ISSN 0289-842X

RIKEN
Accelerator
Progress Report
vol.

19

理化学研究所the Institute of Physical and Chemical Research

RIKEN Accelerator Progress Report 11 (0)(6) Ih

January-December U'71 (Q)~*

Jm i I:: :fitf ~ jiJf
the Inslilute of Physical and Chemical Research
Walco-shi, Saitama, 35
JAPAN

'-0'

Editorss. AmbeY. AwayaY. Chiba

Y. GonoT.lnamura

H. Kamitsubo

s. Kitayama

T. Watanabe

E. ·Yagi

This volume contains recent information of the accelerators at RIKEN (IPCR), informal
reports and abstracts of papers which will be published at scientific meetings or in
publications by staff members, guests, and visitors.

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.

CONTENTS
Page
I.

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1

II.

OPERA TION OF ACCELERATORS

III.
1.

1.

Cyclotron Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ............ 3

2.

RILAC Operation ............................................ . ........... 53.

T ANDETRON -Operation ................................................ 6

RESEARCH ACTIVITIES
Nuclear Physics
1.

Analyzing Power Measurements of (d, 2He) Reactions on 12C,
13C, 14 N, and 90Z r ........................................................ 7

2.

Beta Decay of Polarized Nucleus 15C Produced in Heavy-Ion
Reaction ................................................................ 10

3.

Nuclear Polarization Produced by a Tilted-Foil Method in
35.5 MeV Al Ions ............................................ ............ 12

4.

Deuteron D-State Effects on the Vector Analyzing Powerand Polarization in (d, p) Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . .. ............ 14

5.

Self-Consistent Transport Coefficients for Damped Large Scale
Collective Motion ............................................ ...... . . . . .. 16

6.

Application of Time-Dependent Mean-Field Theory to
Heavy-Ion Collisions ...................................................... 177.

High-Spin States in llOSn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . .. 188.

High-Spin States in 112Sn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ............ 20

9.

Enhanced E2 Transitions between 9- and 8- States in llOSn and
112Sn .................................................................... 22

10.

Aligned Bands in Ge Isotopes in the Interacting Boson Model .............. 25

11.

The sdg Interacting Boson Model Applied to 16sEr .......................... 27

12.

Inelastic Scattering of Polarized Protons Exciting the y- andOctupole-Vibrational Band in 152Sm at 65 MeV ............................ 29

13.

Multiple Coulomb Excitation of 161Dy . . . . . . . . . . . . . . . . . . . . . . . . .. ............ 32

14.

The Life-Time of the Levels in the Ground-State Band in 173Yb

15.

High-Energy Single-Proton States Studied by y-Triton
Coincidence Measurement in the 20SPb(a, t)209Bi Reaction .................. 36............ 34

16.

Page
Search for New Isotopes of Neptunium . . . . . . . . . . . . . . . . . . . . . . .. . . .......... 38

17.

Low Energy Nuclear Fission of 237N p . . . . . . . . . . . . . . . . . . . . . . . . . . .... .. .... . . 40

18.

Low Energy Nuclear Fission of 238U: Correlation between
Angular Anisotropy of Fission Fragment and Fragment Mass

. . . . . . . . . . .. 42

Decay Properties of Light Einsteinium Isotopes. .. . ........ 44

19.

2.

Atomic and Solid-State Physics
1.

Electron Stripping Cross Sections from Multi-Charged Ions by
Neutral Atoms Using Born Approximation Calculation ......... . .......... 46

2.

(p +J1. - ) Formation Cross Section for Collision of J1.+ with (P-p):

Total and Differential Cross Sections ................. . .................... 48
3.

Continuous Energy State Model for Charge Transfer in
Collisions of Fully Stripped Ions with Hydrogen Atoms...... . ..... 50

4.

Effect of Minima in Generalized Oscillator Strengths on Integral
Cross Sections for Excitation of Atoms ........... . .......... . .. ..... .. . .. . 52

5.

Theory of Radiative Electron Capture: Relativistic Treatment
and Gauge Invariance . ......... . .... . .... . ... . ... .. ... . ... .. . . . . . . . . . . . .. 55

6.

Two-Electron Diatomic Molecule: Program Package "MADAM" .... . .... . .. 58

7.

Quantum Mechanical Treatment of Charge-Exchange Processes
Using Frame Transformation . ............................ . .............. 60

8.

The Rotationally and Vibrationally Resolved Photoionization of
H2 by 736A Line .. ...... . ........ . .. . . . .. . ......... . ..... .. ............. 61

9.

Peak Fitting in Beam-Foil Spectrum ............... . . . . . .. . ....... . ....... 62

10.

Tilted-Foil Method with Charge-Nonequilibrium Ions . .. . .......... . ....... 64

11.

Measurement of Lifetimes for Highly-Ionized Aluminium Atoms .... .. ...... 65

12.

Electron Distribution in M- and L-Shells of 33 MeV Ar-Ions in
Solid Targets .. ... . .. .. .. .. . .... . ........ . . . . . ... . ...... . ........ . .... . .. 66

13.

Target Thickness Dependence of Ka Satellite Intensities of
Ar Ions Passing through Thin Carbon Foils. . . . . . . . . . . . . . . . . . .. .. . ... . .... . 68

14.

Cu K X-Rays from Cu Ions on C Target and C Ions on Cu
Target ....... . .................................... . ............ . ........ 70

15.

Measurement of Impact-Parameter Dependent Probabilities andTotal Cross Sections for Target K-Shell Ionization by He Ions . . ... .. ... . ... 73

16.

Data Analysis of Recoiled Ar Ions in the High Charge States by
Means of a "Compound Atom" Model ... .... . ... . ........... . ... . .... . ... 75

17.

Highly-Charged Carbon Ions Produced from Carbon-Containing... . ..... ... ... . .. ... ... 77~olecules in Collisions with Energetic Heavy Ions

Page

3.

18.

Projectile Dependence of Ar- LMM Auger Electrons Ejectedfrom Ar Target by Heavy-Ion Impact (II) . . . ..... . ... .. ... . ............. . .. 79

19.

Projectile Dependence of Energy Distribution of Secondary
Electrons from Al .. .... .... . ........................ . ................... . 81

20.

Chemical Effects on LVV Auger Spectra of Al and Mg .. . . . . . . .. ....... . .. 83

21.

Emission Mossbauer Study of 151Gd Adsorbed on YIG .......... . ........... 85

22.

119Sb Emission Mossbauer Study on Quenched-in Vacancies inGold ......................... . ....... . .. .. ....... . . . ........ . ........... 87

23.

TDPAC of y-Rays Emitted from lllCd(+-l ll In) in Fe304 (II) ................ . . 89

24.

Towards Macroscopic Measurement on Radioactive 6He
Diffusion in Metals . . ..... .. . . ................. . ... . ..................... 91

25.

Eu-Ion Implantation in CaF 2 . . ... .. .. . ...... .. ... . .. .. .. .. .... . ........... 93

26.

Thermal Extraction of Krypton in Aluminum Using Mass
Spectrometer ... . .. .. ..... . .. .. ... . ..... .. ... ..... . . .... . ............. . .. 94

27.

Effect of Small Amount of He on Ductility of Various Metals
and Alloys .... .. ... . ..... . . . ..... . ... .... ... . ............... . .. . .... .. .. 96

28.

Plasma Surface Interaction- ERD Measurement of Deuterium
Retention near Surface of TiC and Graphite Irradiated with
Dissociated D Atoms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... . .. 98

29.

Quantitative Analysis of Hydrogen in Titanium Carbide by ERD ... . .... . ... 100

30.

Lattice Location of H in Ta as Observed by a Channeling
Method ... . ............... .. . . .. . .............. . ............. . . .. ........ 102

31.

Direct Evidence of Stress-Induced Site Change of H in V
Observed by a Channeling Method ........................ . . .. . ..... ... . . . 104

Radiochemistry and Nuclear Chemistry1.

Production of Radioisotopes and Preparation of Labelled
Compounds . . . ..... .. .... . .. . ..... . .... ... .. ....... . . . . .............. . ... 106

2.

29 Al Radiotracer Study on Adsorption of Aluminum by Soils ... . .. . .... . .... 108

3.

Preparation of N on-Carrier-Added 45Ti and 69Ge and Their
Uptake by Plants ....... . ... . .... .. .. . ...... . .. . . ... . ... .... . ... . .... . ... 110

4.

Charged Particle Activation Analysis ..... . .... .. ...... . ...... .. ........... 112

5.

Utilization of N -15 as Activable Tracer ..... . . .. . . ...... . ... . ....... .. ... . . 114

6.

Simultaneous Charged Particle Activation Analysis of Carbon
and Boron in Gallium Arsenide .. ......... . .... . .... . ..... . . . . ... .......... 116

7.

Application of PIXE to Medical Science (III) ... . ............ . ... .. . . .... . . 118

8.

Geochemical Application of PIXE (1) .. . . . .. ... . .... . ...... . ....... . ....... 119

Page

4.

5.

9.

Hydrogen Analysis in Thin Surface Layer of Amorphous Siliconby the Rutherford Forward Scattering Method ............ . ............... 121

10.

Detection Limit of Hydrogen in Elastic Recoil Detection
Analysis . . . ............. . ........................ . . . .. . .. .... ........... 123

1l.

Heavy-Ion Rutherford Backscattering Analysis Applied to theElectronic Materials .. . ........ ....... ... . ...... . .......... . ... . ......... . 125

12.

Elastic Recoil Analysis of Hydrogen for the Study of theFormation of Radiation-Resistant Oxide Film on Silicon ..... . ........... . .. 127

13.

Utilization of the DeHe, p)4He Reaction in Quantitative
Analyses with High Sensitivity of Deuterium in Solids. . . . . . . . . . . ........... 129

14.

Comparative Mossbauer and TDPAC Studies on the
After-Effects of the EC Decays of 119Sb and lllIn in a-Fe203 ................ 131

15.

Time Differential Perturbed Angular Correlation Study on(lllIn--+) ll lCd in In203 ' . .. . ............ . ............... .. ..... . .. .. . . ....... 133

Radiation Chemistry and Radiation Biologyl.

Cellular Lethal Effect of a-Particles on Four Different Cell
Lines .... . ...... .... .... .. ...... .. .. . ... . ...... . .................. . ...... 135

2.

Oxygen Effects on Inactivation of the Human Melanoma Cells
by Accelerated a-Particles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...... .. ... 136

3.

Microdosimetric Considerations of the Effect of Heavy Ions on
Microorganisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . ......... 138

4.

High-Density Excitation by Heavy-Ions: Formations of Dimer
and Clusters of Helium-Excimers in Condensed Phase ....... .... ..... .. . . .. 141

Instrumentation
1.

Test of EBIS for Electron-Ion Merging Beam Experiment . . .. . . . ...... . ... . 144

2.

Test of a Position-Sensitive Parallel Plate Electrostatic
Spectrograph ... . ....... .. ... . ............ .. . . ....... . .... . .. . ....... . ... 146

3.

Parallel Plate Avalanche Counters .. . . . . .. . .. ...... . . ... ... . ....... . ...... 148

4.

Performance of a BaF2 Scintillator as a Charged Particle
Detector .... . ... . ..... . ............................... .. .... . .. . ........ 151

5.

Response of BaF2(Powder)-Plastic and BaF2 Scintillators toProtons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........... 152

6.

RIKEN BGOACS and Ch~teau de Cristal. ....... ... . 154

7.

Radioactive Beam Production at GANIL.... . . .. .... 155

8.

Monte Carlo Calculations of Detector Response to High Energy
Photons . . ....... .... ..... . ... . .. . .... . ............ . ... . .... " .. ...... . .. . 156

Page

IV.

V.

9.

A Test Apparatus for Resonance Ionization Spectroscopy ofAtomic Nuclides .......................................................... 157

10.

Development of the Ion Guide Isotope Separator On-Line for
Heavy Ion Induced Reaction .................................. . ........... 158

1l.

Proposal for Applying Piezoelectric Actuators to Mossbauer
Drive System ................................................ . ........... 159

12.

CAMAC Data Acquisition System with an Auxiliary Crate
Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . ........... 160

NUCLEAR DATAl.

Status Report of the Nuclear Data Group .......................... . ....... 162

2.

On Nuclear Data for Production of 123 1............ 163

ACCELERA TOR DEVELOPMENTl.

Present Status of RIKEN Ring Cyclotron Project .......................... 166

2.

Present Status of RF Resonator for RIKEN Ring Cyclotron ................ 168

3.

Present Status of RF Power Amplifier for RIKEN Ring
Cyclotron .................................................... . ........... 170

4.

Progress in Sector Magnets for RIKEN Ring Cyclotron ........ . ........... 172

5.

Power Supply of the Sector Magnets .......................... . ........... 174

6.

Magnetic Field Measurement for RIKEN Ring Cyclotron ....... ........... 178

7.

Beam Injection and Extraction System of RIKEN Ring
Cyclotron ..................................................... . ........... 180

8.

Beam Transfer Line from RILAC to RIKEN Ring Cyclotron. . .. . ........... 182

9.

Model Study of the Beam Buncher ........................................ 184

10.

Control System of RIKEN Ring Cyclotron ................................ 186

1l.

Sequential Control Using an Intelligent Interface Module .................. 188

12.

Practical Use of an Intelligent CAMAC GP-IB Controller............ 190

13.

Cryopumps for RIKEN Ring Cyclotron Vacuum Chamber. ........... 191

14.

Outgassing Rates of Materials Used in the Vacuum Chamber for
RIKEN Ring Cyclotron ......................... : . . . . . . . . . . .. . ........... 193

15.

Evaluation of an Outgassing Rate from Pretreated Elastomers .............. 195

16.

AVF-Cyclotron as an Injector ............ . ............................... 197

17.

Sixth Harmonic Acceleration in the Baby Cyclotron ........................ 199

18.

VI.

Page
Proposal of Synchrotron Radiation Source .............. . .............. ... 201

19.

Characteristics of Radiofrequency Field in an Alvarez-Type
Resonator Having Chain-Like Electrodes: with Varying
Cell Length . .... ...... . ................ . ....... . .. . .......... . ........... 203

20.

Development of an Electrostatic Quadrupole Lens Having Beam
Steering Capability ...... , ..... . ......... . ................... . ........... 207

21.

Non-Destructive Measurement of Beam Intensity ........... . .. . .... ... .... 210

22.

RILAC Ion Source ............. . ................ . ... . ... .. ................ 212

23.

Test of the RIKEN ECR2 . . . . ... . .... . .... . ... ... ............ . .. .. ....... 214

24.

Characteristics of a Hot Plasma for Highly Charged Ion Source .... ........ 216

RADIA TION MONITORING
1.

Calculation for the Neutron Shielding Design of RIKEN Ring
Cyclotron Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . ... .. ... . 218

2.

Routine Monitoring of RIKEN Accelerators. . . . . . . . . . . . . . . . . . .. . . . .. .. .. . . . 221

3.

Leakage-Radiation Measurement in the Underground Passage of
the Cyclotron Building. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . ..... ... 223

VII.

LIST OF PUBLICATIONSVIII.

LIST OF OUTSIDE USERS AND THEIR THEMES ....... ... ........... . ... .. ... 236

IX.

LIST OF SEMINARS ...................... .... .. . .................. . ............ 237

X.

LIST OF PERSONNEL .. . ... . ......................... .. . . ...................... 239
AUTHOR INDEX. ........................... ... .. . ......... ... ........ 224

1

I. INTRODUCTION
H. Kamitsubo
Collaborative research work using the 160 cm
cyclotron and the variable-frequency heavy-ion
linear accelerator (RILAC) has been extensively
performed this year. In addition to these two
accelerators, a 1 MeV electrostatic accelerator(T ANDETRON) and a 250 k V ion implanter
were dedicated to the collaborative researchworks. During the past one year these accelerators have been operated steadily as before.
A variety of studies on nuclear physics havebeen continued mainly using the 160 cm cyclotron. Collaboration with other institutions has
also been continued on nuclear physics.
Well-developed rotational bands were observed experimentally in the excited states of Sn
isotopes which are spherical at the ground states,
owing to the BGO anti compton spectrometers.
Detailed information on the transition properties
in rare earth nuclei was obtained from the Coulomb excitation experiments performed .at theJapan Atomic Energy Research Institute. Lightion induced reactions were studied at the
Research Center for Nuclear Physics, Osaka
University, by using polarized protons anddeuterons, and an important role of a collective
hexadecapole mode in the y-vibrational band of
152Sm was revealed.
Theoretical studies of nuclear structures were
performed by extending the interacting bosonmodel to include s-bosons and a particle alignment. Heavy ion reaction mechanisms were alsostudied in terms of the transport theory and thetime-dependent H artree- F ock theory.
International collaboration between RIKEN
and the IN2P3 (Institut National des Physique
N ucleaire et Physique Particulaire, France) wasstarted in this period on the nuclear spectroscopy
with BGO anticompton spectrometers and also
on the measurements of moments of nuclei farfrom the stability line.
Experimental work was carried out on the
beam foil spectroscopy and on atomic collision
processes by measuring the spectra of lights,
X-rays and Auger electrons, the impact parameters of scattered projectiles, and the charge distribution of recoiled ions or dissociated target
molecules. Various kinds of ions accelerated by
the RILAC were also used for these studies. The
electron beam ion source, called proto-NICE,
developed at Nagoya University was rebuilt andtested for electron ion merging beam experi-ments at the RILAC.
The theoretical researches on atomic processes have also been performed in various problems such as electron stripping of incident heavy
ions by neutral targets, (;.l+ J.l-) formation bycollision of J.l+ with (;.l-p), charge transfer in low
velocity heavy ion impact, some abnormality
about generalized oscillator strength, andradiative electron capture. Some are closely
related to the experimental research projects at
the RILAC and have led to interesting results.
Mossbauer spectroscopy and perturbed angular correlation studies have been continued toinvestigate the annealing behavior of defectimpurity complexes in metals and the hyperfine
fields in magnetic oxides. The distribution of
implanted or dissolved impurities in various
materials and the lattice location of hydrogen inmetals have been investigated by means of theRutherford back scattering (RBS) method, theelastic recoil detection (ERDA) method, and thechanneling method. Regarding the gas atoms
introduced into metals by implantation, theirdiffusion, and the effect on the mechanical properties, i.e., helium embrittlement, were studied.
Studies of vacancies in metals have started incooperation with a research group of Osaka
University.
Mossbauer spectroscopy and perturbed angular correlation studies have also been continued
to investigate the chemical states of adsorbed
metal ions on magnetic oxides and defect structure in surfaces. The after-effects of the EC
decay of 119Sb and l11In were compared in oxides.
Production of a new probe for surface studies,
carrier-free 151Gd, has begun.
A calibration curve for IR absorptiometry of C
in Si was obtained with high precision bycharged particle activation analysis. 15N and D
have been shown to be useful activable tracers insolid state science when 15N (a, n)I8F and De He,a)p reactions are utilized for detection. Determination of heavy elements by RBS and hydrogenby ERDA in semiconductors and metals has been
continued. PIXE analysis was applied to medical
and geological samples.
Bromospiperone labeled with radiobromine
was synthesized; it has made possible PET visualization of dopamine receptor in the brain ofmon~ey. Adsorption of 29Al on soils and uptakeof 4 5Ti and 69Ge by plants were studied.

2

H. Kamitsubo

Construction of the RIKEN Ring Cyclotron isin progress. During the past one year, field distribution measurements have been performed for
four sector magnets with and without the injection and extraction elements. Fabrication of theother components such as vacuum chambers andan evacuation system, their RF resonators andpower amplifiers and a control system, are under
way at factories.

3
RIKEN Accel. Progr. Rep. 19 (1985)

II. OPERATION OF ACCELERATORS
1.

Cyclotron Operations. Kohara, K. Ikegami, S. Fujita, K. Ogiwara,
H. Takebe, T. Kageyama, and I. Kohno
The 160 cm cyclotron was operated on the 24 ha day basis during the period from Nov. 8,-1984 to
Nov. 7, 1985. Statistics of the machine operation
time is shown in Table 1. The total net beamtime of 3,507.5 h is 5.4% (654.1 h) less than that(382 days) of the last period.

This decrease in net beam time is due todecrease in scheduled beam time and increase in
the time for periodical inspection and repair.
Table 2 shows the beam time allotment tovarious research activities in this period. The
scheduled beam time was decreased by 386.5 h

Table 1. Cyclotron operation in the period XX.

Table 3. Distribution of beam time among particles
accelerated.

Reading of the time
meter on Nov. 07,
1984
Reading of the time
meter on Nov. 07,
(h)
1985
(h)
Difference
Percentage of 365 days

(N

OscillatorIonsourceBeam

86,420.1

90,909.0

53,950.1

90,854.9

95,638.6

57,4.57.6

4,434.8
50.6%

4,729.6
54.0%

3,507.5
40.0%

Schedule in this period:
224 days
Beam time49
Overhaul and installation
Periodical inspection and repair 32
Scheduled shut down
60

Particle

(h)

(%)

p
d
3He2+
4He 2+
7Lj2+
12C4+
13C4+
14N4+
14NS+
0 5+
Ne s +

458
89
446
1,117.5
48
456
120
641
124
1,299
72

9.4
l.8
9.2
22.9
1.0
9.4
2.5
13.2
2.5
26.7
1.5

Total

4,870.5100

Table 2. Scheduled beam time and research subjects in the period XX.
Subject
Nucl. Phys.
Fields other thanNucl. Phys.

Outside users

Nuclear reaction
RI production
Nuclear chemistry
Radiation biology
Radiation chemistry
Solid state physics
Radiation damage
Test of radiation
Radiation damage
RI production
Test of track detector
Test of radiation detector
Radiochemical analysis

Total
Percent in total
Maintenance, operation, and engineering:
88 hExchange of ion sources
Machine inspection and repair 768 h
856 h
Total

Heavy ion
2,236
0
0
60
307
0
0
46
41
0
0
24
46
2,760
56.7%

Scheduled beam time (h)Light ion
557.5
185
640
66
116
22
55
24
101
21
29
60
234
2,110.5
43.3%

Total
2,793.5
185
640
126
423
22
55
70
142
21
29
84
280
4,870.5100%

S. Kohara, et al.

4

x

x

5,000

x
x
x

x
0

x

x

x
x

I;j

0

0

~

0

I;j

4,000

Cl

0

5

0

Q)

E 3,000

~

E
ro

0

0

Q)

C!l

2,000

0

0
0

0

0

1,000

o

0

0

0

I

I

1976 '77 '78 '79 '80 '81 '82 '83 '84 '85
Calendar year

Fig. 1. The cyclotron beam history . • Heavy ions
(Scheduled beam time), 0 Light particles (Sche·duled beam time), x Total (Scheduled beam time),o Net beam time.

compared with that of the last period.
Table 3 shows the distribution of the scheduled
beam time among various particles. Figure 1
shows the cyclotron beam history over the past
10 years.

5
RIKEN Accel. Progr. Rep. 19 (1985)

11-2.

RILAC Operation

Y. Miyazawa, M. Hemmi, T. Inoue, T. Kambara, M. Yanokura, M. Kase,
T. Kubo, E. Ikezawa, K. Kihara,* T. Aihara,* and Y. Chiba

The RIKEN heavy-ion linear accelerator,
RILAC, has been under steady operation andvarious kinds of ion beams have been used forexperiments. Tables 1 and 2 give statistics ofoperation in the period Sep. 1, 1984-Aug. 31, 1985.
The scheduled beam time for 6 days was cancelled owing to trouble in optical fiber cablestransmitting control signals to the 500 k V highvoltage terminal of the injector and in a coaxial
line supplying radio frequency (RF) power fromthe main amplifier to the feeder.
During the period Aug. l-Sep. 15, 1985, the 13th
drift tube of the 2nd resonator was replaced witha new one because of insulation failure in its
quadrupole magnet. At this opportunity, RF
measurements were performed concerning possible calibration errors of the tank voltage pickup in the high frequency region and current
distributions at the short end of the resonator.
Field distributions along the beam axis in theresonator were also checked by the perturbation
method.
Table 3 gives statistics of ions used in thisperiod. Most of users preferred Ar ions as in thelast year, and 36% of the total beam time wasdevoted to this ion. Al and Cu ions were also
requested frequently and beam time for thosemetal ions amounted to about 22% of the total.
The ion source facility installed on the 500 k Vhigh voltage platform was added with some
improvements: a static quadrupole lens,1) which
focuses the beam from the ion source at theentrance of the acceleration column, was installed at the beam exit of the chamber; an anodebore of the ion source was modified from 8 to 10
mm. 2 ) Beams of heavy ions, such as Ar, Kr, andXe, were intensified by a factor of 5 or more. Five
new ion sources adaptable to both gaseous andmetalic elements were completed in the machine
shop of the institute this summer; parameterstudies on their performance are going on.
* Sumijyu Accelerator Service Ltd.

Table 1. Statistics of operation in the period of Sep.
1, 1984-Aug. 31, 1985.
days

%

155
19
46
30
5

42.5
5.2
12.6
8.2

110

30.1

Beam time
Frequency change
Overhaul and improvement
Periodic inspection and repair
Machine trouble
Scheduled shut down

1.4

365

Table 2. Division percentage of beam time byresearch activities.

%
Atomic physics
Solid-state physics
Nuclear physics
Radiochemistry and nuclear chemistry
Radiation chemistry and radiation biology
Accelerator research

42.5
19.4

3.2
21.3
3.9
9.7

Table 3. Statistics of ions used in the period of Sep.
1, 1984-Aug. 31, 1985.
Particles

days%

Particles

days

%

He+
He 2+
C2+
N2+
N3+
15N2+
0+
0 3+
Ne2+
Ne3 +

11

17
2
15
4
6
1
1
4
1

6.8
10.5
1.2
9.3
2.5
3.7
0.6
0.6
2.5
0.6

Ne4+
AP+
Al4+
Ar4+
Ars +
Ar6+
Cu4+
Kr7+
Kr8 +
Xe9 +

4
27
2
53
4
1
6
2
1
1

2.5
16.7
1.2
32.7
2.5
0.6
3.7
1.2
0.6
0.6

References
1) M. Hemmi: p. 207 in this report.
2) Y. Miyazawa: p. 212 in this report.

6

RIKEN Accel. Progr. Rep. 19 (1985)

11-3.

TANDETRON-Operation

H. Sakairi, T. Kobayashi, and E. Yagi

The machine was operated for 107 days for one
year from November, 1983. About 100 days werealloted to overhaul, repair, and improvement.
The species of accelerated ions were 3He, 4He,
11 B, and 12C in the last period. At the end of thisperiod hydrogen acceleration was licenced by the
Science and Technology Agency. The test acceleration is now being carried out and a new ion
source for hydrogen ion production is in a planning stage.
Subjects of experimental studies carried out
during this year were:(a) Thickness measurements of carbon film
coatings (Cyclotron Lab.),(b) Analysis of silicon ohmic contact systems(N uclear Chem. Lab. and NEC),(c) Depth profile of implanted N a ions inhigh-polymers (Biopolymer Phys. Lab. andBeam Analysis Center),(d) Composition of TiC films (Beam Analysis
Center),(e) Depth profile and lattice location of Eu in
CaF 2 (Semiconductors Lab. and Beam Analysis Center),(f) Solubility of D in Si (Nuclear Chem. Lab.),(g) Stress-induced superdiffusion of hydrogenatoms in metals (Metal Phys. Lab. and Beam
Analysis Center),(h) In situ observation of heavy ion-induced

damage in metals (Metal Phys. Lab. andBeam Analysis Center).
Following improvements are in progress:(1) Construction of a new beam line connected
to an electron microscope is at the final stage ofbeam alignment. The microscope, used for in situ
observation of damage process in metals
irradiated with heavy ions, has been equippedwith an X-ray spectrometer to study precipitation or solution of alloying elements during irradiation.
(2) Automation of time-consuming channelingexperiments was planned and a system with apersonal computer (PC-9801) is being prepared at
the work shop.
(3) A recovery system of 3He gas, a source of
3He ions, is under construction. The 3He ions areused for nuclear reaction analysis, a unique toolfor deuterium detection.
Main troubles occurred in the ion sources. The
troubled components were a cesium ion gun in
the sputtering ion source, a high voltage generator for ion extraction from the sputtering ion
source, and a lithium boiler of charge exchanger
connected to a duoplasmatron. Electric powersources for an acceleration voltage generator
and a beam analyzing magnet also experienced
trouble.

7
RUffiN Accel. Progr. Rep. 19 (1985)

III. RESEARCH ACTIVITIES
1.

Nuclear Physics

1.

Analyzing Power Measurements of (d, 2He) Reactions on
12C, 13C, 14 N, and 90Z r
T. Motobayashi, M. Ishihara, N. Matsuoka,* H. Sakai,* T. Saito,*
K. Hosono,* A. Sakaguchi,** S. Shimoura,** and A. Okihana***
NUCLEAR REACTIONS 12,13C, 14N, gOZr (polarized d, 2He ),]= 70 MeV; measured 0'(8}, Ay(8}. DWBA analysis.
Enriched and natural targets.

E

The (d, 2He) reaction has a unique property of
exciting only spin-flip final nuclear states. This isbecause of the strong T = 0 S = 1 final-stateinteraction of outgoing two protons in small
relative energy (around 400 keY). Other light-ion
induced charge exchange reactions which excite
T = To + 1 final states, such as (n, p) and (t, 3He)
reactions, always contain the contribution fromnon spin-flip transitions. Therefore the (d, 2He)
reaction has been expected to be a good probe
for investigating the isovector spin-flip strengthof nucleus, and measurements have been performed on light nuclei.1)-3) However, the results
obtained up to now are not so promising because the angular distributions are somewhat
monotonic irrespective to the transferred angular momentum (1) and there is no significant
enhancement for 1=0 transitions which is
expected from the good kinematical matching.
The present experiment was performed withpolarized deuterons to investigate the 1dependence of spin-dependent observables. We
also measured (d, 2He) energy spectra for a gOZr
target to investigate the spin-flip isovector
strength.
Vector polarized deuterons of 70 MeV provided from the RCNP cyclotron were used tobombard targets set inside a small scatteringchamber. Outgoing two protons were detected
outside the chamber through a thin Mylar win* Research Center for Nuclear Physics, Osaka University.
** Department of Physics, Kyoto University.
*** Kyoto University of Education.

dow by eight sets of the counter telescopes consisting of SSD L1 E and N aI(Tl) or Si(Li) E detectors. These eight telescopes were set in two 2 X 2matrixes. Each counter matrix has 6 combinations of coincidence for 2He detection. The total
effective solid angle for 2He detection is about 2
msr in the present setup. A typical energy spectrum of the (d, 2He) reaction on 12C is shown in
Fig. 1. Peaks corresponding to the ground-statetransition and the 2--4- doublet of about 4.5
Me V excitation energy are observed. For the
ground-state peak the 1=0 transition from P3/2 toP1/2 is the main component. On the other hand,the doublet peak should correspond to the transitions from P3/2 to S1/2 or d S/2 orbits and, therefore,lOU

12C(d,2He) 12S

I·

0.0

80

19.5°

--.l

w

Z

z:

«

60
8.2

:r
u
"-

en

1--

Z
::J

2+

40

0 . 9:l

0

u
20

0
100

~

200

300

Fig. 1. Energy spectrum of the 1 2 C (d, 2He) 12B reac·tion at 70 MeV.

T. Motobayashi, et al.

8

do
dSl

Ed =70MeVl}Jb/sr

100

Ay
• Si
¢ No!
0

++

12

9

- 0. 4

8

0.0

1+

-08
0
- 04
-08

100

ll·c
7.0
8.3

•
10
•

Si

2+
2+

•

-0:1
0 .4

+ 128

¢ No!

tI.l.

4. 5

24-

0
-0 . 4

0

20

40

60

8 cm

20

0

(a)

40

60

(b)

Fig. 2. Differential cross sections (a) and vector analyzing powers (b) of the reactions of 12C (d . 2He) 12B. 12C(d.
2He) 13B and 14N (d. 2He) 14C. Note that for the 14N target yields of two 2+ states at 7.0 and 8. 3 MeV are summed.

transferred angular momentum 1 is not equal too.

Angular distributions of the differential crosssection and the vector analyzing power are
shown in Fig. 2. Solid lines show the results of
DWBA calculations in which one-step chargeexchange spin-flip mechanism was assumed.
Cohen-Kurath4 } wave functions were used to
calculate the spectroscopic overlap of targets
and residual nuclei. It is clearly seen from Fig. 2that 1= 0 transitions have large negative vector
analyzing powers while Ay values for the 1*0(according to the DWBA analysis 1= 1 is dominant) transitions are slightly positive. Overall
features of these A y values are well reproducedby the DWBA calculations as shown in Fig. 2.
This is a very encouraging result in studying the
1=0 spin-flip strength in nuclei.
One of the future programs of the study on (d,2He) reactions is the isovector spin-flip strength
in medium heavy nuclei, for example spin-flip
dipole and 2 nw jump Gamow-Teller resonances.
As a first try of this direction we measured thecross sections and Ay of the 90Z r (d, 2He)90Y reaction. As shown in Fig. 3, broad bumps are seen at
about 7 and 12 MeV excitation energies. They
should correspond to the spin flip dipole resonance (l = 1, S = 1) and the spin-flip part of the E2

-.J

W

Z
Z

<:

I

u
"tn

I-Z
:::J

o
U

Ay
0 .6
0.4
0.2
0
-0.2
- 0.4
- 0 .6

20

40

60

80

Fig . 3. Energy spectrum and vector analyzing power
for the reaction 9°Zr(d . 2He) 90y at 20°.

T. Motobayashi, et al.

isovector resonance (l = 2, s = 1), respectively.
Although in the same energy regions non spin-flip
resonances are expected (in fact the E1 and E2
isovector resonances have been observed in theenergy spectra of the (n, p) reactionS) on the sametarget), they are suppressed by the s = 1 selection
rule of the (d, 2He) reaction.
References
1) D. P. Stahael, R. Jahn, G. J. Wozniak, and J. Cerny:

9Phys. R ev . C , 20, 1680 (1979).
2) K. B. Beard, J. Kasagi , E. Kashy, B. H. Wildenthal, D.
L. Freisel, H. Nann, and R. E. Warner: Phys. Rev. C,
26, 720 (1982).
3) S. Kohmoto, M. Ishihara, and T. Kubo: RIKEN
Aeeel. Progr. R ep. , 18, 8 (1984).
4) S. Cohen and D. Kurath: Nucl. Phys. A, 101, 1 (1967).
5) N. S. P. King and J. L. Ullmann: Proc. Conf. The (p,n) Reactions and N·N Forces, Telluride, p. 373 (1979).

10
RIKEN Accel. Progr . Rep . 19 (1985)

111-1-2.

Beta Decay of Polarized Nucleus 15C Produced
in Heavy-Ion Reaction

K. Asahi, M. Ishihara, T. Shimoda,* T. Fukuda,** N. Takahashi,*K. Katori, ** S. Shimoura, *** N. Ikeda, *** K. Hanakawa, ** A. Nakamura, ***T. Itabashi,**** Y. Nojiri,** and T. Minamisono**
NUCLEAR REACTION 232Th(l5N,15C), E=158 MeV, 13- J
decay of 15C; measured f3-ray asymmetry, NMR; deduced[
magnetic moment, spin polarization.

Studies of the f3-decay of oriented nucleus havebeen valuable sources of information on fundamental interactions and nuclear structures. The
testing ground for such investigations, however,has been limited to nuclei near the stability line.
Recent progress in accelerator and instrumentation has opened a new possibility of access to theregion more removed from the stability line.
Substantial sizes of polarization observed inprojectile-like fragments in heavy-ion reactions 1)
suggest a useful application of these reaction
products to the 13 -decay studies.
We report a study of the p-decay of a neutronrich nucleus 15C (T1/Z =2.449 s, Qp=9.772 MeV) to
the ground state of 15N. This 1/2+~ 1/2- nonunique first-forbidden transition receives contributions from the rank-zero and the rank-one
matrix elements,Z) and is interesting in the studyof many-nucleon systems involving virtual
mesons, since the rank-zero matrix element isdominated by the time-like component Ao of the
weak axial-vector current in which the mesonicexchange effect is predicted to be enhanced. 3)
Experimental discrimination between the rankzero and the rank-one contributions can be madeby observing asymmetry 4 ) in the angular distribution of f3-rays from a polarized nucleus. In thepresent work we thus measure the f3-ray asymmetry in the 15C decay. In addition the asymmetry is utilized to detect the nuclear magnetic
resonance (NMR) for determination of the magnetic moment of 15C, which provides additional
information on nuclear structure of the parent* College of General Education, Osaka University.
** Faculty of Science, Osaka University.
*** Faculty of Science, Kyoto University.
**** Research Center for Nuclear Physics, Osaka University.

state.
A 158 MeV 15N beam from the AVF cyclotron
at the Research Center for Nuclear Physics,
Osaka University, was used. A spectrometer
DUMAS5) provided a means for isotope separation of projectile-like fragments produced in theheavy-ion reaction. 6 ) Reaction products emitted
from the target at OL = 25° were transmitted to
DUMAS, in which those with Bp = 0.99- 1.07 Tm
passed through the momentum slit in the medium
focal plane and then were triple-focussed on a
stopper (high-purity graphite) placed at the second focal point. The setup used for the measurement of the f3-ray asymmetry is schematicallyshown in Fig. 1. f3-Rays emitted from the products implanted in the stopper were detected byusing counter telescopes placed above and below
the stopper. Observed time and energy spectra of
f3-rays revealed that the background contribu-

Collimator\\

AI window

Plast ic
scintillator
Static magnet
RF Coil

15 C beam
from

DUMAS

Stopper(graphite)
Plastic
scintillator

I

I

o 1

3 I. Scm
Fig. 1. Experimental setup used for the measurement of f3-ray asymmetry.

11

K. Asahi, et at.

I

~

1.2

10-

+

15C in Graphite+ :+~---( b)

111

....

-4
-

1.2

'c

3

~

2

+

( a)

u

0.8t2

f

I

I

3

4

..
~

~

a

~
<IJ

>=

I

ro

;:)

1.0t- ------------ ----~+----~ -. -I+<l: -2Io:3, T9=-

0
0..

I

o
111

~

-

E 0.8

(;
c

Y

8 = 25·L+2

Ho= 920 Oe

0

0.95

Bp

1.00
(Tm)

en
en

1.05

(MHz)
I

Fig. 2. Up/ down ratio of fJ-ray yield, measuerd after
the application of an rf field with its frequency
swept over the ranges (a) LI f = 1.3 MHz and (b) LI f
=0.43 MHz.

tion due to activities other than 15C was indeed
small. Spin inversion techni'que using NMR was
utilized in the asymmetry measurement: An up/
down ratio of the f3-ray yield was measured bothwith spins inverted by applying an rf field for
NMR, and with spins unaltered. The result for
the f3-transition to 15N(l/2+) (Gamow-Teller transition) is shown in Fig. 2, from which the value
for the 15C magnetic moment was found to lie in
the region between 1.0 and 2.0 nm. Figure 3
shows spin polarization of 15C in the 23 2 Th(l5N,
15C) reaction deduced from the observed asymmetry on the basis of the known asymmetry
factor A = - 2/3 for this allowed transition.
Development of a setup for more refined measurements of magnetic moment and f3-ray asymmetry for forbidden transition is in progress.

100

I

110
E( 15 C)

I

I

120
(MeV)

130

Fig. 3. Energy dependence of the obtained polarization P multiplied by the asymmetry factor A =-2/ 3, for 15C products in 232Th(15N,I5C) reaction at
E L =158 MeV.

References
1) K. Tanaka, M. Ishihara, H. Kamitsubo, N. Takahashi,

A. Mizobuchi, Y. Nojiri, T. Minamisono, and K.
Sugimoto: l. Phys. Soc. lpn., 44, SuppJ., 825 (1978).
2) E. K. Warburton, D. E. Alburger, and D. ]. Millener:
Phys. Rev. C, 29, 2281 (1984).
3) K. Kubodera, ]. Delorme, and M. Rho: Phys. Rev.
Lett., 40, 755 (1978).
4) M. Morita: Beta Decay and Muon Capture, W. A.
Benjamin Inc., Reading, p. 173 (1973).
5) T. Noro, M. Nakamura, H. Sakaguchi, H. Sakamoto,H. Ogawa, M. Y osoi, T. Ichihara, N. Isshiki, M. Ieiri,
S. Kobayashi, and H. Ikegami: RCNP Ann. Rep.,
1982, p. 189 (1982).
6) K. Asahi, M. Ishihara, T. Shimoda, T. Fukuda, N.
Ikeda, C. Konno, S. Shimoura, K. Katori, Y. N ojiri,
and T. Minamisono: RlKEN Accel. Progr. Rep., 18,
41 (1984).

12
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-3.

Nuclear Polarization Produced by a Tilted-Foil
Method in 35.5 MeV AI Ions

M. Ishihara, H. Ohsumi, S. Kohmoto, K. Asahi, K. Sugimoto, *T. Tanabe, * T. Hattori, ** H. Hamagaki, * and K. Haga ***l

NUCLEAR POLARIZATION via Beam-tilted foil reaction
with 35.5 Me V Al ions; observed resultant nuclear polarization using analyzing power of Coulomb-excitation scattering.

The present report is concerned with investigation on a spin-polarization phenomenon observed for beam ions transmitted through tilted foils.
In such beam-foil reactions atomic spins of ionscan be oriented appreciably.1) The process may
be easily used for production of nuclear polarization by further letting the ions fly in vacuum. 2) In
the free flight, initial atomic polarization will betransferred to nuclear polarization through exertion of hyperfine interaction. So far the phenomenon has been studied and used mainly at low
energies below few 100 ke VInucleon.l),2) In thiswork induced nuclear polarization has been observed for the first time in an energy domain of"-' Me V Inucleon. Such information on higherenergy ions is particularly useful in application
to nuclear spectroscopy, since unstable nuclei ofprimary interest are often produced with highvelocities.
The experiment was performed with Al ionsaccelerated at the RIKEN Heavy-Ion Linear
Accelerator (RILAC). The beam energy was

Tar etFig. 1. Schematic view of the experimental setup.
* Institute for Nuclear Study, The University ofTokyo.
** Tokyo Institute of Technology.
*** Faculty of Engineering, The University of Tokyo.

chosen to be 35.5 MeV. A schematic view of theexperimental setup is shown in Fig. 1. The ionswere transmitted through thin carbon foils. The
atomic polarization was supposed to be generated at the exit surface of the foil and the nuclear
polarization to be induced during subsequent free
flight of ions. A stuck of 2 or 5 foils was used toenhance the polarization by exploiting an accumulative effect of multiple foils. The normal of
the foils was tilted with respect to the beam
direction by a fairly large angle (a = 60°), since
the polarization is expected to be proportional tosin (a). In practice the angle a (hence the polarization axis) was reversed periodically at a shorttime interval.
Observation of the nuclear spin orientation
was made by introducing a new method based onasymmetry of the Coulomb-excitation scattering
process. The second carbon foil placed about 10
cm downstream from the tilted foils served as atarget for the scattering. The scattered particles
were detected with two Si detectors placed in theplane normal to the polarization axis and atsymmetric angles ± 400( ± 5°) with respect to thebeam. The angles were chosen to optimize thebalance among cross section, analyzing power,
and sin ratio. The kinematical condition for thisgeometry afforded another advantage that only
carbon recoils hit the detector eliminating a needfor a complicated particle identification procedure. Two N aI detectors of 6" ifJ x 6"were employed to detect y-rays in the deexcitation of the
Coulomb-excited states, and the scattered particles were registered in coincidence with thesey-rays. This procedure eliminated the contribution from the strong elastic (Rutherford) scattering and served to distinguish different branchesof the Coulomb-excitation. Figure 2 shows acoincidence y-ray spectrum. Two peaks at 0.84
and 1.01 Me V are due to deexcitation of the 1st

13

M. Ishihara, et at.
Table 1. Summary of the left-right asymmetry (A)in the present measurement.
~

1000

It)

+

}

It)

~

~

2
5

t

+

~
cry

i:E
§

300
ChannelNumberFig. 2. y-Ray spectrum observed in coincidence with
Coulomb-scattered particles.

(1/2+) and the 2nd (3/ 2+) excited states to theground state (5/2+), respectively, and the intensities of the peaks represent the strengths of the
Coulomb-excitation processes leading to these
excited states.
Using coincidence rates N+( _)L(R), the left-rightasymmetry A of the scattering was defined by,
A=(l-p)/ (l +p)

(1)

with
p = (N+ L N_ R / N_L N+ R)l/2(2)

where subscripts indicate tilt angle directions (±for a = ±600) and particle detectors (left (L) andright (R)). This asymmetry is a function of
nuclear spin orientation parameters of the Al
beam and is written as
A = (~ PM/ h ) / ( ~ Ph9h )
odd

even

= (PI<j1 + P3<j3) / (<jO + P292 + P494 )Systemasymmetry

Numberof foils+(3)

where Ph are polarization tensors of rank k for
27 Al nuclei and 9h are constant factors determined by kinematical variables and the initialand final spins in the Coulomb-excitation. The
experimental results of A are summarized inTable 1. The system asymmetry was determinedby observing chance coincidence events. The+1.3±1.0%+ 1.5±O.7%+ 1.6 ± 1.1%
+ 2.5±0.8%- O.3±O.5%- 0.07±O.20%

polarization PI and a higher rank tensor P3 may
be determined by applying Eqn. (3) to a pair of
the A values for the 5/2+~ 1/2+ and 5/2+~3/2+
transitions. In the calculation one may ignore thesecond and the third terms in the denominator
which are considerably smaller than the firstterm. The PI values thus obtained are 1.5±0.9%
and 2.3± 0.6% for two and five tilted foils, respectively.
In conclusion a new method based on
Coulomb-excitation analyzing power has beenused successfully and has proven its highefficiency for the measurement of nuclear polarization of high velocity ions. An appreciable
polarization has been found even at 35.5 MeV,
indicating that the polarization phenomenon
prevails over a fairly wide energy range. It is tobe noted that Al projectiles at this energy are
deeply ionized (q = 9.2) after passing throughfoils. This result is encouraging for the application of the tilted-foil method to high energy
nuclear experiments. The present method candetermine not only the polarization but also
higher rank tensors. A non-vanishing value observed for P3 reveals that orbital angularmomenta of I ~ 2 are significantly involved when
the atomic states are excited at the surface of the
foil. This is in contrast to the usual belief that thecontributions from sand p waves are dominant.
References
1) H. G. Berry and M. Hass: A nn. Rev. N ucl. Sci. , 32,1
(1982) and references therein.
2) G. Goldring and Y. Niv: Hyperjine Interaction, 21, 209(1985); Y. Nojiri and B. 1. Deutch: Phys. R ev. L ett. , 51,
180 (1983).

14
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-4.

Deuteron D-State Effects on the Vector Analyzing Powerand Polarization in (d,p) Reactions
T. Kubo and H. Ohnuma*
NUCLEAR REACTIONS 116Sn (d,p)l17S n (0.159 MeV, 3/2+)
at E=55.4 MeV and 118Sn(p,d)117Sn (0.159 MeV, 3/2+) at E=
60.8 MeV, measured A y , DWBA analysis, deuteron D-state
effects.

Since the early work of Johnson and Santos 1)
and Delic and Robson,2) the deuteron D-state
effects in direct (d,p) reactions have been thesubject of many experimental and theoreticalstudies. At low incident energies (less then several tens of MeV), it is well established that the
D-state effects are small on the vector analyzing
power (Ay) and the proton polarization (Py).
Recently, however, it was shown by Cadmus andHaeberli at Ed = 8.22 Me V3) and by our group at
Ed = 22 and 55.4 Me V4),5) that the D-state effects
can be observed clearly for the linear combinations of Ay and Py. They measured both Ay andPy for the ln = 0 transitions in (d,p) reactions:
116Sn (d,p) 117S n (g.S., 1/2+) and 117S n (d,p)118S n (g.s.,0+), and obtained the quantities6) ~=2(Py- Ay)
and Sd = 3Ay - 2Py. Their DWBA analyses clearlyshow the importance of the D-state effects on ~and Sd, in contrast to Ay and Py. The D-state
effects are magnified markedly by transforming
Ay and Py into ~ and Sd.
We point out in the present report that similar
magnification of the D-state effects should beobservable in more general cases, i.e., ln *0 transitions.
According to the expressions given from the
DWBA theory for the observables, the D-state
effects arise from two terms involving the Dstate contribution: the SD term which linearly
depends on the S· and D-state amplitude and the
DD term which depends quadratically on the
D-state amplitude. 6) The analyses in Refs. 3 and 5
showed that the D-state effects observed clearlyfor ~ and Sd arise primarily from the DD terms.
We have made a further analysis, and found that(1) the DD term of Ay (A(DD)) and that of Py(P(DD)) are almost equal in magnitude and oppo* Department of Physics, Tokyo Institute of Technol·ogy.

site in sign, i.e., A(DD)~- P(DD), and (2) thisrelation gives rise to the magnification of the
D-state effects. The DD terms of Ay and Py are
constructively added by transforming them into
~ and Sd' Consequently the contributions of the
DD terms in ~ and Sd become large comparedwith those in Ay and Py, so that the magnificationof the D-state effects is observed.
We have found that the relation A(DD)~- P(DD) holds regardless of In. Figure 1 showsthe exact-finite-range (EFR) DWBA calculations
only with the D-state for Ay and P y in the reaction 116Sn(d, p)117Sn at Ed = 55.4 MeV leading to
1/2+, 3/2+, 5/2+, 7/2+, and 11/2- states: these
correspond to the DD terms. The distorting
potential parameters used are given in Table l. It
is clearly seen that the relation A(DD)~ - P(DD)holds for all the transitions. Furthermore wehave found that this relation exactly holds, i.e.,A(DD) = - P(DD), in the absence of the spin-orbit
distortions. The reason why this relation is notmuch affected by the spin-orbit distortions is that

Fig. 1. EFR DWBA calculations only with the Dstate for Ay and Py in the reaction 116Sn(d,p)l17Sn at
55.4 Me V leading to the states shown in the figure.

T. Kubo, et at.

15

Table l. Distorting potential parameters used in the EFR DWBA calculations. The deuteron parameters are thoseof an adiabatic potential and the proton parameters are those which reproduce the elastic scattering.

d
p

Vo

ro

ao

W

Wo

r,

Clj

Vso

rso

flso

rc

Ref.

96.67
4l.93

l.17
l.197

0.79
0.687

7.93
3.80

10.26
5.10

l.29
l.24

0.633
0.808

6.20
6.11

l.01
l.057

0.75
0.80

l.25
l.25

5, 7
8

0.5

0.5

116S p (d,p)117Sn 55.4 MeV

O.159.3/2:~_/ __"

' _',

,1'

',_/ \"'_/

Ay(d,p)"Ay(p,d).Ay(d,p),----,,/

•••
0.5

",-/

-

S+O

----- s-0.5

-0.3L.....-~-'--L----L.._.J...---:-L:----I

o

30

o

8c.m.(deg)Fig. 2. Angular distributions of Ay in the reactions
116Sn(d,p) 1l7 Sn (O.l59 MeV, 3/ 2+) at 55.4 MeV and
118Sn(p,d)ll7Sn (0.159 MeV, 3 / 2+) at 60.8 MeV
compared with EFR DWBA calculations with(solid lines) and without (dashed lines) the D-state.

the DD terms are determined primarily by thecentral-potential distortions.
The results shown in Fig. 1 suggest that themagnification of the D-state effects can be observed for suitable linear combinations of Ay and
Py also in In =1= 0 transitions.
The magnification of the D-state effects should
also be possible in linear combinations of A y of a(d,p) reaction and that of a (p,d) reaction, as longas the latter corresponds to an approximate
inverse reaction of the former. The angular
distributions of A y for the reactions 116Sn(d,p)117Sn(O.159 MeV, 3/ 2+) at Ed =55.4 MeV (Ay(d,p))and 118Sn (p,d)11 7Sn(O.159 MeV, 3/ 2+) at £p = 60.8
MeV (Ay(p,d)) are shown in Fig. 2 along with the
EFR DWBA calculations with and without the
D-state. Figure 3 shows the linear combinations
Ay(p,d)-Ay(d,p) and 3/ 2Ay(d,p)-Ay(p ,d) definedsimilarly to 5p and Sd. The distorting potential
parameters used are listed in Table 1. It can beseen from Fig. 3 that the D-state effects aremarkedly magnified and the data can not be
fitted by the S-state alone. This result confirms
the suggestion mentioned above.

30

60

8c.m.(deg)Fig. 3. Linear combinations of the Ay of (d,p) reaction and that of (p,d) reaction shown in Fig. 2 (seetext).

It should be noted that the relation A(DD),::::::,- P(DD) is the general nature of the D-state
effects on Ay and Py in (d,p) reactions. In addition, the present results predict that the relation
Ay'::::::' - P y holds at incident energies of several
hundreds of Me V, where the contributions fromthe DD terms become dominant.

References
1) R. C. Johnson and F. D. Santos: Phys. Rev. Lett., 19,364 (1967).
2) G. Delic and B. A. Robson: Nucl. Phys. A , 156, 97(1970).

3) R. R. Cadmus and W. Haeberli: Nucl. Phys. A , 349,
103 (1980).

4) H. Ohnuma, T. Kubo, N. Kishida, T. Hasegawa, N.
Ueda, T. Fujisawa, T. Wada, K. Iwatani, and T.
Suehiro: Phys. Lett. B, 97, 192 (1980).
5) T. Kubo, H. Ohnuma, T. Kishimoto, M. A. Brennan,
Y. Yoshida, M. Sugitani, and T . Suehiro: Phys. Lett.
B, 127, 403 (1983).
6) R. C. Johnson: N ucl. Phys. A, 90, 289 (1967).

7) J. D. Harvey and R. C. Johnson: Phys. R ev. C, 3,636(1971).
8) G. B. Fulmer, J. B. Ball, A. Scott, and M. L. Whiten:

Phys. Rev., 181, 1565 (1969).

16

RIKEN Accel. Progr. Rep. 19 (1985)

III-I-S.

Self-Consistent Transport Coefficients for Damped
Large Scale Collective Motion
S. Yamaji, H. Hofmann, * and R. Samhammer*

FISSION transport equation, linear response theory, two- J( center shell model.
The microscopic expressions for the transportcoefficients are derived by exploiting locallygeneralized RPA-type dispersion relation.I)
These expressions are evaluated for the
dynamics of fission around and behind the barrier by applying the two-center shell modeP) at
finite temperature and a finite coupling of one
particle-one hole excitations to more complicated configurations. 3 )The actual microscopic computations were
performed for the symmetric fission of a ZlZPO
nucleus. From the parametrization of mean field
introduced in Ref. 2, the center-separation Zo istaken as a macroscopic variable. The othervariables such as neck -parameter e and deformation 0 are fixed to be 0.35 and 0.0, respectively.
We calculated the potential energy V (.20) as the
5.0
~

212pO

E=0.35.

.

saddle SCISSIO~>\~ O.OF====-----=====::l---~
o
U

-5.0

15 Zo (fm)212pO

f=0.35
T=2MeV

0.5- - for.o.ofor zero-freq uency

Fig. 1. The stiffness coefficient C and dimensionlessparameter q vs. the center-separation Zo for thesymmetric fission of 212PO.

* Physik-Department der Technischen Universitat Mtinchen.

sum of Coulomb energy and nuclear macroscopic
energy.4)
The stiffness coefficient C, which is equal toaz V(zo)/ aZo z is shown in the upper part of Fig. l.
In the lower part, the dimensionless quantity q =y/2/MRT is shown as a function of zo, where
M, y, and C are coefficients for inertia, friction,and stiffness. This parameter q governs the solution of transport equation and is often used as aphenomenological parameter. 5 ) The analysis of
the mean saddle-to-scission time, mean kinetic
energy at scission, and variance in kinetic energy
for 120 MeV a + 209Bi-)-213 At-)-fission yields theempirical value of order of 1 for the parameterq.5) The solid and dashed lines correspond to the
local frequency no determind by the RPAdispersion relation and the Markoff-limit 0 0 -)-0,6)
respectively.
From the present microscopic calculation oftransport coefficients, we have found that theeffect of the local phonon on the parameter q islarge, especially for large value of stiffness C in
the region between barrier and scission, although
the parameter q for zero- frequency reproduces
the order of magnitude of the empirical value ofq. This indicates that we have to solve the transport equation improved by taking into accountthe effect of the local phonon on the coefficientsin order to study the collective motion of fission.
References
1) H. Hofmann and A. S. Jensen: Nucl. Phys. A, 428, Ie(1984).
2) A. Iwamoto, S. Yamaji, S. Suekane, and K. Harada:
Prog. Theor. Phys., 55, 115 (1976).

3) P. J. Siemens, A. S. Jensen, and H. Hofmann: Nucl.
Phys. A, 441, 410 (1985).
4) H. J. Krappe, J. R. Nix, and A. J. Sierk: Phys. Rev. C,
20, 992 (1979).

5) J. R. Nix, A. J. Sierk, H. Hofmann, F. Scheuter, andD. Vautherin: Nucl. Phys. A, 424, 239 (1984).
6) H. Hofmann and P. J. Siemens: Nucl. Phys. A, 275, 464(1977).

17
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-6.

Application of Time-Dependent Mean-Field Theory to
Heavy-Ion Collisions
K. Ikeda, S. Yoshida, and S. Yamaji(NUCLEAR REACTIONS time-dependent mean-field theory.J

We have studied the numerical application of
Reinhardt's time-dependent mean-field (TDMF)
S-matrix theoryl) to a one-dimensional elastic
scattering problem, in which a 4-nucleon and an
8-nuc1eon system interpenetrate with no energy
loss. The details will be published elsewhere. 2 )The mean-field which is a self-consistent solution of the TDMF equation is iteratively
obtained. This iteration procedure works fairly
well except at lower energies where the ordinary
TDHF evolution of the densities results in high1.0. . . . - - - y - - - , . - - - , . - - - . . , . - - - - . - - 1
0.8

0.6
0.4
-0-

+

0.2
0..0 010.

IS f il 2

Is1P-S-HFI2

20.

30.

ECM

(MeV)

40

50.

Fig. 1. Comparison between 1$11 2 (denoted by open
circles) and 1 Si'i'D-S-H~ 2 (denoted by crosses) thatwere made maximum by choosing the starting time
according to the matching condition.

Table 1. Comparison of the time advance fordifferent definitions.
EcM(MeV)

10

20

30

40

50

_ kJJ. (I!!!:)

76.1

41.9

28.4

21.3

16.8

74.3

41.4

29.6

22.5

19.7

Vrel

C

_ d (arg (Sf!» (I!!!:)

dEeM

C

excitation of the fragments or fusion.
In Fig. 1, the resultant S-matrix elements arecompared with the corresponding values calculated by using the TD-S-HF theory.3) They agree
quite well if we seek the starting time that makes
I SlD-S-H~ maximum, fixing the initial positions of
the fragments in the TD-S-HF calculation. This
matching condition is reasonable since the
TDHF wave packet has a classical character inthe translational motion. 3)
As for the phase, the difference between the
TDMF result and TD-S- HF one is a few tens
percent of 27(.
Rather than showing the phase arg(SfI) of the
S-matrix element, it may be interesting to compare d(arg(SfI))/ dEcM with 2ql/ Vreb where EcM,qI,
and Vrel are the center-of-mass energy, relative
distance, and relative velocity for the initial
preparation stage, respectively. Both of them areinterpreted as the time delay of the scattering
process. The former is the quantum mechanicalcase while the latter is classical. In Table 1 thetime advances which are obtained by changing
the signs of the time delays are tabulated andshow a good agreement between the two quantities. This indicates that they are consistently
interpreted as a time advance of the elastic interpenetration.
The good agreement between the TDMF calculation and TD-S- HF one in this work canmotivate application of the TD-S-HF theory tomore realistic systems for which the TDMF
calculation is very time consuming.
References
1) H. Reinhardt: Nucl. Phys. A, 390, 70 (1982).
2) K. Ikeda, S. Yoshida, and S. Yamaji: Z Phys. A, 323,
285 (1986).
3) J. J. Griffin, P. C. Lichtner, and M. Dworzecka: Phys.
Rev. C, 21, 1351 (1980).

18
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-7.

High-Spin States in 110S n

H. Harada, T. Murakami, H. Tachibanaki, K. Yoshida,
1. Kasagi, T. Kubo, and T. Inamura
NUCLEAR REACTION 98Mo(l60,4n)llOSn, E=76 MeV mea- J[ sured y- y coincidence, deduced levels.

High spin states of llOSn were excited by the98Mo(l60,4n)110Sn reaction with beam energy of
76 MeV. The target used was a 98% enriched
98Mo foil, 0.95 mg/ cm2 in thickness, and backed
with a thin lead layer. Five sets of BGOACS wereplaced at 35, 45, 90, 135, and 145 degrees to thebeam direction, and the distance between thetarget and Ge detector was set to be 15 cm. A
collimator of 4 cm thick heavy metal was set infront of each BGOACS. Event-by-event data
were recorded on a magnetic tape by using a
CAMAC data taking system. 3 ) About 3 x 107 coincidence events were obtained in the present
experiment, more than four times as good statistics as the previous one.
We have found new y-rays which correct theprevious level scheme. They are 846, 1,092, andIn the course of the systematic study of thenuclear structure of Sn isotopes, we have investigated high-spin states in llOSn. Last year, we
reported a sequence of 809, 741, 809, and 448 ke V
y-rays and proposed a tentative level scheme ofllOSn.l) However, the level scheme has been foundto have difficulty in interpreting the intensities ofthe y-rays obtained in y- y coincidence measurements. Thus a y-y coincidence study with muchbetter statistics has been required to correct thelevel scheme of llOSn.
We have performed the y- y coincidence
measurement with five BGO anti-Compton
spectrometers (BGOACS) reported in Ref. 2.
Reduction of Compton scattered events by about
1/3 for a Ge(Li) detector has provided superior
y-ray spectra of the y-y coincidence.

650.US keY gate

...

(0)

en

N

o

750

+

<0

650

+

III

en

en

<0

I

en

o

<0

o

550

N

450
N

en

o

350
250

>

150

QJ
~

50

If) 1000~t-H-<-++-t-t+++++++++f+++++-+-+-t+f-;r-++-+-+-++-++t+++++++++t++--H-+-I++-t-'~+l

I-

Z

900

:::J

809 k~V gate

( b)

o 600

U

700
~

o

600

en

500

goo

700

800

900

1000

1200

ENERGY( keY)

Fig. 1. y-y coincidence spectra gated by 448 keV (a) and 809 keV (b) transitions from the 98Mo(160,4ny)llOSn reaction at 76 MeV.

H. Harada, et al.

1,294 ke V y-rays. In Fig. 1 are shown y-ray
spectra gated by the 448 ke V (a) and the 809 ke V(b) y-rays. As can be seen from Fig. 1, the 846 and1,092 ke V y-rays are seen in both spectra, while

19

1130

the 1,294 keY y-ray is seen only in spectrum (a).
This observation requires the new level at 5,225
ke V as shown in Fig. 2.
In addition to these new y-rays, we have also
found the 904 keY and 1,002 keY transitions asshown in Fig. 1 (b). They are also observed in the
spectrum gated by the 741 keY y-ray. Thus, there
exist band-like transitions consisting of 741, 809,
904, and 1,002 keY y-rays as shown in Fig. 1 (b).
These y-rays are placed on the 5,225 ke V level
together with the 8,091 keY y-ray. The proposedlevel scheme shown in Fig. 2 suggests that the
deformed states become the yrast states of llOSn
above 6 Me V excitation. Angular distribution of
y-rays and the lifetime measurements with
BGOACS are being planned to establish the band
structure in 11OSn.

128 7References

Ex [MeV)
10

9

1002

8

904

7

809

741

6

5

4
3

2
985

2·
1 1211

0

0·

110

5n

Fig. 2. Proposed level scheme of llOSn. Numericalfigures indicate y-ray energy in keY.

1) H. Harada, T. Murakami, H. Tachibanaki, K.
Yoshida, ]. Kasagi, and T. Inamura: RIKEN Aeee!.
Progr. Rep., 18, 22 (1984).
2) M. Fukuda, Y. Gono, Y. Ishikawa, M. Sugawara, T .
Inamura, M. Ishihara, T. Nomura, I. Kohno, H.
Kamitsubo, ]. Kasagi, and T . Murakami: RIKEN
Aeee!. Progr. Rep., 18, 152 (1984).
3) T. Inamura, T. Murakami, ]. Kasagi , H. Kumagai,
and Y. Gono: RIKEN A eee!. Progr. Rep., 17, 124(1983).

20
RIKEN Accel. Progr. Rep. 19 (1985)

111-1- 8.

High-Spin States in 112S n

H. Harada, T. Murakami, H. Tachibanaki, K. Yoshida,
J. Kasagi, T. Kubo, and T. Inamura
NUCLEAR REACTION looMo(160,4n)1l2Sn, E=72, 76 MeV, J( measured y- y coincidence, deduced levels.

The low-lying levels in 112Sn have been investigated extensively and the yrast levels up to
9- state are interpreted as neutron twoquasiparticle states. 1).2) The effect of the generalized seniority mixing predicted by Bonsignori etal. 3 ) has been found in the enhanced B(E2) valuesof the 9-~8 - transitions in llOSn and 112Sn .4) The
spherical nature of the yrast levels are then wellestablished below 4.5 Me V excitation. On theother hand, a feature of the deformed nucleus isalso seen in 112Sn. The deformed rotation-likeband whose members are connected with 468
keY (6+~4+), 663 keY (8+~6+), 741 keY (10+~8+),
and 864 ke V (12+ ~ 10+) transi ti ons has been reported by Bron et al. 5 ) Therefore, it is very interesting to investigate the higher-spin region of

M

to
to

1350

(0)

71.1. keV gate

1200

co

130

oco

(b)

1470keVgate

110
90

> 70
41

-" 50

~ 30
Z
:::l 10

a

u

-1 0
-30

400

(c)

733 keV gate

350
300
250

l

200
ISO

100
50 -

- s~o~o...............'--'-'-'--':;7"!::;:00..........................~8~OO~.............."'O"":-:90-:--0..............................-'-:101:':00:-'-'-'-.......................1-'-:.10':-'-0.................................!.I20-'-0.............................JENERGY ( keV )Fig. 1. y-y Coincidence spectra gated by 744 keY (a), 1,470 keY (b), and 733
keY (c) transitions from the JOOMo(l60,4ny)1l2Sn reaction.

H. Harada, et al.
Ex ( MeV )
1121
l a31
-

9
962

12a' )- - - - liB·)

8
B76

7

-

la3B

932
- - - - 116 · )

97.
BaB

6

5
4

3
2

21

transition energies are considered as rotationallike intra-band transitions. The band shown in
Fig. 1 (a) is connected with the previously known
band by the 744 ke V «(12+)~ 10+) transition and isconsidered to form the yrast levels. The otherband shown in Fig. 1 (b), is connected with thespherical negative parity states. The proposedlevel scheme of 11 2Sn is shown in Fig. 2. Tentative
spin assignments of the band members up to 20+
are based on the stretched quadrupole characterof the angular distribution of the y-rays. Spinparity assignments and lifetime measurements
are highly desirable to confirm the band structure in 1l2Sn. Such experiments are now in progress.
References

Fig. 2. Proposed level scheme of 112Sn. Numericalfigures indicate y-ray energy in keV.

1l2Sn and to see whether the shape coexisting
picture is still effective or not.
y- y Coincidence measurements were carriedout with the BGOACS6) for the looMo(l60, 4n)1l2S nreaction at E(160)=72 and 76 MeV. The target
used was a self-supporting foil, backed with lead,
2 mg/ cm 2 in thickness, and enriched to 95% inlooMo. The same experimental sutup was used
as reported in Ref. 7.
In addition to the previously known band, we
have found other band like transitions in thepresent experiment. In Fig. 1, shown are y-ray
spectra gated with the 744 keY (a) and 1,470 keY(b) y-rays. The y-ray peaks indicated by the1) T. Yamazaki and G. T. Evan: Nucl. Phys. A, 134, 81(1969).
2) A. van Poelgeest, ]. Bron, W. H. A. Hesselink, K.
AHart, J. ]. A. Zalmstra, M. J. Uitzinger, and H.
Verheul: Nucl. Phys. A, 346, 70 (1980).
3) G. Bonsignori, M. Savoia, K. AHart, A. van Egmond,and G. Te Velde: Nucl. Phys. A, 432, 389 (1985).
4) ]. Kasagi, H. Harada, T. Murakami, H. Tachibanaki,
K. Yoshida, and T. Inamura: p. 22 in this report.
5) ]. Bron, W. H. A. Hesselink, A. van Poelgeest,]. J. A.
Zalmstra, M. ]. Uitzinger, H. Verheul, K. Heyde, M.
Waroquier, H . Vincx, and P. van Isacker: Nucl. Phys.
A, 318, 335 (1979).
6) M. Fukuda, Y. Gono, Y. Ishikawa, M. Sugawara, T.
Inamura, M. Ishihara, T. Nomura, 1. Khono, H.
Kamitsubo, ]. Kasagi, and T. Murakami: RIKEN
Accel. Progr. Rep., 18, 152 (1984).
7) H. Harada, T. Murakami, H. Tachibanaki, K.
Yoshida, ]. Kasagi, T. Kubo, and T. Inamura: p. 18 inthis report.

22
RIKEN Accel. Progr. Rep . 19 (1985)

111-1-9.

Enhanced E2 Transitions between 9- and 8- Statesin 110S n and 112S n]. Kasagi, H. Harada, T. Murakami, K. Yoshida,
H. Tachibanaki, and T. Inamura

NUCLEAR REACTION 98.10oMo(l60,4n)llO.1l2Sn , E = 72, 76 J
[ Me V, measured recoil distance, deduced mean lifetimes.
The low-lying states of Sn isotopes with aclosed Z = 50 proton shell have provided theopportunity to investigate the validity of theneutron quasiparticle or generalized seniority(vg ) concept. Recently, the influence of the generalized seniority mixing has been investigated in
the low-lying states of Sn nuclei by Bonsignori etal. ll They showed that most of the low-lying
states have 10-30% of vg =4 admixtures in predominant Vg = 2 configurations. Of particularinterest is the main source of the generalized
seniority mixing which they claimed to be a kindof particle-phonon coupling mechanism, andhence the effect of Vg = 4 admixtures results inenhanced E2 transition probabilities. This enhancement is predicted to be seen for the transitions between high-spin states with the simplest
Vg = 2 configurations.
Within the Vg = 2 configurations, the 9- states
can consist only of the (hll/ 2g 7 / 2) configuration,and the 8- state is predicted to consist mainly of

5106
4894

I 1-

75!23

10-

<

the same configuration. l).2) In 110.112S n , the 9- and8- states are well established and values of E2/
M1 mixing ratio for the transition between them
are also known. 2) Therefore, we have measured
the lifetimes of the 9- and 8- states in llOSn and
112Sn to see whether the E2 transitions are reallyenhanced or not. The predicted B(E2) values withvg ;£ 4 configurations for the 9- - 8- transitions areabout 200 e2 fm 4 1) more than 7 times larger thanthose of the calculation with Vg = 2 configurations.
Levels in llOSn and 11 2Sn were populated in the98.10oMo(l60,4n)llO.1l2Sn reactions with 72-76 MeV
16 0 beams from the RIKEN 160 cm cyclotron. In
addition to n- y- y coincidence and n- y angularcorrelation measurements with a neutron multiplicity filter,3) recoil-distance measurements werecarried out. Stretched foils of 98Mo (98.3% enriched and 950 J.lg/ cm 2 in thickness) and looMo(94.5% enriched and 677 J.lg/ cm z in thickness)
supported with thin gold foil were used as target

ps

20 ~s

4929
4582

I 1-

<

20

ps

10-

<

20

PS

68!9

ps

"'0

..... (Tltn'"'" '"-

(Tl

co

93932
8=
3764
3685

<D

~

175!23 ps
1.67!0 . 14 ns

CD

r-

(Tl

3693

- r-co en

3430
3354

<D

9-

'"

e-

1

0

0

2753

'"" '"
2926

6t

2548

6t

ID

0.90+0.05

r--

--'

~j '"

'""
....

0co

6t

2477 6t

1 105 n1 12

5nFig. 1. Decay scheme of negative parity levels in llOSn and 112Sn observed with
the 98. lOO Mo(l60,4ny)110·lI2S n reactions.

J. Kasagi, et al.

23
10 •

and thick Ta foil served as recoil stopper. yRays were detected with a Ge(Li) detector placed
at 140 to the beam direction in coincidence with
the neutron multiplicity filter. The usefulness ofthe neutron multiplicity filter to reduce unwanted
events is fully described in Ref. 3.
Decay schemes of the negative-parity states inllOSn and 112Sn presented in Fig. 1 are based on
the n- y- y coincidence data. They agree well withthe previous investigation 2) except for the existence of the 8--6t transition in llOSn. Spin andparity assignments given in Ref. 2 are consistent
with the results of the angular distribution measurements in the present work.
The results of the recoil-distance measurements for the 9- and 8- states in llOSn and 112Sn
are shown in Fig. 2. Relative yields of non-shifted
y-ray peaks are plotted against the targetstopper distance. The electromagnetic propertiesof the negative-parity states obtained in thepresent work are shown in Table 1. As can beseen from the table, the B(E2) values of the 9--8transitions are very large, about five times the
single-particle value.
In Table 2 are shown the transition probabil-

112Sn 80S keY

112Sn 263 keY:: 10'

0

+
Go

...,

o

..
o

(g-

~ 10·'

/

"-Go

~•

"-

/

Go
0

= 68 p s-~(e-= 0.90 ns

10·'

0.0
10 • r---r---.---~-r--'
II0S n 163 keY

II0S n •1209+1211 keY
10 11 keY

I

4 5

+

-

N

+

tTl

o

-'"
"-Go
o

.: 10·'

Distance2

3

6

DiStanCe

(mm)

7

B 9

(mm)

Fig. 2. Plots of relative yields of the stopped peaks
against the target-stopper distance for 168, 1,011,
and 1,209 keY y-rays from llOSn, and 263, and 805
keY y-rays from 112Sn.

Table 1. Electromagnetic properties of negative parity levels in llOSn and 112Sn.
Nuc1eid

Ex (keV)'l' (ps)E" (keV)

Ii

If

llOSn

5,106
4,894

75±23
3< <20

1,175
1,130

11-

10-

98-

3,932

175±27

168

9-

8-

0.08±0.03

6.8± 1.1

3,764

1.67± 0.14a

78

8-

7-

0.05±0.03b

2.7±0.3

3< <203< <20
68±9

1,011
1,287
1,235
1,152
263

8811109-

6+
6+
988-

0.13±0.01

4.6±0.6

76

8-

7-

112Sn

4,929
4,582
3,693
3,430

0.90±0.05

B(M1)(0.01tt~)

04.8±1.5

0.04±0.03b6.5±0.4

a ns. b Ref. 2. c B(M2) value in tt~fm2.

Table 2. B(Ml) and B(E2) values of the 9--8- transitions comparedwith the calculations.
Nuc1eid

Configuration of 8- state

B(Ml) (O.Oltt~)

llOSn

Experiment6.8± 1.1(hll/2g7/2 )O. 72(hll/2g7/2) + 0.69(hll/2d5/2)
Calculation with Vg ~ 4aExperiment

13.1
6.8
9.6
4.6±0.6
13.1
4.6
9.8

(hll/2g7/2)

0.59 (hll/2g7/2) + 0.81 (hl112d5/2)
Calculation with Vg ~ 4aa Ref.

3.

B(E2) (e 2fm 4 )200+ 180
-120
55
33
169
150±307435
206

200+ 180- 120
160+ 240-100
6.5±0.8c
0.6±0.l c

150±30260+ 530
-250

10

24

J. Kasagi, et al.

ities between the 9- and 8- states compared withcalculations. With the simplest two quasiparticle
configuration of (hll/ z g 7Iz ) for the 8- states, thecalculated B(Ml) values are about two times
larger than the experimental ones, whereas thecalculated B(E2) values are less than half of theexperimental ones, as indicated at the secondrows in Table 2. The configurations given at thethird rows are obtained so as to reproduce theexperimental B(Ml) values. However, the B(E2)values calculated with these configurations are
smaller than those of the simplest configuration.
The results of the generalized seniority mixing
calculation!) with the effective interaction of thefinite range force are also listed in Table 2. The
experimental B(E2) values are in good agreementwith them, although the B(Ml) values are slight-

ly smaller than those of the calculation. Therefore, it can be concluded that the observed enhanced E2 transitions between the 9- and 8states are due to the small admixtures predicted
in Ref. 1. It should be stressed that the enhancement is observed only for the transitions between
the states with rather simple Vg = 2 configurations
such as the 9--8- transition.
References
1) G. Bonsignori, M. Savoia, K. Allaart, A. van Egmond,and G. Te Velde: Nucl. Phys. A, 432, 389 (1985).
2) A. van Poelgeest, ]. Bron, W. H. A. Hesselink, K.
Allaart, ]. ]. A. Zalmstra, M. ]. Vitzinger, and H.
Verheul: Nucl. Phys. A, 346, 70 (1980).
3) T. Murakami, J. Kasagi, H. Harada, and T. Inamura:
Nuc!. Instrum. Methods A, 241, 172 (1985).

25
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-10.

Aligned Bands in Ge Isotopes in the Interacting Boson Model
N. Yoshida and A. Arima *NUCLEAR STRUCTURE 66,68,70,72Ge; interacting boson)( model, high-spin states.

In a previous report,l) we reported a result of
calculations of energy levels and B(E2) values of
the Ge isotopes in the interacting boson model
coupled with a fermion pair in the g9/2 orbital.
The present report describes a result of further
calculations for these isotopes.
Since the model is almost the same as that used
in Refs. 1 and 2, we here give only an outline of
the model. The Hamiltonian is given by
H=HB+HF+ VBF
The boson Hamiltonian HB is the one fitted to
low-lying levels. The fermion Hamiltonian HF
consists of single-particle energy and the surface
delta interaction. The single-fermion energies
are taken as being close to the quasiparticle
energies. As the interaction between bosons andfermions V BF , we assume the quadrupolequadrupole interaction. The quadrupole operator
includes the terms which allow a boson to change
into a pair of fermions. We determine the parameters in V BF for 68Ge so that the locations andB(E2) values of the three 8+ states are reproduced. The variation of these parameterswith mass number is estimated considering the
microscopic theory of the IBM by Scholten who
took into account the mass number dependence
by using the u and v factors of the BCS theory. 3)
For calculation of B(E2) values, we assume thesame effective charges for proton and neutronbosons and determine them from experimental
B(E2; 2t~O~) values for each isotope. We assume
fermion effective charges to be 1.5 e for protons

10
14-

12-

14-

12-

w

EXP

CAL

EXP

CAL

EXP

CAL

EXP

Fig. 1. Energy levels and B(E2) values in 66.68.70.72Ge. Bands with 7C and II in the figure are proton·and neutron-aligned bands, respectively. B(E2) values are given in units of e2 b2 •* Department of Physics, The University of Tokyo.

26

N. Yoshida, et al.

and 0.5 e for neutrons. In the M1 operator, we
assume 1 jJ,N and 0 for the g-factors of proton
bosons and neutron bosons, respectively. As forthe g-factors of the fermions in the g9/2 orbital,
we assume 1.16 jJ,N and -0.21 J-lN for protons andneutrons, respectively, which are determinedfrom g-factors of 9/2+ levels of neighboring
nuclei.
The calculated and observed energy levels andB(E2) values are compared in Fig. 1, which shows
good overall agreement. The energy level of thefirst 8+ state is lowered as the mass number
increases. This trend is reproduced by the calculation. In 66Ge, the IBM calculation reproduces
the odd-even staggering like 2, (3, 4), (5, 6),'"
observed in the y-band. In 68Ge, the calculationsuggests that the first and the second 8+ states
are both mixed ones of the zero- and the twoneutron-mixed states. By this mixing, we areable to reproduce appreciable amount of E2 transitions to the first 6+ state from both of the first
and the second 8+ states, although they are still
smaller than the observed values. In 70Ge, thelowest 8+state is found from calculation to be ofneutron nature, and the second a boson state. In
72Ge, the first 8+ state seems to be a neutron state,while the second a boson state. The above arguments about the nature of these bands, however,are all dependent largely on the choice of parameters, so we can not draw a reliable conclusion.
As is well known, one of the experimental
methods to determine the character of bands isthe measurement of g-factors. Figure 2 shows the

1.2

4-4- -..._ _-A
A

8;'

~1~
0.8

-

z
~

-

r

0.4
C)

o

-0.4

Fig. 2. Calculated g-factors of 21, boson 81i, protonaligned 8t, neutron-aligned 8t, boson 101i, protonaligned lOt, and neutron-aligned lOt levels in
66,68,70, 72Ge.

calculated g-factors. The calculation reproduces
the g-factor of 2t of 72Ge, but it gives only a halfof the g-factor of 2t of 70Ge. Among the high-spinstates, the states with an aligned g9/2 proton pairare expected to have positive g-factors, and thestates with an aligned g9/2 neutron pair to havenegative g-factors.
References
1) N. Yoshida and A. Arima: RIKEN Aeeel. Progr. Rep.,
18, 26 (1984).

2) N. Yoshida, A. Arima, and T. Otsuka: Phys. Lett., B,
114, 86 (1982).

3) O. Scholten: Ph. D. Thesis, Univ. of Groningen (1980).

27
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-11.

The sdg Interacting Boson Model Applied to 168Er
N. Yoshinaga, Y. Akiyama, * and A. Arima **(NUCLEAR STRUCTURE l6sEr; sdg interacting boson model.)Applying the sdg interacting boson model (thesdg IBM) to l6sEr where the number of active
bosons is 16, we are forced to truncate the model
space because the full space is too large forcomputer analysis. Since l6sEr is a well deformed
nucleus, we take U(15)=>SU(3) schemel) and takeas many as possible SU(3) basis states, whichhave large eigenvalues of the Casimir operatorof SU(3). The basis states taken into account arethose belonging to the SU(3) representations: (64,0), (60,2), (58,3), (56,4)2, (54,5), (52,6)3, (50,7)2, (48,6)\(55,3), (53,4), (51,5)2, (49,6)2, (47,7)3, (58,0), (56,1), (54,2)3, (52,3)3, (50,4)6, (48,5)6, and (46,6)10. Here thesuperscript indicates the multiplicity of the irreducible representation.
We take two-body interactions with SU(3)tensor character (00), (22) and (06) +(60) only.
Other interactions such as (44), (66), (82) + (28),(10,4) + (4,10), (12,0) + (0,12), and (88) tensors are
not included in this analysis. We construct four
two-body interactions V lJ V2J V3, and V4 besides
the Casimir operator of SU(3) and L2 operators.
In terms of them our Hamiltonian reads
H = alVl + a;.V2+ ~V3 + a4V4 + asCSU (3)+(kL 2where a's are parameters to be determined. The
four interactions through Vl to V4 are the linear
combinations of six (22) and four (06) + (60) tensors. Among four interactions three interactions(Vb V2, V3) are used for adjusting the positionsof the f3, K = 01 and K = 41 bandheads. The Vl
produces the anharmonic effect. With the interaction VI only the K = 21 and K = 41 bands are too
low in energy compared with other bands. Theinteraction V2 is used to lower the K = 01 band.
The K = 01 band is adjusted by V3 • The interaction V4 is used to make the eigenstates close to
the SU(3) states (actually the strength of V4 is* Department of Physics, College of Humanities andSciences, Nihon University.
** Department of Physics, Faculty of Science, The University of Tokyo.

