apr. (1996).
A. Yamashita, H. Okajima, K. Ishii, J. Akimitsu, R.
Kadono, N. Kobayashi, Z. Hiroi, M. Takano, and K.
Nagamine: "ILSR on LaCu02.5 " , 51st Ann. Meet.
Phys. ~oc. Jpn., Kanazawa, Mar.- Apr. (1996).
J. Akimitsu, H. Okajima, A. Yamashita, K. Ishii,
T. Yokoo, R. Kadono, N.· Kobayashi, Z. Hiroi, M.
Takano, and K. Nagamine: "Appearence of longrange magnetic ordering in the spin ladder compound LaCu02.5", 7th Int. Conf. on Muon Spin Rotation/Relaxation/Resonance, Nikko, Apr. (1996).
T. Briere, T. P. Das, R. Kadono, A. Matsushita,
and K. Nagamine: "Structure and associated hyperfine properties of hydro genic centers in potassium bromide" , 7th Int. Conf. on Muon Spin Rotation/Relaxation/Resonance, Nikko, Apr. (1996).
R. Kadono, R. M. Macrae, K. Nishiyama, and K.
Nagamine: "Muonium centers in crystalline Ge under illumination", 7th Int. Conf. on Muon Spin Rotation/Relaxation/Resonance, Nikko, Apr. (1996).
R. Kadono, R. M. Macrae, and K. Nagamine: "Muonium centers in heavily n-doped Si under illumination: Evidence for Mu-hole interaction", 7thInt. Conf. on Muon Spin Rotation/Relaxation/Resonance , Nikko, Apr. (1996).
R. Kadono, 1. Watanabe, and K. Nagamine: "Quantum diffusion of positive muon in pure tantalum", 7th Int. Conf. on Muon Spin Rotation/Relaxation/Resonance, Nikko, Apr. (1996).
R. M. Macrae, R. Kadono, F. L. Pratt, K. Tanigaki,
K. Nishiyama, and K. Nagamine: "Longitudinal field
repolarization studies of reorientational dynamics inthe fullerenes C 60 and C 70 ", 7th Int. Conf. on Muon
Spin Rotation/Relaxation/Resonance, Nikko, Apr.
(1996).
M. Matsuda, K. Katsumata, 1. Watanabe, and K.
Nagamine: "ILSR measurement.s of BaNi03", 7thInt. Conf. on Muon Spin Rotation/Relaxation/Resonance, Nikko, Apr. (1996).
1. Watanabe, S. Nakajima, K. Nagase, T. Matsuzaki,
S. N. Nakamura, and K. Nagamine: "Observationof magnetic ordered state in TlBa2 Y l - xCaxCU20y
by IL+SR" , 7th Int. Conf. on Muon Spin Rotation/Relaxation/Resonance, Nikko, Apr. (1996).
Y. Kobayashi, Y. Yoshida, K. Hayakawa, K. Yukihira,S. Nasu , J. Nakamura, E. Vagi, and F. Ambe: "Inbeam Mossbauer spectroscopy in materials science
with RI Beam at RIKEN", 4th Int. Conf. on Radioactive Nuclear Beams (RNB-4) , Omiya, June
(1996).
Y. Itoh, Z.-L. Peng, Y. Itoh, A. Goto, N. Nakanishi,
and M. Kase: "Slow positron production using
RIKEN AVF Cyclotron III" , 33rd Ann. Meet. on Radioisotopes in the Physical Sciences and Industries,
Tokyo, July (1996).
K. Kimura: "Fast dynamics of core and self-trapped<

258

excitons formed at high density in iontracks in BaF 2
and CsCI single crystal", Gordon Res. Conf. on Radiation Chemistry, Newport, U.S.A., July (1996).
Q. Hui , J. L. Persson, Z. J. Jakubek, M.-P. Coquard,
M. Nakamura, and M. Takami: "Formation and dynamics of Ag-He2 exciplex in liquid helium", 20thInt. Quantum Electronics Conf. , Sydney, Australia,
July (1996).
Y. Kasai, N. Yonekura, Q. Hui, M. Nakamura, G.
RouilIe, and M. Takami: "Laser spectroscopy ofmolecules in superfluid helium", 20th Int. Quantum
Electronics Conf. , Sydney, Australia, July (1996).
Z. J. Jakubek, Q. Hui, and M. Takami: "Spectroscopyof silver in cold helium gas (T~4-25 K)", 20th Int.
Quantum Electronics Conf. , Satelite Meet. , Cairns,
Australia, July (1996).
M. Kimura and 1. Shimamura: "Multiple ionization of
He and Ne by slow protons and antiprotons", ITAMP
Workshop on Exotic Atoms, Harvard, U.S.A., July
(1996).
1. Shimamura: "Introduction: Atomic processes associated with antiprotonic atoms", ITAMP Workshop
on Exotic Atoms, Harvard, U.S.A. , July (1996).
1. Watanabe, S. Nakajima, K. Nagase, T. Matsuzaki,
S. N. Nakamura, and K. Nagamine: "J.L+SR study
on magnetic ordered state of TlBa2 Yl-xCaxCU20y",
21st Int . Conf. on Low Temperature Physics (LT21),
Prague, Czech Republic , Aug. (1996).
1. Watanabe, S. Nakajima, K. Nagase, T. Matsuzaki,
S. N. Nakamura, and K. Nagamine: "IL+SR study
on superconducting and magnetic ordered states ofTIBa2 Y l - xCaxCU20y" , Int. Conf. on Physics andChemistry of Molecular and Oxide Superconductors(MOS'96) , Karlsruhe, Germany, Aug. (1996).
E. Vagi and S. Koike: "Site occupancy change of hydrogen in Nb on alloying with undersized Mo atoms",
Int. Symp. on Metal-Hydrogen Systems, Fundamentals and Applications, Les Diablerets, Switzerland,Aug. (1996).
T. Kambara, A. Igarashi, N. Watanabe , Y. Nakai, T.
M. Kojima, and Y. Awaya: "Recoil ion momentum
analyses for 0.5- 1 MeV /u B - He collisions", 21st
Meet. Soc. for Atomic Collision Research, Tokyo,
Aug. (1996).
H. Tsuchida, H. Suzuki, M. Miyabe, M. Imai, A. Itoh,
N. Imanishi , Y. Nakai, T. Kambara, and Y. Awaya:"Fragmentation processes of C 60 by fast charged particles", 21st Meet. Soc. for Atomic Collision Research, Tokyo, Aug. (1996) .
K. Kimura: "Dynamical studies on exciton reactions
formed at high-density in some insulator crystals by
ion irradiation", 8th Int. Conf. on Phys. of Highly
Charged Ions (HCI-96) , Omiya, Sept. (1996).
N. Toshima: "Couple-channel study of collision processes involving highly-charged ions" , 8th Int. Conf.
on the Physics of Highly Charged Ions (HCI-96),
Omiya, Sept. (1996).
P. Bengtsson, K. Ando, T. Kambara, Y. Awaya, and R.

Hutton: "Intercombination lines in highly .charged
ions AI-like and Si-like ions", 8th Int. Conf. on the
Physics of Highly Charged Ions (HCI-96), Omiya,
Sept. (1996).
M. Imai, M. Sat aka, Y. Yamazaki, K. Komaki, K.
Kawatsura, and Y. Kanai: "Electron spectra fromhighly excited Si ions", 8th Int. Conf. on the Physics
of Highly Charged Ions (HCI-96), Omiya, Sept.
(1996).
K. Ishii, T. Nishida, Y. Kimura, M. Fujiwara, T.
Nakano, S. Kawae, K. Ando, and T. Kambara:"Beam-foil spectra of highly charged Neon ions invisible region", 8th Int. Conf. on the Physics ofHighly Charged Ions (HCI-96), Omiya, Sept. (1996).
K. Ishii, T. Nishida, Y. Kimura, M. Fujiwara, T.
Nakano, S. Kawae, K. Ando, and Y. Awaya: "Beamfoil spectra of highly charged Argon ion in visible
region", 8th Int. Conf. on the Physics of Highly
Charged Ions (HCI-96), Omiya, Sept. (1996).
T. Kambara: "Recoil-ion momentum spectroscopy offast collisions with HCI", 8th Int. Conf. on the
Physics of Highly Charged Ions (HCI-96), Omiya,
Sept. (1996).
K. Kawatsura, M. Sat aka, M. Imai, K. Komaki, Y.
Yamazaki, K. Kuroki, Y. Kanai, and N. Stolterfoht:"Charge state dependence of very low projectile autoionizing transitions from 2 Me V IuS + He collisions", 8th Int. Conf. on the Physics of Highly
Charged Ions (HCI-96), Omiya, Sept. (1996).
M. Kimura, A. B. Sannigrahi, J. P. Gu, G. Hirsch,R. J. Buenker, and I. Shimamura: "Charge transfer
in collisions of H+ ions with Si atoms below keYenergies", 8th Int. Conf. on the Physics of Highly
Charged Ions (HCI-96), Omiya, Sept. (1996).
M. Kimura, S. Suzuki, N. Shimakura, J. P. Gu, G.
Hirsch, R. J. Buenker, and I. Shimamura: "Chargetransfer in collisions of B 2+(2S,2P) and B 3+eS) ionswith He atoms below 200 keV" , 8th Int. Conf. on the
Physics of Highly Charged Ions (H CI-96) , Omiya,
Sept. (1996).
M. Matsuda, G. Tatara, K. Katsumata, T. Kambara,
Y. Awaya, T. Mitamura, M. Terasawa, K. Yamada,
Y. Endoh, and S. Hosoya: "Heavy-ion irradiation
effects on the single crystal La1.8SSrO.lSCu04", 8thInt. Conf. on the Physics of Highly Charged Ions
(HCI-96), Omiya, Sept. (1996).
T. Mitamura, M. Terasawa, X. Fan, T. Kohara, K.
Ueda, T. Kambara, Y. Awaya, M. Matsuda, and
G. Tatara: "Heavy-ion irradiation effects on the
super-conducting material, La1.8SSrO.lSCu04", 8thInt. Conf. on the Physics of Highly Charged Ions
(HCI-96), Omiya, Sept. (1996).
Y. Nakai, A. Itoh, T. Kambara, Y. Bitoh, and Y.
A waya: "Mass correlation of fragment ions in fast
C 5 + -C 60 collision", 8th Int. Conf. on the Physics ofHighly Charged Ions (HCI-96), Omiya, Sept. (1996).
M. Sataka, M. Imai, K. Komaki, Y. Yamazaki, K.
Kawatsura, Y. Kanai, H. Tawara, D. R. Schultz, andC. O. Reinhold: "Binary peak electrons observed ato degree for 0.5- 1.0 MeV lu Agq+ and Au q+ ions incollision with a He target", 8th Int. Conf. on the
Physics of Highly Charged Ions (HCI-96), Omiya,
Sept. (1996).
Y. Tamagawa, D. Chiba, T. Takayanagi, K. Wakiya, Y.
Kanai, T. Kambara, and Y. Awaya: "Toroidal spectrometer for measurement of emitted electron spectra arising from collisions between highly charged
ions and neutral atoms", 8th Int. Conf. on the
Physics of Highly Charged Ions (HCI-96) , Omiya,
Sept. (1996).
J. Akimitsu: "Magnetic ordering in spin ladder compounds", RIKEN Symp. on Muon Science '96, Wako,
Sept. (1996).
K. Ishii, T. Nishida, Y. Kimura, M. Fujiwara, S.
Kawae, T. Nakano, K. Ando, and T. Kambara:"Rydberg transitions of highly charged Neon ion in
beam-foil collision", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
K. Kimura, T. Kohama, D. Kawakami, and W.
Hon: "Excitation-density and temperature enhanced
decay of self-trapped excitons in ion irradiatedBaF 2 crystal", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
K. Kimura: "Depth-differential excimer dynamics
along ion tracks of rare gases", Symp. on Phys. ofcollision of cluster system, 1996 Fall Meet. Phys. Soc.
Jpn., Yamaguchi, Oct. (1996).
M. Kimura, I. Shimamura, J. P. Gu, G. Hirsch, and
R. J. Buenker: "Electron capture in H+ + C, N,
0, Si collisions", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi , Oct. (1996).
A. Koyama, A. Yoneda, K. Ogiwara, and M. Uda:
"TEMPERATURE dependence of AI-LVV auger
electron spectra I", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
Y. Nakai: "Fragmentation of C 60 by fast ion impactcoincidence measurement with the charge changeof projectiles", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
T. Okada, H. Kitazawa, J. Nakamura, Y. Kobayashi,
and F. Ambe: "s7Fe Mossbauer effect of CuGe03",
1996 Fall Meet. Phys. Soc. Jpn., Yamaguchi, Oct.
(1996).
Y. Tamagawa, D. Chiba, T. Takayanagi, K. Wakiya,
Y. Kanai, T. Kambara, and Y. A waya: "Measurements of angular distribution for emitted electronenergy analyzer", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
J. Z. Tang, I. Shimamura, M. Kimura, H. Takeuchi,
and H. Sato: "Spectroscopy of alkaline atoms
in liquid-He", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
N. Toshima: "Theory of relativistic ion-atom collisions", 1996 Fall Meet. Phys. Soc. Jpn., Yamaguchi,
Oct. (1996).
T. Wakui, K. Hasegawa, S. Haga, T. Takagi, H.
259

Uematsu, W. G. Jin, T. Minowa, H. Katsuragawa, and M. Wakasugi: "Atomic beam diodelaser spectroscopy", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
X. Fan, M. Terasawa, T. Mitamura, T. Kohara, K.
Ueda, H. Tsubakino, T. Kambara, M. Matsumoto,G. Tatara, and Y. Awaya: "Magnetic propertiesof La1.85SrO.15Cu04 irradiated by swift heavy-ions",
1996 Fall Meet. Phys. Soc. Jpn., Yamaguchi, Oct.
(1996).
I. Watanabe, S. Nakajima, K. Nagase, T. Matsuzaki, S.
N. Nakamura, F. L. Pratt, and K. Nagamine: "ttSR
on TIBa2 Yl-xCaxCU20y in the magnetic and superconducting phase", 1996 Fall Meet. Phys. Soc. Jpn.,
Yamaguchi, Oct. (1996).
Z. J. Jakubek, Q. Hui, .and M. Takami: "Ag-He interaction in superfluid helium and cold helium gas",
12th Interdisciplinary Laser Sci. Conf., Rochester,
U.S.A., Oct. (1996).
Q. Hui, J. L. Persson, Z. J. Jakubek, M. Nakamura,and M. Takami: "Formation of AgHe2 exciplex inliquid helium" , Int. Symp. on Atomic and Molecular
Physics III, Pohang, Korea, Oct. (1996).
Y. Kasai, Q. Hui, M. Nakamura, and M. Takami: "Detection of macromolecules in superfluid helium bylaser induced dispersed fluorescence", Int. Symp. on
Atomic and Molecular Physics III, Pohang, Korea,
Oct. (1996).
A. Igarashi: "Scattering of a photon and a positron byatoms" ,5th RIKEN Symp. on the Theory of Atomic
and Molecular Processes, Yamaguchi, Oct. (1996).
I. Shimamura: "Theory of electron scattering", 5th
RIKEN Symp. on the Theory of Atomic and Molecular Processes, Yamaguchi, Oct. (1996).
Y. Kobayashi, Y. Yoshida, K. Yukihira, K. Hayakawa,
J. Nakamura, E. Yagi, S. Nasu, and F. Ambe: "Inbeam Mossbauer spectroscopy in materials science
with the RIKEN accelerators", 40th Symp. on Radiochemistry, Wako, Oct. (1996).
J. Nakamura, T. Okada, Y. Noro, Y. Kobayashi, H.
Kitazawa, and F. Ambe: "Correlation between huge
hyperfine magnetic field and quadrupole splitting
at Jahn-Teller Ni 2+ ion in CU1-x 61 NixCr204", 40th
Symp. on Radiochemistry, Wako, Oct. (1996).
T. Okada, H. Kitazawa, J. Nakamura, Y. Kobayashi,
and F. Ambe: "57 Fe Mossbauer spectroscopy of
CU1-xFexGe03", 40th Symp. on Radiochemistry,
Wako, Oct. (1996).
Y. Awaya: "X-rays emitted by heavy ions passing
through the target foils", 13th RIKEN Symp. on
Atomic Physics Using Accelerators, Wako, Nov.
(1996).
M. Matsuda, T. Kambara, and G. Tatara: "Material irradiation by the Ring Cyclotron" ,13th RIKEN
Symp. on Atomic Physics Using Accelerators, Wako,
Nov. (1996).
Y. Nakai: "Fragmentation of C60 molecule by heavy
ion impact", 13th RIKEN Symp. on Atomic Physics
260

Using Accelerators, Wako, Nov. (1996).
A. Igarashi: "Positron scattering with atoms", Meet.
of the Recent Progress in Positron Spectroscopy,
Tokyo, Dec. (1996).

