ISSN 0289-842X

RIKEN
Accelerator
Progress Report
vol.

20

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

RIKEN Accelerator Progress Report 11 (0)(6) /b.

January-December U'11 (Q)\Q)

Jm.1t ~m ~ pff"'e Insfilute of Physical and (hemiral Research
Walco-shi, Saitama, 351·01 JAPANEditors
S. AmbeY. AwayaY. Chiba

T. Inamura

M. Ishihara

H. Kamitsubo

S. Kitayama

I. Shimamura

E. Vagi

Y. YanoThis 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 micrqfilm form) without written permission from the publisher.

CONTENTS
Page

I.

INTRODUCTIONII.

OPERATION OF ACCELERATORS

III.
1.

1.

Cyclotron Operation ....... ... ............................................... 22.

Operation of TANDETRON ............................... ... ............... 4

3.

RILAC Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5

RESEARCH ACTIVITIES
Nuclear Physics
1.

r-Ray Angular Distributions in the 98,100Mo (160, 4nr) 1l0,112S nReactions ....... . ................................ .... ....................... 62.

Continuum r-Ray Spectra in the 98,100Mo( 16 0,4n)llO,112Sn
Reactions ................................................................... 83.

Dipole Moment of 222Ra as a System of Ph + 14C MolecularConfiguration .. ....... . ................. . .................................... 10

4.

Level Structure of 217Ra ..................................................... 12

5.

Spectroscopy of 220Ac .... .. .................................... . ............. 14

6.

In-Beam r-Ray Study of 222Th with BGOACS and 41r
Crystal Ball .. . ..... . ...................................................... .. 17

7.

Spin Alignment in Projectile Fragmentation at Intermediate
Energies .................................................................... 19

8.

A Simple Model for Spin Alignment in Projectile
Fragmentation ............................................................... 21

9.

~ Decay of Polarized Nucleus 15C andMagnetic Momentof the 1/2+ Ground State ..................................................... 23

10.

Measurement of Interaction Cross Sections Using He, Li, Be, B, andC Isotope Beams and Radii of Light p-Shell Nuclei ............................ 25

11.

Fragmentation Cross Sections of llLi at 0.8 GeV /Nucleon ....................... 26

12.

NMR on ,a-Emitting 39Ca Produced through Projectile
Fragmentation in High-Energy Heavy-Ion Reactions ...... . ..................... 27

13.

Two-Step Analysis for the 12C (d, 2He) 12B Reaction ............................. 29

14.

Mass-Number Dependence of the Hexadecapole (Y42 ) Transition
Strength to the r-Vihrational Band in Inelastic Proton Scattering
at 65 MeV .. , .......................... . .................... ... ..... . ....... 30

15.

Transport Coefficients for Fission at High Excitations ................ . .......... 33

Page
2.

Atomic and Solid-State Physics
1.

Cross Sections of the Relativistic Radiative Electron Capture by
Use of the Strong-Potential Born Calculation ......... ... ...................... 35

2.

Charge Exchange Collisions on the Solid Surface ........... ~ .................. 37

3.

Calculation of Ionization Cross Sections of Multi-Charged Ionsin Proton Impact by TFD Method Using BEA ................................ 39

4.

Extended Bethe Surface: Behavior of the Generalized Oscillator
Strength along Isoelectronic Sequence . ........ . ............................... 41

5.

R-Matrix Method for Rearrangement Collisions:Dissociative Recombination e + (AB) +~ A + B .................................. 44

6.

Classical-Trajectory Monte Carlo Calculations for
Coulomb-Interacting Three-Body Systems ...................................... .45

7.

Total and Differential Cross Sections for (p.+/[) Formation by
Collisions of p.+ with (p.-p) in the Eikonal Approximation ..................... .46

8.

Bound States of the dtp. System Formed in the Muon-Catalyzed
Fusion Cycle .... ... ......................................................... 48

9.

Energy Levels of Muonic Molecular Ions ...................................... 49

10.

Measurement of Lifetimes of Highly Ionized Aluminium Atoms .................. 51

11.

Identification of Al X 2p3d-2p4f Transition in Beam-Foil
Spectrum ................................................................... 52

12.

Dependence of the Effective K-Vacancy Production Cross Section
on the Target Thickness and Projectile Charge State for Argon
Ions Colliding with Carbon Foils ............................................. 53

13.

Measurement of Impact Parameter Dependent Probabilities for
K-Shell Ionization in Ar-Ca Collisions ......................................... 55

14.

Charge-State Distribution of Cr-Ions after Passage througha Carbon Foil ............................................................... 56

15.

Multiply-Charged Ions from SF 6 Produced by 1.05 MeV /amu
Ar12+-Ion Impact ............................................................ 57

16.

Production of Multiple-Charged Ions from CO and CO 2
Molecules in Energetic Heavy-Ion Impact ....................... ... ........ . .. 59

17.

Energy Spectra of Secondary Electrons Emitted from Al by
Heavy-Ion Impact ................. . . ;... . .................................... 61

18.

Z2-Dependence of Energy of Loss-Electrons Backscatteredfrom Metal Targets ................................... . ..................... 62

19.

Towards Production of Low Energy Pions and Muons Using
Heavy-Ion Reactions ....... .... . . ............................................ 63

20.

Coulomb-Excitation 73Ge Mossbauer Study Using a New-Type
Piezoelectric Transducer .......................... ... ......................... 65

21.

TDPAC Study on (111In ~ )111Cd Ions in Silver Phosphate ..... . ............. . .. 66

Page

3.

22.

An Investigation on the After-Effects of 111 In ( ~ 111Cd) EC
Decay in a-Fe20g ........................................................... 67

23.

Supertransferred Hyperfine Magnetic Fields at 111Cd( ~ 111In)
in Ferrimagnetic Oxides with Spinel Structure ................................. 69

24.

Simulation Experiment on Carbon Coating of the First Wall ofa Fusion Machine ........................................................... 71

25.

Measurement of Hydrogen Isotope in Carbon Films Produced by
ECR Plasmas ............................................................... 73

26.

Hydrogen Trapping by Substitutional Impurity in NbMoo.og Alloys ........ ....... 75'217.

Study of Krypton Bubbles in Kr-Implanted Al by Means ofElectron Diffraction .......................................................... 77

28.

Eu-Ion Implantation in CaF 2 (II) ............................................ 79

29.

Defect-Impurity Interaction in Ni-Implanted Aluminum ......................... 80

30.

Isochronal Annealing of Proton- or a-Irradiated CUgAu at
Low Temperatures . .......... . ............................................... 83

Radiochemistry and Nuclear Chemistry1.

Production of Radioisotopes and Preparation of Labeled
Compounds ........... .. ............................ .. ...................... 86

2.

Charged Particle Activation Analysis ........................................... 88

3.

Analysis of Carbon in Aluminium and Magnesium by
Deuteron Activation ....................... . ................................. 89

4.

Studies on Carbon in Gallium Arsenide ....................................... 91

5.

Diffusion of Nitrogen into Silicon ............ ................................. 92

6.

Utilization of the D(3He, p) 4He Reaction for High-Sensitivity
Quantitative Analysis of Deuterium in Solids .................................... 93

7.

Application of PIXE to Medical and Environmental Science ..................... 94

8.

Application of PIXE and Diffraction Analysis to Ancient
Remains ............................... . ...... . ....... .. ....... .. ........... 96

9.

Behavior of Light Elements in Hydrothermal Treatment ofGlass Surface as Studied by Heavy-Ion Rutherford Forward
Recoil Measurement ... . ............ .. .. .. .. .. ................................ 98

10.

Substitution of Positive Ions in Glass Surface Layer Studied
by Heavy-Ion Rutherford Scattering Analysis ................................... 100

11.

Elastic Recoil Analysis of Implanted H 2+ Ions in
Magnetic Bubble Garnets .......................... . ........................ 101

12.

Behavior of Releasing Agents Coated on Heated Substrates
as Studied by Heavy-Ion Rutherford Scattering ............................... 103

13.

Evaluation of W /GaAs Interface Diffusion by the Rutherford
Back Scattering (RBS) ...........•.......................................... 105

Page

4.

5.

14.

In Situ Emission Mossbauer Study on 119Sb5+( ~ 119Sn ) and
55C02+ ( ~ 57Fe) Ions at a-Fe 203-Aqueous Solution Interface .................... 107

15.

Emission Mossbauer Studies of No-Carrier-Added Sb-119
Electrodeposited on Gold .... ....... ....... .. .... .............. ........... ... 109

16.

Mossbauer Spectroscopic Studies of Ruthenium Compounds ..................... 111

Radiation Chemistry and Radiation Biology
1.

High-Density Excitation by Heavy Ion: Techniques of Subnanosec
Measurement of Emission Decay and a Track-Scope Using OpticalFibers ..................................................................... 113

2.

Modification of a-Particle-Induced Cell Killing and Non-Repairable
DNA Lesion by Hypertonic Treatment ........................................ 115

3.

Oxygen Effect on DNA Double Strand Breaks in Human
Melanoma Cells Induced by a-Particle Beam .......................... .... ... 117

4.

Calculation of Dose around the Path of an Ion and Microdosimetric
Considerations of the Effects of Heavy Ions on Microorganisms .................. 119

Instrumentation
1.

Calibration Test of Si-Detector Telescopes with Large Geometric
Factors for Isotope Identification in the Heavy Cosmic Ray Particles .............. 122

2.

2He Spectrometer ........................................................... 125

3.

Parallel Plate Avalanche Counter-Application in the Coulomb
Excitation Study- ..... .. .................................................... 126

4.

Construction of a Two-Dimensional Multiwire Drift Chamber ................... 129

5.

Test of Electron-Ion Merging Beam Experiment ............................... 131

6.

A Broad-Range Magnetic Charge Analyzer .................................... 132

7.

Design Study of Experimental Facilities for Light and Light-Heavy
Ion-Induced Reactions ...................................................... 134

8.

Projectile Fragments Separator for RIKEN Ring Cyclotron ..................... 136

9.

Beam Plasma Effects in Operating with an Ion-Guide Isotope
Separator On-Line .......................................................... 138

10.

INS Gas-Filled Recoil Separator ............................................. 140

11.

The Experimental Beamline for the First Beam fromRIKEN Ring Cyclotron ..................................................... 142'

12.

Sensitivity Test of Resonance Ionization Spectroscopy ........................... 144

13.

A Rotating Catcher System for Projectile Fragments ............................ 146

14.

Radiation-Detected NMR Measuring System for Short-Lived
Radioactive Isotopes ........................................................ 147

15.

Programed Sequence Generator ....................... .... ............ .... .... 149

Page
16.

IV.

V.

VI.

Test-Bench System for On-Line Data Acquisitions System of
RIKEN Ring Cyclotron Facility ..... . ....... . ................................ 151

NUCLEAR DATA
1.

Status Report of the Nuclear Data Group .......... . .............. . ........... 152

2.

Nuclear Reaction Data for 52Fe Production . ......... . .............. . .......... 154

3.

On Nuclear Data for Production of 77Br ...... . ... . .............. . . . .......... 156

4. ·On 1241 Production Cross Section .................. . .......... . ............... 158

ACCELERATOR DEVELOPMENT
1.

Status of RIKEN Ring Cyclotron Project in 1986
- Commissioning of RIKEN Ring Cyclotron - ............. . ......... . ....... 160

2.

First Trial of Beam Acceleration in RRC .... . .. .... .. . .... . ................ . 162

3.

Present Status of RF Resonator for RIKEN Ring Cyclotron .................... 164

4.

Performance of Power Amplifier of RIKEN Ring Cyclotron ..................... 167

5.

Control System of RIKEN Ring Cyclotron ........... . .. . ....... . ....... . ..... 170

6.

Sector Magnet ... . ................... .. . .. ... .. . .. .... . ... . ................ 172

7.

Beam Transport System for RIKEN Ring Cyclotron .... . ............. . ..... . .. 174

8.

Beam Buncher for RIKEN Ring Cyclotron ... .. ...... .. ... . ...... . .... . ...... 176

9.

Beam Diagnostic Equipment in the Beam Transport Line between
RILAC and RIKEN Ring Cyclotron . .......... ... ........................... 178

10.