668-

2-

5=

6-

6- 487-

45-

4-

Or

~=
(64.0)- 2(56.4) --- (52.6)--- (*·*)K"'4
K=2
4 - 2K=2(*.*)
0= (58.3)
K=O
2K=3

3=
K=O
2- (60.2)

6- (60.2)2-

5=~= i~ 4=,3=~= o~ (56.4)2

1- 8 -

43-

-1

K=O

K=2

Energy levels

-0

K=O

Fig. 1. Energy levels of all positive parity bands
below 2.4 MeV. Solid lines show the theoreticalones and dashed lines show the experimental bandhead energies. The label below each bandhead
represents an SU(3) representation (.t,,u) of its main
component and K quantum number. States withasterisks cannot be assigned to definite SU(3) representations because the probability of their main
components is less than 50%. The SU(3) label (56,4)1and (56,4)2 indicates (56,4)=0 and (56,4)= 1, respectively.

related to the position of K = 1+ bands).
Figure 1 shows the energy levels obtained bydiagonalizing the Hamiltonian with an appropriate set of parameters. The solid lines show thetheoretical energy levels and the dashed lines
show the bandhead energies of experiment. We
see overall agreement with the experiment2).3) ismuch more improved compared to that of Ref. 4.
The most remarkable is the reproduction of theanharmonicity,S).6) that is, E(K=41)/E(K=2t)=
2.5, which is mainly due to the effect ofconfiguration mixing. By first-order perturbation
we cannot reproduce this strong anharmonicity.4)
This K=41 band belongs mainly to (56,4)W=orepresentation where w is the SU (3)-seniority
quantum number.l} Another K = 4+ band arisingfrom (56,4)W= 1 is pushed up at 3.8 MeV. This band
would be degenerate in energy with the K=4+
band from (56,4)W=o in case of a Hamiltonian
consisting of only the Casimir operator of SU(3)and L 2 operator. The predicted K = 01 band has

28

N. Y oshinaga, et al.

N

E

(a)

150

100

<

50

o

Id

8(E2; )J , Ii -- 9 ,Ii 2 2 -2 I If 0).6,3-4 -5 ,,2

" i

"

-20

"-3
14
2

/2

"

"

,,"

-6

-

_4

5- 2

6

"
0

20

9 , 1f)112
Ii 0 2 0 I 0)
"

"

( b)

-4

·6

"

15

8(E2 ; r> ' Ii -

<

10

.6

o

'f

"

5

"

0
-4

.6

"

20

8(E2; fJ,
-4

-6

" "

'j- F,

If)1/2'f ><_6
Ii 0 2 2 I 2
2*
14 ""
"
"
-2"*
(e)

10

o

-2*

"

-20

"

"

.2* :

-4

30

20

-

-4

-20

o

20

IPt1)- ~(lt 1)

Fig. 2. (a) Analysis of E2 matrix elements for the yto 7- transitions. Experimental values are shown by
filled circles while theoretical ones are shown by
open triangles. Points are labeled by It only forexperiment. For more details see Ref. 5. (b) Analysis of E2 matrix elements for the j3 to 9' transitions.
Asterisks indicate that for the 1=2/3 states only
relative intensities have been determined. (c) Analysis of E2 matrix elements for the j3 to y transitions.

the nature of one-phonon state theoretically,?)which is consistent with recent 167Er(d,p) and167Er(t,d) reactions. S) The lowest K = 3+ band ispredicted at a reasonable position, which cannot
be described in terms of the sd IBM-l. Below 4
MeV we have two K = 1+ bands which are notshown in Fig. l. One starts at 2.7 Me V and theother at 3.8 MeV.
The one-body E2 operator is given by four
independent parameters in this model:
Q,., = el (st d,., + h. c.) + e2(d t d),.,<2)+ e3( (d t 9),.,(2) + h. c.) + e4 ( 9t 9),.,(2)This differs from the sd case where only two
independent parameters exist. With three Mo
values tabulated at Table III of Ref. 5 and theabsolute B(E2) of L=2t~L=Ot, the determined
four parameters are (el = - 0.327, e2 = 0.406,
e3 = - 0.420, e4 = 0.519) whose ratio is close to(- 2 J715 : 11//14 : -18//35 : 3/IT77) that isgiven by a generator of SU(3). Figure 2 shows the
Mikhailov plot analyses (MP A) for y~ 9, f3~ 9,
and f3~y. The general experimental trend of theE2 transitions is well reproduced, that is, thetheoretical slope of the y~ 9, f3~ 9, and f3~ y
MPA's is positive, positive, and negative, respectively. It should be noticed in Fig. 2 that thetheoretical MP A's are not like straight lines
because of the effect of band mixing. The theoretical B(E2) prediction gives B(E2; K = 4t ~ K =2t)/B(E2; K=2t~K=Ot)~l.4. This indicatesthat the K = 4t band has the nature of 2y band
theoretically. The E2 transitions for K = 01 ~ 9
are predicted to be as weak as for f3~ 9, which isalso consistent with the experiment.
In summary we have calculated energy levels
and E2 transitions of 16SEr in terms of the sdg
IBM. This model is shown to solve the problemof anharmonicity regarding the excitationenergy of the first K = 4+ band relative to that of
the first K = 2+ one. The level scheme including
the K = 3+ band is well reproduced and the calculated B(E2)'s are consistent with the experimental data.
References
1) Y. Akiyama: NucZ. Phys. A, 433, 369 (1985).
2) W. F. Davidson, D. D. Warner, R. F. Casten, K.
Schreckenbach, H. G. Borner, J. Simic, M.
Stojanovic, M. Bogdanovic, S. Koicki, W. Gelletly,
G. B. Orr, and M. L. Stelts:]. Phys. G, 7, 455(1981).
3) D. D. Warner, R. F. Casten, and W. F. Davidson: Phys.
Rev. Lett., 45, 1761(1980); D. D. Warner, R. F. Casten,and W. F. Davidson: Phys. Rev. C, 24, 1713(1981).
4) H. C. Wu and X. Q. Zhou: NucZ. Phys. A, 417, 67(1984).
5) A. Bohr and B. R. Mottelson: Phys. Scr., 25, 28(1982).
6) T. S. Dumitrescu and I. Hamamoto: Nucl. Phys. A,
383, 205(1982).
7) N. Y oshinaga: Ph. D. thesis, University of Tokyo(1985).
8) D. G. Burke, B. L. W. Maddock, and W. F. Davidson:
Nucl. Phys. A, 442, 424(1985).

29

RIKEN Accel. Progr. Rep. 19 (1985)

111-1-12.

Inelastic Scattering of Polarized Protons Exciting the y- andOctupole-Vibrational Band in 152S m at 65 MeV

T. Ichihara, H. Sakaguchi,* M. Nakamura,* M. Yosoi,* M. Ieiri,*
Y. Takeuchi,* H. Togawa,* T. Tsutsumi,* and S. Kobayashi*
NUCLEAR REACTIONS 152Sm(p,p').Ep=65 MeV, polarized
beam, measured differential cross sections and analyzing
powers, ground state rotational band, y-vibrational band,
octupole-vibrational band; coupled-channel calculation,
rotation-vibration model, asymmetric rotor model, hexadecapole (Y42 + Y 4- 2) term.

The collective vibrational states in deformed
nuclei are of considerable interest in investigating the nuclear structure. 1) In particular, theunderstanding of the y-vibrational band is along-standing problem.
Recent experiments and the analysis of theinelastic scattering of polarized protons exciting
the y-vibrational band in 166Er and 168Er haveshown that the large hexadecapole term (Yt2 +Y4 - 2 ) together with the usual quadrupole term
(1';2) is necessary in order to reproduce theexperiment data. 2). 3)
In order to investigate the systematic trend in
the hexadecapole component of the y-vibrationalband, we have measured the inelastic scatteringof the polarized protons from 15 2Sm.
The experiment has been performed with 65
Me V polarized protons from the cyclotron at the
Research Center for Nuclear Physics, Osaka
University. The data have been obtained using ahigh resolution spectrograph RAIDEN. The
overall energy resolution was 20-26 ke V
(FWHM). The beam current on the target was
30-60 nA and the beam polarization was 78-82• %.4) Figure 1 shows a typical momentum spectrum on the focal plane counter for 152Sm(p,p')
scattering at 818b =48°. The ground state
rotational band, the y-vibrational band, the /3-l52Sm(p,p') Ep .= 65 MeV

10 4

elab. = 48 deg.

Spin UP

~

w

z

Z
<t:
I

10 3

U

"-

(fl
~-

Z
::J
0

10 2

u

10 1

Fig. 1. Typical momentum spectrum on the focal plane counter for 152Sm(p,p') scattering at 65 MeV.
* Department of Physics, Faculty of Science, Kyoto

University.

30

T. Ichihara, et at.
1529'n(P. P 'J

10 5

Ep= 65 MeV

1.0
0.5

10 '

0.0
10'
-0.5
10 2

1.0

10 I

0.5

~ 10 2(f)......

.0

0.0
II: -0.5
W.=; 10 I

::z
0
a...

Z
0

1.0
0.5

..... 10 I

~

fU
llJ

;;:; 0.0

en
en
en

0
II:

Z

>--

10 0

-l

<: -0.5

z

10 1

<:

1.0

U

0.5

10 0

0.0
10- 1

10 0

1.0

10- 1

0.5

o. 0 t--~~--t/--t-"u-f--+---l---+------i
10-2
-0.5
10-'

10

Fig. 2. Measured angular distributions of 152Sm(p,p') scattering at 65 Me V for the ground-state rotational band andy-vibrational band. Solid (dashed) curves show the coupled-channel calculation assuming the ~2 + ~2( Y22 only)
mode y-vibrational model.

vibrational band, and the octupole vibrational •band are strongly excited as shown in the spectrum.
Coupled-channel calculation assuming the yvibrational model has been performed using amodified version of the code ECIS79,5) which
includes the form factors of the surface vibrationin deformed nuclei in order to calculate the j3-,y-,and octupole-vibration in deformed nuclei. Figure 2 shows the results of the calculation. Excellent fits have been obtained if we introduce thehexadecapole term (Y42 + ~-2) in the y-vibrational band.
It has been found that the hexadecapole (~2 +~-2) transition strength in the y-vibrationalband is linear as a function of neutron number inthe 152 < A < 168 region. It would, therefore, be
concluded that the hexadecapole component in
the y-vibrational band is tightly related to the(N ,n3) = (5,2) neutron sub-major shell.
Figure 3 shows the result of the coupledchannel calculation for 0+,2+,4+,1-,3-, and 5states in 15 2 Sm assuming the octupole-vibrational

band. For the octupole vibration, the additional
Y lO term is necessary in order to remove thespurious center-of-mass motion. 6 ) The importance of the correction term is clearly understoodfrom Fig. 3. These results indicate the applicability of the rotation-vibration model of Bohr andMottelson. 1l
References
1) A. Bohr and B. R. Mottelson: Nuclear Structure, W.
A. Benjamin, Inc., Reading, Vol. II (1975).
2) N. K. Glendenning and R. S. Mackintosh: Phys. Lett.
B, 29, 626 (1969).
3) T. Ichihara, H. Sakaguchi, M. Nakamura, T. Noro,
F. Ohtani, H. Sakamoto, H. Ogawa, M. Y osoi, M.
Ieiri, M. Isshiki, Y. Takeuchi, and S. Kobayashi: Phys.
Lett. B, 149, 55 (1984).
4) T. Ichihara, H. Sakaguchi, M. Nakamura, T. Noro,
F. Ohtani, H. Sakamoto, H. Ogawa, M. Yosoi, M.
Ieiri, M. Isshiki, and S. Kobayashi: Phys. Rev. C, 29,1228 (1984).
5) ]. Raynal: code ECIS79, unpublished; Phys. Rev. C, 20,
31 (1979).
6) M. N. Harakeh: Lecture Notes of 1983 RCNP Kikuchi Summer School, p. 133 (1983).

T. Ichihara, et ai.

311529l1(P. P 'J
10 5

Ep= 65 MeV

1.0
0.5

10'

o. a
10 3

-0.5
1.0

10 2

0.5
10 1

0.0

10 2

-0.5

'i:

If)

.......

1.0
10 I

.0

.= 10 I

a:
W

:::z

0.5

0

Il...

Z
0

100

IU
W

N

>-

..J

(f)

<:

z

(f)
(f)

0

10 1

<:

a:

u

10 0
10 I

20

30

40

50

60

8e .•. (deelFig. 3. Measured angular distributions of 152Sm(p,p') scattering at 65 MeV for ground-state rotational band andoctupole-vibrational band. Solid (dashed) curves show the coupled-channel calculations assuming the octupole
vibrational model with (without) center-of-mass motion correction.

32
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-13.

Multiple Coulomb Excitation of 161Dy

T. Inamura, A. Hashizume, M. Ohshima,* T. Ishii,*
S. Kikuchi, * T. Aruga, * and S. Ichikawa *NUCLEAR REACTIONS 161Dy(81Br,8 1Br'y), E=305 MeV; J( measured E y ' nuclear lifetimes; recoil distance method.

It is well known that high-j orbitals such asi13/2 give rise to a large perturbation of therotational levels of deformed nuclei. Recently,
we have demonstrated such a rotational perturbation effect on MI and E2 transitions in 16 7Er as
well as on level energies.l) This perturbation
effect is clearly dependent on signature r, aquantum number classifying rotational spectra;r is defined as r = exp( - ina), where 1 = a mode
2, 1 being the spin value of the rotational state. 2)
The nucleus 161Dy is the one whose groundstate
rotational band is built on the i 13/2 neutron
orbital as in 167Er. Therefore, it would be interesting to study whether there is the same signature dependence in 161Dy as was observed for
167Er. The ground-state rotational band of 161Dy
has been well established up to 33/ 2+,3) and an
energy plot such that [E(1)- E(1 - l)J / 21 VS. 12
shows marked signature dependence as observedin 167Er. However, nuclear lifetimes are not available for highly excited states with spins larger
than 9/2. In order to measure nuclear lifetimes ofhigher spin states, we are making a multiple
Coulomb excitation experiment on 161Dy. Here
we present our preliminary results.
The nucleus 161Dy was multiply Coulombexcited with a 81 Br beam of 305 MeV from the
JAERI tandem accelerator. The 161Dy target wasa self-supporting metallic foil of 2.5 mg/ cm2 inthickness. Deexcitation y-rays were measured
with a Ge(Li) detector placed at 45° to the beamin coincidence with backward scattered projectiles which were detected at 8= 100°-150° to thebeam with a plastic scintillator (0 = 0.5 sr).
Nuclear lifetimes were measured by the recoil
distance method,4) i.e., lifetimes were deduced
from the ratio of the yield lu of the unshifted
y-ray peak to the total (1u +Is) that was plotted
as a function of the recoil distance. The quantity
Is is the yield of the Doppler-shifted peak. Figure* Japan Atomic Research Institute, Tokai.

1 shows the observed ratios against the distance.
Correction for the kinematical effect on therecoil velocity has been made in the analysis. It
should be stated that the Doppler-shift attenuation method 1),4) is inadequate for 161Dy because
y-rays are too narrowly separated to make alineshape analysis.
As is seen from Fig. 1, we have for the firsttime measured lifetimes of 11/2+, 15/2+, 17/2+,
and 19/2+ states. (For 13/2+ there are intruder
y-rays which make it hard to deduce the true
lifetime.) Preliminary lifetimes and B(E2) values
for cross-over transitions are summarized inTable l. Values of B(M1) and B(E2) for stop-overtransitions are to be estimated after completing a
mixing ratio analysis. Branching ratios and conversion coefficients, which are needed to deducethe cross-over B(E2; 1 ~ 1 - 2), were obtained
from Ref. 3. Lifetimes measured for 15/2+ and19/2+ seem unreasonably short. They should be
remeasured in coming experiments. Much higher
spin states could also be studied through multiple
Coulomb excitation with beams of 58Ni or 81 Br.

0.01°O~~~50~0~~1~00~O~+1~50~O~
Distance Cum)

Fig. 1. Ratios of the unshifted component Iu to thetotal (Iu + Is) as a function of target-stopper distance. Solid lines are drawn to guide the eye.

33

T. Inamura, et al.
Table 1. Lifet imes of the ground-state rotationalband members in 161Dy and B(E2) values forcross-over transitions (preliminary).
life
Level Mean
r(ps)
9/ 2+
11/ 2+
13/ 2+
15/ 2+
17/2+
19/ 2+

303.0*
192±20Transition

(keV)

Er

B(E2)
(e 2 b 2 )9/2+ -5/ 2+(GND)
11/ 2+-9/ 2+

100.5
140.4

0.79±0.04*
0.69±0.08

222.8
240.7
311.6

(-)

(43±4) 15/ 2+- 11/ 2+
17/ 2+-13/ 2+
50±6(1.3 ± 0.4) 19/ 2+-15/2+* Ref. 3.

1.2±0.1(- )References
1) M. Ohshima, E. Minehara, M. Ishii, T. Inamura, and

A. Hashizume: Nucl. Phys. A, 436, 518 (1985).
2) M. J. A. de Voigt, J. Dudek, and Z. Szymanski: Rev.
Mod. Phys., 55, 949 (1983).
3) Nuclear Data Sheets, 43, 134 (1984).
4) For example, D. B. Fossan, and E. K. Warburton:
Nuclear Spectroscopy and Reactions, (ed. by ].
Cerny), Academic Press, New York and London, PartC, p. 307 (1974). '.

34

RIKEN Accel. Progr. Rep. 19 (1985)

111-1-14.

The Life-Time of the Levels in the Ground-State
Band in 173Yb

A. Hashizume, T. Inamura, M. Ohshima,* E. Minehara,*
S. Kikuchi, * and H. Kumahora **NUCLEAR REACTIONS I73Yb(58Ni,58Ni'y), E=200 MeV; J( measured E y , I y , Doppler shift, deduced life-times.

By using multiple Coulomb excitation with a
200 MeV 58Ni beam from the JAERI UR tandem
accelerator, the ground-state rotational band up
to spin 27/2- in 173Yb have been excited. I) The
excited states are shown in Fig. 1. It is known
that high-j orbitals give rise to a perturbation onlevel energies and transition moments of groundstate rotational band. We have found the perturbation on transitions in 167Er2) built on i ll/2 ,
7/2+ [633J and also studied the band in I67Dy3)
built on f7/2, 5/2- [523J. As the ground-state
rotational band in I73Yb is built on the neutron
orbital h7/2 , 5/2- [512J, these three nuclei would
show some systematic trend about the perturbation effect.
The Doppler broadened y-ray line shapes wereobserved at 0 degree by using a Comptonsuppressed y-ray detector. The line shapes of thecross over y-rays emitted from the states of the2018, 27/2-)1736(25/2- )1

1471.71112271
1001.9

1

796.2

I

610.6

11
IJ

445.7
3017
179.3
78.5
00

I~

I~

oj.

oj.

~

!

!

23/r
21/2
19/2

....J

W
Z
Z

«
:I:
U

VI

.....
z

::::> 10oU

1~~--~2~0----+rr--~~--~--~100'

CHANNEL NUMBER
Fig. 2. Results of lineshape analysis of the 223.2 ke V
y-ray. Solid curve represents the best fit and dashedones show the range of uncertainties.

-

17/215/2 -5/2[512]1112 9/27/2
5/2-

13/2 -

E(keV)

Fig. 1.

22 ·4 ps(2.0

-

1

1

223·2 keY

The ground-state band in 173Yb excited by

200 MeV 58Ni.
* Japan Atomic Energy Research Institute, Tokai.
** Department of Physics, Hiroshima University.

spin from 11/2- to 21/2- were analyzed. The
experimental line shapes were fitted with a code
which included the effects on the line shape ofangular distribution of recoiling nuclei, feedingfrom higher levels, and the finite size of thegermanium detector. The typical results of analysis were shown in Figs. 2 and 3. The life-times
obtained in the present study were listed in Table
1.
Combining these life-times and y-ray intensities, it is possible to learn the transition probabilities. Detailed analysis are in progress.

A. Hashizume, et al.

Table 1.
350·5 keY
7·0 ps (8)Spin

Ey (cross over)(keV)life-time
(ps)

301.7
445.7
610.6
796.2
1001.91227.1

11/213/215/ 217/219/221/ 2

223.19226.39308.87350.50391.26430.9222.4±2.0
17.4±2.5
10.5± 1.0
7.0±0.8
4.4±0.6
2.7±0.5

...J

Z 10

Newly obtained life-times of levels in 173Yb.

E (levels)
(keV)

....
l1J
Z

35

4

«

:r:
u

-

U")
~

z

::> 10 3oReferencesU

A. Hashizume, T. Inamura, M. Ohshima, E. Minehara, S. Kikuchi, and H. Kumahara: RIKEN Accel.
Progr. Rep., 18, 28 (1984).
2) M. Ohshima, E. Mine-hara, M. Ishii, T. Inamura, and
A. Hashizume: Nucl. Phys. A, 436, 518 (1985).
3) T. Inamura, A. Hashizume, M. Ohshima, E. Minehara, S. Kikuchi, and H. Kumabara: RIKEN Accel.
Progr. Rep., 17, 26 (1983).
1)

101 ~---"'---'----1-----'~-~
o
20
40
100

CHANNEL NUMBER

Fig. 3. Results of lineshape analysis of the 350.5 ke V')foray. Solid curve represents the best fit and dashedones show the range of uncertainties.

36
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-15. High-Energy Single-Proton States Studied by y-Triton
Coincidence Measurement in the 20SPb(a,tyo9Bi Reaction
M. Ishihara, H. Ohsumi, T. Motobayashi, and Y. Nagai*
NUCLEAR REACTION 20SPb(a,t)209Bi at E=60 MeV; J( coincidence energy spectra of tritons and y-rays.

We have been continuing investigation on
highly excited single-particle states in 209Bi using
a proton stripping (a ,t) reaction on 2osPb. Of
primary interest is observation of strength distributions of proton single-particle states in the
excitation region of 6nw such Ij15/2, lill/2' 2g9/2,7/2
states. In 209Bi, single-particle states of 51iUJ
excitation are well explored and known to constitute a main portion of the level scheme in thelower excitation region below 4.0 MeV. On theother hand, the distributions of 6liw states are
rarely known since they range toward the highenergy continuum region.
A standard method to locate single-particle
strengths is to observe differential cross sections
in a single-particle transfer reaction. Such measurements have been carried out recently via
the 20SPb(a, t)209Bi reaction 1),2) and indicatedsignificant strengths of high-spin single-particle
states in the continuum spectral region. It isfound, however, that the information of the crosssections is not sufficient to identify different
single-particle states and to deduce spectroscopic
factors quantitatively. This is because of similarity in angular distribution among different tstates and also due to the presence of a continuum background whose behavior is ambiguous.
This note reports a coincidence measurement
between y-rays and triton ejectiles in the 20SPb(a,t)209Bi reaction at 60 Me V to solve above problems. We have previously found 3) that the highly
excited states between the proton separationenergy s;, (3.8 Me V) and the neutron separationenergy Sn (7.8 Me V) primarily decay by y transitions, which feed directly to low-lying 5nw
single-particle states. These y-rays of Inw transition are most probably due to El decays withspin sequences such as Ij15/2~ li13/2' lill/2~ 1h9/2'
and 2g9/2~2f7/2. If this is the case, the strengths ofthe different 6liw states can be identified and* Faculty of Science, Osaka University.

deduced from observed intensities of these highenergy transitions whose final states can be
distinguished from missing energies.
In the present experiment, two telescopes of Si
solid-state detectors were set at fixed angles of() = 16° with Al absorbers placed in front to protect the detectors from strong elasticallyscattered particles. Five N aI detectors of 6" 4> x
6" were used to obtain y-ray spectra at different
angles. In addition, y-rays were detected with asetup called HERMES consisting of a central
N aI detector of 6" 4> x 10" and four sectors of N aI
detector surrounding it. By using the surrounding
detectors in an anti-coincidence mode, only
peaks with full y-ray energies were registered.
Figure 1 shows a triton spectrum obtained incoincidence with whole y-rays. The region ofinterest is the continuum part between 4.0 and"'-'8.0 MeV, while the spectrum in the lower excitation is well understood to consist of well
separated 5nw states. Figure 2 shows a y-ray
spectrum obtained with HERMES in coincidencewith tritons whose energies correspond to excitation of states between Ex=7.0-7.4 MeV. While
the statistics is rather poor, implication of thedata is clear and promising. The peak of thehighest energy is centered at 7.2 MeV corresponding to the transition to the ground state(lh9/2). The second highest peak around 5.6 Me V
corresponds to the transition to the second
excited state (Ex = 1.6 MeV, lill/ 2). The 3rd bumparound 4.6 Me V may be a partner of a bumparound 2.6 MeV which corresponds to multipletsof h 912@3- configuration. The peaks at 0.9 and 1.6
MeV are partly due to the second-chance decays
in sequence with the high energy transitions of 4.
6 and 5.6 MeV, respectively. The spectrum clearly shows the branching ratios of deexcitation of
the initial continuum states to the 1h9/2 and Ij13/2
states. Thus the strengths of the Ijll/2 and li15/2
states may be unambiguously determined. In asimilar manner the branching ratios were37

M. Ishihara, et at.

Triton spectrum
coincidence with y rays

/1.61MeV

1 600
Q)(0.91Mev (f 7/ 2)~ 1 200

.£:
()

tlc
o

c

60 0.91

C
tV
.£:

1

~
tl
§

........
:J

E% = 7.0-7.4 MeV

Q)

c

<.>

Gamma-ray spectrum

in 208Pb(a,tr)209Si

80

800

40

o

()

20

400

o

o
ChannelChannelFig. 1. The triton spectrum obtained in the 20sPb (cr,t)209Bi reaction at 60 MeV and 0= 16 in coincidence with y-rays.
0

obtained for the continuum states as a functionof Ex over the whole region between S'p and ~. A
final quantitative analysis is now under progress.
References
1) S. Gales, C. P. Massole, S . Fortier, E. Gerlic, ].
Guillot, E. Hourani, ]. M. Maison, ]. P. Schapira, B.
Zweiglinski, P. Martin, and V. Comparat: Phys. Rev.

Fig. 2. The y-ray spectrum obtained with HERMES
in coincidence with tritons feeding excited states of
209Bi at &=7.0-7.4 MeV.
Lett., 48, 1593 (1982).
E. Takada, M. Ishihara, Y. W. Hui, Y. Mihara, T.
Murakami, Y. Toba, and R. E. Tribble: RIKEN
Accel. Progr. Rep., 17, 21 (1983).
3) M. Ishihara, H. Ohsumi, T. Motobayashi, Y. Nagai,
and T. Shimada: RIKEN Accel. Progr. Rep., 18, 39

2)(1984).

38
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-16.

Search for New, Isotopes of Neptunium

H. Kudo, T. Nomura, K. Sueki, Y. Hatsukawa,Y. Horikoshi, * and M. Magara **NUCLEAR REACTION 209Bi+ 2°Ne, E=95-115 MeV; a-]decay, fast-pulsed technique, slow-pulsed technique, He-jet[
transport.

There are a number of undiscovered isotopes
in the transuranium region. We paid attention toa neutron deficient side, and tried to identify new
isotopes of neptunium using 2°N e on 209Bi reaction by detecting a-particles. Irradiations were
performed at the cyclotron in the lab-energy of95- 115 MeV, which corresponds to the excitationenergy of a compound nucleus of 28- 46 Me V. In
this excitation energy region, large cross sections for 209Bi(2°Ne, 3n)2 26 Np and 209Bi(20Ne, 4n)225Np reactions are expected. As 226Np is an
odd-odd nucleus, it is probable that this nucleus
disintegrates by EC decay. If this is the case, we
could measure a-particles from 226U which has a
half-life of 0_5 s and from the successive daughter
nuclides by using a He-jet transport system. The
Q-value for the ground-state a-decay of 225Np
which seems to have the most favorable production condition in the present reaction system is
evaluated as 8.605 MeV from the empirical mass
formula.l) From the systematics by Taagepera
and Nurmia,2) the half-life of 225Np by a-decay isestimated ~s around a few hundreds of microseconds.
The nuclides whose half-lives lie in the range
of a few tens to a few hundreds of nanoseconds
were identified by means of a fast pulsed-beamtechnique developed by Nomura et at. 3 ) In thistechnique, the sharp phase bunching of the cyclotron beam and the fast timing property of a Si
detector make it possible to distinguish delayed
a-particles from promptly emitted charged particles in a nanosecond timing. Time distributionsof a-decays were taken between natural beam
bunches of the cyclotron by use of a time-toamplitude converter, for which beam bursts fromthe cyclotron generate the zero-time signals, thatis, start and stop pulses for the time-to-amplitude* Faculty of Science, Niigata University.
** Faculty of Science, Tokyo Metropolitan University.

.,'"
r<0

r-

<0

~::j~~~~;;~~~~~~~~

~

N

Z

0

"-..

(j)

r-

'"

~

CD

Z

...

=::J

'"

U

N

o

N

N

N

N

N

N

N

N

N

N

N

N

300

o

~
~

rl

~

~

~

~

~

0

~

0

~

~
M

0

~

~
N

0

~

0
0

~
0

~
(0

N

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

ITN
U

N

> > > > > > > > > > > > > > >

-1
W

I

+

+

g ~ t ~; tl'g ~ s~ ~ ~ ~ &:: ~ ~ ~

N

Z

+ +

+

.,'"

~
~

~

~

0

~

N

);!rl~;I'~
400

500

600

CHRNNEL

700

800

Fig. 1. An example of a-spectra obtained in thereaction of 110 MeV 16 0 on 209Bi by a fast pulsedbeam technique.

converter were provided from a fast signal of a
Si detector and the rf-oscillator of the cyclotron.
The nuclides of half-lives of sub-millisecond to a
few tens of milliseconds were measured by aslow-pulsed beam technique. A slow-pulsed beam
was obtained by operating the ion source with apulsing mode. In the in-beam experiments, Bi
target of about 500 J1.g / cm 2 in thickness was
inclined 30° to the beam direction and normal tothe detector surface in order to minimize escapeof recoil products from the target and to obtain

39

H. Kudo, et al.

good resolution of the a-spectrum. To check theelectronic circuit of nanosecond timing, the reaction of 16 0 on 209Bi was employed. An example ofa-spectrum is shown in Fig. 1. Measured halflives ranged from 90 ns (215Fr) to 7.22 h e l l At),and the FWHM of a-spectrum was about 90 keY.
For the measurement of the nuclides of halflives longer than a few hundreds of milliseconds,
a He-jet transport system4 ) was used. In thismeasurement, two Si detectors were mounted for
detection of a-particle emitters. One was placed
just at the exit of gas jet, where accumulationand saturation of radioactivity were observed
depending on the half-life of the nuclide. The
other detector was placed 3-60 cm apart from thecollecting position, and the products deposited on
the collecting tape were moved to the front of
the detector by means of a micro-computercontrolled stepping motor. In order to estimate
the transport efficiency of the He-jet transportsystem, a recoil catcher foil method was employed. The shortest half-life observed was 119
ms of 212m At by the He-jet transport system in
the reaction of 2°N e on 209Bi.
Data analysis is still in progress; however, apreliminary analysis has given no indication of
new isotopes of neptunium so far. Only a few
a-particles were observed above 8 MeV except
for 213Rn, 211mpo, and 212mpo both in the He-jet
and nanosecond timing experiments (see Fig. 2);
this means that neither protactinium isotopes nor
actinium isotopes which are daughter and granddaughter nuclides of neptunium isotopes of interest were measured. Judging from the detection
efficiencies, the production cross sections foreON e, xn) products are less than a few Ji b.

b

b

'"
'"....

....'"'"

1-1

<D

M

<D

t..

.-i
N

:>
OJ
::<:

0

p..

If)

.jJ

o<l;

OJ

.-i
.-i

'"
....
<D

--.J
W

p..

...

N

:>
OJ
::<:

IT

::r: O
U

f-Z

0

p..

E

.-i
.-i

o<l;

~

<D

...

-;:;
M

N

~

r-

M

N

.-i

r-

r-

t..

.-i

If)

:>
OJ
:::;:

""
\D

o

0
If)

r-

:>
OJ
::<:

00

:>
OJ
:::;:

"':

N

.jJ

MN

~

....

=:)

U

N

If)'"

N

'-.,.
(J)

\D

:>
OJ
::;:

0
.-i

Z
Z

0'1
...-i
.-i

N

0

I/)

rr-

.,.;

N

:>
OJ
::<:
0

N

'"
0

~

"0

300

400

500

CHRNNEL

600

700

Fig. 2. A part of the a-spectrum obtained in thereaction of 115 MeV 2°Ne on 209Bi by a He-jet
transport system.

References
1) A. H. Wapstra and K. Bos: At. Data Nucl. Data
Tables, 17, 474 (1976).
2) T. Taagepera and M. Nurmia: Ann. A cad. Sci. Fenn.
A, 78 (VI), 1 (1961).
3) T. Nomura and K. Hiruta: Nucl. Instrum. Methods ,108, 61 (1973).

4) H. Kudo, T. Nomura, and J. Fujita: RIKEN Acce!.
Progr. Rep. , 18, 127 (1984).

40
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-17.

Low Energy Nuclear Fission of 237Np

T. Ohtsuki,* Y. Hatsukawa, T. Miura, H. Nakahara,
K. Sueki, and I. Kohno
NUCLEAR REACTIONS proton induced fission of 237N p; 1[

.Ep=9.0-16.0 MeV, measured y-rays and a-rays, mass yield

curves, excitation functions, statistical analysis.

Since discovery of nuclear fission in 1939, many
experiments have been performed on nuclear
fissions of actinoid elements. No appropriate
theory for understanding of these data, however,has been proposed yet, especially for characteristics of mass-yield curves in fissions. In the deformation process of the fissioning nucleus towardfission, three possibilities have been discussed on
the critical point for mass division: (1) saddle
point, (2) scission point, and (3) somewhere during
the dynamical descent from saddle to scission.
Kudo et at. 1 ),2) reported that their data on fragment angular distributions and excitaion functions observed in the proton-induced fission of
232Th could be consistently explained by assuming two kinds of saddles, one leading to asymmetric mass divisions and the other leading to
the symmetric.
In the present study, we have tried a detailed
investigation of excitation functions in the
proton-induced fission of 237Np3) in the energy
range of 9-16 MeV. We will report preliminary
results of the mass yield curves, total fission
cross sections, and 237N p(p,2n)236pu reaction
cross sections. We have attempted to reproduce
the peak-to-valley (P / V) ratios of these mass
yield curves by statistical calculation using an
ALICE code by assuming two kinds of barriersof different height.
Neptunium targets were prepared by electrodeposition on a 4.8 mg/ cm2 thick Al foil froman ethanol solution at 150 V. The · amount of
Neptunium deposited was determined by a-ray
spectrometry. These targets were wrapped withan Al catcher foil of 4.8 mg/ cm2, and stacked into
9 layers. As a proton energy monitor, 10 mg/cm 2
Cu foils were inserted into the target stack at an
appropriate interval. The bombardment was* Faculty of Science, Tokyo Metropolitan University.

performed at RIKEN Ring cyclotron for 30
min and 5 h, at an incident proton energy of 16
MeV with about 2 J1.A beam current. After bombardment the resulting activities were measured
directly with a Ge(Li) detector. The produced
nuclides were identified from their characteristic y-ray energies, and their formation crosssections were evaluated from the observed
photopeak areas, photo abundances, genetic relationships, the degree of saturation during thebombardment, and the target thickness. The
237N p(p,2n)236pu reaction cross sections wereobtained by a-spectrometry.
100~~~~~.-~~~~

50 E 1' = l~~ ~.~~V
1>

10

,

fE1' ~e~~/~' '. ",

1O~.
=

~

..

",

£;.

S·

§ 10 E1' = l1.?~eV!"-." •

~

w
w
w

o

U

~

i

"

l:~~~,~~ • :"':".

E1'
10t

"q,".~.":~ .,,~

-.

l

.

.

0,.

!
lor .:~
l'

p

.
'&

0

"','.

~

• E 1' = 10.9MeV
1.0•• •o~o·0.

80 90 100 110 120 130140150
Fragment mass

Fig. 1. Mass yield curves from 10 Me V to 15 MeV at
an interval of about 1 MeV. e , experimenntal data;
0 , mirror points.

41

T. Ohtsuki, et al.

c:o:.;:::;
u
(l)

V)
V)
V)

o

U
9 10 11 12 13 14 15 16 17 18
E" (MeV)E" (MeV)Fig. 2. Fission cross sections of proton-induced
fission of 237N p. e, total fission cross section; 0,236pU formation cross section; E. , total reaction
cross section. Solid lines represent the results ofstatistical calculation.

The observed mass-yield curves from 10 MeV
to 15 MeV at an interval of about 1 MeV areshown in Fig. 1. The total fission cross section,
total reaction cross section, and 237N p(p,2n)236pu
cross section are given in Fig. 2. The solid lines
show the best fit obtained by the ALICE code forthe competition of neutron evaporation andfission in which two kinds of threshold energies
are assumed. The parameters used are listed inTable 1. Cross-section ratios for several fission
products are shown in Fig. 3. The cross-section
ratio of the asymmetric to the symmetric product(99Mo/115Cd) is found to vary with incident proton energy; but the ratios among the symmetricproduct (112Pd/ 115 Cd) and the asymmetric(99Mo/91Sr , 97Zr jI43Ce) are found to be insensitive
to incident energies. The experimental P / V
ratios are reproduced well by using the parameter sets given in Table 1, as depicted in Fig. 4.
Table 1. Parameters used in the statistical calculation (ALICE code).

Er
an
hw
fi~roc~ (MeV) (MeV-I) (klan (MeV)

Mode offissionMultiple

Asymmetricfission(p,f)(p,nf)(p,2nf)(p,f)(p,nf)(p,2nf)Fig. 3. Cross section ratios as a function of incident
proton energy. 0 , this work; E. , for comparison (theresults in Ref. 3).

-

1.0-

0.05
14 15 16 17 18

19 20 21 22 23 24

E ex( MeV)

Fig. 4. Cross section ratio of 115Cd to 99Mo. Solid line
represents the result of statistical calculation using
the modified ALICE code. e, this work; ... , forcomparison (the results in Ref. 3).

In conclusion, from the incident-energy independence of cross section ratios observed
among the symmetric or asymmetric products,
the existence of two kinds of threshold energies
is suggested, and the cross section data obtainedin the present study are well reproduced by
the statistical analysis of the neutron
evaporation-to-fission competition on an assumption of two fission barriers, one for the asymmetric and the other for the symmetric mass
division.
References

Symmetric
fission

5.90
5.59
5.76
7.92
6.88
7.32

A I8

1.05

1.0

AI8

1.15

1.0

1) H. Kudo, H. Muramatsu, H. Nakahara, K. Miyano,and 1. Kohno: Phys. Rev. C, 25, 3011 (1982).
2) H. Kudo, Y. Nagame, H. Nakahara, K. Miyano, and1. Kohno: Phys. Rev. C, 25, 909 (1982).
3) P. Polak and A. H. W. Aten, Jr.: J Inorg. Nucl.
Chern. , 42, 641 (1979).

42
RIKEN Accel. Progr. Rep . 19 (1985)

111-1-18. Low Energy Nuclear Fission of 238U: Correlation between
Angular Anisotropy of Fission Fragment and Fragment Mass
Y. Hamajima, * K. Sueki, M. Magara, ** H. Nakahara, and I. Kohno
NUCLEAR REACTION 238U(p,f), £p = 14.5, 16 MeV; FISSION angular distribution, Bohr's channel theory, two kindsof configurations for transition state, mass division, statistical calculation.

Kudo et al. l ) have found using a radiochemical
technique that there exists clear dependence ofangular anisotropy on fragment mass in the 15
Me V proton-induced fission of 232Th, and similar
dependence was confirmed later by Hamajima et
al. with a counter technique. 2) Hamajima et al.,however, observed no clear dependence when the
proton energy was changed to 13 MeV.3) These
data were explained successfully by Bohr's channel theory 4) which had been considered to be wellestablished in low energy nuclear fission, if it was
assumed that the final mass division modes could
be closely related to two kinds of configurations
at the outer barrier, one leading to symmetricmass division and another to asymmetric division' as suggested by Moller and Nilsson. S)
In the present work an experimental study on
the correlation between the angular distributionof the fission fragment and the fragment mass
was extend to the system of 14.5 and 16 MeV
proton-induced fission of 238U.
The uranium target (about 0.1 mg/cm 2 in thickness) prepared by vacuum evaporation of UF 4
onto a carbon film (30 flg / cm 2 ) was bombarded
with 14.5 and 16 MeV protons from the cyclotron.
Details of the experimental set-up, counting anddata analysis have been reported previously.2)
The examples of the observed angularanisotropies (W (8)/ W (90)) for mass ratios (MH /Md of l.0 (circles) and 1.5 (squares) at 16 MeV
are shown in Fig. 1 (a). The solid curves represent the results of least-squares fitting of a functional form of (a+ bcos 2 8). The angular anisotropies (W ( 0 )/ W (90) = 1 + b/ a) obtained fromthe fitting for respective mass ratios for 14.5
(circles) and 16 MeV (squares) are plotted in Fig.
1 (b). The difference in the anisotropies between* Faculty of Science, Kanazawa University.
** Japan Atomic Energy Research Institute.

(a)

1.3
16 MeV p+U

0

MH/ML

0

1.2

0

1.0
1.5

~

0

0
0'1

1.1

~
~

0

CD

1.0

i
0.9
20

30

40

-50 60
DEGREE

I

I

I

90

80

70

(b)
I

I

I

I

o 14.5 MeV

e 16.0 MeV

1.3 f~

0

0
0'1

i

.......

1.2

~

0

0

i

1.1

1.0

: t9

I~

9 M I

9

I

I

I

1.0

1.1

1.2

I

~ ~I
I

I

1.3
1.4
MH / ML# tt ~
-

I

I

I

1.5

1.6

1.7

Fig. 1. Angular anisotropies W (0) / W (90), (a) as afunction of 0 with mass ratios (MH / Md of 1.0 (circles) and 1.5 (squares) for 16 Me V proton-induced
fission of 238U and (b) as a function of mass ratiosfor 14.5 Me V (circles) and 16 Me V (squares). Curvesin (a) are the results of least-squares fitting of aform (a + b cos20). Error bars attached to the data
points in (b) are due to counting statistics andfitting.

14.5 MeV and for 16 MeV is not significant within
the associated errors derived from counting
statistics and fitting. The anisotropies of asymmetric mass divisions seem to be slightly higher
than those of symmetric divisions at these protonenergies. Calculated results of the contributionsof multiple-chance fission (R) , and theoretically
expected angular anisotropies (W), and apparent
anisotropies (Wapp) for 14.5 MeV (a) and 16 Me V

Y. Hamajima, et at.

Table 1. Theoretically predicted angular anisotropies on 14.5 MeV (a) and 16 MeV (b) protoninduced fission of 238U.
(a) 14.5 MeV

p,fAsym. p,nfp,2nfSym. p,f(b)t
Bf(MeV) (MeV)

K02

R(%)

W

5.03
5.98
4.91
7.37

0.68
0.49
0.31
0.60

77.2
56.2
26.0
67.8

60
2
38
100

1.06
1.08
1.16
1.06

(MeV) (MeV)Brt

Ko 2 R(%)

W

5.30
5.98
4.91
7.37

0.72
0.53
0.38
0.63

81.0
61.0
44.5
71.8

1.06
1.08
1.10
1.07

Wapp

1.10
1.06

16 MeVp,fAsym. p,nfp,2nfSym. p,f

46
2
52
100

Wapp

1.08
1.07

Br, fission barrier height (MeV); t, nuclear temperature (MeV); R, contribution to each mode fission (%);
W, angular anisotropy (W (0)/ W (90)); Wapp , apparent
anisotropy (W (0)/ W (90)).

(b) are listed in Table 1. The calculation was
based on extended Bohr's theory 6) and the statistical theory,7) on an assumption of two kinds ofconfigurations, symmetric and asymmetric, forthe transition state where both the fission probability and angular distributions are determined.
Fission barrier heights for asymmetric mass
division used in the calculation were by about 0.5
MeV higher than the reported values S ),9) (seeTable 1). The theoretical anisotropies Wapp of
1.06 and 1.10 for symmetrically divided fission
fragments and asymmetrical ones for the 14.5

43

Me V are shown to be lower than those corresponding to the observed values of 1.l3 and 1.20.
The predicted Wapp of 1.07 and 1.08 for the 16
MeV are also low in comparison with observed
ones of 1.11 and 1.19 for the respective modes ofthe mass divisions. However, the theoreticalprediction that there would not be significant
fragment-mass dependence for both 14.5 and 16
MeV proton induced fissions is consistent withthe present observations. Therefore, present
results also support the conclusion of Refs. 2 and4 that the symmetric mass divisions require extra
energy of about 2 MeV compared to the asymmetric divisions at the transition state where
fission probabilities and apgular distributions are
determined.
References
1) H. Kudo, Y. Nagame, H. Nakahara, K. Miyano, and1. Kohno: Phys. Rev. C, 25, 909 (1982).
2) Y. Hamajima, K. Sueki, M. Magara, H. Nakahara,and 1. Kohno: RIKEN Accel. Prog. Rep., 17,29 (1983).
3) Y. Hamajima, K. Sueki, M. Magara, H. Nakahara,and 1. Kohno: RIKEN Accel. Prog. Rep. , 18, 143(1984).
4) A. Bohr: Proc. 1st UN Conf. on the Peaceful Uses ofAtomic Energy (II), pp. 151, 911 (1955).
5) P. Moller and S. G. Nilsson: Phys. Lett. B, 31, 283(1970).
6) R. Vandenbosch and]. R. Huizenga: Nuclear Fission,
Academic Press, New York (1973).
7) H. Kudo, H. Muramatsu, H. Nakahara, K. Miyano,and 1. Kohno: Phys. Rev. C, 25, 3011 (1982).
8) R. Vandenbosch and G. T. Seaborg: Phys. Rev., 110,507 (1958).
9) B. B. Back, H. C. Britt, O. Hansen, B. Leoux, and D.
]. Garrett: Phys. Rev. C, 10, 1948 (1974).

44
RIKEN Accel. Progr. Rep. 19 (1985)

111-1-19.

Decay Properties of Light Einsteinium Isotopes

Y. Hatsukawa, M. Magara,* T. Otsuki,* M. Nakata,*
K. Sueki, H. Nakahara, and 1. Kohno
NUCLEAR REACTIONS 238U(14N, xn)252-XEs, x=5-7, E1ab =80-103 MeV, 237Np(12C, xn)249-XEs, x=4.5, E1ab =67-81 MeV;
He-jet transport, measured a-spectrum and half-life.

In a previous progress report,l) the decay properties and excitation functions of neutrondeficient Es isotopes (A 2:: 274) produced by thereaction 14N +238U were reported. In the present
work, four isotopes of Es with masses 244
through 247 were investigated further by meansof a-ray spectroscopy. We produced neutrondeficient isotopes of Es by bombarding a 238U
target with 14 N ions and a 237N p with 12C ions at
the cyclotron. Beam energies were E1ab (14N) = 80103 MeV, E 1ab (12C)=67- 81 MeV. The reaction
products recoiled out of the targets were stopped
in a fast flowing He gas (a He-jet system 2»), andtransferred onto the collecting tape heated at
195°C in order to get rid of oil that would deteriorate the resolution of a-spectra. After an appropriate collection period (generally 8 or 3 min), thedeposited recoil atoms were moved to faceSi(Au) surface barrier detectors for a-ray mea-

1surements. a-Decay events were recorded
together with external clock pulses and stored ina magnetic tape in the list mode for data analysis.
The a-particle spectra displayed in Fig. 1 are
the sum of the results obtained by several bombardments of the 238U with 80- 103 MeV 14N ions.
The single peak shape and channel energies were
determined by using a-rays of 211mPo,213Fr, and214Ra produced by separate bombardment ofa 209Bi target with 14N. The a-peaks at 7.73,7.36,
and 7.32 MeV have been assigned to 245Es, 246Es,
and 24 7Es, respectively. In addition, some othera-peaks were also observed, which, from theirenergies and half-lives, could not be assigned toany of the nuclei produced by 14N on Bi or Pb,
possibly included in the 238U target as impurities,
or those produced by transfer reactions of 238U.
Further, from the excitation functions referringto the known a-rays, it is concluded that all the

Table 1. Summary of results.
Nuclide
2
§
o
u

-

10-

Energy(MeV)

Half-life
(min)

7.32

5·24 -+0.52
0.43

7.05
7.22
7.36
7.15

o 7.0

7.2

7.4

7.6

7.8

7.27

Energy (MeV)

Fig. 1. A part of a-particle spectra combined fromfive bombardments of 238Uwith 80-94 MeV 14 N
ions.
* Faculty of Science, Tokyo Metropolitan University.

7.62
7.71
7.73

+0.72
4·70 - 0.55
+ 0.33315· - 0.27+ 0.803·20 -0.50+ 1.907·43 -1.26+ 0.927·73 -0.75+ 0.27118· -0.18+ 0.34137· -0.23+0.14
1·22 -0.11

Branching ratio

0.15
1.00
0.99
1.00
-::::::-0.34
1.00

0.82

45

Y. Hatsukawa, et ai.

peaks but 7.11, 7.47, and 7.52 MeV a-rays belong
to the Es isotopes produced by 238U(I4N, xn)
reactions. (The 7.11 MeV a-peak is assigned tothe decay of 245Cf.) They could be grouped
according to their half-lives and the projectile
energy dependency as presented in Table l. The
errors attached to relative intensities merelyreflect statistical uncertainties in counting andthose given for a-particle energies are mostly
caused from energy calibration. The preliminary
results suggest that 245Es emitts three different
a-rays, and that 246Es has two isomer states, oneof which emitts four and the other two a-rays.
More complete and quantitative discussions oflevel schemes may, however, become possible
only after measurements of y-rays in coincidencewith a-particles.
In order to confirm the above results, bombardments of a 237Np target with 67-81 MeV 12C ionswere performed. The obtained spectra are shownin Fig. 2. a-Rays belonging to 245Es were mainly
observed. Rough estimates of their half-lives arein good agreement with those obtained in the
238U + 14N reaction. More detailed analysis of the200~~~~~~~~",,~,,~
245 Es

180
160
140
120
en

7.70-.

7.72

7.67.

C 100
::J

8 80
60

40
20
0~~~~~~~~~~~8~.0~~

Energy (MeV)

Fig. 2. A part of a-particle spectra combined fromthree bombardments of 237N p with 67 - 71 MeV
12C ions.

data is in progress.
References
1) M. Magara, K. Sueki, H. Nakahara, H. Kudo , Y.

Hamajima, and I. Kohno: RIKEN Aeeel. Progr. R ep.,
18, 37 (1984).
2)

H. Kodo, T. Nomura, and]. Fujita: RIKEN Aeeel.
Progr. Rep. , 17, 127 (1983).

46
RIKEN Accel. Progr. Rep. 19 (1985)

111-2. Atomic and Solid-State Physics
1.

Electron Stripping Cross Sections from Multi-Charged Ions by
Neutral Atoms Using Born Approximation Calculationts. Karashima, X. Zhang,* Q. Ma,* Y. Liu,* and T. Watanabe
In a previous paper!) we have calculated theelectron stripping cross section from energetic
multi-charged ions by collision with a neutral
target, such as
A q+ + B~A(q+l)+ +e+ B(2.')(1)

where 2.' denotes all electronic states including
ionized states. In this study we applied thebinary encounter approximation (BEA) with theelectron velocity distribution obtained from
Thomas-Fermi statistics. In the calculation wemade an assumption that the cross section forelectron stripping from the incident ion by collision with the target nucleus is much larger thanthat by collision with electrons in the target.
Under this assumption the process can be considered to be equivalent to the electron ionization
process by the target nucleus. This assumption isconsidered to be valid if 3q~ ~ (q: charge of anincident particle in units of electronic charge, ~:the atomic number of the target). With this con~ideration we have made calculation only for H
and He targets.
In order to extend our research to the targets
other than H and He, we should take into
account the consideration of electron-electron
collisions in the process. In this case, owing tothe opposite sign of interaction potentials ofelectron-nucleus terms compared with that ofelectron-electron terms, the cross section may bemuch influenced by the interference terms
between the above two interactions. Therefore,
we can not make use of classical approximations
such as BEA which includes no interference
effects.
t Collaborated work of Atomic Processes Laboratory,

The Institute of Physical and Chemical Research(RIKEN) with Theoretical Physics Group in Department of Modern Physics, University of Science andTechnology of China.
* Department of Modern Physics, University of Scienceand Technology of China.

Here we use the Born approximation for theprocesses. In the heavy particle collisions such as
the present ion-atom systems, the Born approximation gives a reasonable results2 ) in the velocity
region above 0.3 times of the orbital electron
velocity to be ionized.
Because of the large reduced mass of the colliding system, the trajectory of an incident particle can hardly be changed by collisions in thevelocity region.
Let us consider the reaction in which atom B is
excited or ionized from an initial state (n', 1') toa final state (n", l"), and at the same time ion A
is ionized from an initial state (n, l) to a continuum state x ejecting one electron (n, n', n":principal quantum numbers and l, 1', l": azimuthal quantum numbers).
The cross section based on the Born approximation can be written as3 )(j(nl~ x; n' I' ~n" l")~2 2j

27th K!

K
max

IN(nl~x ; n' I'~n" l")12KdK

K m1n

(2)

where M is the reduced mass, M = MAMB / (MA +M B); MA and MB are the mass of ion A and target
atom B, respectively, the momentum transfer is
K=Kf-K!, K!=Mv!lh, Kf=Mvf/h ; v! and Vf
are the initial and final velocities of relative
motion, respectively andf 1Jf*(rAI nl)1Jf*(rBI n' 1') VCR, rA, rB)

N = j j

iR K
•

X e

1Jf(rAI x) 1Jf(rBI n" l")drAd rBd R(3)
1Jf (rAI nl) and 1Jf(rAI x) are wave functions of anelectron bound to nucleus A, whereas 1Jf (rBI n'l')and ~(rBI n" l") are wave functions of an electron

bound to nucleus B.
The interaction potential with the relative
position vector R between the particles is givenbys. Karashima, et al.
V(R ,rA,rB-e) - 2 [ZAZB
][2-

ZB

I R-rA I+ZA
IR+rBI1

I R+rB-rA I= ~ (lPBSL { I 1PH-1(S" L")lSL)](4)

47te 2n_ 2

t2 u.u Zs

x [ -On'l', n" I" +T(n'l'~n"l")J T(n1~x) (5)where

T(P~q)=

Jeit.rW*(rlpHF(rl(11)

S" L "

Substitution of Eqn. (4) into Eqn. (3) gives

N (n1~ x ; n' l' ~n" 1")

47

q)dr

(6)

where Land S are the total orbital angularmomentum of electrons and the total spin angular momentum, respectively, and UP SL { I 1p-1 X(S" L") lSL) denotes a fractional parentage
coefficient. In Eqns. (10) and (11), S" L" corresponds to the quantum numbers for the final
possible configurations.
For the final state of the system (A(q+IH +e)
we use an antisymmetric wave function as 4 )1 N.

W1(XJ, X2,·· ·' XN)=N -z ~ (- I)N- 1
i= l

where r in atomic units and t =K Go (Go: Bohrradius).
Therefore, Eqn. (2) has the form

f5(n1~}( ; n' l' ~n" 1") = [8Z:
J/max I - On'!' , n"l"
S
2

1mIn

+T(n'l'~n"1"~21 T(n1~x)12Xt-3dt ] 7tGo 2(7)where s2=(1/2) mvj 2/IH , IH =(l/ 2)me 4 / h2 is theionization potential of hydrogen and m the electron mass.
Using the energy transfer L1E = (tl}K 2 /2M 2
h K f 2/ 2M) / IH , we can obtain~1(Xl,X2'···' X i -b Xi+l,··· , XN )~(k, xd(12)

The wave function ~(k, x) describes an ejected
electron:~(k, x)=~(k, r)6'(f5 l ms)(13)

where 6' ( f5lms) is a normalized spin function.
The ejected one-electron wave function W(k, r)isa Coulomb wave function which describes thefree electron moving in the field of ion A(q+ l )+ :~ (k, r)= e-tn:"r(l + irJ )e i k • rj~jn = KminGo = (K1 -

4Ms2

(8)

where
(15)

and
~ax = Kmaxtlo = (Kj + Kf)Go~ 2Ms[ 1 - ~L1E { 1 + mL1E} ] (9)
m
4Ms2
4Ms2
The initial wave functions for A and B having
the number of electrons PA for A and PB for B in
their electron orbits can be written as follows: 4 )w t= Wt (lPASL)=S"~L " (l PASL { I PA- 1(S" L") lSL )andirJ, 1; i (kr - k • r) }

(14)

Kf)Go

~ L1E(I+mL1E)
2s

X 1 Fl { -( 10)Calculations are in progress for excited-state
wave functions and continuum wave functions
aiming at obtaining the electron stripping crosssections for the various kinds of projectile ionsand traget a toms.
References
1) S. Karashima, T. Watanabe, Y. Awaya, and Y. Liu:
Nucl. Ins tru m. Methods A, 240, 505 (1985).
2) T. Watanabe: J Phys. B, 18, Lll1 (1985).
3) D. R. Bates and G. Griffing: Proc. Phys. Soc. A , 66, 961(1953); A, 67, 663 (1954); A, 68, 90 (1955).
4) G. Peach: J Phys. B, 1, 1088 (1968); B, 3, 328 (1970).

48
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-2.

(J1+ J1-) Formation Cross Section for Collision of J1+ withCu-p): Total and Differential Cross Sectionst
Q. Ma,* X. Zhang,* Y. Liu,* and T. Watanabe
Under the collaboration research projects withthe theoretical group in University of Scienceand Technology of China, the calculation for
JL+ +0L-p)~0L+ JL-)+P was extended. We havealready made calculations for the process only
for the ground initial state 0L-p) and ground final
state 0L- JL+) . by the Classical Trajectory Monte
Carlo (CTMC) approximation as well as by thequantum-mechanical first Born approximation(FBA) and the distorted-wave Born approximation (DWBA).1l- 4 ) The calculation using CTMC
for the ground to the states n (principal quantum
number) = 2 was also made. As a continuation ofthis serial research, the total cross section andthe differential cross section for the process including excited states before and after collisionwere obtained by using FBA. The differential
cross section for the process from the ground to
the ground state was also made.
The method used in the present study wasessentially the same as in previous ones. 3 ),4)
Introducing the coordinate system shown in Fig.
1, we can write the total Hamiltonian in theinitial coordinate system Rand r or in the final
coordinate systemR' andr'. HereR andR' mean
tpe coordinates of relative motion and rand r'
mean the coordinates of inner motion. The large
amount of change in the reduced masses of thebound systems before and after collision is one of
the characteristic features of the present problem. The reduced masses of the system in theinitial state frame, lJ, for the inner motion and JL
for the relative motion are given bylJ

mJ.'rYlp
mJ.' + rYlp'

JL

mJ.'(rYlp+ mJ.')
rYlp + 2 mJ.'o

Fig. 1. Coordinate system of colliding particles. R
and r are the position vectors of the relative motion
and inner motion before collision and R' and r' arethose after collision.

c

....
x

.....

.....
""
C>

(1)

and those in the final state frame are given by(2)

SCATTERING

ANGLE(DEGREE I

Fig. 2. Differential cross section for ,u++{;.t-P)lS{;.t-,u+hs+p for impact energies from 2,176.81 eV to
10 4 e V in the center-of-mass system.

t Collaborated work with Theoretical Physics Group in
Department of Modern Physics, University of Scienceand Technology of China.
* Department of Modern Physics, University of Scienceand Technology of China.

where rYlp and mJ.' are the masses of p and JL,
respectively.
The first Born scattering amplitude in theQ. Ma, et al.

lOt

49

Hamiltonian in the initial form, i.e.,

Enerur in keY
5 10 20 30 40 50

Hi = -1 + ---.L

(4)

r+_

rp+
where r+_ and rp+ and the distance between 11+
and 11- and that between 11+ and p, respectively,

and kl and k f are the wave vectors of relative
motion - in the initial and the final states. The
differential cross sections in FBA are given by~+ + (p- pl2s

- (PY l 1s + P

do- _ kt IfFBA(8) 12
rYlp
dO - 2r;kl,r; mp+ m
The total cross section is given by.......
-4

10

o-=~
2r;kl

f

IfFBA(8)

2
1

dQ

( )
p

•

5

(6)

The only difference in the formula from that in
the previous one3 ),4) appears in the wave functionof the initial and final states, qr I and qrf in Eqn.
(3).

Impact velocltr in 8.U.

Fig. 3. Total cross section for ,u++(u-P)2S~(u- ,u+)15 +p as a function of relative velocity v.

The present study concerned with the processes from Is to Is for the differential crosssection (DCS), from Is to 2s, 2p for the DCS andthe total cross section (TCS), and from 2s to Is
for DCS and TCS. Detailed description of the
reduction of the practical formulas of scattering
amplitude and the discussion of the physicalmeaning of the calculated results will be given
elsewhere.
References

prior form is written asf f dr' exp( - i kfeR')

fFBA(8) =- 2~~2 dR'lJrf(r')Hi exp(i kl eR)qrl(r)(3)

where Hi is the (inter-atomic) interaction

1) A. Ohsaki, T . Watanabe, K. Nakanishi, and K. Iguchi:
RIKEN Accel. Progr. Rep., 18, 41 (1985).
2) A. Ohsaki, T . Watanabe, K. Nakanishi, and K. Iguchi:
Phys. Rev. A, 32, 2640 (1985).
3) Q. Ma, X. Zhang, Z. Liu, Y. Liu, and T. Watanabe:
RIIffiN Accel. Progr. Rep., 18, 45 (1985).
4) Q. Ma, X. Zhang, Z. Liu, Y. Liu, and T. Watanabe:
Phys. Rev. A, 32, 2645 (1985).

50
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-3. Continuous Energy State Model for Charge Transfer in
Collisions of Fully Stripped Ions with Hydrogen Atoms
F. Koike

An investigation has been made for the chargetransfer processes in collisions of fully stripped
ions with hydrogen atoms:
A z+ + H(ls) ~ A (Z-I)+(q) + H+

10- 14•(1)
C

where A represents an atom, Z represents its
atomic number, and q represents a set of atomic
quantum numbers. If Z is high, the initial H Is
state couples with a number of the states ofA (Z - 1)+, and in many cases, the transferred electron is actually distributed into the various qstates. Consequently, we must solve an exceedingly large set of coupled-channel equations if we
represent the electronic state in terms of thechannel-wavefunctions.
In the present report, a decoupling technique is
proposed employing a continuous energy statemodel for the final electronic states. The coupledchannel equations are reduced to a number ofsmaller sets of inhomogeneous coupled-channel
equati011s that can be solved independently ofeach other. As for the approach that could fall inthe same category as the present one, we canpoint out a work of Presnyakov et at. ll In thepresent work, a number of the restrictions
imposed on the application of their theory has
been removed, and the rotational coupling
between the final electronic states has been taken
into account, which they have neglected completely. The outline of the present formalism is
as follows. The probability amplitude for finding
the system in the initial hydrogenic state f4J isgiven by the overlap of the initial state wavefunction 1/1'0 with the total wavefunction lJf, i. e.,
f4J = < 1/1'0 I lJf>. If lJf is expanded in terms of the
final state wavefunctions 1/I'q as lJf j qa q1/l'q andalso if lJf satisfies the semiclassical timedependent Schrodinger equation, i.e., H lJf=i(a/ at)1Jr, we can derive the following coupledequation by differentiating the present overlap
integral with respect to the time t. We haveao = - if q< 1/I'qlH - ia/ atl1/l'0 > *aq'

(2)

It can be shown ) that we can solve Eqn. (2) withrespect to f4J to the lowest order without any
knowledge about aq' if we employ the continuous
2210- 15
~

VI
VI
VI

o

U

10- 1610100

Ion impact energy (keVj amu)(a)

~1O - 14

Fe 26 + +H

E

~

c

o

~VllO-15
VI
VI

o

U
10- 16

Ion impact energy (keV j amu)(b)Fig. 1. (a) Total charge transfer cross sections forSp4+ + H collisions. Solid line: present theory. Symbols: experimental results for the partially stripped
ions: i: Fe l 4+ by Phaneuf et al.,3) .: Fe l 4+ by
Meyer et al.,4) .. : M o l4+ by Meyer et al. 4 ) (b) Total
charge transfer cross sections for Fe 26 + + H collisions. Present theoretical results.

energy state model for the final states. We obtain
f4J(t) = exp [ - i f~oo E * dt' ](3)where E * is the resonance energy that may be acomplex number, and it is given by the pole of
the Green's function of the space spanned by the
initial H Is state.
The final state component is given by lJf - f4J 1/1'0,
and this may be expanded in terms of 1/I'q as51

F. Koike
ljf - fk1/l'o= j qaq1/l'q. Then we have the following
coupled-channel equations for aq , which aresolved numerically. That is

aq= - i < 1/1'0 I H - ia / at I 1/I'q > * fk

-ijq' <1/I'q' I H-ia / at I 1/I'q>*tlq, (4)Because fk is given by Eqn. (3), Eqn. (4) as a whole
represents a set of coupled equations for only aq ;Eqn. (4) is partially decoupled naturally according to the symmetry of 1/I'q.
Even after the present decoupling, the numberof the coupled-channels for the individual subset
of equations is still very large if Z is high. The
use of a super computer (HIT AC S810/ 20) has
been tried in order to facilitate the large scale
numerical calculations. Some of the typicalresults are illustrated in the following. In Fig.
1(a) are shown the total charge transfer crosssections for Sjl4+ + H with the available experimental data for partially stripped ions. The
agreement between the theory and experiment at
Z = 14 suggests the validity of the present method
for higher-Z ions, because the present method isbased on a high-Z approximation. The result for
Fe 26 + + H is illustrated in Fig. l(b) as an exampleof the high-Z system. In Fig. 2 the cross sections
for charge transfer into the states with specified
principal quantum numbers are given for Si l 4+ +H together with other theoretical results.
References
1) L. P. Presnyakov, D. B. Uskov, and R. K. Janev: Phys.

Lett. A, 84, 243 (1981).

~1O - 1 4E

E = 10keVj amu~

E

10- 14

E= 100keVj amu~~ 10- 15o~~

10- 15.~ 10~een:eroro 10-.~<,~". . " "" " ...........,..

j/

16
I
I

u

~

17

t

0...

10- 17

ro
0...

15

n

20

n

Fig. 2. The principal quantum number n partial
cross sections for the charge transfer in SpH + H
collisions. Solid lines: present theory. Broken lines:
unitarized distorted wave approximation. S ) Dotted
line: classical trajectory Monte Carlo calculation. 6 )Dot-dashed line: multi-channel Landau-Zenermodel calculation with modification in which theeffect of the rotational coupling is inc1uded. 7 )2) F. Koike: X III ICPEAC Book of Abstracts, Berlin,
p.405 (1983).
3) R. A. Phaneuf, I. Alvarez, F. W. Meyer, and D. H.
Crandall: Phys. Rev. A, 26, 1892 (1982).
4) F. W. Meyer, R. A. Phaneuf, H. J. Kim, P. Hvelplund,and P. H. Stelson: Phys. R ev. A, 19, 515 (1979).
5) H. Ryufuku and T . Watanabe: Phys. Rev. A, 20,1828(1979).
6) R. E. Olson: Phys.Rev. A , 24, 1726 (1981).
7) R. K. J anev and B. H. Bransden: IAEA Report, INDC
(NDS)-135/ GA (1982).

52

RIKEN Accel. Progr . Rep. 19 (1985)

111-2-4.

Effect of Minima in Generalized Oscillator Strengths on Integral
Cross Sections for Excitation of Atoms
M. Iwai, 1. Shimamura, T. Watanabe, and Y. Awaya

The first Born approximation is valid for excitation of atoms by electrons or ions with
sufficiently high velocities. The differential crosssection in this approximation is expressible as
the product of a simple factor and a quantity
called the generalized oscillator strength (GOS),
which is a generalization of the optical oscillator
strength. The GOS is defined as a function of the
momentum K transferred from the incident particle to the target atom in the collision. The
existence and the general significance of minima
in GOS for many atomic and molecular transitions are discussed in the literature. I )-4) Effects ofthese minima on the integral cross sections havealso been investigated especially for inner-shellionization by heavy particles. 3 ),4) These analyses
have shown frequent appearance of shoulders in
the impact energy dependence of the integral
ionization cross sections.
In the present report we will show appearanceof conspicuous minima, rather than shoulders, inthe integral cross sections for some discrete
excitation processes due to minima in the corresponding GOS. General conditions for appearance of minima in the integral cross section will
. be briefly discussed.
The integral cross section for excitation of thetarget state from I0> to In> by the projectile
with a charge 2 is given, in the first Born approximation, byll
27[22)

lYon = ( r;:LOnfln(K ~.x)
V- 2

Fon(K)d [In(K2)]

In(K ~'n)(1)where v is the relative velocity and Eon denotes
the excitation energy. Here and in the following
we use atomic units. Kmax and K m1n are expressedin terms of the incident wave vector ko and thescattered one k n as
Kmax=~+kn(2)

Kmln=~-kn(3)

The generalized oscillator strength Fon(K) is
defined byl)Fon(K) = (2Eon / K2 ) I <nl ~exp(iK·rJI 0>1 2 (4)jwith K =k o -k n , where rj is the position vector of
the jth electron in the target. In Eqn. (4) the
average over the magnetic quantum number ofthe initial state and the summation over that of
the final state are implicitly assumed.
As a first example the 2s~3p excitation of
Cu 2S + and CU I9 + ions by electron impact, proton
impact, and C6 + ion impact was studied in theplane-wave Born approximation. Information on
this transition in the carbon-copper collisions isuseful in analyzing the Cu K X-ray data taken by
A waya et at. S ) for Cu ions incident on C and for
C ions incident on Cu.
We calculated the ground-state wave functionsof the four-electron target ions in the HartreeFock approximation employing Slater-type
orbitals. For the excited states we construct thewave functions with proper LS symmetry (lP in
this case) using the virtual orbitals generated by
the Hartree-Fock potential of the ground state.
The GOS for the 2S21S~2s3plp transition in
Cu 2S + is shown in Fig. 1. For a hydrogen-likeatom with an effective charge Zeff the GOS for
this transition has zero minima at K = (J5/6)Zeff
and K = (5J 15/18) Zeff. 2) If we choose a value 26
for Zeff for Cu2S + following Slater's rule, the firstminimum occurs at K = 9.7 in excellent agreement with the position of the minimum in thepresent Hartree-Fock result. The magnitude of:~:I.,__~ Kmin(H+f~ ~in(e-)
£::

I

!
,:
,

.'

,/ Kmax (e-)

I.
I
I
I

,

N

:>

I

··t ..... '

-·f.
-2

2

4

0

•••

I

ln K2 (in a.u.)

Fig. 1. Generalized oscillator strength devided by
the excitation energy for 2s---+-3p excitation of
CU25 +. Plots of In(Km1n 2 ) and In(Kma/) against
impact velocity v 2 are also included.

M. Iwai, et at.

53

·~I

·19
.10

.10

N

N

E

E

u

u

c

C

1.5

."
.. ..

N

o

o

1.0

0.5

w

~

~

Impact velocity V2(in a.u.)

Fig. 2. Integral cross sections for 2s----+3p excitationof CU25 + oy proton and electron impact.

the GOS in the hydrogen-like model also agrees
fairly well with the Hartree-Fock result. This
indicates that the hydrogen-like model is valid
for the present systems owing to the large
effective charges that the active electron feels.
Figure 1 also includes plots of In(Kma/) andIn(Km1n 2) against v 2 for both electron impact andproton impact. One readily finds from these plots
the interval of integration in Eqn. (1) contributing
to the integral cross section. For electron impact
both K m1n and Kmax at the threshold energy areclose to the position of the minimum in the GOS.
K m1n decreases (and Kmax increases) with theincrease of v 2 • Therefore, the integral cross section increases monotonically, and no minimum
occurs (Fig. 2a). For proton impact, however, thesituation is totally different. We may actuallyconsider Kmax to be infinity in this case, and only
the position of K m1n decides the integral crosssection. As K m1n passes a zero of Fon(K) with theincrease of v 2 , the integral in Eqn. (1) remains
nearly constant, and the integral cross section
decreases due to the factor 1/ v 2 • As v2 increases
further, K m1n decreases in the region where
Fon(K) increases rapidly, and the integral crosssection also increases rapidly. This gives rise to
the conspicuous minimum in the integral crosssection for proton impact as shown in Fig. 2. The
Kmln-to-v 2 and the Kmax-to-v2 curves for C6+
impact are very similar to those for proton
impact. Therefore, a conspicuous minimum
occurs also for C6+ impact. The integral crosssections for the 2s~3p excitation of CU 25 + and
CU 19+ by the C6+ ion are shown in Fig. 3.
N ext we consider a systematic method ofanalyzing the impact-energy dependence of theintegral cross section. For simplicity let us focus
on heavy-particle impact in which Fon(K) is
negligible near K = Kmax and for K > Kmax. Direct

I

10'Impact energy (in Mev)

Fig. 3. Integral cross sections for 2s----+3p excitationof CU25 + and CU I9 + by the C6+ ion.

Fig. 4. Graphical analysis of extrema in the integral
cross section.

differentiation of Eqn.(I) with respect to v 2 yields
dO'on_
dv2 - - V -2 ( O'on - (2nz2)
Eon F.On (Kmin )2
X / d[ln(Kmln )] / )
2
d(v )

(5)

because Fon(KmaxY"O. Equation (5) clearly indicates that O'on should be decreasing with increasing v 2 when Fon(Kmln) is nearly zero. One finds
from Eqn. (5) that extrema of O'on( v 2) occur when
the following equality holds:
O'on = (2nz 2/ v 2Eon)5'(6)

where the quantity 5' is defined by
5' = Fon(Kmln) ( v 2 / d [l~~~)n 2)J

I)

(7)

and is equal to the area of the rectangle ABCD
shown in Fig. 4. Because the integral cross section, O'on, is the product of (2nz 2/ v 2Eon) and theshaded area (referred to as 5) in Fig. 4, Eqn. (6)amounts to an equality 5 = 5'. At those v2 where
5>5' (5<5'), the right-hand side of Eqn. (5) is
negative (positive) and O'on( v 2) is decreasing(increasing). This affords a systematic method of54

M. Iwai, et al .

analyzing the v 2 dependence of O'on and of investigating the general conditions for the appearance of minima in O'on.
The positions of minima in the GOS and themagnitude of the GOS are appreciably affectedby the wave functions employed; calculations
based on more sophisticated wave functions are
now in progress.
References
1) M. Inokuti: Rev. Mod. Phys., 43,297 (1971); M. Inokuti,

Y. Itikawa, and J. E. Turner: Rev. Mod. Phys., 50, 23(1978).
2) 1. Shimamura:]. Phys. Soc. JPn., 30, 824 (1971).
3) M. Matsuzawa, K. Omidvar, and M. Inokuti:]. Phys.
B; Atom. Molec. Phys., 9, 2173 (1976).
4) S. T. Manson and A. Msezane: ]. Phys. B: Atom.
Malec. Phys., 8, L5 (1975).
5) Y. Awaya, T. Kambara, M. Kase, H. Shibata, H.
Kumagai, T. Mizogawa, Y. Kanai, and K. Shima: p.
70 in this report.

55
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-5.

Theory of Radiative Electron Capture: Relativistic
Treatment and Gauge Invariance
K. Hino and T. Watanabe

At present, no theory on the radiative electron
captue (REC) process satisfies the following conditions completely: (i) The cross section of REC
should be independent of the way to choose theframe of reference, that is, the c.m. frame or thelab. frame: (ii) The charged current of the wholesystem should be conserved. In other words, theREC scattering matrix must be gauge invariant.
The first condition fulfils the relativistic formulation and removes the spurious radiation. Moreover, these two conditions are mutually connected to some extent as is shown below. We use
the natural units (h=c=l) throughout thisreport, and we suppose that a particle always has
a half-spin unless otherwise stated.
Firstly, some preliminaries for the covariant
treatment are introduced. The interaction
Lagrangian density of fermions and photons,
Lint, is given by(1)

where j", is the electromagnetic current of afermion, given by iZ;p. YI'l/I', Z the charge of thefermion, and j", the external c-number source
introduced as a parameter. By the use of Eqn. (1),S-matrix, <0 I U(oo, -(0) I 0>, is given by

f d xL (x)) I 0>
4

where A, B, and C are the channels of a threebody system for a +(b+c), b+(c+a), and, c+(a +b), respectively, and KN is the three-body propagator where the particle, n, behaves as a spectator, and Ko the free propagator. Hereafter, aprojectile ion, a target nucleus, and an active
electron will be labeled with a, b, and c, respectively. H is the inhomogeneous propagatordefined as
H =Ko(1 + 'LIMKM)

1nt

and the Schwinger's functional derivativel} withrespect to j '" is defined as

and K o, K N, and IN are represented by:
Ko= IT S'F,n(7)

n = a,h,c

KA =S' F,aGbc(8)

IA = i:D aV bc = i)) aVa(9)and so on, where S' F,a indicates the (one-boby)
Feynman propagator of fermion, a, and ~c represents the two-body propagator of fermions, b
and c, which follows the two-body BetheSalpeter (B-S) equation. 3 ) VbC and Va stand forthe interaction between the particles, band c.
J> n(x - x') is defined as:ax + mn)0(4)(x - x')(0)

where 2n * is the self-energy of fermion, n, andy(n) is the gamma-matrix of the particle, n. Equation (5) can be symbolically rewritten as:
K=(I-F)-lHoU[ j", (y)J/ oj", (x)=lim{ U[ jl' (y(6)

M+i2n*(X - X')
(2)

(5)

N = A ,B,CJ) n(X - x') = (y(n)<0 I U(oo,-oo) I 0>
= <0 I T exp(i2 INKNINK

K=H+Ko(1)€-+O+€c)<4) (y-x))J-U[j",(Y)J } /€(3)

Equation (3) can lead us to the following convenient relation:- i· oT [U,a,b,'" ] / oj", (x)= T [u,A", (x),a, b,'" ](4)where a and b stand for field operators.
Corresponding to the (non-relativistic) Weinberg equation,2) we establish a covariant equation (the relativistic Weinberg equation) for thethree-boby covariant propagator K as:

where F is the kernel of the relativistic Weinberg
equation.
Now the three-body REC propagator K", isdefined by the use of Schwinger's functional
derivative method, Eqn. (4), as
KI' = <0 I U I O>-l'iO'[ <0 I U I 0> KJ/O'JI'(2)

The fundamental Eqn. (5) can give us an explicit
formal solution of K", by using Eqn. (12) as:
K", =(1- F)-I (HI' + F",K)

(3)

56

K. Hino, et at.

a

c

b

a

c

b

(2)

(1)

a

c

where k# is the energy-momentum vector of theemitted photon. To keep the gauge invariance,
we generally need only a set of Feynman diagrams with the same power of coupling constants. The generalized W ard-Takahashi relation for the three-body problem is useful to pickup such diagrams. This powerful relation reads:b(3)

Dxaz T * [A# (x),···]= aZT * [(i-O'IO'A#(x)),"']
4+ ~Zj ~ T * [(fjtr(x)-O'IO'fjtr(x)j

tr = l- f jtr(x)- 0' / O'fjtr(x)) ,... ]
ac b
(4)

ac b
(5)

ac b
(6)

Fig. 1. Feynman diagrams of the relativistic REC
process. Longitudinal real lines stand for fermions,broken lines for photons and transversal real lines
for three-body B-S amplitudes, respectively.

where
P#= <0 I u I 0>-1- iO'[ <0 I u I 0> P]I O'j#
(P=H, F)
(14)
The S-matrix of REC can be easily obtained
from Eqn. (13) by using the procedure similar tothat derived by Nishijima. 4 ) The final form of
REC S-matrix can be written as:
Sfi= < fB.# I X - 1 3f# I fA>

(15)

where
~

~

A

N

17# = ~ [Y#INKNIN+ I N,#KNI
NAAN]+ INKN W N,# I N+ INKNI #(16)

y# = -(17)~n = a,b,c

hr1 )5' F,nnwhere f jtr indicates the <roth component for thefermion operator of the j-th particle. By inserting three pairs of fermion operators in the formof fjfj (j = a, b, c) into the section denoted bybroken lines in Eqn. (22), necessary Feynman
diagrams are provided, with which the gauge
invariance holds exactly. We obtain four diagrams with the power of coupling constants
4 244 2, six with 444 3, and four with 44 24 2,
which amount to fourteen diagrams. We show
six of them in Fig. 1, which have dominant contribution and satisfy the restriction, Eqn. (21),approximately.
We will now indicate the relativistic crosssection (the photon angular distribution) of the
REC process based on only the first three diagrams of Fig. 1. Such a choice is, in fact, incompatible with the gauge invariance. After somecomplicated trace calculations, the cross sectionin the c.m. frame can be reduced to:<rfi,CM(.QCM)OC{;iNI mcY(4av- 1(1- {32tlI2)5-sin2OCM 1(1 - {3' cos OCM)"" ,#= Y#"" +(I""n,# - ~O'nl~r#(1)5' F,I L)GWNnn (18)- [(Za(I- {32)112 1rna) -In,v= i- O'Inl O'jv = I n,#D' F,#v

(19)-«I-cosOcM)/(1 +{3COSOCM))2] 2

X=I+~INKN

(20)

1

N

where ~ is the electric charge of the particle, n.
fA' the three-body B-S amplitude for the channel
A, should be given by the formula corresponding
to Eqn. (11): fA =(1- Ft1</>A' where <PA represents
the incident wave. fB.# is connected with Vrs by
the relation that fs = f+ By(a) 4 y(b) 4 y(C) 4' multipliedby the photon wave function with the poralization vector e#. And r~) is the vertex function of
the n- th particle.
N ext, we take the gauge invariance of the REC
S-matrix into consideraton. Since the scatteringmatrix must always keep the gauge invariance, amatrix Gfi,# defined as S fi = ep' Gfi,# should satisfy
(21)

(22)

«4 + 4)1 (mb +~))
(23)

where
J-lN = rnamb/(rna + mb)(24){3 = {;iN 1~)v

(25)

{3' = (J-lN 1rna) v(26)v is the relative velocity of the present process
and a is the fine-structure constant. The term inthe square brackets in Eqn. (23) is of the comparable order in the magnitude of coupling between
the photon field and the respective particles, a, b,
and c. This is here called the isotope effect. Thiscross section can be easily reduced to the usual
one by taking the non-relativistic limit and by
setting both Za and 4 in the square brackets
zero. It is because the usual theories proposed by

K. Hino, et al.

setting both hand 4 in the square brackets
zero. It is because the usual theories proposed by
the present time take into no consideration thecontributions of both the projectile ion and thetarget nucleus to the radiative interaction. The
cross section in the lab. frame is linked up withthat in the c.m. frame with the relation that
O"fi,L8b(QL8b) = (1- /3 2)(1 - /3COS(A8b)-2(27)

By the use of the Lorentz transformation like
this, the differential cross section in the lab.
frame is obtained:
crfi,L8b(.QL8b)OC (;J,N / mcY(1- f32)1/2(Zaa / V)5'sin28L8b/(1-/3cos8L8b)4• [(Za/ma)-«4 + Z)/(mb + me))'(l-v cos8L 8b)2/(1-/32)3/2J2(28)

Here, we can gain another differential crosssection, 0"' fi,L8b, directly in the lab. frame without
applying the Lorentz transformation to O"fi,CM:
0"' fi,L8b(QL8b)oc(me(1- V2))-2 h 2(Z8 a / V)5'sin28Lab /(1- v COS8L 8b ) (29)These two cross sections in the same frame,O"fi,L8b
and 0"' fi,L8b, are found different in their form. The
physical meaning of 0"' fi,L8b is explained in termsof the first three Feynman diagrams shown in
Fig. 1. As is generally known, the magnitude ofcoupling between a particle and an external
photon is roughly proportional to the velocity ofthe traveling particle. The projectile ion, a, in thelab. frame propagates with the velocity, v, while
the target atom, (b-c), is nearly at rest. Therefore, the coupling magnitude between the projectile and the photon becomes much dominant tothat of the target atom. On the other hand, thewhole three particles in the c.m. frame movearound with a velocity of the order of v. Suchsituation explaines the cause of the isotope effectin the c.m. frame.
Meanwhile, it is quite necessary for us toconsider the gauge invariance explicitly in orderto overcome the difficulty that both O"fi,L8b andcr'fi,L8b are much different from each other. The
gauge invariance holds nearly true by adding thelast three diagrams to the first ones in Fig. 1.
Particularly, the diagram (5) has definite mean-57

ings, which, in fact, corresponds to the second
term in curl brackets of Eqn. (8) in Ref. 6. Formally, this term was called "spurious radiation"
by Shakeshaft and Spruch. 5 ) From the present
point of view, however, this plays quite an important role to maintain the gauge invariance andthe spurious radiation has, therefore, the real andessential meanings in the radiative scattering
processes as well as in the present radiativeelectron capture process. As denoted by Briggs
and Dettmann 6 ) by using the non-relativistic andsemi-classical method, the diagram (5) gives birth
to the consistent cross section even in the lab.
frame with that in the c.m. frame. On the contrary, most of the formulations proposed by thepresent time based on the non-relativistic quantum mechanics do never gives the desirable crosssections holding the gauge features exactly. The
physical interpretation, for example, of the diagram (5) is as follows: In the lab. frame, the target
electron is firstly ionized to the continuum statewith feeling the distortion from the projectile
ion, .and the coupling magnitude with photon fieldamounts to be of the order of v, because theintermediate electron is traveling with suchorder of velocity through the propagator, SF,C'
The similar discussion will also be held on otherparticles as well as in other frames.
Both the isotope effect and the relativistic
angular distribution of the emitted photon are
not guaranteed to be correct as yet until thewhole diagrams holding the gauge invariance areincluded in the scattering matrix. As for theisotope effect, however, we believe its reality,
because the mass dependence of X -ray yields wasindeed observed in the nucleon-nucleon bremsstrahlung process. The origin of these two effectseems to be the same in spite of the difference in
number of particles participating in scattering.
References
1) ]. Schwinger: Proc. Nat!. A cad. Sci. U.S.A., 37, 452,
455 (1951).
2) S. Weinberg: Phys. Rev., 113, 3232 (1964).
3) E. E. Sal peter and H. Bethe: Phys. Rev., 84, 1232
(1951).
4) K. Nishijima: Prog. Theor. Phys., 10, 549 (1953).
5) R. Shakeshaft and L. Spruch: Phys. Rev. Lett., 38, 175(1977).
6) ]. S. Briggs and K. Dettmann: Phys. Rev. Lett., 33,1123 (1974).

58

RIKEN Accel. Progr. Rep. 19 (1985)

111-2-6.