4.

Radiochemistry, radiation chemistry, and radiation biology

S. Ambe, T. Okada, and F. Ambe:"Emission
Mossbauer studies of 57 C02+ and 119Sb5 + adsorbed
on ,-Fe203 and NiFe204 surfaces", Int. Conf. on the
Applications of the Mossbauer Effect, Rimini, Italy,
Sept. (1995).
Y. Takahashi, Y. Minai, T. Ozaki, S. Ambe, M.
Iwamoto, H. Maeda, F. Ambe, and T. Tominaga:"Multitracer study on influence of metal-humatecomplexation on adsorption of trace elements onclay minerals, silica gel, and hematite", Int. Chem.
Congr. Pacific Basin Soc. (Pacifichem '95), Honolulu,
U.S.A., Dec. (1995).
S. Yoshida, T. Abe, S. Kumata, and T. Torashima:"Effect of heavy-ion beam on the specific stages offertilization cycle of plants" , 6th Radiation Process
Symp., Tokyo, Jan. (1996).
S. Ambe, T. Shinonaga, T. Watanabe, and I.
Yamaguchi: "Multitracer study on absorption of radionuclides in atmosphere-plant system", Int. Workshop on Improvement of Environmental Transfer
Models and Parameters, Tokyo, Feb. (1996).
K. Matsumoto, T. Watanabe, S. Ambe, and I.
Yamaguchi: "Absorption and translocation of radionuclides on plant leaf surfaces", 34th Ann. Meet.
At. Energy Soc. Jpn., Osaka, Mar. (1996).
R. Hirunuma, K. Oda, K. Endo, M. Yanaga, S.
Enomoto, S. Ambe, and F. Ambe: "The effects ofvitamin D on the uptake of trace elements in rats" ,116th Ann. Meet. Pharm. Soc. Jpn., Kanazawa, Mar.
(1996).
N. Ito, H. Narita, Y. Saito, K. Kimura, T. Yaita, S.
Tachimori, S. Ambe, and F. Ambe: "Substituent effect of N, N-dialkyl aliphatic amides on their extraction of noble metals", 70th Spring Meet. Chern. Soc.
Jpn., Tokyo, Mar. (1996).
S. Enomoto, B. Liu, R. G. Weginwar, S. Ambe, and
F. Ambe: "Distribution and pathological studies ofrare-earth elements in diabetes mellitus mice", 9thInt. Symp. on Trace Elements in Man and Animals,
Banff, Canada, May (1996).
S. Enomoto, B. Liu, R. G. Weginwar, S. Ambe, and F.
Ambe: "Multitracer study on the uptake of inorganic
ions by tumor", 9th Int. Symp. on Trace Elements
in Man and Animals, Banff, Canada, May (1996).
S. Enomoto, R. G. Weginwar, B. Liu, S. Ambe, and F.
Ambe: "Biodistribution of gold complexes in mice" ,9th Int. Symp. on Trace Elements in Man and Animals, Banff, Canada, May (1996).
R. Hirunuma, K. Endo, S. Enomoto, S. Ambe, and
F. Ambe: "The effects of vitamin D on behavior

of various trace elements in rat", 8th Symp. on
Roles of Metals in Biological Reactions, Biology andMedicine, Hiroshima, May (1996).
T. Ozaki, S. Enomoto, Y. Minai , S. Ambe, F. Ambe,and T. Tominaga: "STUDY on the accumulation
and roles of rare earth element in ferns by multitracer technique and neutron activation analysis",
8th Symp. on Roles of Metals in Biological Reactions,Biology and Medicine, Hiroshima, May (1996).
N. Sotogaku, R. Hirunuma, K. Endo, S. Enomoto,
S. Ambe, and F. Ambe: "Influence of pH on themetal-binding of various serum-protein investigatedby means of multi tracer technique", 8th Symp. on
Roles of Metals in Biological Reactions, Biology andMedicine, Hiroshima, May (1996).
A. Higashi, T. Kanai, H. Tomura, Y. Futami,
N. Matsufuji, A. Itano, H. Karashima, and Y.
Hishikawa: "Rotatable proton gantry bY' using wobbIer method", 13th Ann. Meet. Jpn. Assoc. Med.
Phys. , Suita, July (1996).
K. Eguchi-Kasai, M. Murakami, H. Itsukaichi , K.
Fukutsu, T. Kanai, K. Sato, and F. Yatagai: "DNArepair and cell killing by charged particles" , 31st Sci.
Ass. of COSPAR, Birmingham, U.K. , July (1996).
A. Higashi, T. Kanai, H. Tomura, Y. Futami, and N.
Matsufuji: "Test experiment by using 160 and 210
Me V proton at RIKEN", 1st Workshop on Charged
Particle Therapy System, Chiba, July (1996) .
M. Suzuki, Y. Kase, T. Kanai, K. Ando , M. Watanabe,
and F. Yatagai: "LET dependence of chromatin
breakage induced by heavy-ion" , 10th Ann. Meet.
Biological Sciences in Space, Kyoto, Sept. (1996).
R. Hirunuma, K. Endo, S. Enomoto, S. Ambe, and
F. Ambe: "Application of the multitracer technique:Effect of vitamin D on distribution of various elements in rats", 4t h Int. Conf. on Nuclear and Radiochemistry, St. Malo , France, Sept. (1996).
Y. Takahashi, Y. Minai, S. Ambe, H. Maeda, F. Ambe,and T. Tominaga: "Multitracer study on stability
constants of humates with various metal ions", 4thInt. Conf. on Nuclear and Radiochemistry, St Malo,
France, Sept. (1996).
T. Ozaki, S. Enomoto, Y. Minai, S. Ambe, F. Ambe,and T. Tominaga: "STUDY on the trace elements inferns" , 60th Ann. Meet. Botanic. Soc. Jpn. , Fukuoka,
Oct. (1996).
C. H. Bae, T. Abe, and S. Yoshida: "Characteristics ofsalt-tolerant plants induced by heavy-ion beams irradiation" , 31st Ann. Meet. Soc. Chern. Reg. Plants,
Kyoto, Oct. (1996).
Y. Einaga, O. Sato, T. Iyoda, Y. Kobayashi, F. Ambe,
K. Hashimoto, and A. Fujishima: "Mossbauer study
on photo-induced and cation driven electron transfer
in a cobalt-iron cyanide", 40th Symp. on Radiochemistry, Wako, Oct. (1996).
R. Hirunuma, Y. Okamoto, N. Sotogaku, K. Endo,
S. Enomoto, S. Ambe, and F. Ambe: "Comparisonof behavior of trace elements between vitamin D-

overloaded and deficient rats using the multitracer
technique", 40th Symp. on Radiochemistry, Wako,
Oct. (1996).
N. Ito, Y. Okamoto, N. Kimura, H. Narita, T. Yaita,
S. Tachimori, S. Ambe, and F. Ambe: "Multitracer
study on the extraction of noble metals with N,
N-dialkyl aliphatic amides", 40th Symp. on Radiochemistry, Wako, Oct. (1996).
T. Ozaki, S. Enomoto, Y. Minai, S. Ambe, F. Ambe,and Y . Makide: "STUDY on the absorption of traceelements into plants by multitracer technique", 40th
Symp. on Radiochemistry, Wako, Oct. (1996).
K. Mukai , A. Yokohama, S. Morimoto, T. Saito, H.
Baba, Y. Ohkubo, A. Shinohara, T. Muroyama,
M. Furukawa, and S. Kojima: "Momentum Transfer in the Reaction Systems of 14N + 165Ho and
40 Ar + 141 Pr at Intermediate Energies" ,40th Symp.
on Radiochemistry, Wako, Oct. (1996).
A. Shinohara, T. Muroyama, A. Yokoyama, S.
Morimoto, T. Saito, Y. Ohkubo, S. Shibata, S.
Kojima, F. Ambe, H. Baba, and M. Furukawa: "Linear Momentum Transfer in the Heavy-Ion Reactionof Copper at Intermediate and High Energies" ,40thSymp. on Radiochemistry, Wako, Oct. (1996).
N. Sotogaku, R. Hirunuma, K. Endo, S. Enomoto, S.
Ambe, and F. Ambe "The bio-trace element-bindingof various serum-protein investigated by means ofmultitracer technique", 40th Symp. on Radiochemistry, Wako, Oct. (1996).
Y. Takahashi , Y. Minai, S. Ambe, F. Ambe, and
Y. Makide: "Multitracer study on the interactionof various metal ions with humic acid and polycarboxylic acids", 40th Symp. on Radiochemistry,
Wako, Oct. (1996).
A. Higashi, T. Kanai, H. Tomura, Y. Futami, and N.
Matsufuji: "Experimental results by using 160 and
210 MeV proton beam at RIKEN", 3rd Workshop
on Charged Particle Therapy System, Chiba, Oct.
(1996).
F. Yatagai , Y. Kagawa, M. Hirano, N. Inabe,
K. Eguchi-Kasai, Y. Furusawa, M. Suzuki, M.
Watanabe, T. Kato, and F. Hanaoka: "Analysis
of mutations in the human HPRT gene induced byheavy-ion irradiation", 25th Ann. Meet. Jpn. Environmental Mutagenesis Soc., Tokyo, Nov. (1996).
S. Koike, K. Anndou, C. Yujan, T. Ariga, N. Hori, M.
Iizuka, T. Kanai, and F. Yatagai: "Skin shrinkage
caused by neon-20 and carbon-12" , 39th Ann. Meet.
Jpn. Rad. Res. Soc. , Osaka, Nov. (1996).
H. Sasaki, F. Yatagai, Y. Furusawa, T. Kanai, F.
Hanaoka, W.-G. Zhu, and P. Meiinati: "LET dependence of interphase cell-death induction by accelerated heavy-ions", 39th Ann. Meet. Jpn. Rad. Res.
Soc. , Osaka, Nov. (1996).
S. Tsubouchi, K. Fukutsu, H. Itsukaichi, K. EguchiKasai, Y. Furusawa, M. Murakami, T. Kanai, S.
Koike, K. Ando, A. Kawano, S. Matsushita, H.
Oohara, F. Yatagai, and E. Kano: "Dose response re261

· lations in acute cell death of pancreatic islets after irradiation of golden hamster with X-ray, 70 MeV proton and 290 Me V carbon beams", 39th Ann. Meet.
Jpn. Rad: Res. Soc., Osaka, Nov. (1996).
F. Yatagai, T. Shimazu, Y. Kagawa, M. Hirano , N.
Inabe, K. Eguchi-Kasai, Y. Furusawa, M. Suzuki,
M. Watanabe, T. Kato, and F. Hanaoka: "Analysis
of mutations in the human HPRT gene induced byheavy-ion irradiation II", 39th Ann. Meet. Jpn. Rad.
Res. Soc., Osaka, Nov. (1996).

5.

Material analysis

Y. Itoh, H. Murakami, and A. Kinoshita: "Positron/
positronium annihilation in low dimensional siliconmaterials" , Int. Symp. on Si Heterostructures: From
Physics to Devices, Crete, Greece, Sept. (1995).
H. Hamanaka, A. Itoh, Y. Kurosawa, K. Hasegawa,
and K. Maeda: "PIXE spectra of charged-up sampIes", 14th Symp. on Materials Science and Engineering Research Center of Ion Beam Technology,
Hosei University, Koganei, Dec. (1995).
W. Hong, S. Hayakawa, K. Maeda, S. Fukuda, M.
Yanokura, M. Maeda, K. Kimura, Y. Gohshi, and I.
Tanihata: "Development of mass-analizing methodof high resolution, TOF-ERDA using ion beam",
1996 Fall Meet. Appl. Phys. Soc. Jpn. , Urawa, Mar.
(1996).
W. Hong, S. Hayakawa, K. Maeda, S. Fukuda, M.
Yanokura, M. Aratani , K. Kimura, Y. Gohshi, and262

1. Tanihata: "STUDY on high mass resolution ion
beam analysis by TOF-ERDA", 43rd Spring Meet.
Jpn. Soc. Appl. Phys. Relat. Soc. , Asaka, Mar.
(1996).
F. 1. Pratt, S. J. Blundell, P. A. Pattenden, W. Hayes,
K. H. Chow, A. P. Monkham, T. Ishiguro, K. Ishida,
and K. Nagamine: "Spin dynamics in conducting
polymers studied by msr" , 7th Int. Conf. on Muon
Spin Rotation/Relaxation/Resonance, Nikko, Apr.
(1996) .
X. Zhao, Y. Itoh, Y. Aoyagi , T. Sugano, K.
Hirata, Y. Kobayashi, T. Ohdaira, R. Suzuki, andT. Mikado: "Positron/positronium annihilation in
nanocrystalline silicon thin films", 5th Int. Workshop on Positron and Positronium Chemistry (PPC5), Lillafiired, Hungary, June (1996).
Y. Itoh, Z. L. Peng, K. H. Lee, A. Goto, N. Nakanishi,
M. Kase , and Y. Itoh: "Slow positron beam production by irradiation of p +, d +, and He ++ on various
targets", 7th Int. Workshop of Slow Position BeamStudy (SLOPOS-7) , Unterageri, Switzerland, June
(1996).
K. Maeda, H. Hamanaka, and K. Hasegawa: "High resolution PIXE using crystal spectrometers combinedwith position sensitive detector", 2nd Int. Symp. on
Bio-PIXE, Beijing, China, Aug. (1996).
K. Maeda, H. Hamanaka, and K. Hasegawa: "In-air
high-resolution PIXE system", 14th PIXE Symp. ,Uji , Oct. (1996).

x. LIST OF SYMPOSIA(Jan.-Dec. 1996)
1) Symp. on Theory of Atomic and Molecular Processes IV
10- 11 Jan., Wako, RIKEN, Atomic Physics Lab.
2) Symp. on I-Ray Spectrosc<?py and Exotic Beams
28 Feb., Wako, RIKEN, Radiation Lab.
3) Symp. on Bio-Trace Elements '96
2'5 Mar., Wako, RIKEN, Nuclear Chemistry Lab.
4) 4th Int. Conf. on Radioactive Nuclear Beams
4- 7 June, Omiya, RIKEN, Linear Accelerator Lab., Radiation Lab., and Cyclotron Lab.
5) Symp. on Nuclear Physics at RI Beam Factory
17 June, Wako, RIKEN, Linear Accelerator Lab.

6) Symp. on Theory of Atomic and Molecular Processes V
4- 5 Oct., Yamaguchi, RIKEN, Atomic Physics Lab.
7) 40th Symp. on Radiochemistry22-24 Oct., Wako, RIKEN, Nuclear Chemistry Lab.
8) Symp. on Development of Positron Application by Using Accelerators
20 Nov., Wako, RIKEN, Cyclotron Lab. and Nuclear Chemistry Lab.
H) 13th Symp. on Atomic Physics Using Accelerators
27 Nov., Wako, RIKEN, Atomic Physics Lab.
10) Symp. on Nuclear Physics of the 21st Century Opened up by I-Ray Spectroscopy
25- 26 Dec., Wako, RIKEN, Radiation Lab.