Replacement of Computer for the Control System of RILAC .... . ... . ........... 181

11.

Present Status of the Vacuum System for RIKEN
Ring Cyclotron . ... .. . .... . ................ . ...... . ........ . .... . ..... . ..... 183

12.

Application of the RF Assisted DC Glow Discharge Cleaning
to the Valley Chamber for RIKEN Ring Cyclotron .. . .. .... ... . ........ .. .... 185

13.

Injection System for an Injector Cyclotron . . .... . ... .. .. .. .............. . . . . . . 188

14.

Focusing Magnetic Channel on the Baby Cyclotron ...... .. .. .. . . ...... . . . . . . . . 191

15.

Sputter PIG Source for RILAC . ... . .. ... . ..... ...... ... ........... . .. . ...... 195

16.

Performance of ECR2 .............. .. . .. ..... . .. . ....... .. ..... . ...... . ..... 198

17.

Three Dimensional Analysis of RF Electromagnetic Field by
the Finite Element Method ..... . . .. ... . ... . ..... . .... . .. . .... .. ... . ... .. .... 199

RADIATION MONIT ORING
1.

Calculation of Neutron Skyshine over the Area around
RIKEN Ring Cyclotron Facility .......... . .. .... . . .... . .. .. ..... ... . . .. . ..... 203

2.

Radiation Safety Control System for RIKEN Ring Cyclotron ... . .. ... . ... . . . . .. 206

Page
3.

Routine Monitoring of RIKEN Accelerators ................................... 208

4.

Leakage-Radiation Measurement in the Cyclotron Building ...................... 210

5.

Calculation for the Design of an Iron Beam Dump for
Shielding of Neutrons ....................................................... 212

VII.

LIST OF PUBLICATIONS ....................................................... 214

VIII.

LIST OF OUTSIDE USERS AND THEIR THEMES .............................. 227

IX.

LIST OF SEMINARS ............................................................ 228

X.

LIST OF PERSONNEL ........................................................... 229
AUTHOR INDEXI.

INTRODUCTION
H. Kamitsubo

The most remarkable achievement in this period isthe commIssIOning of RIKEN Ring Cyclotron(RRC), the construction of which started in 1980.
The main part of RRC was fabricated by Sumitomo Heavy Industries, Ltd.; the control system wasmade by Mitsubishi Electric Corporation. The assembly of RRC was completed in October and theacceleration test of Ar ions started at the end of
November. We succeeded in the extraction of thebeam on December 16, 1986.
Research work with the 160 em cyclotron and thevariable-frequency heavy-ion linac (RILAC) was
extensively performed in the first half of this year.
However, because of unexpected contaminations
found in the hot laboratory and experimental areain the cyclotron building in August, both accelerators
were stopped compulsorily for three months. RILAC
was put back into operation in the middle of November.
Studies on nuclear physics have been continued
mainly using 160 em cyclotron and facilities of otherinstitutions such as Institute for Nuclear Study (University of Tokyo), Research Center for Nuclear
Physics (Osaka University), Lowrence Berkeley
Laboratory, Nuclear Spectroscopy Laboratory (Strasbourg), and GANIL (Caen). The design studies on
experimental equipment for RRC have extensively
been performed by the nuclear physics group throughout this year.
Calculations of cross sections of heavy-ion reactions
and fission process were performed on the basis of
the transport theory. Theoretical research on atomic
collision processes has been performed in connection. with various problems such as radiative electron
capture at high energy, ionization process in collisionof proton with highly stripped ions, and charge exchange collision on solid surface. The structure ofmuonic molecular ions was also studied theoretically.
Experimental work was carried out on the atomic
collision processes and on the beam foil spectroscopy
by measuring the spectra of lights, X-rays and Auger
electrons, charge state distribution of ions after collision, and angular distributions of X-rays and electrons as well as scattered ions. Various kinds of ionsaccelerated by RILAC were used for these studies.
Sub nanosecond measurement of the light emitted
along the heavy-ion trajectory in the gaseous materials was extensively studied.
Mossbauer spectroscopy and perturbed angularcorrelation studies were performed using r-rays
emerging from Coulomb excitated nuclei. Mossbauer
studies with short lived radioisotopes produced by
the cyclotron have been continued.
Analysis of the distributions of implanted or dissolved impurities in various materials has been continued using the Rutherford back-scattering method,
Rutherford forward recoil measurement, elastic recoil
detection method, and nuclear reaction method.
Activation analysis of light element impurities in thesemiconductor materials and high purity materials
were continued. PIXE analysis was applied to
medical, environmental, and geological samples.
Development of new instrumentation and experimental technique has been extensively carried on inthis period. Accelerator development was pursued
as in preceding years.

2

RIKEN Accel. Prog. Rep. 20 (1986)

II.

OPERATION OF ACCELERATORS
1.

Cyclotron Operations. Fujita, K. Ikegami, T. Kageyama, S. Kohara,
K. Ogiwara, H. Takebe, and 1. Kohno

The 160 cm cyclotron was operated on the 24 h a
day basis during the period from Nov. 8, 1985, toNov. 7, 1986. Statistics of the machine operation
time is shown in Table 1. The total net beam-timein this period decreases drastically on account oflong scheduled shutdown of 134 d.
Table 2 shows the beam-time allotment to various
activities during this period. Table 3 shows the
distribution of the scheduled beam-time among
various particles.

Table 1.

Cyclotron operation in the period XXI.

Reading of the time
meter onNov. 08 1985 (h)Reading of the time
meter onNov. 07 1986 (h)Difference (h)Percentage of 365 d

Oscillator

Ion source

Beam90,854.9

95 ,638.6

57 ,457.6

93,985.8 99,050.2 59,334.9
3,411.6
1,877.3
3,130.9
35.7%
38.9%
21.4 %

Schedule in this period:
Beam-time
Overhaul and installation
Periodical inspection and repair
Scheduled shutdown
Machine troubles

Table 2.

Nucl. Phys.

Outside users

5

Scheduled beam-time and research subjects in the period XXI.

Subject

Fields other thanNucl. Phys.

153 d
25
48
134

Nuclear chemistry
Radiation biology
Radiation chemistry
Radiation damage of metal
T est of radiation detector
Radiation damage of polymer
Atomic collision
Radiation damage
RI production
Test of track detector
Radiochemical analysis
Test of single event upset
Proton irradiation on Si

Total
Percentage in total
Maintenance, operation, and engineering:
Exchange of ion source
64 hMachine inspection and repair
250 h
Total
314h

Heavy ionLight ion

1,162

242

o

518
112
23
60
108
54
0

59
372

o
o

o
46

o
o

Total

1,404
- - - - --

518
171

395
60

108
54
46

o

35
50
34
152
0
53

35
50
34
152
251
53

1,890
56.7 %

1, 441
43.3%

3,331
100%

o

o
251

s. Fujita, et al.
Table 3. Distribution of beam-time among particles
accelerated.
Particle

(h)

(%)

p

345
108
271
759
354
740
50
240

10.4
3.2

d
3HeZ+
fHe 2 +
12CH
HNH
aN5+
1605+
1805+

168

Ne6 +
Total

296
3,331

8.1

22.8
10.6
22.2
1.5
7.2
5.0
8.9

3

4

RIKE N Acce\. Prog. R ep. 20 (1986)

11-2.

Operation of TANDETRON

H. Sakairi, T. Kobayashi, E. Vagi, and T. UraiThe TANDETRON was operated for 140 d ofthe past year from November, 1985, during which
IH , 3He, 4He, 11B, and 12C were accelerated.
A negative-ion source of a duoplasmatron typehas been newly equipped to generate negative hydrogen ion beams with sufficient intensity and stability.
A charge exchanger connected to a duoplasmatron, mainly used for negative helium ion generation, had trouble frequently; therefore, a new exchanger was designed and constructed by us. It
increased both beam intensity and the life of charged
lithium twice compared with the former exchanger;
the maintenance also became easier.
An automatic controller using a personal computer
was used to trial in time-consuming channelingexperiments.
Experimental studies have been carried out by

Rutherford backscattering spectroscopy, channelingand nuclear reaction analysis, or by combination ofthese, on the following subjects:(a ) Lattice location of hydrogen atoms in metals(Metal Phys. Lab. and Beam Analysis Center),(b) Depth profile of implanted ions in highpolymers (Biopolymer Phys. L ab. and Beam Analysis
Center) ,(c ) Depth profile and lattice location of Eu in
CaF 2 (Semiconductors Lab. and Beam Analysis
Center) ,(d) Solubility of D in Si (Nuclear Chern. Lab.) ;and(e ) In situ observation of heavy ion-induced
damage in Metals (Metal Phys. Lab. and Beam
Analysis Center).

5

RIKEN Accel. Prog. Rep. 20 (1986)

11-3.

RILAC Operation

Y. Miyazawa, M. Hemmi, T. Inoue, T. Kambara, M. Yanokura, M. Kase,
T. Kubo, E. Ikezawa, T. Aihara,* T. Ohki,* Y. Chiba, and 1. Tanihata

RILAC (RIKEN heavy-ion linear accelerator)
continues to supply various kinds of ion beams formany fields of research. Tables 1 and 2 give statistics of operation for the period of Sep. 1, 1985July 12, 1986.
Five new sputter PIG sources1 ) have been operated
since the fall of 1985. With these sources, ions ofsolid elements, Mgs+, AlB+, SP+, Ti 5 +, Cr 5 +, Ni 6 +, andCu 6 + were delivered to various target stations.
Pulsing of a beam was tried by modulating relative RF phase between accelerating tank 1 and 2.
Figure shows a pulsed beam obtained by phasemodulation of 10 ms. The pulsed beam with a time
range longer than 1 ms was successfully obtainedin this way.
From July 14 to Sep. 16, 1986, the operation of
RILAC was discontinued to construct a beam injection line to the new Ring Cyclotron.
Table 1. Statistics of operation for the period of Sep. 1,
1985-July 12, 1986.
d----Beam time
Frequency change
Overhaul and improvement
Periodic inspection and repair
Machine trouble
Scheduled shutdown

Table 2.

%

-

173
19
22
0
90

54.9
6.0
3.5
7.0
0
28.6

315

100

11

Percentage of beam time for research activities.

%
Atomic physics
Solid-state physics
Nuclear physics
Radiochemistry and nuclear chemistry
Radiation chemistry and radiation biology
Accelerator research* Sumijyu Accelerator Service, Ltd.

35.3
20.2
9.8
18.5
5.8
lO.4

~ 10 ms - 1

l 'Be am signal

julation signal---.ll::.4! =20 0

Fig. 1. A pulsed beam obtained b y phase modulation oflOms.

The No. 2 resonator had a small vacuum leakon a cooling pipe of a shorting plate. The damaged
part was replaced with a new one. To improveseasonal temperature variation in the cubicles of
the RF power supply, an air conditioner was provided for them.
We had a trouble with RF phase fluctuation of
about 20 to 30 ms period in each resonator; it wassuspected to be due to mechanical vibration of someparts. We have confirmed that main vibrating parts
were side pannels of the upper RF linear and theirvibration source was a circulation pump in theFreon cooling system installed near the first tank.
Remedies for them are being investigated.
The operation of RILAC was also discontinued
for the period of Sep. 17-Nov. 11, 1986, when ageneral inspection of the attached hot laboratory
was conducted.
Reference
1) Y. Miyazawa, M . Hemmi, T. Chiba, and M. Kase: p. 195
in this report.

6

RIKEN Accel. Prog. Rep. 20 (1986)

III.

RESEARCH ACTIVITIES

1. Nuclear Physics
1.

r-Ray Angular Distributions in the 98,looMoC 60, 4n r)1l0,1l2Sn Reactions
H. Harada, J. Kasagi, T. Murakami, K. Yoshida,
T. Inamura, and T . Kubo
NUCLEAR REACTIONS 98,100Mo( 160, 4nr) 1l0,llZSn, E = 76, 72 MeV ;( measured r-ray angular distributions, deduced Jr..