Two-Electron Diatomic Molecule: Program Package" MADAM"
H. Sato, E. Ishiguro,* T. Kimura, and T. Takezawa**

Knowledge on the electronic structures ofatoms and molecules is necessary to investigate
atomic collisions. One of the most elaborate
methods for obtaining precise energies and wave
functions of two-electron diatomic molecules is
the James-Coolidge method. l) In a previous
work,Z) we worked out a computer program toobtain the energies and wave functions in the
singlet or the triplet ~+ states of two-electron
diatomic molecules with any nuclear charge byusing this method. This study pursues an extension of the previous one to any state of twoelectron diatomic molecules. 3 ) Reasons to undertake the present study, in spite of a series of
excellent work by Kotos, W olniewicz, and theircollaborators, are i) to make the J amesCoolidge-type wave functions available at our
disposal, ii) to confirm the accuracy of theresults obtained by these authors, and iii) toinvestigate the applicability of the method for awide range of values of the internuclear distancein various states.
By using elliptical coordinates
Ai=(rai+rbi)/ R , J1. = (ra i-rbi)/ R, CPi (i=1, 2)

and
p = 2rlZ / R

is represented by rai and the other inter-particle
distances are given by similar symbols. We use
the atomic units throughout this report.
In order to make applicable to any state andany R, the basis functions of the James-Coolidge
type wave function should be generalized to havesufficient flexibility and proper symmetry. In thefirst place, we introduce the functions
x(m,n,j,k,p,ll,h : al,az,/31,/3z) ==X= (l/27!)(2/ R)3 exp [ - alAI - azAz - /3IJ1.1- /3zJ1.zJ Al m Az nJ1./J1. zkp P MI I t, I
X Mz I t, I exp [ill CPl + ihcpzJ

where
Mi = [(A/ -1)(1- J1.iZ)J lIZ (i = 1, 2)

Next, we define the functions 1/I'(m,n,j,k,p,ll'iz :alJ a z,/31,/3Z) == 1/1' as

f = (X +x) /2 for ~+ state
1/I'=(x- x)/ 2i
1/1' = X

1/I'A= 1/1'( m, n,j, k,p, 11, h : aI, az,/31,/3Z)

1/IB = 1/I'(m, n,j,k,p,ll' iz : al,aZ, - /31, - /3z)

fc = f(n, m,k,j,p, h,lI : az,aI,/3z,/3I)
1/10 = 1/I'(n, m,k,j,p, h, 11 : aZ,al, - /3z, - /31)

where

U(Z) = 4J1.1 / (AI Z- J1.IZ) +4J1.z / (Az Z- J1.z Z)
U(3 )=2/ p

and 4 , 4, and R denote the nuclear charges of
two nuclei and the internuclear distance. The
distance between the electron i and the nucleus A* Department of Physics, Faculty of Science, Ochano-mizu University.
* * Department of Mathematics, College of Science andTechnology, Nihon University.

for other states

where X is the complex conjugate of x.
In a homopolar case, the symmetry adaptedbasis functions 1/I'(m,n,j,k,p,ll'iz : al,az,/31,/3Z) areconstructed fromthe Hamiltonian is expressed as
H = T / R Z+ (4 + 4) UOl/2R + (h - 4) U(Z)
/2R+ U(3) / R+ 44/ R
T = - RZ(LlI + Ll z)/ 2
U(l)= -4AI / (AIZ- J1.I Z)-4Az / (AzZ- J1.zZ)

for ~- stateas
7J!= [( fA + 1/I'c) + (_l) j+k+ t,+t,( 1/IB + 1/Io)J
for singlet g state
7J! = [( 1/1'A + 1/I'c) - ( - l)j + k + t, + t, (1/IB + 1/10) ]for singlet u state
7J! = [(1/I'A -1/I'c) + (-l)i +k +t, + t, ( 1/IB - 1/Io)J
for triplet g state
7J! = [( fA - f c) - ( -l)f+k+t,+ t,( 1/IB -1/Io)J
for triplet u state

where normalization factors are omitted forsimplicity. In a heteropolar case, in which g-u

59

H. Sato, et al.
1.0 ,-------,---,--r-----.---,-- , - - ----.---,--.-------.---,

B.9

B.9

B.B

B.B

'E 0 6

1

.

:-0.5

! 0.4
~ 0.3

...... -<!)---~-- ... ------'"

B.2

0.2

_.e
B.I

eo- _ - -e - - -(9- -

ayR~

~~

0. 1

_C)-"-----_ .... - - - - - -~;'-e--fJ2IR..._...-.fY-----""

itB L...-----l-_-'--_-'-------'-_-'--_.1.....-----'-_ - ' - _.1.....---'-- '
o
3
4
5
6
7
10
Internuclear di stance R [au)0.0 L...-_=:.t.::=--L------l-_-'--_-'------'-_-'--_.1.....---'---'
o
3
4
5
6
7
Iii
Inte r nuclear distance R [au)Fig. 1. Orbital exponents for the lowest Iflu state of
H2•

Fig. 2. Orbital exponents for the lowest 3flg state of
H2•symmetry is mIssmg, merely the combinations
1/;-A ± 1/;-c or 1fp, ± 1/1'0 are sufficient. It is to be notedthat four parameters aI, a2, /31, and /32 are
introduced in the exponent of 1Jf. Moreover, notonly p but also tpl and t{J2 can be involved even inthe ~ states and, therefore, the basis functions
are more flexible than the original ones adopted
by James and Coolidge.
The matrix elements of the Hamiltonian H
and the Unity S with respect to the basis function
1J! 's can be obtained easily from those withrespect to the function x's. The latter matrix
elements can be expressed by the auxiliary
function 3 )X(M,N,],K, P, LI1~'Y ; A l ,A 2 ,Bl ,B2 )f= (1 / 27Z') 2 exp[ - AlAI - A2A2 - BIJ1.1 - B2J1.2 ]/1//12 t/M lL M 2L,exp [iy(tpl - t{J2)]

X AlMA2N

K-11.52-11.54-II'SS-II. 51!

-11.64-11.66-Il.68-Il.7B

1

X dA l dA 2d/1ld/12dtp l dt{J2

The function X 's can be evaluated using Kotani,
Amemiya, and Simose's auxiliary functions.
A package of computer programs named
MADAM (Most Accurate DiAtomic Molecular
calculation) is constructed by employing theabove-mentioned method. MADAM consists ofseveral job steps: calculation of the values ofauxiliary functions, construction of the matrix
elements, and calculation of the energy and wave
function. A lot of machine time is required to
optimize the non-linear parameters aI, a2, /311 and/32 and to find the best set of the basis functions.
We determined these parameters for the lowest
lflu and the 3flg states of H2 adopting 64 basis
functions (m, n,j,k,p, ll ,h = 0,1, and ll+h=l). In
Figs. 1 to 3, results are shown. Besides the full

-11.72 0L-.....l.--lIL-L.----143......5

L.--'7-..L--i......--'
IB--'6

lot etOLlC lear di at ance R [au)Fig. 3. Potential energy curves of the lowest lflu and3flg states of H 2 .

application of MADAM, we also undertake thecalculation of the polarizability of the H2-likemolecules in any state as a natural extension.
The details of the application will be publishedelsewhere.
References
1) H. M. James and A. S. Coolidge:]. Chem. Phys. , 1,825(1933).
2) N. Ueda, H. Sato, E. Ishiguro, and T. Takezawa:Nat!. Sci. Rep. Ochanomizu Univ., 27, 33 (1976).
3) H. Sato, E. Ishiguro, T . Kimura , and T . Takezawa:Nat!. Sci. Rep. Ochanomizu Univ. , 36, 81 (1985).

60
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-7.

Quantum Mechanical Treatment of Charge-Exchange
Processes Using Frame Transformation
I. Shimamura

In ion-atom collisions the ions often capture
electrons from the atoms. This process is referred to as an electron-transfer process or acharge-exchange process. Abundant literatureexists on applications of the semiclassicalimpact-parameter formalism to charge-exchange
processes. In this formalism the electropic
motion is treated quantum mechanically, but therelative motion between the ion and the atom istreated classically. Much less quantum mechanical calculations have been reported so far thansemiclassical calculations. This is partly becauseof the complexity in fully quantum mechanical. calculations and partly because of the stronger
interest in the medium- to high-energy region
than in the low-energy region. The de Broglie
wavelength of the relative motion is much shorter than the dimension of the electron clouds ofthe colliding atoms, unless the collision energy isextremely small. This has been thought to justify
the semiclassical treatment except at extremely
small collision energies. For collision energies ofthe order of 10 eV or 1 eV for which the de
Broglie wavelength is still short, however, therelative motion may depend strongly 0n thechannel. This is a quantum mechanical effect. It
requires a fully quantum mechanical treatmentof the collision process at these energies orlower.
Molecular-base expansion is preferable toatomic-base expansion at low energies. The conventional molecular-base perturbed-stationarystate approach, however, has its fundamental
difficulties associated with the translationalmotion of the electrons bound to either of thenuclei that keep moving during the collision.!)
There has been much formal discussion on theeffect of the electron translational motion and of
the electron translation factor in the wave
function. 2 ) Neglect of this effect would lead toserious errors in the cross sections. Many semiclassical impact-parameter calculations include
the electron translation factor. On the other hand
all fully quantum mechanical calculations published to date simply disregard the electrontranslation factor with a very recent exception. 3 )This recent work has its own drawback in thesense that the angular-momentum conservation
law is violated. The purpose of the present work
is to develop a new and practical method of fully
quantum mechanical calculations including theelectron translation factor.
When the distance R between the ion and theatom is small, the total collision system behavesmuch like a molecule. The molecular-base expansion is appropriate there. When R is large the ion
and the atom maintain their atomic charactereven at low collision energies. Therefore, ,theatomic-base expansion is more physical andpractical at large R. We may set a boundary
between the molecular region and the atomic
region at an appropriately chosen value A of R.
The molecular-channel wave functions definedfor R < A are to be connected smoothly to theatomic-channel wave functions defined for R > A
through the frame transformation at R = A. It is
straightforward to write down coupled equations
for channel functions in the atomic region including the electron translation effect, if we use theso-called Jacobi coordinates. These coupledequations are extremely difficult to solve by useof conventional methods. A new numericalmethod has been devised to solve these equations. In the molecular region the electron translation effect is expected to be small and may beneglected. 4 ) Then this region may be treated in
the conventional molecular-base perturbedstationary-state approximation.
This approach is a generalization of a semiclassical molecular-base atomic-base matching
method of Kimura and Lin 4 ) for fully quantal
calcula tions.
References
1) D. R. Bates and R. McCarroll: Proc. Roy. Soc. Lon don, Ser. A, 245, 175 (1958).
2) ]. B. Delos: Rev. Mod. Pltys .. 53, 287 (1981).
3) M. C. van Hemert: PJzys. Rell. A. 31, 2227 (198:3).
4) M. Kimura and C. D. Lin: PJzys. Rei'. A , 31, 590 (1985);
32, 1357 (1985).

61
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-8.

The Rotationally and Vibrationally Resolved
Photoionization of H2 by 736 A LineS. HaraPhoto ionization of molecules is one of the mostfundamental problems in the study of interactionof radiation with matter. In this report, photoionization of H2 is theoretically investigated.
Intensity distribution of the photoelectron for
the rotationally and vibrationally resolved
molecular photo ionization process is given by
Irr (0) = drr 14n- [1 + /3rr P2 (cosO) ]where drr and /3rr are the cross section and theasymmetry parameters, respectively, for thetransition from the (v" = 0, Jff) state to the (v~Jf) state.
The vibrationally resolved cross section <1v'
and the asymmetry parameter /3v' are reduced toI)
dv' = ~dojj/3v' =[2.0 + ~ /3oj ~Oj]
/ [1.0 + .~ g;~ ]
00
j*O

J*O

The measurement of the ratio
R j ( 0) = IOj ( 0) 1100 ( 0)= (do;! d oo ) X [1 + /30JP 2(cosO) ]1[1 +2.0Pz (cosO) ]at 0=54.T determines dojl doo. Therefore, an independent measurement of Rj (f)) at anotherangle gives /30j and thus /3v' . The ratios <10;! <100 are
obtained for N2 for j=2 and 4 by the deconvolution technique. 2)
When the cross sections for 11J =Jf - Jff ~4
are negligible, <1021 doo and /302 are two essential
parameters for /3v' . It was shown that for thephotoionization of H 2, the cross sections for
11J ~4 are small,3) and that the measurements of
the intensity ratio of the Sand Q rotational
branches at two angles 3),4) determine these twoparameters and /3v' .1)
We have calculated the cross sections doo, d02
and /302 for v from 0 to 5 for the photo ionizationof H2 by 584 A line. 1) Calculation for the final
H1 + e state was carried out, in the two centre
spheroidal coordinates, in the static exchange
approximation with the adiabatic polarization
potential added. Agreement between the calculated results with the values deduced from thefTable 1.

Cross sections and asymmetry parameters.

v'

0

a
b
c
d
e
f
g

0'02 / 0'00

/3Ol

/3v'

0.08560.08500.0872
0 .093(2)0 .091(3)

0.2
0.2
0.643
0.62 (11)0.09 (13)0.2118

0.348

1.858
1.859
1.891
1.882 ( 9)1.841(12)1.67 ( 6)
1.711

a, Ref. 7, p wave; b, present, p wave; c, present, p and fwaves; d, Ref. 3; e, Ref. 4; f, Ref. 8; g, Ref. 6, p and f waves.

experimental data 3),4) is very satisfactory.
Here we present the results for the photoionization of H2 by 736 A line. 5 ) Table 1 gives thepresent calculations with the p wave and withthe p and f waves of the ejected photoelectron.
The results derived from experimental data,3),4)
other theoretical,6),7) and experimentaI S ),9) studies
are also tablated.
The present results and those of Raoult et al. 7 )agree with the experiments3),4) in d02 1 do o. The
present results with the p and f waves give large
values of /302 because of the interference of the pand f waves, and are in good agreement with theexperimental results of Ruf et al. 3 ) The vibrationally resolved asymmetry parameters /3v'
do not depend very much on /302 since the ratios
d 02 1<100 are rather small in the present process.
References
1) S. Hara and S. Ogata:]. Phys. B, 18, L59 (1985).
2) Y. Morioka, Y. Hamada, K. Kihara, S. Hara, and M.
Nakamura:]. Phys. B, 18, 1369 (985).
3) M. W. Ruf, T. Bregel, and H. Hotop:]. Phys. B, 16,
1549 (1983).
4) ]. E. Pollard, D. ]. Trevor, J. E. Reutt, Y. T. Lee, and
D. A. Shirley: Chem. Phys. Lett., 88,434 (1980).
5) S. Hara: ]. Phys. B, 18, 3759 (1985) .
6) Y. Itikawa: Chem. Phys., 37, 401 (1979).
7) M. Raoult, Ch. Jungen, and D. Dill:]. Chim. Phys. , 77,
599 (1980).
8) E. D. Poliakoff, ]. E. Dehmer, P. M. Dehmer, and A. C.
Parr: Chem. Phys. Lett., 96, 52 (1983).

62

RIKEN Accel. Progr. Rep. 19 (1985)

111-2-9.

Peak Fitting in Beam-Foil Spectrum

K. Ando, Y. Awaya, S. Kohmoto, H. Kumagai,
T. Tonuma, S. Tsurubuchi, and K. Sato

Spectra observed in beam-foil experiments
usually have not high spectral resolution,
because of limitation of observation time and/or
weakness of light intensities, etc. Owing to suchinsufficient resolution, many lines overlap witheach other and the accuracy of wavelength ofspectral lines is limited. We tried to make spectral lines fit and deconvolute by assuming a
Gaussian profile in order to determine the line
positions accurately and separate the overlappedlines.
For the background of measured spectra,
light scattering inside a grazing incidence
spectrometer is considered to be mainly responsible; the scattered light distributes continuously
over the whole spectral region, intensity being
strong in the short wavelength region but weakened in the long region. From this viewpoint thebackground can be expressed by a simple equation of polynomials of low orders, e.g., below 5.
For estimation of the background, (1) the whole
data are divided into groups each composed of 50

channels and the lowest 5 data were picked out
from each group; (2) polynomials were estimatedby the least-squares fit with data obtained in (1);(3) the data of (1) were compared with the fitted
polynomials at the same wavelengths, and if thedifference between data and the fitted value waspositive and larger than the standard deviationof fitting, the data were omitted from the next
background fitting. This procedure was repeatedthree times to determine final polynomials. Figure 1 shows three backgrounds, one of whichcorresponds to polynomials determined in eachprocedure.
The peak finding procedure of spectral lines
was carried out in two steps. First, the half widthof spectral lines was found from isolated stronglines with the least-squares fitting of a spectralline profile. Because the half width of a spectralline is the same at any wavelengths for a grazing
incidence spectrometer, this estimated half widthis applied to every line in the next step. Peakpositions of spectral lines were found by the·A L U/VIINU/VI ION

ill

0:

cr.
>-

In -

f--

,- ,
(J'I

.... ,

L

70.00

80.00'

100.00110. 00

120 . 00

130.0014 0.00

150. 00

160.00170.00180 . 00

190.00WR VELENGTH( R)

Fig.1. The spectrum obtained in the beam-foil experiment with estimated backgrounds and first peak fitting. Threebackgrounds correspond to the cycles of the estimation procedures. The final background is approximated by asecond order polynomials.

63

K. Ando, et al.
Table 1. Results of the peak finding of spectrum data. Values in parentheses in thesecond and third columns are the standard deviations of fitting peaks positions
in A and of intensities, respectively.
------------ STEP 5 -----------JUDGE FOR FITTING: 1.51280
No.
Fitted Peak (A)
1
2
3
4
5
6
7
8

173.066 (0.011)
174.591 (0.013)
175.390 (0.016)
176.115 (0.021)
176.773 (0.025)
177.524 (0.019)
178.284 (0.021)
179.302 (0.013)

IERROR: 0
Intensity ERR %Width in A

20.285 ( 6.14) 30
42.415 ( 6.82) 16
63.758 ( 7.55) 11
98.660 (9.15) 9
310.341 (12.13) 3
98.849 (8.52) 8
397.129 (12.42) 3
60.210 ( 7.02) 11

0.550
0.550
0.550
0.550
0.550
0.550
0.550
0.550

o
o

o
o
o
o

~

STEP

o
o

I

NO. OF LIN

o

4

o
o

'0

o

WO

UO

~N '~h-44~--r0
0: O

W

u..O
u..';'

1

o

'0
I

g
o
o

"'I 2.20

174.20176.20178.20IIRVELENGTHCR)'1~72-.2~0-1~74-.~20~
1 76-.~
20~17-8.~20-

IIRVE LENGTHC R)
(b)

(a)

Fig. 2. The first rough estimates by peak fitting applied to a part of a spectrum. (a) shows the data ( + ) and the fitted
spectral lines (solid curve); (b) shows the standard deviation of data (1), the difference between the data and fitted
curve (2), and the smoothed difference (3).
o
o
o

STEP

5
NO.

o

OF LIN8oo..... g
COr'>

a:

0:0

'-'~

>-0

1-0
_N
(f)

zg_
w

1-0

z:!

0,
Fig. 3.

2.20

174.20176.20176.20IIRVELENGTHCA)

Final result of peak fitting.

following method. The difference between thedata and the fitting curve was calculated andthen smoothed, and if the smoothed differences
exceeded the standard deviation of data, it was
concluded that there exist a line. The position of
the maximum smoothed difference was added tothe previous fitting and the fitting was repeated.
These processes are shown in Fig. 2, where (a)shows the data and the first fitting and (b) the
standard deviation, the difference between thedata and the fitted curve, and the smoothed

difference.
Finally, when the smoothed difference is smaller than the standard deviation, the peak finding
process is finished. Figure 3 shows an example ofthe final result of fitting.
By using the peak finding processes, the accuracy of the position of lines is improved by afactor of 2, that is, ± 0.05 A. Although the
improvement of wavelength accuracy was notnecessarily excellent, the overlapping lines wereclearly separated by this procedure.
This peak finding program may be successfully
applied to general spectra. It should, however, be
noticed that in the regions where complex lines
overlap this program can not deconvolute lines
and, sometimes, the ghost lines appear.
The judgement of fitting was made on graphics
of fitting curves. An example of the fitting results
for a highly ionized aluminum spectrum in the
beam-foil experimentl) are given in Table 1.
Reference
1) K. Ando, S. Kohmoto, T. Tonuma, H. Kumagai, Y.
Awaya, S. Tsurubuchi, and K. Sato: RIKEN Accel.
Progr. Rep., 18, 71 (1984).

64
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-10.

Tilted-Foil Method with Charge-Nonequilibrium Ions
S. Kohmoto, K. Ando, and M. Ishihara

We have verified I) by an optical method thatcharge-nonequilibrium ions can be generated byusing thin carbon foils of 0.7 J1g/cm 2 in thickness
for a 14N3+ ion beam of 28.8 MeV incident energysome lines of N IV and N V ions were found t~
survive, which is not the case with thick foil. To
see whether or not ions are polarized after passing through thin tilted carbon foil, we measured
the polarization of light emitted from the ionsabout 1.5 cm downstream from a foil tilted at±45°.
A calcite Glan-Taylor polarizer was usedinstead of a Polaroid one to assure the measurement of low-wavelength lines. Figure 1 shows thelight-intensity variation l' as a function of phase
plate rotation angle {3 for the N IV 341 nm line.
The tilting angles to the beam direction are also
given in Fig. 1. The rotation angle {3 wasadvanced by 5° for each passed ion currents of 6
J1C. The results show that the intensity is gradually lowered on the whole, and the foil seems tobe thickened under the bombardment of ionsprobably because of the insufficient vacuum.
Thus charge state of ions approaches equilibrium, and the number of emitted photons as wellas measurement lap time decrease. The results:vere analyzed by using a function:
1'({3)+5 sin Ll ]sin 2(a -,8)}
X ~ Niexp( - aiq)j=1

where I, M, C, and 5 are the Stokes parameters
to be determined, Ll is the phase angle of thephase plate which is 130.4° at this wavelength,
and the polarizer angle a was fixed to be 0°. The
last term is introduced to simulate the thickening
effect of the foil phenomenologically, where q is
the integrated ion current.
The summation is taken with constraint of
I~Ni= 1. A single exponential term, however, isgenerally sufficient to reproduce the thickenningeffect.
From the analysis, we conclude that the ionsemit highly linear-polarized light at this incident
energy. It was found previously 2 l that, in theenergy region EN < 15 Me V, the circular polarization has a tendency to diminishing when theincident energy is increased. It does not seem todisappear completely at 28.8 Me V incident
energy. Relative Stokes parameters may be
dependent on the foil thickness, which is represented by q in the above equation; the present
measurements are, however, not necessarily precise to investigate it at this stage.
References= (1/2) {I +(Mcos 2{3+ Csin 2{3) cos 2(a - {3)+ [(Ccos 2{3- Msin 2{3) cosLl

1) S. Kohmoto, K. Ando, M. Ishihara, and T. Nomura:
RIKEN Accel. Progr. Rep., 18, 69 (1984).
2) S. Kohmoto, M. Ishihara, T. Nomura, and Y. Gono:
RIKEN Accel. Progr. Rep., 17,48 (1983).

xlO ~2~_~~~~~~_~~a)

4

V\ VJ 1\ht\.tu l~ "., .:iJ '/!J ~.•• \3. .~.~" . ~'

2

>t

r -

.~ 4 ~ A. ~ /\~ n . .
@3

.jJ

J::

• .-1

••

.• ,

2

....

"" 'v \ 1: \ 1 \l\.)
[>. "

b)

•

.jJ

..c:

.!:f
rl

~ -tl> beam

1

I
I

o

1
foil

foil

~"

,

2IT

4 IT

6 IT

o

2IT

4IT

~J

6IT

phase plate rotation angle (- B)

Fig. 1.

Light inte~sity (d~ts) measured as a f~nction of p~ase ~late rotation angle. Tilting angle is opposite for a)an~ b). The c~ntmuous lme~ are calculated WIth the functIOn gIven in the text. Normalized Stokes parameters usedare. a) M / I - (- 13.2±2.7)%, C / I=(-4.3±2.7)%, S / I=(+2.7±3.4)%· b) M / I=(-128+31)% C/I=(-46+3.1)%, S / I=( - 2.4±3.9)%.

, . _ .

0,

.

-

65
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-11.

Measurement of Lifetimes for Highly-Ionized Aluminium Atoms
S. Kohmoto, K. Ando, Y. Awaya, H. Kumagai,
K. Sato, T. Tonuma, and S. Tsurubuchi

the multi-exponential-fitting programme cord
DISCRETE,3) which is based on the eigen-function expansion of the solution of the' Fredholm
integral equation. This programme decides boththe best number of exponentials to be introduced
and the transition probabilities. Curve a) is
composed of two exponential terms with transition
probabilities A =(2.03 ± 0.10) ns- I and (10.71± 0.34) ns- I • Curve b) is reproduced by a single
exponential term with A=(3.11±0.04) ns- 1 •Weare preparing the decay-curve measurement of the cascade transitions to these levels inorder to extract the lifetimes.

The measurement of beam-foil spectroscopy
for Al ionst) has been carried out making use of
RILAC. Spectra were measured at several incident energies in the wavelength region A < 400 A.
Line assignment of spectra has been made anddetails are found in another report. 2 ) We succeeded to measure some decay curves and present
here two of them measured by using of AI3+ ion
beam at the incident energy EAI of 22.38 MeV.
Figure 1 shows the decay curves for a) Al x 2s2p
3P I-2p2 3P2 395.36 A transition and b) Al X 2S2 IS2s2p 1 P 332.78 A transition.
The position of the carbon foil, 5 J1. g/ cm2 inthickness, was shifted along with the beam by
0.05, 0.15, or 0.25 mm for each passed ion currentsof 100 pC. A light guide connected to a photomultiplier was mounted downstream from thetarget assembly in order to detect breakage ofthe foil. A Perkin Elmer computer in an MSC
mode was used to accumulate the photon counts.
These decay curves were analyzed by using

References
1) K. Ando, S. Kohmoto, T. Tonurna, H. Kumagai, Y.
Awaya, S. Tsurubuchi, and K. Sato: RIKEN Accel.
Progr. Rep., 18, 71 (1984).
2) K. Ando, Y. Awaya, S. Kohmoto, H. Kumagai, T.
Tonurna, S. Tsurubuchi, and K. Sato: p. 62 in thisreport.
3) S. W. Provencher:]. Chem. Phys., 64, 2772 (1976).

time (nsec)
0.0

0.5

1.0

x 10 3
III

a)

2

0.4

0.2

0.0
xl0 3
3

+l

s:::
~

2

0

u

1
1
0
0

5

10

15

distance

0

0

2

4

6

(rnrn)

Fig. 1. Measured and calculated decay curves a) for 2s2p 3P I-2p2 3P2 395.36 A transition andb) for 2S2 IS-2s2p Ip 332.78 A transition.

66
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-12.

Electron Distribution in M- and L-Shells of 33 MeV
Ar-Ions in Solid Targets
T. Kambara, Y. Awaya, Y. Kanai, M. Kase,
T. Mizogawa, and H. Shibata

The energy spectra of K,B X-rays from 33 MeV
Ar-ions passing through various solid targets
have been measured in order to study the electron distribution in the L- and M- shells of
Ar-ions on a K X-ray emission as a function of
the target atomic number Z 2. A broad-range
crystal spectrometer was used to get an energy
resolution high enough to resolve these K X-rays
into satellite components which correspond todifferent hole numbers of the L- shell. Since mostof K X-rays are emitted inside the target, we canobtain information about electronic excitationand ionization of the ions in various matters.
The experimental setup and results obtained
from Ka X-ray spectra were given in previous
reports. 1),2) The measurement including the K,B
X-rays was started last year, and preliminary
results have been reported. 2 ) This year the SIN
ratio of the X-ray spectra was improved andadditional data on Nd and W targets were added.
The intensity of each satellite component KL nof the Ka and K,B X-rays was obtained by fitting
a sum of Gaussian curves to the observed X-ray
spectra. The detection efficiency of the proportional counter of the spectrometer was correctedby using an estimated value of absorption by thegas, but the absorption in the window of the
proportional counter was not corrected.
From the satellite intensity distribution of theK,B X-rays, the average number of the L-shellholes is derived in the same way as that from the
Ka X-rays.l} The Z 2 dependence of the L-holenumber is plotted in Fig. 1 for both Ka and K,Btransitions. The L-shell hole number has thesame oscillatory dependence on Z 2 for bothcases but that obtained from the K,B transition isby about 1 larger than that obtained from the Ka
transition. The origin of the oscillatory dependence was explained as the Z 2 dependence ofelectron capture cross section to the Ar L-shellby the level matching effectY
The intensity ratio of K,BLn to KaLn X-rays
with the same number of L-shell holes is also
obtained from the data. The ratio is plottedagainst Z 2 in Fig. 2 for the L-shell hole number

~
.c

E

~ 4
Q)

(5

::I:
-.J

o

80

60

20

Fig. 1. Target atomic number (Z 2) dependence ofthe number of L-shell holes of Ar ions obtained
from Ka and K,B X-ray satellite distributions.

o

~~~

o

__

20

~~

__

40

~~

__

60

~-J

80

Z2

Fig. 2. Target atomic number (Z 2) dependence of
the intensity ratio of Ar K,BLn X-ray satellite components for n L-shell holes (n=3,4, and 5).

from 3 to 5. By comparing the intensity ratiowith that calculated by Bhalla,3} the number of
M23 -shell electrons (3p electrons) is estimated forthese numbers of L-shell holes. The result isshown in Fig. 3 as a function of Z 2. The numberof electrons in the M 23 -shell is smaller than 1 andshows oscillatory dependence on Z 2 which is inphase with that of the L-shell hole shown in Fig.
1.
From the present data, it is concluded that theT. Kambara, et al.

.~

1.0

number of electrons in the L-shell is about 4 andthat in the M-shell is smaller than 1. It is also
speculated that the number of electron in the
M-shell becomes small when the number in the
L-shell is large. It is interesting to compare thepresent data with that of charge state distribution of heavy ions after passage in targets.

E
~

z

~

t)
Q)

Xt
0.5

w

0&

Q.

xi
~

ol
!

CO)

o

20

o!
o
0

x

x

t ~
Xd

~

~

40

60

67

80

References
Fig. 3. Target atomic number (2;) dependence of thenumber of M23 -shell (3p) electrons at the time of
K X-ray emission for different numbers of L-shellholes. Triangles stand for 3 L-shell holes, crosses
for 4 holes, and circles for 5 holes.

1) Y. Awaya, T. Kambara, M. Kase, H. Shibata, H.
Kumagai, K. Fujima, J. Urakawa, T. Matsuo, and ].
Takahashi: Nucl. Ins tru m. Methods B, 10/11, 53(1985).
2) T. Kambara, Y. Awaya, M. Kase, H. Shibata, and H.
Kumagai: RIKEN Accel. Progr. Rep., 18, 73 (1984).
3) C. P. Bhalla: Phys. Rev. A, 8, 2877 (1973).

68
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-13.

Target Thickness Dependence of Ka Satellite Intensities of
Ar Ions Passing through Thin Carbon Foils
T. Mizogawa, Y. Awaya, T. Kambara, Y. Kanai, M. Kase,
H. Kumagai, M. Mostafa Ismail, and K. Shima

Target-thickness dependence of Ar Ka satellite intensities were measured to study the evolution of L-hole configuration of fast Ar ions incarbon foils. Such a type of measurement gives
detailed and direct information about the chargeequilibration process of fast ions in solids andthe origin of the strong dependence of experimental K X-ray production "cross section" on thetarget thickness for extremely thin targets.
Experimental set-up is shown in Fig. 1. A
carbon-foil target was bombarded with 50 MeV
Ar4+ ions from the RIKEN linear accelerator,
and resulting Ar K X-ray spectra were measured
by using a broad-range crystal spectrometer.I) A
value of integrated Ar4+ flux multiplied by thetarget thickness was determined from the mea-lSlit __

~

0.4

04r

X ~

~SPC

~/

6

0.2[
~
0,0 L-----------------------c2.----

Stripperfoil

Q--~~--

2~2 2

1.8
1.6

/.J.

5

J{2

1.4

e- suppressor

f

Q)

1.2
1.0L-------------------------

U

3.6

"0

':;"

Fig. 1. Experimental set-up. The diameters of slits
are 1.5 mm (front) and 2.0 mm. PSPC stands for aposition-sensitive proportional counter. The voltage of -1 k V was applied to the electron suppressor.

7

0.2 ~
2
~----~--~----~Qr-2~~~~==~~~
0.0
0
:t

Ge [111J crystal-vv-~

Faraday cup

~-c
0°0

r

's 3.4
<1)

~
"0
Q)

':;"

3.2
3.0

A2V2
4

>.

~
I

X

2.8
2.6

(

2.4L------=-------------------r--

I J:0~ 2 ~:("~}----

3

Lot

~~

2

04r

~~

L

r

2.0\
rr
:r
1.8 L--_______________________
'0

~ 3

'-...

Ka hyper-"0Q)':;" 2satellites

>.

~
I

X

1

0.8
0.6 L--______________________
Q--4-L-~CQ-Q _0.2[
O. 0 O.!o-....I...---L...---l.--.l..--~5--.l.....---'-----"---'---:;-'110
Channel number

Fig. 2. Ar K X-ray spectra for two different targetthicknesses. Vertical scale is normalized by recoilcarbon yield. For the numbers 0- 7, see text.

Target thickness Cug/ cm 2 )Fig. 3. Target thickness dependence of Ka satellite
intensities. Error bars indicate statistical errors
only. Solid lines are drawn only for eye-guide.

T. Mizogawa, et al.

surement of the yield of recoil carbon using asurface-barrier detector (SBD) placed at 45° tothe beam direction. Ions passed through the target foil are stripped again with a 20 jLg/cm2
carbon foil to be brought into charge equilibrium, and finally collected in a Faraday cup. The
integrated Ar 4+ flux can be determined from theelectric current of the Faraday cup by using thewell-established data of mean charge. 2 ) By combining these data with the recoiled-carbon yields,
the target thicknesses are directly determined. A
Si(Li) detector is also used as a monitor.
Here we report preliminary results. In Fig. 2,
the spectra obtained by using the crystal
spectrometer are shown for two different target
thicknesses. The intensity of each satellite wasdetermined by fitting a sum of 8 Gaussians to theobtained spectra. The results are summarized inFig. 3, in which the vertical axis shows the intensity divided by the recoiled-carbon yield69("effective X-ray emission cross section" for eachsatellite). The satellites have not been assigned
to electronic transitions yet, and the peaks arelabeled 0-7 as shown in Fig. 2. From Fig. 3 it canbe seen that the high-energy group of the satellites grows with an incre"a se in target thickness,and the low-energy group tends to decrease. Thisis considered to be the effect of the increase in
K-L excitation and K fluorescence yield due tothe development of L-holes during the passage of
Ar ions through carbon foils.
Further analysis and experiments are in progress.
References
1) A. Hitachi, H. Kumagai, and Y. Awaya: Nucl.
Instrum. Methods , 195, 631 (1982).
2) See for example, R. B. Clark, I. S. Grant, R. King, D.
A. Eastham, and T. Joy: Nucl. Instrum. Methods, 133,
17 (1976).

70
RIKEN Accel. Progr. Rep. 19 (1985)

III-2-14.

Cu K X-Rays from Cu Ions on C Target and C Ions on Cu Target
Y. Awaya, T. Kambara, M. Kase, H. Shibata,
H. Kumagai, T. Mizogawa, Y. Kanai, and K. Shima

The ionized state of a target Cu atom excitedby C ions and that of Cu projectile ions passing
through a C foil target have been studied by highresolution measurements of Cu K X-rays at thesame collision velocity. It is expected that thedifference of average number of L-holes between
Cu ions and Cu target atoms at the emission of
K X-rays gives the information about the numberof L-holes of Cu ions at a charge equilibrium200

0.69 MeV/amu

100

1000

500

0~~

__

~

__

L-~

__- L_ _

~

__

L-~

__

~

500

250

8.0

8.4

8.8

9.2

Energy (keV)

Fig.1. Spectra of Cu K X-rays obtained from the Cu
ions transversing in C target foil. Incident energies
of Cu ions are given in the figure.

state in the C foil. The preliminary results
obtained with 0.83 MeV / amu projectiles werereported previously.1) Here, we report the resultsof further studies carried at various collisionenergies.
The ex:perimental set-up was the same as thatreported previously.!) The Cu ions and C ionswere accelerated by the linac. The incident
energies were 0.69, 0.83, and 0.97 MeV / amu forboth the ions and l.60 Me V for C ions. The
thickness of the target Cu foil was 0.22 mg/ cm 2and that of the C foil was 0.08 mg/cm 2 • The Cu K
X-rays were measured by using a broad-range
X-ray crystal spectrometer 2 ) with a crystal of
LiF(220) (2d = 2.848 A) placed at 90° with respect
to the beam.
The spectra of Cu K X-rays obtained from0.69, 0.83, and 0.97 MeV / amu Cu ions transversing the C foil and those of Cu target excited by
0.69, 0.83, 0.97, and l.60 MeV /amu C ions areshown in Figs. 1 and 2. KLn denotes theconfiguration of the initial state with single K
and n-multiple L-holes for the transition.
The L-shell ionization probability of target Cu
atoms accompanied by single K-shell ionization,
PL , was obtained assuming the binomial distribution of L-holes. The effect of rearrangement,
which means that the L-hole is filled by an outershell electron prior to filling the K-hole, is taken
into account for obtaining the relative ionization
cross section of simultaneous single K and nL
electrons, O'KL", from the relative intensity of KL nlines. The fluorescence yield for KL n line is also
estimated according to Larkin's statistical law 3 )assuming that the M-holes are filled before emission of K X-rays because the electrons may
easily be fed by the conduction band. The possibility of electron capture from neighbouring Cu
atom by the L-hole of a recoiled Cu atom (bearing a K-hole) was estimated to be negligible prior
to emission of K X-rays. PL values thus obtained
are shown by open circles in Fig. 3 as a functionof E/AUL, where E is the incident energy of
projectiles, A is the mass of projectiles in electron mass unit, and UL is the binding energy of L
electrons. An average number of L-holes is given

Y. Awaya, et at.

71

/
0/

o

/

..J

lit

P / OJ Proj ectiles

Kl 2 -

500;§.....o0.69 MeV/amu( OJ ions on C )/OJ target GtOTS( C ions on ~ .2- - -..

0-- .-.0-'-.- - 0-_e-

0_--- - a.--.-'-0.83 MeV/ .. mua L -_ _ ____
~1

500

0.4

~1__~1~__~1____L-1__~1__~

0. 6

0.8

1.0

E/AUL

o ..

..J..Jo~1It".J'v'....-.--.

O~~~~--~~=C~~~~~~~~~I

C
::J

o

o

1000

0.91 MeV/amu

500

O·"" ""'~r1".''"''''''''Nw'''I
!

!

1500
1.60 MeV/amu
1000

500

1.6

8.0

8.4

8.8

9.2

Energy (ke V)

Fig. 2. Spectra of Cu K X-rays obtained from thetarget Cu foil induced by C-ion bombardment. Incident energies of C ions are given in the figure.

by < I > ~8 X PL. The < I> values without any
corrections, where KL n is assumed to be equal to
the relative intensity of KL n line, are also shownin Fig. 3 by filled circles.
Concerning the Cu ions, the values corresponding to PL of the target Cu atom are also obtained.
The projectile Cu ions are considered to reach anequilibrium state as to Land M electrons after
passing through first a few JLg/ cm 2 of C foil. The
charge of Cu ions in equilibrium state at 0.69,
0.83, and 0.96 MeV/amu is 16.7+,17.3 + , and18.1 +, respectively.4) There is a possibility that
the Cu ions bear some L-holes prior to the collision which induces simultaneous single K and nL
ionization.
The density of atoms in the target foil is sohigh that the successive distant collision with

Fig. 3. Average number of L-holes of Cu ions and Cu
target atoms. See text for open and filled circles for
Cu target.

another C atom should be considered for a Cu ion
which experienced a close collision to have a
K -hole. In such a case the number of L-holes maychange during persistence of K-hole due to theprocesses such as L electron loss, electron capture to L-hole, and L electron excitation. These
effects are estimated from the calculated valuesof the L ionization cross section of Cu ions, theelectron capture cross sections to the L-hole ofCu ions from C atoms, the excitation cross section of L electron of Cu ions to outer-shells, thedensity of C atoms in the foil, the mean life of the
K-hole, and the velocity of Cu ions. The first twocross sections are estimated by the binary
encounter approximation and Brinkman-Kramers
formula. Since neither experimental data nor
theoretical calculations for the excitation crosssection of L electron to the outer-shell for Cu
ions are available, Iwai et al. 5) have calculated
the excitation cross section of L2,3 electron to the
MI orbit. As the results, it is preliminarily foundthat the no significant correction is required forthe number of L-holes.
A constant value of fluorescence yield isassumed for KL n lines is assumed because theAuger transition rate may be small for Cu ions.
The obtained average number of L-holes < I>,
where < I > = ~ nln/ ~/n and In is the relative
intensity of KL n line, are shown in Fig. 3.
The difference between the average number ofL-holes and that of Cu ions and Cu atoms may becorrespond to the number of L-holes carried by
Cu ions transversing in C foil in the equilibrium
state, that is, about one L-hole exists in Cu ionsin average in the range of 0.67 to 0.97 MeV / amu.
References
1) Y. Awaya, T. Kambara, M. Kase, H. Shibata, H.

72

Y. Awaya, et al.

Kumagai, M. Nishida, and K. Shima: RIKEN Accel.
Progr. Rep., 18, 75 (1984).
2) A. Hitachi, H. Kumagai, and Y. Awaya: Nucl.
Instrum. Methods, 195, 631 (1982).
3) F. P. Larkins:]. Phys. B, 4, L29 (1971).

4) K. Shima, T. Ishihara, and T. Mikumo: Nucl.
Instrum. Methods, 200, 605 (1982).
5) M. Iwai, 1. Shimamura, T. Watanabe, and Y. Awaya:
p. 52 in this report.

73
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-15. Measurement of Impact-Parameter Dependent Probabilities andTotal Cross Sections for Target K-Shell Ionization by He Ions
R. Schuch, Y. Awaya, T. Kambara, T. Mizogawa,
H. Kumagai, Y. Kanai, K. Shima, and H. Shibata
Impact-parameter (b) dependence of target
K-shell ionization probability (PK(b» in asymmetric collisions was measured up to large b
above the Bohr K-shell radius. The energy of
projectiles was 1 MeV / amu and the collisionvelocity was much lower than the Bohr K electron velocity in the targets of Ca, Cr, and Cu. It
is expected that the description of initial K-shellstates of target atoms changes from united atom
(u.a.) description to separated atom (s.a.) one
with increasing b and that this is reflected in theexperimental results. Much emphasis was put inthe accuracy of the value of PK(b).
The measurements were performed at theheavy-ion linac. A He+ ion beam of 4.04 MeV
was collimated to 1 mm Xl mm with a divergence of 0.02°. Particles scattered by the edge ofslits were reduced to a negligible amount byusing anti scattering collimators. The target
material of Ca, Cr, and Cu was evaporated on a
2.5 jJ.g/cm 2 C-foil and positioned at 45° relative tothe beam axis. The characteristic K X-rays fromthe target atoms were detected by a 28 mm 2
Si(Li) detector at 90°, in a distance of 16.5 mm
relative to the beam. In the forward scattering
direction a parallel-plate avalanche counter(PP AC) at 193.5 cm distance from the target
covered the laboratory angular region from 0.13°
to 1.4°. The anode of the PPAC was divided into
16 rings with an angular resolution of L18/8= 0.05 each. A coincidence circuit between the
PP AC and the Si(Li) allowed to measure coincident K X-rays for all scattering angles simultaneously. The coincident events consisting of time,
position, and X-ray energy were stored in list
mode. The total number of particles per position
was also measured and served as normalization
for getting absolute K X-ray production probabilities.
For experiments of the total cross section (O"K)
a surface barrier detector with a slit aperture
was mounted at 20°. The agreement of the beamaxis with the geometrical axis of target chamber
was verified independently. Stored X-ray signals
and scattered particle spectra from the same

1.01 MeV IN

He - Co--- SCA RHFS sa
SCA R HFS u.a.

•

-

t

!-

:0
0...

•

SIJ.g/cm 2 Ca on 2.5lJ.g/cm2 C

o 10 IJ.g/cm 2 Ca on 2.5lJ.g/cm2 C
c 20 IJ.g/cm 2 Ca on 2.51J.g/cm2 C

1O-SL.-_-LL.--

2-01L-OO--"----/'0L-OO--"---6--'O'-:-:00--'b [1m]

Fig. 1. K vacancy probability of Ca as a function of
impact parameter at three different target thicknesses.
-

10- 2 ::-

1.01 MeV/N He -Cr- .- - -•• +SCA Dirac Wid . s.a
SCA RHFS s.a
SeA RHFS u.Q.

10- 3 _

-:0
0...

-

10- 4 ::-

lO-S'-_ _' - - l _ - - ' -_ _' - l _ - - - - ' - -_

2000

/'000

_

' - l_ _~'---'

6000
b [1m]

Fig. 2. Same as Fig. 1 for Cr as a target.

runs allowed the determination of total K X-ray
production cross sections.
The target atom K X-ray production probabilities and total K X-ray ones were corrected withfluorescence yields for neutral atoms in order toobtain the values of PK(b). Here multiple ionization of the target atoms in collisions with He
ions is assumed to be negligible. The error
introduced by this assumption in PK (b) should be

74

R. Schuch, et at.

t 1.01 MeV/N He -Zr

1.03 MeV/N He -Cu•o~251J.9/cm z self supp
20 1J.9/cmzon 2.5119 Icm z C--- - SeA RHFS 5 .0 .
SCA RHFS u.o.

:0

c
c;

Cl..

.0

b

'"

...

i
102I-

-

.

~
6

10- '-----'---20-'-0-0---'---t.-'-OOO----'----'--6-l00-l0-l20b[ f m]Fig. 3. Same as Fig. 1 for eu as target.

less than 10%. The impact parameter b was
obtained from the scattering angle by using a
Bohr screened Coulomb potential.
In Figs. 1, 2, and 3 the values of P(b) are shown
for Ca, Cr, and Cu targets in collisions with 1.01
Me V / amu He ions. The error bars given arefrom statistical errors only. The probabilities ofthese different target nuclear charges have about
the same shape as function of b. They indicate a
fiat behaviour up to 1,000 fm, show a steep fall off
above and then a fiat dependence again at b>
3,000 fm. For finding the possible reason for thischange in the shape at large b in multiple collisions, the measurements at three different Ca
target thicknesses (20, 10, and 5 ,ug/ cm2 ) were
made. The three sets of P K (b) agree very wellwithin the error bars, which seems to indicatethat multiple collisions are negligible. The contribution of particles scattered from the C back'ing alone was found to be a small correction.
Figure 4 shows the total cross section forK-shell ionization of the different target species.
The target thickness corresponding to thedifferent symbols are: circle and square are 5 and

24

28

ZT

Fig. 4. Total cross sections for K vacancy production (()"K) as a function of target nuclear charge (Zr) .
Open symbols are from integration of PK(b) , fullsymbols are from a direct measurement (see text).

20 ,ug/ cm 2 Ca on 2.5 ,ug/ cm 2 C, triangle is 15 ,ug/
cm2 Ca on 2.5 ,u g/ cm 2 C, square and triangle are
25 ,ug/ cm2 Cu self supporting, and 20 ,ug/ cm 2 Cu
on 2.5 ,ug/ cm 2 C.
There are two sets of data: the full symbols represent the direct measurements of (fK andthe open symbols show the results of (fK =27r

f bPK(b)db performed numerically with thedata. The two sets of (fK agree fairly well within
the error bars also for the different target thicknesses. The reason for the (fK from the integration of PK(b) being systematically below thedirect measurement of (fK could be an omission of
the PK(b) above the measured b range.
The semi-classical-approximation calculationof P( b) is in progress for the cases of therelativistic Hartree-Fock-Slater K wave functionof united atom (Z = Zr + 2) and these of target
atom (Z=Zr).

75

RIKEN Accel. Progr. Rep. 19 (1985)

111-2-16.

Data Analysis of Recoiled Ar Ions in the High Charge
States by Means of a "Compound Atom" Model

A. Ohsaki, * T. Tonuma, H. Shibata, S. H. Be, H. Kumagai,
M. Kase, T. Kambara, 1. Kohno, and H. Tawara
The partial cross sections for production ofslow recoil Ari+ ions in 1.05 MeV /amu Ne q+ (q=2,7-10) and Ar q+ (q=4, 6, 10-14) ion impact havebeen determinedl) and compared with a "compound atom" model for high-charge state of ionsand with a independent electron approximation(lEA) for low-charge state ions.
Recently Meron and Rosner have developed a"compound atom" model,2) which essentiallyassumes that, during a close collision, some electrons of both projectile and target atoms, which
are not altogether thrown out of the system,
create a common structureless electron cloud,which is later redistributed between both atoms.
The compound atom is initially composed of N;
electrons in the common cloud and Nf electrons
at the final state remain in the cloud after someelectrons are ejected. That is, N; - Nf electrons
are ejected before creation of a quasi-stablecommon cloud. We assume that no further ionization of electrons takes place before separation
once the quasi-stable common electron cloud isformed. Then, Nf electrons are divided into Nl
and N2 electrons, which are the average numbersof electrons captured by the projectiles with thenuclear charge Z. and the recoil ions with ~,respectively, namely:(1)
According to this model, the probability PiN f thatout of N r electrons i electrons escape from therecoil atom is given by

behave like spectators. For the detailed
definition and the notation, see Ref. 2). The sumof PiNr over i is unity; in other words, PiNr represents the probability that the recoil ions have thecharge state i.
The caluculated parameters in this model incollisions of l.05 MeV / amu N e q+ and Ar q+ ionswith an Ar target are given in Table l. The
initial number of electrons Nt in the common
cloud is given by(3)
where q is the projectile charge-state and themean charge < i> of the recoil ions is givenby < i> = ~(Uc)- N 2 • The fact that ~(Uc)= 16.35
in the present case means that two electrons in
the K -shell of Ar atom do not contributesignificantly to composing the common electron
cloud in the compound atom. In the process goingfrom the initial number of electrons N; to thefinal number of electrons Nf in the common

Table 1. Parameters calculated from the compoundatom model in collisions of 1.05 MeV / amu Neq+and
Ar q+ ion impact with Ar target. Nt and M are theinitial and the final numbers of electrons in the common electron cloud. NJ and N2 are the average numbers of electrons redistributed into the projectile andthe recoil ion from M. The mean charge of the recoil
ions, < i>, is given by < i> = ~(u,J- N 2 • Z;(Uc) and~(Uc) are the effective numbers of electrons in the
projectile and the target atom contributing to forming a common electron cloud. For the detailed
description of the parameters, see Ref. 2.

(2)
Ne q+ ion impact
Z; (Uc) =9.55

where (b) donotes the binomial coefficient. Z. (Uc)and ~(Uc) are the effective numbers of electronsof the projectile and the target atoms, respectively, involved in forming a common electron cloud
whose velocity is smaller than a critical velocity
Uc (Electrons with velocities larger than Uc* Institute for Molecular Science.

~(Uc)=16.35

Ar q+ ion impact
Z; (Uc) = ~(Uc)=16.35

q

Nt

Nf

NI

N2

<i>

2
7
8
9
10

23.9
18.9
17.9
16.9
15.9

16.7
15.0
14.5
14.0
13.5

6.2
5.5
5.3
5.2
5.0

10.5
9.5
9.2
8.8
8.5

5.9
6.9
7.2
7.6
7.9

4
6
10
11
12
13
14

28.7
26.7
22.7
21.7
20.7
19.7
18.7

18.6
18.1
16.8
16.5
16.1
15.6
15.1

9.3
9.1
8.4
8.3
8.1
7.8
7.6

9.3
9.1
8.4
8.3
8.1
7.8
7.6

7.1
7.3
8.0
8.1
8.3
8.6
8.8

76

A. Ohsaki, et al.

1.05 MeV/amu NeH+Ar

1.05 MeV/amu Ar q++ Ar• Experimental Data---,- Calculation• Experimental Data---, - Calculation-10-161c:o\~ 10- 17

.

,
\

<f>

V>

e
u

\

~

\v""'/
1\

<f>
<f>

e

I

u

I

I

I

I

I,

,
\

\

I

,

,
,
\

I
I

,

I

,

I

\
\

(a)

o

2

(b)

4

6

8

10

o

12

Recoil ion charge state i

2

4

6

8

10

12

Recoil ion charge stateFig. 1. (a) Partial ionization cross-sections of recoil Ar ions in collisions of 1.05 MeV / amu Ne q + (q=2 and 8) ionswith Ar atoms as a function of the recoil-ion charge-state i. Filled points give experimental data. Broken lines on
the right-hand side represent the charge-state distribution calculated from the compound atom model, where thepeak values of the distribution are adjusted on the basis of the experimental data. Broken lines on the left-handside represent the calculations using the lEA model. The solid lines represent the sums of calculations from lEA
and from compound atom model. (b) Partial ionization cross-sections of recoil Ar ions in 1.05 MeV / amu Ar q+ (q=4 and 14) ions on Ar atoms against the recoil-ion charge-state i. Other explanations are the same as in (a).

cloud, (Nf - N.J electrons are ejected. The number of electrons ejected in this process decreases
with increasing projectile charge state q as indicated in Table 1. The mean charge < i> ofrecoil Ar ions clearly increase with increasing
projectile charge q. The dependence of < i> on
the projectile charge-state q is slightly different
between Ne q+ and Ar q+ ion impact, however.
, To the data analysis of the low-charge state
recoil Ar i + ions, we applied the independent
electron approximation (lEA) which assumes
binomial statistics to be valid for multiple
ionization. 3 ),4) (The procedure of data fitting is
not described here_)
The charge-state distributions of recoil Ar ionsobtained from Eqn_ (2) are shown in Fig. 1 (a) and(b), in which the peak values are adjusted to fit
the experimental data. The solid lines represent
the sums of lEA and compound atom model
calculations. Figure 1 shows that the distributions are very similar to Gaussian and the mean
charges of the distribution increase with increasing projectile charge-state q_ The calculated
charge-state distributions for Ar q+ ion impact

reproduce the experimental data somewhat better than those for N e q+ ion impact. In fact, thedeviation in N eq+ ion impact is clearly observed
at high-charge states, suggesting that this model
is more effective for relatively symmetric collision systems having similar numbers of electrons
in both projectile and target atoms. Therefore, it
is concluded that, though the charge-state distribution of the recoil ions is underestimated fromthe compound atom model for low Z projectiles,
this model can generally reproduce the experimental data on the charge distribution at highcharges.
References
1) T. Tonuma, H. Shibata, S. H. Be, H . Kumagai, M.
Kase, T. Kambara, 1. Kohno, and H. Tawara: Atomic
Collision Res. in Japan- Progr. Rep., No. 11,84 (1985).
2) M.Meron and B. Rosner: Phys. Rev. A, 30, 132 (1984).
3) J. H. McGuire and L. Weaver: Phys. Rev. A, 16, 41(1977).
4) P. H. Mokler and H. D. Lissen: Progress in Atomic
Spectroscopy, Part C, (ed. by H. F. Berger and H.
Kleinpoppen), Plenum Press, New York, p. 321 (1983).

77

RIKEN Accel. Pro¥!". Rep. 19 (1985)

111-2-17.

Highly-Charged Carbon Ions Produced from Carbon-Containing
Molecules in Collisions with Energetic Heavy Ions
H. Shibata, T. Tonuma, K. Baba,* S. H. Be, H. Kumagai,
M. Kase, T. Kambara, 1. Kohno, and H. Tawara

In a previous Progress Report, we presented
some results on the observation of multiplycharged, secondary nitrogen ions (Ni+) up to i =7 from N 2 molecular targets in 1.05 MeV / amu
Ar4+ and Arl2+ ion impactY It has been found in
subsequent work that these Ni+ ions have theinitial energies slightly larger than those forsingle atom targets such as Ari+ and this energy
difference increases with increasing the charge(i) of secondary ions. The observed shift in theinitial energies of multiply-charged atomic ions,compared with those of molecular target, was inagreement with the calculated values under theassumption that these energies are provided
through the Coulomb potential energies between
the dissociating ions when multiply-charged
molecular ions are dissociated.
Some measurements of total ionization crosssections for hydrocarbon molecules were reported, but very few data of partial ionization crosssections are available, though relative production rates for various ions including singly and at
most doubly-charged molecular ions (CmHni+)and singly-charged carbon (C+) ions from somecarbon-containing molecules were measured. Up
to now, no systematic studies have been made for
production of multiply-charged ions. In theseionization processes of molecules, dominant,singly-charged and sometimes relatively weak,
doubly-charged parent molecular ions areproduced through direct ionization processes,
meanwhile most of other observed ions are
believed to be produced through dissociative
ionization processes of the parent molecularions. In many cases, the doubly-charged parent
molecular ions have short life-times. Therefore,
their observed intensities are very low, usually
only 1-2 % of those of the singly-charged parent
molecular ions, as discussed previously.2)
In order to understand the production mechanisms of multiply-charged atomic ions frommolecular targets, we have used a massspectroscopic technique to separate various ions
• UL VAC Corporation.

10~--~----.----.~--~----~--~

1.05 MeV/amu Ar 12 + ion impact
C2H2 target

256
CHANNEL NUMBER

Fig. 1. A typical mass-charge spectrum of ionsproduced from C2 H2 molecules in 1.05 Me V / amu
Ar 12 + ion impact.

from CH 4 and C2H2 molecules produced by 1.05
MeV /amu Ar 12 + ion impact obtained from the
RIKEN linear accelerator. The produced secondary ions are extracted under the influence of a
relatively weak electric field (---...,40 V / cm), accelerated up to 500 V, and then mass-chargeenergy analyzed with a double focusing magnet. 2)
A typical mass-charge spectrum of the ions fromthe C2H 2 molecular target is shown in Fig. 1,
which shows the formation of singly- andmultiply-charged carbon ions (Ci+) up to i = 5, in
addition to dominant singly -charged parent
molecular ions (C 2H 2+) and other molecular ionssuch as C2H+, CH+, and C2+ ions which originate
in dissociative ionization. A similar observation
for CH 4 targets has also been made. It is foundfrom comparison that production of multiplycharged carbon ions, relative to singly-charged
parent molecular ions, is by a factor of about 3,
or sometimes one order of magnitude, higher in
CH 4 targets than in C2H2 targets, even though aC2H2 molecule has twice the number of carbon
atoms in a CH 4 molecule.
For the elucidation of this difference, compari-

78

H. Shibata, et at.

1.05 MeV/amu Ar12+ ion impact

10°

O~--~~~~~~----~~~~--~

xl02

Ar

1.28
0.64
°0~~~~~~~~~~25~6---L--~

CHANNEL NUMBER

Fig. 2. Comparison of spectra of multiply-charged
carbon ions produced from C2 H 2 , CH 4 , and Ar
targets in 1.05 MeV / amu Ar 12 + ion impact.

son is shown in Fig. 2 of spectra for Ci+ ions withi = 2-5 and Hz + ions from CzHz and CH 4 molecular targets as well as for Ar i + ions from atomic
Ar targets. Though the present analyzing system
has no sufficient energy resolution, we canobserve slight shifts of the peak positions forthese multiply-charged carbon ions from CzHz
'targets, compared with those from CH 4 targets.
It should be noted that the peak position of C3+ions from CH 4 targets coincides with that of
Ar IO + (both having m/ e = 4). This indicates thatthe energies of both C3+ and Ar IO + ions are practically identical within the limit of energy resolution of the present system, though both ionshave different origins: Ar IO + ions are produced
through direct multiple ionization, whereas C3 +ions are through dissociative ionization ofmultiply-charged molecular ions. In the CH 4 targets, the potential energy due to this Coulomb
force in multiply-charged molecular ions is part-ed among the dissociating ions and most of theenergy are carried away by four light partner
ions (H+). Then, the energy obtained by carbon
ions should be relatively small. By taking into
account that carbon in CH 4 molecule stays in the
middle of the surrounding hydrogen atoms, thetotal energy of carbon ions from CH 4 molecules
should not be significantly different from theenergy obtained in the recoil process, as observed in Fig. 2.
The situation seems to be different in CzHz
molecules, where multiply-charged carbon ionsare produced through the dissociation ofmultiply-charged molecular ions having two
multiply-charged carbon ions. As discussed in theprevious paper,Z) the dissociation processes are
relatively slow, compared with the direct ionization processes resulting in the production ofmultiply-charged molecular ions. Therefore, in
CzHz molecules, the dissociation of multiplycharged molecular ions (CzH/+) plays a role in
the production of multiply-charged carbon ions.
In these dissociation processes, Cz H/+ ions first
dissociate into two ions with relatively symmetric charge, both of which obtain relatively large
kinetic energies due to Coulomb explosion proportional to p, and finally into Ci+ ions plus H+
ions. Therefore, the initial kinetic energies due tothe Coulomb explosion should be large in CzHz
molecules than in CH 4 molecules. This fact canbe seen from Fig. 2, where the peak positions ofmultiply-charged carbon ions in CzHz molecules
systematically shift toward the high energy side.
It is concluded from the present work that the
production rate of multiply-charged carbon ionsseems to be higher in CH 4 molecules than in CzHz
and the initial kinetic energies of these carbon
ions are generally higher in CzHz molecules thanin CH 4 molecules: this can be understood to be
9ue to the Coulomb explosion mechanism. Similar measurements for CO and CO z moleculartargets are under way.
References
1) H. Tawara, T. Tonuma, S. H. Be, H. Shibata, H.
Kumagai, M. Kase, T. Kambara, and I. Kohno:
RIKEN Aeee!. Progr. Rep., 18, 82 (1984).
2) H. Tawara, T. Tonuma, H. Shibata, M. Kase, T.
Kambara, S. H. Be, H. Kumagai, and I. Kohno: tobe published in Phys. Rev. A, 33, 1385 (1986).

79
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-18.

Projectile Dependence of Ar-LMM Auger Electrons Ejectedfrom A.r Target by Heavy-Ion Impact (II)H. Shibata, T. Matsuo, Y. Kanai, Y. Awaya,
T. Kambara, M. Kase, H. Kumagai, and N. Tokoro

We have measured the energy spectra of ejected electrons in heavy ion-Ar collisions in order toobtain detailed information on energy levels ofhighly ionized atoms and their production mechanism. The spectra of the L23-MM Auger electrons ejected from the Ar target by about 1
MeV / amu He, C, N, Ne, AI, and Ar ion bombardment have been measured at an ejected angle of
135 with respect to the ion-beam direction. The
projectile ions were accelerated with the RILAC.
The experimental apparatus, conditions, andsome results have been reported previously.l),2)
Examples of the ejected electron spectra
obtained are shown in Fig. 1. These spectra are

Target: Ar

0

4.31 MeV He+

80

240

Fig. 2. Ar L-shell Auger spectra produced by about
1 MeV / amu He+, C2+, N2+, Ne2+, and Ar4+ ion
impacts. The continuous background estimated by
the function Ae - BE is subtracted. The number inthe parenthesis for the L-MM notation indicatesthe number of 3p vacancy in the initial state ofAuger transition.

Fig. 1. Energy spectra of electrons ejected from target
argon at 135 from the beam direction by about 1
Me V/ amu He+, C2+, N2+, and Ar4+ ion impacts andthat by 3 ke V electron impact. The lines above spectra indicate the calculated energy values for thecorresponding transitions denoted on their right handside. The number on each line shows the number of 3p
vacancy in the initial state of Auger transition.
0

characterized by a continuous background and acomplicated Auger structure superimposed on
the continuous background resulting from thedirect ionization process. The pattern of thecontinuous background is evaluated assuming an
exponential form of Ae- BE , since this form well
reproduces the features of the lower and higher
energy wings of the measured spectra, where A
and B are fitting parameters and E the ejected
electron energy. Each spectrum was normalized
to the same target pressure and charge of the
projectile, and the continuous background was
subtracted from each ejected electron spectrum
to compare the Auger structure and the yield

80

H. Shibata, et al.

obtained with the different projectile. Such a
comparison of the Auger spectra is shown in Fig.
2 for about 1 MeV /amu He+, C2+, N2+ , Ne 2+, andAr4+ ion bombardments.
The following features are seen from Fig. 2.
1) Intensities of normal Auger lines, L 23 M 23 M23 , L23 -M 1 M23 , and L23 -M 1 M 1 , weaken as theatomic number Z of the projectile increases andbecome negligible small for Ar4+ impact.
2) The cross sections of satellite Auger lines
from the charge states of 7 +, 6+, and 5+ of Ar
enhance as the Z of projectile increases except
for Ar4+.

3) The total yield of L-shell Auger electrons
increases as the atomic number of projectile ofthe same charge state increases.
Further analysis is in progress.

References
1) T. Matsuo, H. Shibata, ]. Urakawa, A. Yagishita, Y.
Awaya, T. Kambara, M. Kase, H. Kumagai, and J.
Takahashi: RIKEN Aeeel. Progr. Rep., 17, 65 (1983).
2) H. Shibata, T. Matsuo, Y. Awaya, T . Kambara, M.
Kase, H. Kumagai, and N. Tokoro: RlKEN Aeeel.
Progr. Rep., 18, 84 (1984).

81
RUffiN Accel. Progr. Rep. 19 (1985)

111-2-19.

Projectile Dependence of Energy Distribution ofSecondary Electrons from AI
A. Koyama, O. Benka, Y. Sasa, and M. Uda

Energy distributions of secondary electrons(SEs) from Al induced by heavy ion impact were
measured with a UHV system. The apparatus
was described in a previous report.1) Ions used in
the present study were He+, He 2+, N 2+, N6+, N e 2+,
Ne8 +, Ar4+, and Ar12+ with the same velocity (1.1
MeV / amu) accelerated by the IPCR linear accelerator. The measuring conditions were almost
the same as those for previous one. 2)
Figure 1 (a) shows energy distributions of SEs
from Al induced by He 2+ and Arl2+ impact, andFig. 1 (b) shows the ratio of these two distributions, RHe,Ar(E) = Y He2+(E)/ Y Ar +(E), where Y is
the yield of SEs per projectile, and E is SE's
energy. In the energy region from 20 to 70 e V, the12ratios are nearly equal to those of the stopping
powers for these two projectiles. That is, theratios are explained in terms of the stopping
power scaling in this energy region of SEs.
However, a prominent reduction of Y A r l2+ (E) isobserved compared with Y He+(E) in the lower
energy region, as seen from the steep increase in
RHe,Ar(E) in the energy region below 20 e V. It is
well known that total yields of SEs induced bylight projectiles are propotional to the stopping
power for the projectiles. Thus the emission
yields of low energy SEs induced by projectiles
with high electric charges are considered todecrease compared with the stopping power scal2

1.3

ld

'.

(a)

(a )

He+1 He2+

llJ. , .. ...

iil.O.......

.....;.:_- . ", .:..:.::......_..

0.7" " -............ '10 .. .... _ .............

1.1.... " ...... ..... _ . ........' - •• .-.1' ..., . , .: .................... ., . - . _••• : _ ..

( b)t-r, t·r
'.

llJ

:;0.8

-'

' , '.

:.. . .: ...:... ... .. ..

,.- .....:.::.:.~:....... ........-..: .

a:

Ht'!+
0.5

-

..................., ....-..._..... ..

1.1•••• -: : •• .... . : : -. ,....: .... ....,...... -......

~.J............,~_...

llJ

-Q8
10~----~~----~------~--

50

100

ElectronW't

Energy (e V )

150

:r~

a:

(c)

N,!' N~+- :::.-:.::.•...'--..::...................:....:....-..:::':-."':'-' ".:'::'. ..'- ......

...........-.::: ....,'.

0.5

1.3 "",

( b)

?lQ.1

llJ

-

:\ ooS-~1.0•. .................""'::..-- . ...... .... .

>'

"
W

.....-........::..- ..........._.._...._.....:.,:..........-.................

~,I" Q01 0~--------L50:-----1OO-'------'150'---­
Electron

Energy (eV)Fig. 1. Energy spectra of SEs induced by the impact
of He 2+ and Ar 12 + with the same velocity (1.1 MeV /.amu): (a) yields of SEs for both projectiles, Y He +(E)and Y Ar ·(E). (b) ratio of the yields for He 2+ andAr 12+, RHe.Ar(E) = Y He .(E) / Y Ar ·(E) .
2

12

2

12

Q7 5

SO
Electron

100
150
Energy (eV )Fig. 2. Ratios of yields for projectiles with the sameatomic number, but with different electric charges:(a) for He+ and He2+, R rHE)= Y He+ (E) / Y He· (E),(b) for N2+ and N6+, R r6 (E) = YN 2+ (E) / YN .+(E) ,(c) for N e2+ and Ne8 +, R r3(E) = Y Ne2+ (E) / Y Neo+ (E) ,(d) for Ar4+ and Ar 12 +, R :;lz(E) = Y Ar4+ (E) / Y Ar12+ (E).
2

A. Koyama, et at.

82

ing.
Figure 2 shows the ratios of yields of SEs for
projectiles with the same atomic number, butwith different electric charges:(a) for He+ and He 2 +,R r!f(E) = Y He+ (E) / Y He2+ (E );(b) for N2+ and N6+,
R ~s(E) = Y N+(E) / Y N<+ (E);(c) for Ne2+ and Ne 8 +,R ~HE) = Y Ne2+ (E) / Y Ne·+ (E);(d) for ArH and Ar 12 +,R :'rz(E) = Y Ar<+ (E) / Y Ar'2+ (E).
The ratios R r!f(E) is almost constant andequal to 0.9 in the energy region below 70 eV.
Above 70 eV, it increases with E and becomeslarger than unity above 100 eV. The values larger than unity are due to backscattered losselectrons stripped from He+. Ratios between
yields for heavier projectiles also show the
shapes similar to that of the ratio for He+ andHe 2 + in the energy region above 20 eV. However
clear humps similar to that seen in Fig. 1 (b)2appear in the energy region below 20 eV. The
height and width of the humps increase from (b)to (d). The appearance of these humps is due tothe large magnitude of the reduction in the yields
for the projectiles with high electric charges
compared with that for those with low electriccharges.
From Figs. 1 and 2, it is concluded that the
reduction of the emission yield of low energy SEs
compared with the stopping power scaling
occurs very generally for the impact of fast
projectiles with high electric charges. This reduction is considered to be caused by the effect ofdense excitation of target electrons.
Refere'nces
1) A. Koyama, Y. Sasa, Y. Ishibe, A. Shiraishi, T. Shiga,
H. Omori, K. Nishi, M. Fuse, and M. Uda: RIKEN
Aeee!. Progr. R ep ., 17, 122 (1983).
2) A. Koyama, Y. Sasa, and M. Uda: RIKEN A eee!.
Progr. Rep., 18, 86 (1984).

83

RIKEN Accel. Progr. Rep. 19 (1985)

III-2-20.

Chemical Effects on LVV Auger Spectra of AI and Mg
M. Uda, A. Koyama, O. Benka, and Y. Sasa

Low energy Auger peaks are frequently superimposed on a very high background composed of
secondary and backscattered electrons. In orderto produce well-resolved and intense Auger lines,
an intense electron source is preferably used but
it often leads to the decomposition and desorption of the surface layer. 1) Accelerated ions produce much higher ionization cross sections thanthat of electrons. Measurements of Auger spectra can be performed within a short period oftime by the use of fast ions. This technique also
provides the advantage of reducing the surface
contamination during observation.
In seeking to enhance chemical-bond effects,
the low-energy Auger peaks of Al and AIF3, andMg and oxygen adsorbed or oxidized Mg were
measured, which are characterized by the transitions between valence bands and shallow innershells. Electron excited spectra were comparedwith those excited by fast ions for these chemicalcompounds.
Fast ions of He 2 + and Ar4+ with the same
velocity (v 2 /2 = 1.14 MeV / amu) were accelerated
by use of the Linac. The beam spot on the target(1 mm in diameter) was defined by a slit, which
was located 10 cm in front of the target. Theenergy analyzed electrons were detected by the
Channeltron. The output signals were amplified
and accumulated by a multichannel scaler. Eachchannel was open for the same amount of integrated beam charge on the target. 3 ke V electrons were also used for the excitation of secondary and Auger electrons whose spectra werecompared with those excited by fast ions. Time
necessary to measure each spectrum wasrestricted within 2 h to prevent surface oxidationand contamination on the target during themeasurement because under these conditions apure Al surface was covered with a monolayer ofcontaminated carbon after 25 h, corresponding to
0.1 monolayers after 2 h of the experiment.
In Fig. 1 Mg L VV Auger electron spectra areshown for a pure Mg metal and oxidized magnesium which were excited by 3 ke V electrons.
Here the targets were biased to + 4.5 V. Surface
oxidation was carried out in 1 X 10- 7 Torr O2 for
500 s (50 L, L; Langmuir) and 1 X 10- 6 Torr O2 for

200 s (200 L), respectively. Peaks 3 and 4 areascribed to normal Mg L 2 •3VV transitions and its
bulk plasmon losses, respectively,u-3) Peak 2
originated from doubly ionized Mg with two
vacancies in the Mg L 2 •3 shells, i.e., a hypersatellite. When oxidation proceeds, peaks 2 and 3
become weak but peak 4 was enhanced as can beseen in Fig. 1. Peak 4 is composed of metal
plasmon loss electrons superposed on Mg L2 •3VV
electrons of MgO,3) because the difference ofenergies for these peaks is only 1 e V. The shift of
the Mg L 2 •3VV main peak to a lower-energy sidee- ( 3KeV )-+ Mg LVV~

/ !.._---______ ._._. ___ .Mr~OOL?~
I..........--.-._._.-

t t t

4

40

3

)

Mg-O
(50L)
Mg

2

50

60

70

80

90

Kinetic Energy ( eV )Fig. 1. Mg LVV spectra induced by 3 ke V electrons
for Mg metal and Mg exposed to pure oxygen for
50 and 200 Langmuirs, respectively. For the peakassignment, see the text.

Ar4+ ( 1.14MeV / emu)~

Mg LVV

Q)

>

=+=
c
Q)

ex::

30

40

50

60

70

80

90

Kinetic Energy ( eV )Fig. 2. Ar H (1.14 MeV / amu) induced Mg LVV spec·
tra for Mg metal and Mg exposed to pure oxygenfor 50 Langmuirs.

M. Uda, et at.

84

Hez+ ( 1.14MeV/amu )e- ( 3KeV )-+ Al LVV-- Al LVV

Al

t

2

30

40

50

60

70

80

90
30

Kinetic Energy ( eV )

40

50

60

70

80

90

Kinetic Energy ( eV )Fig. 3. Al LVV spectra induced by 3 ke V electrons
for Al and AIF3 • For the peak assignment see thetext.

from that of Mg metal to its oxide is caused by
the increase in binding energy of the outermost
electrons in Mg when it is oxidized.
ArH (l.14 MeV/amu) excited Mg LVV spectra
are shown in Fig. 2. A bias potential of + 4.5 V
was applied to the targets. Peak 1 is assigned tothe transition from the initial state with three L2 ,3vacancies, i.e., a hypersatellite. Peaks 2-4 arecommon to those in Fig. l. Peak 1 is more pronounced in ArH excitation than in electron excitation. Such a tendency can be explained fromthe larger ionization cross section for the former
than that for the latter. A chemical effect canclearly be seen in the ArH excited Auger andsecondary electron emission spectra in the
kinetic energy region below 40 eV.
Electron excited Al LVV spectra are shown in
Fig. 3. A bias voltage of + 4.5 V was also applied
to the targets. Peaks 1 and 2 are assigned to Al, L2 ,3 VV and its bulk plasmon loss. Peak 3 isassumed to be Al L2 ,3 VV emitted from AIF3 , thekinetic energy of which is 2-3 eV lower than thatof peak 2. Such a peak assignment was performed by analogy with Auger peaks fromAl 2 0 3 and MgF 2 • 1) Figure 4 shows Al LVV spec-

Fig. 4. He 2 + (1.14 MeV/ amu) induced Al LVV spectra for Al and AIF3 •tra induced by He2+ (l.14 Me V / amu) ions. Low
energy electrons were returned to the targets byapplying +4.5 V. A difference in spectral shape
between Al and AIF3 was much more pronounced
in He2+ than in electron excited spectra.
The ionization cross sections produced by thefast ions used here are much higher than those
produced by electrons. Therefore, surface damage or decomposition, as can be seen in Figs. 1
and 3, during the observation of Auger spectra
can be minimized by adopting a shorter measuring time, which also serve to prevent surface
contamination. In view of decomposition ordesorption, the fast ion excitation is of great
advantage over the electron excitation in Auger
electron spectroscopy.
References
1) P. H. Citrin, ]. E. Rowe, and S. B. Christman: Phys.
Rev. B, 14, 2642 (1976).
2) M. Suleman and E. B. Pattinson: Surf Sci., 35, 75(1973).

3) A. P. Jansen, R. C. Shoonmaker, and A. Chambers:
Surf Sci., 47, 41 (1975).

85
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-21.

Emission Mossbauer Study of 151Gd Adsorbed on YIG
T. Okada, S. Ambe, F. Ambe, and H. Sekizawa

In previous papers,I).2) we showed that emission
Mossbauer measurement was useful in elucidating the magnetic properties and the chemical
states of dilute metal ions adsorbed on magnetic
metal-oxide surfaces. The present paper aims toclarify the magnetic and chemical states of dilutetrivalent europium ions arising from EC decay of
151Gd3+ hydrolytically adsorbed on the surfacesof magnetic oxides by means of the same emission Mossbauer technique as we reported. l) In theactual work, emission Mossbauer spectroscopyof 151Eu with 15 1Gd as the source nuclide has been
applied to non-carrier-added trivalent gadolinium ion hydrolytically adsorbed on the surfacesof yttrium iron garnet (YIG) (N eel temperature:
545 K). In the measurement, Mossbauer analysis
was made on the 21.5 keV y-rays emitted by
15lEu nuclei in the first excited state (151Eu*, halflife: 9.7 ns) arising from EC decay of 15 1Gd (halflife: 120 days) (Fig. 1).
The YIG (Y 3Fe5012) has the garnet type structure. Yttrium or rare earth metal ions occupy thedodecahedral sites of the garnet. The trivalent
europium ions are diamagnetic for the groundstate with J = O. In garnets, however, they aremagnetic because of the second order Zeeman
contribution of the nondiagonal elements connecting J = 0 to J = 1. The magnetization of Eu3+
in garnets is proportional to the applied magnetic field and the exchange field arising from theneighbouring magnetic ions. Therefore, thehyperfine magnetic field at Eu 3+ nuclei in europium iron garnet (Eu3Fe5012: EuIG) has a large
value of 343 kOe at 296 K. We can obtain information not only on europium ions but also on themagnetic ions around them through the hyperfine
magnetic field.
The EU2 03 powder was irradiated to about 3
mC with 16 Me V protons accelerated by thecyclotron. The irradiated EU 2 03 (151Gd) was dissolved in cone. HCl. After evaporation, theresidue was dissolved' in a small amount of distilled water. The solution was put on the top of acolumn of a cation exchanger washed with 0.4
mol dm- 3 a-hydroxyisobutylic acid (a-HIBA)
solution of pH 3.9. With the a-HIBA solution
151Gd3+ was eluted at first and collected.

The a-HIBA chelating agents in the 151Gd3+ fraction were removed by means of the cation exchanger resin. N on-carrier-added 151Gd3+ was
obtained in dilute Hel solution free from thechelating agent. The 151Gd ion was adsorbed on
YIG powder. Their emission Mossbauer spectra
were recorded at 298, 78, and 5 K with ·a conventional spectrometer in an absorber-drive mode.
lSI. Gd 120 d

Fig. 1. Decay scheme of lslEu.

100

z
o
(f)

0:

.~!:'!:t'"

78 k

'\.1
'~:jl

2::

.

(f)

Z

~
.:• •0.....O,'~ • "" , ... ". .

'f \

(f)
~

a:

4:\: . . ~~·:.;:·l::e.oI ~.,100tv;"<~~~,

95

f-

100

94

-10

0
VE LOC TTY (MM/S)

10

Fig. 2. Emission Mossbauer spectra of lSlGd(--+lSlEu) adsorbed on the surfaces of YIG at 298, 78,
and 5 K.

86

T. Okada, et ai.

The absorber of enriched lSlEu 2 03(15 mg lSlEu/
cm2 ) was used. The 21.5 keY y-rays were measured with a Si(Li) detector.
Emission Mossbauer spectra of lSlGd(~lS1Eu)
adsorbed on YIG are shown in Fig. 2. The spectra were fitted with a Lorentzian line. As can beseen from Fig. 2, the curves calculated by leastsquares fitting are in approximate agreementwith experimental points within statisticalerrors. The values of the isomer shift at 298, 78,
and 5 K are -0.51, -0.43, and - 0.46 mm/s,
respectively, relative to EU 2 03' The area ratios
normalized by the integrated area at 5 K areshown in Fig. 3. The values of the area ratio at
298, 78, and 5 K are 0.3, 0.7, and 1.0, respectively.
As seen from Fig. 3, the area ratio of "as adsorbed" specimen at 298 K is nearly the same as thevalue in europium iron garnet (EuIG). It indicatesthat the Eu ions arising from 151Gd adsorbed on
the surfaces of YIG are strongly bonded to thesurrounding anions. It is similar to the situationof Eu ions in EuIG. The width of emission
Mossbauer spectra of lslGd on YIG is independent of temperature and has a constant value of
4.0 mm/ s, which is the same as in non-magnetic
Eu 3 + ions, indicating that the Eu 3 + ions arisingfrom lS1Gd adsorbed on YIG are found to be
diamagnetic.
We can draw interesting conclusions on thebasis of the results obtained from emission
Mossbauer measurements on the Eu ions arisingfrom 151Gd hydrolytically adsorbed on the sur-

o

.....
o

c:::

....

o

(])

• lSlGd_YIG"as adsorbed "

L.

«

o

o

100

200

Tempe rat ure.300 I<

Fig. 3. Temperature dependence of the area ratio of
151Gd emission Mossbauer spectra.

faces of YIG as follows:
1) Eu ions are trivalent from the isomer shift.
2) Eu 3 + ions are bonded tightly to oxygenions as well as in the bulk specimen of EuIG.
3) Eu3+ ions are non-magnetic. It means that
the Eu 3 + ions near the surface layers do not
occupy the dodecahedral sites but the other positions such as octahedral ones.
References
1) T. Okada, S. Ambe, F. Ambe, and H. Sekizawa: ].
Phys. Chem., 86, 4726 (1982) .

2) T. Okada, F. Ambe, S, Ambe, and H. Sekizawa:
RIKEN Aeee!. Progr. R ep. , 18, 90 (1984).

87
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-22.

119Sb Emission Mossbauer Study on Quenched-in
Vacancies in Gold
I. Tanaka, S. N asu, F. E. Fujita, * F. Ambe,
S. Ambe, and T. Okada

Hyperfine interaction studies utilizing the
119Sb emission Mossbauer effect in gold havebeen performed in order to understand the natureof quenched-in vacancies and their complexes
with solute atoms. Mossbauer spectroscopy iswell recognized as a powerful technique to study
on the defects-associated states, which are usually introduced by irradiation with energetic
particles like electrons, protons, neutrons, andtheir own ions, by deformation at low temperatures, or by quenching from high temperatures.
The present investigation has been focused onunderstanding the nature of quenched-in
vacancies in gold, since only vacancies are
introduced by quenching from high temperatures. l )Takamura and his co-workers found thatvacancies in gold interact strongly with highvalent solute atoms like Ge, Sn, and Sb fromprecise investigation using electrical resistivity
and positron lifetime measurements. 2 ) The
vacancy-solute complexes are found to be formed during quenching and on subsequent isochronal annealing. These results suggested that the
119Sb emission Mossbauer study may be the best
candidate to detect the vacancy-solute associations in gold.
119Sb atoms, daughters of I19mTe, produced bya-irradiation of a ft-tin sheet, were carefullycollected by the chemical procedures reported by
Ambe. 3) The 119Sb atoms were electrolyticallydeposited on pure Au (99.999%) foil (14 ,urn inthickness). The specimen foil was wrapped intantalum foil and copper wire and then annealedin purified H2 gas at 1,123 K for 3.0 ks in order tomake a uniform solid solution and avoid theinternal oxidation of Sb atoms. 119Sb emission
Mossbauer measurements were performed withthe combination of 119Sn * source arising from
II9Sb in the specimen and a BaSn03 standard
absorber. All the spectra were taken at 77 K.
The spectrum for as-prepared specimen wasshown to be a nearly single line and suggested* Faculty of Engineering Science, Osaka University.

1. 00

.. ..
'"
."
~

~

..

0.98
0.96
0.94

As Quenched

0.92

To = 1073 K

0.90
0.88

(

0.86

a )

0.84
0.82

1.00
C'
0
(f)
(f)

'E

(f)

c
0

'~

.~

•• ., oi. ,', ~.:

0.96
0.94

303 K

0.92
0.90

Q)

0.88

0
v
n::

' •.

0.98

~
>

... .........' " " ....

0.86

1. 00
0.98
0.96
0.94
0.92
0.90
0.88
0.86
0.84
0.82

-10

-8

-6

-4

-2

Velocity/

mm· 5- 1

Fig. 1. Typical 119Sb emission Mossbauer spectra
obtained immediately after quenching from 1,073 K(a), and on the subsequent isochronal annealing (b)and (c). The solid curves are results of computer
fitting to the experimental data and the dottedcurves show the resolved partial components.

that Sb atoms were almost dissolved into gold
matrix. The specimen was annealed for 30 s at
1,073 K and quenched into brine at 253 K. The
spectrum obtained just after quenching suggested the existence of the Sb-vacancy pairs, as
shown in Fig. 1 (a). Subsequent isochronal annealing was performed; typical spectra observed
during the annealing are shown in Fig. l(b) and(c). Each spectrum shows superposition of threelines: a main line due to Sb dissolved into gold
matrix, a defect line whose isomer shift is locat-

1. Tanaka, et at.

88

To = 1073 K

1.88

0__ _

i \'~~peak186"Ii 1B4·

If

position\~~

As Quenched

182

! I~~
~ lAO

"- 130r:m;o '0'" ,,,,,,I
300

FWHM

~

400

<)-----

500

Amealing Temperature

E()()

/

ed in the larger velocity range, and an oxidized
Sb line whose isomer shift is nearly identical tothat of the SnH state. The intensity of the defectline depends on the isochronal annealing procedure.
Figure 2 shows the Mossbauer parameters
obtained from a least-sQuare-fit assuming a single Lorentz function as the absorption line.
Rather large changes in these parameters wereobserved in the temperature range between 300
and 500 K; this should relate with aggregation of
Sb-vacancy complexes and annihilation of Sbvacancy pairs.
About 90% of Sb atoms were found to beinternally oxidized in the specimen annealed in
Hz gas at 1,173 K for 3.6 ks without wrapping intantalum foil and copper wire. This suggests
anomalous strong affinity between oxygen and
Sb in gold.

K

References
Fig. 2. Dependence of the Mossbauer parameters on
the isochronal annealing after quenching from
1,073 K. Points were obtained by least-squarefitting assuming a single Lorentz function as theabsorption line.

1. Tanaka, S. Nasu, F. E. Fujita, F. Ambe, S. Ambe,and T. Okada:]. Phys. F, in press.
2) ]. Takamura: Point Defects and Defect Interactionsin Metals, (ed. by J. Takamura, M. Doyama, and M.
Kiritani), Univ. of Tokyo Press, Tokyo, p. 431 (1982).
3) S. Ambe: ]. Radioanal. Nucl. Chem., Artie., 81, 77(1984).
1)

89
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-23.

TOPAC of y-Rays Emitted from lllCd(+--lllln) In Fe3 0 4 (II)K. Asai, T. Okada, and H. Sekizawa

Since Cd ions in magnetic oxides are usually inthe form of divalent diamagnetic ions, thehyperfine magnetic fields observed at lllCd in theoxides originate from the neighboring magnetic
ions through the intervening oxygen ions, andthus, they are called the §uper!ransferred hyper!ine magnetic fields, H STHF ' The magnitude ofthese fields gives the covalency parameters of thechemical bonds between the magnetic ions andthe oxygen ions. I) These parameters are important in discussing the super exchange mechanism.
In a previous report,2) we presented some
remar ks on the detectors geometry in the!ime .Qifferential Qerturbed ~ngular forrelation(TDP AC) measurements of the hyperfine magnetic fields at the nuclei in ferro- or ferrimagnets,
and showed experimental results for ll1Cd(~
11 1In) in Fe304. In this report, we discuss theseresults. Details are given in Ref. 3.
Magnetite, Fe304, has the inverse spinel structure, in which one Fe3+ ion in a chemical formula
occupies the A (tetrahedral) site, while remaining
nominal Fe3+ and Fe2 + ions occupy the B (octahedral) sites. This material undergoes a wellknown "metal-insulator" phase transition at the
Verwey temperature, Tv (= 120 K); the conductivity is high above Tv due to the itineration of the
3d electrons of Fe ions on the B sites, whereas it

150

I

Tv

15

100

10

50

5

I

o

<l

Fig. 1. Temperature dependences of the center value Ho and the width L1 H of the distribution of
HSTHF • Symbols 0 and L:::,. denote the values obtainedby the "multiple n/4-method," and. and'" by the"multiple n/2-method."2)

is low below Tv because this itinerationceases. 4),5) It is known that the 111Cd ion arisingfrom lllIn ion occupies the A site of Fe304. 6)
Figure 1 shows the center Ho and the apparent
width L1 H of the distribution of HSTHF observed
at lllCd in Fe3 0 4 as functions of the temperature.
As can be seen, Ho and L1 H change stepwise atabout Tv. It is noted that although the center Hochanges only slightly, the width L1 H increases
appreciably on decreasing the temperature
through Tv. The determined values of Ho and
L1 H at low temperatures are + 121 kOe and 5
kOe, respectively.
In magnetic oxides with the spinel structure,
HSTHF at the nucleus on the A site originates
dominantly in the magnetic moments of thetwelve nearest neighbor ions on the B sites, andcan be regarded as the sum of the contributionsof individual B sites ions. 6) The B sites in Fe3 04
are occupied by the same numbers of the nominal
Fe2+ and the Fe3+ ions on the average. The fact,that the center Ho of HSTHF changes only slightly
on passing through Tv, means that the average ofthe contributions of one Fe3+(B) and one Fe 2+(B)to HSTHF at lIlCd 2+(A) is not much affected by theitineration of the 3d electrons on these Fe(B)ions. The value of this average is evaluated to
be + 10 kOe at low temperatures. The positive
sign means that the direction of HSTHF is parallelto that of the B site magnetization. If we assume
that the magnitude of the contribution of each B
site ion to HSTHF is proportional to the magnitudeof its magnetic moment, the proportionality constant X for lIlCd2+(A) in Fe304 amounts to +2.2
kOe/ jJ.B' Namely, the constant X represents thecontributed HSTHF at Il1Cd 2+(A) when one of thenearest neighbor B site magnetic ions has amagnetic moment of 1 jJ.B. According to a previous NMR study,6) the value of HSTHF at 115In3 + (A)in NiFe204 is + 139 kOe. The derived value of theconstant X for In3 +(A) in NiFe 204 amounts to+ 3.3 kOe / jJ.B' The constant X for Cd2+(A) in
Fe304 determined in the present study is 34%
smaller than the one for the isoelectronic In 3+(A)in NiFe204'
The predominant mechanism of HSTHF at thenuclei of the diamagnetic ions whose electronic

90

K. Asai, et al.

orbitals are filled up to (4d)I°, i.e., Cd 2+, In3+, Sn4+,and Sb 5+, is the spin transfer from 3d orbitals of
the neighboring magnetic ions to 5s orbitals of
the diamagnetic ions through the intervening
oxygen ions. 6 ),7) The smallness of X for Cd 2+(A) in
Fe304 compared with that for In 3+(A) in NiFe 204
is interpreted as due to the smaller covalence in
the Cd 2+(A)-02- bond than in the In3+(A)-02bond. In other words, the amount of the transferof oxygen valence electrons, which are partiallypolarized by the neighboring B site magnetic
ions, is smaller in the former than in the latter.
The difference in X, existing probably between
different B site magnetic ions, is ignored in our
discussion but will be necessary in a further
detailed one.
Then, we discuss the apparent distribution of
the magnitude of HSTHF at lllCd in Fe304' At
temperatures above Tv, the point symmetry of
the A site is cubic, and all the B site Fe ions areindistinguishable because of the itineration of 3delectrons among them. 4),5) This is the reason why
well-defined HSTHF is observed at lllCd on the Asite above Tv. On the other hand, at temperatures
below Tv, the crystal symmetry becomes lower,
and Fe3+ and Fe2+ ions are ionically ordered in
the B sites. 4),5) There are two possible causes
which induce the apparent distribution of HSTHF
at lllCd below Tv. They are (1) fluctuation of therelative populations of Fe3+ and Fe 2+ ions on theneighboring B sites and (2) a small amount of
EFG acting on lllCd along with H LFirst, we consider the cause (1).The differencein the contribution to HSTHF between Fe3+(B) andFe 2+(B) ions is estimated to be 2.2 kOe, if we
assume the same values of X for these ions as-described above. Therefore, HSTHF is expected tohave a distribution with a width of an order of afew kOe if the relative populations of the nearest
neighbor Fe3+(B) and Fe 2+(B) ions vary from one
A site to another. This situation can explain theobserved distribution at least qualitatively, but
further quantitative estimation is not possible,
because the controversy on the ionical order of
Fe ions in the B sites has not yet been settled.

Next, we consider the cause (2). If the magnitude of EFG is small, its effect appears in the
TDP AC spectrum as an apparent distribution of
H STHF .3) It is reported that a quadrupole splittingwith a magnitude of about 0.05 mmls is observedin the Mossbauer spectra of 57 Fe on the A site of
Fe304 below Tv.S) If the same amount of EFG
acts on lllCd, the corresponding apparent widthof HSTHF is estimated to be 1 kOe. Though thisvalue is much smaller than the observed apparent width, the EFG is a possible cause of theobserved distribution because of the following
two reasons: i) The nucleus lllCd(~lllIn) probably feels an extra EFG due to the after-effects ofthe preceding EC decay of lllIn 9 ) because theresistivity is high below Tv; ii) Even if there are
no after-effects of the EC decay, the magnitude of
the EFG felt at lllCd is, in general, different fromthat felt at 57Fe in oxides. For example, theformer is five times larger than the latter in
a-Fe203. 9 ),lO) Quantitative explanation of the observed distribution below Tv remains to be a
future problem.
References
1) N. L. Huang, R. Orbach, E. Sim~nek, ]. Owen, and
D. R. Taylor: Phys. Rev., 156, 383 (1967).
2) K. Asai, T. Okada, and H. Sekizawa: RIKEN Accel.
Progr. Rep., 18, 94 (1984).
3) K. Asai, T. Okada, and H. Sekizawa:]. Phys. Soc.
lpn., 54, 4325 (1985).
4) S. Chikazumi: AlP Can! Proc., 29, 382 (1976).
5) S. Iida, K. Mizushima, M. Mizoguchi, A. Ueki, K.
Kose, K. Kato, K. Yanai, N. Goto, and Y. Motomura: Proc. 3rd Int. Conf. Ferrites, Kyoto, 1980,
Center for Academic Publications Japan, Tokyo,
p. 87 (1981).
6) Y. Miyahara and S. !ida: ]. Phys. Soc. lPn., 37, 1248
(1974).
7) B. J. Evans and L. J. Swartzendruber: Phys. Rev. B, 6,
223 (1972).
8) R. S. Hargrove and W. Kllndig: Solid State Commun.,
8, 303 (1970).
9) K. Asai, F. Ambe, S. Ambe, and H. Sekizawa:]. Phys.
Soc. lPn., 53, 4109 (1984).
10) F. van der Woude: Phys. Status Solidi, 17, 417 (1966).

91
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-24.

Towards Macroscopic Measurement on Radioactive 6He
Diffusion in Meta Is
K. Ishida and K. N agamine

Diffusion properties of helium in metals havebeen attracting subjects, since they play important role in the first wall materials of a nuclear
fusion reactor. Also they are of fundamental
theoretical importance, since helium is the lightest element next to hydrogen and is often theobject of theoretical models.o Since the solubilityof helium is very small, the permeability measurement is not so easy that most of the experiments have been carried out by implantation. In
implantation, due to the limit in sensitivity forhelium detection, we inevitably need a large
amount of helium, which may either cause manybody correlation such as He pair- and He clusterformation, or produce a lot of defects acting as
helium trapping centers. As an alternative and amore sensitive way, we are preparing a newmeasurement using a radioactive 6He isotope.
The experiment will be conducted as described
below.
6He decays with a half-life of 0.8 s throughemitting fJ-rays (e-) having maximum energy of
3.6 MeV. The 6He beam may be available either
through nuclear reactions like proton strippingfrom 7Li or as residual fragments in heavy-ion
collisions, and is separated from the other nuclei
and transported by using well-designed microbeam optics with collimators to obtain a small
beam spot of less than 100 Jim in diameter on asample. After stopping of the pulsed beam in thesample, fJ-rays are detected by arrays of multi. wire proportional chambers (MWPC) as shownin Fig. 1; the MWPC is then used to obtain a
two-dimensional source-profile at the surface ofthe sample as a function of time after stopping of
6He. The probability that the particle is found at
r at time t starting from ro, wher.e rand ro is thetwo dimensional projection, is described by using
the diffusion constant D as

length of only around 100 Jim during its life. We,
therefore, adopted the MWPC system capable ofreading out the cathode signal.
In this MWPC system, we can determine theposition of the fJ-ray by finding the center ofmass of the pulse heights of the fired cathodesignal. For the pulse-height analysis, we use ahigh-density charge sensitive ADC system of
LeCroy Corporation. The system will be triggered with scintilation counter telescopes placed
behind the MWPC and open a time gate of ADC.

6 He beam/
MWPC

Quadrupole
magnetFig.1. Counter arrangement to be used in the experiment.

200

t = 0 sec
0=162 11m

100

E

0

:t.

0200
~

t = 1 sec
0= 188l.1m-;;; 100

c:J
0

u

0
200

t = 4 sec

100

P(r, t) = (1/471Dt) exp( - (r - ro)2 I 4Dt)

Thus, we can obtain the diffusion constant D.
Although there has been no definitive experimental value of D, theoretical estimation ofinterstitial diffusion constant gives a value ofaround 10- 4 cm 2/s,2) which gives a diffusion

Fig. 2. Simulated distribution of 6 He profile at t = 0,1, and 4 s measured by tracing back along the fJ-ray
trajectory, where (J' is the standard deviation.
Diffusion constant was taken to be 10- 4 cm2 /s. For
the beam size, range width, and multiple scattering, see text.

92

K. Ishida, et al.

The signal from each wire is amplified, delayed,and supplied to the ADC. The ADC digitizes the
charges and then transmits the digital data to thecomputer, while the time difference between the
beam and the decay is given from the TDC
reading of the trigger signal.
The position determination by the cathoderead-out has intrinsic resolution of below 100,urn. In our case, since the f3-rays suffer multiple
scatterings in the gas of MWPC, we plan to use
a low density gas, for example CH 4 and He,
without reducing the operation properties of thecounter. In Fig. 2, the simulated data of ourexperiment are shown, where we assumed thebeam spot size of 100 ,urn, the range width of 20,urn, and the counter resolution of 80 ,urn, and themultiple scatterings of 6He and f3-ray were calculated for the real geometry. The data shows alarge dependence on time as a result of He
diffusion and that our method is useful as a
powerful means of diffusion measurements.
References
1) D. J. Reed: Radiat. Eff, 31, 129 (1977).
2) B. N. Singh, T. Leffers, W. V. Green, and M.
Victoria: ]. Nucl. Mater., 125, 287 (1984).

93
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-25.

Eu-Ion Implantation in CaF2

K. Aono, M. Iwaki, and S. Namba

Calcium fluoride is a popular fluorite which
fluoresces on heating. A study is made on theluminescence during Eu+ -implantation into CaF2
and its luminescence color depending on Eu+doses. In the present work, Eu-depth profiles in
Eu+-implanted CaF 2 have been investigated bymeans of a He+ backscattering technique using
the TANDETRON.
Calcium fluoride substrates used were (111)oriented wafers, which were chemically cleaned.
The Eu+ -implantation in CaF2 was performed todoses of lOlL 10 16 Eu+ cm- 2 at 100 keVin the
random direction at 1 X 10- 6 Torr. The target
during ion implantation was held at room temperature due to the low dose rate of about 0.2 j1.A
cm- 2 • Coloring of CaF2 due to damage by 100
ke V Eu+ -ion implantation was not observed in
the visible region. The Rutherford backscattering measurement was carried out by using 1.5
MeV He+ with a fluency of 10 j1.C to estimate
compositions of surface layers of CaF 2 • Backscattered particles were detected by using a solidstate detector at a scattering angle of 15W.
The Eu-depth profiles in the random spectra of
as-implanted specimen are of a Gaussian-type asshown in Fig. 1. The depth corresponding to thepeak in the spectra is about 33.3 nm for the 10 16
cm- 2 implanted specimen, 31.2 nm for 10 15 cm- 2 ,E " surface
~

:§'

I

C
:J

cPo

o
~ 1000

!

!

(nm)

!

(a )o

°(x 1)0

a;

'>,
tl.O

° (X 4.5)

C

.;::

()

I

3 '0

"0

~ro

30.020.010.00.~. °• (b ) \

500

° •

VI

~

()

ro
CD

0 .

0'

( x 8) •

o~~
I
(C),
?i~.<>-

1.2

1.3
Energy (MeV )1.4

Fig. 1. Random spectra for Eu implanted in CaF2 •(a) the 10 16 cm- 2 Eu-implanted specimen.
(b) the 10 15 cm- 2 Eu-implanted specimen.
(c) the 10 14 cm- 2 Eu-implanted specimen.

and 27.1 nm for 10 14 cm- 2 , which are in good
agreement with the predicted range of 33 nm
calculated by the LSS theory. The standard
deviation calculated from the FWHM of thespectra is about 11.5 nm, which is a little larger
than the predicted value of 9 nm.
It is concluded that the average predicted
range of Eu implanted in CaF 2 is in fairly good
agreement with that predicted by the LSS range
theory.

94
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-26.

Thermal Extraction of Krypton in Aluminum Using Mass
Spectrometer
K. Takaishi, * T. Kikuchi, * K. Furuya, * 1. Hashimoto, *H. Yamaguchi,* E. Vagi, and M. Iwaki

Inert gases injected into metals by ion implantation tend to form bubbles. For Kr implantation, Evans and Mazey have examined thestructure of Kr bubbles in Cu, Ni, and Au 1) andobserved Kr bubbles formed in a solid phase. The
existence of bubbles in the solid phase indicatesthat the high pressure is involved in bubbles. On
the diffusion of Kr Gurevich et al. 2 ) have measured the diffusion coefficients of Kr in Al foils
by using 85Kr as a tracer and estimated them tobe an order of 10- 8 to 10- 7 cm 2 Is in a temperature
range of 700-800 K. The theoretical investigationon the bubble diffusion of inert gas in solids
suggests that the diffusion coefficient depends on
the bubble radius. 3 ) However, the behavior of Kr
bubbles in Al has not been clarified. Therefore, inthe present study we examine the behavior of Kr
bubbles in Al using a thermal extraction-mass
spectrometer and an electron microscope
equipped with an energy-dispersion X-ray
spectrometer.
The specimens were single-crystal Al foils of
99.99% in purity grown by a strain annealing
method. The Kr implantation was carried out at
an energy of 50 ke V and at room temperature~ith a current density of 0.5 J1.A/cm 2 up to a doseof 10 16 Kr I cm 2 • In order to avoid the implantation
under the channeling conditions the direction of
implantation was 8° off the normal to the specimen surface.
The thermal extraction of implanted Kr was
performed by heating at a constant rate or byisothermal annealing. The extraction by heating
at a constant rate was ~.rried out in the range of
289-1,170 K with a rate of 20 K/min. The isothermal annealing was carried out in the temperature range of 700-900 K for 25 min from 5 minafter the furnace temperature was stabilized.
The amount of extracted Kr during these heat
treatment was determined by a calibration curve
obtained by using a small amount of Kr gas of
99.99% in purity.
For the electron microscopic observation, thin
* Faculty of Science, Science University of Tokyo.

films suitable for electron microscopy preparedby conventional electropolishing were implantedby the same method as described above. The
implanted thin films were examined by an H -800
electron microscope equipped with an energydispersion X-ray spectrometer operated at 100
kV.
It was recognized that Kr in Al foils can beextracted during heating at a constant rate in therange from about 540 to 1,100 K. In order toobtain detailed information, isothermal annealing was carried out at temperature of 713, 748,
772, 781, 793, and 813 K. The typical result at an

I

10

,..

0

~
B

8

:E
......

6
~
i:: 4
0
;

(,)

~

LL.

2

a

a 20 40 60 80 100
Annealing time (5)Fig. l. Early stage of extraction of Kr at various
temperatures between 713 and 813 K.

-

- 7

-

-

-

Gu-evi<:t1etal .

- - Pre;ert wor1<

1.2 ev -

_

- 8

c

- 9

C)

..!2 -12
-13
-14

1.2

1.3

1.4

1000/T (K-')

Fig. 2.

Plot of logD VS. 1/ T.

K. Takaishi, et al.

Fig. 3. Kr bubbles in Al implanted to a dose of 10 16
Kr/ cm 2 at an energy of 50 keY. As implanted
specimen.

250
200

...

~ 150
E
:J
c: 100

AI

1:
:J

8 50

Kr

o tJ ~Ift,NJ.o'" "J.
o
5
i

~
10
15
Energy (KeV)

20

Fig. 4. Energy-dispersion X-ray spectrum in an implanted specimen, where the first and the second
peaks are ascribed to Al and Kr, respectively.

early stage of extraction is shown in Fig. 1,
where Mt and M<x> represent the amount of
extracted Kr for t sand t=oo, respectively. In
this stage the fraction can be expressed by95

where D is the diffusion coefficient and L is thedepth of implantation. From Eqn. (1), thediffusion coefficient of Kr in Al was estimated tobe 10- 15 to 10- 14 cm2 /s in the temperature range
from 713 to 813 K (Fig. 1). The activation energy
for diffusion of Kr was determined and found to
be about 1.4 eV as shown in Fig. 2. The diffusion
coefficient obtained by the present work is smaller by seven orders of magnitude than thatobtained by Gurevich et al. 2 ) using 85Kr as a
tracer (Fig. 2). We consider that the difference inthe diffusion coefficient is ascribed to thedifference in the existing state of Kr in AI: In theexperiment of Gurevich et al. Kr existed as isolated atoms, while in our specimens Kr existed inbubbles with an average diameter of about 8 nm
as shown in Fig. 3. An energy-dispersion X-ray
spectrum taken in the selected area containing
bubbles is shown in Fig. 4, where the first and thesecond peaks are ascribed to Al and Kr (around12.59 keY), respectively. According to a bubble
diffusion theory by Kelly,3) the movement of abubble can be described as vacancy motion fromone position on the bubble surface to anotherposition by diffusion in the surrounding matrix.
From this viewpoint, the difference in the
diffusion coefficient between Gurevich et al. 2) andthe present study may be explained in terms of
bubble diffusion.
References
1) ]. H. Evans and D. ]. Mazey:]. Phys. F, 15, L1 (1985).
2) M. E. Gurevich, L. N. Larikov, V. M. Tyshkevich, andV. M. Falchenko: Ukr. Fiz. Zh., T24, 658 (1979).
3) R. Kelly: Phys. Status Solidi , 21, 451 (1967).

96
RIKEN Accel. Progr. Rep. 19 (1985)

III -2-27.

Effect of Small Amount of He on Ductility of Various
Metals and Alloys
Y. Higashiguchi,* E. Yagi, Y. Suzuki,* and H. Kayano*

The helium embrittlement was investigated on
various materials; Nb, Nb-40V, V, V-20Ti, Ti-6.5
AI, and cold worked 316 stainless steel. Amongthem Nb-40V, V-20Ti, and Ti-6.5AI alloys wereprepared by arc-melting and cold-rolled to sheetsof 0.3- 0.2 mm in thickness, then annealed at 1,473
K, 1,273 K, and 1,123 K for 3 h, respectively, in a
vacuum of l.3 x 10- 3 Pa. a-Particles of 36 MeV
were injected into the specimens at room temperature by using the cyclotron. An edge-shaped
graphite degrader was set in front of the specimens to achieve uniform depth distribution of
injected helium. Total helium doses were 7.1 x
10 15 and 2.2 x 10 16 He/ cm2 , which corresponded to
the He concentrations of 5- 6 appm and 10-20
appm, respectively. The concentrations are listed
in Table l.
Tensile test was carried out for all specimens
at 973 K in a vacuum at a strain rate of 8.3 x 10- 5
S-I. The stress-strain curves are shown in Fig. l.
Numbering of -1, -2, and -3 in Fig. 1 represents the controlled specimens (uninjected specimen), the specimens injected with low He dose
and the specimens injected with high dose, .
respectively. The He injection increases the yieldstress in pure Nb and pure V, but not in Nb andV alloys. In all specimens the ductility decreases
with increasing concentration of injected He.
The mechanism of He embrittlement has been
considered as follows. He atoms or their small
bubbles gathering at grain boundaries duringhigh temperature deformation grow to large
bubbles, which lowers the grain boundary
energy. Therefore, the fractured surface was 'observed by a scanning electron microscope(SEM). The results are shown in Fig. 2 for Nb
and its alloys as an example. The intergranularfracture pattern was observed in the He-injected
Nb-40V but not in the He-injected Nb. A similar
result was observed in V-20Ti ·and V. Microstructures around the fractured area were observed in all specimens by a transmission electron microscope (TEM). No bubbles were visible* The Oarai Branch, The Research Institute for Iron,
Steel and Other Metals, Tohoku University.

both in matrix and in grain boundaries in all
specimens. Hence the effect of a small amount ofHe should be considered. The elongations of thecontrolled specimens (Eo) and the 2.2 x 10 16 Hel
cm2 injected specimens (EH) were listed in Table
2. The ratio CHI Eo and the magnitude of reductionin the elongation per unit He concentration (1EHI Eo)1 CH (CH : He concentration) were obtained
and listed in Table 2. The latter fraction wasplotted as a function of the He concentration in
Fig. 3. Approximately all points fall on a straightline in the He concentration range covered in thepresent experiment. In order to obtain a more
precise relation it is necessary to investigate thedependence of the fraction in question on the
microstructures such as a grain size, a dislocaTable 1. Concentration of injected helium in each specimen for 7.1 X 10 15 and 2.2 x 10 16 He/ cm2 •He concentration (appm)
7.1 X1015 He/ cm2 2.2 X10 16 He/ cm2
6.4
21
Nb
5.0
16
V
19
Nb-40V
V-20Ti
16
6.4
13
Ti-6.5AI
SUS316 (20% cw)
5.8
12Specimens

800
Controlled

600

'0
III
III

t
tn

N-1
Y-1
NY-1
YT-1
5-1

Ti - 6.5AI

T-1(20'/.CW)

d

0-

~

Nb
Y
Nb-40YY- 20Ti
SUS 316400----=--

He appm
5- 6 10-20
N-2
N-3
Y-2
Y-3
NY-3
YT-3

5-2

T- 3

5-3

T-l

Strain E I 0J0

5- 3

-57.1

2 0'0

Fig. 1. Stress-strain curves obtained from tensile
test at 973 K at a strain rate of 8.3 x 10- 5 S- I .

Y. Higashiguchi, et at.

97

Fig. 2. Scanning electron micrographs of fractured surface of Nb and Nb-40V alloy. (a) Controlled (He-uninjected)
Nb, (b) He-injected Nb (21 appm He), (c) Controlled Nb-40V, and (d) He-injected Nb-40V (19 appm He).
Table 2.

Reduction of elongation by helium injection.

Specimens
Nb
Nb-40VV
V-20Ti
SUS316Ti-6.5Al

Controlled
eo~

22.5
14.2
30.0
7.1
13.5
57.1

2.2 X 10 163
He/ cm

I

eH~

6.5
3.0
9.5
2.9
5.8
13.0

0.10>-

0.29
0.21
0.31
0.41
0.43
0.28

0.03380.04930.04310.03680.04750.0553Tensile tested at 973 K, E = 8.3 X 10- 5 S - 1

E
a.
a.

~

I

~~

Nb l

6

V

0

"'

Nb-40V.V-20Ti.
SU5316 t:.

"
""

-

" TT~~5~~ &"::: 0.051-

t:.

o
~

",

."
f-

I

I

-

0" •

:I:

~

-

~

c3

I

10

0

"" I

20

He Concentration CH lappmtion density, and precipitates present before He
injection. However, it can be said that a smaller
He concentration has a larger effect in reducing
the ductility and the magnitude of reduction in
the elongation per unit He concentration is near-Fig. 3. Magnitude of reduction in elongation perunit He concentration as a function of He concentration.

ly the same for all specimens.

98

RIKEN Accel. Progr. Rep. 19 (1985)

1II-2-28.

Plasma Surface Interaction-ERD Measurement of Deuterium
Retention near Surface of TiC and Graphite
Irradiated with Dissociated D Atoms
Y. Sakamoto, Y. Ishibe, K. Okazaki, H. Oyama,
K. Yano, M. Yanokura, and I. Kohno

Titanium carbide and graphite are promisingmaterials for vacuum wall surfaces in contact
with plasma because of their heat-resisting properties and relatively low atomic numbers. For
example in tokamak devices, they are candidates
for limiters and first walls of thermonuclear
fusion devices by reason in particular that 'they
are low-atomic number materials. In our previous studies,1) we have successfully carried out
wall conditioning using ECR (Electron Cyclotron
Resonance) hydrogen plasma on the basis ofchemical sputtering. In this case, neutral hydrogen atoms play an important role because of
their chemical activity. The purpose of this study
is to investigate the plasma surface interaction
between the surfaces of TiC and graphite anddeuterium atoms produced in the ECR deuterium
plasma in order to clarify the behavior of deuterium atoms in near the surface taking part in thechemical sputtering.
Figure 1 shows a schematic drawing of the
ECR deuterium plasma irradiation apparatus. A
microwave (2.45 GHz) power of 200 W is launched through a helical antenna with resonancemagnetic field of 0.0875 T for production ofplasmas. The electron density and electron temperature of a typical plasma were 9.6 X 109 cm- 3
2.45GHz MI CROWAVELAUNCHERI

and 4.7 eV, respectively, for the gas pressure of
2 X 10- 2 Pa. Samples were set 200 mm apart fromthe center of the plasma column in parallel withthe resonance magnetic field so that they could be
irradiated with only neutral atom fluxes which
are estimated to be about 10 15 atoms cm- 2 s- 1 •TiC samples were prepared by means of CVD(Chemical Vapor Deposition) coating with film
thickness of 20 )lm on poco graphites, whichwere also used as graphite samples. These samples contain inevitably many hydrogen atoms asshown in Fig. 3 because they were prepared by
the CVD method.
The ERD (Elastic Recoil Detection) by using
an Ar4+ beam of about 50 Me V was applied to themeasurement of the near-surface concentrationof deuterium atoms. 2 ) The arrangement is shownin Fig. 2. An aluminum foil of 20 .um in thickness
was inserted just before the detector (SSD 1) inorder to eliminate the components like Ar, Ti,
and C from recoiled beams.
Figure 3 shows the depth profiles of Hand D in
the near surfaces of TiC and graphite after 1 h
irradiation with dissociated deuterium atoms
during rise in the sample temperature. In thiscase, the deuterium atom fluence is estimated to
be about 2 X 10 19 atoms cm- 2 • Incident deuterium
MOVABLEDOUBLE PROBEI

CERAMIC SEAL -Fig. 1. Schematic arrangement of ECR plasma irradiation apparatus.

99

Y. Sakamoto, et al.

atoms with energy of about 5 eV are mainly
produced by the dissociative excitation process. 3 )As seen in Fig. 3, deuterium atoms diffuse from,the surface to inside, ranging over several hundreds of nanometers in TiC as the sample temperature is increased. Deuterium atoms in thegraphites are localized at the near surface.

Ar+ 4
50 Mev,

30°'..-'\

References
Al foil-

20 IJm1) S. Ishii, K. Okazaki, Y. Sakamoto, and K. Yano: Jpn.
]. Appl. Phys., 22, L403 (1983) .
2) K. Yano, Y. Ishibe, H. Oyama,Y. Sakamoto, M.

. /~
V

,

"0

Yanokura, and 1. Kohno: Proc. 7th International
Symposium on Plasma Chemistry, Vol. 2, p.518 (1985).
3) B. L. Carnahan and E. C. Zipf: Phys. Rev., 16, 991

SSD 2

SSD 1
SSD 1

H,D

SSD 2

H,D,Other elements(1977).

Fig. 2. Diagram of experimental apparatus for profiling
Hand D.
TIC

10 'GRAPHITE

T = 100 °C

H

10'

o

10 '

10'

10°
:) 0
10'

..J

W

10
0 0

I

".1

10'

Z
Z

-J
W

I

~

<!
:I:
U

10°

o0

;nI-

t-

Z

:::l

~

H
T - 200·'

o

10'

Z
Z

<{

Cf)

1

10

2

0

U
10'

4

H

:l

0

U

D