263

XI. LIST OF SEMINARS(Jan.-Dec. 1996)
Radiation Lab., Cyclotron Lab., andLinear Accelerator Lab.

1) V. Kapin, Kyoto Dniv. (Kyoto), 1 Jan .
. "Study of RFQ accelerating structures base on
multi-conductor transmission line resonators"
2) J. Arje, Dniv. Jyvaskyla (Finland), 23 Jan.
"Developments and studies at the 18 GHz ECRIS"
3) T. Shigetani, Tokyo Metrop. Dniv. (Tokyo), 25Jan.
"Structure functions of hadrons in the QCD effective theory"4) S. H. Lee, Yonsei Dniv. (Korea), 5 Feb.
"Instantons and chiral symmetry restoration in
QCD with N f flavors"
5) K. Takahashi, Max-Plank-Inst. Tech. Univ. Munich (Germany), 7 Feb.
"N ucleosynthesis of heavy elements and nucleocosmochronology"6) N. Bhattacharya, VECC, Calcutta (India), 14
Feb.
"The superconducting cyclotron project at Calcutta"
7) M. Fukuda, JAERI, Takasaki (Gunma), 16 Feb.
"High intensity proton acceleration at the PSI
cyclotron facility and simulation of beams usingtransfer matrics"
8) H. Ui, Hiroshima Univ. (Hiroshima), 19 Feb.
"A novel application of spontaneously broken local gauge theory to molecular dynamics: Are corioli and centrifugal force Fictious force?"9) P. von Brentano, Univ. Koeln (Germany), 26 Feb.
"Experiments on multiphonon states in Gamma
soft nuclei"10) W.-D. Schmidt-Ott, Univ. Gottingen (Germany),
27 Feb.
"Alignment and polarization measurements for
projectile fragmentation at the GSI Energy"11) Colloquium for master's thesis based on work at
Ring Cyclotron in 1995, 13 Mar.
12) H. E. Conzett, LBL, Univ. California (U.S.A.), 15
Mar.

264

"The vanishing analyzing power in ep elastic scattering: Symmetries and dynamics"
13) V. W. Hughes, Yale Univ. (U.S.A.), 18 Mar.
"N ucleon spin structure"14) D. Diakonov, St. Petersburg Nuclear Physics Institute (Russia), 25 Mar.
"Baryon number violation at high energies/temperatures/densities in the electroweak
theory"15) S. Biri, ATOMIKI, Debrecen (Hungary), 27 Mar.
"(1) Status of the hungarian ECRIS program; (2)Computer simulation of ECRIS magnetic traps"16) D. Bibet, GANIL (France), 27 Mar.
"Status of acceleration facility and the SPIRAL
project at GANIL"

17) A. Krasznahorkay, Inst. Nucl. Res. Hungarian
Acad. Sci. (Hungary), 25 Apr.
"Experimental study of exotic nuclear shapes"18) A. A. Grib, St. Petersburg Univ. Economics andFinance (Russia), 26 Apr.
"Particle creation in the early universe"
19) F. Ye, IMP, Lanzhou (China), 15 May"Operation and improvement of HIRFL"

20) P. Bozek, Kyoto Univ. (Kyoto), 28 May"Observation of the Mott momentum in heavy ion
collisions"21) D. Ghose, VECC, Calcutta (India), 30 May"Helium extraction from thermal spring gases"
22) W. von Oertzen, Hahn Meitner Inst. (Germany),
12 June"Dimers and chain states based on the 0: + 0: potential and two-center states in 9Be, lOBe"23) I. J. Thompson, Univ. Surrey (U.K.), 20 June
"Few-body structure of halo nuclei"24) H. Shimizu, RIKEN (Saitama), 28 June
"Developmentofsuperconducting-tunneljunction particle detector"25) J. Schubert, MSU, Michigan (U.S.A .), 1 July
"A design of an 8 Tesla superconducting cyclotron"26) E. Hiyama, Kyushu Univ. (Fukuoka), 16 July
"Structure of neutron-rich and proton-rich hypernuclei"

27) B. Vaishali, VECC, Calcutta (India) , 17 July
"Design of ECR ion source for RIB Facility at Calcutta"
28) I. J. Thompson, Univ. Surrey (U.K.), 18 July
"Few-body physics for experimentalists"
29) A. Luccio , BNL/RIKEN (U.S.A./Saitama), 19
July"Spin tracking in RHIC"
30) S. Hirenzaki, Nara Women's Univ. (Nara), 23
July"Deeply bound pionic atoms"
31) A. van der Woude , KVI (The Netherlands) , 29
July"The isoscalar monopole resonance in cold and hot
nuclei"32) T. Kuehl , GSI (Germany) , 1 Aug.
"Atomic physics goes full circle"33) H. Sagawa, Univ. Aizu (Fukushima) , 5 Aug.
"Single-particle and collective properties of drip
line nuclei"34) L. Yixiao, Inst. Modern Phys. , Chinese Academyof Science (China) , 7 Aug.
"Nuclear physics research in IMP: Studies of hot
nuclei and nuclei far from stability"35) W. Yifang, Inst. Modern Physics,
Academy of Sciences (China), 19 Aug.
"Status and upgrade of HIRFL"

Chinese36) A. Bonasera, INFN, Catania (Italy) , 19 Aug.
"Critical chaos"37) A. Ono, Tohoku Univ. (Sendai) , 9 Sept.
"Antisymmetrizedmolecular-dynamics
with
Vlasov equation and multifragmentation in heavy
ion collisions"38) F. Caspers, CERN , Geneva (Switzerland), 18
Sept.
"Recent progress of stochastic cooling"39) S. Kuyucak, Australian Nat!. Univ. (Australia),
30 Sept.
"Description of deformed and superdeformed nuclei in the interacting Boson Model"40) A. N. Skrinsky, BINP, Novosibirsk (Russia), 9Oct.
"Accelerator development at Novosibirsk: Status
and prospects"41) M. Kumada, NIRS, Inage (Chiba), 11 Oct.
"Propose of a cyclotron which has quick responces"42) Y. S. Chen, China Inst. Atomic Energy (China),
28 Oct.
"Identical bands and quantized alignment in superdeformed nuclei"43) W . Pelzer, HMI, (Germany), 6 Nov.
"Status of the ISL (Ionen Strahl Lab.) project"44) W. Pelzer, HMI, (Germany), 11 Nov.
"Some design aspects of the ISL accelerators"45) Y. Oganessian, Joint Inst. Nuclear Research(Dubna), 12 Dec.
"Recent study at JINR"46) S. Ben-Hao, China Inst. Atomic Energy (China),
13 Dec.
"(1) Strange antibaryon production data and the
reduction of strange quark production in sulphurnucleus collisions at CERN Energy;(2) Liquid-gas phase transition and decay modetransformations shown in the decay of projectile
remnant in Au + Au reaction at GSI Energy"47) Z. Ma, China Inst. At. Energy/RCNP(China/Osaka) , 18 Dec.
"Study of unstable nuclei in relativistic and nonrelativistic approaches"48) Z. Ren, Nanjing Univ. (China), 19 Dec.
"Mean-field study on nuclei far from stability"
49) Z. Sun, China Institute of Atomic Energy(China) , 19 Dec.
"What can we learn from the dimuon measurement for the spin structure of the nucleon with
PHENIX?"
50) A. Chakrabarti, VECC, Calcutta (India), 25 Dec.
"Design of a 4-rod RFQ linac for VECC-RIB";"Reaching the proton drip-line & beyond with low
energy proton-rich radioactive ion beam"

Atomic Physics Lab.
1) M.-T. Huang, Kansas State Univ. (U.S.A.), 9 Jan.
"Charge capture from Rydgerg targets: Comparing experiment with theory"2652) A. Warczak, Univ. Cracow (Poland), 25 Jan.
"Radiative electron capture in fast HCI-atom collisions"

3) J. Burgdorfer, Univ. Tennessee (U.S.A.), 8 Feb.
"On the relation between double ionization byphotons and charged particles"

Nuclear Chemistry Lab ..
1) C. Chai, Inst. High Energy Phys. (ChinaL 13 Dec.
"Study of characterization and chemical species ofinorganic components in environmental and biological systems by nuclear analysis"
Seminars on Physics at the RI Beam Factory4) J. Eichler, Hahn-Meitner-Institut (Germany), 15
Feb.
"Electron-positron pair production in relativisticcollisions between heavy ions"

1) Y. Suzuki, Niigata Univ. (Niigata), 29 Jan.
"Shell structure of unstable nuclei in a multicluster theory"5) J. H. McGuire, Tulane Univ. (U.S.A.), 16 Feb.
"An overview of the dynamics of electron correlations"

2) T. Suzuki, RIKEN (Saitama), 26 Feb.
"Nuclear radii of Na and Mg isotopes studied via
the interaction cross sections"

6) I. L. Baigman, Lebedev Physical Institute(Russia), 16 Feb.
"Semiclassical approach to transitions between
Rydberg states induced by collisions with charged
particles"3) Y. Kanada-En'yo , Kyoto Univ. (Kyoto), 18 Mar.
"Structure of light unstable nuclei studied withAMD"7) T. Aberg, Helsinki Univ. Technol. (Finland), 24
Apr.
"Double photoionization and related phenomenain the inner-shell XUV region"

8) J. Horacek, Charies Univ., Prague (Czech Republic), 26 Dec.
.
"Vibrational excitation and dissociative attachment in electron collisions with HBr, DBr, and
HI"

266

4) T. Otsuka, Univ. Tokyo (Tokyo), 13 May"New regime of nuclear structure explored by thequantum Monte Carlo Shell Model"
5) R. F. Casten, Yale Univ. (U.S.A.) , 26 Nov.
"Measurement of key signatures of nuclear structure with radioactive beams by low energy
Coulomb excitation"6) K. Takahashi, Max-Planck-Inst. Astrophysics(Germany) , 2 Dec.
"Possible RIB and storage ring experiments onheavy nuclei of astrophysical interest- and optimistic view of a theorist"

XII. LIST OF PERSONNEL'*RIKEN Accelerator Research Facility
ISHIHARA Masayasu t1
iE ~ (Facility Director)
AWAYA Yohko ~ ~ 'fl. -+ (Vice Facility Director)(Vice Facility Director)
YANO Yasushige -jc!ff ti: £Linac Division
CHIBA Toshiya q:. ~ ~rJ liJ(;
IKEZAWA Eiji i@. if{
KOHARA Shigeo /J\~HEMMI Masatake ~ Jt~
KASE Masayuki ;VD ifi l§ Z
MIYAZAWA Yoshitoshi g if{ 1£ fiX*lRing Cyclotron Division
FUJITA Jiro Hi EB.M
IKEGAMI Kumio H!!.1:1L := ~KAGEYAMA Tadashi J3 LlJ iE
KASE Masayuki ;VD ifi l§ Z
KUBO Toshiyuki !A f* fi:x ¥NAKAGAWA Takahide}II q: ~o KUNO Hiroki ~!ff r.t. W
YOKOYAMA Ichiro tfi LlJ - .M

GOTO Akira f! Hi ~*1
INABE Naohito m ill M1 A
KAMIGAITO Osamu 1:j:~7H~­
KOHARA Shigeo /J\£
NAGASE Makoto
iii ~OGIWARA Kiyoshi ~ mi t1f
SAKAM OTO N aruhiko jJj
nX. fit

Experimental Support Division
ICHIHARA Takashi
1m ~KAN AI Yasuyuki ~ 1t 1* Z
KUMAGAI Hidekazu !i~ ~ ~ ~D
MORITA Kosuke ~ EB ~ 11'
WATANABE Yasushi ~ ~KAMBARA Tadashi fJ1t 1m iE * 1
KOBAYASHI Toshio /J\ 1* {~ iff.
MATSUZAKI Teiichiro m~tJt-.e~
OKUBO Yoshitaka *!A1*~M
YATAGAI Fumio ~EBJt)(*

Radioisotope Facilities Division
AMBE Fumitoshi 'Y; $ )( fi:x* 1
KOBAYASHI Yoshio /J\:.t*. ~IWAMOTO Masakoa'** =*=*m*

Radiation Protection Group
FUJITA Shin Hi EB fR
NAKANISHI Noriyoshi
1§* *c %*1* '* *** iE -+;6-* ~ ~~ =NAKAJIMA Shunji
UWAMINO Yoshitomo

1: Jt • ID1

Secretariat
NAKAMURA Toshiko *1t t L-+
YOSHIDA Tohru '6 EB ~*2

NUMATA Shigeo

Steering Committee
AMBE Fumitoshi 'Y; $ )( fi:x
AWAYA Yohko ~ ~ ?§.-+HANAOKA Fumio 1E /iYiI )( iff.
IN 0 UE Yorinao 1t J: fi il
KAMBARA Tadashi fif! 1m iE
KOBAYASHI Toshio /J\:.t* {~ it
MATSUOKA Masaru
liYiJ
Jm
MIYAZAWA Yoshitoshi g if{ 1£ fix
TAKAMI Michio M Jt :ii ~YAGI Eiichi j\
5R YATAGAI Fumio ~EBJ!)(*YOSHIDA Tohru '6 EB ~AONO Masakazu w!ff iE ~D
GOTO Akira f! Hi ~IN AMURA Takashi T.
1t ~ISHIHARA Masayasu t1 1m iE ~KATSUMATA Koichi MJ X f.li: KUMAGAI Noritaka !i~ ~ ~ q:
MATSUZAKI Teiichiro m~t~-.e~
NAG AMINE Kanetada 7']( ~ ~ ,~,TANIHATA Isao ~~YAN 0 Yasushige -jc If ti: ~YOSHIDA Shigeo '6 EB~

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*1 Group Leader, *2 Manager, *3 Chairperson

267

Scientific and Engineering Personnel

Cosmic Radiation Laboratory
KATO Hiroshi .110 Jli W

KOHNO Tsuyoshi

fiiT lff~(Visitors)
HASEBE Nobuyuki :f{<fr-tflH~ff (Fac. Gen. Educ., Ehime Univ.)
KASHIWAGI Toshisuke ;ft3
llJ 1t- (Fac. Eng., Kanagawa Univ.)
KATO Chihiro 110 Jli =f ~ (Fac. Sci., Shinshu Univ.)
MUNAKATA Kazuoki
1t - ~ (Fac. Sci., Shinshu Univ.)
MURAKAMI Hiroyuki f;j" 1: m Z (Fac. Sci., Rikkyo Univ.)
NAGATA Katsuaki 7k Ell MJ PJI (Fac. Eng., Tarnagawa Univ.)?!f:.. (Fac. Sci., Rikkyo Univ.)
NAKAMOTO Atsushi q:.
YAMAGIWA Iwao III ~ •(Grad. Sch. Sci. Eng., Saitarna Univ.)
YANAGIMACHI Tomoki t!iP JUT M tM (Fac. Sci., Rikkyo Univ.)

*

*

*

(Students)
ITO Tornoyuki W Jli M IT (Fac. Sci. Eng., Waseda Univ.)
ITSUMI Norifurni ~ ~ 1! ~ (Fac. Sci. Eng., Waseda Univ.)
SHINO Tomoaki 1Il i!jt ~ (Fac. Sci. Eng., Waseda Univ.)
TAKASHIMA Takeshi rWJ ~ 11 (Fac. Sci. Eng., Waseda Univ.)