In a previous progress report,l) the existence of
deformed bands in high-spin region of llOSn and
llZSn has been reported. The spins of the nevv members (J ~ 12 n) of the deformed bands have beententatively assigned. In the present work, we havemeasured r-ray angular distributions for the unambiguous spin assignments of the members of the deformed bands. High spin states in llOSn and 112Sn
were excited by the 98,looMo(160, 4n) llO,112S n reactions at E (IGO) = 76 and 72 MeV, respectively. The
angular distributions of r-rays were measured by two
sets of BGO anti-Compton spectrometerZ) in coincidence with neutrons detected by a neutron multiplicity filter. 3)

Relevant parts of the decay scheme of 1l0Sn and
1 and 2, respectively. Levels
above r--I 5 MeV were established in the course ofthis work. Levels assigned to the members of thedeformed bands are drawn by thick-heavy lines inthe decay scheme. Examples of the measured angular
distributions of r-rays from the band members in
112Sn are shown in Fig. 3. The solid curves in the
figure are the best fit results of the function W ( f} ) =N· (1 + A z'Pz( cos 0 ) + A 4 ·P 4 (cos 0) ) . They show
the characteristics of the stretched E2-type transition. The 663 and 741 keV transitions have beenllZS n are shown in Figs.

(22+)
10076 121-)

9492 (20lI8488 186034 128g6399 13 -;~~~T 1294I ~ --+---4777--"'--r-/~~=.9;-T=~~~1~68~~~~~r--L
r 3686
1011

D

P

V276

55641,;:+[3281 Q

S2 0

883

~

745

0

I

10'9

8·

5684

865 1003
741

1235

8

4819
4680
4078

663
~==;==::lt:===r=="""""TT--rr--..."...~-..~3414_---'>L-.:j==-, - - _ - - " - _ 4'1'
2549-'>L..-~_:r_-=~...;..

1257 .....-+_
2

~630

•

468

4
9
52_
"",9::.. . 1_ _r----r-_lf.lL..-_ _lnlL27_ _1.-l1>L89_

__

D

1257

V

Q

1125n

1105n

Level scheme of 110Sn.

1,· ~49~+ N,,----~L-=::::::==:r"T8=-:b::2247 -"'-

_

6362

I

678

798

1209

1211 ....
2·_ _ _ _ _[3r98..c.5-,-_ _ __Fig. 1.

8

1~·

U

846

3764. _
8

7213

851

1471

809

8145

~

16·

V

I

9184

932

808

741

1130

18+

t

7207 (15- )

t
t

1039

876

809
6775 14(20·)

9628083 or)*7584 16

1148

t
t

If4

10332

I

I
1031

9045 0 9 -)904

1Fig. 2.

Level scheme of 112Sn.

H. Harada, et al.

6 ~ro-rN = 21. +- .76
A2 = .37 +- . II
A4 = .04+- .16

1. S'93'2i(.V1- I-,-,----,

7100

N = 12. +- 1. 2
A2 = .32 +- .32
A4= -.03+ - .39, , -,",", .,, •"'J""'j ;f

1.3~trl .•.

1.1

0.9
0.7

?
.
'''-'"?
0.'/ .
/.v

36. +- .83
A2 = .42 +- .07
A4=-.19+- .09: : _"'-' "?

7 I

.v

N = 36. +- .76
A2 = .26 +- .07
A4=-.IB+- .09

O.S

C05 2 (e J74.v
N = 21. +- . 55
A2 = . 41 +- . 09
A4=-.1 5 +- .1 2

0.0

I'

>Q)
L

50

8'

25

1
1100=0.37

Nknown as a+ ~ 6+ and 10+~ a+ transitions in Ref. 4.
Therefore, the band built on the 5,564 keY state is
proposed to have positive parity. The lifetime limit
obtained for the 5,564, 6,362, 7,213, and 8, 145 keYstates from Doppler shift and the recoil distancemeasurement 5 } also supports the positive parity assignment. For the other band in 112Sn, displayed on
the left side of Fig. 2, the angular distributions of
the 1,471 , 876 and 962 keY r-rays also show thecharacteristics of the stretched E2-type transition,
while that of the 808 keY r-ray could not be measured because of the existence of an unresolved
805 keY (7- ~ 6+) r-ray. The lifetime limit for the
1,471 keY transition obtained from the recoil distancemeasurement also supports a negative parity assignment to the band. For the band in llOSn, the angular
distributions of the 809, 741, and 904 keY r-rays arealso consistent with the stretched E2-type transitions.
The positive parity assignment is suggested from thesimilarity of the level sequence as in 112Sn.
The intra-band transitions of the deformed bands
shown in Figs. 1 and 2 are the most intensive onesin high excitation energy Ex ;? 5 MeV. T herefore, it

18

•

..
20'

16'1

12'

nCl)=0.44

~

~
(\J

llOSn

'" 112Sn•

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

0.00 0. 05 0.10 0. 15 0.20 0.25 0.30 0.35("n(O ) 2

0.5

Fig. 3. Experimental angular distributions of r·rays measured
in the looMo (160, 4n) 112Sn reaction at E (160) =72 MeV.
The solid curves are fits of the experimental da ta to the
angular-distribution function W(O) .

lV75(Me V2 )Fig. 4. Moment of inertia vs. squared frequency.

is concluded that the deformed bands form the yrast
lines at high spin region] ;? 14 Ii, in both nuclei.
The moment of inertia vs. squared frequency plot
for the positive parity bands in llOSn and 112S n isshown in Fig. 4. Upbend in 112S n occurring at/i{JJ -' 0.37 MeV corresponds to the band crossing
from the previously known band 4 ) to the newly established band. It should be noticed tha t the valuesof the moment of inertia are almost constant In
higher frequency region for both nuclei.
References
1) H. Harada, T . Murakami, H. Tachibanaki, K. Yoshida,
J. Kasagi, T. Kubo, and T . Inamura: RIKEN Accel.
Prog. Rep., 19, 18 (1985) .
2) 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. Prog.
Rep., 18, 152 (1984) .
3) T. Murakami, J. Kasagi, H. Harada, and T. Inamura:
Nucl. Instrum. M ethods A, 241, 172 (1985) .
4) J. Bron, W. H. A. Hesselink, A. van Poelgeest, J. J. A.
Zalmstra, M. J. Ditzinger, H. Verheul, K. Heyde, M.
Waroquier, H . Vincx, a nd P . van Isacker: Nucl. Phys .
A, 318, 335 (1979) .
5) J. Kasagi, H. Harada, T. Murakami, K. Yoshida, H.
Tachibanaki, and T. Inamura: Phys. Lett. B , 176, 307(1986) .

8
RIKEN Accel. Prog. R ep. 20 (1986)

111-1-2.

Continuum r-Ray Spectra in the 98,lOoMoC6 0,4n)1l0,1l2Sn
Reactions
K. Yoshida, J. Kasagi, T. Murakami, H. Harada,
T. Kubo, and T. Inamura

NUCLEAR REACTIONS 98,100(160,4n)1l0,1l2Sn, E=76, 72 MeV ;[ measured continuum r-ray spectra and anisotropy.

In order to study the nature of r-ray decays above
the yrast line, we have measured continuum r-rays
emitted from highly excited states in the 98,looMo+
160 fusion reactions. Special care has been made in
the present work in a treatment of the Compton
process in r-ray detectors and in the selection of areaction channel.
r-rays emitted from highly excited states populated by heavy-ion fusion reactions cannot be resolved individually and form continuum spectra because of the high density of states. The Compton
process in a r-ray detector always smears out theactual distribution of continuum r-rays. Because of
their high peak-to-total ratio, NaI detectors havebeen commonly used in previous experiments on
continuum r-rays. However, a Compton-suppressed
Ge detector has a particular advantage since it has
high resolution as well as a high peak-to-total ratio.
The high resolution ensures the quality in subtractionof the known yrast transitions, so that one can obtainreliable continuum spectra down to the low energy
region where strong discrete lines exist.
It is important to select a proper reaction channel
because continuum r-rays emitted from various residual nuclei cannot be distinguished in spectrum.
We have selected the residual nuclei llO,1l2Sn forthe present purpose. From our previous studies,1,2)
a rotation-like collective band appears above Ex >3 MeV together with the neutron quasi-particle
states, and two other collective bands have been
identified above Ex > 6 MeV in 112Sn. In contrast,
only one collective band is observed above Ex >6 MeV in llOSn.
Experiments were performed with 76 MeV (for\.ISMo+ 1GO) and 72 MeV (for 1ooMo+ 16 0) 160
beams from the RIKEN 160 cm cyclotron. Two
BGOACS Ge detectors 3 ) were employed for r-ray
detection: one was placed at about 100 0 with respect to the beam axis and the other at about 140 0 •A neutron multiplicity filter 4 ) was employed to selectthe reaction channel. Foils of enriched molybdenum
1.0 (98Mo, 96.9ro) and 2.0 (1ooMo, 94.5ro) mgjcm 2

1

in thickness, backed with lead, were used as targets.
Observed spectra were corrected for the detector
response to obtain actual r-ray intensity spectra. The
detector response functions were calculated by aMonte Carlo simulation program 3 ) modified to include the pair creation process and scattering froma lead collimator. The spectra were calculated at
19 incident r-ray energies between 50 keY and4,500 ke V and were compared with the spectra fromr-ray sources such as 137CS, 133Ba, 22Na, GOCo, 152Eu,
and 56CO. The experimental spectra were well reproduced by the calculation although small correction was needed in the low energy region. On thebasis of these results a set of detector response functions at intervals of 4 keY r-ray energy was obtainedby interpolation.
The Compton background was removed from theobserved spectra by an iterative method using thefollowing relation
T( m+1) = T(m) + M
RT(m )( 1)
where T(m) is the m-th estimate of the true spectrum,
A1 is the observed spectrum, and R is the response
function. After twenty iteration processes, the Compton background was almost completely removed and

15000
6O

10000 r-

<lJ

c

CO

("') Observed

-

5000

C

iO

..c
u

"

C/)

0

I

I

§ 10000 r-(b)

Correct ed

0

u

-

5000 r-0oFig. 1.

I

I

500

1000

1500

ErlkeVl

Observed (a) and corrected (b) spectra for 60Co.

K. Yoshida, et al.

1000

improved to 0.9, compared with the ratio of 0.4
before correction (Fig. 1).
In Fig. 2 are shown the unfolded spectra obtainedfor 110Sn and 112Sn before subtraction of discretelines. The bumps around Er ~ 1 MeV are clearlyseen in both llOSn and 112Sn under the intensive discrete lines for the good resolution of Ge detectors.
Further analysis is in progress to study the propertiesof these bumps .

800
600
400
200
-u
.......

9

0

Q)

>-

800

References
1) A. van Poelgeest, J. Bron, W. H. A. Hesselink, K. AHart,
J. J. A. Zahnstra, M. J. Vitzinger, and H. Verheul: Nucl.
Phys. A, 346, 70 (1980) .
2) H. Harada, J. Kasagi, T. Murakami, K. Yoshida, T. Inamura, and T. Kubo: RIKEN Accel. Prog. Rep., 19, 19

600
400
200

(1985) .

0.0

Fig. 2.

1.0

2.0

Er(MeV)

3.0

Corrected spectra for 110Sn (a) and 112Sn (b) at 100 0 •the peak-to-total ratio for the 60CO spectrum was3) 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. Prog. Rep.,
18, 152 (1984) .

4) T. Murakami, J. Kasagi, H. Harada, and T. Inamura:
Nucl. Instrum. Methods A, 241, 172 (1985) .

10
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-3. Dipole Moment of 222Ra as a System of Pb + 14C
Molecular Configuration
N. Yoshinaga and S. Yamaji

NUCLEAR STRUCTURE two-center shell mOdel,)[ dipole moment, 222Ra.