~~~M j
H

~:l J

o~

Z

T = 300°C

10'

10 '

10'
0

128
1 0'

j

0

T .. 400 ·C
10 '

10'
10'

10

0~0L---~------~----~--1--~~~~

O.511mCHANN EL NUMBER

o

10
0

0

l\.lm

O.5\.lm

0

CHANNEL NUMBER

Fig. 3. Depth profiles of Hand D in the near surfaces of TiC and graphite irradiated with deuterium atoms duringrise in the sample temperature.

100
RIKEN Accel. Progr. Rep. 19 (1985)

111·2·29.

Quantitative Analysis of Hydrogen in Titanium Carbide by ERD
T. Kobayashi, H. Sakairi, M. Yanokura, S. Hayashi,
M. Aratani, M. Iwaki, and S. Oohira

Application of the Elastic Recoil Detection
analysis (ERD) to quantitative analysis of hydrogen in solids is in progress. Preliminary results
have been reported in the last volume,l) in whicha 2 ,urn-thick, TiC film plated on an Al substrate
was implanted with deuterium with a fluence of
5 x 10 16 D/cm 2 • The implantation was expected to
be a concentration standard for hydrogen analysis. Ar ions of 50.5 MeV were used for ERD to
obtain depth profiles of Hand D concentrations.
This year studies were performed on(1) Determination of the TiC film composition(necessary for precise quantitative analysis of H
and D) by Rutherford Backscattering Spectrometry (RBS);(2) Aging effects on Hand D concentrations
and their profiles; and(3) Determination of the TiC composition by
ERD.

ENERGYCMEV)
0.14

0.40

0.66

SURFACE (C)

1. 46

1. 19

0.93

SURFACE (T I )

o
o

~

'"

0

g
0

.+----=~-----~--t

o
o
o

N

o
o+--,
___,-__,--,__.--,__
050 . 00

150.00250.00350.00.. ..

,-~450.00~550.00CHANNEL NUMBER
Fig. 1. Lower: RBS spectrum of He ions scatteredby a TiC film; a solid line represents a theoretical
spectrum for Ti atoms. Upper: a spectrum obtainedby subtracting the solid line component from theexperimental spectrum, which gives the C contribution.

(1) TiC film used in the ERD study was also
analyzed by RBS with 1.5 MeV He4+ ions fromthe RIKEN tandetron. An energy spectrum of He
ions backscattered at an angle of 125 was shownby open circles in Fig. 1. The low energy spectrum was divided to two components formed byTi and C by extrapolating the high energy spectrum (contributed from Ti only) to the low
energy region with an approximate expression
for energy dependence of backscattering yield
0

Y(El),2)

Y (E)""-' const.
1(Eo + El)2

where Eo and El are energies of incident ions andout-going ions, respectively, and energy struggling of ions and a finite energy resolution in themeasurement system are neglected.
From an "assumed" concentration ratio of Ti
to C, the stopping power of the TiC sample for
4He ions was calculated, the result of whichallowed the RBS spectrum to be analyzed andprovided a "calculated" concentration ratio of Ti
and C. Repeating the above procedure led to aself-consistently determined ratio, TilC = 1/3.74.
With this ratio, analysis of ERD spectrum
obtained on the deuterium-implanted TiC gave adeuterium content of 4.88 x 10 16 D/ cm 2 whichshows a good agreement with the implantationdose, 5 x 10 16 D/cm 2 • It is also deduced that thecontent of hydrogen distributed uniformly, which
was introduced during the specimen preparationof TiC, is about 4 at.%.
(2) In the ERD study carried out last year,
successive experiments provided similar spectrain shape and size, which suggested that the ion
irradiation during ERD experiments has noeffect of changing, the distribution of hydrogenand deuterium. The sample used last year wasagain analyzed by ERD this year, about 5 months
after the previous ones. Resulting spectrum wasshown in Fig. 2 together with the previously
obtained spectra: spectrum (a) is the first result
obtained 2 weeks after the film preparation; (b),the second one obtained 2 h after the first experiment; and (c), the present one. No changes areobserved among the spectra, leading to the con-

101

T. Kobayashi, et ai.

01 . 14Il'I

ENERGY( MEV)
2.21

3.26

4.36

5.43

6.50

H

I D

I

Ti

channel number

70.00

130.00190.00250.00310.00370.00CHANNEL NUMBER
Fig. 2. ERD spectra of Hand D recoiled by Ar ionsfrom the TiC film, obtained (a) 2 weeks after thefilm preparation, (b) 2 h after the first experiment,and (c) in the latest experiments 5 months after theprevious one.

elusion that hydrogen and deuterium in titanium
carbide are stabilized at room temperature.
(3) The composition of TiC films is expected
to be estimated from ERD spectra of recoiled Ti
and C ions as from RBS spectra. The use ofincident ions lighter than Ti such as Ar, however,makes the spectra for Ti and incident ions overlap and reduces accuracy of the analysis. Suchoverlap, however, can be removed by employing
incident ions heavier than Ti. Thus the ERD wastested with 95.9 Me V Kr ions under almost thesame experimental arrangement as in the Ar
ERD. Recoiled H, D, C, and Ti ions were detected
at an angle of 4T. By another detector only
recoiled Hand D ions were detected at an angleof 3T, with a 26 .urn-thick Al foil absorber infront of the detector.
In Fig. 3, the upper spectrum consists of whole
spectra for recoiled Ti, C, D, and H, and thelower spectrum is for D and H. In preliminary

Fig. 3. ERD spectra of a TiC film obtained with Kr
ions. Surface positions in the spectra corresponding
to each elements are indicated. Upper: detected at
an angle of 4T; Lower: detected at an angle of 3T,
through an absorber for C and Ti ions. (Two spectra differ in units of the abscissa.)

analysis agreement on the composition of thefilm seems well between ERD and RBS, andtherefore it is expected that ERD is a sufficient
tool to determine both the material composition
and the hydrogen content.
With heavy ions such as Kr, however, theeffect of irradiation on samples must be analyzed
in the further study. A particularly interesting
problem in future is a relation between hydrogencontents and preparation conditions of TiC films,
which can present explanations for the mechanisms of TiC film formation by reactive ion
plating.
References
1) T. Kobayashi, S. Hayashi, H. Sakairi, M. Iwaki, M.
Aratani, M. Yanokura, and S. Oohira: RIKEN Aeee!.
Progr. Rep., 17, 103 (1984).
2) L. C. Feldman, J. W. Mayer, and S. T. Picraux:"Materials Analysis by Iron Channeling," Academic
Press, New York, p. 220 (1982).

102
RIKEN Accel. Progr. Rep. 19 (1985)

111-2-30.

Lattice Location of H In Ta as Observed by a Channeling Method
E. Yagi, S. Nakamura, T. Kobayashi, F. Kano,
K. Watanabe,* and Y. Fukai*

In previous studies we have determined lattice
locations of H in V,i) Nb,Z) and Ta 3) by the channeling method using a nuclear reaction 1 H(l1 B,
a )aa, and studied the effect of internal strain,
which was introduced by precipitation and redissolution of ,8-phase, on the lattice location of H
in Vl) and Nb. Z) It was observed that the hydrogen location in V is more sensitive to the strain
than in Nb. The previous experiments on Ta,3)
which was the first experiment for the determination of hydrogen location, was carried out with a
11 B beam collimated to have divergence of lessthan 0.11°. This collimation was worse than thatin the experiments on VI) and Nb. Z) Therefore,such fine structures in the channeling angularprofiles as observed for V and Nb were notobserved. In the present study, the channelingexperiments on H in Ta were repeated with abetter collimated beam with divergence less than
0.076° arid better statistics than in the previous
experiment, and the effect of the internal strain
on the location of H was investigated.
The specimen was a single crystal TaH o.o7
(a-phase). Hydrogen was introduced from gas
phase. The channeling angular scan was madeJor < 1 0 0>, < 1 1 0>, and {I 0 O} channels atroom temperature with 2.08 MeV llBz+ beam.
The each data point was obtained by accumulating the yield up to the dose of more than 2.7 J1. C(1. 2 llC in the previous experiment). The moredetailed description on the experiment was givenin the previous papers. 1 )-3)
The fine structures in the profiles of a-particle
yields were observed as for V and Nb; a single
central peak in the < 1 00> channel, a central
peak superposed with su13sidiary peaks locatedat about ± 0.04° in the < 110> channel, and a
dip superposed with a small central peak in the{I 0 O} channel. These profiles unumbiguously
indicate that most of H atoms are located at T
(tetrahedral) sites. After this experiment the
specimen was cooled to 200 K and kept there for
24 h. Then it was heated to 373 K and kept therefor 6.5 h. After furnace-cooling to room tempera* Faculty of Science and Engineering, Chuo University.

• H

[lOa}
(a )

( b)

° Ta

O ~--~--~I~--~--~-r~--~I--~--~

-1

o

-1
ANGLE

0

(deg.)

Fig. 1. A change of {I OO } angular profiles of aparticle yield (e) and backscattered II B yield (0 ) in(a) the virgin a-state and (b) ,a-redissolved a-state.
Full and dashed curves are drawn to guide the eye.

ture, the channeling angular scan was madeagain for {I 0 O} channel. The result is shown in
Fig. l. Although this heat treatment made the dipof backscattered 11 B-yield shallower, the angularprofile of a-yield still exhibits a feature characteristic of T -site occupancy. This result leads tothe conclusion that the hydrogen location in thea-phase of Ta-H system was not changed by thisheat treatment. This result is essentiallydifferent from that on H in V; the {I OO} aangular profile was changed markedly by thesimilar heat treatment.
As described in the case of V, 1) most of hydrogen atoms precipitate into the ,8-phase on coolingand the precipitates are redissolved on reheating,but this process introduces an appreciably large
strain into the ,8-redissolved a-phase. Comparison of the present result with that on H in V
indicates that hydrogen location in V was changed even when the {I 0 O} llB-dip recovered to 75%
of its original value by redissolution of the ,8phase, while in Ta the hydrogen location was notchanged despite much smaller recovery of the{I OO} 11 B-dip, i.e., only 55%. The observed frac-

E. Yagi, et al.

tion of such recovery suggests that the heat
treatment introduced much larger internal strainin Ta than in V. Therefore the present result
indicates that the lattice location of hydrogen isless sensitive to the strain in Ta than in V.

103

References
1) E. Yagi, T . Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe: Phys. Rev. B, 31, 1640 (1985).
2) E. Yagi, S. Nakamura, T. Kobayashi, K. Watanabe,
and Y. Fukai:]. Phys. Soc. lpn., 54, 1855 (1985).
3) E. Yagi, T. Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe:]. Phys. Soc. lpn., 52, 3441 (1983).

104

RIKEN Accel. Progr. Rep. 19 (1985)

III-2-31.

Direct Evidence of Stress-Induced Site Change of H In V
Observed by a Channeling Method
E. Yagi, T. Kobayashi, S. Nakamura, F. Kano,
K. Watanabe,* Y. Fukai,* and S. Koike**

Recently, Suzuki et at.Il , reported that the
diffusivity of H in V is enhanced enormously byapplying tensile stress lower than the elastic
limit along the < III > direction, and concluded
with the help of their Huang scattering experiments that it is a consequence of stress-inducedsite change T (tetrahedral site)~ 4T (a groupof four T sites). However, their observation of"superdiffusion of 4T hydrogen" has since beenquestioned by Metzger 2) and Schober and
Golczewski,3) and still remains in dispute. Morerecently, we have observed that the site of H in V
was changed by thermal cycling. 4 ) In that study,
the lattice location of H was determined by thechanneling method using a nuclear reaction
IHC1B,a)aa. In an original specimen of aVHO,l prepared and measured at 150°C, the lattice location was found to be a T-site. Whenthe specimen was cooled to room temperature ·and reheated to 150°C, however, a drasticchange in a {I 0 O} channeling angular profile for
H was observed; this indicated the site change
from T-sites to displaced-T or 4T configuration.
The measurement of the broadening of X-ray(2 0 0) diffraction line showed that the internal
stress was introduced by this thermal cycling,
apparently because of precipitation and redissolution of the p-phase. Thus we concluded thatthe observed site change was induced by theinternal stress and the observation should beconnected to the occurrence of the superdiffusionof H in V. In the present paper we report direct
evidence for the stress-induced site change of H
in V obtained by performing channeling experiments under well-controlled external stress.
Specimens were cut from a single crystal(99.95% pure vanadium supplied by Aremco
Corporation) into a parallelepiped of 2 mm thick,
4 mm wide, and 6 mm long with a wire saw andelectro-polished. The largest face was a {II O}
plane and the longest edge was parallel to the< 1 0 0> direction. The specimen was annealed* Faculty of Science and Engineering, Chuo University.
* * Faculty of Science, Science University of Tokyo.

at about, 1,500°C for 75 h at 10- 10 Torr, andsubsequently doped with hydrogen from gas
phase up to a concentration of VHO.OIO-O.015' The
channeling experiments were carried out by
using a 2.02 Me V 11 B2+ beam in the similar way
to that in the previous experiments. 4 )-6) In thepresent experiment, for the {I 0 O} planar channel
configuration, both backscattered 11 B and emitted a-particle yields were measured as a functionof angle between the incident beam direction and(a)VH 0010(b)VH 0010

(001)
j

(c)VHO.OlO(010) 0I~l.°Vji' v~'!

0.9

• H

(010)

v

.,

o

~Q8

>-

(d)VH 0014

o

W

N

~1.0

2:

a:

~o.9

0.8

(t) VH Ol(e)VH0015

\!Iv
j

j

i'~ ' T-----rn--~<~"F. .

11(001)

d-T or 4 T

-1

0

-1

0

1

-1

0

ANGLE(deg)Fig. L (0 0 1) and (0 1 0) channeling angular profilesof backscattered 11 B and a-particle yields underthe [001] compressive stress 0"=7kg/ mm2 (a),(b), (d), and (e» or after releasing the stress (c) in
VH O. 010 , VH O. OI4 , and VH O. OI5 (room temperature).
(010) angular profiles in VH O. 1 at 150°C under 0"=
o is shown in (t). The full curves and the dashedcurves are drawn to guide the eye. The insets
indicate the projections of T-sites and displaced-T
or 4T configuration onto the plane perpendicular tothe (0 0 1) or (0 1 0) planar channel. The lines represent the projections of atomic planes, and thesquares the projected positions of interstitial sites
with their relative weights indicated by numbers insquares.

E. Yagi, et at.

a {I 0 O} planar channel.
Under the compressive stress «(5' = 7 kg/ mm 2)
applied in the [00 1J direction, angular scan wasmade for a (00 1) planar channel (perpendicular
to the direction of the applied stress) and a (0 1 0)
planar channel (parallel to the direction of theapplied stress). Angular profiles thus obtained on
the specimen of VH O.010 are shown in Fig. 1 (a)and (b), and the result obtained after releasing
the stress in Fig. 1 (c). Results of additional
measurements on other specimens under theconditions corresponding to Fig. 1 (a), (b), and (c)are shown in Fig. 1 (d) for VH o.o14 , 1 (e) for
VH O.oI5, and . 1 (f) for VH O. 1 , respectively. The
angular profile in Fig. 1 (f) is the one obtained on
a- VH O. 1 prepared at 150°C as described in aprevious report. 4 )The results shown in Fig. 1 clearly indicatethat hydrogen location under the uniaxial compressive stress of 7 kg/mm 2 is distinctly different
from that in the stress-free state. The angularprofile shown in Fig. 1 (c), which coincides withthat in Fig. 1 (f), indicates that hydrogen location
recovers to T -sites after releasing the stress.
Under (5'=7 kg/mm2, the (001) and (010) aangular scans give similar profiles consisting of awide dip with approximately the same width asthat of the 11 B-dip and a subsidiary peak locatedat about 0.25°, the (00 1) dip being shallower thanthe (0 1 0) dip. They are very similar to thea-angular profile obtained after thermal cycling
in our previous experiment on H in VH O. 1 .4) The
present result indicates that, under the external

105

stress, a major proportion of H atoms occupies
interstitial sites displaced from the normal position of T -sites.
From the consideration on the angular profiles,
the only explanation for the H configuration ismade in terms of displaced-Tor 4T configuration, in which the position of maximum densityof H is displaced towards the O-sites (octahedral sites) by 0.44 A.
Summarizing, we can definitely conclude thatthe configuration of H in V is extremely sensitive
to the presence of stress; the transition T ~displaced-T or 4T can be induced by applying thecompressive stress lower than the elastic limit,
and the transition can be reversed by releasing
the stress. More detailed results are described inRef. 7.
References
1) T. Suzuki, H. Namazue, S. Koike, and H. Hayakawa: Phys. Rev. Lett., 51, 798 (1983).
2) T. H. Metzger: Phys. Rev. Lett., 52, 476 (1984).
3) T. Schober and J. Golczewski: Phys. Rev. Lett., 52, 478(1984).
4) E. Yagi, T. Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe: Phys. Rev. B, 31, 1640 (1985).
5) E. Yagi, T . Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe: l. Phys. Soc. lPn., 52, 3441 (1983).
6) E. Yagi, S. Nakamura, T. Kobayashi, K. Watanabe,
and Y. Fukai:]. Phys. Soc. lpn., 54, 1855 (1985).
7) E. Yagi, T. Kobayashi, S. Nakamura, F. Kano, K.
Watanabe, Y. Fukai, and S. Koike: Phys. Rev. B, 33,
5121 (1986).

106
RUffiN Accel. Progr. Rep. 19 (1985)

111-3.

Radiochemistry and Nuclear Chemistry1.

Production of Radioisotopes and Preparation of Labelled
Compounds

T. Nozaki, S. Ambe, M. Iwamoto, E. Gotoh, T. Kitsunai, H. Nakatani,Z. Huang, Y. Minai, 1. Arai, M. K. Kubo, M. Suehiro, and F. Yokoi

The following studies were undertaken in thisperiod: (1) synthesis of 77Br-Iabelled bromoperidol and bromospiperone (Fig. 1) for the study of
dopamine receptors in the brain; (2) fabricationof automatic synthesizer for llC-labelled compounds and their use; (3) production of 45Ti, 69Ge,
and 48V and measurement of their uptake byplants, and (4) measurement of the adsorption of
Z9 Al and some other radionuclides by soils.
Details of studies (3) and (4) are given separately
in this volume.
For comparative study of dopamine-receptor
visualizing agents, 77Br-labelled bromoperidol(A) and bromospiperone (B) were synthesized
and their behavior in rats and mice was studied.
Bromine-77 was produced by the 75 As(a, 2n)17Br
reaction on a GaAs target, separated as sublimate by RF fusion of the target with copper, andmade no-carrier-added aqueous solution.
From this 77Br, A was synthesized by the
Sandmeyer reaction as reported previously.I) For
the synthesis of B, the oxidative bromination
was examined with HzO z and Chloramine-T as
oxidant. All the products were purified by HPLC
with an ODS column. The results of the synthesis
are shown in Table 1. Chloramine-T was foundto be clearly superior to HzO z for the synthesis of
B. The comparison of the two bromination
methods leads to the following summary. (1)Although the Sandmeyer reaction gives A as asingle radioactive product, time-consuming
purification processes are needed due to the formation of a lot of non-radioactive by-products.
(2) Although B yielded by the oxidative bromination is accompanied with radioactive byproducts, it can be purified more easily and rapidly. (3) By the Sandmeyer reaction radiobromine
can usually be introduced at any aromatic position whenever the corresponding amine is
obtained; but no choice of labelling position isallowed for the oxidative bromination. (4) As foroF-o~ (CH'ha:

Q
Br

Bromoperidolo0F-o-~(CH'hC>tJoN

Bromospiperone

Fig. 1.

Br

Bromoperidol and Bromospiperone.

Table 1. Yield and specific activity.
Bromospiperone
Bromoperido1 - - - - -- - H 2 0 2 Chloramine-T
Synthesistime (min)Purification
time (min)Yield (%)
Specific
activity(Ci/mo1)

15

60

5

90

100

80

16.0

36.0

45.6

6x103

> 1 X 106

>5 x 105

the reaction time, oxidative bromination can becompleted much more rapidly than the Sandmeyer reaction and can be used for the labellingwith 75Br.
The two 77Br compounds were administeredintravenously into rats and mice, and their distribution patterns in the body were followed up to
4 h after the administration by sacrificing theanimals. For the 77Br taken up in the brain, finedistribution within this organ was examined byradioautography and the binding state was studied by sucrose gradient ultra-centrifugation of
the homogenate and by filter-paper electropho-

T. Nozaki, et at.

resis of the extract. The results lead to the following conclusions. (1) Both A and B show accumulation at the position in the brain where thedopamine receptor is in high concentration. (2)Some parts of the aq::umulated bromine compounds are bound to the fraction of the cell
where the receptor exists. (3) These radioactive
compounds in the bound states are replaced by
non-radioactive compounds with the same orsimilar chemical structures and properties. (4)Bromoperidol shows rapider clearance from theblood and higher uptake into the brain. Its considerable portion, however, is bound nonspecifically in the brain, resulting in the deterioration of the SIN ratio in imaging. (5) No notablecleavage of C- Br bond was observed for thesecompounds in vivo.
The automatic synthesizer of llCHsI fabricated previously are working in the National

107

Nakano Chest Hospital. We intend to use it forthe synthesis of a-methyl (IIC)-fatty acids andtheir derivatives by malonic ester synthesis.
Recently, Dr. Hara, the National Nakano Chest
Hospital, developed a suitable synthetic method
for pyruvic acid labelled with llC at the carboxyl
position using an enzyme, and demonstrated its
extreme usefulness for various kinds of diagnosis
and fundamental study concerning metabolism.
An automatic synthesizer of this compound isunder fabrication in our institute. Details concerning the synthesizer will be reported next
year.
Reference
1) M. Suehiro, F. Y okoi, M. K. Kubo, M. Iwamoto, T.
N ozaki: Proc. IAEA Conf. Labelled Compo Radiopharm., p. 311 (1984).

108

RIKEN Accel. Progr. Rep. 19 (1985)

1II-3-2.

29AI Radiotracer Study on Adsorption of Aluminum by Soils
Y. Minai, S. Ambe, and T. N ozaki

In recent a few years, our group has studied
cyclotron production of 29 Al via the 26Mg(a ,p)29 Al reaction and its biological use as a tracer.
Preliminary results were presented in the recent
volumes of this report. 1 )-3) In this period, we
studied the adsorption of aluminum from aqueous solution by soils. Also, possible radiochemical impurities in the product were examined
and the removal was studied.
Typical Japanese soils from rice fields in
Fukui and Tochigi and from forests near theserice fields were used for adsorption study ofaluminum. These soils were supplied by Dr. K.
Yuita. Each soil sample (5 g) was well mixed
with 29 Al aqueous solution (50 ml) of pH about 2,
4, or 7. In order to observe adsorption kinetics,
a part of mixture was taken at a given interval(maximum mixing time was 20 min) and centrifuged to give supernatant solution. Then thesolution was withdrawn and its radioactivity andpH were measured with a Ge(Li) detector and a
pH meter, respectively.
Typical results are presented in Fig. 1. In thefirst few minutes, the adsorption of aluminum
proceeded rather quickly. With the mixing time,decrease in activity remaining in the solution andincrease in pH were observed for all the soil
samples. This implies that adsorption of aluminum hydroxides formed at neutral pH is an
important process. For the forest soils from
Fukui and Tochigi and for the rice-field soil from
Fukui, the activities remaining in the solutions
were different while pH values were almost thesame pH. For the rice-field soil in Tochigi
adsorption kinetics similar to that for the ricefield soil in Fukui was observed, though the pHchange was completely different between them.
The physical properties including particle size
distribution of the soils are different fromone another.4) Various chemical compositions- - (e.g., the content of organic carbon) are also
different. 4) These differences in physical andchemical properties may influence the adsorption
behavior of aluminum onto soils. Complex formation of aluminum with organic materials dissolved from the soils seems to suppress the adsorption of aluminum from the solution espe-

cially for the forest soil from Tochigi.
In Fig. 2 the variations of activity and pH of
the HCI solution with addition of disodium ethylenediaminetetraacetic acid (EDT A) are plottedagainst the contact time. Figure 2 shows that
addition of EDT A suppresses the adsorption of
29 Al without notable change in the pH. This
result suggests that formation of the EDT A
complex of 29 Al stabilizes aluminum in a solution

2
c:

0

:.;:;

3

:J

(5
IJ)

Q).

£
.~
0.0

4

50

::r::

5

c:

'c

a.

.~

E

6

~

~

0

15

20

7

Time (min)Fig. l. Variations of the relative activity (solid line)
and pH (dotted line) of 29 AI-HCI aqueous solution
during contact with soils . • , forest soil from Fukui;
0 , rice-field soil from Fukui; ., forest soil from
Tochigi; and 0 , rice-field soil from Tochigi.

3-~---o-- -- -- - --- ---0
.~
0.0

4

::r::

50

a.

5

c:

'c

.~

E

6

~

~

0

~--~--~--~15~--2~0~7

Time (min)Fig. 2. Variations of the relative activity (solid line)
and pH (dotted line) of 29AI-HCI aqueous solution
with addition of EDTA during contact with soils.
., forest soil from Fukui; 0 , rice-field soil from
Fukui; ., forest soil from Tochigi; and 0 , rice-fieldsoil from T ochigi.

Y. Minai, et al.

phase.
Details on these and previous results 1)-3) will be
published in near future.
References
1) Y. Minai, T. Nozaki, S. Ambe, and M. Iwamoto:
RIKEN Aeeel. Progr. Rep., 16, 120 (1982).

1092) T. Nozaki, S. Ambe, M. Iwamoto, and Y. Minai:
RIlffiN Aeee!. Progr. Rep., 17, 95 (1983).
3) T. Nozaki, S. Ambe, M. Iwamoto, Y. Minai, M. K.
Kubo, E. Tsuchida, M. Yuasa, Y. Ogata, H. Nishida,
M. Suehiro, and F. Yokoi: RlKEN Aeee!. Progr. Rep.,
18, 121 (1984).

4) K. Yuita: private communication.

110

RIKEN Accel. Progr. Rep. 19 (1985)

III-3-3.

Preparation of Non-Carrier-Added 45Ti and 69Ge andTheir Uptake by Plants
M. K. Kubo, Y. Minai, T. Nozaki, and T. Tominaga*

While titanium and germanium are both present as minor constituents in biological systems,
their role and behavior are still unclear. This ispartly because adequate radioisotopes for invivo study of such elements in organisms havenot been prepared. The aim of the present study
is to prepare their radioisotopes (45Ti and 69Ge)
and labeled compounds suitable for radiotracer
studies and to investigate their uptake by plants.
The excitation functions for the production of
45Ti (3.09 h, /3+ 86% +EC) and 69Ge (39 h, EC
64% + /3+), i.e., 45S c (p,n)45Ti and 69Ga(p,n)69Ge,
were obtained by means of the stacked foil
method. The proper incident proton energy forthe production of these nuclides was found to be
12 MeV in order to obtain maximum yields,
minimizing the generation of radioactive impurities unseparable by radiochemical techniques.
1. 45Ti: The target material (SC 2 03 powder
wrapped in Al foil) was bombarded with a 12
Me V proton beam from the cyclotron and thendissolved in 12 M HCl. After the extraction of
45Ti into a chloroform solution with oxine, 45Ti
was back-extracted into a dilute citric acid solution. Although this solution contained less than 3
ppm Sc, no y-rays other than those from 45Ti
were observed. The radioactivity of the solution
was about 2 x 106 Bq/ ml.
Young cucumber with root was immersed inthis solution, and the uptake of 45Ti was monitored by counting the 0.511 MeV photons from theleaf part by a collimated Ge(Li) detector. 45Ti
was found to reach the leaves fairly rapidly.
Changing the component of the solution andother factors, the 45Ti uptake process is now
being studied systematically. In Fig. 1 the 45Ti
accumulation in the leaves for light-on and -offcondition was plotted against the amount ofwater absorbed from the root. The uptake of 45Ti
and water was affected by light. 45Ti was notextracted from the leaves by organic solvents ordilute acids, but extracted by an H 2 0 2 solution.
45Ti may gradually become strongly bound to cell.
* Faculty of Science, The University of Tokyo.

dark

light

light

dark

0
0

400,-...

0

tn

Q.

•

Q.o

~

$
tn

•

300 ~
ro

--<>-

.c

E
~

~
Q.o

'0

20

Q.o

.D

•

200 ~
~

0

::::

tn

.D

ro

100 ~

Q;

u

«

n;
3
0
12

Tim e (h)Fig. 1. The change of the activity in the leaves (e)and the amount of water absorbed from the root(0 ). Light was turned on and off every 3 h. Activity
is corrected to the start time of the experiment.

200~-------------------------'.........

,. .

If)

Q.

u

150 t

........

If)
Q)

>
ro

~

/: .••.:.~

(1J

:5

...

100 1-

C..; ... .
>..
.

Carrier
3ppm

::.

501-

....
..:': '.
I

I

I

L

10

20

30

40

50

Time (h)Fig. 2. The absorption of 69Ge by cucumber. Carrier
Ge solution was added 30 h after the beginning of
the experiment to make up 3 ppm Ge condition.
The decay of 69Ge is corrected to the start time ofthe experiment.

M. K. Kubo, et ai.

2. 69Ge: Irradiated Ga 2 03 powder was dissolvedin 12 M HCI and 69Ge was separated by distillation of 69GeC1 4. H 2 69 Ge03 aqueous solution was
obtained finally.
The 69Ge uptake by cucumber from this solution was examined by the method similar to 45Ti.

111

69Ge was also absorbed from the root and migrated to the leaves rather fast. Addition of carrier
did not affect this process (Fig. 2). Unlike 45Ti,
69Ge seemed to be in dissolved state in the leaves,since 69Ge was easily extracted from the leaves
by water.

112

RIKEN Accel. Progr. Rep. 19 (1985)

111-3-4.

Charged Particle Activation Analysis

T. Nozaki, Y. Itoh, M. Iwamoto, Y. Ohkubo,
T. Kimura, and H. Fukushima

In this period the following studies were undertaken: (1) reexamination of calibration curves for
the IR spectrophotometry of oxygen and carbon
in semiconductor silicon; (2) analysis of carbon ingallium arsenide; (3) preliminary study for theuse of N -15 as activable tracer of nitrogen insolid state sciences; (4) analysis of carbon inaluminium; (5) surface oxygen analysis under
different atmospheric conditions. Also, various
samples, about 250 in all, were analyzed forcarbon or oxygen in the trust analysis system by
the Japan Chemical Analysis Center.I) Details ofstudies (2) and (3) are presented individually inthis volume.
The IR spectrophotometry is used for routine
analysis of oxygen and carbon in semiconductor
silicon, though it is of much less sensitivity thancharged particle activation analysis. Since semiconductor silicon has become an international
trade commodity and since the necessity for thecontrol of its oxygen and carbon concentrations
has become widely recognized, it is now urgently
needed to obtain highly reliable calibration
curves for the two IR determinations and to usethem under international consensus. Japan Electronic Industry Development Association thusorganized a committee for this purpose and also
for the precipitation of IR standard samples withvarious, excitly known oxygen or carbon concentrations to distribute all over the world. For
oxygen, reliable calibration curve was obtained
and IR standard samples were prepared anddistributed already.2) National Bureau of Standard, U.S.A., however, proposed to repeat thesame procedure as we undertook to get the calibration curve, with American and European laboratories taking not only in the round robin IR
measurement but also in the charged particle
activation analysis. Thus, samples were prepared and the schedule was set. In Japan boththe IR measurement and activation analysis
have just been completed.
For carbon, about 70 samples were preparedand submitted to round robin IR measurement by
about 20 laboratories including those of foreignorganizations. After the IR measurement, each of

"I 5
E
~
+-'

c

4

Q)

'u

::: 3
Q)

o
u

c

o

2

'~ 1
VI

.0

<t:

2

3

4

Carbon concentration (x 10 17 'cm- 3 )Fig. 1. Calibration curve for IR spectrophotometryof carbon in silicon (Provisional result).

24 sample wafers was cut into two pieces and theresultant 48 silicon plates were analyzed bycharged particle activation. For this analysis we
improved the procedure. Formerly the sample
activated by the 12C(3He,a )llC reaction was dissolved in a HF-HN03-KI04 solution. In thismethod, however, a small part of the IIC was
found to sometimes escape in the form of IICO
without being absorbed by the alkaline solution. 3)
N ow we dissolve the sample after bombardment,
surface etching and, pulverization in a N aOH
solution containing carbonate carrier (30 mmol).
The solution was heated to dryness and further
to dull red in a microwave oven. Then sulfuric
acid was added to the resultant mass to generate
11 CO 2, which was converted into Li 2 C0 3 precipitate for counting. The annihilation radiationfrom the filtered precipitate was measured by awell-type N aI scintillator (for C concentrations
over 0.5 ppm wt) or a pair of BGO scintillators
operated in coincidence (for lower C concentrations). In Fig. 1 is shown the resultant calibration
curve, which agrees fairly well with the curve wereported many years ago. 4) This result is as yet
rather provisional, because their still exist someuncertainties in the data treatment and also in
the activation analysis, in which some corrections due to the difference in the physical andchemical state between the Li 2C0 3 and the activation standard of graphite and to the interference of oxygen via the 160(3He, 2a )llC reaction.
The final result will be obtained in a few months.

T. Nozaki, et al.

Effects of light element impurities on the property of matrix has attracted a lot of interest in
the study and production of semiconductor materials. Recently the necessity of similar analysis
has been pointed out by metal industries forsome other matrices. N ikkeigiken Co., a producer of aluminium, collaborates with us for the
study of carbon in aluminium, for which even thephase diagramme is unknown in extremely
low carbon concentration ranges. For theradioactivation of carbon, the 12C(3He,pn)llC
reaction can not be used, because of the interference of boron via the lOB(3He,pn)11C reaction.
Thus the 12C(d, n)13N reaction should be adopted
and the 13N(10 min half-life) should be separated
quickly. We first studied the separation of the
13N, and set up the following separation procedure: (1) dissolve the sample after bombardment
and surface etching in conc. hydrochloric acidcontaining NH3 as carrier, (2) add granular
N aOH to the solution, and distill 13NH3, and (3)catch the distillate by a sodium tetraphenylboron
solution, and then collect ammonium tetra-

113

phenylboron precipitrate. Various aluminium
samples suitable for the measurement of somephysical constants and of the behavior of carbon
in aluminium have been collected and are going
to be analyzed.
The surface oxygen analysis has been
continued using a new bombardment apparatus,S)
and a summary of the results will be publishedsoon.
References
1) T. Nozaki, Y. Itoh, M. Iwamoto, H. Shinyashiki, K.
Nomura, T. Kimura, and H. Fukushima: RlKEN
Accel. Progr. Rep., 17, 96 (1983).
2) T. Iizuka, S. Takasu, M. Tajima, T. Arai, T. Nozaki,
N. Inoue, and M. Watanabe:]. Electrochem. Soc. , 132,
1707 (1985).

3) T.Nozaki, Y. Yatsurugi, and N. Akiyama: ].
Radioanal. Chem. , 4, 87 (1970).
4) Y. Endo, Y. Yatsurugi, N. Akiyama, and T. Nozaki:
Anal. Chem., 44, 2258 (1972).
5) T. Nozaki and M. Iwamoto: IPCR Cyclotron Progr.
Rep., 11, ll6 (1977).

114

RIKEN Accel. Progr. Rep. 19 (1985)

111-3-5.

Utilization of N-15 as Activable Tracer
T. Nozaki and Y. Itoh

The solubility and diffusion constant haveremained obscure for nitrogen in most solid
substances. Nitrogen is abundant in nature, andthe determination of its trace in a solid bulk isoften interfered with nitrogen on the surface andfrom the environment. Natural abundance ofnitrogen-I5 is 0.365%. We intend to use N-I5 as

250:0 200

E
c
0

:.::;

u

<I>

150

,....,

VI

\

VI
VI

0

U 100
50
10

15

20

Energy (MeV)

Fig. 1. Excitation function for the 15N (a ,n)18F reaction (indicated by the smoothening of the histograms).

.-- ..

activable tracer for the measurement of theabove two physical constants first in semiconductor silicon. The following three nuclear reactions
are regarded as promising for the activation: (1)15N +p~12C + a + y (4.4 MeV): (2) 15N +d~160+n(or p and p-) + Y (6.13, 7.11 MeV), and (3) 15N (a,n)18F. Reactions 1 and 2 are the reverse reactions
used for the depth profiling of H and high sensitivity determination of D, respectively. 1)
We measured the excitation function and thicktarget yield for Reaction 3. Stacked targets of
30.2±0.5% enriched Na 15 N0 2 on aluminium foils
were prepared by the precipitation method andused for the excitation function measurement.
The thick target yield was measured with the
Na 15 N0 2 disk prepared by pressing. The results
are shown in Figs. 1 and 2. The thick target yieldfor the 160eHe, p)l8F is also shown in Fig. 3. 2) We
have already developed a very suitable method
for separating 18F from any matrices, and now
can determine as low as 1 ppb of oxygen. 3) From
Fig. 2, it is thus clear that down to 1 ppb of 15N
can be determined. We formerly developed also amethod of activating 0 with equal probability
along the depth by rotating a set of aluminium
absorbers in the incident 3He path.4) A similar
method can be used in the activation of 15N. The
a-particle energy for this activation, however,should be limited to 23 Me V for samples containing 0, which for higher energies gives 18F by the...,... ••.0..-

1 X 109

F·

I

."

I.

X 10 9.~.

1.5t-----t---+--+_

1.0r--

7"I------,f.---_+__

~

:::t
~
c.

/

.:g

r

!

10

O.O~-~-~!=____,~

o

15

20

Energy (MeV)

5

50

100

150

Range (mg / cm 2 )6' 1'0 1'5 2'0 2'5

3'0

3'5

Energy (MeV)

Fig. 2. Thick target yield for the 15N(a , n)18F reaction. • : Observed. 0 : Calculated from the excitation function.

Fig. 3. Thick target yield for the 160eHe,n)18F reaction.

T. Nozaki, et al.

160(a, pn)18F reaction.

We intend to measure the solubility anddiffusion constant of N first in semiconductor
silicon at various temperatures. Shallow parts(~ 50 Jim from the surface) of the sample will beanalyzed by Reactions 1 and/or 2, and Reaction
3 will be used for deep portions. We are keenlyinterested in examining closely whether any
enhanced solubility and diffusion be observed in
the sample portion near the surface as compared115

with deeper portions.
References
1) S. Hayashi, H. Nagai, M. Aratani, T. Nozaki, M.
Yanokura, I. Kohno, O. Kuboi, and Y. Yatsurugi:
RIKEN Accel. Progr. Rep., 18, 134 (1984).
2) T. Nozaki, M. Iwamoto, and T. Ido: Int. ]. Appl.
Radiat. Isotopes, 25, 393 (1974).
3) T. N ozaki:]. Radioanal. Chem., 72, 527 (1982).
4) Y. Itoh and T. Nozaki:]. Radioanal. Chem., 70, 329(1982).

116

RIKEN Accel. Progr. Rep. 19 (1985)

111-3-6.

Simultaneous Charged Particle Activation Analysis of
Carbon and Boron in Gallium Arsenide

T. Nozaki, Y. Itoh, Y. Ohkubo, T. Kimura, and H. Fukushima
Carbon in semiconductor GaAs is thought tobe an electrically active impurity, and its exact
determination is urgently needed in the researchand production of this material. In this determination, an absolute carbon content in the bulk
matrix should be known free from surface carbon and external contamination. Various methods,1)-5) have been used for this purpose, but someproblems still exist in the sensitivity, reliability
or exactitude. For most of the methods, a calibration curve or a reference sample is needed inorder to obtain an absolute carbon concentration.
Charged particle activation analysis is an
exception; graphite can be an ideal referencematerial. The 12CeHe,a)IIC reaction is mostly
used for the activation of carbon in various
matrices, but boron interferes with this analysis
by giving lIC via the lOB(3He,pn)lIC reaction.
Most of present gallium arsenide semiconductors
are produced by the liquid encapsulated
Czochralski (LEC) method and contain a muchhigher concentration of boron than carbon.
Hence, the 12C(d,n)13N reaction should be adopted
for activation and the 13N rapidly separated and.measured (13N: 9.96 m, /3+, no y). It is clear thatcarbon and boron can be determined simultaneously when individual separation of the 13N andllC formed by IOB(d,n)llC and 11 B(d,2n)llC is possible. Photon activation analysis by the 12C( y,n)IIC reaction can be interfered with a much higher
concentration of boron through the protongenera ting reactions [69Ga( y ,p )68Zn , 71Ga( y ,p)70Zn, and 75As(y,p)14Ge] and the succeeding llB_(p,n)llC reaction. A simple calculation leads to a
result that for LEC GaAs the llC activity inducedby this secondary reaction could be comparable
to that by the 12C(y,n)llC reaction.
We made efforts to find out a simple procedure
for separating 13N and IIC in GaAs based on dry
fusion. 6),7) By the recoil implantation of l3N andliC into GaAs plates in the reactions l60(p,a)13N
and 14N(p,a)llC induced in O2 and N2 near theplates, we were able to prepare suitable samples
for this study and then to prove that in our
procedure given below the 13N and liC were

He gasSample in radio ·frequency induction
furnace (Ga As,Cu )He gas
70m llminCuOt-- 900' C

Molecular sieve 5A
Ascariteliq. N2 temp.
I+- (llC,trap) I-(l 3N,trap)

Fig. l. Schematic diagram of separation procedures.

separated in individual columns with satisfactory purity.
A GaAs plate (2 x 1.5 cm2 in area, 0.5-2 mm inthickness) was bombarded for 10 min with adeuteron beam (10 MeV, 1.5 j.l.A). After removing
surface contamination of the bombarded plate,as shown in Fig. 1, the sample was fused byradiofrequency heating together with copper
grains in a helium stream passing through columns of CuO heated to 900°C, Ascarite, andMolecular Sieve 5A cooled with liquid nitrogen.
The radioactivity of 13N trapped in the molecularsieve was measured by coincidence counting ofannihilation radiations with a pair of bismuth
germanium oxide scintillators. The llC in
Ascarite was counted by a well-type N aI detector.
It took about 20 min to initiate counting after
bombardment. A graphite plate and B20 3 powder
were used as activation standards for carbon andboron, respectively.
The detection limit in this method is estimatedto be 2 X 10 14 atoms cm- 3 for both carbon andboron. Carbon concentrations between 8 x 10 14
and 3 x 10 16 atoms cm- 3 have been found, depending on the sample history. For boron, LEC crystals have been found to contain 1 X 10 15 to 8 X 10 17
atoms cm- 3. The absorptivity of carbon in GaAs
has not been clear in IR spectrophotometry. Our
results have given carbon concentrations a few
times smaller than the values given by FTIR
measurement calibrated indirectly from the electrical conductivity. 3)
Studies are in progress to obtain a more reliable calibration curve for IR spectrophotometry
and to obtain results meaningful in semiconduc-T. Nozaki, et al.

tor science and technology.
References
Y. Homma and Y. Ishii:]. Vac. Sci. Technol. A, 3,356(1985).
2) Y. Homma, Y. Ishii, T. Kobayashi, and]. Osaka:].
Appl. Phys. , 57, 2931 (1985).
3) M. R. Brozel, J. B. Clegg, and R. C. Newman:]. Phys.
D: Appl. Phys., 11, 1331 (1978).
4) G. B. Stringfellow, K. Koschel, F. Briones, ]. Glad1)

117

stone, and G. Patterson: Appl. Phys. Lett. , 39 581(1981).
'
5) M. Valladon, G. Blondiaux, C. Koemmerer, J. Hallais,
G. Poiblaud, A. Huber, and]. L. Debrun:]. Radioanal.
Chem., 58, 165 (1980).
6) A. Marschal, 1. Gosset, and C. Engelmann: ].
Radioanal. Chem., 8, 243 (1971).
7) ]. M. A. Lenihan, S. ]. Thomson, and V. P. Guinn:
Advanced in Activation Analysis, Academic Press,
London and New York, Vol. 2, p. 47 (1972).

118

RIKEN Accel. Progr. Rep. 19 (1985)

111-3-7.

Application of PIXE to Medical Science (III)K. Maeda, H. Kusuyama, Y. Sasa, Y. Y ok ode, and M. Uda
Elemental analysis of biological samples is ofprime importance from the diagnostic and therapeutic viewpoints. We have continued a study on
the application of the particle induced X-ray
emission (PIXE) analysis to medical science. In
previous reports,l),2) we described the analysis ofsome human tissue samples using 5 Me V protons
accelerated by the cyclotron as projectiles. Fromthe end of the last year, He+ ions with energy up
to 8 Me V have been available from the linac andgreatly improved sensitivities for detection ofelements having medium atomic numbers.
The samples analyzed were (1) malignant
tumors, benign tumors, and normal tissues
around tumors taken from patients sufferingfrom diseases in thyroid, kidney, bladder, andtestis, and (2) urinary calculi taken from patientsof stone diseases. Freeze-dried tissue samples
were sectioned with a microtome to about 10 Jim
thick slices and then backed with 1 Jim thickpolypropylene or 4 Jim thick Mylar film. Calculus
samples were mechanically broken in appropriate form for scanning analysis and served astargets without pre-treatments.
Representative spectra induced by 8 Me V He+
ions are shown in Fig. 1. The samples are tumor
and normal tissues in a thyroid gland. LX-ray
peaks of iodine, which could not be distinguished
10 4
10 3

~c 10

2

~§ 10

1

K
nco

n

8 MeV He+

(0)

8 MeV He+

(b)

Cu
Fe n

n

Zn

n

0

.3
~

10°
10 4

V>

c

~ 10 3
>-

! 10

2

10

1

[-K

Br
II

r-;'
I

10°
10

20

30

X-Roy Energy (keV)

Fig. l. PIXE spectra of (a) twnor and (b) normal
tissues in a thyroid gland taken from a patient of
colloid adenoma. A 1 mm thick polyethylene film
was used as an X-ray absorber. y-Rays at 29.6 keY
are due to 4°K produced by the 37Cl(a,ny) reaction.

(0)

p Co
I n

8 MeV He+§(b)

B10 4 ..
.....

8 MeV He+

Q.

'"
U

(J')

§ 10 3

8

::: K

81
n

Zn

n

he Zn
n

~

~

! 100+--T""""""-.&.UW.fJI--J----.~ ! I O°+--T--r--I-.L..JII,.A&IIJ~II&JA~
o

100
200
300
Channel NlJT1ber

0

100

200
300
400
Channe I Numbe r

500

Fig. 2. PIXE spectra of a ureter stone. (a) A 1 ,urn
thick polypropylene and (b) a 1 mm thick polyethylene films were used as X-ray absorbers.

in the 5 MeV H+ induced spectral) because low
energy characteristic X-rays were superimposedon a high background due to continuous X-rays,
are clearly observed in the spectrum obtained
from normal tissue. Peak to background ratios
for K X-rays of Fe, Ni, Cu, and Zn are also muchhigher in 8 MeV He+ impact than in 5 MeV H+
impact. Previously, we found deficiency of iodine
in diseased thyroid tissues l) and enrichment ofiron in renal cancers. 2) The PIXE analysis of thetissue samples with 8 MeV He+ impact supports
such findings.
Analysis of calculus composition is an interesting subject of the PIXE because the precise
mechanism of stone formation is still unknown inspite of frequent occurrence of bilary and urinary stone diseases. We have analyzed several
human bladder and ureter stones. Na, Mg, P, andCa as major elements and K, Fe, Zn, and Sr as
minor elements were detected in all the stones
analyzed here. The Mg content of the bladderstones was very high as compared to that of theureter stones. Pb was found, in relatively highconcentration, in a ureter stone taken from afemale patient who had been working in an
automobile service station for many years. The
PIXE spectra obtained from this stone are shownin Fig. 2.
References
1) M. Uda, K. Maeda, Y. Yokode, and Y. Sasa: RIKEN
Aeeel. Progr. Rep., 17, 134 (1983).
2) K. Maeda, H. Kusuyama, Y. Yokode, Y. Sasa, S. E1.
N asr, M. Kobayashi, and M. Uda: RIKEN Aeeel.
Progr. Rep., 18, 128 (1984).

119

RIKEN Accel. Progr . Rep. 19 (1985)

111-3-8.

Geochemical Application of PIXE ( I )H. Yabuki, A. Okada, S. Yabuki, K. Maeda,
Y. Sasa, and M. Uda

Since 1960's, an electron microprobe has been
widely used for non-destructive determination ofmajor elements (more than ca. 1,000 ppm) in
microscopic objects. Recently, however, theimportance of the information about elements
present in each constituent in geological samples
in concentrations below their detection limits has
been emphasized. The particle-induced X-ray
emission (PIXE) spectroscopy is expected tomeet the request for in situ quantitative analysisof trace elements with high precision.
We have initiated the application of PIXE togeological and cosmological samples. Here we
report the preliminary results of qualitative analyses by PIXE using the linac
The experimental setup used has been described by Maeda et al.1),2) As target objects, weused polished thin sections, 30 ,urn or thicker,
prepared for conventional geological use. The
targets were bombarded with He+ ions accelerated by the linac to 2.0 MeV / amu and emmited
X-rays were detected with a Si(Li) detector. The

size of ion beams focused on the targets waslarger than 0.5 X 0.5 mm 2 • Appropriate absorbers
were selected and inserted between the sample
and the detector to obtain better statistics in ahigh energy X-ray region.
The samples under study and the elements
detected by this method are listed in Table 1.
Figures 1 (a) and (b) show the representative
PIXE spectra obtained from apatite and fergusonite, respectively. Major elements as well as
minor or trace ones, especially a series of rareearth elements, were successively detected invarious minerals. Cobalt (~0.5 wt %) was not
identified in iron meteorite because of the presence of adjacent high peaks of iron and nickel.
References
1) K. Maeda and M. Uda: Reports I.P.C.R., 58,96 (1982)(in Japanese).
2) K. Maeda, Y. Sasa, and M. Uda: RIKEN Aeeel.
Progr. Rep., 17, 123 (1983).

Table 1. Results of qualitative analysis of various minerals andan iron meteorite (Odessa) by PIXE spectroscopy.
Sample name (Locality)

Formula or major elements

Detected elements

Fergusonite (Japan)(Y ,Er,Ce,Fe)(Nb,Ta, Ti)04

Samarskite (Japan)
Monazite (Japan)(Y,Er,Ce,U,Ca,Fe,Pb,Th)(Nb,Ta,Ti,Sm)20S(Ce,La,N d)P0 4

Gadolinite (Norway)

Be2FeY202(Si04)2

Columbite (Japan)
Beryl (Korea)
Biotite (Japan)(Fe,Mn)(Nb,Ta)zOs
BesAl2Si6018
H 2K(Mg,FehAl(Si0 4h

Apatite (Japan) .

3CaS(P04)2 . CaF2

Apatite (Mexico)

3CaS(P04h . CaF2Iron meteorite (U. S. A. )Fe,Ni,Co

P ,CI,Ca,Ti,Fe,Zn,Se,
Y ,Zr,Nb,Cd,Ce,N d,Gd,
Er,Yb,Ta,Bi,Th,U
Cl,Ca,Sc,Ti,Mn,Fe,Nb,
Ta,Au,Pb,U
N a,Al,Si,P,Rh,Ag,Te,
Cs,La,Ce,N d,Gd(?),Er(?),Tm(?),Th
Al,Si,CI,Ti,Y,Nb,Cd,Te,
Nd,Gd,Dy,Er,Yb,Ta,Ar,
Th,U
Si,Ti,Mn,Fe,Ge,Nb, Ta
AI,Si,K,Fe,Zn,Cs,La
Al,Si,K,Ca, Ti,Mn,Fe,
Zn,U(?)
P,Ca,Mn,Fe,Sr,Y,Ce,
Nd,Sm
P,Ca,Fe,As,Y,La,Ce,Nd,
Sm,Gd
Cr,Fe,Ni,La,SmH. Yabuki, et al.

120

>-

I-

102

(I)

z:
W

I-

:::

As

101

,;

/11

i\

200

~\

300

400

CHANNELS

(a)

,
,.,,
'!Ii

:;n.

II!!

100

.

i!llll 1..n
IIi

100
500

100

200

300

CHANNELS(b)

Fig. 1. PIXE spectra obtained from (a) apatite (Durango, Mexico) and (b)fergusonite (Suishoyama, Japan) irradiated with 8.1 MeV He+. 27 mg/ cm2
polyethylene film was used as an absorber.

400

500

121
RIKEN Accel. Progr. Rep. 19 (1985)

111-3-9.