Cyclotron Laboratory
ARIGA Takehiro :ff l( 11 W
FUJITA Shin Jli Ell *JT
IKEGAMI Kurnio H!Ll:1L':='~ISHIDA Satoru ;0 Ell 't:g:
KAGEYAMA Tadashi ~ ~ lE
KASE Masayuki 1.10 iii l§ Z
KOHARA Shigeo /J'\ Jj I X
KUROKAWA Meiko ~ }I/ PJI -fNAGASE Makotoiii ~NAKAGAWA Takahide q:t}1I q: ~NAKANISHI Noriyoshi q:t g§%
OKUNO Hiroki .. lff fA tM
PU Yuehu ii ~ J}ESHIMOSAKA Takuya r:t}X ~ ~TAGAYA Yu $110:fr f.1i
WAKASUGI Masanori ~ ~ l§ ~YANO Yasushige
lff ti: m*3

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*1 Senior Scientist,*2 Senior Visiting Scientist,=

FU JITA Jiro JJi Ell.f!B
GOTO Akira f~ ii ~*1
INABE Naohito fill ill. M1 A
JIN Wei-Guo -it t1tJ 00
KAMIGAITO Osarnu J:.j:~Ji·{~­KATAYAMA Takeshi J:t W :it WJ*2
KUBO Toshiyuki !A 1* it ¥MORITA Kosuke ~ Ell
1tNAKAGAWA Keiko q:t)1I ~ T
NAKAJIMA Shunji q:t ~ ~~OGIWARA Kiyoshi ~ Jj
OTSUKA Takaharu *:i:j( q: ~s *2
SAKAMOTO Naruhiko :lJX
JJX. ~SUZUKI Toshio if;
it ~ *2
UESAKA Tornohiro J:.:lJX tx ~$YAMAJI Shuhei W ~ f~ .lJZ*1
YO KAYAM A Ichiro ;f1( ill - i!Bm* **3 Chief Scientist(Visitors)
ABE Yasuhisa /fliT $ ~!A (Yukawa Inst. Theor. Phys. , Kyoto Univ.)
AKUTSU Takao /fIiT!A~*?Cx (NASDA)
AOKI Shiro W
WJ i!B(NASDA)
ARAI Eiichi *JT =tr 5R (Res. Lab. Nucl. React., Tokyo Inst. Technol.)
ARAKAWA Kazuo m}I/ f[J X (JAERI, Takasaki Rad. Chern. Res. Estab.)
ARJE Juha (Jyvaskyla Univ., Finland)
BABA Shinji .~!£ ffi(NASDA)CHAKRABARTI Alok
(Var. Energy Cyclotron Cen., India)
DATE Schin W it 1$ (JASRI)
DEAN David(Oak Ridge Natl. Lab., U.S.A.)
EJIRI Hiroyasu ~I fK~(Fac. Sci., Osaka Univ.)
EN'YO Hideto ~ 1j- ~ A (Fac. ScL, Kyoto Univ.)

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FUJIOKA Manabu Jfi 1M] ~ (Cyclotron Radioisot. Cen., Tohoku Univ.)
FUJISAWA Takashi Jfi ~ r.Q ~ (Denki Kogyo Co. Ltd.)FUJISHIMA Shiro Jfi §b ~ J!~ (I.H.I.)
FUJITA Yoshitaka Jfi IE tE .q: (Fac. Sci., Osaka Univ.)
FUJIWARA Mamoru Jfi 1m ~ (RCNP, Osaka Univ.)
FUKUDA Mitsuhiro
IE -Yt(JAERI, Takasaki Rad. Chern. Res. Estab.)
FUKUMOTO Sadayoshi~.
(KEK)
FURUNO Kohei it ff J'!..IfZ (Tandem Accel. Cen., Univ. Tsukuba)
FURUSE Kaoru it iii •(NASDA)Jt ~ Z (N.I.R.S.)
FUTAMI Yasuyuki
GOKA Tateo li!It X (NASDA)
HADA Takashi 51;} IE ftij ~ (NASDA)
HAMA Hiroyuki ~ JA"* (LM.S.)
HAMAMOTO Ikuko ~~ -f(Lund Inst. Technol., Lund Univ., Sweden)~!H(Sapporo Gakuin Univ.).
HARADA Toru 1m IE~ fD(NASDA)HASHIMOTO Miwa ~?€l (Inst. Nucl. Study, Univ. Tokyo)
HASHIMOTO Osamu ~
tf:l (RCNP, Osaka Univ.)
HATANAKA Kichiji 1:HJ 9=t
HATSUKAWA Yuichi *JJ)I[ lift (JAERI, Tokai Res. Estab.)
HATTORI Toshiyuki m~ $ {~"* (Res. Lab. Nucl. React., Tokyo Inst. Technol.)
HAYANO Ryugo 1f!. ff 'jj~ 1i (Fac. Sci., Univ. Tokyo)
HEIGUCHI Kazuhiko .IfZ D fD ~ (Sch. Medicine, Niigata Univ.)
HIES Markus G.
(Dept. Phys., Mainz Univ., Germany)
HIRAO Yasuo .IfZ ~ ~ ~ (N.LR.S)
HIROSE Takayuki JA iii .q:"* (NASDA)
rf'l' jj!!ift (Aizu Univ.)
HONMA Michio
HONMA Toshihiro
rl'l' ~ JA (Cyclotron Radioisot. Cen., Tohoku Univ,)
HORIBATA Takatoshi 1)ffi!liM.q: {~ (Fac. Eng., Aomori Univ.)
HORIGUCHI Takayoshi 1)ffi IJ ~.5! (Fac. Sci., Hiroshima Univ.)
HORIUCHI Hisashi 1)ffi pg 7N! (Fac. Sci., Kyoto Univ.)
HOSONO Kazuhiko *IB ff fD ~ (RCNP, Osaka Univ.)
IGARASHI Toshio 1i jJ1fi!dft (NASDA)
IKEDA Akitsu H!! IE f}( ~* (Shizuoka Inst. Sci. & Tech.)
IKEDA Kiyomi H!! IE~(Fac. Sci., Niigata Univ.)
IKEDA Nobuo H!! IE 1$ X (Inst. Nucl. Study, Univ. Tokyo)
IKEZOE Hiroshi H!! ~~ tf (JAERI, Tokai Res. Estab.)
IMAI Kenichi A,
ll! (Fac. Sci. , Kyoto Univ.)
IMAMURA Mineo A,;t;j"lift (Inst. Nucl. Study, Univ. Tokyo)
INOUE Makoto
1:. ffi (Inst. Chern. Res., Kyoto Univ.)
ISHIZUKA Takeo 1:1:1:* ~ ~ (Fac. Sci., Saitama Univ.)
ITO Yasuo W Jfi ~ ~ (Atomic Energy Res. Cen., Univ. Tokyo)
ag (JAERI, Tokai Res. Estab.)
IWAMOTO Akira :E
IWASHITA Yoshihisa :E r =Jj)..... (Inst. Chern. Res., Kyoto Univ.)
IZUMOTO Toshiaki 71{
flJ. (CoIl. Sci., Rikkyo Univ.)
JEONG S. C.
(Inst. Nucl. Study, Univ. Tokyo)
JIN Weigou ~ ~ 00 (Fac. Sci., Toho Univ.)
JYAN Donshin ~I tl J'!. (Peking Univ., China)
KAMIMURA Masayasu 1:.;t;j" lE ~ (Fac. ScL, Kyushu Univ.)
KAMMURI Tetsuo jtf ~ X (Fac. ScL, Osaka Univ.)
KANAZAWA Mitsutaka ~ ~ -Yt ~ (N.LR.S.)
KATAYAMA Ichiro Jt llJ - J!~ (Inst. Nucl. Study, Univ. Tokyo)
KATO Kiyoshi 11[1 ii ~ =Jj (Fac. Sci., Hokkaido Univ.)
KATO Shohei 11[1 ii l!§.IfZ (Fac. ScL, Osaka Univ.)
KATORI Kenji HE 1fX. ~(Fac. Sci., Osaka Univ.)
KATSURAGAWA Hidetsugu ~)I1 ~ rfflPJ (Fac. Sci., Toho Univ.)
KAWAGUCHI Takeo JII D ~ ~ (Mitsubishi Electric Co., Ltd.)KAWAI Mitsuji fit]" {} -Yt ~ (Fac. Sci., Kyushu Univ.)
KITAGAWA Hisashi ~t )1/
rt.J (Inst. Phys., Univ. Tsukuba)

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KOHAMA Akihisa /J'\ il ~$ ~ (Fac. Sci., Univ. Tokyo)
KONDO Michiya :ilL Ii J!t 1:1! (RCNP, Osaka Univ.)
KOSAKO Toshiso /J'\f~i1fix;J± (Atomic Energy Res. Cen., Univ. Tokyo)
KOTAJIMA Kyuya tim~~~ (Fac. Eng., Tohoku Univ.)
KUBOYAMA Satoshi ~f*IlJ~1i] (NASDA)
KUDO Hisaaki I Ii ~ ag (Fac. Sci., Niigata Univ.)
KUMATA Masayuki n~ m ~ Z (N .I.R.S.)
KUSANO Junichi 1/f. ff ~*(Yuuai Corp.)
LEE Kong Ok~ 3i(Rika Women's ColI., Korea)
LEE Sang Mu*EI(Inst. Phys., Univ. Tsukuba)
LI Hongling
i:Jt If; (RCAST, U niv. Tokyo)
LI Peng Zi(Wuhan Univ., China)
MAEDA Kazuhide Jiij B3 f[J ~ (Fac. Sci., Kyushu Univ.)
MARUMORI Toshio A ~ ~ X (Fac. Sci. Tech., Sci. Univ. Tokyo)
MATSUDA Sumio ~ B3 M! X (NASDA)
MATSUI Yoshiko ~7i -f- (Fac. Tech., Univ. Tokyo Agri. Tech.)
MATSUKI Seishi ~fiE ~ (Inst. Chern. Res., Kyoto Univ.)
MATSUMOTO Akihiro ~Bi ~$ (NASDA)
MATSUSE Takehiro ~ iii ~ ~ (Dept. Phys., Shinshu Univ.)
MATSUYANAGI Kenichi ~ {PP .PJf - . (Fac. Sci., Kyoto Univ.)
MATSUZAKI Kazuhiro ~ ~ - .~ (N ASDA)
MIDORIKAWA Shoichi ~)II. (Fac. Eng. , Aomori Univ.)
MINAMISONO Tadanori r¥J I%J ,t, JlJJ (Fac. Sci. , Osaka Univ.)
MITSUMOTO Toshinori ~{~ ~(Sumitomo Heavy Industries , Ltd.)ii :E- (RCNP, Osaka Univ.)
MIURA Iwao
1:1! (Fac. Sci., Osaka Univ.)
MIYATAKE Hiroari g Jit
MIZOTA Takeshi ~ IE Jit;E; (FEL Res. Inst. Inc.)(RCNP, Osaka Univ.)
MIZUNO Yoshiyuki 7]( ff ~ Z
MIZUSAKI Takahiro 71< ~ r'el ~ (Fac. Sci., Univ. Tokyo)
MORI Yoshiharu ~ ~?f1 (Inst. Nucl. Study, Univ. Tokyo)(Variable Energy Cyclotron Cen. , India)
MUKHOPADHTAY M.
MURAKAMI Hideoki 11 1: ~ ~ (Tokyo Gakugei Univ.)
MURAKAMI Tetsuya 11 1: :g 1:1! (Fac. Sci. , Kyoto Univ.)(Univ. Tokyo, Mercantile Marine)
MURAYAMA Toshiyuki 111lJ *IJ ¥MUROYA Shin ~ ~ -L.\ (Sch. Sci. & Eng. , Waseda Univ.)
MUTO Kazuo Jit »i - itt (Fac. Sci. , Tokyo Inst. Technol.)NAGAI Yasuki 71<~ W (Fac. Sci. , Tokyo Inst. Technol.)
Ef3(NASDA)NAGAI Yuki 71<
NAITO Ichiro pq jfi -!!~ (NASDA)
NAKADA Hitoshi ~ B3 t
(ColI. Art & Sci., Chiba Univ.)
NAKAHARA Hiromichi ~ 1* ~:i!t (Fac. Sci. , Tokyo Metrop. Univ.)
NAKAI Kozi ~~(KEK)
NAKAMURA Hiroyuki ~ 11 tfl- Z (Fac. Sci. , Kyushu Univ.)
NAKAMURA Ichiro r:p if1 m!!~ (Fac. Sci. , Saitama Univ.)
NAKAMURA Masao 4' if1 iE X (NASDA)
NAKAMURA Takashi ~ 11 ~ Ii] (Cyclotron Radioisot. Cen. , Tohoku Univ.)
NAKAO Noriaki r:p ~ i\!i aEla (Inst. Nucl. Study, Univ. Tokyo)(Inst. Nucl. Sci. Tech. , Vietnam)
NGUYEN DINH Dang
NIIMURA Masanobu '*JT 11 iE {§ (Sch. Sci. & Eng. , Waseda Univ.)
NODA Akira ff B3 •(Inst. Chern. Res. , Kyoto Univ.)
NODA Kouji ff E8 jJf: Ii] (N.I.R.S.)NOMURA Toru ff if1 7- (Inst. Nucl. Study, Univ. Tokyo)
NOZAKI Tadashi ff ~ iE (Kagami Memorial Lab. Materials & Sci. , Waseda Univ.)
OGAWA Kengo /J'\ )11 f!iI! -Ef (Fac. Educat., Chiba Univ.)
OHIRA Hideharu
Jf- ~(NASDA)
OHKAWA Tomohiro)11 ~(Mitsubishi Heavy Industries, Ltd.)OHTOMO Kiyotaka
tx m ~ (Sumitomo Heavy Industries, Ltd.)OHTSUKI Tsutomu
Wi fJJ (Lab. Nucl. Sci., Tohoku Univ.)