Nuclei in the actinide region have characteristicfeatures essentially different from those in the otherregions: one is strong E1 enhancement and the otheris HC decay. There are three models to explainthese characteristics. The first one is the octupole
deformation model,1) which predicts that permanent
octupole deformation is energetically favorable inthis region. The second is the Vibron model proposed by Iachello. 2 ) His idea consists in that aclustering effects are important for the actinide
nuclei so that sand p bosons which simulate aclustering effects must be added to the ordinary s
and d bosons. These sand d bosons are the basic
elements in the interacting boson modeP) The thirdmodel is the octupole vibration model, which is rather
traditional.
Up to now, there are no definite experimental
data which selectively exclude one of these models.
This is partly due to the fact that the octupole deformation model is microscopical and suitable toexplain the intrinsic ground state, while the Vibron
model is a macroscopic model and suitable to explain
the excited states. Our original motivation is tocompare these models and find out which is moresuitable to describe the nuclei in this region. We
analyzed 222Ra using the two-center shell model,
which sometimes simulates octupole deformation andsometimes molecular configuration such as Pb + HC.
In Fig. 1 the defined nuclear shape of 222Ra isshown. By assuming axial symmetry, the shape isdefined byfor z~zm(R22":":CZ-Z2)2) for z~zm

p(z)2=(R 12_(Z-Zll')(1)where R1 and R2 are determined by(2)(Rt! R 2 )3 = (At! A 2 )and volume conservation. The nuclear radius R is
defined by R= 1.18 A l /3 fm.
I t is known experimentally that the electric intrinsic dipole moment in this region is at most 0.5 fm(Note we omit electric charge e). Therefore at first
we try to see how large is the macroscopic dipole
moment in our model. The dipole moment in theliquid drop model is calculated by Strutinsky's
method 4 ) :
DLDM=

r

JShapedv zp~(z)(3)

where pz (z) is the proton distribution in a nucleus.
The macroscopic dipole moment as a function ofa center separation Zo is shown in Fig. 2, whichindicates that the experimental dipole moment isDeformation

DipoleMoment
(tm)

Q5

5

0.4

4

Q3

3

02

2

0.1
~------~~--~~~--+-----------------z

i

Zcrit

Fig. 1. Nuclear shape defined in Eq. (1) in text. Zl and Z2
are the centers of Pb and C clusters; Zo is the center separation.

5

6
Zcrit

Fig. 2. Dipole moment and deformation parameters as afunction of the center separation Zoo At two Zcr i t points,
C cluster appears on the 222Ra surface and Pb and C
clusters separate from each other.

N. Yoshinaga , et al.

reproduced at the center separation Zo = 7 fm, provided that all contributions come from the liquidpart. Figure 2 also shows the deformation parameters (/32, /33, (34) as a function of the center
separation.
In order to see how deep the configuration of
separation Zo = 7 fm is in potential energy, we calculate the total energy by the micromacroscopic method.
The macroscopic part is defined by Krappe et al. 5 )as
ELDM = E surf

+ Ecoul(4)

while the microscopic potential is defined by

V= Vc+ VLS+ Vcoul+ Vpairing(5)
where V c is the folded Yukawa potential definedb y6)
Vc(r) = -(Vo/4rra ) JexP ( - Ir -r'I)/(lr- r'l/a)S(6)

For theoretical good reproduction of the Pb + 14e
system a harmonic oscillator potential is inadequate.
At a large center separation the nucleons must be
filled in properly to reproduce the Pb + 14C configuration. A two-center harmonic oscillator potential does not satisfy this condition. This calculationshows that the total energy has a second minimum

11

around Zo = 7 fm.
In conclusion, we obtained the total energy as afunction of the center separation Zo and foundthat the local minimum exists around Zo = 7 fm. At
that point of Zo = 7 fm, DLDM = 0.5 fm and /32=
0.07, /33= 0.10, f34= 0.13, where f32 and f33 are nearly
equal to f3 2= 0.12, f33 = 0.11 obtained by Leander.l)
Using the folded Yukawa potential, we obtained the
Pb + 14C configuration and a reasonable dipole moment: D LDM =6.3fm and D shell =6.8fm at Zo=
14 fm. This good agreement between macro- andmicro-scopic calculations is due to the fact that thetwo microscopic levels centered Zo = 14 fm apart arefilled in properly by 20sPb and by 14C, respectively.
References
1) G. A. Leander: Proc. Niels Bohr Centenial Conf. on'Nuclear Structure 1985,' Copenhagen (eds. R. A.
Broglia, G. B. Hagemann, and B. Herskind) , p . 249(1985) .
2) F. Iachello: Phys. Lett. B., 160, 1 (1985) .
3) A. Arima and F. Iachello: Ann. Rev. Nucl. Part. Sci.,
31, 75 (1981) .
4) v. Strutinsky: ]. Nucl. Energy, 4, 523 (1957) .
5) H. J. Krappe, J. R. Nix, and A. Sierk: Phys. Rev., C, 20,
992 (1979) .
6) P. Moller and J. R . Nix: Nucl. Phys. A, 361, 11 (1981) .

12
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-4.

Level Structure of 217Ra

M. Sugawara, Y. Gono, T. Kohno, and M. Fukuda

NUCLEAR REACTIONS 20SPb(13C,4n)217Ra, E=75Mev:)
measured Ep IT' r-r coin., rr ((}), oriented nuclei, 217Ra deduced[
levels, j, 11:, B(El) /B(E2).

A level scheme for 217Ra was previously reportedby three groupS.1-3) Levels up to 4,186 keY (47/2)
state have been studied by Roy, et at. 2 ) An in-beam
r-ray study of 217Ra was performed using five setsof BGOACS (Anti-Compton Spectrometer) to extend the level scheme to higher spin states. Fivedetectors were placed at -135°, -45°, 30°, 90°,
and 150 0 with respect to the beam axis. Excitedestates of 217Ra were populated by the 20sPb 3C, 4n)reaction at E = 75 MeV and r -r coincidence measurement was performed using this detector system.
The r - r coincidence data also provided the information on the DCO (Directional Correlation from
Oriented nuclei) of r-transitions from which spinvalues were deduced.
A proposed level scheme is shown in Fig. 1. The

5001 - - - . . . . - 4824 (s~) 176.8

141.7

(3Jf)

2523

2306

197Z

1898

'"
'"
:;;:

~

2~{n;

1612
..;
'"
M
'<t"

1~-

1174

1050
0

,...:

~

1~{

667
1~+

331

.217

Fig. 1.

Ra

A proposed level scheme of 217Ra.

M. Sugawara, et ai.

13

Ex
(MeV)

6
-09)

--19-

5
--17--17-

4

--15-

3

--1'2

o

--0-+

-~+

214Ra

215Ra

~+

W-- 2
Ra

..

--0
21BRa

Fig. 2. Systematics of negative parity states in Ra isotopes.

level scheme could be extended to 5,001 keY stateand several non-yrast states were newly found be-

B(E%CE2)
-6

-2

00" (

2+

9/+ 'J</2 2

qt2 1~2 1~+2 1~-2 2.1/2 23;2 2~2 2'f,.2 2~2 3},;-2 3~2 3~2 3Jr2 3~-2 ~2 "%"2

3 101m2

tween 2,303 and 3,630 ke V. The negative parity
was inferred to be assigned to the states above
4,187 keV (47 /2) on the basis of the systematics ofnegative parity states in Ra isotopes. Figure 2,
which shows the systematics of negative parity statesin Ra isotopes, indicates that the excitation energy
is almost constant for spin states higher than 19for even isotopes, or 47/2- for odd ones although
the neutron number increases from 216Ra to 219Ra.
B(E1) /B(E2) branching ratios were also deduced
from the r-r coincidence data. Figure 3 shows theB(E1) /B(E2) values for several states in 217Ra
together with those in 218Ra. The decreasing trendof the B (E1) /B (E2) ratios with increasing spin
resembles the case in 218Ra. This result is different
from that reported by Roy, et al.,2) in which staggering but almost constant B (E 1) /B (E2) ratios areobserved with increasing spin.
References

3- 4+ 5- 6+ 7- 8+ 9- 10+ 1( ll'3- 14+ 15- 16+ 17-

111:.

Fig. 3. B (El) /B (E2) ratios in 217Ra in comparison withthose in 218Ra.

1) T. Lonnroth and C. Baktash: Phys. Ser., 28, 459 (1983) .
N. Roy, D. J. Decman, H. Kluge, K. H. Maier, A. Maj,
C. Mittag, J. Fernandez-Niello, H. Puchta, and F. Riess:Nucl. Phys. A, 426, 379 (1984) .
3) M. Sugawara, Y. Gono, and Y. Itoh: l. Phys. Soc. lpn.,
53, 2956 (1984) .

2)

14

RIKEN Accel. Prog. Rep. 20 (1986)

111-1-5. Spectroscopy of 22°Ac
M. Fukuda, Y. Gono, T. Kohno, M. Sugawara,
Y. Hatsukawa, and H. Taketani*

NUCLEAR REACTIONS 2osPb(15N, 3n), E= 78 MeV;
209Bi(1s0,3n), E=88MeV; measured Er,I r, r(f),[ r-r coin, Ea , la. 220Ac deduced levels, j, 7r, T 1 / 2 •The excited states of 220Ac were studied by meansof in-beam r-ray spectroscopy and a-spectroscopy
with a He-jet system.
(1) r-Spectroscopy
220 As was populated through the 20sPb (15N, 3n) 220Ac reaction. An 18 mg/cm 2, 99% enriched 20sPb
target was bombarded with a 15N beam from the
RIKEN 160 cm cyclotron. Measurements were perfonned on the excitation functions, r-ray anisotroples, r-r coincidence and lifetime. In r-r
coincidence, five Ge-detectors with BGO antiCompton shields were used. Coincidence data wereaccumulated for 41 h with an average beam currentof 0.7 pnA at EB = 78 MeV. In the other measurements, singles spectra were taken mainly with 1 cm 3
LEPS. About 30 r-rays were assigned to 220Ac fromthe excitation function and the coincidence relation.
A proposed level scheme of 220Ac constructed fromthe coincidence data is shown in Fig. 1. Multi-••• - - - - - - - - - - - 2129

+
H8 -

1834

•••• ·295.8
I+7 +-.,..---r---- 1689
446.4
+
I+6-

417.3

1387

I+5 +
116.1--""--f---1272

385.4
399.5

1002
~

779

-----,-----~~ 106.8~ ~ ~+3 + 872_ _--"-_I _329 . 5
2:tI+••~.---+--~
265.1_____~ __ ~7_0. . /202 . \:t:309 . 0•••• 246.1_-ooA,---407•• ••• 224.1- - - - ~ - - - - -224.~••• ·159.9. - - - -. - - - - - 183____ _ ~____ . 64•• ··183.1-----~----O

Fig. 1. Proposed level scheme of 220 Ac constructed fromr-ray data. Dotted lines indicate the uncertain levels.

* Department of Applied Physics, Tokyo Institute of Technology.

1polarities of the transitions were deduced from r-ray
anisotropies on the assumption that the transitions
are of stretched type. The types of the transitions(electric or magnetic) were determined from theintensity consideration. In the level scheme, alternating parity states connected by strong E1 transitions
were found, similar to the other nuclei in thisregion. The average value of B(E1) /B(E2) deduced
from the branching ratio between E1 and E2 transitions is 2 X 10- 6 fm- 2. From this, the B(E1) value
10- 2 w.u. was obtained for 220Ac, assumingofB(E2)100 w.u. which is similar to the value in
21SR a (Ref. 1). This B (E 1) value is similar to thosein the neighbouring even-even or odd-A nuclei(218-22°Ra, 220-224Th, 219Ac) (Ref. 2), but is 10 3
10 4times larger than the typical value of transitions
between the single particle states in this mass region.
(2) a-Spectroscopy
We also studied the excited states of 220Ac byobserving the a-decay of 224Pa to them. 224Pa wasproduced by the 209Bi(180, 3n) 224Pa reaction. Three
209Bi targets of 0.5 mg/cm2 deposited on 50 p.g/cm 2
carbon foils were bombarded with an 180 beam at
EB = 88 MeV provided by the cyclotron; a typicalbeam current was 20 pnA. Fusion products recoiled
out from the targets were transported by He-gas
mixed with oil and N aCI through thin capillary toa counting room and collected on a tape. During
the collection, radiated a-particles were detectedwith a Si;..surface barrier detector of annular type
faced to the tape. The tape was moved every two
seconds to reflesh, because the half-life of 224Pa is
1 s. Energy information of the detected a-particle
was recorded on a magnetic tape with its time infonnation by 100 Hz clock. In this experiment, 8 X
10 3 counts of 7.49 MeV a-group of 224Pa were collected during 43-hour run. The 7.49 MeV peak is
the only peak of 224 Pa that was previously observed(Ref. 3). In order to find a-groups of 224Pa which
feed to excited states of 220Ac, we used the following
genetic relation.
,-..J

,-..J

,-..J

M. Fukuda, et al.

15

160

(a)

m
(OJ

.,.a..