Hydrogen Analysis in Thin Surface Layer of Amorphous Siliconby the Rutherford Forward Scattering Method
K. Saito,* H. Yamaguchi,* H. Nagai, M. Yanokura,
M. Aratani, S. Hayashi, Q. Qiu, and T. N ozaki

Hydrogen is one of the main impurities forsome semiconductor materials such as amorphous silicon (a-Si: H) films and insulation films.
Since the properties of these materials are seriously affected by hydrogen content, precise analysis of hydrogen has been requested in the semiconductor production process.
Generally, well- known methods such as Infrared Spectrometry (IR), Secondary Ion Mass
Spectrometry (SIMS), or Mass Analysis havebeen used in routine analysis. However, for the
precise quantification of hydrogen, well characterized standard samples are required in thesemethods. In the present study, the Rutherford
Forward Scattering (RFS) method!) was applied
to the analysis of a-Si: H films by using the linac.
In this method, no standard samples are required.
1. Accuracy of Hydrogen-depth Analysis by
the RFS Method
Accuracy of hydrogen-depth analysis waschecked from the depth profile of hydrogen implanted into single crystal of silicon substrate
determined with the energy of 35 ke V and thedose of 5 x 10 16 ions/cm2 • Measurements were
performed on the samples for three times andGaussian type profiles, as expected from the
LSS** theory, were obtained as shown in Fig. 1.
The depth at the peak of profiles agreed withthe value calculated by using LSS theory and thetotal hydrogen content obtained from the integration of the profile agreed with implantationdose within the error of 10%. A small peak foundat the surface was attributed to absorbed hydrogen. The height of this peak varied due to reabsorption of recoiled hydrogen.
2. Quantification of Hydrogen in a-Si:H
Films
The contents of hydrogen in a -Si: H films were

determined by the RFS method and the obtained
values were used for calibration for IR or SIMS
analysis. Samples examined were hydrogenateda-Si: H films grown by a plasma CVD method on
silicon substrates under different conditions.
Results of hydrogen analysis obtained by the
RFS method are shown in Fig. 2 which represents
concentration-depth profiles of the samples withdifferent concentrations and different film thicknesses.
The IR and SIMS analyses were performed forthe same samples. Absorbance of the Si-H bondat 4.8 ,.urn was measured by IR analysis and the5

H (ion-imPlanted)
35KV 5X1016 cm- Z

Fig. 1. Depth profiles of hydrogen in hydrogen implanted standard sample measured by the RFS
method.

~a-Si:H Films

5* R&D Center, Toshiba Corp.
* * LSS: Profiles of implanted atoms were theoreticallyestimated originally by ]. Lindhard, M. Scharff, and H.
E. Schiott in 1963. Detailed data calculated with com·puter were listed in 'Projected range statistics,' J.
Gibbons, W. Johnson, and S. Myroies, 1975.

2.5

2

1.5
Depth (pm)Fig. 2. Depth profiles of hydrogen in the amorphoussilicon sample measured by the RFS method.

122

K. Saito, et ai.

0.06
J:

0.05

-0-: IR-...-: SIMS

I

(;;

0.04
>-

Q)

u
c:

0.03

0.10

0

..c
L.
0

1/1

:5

0.02

Q)

..c

<t

~

0.05 .~

ion intensity ratio H+ /Si+ was measured by
SIMS. The relation between these values andcontents of hydrogen determined by the RFS
method is shown in Fig. 3. Fairly good linear
relationships were obtained.
From these results, the RFS method was foundto be useful as a standard method for hydrogencalibration in IR or SIMS analysis.

~

o

0.01

Q)

ct:

H Concentration (atm %)Fig. 3. Correlation of hydrogen contents determinedby the RFS method to the values obtained by IR
and SIMS methods.

Reference
1) H. Nagai, M. Aratani, S. Hayashi, T. N ozaki, M.
Yanokura, I. Kohno, O. Kuboi, and Y. Yatsurugi:
RIlffiN Aeeel. Progr. Rep., 17, 102 (1983).

123
RUffiN Accel. Progr. Rep. 19 (1985)

111-3-10.

Detection Limit of Hydrogen In Elastic Recoil Detection Analysis
H. Nagai, M. Aratani, S. Hayashi, * Q. Qiu, T. N ozaki,
M. Yanokura, 1. Kohno, O. Kuboi, Y. Yatsurugi, and A. Hayashi

Elastic recoil detection analysis has been usedsuccessfully in the analysis of hydrogen on andnear the surface of a solid of relatively highhydrogen content.I) We intended, next, to apply
this method to samples of low hydrogen contentssuch as quartz. However, various results
obtained by us suggested that the surface hydrogen would interfere with the bulk hydrogen
analysis. 2 )To examine this interference and to determine
the detection limit, we measured bulk and surface hydrogen for the following samples by theprocedure reported previously:3) (1) a siliconwafer, (2) silicon wafers oxidized with H 2 0 at
830°C to 12 and 34 nm in thickness, and (3) siliconwafers oxidized by chemical vapor deposition to
13 and 20 nm in thickness. Argon ions were usedas the incident particles. The beam current was
30 to 50 nA, and the counting was continued for
30 to 90 min.
Typical energy spectra of low hydrogen samples are shown in Fig. 1. The individual spectrum
consists of two parts: a large peak and a continuum covering the entire channels below the peak.
The peak is clearly due to the surface hydrogenrecoiled by a single scattering, and the continuum is supposed to result from the surface hydrogen after multiple scattering and bulk hydrogen
after single scattering. The apparent bulkhydrogen content obtained from the height and/or area of the continuum is thus thought to becorrelated with the surface-hydrogen amount.
The results of the measurement on five kinds ofsamples of low bulk-hydrogen contents areshown in Fig. 2. It is clear that the apparent
bulk-hydrogen content is proportional to thesurface-hydrogen amount. On average, 10 16
atoms/ cm 2 surface hydrogen gives a count rate
identical with that given by 2.6 X 10 18 atoms/cm3
bulk hydrogen in the bulk hydrogen region of thespectrum. We thus conclude that the detection
limit for bulk hydrogen in a thick quartz sample
is 1 to 2 X 10 18 atoms/ cm3 (about 1 wt. ppm), when
its surface-hydrogen amount is about 5 X 10 15

1 0 ' , - - - - - r - - - - - . - - - - - . -- - - - - - . - - - - , - - - - - - - . - - - - . - - ,

10'

10'

...J

~

SURFACE HYDROGEN( 2.53 MeV)

10 '

Z

ex:

BULK HYDROGEN:r:u........
Vl

I-

Si-WAFER

Z
=:J

o

lOl

U

Si-WAFER + S;02(34 nm),S6

CHANNEL NUMBER
Fig. 1. The energy spectra of hydrogen atoms
recoiled by 49.73 MeV Ar-ions in the Si·wafer andsurface oxidized samples. The spectra were divided
into two region. Large peaks in the higher energy
region are due to recoiled surface hydrogen, andcontinua in lower energy region are due to recoiled
bulk hydrogen.
1018\(atoms/cm 3)
4

~ 3
(!J

0

c::
0

~ 2
::.<:
...J

::::>
a:l

1

<>
0

00

5

10

SURFACE HYDROGEN
Fig. 2. Apparent bulk·hydrogen contents vs.
surface-hydrogen amounts. Sample: £. = siliconwafer; 0 ,0 =Si0 2 films prepared by oxidation ofsilicon wafers with H 2 0 at 800°C (12 nm and 34 nm);e,_ =Si0 2 films prepared by oxidation of siliconwafer by CVD (13 nm and 20 nm).

atoms/cm 2 which is the average value in thepresent experiment.
References* Shimadzu Corporation.

1) Y. Yatsurugi, O. Kuboi, M. Hashimoto, H. Nagai, M.

124

H. Nagai, et al.

Aratani, M. Yanokura, 1. Kohno, and T. N ozaki:
Appl. Phys. Lett., 44, 246 (1984).
2) H. Nagai, M. Aratani, S. Hayashi, M. Yanokura, 1.
Kohno, T. Nozaki, Y. Yatsurugi, and O. Kuboi:

RIKEN Aeeel. Progr. Rep., 18, 130 (1984).
3) H. Nagai, M. Aratani, S. Hayashi, M. Yanokura, 1.
Kohno, T. Nozaki, Y. Yatsurugi, and O. Kuboi:
RIKEN Aeeel. Progr. Rep., 17, 102 (1983).

125
RUffiN Accel. Progr. Rep. 19 (1985)

111-3-11.

Heavy-Ion Rutherford Backscattering Analysis Applied
to the Electronic Materials
K. Ikeda, N. Ito, M. Yanokura, Q. Qiu,
M. Aratani, and T. Nozaki

In the fabrication of a Schottky-barrier diode,the conditions for the deposition of metal layers
affect the electrical characteristics. We applied
heavy-ion Rutherford backscattering 1 ),2) (RBS) to
the study of the behavior of each layered metalat heat treatment in the production of the diode,making use of its nondestructiveness, good depth
resolution for heavy metals, and insensitivenessto light elements. In this report, the estimation is
given for the behavior of metal layer systems
used frequently in Schottky-barrier diode and thechange is qualitatively explained in heat treatment of them at various temperatures.
The structure of the present samples before
heat treatment is shown in Fig. 1. Molybdenum,
platinum, and aluminum were successively deposited on a silicon wafer by sublimation. The
sample was then heated at various temperaturesin nitrogen atmosphere. The temperature was set
successively higher following the series from

~

~l
Mo

Sample A to Sample E. After heat treatment thealuminum layer was removed from the samples
in order to observe detailed behavior of Mo andPt layers.
The arrangement for the RBS measurement isshown in Fig. 2. The incident ion was 14 N2+ with
19 MeV in energy and several nA in beam current. The incident angle and the detector angle
were 90 and 15T, respectively, and the beam
spot was 1.5 x 1.5 mm2 • The measurement wascontinued for 10-30 min.
The backscattering spectra of Mo- Pt-Al systems are shown in Fig. 3. The solid lines A, B, C,
and D are for heat treated samples and the dottedline is for an as-deposited sample. Spectra of
AI-etched samples are shown in Fig. 4. The metal
system is seen to mix in the heat treatment, as isevidenced from the facts that (1) platinum reacts
with aluminum at low temperatures to give a
stoichiometric compound 3 ),4) (about 1 : 1), which
does not change by temperature elevation; (2)platinum spreads up to the surface of aluminumlayer; and (3) a small part of molybdenum0

N-S i sub.

Fig. 1. Samples used in the present study.

Fig. 2. Experimental arrangement.

Fig. 3. RBS spectra of Mo-Pt-Al system on Si
substrate. Treatment temperature, A < B < C < D;
doted line, evaporated sample; Ep, and EMo, maxi·
mum energy of Pt and Mo; E'p, and E'M o, maximum
energy of evaporated sample.

126

K. Ikeda, et at .
10'

etched AI

.'

10'

/

100

10 '

d

1

B

e'

10 '

1/

".. /~,/:~'''#
,0 ,-

10 '

10

,c

/'

,, /

J
/,'

10 '

- 0 - as evap.

-.-,:,-- a
--0--

A

10'

10 '
0 0

5 1l

CHA NNEL NUMBE R

E~o EMo

as eVBpannealed

Si~1-10 -20 - 30 -40

tover annealed-50

VR ( V )Ept

Fig. 4. RBS spectra of Mo-Pt-AI system (AIetched). E"Mo, maximum energy of as evaporated
sample (AI etched).

b-- • ._- c

SBD I R VS. VR

Fig. 6. V- I characteristics of Schottky -barrier
diode. Treatment temperature: a < b < c.

change was observed in the RBS spectrum. From
this result, the Al layer is considered to promote
the inter-layer reaction.
The movement of each element in each heat
treatment is shown in Fig. 5. The change inelectrical characteristics (reverse biased V-I
curve) of Schottky-barrier diode caused by heat
treatment is shown in Fig. 6. These results indicate that lower temperature is preferred for theheat treatment in the production of the electric
device, also, heavy-ion RBS has proved to behighly effective for the study of heat-treatment
behavior of layered metals.

Fig. 5. Modified diagram of Mo- Pt-Al system.

References
diffuses into the platinum layer and also reacts
with silicon to form silicide. In highertemperature heat treatment, this system gave
considerably different features. In the spectrumof aluminum-etched sample, only molybdenum
peak was observed. This result suggests that a
considerable portion of Al diffused into the Mo
layer to make most of Mo be etched off with Al
and that the Mo peak thus was derived from the
Mo-Si layer. When the sample of the Pt-Mo
system with no Al layer 'Yas heated, much less1) M. Yanokura, M. Aratani, H. Nagai, S. Hayashi, 1.
Kohno, T. Nozaki, O. Kuboi, and Y. Yatsurugi: Proc.
8th Symp. on Ion Sources and Ion-Assisted Techno!.,p. 425 (1984).
2) K. Ikeda, N. Ito, T . Aimi, S. Hayashi, M. Yanokura,
I. Kohno, H. Nagai, M. Aratani, and T . Nozaki:
RIKEN A eee!. Progr. Rep. , 18, 101 (1984).
3) Landolt-Bomstein, Neue Serie, Band III, "Structural
Data and Intermetallic Phases," Springer-Verlag,
Berlin, Heidelberg, New York, p. 268 (1971 ).
4) V. R. Huch und W. Klein: Z. Anorg. AUg. Chem ., 329,
123 (1964).

127
RIKEN Accel. Progr. Rep. 19 (1985)

111-3-12. Elastic Recoil Analysis of Hydrogen for the Study ofthe Formation of Radiation-Resistant Oxide Film on Silicon
K. Yamamoto, M. Aratani, M. Yanokura, Q. Qiu,
H. Nagai, 1. Kohno, and T. Nozaki
Recent developments in semiconductor integrated circuits, especially Si-MOS· LSI, depend
on various progresses in fundamental techniques
including improved preparation of high-quality
oxide films on substrate silicon. The characteristics of the devices are generally influenced byphysical and chemical states of the oxide film,
such as its composition, defects and impurities in
it, and mechanical stress and electric voltage
applied on it. Hydrogen in the oxide film has
been qualitatively confirmed to have someinfluence on the diffusion of other elements andon some electrical properties. It is also known
that low-temperature processes should be used in
the oxide film formation in order to obtainradiation-resistant devices.
Precise determination of impurities in the film,
especially of light elements, has thus become
essential for future development of the electricelements. However, since no method of analysis
was applicable to hydrogen in solids with enoughsensitivity and accuracy, no reliable knowledge~5;~.

Si Wafer

Fig. 1. Structure of the sample for characterizationof hydrogen on Si0 2 /Si interface.

has been obtained concerning the concentrationand distribution of hydrogen in the oxide film
and, consequently, no technique has been developed for the control of them.
We paid attention to recent advances l ).2) in theheavy-ion Rutherford forward recoil measurement applied to the determination and depthprofiling of hydrogen in amorphous silicon 3 ),4)
and silica,S) and tried to apply the method to theanalysis of thermal oxide film. This sample wasx10 2
2.56 r-~-~-~-~-~-~-~-~- - - WITHOUT- - - AFTER

ANNEALING
ANNEALING

1 .92
....J

I.LJ

Z
Z

..:
:J:

u

....... 1.28
Vl
IZ

=>

o

u

0.64

Fig. 3. Spectra for thermal oxide film with andwithout annealing at 1,000°C for 60 min in nitrogen.
x10 22.56 r:-----~~-~--~--~--~--~--_,

2
x10
x10 2
2.56 r:----~~-~-~-~-~-~-_, 5.12
- - - - SHORT
-

-

LONG

MEASUREMENT(Ar IRRADIATION)
MEASUREMENT{Ar IRRADIATION)

1 .92
_

1. 92

GAMMA-IRRADIATIONWITHOUT ANNEALI NG- - AFTERGAMMA·IRRADIATION

-l
W

-l

- - AFTER

3.84

I.LJ

AFTER

Z

ANNEALING

:z

..:
:J:

Z
Z

~ 1.28

:J:
U

I-

..:

Vl

.......
1.28
Vl

2.56

:z
=>

o

u

IZ

0.64

=>
o
u

0.64

1. 28

Fig. 2. Stability of hydrogen distribution for prolonged measurement time.

Fig. 4. Spectra for thermal oxide film with andwithout annealing under the same conditions as inFig. 3 after irradiation with 1 x 106 rad (Si) gamma·
rays.

128

K. Yamamoto, et al.

of still lower hydrogen concentration and smaller thickness than usual silica samples. Samples
were prepared in Toshiba Corporation, R&D
Center, with special care for keeping surface
adsorbed hydrogen as low as possible in order todistinguish the position of interface from thebulk of substrate and film in the spectrum. For
this purpose, oxide surface of the sample wascovered with evaporated aluminum films of
about 1 J.lm in thicknesses. The structure of thesample is illustrated in Fig. 1. In Fig. 2, two
spectra of the same sample are superposed forcomparison with those measured at different
times; integrated 40 Ar4+ ion fluence as expressedby recoil Si ion counts was 8.5 x 10 4 and 2.05 X 105
for them. This result shows that slight elevationof temperature of the sample due to prolonged
measurement time has no influence on hydrogen
distribution. Figure 3 illustrates spectra obtainedwith thermal oxide film of 1,600 A in thickness
produced by hydrogen combustion method withand without annealing at 1,000°C for 60 min innitrogen. Heat treatment at 1,OOO°C for 60 min
shows a slight decrease in hydrogen concentration in the sample. In Fig. 4 are given spectra
obtained with the same samples in the samemanner as that in Fig. 3 but after irradiation
with 1 X 106 rad (Si) gamma-rays under + 5 V
applied voltage. The position of hydrogen peakis seen to shift to lower energy than before irradiation. This shift corresponds to a higher concentration of hydrogen on the interface than in theoxide.
Following model can be assumed from theseresults.

Generation of eletron-hole pair by[Step 1J
gamma-ray irradiation:
gamma-ray~e-h+[Step 2J
hole:

Dissociation of Si-H bond by the=Si-H+h+~ =Si-+H+[Step 3J
Drift of the H+ according toapplied electric field to cause the dissociation of
Si-H and Si-OH bonds on its path:=Si-H + H+~ =Si+ + H2
=Si-OH + H+~ =Si+ + H 20
These reactions in the oxide film, with which theexistence of hydrogen is concerned, lead to theformation of positive and negative charges in thefilm and some surface electric state at Si02/Si
interface. The preparation process of radiationresistant oxide film is thus supposed to correspond to the condition under which low hydrogen-content film is formed. The study will be
continued to elucidate detailed mechanisms.

References
1) H. Nagai, M. Aratani, T. Nozaki, M. Yanokura, and1. Kohno: Proc. 6th Symp. on Ion Sources and IonAssisted Technol., p. 221 (1982).
2) H. Nagai, M. Aratani, T. Nozaki, M. Yanokura, 1.
Kohno, O. Kuboi, and Y. Yatsurugi: RIKEN Accel.
Progr. Rep., 16, 125 (1982).
3) Y. Yatsurugi, O. Kuboi, M. Hashimoto, H. Nagai, M.
Aratani, M. Yanokura, 1. Kohno, and T. Nozaki:
Appl. Phys. Lett., 44, 246 (1984).
4) O. Kuboi, M. Hashimoto, Y. Yatsurugi, H. Nagai, M.
Aratani, M. Yanokura, S. Hayashi, 1. Kohno, and T.
N ozaki: Appl. Phys. Lett., 45, 543 (1984).
5) M. Aratani, H. Nagai, M. Yanokura, O. Kuboi, S.
Hayashi,!. Kohno, and T. Nozaki: 7th Int. Conf. Ion
Beam Analysis, Berlin (FRG), 7-12, July (1985).

129
RIKEN Accel. Progr. Rep. 19 (1985)

111·3·13.

Utilization of the D(3He,p)4He Reaction in Quantitative
Analyses with High Sensitivity of Deuterium in Solids
Q. Qiu, T. Kobayashi, M. Yanokura, M. Imai,
Y. Yatsurugi, and T. Nozaki

Up to now, many methods have been recommended for detection of hydrogen in solids. In allof these methods, the sensitive portion is limited
to a surface layer of about several hundred nm
thickness. For quantitative analysis of hydrogen,a high sensitivity is often required. The interference of environmental contamination is also a
serious problem. We have chosen deuterium as
an activable tracer in the study of hydrogen issolids, and utilized the D(3He,p)4He reaction for
detection.
The cross section of the D(3He,p)4He reaction
at a laboratory angle of 86° shows a peak valueof 70 mb/sr at an incident 3He energy of 645 keY;
its resonance width is about 350 keV,o The
energy of emitted protons of about 13 MeV does
'He BEAM

~

1

1
1

I
I

- 1 - COLLIMATOR

not strongly depend on the emission direction.
The deuterium concentration in solids isobtained by counting these 13 MeV protons.
The experimental setup is shown in Fig. l. A
beam of 3He+ ions was supplied from the TANDETRON (maximum terminal vo!tage: 1 MV).
The incident beam energy was 900 keY, whichcorresponds to the depth of about l.3 J.lm insilicon wafer. The beam current was about 10
nA, and the beam spot had a diameter of 3 mm.
We detected 13 MeV protons using an annular
plastic scintillator (NE102A, 73 mm X 10 mm),which had a wide solid angle of about 0.8n. The
4He particles emitted by the reaction and scattered 3He particles were stopped with a 10 J.lm
aluminium foil on the plastic scintillator. Twophotomultipliers were coupled to the plastic
scintillator and operated in coincidence for the
suppression of background counts.
Figure 2 shows three typical spectra for protons in the D(3He,p)4He reaction. They wereobtained separately from A: aD-containing
amorphous silicon film (4.860 A); B: a sample ofsingle crystal silicon saturated with D at themelting point; and C: background. The samples

"'0

-l

wb
z~

Z

a:
I,..,
uo
'-...

~~\
11\

~

(f)

I-

ZN

::::>0

o
u

I~

~

0

Fig. 1. Schematic diagram of the experimental
setup.

CHRNNEL NUMBER

Fig. 2. Spectra of protons in D(3He,p)4He reaction.

130

Q. Qiu, et al.

were supplied by Komatsu Electronic Metals Co.,
Ltd. The background in the signal region
amounts to about 0.07 cps, which determines adetection limit of this method to be about 2 X 10 16
atoms/cm 3 •Because the resonance width is very wide, thedepth profile can not be obtained, unlike theH(1sN,ay)1 2 C reaction. By a fine etching technique, however, depth information of deuteriumin solids can be obtained with a step size ofseveral micrometers. Weare investigating thesolubility of deuterium in single crystal siliconusing this method.
Reference
1) ]. W. Mayer and E. Riminin: Ion Beam Handbook forMaterial Analysis, Academic Press Inc., New York(1977).

131

RIKEN Accel. Progr. Rep. 19 (1985)

111-3-14. Comparative Mossbauer and TDPAC Studies on the
After-Effects of the EC Decays of 119Sb and I11ln in a-Fe2 0 3
F. Ambe, K. Asai, S. Ambe, T. Okada, and H. Sekizawa
Mossbauer spectroscopy and TDP AC (timedifferential perturbed angular correlation) of
y-rays have many characteristics in common as
hyperfine spectroscopies, but they have manydifferences too. Comparison of Mossbauer emission spectra of (l19Sb ~)119Sn and TDPAC ofellln~)ll1Cd is especially interesting, because
the EC decays of the source nuclides can produce
isoelectronic 119Sn H and 111Cd 2+ ions in solids.
Mossbauer emission measurements on (1l9Sb~)1l9Sn in insulators provide valuable information on the chemical states of 119Sn down toliquid nitrogen temperatureY·2) On the contrary,
the after-effects associated with the EC decay oflllIn are usually so large in non-conductive
materials that the TDP AC spectra are attenuated strongly at room temperature providing little
information on the atomic environment of lIICd. 3)
To clarify the origin of the apparently large
difference in the after-effects of the EC decays,
we compared the Mossbauer emission spectra of(1l9Sb~)119Sn and TDPAC of ellln~)lllCd in thesame matrix, the corundum-type anti ferromagnetic oxide, a-Fe203.4)
The source nuclide 119Sb was separated
repeatedly from 119mTe, which had been producedby a-irradiation of tin with the cyclotron,S) while
lllIn was obtained commercially. The samples
were prepared by hydrolytic adsorption of nocarrier-added 119Sbs + and IllIn3+ on a-Fe203 particles followed by calcination in air at 800°C for 1
h and at 1,000°C for 2 h, respectively. Their
Mossbauer emission spectra and TDP AC spectra
were recorded at various temperatures with conventional experimental setup. The absorber used
for the Mossbauer emission measurement was
BaSn03 (0.9 mg 119Sn / cm 2) kept at room temperature.
Typical Mossbauer emission spectra of (1l9Sb~)119Sn in a-Fe 203 are shown in Fig. l. Eachspectrum consists dominantly of magnetic sextetof SnH , with asymmetry ascribable to the electric quadrupolar interaction, over the temperature range studied. The curves in Fig. 1 wereobtained by least-squares fitting of the experimental points with six Lorentzian lines of the

100
607 K

99

~ 98
c
o

'iii 100
til

E
~ 98
~

t-

100

98

96
-15

o

-5

-10

Velocity

10

5

15

(mm/s)

Fig.1. Mossbauer emission spectra of el9Sb~)l19Sn
in a-Fe 2 0 3' Each curve is the result of fitting withsix Lorentzian lines of the same width.

~150

75~
:::=.

.0<:

c
~

iii

~100

50 ~

til

til

I

I

oT
o

I

I

I

I

I

I

,To

100

200

300

400

500

600

700

Temperature (K)Fig. 2. Hyperfine magnetic fields at 119Sn and lllCd
nuclei in a-Fe 2 03 derived from the Mossbauer andthe TDP AC spectra.

same width. As seen in Fig. 1, the results of thefitting are satisfactory down to 7 K, though aminute contribution of Sn H in lower magnetic
fields as well as that of Sn2+ cannot be ruled out.
The isomer shift is slightly positive against
BaSn0 3 kept at room temperature (0.2 mmls at 7

132

F. Ambe, et at.

1.8

-

~E \

-

1.6 r- 0 ,

"'0
~1/~o
."
° 0----""

S

0

~

·-

Q..>

C
...J

-

1.2 r-

OL-___~I~___~I______~~~JL~

o

200
400
Tempera! ure (K)600

Fig. 3. Line width of the Mossbauer emission spectra of (l19Sb--+)1l9S n in a-Fe203'
x 107';iIZ.6 f-

-

:0
~

-0-0-0- _
0

0

_
0

32_5 r-

-

0
10 -

-

b

~

\

d

3

d 5 r3

<J

-

0"'-.

°0

I

I

200

400

0_°_ 01-

600Temperature (K)800Fig. 4. Center and width of the distribution of WQ
giving the best fit for the TDPAC spectra of (lllIn--+)lllCd in a-Fe203'-K and 0.1 mmls at 607 K). The value of e2 qQ
estimated from the asymmetry of the spectrais - 0.5 ± 0.2 mml s. The hyperfine magnetic fields
at the 119Sn nuclei are given in Fig. 2. The mean
full-widths at half-maximum of the lines areshown in Fig. 3.
The TDPAC coefficient A22 • G22 (t) of (1lIIn-4)
lllCd in a-Fe 2 03 at 693 K and above is reproduced well by an analysis with a unique set of
WL and WQ, while assumption of a distribution of
WQ is necessary to obtain satisfactory results inthe analysis at lower temperatures. 6 ) The valuesof WQ and the relative width L1 wQI WQ giving thebest fit are shown in Fig. 4. The hyperfine mag-netic fields derived from WL are given in Fig. 2.
It can be concluded on the basis of the observations described above that the EC decay of 111In
gives rise to a distribution of e2 qQ at the I1ICd
nuclei and results in decrease in the anisotropy of
the TDPAC spectra at low temperatures. On theother hand, the shift of each Mossbauer linec(= e2 qQ(3cos2 8 -1)/8), due to the quadrupolarinteraction, is only of the order of one tenth orless of the line width(E::::;:0.06 mmls above theMorin temperature (260 K) and -0.12 mmls
below it; (line-width)<:1.4 mm/s). Therefore, a
distribution of e2 qQ around the intrinsic value,
due to the EC decay of 119Sb, brings about only
broadening of the lines in the Mossbauer spectra.
The increase in line-width at low temperatures
seen in Fig. 3 is attributed, at least partly, to theincrease in the width of distribution of e2 qQ.
In the present case of a-Fe 2 03 matrix, apparently much pronounced after-effects of the III In~ lllCd decay observed in the TDPAC spectra
as compared with those of the 119Sb ,g 119Sn in
the Mossbauer spectra are thus attributed mainly to the fact that the EC decays bring about arelative distribution in e2 qQ much larger than in
hyperfine magnetic field. The distribution in e2 qQ
affects the TDP AC spectra much strongly thanthe Mossbauer spectra, because I Q I of theintermediate level of lllCd nucleus (Q=0.77b) ismuch larger than that of the first excited level of
119Sn (Q= -0.065b).
Temperature dependence of the observed
hyperfine magnetic fields at 119Sn and lllCd (Fig.
2) is proportional to the reported one at 57Fe in
a-Fe 2 03 7 ) within experimental uncertainties.
References
1) F. Ambe, S. Ambe, H. Shoji, and N. Saito:]. Chem.

Phys., 60, 3773 (1974).
2) T. Okada, S. Ambe, F. Ambe, and H. Sekizawa: ].
Phys. Chem., 86, 4726 (1982).
3) P. Lehmann and J. Miller: ]. Phys. Radium, 17, 526(1956).

4) F. Ambe, K. Asai, S. Ambe, T. Okada, and H. Sekizawa: Hyp. Int., 29, 1197 (1986).
5) S. Ambe: ]. Radioanal. Nucl. Chem. Artie., 81, 77(1984).

6) K. Asai, F. Ambe, S. Ambe, and H. Sekizawa:]. Phys.
Soc. lPn., 53, 4109 (1984).
7) F. van der Woude: Phys. Status Solidi, 17,417 (1966).

133
RIKEN Accel. Progr . Rep. 19 (1985)

111-3-15.

Time Differential Perturbed Angular Correlation Study on(1111 n-4 )lllCd in I n2 0 3
F. Ambe, K. Asai, S. Ambe, and H. Sekizawa

Time-differential perturbed angular correlation (TDP AC) of y-rays is a useful hyperfine
technique utilizing unstable nuclei and has many
similarities to Mossbauer spectroscopy. However, application of the former to solid-statephysics and chemistry is still much more limited
than that of the latter. For the most popular
TDPAC source nuclide lllIn decaying to lllCd,
after-effects of the Auger process accompanying
the EC decay are usually very large in nonconductive compounds. Consequently, theanisotropy in TDPAC spectra is attenuatedstrongly at room temperature and provides little
information on the chemical state of llICd.l),2) It
has been shown recently that time spectra freefrom the after-effects can be obtained on (Ill In~)lllCd even in insulators from measurement at
higher temperatures. 3)-5)In literature, there are conflicting reports on
the temperature dependence of TDP AC spectraof (IllIn 3+- )lllCd in In203' In 1964, Salomon reported that the time spectrum at room temperature exhibited no periodic behavior because of
the heavy after-effects, but the one at 280°C wasinterpretable assuming an electric quadrupolarinteraction frequency with 10% of spread due tothe diminished after-effects.6) Later, Uhrmacher
and BoIse observed TDPAC spectra of lllIn203
down to 14 K, which are reproduced well with
two sets of electric quadrupolar components inaccordance with the two different lattice sites of
In 3+ in the oxide. 7 ) To clarify the large discrepancy observed in the earlier work, we measured
TDPAC of (1lIIn 3+_)lllCd in carefully prepared
IllIn203 samples and made a detailed analysis on
the time spectra obtained.
Indium metal (99.9999%) was dissolved in concentrated HCI. After addition of lllIn, indiumhydroxide was precipitated from the solution by
neutralization with ammonia. The lllIn 203 samples were prepared by dehydrating the hydroxide
at l,lOO°C for 1 h in air. The TDPAC spectra of
171 - 245 keY y-y cascade emitted from (llIIn-)lllCd in the In203 samples were measured atvarious temperatures with a conventional fastslow coincidence setup using two N aI(TI) detec-

0.15 -(a )0.10 -

o

50

100

150

Time

200

250

(ns)

Fig. l. The TDPAC spectrum of (lllIn-)lllCd in
In2 0 a at 400°C. (a), experimental points and theresult of analysis with a sum of two sets of electric
quadrupolar components; (b) and (c), calculated
curves corresponding to each of the two sets; (d),difference between the experimental points and thesum curve.

tors.
The TDP AC spectrum obtained at 400°C isshown in Fig. 1 (a). As the curve in Fig. 1 (a)shows, the spectrum is analyzable as the sum of
two sets of electric quadrupolar components «b)and (c»), not suffering from after-effects of the EC
decay. Figure 1 (d) shows the difference between
the experimental points and the sum curve. No
exponential attenuation of the anisotropy reported by Uhrmacher and BoIse) is observed in our
spectrum. At room temperature, a spectrum withlittle structure was observed as a result of smearing out by the after-effects. This observation is inagreement with that reported by Salomon6) andnot with that by Uhrmacher and Bolse. 7 )134

F. Ambe, et al.

References
1) P. Lehmann and]. Miller:]. Phys. Radium, 17, 526(1956).
2) H. Haas and D. A. Shirley:]. Chern. Phys., 58, 3339
(1973).
3) P. W. Martin, S. R. Dong, and]. G. Hooley:]. Chern.
Phys., 80, 1677 (1984).

4) K. Asai, F. Ambe, S. Ambe, and H. Sekizawa: l. Phys.
Soc. lPn., 53, 4109 (1984).
5) F. Ambe, K. Asai, S. Ambe, T. Okada, and H. Seki·zawa: Hyp. Int., 29, 1197 (1986).
6) M. Salomon: Nucl. Phys., 54, 171 (1964).
7) M. Uhrmacher and W. BoIse: Hyp. Int. , 15/ 16, 445(1983).

135
RIKEN Accel. Progr. Rep. 19 (1985)

111-4. Radiation Chemistry and Radiation Biology
1.

Cellular Lethal Effect of a-Particles on Four Different
Cell Lines
H. Majima, K. Eguchi, I. Kaneko, K. Nakano, and S. Okada

It is observed in vitro and in vivo that highLET (linear energy transfer) radiation enhances
cellular lethalityy,2) Cells are known to havevarious radiosensitivities to X-rays (low LETbeam). The question is whether there is any
relationship between cellular sensitivity to low
LET radiation and that to high LET radiation.
In the present study, the biological effect of
a-particles accelerated with the ·cyclotron wasstudied with four different mammalian cell lines:
CHO (Chinese hamster ovary cells), V -79(Chinese hamster lung cells), HMV-I (a humanmelanoma cell line), and A-7 (a human glialblastom a cell line). Survival curves of each cell line
were obtained, and the RBEs were calculated
from the ratios of doses that produce an identicalbiological effect for X-rays and a-particles.
The four cell lines were cultured at 37°C as
monolayers in plastic flasks (LUX company limited, U.S.A.) containing McCoy's Medium 5a(GIBCO, U.S.A.), in air plus 5% CO 2. The medium
was supplemented with 10% calf serum and 5%
fetal calf serum. The cells were irradiated witha-particles (LET-38 keY / Jim) or X-rays (200kVp, 20 rnA, H.V.L.=20.6 mm AI), and thenincubated for colony formation. The surviving
fractions were obtained with corrections of theplating efficiency and the cell multiplicity.
The values of RBE were listed in Table l.
Every cell line tested showed RBE of higher than1, which are in the range of RBE reported forradiation similar LET.

Table 1. RBE values of a-particles for four celllines.
10% dose (Gy)
Cell

X

a

4.3

1.9

V-79

6.5

HMV-I

5.5

A-7

5.5

CHO

RBEc

1 % doseb (Gy)

RBEd

X

a

2.3

7.3

3.8

1.9

2.4

2.7

10.5

4.8

2.2

1.7

3.2

9.7

3.3

2.9

1.9

2.9

8.4

3.5

2.4

Dose required to obtain 10% survival fraction.
Dose required to obtain 1% survival fraction.
C RBE at 10% survival fraction (10% dose X/ 10% dose
a
b

a).
d

RBE at 1% survival fraction (1% dose X/ 1% dose a).

Among these four cell lines, the most resistantcell line to X-rays was V -79, and the most sensi ctive line was CHO. The RBE for V-79 was higher(2.7, ratio at 10% dose) than that for CHO (2.3).
And the highest RBEs were found for HMV -I(3.2) and A-7 (2.9), of which radiosensitivities
to X-rays were in middle range among thosefour cell lines. These results show little relationship between radiosensitivity and RBE.
References
1) G.W. Barendsen: Curro Top. Radiat. Res. Q., 4, 293(1968).
2) T . Ohno, T. Nishimura, K. Nakano, and I. Kaneko:
Int. ]. Radiat. Biol. , 45, 21 (1984).

136
RIKEN Accel. Progr. Rep. 19 (1985)

111-4-2.

Oxygen Effects on Inactivation of the Human Melanoma Cells
by Accelerated a-Particles
K. Eguchi, I. Kaneko, T. Kosaka, T. Takahashi, and K. Nakano

Reduction of the oxygen enhancement ratio(OER) on cell inactivation is one of the major
features of high LET radiations in comparison
with low linear energy transfer (LET) radiations.
Heavy ion beams effectively kill even hypoxic
cells,l) which are probably present in solid
tumors and"lead to failure in the radiation cancer
therapy. Therefore, such a report 1) prompted us
to examine the oxygen enhancement ratio ofaccelerated ions in inactivation of highly radioresistant cells and for any cell damage specific toaccelerated ions. A special apparatus used forirradiation under hypoxic conditions with ionsaccelerated on the RIKEN cyclotron was devisedin cooperation with the RIKEN technology division (Figs. 1 and 2). By using this apparatus
highly radioresistant human melanoma cells(HMV-I) were irradiated with a-particles underaerobic or hypoxic conditions, and OER andOGF (oxygen gain factor) were calculated.
Dosimetry was carried out in cooperation with
Dr. A. Maruhashi, Univ. of Tsukuba.
1) Chambers for hypoxic irradiation
An apparatus made of stainless steel and

1

2~-tHE:..--'-"-------+

Fig. 2. Apparatus for a·particle irradiation. A hori·zontal beam passing through the slit (1) is scatteredthrough gold foil (2). A hypoxic chamber (6) withbiological sample (7) is fixed in sample wheel (3).
Scattered beam is led to open air through a aluminum window (5) and then irradiated sample (7)through a window (8). Irradiation dose is monitored with a Farady cup (4 ).

Table 1. Oxygen effect on inactivation of humanmelanoma HMV-I cells by a·particle.
LET(keV / ,urn)Fig. 1. Apparatus for gas exchange. A: Hypoxic
chamber is connected to a gas regulator; B: Hypoxic irradiation chamber.

60Co-y-ray
a-Particle
Mylar 6 ,urn
Al 16,um
50,um
100,um

RBE8

0.3
38.7
41.5
43_5
57.7

OERb

OGF

2.1

1.4
1.6
2.0
2.6

8 RBE values at 1% survival level.
bOER values at 1% survival level.

(1.2)
1.4
1.5

(1.8)
1.5
1.4

137

K. Eguchi, el al.

Dose (Gy)Dose (Gy)Dose (Gy)5

Dose (Gy)o\ 1a-particles

~,

.C

0.1-

.2
+u
o
L

u_

1'1\ 1
'\

0 .01

01

I \~

c
>

5

0.001

Aer.

\

a-particles\1\.\~AllDOl'm

\4
\

\
\

0' ~ Hyp
•

~

\1\

I ,

s

(f)

10

5
~

\

at

I

\

\' .

1\

Hyp

0.000 1L-.-_..1....._---L_---l'--_....L..-....L-..l..._-'--~L_.J._l.___L__L____L__L__ _ _ _..l..._....:..\..;.O_ _- - - '_ _ _ _- L -_ _ _- - - I

Fig. 3. Dose-survival curves for HMV- I cells irradiated with a-particles under aerobic and hypoxic conditions.

Teflon was used in order to protect the cells
environment from the toxicity and to be sterilized for prevention of biological contamination.
The apparatus enables us to exchange the atmosphere on the samples simultaneously for 4 chambers (Fig. 1). After replacement of air by nitrogengas, the irradiation chambers are sealed,removed from the apparatus, and then set infront of a 25 ,urn thick aluminum window (Fig. 2).
Twenty two MeV a-particles were led to open
air through the window. Each chamber was
rotated during irradiation to assure uniform irradiation. The window of hypoxic chamber (8 inFig. 2) is made of aluminum and is exchangeable.
2) Effect of a-particles with different LET's
on HMV-I
LET of a-particles in the sample is varied bychanging the thickness of the aluminum windowof the hypoxic irradiation chamber. The relative
biological effectiveness (RBE) for cell inactivation increased with increasing LET as listed inTable 1.

3) Oxygen effect on cell inactivation
Cell survival curves under aerobic or hypoxic
conditions are shown in Fig. 3. Each experiment
was repeated twice. The curves in Fig. 3 werefitted to a linear-quadratic relationship by a linear regression analysis. The OER and the OGF of
a-particles to y-rays are listed in Table 1. The
OER of a-particles was about 1.5, which is lessthan that of y-rays (2.1). The OER value for 41.5
keV /,um a-particles was the lowest in the curvesin the present study; however, this result may not
be accurate because aluminum of 16 ,urn thickness is too thin and easily broken in the procedure of exchanging gas. When 100 ,urn thickwindow was used, largest correlation coefficient
was obtained among hypoxic survival curves. An
aluminum window of 100 ,urn thickness wasfound to be most useful for this purpose.
Reference
1) E. A. Blakely, C. A. Tobias, T. C. H. Yang, K. C.
Smith, and]. T. Lyman: Radial. Res., 80, 122 (1979).

138

RIKEN Accel. Progr. Rep. 19 (1985)

III-4-3.

Microdosimetric Considerations of the Effect of Heavy
Ions on Microorganisms

T. Takahashi, F. Yatagai, K. Izumo, S. Konno, and T. Katayama
In a recent paper,1) inactivation cross sectionsof B. subtilis spores for heavy ions were analyzed
by assuming that the area of the sensitive element or the target is nearly equal to the spore
core area, in contrast to Katz's theory in its
original form. In the present paper, the authors
try to obtain an analytical expression forinactivation cross sections for the spores, vegetative cells of E. coli BS. 1 and B/r as a function of
LET, since such an attempt may be useful as astep toward a clear insight into the heavy- ion
action on microorganisms.
According to Butts and Katz,2) the density ofenergy delivery (erg/ cm3) as a function of distance from the trajectory of an ion is given by asimple formula Az = CZ*2(1- X / Xm) - a/(2 71af32 X
X2). Here, X is the distance from a trajectory, C
is a constant (C = 0.85 ke V /,um for water), a istaken to be unity in Ref. 2, f3 is the velocity of ion
relative ' to that of light, Xm is the maximum
range of a-electrons, and the effective charge Z*
is given by Z* = Z [1- exp( -125/3Z-2/3)] , where
Ze is the nuclear charge of the projectile. The
formula Az has been proved to be useful forinterpretation of biological effects as well as forthat of LET dependence of scintillation andtrack widths in emulsions. According to Ahlen,3)
however, the "prompt primary dose" (Dp) which
includes dose due to distant collisions may be
added to Butts and Katz's dose because thedistant-collision dose might be effective to biological systems. For H 20, e. g., one would expectthat ----""20% of the distant collision dose involves
inner shells for which deexcitation leads toAuger emission. Ahlen pointed out that the
prompt-dose profile should differ from delayedelectronic dose by about 20% and the prompt
dose will be distributed throughout a cylinder ofradius 15 A. In the present paper, Dp added to
Butts and Katz's dose was denoted by A.A (KatzAhlen dose). Chatterjee and Schaefer 4 ) established an expression (Des) for the core dose andthe penumbral dose. Des is normalized to thestopping power. Takahashi, et al.1) attempted toanalyze the inactivation cross section of B.
subtilis spores by using Az, A.A, and Des.

The energy dependence of the inactivation
cross section of B. subtilis spores for heavy ions(carbon through neon) was found to be only
slight as shown in Fig. 1. The 37% dose for
gamma-rays was 63.5 krad. To interpret theseresults and He ion data, analysis has been carried out along lines similar to Katz's theory,S) but
parameters were chosen so that they have anexperimental basis. For dose evaluation, a cylindrical target with nearly the same radius a as thespore core is assumed and mean dose 15 (r) is
calculated. Here, r is the distance between thecenter of a target and the path of an ion. It is also
possible to calculate the mean dose for a spherical target (Fig. 1). The inactivation cross section
S for nitrogen or carbon ions is fairly well explained if we assume that S is expressed asa

21l(fo ~n rdr + fa'" Po rdr)

where ~n is larger than Po. Here, ~n = 1exp(D(r)/E 1n ) is the probability of inactivation
when the ion impinges upon and goes through thespore core (r<a) and Po =1-exp(D(r)/Eo) is
the probability of inactivation when the ion
passes by the spore core and the trajectories of
~

1.2

xC
N

E

-.3
C/)

l>

1

Ref.11

®O

1.0

1)

c:

2u 0.8

0

Ne

Ref.1

•UPb} Ref.7
o

2)

Q)

Vl

~

eu

0.6

§ 0.4 ~:.;::;
ro

£ 0.2
u

5

0

---------__ 4)~0--~2--~4--~6~-8~~10----

Energy (MeVj u)

Fig. 1. Experimental and theoretical inactivation
cross sections. 1- 4: Theoretical curves calculated
by using Des for a spherical target whose crosssectional area is assumed to be 0.25 pm2 • 1, U ion,E)' = 45 krad, en = 10- 63.5 krad; 2, U ion, £& = E1n =63.5 krad; 3, N ion, Eo= 45 krad, E1n = 12 krad; 4, N
ion, £& =E 1n = 63.5 krad. Calculation for the cylindrical target gave nearly the same result as shownin Fig. 7 of Ref. 1.

T. Takahashi, et at.

139

E. coli 8s-1

x He Ref .ll

1.0

Eo=1 .26krad
a=3.998x1Q- Scmr.:. . .· :".';.~~.-x-x~~~ x

x·".~

E

~

2

0.5 - rra

0.3 -LET: (keV/ j.lm)

a-oartlcles

C ions• : N Ionsx :0.2'=-=-______~~-----_____;;~----10
100
1000

Fig. 2. Relation between Eo and LET. Solid line
shows that the relation is represented approximately by Eqn. (1).

LET (KeV / .um)

Inactivation cross section S VS. LET for E.
coli E5 .1. Solid lines show the calculated result for a

Fig. 4.

Inactivation cross section S (j.l m 2)

o~o~

o
0
~
~ ______~________tn____~~, -_____

5cylindrical target by using IkA. The cross sectional
area 7Ca 2 of the target was determined by leastsquares analysis. Eo value was assumed to be thesame as the 37% dose for gamma-rays.

E. coli Si r

Eo=3.65krad

1.0

a .=3.669 x 1O-scm .

E::t 0.5~ 0.42 - rra 2
V)

0.3

..

0.2

, ..

• : a-particles '
x : C

Ions

• : N Ions
0 . 1L-_~_-----:~_ _ _----;-;!;::n_ __Fig. 3. Inactivation cross sections S of Bacillus
subtilis as a function of He ion energy. x , Experimental; 1- 8, Theoretical curves for 7Ca 2= 0.22 ,um2
calculated by Des (cylindrical model). 1, Eo = 10
krad; 2, EO'= 63.5 krad, E1n =10 krad; 3, Eo = 15 krad;
4, Eo = 20 krad; 5, Eo = 30 krad; 6, Eo = 40 krad; 7,
Eo = 50 krad; 8, Eo = 63.5 krad. The thin solid line
shows the calculated inactivation cross section
under the assumption that Eo is a function of LET
and is given by Eqn. (1).

its a-electrons come into the spore core (r > a).
This implies that radiosensitivity of the spore forthe core of heavy ion, 1/ E1n is higher than that ofa-electrons 1/ Eo (Fig. 1). For He ions, without
separating ~n and Po, inactivation cross sections are assumed to be expressed as27l';:'~ Prdr,

where P=I - exp(D( r )/ Eo) and Eo is a dose atwhich there is an average of one hit per target.
From Fig. 3, it is clearly seen that Eo is not a
constant but it decreases from about 45 krad to
10 krad as ion energy decreases. Since Eo (krad)
is a function of LET (which is expressed by L
ke V / pm), it can be expressed approximately bya single curve if the following expression

10

100

_

1000

LET (KeV ( um)Fig. 5. S VS . LET for E. coli B/ r. Solid lines arecalculated for a cylindrical target by using Ik A.

Eo(L)=59 exp(-0.02cL)+10(1)

is assumed as shown in Figs. 2 and 3 (thin solidline). The general trend seems explicable from
Horneck's experiment6 ) which showed decrease
in repairability with increasing LET, but as tothe functional form, no explanation is possible atthe present time. The difference between experimental inactivation cross sections measured by
Facius, et al. 7 ) and calculated results for U ions(Fig. 1) may be attributable to the thermal spikeor shock wave.7 )-9) Higher radiosensitivity (1/ Eo)for a-electrons, which would give higher crosssections, should be ruled out from the reasonsdescribed in Ref. 1, where discussions were madebased on Howard- Flanders' figure on the fractionof energy dissipation per unit interval of ke V /pm. 10 ) The RBE peak appears at about 150 keY /pm which corresponds to about 0.8 MeV / u He
ions (Fig. 9 of Ref. 1).
For E. coli BS. 1 and B/ r, the procedure was

140

T. Takahashi, et at.

found to be useful but no change in Eo value wasnecessary to interpret inactivation cross sectionsfor He ions. Even for C and N ions, it waspossible to interpret inactivation cross sections
by assuming E1n = E tS = Eo (Figs. 4 and 5). It wasdemonstrated that for E. coli, RBE monotonously decreases as LET increases and the peak of
RBE does not appear for both strains. I !) The Eovalue for E. coli B/r is 3.65 krad whereas that forB5 - 1 is 1.26 krad as shown in Figs. 4 and 5. The
difference in Eo value may be ascribed to thehigher repair capability in E. coli B/r, which is
independent of LET, than that in spore.
References
T. Takahashi, F. Yatagai, and S. Kitayama: Adv.
Space Res., 3 (8), 95 (1983); T. Takahashi and F.
Yatagai: RIKEN Acce!. Progr. Rep., 16, 139 (1982).
2) J. J. Butts and R. Katz: Radiat. Res., 30, 855 (1967).
1)3) S. P. Ahlen: Rev. Mod. Phys., 52, 121 (1980).
4) A. Chatterjee and H. ]. Schaefer: Radiat. Environ.
Biophys., 13, 215 (1976).
5) R. Katz: 9th Int. Conf. Solid State Track Detectors(1976); R. Katz, B. Ackerson, M. Homoyoonfer, and S.
C. Sharma: Radiat. Res., 47, 402 (1971).
6) G. Horneck: 1st Int. Conf. Cell and Molecular Biology
in Space, Toledo (1978).
7) R. Facius, M. Schafer, and H. BUcker: Adv. SpaceRes., 3 (8), 85 (1983); M. Schafer, R. Facius, K. BaItschukat, and H. BUcker: 7th Symp. Microdosimetry(1980).
8) T. Takahashi, F. Yatagai, and A. Matsuyama: Sci.
Papers l.P.C.R., 74,51 (1980).
9) T. Takahashi, F. Yatagai, T. Katayama, A. Yunoki,
Y. H. Kang, D. S. Kim, 1. Kaneko, and S. Okada:
RIKEN Acce!. Progr. Rep., 18, 147 (1984).
10) P. Howard-Flanders: Adv. BioI. Phys., 6, 553 (1958).
11) F. Yatagai, T. Takahashi, and A. Matsuyama: J.
Radiat. Res., 16, 99 (1975).

141
RIKEN Accel. Progr . Rep. 19 (1985)

111-4-4.

High-Density Excitation by Heavy-Ions: Formations of Dimer andClusters of Helium-Excimers in Condensed Phase
K. Kimura, M. Kataoka, K. Hara, and T. !ida

Weare interested in the high-density electronic
excitation induced by heavy-ion impingement
and also in dE / dx dependence of excitation
along the path of heavy-ions. This report
describes that new emission bands found in N -ion
impinged dense helium gas and liquid are
attributed to emissions from clusters composedof helium-excimers. Recently, one of the present
authors has reported that N -ion impinged dense
helium gas (------400 Torr at 5.2 K) presents new
triplet emission bands centered at 4,587 A andthey are assignable to vibronic bands of the
dimer of helium-excimers.ll One of constituent
excimers of the excimer-dimer has been shown tobe the lowest triplet metastable excimer a 3 (lifetime is ------ 1 ms) and the other is b 3 , c 3 , or d 3 , where
the alphabetical notation of the excimers isaccording to Herzberg. It has also been shownthat overall reactions for the high-density excitation by N -ions are exhibited by
He*+2He,(1)

where He2*=a, b, c, d,"', A, B, C, D,'"(2)
d3+He2,l*-+He2,m*+He2,n* or He2.k*+hv(3)

5. OX10 4~5~8~~~~~~~~~~~~~~~~~~~
4 . 05cn4 . 0XI0
E; 3 . 0Xl0 4~2 . 0Xl04~ 1 . 0Xl0 4n ~~~~~~~~~b;~~~~~~~~

4.. OX 104.
~ ']. (IX 1 04.
~
dW 2 . (IX 1 (! .
~ 1. (IX 1(1.1·u)u)~ "3. (IX 1 0 4.

~ 2, CJX 104.
~ 1 . ClX104.
cn 4. 0X104~:3 . 0X104~2.0X l 0 4~ 1.0Xl04

n ~~~~~~~~~~~~~~~~~~
4
4. OX10~3 . 0Xl0 4
U)~2 . 0Xl04.I
CL

1. OXI0 4

Io ·~~~~~~~~~~~~~~~~~~~~~WAVEN UMSE'RI (l/CMJ.

Fig. 1. Pressure dependence of emission spectra of N -ion impinged dense helium gas at 5.5 K and liquid at 3.9 K. Real
.spectral intensity can be obtained by deviding that read on the spectrum by a scale factor which is given just in
the upper area of each band. Notation such as f-b denotes the excimer-emission and those of Di and Cl denote theexcimer-dimer and excimer-cluster emissions.

142

K. Kimura, et at.

IX

.8
Q)

>
ro

:;::;

.

Q)

~ 1.0

!

Q)

:;::;

<Ii

@

0

-~------ -~--- "--~

c

2c
c
o
. <Ii

o

o

VI

'E

+.==~~~

100 200 300 400 500 600 700

L.LJ

Pressure/ Torr

Fig. 2. Pressure dependence of emission· intensities
relative to that for the f-b emission. 6, h-b; X,
Di·emission; 0 , e, @], \1 , D, and + stand for the
Cl-emissions at 4,493, 4,785, 5,117, 5,619, 5,554,
and 5,234 A; measurement was carried out at 5.5
K.

a 3 + He2,i *-4 He2,j * + He2,k * or He 2,m * + hv
(4)

or in a general form,

He2,k * + He2,l *-4 He2,m * + He2,n * or He2,i * + hv

(5)
a +c ,b , d -4excimer-dimer (Di)
3

3

3

(6)

3

Of the above reactions, reactions (2)- (6) arevery characteristic. Namely, reactions between
excimers lead to the conversion of the excimers
into other excimers, the dimer-formation, and thephotoemission, but do not lead to quenchingprocesses; this is quite different from the usual

density-effect for excited large molecules whose
collisions lead to quenching.
For liquid helium, whose density is 20 times
larger than that of the gas sample used here or inwhich energy dissipation increases in a similarmanner, the emission spectrum was found topresent new bands quite different from the gas
spectra in the wavelength region from 4,000 to
6,800 A. Now, neither excimer-emissions nor the
Di-emission (emission from Di) can not be observed. All broad bands observed at 5,600, 5,220,
5,110,4,980,4,780, and 4,480 A can be attributed
to new ones which have not been found so far by
the methods using electron impingement. In alast progress report, we have tentatively
proposed that these new bands are due to emissions from the clusters composed of the heliumexcimers. The present report presents important
experimental result which supports the previous
tentative assignment.
Spectra given in Fig. 1 show the variation of
the emission spectra with increasing gas pressure
at 5.5 K up to liquid state at 3.9 K. This pressure
dependence corresponds to shortening in an average atomic-distance from""'" 10 A to """'3 A or to
an increase in energy dissipation from ---.....0.2
eV / A to """'20 eV / A. At 103 Torr, only excimeremissions are observed in Fig. 1, but neither Dinor Cl-emission are yet recognized. As the pressure increases up to "'-"""-200 Torr, the Di-emission
appears and at 423 Torr, both Di- and CIemission are observed, while the excimeremissions are suppressed. With further increase
b

0

b

(A)

~

(8)

~
a

00

o

50
T I HE/NS

Fig. 3.

100

50

100

T IM E/NS

Decay curves of the CI·emissions at 5,105 (A) and 5,557 (B) A at several gas pressures at 5.5 K.

K. Kimura, et at.

in pressure, the Di-emission are suppressed, while
the Cl-emission increases. In this pressure-range,
the excimer-emissions can not be recognizedexcept for the intense one for the f~b transition
and those due to the transitions between higher
Rydberg states which appear in the wavelength
region larger than 6,000 A .1) In the liquid phase,both excimer- and Di-emissions are completely
suppressed in the wavelength region where theCl-emission appear. The pressure dependence ofthe emission intensities is shown in Fig. 2, where
the emission intensities are plotted relatively tothat for the f~b excimer-emission. The f state
can be regarded as the best standard for thedensity-effect, since its lifetime is short ("'-'4 ns)
and free from second order reaction 2. Figure 2
shows obvious density dependence of the Di- andCl-formation, suggesting that following reactions
become important with density,
Di + Hez * ~ (He2 *)a(7)(He2*h + He2 * ~ (He2*)4(8)

and further clustering where He 2* is considered
to be lower lying excimers, b 3 , c3 , or d 3 as shown
later. The result that the broad band near
5,600 A appears at pressure higher than 500
Torr in contrast with other Cl-emissions beginning to appear near 300 Torr suggests that thisband may be due to the cluster composed of alarger number of excimers. This may be supported by the result that the emission intensities
without those at 5,557 and 5,234 A begin to
decrease from "'-'500 Torr.
N ext, two typical decay data are presented inFig. 3, in which (A) and (B) show pressuredependent decay curves of the emission bands at
5,557 and 5,105 A, respectively. A common result
derived from the two emission bands is that the143

decay-curve can be separated into the fast andthe very slow components. The former component increases with pressure, although the one
for 5,105 A decays much faster than that for
5,557 A. The latter component, which has solong decay time that their changes cannot berecognized in this time-range, increases withpressure. This component makes principal contribution to the total emission intensity compared with the fast component. The slow decay
component may be explained by taking into
account of the regeneration (2), since Cl-states
impossibly has such long spontaneous lifetimes,
because of their allowed transitions. Namely, thelong decay times of the Cl-emissions should be
decided by bimolecular regeneration-reactions
which can produce c3 , d 3 , and perhaps b 3 as longas the a 3 exist; the concentration of the a 3 isconsidered always to be the highest of all
excimers under the present experimental
conditions. I) This explanation is the same as thatdone in Ref. 1 for the very long decay time of the
Di-emission. The fast decay components andtheir increase with pressure can be explained as
due to a large initial concentration of the excimers. The faster decay for the 5,105 A band
than that for 5,557 A may be easily understoodfrom the stepwise clustering shown in reactions(7) and (8). The decay curves for the other Clemission, those at 4,493, 4,785, 5,234, and5,619 A, are classified as follows. Those at 5,234
and 5,619 A bands have the similar decay to thatat 5,557 A, while those at 4,493 and 4,785 A are
similar to that at 5,105 A. This classificationagrees well with that for the pressure dependence
shown in Fig. 2.
Reference
1) K. Kimura:]. Chern. Phys., 84, 2002, 2010 (1986).

144
RIKEN Accel. Progr . Rep. 19 (1985)

111-5. Instrumentation

1.

Test of EBIS for Electron-Ion Merging Beam Experiment
S. Ohtani, Y. Awaya, Y. !toh, T. Kambara, Y. Kanai, T. Koizumi,
T. Mizogawa, K. Okuno, H. Shibata, S. Takagi, and S. Tsurubuchi

We are starting an ion-injected EBIS (Electron
Beam Ion Source) experiment using the linac.
The purpose is to study collisional processes ofelectrons and heavy ions by a merged electronion beam method using a heavy ion beam. The
EBIS apparatus used is called "proto-NICE,"l)which has been developed at Institute of Plasma
Physics, Nagoya University.
In the present stage, the proto-NICE has beenrebuilt in the experiment area of the linac andthe test operation of an electron gun and extraction of the produced ions are being carried out.
Figure 1 shows a schematic view of the protoNICE. The electron gun is of a Frost type2 ) with
about 2 micro-perveance and operated under theconditions of the Brillouin flow. The typicalcurrent density of the electron beam is estimatedto be more than 10 AI cm 2 • At present, more than
95% of the electron beam emitted from the cathode (about 100 rnA) can reach the electron collector electrode. Fourteen drift tubes with an internal diameter of 6 mm, whose potentials arevariable independently, are used to provide goodconditions for EBIS operation. The produced
COMPENSATIONCOILSHIELD

f-IAIN

COIL

ions are extracted and their charge states areanalyzed by using a sector magnet. An exampleof the charge state distribution of the ionsc:.2

Magnet current

Fig. 2. Typical spectrum of the charge-state distribution of ions extracted from the proto-NICE analyzed by a magnet. The ions are from residual gas
with H, C, N, 0, and 13C02 gas supplied from theoutside. The measurement was carried out under
the conditions that the electron beam intensity was
76 rnA at 1.9 ke V and the background pressure wasabout 2.6 x 10- 8 Torr.

COMPENSATIONCOILSHIELD

Fig. 1. Schematic view of the proto- NICE. The distance between the cathode and the ion lens is about 60 crn.

S. Ohtani, et al.

extracted from the proto-NICE is shown in Fig.
2. In this case 99% enriched 13C02 gas was supplied from the outside to separate produced
naked carbon ions from background H2 + ions.
The Nand 0 ions in Fig. 2 are from the 13C02 gas
and the residual gas, mainly CO 2 , H 2 0, and N 2 •Typical intensities, at present, of the extracted
Li-like ions of C3+ and 0 5+ are about 106 cps, andthat of naked carbon ions, 13C6+, was about 50

145

cps. We also observed about 250 cps of naked
nitrogen ions 15N7+ by supplying enriched 15N 2
gas.
References
1) H. Imamura, Y. Kaneko, T. Imai, S. Ohtani, K.
Okuno, N. Kobayashi, S. Tsunibuchi, M. Kimura, and
H. Tawara: Nucl. Instrum. Methods, 188, 233 (1981).
2) R. Frost: Proc. IRE, 56, 1800 (1962).

146
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-2.

Test of a Position-Sensitive Parallel Plate Electrostatic
SpectrographY. Kanai, Y. Itoh, T. Koizumi, H. Shibata, T. Matsuo,
H. Kumagai, T. Kambara, M. Kase, T. Mizogawa, and Y. Awaya
Analysis of charged particles can be carriedout magnetically or electrostatically. For low
energy electrons (E < 10 keV), electrostatic analyzers are available. A parallel plate electrostatic analyzer has a structure simpler than thatof other electrostatic analyzers and may be constructed accurately. We have constructed aposition-sensitive parallel plate electrostatic
spectrograph using a position-sensitive electron
detector, described in a previous report,l) in
which a tandem microchannel plate (MCP:
Hamamatsu Photonics F1552-03 X 2) and a Si
position-sensitive detector (PSD: Hamamatsu
Photonics S1352) are used in order to measure
the electrons ejected in heavy-ions atom collisions.
A schematic drawing of the spectrograph isshown in Fig. 1. The spectrograph is composed ofthree parts: (1) a triple aperture lens; (2) a 45°
type electrostatic parallel plate analyzer; and (3)a position-sensitive electron detector. The advantage of using the position-sensitive electron
detector is that it allows us to obtain broadrange energy spectra of electrons at a time. The

potential Vo of Analyzer plate 2 determines theenergy Eo of the electron detected at the center of
MCP: Eo = e Vo in the ideal case. The potential
difference Vd between Analyzer plates 1 and 2
determines the width Ew of the electron energy
spectra obtained at a time: Ew = 0.45 e Vd in thepresent case.
Typical results obtained with the 1.5 ke V electron impact Ar L-MM Auger electrons are shownin Fig. 2, in which the values of Vo and Vd of each
spectrum are given. We can obtain spectra withrelatively high resolution as Vd is decreased. The
spectra in Fig. 2 (b) corresponds to the highest
energy group of the peaks shown in Fig. 2 (a).
The L3-M 2,3M 2.3(3P) and the L2-M2,3M2.3(1D) peaks
are clearly separated from each other in Fig. 2(b).

We have also carried out preliminary measure(a)Vo =-190V
Vd =-190V

56

o 1 2 3 4 5cm

Fig. l. Schematic drawing of the Spectrograph. 1,
Triple aperture lens; 2, Analyzer plate 1; 3, Guard
rings; 4, Analyzer plate 2; 5, Position-sensitiveelectron analyzer (Mep, PSD); 6, Holder.

Electron energy

Fig. 2. Typical results of electron impact Ar L-MM
Auger electrons.

147

Y. Kanai, et al.

L-M M
2,3

10

2,3 2,3

Vo =-180 V

L -M M

Vd =-180 V

2,3

2,3

1

L -M M
2,3

160

1

1

180
Electron energy

200

Fig. 3. Preliminary results of Ar L-MM Auger electrons in He+ -Ar collisions.

ment of the Ar L-MM Auger electrons in He+ -Ar
collisions. The results are shown in Fig. 3. The
background level is higher than that in the electron impact case. A part of the background is dueto the dark counts of MCP of about 0.9 counts
per second. The high background level is an
obstacle to measurement of the electrons ejectedin heavy-ions atom collisions; an effort of reducing the background is in progress.
Reference
1)

H. Kumagai, Y. Itoh, T. Koizumi, H. Shibata, and Y.
Awaya: RIKEN Accel. Progr. Rep., 18, 162 (1984).

148
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-3.

Parallel Plate Avalanche Counters

H. Kumagai, T. Kubo, M. Ishihara, M. Fuse, and E. Gotoh

The parallel plate avalanche counter (PP AC)l)has an excellent timing property, high counting
rate capability, and superior registance against
radiation damage. Previously we constructed a
prototype model of the one-dimensional positionsensitive PP AC and studied its fundamental
characteristics. 2) Based on the techniques established through this work, we have newly constructed two PP ACs of different types. In thisreport we present the result of investigation on
the timing characteristics, the position resolution, and the detection efficiency for these detectors as well as for the previous one, using particle beams obtained from a radioactive source,
the Cyclotron, and the RIKEN heavy-ion linear
accelerator (RILAC).
1) A one-dimensional position-sensitive
PP AC with a grid
Structure of this counter and the associatedgas- feed system and electronic circuits are described in Ref. 2. Briefly, the chamber of thecounter contains two pairs of electrodes: one(with a grid) for position detection and the otherfor provision of a stop signal for timing measurements. The counter, which was filled with isobutylene ga,s (10 Torr) and applied voltage 800 V,

was exposed to a uniform-intensity beam ofa-particles from a 24 1Am source. Pulse-hight
distribution of the grid signal is shown in Fig. 1.
Figure 2 shows the obtained position spectrum,in which each peak seen corresponds to theposition of the respective grid wire strung at 2mm intervals. Figure 3 shows the result for thetiming characteristics, which was obtained byusing a finely collimated a-beam from 241Am andwith an applied voltage of 850 V. A full-width-athalf-maximum (FWHM) of 0.82 ns observed forthe peaks implies that a time resolution intrinsic
to each pair of electrodes is 0.58 ns.
2) A position sensitive PPAC with a multistrip cathodeWe have constructed a one dimensional position sensitive PP AC whose cathode consists of ahundred strips of conductors (46 X 0.9 mm 2) with
0.1 mm inter-strip spacing. These strips are formed on a printed circuit board (100 X 46 mm 2), andall contiguous strips are connected to each otherby chip resisters of 100 n. An anode, made of a 60
J1g/ cm 2 thick Au layer evaporated on 1. 5 J1m
thick Mylar foil, has a sensitive area of 100 X 20mm2. The cathode and the anode are aligned
parallel to each other with a 3 mm gap. Figure 4
shows the result of measurement of the position

.10

'
2.05
~-..-----r-----r-----,----,.--,....--.....-------,

a-particleLTgisobutylene(Am-241)-10·
3 . 2 8 , - _ . . . . . - - - _ - , - - _ - - - . - _ - - - , - _ - - - ,_ _. . - - _ - . - - - _ - ,10.0 Torr

3000 cps

iSO-butylene

a-particle

800 V
2.87

(Am-241)

10.0 Torr

3000 cps

800 V

1.28

2.05

0 .77

O.SI

1.23

0.25

0.82

°O~~~-~-~--~''-~--~--~~

0.~1

CHANNEL NUMBER

Fig. 1. Pulse-height distribution of signals from thegrid of a one-dimensional position-sensitive PP AC
exposed to a uniform-intensity beam of a-particles
from a 241 Am source.

O~0~~-~--~-~,2 -~-~--=~~CHANNEL NUMBER

Fig. 2. Position spectrum obtained by using thesame setup as that in Fig. 1.

149

H. Kumagai, et at .
• ,0"

1 . 5 4 , - - - , - -- - r - -- - - - r - - - - - , - -_ _. - - - - r - - - - - , - - - - - ,iso-butylene
10.0 Torr
800 V

a-particle

1.43(l\III-241)- 10"

1 . 5 4 , - _ - r - - _- - , - _--.--_---.-_--,. _ _,.--_...,.....-----,
N-85 MeV

iso-buty1ene

1 .43

10.0 Torr
750 V

1·23

1.02

1.02

0.82

0.51

0.51

0.41

0.4 1

0.20

o.zo

0~0-~-~--~\~-~S~12~~-~-~-~CHANNEL NUMBER

J,

2.6

j

CHANNEL NUMBER

Fig. 3. Timing characteristics of thedimensional position sensitive PP AC.

one-

e'O"

3 . 2 8 , - - _ - , - - _ - r - _ - , . . - _ - - - , - _ - - ,_ _.,.....-_-,....-_--,

2.87

0.54 ns~r---a.-particle

iso-butane(l\III-241)

6.00 Torr

2000 cps

600 V

1. 23

0.41

0~0L-~-~--~-~12-~-~-~~~CHANNEL NUMBER

Fig. 4. Position spectrum obtained with a positionsensitive PPAC with a multi-strip cathode. Conditions for the incident particles used are same as
those given in Fig. 1.

detection characteristics, obtained by the same
incident beam as that was used for determinationof the spectrum of Fig. 2, with filled iso-butanegas (6.0 Torr), and an applied voltage of 600 V.
The interval between adjacent peaks of the spectrum shown in Fig. 4 correspond to 1 mm spacing
between the cathode strips. This PPAC will be
used by an atomic physics research group with amagnetic analyzer for measurement of charge
distributions of scattered particles in atomic
collisions.
3) Disc-type PPACs
In order to investigate the timing characteristics and the counting-rate capability using beams
obtained from the Cyclotron or RILAC, we haveconstructed two PPACs of a small-size withdisc-shaped electrodes: one (PP AC-30) with bothFig. 5. Timing characteristics of the disc-type
PPACs of a small size, obtained for the incident
particles of 14 N at 85 MeV.

electrodes 30 mm in diameter and with a 3 mm
gap and the other (PPAC-6) with both electrodes
6 mm in diameter and with a 3 mm gap. The twocounters are placed in parallel 6 mm apart fromeach other. The time resolution was measured byusing an 85 MeV 14N beam from the Cyclotron.
The result is shown in Fig. 5. A FWHM of thepeak of 0.54 ns was observed, which corresponded to the time resolution intrinsic to each counterof 0.38 ns.
The counter response to high counting rates
was investigated by using a 6.8 MeV a-particle
beam accelerated with the RILAC. Experimental
arrangement is shown in Fig. 6. The a-particles
traversed through 2 mg/ cm 2 thick Au foil (abeam spot size of about 5 X 5 mm 2 ), entered
PP AC-6 and PPAC-30 placed at 0°, and finallywere collected in a Faraday cup, at which thebeam current was measured with a current
meter. The beam intensity was also monitored bydetecting scattered particles from the Au foilusing a SSD placed at 20°. Signals from the two
PP ACs and the SSD, together with the output of
the beam current meter converted into a pulse
signal by means of a voltage-to-frequency converter unit, were fed to an on-line data acquisition system. 3 ) The system was operated in an
8-parameter multi-channel scaling (MCS) modewith an advance signal of 0.1 s, thus enabling us
to record data every 0.1 s. The result of investigation on the counting rate capability is shown in
Fig. 7, where the counting rates in the detectors
are plotted as function of beam current (bothaxes are in logarithmic scale). Only three data
points were plotted for PP AC-6, since further
measurement has not been made for this counterdue to damage of the electrodes induced by the

H. Kumagai, et at.

150

SSO

0=8mm
PPAC-6

PPAC-30
Faraday cup

He-ionE=6.8Mev
f=35MHz

0=64mm

125mm--1
TargetAu 2mg/cm'

Winddow
Counter Gase
0=30mmiso-butylene
2.5,um mylar
lO.OTorr

Fig. 6. Experimental arrangement used in the investigation of the counting rate characteristics using a-particle
beam from the RILAC.
10'~_ _ _ _ _ _ _ _ _ _ _ _- , - l OO O
N=J . 2I B xlO I 'I-Ie - i o n

SSD

E===6. SMe v

f =- ) S Mll z

P PAC - )0

100

1 0'

.,u
"-

""

"

o
u

10 z
10

0.1

glow discharge. The curve for the PP AC-30
increases linearly in the region of low counting
rates but begins to deviate from linearity at acounting rate of about 2 X 106 cps, exhibiting atendency towards saturation at higher counting
rates. Though the position distribution of thebeam intensity was not uniform, it can be concluded that the saturation begins to take place at
a local density of incident particles of 7 x 105 cps/
cm2 at the central region of the sensitive area,
based on the observed curve for the counter(PP AC-6) of a smaller-size. The broken line in
Fig. 7 represents the number of incident particles
deduced from measured beam current. Observed
10% deviation from the PP AC-30 curve in the
low intensity region can be attributed tomisalignment of the Faraday cup and the uncertainty (±6%) in the beam current meter used.

10

I,( pA )

Fig. 7. Result for the counting rate characteristicsof the disc-type PP ACs. Counting rates in PPAC-30,
PP AC-6, and SSD (beam monitor) are plotted asfunction of beam current. Broken line represents
the number of particles per unit time deduced fromthe beam current.

References
1) H. Stelzer: Nucl. Instrum. Methods, 133, 409 (1976).
2) H. Kumagai, S. H. Be, M. Ishihara, Y. Ikegami, M.
Fuse, and E. Gotoh: RIKEN Accel. Progr. Rep., 18,
164 (1984).
3) H. Kumagai, S. Sasagase, and T. Wada: Reports 1. P.
C. R . (in Japanese), 62, 114 (1986).

151
RIKEN Accel. Progr. Rep. 19 (1985)

III-5-4.

Performance of a 8aFz Scintillator as a Charged
Particle Detector

T. Murakami, ]. Kasagi, H. Tachibanaki, K. Yoshida, and T. Kubo

We have tested the performance of a BaF2
scintillator as a charged particle detector, since
the BaF2 was found to have many attractive
features as described in Ref. l. So far, we haveinvestigated the possibility of the particle identification by a pulse-shape-discrimination technique and measured the response of the scintillator to protons, deuterons, and a-particles. 2) No
information on the response to heavy particles isavailable. In the present study we have measured
the response to 160 and 40 Ar particles.
The scintillator response was measured withelastically scattered 160 and 40 Ar ions obtained
from RILAC. A thin gold foil was bombarded by
16 0 beams with energies ranging from 9.5 MeV to
22 MeV and by 40 Ar beams from 23 Me V to 54
Me V. The BaF2 crystal used was rectangular one

/

p,.V

>-

j

;!7d

~10

16 0

//

~0.l

c
>en
....

!

j/a
.'

~

c

./

~

/ I

>-

:!!

~
....J

I

2

40Ar

/

100

10
Energy (MeV)

Fig. 1. Light output (L) of a BaF2 scintillator forvarious particles in units of y-ray energy deter·
mined by 60CO and l37Cs.

Table 1. Relative values of L for a BaF2 and aplastic scintilla tors.

BaF2
Plastic

Proton

a

16

100

59
27

13

100

0

3.9

with dimensions of 2 x 4 x 1 cm 3 • In order todetect the fast component efficiently, the photomultiplier with a quartz window (Hamamatsu,
R329-Q) was employed. The crystal was wrappedwith a conical mirror and attached to thephotomultiplier by using silicone grease. The
detector was set at 300 with respect to the beam
direction. Dynode pulses were fed into apreamplifier (ORTECl13) and an amplifier(ORTEC572), then digitized by a NIM ADC.
Figure 1 shows the light output, L, for various
particles as a function of particle energy. The
units for L represented by the y-ray energy were
determined by the output for 60CO and 137CS.
Several features are observed in Fig. 1. First, L
for protons is almost linear with particle energy.
Furthermore, the amount of L for all particles isroughly described by the relation L"-' En. The
case of n = 1 corresponds to the data for protons.
The value of n becomes larger for heavier particles and it reaches about 1.5 for the case of 40 Ar.
Second, the amount of L at the same particle
energy is largest for protons and it decreases forheavier particles, that is a common feature of
scintillation detectors. However, the BaF2 scintillator emits larger output for heavier particles
than other kinds of scintillators. Relative valuesof L for protons, a-particles, and 16 0 particles of
20 MeV are tabulated in Table 1, where the valueof L for protons is normalized to 100. Also ~hown
are the ratios for plastic scintillators cited from
Ref. 3. The ratios of L to detect heavier particles
are 2 or 3 times larger for the BaF2 scintillator
than for the plastic scintillator.
As a result we conclude that the BaF2 scintillator is suited for charged-particle detection.
References
1) T. Murakami, J. Kasagi, T. Inamura, and M. Ishihara: RIKEN Aeee!. Progr. Rep., 18, 160 (1984).
2) T. Murakami, J. Kasagi, Y. Nagashima, T. Naka·gawa, W. Galster, W. Yokota, and S. M. Lee:
UITAe, 50, 31 (1985).
3) F.D. Becchetti, C. E. Thorn, and M. J. Levine: Nucl.
Instrum. Methods, 138, 93 (1976).

152
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-5.

Response of BaF 2(Powder)-Plastic and
BaF2 Scintillators to Protons

S. Kubota, T. Motobayashi, ]. Ruan (Gen),* T. Shimizu,**
I. Kohno, and M. Ishihara
We have developed a BaF2 -plastic mixture(scintillator) which has a response as fast as thatof BaF2 crystal, wavelength of 410+30(-20) nm,
and good mechanical properties. The response
curves of this scintillator and BaF2 wereobtained for proton beams of < 15 MeV.
The barium-fluoride plastic scintillator (BPS)
consists of BaF2 powder (70 wt %) and methylmethacrylate (30%). Luminescence from powder
BaF2 is converted by '"'-'1% buthyl-PBD (2-(4-tbutylphenyl)-5-4-( 4-bipheny 1)-1,3,4- oxadiazole)and 0.02% BDB (4,4-bis-(2,5-dimethylstyryl)diphenyl). The reflective index for resin (methylmethacrylate) is matched to that of BaF2 •In this experiment, 15 MeV proton beams fromthe cyclotron were elastically scattered from a
Au target and extracted from a vacuum chamber
through a 15 ,urn Mylar window. Passage
through Al absorbers allowed us to vary the ion
energy entering the scintillator. Proton energy
was measured with a silicon semiconductor
detector calibrated with 5.16 MeV (239PU), 5.49
MeV (241Am), and 5.80 MeV (244Cm) a-particles.
The light outputs from BPS and BaF2 (Horiba,
Kyoto, 20 mm dia. X 10 mm) were measured witheither an R329 (borosilicate glass window) or an
R1668 (fused silica window) photomultiplier. An
aluminium foil was used as a light reflector.
Figure 1 shows energy spectra obtained with
BPS (R329) and BaF2 (RI668) for scattered pro-tons without an absorber. As shown in Fig. 1, 4.4
MeV y-rays were also detected. These y-rays
were induced by proton bombardment at a carbon plate used as a beam stopper. The FWHM
energy resolutions for 15.4 MeV protons were
12.l%, 9.8%, and 16% for BPS (R329), BaF2
1

BPS (R32 9) :p(o), e(6)BPS(RI668) :p(e), e(A)BaFdR 1668): p( x), e(o)

I

0

0

o/X

2001-

E
.~

0

IX

1 !~/ /"
100,.~ /y"

CJ

)g;/"

o~v
o

5

10

15

Proton energy (MeV)

Fig. 2. Light response curves for protons and 4.4 and0.661 MeV' photoelectrons.

SOns/div

Fig. 1. Energy spectra of 15.4 MeV protons measured with BPS (R329) and BaF z (RI668).
* Rikkyo University.
* * Kyowa Gas Chemical Ind. Co., Ltd.

Fig. 3. Oscilloscope traces for the scintillation
pulses from BPS for 15 MeV proton beam excitation (upper trace) and relativistic electron beam
excitation (lower trace).

s. Kubota, et at.
(R1668), and BPS (R1668), respectively. Figure 2
shows response curves of BPS (R329), BaF2
(R1668), and BPS (R1668). The relative pulse
height for BPS (R329) is normalized at 15.4 MeV
to that for BaF2 (R1668). Data points for 4.4 and0.661 MeV electrons are also shown. The
response curves for BPS and BaF2 crystals areclearly convex over the entire energy region
studied. The light outputs of both scintillatorsfor 4.4 MeV protons are 80% of those for electrons of the same energy.

153

Figure 3 shows oscilloscope traces for the
scintillation pulses from BPS excited by 15 Me V
proton beam (upper trace) and by relativistic
electrons (lower trace). The slow component
fraction of 600 ns for proton beam excitation isgreater than that for electron excitation. Thislarge difference will be used for n-y-pulse shapediscrimination.
The new BaF2 -plastic scintillator we havedeveloped will be extended in size and will beapplied to many fields .

154
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-6.

RIKEN BGOACS and Chateau de Cristal

Y. Gono, M. Fukuda, T. Kohno, M. Sugawara, H. Kamitsubo,
F. A. Beck,* T. Byrski,* G. Costa,* C. Gehringer,* B. Haas,*lC. Merdinger,* B. Nourredine,* S. Rouabah,* and l P. Vivien*
Six sets of anti-compton shields (ACS) made ofbismuth germanate (BGO) crystals were constructed in 1984.1) Four of them were sent to CRN(Centre de Recherches Nucleaires), Strasbourg,
in August, 1985, and used with Chateau deCristaF> for the in-beam y-ray spectroscopy
studies. The Chateau de Cristal is a 47l'y-ray
detector system consisting of 74 hexagonal BaF2
counters. A picture of BGOACS and Chateau deCristal set in the beam line of MP tandem at
CRN Strasbourg is shown in Fig. 1. This combined system was almost ready for experiments
in November, 1985, and has been used for sometest experiments.
Since the Chateau de Cristal is a national
project in France, many groups proposed experiments. The RIKEN group proposed a joint experiment with Orsay and Strasbourg group (Ch.
Briancon; G. Bastin, F. Hannachi, M. G. Porquet,
C. Schuck, ]. P. Thibaud, and N. Schulz) on Th
isotopes. A test experiment has been successfully
made on 222Th using the 2osPb(lsO, 4n)222Th reaction in November, 1985.

* Centre de Recherches N ucleaires Strasbourg.

Fig.I. RIKEN BGOACS with Chateau de Crista} set
in CRN Strasbourg.

References
1) M. Fukuda, Y. Gono, Y. Ishikawa, M. Sugawara, T.
Inamura, M. Ishihara, T. Nomura, I. Kohno, H.
Kamitsubo, J. Kasagi, and T. Murakami: RIKEN
Accel. Progr. Rep., 18, 152 (1984).
2) F. A. Beck: Proc. Int. Conf. on Instrumentation for
Heavy Ion Nuclear Research, Oct. 22-25, p. 129 (1984).

155
RUffiN Accel. Progr. Rep. 19 (1985)

111-5-7.

Radioactive Beam Production at GANIL

R. Bimbot,* P. Aguer,** G. Bastin,** R. Anne,*** H. Delagrange,***Y. Schutz,*** Y. Gono, K. Hatanaka, and H. Kamitsubo

A radioactive beam production experiment
was performed at GANIL (Grand Accelerateur
National d'Ions Lords) in 1985 using LISEl)(Ligne d'Ions Super-Epluches). The primarybeam of 180 (E = 65 MeV/A) was provided by
GANIL. Production rates of 16C (T1/2 = 0.75 s), 17N(Tl/2 = 4.17 s) and other elements were measured.
Targets used were Be (569, 1,036 mg/ cm 2), AL(622, 1,138 mg/cm 2) and Ni (748, 1,351 mg/cm2).
Reaction products were transported by LISE andidentified with a LlE(500 JLmX 300 mm 2)- E(5,000
JLm X 300 mm 2) counter telescope of Si detectors.
Time-of-flight information was recorded at thesame time. Since the targets were very thick, theenergy spread of the reaction products was large.
Consequently various kinds of reaction products
were brought to the detector position by one
momentum setting of the magnets. Those reaction products were separated from each other byusing an energy degrador of Al (150 mg/ cm 2)placed between two dipole magnets. The
differences in energy loss among various ions by
the degrador were large enough in the present
experiment to separate the reaction products.
The ions of 16C and 17N were obtained rather
purely up to about 106 and 107 pps, respectively,
with the primary beam intensity of 1012 pps. The
target dependence of the yields was almost constant if this quantity was calculated per one
target atom. This leads to a conclusion that thetargets of lighter elements give larger yields ofthe radioactive beam when target thicknesses
are adjusted to give the same energy losses forthe reaction products. An example of the yield* lnstitut Physique Nucleaire Orsay.
** CSNSM Orsay.
*** GANIL.