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270

***

OHYA Jiroi!~ (NASDA)
OKAMURA Hiroyuki 1M] l1 iJ.L. Z (Fac. Sci., Univ. Tokyo)
OKUMURA Susumu ~ l1 :i1t (JAERI, Takasaki Rad. Chern. Res. Estab.)
1m i:l ft (CoIl. Art. Sci., Univ. Tokyo)
ONISHI Naoki
ONO Akira /J' If ~ (Fac. Sci., Tohoku Univ.)
ORMAN Erich(Tennessee Univ., U.S.A.)OSUGA Toshiaki *3jr~iiiPJI (ColI. Art & Sci., Chiba Univ.)(Fac. Sci., Saitama Univ.)
OTA Kiyoshi :* B3
QUAN Zhuo-Shu ~ ~ W (ColI. Eng., Hosei Univ.)
SAGARA Kenshi ll3 ~ !it.¥ (Fac. Sci. , Kyushu Univ.)
SAITO Motozo ~ Bi Ml ~ (Former Staff of RIKEN)SAKAI Hideyuki ~i!!i~ 1T(Fac. Sci., Univ. Tokyo)
SAKATA Fumihiko :l:JX B3 )( ffi (Inst. Nucl. Study, Univ. Tokyo)
SATO Ken-ichi it. Jli ~ ~ (Dept. Phys., Tohoku CoIl. Pharm.)
SATO Kenji it. Jli f!il
(RCNP, Osaka Univ.)
SATO Yukio i~ Jli~(N.I.R.S.)
SEBE Takashi ~ $q: (CoH. Eng., Hosei Univ.)
SEKINE Toshiaki ~1~ PJI(J AERI, Tokai Res. Estab.)
SHIBATA Tokushi ~ B3 iI!t ,'G!, (Inst. Nucl.Study, Univ. Tokyo)
SHIKAZONO Naoya J.fE ~ i:l EX (JAERI, Tokai Res. Estab.)
SHIMIZU Akira
71< ag (RCNP, Osaka Univ.)
SHIMOMURA Kouichiro --rl1~*-i!~ (Meson Sci. Lab. , KEK Brunch, Univ. Tokyo)
SHIN Kazuo ~ f[] ~ (Fac. Eng., Kyoto Univ.)
SHINDO Hiroyuki ~Jf iii ~ Z (N ASDA)
SHINOZUKA Tsutomu 1II!j( M1 (Cyclotron Radioisot. Cen. , Tohoku Univ.)
SHIRAI Toshiyuki B
iii Z (Yukawa Inst. Theor. Phys. , Kyoto Univ.)
SHUGYO Shin-ichi f~ 1T ~Jf (NASDA)~ 1r(Fac. Sci., Tokyo Metrop. Univ.)
SUEKI Keisuke
SUGAIIsao 'it
Wk (Inst. Nucl. Study, Univ. Tokyo)
SUGIMOTO Kenji ~~?S(NASDA)SUGIYAMA Hiroki ~ LiJ
m (NASDA)SUMIYOSHI Hiroyuki 11 is ]A 1T (Matsusho-Gakuen Junior ColI.)
SUZUKI Toshio j~{~~(ColI. Sci. Tech. , Nihon Univ.)
TAGISHI Yoshihiro B3 j$ •(Tandem Accel. Cen., Univ. Tsukuba)
TAJIMA Naoki B3 ~~ Ii W (ColI. Art Sci., Univ. Tokyo)
TAKADA Masashi M B3 J{;S (N.I.R.S.)
TAKEMASA Tadashi JEt jJ)( jf' ± (Kyoto Univ. Education)
TAKEUCHI Suehiro 1t P'J *]A (JAERI , Tokai Res . Estab.)
TAKIGAWA Noboru it )I[ ¥t (Fac. Sci., Tohoku Univ.)
TAMAGAKI Ryozo ~ :l:g ~ ~ (Fac. Sci., Kyoto Univ.)
TAMURA Takashi B3 l1 M;S (NASDA)
TANABE Kazuko B3 ill f[] ~ (Otsuma Women's CoH.)
TANABE Kousai B3 ill q: EX (Fac. Sci., Saitama Univ.)
TANAKA Jinichi B3 'i=' t m (Inst. Nucl. Study, Univ. Tokyo)
TANAKA Kazuhiro B3 'i=' fD" (Medical Dept. , Jyuntendo Univ.)
TANAKA Yasushi B3 'i=' 1*;s (Kyokuto Boeki Kaisha, Ltd.)TANIKAWA Masashi ~ )I[ Jm.¥ (Fac. Sci., Univ. Tokyo)
TOHYAMA Mitsuru :it LiJ ~iMl (Kyorin Univ.)
TOMIMASU Takio ~:lI $*~ (FEL Res. Inst. Inc.)TOMINAKA Toshiharu 'g 'i=' lll?S (Hitachi, Ltd.)TOMITANI Takehiro ~ ~ JEt ~* (N.I.R.S.)
TOMIZAWA Masahito ~ ~* JE A (Inst. Nucl. Study, Univ. Tokyo)
TOMODA Toshiaki IX B3 iii:lit (Fac. Eng., Aomori Univ.)
TORIYAMA Tamotsu ,~LiJ 1* (Dept. Phys., Musashi Inst. Technol.)
TSUBAKI Noriyuki ~ jtlJ
(NASDA)TSUKINO Akihisa Ji If :ft ~ (NASDA)UTSUNOMIYA Hiroaki *trsgiJ.L.~ (Fac. Sci., Konan Univ.)
VITTURI Andrea(U niv. Padova, Italy)

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271

WADA Michiharu f[J m:iR ta (Inst. Nucl. Study, Univ. Tokyo)
WADA Ryoichi f[J m ~ ~ (Texas A & M Univ., U.S.A.)(Fac. Sci., Konan Univ.)
WADA Takahiro f[J m ~WAKAI Masamichi li
iE:iR (Fac. Sci., Osaka Univ.)
WAKUTA Yoshihisa f[J~m.~ (Fac. Eng., Kyushu Univ.)
WATANABE Ikuo Vi ill 1m ~ (Toshiba Corp.)
WATANABE Shin-ichi Vi ill i$ ~ (Inst. Nucl. Study, Univ. Tokyo)
WEI Baowen ft 3i)( (Inst. Modern Phys., Acad. Sinica, China)
WONG Ji Chen
(Inst. Modern Phys., Acad. Sinica, China)
XIA Jiawen ~ {i)( (Inst. Modern Phys., Acad. Sinica, China)
YABANA Kazuo ~ 1t ~ ~ (Fac. Sci., Niigata Univ.)
YAMADA Taiichi LlJ m~ ~ (ColI. Eng., Kanto Gakuin Univ.)
YAMANOUCHI Mikio LlJ pq ~ Iii (Inst. Phys., Univ. Tsukuba)
YAMAZAKI Hirohito ill ~ Jl t
(Lab. Nucl. Sci., Tohoku Univ.)
YAMAZAKI Takashi ill ~ ft (RCNP, Osaka Univ.)
YE Feng JJt(Inst. Modern Phys., Acad. Sinica, China)
YOKOUCHI Shigeru ~ pq :& (Osaka Vacuuin Ltd.)YONEMARU Mitsunori
A 7t(NASDA)YOSHIDA Nobuaki
III '§(Fac. Sci., Univ. Tokyo)
III ,~, f!~ (Dept. Phys., Ishinomaki Senshu Univ.)
YOSHIDA Shiro
YOSHINAGA Naotaka is 71< ~ q: (Fac. Sci., Saitama Univ.)
YOSHIOKA Yasuhiro a 1M] Jjt iJL (NASDA)YOSHIZAWA Yasukazu a V{ Jjt f[J (Fac. Eng. , Kyushu Univ.)
ZHAN Li(Inst. Modern Phys., Acad. Sinica, China)(Inst. Modern Phys., Acad. Sinica, China)
ZHAO Jin Hua

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(Students)
AKABORI Taisuke -jffi:t)ffi ~ f;(:j (Dept. Phys., Musashi Inst. Technol.)
AKIYOSHI Hiromichi 1Jc
f1c -=JC (Fac. Sci., Kyushu Univ.)riI iff (Lab. Nucl. Sci., Tohoku Univ.)
AOKI Yuka W
BUSAKI Toru -$ ~ ~ (Fac. Sci., Kyushu Univ.)
FUJITA Takeshi :iIi~
(Fac. Sci., Kyushu Univ.)
HASHIMOTO Satoshi m
W (Fac. Sci., Univ. Tokyo)
HIRAKAWA Tetuya f }I/ rg -m (Fac. Sci. , Saitama Univ.)
KIM Eunn Joo(Fac. Sci., Tohoku Univ.)
KOBAYASHI Kentarou /J\t*1!i!*f!~ (ColI. Sci. Tech. , Nihon Univ.)
KURATOMI Kouichi ~ g iJL ~ (Dept. Phys. , Musashi Inst. Technol.)
KURITA Tetsuro ~rg f!~ (Inst. Sci. , Univ. Tsukuba)
KUROSAWA Tadahiro ~ ~ ,~, iJL (Fac. Eng., Tohoku Univ.)
LIU Xin(Inst. Phys., Univ. Tsukuba)
MATSUI Shinjirou m*-m =f!~ (Fac. Sci., Saitama Univ.)
MIURA Takashi ~ Hi
(Inst. Phys., Univ. Tsukuba)
MOGI Yoshihiko :&~ ~(ColI. Sci. , Chuo Univ.)
NAKAO Makoto r:p fif. ID£ (Cyclotron Radioisot. Cen., Tohoku U niv.)
OHSHIMA Nagayasu~ 71< Jjt
(KEK)
OHTSUKA Takahiro±j(JA (Dept. Phys. , Musashi Inst. Technol.)
01 Makito(ColI. Art. Sci., Univ. Tokyo)
ONO Shinji /J\ ff '1Ji
(Fac. Eng., Kyoto Univ.)
OZAWA Shuichi /J\ ~ f~ ~ (ColI. Sci., Rikkyo Univ.)
SASAHARA Takafumi itt 1* q:)( (ColI. Sci., Chuo Univ.)~(Inst. Phys., Univ. Tsukuba)
SASAKI Haruka -ft./.{SASAKI Michiya -ft. /.{-m (Fac. Eng., Tohoku Univ.)
SATO Takehiko -ft. Jfi it ~ (Fac. Sci., Tohoku Univ.)
SONE Hayato ~ 1'& :i*: A (Fac. Sci. Tech., Sci. Univ. Tokyo)
TANIGUCHI Shingo :§. lJ J{. ~ (Cyclotron Radioisot. Cen., Tohoku Univ.)
TOMITA Shigeo ~ m f.OC -X (Inst. Phys., Univ. Tsukuba)
TSURUTA Kaoru ~ m •(Fac. Sci., Kyushu Univ.)
UCHIYAMA Yoshiko pq ill fi -f- (Fac. Sci., Univ. Tokyo)

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WAKAMATSU Fumihiko ~ ~ )( It (Fac. ScL, Kyushu Univ.)WAKUI Takashi i~ 1t
i0 (Fac. Sci., Toho Univ.)~ t!B(Tokyo Gakugei Univ.)
YAM AM OTO Shiro LlJ
YODA Tetsuhiko ft( EE ~ It (Lab. Nucl. Sci., Tohoku Univ.)
YUKI Hideyuki *5:tJ& ~ 1T (Fac. Sci., Tohoku Univ.)**

Linear Accelerator Laboratory
CHIBA Toshiya =f ~ til EX
FUKUDA Shigekazu W; EE It _*1
IKEZAWA Eiji HI!. iR.
KASE Masayuki 11D iii l§ L
KORSHENINNIKOV Alexei
MIYAZAWA Yoshitoshi g iR.1i ~MOMOTA Sadao BEBftr.$~*l
OZAWA Akira /J\ iR.
SUZUKI Takeshi ~~1@
TONUMA Masao F H1 iE lit
YOSHIDA Koichi a EB 1t -

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FU JIMAKI Masaki Jii {!: iE tM
HEMMI Masatake ~ ~ iIX Jlt
ITO Sachiko W ii :f~ -=f*1
KOBAYASHI Toshio /J\ ~* 1~ lit*2
KUMAGAI Hidekazu ft~ ~ ~ to
MOCHIZUKI Yuko S. '5!. Ji 11 --r*l
OGAWA Yoko /J\ )11 ~$ -=f*1
SUGAHARA Yuichi ~ mt lit _*3
TANIHATA Isao ~ :kHI ~ X*4
YANOKURA Minoru *!f~ ~*2 Senior Scientist,*3 Postdoctoral Researcher,*4 Chief Scientist(Visitors)
ADACHI Shizuko ti: J! ij¥ --r (ICFD)
ARATANI Michi m ~ ~ ~ (Inst. Enviromental Sci.)
BOLBOT Michael(Notre Dame Univ., U.S.A.)
BOYD Richard(Ohio Univ., U.S.A.)
BROCKMANN Roff (Inst. Phys. , Univ. Mainz, Germany)
DAVID Dean J(CALTEC, U.S.A.)
DEMYANOVA AlIa S.
(Kurchatov Inst. Atomic Energy, Russia)
FU JIWARA Mamoru Jii mt ~ (RCNP, Osaka U niv.)
GOLOVKOV Mkheil S(Kurchatov Inst., Russia)
GONCHAROV Sergei A(Kurchatov Inst., Russia)
HIRENZAKI Satoru It:il~ t~ (Fac. Sci., Nara Women's Univ.)
HORIUCHI Hisashi :tjffi P'J 7N! (Fac. Sci., Kyoto Univ.)
IWAMOTO Akira :fiag (JAERI, Tokai Res. Estab.)IZUYAMA Takeo 1¥.liLlJ1@x (Fac. Sci., Toho Univ.)
KATORI Kenji g[ I{X ~(Fac. Sci., Osaka Univ.)
KIKUCHI Jun *1:ttI! /Ilfi (Sci. Eng. Res. Lab., Waseda Univ.)
KIMURA Kikuo **1%7-.lil (Fac. Eng., Nagasaki Inst Appl. Sci.)
KOLATA James(Notre Dame Univ., U.S.A.)MARUYAMA Tomoyuki A LlJ ~ L (Fac. Sci., Kyoto Univ.)
MATSUTA Kensaku ~ $ 1@ m (Fac. Sci., Osaka Univ.)
MATSUYAMA Yoshitaka ~ LlJ 7f q: (Inst. Nucl. Study, Univ. Tokyo)
MATUOKA Nobuyuki ~ [tri] 1$ 1T (Res. Cen. Nucl. Phys., Osaka Univ.)
MITTING M.
(GANIL, France)
MIYAKE Yasuo -= IlJI fflt t!B (Fac. ScL, Univ. Tsukuba)
MIYAMURA Osamu gf~(Fac. Sci., Hiroshima Univ.)
MOCHIZUKI Keiko '5!. Ji I --T (Fac. Sci., Osaka Univ.)
MORIMOTO Koji *'l¥ Ii) (JST)MURAOKA Mitsuo[tri] 1t ~(Fac. Eng., Aomori Univ.)
NOJIRI Yoichi !f Jfi.. i$ (Fac. Sci., Osaka Univ.)
OGAWA Kengo)111l ~(ColI. Arts. Sci., Chiba Univ.)
OGLOBLIN Alexei A.
(Kurchatov. Inst., Russia)
OHNISHI Akirag§
IlJI (Fac. Sci., Hokkaido Univ.)
OHTSUBO TakashiP¥ ~ (Fac. Sci., Niigata Univ.)
OJIMA Minoru /J\ IIJ.~ f.t (Fac. Sci., Osaka Univ.)

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OMATA Kazuo /J~ f~ fD X (Inst. Nucl. Study, Univ. Tokyo)
ORYU Shinsho ~ JL -1!t 1~ (Fac. Sci. and Tech., Science Univ. Tokyo)
OYAMATSU Kazuhiro il ~ fD ~ (Dept. Energy Eng. Sci., Nagoya Univ.)
PETRASCU Horia(Inst. Phys. Nucl. Eng., Romania)
PETRASCU Marius(Inst. Phys. Nucl. Eng., Romania)(Ohio State Univ., U.S.A.)RAIMANN Gerhard
SAGAWA Hiroyuki ftc )1/ iJ.L. ¥(Cen. Mathematical Sci. , Aizu Univ.)
1T (Fac. Sci., U niv . Tokyo)
SAKAI Hideyuki i!
SATO Kazuhiro ft. Jfi fD r.t. (Tokyo Fire Dept.)(California Univ., U.S.A.)
SEKI Ryoichi ~ .E! SHERRIL B.
(Michigan State Univ., U.S.A.)~(Fac. Sci., Tohoku Univ.)
SUDA Toshimi ~.Q EEl
SUGANUMA Hideo "if iB ~ X (RCNP, Osaka Univ.)
SUGAWARA Masahiko "if ®: l§"ffi (Fundam. Sci., Chiba Inst. Technol.)SUZUKI Hideyuki jfr(KEK){g it (Fac. Sci., Kanazawa Univ.)
SUZUKI Tsuneo jfr
SUZUKI Yasuyuki n'§ Z(Fac. Sci., Niigata Univ.)
TACHIBANA Takahiro :m; q: tw: (Senior High School of Waseda Univ.)
TAKAHASHI Yutaka r'al ~ ~ (Fac. Sci., Osaka Univ.)
TOKI Hiroshi ± d!i tf (RCNP, Osaka Univ.)TORBJOEN Baeck(Phys. Dept. Frescat., Sweden)
VARGA Kalman(Inst. Nucl. Res., Hungarian Acad. Sci., Hungary)(Fac. ScL, Konan Univ.)
WADA Takahiro fD EEl ~YAGI Hirosuke ;\~.j(Fac. Sci., Univ. Tsukuba)
YORANN Alhassid(Yale Univ., U.S.A.)ZAHAR Mohamed(Dept. Phys., Notre Dame Univ. , U.S.A.)***'J*** * Z* *(Students)
BOKU Yudan 1~ ~ ~ (Fac. Sci. Eng., Waseda Univ.)
HIBINO Masaru B ltff 11 (Fac. Sci. Eng., Waseda Univ.)
HIYAMA Emiko ~Ew~~-f- (Fac. Sci., Kyushu Univ.)
HONG Wang i~ 5G (Fac. Eng., Univ. Tokyo)(Grad. Sch. , Osaka Univ.)
IKEDA Takayuki it!!. EEl ~ Z
ISHIGA Kenichi ;£ ~ tt (Grad. Sch., Osaka Univ.)
KANO Kenji Pi- tt?S (Fac. Sci., Univ. Tsukuba)
KATO Toshiyuki 110 Jfi {~¥ (Fac. Sci. Eng. , Waseda Univ.)
V'J(Fac. Sci. , Saitama Univ.)
KIUCHI Hiroshi
KONO Sachiko If' ff 1~ -f- (Fac. Sci. Eng., Waseda Univ.)
KOZU Tomotake 1$ ~f 1Ji..:li:t (Fac. Sci. Eng., Waseda Univ.)
MARUYAMA Yukiko j;{.wiE*r.-f- (Fac. Sci., Osaka Univ.)
MATSUMOTO Akiko ~flsa -f(Fac. Sci. Eng. , Waseda Univ.)
MIKI Keitaro(Fac. Sci. , Konan Univ.)
OZAKI Kiminori ~ ~ 1} ~ (Fac. Sci. Eng., Waseda Univ.)
SAITO Masanori jll Jii. 1£ ~ (Fac. Sci., Osaka Univ.)
SAKAGUCHI Takao :I:R IJ ... ~ (Fac. Sci. Eng. , Waseda Univ.)
SHIMOOKA Masaaki l'" It!iJ 1£ I3JJ (Fac. Sci. , Kyoto Univ.)
TAKAHASHI Kenichi r'al ~ 'it (Drad. Sch. , Waseda Univ.)
TAKEHANA Naohiro t'r 1E
iJ.L. (Fac. Sci. Eng. , Waseda Univ.)
TAKENAKA Sunao t'r!=f:1(Fac. Sci. Eng., Waseda Univ.)
TANIHATA Chiharu :§. j:ffi =f(Fac. Sci., Waseda Univ.)
TERUHI Shigeru ,~~ B ~ (Fac. Sci. Eng. , Waseda Univ.)
YUNOKI Akira fm~(Grad. Sch., Waseda Univ.)
i-ij p.~ (Fac. Sci., Univ. Tokyo)
WANG Haiming I* *.:=.*t5t*.eB