128

<X)
~

r-:

N
N

...J

W

Z
Z

<x:

96

:r:

o

"(f)

rZ

:::::>

64

<X)

o
o

0

()

~

c{

,...:

N
N
N

32

0
1400

1460

1520

1640

1580

1700

1760

1820

1880

...J

U::

w

z

Z

<x:

N
N

~
0

0

"Z
:::::>

0

r::

(f)

2000

(b)

\D
.-;
N

()

oc{

96

I

r-

1940

ai

(Cl

r-..:

64

0
0

"",<-

0

C')

m

.-;
N

0;)

32
<D

0;
0;)

0
1400

1460

1520

1580

1640

1700

1760

1820

1880

1940

2000

CHANNELS

Fig. 2. Time correlation of a-particles. Two succeeding a-particles whose time interval
is less than 100 ms were sorted. (a) Preceding a-particles, (b) following a-particles.

224Pa~ 220Ac~ 216Fr?2!:; 212At ~ 208Bi
a

a

a

a

In an off-line analysis, time correlated a-particles
were sorted under a restriction that a time interval
between two succeeding a-particles was less than
100 ms. Energy spectra of preceding and following
a-particles are shown in Fig. 2 (a) and (b). Bymeans of this kind of time correlation of a-particles,
we have newly found six a-groups of 224Pa. aEnergies and branching ratios of these nuclides areshown in Fig. 3.
One possible interpretation for the fact that thelevel scheme of 220Ac from a-decay data could not
be conbined to that from in-beam r-spectroscopy is
the high-a neutron orbit of the ground state of 224Pa,
because r-rays are considered to be emitted fromstates along yrast line while a-transitions in thiscase tend to feed to those away from yrast line. This
high-a neutron orbit also explains well the a-energy
systematics of N = 133 isotones (Ref. 3). But it isincompatible with the octupole deformation model

1224
Ea"'"
keV

343
313

240
216
195
143
122

40

o

%
0.7(2)

MeV
7.191

1.3(4}

7.221

3.6(5)

7.292

1.9(3)

7.316

1.4(3)

7.337

4.4(5)
17(2)

7.388
7.408

66(3)

7.489

2.9(6)

7.528

Fig. 3. a-Decay scheme of 224Pa.

Pa

16

M. Fukuda, et al.

(Ref. 4) which was proposed to explain the featuresof actinide nuclei (strong El transitions, alternating
parity states, parity doublets, etc.). Further study
is necessary to make the relation of them clear.
References
1) A. Celler, Ch. Briancon, J. S. Dionisio, A. Lefebvre, Ch.
Vieu, J. Zylic, R. Kulwssa, C. Mittag, J. Fernandez-

Niello, Ch. Lauterbach , H. Puchta, and F. Riess: Nucl.
Phys. A, 432, 421 (1985) .
2) Y. Gono, T. Kohno, M. Sugawara, Y. Ishikawa, and M.
Fukuda: Nucl. Phys. A , 459, 427 (1986) and references
therein.
3) J. Borggreen, K. Valli, and E. K. Hyde: Phys. Rev. C,
2, 1841 (1970) .
4) G. A. Leander and R. K. Sheline: Nucl. Phys. A, 413,
375 (1984) and references therein.

17
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-6.

In-Beam r-Ray Study of 22~h with BGOACS and 41!'
Crystal Ball
T. Kohno, Y. Gono, Ch. Briancon, * F. A. Beck, **and Chateau de Cristal Collaboration

NUCLEAR REACTIONS 2osPb(I sO,4n), E=95 MeV, measured r-r coin., r-multiplicity, r-ototal energy, 222Th deduced
levels. 12 sets of Ge with BGOACS and BaF 2-ACS, BaF 2
crystal ball, enriched target.

Several nuclei in the Ra-Th region are expected
to show a stable octupole deformation, and acharacteristic feature of these nuclei is the existenceof alternating parity states connected by enhanced
E1 transitions. In this work the excited states of222Th were studied by means of in-beam spectroscopic techniques. Since the excited states up to
J1T = 17- are known in 222Th/) we aimed to observe

higher spin states and side bands.
An experiment was carried out using 12 sets of
Ge detectors with RIKEN BGOACS2) and BaF 2ACS, 2 planar Ge detectors, and BaF 2 47r: crystal
ball (Chateau de Cristal) 3 ) set in the beam line of
an MP tandem accelerator at CRN Strasbourg.
r-r Coincidence was measured with the 2osPb(1s0,4n) 222Th reaction at 95 MeV. r-Ray multiplicity

3500 , - - -- - -- - - - - - - - - -- - -

.-4

2800

I:-

-l

.-4

W

Z
Z

<{ -

G 2100a:w
0...

~ 1400

~

o
o

700

OL-~~_~_~o_ _ ______~

100_ _ _ _ _ __ L_ _ _ __ __ L_ _ _ __ _

200

400

300

~~

500

1500 ~r----------------------------------_,

<:>

..-t
CQ

1200
.-J

W

~
~

o

co

900

a:

w

C"I

0...

~

co

'I#'
'I#'

CQ

CQ

CQ
CQ

600

CQ
C)
CQ

~
o

I:-

o

C)

<:>

.-4

'I#'

.-4

CN

'I#'
'I#'

co

'I#'

'I#'