1.0

0.1
0
...J

W

>=
W

>

i=

:3
w
a::

0.01

1.2

1.3

1.4

1.5

MAGNETIC FIELD (T )Fig. 1. Relative yields of 14.15.16C ions from the Be+
180 reaction at 65 MeV/A. Horizontal axis is themagnetic field strength of the second dipole magnet.

curves for carbon isotopes is shown in Fig. l.
Reference1)

M. Langevin and R. Anne: Proc. lnt. Conf. on Heavy
Ion Nuclear Research, Oct. 22-25, p. 191 (1984).

156
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-8.

Monte Carlo Calculations of Detector Response
to High Energy Photons
H. Tachibanaki, T. Murakami, and J. Kasagi

A detector for high energy y-rays up to 50
Me V is presently being constructed. Large N aI
crystals and recently BGO scintillators are widely used as high energy photon detectors. 1 ),2) However we have decided to employ a BaF2 scintillator because it is superior to N aI or BGO on thefollowing points: BaF2 has 30% larger efficiency
than NaI. It has a good timing resolution whichis essential to discriminate the events of y-ray
from those of neutrons. Cost is much lower than
BGO. A number of segments can be easily assembled to one detector.
We have written a computer program tocalculate detector response functions for highenergy y-rays. Although a lot of simulation
programs have been reported, they deal with thedetectors of N aI or Ge. 3 ) Our program provides
the response functions for various detector material including BaF2 , BGO, and N aI. The aims ofthis program are as follows.
1) It is used to obtain an optimum design withregard to response functions, detector volume
and cost.
2) The response functions for y-rays of various energies are necessary to unfold an experimental spectrum when it is compared with thecalculated one. Since it is difficult to prepare theexperimental response functions for wide energy

5"cpx4"Nal
l1 S (p, y)1 2 C

2400

• CAL
-EXP

If)

~1600
::>

o

u

800

range, the calculated ones will be employed after
the program verification.
The Monte Carlo program simulates the interaction between y-rays (electrons and positrons)
and detector material. The physical processes
considered in the program are as follows: (1)Compton effect, (2) photoelectric effect, (3) pair
production, (4) bremsstrahlung production, (5)positron annihilation, and (6) continuous energy
loss of electrons or positrons. Energy and/or
angular distributions of y-rays and electrons aretreated as correctly as possible. The obtained
response is folded with a distribution function tosimulate the effect of finite resolution of theactual instrument. This distribution function is
given by the Gaussian distribution whose width
depends on the y-ray energy.
The computation was proceeded by FACOM
at the RIKEN Computer Center. An example ofthe calculated results is shown in Fig. 1. In thiscalculation, y-rays of 17 and 12.5 MeV are
assumed to be injected on the 5" if> X 4//NaI crystal without collimation. The intrinsic resolutionof 600 ke V at 17 MeV is used. In the figure also
shown is the experimental spectrum obtained
from the llB(p,y) reaction at £p=1 MeV, which
produces the 17 MeV and 12.5 MeV y-rays. The
calculated results are normalized to the 17 MeV
peak of the experimental one. In general,
response functions for high energy y-rays arecharacterized by huge low-energy tails and thecalculation reproduces these tails very well. CPUtime of 40 s is required to calculate the detector
response for about 20,000 events of y-rays.
The calculation for other material are now inprogress and the design of a high energy y-ray
detector is being discussed.
References
1) A. M. Sandorfi and M. T. Collins: Nucl. Instrum.

oFig. 1. Calculated (dots) and measured (solid lines)
response of 5" <p x 4" N aI to the y·rays of 17 and12.5 MeV.

Methods, 222, 479 (1984).
2) D. J. Wagenaar, N. R. Roberson, H. R. Weller, and D.
R . Tilley: Nucl. Instrum. Methods, A, 234, 109 (1985).
3) D. W. O. Rogers: Nucl. Instrum. Methods, 199, 531(1982).

157
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-9.

A Test Apparatus for Resonance Ionization Spectroscopy ofAtomic Nuclides
T. Inamura, K. Morita, K. Ando, H. Katsuragawa,T. Minowa, and M. Shimazu

A resonance ionization technique is one of themost powerful methods of spectroscopy of elements in trace amounts. Its high selectivity andsensitivity for all of the elements (except He andN e) in the periodic table have well been recognized in the last decade.l) To make a full use ofthis excellent laser technique, however, it is stillneeded to develop an innovative device for eachexperimental purpose.
Here we briefly describe a test apparatus withwhich we will study how to improve the sensitivity up to its ultimatum, i.e., a single-atom detection in about 10 19 atoms. In Fig. 1 is presented a
photograph of the apparatus. Figure 2 shows theschematic presentation of the experiment using
the apparatus.
Test species are put on a tantalum tray (1) and

Fig. 2. Schematic presentation of our experiment. (1)tantalum tray; (2) resonance cell; (3) ceratrons; and(4) mirrors.

then vaporized by heating with an electric heateror with laser beams. The vaporized species are
ionized by a resonance ionization method withother lasers. Ions and electrons thus produced in
the resonance cell (2) are detected with ceratrons(3) placed face to face: They are measured incoincidences to improve the signal-to-noise ratio.
A pair of mirrors (4) is placed in parallel between
the detectors to increase efficiency of ionization:
The laser beams will be reflected five to tentimes between the mirrors.
First we try spectroscopy of stable isotopes totest our method, and we proceed to spectroscopyof radioactive isotopes. In the end we aim tomeasure hyperfine structure to determine spins
and moments of nuclei far from the stability line
and also to measure isotope shifts to deduce thechange in charge radius of these nuclei as afunction of the number of neutrons.
This test apparatus will also be used for the
study of the way to boost the efficiency of theion-guided isotope separator on-line (IGISOL).2)
References
Fig. 1. Photograph of a test apparatus for resonanceionization spectroscopy. Lasers come into the resonance cell through a window on the right of the
middle part of the chamber; an electric heater is in
the bottom; infrared lasers will be introduced.through a small window of the bottom (at the front)
or through a window on the top when test species
are vaporized by lasers.

1) G. S. Hurst: Resonance Ionization Spectroscopy 1984,(ed. by G. S. Hurst and M. G. Payne), The Institute ofPhysics, Bristol and Boston, p.7 (1984).
2) K. Morita, T. Inamura, T. Nomura, ]. Tanaka, H.
Miyatake, K. Sueki, M. Fujioka, T. Shinozuka, M.
Yoshii, H. Hama, K. Taguchi, H. Kudo, Y. Hatsukawa, K. Furuno: p.158 in this report.

158

RIKEN Accel. Progr. Rep. 19 (1985)

III-5-10.

Development of the Ion Guide Isotope Separator
On-Line for Heavy Ion Induced Reaction

K. Morita, T. Inamura, T. Nomura, ]. Tanaka, H. Miyatake,
K. Sueki, M. Fujioka, T. Shinozuka, * M. Yoshii, * H. Hama, *K. Taguchi,* H. Kudo, Y. Hatsukawa, and K. Furuno**

An Ion Guide Isotope Separator On-Line(IGISOL) system has been constructing at Cave 1of INS SF-cyclotron.
An Isotope Separator On-Line (ISOL) technique has been a powerful way for the study ofshort lived exotic nuclides. The essential part of
the ISOL is an ion source; the features of the
ISOL can be mostly decided by its ion source.
The IGISOL was developed at UvaskyHi
University!) and Tohoku University as a new
method of the ISOL. The purpose of our development is to apply the IGISOL to the study of
exotic nuclides produced by higher-energy heavy
ion-induced reactions.
The difference between the IGISOL and theordinary type ISOL is that the former system
requires no ionizer. For the IGISOL, energetic
recoiled isotopes produced by nuclear reactions
are stopped in the helium gas. During thermalization in the gas, the ionic charge of the recoiled
isotopes decreases via charge exchange processes, and finally become 1 + because of the highionization potential of helium atoms. The 1 +ions are then transported to the low-pressure
region by gas jet, and accelerated by an electrostatic field, and separeted with masses by amagnetic field. Because the IGISOL has no ionizer, there are advantages as: the system can be
operated at room temperature and the extraction
efficiency of ions is not affected strongly by thenature of isotopes.
Figure 1 shows the ion-guide stage of the isotope separator we developed. The ion guidevacuum chamber is evacuated with a mechanicalbooster pump having a high pumping speed of
4,200 m 3 /h. This vacuum chamber is isolatedwith thin stainless-steel foil (10 .urn) from a cyclotron beam duct, and floating on the high voltageof the mass separator. The target chamber is 5.5
cm long and has a volume of 11 cm3 • The diame* Cyclotron and RI Center, Tohoku University.
** Tandem Accelerator Center, University of Tsukuba.

DP

Fig. 1. Ion-guide stage of the ISOL. 1, Vacuum
chamber; 2, Target chamber; 3, Target; 4, Window(10 ,urn SUS); 5, Skimmer; 6, Extraction electrode;7, Einzel lens.

ter of the exit hole of the target chamber is 1.5
mm. The diameter of the skimmer is 1.5 mm.
The extraction efficiency of ions and the transportation efficiency were checked by using the
27 AI(a, 2p)29 Al and 27 Al(a, 2pn)28 Al reactions.
Incident energy of a-beam was 35 MeV, andrecoil energy per nucleon of 29Al and 28 Al was 146
keV lu. The pressure of the target chamber was
50 mbar. The extraction efficiency was about 3 %to the stopped ions. The transportation efficiency
was 30%. Further test experiment is now inprogress.
Reference
1) J. Aysto, J. Arje, V. Koponen, P. Taskinen, H.
Hyvonen, A. Hautojarvi, and K. Vierinen: Phys. Lett.
B, 138, 369 (1984).

159
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-11.

Proposal for Applying Piezoelectric Actuators to
Mossbauer Drive System
N. Sakai, F. Ambe, and K. Asai

In-beam Mossbauer spectroscopy using y-rays
from Coulomb-excited nuclei often requires tocool both a source and an absorber at liquid N z
temperature, because these Mossbauer y-rays
have relatively high energy of tens of kiloelectron volts, and the resulting recoil-free fraction of them are very small at room temperature.
Therefore, a usual electromechanical drive system, which is practically held at room temperature, must solve a problem of how to keep the
Doppler-modulated absorber at low temperatureand in a high vacuum of the accelerator.
Although a piezoelectric drive system canresolve the problem, the system has two shortcomings: the obtainable maximum velocity is of
the order of 100 jlm/s, and the useful frequencyof this device is around 100 kHz, depending on its
shape. Then, hitherto, the application of thisdevice to the Mossbauer drive system has been
restricted to some particular nuclei.
A piezoelectric actuator can overcome theshortcomings of the usual piezoelectric device
mentioned above. The actuator consists in principle of a piezoelectric thin plate sandwiched bymetallic electrodes, and one of the electrodes ismade of a metallic thin plate. It vibrates in thetransverse direction when an a.c. voltage isapplied between them. A proposed drive systemusing two piezoelectric actuators is shown in
Fig. 1. An absorber holder is connected to two
actuators which vibrate in phase with the same
amplitude. The vertical motion of the holder canbe achieved with this device. It will be necessary
to connect the absorber holder and the actuatorsb/ '----

c==J~~---~ ;---t----\ V~ v
\, \
a

c:=J
a

Fig. 1. Piezoelectric· actuator device for Mossbauer
drive system.
a, piezoelectric actuator; b, absorber holder.

with V -shaped metallic plates, as shown in Fig. 1,
to compensate a slight change in the horizontal
length of the actuators during their vibration.
The measured displacement at the top of a freeactuator (10 mmx30 mmXO.7 mm) is about 1 mm
at the frequency of 30 Hz, which corresponds to
188 mm/s. This velocity is sufficient to measure a
Mossbauer spectrum with any Mossbauer
nucleus. The actuator itself can be used at liquidN z temperature.
A disadvantage of the actuator drive system
will be its inferior reproducibility of the velocity.
Since the mass of the actuator is very small, thechange in mass of the absorber will affect strongly the vibrating amplitude of the actuator. Nevertheless, it is possible to increase the mass of theactuator by enlarging its size and strengthening
its power. Moreover, it is easy to make a velocity
monitor to detect the velocity of the absorber: forexample, by using a small permanent magnet on
the absorber holder together with a pick-up coil.

160
RIKEN Accel. Progr. Rep. 19 (1985)

111-5-12.

CAMAC Data Acquisition System with an Auxiliary
Crate Controller
T. Ichihara, T. Inamura, K. Asahi, and M. Ishihara

A data acquisition system for the experiments
at the GANIL (under Japan-France collaboration
program) and for the test and development of the
new data-acquisition system at the RIKEN Ring
Cyclotron facility is now under construction. The
system is divided into two parts:(1) ACES 2180 CAMAC Auxiliary Crate
Controller (ACC) system(2) A Micro V AX- II system of a minimum
configuration.
The configuration is shown in Fig. 1.
The CES 2180 ACC is the fastest ACC commercially available. It is a single-board CAMAC
module built around a Digital Equipment latest
16/32-bit microprocessor, J-11.
This ACC provides following hardwares:-16/32-bit, 267 ns-cycle Digital Equipment J-ll
microprocessor- Auxiliary Crate Controller logic-mixed EPROM/static RAM configuration- DEC compatible RS-232C interface- interval timer-front-panel Q22 bus for system extensions including coprocessors, memory extensions, andstand-alone system with disk driver and operating system.
The most Important feature is that any software written for the PDP-II can be executed in
the CES 2180 ACC as far as it can be loaded
inside the 2180 ACC's memory (128 kB).
The CAMAC access time (peak value) is about
2.3 ,us/16 bit-Read (890 kb/s) and 1.9 ,us/16 bitWrite (1.1 Mb/s). A dual floppy-disk driver (RX50) with the RQDX2 Interface is connected to the
ACC for software development as a stand-alone
system. The operating system (OS) which wehave chosen for 2,180 ACC is RT-l1, a real time
single task OS. The interrupt response time of
RT-11 OS is the fastest (zero OS overhead)among the OS's for a PDP-l1 family ( e.g., RSX11 M). In future, all software development will be
carried out on the host processor (Micro V AXII).
Generally the ACC is used for event-by-event

CAMAC
VT-2~

AC

ACf:, : CES 2100 (J11)

cc : Kj net i C 3920

C Cl-----.,
C

922 Bus

Micro VAX II
2MB
RS-232C

VT-~

Q

B
A
Micro

VMS

31t.f34e0<Bx25·
LA- 50

Fig.1. A block diagram of the Micro VAX-II and CES 2180 ACC (]-11) data acquisition system for'the GANIL experiments and for test and development of RlKEN Ring Cyclotron data acquisition
system.

T. Ichihara, et al.

data acquisition initiated by the interrupt (event
signal from the experimental logic) and for thedata-buffering. When the buffer is full, it changes
the current buffer (double buffering) and tells tothe host processor that the buffer is full throughlook-at-me (LAM) interrupt.
The host processor is a Micro VAX-II, anewest member of a VAX family. The CPU has
a capacity of about 85-90% and the price is about
10-20% of the VAX-11/780. The CPU consists ofa one-chip ZMOS microprocessor (40 MHz clock)78032 and a one-chip floating point coprocessor
78132 . The interrupt response time of the Micro
VAX -II is about 30,u s in the device driver level(OS level) and is about 400,us in the asynchronous
system trap (AST) level (user process level including the overhead of the OS).
The operating system (OS) is a Micro VMS,
which supports both the real-time multi-task
environment and time sharing system (TSS) environment at the same time.
The interface between the Micro V AX -II and a
CAMAC crate is a Kinetic 3920-2920Z2B dedicated crate controller (DCC), which is capable ofdirect memory access (DMA) in block-made
CAMAC operation.
We have already developed device-driver software for the Kinetic DCC in the Micro VMS
environment and the data transfer rate in a DMA
mode is about 400 kB/s. The maximum I/O
bandwidth of the Q22 bus is 3.3 Mb/ s, whereas
the internal memory bandwidth is 10 Mb/s,161

which indicates that the CPU Micro VAX 78032
can run at full speed without being affected bysimultaneous Q-bus DMA I/O transfer to private
memory.
After receiving the interrupt (LAM) from the2180 ACC, the host processor starts the datatransfer from the buffer of the ACC to the bufferof the Micro VAX-II in a Q-stop block mode
(DMA mode), and then analyzes the event-byevent data, creates the on-line multi-parameter
histogram, and displays it on a semigraphic color
terminal (VT-241).
Examination of the basic function of the CES
2180 ACC and the Micro V AX- II has been completed and no serious trouble has been encountered. The specific feature of this data acquisition
system is that all the central processors used are
one-chip micro processors, }-11 and VAX-78032
CPU's.
We intend to extend this system, in the near
future, including high speed magnetic tapes (6250
BPI), bit-map high-resolution high-speed color
graphic display, high-resolution color hardcopy,
large amount memory and disk, optical disk
driver if available, CAMAC serial highway
driver (SHD), etc. toward the final form. As forthe front-end of the data acquisition system at
RIKEN Ring Cyclotron facility, a VME-based
CAMAC systeml) is also under consideration.
Reference
1) IEEE Trans. Nucl. Sci., NS-32, No.4 (1985).

162
RIKEN Accel. Progr. Rep. 19 (1985)

IV. NUCLEAR DATA
1.

Status Report of the Nuclear Data GroupA. Hashizume, Y. Tendow, Y. Ohkubo, and T. Nozaki
In this period main efforts have been directedto the operation of the programs related to the
EXFOR systems and compilation of new EXFOR
files of the nuclear reaction cross sections concerning the productions of llC, 13N, 15 0, 18F, 28Mg,
52Fe, 67Ge, 74As, 77Br, 82Br, 77Kr, 81Rb, 82mRb, 111ln,
123Xe, 127Xe, 123 1, 1241, 1251, nuclei. 1).2) We have also
compiled the reaction cross sections of various
combinations of incident particles and target
nuclei described in the same reports. In thisrespect, it was decided in the consultants meeting
held in October in Paris to make good contact
with the charged-particle center in Moscow(Cal ad) to avoid duplications.
(1) We have continued to implement the program systems offered from IAEA. These programs are written by PLI language which is thefirst case for a FACOM 380M at RIKEN. Amongthe program systems, the EXFOR System consisting of four program groups, that is, Check
Entry Run, Extract from Master Run, Prepare
Edited Exfor Listing Run, and Prepaire Author
Proof Listing Run has been implemented. Check
New Entry Run checks errors and gives diagnosis of the new files. Extract from Master Run
makes the lists of entries and subentries. Prepaire
Edited Exfor Listing Run makes the edited listings which are more legible than the original fileformat. In general, data given in the EXFOR
format should be confirmed by the original
authors. Prepair Author Proof Listing Run gives
the list of data confirmed by the authors. For
Dictionary System, the program GENDICT
which makes a VSAM file from the Dictionary
file has been operated. This Dictionary file isrenewed every three month. The VSAM file isreferred by the Check New Entry Run program.
(2) The compilation of data to make a new
file in the EXFOR format has become a routine

work. The data represented by graphs in reports
were read by using a graph reader. A graphreader TEKTRONIX 4051 was replaced by a
TEKTRONIX 4052. By using this system, theamounts of data became about 1.5 MB, in which
total reaction cross sections, differential crosssections, polarizations, and theoretical curves
such as DWBA analysis are included. The thirdand forth EXFOR files (R003, R004) were transmitted to Nuclear Data Section in IAEA. The
number of subentries amounted to 274. The third
file consists of corrections of the first and second
files. From the third file, the error check wasmade by the Check New Entry Run program
mentioned above.
(3) The references of 1-131 concerning reaction cross sections, differential cross sections,individual yields and product yields werecompared with the Recent References compiled
by Brookhaven National Laboratory Data Center (BNL), and the coverage of references waschecked. This revision has been begun with contact with BNL. The complete reference files aswell as recent Evaluated Nuclear Structure Data
File (ENSDF) were obtained from BNL. Programs to compile the recent reference file and
ENSDF have been made.
(4) For the mass chain evaluations of nuclear
structure data, we have finished the evaluation of
the A = 120 chain and, after inspection of other
1apanese groups, the file was sent to BNL for
publication.
References
1) "Report on the 7th IAEA Consultants Meeting" of
Nuclear Reaction Data Centers, INDC (NDS-154)(1984).
2) A. Hashizume, Y. Tendow, and T. Nozaki: RIKEN
Accel. Progr. Rep., 17, 74 (1984).

163
R1KEN Accel. Progr. Rep. 19 (1985)

IV-2.

On Nuclear Data for Production of 123 1
A. Hashizume and Y. Tendow

Owing to the suitable nuclear decay properties,
123 1 is considered one of the best radionuclides forin vivo diagnostic nuclear-medical studies using
single-photon emission computed tomography.
Although more than twenty kinds of reactions
have been proposed for the production of 123 1,
selection should be made from several essential
view points, that is, the price of enriched isotope
for a target, ease of recovery and recovery percentage of the isotope after irradiation, beamrequirements whether the kind of incident beam
and its energy are easily available, the production yield rate, the chemical separation yield, andimpurities of other radioactive iodine isotopes
for the final product.
124Te(p, 2n) reaction. This reaction has beenused most extensively in the routine productionof 1231. Its excitation function is shown in Fig. 1.
By using a 99.87% isotopically enriched isotope,each point was determined with uncertainties ofbetween 4% and 12% except for the lowest
energy point. The cross sections were also measured with a 91.86% enriched isotope as a target.
As a whole, the cross sections were obtained at

precision of about 10% , but the production rates
as a function of energy reported by different
authors differ more than about a factor of two.
There are many reports concerning practicalproduct yields of 123 1 as illustrated in Fig. 2,
which shows that the reported product yields arescattered in a wide range. A part of the reasons
may be attributed to the loss of 123 1 during irradiation. If the precaution is not sufficient, the product yield will be a function of beam intensity due
to loss of iodine during the irradiation.
127I(p, 5n)123Xe reaction. The excitation functions have been reported by four different
authors. The functions are shown in Fig. 3, in
which the values reported by Syme et al. aremost elaborated taking into account the various
errors included in the measurement. Each author
took the precautions for the loss of the target orreaction products during irradiation. One of thereason for differences between these absolute
cross sections may be attributed to the value ofbeam current integration. Paans and Wilkins
have measured the beam current directly; Dickand Syme used the monitor reaction such as
27 Al(p, 3pn)24N a and 12C(p, pn)llC. It seems thatthe results of Dick and Syme are comparatively

102. - - - - - - - 12-4T-e-(p,2-n-)12
- 3I-

-'

....

.c

~1Q1

........

U

S
"0
v
';;'
v

::l

"0

~ 10°
o

1O°L-..-.-L----L-----,1::------:1::------='=
25:-----=-'
30

Energy of pr otons (Me V)

Fig. 1. Excitation function of 123Te(p, 2n)1231 on
99.87% and 91.86% isotopic enrichment of 124Te (K.
Kondo et al. : Int. ]. Appl. Radiat. Isot., 28, 395(1977)).

1O- 1-!-:20, --------=':
25=------:3735
0 ---~
Energy of prot ons (Me V)

Fig. 2. Practical yields of 123 1 in the 124Te(p, 2n)1 23 1
reaction.

164

A. Hashizume, et at.

l03r - - - - - - - - - - - - - - - - - - - - - - - - - - ,Energy of protons (Me V)

Fig. 3. Comparison of excitation functions of the 1271(p, 5n)1 23 1 reaction (Syme et at.: Int. ]. Appt. Radiat. Isot., 29(1978); Diksic et at.:]. Inorg. Nucl. Chem., 39, 1299 (1977); Paans et at.: Int. ]. Appl. Radial. Isot., 27, 465 (1976);
Wilkins et at.: Int. J. Appl. Radiat. Isot., 26, 279 (1975)).
l03r - - - - - - - - - - - - - - - - - - - - - - - - - - - - ,Energy of deuter ons (MeV)

Fig. 4.

Excitation function of 122Te(d, n)1 23 1 reaction (Zaidi et at.: Int. ]. Appt. Radiat. Isot. , 34, 1425 (1983)).

good.
Deutron induced reactions. The 122Te(d, n)123Xe
and 127Te(d, 6n)123Xe reactions have been reported. Zaidi insisted that the 122Te(d, n) reaction can
produce 123I with better purity than that using the124Te(p, n) reaction. The cross sections are plotted in Fig. 4. There is only one measurement
concerning the absolute value for this reaction.
Alpha induced reactions. The 121Sb(a, 2n),123Sb(a, 4n) and also 122Te(a , 3n)123Xe reactions
are the scope of interest. The cross sections for
121Sb(a, 2n)123I have been measured from theinterest to compare them with a theory. Absolute
cross sections in the energy range from thresholdto 27 Me V have been measured and comparedwith a statistical theory in which the competitionof y-decay was taken into account.
The product yield rate of 123Sb(a, 4n) has beenmeasured in the incident energy range between
50 and 75 MeV.
The 122Te(a, 3n) reaction is a method to produce 123Xe with minimum impurities such as 124I,
125I and others; however its cross section is notfound in our survey.
Other reactions. Among other reactions explained above, 3He induced reactions with
122.123Te as targets have a high 123Xe yieldcompared with alpha particle induced reactions.
However there are no reports on the absolute
cross sections.
It is known that the spallation reaction induced by high energy protons have relatively

A. Hashizume, et al.

high yield of 1231. The cumulative cross sectionsfor 123Xe decrease slowly with increasing incident proton energy. Typical cumulative crosssection values are 40 and 29 mb at 342 and 660
MeV, respectively.
About impurity. The long-lived 1241(4.2 d),1251(60.2 d) etc.increase the absorbed dose of apatient when his thyroid is administrated by 1231.
In addition, the tomography is obscured bycontaminated gamma-rays. Because of these reasons, the existence of impurity in 1231 is the mostcritical factor to determine the producing reaction. By using 96.2% isotopically enriched 124Te
as a target in the (p, 2n) reaction, the impurity of

1651241 and 1211 in 1231 were found to be 0.05 and 0.5%,
respectively. These values are comparable withthose in the 122Te(d, n) reaction using a 95.4%
enriched Te target. The impurities caused in 1231
by the latter method were reported to be 0.09,
0.04, 0.86, and 0.09% for 124 1, 1261, 13°1, and 131 1,
respectively. There is a paper which reports thatno impurity was found except 1% of 131 1 by using
the 127I(d, 6n) reaction; in this case there is noneed of using enriched isotope. In conclusion,
122Te(d, n)123Xe and 124Te(p, 2n)1 23 1 are mostpromising reactions providing 1231 containing
minimum impurity.

166
RIKEN Accel. Progr. Rep. 19 (1985)

V. ACCELERATOR DEVELOPMENT
1.

Present Status of RIKEN Ring Cyclotron Project
H. Kamitsubo

Although the construction of RIKEN Ring
Cyclotron is a little behind the schedule, it hasreached the final stage. Four sector magnets
together with trim coils were assembled in thecyclotron vault in 1984 and their power supplies
were also set up in the basement of the cyclotron
vault. Injection and extraction elements were
fabricated and carried in, too. Vacuum chambers, RF resonators and their power amplifiersystem are in the works. Two computers andseveral sets of CAMAC modules were carried inand are in operation to develop the computer
programs for control of the cyclotron. The building including experimental rooms, a beam transport area, and rooms for power supplies areunder construction and will be completed inMay, 1986. Radiation-monitoring and the safetysystems of the facilities are also being fabricatedin the factory.
Measurements of field distributions as well as
excitation characteristics of sector magnets were
performed. Even at a fixed excitation current, thefield strength of a large scale electromagnet
changes very slowly before it reaches the final
value. A time constant of this variation is verylarge and, for the present sector magnets, it takes
more than 1 h to settle the field at the final value
within an accuracy of 10- 4 • The current setting
procedure of the magnets was investigated to get
the final value of the field within a time as short
as possible.
Distributions of the base field produced by thesector magnet were measured for the south sector magnet (S-sector magnet) at excitation currents of 300, 520, 640, 710, 800, 940, and 1,050 A.
Field perturbations induced by injection elements were investigated at the same excitation
currents as mentioned above by setting up eachelement at the position and measuring the field
distributions over four sector magnets.
Field distributions produced by trim coils were
measured along the center line of the S-sector
magnet at the same values of the main coilcurrents as above by exciting each trim coil at

the maximum current of its power supply andthen at two thirds and one third of the maximum
current. From these data it was confirmed thatisochronous fields can be produced for all theions in the designed energy region. These measurements were finished in December, 1985.
Two of four magnet chambers, which arevacuum chambers in the pole gaps of the sector
magnets, were completed. Cleaning up of theinner surfaces was repeated by spraying neutral
detergent (NEOS K), solvent (ftuorohydrocarbon), acid (NEOS CM305FP), counteragent(NEOS CM308), and demineralized water. Then
air leakage through the welding parts of thechamber was carefully checked. The other two
will be completed soon and all of them will be
installed one by one in early 1986.
All cryopumps, turbomolecular pumps andother vacuum components have been carried in
and ready for assembling. Valley chambers andthe RF resonators are in the works and will becompleted by the end of March, 1986. Surface
cleaning and leakage test are to be done at thefactory.
Static RF characteristics such as resonancefrequency, Q-value, shunt impedance, and dee
voltage distribution are also to be measured for
the RF resonators at the factory. Low level
amplifiers and power amplifiers have been
almost completed at the factory and cold tests
were performed to measure the static characteristics of the amplifier system.
Final design of a beam transport lines between
the RILAC and RIKEN Ring Cyclotron andbetween RIKEN Ring Cyclotron and experimental rooms has been finished and ordered to thecompanies. Several pulse magnets will be installed to realize time sharing of a beam between
the linac experimental site and RIKEN Ring
Cyclotron and also between two experimentalsites in the down stream of RIKEN Ring Cyclotron. Beam pipes, magnet chambers and chambers for beam diagnostic devices will be made ofalminum. We expect that an acceleration test

H. Kamitsubo

will start at RIKEN Ring Cyclotron in October,
1986.
Design of the experimental facilities which will
be built in the experimental halls has been performed in collaboration with universities andother research institutions. The budget for these167

facilities and the remaining part (phase 3) of thebuilding as well as another injector, an AVF
cyclotron, will be allocated in 1987 through 1988.
Design study of the A VF cyclotron is also inprogress.

168

RIKEN Accel. Progr. Rep. 19 (1985)

V-2.

Present Status of RF Resonator for RIKEN Ring Cyclotron
K. Ogiwara, T. Fujisawa, S. Kohara, Y. Oikawa, and 1. Takeshita

The radio-frequency (RF) system of RIKEN
Ring Cyclotron (K = 540) is required to work in afrequency range of 20 to 45 MHz and to generate
the maximum acceleration voltage of 250 kV. We
developed a new type variable-frequency
resonator l ) called a movable box type, to avoid
difficulties arising in a usual coaxial resonator
equipped with a movable short end; one difficultyis due to a large total height of the resonator andthe other is to sliding contactors enduring highcurrent density on the inner conductor.2) This
resonator is a compact half-wave length coaxial
type (2.1 m (H) x 3.5 m (W) x l.6 m (D))(See Fig.l).
The delta-shaped dee whose radial length is
2.7 m is supported in a median plane by verticalstems from the both sides. The resonant frequency is varied with a pair of boxes surrounding the stems. Both inductance and capacitanceof the resonator are varied by moving the boxes
so that travelling distances of movable parts andthe total height of the resonator can be saved
remarkably compared with a usual movable
shorting plate type, which varies only inductance. The problem in sliding contactors disappears in the new type resonator because themovable boxes are contact only with outer walls
where current density is low. Now, a pair of theresonators are being constructed by Sumitomo
Heavy Industries Co., Ltd., and will be installed
at RIKEN in 1986.
Figure 1 shows the actual resonator underconstruction. The vacuum chamber is divided
into two compartments by a wall having manyholes for evacuation. The main part is the RF
resonator, and the other is a space for the finetuner and coupler positioning mechanism and avacuum system. The stem, dee, and outer wall
are made of copper-clad stainless steel which has
many cooling channels engraved on the surfaceof the stainless steel under the copper overlay.
Figure 2 shows the cross sectional view of theclad. A cryo-panel for evacuation is installedinside the stem. The movable box and the finetuner are constructed with stainless steel frames
and copper sheet covers. The movable box is
supported by three rods which accomodate thepiping for cooling water and pneumatic pressure.

a)b)Chamber of RF resonator.

Upper half of the dee and stem.

c) Movable boxes.
Fig. 1. Picture of the movable box type resonator.

K. Ogiwara, et al.

169

Sliding contact fingers made of silver rods arepressed to the outer conductor by pneumaticpressure_ The main cryo-pump and turbomolecular pump are mounted on the outer wall of
the compartment for the mechanism. All thesystems are installed on a platform car and canbe moved about 2 m from the valley space
between the magnets leaving the side walls to
make the resonator accessible for maintenance.
Cooling channels

References

Fig. 2. Cross sectional view of the copper-clad stainless steel having water cooling channel.

1) T. Fujisawa, K. Ogiwara, S. Tohara, Y. Oikawa, I.
Yokoyama, I. Takeshita, Y. Chiba, and Y. Kumata:Sci. Papers IPCR., 79, 12 (1985); K. Ogiwara, T.
Fujisawa, Y. Oikawa, and S. Kohara: RIKEN Aeee!.
Progr. Rep., 18, 172 (1984).
2) K. Ogiwara, M. Hara, and T. Fujisawa: Rep. IPC.R.,
57, 222 (1981).

170
RIKEN Accel. Progr. Rep. 19 (1985)

V -3.

Present Status of RF Power Amplifier for RI KEN Ring Cyclotron
T. Fujisawa, S. Kohara, K. Ogiwara, 1. Yokoyama,
M. N agase, and Y. Chiba

The basic parameters of the RF system of
RIKEN Ring Cyclotron (K = 540) are summarized in Table l. The design of the RF systeml)
has been completed and main parts of theamplifier system are being constructed at a factory. All of the system are to be installed at
RIKEN in the middle of 1986.
Figure 1 shows a block diagram of theamplifier system. An RF reference signal is fed
from the injectors in normal operation and alocal synthesized signal generator is prepared formaintenance. The signal is split and fed to two
amplifier systems and a beam buncher system.
The amplitude and phase of the signal are adjusted by the amplitude and phase modulators,

respectively. The signal is modulated by thepulse modulator until multipactorings in theresonator are broken through. The RF power isamplified by the three stages amplifier system
and is fed into the resonator through a 50 .n
coaxial feeder line ("-'1.8 m length) which is
coupled with the resonator in good impedance
matching by means of a variable capacitive
coupler. The pre-amplifier is of a wide-band
solid-state type. The driver and the final
amplifiers are of tuned tetrode amplifiers. The
input circuit of the driver is a pair of all-pass
networksY·2) Tuning and impedance matchingfor the resonator are carried out automaticallyby detecting the incident and reflected wave on
the feeder line. Acceleration voltage and phase ofeach resonator are also adjusted automaticallyby comparing the signals picked up from theresonator with the reference signals. Setting andlogging of all parameters are performed with thecomputer control system.
Figure 2 shows a photograph of the final
amplifier under construction. The power tube,
RS2042SK, is used as grounded grid configuration. I ) The plate tuning element is an adjustable
A/4 coaxial stub whose stroke is l.2 m. The
center conductor of the stub is a copper pipe of 18

Table 1. Basic parameters of the RF system.
Number of resonators
RF frequency
Harmonic number
RF peak voltage
Frequency stability
V oltage stability
Phase stability
Mean injection radius
Mean extraction radius
Dee angle
Output power of each RF amplifier

220"-'45 MHz
5, 9, 10, 11
250 kV
10- 8
10- 4
<1"
89.3 cm
356 cm23S
300 kW

To Buncher andthe other amplifier

Signalfrom injector

I

E
E

E

I
I

I

From dee voltage pick up
I~---- - - - - - --Fig. 1.

---

Block diagram of the amplifier system.

T. Fujisawa, et at.

Fig. 2. Photograph of the final amplifiers. A: Inner
conductor of the plate stub, B: Movable shorting
plate of the plate stub, C: Feeder line, D: RS2042SK
tetrode, E: Impedance matching capacitor, F: Cathode tuning circuit, G: 50 kW dummy load. H: Box
surrounding the plate blocking capacitor. The
screen and control grid bypass capacitors aremounted on the base plate below the tetrode. The
driver amplifier is in the aluminum box at lower
left side.

cm in diameter in which cooling water pipes anda DC power line for the tube pass through. The
plate DC blocker is a cylindrical capacitor (2,350
pF) whose insulator is made of Kapton film (125,urn X 16 turns). The screen (0.09 ,uF) and control
grid (0.115 ,uF) bypass capacitors are parallel
plate disc capacitors, whose insulators are madeof 50 ,urn copper-clad Kapton films. A vacuum
variable capacitor for load resistance matching171

is mounted on the output port of the amplifier.
The cathode circuit consists of a variable tuning
capacitor (20 to 600 pF) and a fixed A/4 coaxial
stub, through which the filament current is supplied from a power source at ground potential.
Two plate power supplies, which are located ina building about 100 m far from the cyclotron
vault, are provided for the two final tubes,
respectively. The output voltage can be set at 10,
12, and 14 kV by changing the taps on the primary windings of the transformer and the maximum current is 40 A. The voltage ripple at the
rated load is better than 2% in peak to peak. The
voltage ratio of the full load to the non-load isbetter than 95%. The power supply is protectedby an over current relay, an overvoltage relay,
and an undervoltage relay at the DC side, and byan over current relay, a ground relay, and aphase unbalance relay at the AC side. The rube isprotected by an ignitron crowber circuit. Within
30 ms after the ignitron is fired, the primary 6.6
k V line is opened by a vacuum circuit breaker toprotect the power supply.
References
1) T. Fujisawa, K. Ogiwara, S. Kohara, Y. Oikawa, 1.
Yokoyama, 1. Takeshita, Y. Chiba, and Y. Kumata:Sci. Papers I.P.C.R., 79, 12 (1985); K. Ogiwara, K.
Fujisawa, Y. Oikawa, and S. Kohara: RIKEN Accel.
Progr. Rep., 18, 172 (1984); T. Fujisawa, K. Ogiwara,
S. Kohara, and Y. Kumata: RIKEN Accel. Progr.
Rep., 18, 174 (1984).
2) S. W. Mosko, J. D. Raylander, and G. K. Schulze:
IEEE Trans. Nucl. Sci., NS·24, No.3, June, 1786
(1977).

172
RIKEN Accel. Progr. Rep. 19 (1985)

V -4.

Progress in Sector Magnets for RIKEN Ring Cyclotrons. Motonaga
Final measurement of the magnetic field of thesector magnets was finished in December, 1985.1)
Detailed analysis of the field data is now inprogress. Installation of acceleration vacuum
chambers in the magnet part will start in January, 1986.
1) Power supplies
Description of the power supplies for main andtrim coils has been presented elsewhere. 2 ) Testsof all power supplies were carried out during aperiod from August, 1984, to February, 1985, to
obtain strict current stability. Current stabilitiesof 2 X 10- 6 and 1 X 10- 5 for 8 h were achieved forthe main coil and trim coil power supplies,
respectively.3) Their power efficiencies are listed
in Table 1.

The power supplies are controlled by a computer through CAMAC modules. All power supplies were operated by a computer control system throughout the magnetic field measurement
performed during a period of February to December, 1985. Overall performance of the system wasvery well.
2) Field measurement
Field measurement was started in February,
1985.

At first, the optimum procedures were investiga ted to ensure fast setting and good reproducibility of the magnetic field and the bestprocedure of the field setting was established.
Reproducibility of the field was obtained to bebetter than 5 X 10- 4 and required time to obtain a

Table l. Current specification, electric power, and power efficiency for various types of main coil and trim-coil
power supplies. All power supplies having a total of 67 output terminals are housed in 11 cubicles. Total input
power of the power supplies is 1,lS3kW. Total required power is estimated to be about 1,329 kW, if the power
factor of the power supplies is assumed to 0.S9. Power efficiencies of almost all the trim coil power supplies arepoor because of their high current and low voltage.
Input power(kW)

Output power(kW)

Current(A)

Voltage(V)

Number of
outputterminals

Powerefficiency(Output power J
Input power

414
lS2

355
l33

1,050
1,050

352
126

1
5

0.S6
0.73

94

50

0.53

37
27
55
56

26
6.5
33
30

1
10
9
10

0.70
0.24
0.6
0.54

TC12

33

10

3

0.30

*TD12
*TD3-1

109
SO

22
21

450, 500
500
245, 390
540

12
6

0.20
0.26

*TD3-2

96

22

545

16, 1935, 34
53
12, 7
62
34.5
19
9, 4.S
5.2
5, 45.5
6, 6.2
6.6, 6.5
6.5, 6.5
6.2, 6.3
6.S, 6.7
6.6, 6.7

4

TA3
TB12
TB3
TB45

330, 410
520, 550
490
410, 220530
540, 5S0

6

0.23

Type

Main coil
M1
M2
Trim coil
TA1245* Polarity of these power supplise can be changed.

S. Motonaga

stable field was about 3 h. 3 )For a period of April-July, 1985, measurementof base field distributions and a field of each trim
coil was performed for one sector magnet toestimate trim coil currents necessary for forming
an isochronous field. The measurement was carried out for seven field levels of 6, 10, 12, 13, 14,
15, and 15.5 kG.
From September to December, after installation of the magnetic elements for injection andextraction, the magnetic fields inside them were
measured for three base fields of 10, 14, and 15.5
kG. Each element was excited at its level corresponding to the base field. 4 ) In this period a field
effect caused by the magnetic elements wasmeasured. It was found that this effect can becompensated by adjusting of the trim coil currents of four sector magnets.
A final subject of the measurement was theformation of isochronous field for selected ionsby use of the above field data. Calculation of
optimum trim coil currents was performed for
210 MeV proton, 70 MeV lu C6+, 28 MeV lu Ar 13 +,and 22 MeV lu Xe l 4+. From this calculation, it

173

was found that the maximum powers of the trim
coils power supplies are lower than thoserequired for the formation of the isochrorious
field in the nose region, then it was decided thatiron shims should be placed in the nose region of
the sector magnets. Magnetic fields producedwith the help of these iron shims will be
remeasured after installation of the vacuum
chambers for the sector magnet parts.
References
1) A. Goto, H. Takebe, S. Motonaga, K. Hatanaka, Y.
Yano, T. Wada, N. Nakanishi, and M. Hara: p.178 inthis report.
2) H. Takebe, S. Motonaga, T. Wada, 1. Takeshita, and
H. Kamitsubo: Proc. 5th Symp. on Accelerator Sci·
ence and Technology, KEK, p. 197 (1984); S.
Motonaga, H. Takebe, T. Wada, A. Goto, 1. Take·shita, J. Fujita, H. Kamitsubo, J. Abe, H. Saito, andT. Mita: RIl<EN Accel. Progr. Rep., 18, 170 (1984).
3) H. Takebe, S. Motonaga, and T. Wada : p. 174 in thisreport.
4) Y. Yano, A. Goto, K. Hatanaka, H. Takebe, and S.
Motonaga: p. 180 in this report.

174
RIKEN Accel. Progr. Rep. 19 (1985)

V -5.

Power Supply of the Sector Magnets
H. Takebe, S. Motonaga, and T. Wada

The sector magnets of RIKEN Ring Cyclotron
were assembled in the cyclotron vault in April,
1984, and the power supplies (PS's) for main andtrim coils were brought in July. The maximum
currents of the PS's and the connecting coils arelisted in Table 1. From July to December, PS's
were finally adjusted and the stability, ripple,
and so on were examined. Table 2 lists theachieved stability of the PS's of the main andtrim coils. The stabilities and ripples are sufficiently smaller than the guaranteed values.
From January to December in 1985, the PS's
were operated to measure the characteristics andfield distributions of the sector magnets. During
this period, total operating time was about 3,400h, and only one transistor was broken, tens offuses and tens of lamps (tungsten type) were cut
down (the total number of the transistors isabout 7,000 and oven control and interfaces circuits were being turned on for about 8,000 h).
The power supplies of the main and trim coils
are controlled by a control computer: a MitsuTable 1.

Table 2.
Name

Current stability of the power supply.
Guarantee

Measured( X 10E-4(X 10E-4(X 10E-4/ 8 h)/ 8 h)/24 h)

M1

0.1

M2

0.1

M2,1-4
TA124STA3
TB12
TB12,1 - 8
TB3
TB3,1 - 8
TB4S
TB4S, 1- 8
TC12
TD12
TD3-1
TD3-2

3.8
1.0
1.0
1.0
2.0
1.0
2.0
1.0
2.0
1.0
1.0
1.0
1.0

0.075 (1, 050A)
0.1 (1,OSOA)
0.02 (300A)
0.05 (l,OSOA)
0.07 (l,OSOA)
0.02 (SOOA)
0.1
Following values are
0.1
in a maximum current.
0.1
0.15 - 0.2
0.2- 0.3
0.1
0.1 -0.15
0.2- 0.15
0.1 - 0.2
0.1-0.35
0.1-0.1S
0.1-0.25
0.1-0.25

Maximum current and connecting coils.

Name

Current Coil#

Name

Current Coil#

Name

Current Coil#

M1
M2-0
-1
-2
-3
-4
TA1245
-1
-2
-3
-4
TA3
TB12-0-1-2-3-4
TB12-1
-1
-2
-3
-4
TB3
-1

10S9.0A Main 11065.0A Main 2- 101.0A W-sector- 101.0A N-sector-101.0A E-sector-101.0A S-sector

-2
-3
-4
-S
-6
-7
-8
TB45-0-1-2-3-4
TB4S-1
-1
-2
-3
-4
TC12
-1
-2
-3
TD12
-1
-2

50.SA W18-19
50.5A N10-11
50.5A N18-19
50.5A ElO-11
50.5A E18-19
50.5A S10-11
50.5A S18-19
554.9A #14-15
40AA W
40AA N
40AA E
40AA S
596AA #22
50.5A W
50.5A N
50.5A E
50.5A S

-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
TD3-1
-1
-2
-3
-4
-5
-6
TD3-2
-1
-2
-3
-4
-5
-6

404.0A E#6
404.0A N#28
404.0A W#26
404.0A W#27
404.0A W#6
404.0A N#6
404.0A E#28
404.0A S#26
404.0A S#27
404.0A S#6

333.3A #8
414.0A #9
535.0A #12- 13
565.8A #23-24
493.6A #16-17, #20-21
232.3A #7
55.5A W
55.5A N
55.5A E
55.5A S424.2A #25
50.5A W
50.5A N
50.5A E
50.5A S
535AA #10-11 , #18-19
50.5A W10-11455. 1A #3-N- E
505AA #3-W
505.3A #3-S
252.5A W#28
252.5A S#28

55S.5A W#4
55S.5A W#5
555.5A N#26
555.5A N#27
555.5A N#4
555.5A N#5
555.5A S#4
555.5A S#5
555.5A E#26
555.5A E#27
555.5A E#4
555.5A E#5

175

H. Takebe, et at.
Table 3 (a). Pin assignment of the output port fromthe DIM.
Port
Pin DO

#

Data

#

/ DT

1

Contents

hi = O(Open)

low=1(Close)Table 3 (b). Pin assignment of the input port to
the DIM.
Port
Pin DO Data Contents# / DI#

hi=O(Open)

low=1(Close)

Ok
Ok
Ok
Ok
Ok
Ok
Ok
Ok

Not
Over
Not
Not
Fault
Over
Cut
Break down

Remotes
On
On
Ready

Local
Off
Off
Not off ready

1

GND
GND

45"-'50

GND
GND
2
3 DI-O o
Water flow
4
1
Water temp.
2
Door
5
3
Mag inter lock6
4
Off fault
785Over curr
9
Fuse
6
10
Transister
7
11
GND
12
GND
13 DI-l oLocal/remote
14
1
Oven
15
2
Main CB3
Off/ready
16
17
4
NC
18
NC
5
NC
19
6
NC
20
7
GND
21
22
GND
23 DI-2 oPolarity 1
24
1
Polarity 2
25
2
Polarity 3
26
3
Polarity 4
27
4
Polarity 5
528
Polarity 6
29
Polarity 7
67
Polarity 8
30
31
GND
32
GND
33 DI-3 oPolarity 9
34
1Polarity 10
2
Polarity 11
35
Polarity 12
36
3
4
37
NC
NC
38
5
NC
39
6
NC
40
7
41
GND
GND
42
GND
43
44
GND
45"-'50

bishi 32 bit minicomputer, M350/ 60-500 (M60),
through a CAMAC interface and CIM-DIM
modules. I)
Table 3 shows the pin assignment of a connector between the DIM input/output ports andthe PS. These lines are isolated by using photocouplers of 12V negative logic. 2 ) The output
signals to the PS from the DIM port consist of 16
bit currrent data, 4 bit DAC adress data, 2 bitpolarity data, 1 bit strobe signal, 1 bit ON command, and 1 bit OFF command. The DIM input
signals consist of 12 bit interlock and status
signals, and 12 bit (max.) polarity data from thePS.
Table 4, shows the structure of the programsfor the PS control sequence. At the 1st level, 2
byte read/write routines (CIM-DIM handler:
DIMI, DIMO) for the DIM input/output port weredeveloped by using CAMAC handlers supplied
from Mitsubisi Electronic Company. At the 2ndstage, PS control subroutines, for example, PS
on, PS off, polarity change, current set, current
step set, and status read, are developed.
A flow chart of this current step set program isshown in Fig. 1. When the PS name, the DAC
number, and objective current data are given

2
3
4

5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

DO-O
DO-O
DO-O
DO-O
DO-O
00-0
00-0
DO-O

DO-l
00-1
00-1
00-1
00-1
00-1
00-1
00-1

DO-2
DO-2
DO-2
DO-2

27
28
29
30
31
32
33
34
35
36

37
38
39
40
41
42
43

44

1

2
3

4
5

6
7

DAC data (LSB)
DAC data
DAC data
DAC data
DAC data
DAC data
DAC data
DAC dataoo

DAC data
DAC data
DAC data
DAC data
DAC data
DAC data
DAC data
DAC data (MSB)

o
o
o
o
o
o
o
o

Address 0
Address 1
Address 2
Address 3
NC
NC
Polarity+
Polarity-ooooStrobeOn command
OFF/ reset
NC
NC
NC
NC
NC

o
o
o

GND
GND

22
23
24
25
26

o

o
1
2
3
4
5

6
7
GND
GND

o
1
2

3
5
4

6
7
GND
GND

DO-3

o
1

2
3
4
5

6
7

o

o
o
o
o

o

1
1
1
1

o
o

GND
GND
GND
GND

Ml: Sun coller status+

Polarity+ Water level Ok
+
+

+
+
+
+

Temp Ok
Cool Water Ok
Pump Ok
Cool Pump Ok
Heater On
Chiller On

+
+
+
+

H. Takebe, et at.

176

from the main program as arguments, this routine obtains a conversion factor for 16 bits DAC
data, the current step, and the other parametersfrom the main memory (Global Common Area) of
the data-base table. After checking the PS status
and the last current (from the memory and theADC current monitor of the DIM), the current ischanged with a certain step (2A - 3A) to the aimed
current. In each 10 steps, actual current, obtainedby the ADC current monitor of the DIM, iscompared with each set current. If the difference
between them exceeds a given value, this program displays an error message and stop thiscurrent set sequence. Actual speed of this current
step set is about 10 steps/so
This current step set routine is written in

FORTRAN language of the M60 computer atthis time. At the next time, multiple task of thecurrent step set is needed for a fast setting andfor bypass control type PS's (M2, TBI2, TB3,
and TB45), then a micro program of the DIM will
be developed.

NOT

LAST CURR omemory readcurr=LAST.CURR
n=O

Table 4. Sector magnets control programs.
Programs

Structure
User application
proram

AUTOTM, MAP, SCL TRM,
PSVIPOPS-Controle
proramPS-ON, CYCLA, PS-END,
PS-SVY

PS-Interface
subroutines

PS-ON, PS-OFF, STATUS,CURRENT-SET,POLARITY-CHENGE,
ADC-READ, STROBE,
CURRENT -STEP-SET

CIM, DIM handler
subroutinesI

CAMAC handler
subroutines

NO

n=n+l

n

< 10

11=0

CIMINT, DIMINT, DIMO, DIMI,DIMTST
15 A )CFSA,CDREGI

CIM micro
prorams
DIM micro
programs

Fig. 1. Flow chart of the current step set program.

TRIM_ _ -.SO.LL.J1AK·cQRR..;. _MAIN'COIL MAX.CURR.

1. 01 I
1. 00 I

0.99 Io

JO

60
TIME IN MINITES

90

120

lBO

Fig. 2. Time chart of the excitation for the sector magnets main coil and trim coils (CYCLING).

H. Takebe, et al.

In magnetic field measurements of thesector magnets, following excitation method(CYCLING) was taken (see Fig. 2) in order toobtain a good reproducibility of the field distribution and to get a fast stability.
1. All PS's are operated at maximum current.
2. Wait 20 min.
3. All PS's are turn off.
4. Wait 7 min.
5. Current X 1.01 of main coil is excited.
6. Wait 20 min.
7. Current x 0.99 of main coil is excited.
8. Wait 10 min.
9, Current X 1.00 of main coil is excited.

177

10. Wait 50 min.
Total setup time of the sector magnet excitation is about 2.5 h. For a lower magnetic field «13 kG) this setting method is very important.
References
1) T. Wada, ]. Fujita, K. Shimizu, 1. Yokoyama, T.
Kambara, and H. Kamitsubo: RIKEN Aeeel. Progr.
Rep., 18, 185 (1984).
2) H. Takebe, S. Motonaga, T. Wada, 1. Takeshita, and
H. Kamitsubo: Proc. 5th Symp. Accelerator And
Technology, p. 197 (1984); S. Motonaga, H. Takebe,
T. Wada, A. Goto, 1. Takeshita, J. Fujita, H.
Kamitsubo, J. Abe, H. Saito, and T. Mita: RlKEN
Aceel. Progr. Rep" 18, 170 (1984).

178
RIKEN Accel. Progr. Rep. 19 (1985)

V -6.

Magnetic Field Measurement for RI KEN Ring Cyclotron
A. Goto, H. Takebe, S. Motonaga, K. Hatanaka,
Y. Yano, T. Wada, N. Nakanishi, and M. Hara

Measurement of the magnetic field of the sector magnet was performed during the past year
from January to December. The measuring system was almost the same as one that had beenused in a preliminary measurement performed at
the factory three years ago,l) except for the following: the guide rail for the Hall assembly was
extended to make it possible to measure the fieldover the whole range of 360°, a DEC LSI-II micro
computer was replaced by a super minicomputer(M60: M350-60/500) for control of the measuringsystem, and all the power supplies were
controlled by the computer through the CAMAC
modules named CIM and DIM. Working conditions of the system were very well throughout themeasurement.
At first, the field setting procedure was studied
to obtain reproducible and fast stabilizing field
distribution. Various modes of setting procedures were examined and it was found that thebest procedure is first to excite the magnet by useof all the main and trim coil power supplies up to
the maximum field level and then to deexcite it
before reaching the final level. The former process is essential to obtain reproducible distribution and the latter is necessary to stabilize the
distribution as quickly as possible. Reproducibility of the field distribution was found to bebetter than 5 X 10- 4 • Consuming time to reach astable field level was about 1.5 h for higher
excitations and 3 h for the lowest.
Trim coil fields were measured along the sector center line at an interval of 10 mm for sevenlevels of main coil currents (300,520,640, 710, 800,
940, and 1,050 A). These main coil currents correspond to the base fields of 6, 10, 12, 13, 14, 15, and15.5 kG, respectively. The measurement was
performed only for one sector magnet (S-sector
magnet). Three levels of currents were chosen
for each trim coil to obtain a non-linearity of theeffectiveness of the trim coil field. For the firstcycle, every coil was excited coil by coil by
one-third of the maximum current of its power
supply and the field distribution was measured ateach step. In the same way, for the second cycle
two-thirds of its maximum current was fed toeach coil and, for the last cycle, its maximum
current. It is noted that the current once fed to acoil never be switched off again throughout theabove procedure. This is because we found, in apreliminary measurement, that the data taken insuch a way that the current was switched off
after each step of measurement gave a poor
prediction for an isochronous field distribution.
The measurement at each step was started 10 to
15 min after excitation of a trim coil. In thecourse of these measurements, differences in field
distribution among four sector magnets were
measured in two cases in which trim coils were
not excited at all (base field) and they were kept
at the maximum excitation. The maximum ofthese differences was 60 G for both cases.
To estimate the required isochronous field
distribution along the sector center line, we haveused the method of GANIL,2) in which equilibrium orbits are calculated and the ratios between
the average radius and average field strength
along the orbits and those at the sector centerline (Kb and Kr values) are deduced. Map data of
the field distribution are then indispensable forthat purpose. Measurement of the field map was
carried out under two situations. One is the situation in which no injection and extraction elements are present around the sector magnets(unperturbed field) and the other the situation inwhich they* are present (perturbed field) . Unperturbed fields were measured for the S-sector
magnet only at the same field strengths as thosefor the trim field measurement. The azimuthal
range of the map was 90 (from valley to valley)
with intervals of 0.25°, 0.5°, 1°, and 2° according
to the sharpness of the azimuthal distribution.
The radial interval was 20 mm over the whole
region. The number of the mesh points was
15,765. It took about 4.5 h for each measure0* In this case no extraction elements were set because
otherwise the map data could not be taken owing totheir disturbances to the measuring apparatus. However, it can be said that there is no problem because
perturbations caused by these elements were found tobe small from another measurement.

179

A. Goto. et at.

ment. Not only the base field distribution but also
the field distributions when the trim coils
were excited were measured for each main coilcurrent. The latter measurement is necessary
because in our case the field rise of an isochronous field is rather high for some kinds ofions and, therefore, the azimuthal distribution is
expected to change. Every trim coil was excited
at a half maximum and the maximum of its
power supply. Thus a total of 21 map data weretaken for unperturbed field distributions. Perturbed fields were measured for four sector
magnets. The radial interval was taken to be 35
mm in order to reduce the measuring time. The
time taken for each measurement was 2.5 h.
Each injection element was excited corresponding to the main coil current during the measurement, but the trim coils were not excited at all.
By use of the above data, an isochronous field
distribution along the center line of each sector
magnet can be calculated and currents of themain and trim coils necessary to produce it canbe obtained. The procedure to obtain Kb and Kr
values for each sector magnet for perturbed
fields is as follows: at first, equilibrium orbits inthe unperturbed field are calculated. Then, average field strengths along these orbits are calculated for perturbed fields. Kb values for perturbed
fields are thus obtained. (Kr values are the sameas those for unperturbed fields.) These Kb and Kr
values are calculated for each sector magnet fora number of combinations: seven cases of main
coil currents of 300, 520, 640, 710, 800, 940, and
1 ,050A times three cases of all the trim coilcurrents with zero, their half maximum, andmaximum. Main and trim coil currents required
to achieve an isochronous field are obtainedusing this data base. In order to check the valid-

ity of the above method, the field distributions
calculated by using this method for the argon ion(28 MHz), which is expected to be the first ion
accelerated, were realized and measured for four
sector magnets. It was confirmed from the computer simulation that the ion can be accelerated
in this field very well and the method is reliable.
From a series of measurements mentioned
above, we found that the powers of the trim coil
power supplies for the injection region are notenough. The currents required for these power
supplies were found to exceed their maximum
currents designed. Therefore, it was decided thatiron shims be placed beneath the trim coils.
Their thicknesses are 1, 0.5, and 0.2 mm for theregions covered by trim coils No. 1-3, No.4, andabout' half of the coil No.5, respectively.
Effects of the stainless steel membranes of
vacuum chambers could not be measured at thistime. As of January 1986, installation of thevaccum chambers is being carried out, and soafter that these effects as well as the effects ofiron shims will be measured using anothermeasuring apparatus. We believe that, except forthese terms, the data obtained during the past
year's measurement form an almost complete setof data to produce isochronous field distributions.
References
1) H. Takebe, 1. Takeshita, ]. Fujita, T. Wada, 1.
Yokoyama, N. Nakanishi, S. Motonaga, and T. Sato:
Sci. Papers I.PCR., 77, 20 (1983).
2) M. Barre, D. Bibet, A. Chabert, A. Dael, C. Eveillard,
P. Lapostolle, ].F. Libin, M. Ohayon, and]. Sauret:
9th Int. Conf. on Cyclotrons and their Applications,p. 371 (1981).

180
RIKEN Accel. Progr. Rep. 19 (1985)

V -7.

Beam Injection and Extraction System of RIKEN Ring Cyclotron
Y. Yano, A. Goto, K. Hatanaka, H. Takebe, and S. Motonaga

RIKEN Ring Cyclotron has two types of injectors: the RILAC and the K65 A VF cyclotron.
A beam accelerated by one of these injectors is
led to RIKEN Ring Cyclotron through an injection beam transport line, which is positioned 4 m
above the median plane of RIKEN Ring Cyclotron. In the north-west valley of this Cyclotron, abeam is levelled down to the median plane at aslope of 45 degrees by a "canted injection system." It consists of a couple of 45 degree bending
magnets, a couple of quadrupole doublets and aquadrupole singlet. These quadrupole magnets
and the drift spaces between them are screened
from the leakage magnetic flux from the sector
magnets. This system makes achromatic beamtransport in vertical direction possible.
Figure 1 shows a layout of the beam injectionand extraction system and Table 1 lists its characteristics. In the central region of the Cyclotron,
a beam is put onto the median plane by BM2, one

Fig. 1.

of the vertical bending magnets mentioned
above, and is led radially to the first acceleration
orbit by following elements: a bending magnet,
BMI, a couple of magnetic inflection channels,
MIC2 and MICl, and an electrostatic inflection
channel, EIC.
The beam accelerated up to the outermost
radius is peeled off by an electrostatic deflection
channel, EDC, and is extracted out of the Cyclotron through a couple of magnetic deflection
channels, MDCl and MDC2. A couple of bending
magnets, EBMI and EBM2, lead the extracted
beam to the beam handling system.
The above four bending magnets are of amodified window frame type. They are placed in
the atmosphere and fixed in position. On the
beam-entrance side of BM2, a magnetic fieldclump is mounted which has a symmetric shapewith respect to the median plane of the Cyclotron. This field clump absorbs the leakage mag-

Layout of the beam injection and extraction system.

181

Y. Yano, et al .
Table 1.
Element
BM2
BMI
MIC2
MICI
EIC
EDC
MDCl
MDC2
EBMI
EBM2

Characteristics of the beam injection and extraction system.

Radius ofcurvature
46.0 cm
45.7
41.5
49.8
364.5
straight
212.6
229.9
229.5
215.0

Bend angle

Maximum fieldGap width45.0 deg.
102.75
78.69
39.7
3.62
1.08
17.79
24.66
15.0

50.0k V / ern
50.0
1.62 T
1.51
1.51

18.0
18.0

30.2

1.61

42.0

netic flux from BM2, which is harmful to theaccelerated beam because it sweeps out the beamvertically. Eight turns of twenty-four turn coilsof BMI are divided into two portions: a beam
entrance and an exit sides. Different magnetic
field strengths can be set in each portion withtwo power supplies. This enables BMI to have afunction of steering the beam radially both in its
position and direction.
The magnetic channels are inserted between
pole gaps of the sector magnets and also fixed inposition. MICI and MIC2 consist of floating ironshims and coils, while MDCl and MDC2 consistof coils only. The configurations of the ironshims and coils or the coils were designed so thatuniform magnetic fields of a sextupole component better than 1 X 10- 3 / cm 2 can be produced
inside the channels. Every magnetic channel
except MIC2 is equipped with the other coils
wound by the side of the above coils. Such coils
are called "compensation coils" and are used toreduce the magnetic field perturbations brought
about by the magnetic channels in the sector
fields outside them. These compensation coils
and the coils for adjusting the beam trajectory
are connected in series. MIC2 has no compensation coils because of the lack of space. The ironshims and coils are mounted on a stainless-steel

1.66
1.67
1.87
1.59

T

42.0 mm
42.0

Entrance/ exit
face angle
45.0/ 0.0 deg.
15.0/ -13.5

42.0
15.0/ 15.0

frame; these are contained with a vacuum tightcase of 3 mm thick stainless steel plates. The
beam passage is provided by a stainless-steel
pipe of 24 mmcP in aperture. The inside of thisvacuum-tight case is filled with epoxy resin.
The electrostatic channels are of a conventional type. Their radial positions at beam
entrance and exit can be remotely adjusted by ±10 mm each. The maximum DC voltage of 100 kV 'is applied to the 18 mm wide gap between theanode and the cathode.
From September to December, 1985, we carriedout comprehensive magnetic field measurements,
installing the beam injection and extraction elements except the electrostatic channels and themagnetic shield for the canted injection line ateach due position. The magnetic field maps
inside the elements as well as those in the sector
magnets were measured at seven sector fieldlevels from 7 kG up to 15.5 kG. The magnetic
field distributions inside the elements wereobtained nearly as expected. On the basis ofthese data, small modifications will be made foreach element to improve the distributions. The
magnetic field perturbations in the sector magnets could be corrected by the trim coils. The
detailed analysis of the data is under way.

182
RIKEN Accei. Progr. Rep. 19 (1985)

V -8.

Beam Transfer Line from RILAC to RIKEN Ring Cyclotron
K. Hatanaka, T. Inamura, Y. Yano, A. Goto,
M. Kase , K. Ozawa, * and H. Kamitsubo

in diameter and the number of windings is 30
turns per pole. Each coil permits the excitation
current up to 260 A. The total length of the line
is about 64 m and the vacuum pipe is made ofaluminum alloy. The system is required to beheld at pressure lower than 2 x 10- 7 Torr. The
aluminum vacuum system will enable us toachieve the required performance with a small
number of evacuating pumps.

The desigh of the beam transfer line from theheavy-ion linac (RILAC) to RIKEN Ring Cyclo·tron was completed in 1984 and the elements of
the line are now under construction.
The system consists of 8 dipole magnets, 14
quadrupole doublets, 13 quadrupole singlets, andmany kinds of beam diagnostic devices. Parameters for the dipole magnets are summarized inTable 1. The end profiles and the cross sectional
shapes of the pole of the dipole magnets were
determined from the numerical calculation of amagnetic field with the computer program
TRIM.o The pole of the quadrupole magnet is
170 mm long and the diameter of the inscribedcircle of the pole is 70 mm. The quadrupole
magnet has complete four-fold symmetry inorder to eliminate the octupole component in themagnetic field. The pole width is 70 mm, possessing a hyperbolic shape. In order to obtain thewide fiat region of the effective length, which isestimated to be 200 mm, the optimum end-cut
shape was determined by referring the experimental results obtained at KEK and INS. 2 ) The
cOlI is wound of copper hollow-conductor having
a cross section of 6 x 6 mm 2 with a hole of 4 mmTable 1.

Table 2. Designed values of electrical characteristics of DALO.
Resistance
Coil
Cable
Inductance
Coil
Cable
Power loss
Coil
Cable
Coil
Cable
Rise time
Fall time

2.8 mO
0.2 mO72 ,uH3,uH
3.5 kW } AC mode
8.7 kW
8.0 kW } DC mode
16.0 kW
2.5 ms < t < 5 ms
2.5 ms < t < 5 ms

Parameters of the dipole magnets in the transfer line.

Name of magnet

DALO

DMLI

DML2

DMJ3 & DMJ4

DMS5

DMS6

DMS7

Deflection angle(deg.)

5.73

20.0

20.73

90.0

40.0

40.0

45.0

Curvature radius
(m)

3.0

1.0

1.0

0.8

0.6

0.6

0.46

Maximum field
(T)

0.27

0.8

0.8

1.0

1.31

1.4

1.71

Pole gap
(mm)

60

60

60

60

60

60

42

Size of hollow-conductor(mm)

D9- tb6

D6-tb 4D6- tb4

D9-tb6

D9- tb6

D9- tb6

D9-tb6

80
600

256
200

132
450

168
450

168
450

140
500

60

66

83

54

63

47

Total number of windings
Maximum excitation current(A)
Maximum voltage

8
1,700
4.9

(V)

• College of Humanities and Science, Nihon University.

K. Hatanaka, et al.

One of the characteristic features of the beamline is beam sharing between RIKEN Ring Cyclotron and the RILAC experimental halP) For thispurpose, the first dipole magnet in the line
(DALO) is excited by pulsed current. The DC
excitation of this magnet is also possible. Electrical parameters for the magnet are listed in Table
2.

183

References
1) ].S. Colonias and J.H. Porst: Magnet Design Applications of the Magnetostatic Problem Called TRIM,
UCRL-16382 (1965).
2) M. Kumada, H. Someya, I. Sakai, and H. Sasaki:
Proc. 2nd Symp. on Accelerator Science & Technology, p. 73 (1978).
3) K. Hatanaka, T . Inamura, Y. Yano, K. Yamaguchi,
and H. Kamitsubo: RIKEN Aeee!. Progr. Rep., 18, 181(1984).

184
RIKEN Accel. Progr. Rep. 19 (1985)

V -9.

Model Study of the Beam Buncher

A. Goto, T. Fujisawa, I. Takeshita, and K. Ogiwara

A life size model of the beam buncher wasconstructed according to the design given in aprevious progress report,l) and its electrical characteristics were measured. Figure 1 shows aphotograph of the model; a schematic drawing isshown in Fig. 2. Measurements were performedfor various combinations of positions of thecapacitive frequency tuner (d) and the shorting
plate (s). The definitions of values d and s are
given in Fig. 2. Figure 3(a) gives resonant frequencies, Q values, and shunt impedances

against s for d = 84 mm (max) and Fig. 3(b) is thesame as Fig. 3(a) except for d = 10 mm, together
with the resonant frequencies for d = 5 mm. The
shunt impedance was deduced from measurements of the drift tube voltage and the rf excitation power. The drift tube voltage was measured
cal

100

meas

4

10

FrequencyCQ value~

Shunt
Impedance

so
N

I

,

~

, x

. ' ..

~Cl.

E

'x

40

~
c

d =84 mm (max).,;-;--;-x-

5
~

Cl>

:::J

~

a

U)

5X1o'

......9 .. ..... . .° .......9.. 500···· ..0 ....

o200~-----5~0-0------10~0-0------15~00~
S (mm)

(a)
cal

100

Frequency

meas

.

4

10

(.)

Q value

c

~

Shunt
Impedance

~
c

iE m

80

Cl>

N

:::J

I

~

C

.2
U)

>

a

5X1o'

;----,1(_Fig. 1. Photograph of the model buncher.
'-.
40

d=5mm

500

Voltage pick up~0~-----5~OO------~10~0-0------15~OO~
S (mm)(b)
Shorting
plate
Sliding
contact
Outer
conductor
Inner conductor

Fig. 2. Schematic drawing of the model buncher.

Fig. 3. (a) Measurements of resonant frequencies, Q
values, and shunt impedances against the positionof the movable shorting plate for d = 84 mm (max).
The calculations using the transmission line
approximation are also shown for comparison. (b)The same as Fig. 3(a) except for d = 10 mm. The
measurements of resonant frequencies are also
shown for d = 5 mm.

A. Goto, et al.

1000

d = 84 mm (max)

500

50
A

"4

20

o

500

1000
S (mm)

1500

Fig. 4. Higher modes of resonance when the tuner isat the position of the side wall. A parasitic resonance can also be seen at about 210 MHz. Solidlines are the calculations using the transmission
line approximation.

with a calibrated voltage pick-up. The excitation
power was obtained by measuring input rf current, voltage, and their phase on the feeder. The
calculations based on the transmission line
approximation shown in these figures are in good
agreement with the measurements, though theagreement in resonant frequencies is slightly
poor when d is small. Measurements of reso-

185

nances of higher modes and parasitic modes up
to 500 MHz were performed, and the results areshown in Fig. 4, together with the calculations. It
was found that, besides the resonances of higher
modes, there is a rather strong parasitic resonance in the vicinity of 210 MHz. This is theresonance of a 1/2 A wave standing on the support of drift tubes and having a node at its
center. In fact, its resonant frequency is almost
constant independently of the position of theshorting plate. Electric field distributions werealso measured along the axis of the drift tubes by
a perturbation method. The shape and amplitudeof the distribution were almost the same for all
the four gaps. The rf power is fed into theresonator through a 50 n coaxial feeder line
coupled with the resonator by a tunablecapacitive coupler. The measurement confirmedthat the impedance matching could be achieved
as expected by using this coupler.
It was found from the above measurementsthat the model works well in accordance with thedesigh, and we have fixed the specifications forthe beam buncher. The length of the coaxial part(s) was decided to be 60 cm and maximum powerof a power amplifier to be 750 W. The beam
buncher system is scheduled to be completed by
the end of luly, 1986.
Reference
1) A. Goto, T. Fujisawa, and 1. Takeshita: RIKEN
Aeeel. Progr. Rep., 18, 184 (1984).

186
RIKEN Accel. Progr. Rep. 19 (1985)

V-IO.

Control System of RIKEN Ring Cyclotron
T. Wada, ]. Fujita, K. Shimizu, 1. Yokoyama,
T. Kambara, and H. Kamitsubo

RIKEN Ring Cyclotron 1) is controlled bymeans of three mini-computers, which are linked
with one another through an optical fiber 100p.2)
A CAMAC serial crate network and a GP-IB areused for the control of accelerator devices. The
computers are of the same type, a 32-bit industrial computer MELCOM 350-60 / 500 of Mitsubishi Electric Corp.
Computer #1 controls the ring cyclotron
through the CAMAC bit serial loop. Computer #2 is used to store the base of the whole control
Table 1. Configuration of computer #3.
MemoryFixed disk
Magnetic tapeLine printerPlotter
20" graphic display
Hard copy
20" character display
Rotary encoder
Plasma display
Toutch panel and CRT
GP-IBCAMAC SHD

3 MB
202 MB
1 (1,600/ 800 bpi)
1 (390 1pm)
1 (10 pens)
1 ( 7 color)1
1 ( 7 color)4112 (400 kB/s)
1 (5 MB/ s)

Left

Centersystem into disk files. Computer #3 controls theheavy ion linac (RILAC) through a GP-IB using
optical fiber links. 3 )Computer #2 was already installed in August,
1984, and has been used for programs, data basedevelopment,4) and field measurements of thefour sector magnets;5) The computer was installed temporarily in RIKEN Ring Cyclotron
vault. Despite of operation in unconditioned
atmosphere, no hardware errors took place during 13 months.
Computer #3 and the GP-IB interface was installed in October, 1985, in the control room of
the RILAC. Table 1 lists the configurations of thememory and peripheral devices. The RILAC has
been controlled by a HP-1000 computer througha GP-IB. This network will be reconnected to the
new MELCOM computer. Some newly developed
beam diagnostic devices will be controlled
through a CAMAC serial loop using CIM andDIM modules. 6 ) The program conversion is now
in progress.
Computer #1 and an operator console will be
installed in May, 1986, and then the three computers will be linked with one another by optical

Right

Fig. 1. Top and front views of operator console.

T. Wada, et at.

DEVICE
COIL 1

VALUE
100 A

STATUS
101110

DEVICE
COIL 2

I~~~~ I [QJ [IJ[)EVICE
COIL 3

VALUE
200 A

STATUS
0100101~~~~10
Fig. 2.

m

187

VALUE
150 A

STATUS
110011

I~~~~I IT]
DEVICE
COIL 4

VALUE
250 A

m

STATUS
110011~0[IJ

An example of display on the touch pannel display.

fiber cables and RS 232C serial lines. The seriallines are used to transfer data using an UUCP
function of UNIX system. Figure 1 shows theoperator console which consists of three parts(center, left, and right parts). The left and theright parts are made equivalent to each other forthe convenience of accelerator diagnostics. At
least two operators can access the accelerator
system independently using the left and the rightparts.
In the first design of the operator console,rotary encoders and push buttons were to be used
for the manual control of each device. This has,
however, difficulty in changing the number of
encoders and buttons, and the encoder system
was replaced with a touch pannel system. Figure
2 shows an example of displays on the touchpannel CRT. The number or functions of 'buttons' can be easily changed depending oncontrolled devices. The touch pannel is a model
1024 of Japan Binary Corp., and the CRT is a
DEC model VT241.
For the operator console of RILAC, a rotary

encoder system is used because of its compatibility to a HP-1000 computer system. A plasma
display and four rotary encoders of 100 pulses
per turn are arranged on a pannel.
References
1) S. Motonaga: Proc. 1985 Particle Accelerator Conf.,
Vancouver, Canada, p. 2712 (1985).
2) T. Wada, ]. Fujita, K. Shimizu,!' Yokoyama, T.
Kambara, and H. Kamitsubo: Proc. 1985 Particle
Accelerator Conf., Vancouver, Canada, p. 2095 (1985).
3) T. Kambara and M. Odera: Proc. 5th Symp. on
Accelerator Science and Technololgy, Tsukuba, p.
364 (1984).
4) T. Wada, ]. Fujita, K. Shimizu, I. Yokoyama, T.
Kambara, and H. Kamitsubo: RIKEN Aeee!. Progr.
Rep., 18, 185 (1984).
5) A. Goto, H. Takebe, S. Motonaga, K. Hatanaka, Y.
Yano, T. Wada, N. Nakanishi, and M. Hara: p. 178 inthis report.
6) K. Shimizu, T. Wada, ]. Fujita, and I, Yokoyama:
Proc. 10th Int. Conf. on Cyclotron and their Applications, East Lansing, Michigan, USA, p. 392 (April
1984).

188
RIKEN Accel. Progr. Rep. 19 (1985)

V-II.

Sequential Control Using an Intelligent Interface Module
K. Shimizu, M. N agase, H. Takebe, and S. -Motonaga

Current regulators are used for exciting themagnet coils of RIKEN Ring Cyclotron. Eachregulator has a control element, an error voltage
amplifier, a standard registor and a 16 bit D-A
converter (DAC) for accepting a digital reference. It is required that each output of theseregulators increases linearly with time. However, since the time constant of the magnet coils
is very long, it takes at least twenty minutes inincreasing all the regulator outputs to predetermined final values. Although such a long time
sequential control can be done with a host computer, it is not always effective in the usage of thehost computer. Two types of intelligent interface
Inodules (CIM and DIM)l) are used in our control
system. 2 ) In particular, the DIM can perform
various kinds of controls independently of acontrol computer by only firmwaring respective
programs into its ROM. Therefore, a program
which enables the DIM to perform the sequential
control was developed. Protocol on the program
will be explained below.
Parameters are sent to the DIM firstly to start
the sequential control. These parameters consistof the following items.
1. Number of DACS: number of the controlled
regulators.
2. Resetting Interval: repetition time on varinga reference as a jump function based on a linear
function.
3. DAC Number: this means a regulator number.
4. Initial Value: initial output current of eachregulator.
5. Final Value: final output current of eachregulator.
6. Reference Step Value: increment of eachreference.
7. Allowable Deviation: upper limit of thedifference between each reference and an output
current borne by it.
Figure 1 shows the format of the parameters.
A CIM/DIM system provides various instructions. A block information transfer instruction isused for sending the parameters to the DIM.
After sending the instruction, the sequential control is performed if an instruction for starting it

Number of DACs
Resetting Interval~(Upper Byte)(Lower Byte)

DAC Number
Initial Value(Upper Byte)~(Lower Byte)

Final V.a lue(Upper Byte)~(Lower Byte)

Reference Step Value (Upper Byte)'"(Lower Byte)

Allowable Deviation
DAC Number

v..

.,

'[Allowable Deviation

Jr

Fig. 1. Format of parameters.

Initial Value Setting

Reference Addition

Controlled Current Detection

NO

Deviation Excess

Complete

Fig. 2. Operation flow diagram.

K. Shimizu, et at.
LSB~

L :c N~b", 0' Bit N~b",.'NO:'

l:Instrument Failure
O:Normall:Deviation Excess

o:Not Complete
1 :Complete

Fig. 3.

Fonnat of the message coming from DIM.

0000
Parameter Area
0070
DAC Data File (16 Bits)
0090
ADC Data File (12 Bits)(Hex.)

Fig. 4.

Memory map.

is sent to the DIM.
Figure 2 shows the operation flow diagram ofthe sequential control. The DIM gives each initial reference to each regulator as the Initial
Value Setting step sequentially. Then, the following operation is repeated at the resetting interval
until all the regulator outputs reach respective
final values. In the reference addition step, theDIM adds each reference step value to the previous reference and gives the result to each regulator as the following reference sequentially.
The DIM detects the output current of eachregulator through its 12 bit A-D converter andchecks the difference between the detected current and a reference bearing the output current in
the controlled current detection and deviation
check steps sequentially. Then, DIM checks
whether instrument status is normal or not andwhether all the output currents reached the final
values or not.
When the difference exceeds each allowabledeviation in the deviation check or the instrument status is not normal in the instrument status check, the DIM stops performing the sequential control and sends a signal to the control
computer through a CIM connected to it.
When all the output currents reached the final

189

values, the DIM also sends the signal to thecontrol computer. After the recognization of thesignal, if a message is fetched from the DIM withan instruction, the cause of the generation of thesignal (Deviation Excess, Instrument Failure,
Complete) is found out from the message.
The format of the message is shown in Fig.3. In
the format, the most significant bit represents
whether the sequential control is complete or not.
Deviation excess is defined on the second upper
bit. An instrument failure is defined on the third
upper bit. The lower four bits are used for representing a DAC number related to the deviation excess or a bit number related to the instrument failure in the status information.
Figure 4 shows a memory map used for thesequential control. The parameters from thecontrol computer are _stored in the parameter
area, where the most significant bit in each byte
assigned to the DAC number is set if each regulator output reached its final value. The reference
and output current of each regulator are rewritten into the DAC Data File (16 bits) and ADC
Data File (12 bits) at every the resetting interval,
respectively. As the contents of the memory canbe read out with another block informationtransfer instruction, each situation of the sequential control can be found out. It will be understood from the explanation mentioned above thatthe control computer can execute other tasks
during the DIM performs the sequential control.
The DIM can reduce the load of the control
computer because it can be used not only forinterfacing between the control computer andinstruments but also for controlling thus instruments sequentially. Furthermore, the DIM can
respond to request from the control computereven during it performs the sequential control.
Such a function of the DIM is superior to that ofa general purpose sequential controller. The
function makes the control system more flexible
and powerful.
References
1) K. Shimizu: Nucl. Instrum. Methods Phys. Res. A,
236, 109 (1985).

2) K. Shimizu, J. Fujita, T. Wada, and 1. Yokoyama:

RIKEN Aeee!. Progr. Rep., 17, 141 (1983).

190
RIKEN Accel. Progr. Rep. 19 (1985)

V-12.

Practical Use of an Intelligent CAMAC GP-IB Controller]. Fujita

An outline of an intelligent CAMAC GP-IB
controller module was described in a previous
report.I) The present report describes the module
used practically in RIKEN Ring Cyclotron magnetic field measurement.
A present configuration of the magnetic fieldmeasurement system is shown in Fig. 1, where an
M60/500 Mitsubishi computer 2 ) and an LSI-l1
microcomputer systems3 ) are depicted simply andother instruments not related directly to the
GP-IB route are not shown. The LSI-II is used
for controlling GP-IB devices and linking both
systems via handshake between two CAMAC 16
bits I/O registers. Since only two bytes are transferred by one access to the 16 bits I/ O registerand block transfer is not carried out in thissystem, it takes about 6.8 x (N /2) ms for M60 toreceive data of N bytes and, conversely, 5.1 x(N /2) ms to deliver them to the LSI-11.
Replacement of the LSI-1I system with the
GP-IB controller module will make configurationof the measurement system very simple, as
shown in Fig. 2, and will shorten data handlingtime as mentioned below. The module has capability of CAMAC block transfer with a 24 bits
full word mode. The block transfer rate of a
CAMAC serial loop in the M60 system is 20 kB/
s. Data receiving and delivering times in thesame case as before are about 9.6+0.15 x (N /3)
ms and 10.4+0.15 x (N /3) ms, respectively.
Therefore, the data transfer time in this system
is reduced to 1/3 of that in the former system for
N = 12 bytes, and 1/20 for N = 120 bytes.
In order to make use of the GP-IB module easy,a library file, /usr/rlib/gpm.tl, on UNIX and an
object ~odule file, SYSOOI/ROF;GPMINI, on

Fig. 2. Replaced system with an intelligent GP-IB
module. GPM; an intelligent GP-IB module.