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BEAUMEL Didier* 1
GAl Moshe*2
HAHN Kevin 1. *1
HIRAI Masaaki .IJZ 1+ iE I'IfJ
IDEGUCHI Eiji 1+-¥IJ5R?a*3
ISHIHARA Masayasu :£ Jl iE ~*5
LUCCIO Alfredo*1
NOTANI Masahiro lff -Br.t.
SAITO Naohito :g Jii li A
SUN Zuxun*2
WATANABE Yasushi ill ~YOSHIDA Atsushi ~ EB ~X***

DEVI Yelamanchili Durga*1
GOTO Yuji 1& Hi !t
HAYASHI Naoki ;f* li m*3
ICHIHARA Takashi m Jl .$:IMAI Kenichi 4' 1+ l! _*4
KISHIDA Takashi .i¥ EB j)i
MENGONI Alberto*1
OKAMURA Masahiro fM] l1 J§ **3
SAKURAI Hiroyoshi ~ 1+ if 11
TERANISHI Takashi {f gg ~WATANABE Yutaka ill ill=**1 Visiting Researcher, *2 Eminent Scientist, *3 Special Postdoctoral Researcher,*4 Senior Visiting Scientist, *5 Chief Scientist(Visitors)
ABE Yasuhisa IiiiJ $ ~!J.... (Yukawa Inst. Theor. Phys. , Kyoto Univ.)
ADACHI Minoru )E Jr Jf (Fac. Sci., Tokyo Inst. Technol.)
ANDO Yoshiaki !i lii ~ it (ColI. Sci., Rikkyo Univ.)
ASAHI Koichiro :h!!. fJ!:-f!~ (Fac. Sci., Tokyo Inst. Technol.)
BECK F. A.
(Groupe RSN, Strasbourg, France)
BROGLIA R.
(Univ. Milano & INFN, Italy)
CASTEN Rick(Phys. Dept. , Brookhaven Natl. Lab., U.S.A.)
CHAE Soo Joh ~ i* (Dept. Phys., Seoul Natl. Univ. , Korea)~(Inst. High Energy Phys.)
DON Yubin 1i
DOOI Makoto ~ 1+ A (Univ. Tsukuba)
EN 'YO Hideto ~ -9- ~ A (Fac. Sci., Kyoto Univ.)
FLOCARD Hubert(Div. Phys. Theorique, Inst. Phys. : Orsay, France)
FUCHI Yoshihide ~1 PJ ~ (Inst. Nucl. Study, Univ. Tokyo)
FUKUDA Mitsunori ti B3 -Jt 111ft (Osaka Univ.)
FUKUDA Tomokazu ti B3 ~ fD (Inst. Nucl. Study, Univ. Tokyo)
FURUTAKA Kazuyoshi t!l ~ fD tJ! (JAERI, Adv. Sci. Res. Cen.)
GONO Yasuyuki ~ ill ~ Z(Fac. Sci., Kyushu Univ.)
HAMAGAKI Hideki ~:tl[ ~ W (Inst. Nucl. Study, Univ. Tokyo)
HAMAMOTO Ikuko ~~ -T(Lund Inst. Technol., Lund Univ. , Sweden)
HASEGAWA Takeo ft-B-}I/ff:\x (Fac. Eng., Miyazaki Univ.)
HATSUDA Tetsuo fJ] EB t:r ~ (Univ. Tsukuba)
HONMA Saburo
rIOt' .=:. f!~(Inst. Nucl. Study, Univ. Tokyo)
HOSAKA Masahito 1*:I:JX ~~ A (Inst. Nucl. Study, Univ. Tokyo)
ICHIMURA Munetake m f1
ff:\ (ColI. Arts Sci. , Univ. Tokyo)
IEKI Kazuo~ fD X(ColI. Sci. , Rikkyo Univ.)
KAMAE Tsuneyoshi ~ ~I ~ PJ (Fac. Sci. , Univ. Tokyo)
KASAGI Jirota !2:*?af!~* (Lab. Nucl. Sci. , Tohoku Univ.)
KATAYAMA Ichiro h LlJ - f!~ (Inst. Nucl. Study, Univ. Tokyo)
KATO Seigo 110 »i ~ ~ (Fac. Ed., Yamagata Univ.)~(Fac. Sci., Osaka Univ.)
KATORI Kenji
KAWASHIMA Hideo }I/ ~ :9t!t (Inst. Nucl. Study, Univ. Tokyo)
KIM Jong Chan
(Dept. Phys., Seoul Natl. Univ. , Korea)
KITAO Kensuke *$~l!!IJJ (Data Eng. Inc.)KODAIRA Jirou /J'\.IJZ?a f!~ (Fac. Sci., Hiroshima Univ.)
KOIKE Yuji /J'\ a!!.
PJ (Fac. Sci., Niigata Univ.)
KOSOWER David A.
(Service de Physique Theorique Centre d'Etudes Saclay, France)
KUBONO Shigeru !J....1*lff ~ (Inst. Nucl. Study, Univ. Tokyo)
KUMANO Shunzo n~ lff f~ ~ (Fac. Sci. and Eng., Saga Univ.)
KUSAKARI Hideshige 1f! xU :9t iff. (Fac. Ed., Chiba Univ.)
LEE Sang Mu
if§ ~ (Inst. Phys., Univ. Tsukuba)

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LIU Guanhua IU(Inst. Mod. Phys., Acad. Sinica, China)
LOUKIANOV Serguei(JINR, Flerov Lab. Nucl. Reactions, Russia)
LUO Yixiao(Inst. Mod. Phys., Acad. Sinica, China)
MAEDA Kazushige ifrj m f[J It (ColI. Gen. Ed., Tohoku Univ.)
MAO Yajun(China Inst. Atom. Energy, China)
MATSUI Tetsuo ~ =Jt fg ~ (Yukawa Inst. Theor. Phys., Kyoto Univ.)
MATSUYANAGI Kenichi ~ tp~ iff ~ (Fac. Sci., Kyoto Univ.)
MIN Byung-Joo I¥J ~ ~ (Korea Atomic Energy Res. Inst., Korea)
MITARAI Shiro ~~Ht;E;i!~ (Fac. Sci., Kyushu Univ.)
MITSUOKA Shinichi 1t 1M] J{. ~ (JAERI, Adv. Sci. Res. Cen.)
MIYACHI Takashi g:itt! q: (Inst. Nucl. Study, Univ. Tokyo)
MIYATAKE Hiroari g Ji:t ~ -ill. (Coll. Gen. Ed., Osaka Univ.)
MORII Toshiyuki ~ =Jt 1~ fr (Kobe Univ.)
MORIKAWA Tsuneyasu ~}I1 ,t~(Fac. Sci., Kyushu Univ.)
MORINOBU Shunpei ~ ffi 13t -¥ (Fac. Sci., Kyushu Univ.)~*~(ColI. Sci., Rikkyo Univ.)
MOTOBAYASHI Toru
MOTTELSON Ben R.
(NORDITA, Copenhagen, Denmark)
MUELLER Ludwig(Univ. Padova, Italy)
MURAKAMI Takeshi f;J" 1: 1l (N at I. Inst. Radiol. Sci.)
NAGAI Yasuki 7]( =Jt(Fac. Sci., Tokyo Inst. Technol.)
NAGAMIYA Shoji 7]( g lE ~il (Columbia Univ., U.S.A.)~ ~ -X(Inst. Phys., Univ. Tsukuba)
NAGASHIMA Yasuo
NAKAJIMA Mitsuo~ 7C -X(The Graduate School at Nagatsuta, Tokyo Inst. Technol.)
NAKAMURA Shogo
f;J" lE ¥ (Fac.' Ed., Yokohama Natl. Univ.)
NAKAMURA Takashi
f;J" /Si PJ (Fac. Sci. , Univ. Tokyo)
NAKAYAMA Shintaro
Ll.Jffi*i!~(ColI. Gen. Ed. , Tokushima Univ.)
NIIZEKI Takashi *JT ~ ~ (Fac. Sci., Tokyo Inst. Technol.)
NORO Tetsuo !f g fg"* (Res. Cen. Nucl. Phys., Osaka Univ.)
ODAHARA Atsuko /J,mrntI-f-=f (Fac. Sci., Kyushu Univ.)
OGAWA Masao /J\}II ff 1:: (The Graduate School at Nagatsuta, Tokyo Inst. Techno!.)OKAMURA Hiroyuki /tn] f;J" iJ.L Z (Fac. Sci., Univ. Tokyo)(Fac. Sci., Tokyo Inst. Technol.)
ONUMA Hajime
ORIHARA Hikonojyo ~'*~Z~ (Cyclotron and Radioisotope Cen. , Tohoku Univ.)~ J{. tlf
(JAERI, Adv. Sci. Res. Cen.)
OSHIMA Masumi
OTSUKA Takaharu±j( q: til(Fac. Sci., Univ. Tokyo)
OYAIZU Michihiro /J\;W~~f7CJ1\ (Inst. Nucl. Study, Univ. Tokyo)
PENIONJKEVITCH Yuri
(JINR, Flerov Lab. Nucl. Reactions, Russia)
RUAN (GEN) Jian-Zhi ~jG !it til (ColI. Sci., Rikkyo Univ.)
SAGAWA Hiroyuki itr. }II iJ.L
(Cen. Mathematical Sci., Aizu Univ.)
SAKAGUCHI Harutaka :I:JX IJ ~il ~ (Fac. Sci. , Kyoto Univ.)
SAKAI Kenji ii =Jt ~(Fac. Sci., Tokyo Inst. Technol.)
SAKAI Mitsuo :I:JX =Jt 1t -X (Inst. Nucl. Study, Univ. Tokyo)
SAKURAGI Hiroyuki ~iJ.L Z (Fac. Sci., Osaka City Univ.)
SATO Hikaru itr... Pi!f (Natl. Lab. High Energy Phys.)
SATO Hiroshi itr... "Y:t. (Seikei Univ.)
SCHAEFER Markus(Physicalisches Inst., Univ. Goettingen, Germany)
SCHMIDT-OTT Wolf-Dieter(II, Physicalisches Inst., Univ. Goettingen, Germany)
SHIBATA Toshiaki ~ m llJ IIJi (Fac. Sci., Tokyo Inst. Technol.)
SHIMIZU Hajime
7j(~(Fac. Ed., Yamagata Univ.)
SHIMIZU Yoshifumi m7j( ~)( (Fac. Sci., Kyushu Univ.)
SHIMODA Tadashi r m lE (ColI. Gen. Ed., Osaka Univ.)
SHIMOURA Susumu r ~m !!1- (ColI. Sci., Rikkyo Univ.)
SHIRATO Syoji B ± &1'(ColI. Sci., Rikkyo Univ.)
SIGNORINI Cosimo(Phys. Dept., Inst. Nazionale di Fisica Nucl., Italy)l§ ~(Chiba Inst. Technol.)
SUGAWARA Masahiko 1fl§ -tit (Jpn. Synchrotron Rad. Res. Inst.)
SUZUKI Masayo ~SUZUKI Yasuyuki ~R Z (Fac. Sci., Niigata Univ.)
TAKADA Eiichi ~ m5R ~ (Natl. Inst. Radiol. Sci.)

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TAKAHASHI Noriaki r.Q g; ~ PJJ (Coll. Gen. Ed., Osaka Univ.)(Fac. Sci., Univ. Tokyo)
TAKAHASHI Tadayuki r.Q g; ,~, ¥TAKAKU Seisaku r.Q 7-..
f'F (Inst. Nucl. Study, Univ. Tokyo)
TAKIGAWA Noboru it@: )11 ¥t (Fac. Sci., Tohoku Univ.)
TANAKA Masahiko 83 qt ~ It (Inst. Nucl. Study, Univ. Tokyo)(Fac. Sci. Technol., Sophia Univ.)
TANOKURA Atsushi 83!f~TERAKAWA Atsuki =# )11 .. tit (Cyclotron and Radioisotope Cen., Tohoku Univ.)
THOMPSON Ian Joseph(Univ. Surrey, U.K.)
TOKI Hiroshi ± If!t tW (Res. Cen. Nucl. Phys., Osaka Univ.)
TOYAMA Takeshi 7i- W ~ (Natl. Lab. High Energy Phys.)TOYOKAWA Hidenori ~ )11 ~ WI/ (Res. Cen. Nucl. Phys., Osaka Univ.)
UENO Hideki 1::.!f ~ tit (Fac. Sci., Osaka Univ.)
UNO Masahiro *!f iE(Ministry Ed., Sci. Culture)
WAKAMATSU Masashi ;ff ~ iE i0 (Fac. Sci., Osaka Univ.)
WANG Yifang(Inst. Mod. Phys., Acad. Sinica, China)
WU Heyu ~ f[](Inst. Mod. Phys., Acad. Sinica, China):f;t ~ (Fac. Sci. Technol., Sophia Univ.)
YAMAMOTO Sukeyasu ill
YAMANISHI Teruya W gg !f -t!! (Res. Cen. Nucl. Phys., Osaka Univ.)
YAZAKI Koichi -jc ~ fa: (Univ. Tokyo)
YOSHINAGA Naotaka
71< p!;j 4(ColI. Liberal Arts, Saitama Univ.)YOSOI Masaru JIi!~3t 11 (Fac. Sci., Kyoto Univ.)
ZHOU Xiaohong(Inst. Mod. Phys., Acad. Sinica, China)