300

O L--

_

500

___

~

_

600

_ __ _ _

~

_

700

.-4

co
'I#'

~~~

_ _ _ _ __ L_ _ __800

_ _ _ L_ _ _ _ _ _900

CHANNEL NUMBER

Fig. 1.

* CSNSM Orsay.
** CRN Strasbourg.

An example of coincidence spectra gated on the multiplicity and total energy.

~~

1000

18

T. Kohno, et al.

and total energy as well as r-ray energy for COIncidence events were recorded event by event onmagnetic tapes for off-line analysis.
When the nuclei in this region are produced,(21- )-----,----I

I
I

I

481

I

(19-)

,.

01
462
17 85
441
15

-

72
417
13 65

11

-

61

393

368

fission events strongly compete with fusion events.
An electrostatic separator was previously used 4 ) to
discriminate .evaporation residues from this strong
fission background. In this work we were able toobserve r-rays from 222Th in singles spectra clearlyby using the ACS. Since it was shown that the SIN
ratios of the r-rays from 222Th are best under thecondition of low multiplicity and low total energy,
the data of r-r coincidence measurement wereanalyzed by gating on the multiplicity between 2
and 8 and the lower part of the total energy
spectrum. These conditions predict a disadvantage
for the observation of high spin states.
Figure 1 shows an example of gated spectra.
Strong lines in the low energy region represent
enhanced E 1 transitions which connect positive- andnegative-parity bands. The excited states up to J1I" =(21-) have been assigned tentatively. Althoughseveral r-rays were found in a side band, the relation between these lines and the ground stateband has not been identified because of their low
intensities. A partial level scheme is shown in Fig.
2. Analysis of data is now in progress.

9-

References

61

332
7

-

74
6-

2+
0+

273

267
183

222Th

Fig. 2.

A partial level scheme of 222Th.

1) D. Ward, G. D. Dracoulis, J. R. Leigh, R. J. Charity ,D.]. Hinde, and ]. O. Newton: Nucl. Ph),s. A, 406, 591(1983) .
2) M. Fukuda, Y. Gono, Y. Ishikawa, M. Sugawara, T.
Inamura, M. Ishihara, T. Nomura, I. Kohno, H.
Kamitsubo, J. Kasagi, and T. Murakami: RIKEN
Aeeel. Prog. Rep., 18, 152 (1984) .
3) F. A. Beck: Proc. Int. Conf. on Instrumentation for
Heavy Ion Nuclear Research, Oct. 22-25, p. 129 (1984) .
4) W. Bonin, H. Backe, M. Dahlinger, S. Glienke, D. Habs,
E. Hanelt, E. Kankeleit, and B. Schwartz: Z. Phys. A,
322, 59 (1985) .

19
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-7.

Spin Alignment in Projectile Fragmentation at
Intermediate Energies

K. Asahi, M. Ishihara, T. Ichihara, Y. Gono, A. C. Mueller,* R. Anne,
D. Bazin,* D. Guillemaud-Mueller,* R. Bimbot,** W. D. Schmidt-Ott,*** and J. Kasagi

NUCLEAR REACTION 18 0 + 9Be, E(180) /A=65 MeV/u; f3-]
delayed r-rays from . 14B, measured W r((J); deduced spin alignment of 14B products, T l/Z (14B) .

Recent extensive studies of the heavy ion reactionsat intermediate energies1,Z) have revealed that the
projectile fragmentation is the dominant process already at these energies. Isotope production using
the projectile fragmentation process can be a very
powerful tool to study nuclei far from the stability
line, as demonstrated in the recent successive discoveries of new isotopes. 3 ,4) This is not only becauseof the high production rates available for the wide
ranges of unstable nuclei but also due to the strong
kinematical focusing of the product nuclei with respect to both the emission angle and the velocity,which facilitates the isotope separation by means ofmagnetic analysis during flight. The usefulness would
be further augmented if these product nuclei are
spin-oriented, since then the more detailed spectroscopic investigations such as the observation ofangular distribution of radiations from oriented nuclei
becomes possible. Measurement of the spin alignment in projectile fragmentations is also interestingfrom the view point of reaction mechanisms, since
it provides a unique testing ground for models
describing the reactions. We thus started an experiment to measure the alignment of the projectile
fragments using intermediate-energy heavy-ion beams
at GANIL.
Spin alignment in 14B produced in 18 0 + 9Be reaction at E(180) / A = 65 MeV lu is investigated.
Nucleus 14B is chosen because i) the short lifetimeof 14B allows us to get rid of the spin relaxation
effect during the period until the f3-ray emission,ii) the angular distribution of ,8-delayed r-rays froma spin-aligned state has a large anisotropy, andiii) the high energy of the r-ray eases background* Grand Accelerateur National d'Ions Lourds (GANIL),
Caen, France.

** Institut de Physique Nudeaire, Orsay, France.
*':'* Physikalisches

Institut,
UniversWit
Gottingen, Fed. Rep. of Germany.

Gottingen,contaminations in the detection. Spectrometer LISE5)
is used for the isotope separation of the reaction
products. LISE is the spectrometer consisting of
two dipole magnets, with the first one providing adispersion according to the magnetic rigidity at anintermediate focal plane (Fl) whereas the second
restoring the achromatism at the final focus point(F2). A wedge-shaped energy degrader is inserted
at Fl to afford an additional analysis of particles
according to the differences in stopping power fordifferent Z numbers.6) Use of the degrader indeed
purified remarkably the isotope distribution observed
at F2 by means of time-of-flight and .dE measurements using a silicon detector.
We report below the preliminary results obtained
up to now. 14B products were stopped in a stopper
foil (Pt) placed at F2. The beam was pulsed sothat the r-rays were detected during the beam-off
periods. Static magnetic field Bo = 310 mT parallelto the fields of the dipole magnets in LISE wasapplied to the stopper in order to preserve 7 ) the
spin alignment for duration longer than the nuclear
lifetime. In addition a small solenoid was installed
to produce a field of about 0.5 mT in the direction
parallel to the axis of the 14B beam incident on the
stopper. This field destroys the spin alignment when
Bo is off, and assures at that condition the equalityof the r intensities at the two detection angles mentioned below. The 6.09 MeV r-rays emitted afterthe ,8 decays of 14B were detected using two NaI (TI)
scintillation counters (15 cm in diameter, 15 cm inlength) placed at 0° and 90° to the direction of Bo·
Angular distribution of the 6.09 MeV r-rays in thepresence of the external field Bo perpendicular to
the initial alignment axis is given by
Wr ( 0) = 1 - (1 14) AP 2 (cos 0)

where the initial alignment A is defined as A =(2a +2 - a+ 1 - 2ao - a_1 + 2a_z) I 2 in terms of

20

K. Asahi, et al.

the population probability am for the magnetic sublevel m. The 0 0 /90 0 ratio R = N r(OO) / N r (90 0 )of the r-ray yield was measured both with Bo on(i.e., with the spin alignment preserved) and off(with the alignment destroyed). A was deduced
from the change of R between the two conditions by

A = (8/3)( 1- RON/ ROFF)
where ON and OFF refer to the measurements with

Bo on and off, respectively.
In Fig. 1 the result for spin alignment is shown
together with the measured momentum distributionof the 14B particles. For the momentum window
Jp/p = ±2.3% around the peak in the fragment
momentum distribution, the spin alignment of 14B,
A = + (3.8 ± 2.3) %, was obtained. The positive
sign of the present result seems to conform theprediction from a simple model of the projectile
fragmentation,8) though a more improved statistics
is required to draw any definitive conclusion. The
measurements for different momentum regions arealso anticipated, since the simple fragmentation

---t-

c
Q)

§

0

.~
~ -5

C

18 0(65 MeV/u) + 9 Se

'E
Ui

_ 14S • X

C
:l
ou

~500

-4

-2

0
lIP/P (0/0)

4

Sp (T'm)

Fig. 1. Preliminary result for spin alignment of l4B
produced in the reaction 18 0 (65 MeV lu) + 9Be.
Observed momentum distribution for l4B is also
shown.

argument8 ) leads to negative alignments in the
momentum regions corresponding to the tails of thepeak in the fragment momentum distribution.
The halflife of 14B has been deduced from theleast-squares fitting of a theoretical function to thetime spectrum of the 6.09 MeV r-rays obtained in
the course of alignment measurement. The result is:
T1/2 = (13.7 ± 0.6) ms.
Two measurements arereported previously for the halflife of 14B, but differ
substantially from each other. The presently obtained
value is considerably shorter than the value reported
by Alburger et at. 9 ) and in agreement with therecent measurement by Curtin et al. 10 ) within theexperimental error. Transition probability deduced
from the present value is smaller than that obtainedby the shell model calculation 10) by only 19 %. This
reduction in transition probability is much smaller
compared to the commonly observed reduction of
about 50 % for the s-d shell nuclei.
References
1) V. Borrel, D. Guerreau, J. Galin, B. Gatty, D. Jacpuet,
and X. Tarragao: Z. Phys. A, 314, 191 (1983) .
2) D. Guerreau: Nucl. Phys. A, 447, 37c (1985) .
3) M. Langevin, E. Quiniou, M. Bernas, J. Galin, J. C.
Jacmart, F. Naulin, F. Pougheon, R. Anne, C. Detraz,
D. Guerreau, D. Guillemaud-Mueller, and A. C. Mueller:
Phys. Lett. B, 150, 71 (1985) .
4) D. Guillemaud-Mueller, A. C. Mueller, D. Guerreau, F .
Pougheon, R. Anne, M. Bernas, J. Galin, J. C. Jacmart,
M. Langevin, F. Naulin, E. Quiniou, and C. Detraz: Z.
Phys. A, 322, 515 (1985) .
5) M. Langevin and R. Anne: Instrumentation for Heavy
Ion Nuclear Research (ed. D. Shapira), Vol. 7, Har-'
wood Academic Publishers, London, p. 191 (1985) .
6) R. Bimbot, S. Della-Negra, M. Manasijevic, P. Aguer,
G. Bastin, R. Anne, H. Delagrange, Y. Schutz, F. Hubert,
Y. Gono, and K. Hatanaka: J. Phys (Paris), 47 (Suppl.
C4-8) , 241 (1986) .
7) K. Sugimoto, K. Nakai, K. Matuda, and T. Minamisono: Phys. Lett. E, 25, 130 (1967) .
8) K. Asahi and M. Ishihara: p.21 in this report.
9) D. E. Alburger and D. R. Goosman: Phys. Rev. C, 10,912 (1974) .
10) M. S. Curtin, L. H. Harwood, J. A. Nolen, B. Sherrill,
Z. Q. Xie, and B. A. Brown: Phys. Rev. Lett., 56, 34(1986) .

21
RIKEN Acce1. Prog. Rep. 20 (1986)

111-1-8. A Simple Model for Spin Alignment in Projectile Fragmentation
K. Asahi and M. Ishihara

NUCLEAR REACTION projectile fragmentation model, Wigner[ distribution; spin alignment of fragments.

The production of projectile-like fragments inheavy ion reactions at high energies has been discussed in terms of projectile fragmentation models. 1 )These models well expain the widths of both thelongitudinal and transverse momentum distributions
for ejected fragments. Recent experimental studies 2 )have shown that these models seem to hold also for
the intermediate energy regions: Observed mass andcharge distributions of the fragments conform wellto these models, though some effects due to the final
state interactions and the dissipative process manifest
themselves in the momentum distribution. For better
understanding, more comprehensive studies extending
to other observables are awaited. In this report, we
discuss what is to be expected for the spin alignment of ejectiles in the projectile fragmentation, on
the basis of a simple fragmentation model. 3 )In the projectile fragmentation picture, themomentum distribution of an outgoing fragment
reflects the momentum distribution of the cluster
which is removed from the surface of the projectile
nucleus. Although the uncertainty principle prohibits us from defining the probability of finding aparticle with a definite momentum at a definite
position, the quantal analogue to this quantity,
represented by the Wigner transform W of the onebody density matrix p' can be introduced:

J

W(R,k)= d 3x/(2n)3x exp (-ik·x)<R-x/2IpIR+x/2>
The following expression in terms of W for the
momentum distribution of the fragmentation crosssection at high energies is derived 3 ) from the Glauber
theory of multiple scattering4 ):1

d 3 a/dk 3 = d 2sD(s) j" dzW(s,z;k.b kif)

Here R=(s, z) and k=(kl.' kif) denote respectively
the position and momentum of a removed cluster,and z axis is taken parallel to the incident beam
direction. The weighting function D (5) contains thereaction dynamics and localizes the reaction to the1

nuclear surface.
As the simplest example we take 160 for the projectile nucleus and consider the process where one
nucleon is removed from the Op orbit. We employ
for simplicity the harmonic oscillator wave function<Pm with the oscillator parameter b to describe theorbit (l, lz) = (1, m), and neglect the intrinsic spinof the nucleon. Then the corresponding Wigner
distribution is written in the formJ

Wm(R, k) = d 3x/(2n)3x exp (-ik·x)<Pm(R-x/2)ifJm*(R+x/2)
leading to the cross section
dam/dk;; =Jd sD(s) j" dz l d kl. Wm(s,z;kl., kif )2

2

Setting D (s) oc 0 (5-50) and after a brief manipulation, we obtain the expressions for the longitudinal
momentum distribution:
da /dk;;=da +tldk;;+dao/ dkll+da -ti dk;1
=N·exp (-b2kl/)· [1 + (kl;/ r)2]

and for spin alignment:
A= [da +tldk;;- 2dao/dk;;+da _tldk;; ]/[2da/dk;;]= [(1/2) - (k;;/ r)2]/[1 +(k;;/ r)2]

r

where
= 50/ b2 • The longitudinal momentum of
the outgoing fragment is given by p = po - kI;' where
po denotes the fragment momentum corresponding
to the projectile velocity.
The result is schematically displayed in Fig. 1,
where b = 1.75 fm and So = 3 fm are taken. Alignment takes a positive maximum at the peak p = Po,
whereas it decreases as p increases or decreases fromPo, approaching a negative value in the tail regions