M60 are constructed. These files consist of four
subroutines, GPMINI, GPMSND, GPDRCV, and
GPMWRK.
GPMINI must be issued once at the beginningof a main program. It defines CAMAC addresses
with regard to the module and sets it to an initialstate.
GPMSND transforms a given character stringof an EBCDIC code in M60 to an ASCII one,rearranges the string locations of 32 bits fullword in M60 to CAMAC 24 bits word, and sends
the resulting ASCII string to the module.
GPDRCV makes acknowledgement of preceding GPMSND and, at the same time, if data from
GP-IB devices are stored in the module, receives
them. It must be used somewhere to complete one
cycle of state transition in the module after
GPMSND is called.
GPMWRK is a serial combination of GPMSND and GPDRCV, and executes sending message and receiving data continuously.
At present actual programs for measuring themagnetic field are being developed.
References
1) ]. Fujita: RIKEN Aeee!. Progr. Rep., 18, 187 (1984).
2) T. Wada, J. Fujita, K. Shimizu, I. Kambara, and H.
Kamitsubo: RIKEN Aeee!. Progr. Rep., 18, 185 (1984).
3) J. Fujita, T. Wada, and H. Takebe: RIKEN Aeee!.
Progr. Rep., 15, 177 (1982).

Fig.1. Present magnetic field measurement system. SHD, Serial Highway Driver; UPA, U-Port Adapter; SCC, Serial
Crate Controller; lOR, 16 bits I/O Register module; CC, JLSI-IO Crate Controller.

191
RIKEN Accel. Progr. Rep. 19 (1985)

V-13.

Cryopumps for RIKEN Ring Cyclotron Vacuum Chamber
N. Ohsako, * K. Morimoto, * T. Kikuchi, * K. Ikegami,
S. Nakajima, Y. Oikawa, and S.H. Be

For evacuation of RIKEN Ring Cyclotron
vacuum chamber, we have developed two typesof cryopumps and constructed ten cryopumps of1 X 104 1ls for nitrogen (ANELVA model CAP200) and four panel type cryopumps of 5 X 10 3 1ls(ANEL VA model CAP-610). These are designed
to have large adsorptive capacity for hydrogenbecause the regeneration interval of these pumps
is limited by adsorptive capacity.
A cross sectional view of CAP-200 cryopump isshown in Fig. 1. The pump housing of 500 mm indiameter surrounds the cryopanels which arecooled to cryogenic temperature by means of a
G- M refrigerator (Sumitomo Heavy Industry Co.
model SRD-208). A quantity of charcoal stuck on
the inner surface of the second stage cryopanelsof each cryopump is "'-'300 g. A refrigeration
capacity of the SRD-208 cryogenerator is 8 wattat 20 K on the second stage and 70 watt at 77 K
on the first stage. The CAP-610 has a geometry
like a waterwheel as shown in Fig. 2 and isdirectly inserted in the stem of the resonator. A
quantity of charcoal stuck on the inner surface ofthe second stage cryopanels is "'-'270 g. A refrigerator (SRD-208) is also employed in thiscryopump.
The performance tests for these pumps werecarried out on a test chamber. After evacuating

the test chamber to 10 Pa by a mechanical pump,
the cryopump was turned on. The temperature of
the second stage cryopanels was reduced below
20 K within 150 min for CAP-200 and within 220
min for CAP-610. Furthermore the pressure
became below 1 X 10- 4 Pa at the end of cooldown
time, and after 13 h below 1 X 10- 7 Pa without
baking.
Figure 3 shows results of pumping speed measurements. Pumping speeds at various pressures
were determined from equilibrium pressure measured at various flow rates of inlet N 2 or H2 gas.
The average pumping speed of CAP-200 is '"'-'1 X
10 4 lis for nitrogen and "'-'2 X 104 lis for hydrogen, and that of CAP-610 is "'-'6.3 X 103 lis fornitrogen and '"'-'8.3 X 103 lis for hydrogen. They
are in good agreement with calculations.
Finally we investigated an adsorptive capacity
for hydrogen of these cryopumps keeping a flowrate ('"'-'18 Pa lis) of gases constant. Figure 4
shows that the equilibrium pressure increases,
i. e., the pumping speed decreases, with anincrease in a total amount of hydrogen adsorbed

MOUNTING FLANGECHARCOAL
1st STAGELOUVER

2nd STAGE
CRYOPANEL

1st STAGE
CRYOPANEL

(a)

E
E

r--.

C")

CD

Fig. 1. Cross sectional view of CAP-200 cryopump.
'" ANEL VA Corporation.

(b)

Fig. 2. Cross sectional view of CAP-610 cryopump.
(a) a front view, (b) a bottom view.

192

N. Ohsako, et al.

10-1r---.---.----.-----.____~--~°~ 2x10 4~

CAP· 200(H,) _°_--",,-0--cor---..uo----(o>----=-----<D-00

o

UJ
UJ

0..
(J)

r0-

t9
Z

~ 10-2o..

a::~ 1 x10
::>
0..

4

•

CAP-200(N,)...

CAP-610(H,)

w ,. : • we
0

0

0

0

•

•

• ~. ••

o

0

:J
(J)
(J)

w

a:
0..

CAP- 610(N,) ®

®

®

®

@

@

@

~
:J

a:
co
:::i

:5 10- 3o

UJPRESSURE(Pa)

Fig. 3. Results of pumping speed measurement forcryopumps.

on charcoal. From Fig. 4 we can see that theadsorptive capacity for hydrogen without seriously decreasing the pumping speed (until the
speed becomes one half of the initial value) is"-'6 x 103 Pa m 3 for CAP-200 and "-'6.5 X 103 Pa m 3
for CAP-610. The adsorptive capacity, however,depends on the equilibrium pressure anddecreases with a decrease in pressure.1) Since
partial hydrogen pressure in the vacuum chamber of the ring cyclotron will be of the order of1 x 10- 6 Pa, the adsorptive capacities of thesepumps may be estimated to be one half or one
third 2 ) of the values measured above.

3
AMOUNT OF ADSORBED HYDROGEN (Pa m /g)

Fig. 4. Variation of an equilibrium pressure with a
total amount of adsorved hydrogen.

References
1) "Ie Vide les Couches Minces" supplement "Vide et
Cryogenie," ed. by Societe Frant;aise du Vide, p. 17(1984).
2) "Basics of Cryopumping," Air Products and Chemicals Inc. (1980).

193
RIKEN Accel. Progr. Rep. 19 (1985)

V -14.

Outgassing Rates of Materials Used in the Vacuum Chamber
for RI KEN Ring Cyclotron
K. Ikegami, Y. Ishibe, and S. H. Be

The vacuum chamber of RIKEN Ring Cyclotron uses various materials such as stainlesssteel (SUS), alumina, and viton O-ring. For evaluation of the gas load due to outgassing fromthese materials and the corresponding pumping
requirements, measurements of the outgassing
rates are indispensable. The apparatus formeasuring the outgassing rates is shown in Fig.
l. The test chamber, which is made of SUS andhas an inner surface area of 1,800 cm2 , wasevacuated through an orifice of 11 mm in diameter open to a high-vacuum chamber placed under
the test chamber. The orifice is capable of conducting N2 at 10 lis or H 20 at 12 lis. The
high-vacuum chamber was evacuated directlywith a turbomolecular pump of 300 I I s and abacking rotary pump of 250 llmin. An ionization
gauge in the test chamber was used for measuring an increase in the pressure by outgassing anda variable leak valve for gas inlet. A quadrupole

mass analyzer connected to the high-vacuum
chamber was used for observing residual gases
and the components of released gases. The outgassing rates were determined from a surface
areas of the respective materials and the pressure differences between two chambers, by using
the orifice conductance of 12 lis for H 20 because
the gases was composed mainly of water vapor.
Figure 2 shows the outgassing rates for various materials, which decrease with time after thestart of pumping. The rate for SUS-304L polishedmechanically by a glass beads blast (G.B.B.) is of
the order of -----10- 7 Pa m 3 /s m2 at 150 h after
pumping and this value is lowered by a factor of

10- 3 < k - " " " " " ' - - - - - - - - - - - - l~ 10-4 t--~~r_'~-~----__l

E
hl
E
<'Ii

Helico flex or Viton Q-ring

VI

'-.

~ 10- 5..............------"~ ----'~\-----__I

2

~

DO

c::

.iii
~ 10 - 6 r-----~----___\:__-~

~
::::I

o

10- 7 t-----------"~--__lIoni. gauge

JIS 235
1O -8 1--.~__:I:_____:_1=--=:l_=_~~__:___=~~-=---'

Turbomolecularpump

2

50 100200 500
1000

Evacuating time (hour)

Pumping speed of

300 l/secI

5 10 20

to Rotary pump of
250 l/min.

Fig. 1. Schematic diagram of the apparatus formeasuring outgassing rates.

Fig. 2. Outgassing rate for various materials vs.
time. (1) Unbaked viton O-ring. (2) Viton O-ring
immediately after baking in vacuum. (3) Thinalumina layer deposited with Si02 • (4) Thin alumina
layer flash-coated on a copper plate. (5) Solder
applied to a thin copper plate. (6) Stainless-steel(304L) polished mechanically by G.B.B.

194

K. Ikegami, et al.

5 compared to that for untreated SUS-304L,
which is not shown here. The SUS-304L is to be
used for RIKEN Ring Cyclotron chamber. The
outgassing rates from a solder of Sn-Ag alloy
and a thin alumina layer flash-coated on a copper
plate were also measured. The solder is to be
used in welding a water cooling pipe to an innerpart of the dee in the resonator; its outgassing is"-' 10- 6 Pa m 3 / s m Z after 100 h. The thin alumina
layer is used as an insulator for trim coils in the
sub-vacuum chambers of four sector magnets
and for coils of magnetic channels; its outgassing
rate is "-'4 X 10- 6 Pa m 3 /s m Z at 150 h after thestart of pumping. The outgassing rate from athin alumina layer deposited with SiOz is "-'10- 5Pa m 3 / s m Z , which is over 2 times greater thanthat from an alumina layer only. From theseresults, we chose the alumina layar as a suitable
insulator.
We also measured the outgassing rates forviton O-rings (Dainichi Densen, 320-75) pre-baked for 24 h at 120°C in a vacuum. Since
detailed results of the prebaking and degassing
will be described by Y. Ishibe et at., 1) a part of
the results is shown in Fig. 2 in comparison withother materials. The O-rings were placed into astandard rectangular groove on the top flange ofthe test chamber and assumed that only a part ofthe surface, a half of a total surface area, is
exposed to a vacuum. The outgassing rate
involving permeation from the O-ring immediately after baking was "-'2 x 10- 5 Pa m 3 /s m Z at 100
h after the start of pumping. This value is lower
than one third of that for an unbaked O-ring.
These experimental results show that the outgassing rates of materials depend strongly on thestate of the surface such as polished or unpolished, and baked or unbaked.
Reference
1) Y. Ishibe, K. Ikegami, and S. H. Be: p. 195 in thisreport.

195

RIKEN Accel. Progr. Rep. 19 (1985)

V -15.

Evaluation of an Outgassing Rate from Pretreated Elastomers
Y. Ishibe, K. Ikegami, and S. H. Be

An operating pressure requried for the vacuum
chamber of RIKEN Ring Cyclotron is of theorder of 10- 6 Pa, which is determined from anevacuating capacity of vacuum pumps and an
outgassing rate from surfaces of materials usedin the vacuum system including vacuum seals.
The materials include stainless steel, copper,
aluminum, ceramics, viton O-ring, etc. and outgassing rates from these respective materials
depend on a pump down time; the rates decrease
with time. In the present case, the overall outgassing rate estimated from published data 10-50 h
after the start of pumping is '"'-'4 X 10- 4 Pa m 3 Is,
and that from viton O-rings used as parts ofvacuum seals is approximately 1'""'-'2 x 10- 4 Pa
m 3 Is, corresponding to about one or two thirds ofbo

the overall outgassing rate. Since O-rings arealso permeable to gases, we plan to use double
O-rings, the space between which "is evacuatedwith a separate pump to prevent permeation of
atmospheric gas.
In order to reduce the outgassing rate, we havecarried out preliminary experiments with prebaked elastomers. Two procedures were
examined for degassing: baking in air in thetemperature range from 120 to 200°C and baking
at '"'-'1 Pa at 150°C.
Weight-recovery rates «wt-wo)1 w) of elastomers are shown as a function of time after
baking in air in Fig.l. Here w is the initial weightof an O-ring, Wo is the weight immediately after
degassing, and Wt is the weight at given time.
Figure 1 indicates that the weight recovery rates
for two elastomers increase with time; Theseelastomers increase their weights continuously
over 400 h, when the weights level off. The recovery rate of the viton O-ring, however, is consider-

0

OJ

+'

~ 10- 3

;>,
~

OJ

!>

o

()

~-~--

OJ

.

~

+'

..c:

.~ 10 - 4
OJ

:;:

..

~

~~~~~~--~~~~~--~~~--

10 1

10 2

Time

10

3

(hour)

Fig. 1. Weight-recovery rates of elastomers bakedin air as a function of time. a, fluoroelastomer(viton) baked for 10 h at 200°C; b, nitrile rubber(NBR) baked for 20 h at 120°C.

>,
~

Q)

:>
o

Table 1. Weight-loss rate after baking in air and at----1 Pa.

()~ 10- 2
+'

..c:

tl'

'M

Material

OJ

Silicone

!>

~

Rate

OJ

NBR

Viton

'M

+J

...,<1l(W-:Wo )in atmosphere(w-:Wo )in vacuum

1.2 x 10- 2(120°C 20 h)

1 X 10- 2(120°C 20 h)

2.5 X 10- 3(210°C 10 h)

4.4 x 10- 2(150°C
one day)

4.6 X 10- 2(150°C
one day)

8.3 X 10- 4(150°C
one day)

OJ
p::

10 2
Time

(hour)

Fig. 2. Relative weight-recovery rate Rab of elastomers baked at ----1 Pa as a function of time. a,viton; b, NBR; c, silicone.

196

Y. Ishibe, et al.

u

51

i 10-

3

If

10 0

c
d
b

a

o
~

10'

-2
.Q

Time

10

10 2

(hour)

III

pc:

Fig. 4. Outgassing rate from viton O·ring after
baking in vacuum; a, just after degassing by bak·ing; b, after exposure to 100 % humidity at R.T. for
5 h; c, after 240 h at 100 % humidity; d, original
elastomer without degassing.
Time(hour)

Fig. 3. Time-dependent relative weight-recovery
rate of viton O-ring under different stored conditions after baking. Baking conditions: 006, one
day at 150°C at ~ 1 Pa; • • • , one day at 150°C in
air. Stored conditions: 0., with silicagel; 0 ., inair; 6 .... , in saturated water vapor.

ably lower than that of the NBR O-ring. The
weight loss rates for various elastomers pretreated in air and at reduced pressure are given
in Table 1. The weight loss rates cannot directlycompared with each other because the pretreatment was carried out under different degassing conditions. However, the weight loss rate ofviton O-ring is about one order of magnitude
smaller than those for other elastomers.
Time-dependent relative weight recovery rates
calculated from Rab = (Wt - wo)/(w - wo) for elastomers baked at '"'-'1 Pa are shown in Fig. 2,
which shows that Rab for the viton O-ring reaches
1, namely its weight becomes the same as theinitial weight. This means that gases are reabsorbed to the same level as that before degassing. On
the other hand, Rab'S for silicone and NBR O-ringlevel off at Rab = 0.1. A reason for this difference
is not clear; we think that the weight loss for theviton O-rings is due mostly to the desorption ofgases, and that for silicone and NBR O-rings isdue to the removal of a plasticizer together withabsorbed gases.
The relative weight-recovery rates at different
relative humidities in air were also investigated;
the results are shown in Fig. 3, which suggeststhat the humidity of the ambient atmosphere inwhich elastomers are stored plays an importantrole in reabsorption of gases.
Finally, we measured the outgassing rate fromviton O-rings after baking, and the results areshown in Fig. 4. The details for measuring theoutgassing rates will be reported by Ikegami
et al. in this report. I ) As shown in Fig. 4, the outgassing rate increases with an increase in exposure time in air, and depends strongly on the storing conditions. We also found that the outgassing
rate from the viton O-ring just after baking
decrease by about one order of magnitude fasterthan that from the O-ring without baking.
In conclusion, the pre-treatment of degassing
by baking is useful to decrease the outgassing
rate of elastomers.
Reference
1) K. Ikegami, Y. Ishibe, and S. H. Be: p. 193 in thisreport.

197
RIKEN Accel. Progr. Rep. 19 (1985)

V -16.

AVF-Cyclotron as an Injector

N. Nakanishi and T. Kageyama

RIKEN Ring Cyclotron is planed to have two
injectors. One is a variable frequency linac
RILAC, which was completed in 1980, and theother is an AVF cyclotron which will be constructed in the near future. This report describes
fundamental parameters for the A VF cyclotron.
In designing the new cyclotron, we took thefollowing points into consideration: 1) the A VF
cyclotron must be matched precisely to the post
accelerator, RIKEN Ring Cyclotron, in view ofbeam optics; 2) the cyclotron must be adaptable
to external ion sources; 3) the cyclotron will be
used mainly as an injector; 4) the most portionsof the cyclotron will be made by orthodox techniques, because of a few man power and an
insufficient budget.
Matching conditions between two cyclotrons
include the constancy of a longitudinal distance
between beam pulses, a beam velocity, and aparticle regidity. From these conditions we canobtain expressions, N a · Ral Ha =Ns . Rsl lIs, fa .
Ra = Is . Rs, and qa . Ba . Ra = qs . Bs· R s, where Ra
and Rs are mean extraction radius of the AVF
cyclotron and mean injection radius of the ring
cyclotron, Ha and Hs, fa and Is, qa and qs, and Ba

and Bs are harmonic numbers, orbital frequencies, charge states, and mean magnetic flux
densities in respective cyclotrons. Using above

2.0

1.0

E

I~

0.5

0.2
F'f (MHz)

8

10
2

12
4

14

16
6

20

24

8 10

15

20

E (MeV!u)Fig. 1. Relation among energy per nucleon, magnetic field, and RF frequency. The number on eachline is the mass to charge ratio.

Table 1. Selected parameter groups for A VF cyclotrons.

"1 = sin(H • dee angle/2)

Type

K (MeV)

Ra(m)

Rs(m)

Ha

Hs

Na

Ns

l / NsDee angle

"1a

"1s

A
B
C

no

0.893
0.714
0.714

0.893
0.893
0.893

3
2
4

6
5
5

1
1
1

2
2
1

0.5
0.5
1.0

60°
90°
45°

1.0
1.0
1.0

0.94
0.85
0.85

70
70

Table 3. Design characteristics of the A VF cyclotron.
Table 2. Beam energies obtainable at the A VF
cyclotron.

A/q

TypicalnucleiE (MeV/ u)

Bext(T)!o(MHz)1p+13.3-8.8

0.74-0.60

11.25-9.18

3/2

3He2+

13.3-3.9

1.10-0.60

11.25-6.122

13.3-2.6

1.47-0.65

11.25-5.00

3d+, «2+12CH

7.9-2.6

1.70-0.98

8.67-5.00

420N eS +4.4-2.6

1.70-1.31

6.50- 5.00

5

40

ArB+

2.8-2.6

1.70-1.63

5.20-5.00

K-value
No. of sectors
Extraction radiusMax. mean magnetic field
Max. magnetmotive force
No. of harmonic coils
No. of dees
No. of cavities
Dee angle
RF range
Dee voltage
Harmonic No.
Ion source
Pressure70
40.174 m
1.7 T
4 X10 5 AT
4
2
2
90·
10-22.5 MHz
50kV
2Internal and External
5xlO- 7 Torr

198

N. Nakanishi, et ai.

Table 4. Maximum beam energies obtainable at
RlKEN Ring Cyclotron.
T ypical
nucleip+
3He2+d+, a 2 + /2C6+
2° Ne 9 +40 Ar1S+

E1n
Eext(MeV) (MeV)
10.0
9.3
7.0
5.9
4.4

210
193
134
109
78

B (T)
0.87- 11.06
1.26-1.52
1.45-1.66
1.47-1.66
1.53-1.67

fo
(MHz)

Vz ext

7.7
7.5
6.5
6.0
5.1

0.51
0.57
0.67
0.73
0.75

relations and imposing other restrictions, weselected three possible types of A VF cyclotron.
These parameters are tabulated in Table 1. Fromexamination of beam energies, cyclotron sizes,
dee angles, acceleration efficiencies, and others,
we finally decided to employ the type B. Beamenergies obtainable for typical nuclei are listed

in Table 2, and the relation among beam energy,
magnetic field strength, and orbital frequency isshown in Fig. 1. Design characteristics of the
A VF cyclotron are shown in Table 3. Maximum
beam energies obtainable at RIKEN Ring Cyclotron are also given in Table 4 along with usedmagnetic strengths, radio- frequencies, and axial
betatron frequencies.
Although an internal ion source will also beused, the cyclotron must be designed to be adaptable to external ion sources such an ECR ion
source, and polarized ion sources. To this end
extensive studies should be carried out for anaxial injection system, a reflection system, anddee structure in a central region as well as abasic design study of the A VF cyclotron. Suchstudies are in progress.

199
RIKEN Accel. Progr. Rep. 19 (1985)

V -17.

Sixth Harmonic Acceleration in the Baby Cyclotron
T. Karasawa

In the Baby Cyclotron, protons are accelerated
with a second harmonic mode and deuterons
with a fourth harmonic mode. We have studied
capability of the sixth harmonic-mode acceleration in the central region by the use of numericalorbit calculation.
The procedure of the calculation is the same asthat used by Nieuwland and Hazewindus. 1) We
employ a left-handed rectangular coordinate
system, with the origin at the center of the cyclotron; the z axis is the direction of the magnetic
field and x = 0 is a center line of the dee. The
horizontal geometry of the central region (ionsource, puller, 30 degree dee and dummy dee) isshown in Fig. 1. The aperture of the puller is 5
mm and that of the dee and the dummy dee is 10mm. The magnetic field distribution is shown in
Fig. 2.
Figure 3 shows an example of the orbits ca1cu-

lated for four rays leaving the ion source withdifferent starting phases: - 27 degree, - 36
degree, - 45 degree, and - 54 degree at a RFphase, where 0 degree corresponds to the peak
RF voltage. The accelerating parameters of theions are as follows. The ion-source position is (x,y)=( - 8, 9.5) in mm and the dee voltage is 24 kV
at B = 1.5 Tesla for 15N5+ ion. When suitablecondition is applied, we could accelerate a wellcentered beam with a sixth harmonic mode in thecentral region. The difference of electrode shape® Dummy Dee© Cycl otron Cent er@ Dee

CD Ion Source® Puller(A)

Fig. 1. Horizontal geometry of the central region.

(0 )

~

::S omlIDy(A ),(B),(C) ,(O): starting phase ; see Table 1.

(B)
r (em)

Fig. 2.

Relative magnetic field distribution.

Fig. 3. (A; Calculated horizontal orbit. (B) Calculated
horizontal orbit (enlarged).

200

T. Karasawa

a = Dee Angle2{3 = Puller Angle

3(turns)(A), (B), (C), (0) : start ing phase; see Table 1.

Fig. 4. Definition of the dee angle and the puller
angle.
Table l. Orbit center and RF phase after three
revolution.
Symbol
(A)
(B)
(C)

CD)

Starting
phase (degree)
-27
- 36
-45
-54

Orbit center (x, y)
mm mm
1.2,
- 0.4,
-0.8,
-0.8,

2
-2
-5
-8

RF phase(degree)
95
113
116
111

between sixth and the fourth harmonic mode is
as follows. The dee angle is narrowed from 35 to
30 degree and puller angle is narrowed from 42 to
33 degree. These angles are shown in Fig. 4.
The orbit center and the RF phase at crossing
the y axis (center line of the dee) after three
revolutions are tabulated in Table l.
Vertical motions are calculated simultaneously with horizontal motion with an initial condition that z(O)=l and dz(O)=O, where z is thevertial displacement; the results are shown in

Fig. 5. Calculated vertical orbit.

Fig. 5,The vertical focusing in the sixth harmonicmode is, for most phases, stronger than in the
fourth harmonic mode; however, it also shows
stronger phase dependence. It is necessary to
shift the RF phase towards the declining phase of
the cosine; this means that a specific range of thestarting phase should be selected.
These results will be applied to acceleration of
N ions in the Baby Cyclotron. Until we put thesixth harmonic acceleration mode into practice,following problems should be solved. Both sixthand fourth mode acceleration are realized by useof the same puller, dee, and dummy dee except
for ion source position and relative magnetic
field distribution.
Reference
1)

J.M. van Nieuwland and N. Hazewindus: Philips Res.
Rep., 29, 528 (1974).

201
RIKEN Accel. Progr. Rep. 19 (1985)

V -18.

Proposal of Synchrotron Radiation Source
M. Hara, T . Wada, and H. Kamitsubo

The synchrotron radiation source provides
intense, polarized, and continuously-tunable radiation in a wide range of wavelength. The photon
beam is used in a variety of fields such as physics,
chemistry, biology, engineering, medicine, andagriculture. Synchrotron radiation (SR) is
becoming an important tool in many branches ofscience, especially in interdisciplinary fields. In
Japan, the Photon Factory at KEK 1) is only facil ities that can provide hard X-ray as SR, and it
has made a remarkable success. Recently, insertion devices such as wigglers or undulators have
rapidly been developed and radiations from these
insertion devices are becoming more important
than that from a bending magmet. In the future,
more demands are expected on the radiation
with higher energies and higher intensity. Now,
we should have a plan to construct new SR
facilities.
There are three reasons favorable to construct
SR facilities in RIKEN. Firstly, RIKEN has a
tradition as a pioneer in the field of accelerator
in Japan. We have made four cyclotrons and one
heavy-ion linac. 2 ) Now we are constructing a ring
cyclotron 3 ) that is a first class heavy-ion cyclotron in the world. We have enough potential andexcellent staff to construct SR facilities. Secondly, in RIKEN, basic and application research inphysics (nuclear, material and applied), chemistry, pharmacology, biology, agriculture, medicine, and fundamental technology are treated.
Active cooperation is expected in the design anduse of SR. Thirdly, all the accelerator facilities
in RIKEN are opened to researchers of privatecompanies, universities, and research institutes
in the world.
(1) An Outline of the Facility
Proposed general facilities are composed of a 6
Ge V main storage ring, a booster synchrotron, al.5 Ge V storage ring, a l.5 Ge V injector linac, apositron production linac and high energy electron beam utilization facilities including a pulse
stretcher ring and spectrometers.
1) 6 GeV main ring
Energy of the main ring is determined so thatphotons in a wavelength range from submillimeter to 0.1 A can be used from radiation

with a bending magnet. The wavelength of 0.1 A
comes from the K-absorption edge of uranium.
The specification of the 6 Ge V ring is:
Energy 6 GeV
Current 200 rnA
Circumference about 1,000 m
In order to get stable photon beams without
serious ion-trapping instability, positrons can be
stored and a full energy injection system should
be adopted. Many long free spaces are provided
and cares are taken to the flexibility of a lattice.
2) l.5 Ge V ring
The small ring for XUV is:
Energy l.5 Ge V
Current 300 mA
Circumference about 150 m
Not only electrons but also positrons can be
stored, and lines for wigglers, undulators, andfree electron lasers are also provided.
Both rings are to be designed to get photon

BRIG HTNESS
~

0-

m

"";o~

__~+-~__+T~~~+-__~__~~__~

",.
•

0

~ ~---~+~+--+rT~r-~~~--~---+--~

"

u

w
t/)

'"0

~

~--+--r~+-~--~~---4--~~-+--~

<::)

Ie

CL
rn~

rn O

~-~--+-,r~--r---r-~~~---4---+~~
1:

'-"

a::

m

IO,,,nm'IO·,rrrm'I O-'

10
~RVE

0

10

" 10

10

10

LE NGTH ( RNGSTRD M)

Fig. 1. Spectral brightness of synchrotron radiation.
(a) 6 Ge V ring, B 0 = 5.0 T, wiggler; (b) 6 Ge V ring,B 0 = 1.0 T, dipole magnet; (c) 2.5 GeV ring, B 0 = 1.0
T, dipole magnet (Photon Factory at KEK); (d) l.5
Ge V ring, B 0 = l.0 T dipole magnet.

10'

202

M. Hara, et al.

beams with high brilliance and high stability.
The spectral range and brightness of the sources
are given in Fig. 1. Not only ordinal radiation
courses but also undulator courses for a freeelectron laser (FEL) are inserted. High energy
monochromatic and polarized y-ray using
inverse Compton scattering of laser light withhigh energy stored electrons (positrons) is used.
3) Booster synchrotron
The booster synchrotron is used to full energy
injection to the 6 Ge V ring.
4) 1.5 Ge V linac
This is an injector to the 1.5 GeV SR ring andalso to the booster synchrotron. This injector has
two preinjectors: one is 5 MeV electron linac andthe other is 250 MeV positron linac. The beam isused also for nuclear physics. The specificationof this linac is:
Energy (no load) 2.0 Ge V
(100 rnA) 1.5 GeV
100 rnA
Current
Pulse width
0.2-1.0 J1.s
11E / E
about 1%
repetition rate
50 Hz5) Positron production linac
This is composed of two parts. One is anelectron linac to produce positrons and the otheris to accelerate positron beams. Their character-istics are:e-linace+linac
Energy300 MeV 250 MeVPeak current
5A
5 rnA
Pulse width
3-20 ns
3-20 ns
50 Hz
50 Hz
Repetition rate
Frequency
3 GHz
3 GHz
6) Injector utilization facility
Efficient use of injectors are also considered. A
positron beam is used to be transported to thepositron utilization laboratory. A low energy
intense positron beam is useful in materials science, especially to diagnostics and characterization of materials. A high energy electron beam isalso used for nuclear physics with a pulse
stretcher, spectrometers, for pulsed neutron
source, or for meson production.
References
1) H. Huke, N. Kajiura, Y. Kamiya, N. Kanaya, T.
Katsura, M. Kihara, H. Kitamura, H. Kobayakawa,
M. Kobayashi, T. Koide, C.O. Pak, S. Sato, S.
Shibata, T. Yamakawa, and Y. Yamazaki: IEEE
Trans. Nucl. Sci., NS-30, 3130 (1983).
2) M. Odera, Y. Chiba, T. Tonuma, Y. Miyazawa, T.
Inoue, T . Kambara, M. Kase, T. Kubo, and F.
Yoshida: Nucl. Instrum. Methods, 227, 187 (1984).
3) S. Motonaga: IEEE Trans. Nucl. Sci. , NS-32, 2712
(1985).

203
RIKEN Accel. Progr. Rep. 19 (1985)

V -19. Characteristics of Radiofrequency Field in an Alvarez-Type
Resonator Having Chain-Like Electrodes with Varying Cell Length
M. Odera and M. Hemmi
Characteristics of the electromagnetic field ina chain electrode resonator having constant cell
length have been reported previously.l) In order
to investigate an effect of uneven cell lengths on
the RF field, a model having a varying cell length
satisfying a synchronous acceleration condition
was constructed in June 1985. Figure 1 shows aphotograph of its electrode array redesigned
from that of the former model to facilitatechange in cell geometries. A cell length of 60 mm
at injection and a mean acceleration gradient of
1 MV 1m along the accelerator axis wereassumed. This cell length at injection corresponds to the velocity of injected ions of 6 % of
the light velocity or energy of L7 MeV In for
acceleration frequency of 300 MHz. A charge tomass ratio of 1/2 was assumed to give a notablechange in cell length by acceleration. The lastcell length was 66.29 mm.
Measured gap voltage decreases with acceleration as shown in Fig. 2. The distributions shown
392.40MHz

851107

Beam
entrance

Beam
exit

Fig. 3. Distribution of gap voltage when all horizontal components are removed. It increases towards
exit end and shows characteristics of an Alvarez
resonator.

375.34MHz

851125

Fig. 1. Electrode array of the new acceleration
model.

297.88MHz

850905

Beam ...
exit

Beamexit -

Beam
entrance

Fig. 2. Distribution of acceleration voltage in thegaps of the acceleration model. It is really a distribution of voltage squared. Distributions in theother figures are also squared one. Note that peakvoltage decreases towards exit end.

Beam
- entrance

Fig. 4. Gap voltage distribution when T -shaped
horizontal stems are fixed only on the right-handside (viewed toward downstream) of the resonator.
Neither semi-circular forcusing electrodes nor
transversal plates with acceleration aperture areattached to the horizontal stems. Peak voltage
increases towards exit end and still shows Alvarez
tendency.

204

M. Odera, et at.

322.19MHz
360.99MHz

Beam.
exit
Beam
exit -

851223851216Beam- entrance

Fig. 5. Gap voltage distribution when the horizontal
stems are fixed on the both sides of the resonator.
No focusing electrodes nor transversal plates areattached to the horizontal stems. Distribution
shows a slight decrease, contrary to the Alvareztype tendency shown in Fig. 4

in Fig. 2 and in the other figures are those of thebead pulling measurements and represent squareof voltage distributions. The decreasing gap
voltage is contrary to that for an usual Alvarez
structure, where the gap voltage increases withcell length when a ratio of gap to cell length andtransversal dimensions of the cavity were kept
constant. Similar voltage decreasing tendency
was also observed in a model study of the
RILAC. 2 ) The comparison suggests that fieldcharacteristics inside the chain structure resemble that of a single element resonator rather thana system composed of a number of weakly coupled resonators having the same resonant frequency, such as an Alvarez structure. In spite of
the seeming similarity, the chain resonator does
not show characteristics of the coupled resonatorsystem of the Alvarez cavities.
Initially, the gap distances of the acceleration
model were different for each cell to keep a ratioof gap to cell, g / L, constant as is usual for
Alvarez linacs. The distances were readjusted
for all gaps to be the same so that the resonant
frequency of each cell should decrease withincrease in the cell length more rapidly than thatin the case of the constant g / L ratio. This
modification still gave no increasing distribution
towards downstream which should be expected
for a coupled resonator system.
On the other hand, it is well known that thefield distribution in the Alvarez cavities can betuned by introducing elements which increase
coupling between neighboring cells. A multi-stem
structure of Giordan0 3 ) and a post-coupler structure of Swenson 4 ) are such structures and used

Beam
2ntrance

Fig. 6. Gap voltage distribution when all the focusing electrodes are set in their proper positon but
transversal plates are not set for the horizontal
member.

widely in the modern Alvarez linacs. By choosing suitable parameter values, the distance of anearest undesirable resonant frequency from afrequency of a wanted mode can be made large
and the field distribution becomes relatively insensitive to geometry errors. The resonator issaid "stabilized" in such case. In our chain structure where the horizontal and the vertical members are interlaced, coupling strength may be toostrong to leave each cell to have "eigen" frequency. Notion of the coupled resonator system
may not be applicable to the chain structure.
In order to test this supposition, the originalschedule of test acceleration of electrons was
postponed to study this problem of field distribution further.
Firstly, the horizontal electrode assembly wasremoved so that the structure configuration
becomes that of Alvarez's. For the sake of simplicity of assemblage and alignment of theresonator after each alteration of geometry, thedistances were kept the same for all the gaps
hereafter. Figure 3 shows measured gap voltage
distribution which increases with an increase incell length. With vertical members only, fieldcharacteristics resumes those of the Alvarez as
expected. As seen from Fig. 3, there is no electricfield inside square frame made of aluminum bars
having a 10 x 10 mm cross section. The frame
perfectly shields ions traveling inside the framefrom the RF field, in spite of its structure open on
both sides of the frame. For this configuration,
deformation of the TM 010 field distribution near
the central axis by the frame is different fromthat by the cylindrical drift tube and may haveintroduced some difference in the couplingstrength of the cells from that in the Alvarez. But
it does not seem large enough to make distribution different at least.
Next, only the right-hand side of the horizontal

205

M. Odera, et al.

stems, viewed toward downstream, was attached. Focusing electrodes were removed toleave only weak coupling between neighboring
cells of the vertical member via horizontal stems.
325.82MHz

860117

Beam~ntrance

Beam
exit

Fig. 7. Gap voltage distribution when all the focusing electrodes are removed from the vertical aswell as horizontal stems. Transversal plates andacceleration electrodes are in each positions. Peakvoltage behavior is similar to that of Fig. 2.

1000

Figure 4 gives gap voltage distribution thus
obtained. There is no substantial difference fromthe distribution shown in Fig. 3 where the horizontal stems are missing.
Then, left-hand side horizontal stems without
the focusing electrodes were also added. The gap
field showed a decreasing tendency with increasein cell length as shown in Fig. 5. The presence ofthe horizontal stems on both sides changed
resonator behavior from that of Alvarez-type tothe single element resonator type. Probably, tuning of the coupling strength in fine steps shouldhave been tried to find out point of transition
between increasing and decreasing distributions.
However, the model is not provided with suchtuning mechanism at present.
Furthermore, the semi -circular poles for focusing were attached to the horizontal stems toincrease coupling strength between cells. Figure
6 shows a distribution for this case. Sag of the
distribution becomes more pronounced and the984.37928.12902.86900929.28928.75838.06 ---- 838.73.....
823. 13 ' - __836 . 74 797 .89
795.65800.....

765.07-- - -- 77:3~{3 - - - - N 700
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581 .05~c 500584
557

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540.32

0

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<V

0::

400

392.40(TM 010)

Q= 9 ROO
300

375.34(TM 010)360.99(TM 010)

Q= 8006

322.19(TM 010)

Q= 4600

325.82 (TM 010)
297.88(TM 010)

Q = 6800

Q= 4000
200(a) Without horizon- (b) With right hand (c) With both hori- (d) All the semicircular electtal elements
horizontal stems
zontal stems
rodes attached(Alvarez confiwithout semiwithout semi-cirbut without horiguration)
circular electrodes
cular electrodes
zontal acceleration electrodes.

(e) Chainstructure( f ) Chain strctureWith all the
focusing electrodes
removedFig. 8. Shift of resonant frequencies by loading of electrodes of the resonator in various ways. Dotted lines connect
frequencies which show similar gap voltage patterns.

206

M. Odera, et al.

resonant frequency much decreases by increasein capacitive load.
Figure 7 shows a gap voltage distribution forthe chain structure with all the focusing electrodes removed from vertical as well as horizontal stems. Transversal plates which hold acceleration electrodes are in each position. The number of acceleration gaps is the same as that ofFig. 2 and an overall tendency of the voltage
distribution is similar, though resonant frequency is much higher.
Figure 8 shows the change in resonant frequency with changes in the electrode configurations. Q-values as well as frequencies decrease
with an increase in coupling between neighboring cells. Though comparison was not madethoroughly, frequencies which were found tohave the same voltage distribution pattern wereconnected by dotted lines. Further study of thecharacteristics of RF field in the chain structure
is in preparation.
References
1) M. Odera and M. Hemmi: Sci. Papers IP C.R., 79, 51(1985); M. Odera, M. Hemmi, and A. Goto: IEEE,
NS-32, 3222 (1985).
2) M. Odera, Y. Chiba, M. Hemmi, Y. Miyazawa, T.
Tonurna, T. Inoue, T. Kambara, M. Kase, M. Yanokura, T . Kubo, E. Ikezawa, T. Chiba, A. Shimamura,and F. Yoshida: Sci. Papers IP C.R., 79, 34 (1985).
3) S. Giordano: BNL, AGCSD-7 (1966); S. Giordano and
J.P. Hannwacker: IEEE, NS-14, 290 (1967).
4) D. A. Swenson, E. A. Knapp, J. M. Potter, and E. J.
Schneider: Proc. 6th Conf. on High Energy Accelerators, Cambridge, p. 167 (1967).

207
RIKEN Accel. Progr. Rep. 19 (1985)

V -20.

Development of an Electrostatic Quadrupole Lens
Having Beam Steering Capability
M. Hemmi

At present, an effort is being paid to increase
intensity of beam accelerated by the RILAC. Ion
source improvement!) and modification of thebeam handling elements between the ion source
and the entrance to the accelerating column of
the injector are being made for that purpose. An
electrostatic quadrupole doublet lens (ESQ) was
fabricated and recently set at the exit of the ion

Vp

Vn

Fig. 1. Asignment of polarity and adjustment ofvoltage difference between paired electrodes of theelectrostatic lens (ESQ).

source chamber to investigate its performanceand reliability. Preliminary results of investigation were given in this report. 2 ) The device works
very well and the beam intensity was increased
by a factor of 2-5 for Ar2+ ions extracted at 7 k V
on the ion source test bench. Then the device wasTable 1. Specifications of the ESQ/EST device.
Total length: 200 mm (190-207 with bellows)
Size of vacuum flange: NW ·63
Aperture (A): 63.5 mm (2.5")
Curvature of electrode surface: 80 mm R (1.25 A)
Length of the electrodes (L): 35 mm
Electrode potential (VQ ): 0-5 kV
Voltage gradient (G): 0-1.57 kV/cm
GXL: 0-5 kV
Pot. difference for steering (Vst ): 0 ± 1 k V
Distance between electrodes: 56 mm
Power supply
Voltage: 0-6 k V (6·channel)
Stability: 10- 4
Dimension: EIA-19", 2U (88 mm)

Fig. 2. Layout of the beam handling equipments including the ESQ/EST device in the ion source
housing on the high voltage terminal.

208

M. Hemmi

Up

Down

Right

Left

Compatibility of the two functions was studied
experimentally. Polarity asignment and magnitude adjustment of voltage applied to each electrode of the ESQ/EST device are shown in Fig. 1.
QOI plays a role of EST by given voltage
difference between paired electrodes, as VI Vz ,V3 V4 while maintaining VI + Vz = const, Va +V4 = const, and VI + Vz + V3 + V4 = 0 to preserve
approximate quadrupole characteristics. The
voltage allotment is made by using an arithmetic
circuit based on operational amplifiers. Table 1
gives geometrical and electrical parameters of
the ESQ/EST assembly. Its layout among thebeam transport equipments between the ion
source and the accelerating column is shown in
Fig. 2.
The first photograph of Fig. 3 shows beamprofiles measured at the position corresponding
to the entrance of the accelerating column on theion source testing stand. An almost flat profile isfor beam without applied voltage on ESQ andanother showing a peak with focusing field. A
beam intensity measured by a Faraday-cup at
the position was found increased by a factor of 2
- 5 by use of the ESQ. The second photographgives an example of the ESQ functioning as EST.
As seen from the photograph, no significant
deterioration of the focusing effect was generated by use of uneven voltage within 10% for the
ESQ electrodes in order to steer the beam.
Structure and outer appearance of the ESQ/EST device are shown schematically in Fig. 4.
The beam trajectory controlled by this device

*

*

Up

Down

Right

Left
Photograph-2

Fig. 3. Effects of the ESQ/ EST device. Photograph·1; Flat profile is for beam without voltage on the
ESQ electrodes and peak is for the case whenvoltage is on. Photograph-2; Beams deflected by useof uneven voltage on the electrodes as EST function. Little deterioration of the beam profile isobserved within the voltage difference used.

installed in the ion source housing on the highvoltage terminal. The intensity of 40 Ar4+, forexample, was increased by a factor of 3 on thetarget.
The ESQ features a double role of a focusinglens and a beam steering element (EST). The
capability shows a better overall performanceover the usual ESQ alone device considering
space it occupies and cost, though the capability
may not be optimal compared with a larger
system composed of separate ESQ and EST.
~------

190-207

r-- !
56

l
o

I

Fig. 4. Construction of the ESQ/ EST device.

100mm

50
I

I

I

r

I

M. Hemmi

can made constant of the ion species by choosing
voltage on the electrodes always proportional tothe beam extraction voltage of the ion source aspredicted from the theory of electrostatic lens.
Therefore, installation of the lens system adds nosurplus load to linac operators by keeping the
proportionality principle. A tracking circuit tofulfil this condition is under preparation. It is
expected that, after completion of the circuit,

209

functioning of the ESQ/EST device becomesfully automatic and the beam keeping undercomputer control can be easier.
References
1) Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase:
p. 212 in this report.
2) Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase:
Fig. 1, p. 212 in this report.

210
RIKEN Accel. Progr. Rep. 19 (1985)

V -21.

Non-Destructive Measurement of Beam Intensity
M. Kase and E. Ikezawa

During operation of an accelerator, especiallya multi-stage accelerator, it is often necessary
for operators to obtain the information aboutbeam intensities at several positions along abeam line. For this purpose, Faraday cups
equipped with an electric or magnetic suppressor
for secondary electron emissions have been installed on each acceleration stage of the linac.
However, the beam destructive measurementwith these probes needs several-step operation,i.e. selection of the probe, actuating and setting iton the beam, reading beam currents on it, and,
finally, removing it from the beam line. Sometimes operators have to repeat these procedureseveral times. It takes much time and shortens
the life of welded bellows used as a vacuum sealof the probe. And, in the course of experiments
carried out at the end of the beam line, such
destructive measurements should interrupt them.
Therefore the non-destructive measurement ofbeam intensity is desired for a multi-stage accelerator having a long beam line like the RIKEN
linac- RIKEN Ring Cyclotron facilities.
Among several methods applicable to the nondestructive beam-intensity measurement, wehave chosen a method using the ionization
process of a beam with residual gas inside abeam pipe, because its measurement principle isvery simple and needs no special electronics. It
can be also said that this method is suitable for aheavy-ion accelerator because of the large ion-

ization cross sections of heavy ions.
We made a prototype of the non-destructivetype beam-intensity monitor, installed it in the
RILAC beam line, and carried out some preliminary tests. Schematic drawings of the monitor
are shown in Fig. 1. It consists of a pair ofparallel plate electrodes, between which thebeam passes through. One electrode (B) is biased
at a positive voltage, and the other (A) is connected, via a vacuum feed through, to a highimpedance input of electrometer and kept at the
ground potential. The electrons and ionsproduced between the two electrodes in the ionization process with the residual gas are collected efficiently in the relatively low electricfield, since they have generally very small
momentum and their density is so low that noappreciable recombination processes take place.
In practice, the electric current L obtained fromelectrode (A) changes very slowly for the bias
voltages over + 100 V.
The signal L given by

L = KlbifjpLA,(1)where K is the constant (3.5 X 10 16 [Torr- 1 cm- 3 ]),Ib the beam current in particle amperes, ifj thecross section of ionization of ions in the beams
with residual gases, p the vacuum pressure and L
the collision length, that is nearly equal to thelength of the electrode, t. A factor of A is theenhancement factor for the electron emissions byslow ion bombardment on surface of the elec-

Space for Amplifier

~ SUS
~ Cu

o Insulator

Shield-H- - t - -f : + - - - Beam

Fig. 1. Schematic drawings of the non-destructive-type beam-intensity monitor.

M. Kase, et al.
Table 1. Sensitivity coefficients of the intensity
monitor for ArH beam.

5

Acceleration
stage

Beam energy[MeV l u][Torr-I]

Injector
Cavity 1
2
3
4

0.04
0.20
0.56
0.83
1.1

2.3 x 102
2.2 x 102
2.1 x 102
1.2 x 102
8.5 x 101

trode (A).
It is difficult to estimate the ionization crosssection O"j accurately, which depends on the accelerator conditions, such as ion species, beamenergy, and the gas contents inside the beam
pipe. Furthermore, the accurate estimations of L
and A are not easy. Therefore a calibration ismade using a Faraday cup and a vacuum gauge
which are installed near to the monitor. Once
Ib and p are obtained simultaneously withthese instruments, the sensitivity coefficient, S(=KO"ILA), is given from Eqn.(l). Then, the beam
intensity Ib can be obtained from a relation of
Ib = LISp using the measured Land p values.
The values for S obtained experimentallyusing the RILAC ArH beam are listed in Table l.
The coefficient S becomes smaller and smaller as
the beam energy increases. In general, 0"1 has alarge value for the RILAC injection energy (20-211

110 keY lu) and becomes small as the beamenergy increases.
In a long duration, the gas contents maychange to some extent, causing the variation in
S. However, if an ionization pressure gauge isused as a vacuum gauge, this effect is partly
cancelled out, because the ionization cross sections of 100 eV electron and 100keV lu ions vary
in a similar way. It is better, however, to repeat
the calibration periodicallyThis measurement is very sensitive to theeffect of a stray beam which hits directly upon
the electrode surface. It causes a large error in
the measurement. A shield plate that prevents
such stray beam from hitting on the electrodemust be set in front of a sensitive region.
The beam, during traversing through theprove, is bent somewhat by the electric field. Thiseffect is important when the beam energy is low,i. e. in the injection beam line of the RILAC. For
example, when the injection voltage is set at 400
kV, the bending angle is as small as 0.3 mrad.
The effect can be well compensated by a steering
magnet.
The small change at the bias voltage over 100
V is probably due to the change in the factor A.
It is expected that the factor A is increased byproper selection of the material of the electrodesurface and its structure. If A is large, the signal
handling becomes easy.

212
RIKEN Accel. Progr. Rep. 19 (1985)

V -22.

RILAC Ion Source

Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase

Beam intensities of Ne, Ar, Kr, and Xe ionsobtained from the PIG ion sources of the linac
have been measured for two types of anodebores. The purpose is to improve the PIG sourcesin supplying more highly-charged heavy ions forthe linac. Figure 1 shows a schematic plane viewof the ion source facilities installed on a highvoltage platform. The test facilities used forthese measurements were also improved thissummer.
As illustrated in Fig. 1 an electrostatic quadrupole doublet (e.s.q.d.) was installed instead ofan einzellens to focus beams at the Faraday cup;
beam intensities at the Faraday cup were increased up to three times that obtained without
the e.s.q.d.
The source anode is made of copper, which iscooled with water, and has an bore of 8 mm indiameter. The anode slit of 1 mm in width and 20
mm in height, through which ions are extracted,
is made of molybdenum and protrudes 1 mm into
the arc bore. The puller electrode, at negative
potential (30 k V max.), consists of two replaceable molybdenum blades located 2.5 mm from theanode slit and spaced 2 mm apart. The beam isbent at an angle of 120 in the source magnet as0

shown in Fig. 1 and the currents for various
charge state are collected by a Faraday cup withan entrance diamater of 28 mm.
The spectra of beams of Ne, Ar, Kr, and Xe
have been measured for the PIG sources withanode bores of 8 and 10 mm by changing theextraction voltage. The magnetic field was 3-5
kG and the extraction voltage was varied from 0
to 25 kV. Figure 2 shows the charge state spectra
for Ne, Ar, Kr, and Xe ions from the source withan anode bore of 10 mm. The arc discharge is in
DC operation. The maximum source output currents is limited by the drain current of 30 rnA ofthe extraction power supply. A large part of thedrain current is induced when low charge stateions drawn from the ion source hit the extractor
surface. Gas flow in the ion source is subsequently reduced to the minimum value required tomaintain stable arc discharge and to maximize
the high charge states of ions. Figure 3 shows the
charge distributions for the both types of anodebores. From these measurement, it can be said
that the beam intensity increases with increasing
anode bore-diameter. For large anode bores, thestable arc discharge have been obtained in low
magnetic field with low gas flow ratings.

Insulater
Valve

Steerjng
mag.

o
I

500mm
I
To vacuum pump

Fig. l. Sectional view of linac ion source, showing the beam transport system.

213

Y. Miyazawa, et al.

Arc = 600V/ 1. 2A
100.....------,-------.------r-Bomb = 300VlO.3A
Gas = 0.16 cc/ min.
Mag. field = 5.05kG~ 10
Anode bore = 10 mm

Arc=300V/ 3A
1OO.------.------..-----r-Bomb = 470V/ 0.5 5A
Gas = 0.96 cc/ minMag. field = 3.1 kG~..3 10
Anode bore= 10mm.

..3

+oJ

:::J

......

:::J

.e

.e

:::J

o

:::J
0

CIJ

~

CIJ

~

:::J

~

:::J
0

0.1

0.1

(/)

5

20
10
15
Extraction voltage (kV)

5

25

25

15
10
20
Extraction voltage (kV)
(c)

(a)

Arc =400V/3.1A
Bomb=450VlO.47A
100r------.----r---Gas=0.1 cc/min
Xe s+Xe 6+
Mag. field=5.2kG
Xe 7+ Anode bore = 10mm
~ 10100 .------.------.------r--'""'rc = 375 V/ 3.3A
Bomb=400V/ 0.43A
Gas = 0.35 cc/ min.
Mag. fild=4.1 kG~ 10..3Arode bore = 10mm..3......

......

:::J

.e

:::J

.e

:::J

:::J

o

o

CIJ

CIJ

5 0.1

:::J

~

~

o

(/)

(/)

5

25

10
15
Extraction voltage (kV)105Extraction voltage

(b)

20

(d)

Fig. 2. Charge state spectra for Ne, Ar, Kr, and Xe ions obtained with an anode bore of 10 mm in DC arc operation.
(a) Charge state spectrum in neon gas discharge, (b) Charge state spectrum in argon gas discharge, (c) Charge state
spectrum in kripton gas discharge, (d) Charge state spectrum in xenon gas discharge.

100~~-'-'~"~~~ 1::, f~\Ne _ II \,.\
/.\

f/

lOr

i 1~

Ar

-

.,,

-

\
)(

0.1- Anode bore Bmm -

/

~::l.

-

\.

Anode bore Bmm \ \Arc = 440V/ 3A\
Gas = O.47cc/ min
0.1 Mag. field = 4.35kG \

~....

k

Arc = 51OV/ l.lA
Gas = 1.45cc/ minMag. field = 4.1 kG

::;

\\

1 2 345
Charge state

2 345 6 7 8Charge state

(a)

(b)

10

'-

1f--·/

I
I
I

\

.\-

\

\

o

\

(/)

...

.\

"'x
\

\/ .\.
\\

0.1 t-

X--X--x

\

/\~

x

.\

. / =Bmm

\

:::J

-

-

'x

I

.

/.- .........

jx// 'x,.\a'

Xe

Anode bore = lOmm.......
./>\ .......... _.

, '"x
,

+-'

\
\

1-

10f--

'-'

\

)(

)\-

Kr

x
, .\

Anode bore Bmm
Arc = 550V/ 1.3A
Gas = 0.19cc/ minMag. field = 5.05kG

\

.-

~ \
\

\

i

0.1

Anode bore Bmm ""Arc=510V/ O.9A
Gas = 0.12cc/ min~Mag. field = 5.05kGx

1 2 3 4 5 6 7 8 9 10Charge state(c )2 3 4 5 6 7 8 9 101112
Charge state(d)Fig. 3. Charge state distributions for Ne, Ar, Kr, and Xe ions in a DC operation of arc discharge. Solid line
represents that for an anode bore of 10 mm and dotted line for 8 mm. Arc condition for solid line is given in Fig.
2.

214
RIKEN Accel. Progr. Rep. 19 (1985)

V -23.

Test of the RI KEN ECR2

M. Yanokura, S. Ishii, and Y. Sakamoto

Construction of the RIKEN ECR 2 ion source
shown in Fig. 1 was completed in June, 1985, andpreliminary tests have been started. The ECR2,
designed to operate at a frequency of 2.45 GHz,
consists of two stages, and is similar to
MINIMAFIOSl) with respect to size. The firststage, which supplies plasma to the second stage
to facilitate maintenance of ECR plasma andfurther charge stripping of the ions in a highvacuum-stage, was initially operated in an overdense mode 2 ). A coaxial antenna was used to
inject microwave into the first stage located in an

Fig. 1.

Photograph of the RIKEN ECR2.

raxial magnetic field of less than 0.5 kG. The
plasma was controlled by adjusting the microwave power-level and by gas pressure variable
over the range of 10- L 10- 4 Torr. The microwave
power injected into the first stage was oqtained
from the main supply for the second stage by useof a power divider. The second stage is separated
from the first one by a small piece of tubing of asmall diameter for effective differential pumping.
Pressure in the second stage was maintained at
10- L 10- 4 Torr during source operation. Since
this pressure range, however, is not sufficiently
low for efficient production of highly charged
ions, the first stage and the differential pumping
section were modified to improve the second
stage vacuum.
In the second stage, electrons confined in aminimum-B field were heated by resonant
absorption of the microwave injected radially.
The minimum-B structure was produced bysuperposition of an axial mirror field and aradial hexapole field. Three conventional watercooled solenoids were used to establish the axial
magnetic field. The hexapole field was produced
by an assembly of SmCo s permanent magnets
positioned on the cylindrical vacuum wall of the

Ar l+

2+

r

2

2

3+

5+ (02+)

1:
~

c

5u

~
:::J
U

E 0.1

4R

E

~ 10 1

o

6+

OJ

11

\

III
N

~o

z

0,01

o
60· magnet currents

Fig. 2. Charge distribution of the extraced Ar beam.
Input microwave power is about 200 Wand vacuum pressure of the second stage is 1.2 x 10- 4 Torr.
Extraction high voltage is 7 kV.

\\2X10'-

"0

~
~

-4
1.8xl0 torroo123456
Ar Charge stateFig. 3. Vacuum pressure dependence of charge distribution for extracted Ar beam.

M. Yanokura, et at.

second stage. The permanent magnet assembly
was cooled with water circulated around thesame vacuum wall.
The source is divided into three sections, eachof which is supported separately with precision
tracks. The three solenoid coils are supportedwith the same tracks and freely movable tochange the axial mirror ratio of the second stage.
Ion extraction was conducted by using the threeelement extraction electrode which includes aneinzel lens. The position of the extraction electrode can be varied by means of a welded bellow
mechanism. The extraction gap can also bevaried with shims. The entrance slit assembly of
the charge analysing system was located about
50 cm downstream from the source anode; theobject-image distance for the 60° magnet was 106
cm. Two Faraday cups were used to measure
beam currents: one, which is located in thestraight section downstream of the magnet, is for
total extracted currents measurement; the otherbehind the exit slits is for charge selected beam
currents measurement.
The first result of operation of the ECR2 was
not satisfactory; only few nA of Ar 6 + was215

obtained as shown in Fig. 2. There are two main
reasons for the unsatisfactory result. One isunfavorable pressure in the second stage. In
operation, the pressure was around 10- 5 Torr inwhich the recombination cross section becomesvery large. Even if high charge state ions wereformed, they would be degraded rapidly to low
charge-state ions. The other reason is poor
impedance matching between the plasma and themicrowave antenna in the first stage. A largepart of the injected microwave was reflected at
the plasma surface. After improvement of thefirst stage and the differential pumping section,pressure of the second stage became around 10- 6
Torr. Charge distribution of the extracted beams
shifts to the high charge state as shown in Fig. 3.
Weare now planning to change geometry of thecoaxial antenna, to minimize the reflection of
injected microwave power.
References
1) R. Geller, B. Jacquot, and M. Pontonnier: Rev.

Instrum., 56, 1505 (1985).
2) S. Ishii: Sci. Papers IP.C.R. , 74, 27 (1979).

Sci.

216
RIKEN Accel. Progr. Rep. 19 (1985)

V -24.

Characteristics of a Hot Plasma for Highly Charged Ion Sources. Ishii, M. Yanokura, and Y. Sakamoto
Highly charged ions are produced in plasma bycollision of hot electrons with atoms. To findoptimum conditions for producing such ions wehave set up a hexapole-mirror device eligible forplasma diagnostics. The device has been described previously in this report. 1),2) Before
extracting and analyzing ion beams, we
examined plasma parameters of the hot plasma.
Both mirror and hexapole magnetic fieldstrengths of the present device can be varied bychanging driving currents. It is well known thatthe minimum-B fields such as a hexapole field
are effective in stabilizing plasmas. To makesure the function of this device we produced
dense plasma in the same way as described inRef. 3 and injected it pulsedly to the hexapolemirror field. Figure 1 shows floating potentials ofa Langmuir probe and its ion saturation currents(a) without and (b) with the hexapole field. The
stabilization effect is clearly demonstrated.
The plasma is round in cross section at themagnetic mirror where it is generated and isdeformed as flowing down along the field lines offorce. To take a sight of this behavior we measured radial density profiles by using two probes.
Figure 2 shows an example of the measured
radial density profiles together with a sketch of
the cross-sectional view of the plasma and hexapole conductors. The experimental curves elucidate the asymmetrical shape of the plasma crosssection.
Hot plasmas were generated by 2.45 GHz
microwave, the resonance zone of which was
located between the axial magnetic mirrors.
Available power of this microwave was 4 kW.
The density measurement was conducted byusing a 35 GHz microwave interferometer and aprobe located at the plasma edge (r=43 mm).
The interferometric measurement provides only
line densities without knowing radial profiles,
while the probe measurement giving the profiles
is possible only at low powers. Figure 3 shows
dependences of the electron density of the edge
plasma and the line density on argon gas pressure. Electron temperature determined by theprobe measurement ranges from 5 to 10 eV.
Figure 4 shows the arrangement for hard

a

b

~

5 ms/div

Fig. l. Time variations of floating potentials (upper
traces) and ion saturation currents (lower traces) of
Langmuir probes without (a) and with (b) the hexapole field. The ordinates are in arbitrary scale.
Experimental condition: microwave power "(9GHz)= 2 kW, argon pressure =4 X 10- 4 Pa.

Ih=4.8 kA

t

M

Ie

Im= 250 A
PjJ=0.3 kW (9GHz)

(D

-g
II

c:

O·s

o

20

40

rp (mm)60

Fig. 2. An example of radial density profiles
obtained with the Langmuir probes. The inserted
sketch depicts the cross-sectional view of theplasma and location of the probes. Directions of thehexapole currents are indicated by enclosed dots
and crosses around the plasma. Dark and lightpoints in the experimental plots were obtained withthe upper and lower probes, respectively.

217

S. Ishii, et al.

15

-•

•

fne dl

ME

--

'i'

E
E
'l'

..-52

•

~

5

II>

c

=0

I.

o

"

Iil

.'-

\L~, ,....r

5 I-II-.. --,t

C")

E

II

I

iii

-~

rt 10

i

Ell

10 E

3:

I

--

II

III.

I
.l1l:I 11111

11

100 200 300 400 500
E (keY )p =1·3 xl 0-3 Po
ArP}J = 2 kW
Im= 230A
Ih =4·8 kA

II>

C

'--,

Fig. 5. Hard X-ray spectrum of the hot plasma. The
ordinates indicate photon counts per second.

Fig. 3. Pressure dependence of electron density ne,
line density J nedl, and hard X-ray power Px of the
hot plasma. Microwave power (2.45 GHz)=2 kW.

Pb shields

Permalloy~~::;[t: ~PHAo glassTPM®l-07m-J
Fig. 4. Scheme of X-ray measurement. PM: photomultiplier, PHA: pulse height analyzer.

is shown in Fig. 5, which suggests that there
exists a minority of electrons whose energy
ranges up to 200 ke V. The energy scale wascalibrated with reference to a barium radioisotope Ba 133 • As the soft X-ray range should be
cut off by absorption of the view port and thedetector housing of this arrangement, we tentatively took integrated radiation power over the
hard X -ray range as a measure of power loadingof the hot plasma. This quantity is shown in Fig.
3 as a function of argon gas pressure. Electronenergy necessary for highly charged ions covers
the soft X-ray range. A measuring equipment forthe soft X-ray is urgently required to qualify thepresent plasma as a highly charged ion source.
References
1) S. Ishii, Y. Sakamoto, and M. Yanokura: RIKEN

X-ray measurement. The view solid angle of the
N aI scintillator is finely collimated by using alead orifice so that the wall of the-vaeuum vessel
is out of scope. An example of the X-ray spectra

Acce!. Progr. Rep., 17, 177 (1983).
2) S. Ishii, H. Amemiya, Y. Sakamoto, and M. Yanokura: RIKEN Acce!. Progr. Rep., 18, 205 (1984).
3) S. Ishii: Sci. Papers LP.C.R., 74, 27 (1980).

218
RIKEN Accel. Progr. Rep. 19 (1985)

VI.

RADIATION MONITORING
1.

Calculation for the Neutron Shielding Design of RIKEN Ring
Cyclotron Facility
T. Shikata, N. Nakanishi, S. Fujita, and T. Kosako*

By using the neutron-photon multigroup crosssection library DLC-87/HILO for neutronenergies from thermal to 400 Me V and photon
energies from 10 keY to 14 MeV, recalculation ofshielding for RIKEN Ring Cyclotron was performed. Calculation was carried out using the
one-dimensional discrete ordinate code ANISN
with S16 for the slab scheme and that with S8 forthe spherical scheme, respectively. In both cases
P3 expansion was used. Fluence-to-dose equivalent conversion factors for neutrons recommended by ICRP Pub1.21 were used. Neutron spectraused for our calculation are those generated byreactions of (1) 200 Me V protons with a thickaluminum target 1) and (2) 135 MeV / A carbon ionswith a thick iron target. For the lack of data, wehave approximated the spectrum obtained with areaction of 100 MeV / A 12C on 56Fe target 2) byextrapolation above 35 MeV. These neutronenergy spectra correspond to the ion beams of
6 X 10 12 pps are abbreviated hereafter as (p+ AI)
and (C+ Fe), respectively.
The obtained results can be classified into two
kinds of charts, which are useful for determination of the concrete-wall thickness of the building and local iron or heavy concrete shield. Using

1011

10 10
109

E 10

7

,.s

Thickness of a concrete part (m)(a)

Thickness of a concrete part (m)(b)

Fig. 1. Neutron dose rate multiplied by squared source distance as a function of thickness of a concrete part. (a),Concrete-iron case; (b), Concrete-heavy concrete case.
* Research Center for Nuclear Science and Technology,
The Unjversity of Tokyo.

219

T. Shikata, et at.

Q)
(.)

'"

~

~~~~~----Q)~ ~--~~~-l~=~O~.s::::c::~l = llol =hl=ll +L1 LJ ~

Q)

'"

Q)

Q)

g ~---R~lo-------

C5'" '----------:R::'-l-O-:R-f-~R~12-----

Thickness of a slab(a)Thickness of a shell(b)

Fig. 2. Neutron dose rate on the surface of a local
shield as a function of thickness. (a), Slab shield(source S is not enclosed); (b), Spherical shell(source S is enclosed) .

one chart we can chose an arbitrary combination
between thickness of concrete wall of the building and that of local iron or heavy concrete
shield (ReNo and R I" respectively) at a given dose
rate. The results calculated for (C + Fe) are
shown in Fig. 1, which were obtained from thetransport calculation of source neutrons througha double layer slab composed of a concrete andan iron or a heavy concrete with normal incidence. The other chart can be utilized for aspherical shield enclosing a point neutron source,
when the thickness of the spherical shield RIowill
be inadequate because of reflection of backward
emitted neutrons. The necessary thickness can be
determined by searching the thickness of a spherical shell so that dose rates at both surfaces of aspherical shell and a slab of thickness RIo, which
are situated at the same distance from thesource, become the same. For this purpose, it isnecessary to obtain the relation between the dose
rate at the surface of a local shield and the(C + Fe)
8= 0' -20'

E

:2

~

'-...

£

E

'-...

Q)

E

l

Q)

l

Qj

' .0

£

"iii
c:

.g

<f)

m

c:

.g

c:

m

c:

m

'0

'0

Q)

u

Q)

~::l

u

~::l

<f)

<f)

Q)

Q)

:5

:5

c:

0

c:
0

2

2

~

~

Q)
<f)

Q)

0

<f)

0

0

0

10 1

3
Thickness of an iron slab (m )(a)Thickness of an iron spherical shell (m )(b)Fig. 3. Neutron dose rate on the surface of an iron local shield as a function of thickness. fj stands for an emission
angle of neutrons with respect to the beam direction. (a), Slab case corresponding to Fig. 2 (a); (b), Shell casecorresponding to Fig. 2 (b).

220

T. Shikata, et at.

thickness, by taking a distance from the source
to the shield I as parameter, for both the slab andthe spherical shell. One can understand how todetermine the necessary thickness of a sphericalshell RIn(n will be about 2) from a schematic
figure shown in Fig. 2 by the iteration method.
This increment of thickness RI. - RIo increases as
the parameter I decreases. A pair of the calculated relations corresponding to Fig. 2 is shownin Fig. 3 as an example.

Thus the thickness of concrete walls of thebuilding and corresponding local shield will be
designed easily from the charts shown in Figs. 1
and 3.
References
1) H. A. Smith: IUCF Int. Rep., No. 74-6, Radiation
Shielding Note 1 (1974).
2) ]. Drouet and A. Leleux: D. CEN -S/ SPR/ SRl/78-342
GRA-066JD/ AI 5 mai (1978).

221
RIKEN Accel. Progr. Rep. 19 (1985)

VI-2.

Routine Monitoring of RIKEN Accelerators

I. Sakamoto, S. Fujita, M. Yanokura, T. Kobayashi,
O. Kurihara, and 1. Kohno

The present report describes the results ofroutine radiation monitoring carried out for the
cyclotron, RILAC, and T ANDETRON from
April, 1984, to March, 1985. Aspects of the leakage radiation from the cyclotron are described ina succeeding report.
1) Residual radiation of the cyclotron
In August, 1984, the cyclotron had been operated for about 22 h with 20 MeV deuterons andwith a target beam current of 10 jJ.A. The dose
rates due to residual activities of the machine
were measured 25 days after shutdown. The
result is shown in Table 1.
The external exposure doses of two workers
during replacement of the septum were 20 and 50
mrem.
Table l. Dose rates of residual activities.
Location

Dose rate (mR/ h)

ca. 50 cm apart from septum(before replacement of septum)
ca. 30 cm apart from septum holder(after replacement of septum)

100
100

2)

Surface and air contamination in thecyclotron building
The surface contamination has been kept
below 10- 5 ,uei/cm2 on the floors of the cyclotron
vault and the experimental areas, and below 10- 6
jJ.Ci/cm2 on the floors of the underground passage, hot laboratory, and chemical laboratories.
The radioactive nuclides found by y-ray
spectrometry were 65Zn , 1850S, 183Re, and 184Re in
the cyclotron vault and 67Ga, 75Se , 77Br, and 137CS
in the hot laboratory and chemical laboratories.
The contamination was wiped off twice a year,
and immediately after this decontamination, theactivities on the floor of the most of above places
were reduced to below 10- 7 ,uCi/cm2 •When the radioactive substances were handled
in the hot laboratory and chemical laboratories,
the air in the draft chamber was activated. The
air in the draft chamber was exhausted; theradioactivity in the exit was below 10- 13 ,uCi/
cm3 .
3) Drainage
The radioactivities in drain water from thecyclotron and the linac building were found to be

Table 2. Annual exposure doses received by RIKEN accelerator workers from April, 1984 to March, 1985.
N umber of persons
Workers
Cyclotron operationand maintenance group
Linac operationand maintenance group
Nuclear physicists
Accelerator physicists
Physicists in other fields
Nuclear chemists
Radiation chemists
Biological chemists
T ANDETRON workers
Health physicists
Total

> 100

Dose
undetectable

10- 100(mrem)(mrem)

0

7

1

8
4
10
18
1
1
7

2
5
3
4
4

2

Total

Collective
dose(man-mrem)

8

890

10
9
13
22
7
1
7

50
100
80
80
610

11

11

6

6

66

Average annual dose per person: 19.2 mrem.
Maximum individual annual dose: 390 mrem.

25

3

94

1.810

222

I. Sakamoto, et al.

of the order of 10- L 10- 5 ,uCi/cm3. The total
activities in aqueous effluents was about 920 ,uCi,
in which the main radioactive nuclide wastritium, the radioactivity was about 670 ,uCi, andthe other nuclides found by y-ray spectrometry
were 57CO, 67Ga, 75S e , 77Br, 137CS, and 183Re.
4) Radiation monitoring of RILAC and TANDETRON
Leakage radiation during operation of the
RILAC was measured in the circumference of thelinac building every month. No leakage of y-rays
and neutrons from the linac building was detected. No contamination of the surface and air due
to residual activities was found in the control
area in the linac building.
X-ray monitoring was carried out for the
T ANDETRON when helium ions were accelerated. When a titanium target was bombarded with
1 MeV He+ ions at 15 nA, the maximum irradia-

tion dose rates measured around T ANDETRON
was 0.02 mR/ h. No leakage X-rays was detectedaround the target chamber and outside the TAN DETRON room.
5) Personnel monitoring
The external exposure doses to personnel were
measured by using y-ray and neutron film
badges. The doses received during the present
period by accelerator workers are shown in
Table 2. The collective y-ray dose to all workers
was 1,810 man-mrem, while the collective doseowing to thermal and fast neutron exposures
were too small to be detected. The collective
dose to the workers was about 190% of the value
in the preceding period.
In this period the average annual dose perperson was 19.2 mrem, and the maximum individual annual dose was 390 mrem.

223
RIKEN Accel. Progr. Rep. 19 (1985)

VI-3.

Leakage-Radiation Measurement in the Underground Passageof the Cyclotron Building
1. Sakamoto, S. Fujita, and I . Kohno

Leakage doses measured from April, 1984, to
March, 1985, with y-ray and neutron film badges
placed at two positions on the underground passage (points A and B in Fig. 1) are shown in
Table 1. In this period, the beam time allotted todeuteron acceleration was 125 h (72 h in May, 9 h
in June, 14 h in July, 22 h in August, and 8 h in
December). Fast neutrons were generated at theend of the beam course No. 2 by bombarding athick beryllium target with 20 MeV deuterons inAugust; the average beam current was 10 jJ.A.
The doses of y-rays, thermal neutrons, and fastneutrons were 800 mrem, 250 mrem, and 1,440
mrem, respectively.

Table 1. Leakage-radiation dose (in mrem) in theunderground passage of the cyclotron building
from April, 1984 to March, 1985.
Position*A
Radiation

B

Other Total
monthsAugust December
Deu- Deu- Other
teron teron ionsy-Rays (mrem)
Thermalneutrons(mrem)
Fast neutrons(mrem)
Total (mrem)

800

40

120

3,060 4,020

80

250

10

30

750 1,040

20

1,440

50

30

700 2,220

50

2,490

100

180

4,510

* indicated in Fig. 1.

!

!

,

!

!

!

012345m

Experimental area (L) :
I
I
I

DN

I

Undergroundpassage

I
I/.

Underground passage :

Ax

I
I
I

I

: t
I
I

,WT

DN

[

I

I
I

[J

J

I

'-+ooo~IoWoWL-

Hand foot cloth monitor_J

Control room
Basement

Ground plan

Fig. l.

Measurement positions of neutron and y-ray doses in the cyclotron building.

7,280 150

224

VII. LIST OF PUBLICATIONS

1.

Accelerator development and accelerator
physics
1) S. Motonaga: "Present Status of RIKEN
Ring Cyclotron," IEEE Trans. Nucl. Sci.,
32, 2712 (1985).
2) M. Odera, M. Hemmi, and A. Goto: "Field
Characteristics of an Alvarez-Type Linac
Structure Having Chain-Like ElectrodeArray," IEEE Trans. Nucl. Sci., 32, 3222
(1985).
3) T. S. Park, W. S. Lee, and S. H. Be:"Design of Accelerator for Negative Ion
Beams by Computer Simulation," ]. Appl.
Phys., 58, 1701 (1985).
4) Y. Sakamoto: "Discharge Cleaning and
Surface Conditioning," Kakuyugo Kenkyu(in Japanese), 53, 7 (1985).
5) H. Oyama, S. Ishii, and Y. Sakamoto:"Technical Development for ECR Discharge Cleaning," Kakuyugo Kenkyu (inJapanese), 54, 79 (1985).
6) K. Shimizu: "New General Purpose Interfacing Modules for an Accelerator Control
System," Nucl. Instrum. Methods A, 236,
109 (1985).
7) T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, 1. Yokoyama, 1. Takeshita, Y.
Chiba, and Y. Kumata: "Design of Radio
Frequency System for the RIKEN Separated Sector Cyclotron," Sci. Papers I P. C.
R., 79, 12 (1985).
8) M. Odera, Y. Chiba, M. Hemmi, Y.
Miyazawa, T. Tonuma, T. Inoue, T. Kambara, M. Kase, M. Yanokura, T. Kubo, E.
Ikezawa, T. Chiba, A. Shimamura, and F.
Yoshida: "RILAC, Frequency Tunable
Linac for Acceleration of Heavy-Ions,"
Sci. Papers I P. C. R., 79, 34 (1985).
9) M. Kase, T. Kambara, and M. Odera:"RILAC Beam-Energy Tuning Method( I )," Sci. Papers I P. C. R., 79, 45 (1985).
10) M. Odera and M. Hemmi: "Proposal of a
New Alvarez-Type Linac Structure with
Chain-Like Electrodes," Sci. Papers I P. C.
R., 79, 51 (1985).
11) Y. Sakamoto, H. Oyama, and S. Kakinuma: "ECR Discharge Cleaning Device
with Permanent Magnet," Shinku (inJapanese), 5, 385 (1985).
12) K. N agamine: "Large Superconducting
Solenoid and Its Cooling System for Muon
Channel," Teion Kougaku (in Japanese), 20,

187 (1985).
13) S. Motonaga: "Separated Sector Cyclotron
Project at RIKEN ," Proc. 9th Symp. on Ion
Sources and Ion-Assisted Technology,
Tokyo, p. 163 (1985).
2.

Nuclear physics and nuclear instrument a tion
1) K. Nagamine: "Muon Catalyzed Nuclear
Fusion," Butsuri (in Japanese), 40, 787(1985).
2) T. Doke, A. Hitachi, J. Kikuchi, K.
Masuda, S. Tamada, A. Mozumder, E.
Shibamura, and T. Takahashi: "Estimation of the Fraction of Electrons Escaping
from Recombination in the Ionization of
Liquid Argon with Relativistic Electronsand Heavy Ions," Chem. Phys. Lett., 115,
164 (1985).
3) T. Hashimoto, Y. Aoyagi, H. Kudo, and T.
Sotobayashi: "Range Calculation of
Alpha-Recoil Atoms in Some Minerals
Using LSS-Theory," ]. Radioanal. Nucl.
Chem. A, 90, 415 (1985).
4) J. Kasagi, T. Murakami, and T. Inamura:"Use of Charge Integration ADC's with
Pulse Shape Discriminators for NeutronGamma Discrimination," Nucl. Instrum.
Methods A, 236, 426 (1985).
5) S. Kato, N. Matsuoka, T. Noro, T. Saito,
H. Sakai, M. Nakamura, M. Y osoi, T.
Ichihara, K. Hatanaka, and H. Ogawa:"Analyzing Power Measurements for d- 12 C
Elastic Scattering between 35-70 MeV,"
Nucl. Instrum. Methods A, 238, 453 (1985).
6) T. Murakami, J. Kasagi, H. Harada, andT. Inamura: "Performance of a Neutron
Multiplicity Filter Composed of Six Liquid
Scintillation Detectors," Nucl. Instrum.
Methods A, 241, 172 (1985).
7) K. Nisimura, H. Shimizu, K. Imai, T. Ichihara, N. Matsuoka, K. Hatanaka, H.
Sakai, T. Saito, K. Hosono, M. Kondo, andA. Okihana: "Elastic Scattering of 56 Me V
Polarized Deuterons on 4 He," Nucl. Phys.
A, 432, 378 (1985).
8) M. Ohshima, E. Minehara, M. Ishii, T.
Inamura, and A. Hashizume: "Multiple
Coulomb Excitation of 167Er," Nucl. Phys.
A, 436, 513 (1985).
9) M. Sugawara, Y. Gono, Y. Ishikawa, M.
Fukuda, and 1. Fujiwara: "In-Beam y-Ray

225

Study of 21 2PO," Nucl. Phys. A, 443, 461

Gizon, T. Bengtsson, and Y. Gono: "Possible Shape-Change Observed at High Spinin 123CS," Z Phys. A, 321, 353 (1985).

(1985).
10) A. Goto, H. Kamitsubo, N. Matsuoka, and

H. Sakaguchi: "Prior-Form DWBA Analy
sis of eHe, pd) Elastic Breakup at 90 MeV,"
Nucl. Phys. A, 444, 248 (1985).
11) Y. Nojiri, K. Asahi, K. Matsuta, T. Takeyama, and T. Minamisono: "Nuclear Spin
Polarization by the Tilted Foil Technique," Nuclear Spectroscopy and Nuclear
Interactions, World Scientific Publ. Co.,
Singapore, p. 25 (1984).
12) H. Sakamoto, M. Nakamura, H. Sakaguchi, H. Ogawa, S. Kobayashi, S. Kato, N.
Matsuoka, K. Hatanaka, and T. Noro:"Polarization Transfer in the Deuteron
Break-up Reaction at 56 MeV," Phys. Lett.
B, 115, 227 (1985).
13) K. Ieki, M. Ishihara, T. Inamura, S. Kohmoto; H. Utsunomiya, K. Sueki, and H.
Kudo: "Spin Polarization of Residual Nuclei in (14N, a) Reactions at 115 MeV,"
Phys. Lett. B, 150, 83 (1985).
14) N. Yoshida and A. Arima: "Aligned Bandsin Ge Isotopes in the Interacting Boson
Model," Phys. Lett. B, 164, 231 (1985).
15) J. Kasagi, B. Remington, A. Galonsky, F.
Haas, J. J. Kolata, L. Satkoviac, M.
Xapsos, R. Racca, and F.W. Prosser: "N eutron Spectra and Level Density Parameters from the 160 + 12C Fusion Reactions,"
Phys. Rev. C, 31, 858 (1985).
16) G. Caskey, A. Galonsky, B. Remington, M.
B. Tsang, C. K. Gelbke, A. Kiss, F. Deak,
Z. Seres, J. J. Kolata, J. Hinnefeld, and J.
Kasagi: "Asymmetric Neutron Emission in
14N + 165Ho Reaction at 35 MeV IN ucleon,"Phys. Rev. C, 31, 1597 (1985).
17) S. Kato, K. Okada, M. Kondo, K. Hosono,
T. Saito, N. Matsuoka, K. Hatanaka, T.
N oro, S. N agamachi, H. Shimizu, K.
Ogino, Y. Kadota, S. Matsuki, and M.
Wakai: "Inelastic Scattring of 65 MeV
Protons from 12C, 24Mg, 28Si, and 32S," Phys.
Rev. C, 31, 1616 (1985).
18) T. Inamura, A. C. Kahler, D. R. Zolnowski,
U. Garg, T. T. Sugihara, and M. Wakai:"Gamma-Ray Multiplicity Distribution
Associated with Massive Transfer," Phys.
Rev. C, 32, 1539 (1985).
19) K. Morita, S. Kubono, M. H. Tanaka, H.
Utsunomiya, M. Sugitani, S. Kato, J.
Schimizu, T. Tachikawa, and N. Takahashi: "Possible Quasimolecular Bands in
2
3 S," Phys. Rev. Lett., 55 , 185 (1985).
20) V. Barci, H. EI-Samman, A. Gizon, J.

3.

Atomic and solid-state physics
1) M. Uda, A. Koyama, K. Maeda, and Y.
Sasa: "Valence Electron Rearrangement
Prior to X-Ray or Auger Emission," Proc.
Int. Conf. on X-Ray and Inner-Shell
Processes in Atoms, Molecules and Solids(ed. by A. Meisel and J. Finster), Leipzig,
p. 307 (1984).
2) T. Watanabe:"Atomic Physics Using
High Energy Heavy Ions," Proc. RIKEN
Symposium on Nuclear Physics Researchin Impact Energy Range of 10-100 MeV lu,
Wako, SSC-PI, p. 38 (1984).
3) M. Kase, T. Akioka, H. Mamyouda, J.
Kikuchi, and T. Doke: "Fano Factor inPure Argon," Nucl. Instrum Methods A,
227, 311 (1984).
4) A. C. Roy and T. Watanabe: "Doubly
Differential Cross Sections for ElectronImpact Ionization of Helium," Atomic
Collision Res. in Japan-Prog. Rep., No. 11,
p. 3 (1985).

A. Ohsaki, T. Watanabe, K. Nakanishi,
and K. Iguchi: "Classical TrajectoryMonte Carlo Calculation for Collision
Processes of e+ + (e-p) and Ji+ + (ji-p),"
Atomic Collision Res. in Japan-Prog. Rep.,
No. 11, p. 9 (1985).
6) Q. Ma, X. Zhang, Z. Liu, Y. Liu, and T.
Watanabe: "Quantum Mechanical Study
for the Process of Ji+ + (ji-)~(Ji+ Ji-) +p,"
Atomic Collision Res. in Japan-Prog. Rep.,
No. 11, p. 13 (1985).
7) K. Hino, N. Toshima, 1. Shimamura, andT. Watanabe: "Theory of Radiative Electron Capture I: N onrelativistic Treatmentof Theoretical Paradox," Atomic Collision
Res. in Japan-Prog. Rep., No. 11, p. 53

5)(1985).
8)

K. Hino and T. Watanabe: "Theory ofRadiative Electron Capture II: Relativistic(Semi-Covariant) Treatment," Atomic Collision Res. in Japan-Prog. Rep., No. 11, p.
57 (1985).