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AOI Nori W 3t ~ (Fac. Sci., Univ. Tokyo)
FUJISAWA Eiji Jii i~(Fac. Sci., Tokyo Inst. Technol.)
FUJITA Satoshi Jii 83 rg R (Fac. Sci., Univ. Tokyo)
FUJIWARA Hideki Jii 1* ~ tEt (ColI. Sci., Rikkyo Univ.)
FUKUDA Naoki 1& 83 iI!r tit (Fac. Sci., Univ. Tokyo)(Fac. Sci., Univ. Tokyo)
FUKUSAKA Shouichi 1&;I:Jj ~-\j- HARUYAMA Seigo ~ W fiE ~ (Fac. Sci., Univ. Tokyo)(ColI. Sci., Rikkyo Univ.)
HIGURASHI Yoshihide B ¥ t~
HISANAGA Isamu 7-.. 7k ~ (ColI. Sci., Rikkyo Univ.)
IINO Hayato ~!f ~ A (ColI. Sci., Rikkyo Univ.)
IKEDA Takashi HI? 83 .. (Fac. Sci., Univ. Tokyo)
ITO Kazuya fit Jii f[] -t!! (Cyclotron and Radioisotope Cen., Tohoku Univ.)
IWASAKI Hironori ;fi ~ 5.L:!f4 (Fac. Sci., Univ. Tokyo)
IWATA Yoshiyuki ;fi 83 1'1 Z (ColI. Sci., Rikkyo Univ.)
IZUMI Hideaki ~ 7Jc ~ I:lJJ (Fac. Sci., Tokyo Inst. Technol.)
KANG Sung Tae ~ JJX: ~ (ColI. Sci., Rikkyo Univ.)=# iE '!! (Fac. Sci., Kyushu Univ.)
KID ERA Masanori
KIJIMA Takeshi~:t (ColI. Sci., Rikkyo Univ.)
KOBAYASHI Syusaku /J . .
~ J.ff(ColI. Sci., Rikkyo Univ.)
KUROKAWA Nobuo ~ fiiJ ~ it (Fac. Sci., Tokyo Inst. Technol.)
MATSUZAKI Keiichi~ !!- (Fac. Sci., Univ. Tokyo)
MINEMURA Toshiyuki ~ if1 {~1T (ColI. Sci., Rikkyo Univ.)
MIYACHI Takahiko g:ttl! -ffi It (Inst. Nucl. Study, Univ. Tokyo)
MIYAZAKI Kousuke g ~ :7't 1r (Fac. Sci., Kyushu Univ.)
MIZOI Yutaka ~ 3t ~ (Inst. Nucl. Study, Univ. Tokyo)
NAGATA Kazuhiro 71< 83 lD r.t. (Fac. Sci., Univ. Tokyo)
NAKANO Joe qt!f Ml (Inst. Nucl. Study, Univ. Tokyo)
NISHIO Teiji gg ff. *~ ~il (ColI. Sci., Rikkyo Univ.)
NONAKA Takamasa !f qt ~ iE (Fac. Sci., Univ. Tokyo)
NOZAKI Mari !f IIffif Jt. llJ (ColI. Sci., Rikkyo Univ.)
OGAWA Hiroshi /J . . )I1 t!J RBPJ (Fac. Sci., Tokyo Inst. Technol.)
OHMORI Takamasa~~(ColI. Sci., Rikkyo Univ.)
ONODERA Atsushi /J"'!ff~1fz (ColI. Sci., Rikkyo Univ.)
OONISHI Tetsuya
gg rg ~ (Fac. Sci., Univ. Tokyo)

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277

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OTSU Hideaki~~ ~ ~(Fac. Sci., Univ. Tokyo)
OZAWA Yojiro /J'\iRi$=.M (ColI. Sci., Rikkyo Univ.)
SAITO Yoshitaka IN TJi 7i ~ (Fac. Sci., Univ. Tokyo)
SAKAMOTO Naoki :Ijjli
(ColI. Sci., Rikkyo Univ.)
SATO Hiromi ftL ii J1;. HiJ (Fac. Sci., Tokyo Inst. Technol.)
SATO Koji ftL ii ffIf
(Fac. Sci., Univ. Tokyo)
SATO Yoshiteru ftL TJi ~(Fac. Sci., Univ. Tokyo)
SEKIGICHI Kimiko fMJ lJ t -1- (Fac. Sci., Univ. Tokyo)
SEKINE Mizue fMJ lH ffM ~ (ColI. Sci., Rikkyo Univ.)~(Fac. Sci., Kyushu Univ.)
SHIBATA Masataka ~ EH
(ColI. Sci., Rikkyo Univ.)
SHIRATO Yoshiyuki B ± $!. L{~1T(Fac. Sci., Kyushu U niv.)
SHIZUMA Toshiyuki ~~(Fac. Sci., Tokyo Inst. Technol.)SUZUKI Ken j~
SUZUKI Masataka j~
iE $ (ColI. Sci., Rikkyo Univ.).q: ¥ (Fac. Sci., Tokyo Inst. Technol.)SUZUKI Takayuki j~
TAKEUCHI Satoshi JEt pq Jf2 (ColI. Sci., Rikkyo Univ.)
TANAKA Junichi EH r:p *41 (Fac. Sci., Univ. Tokyo)
TANIMOTO Sayaka ~I3JJ tE (Fac. Sci., Osaka Univ.)
TSUDA Masaki ~~ EB 1]! W (Fac. Sci., Tokyo Inst. Technol.)
TUCHIDA Hideo ± 00 ~ X (Fac. Sci., Kyushu Univ.)
UCHIYAMA Yasuhito pq t1J ~ t(Fac. Sci., Tokyo Inst. Technol.)
UDA Makoto ~ EB IDJX (ColI. Sci., Rikkyo Univ.)
WAKASA Tomotsugu ~ ~ ~ ftBPJ (Fac. Sci. , Univ. Tokyo)
WATANABE Hiroshi ill ~ 'j[ (Fac.Sci., Kyushu Univ.)
YAKO Kentaro ~1oJ~*i!~ (Fac. Sci., Univ. Tokyo)
YAMADA Kazunari t1J EB - fiX. (ColI. Sci., Rikkyo Univ.)
YAMANO Tetsuya t1J ff fg' -m (ColI. Sci., Rikkyo Univ.)
YANAGISAWA Yoshiyuki ~p iR if 1T (ColI. Sci. , Rikkyo Univ.)
YOKOYAMA Go II LlJ ~rJ (Fac. Sci., Univ. Tokyo)
YONEDA Kenichiro *=OOfl:-.M (Fac. Sci., Univ. Tokyo)
YONEYAMA Shigenobu *= t1J ~ {§ (Fac. Sci., Tokyo Inst. Technol.)
S(Fac. Sci., Tokyo Inst. Technol.)
YOSHIDA Toru "5 EB
YOSHIMI Akihiro "5 Je. f5 i$ (Fac. Sci., Tokyo Inst. Technol.)

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ANDO Kozo 1i Hi ~rJ .:=:.
IGARASHI Akinori li ji\I3JJ~IJ
KAN AI Yasuyuki ~1* L
KOJIMA Takao M. /J'\ ~ ~ X
MARTINSON Indrec*3
NISHIDA Masami It§ EB~
OURA Masaki~m if. W
SHIMAMURA Isao ~;t1 JIm *2
WATANABE Naoki vt:oo Ll fit

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AWAYA Yohko ~ ~ ?§. -1-*1
KAMBARA Tadashi t$
if. *2KITAJIMA Masashi ~t ~ It!=t ~LIN Chii-Dong~ **3
NAKAI Yoichi r:p~l1i NYSTROM Bosse*4
SCHMIDT-BaCKING Horst*3
URAMOTO Seiiti ~m
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*1 Chief Scientist, *2 Senior Scientist, *3 Eminent Scientist, *4 Visiting Researcher(Visitors)
ACHLER Matthias(Inst. Kernphysik, Univ. Frankfurt, Germany)
AZUMA Toshiyuki *{~1T(ColI. Arts Sci. , Univ. Tokyo)
CHIMI Yasuhiro ~ Jt ~ rJ.L (JAERI, Tokai Res. Estab.)
COCKE C. Lewis, Jr.
(Kansas State Univ., U.S.A.)
DEPAOLA Brett D.
(Kansas State Univ., U.S.A.)
ENGSTROM Lars
(Lund Inst. Technol., Lund Univ., Sweden)
FUJIMA Kazumi Hi rl3' - ~ (Fac. Eng., Yamanashi Univ.)
FUKUDA Hiroshi
00.
(Sch. Administration and Informatics, Univ. Shizuoka)
HARA Shunsuke{~11'(Dept. Gen. Educ., Tsukuba ColI. Technol.)'*:m *

278

HARSTON Michael R.
(Dept. Math., Univ. Nottingham, U.K.). ). ,HINO Ken-ichi B If 1m (Dept. Appl. Phys. Chern., Univ. Electro-Commun.)HIRAYAMA Takato lJZ LlJ if: A (Dept. Phys., Gakushuin Univ.)
HULDT Sven
(Lund lnst. Technol., Lund Univ., Sweden)
HUTTON Roger(Lund Inst. Technol., Lund Univ., Sweden)
ICHIMURA Atsushi
f1 ~-* (Inst. Space and Astr. Sci.)(Dept. Eng. Sci., Kyoto Univ.)
ISHII Keishi ;;S 1t • Z(JAERI, Tokai Res. Estab.)
ISHIKAWA Norito ;;S}ll $ A
ISOZUMI Yasuhito 11.+ft~A (Inst. Chern. Res. , Kyoto Univ.)
ITO Shin 1ft Jii A (Radioisot. Res. Cen., Kyoto Univ.)
ITOH Akio 1ft Jii f}( ~ (Fac. Eng., Kyoto Univ.)
ITOH Yoh f1t iii ~~ (Fac. Sci., Josai Univ.)
IWASE Akihiro ;fi ifJi ~(J AERI, Tokai Res. Estab.)
JAGER Martin(Inst. Kernphysik, Univ. Frankfurt, Germany)
KAWATSURA Kiyoshi )11 ffij ~!t (Fac. Eng. Design, Kyoto Inst. Technol.)
KIMURA Masahiro
fj 1£ JJ{ (Fac. Sci.: Osaka Univ.)
fj if 1:: (The School of Allied Health Sciences, Yamaguchi Univ.)
KIMURA Mineo
KINK Ilmar(Lund Inst. Technol., Lund Univ., Sweden)
ffi X (Dept. Phys., Tokyo Metrop. Univ.)
KOBAYASHI Nobuo IJ\
KOHARA Takao IJ\
q: X (Fac. Sci., Hirneji Inst. Technol.)
KOIKE Fumihiro IJ\ H!l. X tf (Sch. Med., Kitasato Univ.)
KOIZUMI Tetsuo IJ\ JF. fg X (Dept. Phys., Rikkyo Univ.)
KOMAKI Ken-ichiro IJ\4t.pjf-i!B (ColI. Arts Sci., Univ. Tokyo)
KOROBOV Vladimir 1.
(Joint Inst. Nucl. Res., Russia)
KUROKI Kenro ~1m i!~ (Natl. Res. Inst. Police Sci.)
KUROTA Naoshi ~ 83 ill it- (JAERI, Tokai Res. Estab.)
MATSUO Takashi ~ ~(Dept. Pathol. , Tokyo Med. Dent. Univ.)
MATSUZAWA Michio ~ ~~ :1m 1:: (Dept. Appl. Phys. Chern., Univ. Electro-Commun.)
MERGEL Volker(Inst. fur Kernphysik, Germany)
MITAMURA Tohru ~83fj M (Fac. Eng., Hirneji Inst. Technol.)
MIZOGAWA Tatsumi ~ JII 1lR E (Nagaoka ColI. Technol.)
MOKLER Paul
(GSI, Germany)
MUKOYAMA Takeshi rQ) LlJ ~ (Inst. Chern. Res. , Kyoto Univ.)
NAKAMURA Masato q:t fj iE A (CoIl. Sci. Technol., Nihon Univ.)
NELMS Nick
(Leicester Univ., U.K.)
NISHIDA Nobuhiko @ 83 ffi 1$ (Fac. Sci., Tokyo Inst. Technol.)
OHTANI Shunsuke~ {~1r(Inst. Laser Sci., Univ. Electro-Commun.)
OKAYASU Satoru 1M] tt;; 'I~ (JAERI, Tokai Res. Estab.)
OKUNO Kazuhiko b'J. If fD ~ (Dept. Phys., Tokyo Metrop. Univ.)
SAKATA Hideaki :l:Ji 83 ~ at) (Fac. Sci., Tokyo Inst. Technol.)
SAKURAI Makoto f* 1t ~ (Fac. Sci., Kobe Univ.)
SATO Hiroshi f~ iii ~ ~ (Fac. Sci., Ochanomizu Univ.)
SATOH Kazuhiko f~ iii - ~ (Fac. Sci., Tokyo Inst. Technol.)
SATOH Yukinori f~ iii $ *c. (Res. Inst. Sci. Meas., Tohoku Univ.)
SEKIOKA Tsuguhisa ~ 1M] HUPJ 7,. (Fac. Eng., Himeji Inst. Technol.)~(Res. Cen. Nucl. Sci., Univ. Tokyo)
SHIBATA Hiromi ~ B3
SHIMA Kunihiro 8b ~ tf (Tandem Accel. Cen., Univ. Tsukuba)
SHIMAKURA Noriyuki ~ ~ *c. Z(Fac. Sci., Niigata Univ.)
SUZUKI Isao ~ft"#J (Electrotech. Lab.)TAKAYANAGI Toshinobu ~:WP {~~ (Dept. Phys., Sophia Univ.)
TANG Jian-Zhi(Dept. Physics, Univ. Tennessee, U.S.A.)TAWARA Hiroyuki ~ tf Z (Natl. Inst. Fusion Sci.)TERASAWA Mititaka '# ~~ it q: (Fac. Eng., Himeji Inst. Technol.)(Inst. Appl. Phys., Univ. Tsukuba)
TOSHIMA Nobuyuki pi Ii(~ ffi $WAKIYA Kazuyoshi nh1 ~ - ~ (Dept. Phys., Sophia Univ.)(Dept. Appl. Phys. Chern., Univ. Electro-Commun.)
WATANABE Shinichi Vi ill. ffi YAGISHITA Akira :WP p
Pt)(Natl. Lab. High Energy Physics)
YAMAZAKI Yasunori LlJ ~ ~(ColI. Arts ScL, Univ. Tokyo)

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279

YODA Jun ~ IE iOO (N atl. Res. Lab. Metrol.)
YOSHINO Masuhiro 5 If :tiif. ru.. (Lab. Phys., Shibaura Inst. Technol.)
ZORAN Valriiu L.
(Inst. At. Phys., Inst. Nucl. Eng., Rumania)ZOU Yarning ~B .3E fiJI (Jiao Tong Univ., China)(Students)
fr (Dept. Phys., Sophia Univ.)
CHIBA Daisuke =f ~FAN Xiao Jun ~ DJt n (Fac. Eng. Himeji Inst. Technol.)
FUJINO Atsushi ii If *1c (Dept. Phys., Rikkyo Univ.)
FUJIWARA Masamichi ii
iE ~iMJ (Dept. Eng. Sci., Kyoto Univ.)
KANEKO Shinichi 1t -f- .. ~ (Fac. Sci., Tokyo Inst. Technol.)
KAWAE Sotaro )IIrr**.M (Dept. Phys., Sophia Univ.)
KIMURA Yasuyuki
11 $ Z (Dept. Eng. ScL, Kyoto Univ.)
NAKANO Tomohide 1JP If 1X.. ~ (Dept. Eng. Sci., Kyoto Univ.)
OKUMA Ryujift~ ~(Dept. Phys., Rikkyo Univ.)
ONO Yasuhiro /j, If
ru.. (Fac. Sci. Tokyo Inst. Technol.)
SAWADA Hirokazu ~ HI ~ f[] (Fac. Sci., Tokyo Inst. Technol.)
SHIMIZU Masakuni m- 71< iE(Fac. Sci., Tokyo Inst. Technol.)SUZUKI Hajime it(Fac. Eng., Kyoto Univ.)
TAKEUCHI Hiroko 1t pq ~ -f- (Dept. Phys., Ochanomizu Univ.)
TAMAGAWA Yoshihisa 3i )11 1¥-!A (Dept. Phys., Sophia Univ.)
TSUCHIDA Hidetsugu .± HI ~(Fac. Eng., Kyoto Univ.)