The qualitative features observed in this result canbe understood in a more intuitive way, as illustrated
on the bottom of Fig. 1. The process leading to theoutgoing momentum smaller than Po (see Fig. 1 (a) )involves the removal of nucleon moving in the
direction parallel to the projectile velocity Vo in the
projectile nucleus. For peripheral collisions (R 1-

K. Asahi, et al.

22(I !2 ) - (k ll /r)2

+

A=

I

+

(ku/ r l2

+-'
C
OJ

§ 0 1--- -- - /~-------'--=---- ,.- -----l..... P
OJ.......
o

c

o
+-'
U
OJ
U)
U)
U)

o
L

U

p

'.

'6,..,

v. . . . .

1....(. . ..•.. .'. . .•. . .•. . .•... . .:•. . . . . .••.... . ,00.

jectile-rest frame), this implies that nucleon withorbital angular momentum parallel to the vector
R X Vo is removed, leaving the fragment spin in the
direction perpendicular to ' Vo (negative alignment).
A similar consideration for p > po leads to the same
result for the alignment. On the other hand for
p :::: po, motion of the removed nucleon in the projectile is perpendicular to Vo~ resulting in the positivespin alignment for the outgoing fragment.
The result would be modified to a certain extent
if one takes into account the deexciting stage subsequent to the production of some intermediate
excited nucleus in the abrasion process. The characteristic feature discussed here for spin alignment,
however, is expected to persist. The present resultshows that the observation of the spin alignment in
the projectile fragmentation would afford an opportunity for testing models for reaction mechanisms.
It also has an important implication that the projectile fragmentation might provide a promising tool
to produce spin-aligned unstable nuclei which should
no doubt be extremely useful for detailed spectroscopic studies of the nuclei far from stability.

projectile(0)

V < Vo(c)

V > VoFig. 1. Predicted behavior of fragm ent spin alignment basedon a simple projectile fragm entation consideration. On thebottom , situations for the outgoing velocity (a) v < Vo, (b)v :::: Vo, and (c) v> Vo are intuitively illustrated, where
Vo denotes the velocity of the projectile.

v o, where R is the position of nucleon III the pro-

References
1) A. S. Goldhaber: Phys. Lett. B , 53, 306 (1974) .
2) R. Dyras: J. Phys. (Paris) , 47 (Suppl. C4-8) , 13 (1986) .
3) J. Hufner and M. C. Nem es: Phys. R ev. C, 23, 2538
(1981) .
4) P . J. Glauber: Lectures in Theoretical Physics (eds. W. E.
Br itten and L. G. Dunham), Vol. 1, Interscience, New
York, p. 315 (1959) .

23
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-9.

jj Decay of Polarized Nucleus 15C and Magnetic Moment of
the 1/2+ Ground State

K. Asahi, M. Ishihara, T. Shimoda,* N. Ikeda,** T. Fukuda,***N. Takahashi,* K. Katori,*** S. Shimoura,** A. Nakamura,** K. Hanakawa,***T. Itahashi, **** Y. Nojiri, *** and T. Minamisono***
NUCLEAR REACTION 232Th(15N, 15C), E= 158 Mev, fi deCay]of 15C; observed fi-ray asymmetry, NMR; determined magnetic[ moment for the ground state.

Measurement of magnetic moment provides useful
information on nuclear structure and interaction.
Moreover, the g factor for a nucleon residing in
the S1/2 orbital is of special interest since it amounts
to a direct observation of the intrinsic moment of
a nucleon embedded in the nucleus. Possible effects
on the magnetic moment due to modification of
nucleon properties in a nuclear medium have been
discussed recently.I,2) On the other hand it is only
for a few nuclei that the 1= 1/2 magnetic moment
is already known experimentally. This is because
the 1= 1/2 states do not bear the rank-2 spinorientation (alignment) which facilitates observationof spin precession through the angular distributionof the de-excitation r-rays. Under these circumstances the observation of asymmetry in fi-ray angular distribution from polarized nucleus is the only
sensitive means to determine the 1= 1/2 moment.
We have measured the magnetic moment for the
ground state of a neutron-rich nucleus 15C (Irr = 1/2+,
T I / 2 = 2.449 s, Q{3 = 9.772 MeV). The nuclear magnetic resonance (NMR) has been observed by detecting the change in asymmetry in the angular distribution of f3-rays from Gamow-Teller transition to the
1/2+ excited state of 15N. 15C decays also with a36.8 % branch to the 1/2- ground state. 3) The
measurement of f3 asymmetry for this 1 /2 +~ 1/2first-forbidden transition is by itself interesting since
the role played by virtual pion in the weak axial
current is predicted to enhance in this class of transition. 4 ) This interest affords an additional motivation
to the present study of 15C magnetic moment, since
the spin control technique by means of NMR is
indispensable for the precise measurement of f3
asymmetry.

* College 01 General Education, Osaka University.
** Faculty of Science, Kyoto University.
*** Faculty of Science, Osaka University.
**** Research Center for Nuclear Physics, Osaka University.

A 158 MeV 15N beam from the AVF cyclotron at
the Research Center for Nuclear Physics, Osaka
University, was used to produce spin-polarized 5) l5C
nucleus by (15N, 15C) reaction. The setup used forthe measurement has been reported previously. 6) A
spectrometer DUMAS7) provided a means for isotope
separation of projectile-like fragments. The reaction products emitted from the target at 8 L = 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 triplefocussed on a stopper foil placed at the second focal
point. For a stopper substance we employed highpurity graphite, in which the spin-lattice relaxation
time TI for l3C has been reported 8 ) to be as longas 89 s at room temperature. Static magnetic field
Bo = 74.5 mT perpendicular to the reaction plane wasapplied on the stopper.
Beam was pulsed with a repetition period of 10 s
and a beam-on period of 3 s. f3-Rays emitted fromthe products implanted in the stopper were detectedduring the intervening beam-off period by using
counter telescopes placed above and below the stopper. A radio-frequency (RF) field perpendicular to
Bo for NMR was applied for 20 ms duration preceding the fi detection period, with the frequency swept
in the specified range v to v + Llv. Spins were thus
inverted when the range of sweep was across theresonant frequency Vo, by means of the adiabatic fastpassage method of NMR. The spin inversion was
detecteded as change in the measured up/down ratioof the f3-ray yield.
The results of the resonance scans performed forseveral different values of Llv are displayed in Fig. 1.
From the spectrum obtained with the narrowest
window (Llv = 0.075 MHz), the g factor for the 15C
was found to be Ig I = 2.63 ± 0.14. The overall uncertainty associated with this measurement is determined solely by the RF window width Llv in which

K. Asahi, et al.

24

factor. A simple estimate of correction for the firstorder core polarization,l1) 0 gIst = 0.23, explains onlya small part of the observed deviation OU exp =+ 1.20 ± 0.14 from the Schmidt value (assuming anegative sign for the observed value). This is incontrast to the case for the 5/2+ excited state of 15C,
for which a vd 5 / 2 single particle model including thefirst-order correction well explains the observed U
factor. 12 ) Clearly, a more elaborate theoretical treatment is needed to clarify the situation for the 15C
ground state.

oReferences

frequen cy ( MHz)

Fig. 1. Up / down ratio of (3-ray yield, measured after ap plication of the RF field with the frequency swept over the
specified ranges (represented by horizontal bars). T h ewidth of the range for th e frequency sweep was chosen
to be (a) Llt./=O.94 MHz; (b) Llt./=1.17MHz; (c) Llt./ =0.43 MHz; and (d) Llt./=O.075 MHz.

the resonance is located. Neither of instrumental
uncertainties including that of the external fieldcalibration procedure contribute significantly to theuncertainty in the final number.
The 15C ground state wave function can be
written 3 , 9 ) as 14C (0+) X vls1/ 2 with small admixturesof other configurations such as 14C (2+) X vOd 5 / 2 and14C (2+) X vOd 3 / 2 • In fact an experimental spectroscopic factor close to unity has been reported for
14C (d, p) 15C (1/2+) reaction. 10) The observed U factor, however, deviates substantially from the Schmidt
value US chm idt = Un = -3.83 for the single SI/2 neutron
configuration, where Un denotes the free neutron U

1) G. Karl, G. A. Miller, and J. Rafelski: Phys. Lett. B,
143, 326 (1984) .
2) T. Yamazaki: Phys. Lett. B, 160, 227 (1985) .
3) E. K. Warburton, D. E. Alburger, and D. J. Millener:
Phys. Rev. C, 29, 2281 (1984) .
4) K. Kubodera, J. Delorme, and M. Rho: Phys. Rev. L ett.,
40, 755 (1978) .
5) K. H. Tanaka, Y. Nojiri, T. Minamisono, K. Asahi, and
N. T akahashi: Phys. R ev. C, 34, 580 (1986) .
6) K. Asahi, M. Ishihara, T. Shim oda, T. Fukuda, N. Takahashi, K. Katori, S. Shimoura, N. Ikeda, C. Konno, H.
Hanakawa, A. Nakamura, T. Itahashi, Y. Nojiri, andT. Minamisono: ]. Phys. Soc. ]pn., 55, Suppl., 1032 (1986) .
7) T. Noro, T. Takayama, H. Ikegami, M. Nakamura,
H. Sakaguchi, H. Sakamoto, H. Ogawa, M. Yosoi, T.
Ichihara, N. Isshiki, M. Ieiri, Y. Takeuchi, H. Togawa,T. Tsutsumi, and S. Kobayashi: ]. Phys . Soc. ]pn., 55,
Suppl., 470 (1986) .
8) G. P. Carver: Phys. Rev. B, 2, 2284 (1970) .
9) D. E. Alburger and D. J. Millener: Phys. Rev. C, 20,1891 (1979) .
10) F. E. Cecil, J. R. Shepard, R. E. Anderson, R. J. Pe terson, and P. Kaczkowski: Nucl. Phys. A, 255, 243 (1975) .
II) H. Morinaga and T. Yamazaki: Beam Gamma-Ray Spectroscopy, North-Holland Pub!. Co., Chap. 3, Amsterdam(1976); H. Noya, A. Arima, and H. Horie: Prog. Theor.
Phys., 8, Supp!., 33 (1958) .
12) J. Asher, D. W. Bennett, B. A. Brown, H. A. Doubt, and
M. A. Grace: ]. Phys. G, 6, 251 (1980) .

25
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-10.

Measurement of Interaction Cross Sections Using He, Li, Be, B,
and C Isotope Beams and Radii of Light p-Shell Nuclei
1. Tanihata, H. Hamagaki,* O. Hashimoto,* Y. Shida,* O. Yamakawa,*
T. Kobayashi,** K. Sugimoto,*** and N. Takahashi***Heavy-ion collisions, Radioactive beam, High-energy collisions,Interaction cross section, Nuclear radii, Isobaric dependence,[ p-shell nuclei.

I t has been shown that nuclear radii can be determined from a measurement of interaction cross sections of high-energy heavy-ion collisions. 1,2) In
particular, the use of unstable nuclear beams provides a unique tool for determining radii of unstable
nuclei.
The secondary beams of 4,6,8He, 6-9,llLi, 7,9-12,14Be,
8,13-15B, and 10,12C were produced through the projectile fragmentation of 800 MeV/nucleon llB and
2°Ne accelerated by the Bevalac at the Lawrence
Berkeley Laboratory. The energy of the secondary
beams was 790 MeV/nucleon at the target. Theinteraction cross sections ((Jr) were measured using
Be, C, and Al targets by a transmission experimentwith a large acceptance spectrometer. The experimental procedures were the same as those reported
in the previous papers. 1,2)
The root-mean-square (rms) radii of nucleon
3.5
II

He

.. Li

g

..
3.0

a

Be
B
C

'"::s

:e

I

«I

p::;

§
...

£

~

::'2

2.5

/1

d l-II~----:/~

1

matter distribution t have been determined using
Glauber-type calculations. 3) The obtained rms radii
are shown in Fig. 1 as a function of the neutron
number (N). It is seen that the radii of Li and
Be isotopes show similar behavior with N. The radiiof nucleus with N = 6 and 8 (P3/2 and P1/2 closed,
respectively), except 8He and llLi, are close to the, prediction from a Hartree-Fock calculation based on
spherical nucleus. 3) A large increase in the rms
radius is seen at N = 7. It is considered that theincrease in radius is due to deformation of llBe (oradmixture of sd-shell components). 3) The nucleus
llLi, with the neutron number of p-shell closure in
the naive shell model, shows a radius considerablylarger than neighboring nuclei. I t suggests the existence of a large deformation and/or of a long tailin the matter distribution due to weakly boundnucleons. Further increase in the radius of 11Li fromthat of llBe may therefore suggest that N = 8 is nota neutron magic number for Li isotopes.
Appreciable differences in radii are observed between pairs of isobars with different isospin, 6He6Li, 8He- 8Li, and 9Li- 9Be. The larger radii of theneutron-rich isotopes 6He and 8He, which have only
two protons, may suggest the existence of thickneutron skins. On the other hand, pairs of mirror
nuclei (the same isospin isobars) 7Li- 7Be, 8Li- 8B,
and lOBe_10C show equal radii. It indicates that thedifference in the Coulomb interaction does not affectthe nuclear radius in visible size for light p-shell
nuclei.
References

Neutron Number

Fig. 1. Root-mean-square radii of nucleon distributions
determined from the interaction cross section of 790 MeV /nucleon heavy-ion collisions. Radioactive nuclear beams
were used for obtaining the radii of ,a-unstable nuclei.
Lines in the figure are only guides for eyes.

* Institute for Nuclear Study, The University of Tokyo.
** National Laboratory for High Energy Physics.
*** Faculty of Science, Osaka University.

1) I. Tanihata, H. Hamagaki, O. Hashimoto, S. Nagamiya,
Y. Shida, N. Yoshikawa, O. Yamakawa, K. Sugimoto, T.
Kobayashi, D. E. Greiner, N. Takahashi, and Y. Nojiri:
Phys. Lett. B, 160, 380(1985).
2) I. Tanihata, H. Hamagaki, O. Hashimoto, Y. Shida, N.
Yoshikawa, K. Sugimoto, O. Yamakawa, T. Kobayashi,
and N. Takahashi: Phys. Rev. Lett., 55, 2676 (1985) .