9) K. Fujima, T. Watanabe, and Y. Awaya:"K-Hole Production Probability by the
Rotational Coupling in Ar- Ti, Co, and Zn
Systems," Atomic Collision Res. in J apanProg. Rep., No. 11, p. 65 (1985).
10) H. Tawara, T. Tonuma, S. H. Be, H.
Shibata, H. Kumagai, M. Kase, T. Kambara, and 1. Kohno: "Highly-Ionized226

Atomic Ions Produced in Energetic Heavy
Ion Impact on Molecular Targets,"
Atomic Collision Res. in Japan-Prog. Rep.,
No. 11, p. 78 (1985).
11) S. H. Be, T. Tonuma, H. Kumagai, H.
Shibata, M. Kase, T. Kambara, 1. Kohno,
and H. Tawara: "Multiple Ionization of
Rare-Gases by l.05 MeV / amu Heavy Ion
Impact," Atomic Collision Res. in JapanProg. Rep., No. 11, p. 81 (1985).
12) T. Tonuma, H. Shibata, S. H. Be, H.
Kumagai, M. Kase, T. Kambara, 1. Kohno,
and H. Tawara: "Production of Highly
Charged Slow Ar Ions Recoiled in l.05
MeV /amu Ne Q+(q=2, 7-10) and Arq+(q=4,
6, 10-14) Ion Bombardment," Atomic Collision Res. in Japan-Prog. Rep., No. 11, p. 84(1985).
13) H. Shibata, Y. Awaya, T. Kambara, M.
Kase, H. Kumagai, T. Matsuo, and N.
Tokoro: "Ar L-MM Auger Electron Spectra in Heavy-Ion-Ar Collisions," Atomic
Collision Res. in Japan-Prog. Rep., No. 11,
p. 90 (1985).
14) T. Kambara, Y. A waya, M. Kase, H.
Kumagai, and H. Shibata: "Target Atomic
N umber Dependence of Ka and K,B X
Rays from 33 MeV Ar Ions in Solid Targets," Atomic Collision Res. in J apanProg. Rep., No. 11, p. 93 (1985).
15) Y. Awaya, T. Kambara, M. Kase, H.
Shibata, H. Kumagai, T. Mizogawa, Y.
Kanai, and K. Shima: "High Resolution
Measurement of Cu K X Rays from Collision Systems of Cu Ions on C Target and C
Ions on Cu Target," Atomic Collision Res.
in Japan-Prog. Rep., No. 11, p. 96 (1985).
16) S. Karashima, T. Watanabe, T. Kato, and
H. Tawara: "Stopping Power Theories for
Charged Particles in Inertial Confinement
Fusion Plasmas (Emphasis on Hot and
Dense Matters)," IPP J -AM-42, Inst.
Plasma Phys., Nagoya Univ. (1985).
17) T. Watanabe and K. Hino: Theory of IonAtom Collisions at High Energy I: N onRadiative and Radiative Electron Capture," Rep. 1st Joint Seminar on Atomic
Phys., Solid State Phys., and Material
Science in the Energy Region of Tandem
Accelerators, JAERI-M 85-125, p. 3 (1985).
18) S. Karashima and T. Watanabe: "Theory
of Ion-Atom Collisions at High Energy II:
Charge Stripping Cross Sections," Rep. 1st
J oint Seminar on Atomic Phys., Solid
State Phys., and Material Science in the
Energy Region of Tandem Accelerators,

JAERI-M 85-125, p. 22 (1985).
19) T. Matsuo, H. Shibata, ]. Urakawa, A.
Yagishita, Y. Awaya, T. Kambara, M.
Kase, and H. Kumagai: "Auger Electronsin Ar4+ + Ar Collisions," Rep. 1st Joint
Seminar on Atomic Phys., Solid State
Phys., and Material Science in the Energy
Region of Tandem Accelerators, JAERI-M
85-125, p. 85 (1985).
20) H. Tawara, T. Tonuma, S. H. Be, H.
Shibata, M. Kase, T. Kambara, H.
Kumagai, and 1. Kohno: "Production ofMultiply Charged Ions in Energetic Heavy
Ion + Molecular Target Collisions," Rep.
1st Joint Seminar on Atomic Phys., Solid
State Phys., and Material Science in the
Energy Region of Tandem Accelerators,
JAERI-M, 85-125, p. 100 (1985).
21) E. Yagi, A. Koyama, S. Nakamura, H.
Sakairi, and R. R. Hasiguti: "DefectTrapping by Sn Atoms Implanted in AI,"
Jpn. ]. Appl. Phys., 24, 137 (1985).
22) S. H. Be, and K. Yano: "Cluster Beam
Production by a Slit-Throat Nozzle," Jpn.
]. Appl. Phys., 24, 589 (1985).
23) H. Aizawa, K. Wakiya, H. Suzuki, F.
Koike, and F. Sasaki: "Autoionising Statesof K+ and K Excited by Slow K+ Impact on
He," ]. Phys. B: At. Mol. Phys., 18, 289(1985).
24) ]. Mizuno, T. Ishihara, and T. Watanabe:"Energy Exchange between Two OutgoingElectrons in the Post-Collision Interaction
Process," ]. Phys. B: At. Mol. Phys., 18,1241 (1985).
25) Y. Morioka, Y. Hanada, K. Kihara, S.
Hara, and M. Nakamura: "Rotational
Intensity Distribution of the N 2 Photoelectron Spectrum," ]. Phys. B: At. Mol.
Phys., 18, 1369 (1985).
26) S. Hara: "Theoretical Study of Photoionisation of H 2," ]. Phys. B: At. Mol.
Phys., 18, 3759 (1985).
27) S. Hara and S. Ogata: "Photoionisation of
the H2 Molecule," ]. Phys. B: At. Mol.
Phys., 18, L59 (1985).
28) T. Watanabe: "Comment on the Relation
between the Cross Section for Electron
Stripping from a Helium-like Ion in Collision with Atomic Hydrogen and the KShell Ionisation Cross Section for Proton
Impact," ]. Phys. B: At. Mol. Phys., 18,
L111 (1985).
29) N. Sakai and H. Sekizawa: "A New Technique of Mossbauer Spectroscopy without
Using Doppler Modulation," ]. Phys. Soc.

227

lPn., 54, 474 (1985).
30) E. Yagi, S. Nakamura, T. Kobayashi, K.
Watanabe, and Y. Fukai: "Lattice Location of Hydrogen in a-Phase in Nb-H
System as Observed by Channeling
Method," ]. Phys. Soc. lpn., 54, 1855 (1985).
31) K. Asai, T. Okada, and H. Sekizawa:"TDP AC of y-Rays Emitted from 111Cd(~111In) in Fe304," ]. Phys. Soc. lPn., 54,
4321 (1985).
32) S. Karashima and T. Watanabe: "Charge
Equilibrium of Fast Heavy Ions Traversing through Gaseous Media," Laser andParticle Beams, 2, 477 (1985).
33) S. Karashima, T. Watanabe, Y. Awaya,
and Y. Liu: "Electron Stripping Cross
Section from Multiply Charged Ions by
Neutral Atoms," Nucl. Instrum. Methods,
A, 240, 505 (1985).
34) S. M. Shafroth, Y. Awaya, M. Kase, T.
Kambara, H. Kumagai, M. Nishida, H.
Shibata, and H. Tawara: "Angular Distribution of REC for Ar4+ on C at 1 MeV /amu," Nucl. Instrum. Methods A, 240, 546(1985).
35) T. Tonuma, S. H. Be, H. Kumagai, H.
Shibata, M. Kase, T. Kambara, 1. Kohno,
and H. Tawara: "Ionization of He, Ne, and
Ar Atoms by 1.05 MeV /amu C<7+(q=2-6)
and Ar<7+ (q=4-14) Ion Impact," Nucl. Instrum. Methods, B, 9,429 (1985).
36) Y. Awaya, T. Kambara, M. Kase, H.
Shibata, H. Kumagai, K. Fujima, J. Urakawa, T. Matsuo, and J. Takahashi: "Target Atomic Number Dependence of Simultaneous K-Shell and L-Shell Ionization of
Projectile Heavy Ions," Nucl. Instrum.
Methods, B, 10 & 11, 53 (1985).
37) K. Maeda, M. Uda, and Y. Hayasi: "Oxygen Ka Emission Spectrum Free from
Multiple-Vacancy Satellites," Phys. Lett.,
A, 112, 431 (1985).
38) M. C. van Hemert, E. F. van Dishoeck, J.
A. van der Hart, and F. Koike: "Quantum
Mechanical and Impact-Parameter Treatment of He 2 +-H Collisions," Phys. Rev. A,
31, 2227 (1985).
39) A. Ohsaki, T. Watanabe, K. Nakanishi,
and K. Iguchi: "Classical TrajectoryMonte Carlo Calculation for Collision
Processes of e+ + (e- p) and J1.+ + {j1.-p),"
Phys. Rev. A, 32, 2640 (1985).
40) Q. Ma, X. Zhang, Z. Liu, Y. Liu, and T.
Watanabe: "First-Order Distorted-Wave
Born Cross Sections for j1.+ + (j1.-p)~{j1.+ j1.-) +p," Phys. Rev. A, 32, 2645 (1985).

41) A. C. Roy and T. Watanabe: "Doubly
Differential Cross Sections for ElectronImpact Ionization of Helium," Phys. Rev.
A, 32, 3090 (1985).
42) K. Fujima, T. Watanabe, and H. Adachi:"Analysis of the Electronic Properties ofExtremely Condensed Matter by the
Discrete-Variational X Method: Application to Cold Neon Plasma," Phys. Rev. A,
32, 3585 (1985).
43) E. Yagi, T. Kobayashi, S. Nakamura, Y.
Fukai, and K. Watanabe: "Stress-Induced
Site Change of H in V Observed by Channeling Experiments," Phys. Rev. B, 31,1640(1985).
44) K. Ishida, K. Nagamine, T. Matsuzaki, Y.
Kuno, K. Nishiyama, T. Yamazaki, E.
Torikai, H. Shirakawa, and J. H. Brewer:"Diffusion Properties of Muon Produced
Soliton In trans-Polyacetylene," Phys. Rev.
Lett., 55, 2009 (1985).
45) T. Watanabe: "Electron Capture Processes of M ulticharged Ions from H and He(Theory)," Proc. First Asia-Pacific Physics
Conference, Singapore 1983, Vol. 1, Eds. A.
Arima, C. K. Chew, T. Ninomiya, P. P.
Ong, K. K. Phua, and K. L. Tan, World
Scientific Publishing Co. Pte. Ltd., p. 644(1985).
46) K. Okazaki, A. Minoh, S. Ishii, Y. Ishibe,
H. Oyama, Y. Sakamoto, and K. Yano:"LIFS Measurement of Sputtering Particle
Density by Plasma Irradiation to a Metal
Sample," Shinku (in Japanese), 5, 388(1985).
4.

Radiochemistry, radiation chemistry andradiation biology
1) Y. Hoh, T. Nozaki, T. Masui, and T. Abe:
"Calibration Curve for Infrared Spectrophotometry of Nitrogen in Silicon," Appl.
Phys. Lett., 47, 488 (1985).
2) N. Sakai, F. Sakai, and H. Sekizawa:"Mossbauer Study of 60CO y-Ray Irradiated FexMgI-ANH4h(S04h· 6H 2 0," Bull.
Chem. Soc. lPn., 58, 574 (1985).
3) K. Kimura: "Large Yield of Photoemission
near Maximum Stopping Power in the
Track of N -ion Impinged Helium Gas;
Possibility of Cluster Formation of Excimers in Liquid Helium," Hoshasen (Ion.
Radiat.)(in Japanese), 11, 94 (1985).
4) T. Takahashi, K. Eguchi, T. Katayama and
1. Kaneko: "Recent Topics on Biological
Heavy-Ion Action and the Track Structure," Hoshasen (Ion. Radiat.) (in228

6) S. Motonaga: "Present Status of RIKEN
Ring Cyclotron," 1985 Particle Accelerator Conf., Vancouver, Canada, May (1985).
7) T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, 1. Yokoyama, 1. Takeshita, Y.
Chiba, and Y. Kumata: "Design of Radio
Frequency System for the RIKEN Separated Sector Cyclotron," 1985 Particle Accelerator Conf., Vancouver, Canada, May(1985).
8) S. Motonaga: "Separated Sector Cyclotron
Project at Riken," Proc. 9th Symp. on Ion
Sources and Ion-assisted Technology,
Tokyo, june, p. 163 (1985).
9) S. Ishii: "Development of an Efficient Highly Charged Ion Source," 9th Symp. on Ion
Sources and Ion-Assisted Technology,
Tokyo, june (1985).
10) T. Shikata, N. Nakanishi, and S. Fujita,
and T. Kosako: "Calculation for the N eutron Shielding Design of the RIKEN SSC,"
1985 Fall Meeting Phys. Soc. jpn., Kofu,
Oct. (1985).
11) A. Goto, H. Takebe, S. Motonaga, K.
Hatanaka, Y. Yano, T. Wada, N. Nakanishi, M. Hara, and S. H. Be: "Magnetic
Field Measurement for the RIKEN Ring
Cyclotron," 1985 Fall Meeting Phys. Soc.
jpn., Kofu, Oct. (1985).
12) M. Yanokura: "RIKEN ECR2 (2)," 1985
Fall-Meeting Phys. Soc. jpn., Kofu, Oct.
(1985).

japanese), 11, 122 (1985).
5) M. Yanokura: "Heavy-Ion RBS," Isot.
News, No. 373, p. 6 (1985).
6) Y. Itoh and T. N ozaki: "Solubility andDiffusion Coefficient of Oxygen in Silicon," lPn. ]. Appl. Phys., 24, 279 (1985).
7) T. Nozaki, Y. Itoh, Y. Ohkubo, T. Kimura,and H. Fukushima: "Simultaneous Charged Particle Activation Analysis of Carbon and Boron in Gallium Arsenide," lpn.
]. Appl. Phys., 24, 801 (1985).
8) Y. Sugita, H. Kawata, S. N akamichi, T.
Okabe, T. Watanabe, S. Yoshikawa, Y.
Itoh, and T. N ozaki: "Measurement of the
Out-Diffusion Profile of O)(ygen in Silicon," lPn. ]. Appl. Phys., 24, 1302 (1985).
9) M. Nakamura, Y. Mochizuki, K. Usami, Y.
Itoh, and T. N ozaki: "Infrared, Raman,
and X-Ray Diffraction Studies of Silicon
Oxide Films Formed from SiH 4 and N 2 0
Chemical Vapor Deposition," ]. Electrochern. Soc.: Solid-State Sci. Technol., 132,482 (1985).
10) M. Nakamura, Y. Mochizuki, K. Usami, Y.
Itoh, and T. N ozaki: "Infrared Absorption
Spectra and Compositions of Evaporated
Silicon Oxides (SiO x )," Solid State Commun., 50, 1079 (1984).

(Papers Presented at Meetings)
1.

Accelerator development and accelerator
physics
1) T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, Y. Chiba, and Y. Kumata:"Design of Radio Frequency System for
the RIKEN Separated Sector Cyclotron,"
RCNP-Symp. Accelerator Engineering for
the RCNP Project, Osaka, Feb. (1985).
2) M. Yanokura: "Report of RIKEN ECR2,"
RCNP 1. S. Workshop, Osaka, Mar. (1985).
3) A. Goto, T. Fujisawa and 1. Takeshita:"Design of Beam Buncher in the RIKEN
Ring Cyclotron Injection Beam Transport
Line," 40th Ann. Meeting Phys. Soc. jpn.,
Kyoto, Apr. (1985).
4) T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, and Y. Chiba: "Design of HighPower Amplifier of the RIKEN SSC," 40th
Ann. Meeting Phys. Soc. j pn., Kyoto, Apr.
(1985) .
5) N. Nakanishi, T. Shikata, S. Fujita, and T.
Kosako: "Calculation on Design of Beam
Dump in RIKEN SSC," 40th Ann. Meeting
Phys. Soc. jpn., Kyoto, Apr. (1985).

2.

Nuclear physics and nuclear instrumentation
1) M. Sugawara, G. Iwasaki, Y. Gono, M.
Fukuda, Y. Ishikawa, T. Kohno, M. Adachi, H. Taketani, and P. Aguer: "In-BeamElectron and Alpha-Particle Measurements Utilising Super Conducting Solenoid," 40th Ann. Meeting Phys. Soc. j pn.,
Kyoto, Mar. (1985).
2) Y. Gono, M. Fukuda, Y. Ishikawa, and
M. Sugawara: "BGO Anti-Compton Spectrometer and Monte Carlo Simulation,"40th Ann. Meeting Phys. Soc. jpn., Kyoto,Mar. (1985).
3) T. Motobayashi, H. Sakai, N. Matsuoka,
T. Saito, K. Hosono, A. Okihana, M. Ishihara, A. Sakaguchi, and S. Shimoura: "(d,2He) Reaction with Polarized Deuteron,"40th Ann. Meeting Phys. Soc. j pn., Kyoto,
Apr. (1985).
4) T. Murakami and J. Kasagi: "Charged
Particle Detection with a BaF2 Scintillator," 40th Ann. Meeting Phys. Soc. jpn.,

229

Kyoto, Apr. (1985).
5) H. Harada, T. Murakami, H. Tachibanaki, K. Yoshida, ]. Kasagi, and T. Inamura:"Excited Levels of 110S n Produced by 98Mo_(160, 4ny) 11 °Sn(II)," 40th Ann. Meeting
Phys. Soc. ]pn., Kyoto, Apr. (1985).
6) T. Murakami, H. Harada, H. Tachibanaki, K. Yoshida, ]. Kasagi, and T. Inamura:"Excited Levels of 112Sn Produced bylooMo(l60, 4ny)112Sn," 40th Ann. Meeting
Phys. Soc. ]pn., Kyoto, Apr. (1985).
7) T. Inamura: "Present Status of RIKEN
Ring Cyclotron and Nuclear Data Acquisition System," Workshop on Fast Data
Acquisition System Based on CAMAC,
Wako, ] une (1985).
8) H. Harada, T. Murakami, H. Tachibanaki, K. Yoshida, ]. Kasagi, and T. Inamura:"Negative-Parity High Spin States in 110Sn
and 11 2Sn," Symp. on Highly Excited andHigher Spin States in Atomic Nuclei,
Kyoto, ] uly (1985).
9) T. Murakami, ]. Kasagi, H. Harada, H.
Tachibanaki, K. Yoshida, T. Kubo, and T.
Inamura: "High Spin States in 11 2Sn,"
Symp. on Highly Excited and Higher Spin
States in Atomic Nuclei, Kyoto, July
(1985).
10) K. Asahi, M. Ishihara, T. Shimoda, T.
Fukuda, N. Takahashi, K. Katori, S.
Shimoura, N. Ikeda, C. Konno, K.
Hanakawa, T. Itabashi, Y. Nojiri, and T.
Minamisono: "Beta Decay of Polarized
Nucleus 15C Produced in Heavy-Ion Reaction," 6th Int. Symp. on Polarization Phenomena in Nuclear Physics, Osaka, Aug.
(1985).
11) H. Ohsumi, M. Ishihara, S. Kohmoto, K.
Asahi, K. Sugimoto, T. Tanabe, T. Hattori,
H. Hamagaki, and K. Haga: "Nuclear Spin
Polarization of 27 Al Produced by TiltedFoil Method and Determination of the
Polarization by Coulomb Excitation," 6thInt. Symp. on Polarization Phenomena in
Nuclear Physics, Osaka, Aug. (1985).
12) T. Kubo and H. Ohnuma: "Deuteron DState Effects on the Vector Analyzing
Power and Polarization in (d, p) Reactions," 6th Int. Symp. on Polarization
Phenomena in Nuclear Physics, Osaka,
Aug. (1985).
13) S. Yamaji, H. Hofmann, and R. Samham
mer: "Self-Consistent Transport Coefficients for Damped Large Scale Collective
Motion," Conf. on Fission Held at RCNP,
Osaka, Sept. (1985).

14) T. Ichihara, T. Inamura, and M. Ishihara:"RIKEN Ring Cyclotron Nuclear Data
Acquisition System Based on CAMAC,"
1985 Fall Meeting Phys. Soc. ] pn., Kofu,
Oct. (1985).
15) H. Ohsumi, M. Ishihara, S. Kohmoto, K.
Asahi, K. Sugimoto, T. Tanabe, H.
Hamagaki, T. Hattori, and K. Haga: "SpinPolarization of 27 Al by Tilted-Foil Method
Detected by Means of Coulomb Excitation," 1985 Fall Meeting Phys. Soc. lpn.,
Kofu, Oct. (1985).
16) T. Ichihara, T. Inamura, and M. Ishihara:"Preparation for the CAMAC-based Data
Aquisition System at the RIKEN Ring
Cyclotron Facility," 1985 Fall Meeting
Phys. Soc. ]pn., Kofu, Oct. (1985).
17) T. Ichihara, H. Sakaguchi, M. Nakamura,
M. Yosoi, M. Ieiri, Y. Takeuchi, H. Togawa, T. Tsutsumi, and S. Kobayashi: "Inelastic Scattering of Polarized Protons
Exciting the y-Vibrational Band in
Deformed Nuclei at 65 MeV," 1985 Fall
Meeting Phys. Soc. ]pn., Kofu, Oct. (1985).
18) T. Motobayashi, H. Sakai, N. Matsuoka,
T. Saito, K. Hosono, A. Okihana, M. Ishihara, A. Sakaguchi, and S. Shimoura:"Spin Flip States Studied by the 90Zr (d,2He) Reaction," 1985 Fall Meeting Phys.
Soc. ]pn., Kofu, Oct. (1985).
19) N. Yoshida and A. Arima: "High-Spin
States in Ge Using the IBM," 1985 Fall
Meeting Phys. Soc. lpn., Kofu, Oct. (1985).
20) R. Bambot, S. Della-Negra, R. Anne, H.
Delagrange, Y. Schutz, P. Aguer, G.
Bastin, Y. Gono, and K. Hatanaka: "RadioActive Beam Production at GANIL," 1985
Fall Meeting of the Phys. Soc. ]pn., Kofu,
Oct. (1985).
21) A. Yunoki, A. Hitachi, K. Masuda, S.
Suzuki, T. Doke, ]. Kikuchi, and T. Takahashi: "Electric Field Effect on the Scintillation of Liquid Argon Induced by aParticles," 1985 Fall Meeting Phys. Soc.
]pn., Chiba, Oct. (1985).
22) S. Suzuki, A. Yunoki, A. Hitachi, T. Doke,K. Masuda, and T. Takahashi: "Photoionization in Liquid Argon Admixtured by
Small Amount of TEA and TMA," 1985
Fall Meeting Phys. Soc. ]pn., Chiba, Oct.
(1985).
23) M. Magara, K. Sueki, H. Kudo, Y. Hamajima, Y. Hatsukawa, H. Yoshikawa, H.
Nakahara, and 1. Kohno: "Study of Es
Isotopes Produced by 238U + 14N Reaction,"
29th Symp. on Radiochemistry, Funabashi,

230

Oct. (1985).
24) T. Shimizu, S. Kubota, T. Motonaga, ].
Ruan (Cen), F. Shiraishi, and Y. Takami:"A New Barium-Fluoride Plastic Scintillator," IEEE Nuclear Science Symposium,
San Francisco, Oct. (1985).
3.

Atomic and solid-state physics
1) T. Matsuo, H. Shibata, ]. Urakawa, A.
Yagishita, Y. Awaya, T. Kambara, M.
Kase, and H. Kumagai: "Auger Electronsin Ar4+ + Ar Collision," 1st Joint Seminaron Atomic Physics, Solid State Physics
and Material Science in the Energy Regionof Tandem Accelerators, Tokai, Jan.
(1985).
2) E. Yagi: "Diffusion of Positive Muons inIron," 1st Joint Seminar on Atomic
Physics, Solid State Physics and Material
Science in the Energy Region of Tandem
Accelerators, Tokai, Jan. (1985).
3) Y. Awaya: "Experiments of Atomic Collisions at RIKEN," 6th Symp. on Atomic
Collisions by Using Accelerators, Wako,
Feb. (1985).
4) E. Yagi: "Determination of Lattice Locations of Hydrogen in Solids by Channeling- Method," Riken Symp. Characterization of
Semiconductor Materials and Hydrogen
Analysis by Using Accelerators, Wako,
Feb. (1985).
5) T. Kambara, Y. Awaya, M. Kase, H.
Kumagai, H. Shibata, and T. Tonuma:"Target Isotope Dependence of REC xRay Yields," 40th Ann. Meeting Phys. Soc.
Jpn., Kyoto, Mar. (1985).
6) H. Tawara, H. Shibata, T. Tonuma, S. H.
Be, M. Kase, T. Kambara, H. Kumagai,
and I. Kohno: "Production of Multicharged Secondary Ions in Collisions ofEnergetic Heavy Ions with Molecular
Targets," 40th Ann. Meeting Phys. Soc.
Jpn., Kyoto, Apr. (1985).
7) S. H. Be, T. Tonuma, H. Kumagai, H.
Shibata, M. Kase, T. Kambara, I. Kohno,
and H. Tawara: "Total Cross Sections for
Ionization of Rare-Gas Atoms by Heavy
Ion Collisions," 40th Ann. Meeting Phys.
Soc. J pn., Kyoto, Apr. (1985).
8) Y. Awaya, T. Kambara, M. Kase, H.
Shibata, H. Kumagai, and K. Fujima: "K
X -Rays of 33 MeV Ar Ions Passing
through Solid Targets (I)," 40th Ann.
Meeting Phys. Soc. Jpn., Kyoto, Apr.
(1985).
9) T. Kambara, Y. Awaya, M. Kase, H.

Shibata, and H. Kumagai: "K X-Rays of 33
Me V Ar Ions Passing through Solid Targets (II)," 40th Ann. Meeting Phys. Soc.
Jpn., Kyoto, Apr. (1985).
10) K. Fujima, T. Watanabe, and Y. Awaya:"K X-Rays of 33 MeV Ar Ions Passing
through Solid Targets (III). The Calculation for Ar K Ionization Cross Section Dueto Rotational Couplings," 40th Ann. Meeting Phys. Soc. Jpn., Kyoto, Apr. (1985).
11) H. Shibata, T. Matsuo, Y. Awaya, T.
Kambara, M. Kase, H. Kumagai, and N.
Tokoro: "Projectile Dependence of Ar
L-MM Auger Electron Spectra," 40th Ann.
Meeting Phys. Soc. J pn., Kyoto, Apr.
(1985).
12) Y. Awaya: "Atomic Process Time andNuclear Reaction Time," 40th Ann. Meeting Phys. Soc. J pn., Kyoto, Apr. (1985).
13) H. Sato, N. Shimakura, and T. Watanabe:"Charge Transfer Processes between a
Multicharged Ion and He in Low Energy
Regions," 40th Ann. Meeting Phys. Soc.
J pn., Kyoto, Apr. (1985).
14) T. Watanabe: "Similarity of Process
between Electron Stripping and InnerShell Ionization," 40th Ann. Meeting Phys.
Soc. ] pn., Kyoto, Apr. (1985).
15) Q. Ma, X. Zhan, Z. Liu, Y.· Liu, and T.
Watanabe: "Born Approximation Calculation for J.l+ + (J.l-p)-+{J.l+ J.l - ) +p II," 40th
Ann. Meeting Phys. Soc. ] pn., Kyoto, Apr.
(1985).
16) K. Hino, I. Shimamura, and T. Watanabe:"Relativistic Theory on Radiative Electron Capture I," 40th Ann. Meeting Phys.
Soc. Jpn., Kyoto, Apr. (1985).
17) S. Karashima, H. Kawagoshi, and T.
Watanabe: "Electron Stripping Cross Sections of Incident Highly Charged Ions II,"
40th Ann. Meeting Phys. Soc. Jpn., Kyoto,
Apr. (1985).
18) K. Ishida, K. Nagamine, Y. Kuno, T.
Matsuzaki, H. Shirakawa, and ]. H.
Brewer: "Muon Spin Resonance Studies on
Polyacetylene II," 40th Ann. Meeting Phys.
Soc. J pn., Kyoto, Apr. (1985).
19) A. Koyama, O. Benka, Y. Sasa, and M.
Uda: "Energy Distribution of Secondary
Electrons Induced by He+ and He2+ ," 40th
Ann. Meeting Phys. Soc. Jpn., Kyoto, Apr.
(1985).
20) A. Koyama, Y. Sasa, and M. Uda:
"Secondary Electrons Emitted from Al
under Bombardment with He+ and He++ ,"40th Ann. Meeting Phys. Soc. Jpn., Kyoto,

231

Apr. (1985).
21) E. Yagi: "Comment on the Quantum
Diffusion of Light Particles in Metals,"
40th Ann. Meeting Phys. Soc. J pn., Kyoto,
Apr. (1985).
22) K. Asai, T. Okada, and H. Sekizawa: "AStudy of Ferrites with the Spinel Structure
by Means of TDPAC of y-Rays Emitted
from 11lCd(~11lIn)," 40th Ann. Meeting
Phys. Soc. Jpn., Kyoto, Apr. (1985).
23) K. Kimura: "Unusual Emission Spectrafrom Heavy-Ion Impinged Liquid Helium(III)," 40th Ann. Meeting Phys. Soc. Jpn.,
Kyoto, Apr. (1985).
24) K. Asai, T. Okada, F. Ambe, S. Ambe, and
H. Sekizawa: "TDPAC of y-Rays Emitted
from 1l1Cd(~1l1In) in Magnetic Oxides,"XX Winter School on Physics, Cracow,
Apr. (1985).
25) Y. Yokode, F. Koizumi, T. Furusaka, S.
Kawamura, A. Kida, and H. Tomita: "Elemental Analysis of Tissues Using Ion Induced X-Ray Spectroscopy," 9th Meeting
Soc. Head and Neck Tumor Jpn., Tokyo,
Apr. (1985).
26) K. Fujima and T. Watanabe: "Atomic
Models in Hot and Dense Plasmas,"
Senimar on Atomic Models in High Density Plasmas, Nagoya, June (1985).
27) H. Shibata, S.H. Be, T. Tonuma, H.
Kumagai, M. Kase, T. Kambara, 1. Kohno,
and H. Tawara: "Ionization of Rare Gas
Atoms in 1.05 Me V / amu Fully Stripped
Ion Impact," 14th Int. Conf. on the Physics
of Electronic and Atomic Collisions, Stanford University, Palo Alto, U.S.A., July
(1985).
28) H. Tawara, T. Tonuma, S.H. Be, H.
Shibata, H. Kumagai, M. Kase, T. Kambara, and 1. Kohno: "Production of Multiply Charged Ions from Molecular Targets
in Heavy Ion Impact," 14th Int. Conf. on
the Physics of Electronic and Atomic
Collisions, Stanford University, Palo Alto,
U.S.A., July (1985).
29) S. Hara and H. Sato: "The Lowest l~t
Autoionizing State of H 2," 14th Int. Conf.
on the Physics of Electronic and Atomic
Collisions, Stanford University, Palo Alto,
U.S.A., July (1985).
30) S. Hara: "The Rotationally and Vibrationally Resolved Photoionization of
H2 by 736A line," 14th Int. Conf. on the
Physics of Electronic and Atomic Collisions, Stanford University, Palo Alto,
U.S.A., July (1985).

31) T. Kambara, Y. Awaya, M. Kase, H.
Shibata, and H. Kumagai: "High Resolution Measurement of Ka and Kf3 X Rays
from 33 MeV Ar Ions in Solid Targets,"
14th Int. Conf. on the Physics of Electronicand Atomic Collisions, Stanford University, Palo Alto, U.S.A., July (1985).
32) 1. Shimamura and A.C. Roy: "Transitionsof Molecules between High-AngularMomentum States," 14th Int. Conf. on the
Physics of Electronic and Atomic Collisions, Stanford University, Palo Alto,
U.S.A., July (1985).
33) 1. Shimamura: "Rotational Excitation of
Molecules by Slow Electrons," 14th lnt.
Conf. on the Physics of Electronic andAtomic Collisions, Stanford University,
Palo Alto, U.S.A., July (1985).
34) T. Nakanishi, T. Watanabe, A. Ohsaki,
and K. Iguchi: "Classical TrajectoryMonte Carlo Calculation for jJ.+ + {ji.-p)~{ji.+ jJ.-)+p and e++(e- p)~(e+ e -) +p," 14th
Int. Conf. on the Physics of Electronic andAtomic Collisions, Stanford University,
Palo Alto, U.S.A., July (1985).
35) Y. Awaya, T. Kambara, M. Kase, H.
Kumagai, S. Shibata, T. Mizogawa, and K.
Shima: "High Resolution Measurements of
Cu K X Rays from Collision Systems of Cu
Ions on C Target and C Ions on Cu Target," 14th Int. Conf. on the Physics ofElectronic and Atomic Collisions, Stanford University, Palo Alto, U.S.A., July
(1985).
36) H. Shibata, T. Matsuo, Y. Awaya, T.
Kambara, M. Kase, H. Kumagai, and N.
Tokoro: "Projectile Dependence of L-MM
Auger Electrons Ejected from Ar Target
by Heavy Ion Impact," 14th Int. Conf. on
the Physics of Electronic and Atomic
Collisions, Stanford University, Palo Alto,
U.S.A., July (1985).
37) K. Hino, 1. Shimamura, and T. Watanabe:"Relativistic Treatment of Radiative Electron Capture," 14th Int. Conf. on the
Physics of Electronic and Atomic Collisions, Stanford University, Palo Alto, U.S.
A., July (1985).
38) Q. Ma, X. Zhang, Z. Liu, Y. Liu, and T.
Watanabe: "Quantum Mechanical Study
for the Processes of jJ.+ + (jJ.- p)~ {ji.+ jJ.-)+ p," 14th Int. Conf. on the Physics ofElectronic and Atomic Collisions, Stanford University, Palo Alto, U.S.A., July
(1985).
39) S. Karashima, T. Watanabe, and Y. Liu:

232

"Electron Stripping Cross Section from
Multicharged Ions by H and He," 14th Int.
Conf. on the Physics of Electronic andAtomic Collisions, Stanford University,
Palo Alto, U.S.A., July (1985).
40) S. Kakinuma, H. Oyama, and Y. Sakamoto: "Study of Resuscitation Mechanismand Deoxidation Process for TitaniumTitanium Oxide System by Synergism ofBoth Hydrogen Ions and Neutral Atoms
and Molecules," Proc. 7th Int. Symp. on
Plasma Chemistry, Eindhoven, The Netherlands, July, p. 430 (1985).
41) 'K. Yano Y. Ishibe, H. Oyama, Y. Sakamoto, M. Yanokura, and I. Kohno:"Deuterium Retention and Depth Profile in
N ear Surface of TiC and C Irradiated with
Dissociated Deuterium Atoms in an ECR
Plasma," Proc. 7th Int. Symp. on Plasma
Chemistry, Eindhoven, The Netherlands,
July, p. 518 (1985).
42) T. Watanabe: "Photoexcitation, Photoionization and Photo-Chemical Processes ofAtoms and Molecules," Advanced Summer
School of Phys. Soc. J pn. on Synchrotron
Radiation, Tokyo and Osaka, July (1985).
43) Y. Awaya: "High Resolution Measurements of X-Rays from Heavy Ions Passing
through Thin Foils," 10th Meeting Soc. for
Atomic Collision Research, Chofu, July
(1985).
44) T. Watanabe: "Muon and Positron Scattering Problem by CTMC, FBA and
DWBA," J apan- UK Seminar on Theory ofAtomic Collisions, Susono, Aug. (1985).
45) T. Watanabe: "Theory of Radiative Electron Capture (REC)," J apan-UK Seminaron Theory of Atomic Collisions, Susono,Aug. (1985).
46) T. Watanabe: "Electron Stripping Processof a Fast Ion by Collision with a Neutral
Atom," Japan-UK Seminar on the Theoryof Atomic Collisions, Susono, Aug. (1985).
47) T. Watanabe: "Models for State Resolved
Charge Transfer Process," J apan- UK
Seminar on the Theory of Atomic Collisions, Susono, Aug. (1985).
48) I. Shimamura: "Quantum MechanicalTreatment of Charge Exchange Processes
Using Frame Transformation," Japan-UK
Seminar on the Theory of Atomic Collisions, Susono, Aug. (1985).
49) I. Shimamura: "Rotational Excitation of
Molecules by Electron Impact," Japan-UK
Seminar on the Theory of Atomic Collisions, Susono, Aug. (1985).

50) K. Fujima: "Statistical Theory of Multiple
Charge Transfer," Japan-UK Seminar on
Theory of Atomic Collisions, Susono, Aug.
(1985).
51) T. Kambara, Y. Awaya, M. Kase, H.
Kumagai, H. Shibata, T. Mizogawa, andK. Shima: "Cu K X Rays from Cu-C and
C-Cu Collision Systems," 9th Int. Seminaron Ion-Atom Collisions, Flagstaff, U.S.A.,
Aug. (1985).
52) Y. Awaya: "Experiments on the Target
Isotope Dependence of REC X-Ray
Yields," 9th Int. Seminar on Ion-Atom
Collisions, Flagstaff, U.S.A., Aug. (1985).
53) T. Watanabe: "Charge Changing Processes in Ion-Atom Collisions," China-Japan
Joint Meeting on Atomic and Molecular
Physics, Chengdu, China, Aug. (1985).
54) T. Watanabe: "Research Activity on
Atomic Physics in the Institute of Physicaland Chemical Research (RIKEN)," ChinaJapan Joint Meeting on Atomic andMolecular Physics, Chengdu, China, Aug.
(1985).
55) K. Fujima and T. Watanabe: "Electronic
Properties of Hot Dense Plasma," Int.
Symp. on Atomic Processes in Fusion
Plasma, Santa Cruz, U.S.A., Aug. (1985).
56) A. Koyama, O. Benka, Y. Sasa, and M.
Uda: "Energy Spectra of Secondary Electrons from Al Induced by High Speed He++
and Ar 12 + Impact," 11th Int. Conf. on
Atomic Collisions in Solids, Washington,
D.C., U.S.A., Aug. (1985).
57) M. Uda, A. Koyama, Y. Sasa, and O.
Benka: "Chemical Effects on Auger Spectra Induced by Fast Ions," 11th Int. Conf.
on Atomic Collisions in Solids, Washington, D.C., U.S.A., Aug. (1985).
58) O. Nomura, K. Kon, Y. Kogure, and K.
Kimura: "Electronic States of Excited
Helium Molecules," Symp. on Molecularand Electronic Structures, Tokyo, Sept.
(1985).
59) Y. Awaya: "Studies on Charge Distribution of Heavy Ions after Passing throughthe Foil," 1st Symp. on Interaction of Ion
Beam with Solids, Kyoto, Sept. (1985).
60) I. Shimamura: "Theory of Electron Transfer in Ion-Atom Collisions," Japan-UK
Joint Symp. on Molecular Quantum Chemistry, Okazaki, Sept. (1985).
61) K. Takaishi, T. Kikuchi, K. Furuya, I.
Hashimoto, H. Yamaguchi, E. Yagi, and
M. Iwaki: "Thermal Extraction of Krypton in Aluminum Using Mass Spec-

233

trometer," 24th Colloq. Spectroscopium
Interna ti onale, Garmisch -P artenkirchen,
Sept. (1985).
62) E. Yagi: "Lattice Location Study on
Hydrogen in Metals by Channeling
Method," Symp. Problems of Solid State
Physics and Mater. Sci. on MetalHydrogen System, Hakone, Sept. (1985).
63) N. Sakai and H. Sekizawa: "Observationof Mossbauer Spectrum without Utilizing
Doppler Motion," ICAME'85, Leuven,
Sept. (1985).
64) A. Koyama, O. Benka, Y. Sasa, and M.
Uda: "Energy Distributions of Secondary
Electrons from Al Induced by Heavy Projectiles," 1985 Fall Meeting Phys. Soc.
lpn., Chiba, Oct. (1985).
65) M. Uda, A. Koyama, Y. Sasa, and O.
Benka: "Chemical Effects on Auger Spectra Induced by Fast Ions (II)," 1985 Fall
Meeting Phys. Soc. lpn., Chiba, Oct. (1985).
66) O. Benka and M. Uda: "A MolecularOrbital Model for the Effect on F K-X-Ray
Spectra," 1985 Fall Meeting Phys. Soc.
1pn., Chiba, Oct. (1985).
67) 1. Tanaka, S. Nasu, E. Fujita, F. Ambe, S.
Ambe, and T. Okada: "Mossbauer Effectof 119Sb in Au," 1985 Fall Meeting Phys.
Soc. lpn., Chiba, Oct. (1985).
68) T. Tonuma, A. Ohsaki, H. Shibata, M.
Kase, T. Kambara, H. Kumagai, S.H. Be,
1. Kohno, and H. Tawara: "Analysis Using
Compound Atom Model of Secondary Ions
Produced in 1.05 MeV amu- 1 Ar q+ + Ar
Collisions," 1985 Fall Meeting Phys. Soc.
1pn., Chiba, Oct. (1985).
69) A. Koyama, M. Uda, Y. Sasa, and O.
Benka: "Secondary Electron Energy Spectra Emitted from Al Induced by Heavy Ion
Impacts," 1985 Fall Meeting Phys. Soc.
lpn., Chiba, Oct. (1985).
70) E. Yagi, T. Kobayashi, S. Nakamura, F.
Kano, K. Watanabe, and Y. Fukai:"Hydrogen State in Vanadium under
Uniaxial Stress," 1985 Fall Meeting Phys.
Soc. lpn., Chiba, Oct. (1985).
71) K. Asai, T. Okada, F. Ambe, S. Ambe, and
H. Sekizawa: "A Study of the Hyperfine
Magnetic Fields at lllCd(+-lllIn) in Magnetic Oxides by means of y-y Perturbed
Angular Correlation," 1985 Fall Meeting
Phys. Soc. 1pn., Chiba, Oct. (1985).
72) K. Kimura, M. Kataoka, K. Hara, and T.
!ida: "Unusual Emission Spectra from
Heavy-Ion Impinged Liquid Helium (IV),"
1985 Fall Meeting Phys. Soc. lpn., Chiba,

Oct. (1985).
73) K. Kimura: "Possibility of Dimerization
and Clustering of Helium-Excimers
Produced by Heavy-Ion Impingement,"
1985 Fall Meeting Phys. Soc. lpn., Chiba,
Oct. (1985).
74) T. Watanabe: "Positron Collision from
Atoms and Molecules," 1985 Fall Meeting
Phys. Soc. lpn., Chiba, Oct. (1985).
75) A.C. Roy and T. Watanabe: "The Calculation for Double Differential Cross Sectionof Helium Ionization Process by Electron
Impact," 1985 Fall Meeting Phys. Soc.
1pn., Chiba, Oct. (1985).
76) S. Karashima and T. Watanabe: "Electron
Stripping Cross Section of Incident Multicharged Ions III," 1985 Fall Meeting Phys.
Soc. lpn., Chiba, Oct. (1985).
77) 1. Kohno, M. Yanokura, S. Motonaga, H.
Kamitsubo, M. Yatsuhashi, T. Suematsu,
and H. Kobayashi: "Effects of the Fast
Neutron Irradiation on Cable Materials,"IEEE 1985 Nuclear Science Symposium,
San Francisco, U.S.A., Oct. (1985).
78) Y. Sakamoto and N. Noda: "Nuclear
Fusion Devices and the Carbonization of
the Wall Surface," Riken Symp. Modification of Solid Surfaces with Plasma, Wako,
Nov. (1985).
79) Y. Ishibe and K. Okazaki: "Carbonization
Experiment in RIKEN ECR-2 Device,"
Riken Symp. Modification of Solid Surfaces with Plasma, Wako, Nov. (1985).
80) S. Amemiya and K. Yano: "Characterization of Carbon Films, with Plasma," Riken
Symp. Modification of Solid Surfaces with
Plasma, Wako, Nov. (1985).
81) 1. Shimamura: "R-Matrix Method andAtomic Collisions," Symp. on Atomic
Physics, Nagoya, Nov. (1985).
82) Y. Awaya: "Experiments by Using HighEnergy Multiply Charged Ions," Symp. on
Atomic Physics, Nagoya, Nov. (1985).
83) Y. Ishibe, H. Oyama, K. Okazaki, K. Yano,
Y. Sakamoto, N. Noda, and Y. Hori: "Carbon Coating with ECR Plasmas," Proc.
26th Vacuum Symp., Tokyo, Nov., p. 116(1985).
84) M. Uda: "PIXE Analysis for Medical Science," 3rd Seminar on Science and Technology-Small Accelerators and Their
Application, Interchange Association
lapan, Tokyo, Nov. (1985).

234

4.

Radiochemistry, radiation chemistry andradiation biology
1) Y. Ito, Y. Tabata, and K. Kimura: "Electron Scavenger Effects on the Fluorescence Induced by Single High-LET Particle," 7th Int. Conf. on Positron Annihilation, New Delhi, India, Jan. (1985).
2) T. Takahashi: "Effect of Heavy Ions on
Microorganisms," RIKEN Symp. on
Studies by Using RIKEN Accelerators1984, Wako, Mar. (1985).
3) T. Takahashi, F. Yatagai, T. Katayama,
and K. Masuda: "Analysis of Lethal EffectInduced by Heavy-Ion Bombardment,"
32nd Spring Meeting J pn. Soc. Appl. Phys.
and Related Societies, Tokyo, Mar. (1985).
4) K. Asai, F. Ambe, S. Ambe, T. Okada, and
H. Sekizawa: "TDP AC Studies on 111Cd( +111In) in a-Fe 203 at High Temperature,"
50th National Meeting Chern. Soc. J pn.
(Spring), Tokyo, Apr. (1985).
5) S. Ambe, F. Ambe, and T. Okada: "Adsorption Kinetics of Carrier-Free 119Sb(V) onto
a-Fe203," 50th National Meeting Chern.
Soc. Jpn. (Spring), Tokyo, Apr. (1985).
6) M. Aratani, H. Nagai, M. Yanokura, O.
Kuboi, S. Hayashi, 1. Kohno, and T. N ozaki: "Forward Scattering Analysis by
Heavy-Ion Beam Applied to the Study ofHydrogen in Amorphous Silicon and Silica," 7th Int. Conf. on Ion Beam Analysis,
Berlin, FRG, July (1985).
7) F. Ambe, K. Asai, S. Ambe, T. Okada, and
H. Sekizawa: "Comparative Mossbauer
and TDPAC Studies on the After-Effectsof the EC Decays of 119Sb and 111In in aFe203," Int. Conf. Applied Mossbauer
Effect, Leuven, Sept. (1985).
8) F. Ambe, S. Ambe, T. Okada, and H.
Sekizawa: "In situ Mossbauer Emission
Spectroscopy of 57Co2+(~57Fe3+) and
119Sb5+(~1l9Sn4+) at the a-Fe 203- A queous
Solution Interfaces," Int. Conf. Applied
Mossbauer Effect, Leuven, Sept. (1985).
9) T. Takahashi, K. Eguchi, A. Hashizume,
and T. Inada: "Data Requirements in
Heavy Ion Radiotherapy-Considerations
on Available Physical Quantities-,"
IAEA Advisory Group Meeting on
Nuclear and Atomic Data for Radiotherapy and Radiobiology, Rijswijk, The Netherlands, Sept. (1985).
10) F. Ambe, S. Ambe, T. Okada, and H.
Sekizawa: "In situ Mossbauer Studies of
a-Fe 203/ Aqueous Solution Interfaces withAdsorbed 57C02+ and 119Sb5+ Ions," 1985

ACS Ann. Meeting, Chicago, Sept. (1985).
11) M. Yanokura, Q. Qiu, M. Aratani, H.
Nagai, 1. Kohno, and T. Nozaki: "Utilization of Linear Accelerator for the Study ofthe Formation of Radiation-Resistive
Oxide Film on Silicon," 29th Symp. on
Radiochemistry, Funabashi, Oct. (1985).
12) T. Ohtsuki, Y. Hatsukawa, T. Miura, K.
Sueki, H. Nakahara, and 1. Kohno: "Proton Induced Fission of 237N p," 29th Symp.
Radiochemistry, Funabashi, Oct. (1985).
13) N. Ito, K. Ikeda, M. Yanokura, S. Hayashi,
Q. Qiu, H. Nagai, M. Aratani, 1. Kohno,
and T. Nozaki: "Heavy-Ion Probe Rutherford Backscattering Applied to the Fabrication Process of Schottky-Barrier
Diode," 29th Symp. on Radiochemistry,
Funabashi, Oct. (1985).
14) Y. Hamajima, K. Sueki, M. Magara, H.
Nakahara, and 1. Kohno: "Mass Division
on Low Energy Nuclear Fission of 238U,"
29th Symp. on Radiochemistry, Funabashi,
Oct. (1985).
15) K. Asai, F. Ambe, S. Ambe, T. Okada, and
H. Sekizawa: "TDPAC and Emission
Mossbauer Studies on the After-Effects ofthe EC Decays of 111In and 119Sb in aFe203," 29th Symp. on Radiochemistry,
Funabashi, Oct. (1985).
16) F. Ambe, K. Asai, S. Ambe, and H.
' Sekizawa: "Time Differential Perturbed
Angular Correlation Study on (111In~)
111Cd in In 203," 29th Symp. on Radiochemistry, Funabashi, Oct. (1985).
17) T. Nozaki, Y. Itoh, Y. Ohkubo, T. Kimura,and H. Fukushima: "Simultaneous Charged Particle Activation Analysis of Carbon and Boron in Gallium Arsenide," 29th
Symp. on Radiochemistry, Funabashi, Oct.
(1985).
18) Y. Minai, S. Ambe, and T. Nozaki: "Preparation and Application of 29 Al Producedby the 26Mg(a,p)29AI Reaction," 29th
Symp. on Radiochemistry, Funabashi, Oct.
(1985).
19) T. Nozaki, Y. Itoh, Y. Ohkubo, T. Kimura,
H. Fukushima, and Y. Kadota: "Determination of Carbon in Galium Arsenide with
Reaction of 12C(d, n)l3N ," 46th Fall Meeting J pn. Soc. Appl. Phys., Kyoto, Oct.
(1985).
20) K. Eguchi, 1. Kaneko, T. Kosaka, K.
Nakano, and Sushiana: "Non-Repairable
DNA Lesions in HMV-I Cells Irradiatedwith N-Ion Beams," Ann. Meeting Jpn.
Soc. Radiation Research, N ara, Oct. (1985).

23521) K. Kimura, T. Azuma, Y. Aoki, T. Kuriyama, K. Akasu, Y. !toh, and Y. Tabata:"Roles of Helium-Excimer-Clusters in
Heavy-Ion Impinged Condensed Helium,"
28th Conf. on Radiation Chemistry,
Sapporo, Nov. (1985).
22) K. Kimura: "Formation of the Dimer andCluster of Helium-Excimers in the HeavyIon Irradiated Dense Helium at 3.9-5.2 K,"
28th Conf. on Radiation Chemistry,
Sapporo, Nov. (1985).
23) Y. Ito, T. Azuma, Y. Aoki, Y. Katsumura,Y. Tabata, and K. Kimura: "A Study of
the Spur and Track Using a Technique ofthe Single-Particle Hitting and SinglePhoton Counting," 28th Conf. on Radiation
Chemistry, Sapporo, Nov. (1985).
24) M. Yanokura, Q. Qiu, K. Ikeda, N. Ito, M.
Aratani, and T. Nozaki: "Heavy-Ion Rutherford Backscattering Analysis Applied to
the Electronic materials," 4th Symp. on
Ion Beam Technology, Hosei University,
Tokyo, Dec. (1985).

236

VIII. LIST OF OUTSIDE USERS AND THEIR THEMES(Jan.- Dec. 1985)
1) T. Kimura and H. Hukushima"Radiochemical Analysis of 160, 14N
and 12C in Si Crystal and GaAs"

Japan Chemical Analysis Center

2)

H. Nakahara"Production of 97Ru"

Faculty of Science, Tokyo
Metropolitan Univ.

3)

S. Orito and S. Nakamura"Test of Sensibility of CR39 Track
Detector for High Energy Proton"

Faculty of Science, Univ. Tokyo

4)

H. Homareda"Production of 43K"

Faculty of Medicine,
Kyorin Univ.

5) Y. Moriguchi"Radiation Damage of Cover Glassfor a Solar Cell"R&D Div., Asahi Glass Co., Ltd.

6)

T. Hayashi"Radiation Damage of Cover Glass fora Solar Cell"

Institute of Space and Astronautical
Science7)

K. Yamamoto"Study of Single Event Upset in
Microprocessors by Bombarding 14N
and 40 Ar Particles"

Semiconductor R&D Lab.
Toshiba Co., Ltd.

8)

S. Yoshida and M. Goto
"Study of Effect by Bombarding HighEnergy Proton on a GaAs Solar Cell"

LSI R&D Lab.
Kamakura Works
Mitsubishi Electric Co., Ltd.

9)

K. Omura and T. Abe"Calibration of Space Environment
Monitor Carried on a Satellite with
Variable Particles"

Kamakura Works
Mitsubishi Electric Co., Ltd.

237

IX. LIST OF SEMINARS(J an. -Dec. 1985)

1) S. K. Nanda, Univ. Minnesota-LAMPF(USA), 25 February"Observation of MI-Excitations in Intermediate Energy Proton Scattering""SA TURNE II-A Heavy Ions and Polarized Particles Synchrotron for Intermediate Energy Physics"14) M. Sugita, Univ. of Tokyo (Tokyo), 9 July2)

A. Shimizu, RCNP (Osaka), 13 March"Vacuum Characteristics of Alminium
RF-Cavity and Design of Evacuating System for Accelerators"

3) F. A. Beck, CRN (France), 16 March"Cha.teau de Crystal"4) R. Schuch, Max Planck Institut (West Germany), 19 March"On the Plan of the Cooler Ring at Heidelberg"
5) W. von Oertzen, Hahn-Meitner-Institut (Berlin), 26 March"Transfer Reactions with Intermediate
Energy Heavy Ions"
6) 1. Tanihata, INS (Tokyo), 27 March"Experiments with Beam of Unstable
Nuclei"7) S. Iwasaki, Univ. of Chiba (Chiba), 8 May"Structure of K = 1+ Band in Deformed
Nuclei"8) J. Arje, Jyuasky la Univ. (Finland), 28 May"IGISOL; Now and in Future"9) S. Takeda, ISIR (Osaka), 31 May"N ovel Accelerators"
10) T. Katayama, INS (Tokyo), 7 June
"Beam Cooling"11) M. Oshim:a, JAERI (Ibaraki), 25 June
"Shape Change at High Spin States inDeformed Nuclei"12) H. Shimizu, Tokyo Inst. Technol.(Tokyo), 2
July"Nucleon-Nucleon Scattering and Dibaryon"13) M. Olivier, Saclay (France), 5 July

"Shape Change Transition in the Regionof Z=40"
15) Y. Sakuragi, INS (Tokyo), 15 July
"N on-Central Force between Two Nuclei
and Polarized Heavy Ion Scattering"16) R. Wada, GSI (West Germany), 19 July
"Production Mechanism of Light andMedium Heavy Fragments at 48 and 84
MeV/N"
17) K. Yazaki, Univ. of Tokyo (Tokyo), 24 July
"Nuclear Shell Model or Quark Shell
Model?"
18) K. Yoshida, INS (Tokyo), 25 July
"GeV Electron Accelerators"
19) T. N umao, TRIUMF (Canada), 2 August"Experiments at TRIUMF"
20) P. Egelhof, Maintz Univ. (West Germany), 22
August"High Precision Spectroscopy on Light
Nuclei Using Aligned Beams and MuonicAtoms"
21) C. Gagliardi, Texas A & M Univ. (USA), 3
September"(n,p) Scattering at Intermediate Energies"
22) K. Seth, North Western Univ. (USA), 4 September"Perspectives in Intermediate Energy Proton and Pion Physics"
23) B. Mayer, Saclay(France), 5 September"Experiments Using Intermediate Protons
and Antiprotons"
24) D. Fick, Marburg Univ. (West Germany), 6
September"Polarized Li Ion Source and Applications

23832) N. Takigawa, Tohoku Univ. (Miyagi), 14

to Nuclear and Surface Physics"25) J. Raynal, Saclay (France), 6 September"Coupled-Channel Description of Inelastic
Scattering with a Dirac Equation"

November"Heavy Ion Fusion Reactions below the
Coulomb Barrier"33) K. Kaneko, INS (Tokyo), 15 November26) H. Sagawa, Univ. of Tokyo (Tokyo), 17
September"Vibration and Vaporization of Thermal
Nuclei"27) B. Milller, Frankfurt Univ. (West Germany),

28)"Present Status of Measurement of Vacuum in the Region of 10- 2 '-""'10- 12 Torr"
34) J. Aysto, Jyuasky la Univ. (Finland), 22

September"Trends in the Study of Light Proton Rich
Nuclei"24 September"Collective Pion Radiation from Nuclear
Collision"35) K.

J. Kasagi, Tokyo Inst. Technol. (Tokyo), 1
October"N eutron-Fragment Coincidence Measurement in 14N + 165Ho and Ni Reactions"36) T.

29) A. Iwamoto, JAERI (Ibaraki), 22 October"Particle Emissions from Preequilibrium
States in Heavy Ion Collisions"30) H. Toki, Tokyo Metropolitan(Tokyo), 29 October"Pion Absorption in Nuclei"

Univ.

31) H. Tanaka, Hokkaido Univ. (Hokkaido), 6
November"Multiple Scattering and a-particle"

Sugawara-Tanabe, Univ. of Tokyo(Tokyo), 26 September"Thermal High Spin Giant Dipole Resonance"
Kajino, Tokyo Metropolitan Univ.
(Tokyo), 6 December"Pionic Fusion and Cluster Correlation in
Nuclei"

37) D.W.L. Sprung, McMaster Univ. (Canada),
10 December"Some Aspects of Hatree-Fock Calculations of Nuclear Structure"38) Y. Koike, RCNP (Osaka), 12 December"Application of Three-Body Faddeev
Equation to Nuclear Scattering"239

x. LIST OF PERSONNEL
Members of the Board
AWAYA Yohko ~ J¥.?g-T

CHIBA Y oshiaki

T ~ iff ~HASHIZUME Akira ~ JT\ AA
KAMITSUBO Hiromichi .l::If 7R J1!
KIRA Akira a.N. ~ISHIHARA Masayasu :;s 1* lE
KANEKO Ichiro ~ -T - a~
KOHNO Isao rilJ Jf r}]

KURIHARA Osamu ~NOZAKI Tadashi !f ~NAGAMINE Kanetada
OKADA Shigefumi I1Dj EB

'*

1~

lE

SAKAIRI H ideo ±bZ A ~ tit
SEKIZA WAH isashi M 1R n16
W AT AN ABE Tsutomu ~ g.~ 11'"SAKAMOTO Yuichi ±bZ
UDA Masayuki ~ EB fiC;**

~ ~ J~

mY:.

* tit z. . chairman

Cyclotron Operation and Maintenance GroupFU JIT A Shin ~ EB if
KAGEY AMA Tadashi ~ 0-J lE
KOHNO Isao rPJ!f r)]
T AKEBE Hideki 1tt g.~ ~ 1if

IKEGAMI Kumio tfu-.tiL =: ~'* m

KOHARA Shigeo /j\~
OGIWARA Kiyoshi ~ ®: ~Linac Operation and Maintenance GroupCHIBA Y oshiaki

T ~ iff ~HEMMI Masatake ~ ~ il& 1tt
INOUE Toshihiko if: -.t 19.~ ~=IKEZAW A Eiji tfu rR ~'*KAMBARA Tadashi 1$lE
KUBO Toshiyuki :;z 1* 19.~ ¥Y ANOKURA Minoru 9(Jfit ~KASE Masayuki tm ~ ~ Z.
MIY AZA WAY oshi toshi '§ 1R {t 19.~

Scientific and Engineering Personnel

Cyclotron Laboratory
BE Suck Heem~~

FUJITA Jiro ~ EB

= a~

'*

HARA Masahiro~ iJb.
IN AMURA Takashi fm *1 ~KARASA W A Takashi ~ rR q:
MORITA Kohsuke~ EB ~ 1l'

NAGASE Makoto~ W.Q

NAKANISHI N oriyoshi
SAKAMOTO Ichiro ±bZ~

cP rffi *2 ~*-a~

FUJI SA W A Takashi ~ rR rWJ it:
GOTO Akira ~ ~ ~HATANAKA Kichiji ~ cP a m
KAMITSUBO Hiromichi -.t P¥ 7R J1!
KOHNO Isao ~ilJ Jf r}]*

MOTONAGA Shoshichi 5C
SiS -t
NAKAJIMA Shunji cP ~ ~~OIKAWAY oshifumi ~ JII J(; fl~
SHIKA T A Takashi IZB 11 ~ ~

=

240

m7]( .:to ~SHIMIZU Kazuo

W ADA Takeshi .:to El3

T AKESHIT A Isao t'r T ~ X.

11

Y AMAJI Shuhei:m

Y AN 0 Yasushige *- H 3l:
YOSHINAGA N aotaka 5" 7k ri16 $=(Visitors)

LlJ ~ 1~ ~YOKOYAMA Ichiro *1i LlJ -~~*DOKE Tadayoshi J!!
,'i5;', ~* (Sci. and Eng. Res: Lab., Waseda Univ.)
FUJIOKA Manabu Ii flOj ~ (Cyclotron and Radioisotope Center, Tohoku Univ.)*

FUKUMOTO Sadayoshi 1i~ ~ (KEK)FURUNO Kohei r:!l H ~ ~ (Inst. Phys., Univ. Tsukuba)
GOU Minyan ,~ 1!J!i ~ (Inst. Mod. Phys., Academia Sinica, China)
HIRAKI Akio ~Bg X. (Fac. Eng., Osaka Univ.)
fAX .:to X. (Dept. Phys., Tokyo Inst. TechnoU
IEKI Kazuo
INOUE Makoto #.L 1~ (RCNP, Osaka Univ.)
ISOYA Akira ~ *- ~ (School Sci., Tokai Univ.)
KAMIMURA Masayasu .L M IE
(Dept. Phys., Kyushu Univ.)
KASAGI Jirota ~*m~~* (Dept. Phys., Tokyo Inst. Techno!')KA TORI Kenji Jm 1tX ~(Dept. Phys., Osaka Univ.)
KA TSURAGAWA Hidetsugu f.i JII
iIJ (Dept. Phys., Toho Univ.)
KIKUCHI Fumio 1iij:l:tQ::z ~ (Dept. Math., College of General Education, Univ. Tokyo)
KONDO Michiya Jli: l1i J!! -lli (RCNP, Osaka Univ.)
KUDO Hisaaki I l1i ~ BB (Dept. Chern., Niigata Univ.)
MINOWA Tatsuya ~ ~ Ji ~ (Dept. Phys., Toho Univ.)
MIURA Iwao .=: 1m E (RCNP, Osaka Univ.)
MIYATAKE Hiroari 15:ft.t ~ -lli (Inst. Nucl. Study, Univ. Tokyo)
MURAKAMI Takeshi t1.L ~ (Dept. Phys., Tokyo Inst. TechnoU
N AGAKAW A J ohsei 7)< JII fAX IE (N at. Res. Inst. for Metals)
NAGAMIY A Shoji 7.k '8 IE tEl (Dept. Phys., Univ. Tokyo)
NAKAHARA Hiromichi r:p mt iJL ~ (Dept. Chern., Tokyo Metropolitan Univ.)
NOMURA Toru H M 7* (Inst. Nucl. Study, Univ. Tokyo)
ODERA Masatoshi IJ\ ~ IE 1~* (Sci. and Eng. Res. Lab., Waseda Univ.)
SA TO Kenichi 1ti: Ii .. - (Division Phys., Tohoku College of Pharmacy)
SHIRAISHI Haruki El 15 ~ W (N at. Res. Inst. for Metals)
SHIMAZU Mitsuyoshi ~ i$ frm ~ (Dept. Phys., Toho Univ.)
SUEKI Keisuke"@: 11- (Inst. N ucl. Study, Univ. Tokyo)
TAKEKOSHI Hidekuni t'r JJI*~ (Inst. Chern. Res., Kyoto Univ.)
TAKEMASA Tadashi :ft.t i& jt ± (Dept. Phys., Saga Univ.)
TANAKA Jinichi B3 r:p 1= rP (Inst. Nucl. Study, Univ. Tokyo)
TORIZUKA Kanji ~ ~ % ~ (Fac. Med., Kyoto Univ.)
YAMAMOTO N orikazu LlJ~.:tO (Nat. Res. Inst. for Metals)
YONG Shangyun f~
ri16 ii (Inst. Mod. Phys., Academia Sinice, China)
YOSHIDA N obuaki 5" El3 E1r ~ (Dept. Phys., Univ. Tokyo)
YOSHIDA Shiro 5 El3 ,~, ~~ (Dept. Phys., Tohoku Univ.)

*

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241(Students)
HARADA Hideo ~ EB 3'§ ~~ (Dept. Phys., Tokyo Inst. TechnoU
HATSUKAWA Yuichi fn}ll a:t - (Dept. Chern., Tokyo Metropolitan Univ.)
OZAWA Keiko IJ\ ¥R ~ T (College Hum. and Sci., Nihon Univ.)
SHIDA Kenji ~ EB ~U(Fac. Sci. and Eng., Chuo Univ.)
1[ (Dept. Phys., Tokyo Inst. Techno!')T ACHIBAN AKI Hiroshi ~W AKASUGI Eiichi ;fi ~(Fac. Sci. and Eng., Chuo Univ.)
YOSHIDA Koichi "5 EB ]It - (Dept. Phys., Tokyo Inst. Techno!')= **-Linac Laboratory
CHIBA Toshiya :t ~ flj ~GONO Yasuyuki ~~. ~ Z
INOUE Toshihiko #..t w.!J. ~no

KASE Masayuki
il¥~ ~ Z
KUMAGAI Hidekazu 1m ~ 3'§ fD
MIZOGAWA Tatsumi i-1ij )11 ~ a
Y ANOKURA Minoru 9(lf1% ~CHIBA Y oshiaki :t ~ iff ~HEMMI Masatake ~ ~ i& ft\
KAMBARA Tadashi ~$ ~ 1£
KUBO Toshiyuki ),.. 1* w.!J. $MIY AZA WAY oshitoshi '§ ¥R f~ 1Ji&:
TONUMA Tadao p
1£ a:tm(Visitors)
FUJIWARA Ichiro Ii ~ - ~~ (Inst. Atomic Energy, Kyoto Univ.)
ITO N oriaki f1t Hi Jt BB (Dept. Crystalline Materials, Nagoya Univ.)
SUGAW ARA Masahiko rg ~ ~ jfft (Fund. Sci., Chiba Inst. TechnoU(Student)
FUKUDA Mitsunori 1& EB ]It JII& (Fac. Sci., Tokyo Inst. TechnoU

Radiation Laboratory
ASAHI Koichiro Jill

KONNO Satoshi~ Jf

TAKAHASHI Tan

HASHIZUME Akira ~ m*If-~~ICHIHARA Takashi m ~IZUMO Koichi te ~ ]It rWb ~$W

ISHIHARA Masayasu 15 ~ 1£
KOHNO Toshiyuki yPJ Jf f3t Z
OKANO Masaharu

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TENDOW Y oshihiko 7.. ~ 75 jfft

(Visitors)
OOKE Tadayoshi ~J~ ~ (Sci. and Eng. Res. Lab., Waseda Univ.)
FUJIOKA Manabu Hi f1UJ
~ (Dept. Phys., Tohoku Univ.)
HASEGAWA Takeo ~~)IIj\~ (Inst. Nucl. Study, Univ. Tokyo)
jj[ (Sci. & Eng. Res. Lab., Waseda Univ.)
HITACHI Akira F3 te
110 Masahiro ~ P€ IE J1;. (Fac. Med., Univ. Tokyo)
KANG Yung-Ho
m- (Dept. Natural Sci., Kyung-Pook Univ.)
f~ (Fac. Eng., Saitarna Univ.)
KOBAYASHI Hisanobu /J\
KUBOTA Shinzou ~ EB {~ ~ (Fac. Sci., Rikkyo Univ.)
LEE Sang Mu
f§ N, (Univ. Tsukuba)
MASUDA Kirniaki ~ EB 0- ~ (School Sci. Eng., Waseda Univ.)

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AA

242

* **

MOTOBAYASHI Toru
~ (Fac. Sci., Rikkyo Univ.)
MURAMA TSU Hisakazu *1 tl ).,.. fD (Nat. Lab. High Energy Phys.)
NAGAHARA Teruaki 71< mt !3R ~ (Inst. Atomic Energy, Rikkyo Univ.)*- ~ * ~ (Fac. Sci., Osaka Univ.)*-

OHSUMI Hideaki

OHTSUKA Hideko~ *-T
OHTSUKA Rikuro 7::. ~ ~ ~~ (Nagoya Inst. Techno!')ON AI Y oshio ~ pg ~~::fi2: (Dept. Phys., Cancer Inst.)
SHIBAMURA Eido~

*1 ?If j![ (Saitama College of Health)(Students)= rm :* - (Dept. Chern., Tokyo Metropolitan Univ.)

MIURA Taichi

SUZUKI Satoshi if;

* Jet
A.
*

(School Sci. Eng., Waseda Univ.)

YANAGA Makoto ~ 71< ~YUNOKI Akira .:fiE~(Dept. Chern., Tokyo Metropolitan Univ.)(School Sci. Eng., Waseda Univ.)

Atomic Processes Laboratory
ANDO Kozo

77: ~ 1lQI~ ~J=J I±l

AWAYA Yohko~ ~ ~-T

HITACHI Akira~

KAN AI Y asuyuki~ it 1* Z

KOHMOTO Susumu

r"i1J

NISHIDA Masami gg B3 ~ ~SHIMAMURA Isao

~ *1

IW AI Masahiro ::6- it IE 1W

W A T AN ABE Tsutomu ¥Jl g~

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FUJIMA Kazumi ~ Fa' - ~ (Dept. Phys., Chuo Univ.)
HARA Shunsuke mt 13t 1r (Dept. Phys., Univ. Tsukuba)
ISHII Keishi 15 it ~ Z (Dept. Eng. Sci., Kyoto Univ.)
ISMAIL M. Mostafa (Dept. Phys., Cairo Univ.)
ITOH Yoh 1fT ~~ (Fac. Sci., Josai Univ.)
KARASHIMA Shosuke ~ ~ !3R 1r (Dept. Electr. Eng., Tokyo Univ. Sci.)**

KOBA Y ASHI N obuo /J\
1B::fi2: (Dept. Phys., Tokyo Metropolitan Univ. )KOIKE Fumihiro /J\ tfu )( 1W (School Med., Kitasato Univ.)
KOIZUMI Tetsuo /J\ ~ f!f::fi2: (Dept. Phys., Rikkyo Univ.)
KOY AMA N aoto /J\ l-U Ii A. (Dept. Eng. Phys., Univ. Electrocommunications)***

LIN Chii-Dongl@=(Dept. Phys., Kansas State Univ.)
MA TSUMOTO Atsushi tl¥¥ (Inst. Plasma Phys., Nagoya Univ.)
MATSUO Takashi tl ~(Dept. Pathology, Tokyo Med. and Dent. Univ.)
MA TSUZAW A Michio tl ~ Jm 1:. (Dept. Eng. Phys., Univ. Electrocommunications)
MCDOWELL M. R. Coulter (Dept. Math., Royal Holloway & Bedford New College)**

OHTANI Shunsuke *-:fr 13t 1r (Inst. Plasma Phys., Nagoya Univ.)
OKUNO Kazuhiko ~ If fD ~ (Dept. Phys., Tokyo Metropolitan Univ.)

11: ~ ~ ~ (Dept. Phys., Ochanomizu Univ.)
SATO Kuninori 11:;§i 00 :« (Inst. Plasma Phys., Nagoya Univ.)
SATO Hiroshi

SCHUCH Reinhold (Dept. Phys., Heidelberg Univ.)
SHIBATA Hiromi ~ B3 m~ (Research Center for Nucl. Sci. & Technol., Univ. Tokyo)
SHIMA Kunihiro~

SHIMAKURA Noriyuki*~ 1W(Inst. Appl. Phys., Univ. Tsukuba)~ ~ *'2 Z(General Educ. Dept., Niigata Univ.)

243

=*

TAKAGI Shoji ~~ jf (Dept Phys., Toho Univ.)
TAWARA Hiroyuki {~ iW Z (Inst Plasma Phys., Nagoya Univ.)
TOKORO Nobuhiro pJT {$ 7J:. (Res. Lab. Nucl. Reactors, Tokyo Inst. TechnoU
TOSHIMA Nobuyuki p~!lIj {~¥ (Inst. Appl. Phys., Univ. Tsukuba)(Fac. Technol., Tokyo Univ. Agric. TechnoU
TSURUBUCHI Seiji • mil ~URAKAWA Junji ~)I[ }II& rEI (Nat. Lab. High Energy Phys.)=(Students)
HINO Kenichi E3.1f @ - (Dept. Appl. Phys., Univ. Tokyo)
NAKANISHI Kiyotaka cP iZ9~ (Dept. Chern., Waseda Univ.)m

Metal Physics Laboratory

Ll! BB ftff
SHIOT ANI N obuhiro m~ s "5b.

ISHIDA Katsuhiko 15 ill 1m Jft
NAGAMINE Kanetada 7]< ~ ~ J~'
YAGI Eiichi /\KOY AMA Akio

* *-

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(Students)
KANO Fumitoshi mg.lf::>t ~ (School Sci. Eng., Waseda Univ.)
NAKAMURA Shiho cP *1 ;:t, 1* (School Sci. Eng., Waseda Univ.)

Magnetic Materials Laboratory

ASAI Kichizo ~ if: 5 ji
SAKAI Nobuhiko i:& if: {~ Jft

OKADA Takuya [1Oj ill -$: -lli
SEKIZAWA Hisashi 00 rR. f6j

Plasma Physics Laboratory

ISHII Shigeyuki 15 if: PX 1T
OY AMA Hitoshi *- Ll! ~YANO Katsuki 9C.If 1m ~ISHIBE Yukio 15 $ 1T ftff
OKAZAKI Kiyohiko lNJ~mJ:t3
SAKAMOTO Yuichi :1:,& ftt -*Semiconductors Laboratory(Visitor)
AONO Keikow.lf:f1 -T (College of Liberal Arts, Kitasato Univ.)

Solid-State Chemistry Laboratory

KOBAYASHI Masayoshi ;J\SASA Y oshihiko fi l< ~ Jft** :lfl~

MAEDA Kuniko M ill =F~ -T
UDA Masayuki ~ ill JJt z(Visitors)
BENKA Oswald (Johannes Kepler-Univ. Linz, Austria)
KUSUYAMA Hiroyuki mJ Ll! "5b. Z (Cancer Institute Hospital Tokyo)(School Med., Nihon Univ.)
YOKODE Yutaka f1i tfj

m

244

Radiochemistry Laboratory
AMBE Fumitoshi ?i: g~ Y:. 1iJ~

AMBE Shizuko ?i: g~ ~ T

m:fr ~ ~ARA T ANI MichiHA Y ASHI Shigeki*** a fi.J*

IW AMOTO Masako :!5 /.$: lE -T

ITOH Yoshiko 1tt
J!j -TNOZAKI Tadashi !:f IiffiJ IE

OHKUBO Yoshitaka*~1*~rWJ*through March 31, 1985
(Visitors)
AIMI Toshihiko l§ ~ 13t ~ (NEC Corporation)
FUKUSHIMA Hiroto mi ~~ ~ A (Japan Chemical Analysis Center)
HASHIMOTO Tetsuo ~ /.$: rg(Fac. Sci., Niigata Univ.)
HUANG Ziwei ~ T(Inst. Biology, Pedology and Psamology Res., China)
IKEDA Kazuko ttE EE to T (NEC Corporation)
IMAI Masato 4-:# JE A (Komatsu Electronic Metals Co., Ltd.)ITOH N obuyuki ftt ~ 1B" Z (NEC Corporation)

m

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KIMURA Toshimasa
l11iJ!J. IE (Japan Chemical Analysis Center)
KUBOI Osamu ~1*:# !J)( (Komatsu Electronic Metal Co., Ltd.)MINAI Yoshitaka ~ ~ 1~ ~ (Fac. Sci., Univ. Tokyo)
NAGAI Hisao 71<:# r% ~ (College Hum. and Sci., Nihon Univ.)
NASU Saburo ~~ ~ ~ ~~ (Fac. Eng. Sci., Osaka Univ.)OOHIRA Shigeo
m ~ (Nikkei Techno Res. Co., Ltd.)SUEHIRO Makiko
r.t ~ T (Tokyo Metropolitan Geriatric Hospital)
YA TSURUGI Yoshifumi J\ W "5)[' (Komatsu Electronic Metals Co., Ltd.)YOKOI Fuji ~:# J.ffi.1. % (Mental and Muscular Disorders, National Center for Nervous)
HA Y ASHI Akira:f*~ (NSG Yamaguchi Corporation Ltd.)YAMAMOTO Kazuhiko LlJ /.$: to ~ (Toshiba Corporation, R&D Center)*:s:P:*(Students)
ARAI Iwao ~#1ififBx (Fac. Pharm., Sci. Univ. Tokyo)
KUBO Kenya ~ 1* ~ ~ (Fac. Sci., Univ. Tokyo)
TANAKA Isao EE r:pr:)] (Fac. Eng. Sci., Osaka Univ.)QUI Qi Ii~=If (Nucl. React. Res. Lab., Tokyo Inst. TechnoU

Radiation Chemistry Laboratory
KIMURA Kazuie* l1 - *(Visitor)
ITO Yasuo ftt ~*~(Res. Center Nucl. Sci. and Technol., Univ. Tokyo)(Students)
HARA Korehisa rn'{ ~ ~ (Dept. Phys., Chuo Univ.)
IIDA Tsuyoshi i& EB
IPllU (Dept. Phys., Chuo Univ.)
KA T AOKA Masayoshi h /1fij :f,'}:R; (Dept. Phys., Chuo Univ.)

245Radiobiology Laboratorym

EGUCHI Kiyomi iI 0~
NAKANO Kazushiro r:p If iiD :IpX

KANEKO Ichiro ~ -T - ~~OKADA Shigefumi ~ H3 m: )((Visitors)
KOSAKA Toshiyuki IJ\:l;& 13t Z (College Agric. Vet. Med., Nihon Univ.)
MAJIMA Hideyuki ~ ~~ =* fr (Fac. Med., Univ. Tokyo)
OKADA Gensaku ~ H3 $i fF (Tokyo-Toritsu-Itabashi-Kango-Senmon-Gakko)

Safety Control Affairs Office

KAGA Y A Satoru 110~Jli '~-g:
KURIHARA Osamu ~ @: 1~
MIYAGAWA Makoto '§ JII ~ ~SHINOHARA Shigemi ~ @: N, a
USUBA Isao ~ ~ ~Beam Analysis Center*

IW AKI Masaya :fi iE ~SAKAIRI Hideo :l;& A ~ 1£1(Visitor)
OOHIRA Shigeo 7::.:lfZ

KATOU Takeo 110 J1j ft\ 1£1
MA TSUZAWAY asuhide tl iR ?7: =*SAKAMOTO Ichiro :l;&~~
T AKI Kenro ~ ~u AA*-

KOBAYASHI Takane IJ\

m: ~ (Nikkei Techno-Research Co.)

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AIHARA Toshimitu E @: flj
AKIY AMA Y oshimi f'Jc!l.! 1t a*

mt.:§: :9§:mJ 12
HAMAJIMA Yasunori m~ ~ $ 42
HAMAGAKI Hideki

5277E )11 fD Z

HANAKAWA Kazuyuki

AMBE Fumitoshiff~ )(~!Z 85,87,131,133,159
AMBE Shizuko y; g~ ~ T 85 ,87,106 ,108,131 , 133

HARA Korehisa

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HARA Masahiro@:

ANDO Kozo y; J1j 1lijJ~ == 62,64,65,157
ANNE R. 155
AONO Keiko W Jf {t T 93

*E 5b 178,201
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HARA Shunsuke @:HARADA Hideo @: E8 :9§ ~~ARAI Iwao*'Tit li~x

ARA T ANI Michi106]it ~ ~ ~~ ~ AA A

ARIMA Akito

100, 121,123,125,127

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ARUGA Takeo fi ji :Jt\ X 32
ASAHI Koichiro 1t§ *j:f:-~~ 10,12 , 160
AS AI Kichizo¥i it E Ji 89,131,133,159~ Jffl ~ T f~4~I4~5,66,68,70,73,79,

AWAYA Yohko

BABA Kei ~:l:~
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BECK Francis A. 154
BENKA Oswald 81,83
BIMBOT R. 155
BYRSKI Thaddee 154
CHIBA Toshiya T ~ flj ~ 212
CHIBA Y oshiaki T ~ fr:r ~COSTA Gilles 154
DELAGRANGE H. 155
EGUCHI Kiyomi 1I 0 ~ ~

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HASHIMOTO Iwao
HASHIZUME Akira

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HA T AN AKA Kichiji tIE r:p E tEl 155 , 178 , 180 ,182
HATSUKAWA Yuichi fJ] )11 ftl- 38,40,44 , 158
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HAY ASHI Akira ~*fffi: 123
HAYASHI Shigeki~*

HEMMI Masatake~ ~ 1&:Jt\a;fij

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HUANG Ziwei Ii
T ~ICHIHARA Takashi
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IEIRI Masaharu

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IlijJUFUJIOKA Manabu

1fu rn fD -T 125
1fu E8 fD R] 17
IKEDA Nobuo 1fu B3 f$ X 10

FUJISAWA Takashi

IKEGAMI Kumio

J1j ~ $ 158
J1j ¥R ~ ~ 168,170,184
FUJITA Fransisco Eiichi J1j B3 3t 87
FUJITA Jiro J1j B3~~ 186,190
FUJITA Shin ~ B3*'T 3,218,221,223
FUKAI Yuh 7~ it~ 102,104=*

FUKUDA Mitsunori ~ E8
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FUKUSHIMA Hiroto~~
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GONO Yasuyuki ~~. ~ ~148

FURUNO Kohei
FUR UY A Keiichi

GOTOH Eiichi

1& ~ 3t -94

154,155
106

GOTOH Eiichiro 1&J1j*- ~~ 148
GO TO Akira 1& fk~ 178, 180, 182, 184
HAAS Bernard 154
HAGA Kaiichi
HAMA Hiroyuki

7§ ji ~ 1~

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100,121,123* * 7X.

HIGASHIGUCHI Yasuhiro
HINO Ken-ichi 8.1f 1ll HOFMANN Helmut 16

IIDA Tsuyoshi
135,136

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IKEDA Kazuko
IKEDA Kazushi

1fuL11~ ~=IKEZAW A Eiji

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INOUE Toshihiko

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ISHIGURO Eiichi E ~ 3t 58

ISHIBE Yukio

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ISHIHARA M asayasu

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ISHII Shigeyuki 15 it ~ iTlE £7,10,12,36,64,
148,152,160
214,216?~ISHII Tetsuro E it f!f ~~ 32
ISMAIL Mohsen Mostafa 68

fN ~ &f!A 10

ITABASHI Takahisa

ITO N obuyuki fft fk f~ Z 125
ITOH Y oh fft fk~ 144,146* T

ITOH Y oshiko

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IWAKI Masaya :!5
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138

MA Qiancheng

KAGEYAMA Tadashi ~ W lE 3,197
KAMBARA Tadashi t$ @:IE 5,66,68,70,73,75,
77,79,144,146,186

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KAMITSUBO Hiromichi
KAN AI Yasuyuki

ii: it 1* z~~6 68,70,73,79,144,

ii: T -.e~ 135,136
KANO Fumihisa 00 lIf X ~ 102,104
KANEKO Ichiro

KATAYAMA Toshiko-7

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KAYANO HideolIf ~96
KIHARA Kiyotaka
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MA TSUO Takashi fl ~79, 146
MA TSUOKA N obuyuki fl f10j 1$ ff 7
MERDINGER Jean-Claude 154

tlJf 1* ~ fr 34
MINOWA Tatsuya ~ ~ Ji ~ 157*-

MIURA Taichi ~ 1m
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MIY A TAKE Hiroari '§:Itt '-¥ tt1

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MORIMOTO Katsunao ~MJ @: 191
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MIYAZAWA Yoshitoshi '§ ¥R f* m!z 5,212
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KA TORI Kenji 00 1& ~10
KA TSURAGAWA Hidetsugu tt} II ~!lUII]

118,119mIE ~ 38,42,44

MAGARA Masaakim

18,20,22,151,156
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110 ~i'i S

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MAEDA Kuniko

MINEHARA Eisuke~*m.e~*k·

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KASAGI Jirota

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7,36,152

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NAGAMINE Kanetada

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KOBAYASHI Takane IJ\
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KOHARA Shigeo IJ\ 1* £3,168,170
KOHMOTO Susumu iUJ
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KOHNO Isao iUJ Ifr)] 3,40,42,44,75,77,98,

NAKAJIMA Shunji $ ~ ~~191
NAKAMURA Akihiko $ fi ~ ~ 10
NAKAMURA Masanobu $ filE f~ 29****

KOBA YASHI Shinsaku**

123,127,152,221,223
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KOSAKO Toshiso IJ"f6::ti1lf.!ztt 218
KOYAMA Akio IJ\ W SB 1k1 81,83
KOIKE Shigetoshi*

KUBO M. Kenya ~ 1* ~ ~ 106,110
KUBO Toshiyuki ~ 1* 1lf.!z ~ 5,14,18,20,148,151
KUBOI Osamu ~1*# lj)( 123
KUBOTA Shinzou

mB3 f~ -= 152

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NAKATA Masami $ B3 IE ~ 44
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NOURREDINE B. 154
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129,162203m 3,168,170,184

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112,116,162:* ~ m 14
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OHNUMA Hajime

*OHTSUKI Tsutomu 1\. tm"ib 40,44
OIKAWAY oshifumi ~ JII jb fl~ 168,191

TAKAGI Shoji ~W~
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OKADA Shigefumi ffDj B3 m;;z:. 135
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TAKAHASHI Tan

OKADA AkihikoffDj~m.tGc!:i

OKAZAKI Kiyohiko

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