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FUJITA Ayumi iilE~~h*1
ISHIDA Katsuhiko ;fi EH MJ ~KOYAMA Akio /j, t.lJ ag Iii
MATSUZAKI Teiichiro fJ}~tt1tmf!~*3
NAKAMURA Satoshi N. q:t 11 fg"
YAGI Eiichi )\5R ~*3**

HIGEMOTO Wataru f£'~i*1
KADONO Ryosuke r~ lff ~ :W!KRISHNAMURTHY Vemuru*2
NAG AMINE Kanetada 7k ~ ~ 1~,*4
WATANABE Isao ill ~ J}] Iii*1 Special Postdoctoral Researcher, *2 Visiting Researcher, *3 Senior Scientist,*4 Chief Scientist(Visitors)
AKIMITSU Jun fX -:It f,4! (ColI. Sci. Eng., Aoyama Gakuin Univ.)
ASAI Kichizo i~
5 Ji (U niv. Electro-Commun.)
BRIERE Tina Marie(Dept. Phys., State Univ. New York, Albany, U.S.A.)DAS Prasad Tara
(Dept. Phys., State Univ. New York, Albany, U.S.A.)
HASHIMOTO Masashi ~~ ~(JAERI, Tokai Res. Estab.)
KATO Mineo 110 JIi. !if 1:: (JAERI, Tokai Res. Estab.)
KINO Yasushi
lff Jl;t; (Fac. Sci., Tohoku Univ.)
KUROSAWA Kiyoyuki ~ ZR
1T (JAERI, Tokai Res. Estab.)
MACRAE Roderick M.
(JSPS Fellowship)
MATSUSHITA Akira ~ rfiJI (Contract Researcher)
NISHIDA Nobuhiko g§ EH ffi ~ (Fac. Sci., Tokyo Inst. Univ.)
NISHIYAMA Kusuo g§ LiJ
1:: (Fac. Sci., Univ. Tokyo)
PRATT Francis Laurence(Dept. Phys., Univ. Oxford, U.K.)
SHIMOMURA Koichiro r11~~f!~ (Fac. Sci., Univ. Tokyo)
STRASSER Patrick(Nucl. Phys. Div., Inst. Nucl. Study, Univ. Tokyo)
TANASE Masakazu fflij iii iE f[] (JAERI, Tokai Res. Estab.)
TORIKAI Eiko 1~.1l9!: -f- (Fac. Eng., Yamanashi Univ.)
YONEDA Akira
IE Jt (Messege Co., Ltd.)

*

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(Students)
DAWSON Wayne(Fac. Sci., Univ. Tokyo)
SASAHARA Takafumi 1if.q:)( (Fac. Sci. and Eng., Chlio Univ.)

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280

Magnetic Materials Laboratory
KATSUMATA Koichi Mf.x *1i. _*1
OKADA Takuya 1M] B3 ~ -tl! *2*1 Chief Scientist,*2 Senior Scientist,

Inorganic Chemical Physics Laboratory
AMBE Shizuko ~ $ W:rMATSUO Yukari ~~EI31(fIJ

MATSUDA Masaaki ~ B3 ~ aBa
TATARA Gen $ /:l 1l v**3
*3 Visiting Researcher

MAEDA Kunuko
TAKAMI Michio

WIB3n:r-i¥li Ji m ~** Chief Scientist**(Visitors)
1~ 1E(Dept. Fisheries, Kyoto Univ.)
ARAI Nobuaki J1t.
ISHII Keizo ;fi!f ~ (Cyclotron Radioisot. Cen., Tohoku Univ.)
KAWAI Jun iiiJ 1} if1) (Dept. Metallurgy, Kyoto Univ.)

Nuclear Chemistry Laboratory
AMBE Fumitoshi ~ $ )( fix*
ITOH Yoshiko W 7i :rKOBAYASHI Yoshio /J\~
OHKUBO Yoshitaka *?"H~~~i¥li* ** •* *,±ENOMOTO Shuichi tI~
IWAMOTO Masako ;fiiE .:::;MAEDA Haruka WI B3 ~ "b~* Chief Scientist(Visitors)
AMANO Ryohei 7C ff 1l1JZ (Pac. Med. , Kanazawa Univ.)
ASAI Kichizo i~
6" Ji:l (U niv. Electro-Commun.)
BABA Hiroshi j~ i£(Fac. Sci., Osaka Univ.)
CHOU Ju(Changchun Inst. Appl. Chern., China)
ENDO Kazutoyo :il Ki fD ~ (Showa ColI. Pharm. Sci.)FURUKAWA Michiaki il)I1 ~ PjJ (Fac. Sci. , Nagoya Univ.)
FURUSATO Naohisa il lIt Ll?" (ColI. Sci. Eng., Aoyama Gakuin Univ.)
HIRUNUMA Rieko !k¥.fgfIJ~I:r- (Showa ColI. Pharm. Sci.)
HSIA Yuanfu ][ 5C 1l (Dept. Phys. , Nanjing Univ. , China)
HULETT D. Lester(Oak Ridge Natl. Lab., U.S.A.)ITO Nobuhiko W Ki 1$ ~ (Sch. Veter. Med. Animal Sci., Kitasato Univ.)
ITO Yasuo W Hi ~ ~ (Res. Cen. Nucl. Sci. , Univ. Tokyo)
KANAZAWA Ikuzo ~ if{ ~ -=: (Fac. Educ. , Tokyo Gakugei Univ.)
KATAYAMA Masayuki J:t LlJ yt: Z (Fac. Agr., Univ. Osaka Pref.)
KIMURA Kan
It ~ (ColI. Sci. Eng., Aoyama Gakuin Univ.)
KOJIMA Sadao /J\ ~ ~ ~ (Nucl. Med. Cen. , Aichi Medical Univ.)
KOMURA Kazuhisa /J\ It fa 7-.. (Pac. Sci., Kanazawa Univ.)
KUNUGIYAMA Iwao fI" LlJ Jilt (Sch. Veter. Med. Animal Sci., Kitasato Univ.)
LIU Bin JIJ ~~ (Dept. Tech. Phys., Peking Univ., China)
MINAI Yoshitaka ~ ~ {i q: (Pac. Sci., Univ. Tokyo)
MURAKAMI Hideoki It 1:
J!. (Fac. Educ., Tokyo Gakugei Univ.)
NAKAMURA Jin q:t It t
(Univ. Electro-Commun.)
NASU Saburo J}~ ~j -=.e~ (Fac. Eng. Sci., Osaka Univ.)
OKAMOTO Yoichi 1M]~$ (Showa ColI. Pharm. Sci.)OZAKI Takuo ~ Jijf ~.e~ (Fac. Sci., Univ. Tokyo)
PENG Zhilin ~ ~a(Wuhan Univ., China)
SAITO Tadashi
Hi Li (Fac. Sci., Osaka Univ.)
SHIBATA Sadao ~ B3 ~ X (Natl. Inst. Radiol. Sci.)(Inst. Nucl. Study, Univ. Tokyo)
SHIBATA Seiichi ~ B3 ~ SHINOHARA Atsushi 1Il rnt Jf- (Fac. Sci., Nagoya Univ.)

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281

TANAKA Akira EB 4t ~ (Showa ColI. Pharm. Sci.)
WANG Haifang . (Peking Univ., China)
WEGINWAR Rajiv G.
(Chandrapur ColI. Engineer., India)
YANAGA Makoto ~ 71< ID£ A (Jikei Univ. Sch. Med.)YASUDA Hiroshi 1* EB ~ i0 (NatL Inst. Radiol. Sci.)
YOKOTA Yuko ;ntt EB-f- (ColI. Sci. Eng., Aoyama Gakuin Univ.)
YOKOYAMA Akihiko ;ntt LlJ IlJJ fJ (Fac. Sci., Osaka Univ.)
YOSHIDA Yutaka
83 If (Shizuoka Inst. Sci. Technol.)*a(Students)~ ~!A(Fac. Sci., Nagoya Univ.)
DAIRAKU Tomohisa
ENDO Rieko )iJJjJ.lft-f- (Fac. Sci., Tokyo Metrop. Univ.)
HANYU Takafumi )J3J 1:: .. )( (Showa ColI. Pharm. Sci.)
HAYAKAWA Nobutaka -!J! )1/ 15 ~~ (Showa CoIl. Pharm. Sci.)
INOUE Takakazu
L .. f[] (Fac. Sci., Osaka Univ.)
ITOH Masahiro W JIi {§(Shizuoka Inst. Sci. Tech.)
ITOH Naoya W JIi ill: ~t (ColI. Sci. Eng., Aoyama Gakuin Univ.)
ITOU Mayu W JIi Jff EI3 (Sch. Veter. Med. Animal Sci., Kitasato Univ.)
aBa(Sch. Veter. Med. Animal Sci. , Kitasato Univ.)
IWATSUKI Akira :fi R
KASAHARA Ichiro ~ JJ ~ t!)} (Showa ColI. Pharm. Sci.)
KATAYAMA Osamu h LlJ 111: (Fac. Sci., Toho Univ.)
KAWASAKI Yuko )1/ ~ #i -f- (Fac. Sci., Toho Univ.)
KAWASHIMA Yasuko ')1/ ~-f- (Sch. Hygien. Sci. , Kitasato Univ.)
MASUDA Yasuhisa ~ 83 ~!A (Shizuoka Inst. Sci. Tech.)
MORIMOTO Shinya ~iDG (Fac. Sci. , Osaka Univ.)
MUKAI Kazuhiko loJ flJ fJ (Fac. Sci., Osaka Univ.)(Fac. Sci., Nagoya Univ.)
MURATA Chihiro ;f:'t 83 =f
MUROYAMA Toshiharu ~ LlJ 1~ ~~ (Fac. Sci., Nagoya Univ.)
NAKAGAWA Akihiro 4t )11 ~(Shizuoka Inst. Sci. Technol.)
NAKAJO Terunobu 4t f~ ~ 1$ (Tokyo Gakugei Univ.)
NISHIZAWA Satoshi g§ if{(Sch. Hygien. Sci ., Kitasato Univ.)ODA Hirotaka /J'\ EB Jt.. (Fac. Sci., Nagoya Univ.)
ODA Kaori /J'\ 83 W ~ (Showa ColI. Pharm. Sci.)
OIKAWA Shinji & )11 • PJ (Fac. Sci., Kanazawa Univ.)~ 71<(Tokyo Gakugei Univ.)
OSHIMA Nagayasu
SASAKI Jin fti:-'<* t. (Tokyo Gakugei Univ.)(Shizuoka Inst. Sci. Technol.)
SAWADA Naoto ~ 83 ill: A
SEKIGUCHI Akiko ~ IJ IlJJ -f- (ColI. Sci. Eng. , Aoyama Gakuin Univ.)
SHIBUYA Eriko i!Z:§'~ItIJ-f- (Showa ColI. Pharm. Sci.)
SOGA Kyoko ~ ~ ~ -f- (Fac. Sci., Nagoya Univ.)
SOTOGAKU Naoki j} jl} ill: 1M (Showa ColI. Pharm. Sci.)(Fac. Sci., Univ. Tokyo)
TAKAHASHI Yoshio ;Wj frjj ~TANAKA Kenya EB 4t -liJf -t!1 (Fac. Sci. Technol., Chuo Univ.)
YASHIKI Kazuhiro ~ im ~ &. (Fac. Sci., Toho Univ.)

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Chemical Dynamics Laboratory
KIMURA Kazuie *;f:'t ~ f(Visitor)
KAZAMA Shigeo

J!\. rJ;l, m~ft

USHIDA Kiminori(Dept. Phys. , Chuo Univ.)(Students)
HONG Wan i:!t 7t (Dept. Chern., Univ. Tokyo)
KAWAKAMI Daisuke filJ L(Dept. Phys., Chuo Univ.)
KOHAMA Takanori /J'\ ~ ~ i\!( (Dept. Phys., Chuo Univ.)

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282

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Cellular Physiology Laboratory
HANAOKA Furnio :rt Itfi) ')( ~i*
YATAGAI Furnio :frEBJlXx*** Chief Scientist,

KITAYAMA Shigeru~t LiJ

itt** Senior Scientist(Visitors)
ANDO Koichi tfi ii J.!. (Natl. Inst. Radiol. Sci.)
FUKUMURA Akifurni :m; lj PJI(Natl. Inst. Radiol. Sci.)
FURUSAWA Yoshiya l!l ~ {t -ill. (Natl. Inst. Radiol. Sci.)
HAMA Yoshirnasa ~ ~ {§ (Sci. Eng. Res. Lab., Waseda Univ.)~(Fac. Med., Keio Univ.)
HASHIMOTO Shozo
HOSHINO Kazuo 1[!ff - ~i (Natl. Inst. Radiol. Sci.)IIZUKA Masayuki ji ±£ iE Z (Natl. Inst. Radiol. Sci.)
ITO Hisao W 7.. X (Sch. Med., Chiba Univ.)
ITOH Hiroko W ii ~ -f- (N at I. Inst. Radiol. Sci.)(Natl. Inst. Radiol. Sci.)
ITSUKAICHI Hirorni 1i. B rtH} 0 h
KANAI Tatsuaki ~ =tt j! PJI (Natl. Inst. Radiol. Sci.)
KASAl Kiyorni 11. =tt m- ~ (Natl. Inst. Radiol. Sci.)
KAWACHI Kiyornitsu filI pq m-:J't (Natl. Inst. Radiol. Sci.)
KIKUCHI Masahiro *J:t1B iE t-!!J (JAERI, Takasaki Rad. Chern. Res. Estab.)
KIMOTO Masafurni
5C iE(Natl. Inst. Radiol. Sci.)
KOBAYASHI Yasuhiko IJ'\ ~* ~ ~ (JAERI, Takasaki Rad. Chern. Res. Estab.)
KOHNO Toshiyuki iliJ!ff f~ Z (Natl. Inst. Radiol. Sci.)
KOIKE Sachiko IJ'\ at!. ¥ -f- (Natl. Inst. Radiol. Sci.)
KOJIMA Eiichi IJ'\ §b 5R (Natl. Inst. Radiol. Sci.)
KOSAKA Toshifurni IJ'\:f:JX f~ X (Dept. Vet. Radiol., Nihon Univ.)
KUBOTA Nobuo ~ EB :§: X (Fac. Med., Yokohama City Univ.)
MATSUFUJI Naruhiro ~ ii ~ ill. (Natl. Inst. Radiol. Sci.)
McINTYRE Cindy L.
(Radiobiol. Unit, Med. Res. Counc., U.K.)
1E1l (Natl. Inst. Radiol. Sci.)MINOHARA Shinichi ti
MIYAHARA Nobuyuki g-ffi ¥ (Natl. Inst. Radiol. Sci.)
MURAISO Chidori lj ~ ~(N at I. Inst. Radiol. Sci.)
MURAKAMI Masahiro lj 1::. iE ill. (N at I. Inst. Radiol. Sci.)
NAKAI Hirokazu r:p =tt ill. to (Dept. Agric., Shizuoka Univ.)
iJ.L. (Dept. Gen. Cult., Okayarna Univ.)
OHARA Hiroshi(Fac. Med., Univ. Tsukuba)
OKUMURA Toshiyuki ~ lj fix Z
SASAKI Hiroshi ftc/.Z* iJ.L. (Fac. Med., Kyushu Univ.)
SHIKAZONO Naoya !'[ IjJ iR ~ (JAERI, Takasaki Rad. Chern. Res. Estab.)
SOGA Furninori ~ ft X '§ (Inst. Nucl. Study, Univ. Tokyo)
SUDO Michio ~JiJii~~~i (Natl. Inst. Radiol. Sci.)TAGUCHI Yasuko EB lJ ~ -f- (Natl. Inst. Radiol. Sci.)
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理化学研究所
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