3) A. Brown: private communication.

t Nuclear matter radii shown here correspond to the rms
radii of point nucleon distribution.

26

RIKEN Accel. Prog. Rep. 20 (1986)

111-1-11.

Fragmentation Cross Sections of llLi at 0.8 GeV / Nucleon
T. Kobayashi,* K. Omata,** K. Sugimoto,*** T. Shimoda,***N. Takahashi,*** Y. Shida,* I. Tanihata, and O. Yamakawa*

Heavy-ion collisions, Radioactive beam, High-energy collisions, 1[ Projectile fragmentation, Nucleon distribution, llLi.

Recently, high-quality secondary nuclear beams
were produced by the INS-LBL collaboration at
the Lawrence Berkeley Laboratory, and were used
for studying the matter radii of light nuclei by interaction cross section measurements. l , 2) This new technique allows us to study the various properties of {3unstable nuclei through, for example, the projectile
fragmentation of exotic nuclei. We report the firstmeasurement of projectile fragments produced by thebreakup of extremely neutron-rich nuclei (llLi and6,8H e) at 0.79 GeV j nucleon incident energy.
The experiment was carried out at LBL Bevalac.
T he experimental-setup is approximately the sameas that described in Ref. 1. Projectile fragments weredetected inclusively by the magnetic spectrometer(HISS). Figure 1 shows production cross sectionsof Li and He isotopes from llLi + C reaction as
a function of mass number of the fragment. One
interesting speculation is that it may be possible todeduce the information on the neutron skin in these

:t'

Li

10 2
~

..s
rj

~ 10 1

extremely neutron-rich nuclei by measuring the fragmentation cross sections into various isotopes. Thiskind of measurement is complementary to the interaction cross section measurement which is sensitive
to the nuclear matter distribution. 2 ) A difference between H e fragment and Li fragment in the massdependence is what we would expect on the basisof a naive abrasion modeP ) consistent with the existence of thick neutron skin: note that llLi has 3
protons and 8 neutrons. It is, however, necessary totake into account the ablation stage (slow evaporation stage) in the calculation to estimate proton andneutron radii from the experimental values.
Fragmentation cross sections of llLi into 9Li and
6He were also measured with a lead target. Ratiosof cross sections (a(llLi + Pb~ 9Li) ja(llLi +C ~9Li ) = 9.1 ± 1.9 and a(llLi + Ph ~ 6He) ja(llLi +C ~ 6He) = 4.2 ± 3.1) indicates an importance ofelectromagnetic dissociation of llLi nucleus from ahigh Z target. 4 )An attempt was also made to search for lOHe
isotope (one proton removal from 11Li) from the
projectile fragmentation of 11Li beam on a carbon
target. This seems to be a much better method to
produce lOHe compared with a spallation method
due to a kinematic focusing (100 % detection efficiency ) and a large one-proton removal cross section .
At present, the upper limit of the production crosssection is 50 f1. b.

IIJ

..

.,
...u0

r

f
Fragmenl Mass

Fig.!. Fragmentation cross sections of ll Li on a carbon
target.

* National Laboratory for High Energy Physics.
** Institute for Nuclear Study, The University of Tokyo.
*** Faculty of Science, Osaka University.

References
1) I. Tanihata, H. Hamagaki, O. Hashimoto, S. Nagamiya ,Y. Shida, N. Yoshikawa, O. Yamakawa, K. Sugimoto,T. Kobayashi, D . E. Greiner, N. Takahashi, and Y.
Nojiri: Phys. L ett. B, 160, 380 (1985) .
2) I. Tanihata, H. Hamagaki, O. Hashimoto, Y. Shida, N.
Yoshikawa, K. Sugimoto, O. Ya makawa, T . Kobayashi,
and N. Takahashi: Phys. Rev. Lett., 55, 2676 (1985) .
3) J. Hufner, K. Schater, and B. Schurman: Phys. Rev . C,
12, 1888 (1975) .
4) D. L. Olson, B. L. Berman, D. E. Greiner, H. H. Heckman, P. J. Lindstrom, and H. J. Crawford: Phys. Rev.
C, 28, 1602 (1983) .

27

RIKEN Accel. Prog. Rep. 20 (1986)

111-1-12. NMR on p-Emitting 39 Ca Produced through Projectile
Fragmentation in High-Energy Heavy-Ion Reactions
K. Matsuta, *1 T. Minamisono, *1 Y. Nojiri, *1 K. Sugimoto, *1 K. Takeyama, *1
K. Omata,*2 Y. Shida,*2 I. Tanihata, T. Kobayashi,'103 S. Nagamiya,*4 K. Ekuni,*5
S. Shimoura, *5 J. R. Alonso, *6 G. F. Krebs, *6 and T. J. M. Symons'l'a

Heavy-ion collisions, Radioactive beam, Isotope production, Projectile[ fragmentation, Nuclear magnetic moment, Mirror nuclei, 39Ca.

A new experimental method has been developed
for the studies of magnetic moments of mirror nuclei
in the f7/2 region. As at least one partner of mirror
pairs in this region is short-lived (0.1 to 1 s) (3emitter, the preparation of spin polarized separated
isotope samples for NMR (nuclear magnetic resonance) studies presents a challenge. The method
developed uses the Lawrence Berkeley Laboratory
Bevalac to (1) produce short-lived nuclei by meansof projectile fragmentation in high-energy heavy-ion
reactions, ( 2 ) separate and purify the desired isotopes from other reaction products and from theprimary beam by magnetic analysis and suitablylocated energy degraders/} (3) produce nuclear spinpolarization through ion interactions with tilted
foils,2} (4) implant the isotopes in a crystalline
catcher, and (5) detect NMR by means of (3-decay
asymmetry of the polarized nuclei. 3)
The method has been developed using 39Ca (]1r =3 j 2+, T 1/2 = 0.86 s), for which the magnetic moment
has been previously measured. 4}
A secondary beam of 39Ca ion was produced bystriking a 1.27 cm beryllium target with 40Ca ions
extracted from the Bevalac at 220 MeV jnucleon.
To reduce the momentum spread inherent in the
fragmentation process and due to the target thickness, a thin wedge momentum compensator was used
at a momentum-dispersive focusing point in the beamtransport separator line. As a result, the total energy
spread at the final stopping point of the 39Ca ions
was reduced to 3 MeV jnucleon (HWHM). Such alow energy spread is essential for proper utilizationof the tilted-foil technique. A stack of 10 foils, tilted*1 Faculty of Science, Osaka University.
*2 Institute for Nuclear Study, The University of Tokyo.
*3 National Laboratory for High Energy Physics.
*4 Faculty of Science, The University of Tokyo.
*5 Department of Physics, Kyoto University.
*6 Lawrence Berkeley Laboratory, University of California.

1

Decay of 39Ca~'''OO~~~- - - ; _ _ _0-£1:......
o

1000

100

'

;

1----

====L~-~~.::.-:-~.====-==~=-7.:-'::=:=

~

_'-.

..

:-~d'"" """",~~:;:: ---=----. ---t-··_·_----~-

10+-~--+-~--+-~--+-~--+-~--r-~~

o

10

20

30

40

50

_ 60

Time (Channel)

Fig. 1. The time spectrum of f3-rays emitted from 39Ca
stopped in the CaF2 stopper. 39Ca were produced throughthe projectile fragmentation of 40Ca and separated by asecondary beam line at the Bevalac; it shows an extremely
small background.

at 60° relative to the beam axis and located in afield-free region just upstream of the catcher, was used
to polarize the ions. Final implantation (stopping)of the 39Ca ions occurred in a CaF 2 single crystal of
0.2 mm in thickness located in a 0.48 T magnetic
field. Since the observed efficiency for producing,analyzing, and stopping of 39Ca ions was 1 part in
10 5 of the primary 40Ca beam, and the contaminationof other short-lived ions in the stopping catcher was
sufficiently low, the 39Ca decay time spectrum wasobserved cleanly down to 1 part in 103 (Fig. 1).
RF was applied to induce depolarization of the
stopped 39Ca ions in the crystal. An asymmetry
change in the (3-ray distribution was successfully
observed, R = 2APr; = + (0.65 ± 0.19) %, where theasymmetry parameter A is predicted to be A = + 0.8,
P is the polarization, and r;, the correction for the

28

K. Matsuta, et al.

large solid angle of the f3-ray counters, is r; ~ 0.5.
A null calibration measurement gave R = - (0.13 +0.19) %.
The present work was supported in part by the
Yamada Science Foundation and the Grant in Aid
for Scientific Research from the Ministry of Education, Science and Culture of Japan. The study ispartially supported also by the U.S. Department ofEnergy under contract No. DE-AC03-76SF0098, by
the INS-LBL Collaboration, and by the Japan-U.S.
Cooperative Research Program from the Japan
Society for the Promotion of Science.
References
1) Y. Nojiri, K. Matsuta, T. Minamisono, K. Sugimoto,K. Takeyama, H. Hamagaki, S. Nagamiya, K. Ornata,
Y. Shida, I. Tanihata, T. Kobayashi, S. Matsuki, S.
Shimoura, J. R. Alonso, G. Krebs, and T. J. M. Symons:
Proc. VIIth Int. Conf. Hyp. Int., Bangalore, India, Sep.
8-12 (1986) to be published.
2) Y. Nojiri, K. Matsuta, T. Minamisono, K. Sugimoto,K. Takeyama, H. Hamagaki, S. Nagamiya, K. Ornata,
Y. Shida, I. Tanihata, S. Matsuki, S. Shimoura, J. R.
Alonso, T. Kobayashi, G. Krebs, and T. J. M. Symons:l. Phys. Soc. lpn., 55, Suppl., 391 (1986) .
3) T. Minamisono: l. Phys. Soc. lpn., 34, Suppl., 324 (1973) ;K. Sugimoto, A. Mizobuchi, K. Nakai, and K. Matuda:
Phys. Lett., 18, 38 (1965) .
4) T. Minamisono, J. W. Hugg, D. G. Mavis, T. K. Saylor,
H. F. Glavish, and S. S. Hanna: Phys. Lett. B, 61, 155(1976) .

29
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-13. Two-Step Analysis for the 12C(d,2He)128 Reaction
T. Motobayashi, M. Ishihara, H. Sakai, * N. Matsuoka, * K. Hosono, *T. Saito,* A. Okihana,** S. Shimoura,*** and A. Sakaguchi****NUCLEAR REACTIONS 12C (d, 2He) 12B, E = 70 MeV; measured[ a(8), Ay(8), DWBA and two-step analysis.
Charge exchange reactions are suitable for studying isovector excitation modes of nuclei. To extract
quantitative information about their strength, usually
the DWBA (Distorted Wave Born Approximation)(or sometimes DWIA (Distorted Wave Impulse
Approximation)) calculations are performed assuming a one-step reaction mechanism. Therefore, it
is important to estimate the contributions of thetwo-step process especially at low incident energies.
We report here the two-step analysis for the (d, 2He)
reaction on 12C at E in = 70 MeV. Experimental
procedures and one-step DWBA calculations havebeen reported elsewhere. l )In the present calculation, the processes via d-p2He and d- 3He- 2He channels were taken into account.
The code TWOFNR2) in its exact finite range
option was used to calculate two-step amplitudes.
Intermediate states involved in these two-step processes are 1/2- ground state and 3/2- excited state(Ex = 3.68 MeV ) of 13C for the d-p-2He process and3/2- ground state and 1/2- excited state (Ex =2.12 MeV) for the d- 3He- 2He process. Spectroscopic
amplitudes involved in the above processes were
calculated by the INS shell model code 3) based on
the Cohen-Kurath wave functions. 4 ) T he opticalpotential parameters for incident and intermediatechannels were taken from the studies of elastic scattering.5 , 6 ) The potential of the outgoing channel
was taken to be the same as that of the incident
channel. Single particle wave functions were generated by the usual separation energy method. The
non-orthogonality terms were wholly taken into account by the method described in Ref. 7.
The results are shown in Fig. 1 together with theexperimental data. General features of the experimental angular distributions of the cross section andthe vector analyzing power are reasonably describedby the calculations. Although the theoretical crosssection for the two-step process is smaller than thatof the one-step process, inclusion of the two-step* Research Center for Nuclear Physics, Osaka University.

** Kyoto University of Education.

*** Department of Physics, Kyoto University.
**** National Laboratory for High Energy Physics.

1dcr~~~__~~~__~~____~

em-()lb/sr)

Ed = 70 MeV.. '.....

one+two....-.
.........

20
O.l.

40

60

ecm

,r-.

?< "\
O~
... .. \ - \III-O. l.

- 0 .8........... \~0. -" <P-J,'i,-Q--- --- -- ' ....... ~~:~=:::=::::::.
.........

Fig. 1. Differential cross sections and vector analyzing powers of the reaction 12C (d, 2He) 12B. Open circles indicate
the experimental data. Dashed-dotted lines represent thetheoretical two-step contributions which are coherent sumsof the amplitudes of the d -3He-2He (double dashed-dottedlines) and d-p-2He (dotted lines) processes. Broken lines
represents the one-step DWBA calculation. Solid lines indicate the full calculation which is the coherent sum of oneand two-step amplitudes. Normalization of the one-step
calculation is determined so that the full calculation may
fit the experimental cross section.

process clearly improves the fit to the data.
References
1) T. Motobayashi, M. Ishihara, N . Matsuoka, H. Sakai,
T . Saito, K. Hosono, A. Sakaguchi, S. Shimoura, andA. Okihana: RIKEN Accel. Prog. Rep., 19, 7 (1986).
2) M. Igarashi: private communication.
3) K. Ogawa: p r ivate communication.
4) S. Cohen and D. Kurath: Nucl. Phys. A , 255, 315 (1975) .
5) K. Hatanaka, N. Matsuoka, T. Saito, K. Hosono, M.
Kondo, S. Kato, T. Higo, S. Matsuki, Y. Kadota, andK. Ogino: Nucl. Phys . .4" 419, 530 (1984) .
6) T. Tanabe, K. Koyama, M. Yasue, H. Yokomizo, K. Sato,
J. Kokame, N. Koori, and S. Tanaka: l. Phys. Soc. lpn.,
41, 361 (1976) .
7) M. Igarashi: Phys. Lett. B, 78, 379 (1978) .

30
RIKEN Acce!. Prog. Rep. 20 (1986)

111-1-14. Mass-Number Dependence of the Hexadecapole (Y42)
Transition Strength to the r-Vibrational Band in Inelastic
Proton Scattering at 65 MeV
T. Ichihara, H. Sakaguchi, * M. Nakamura, * M. Y osoi, * M. Ieiri, *Y. Takeuchi,* H. Togawa,* T. Tsutsumi,* and S. Kobayashi*

NUCLEAR REACTIONS 152,154S m , 160Gd, 164Dy, 166,16SEr, 176Yb,
182,184W, 1920S (p, p') Ep = 65 MeV; measured differential cross[ sections and analyzing powers; coupled-channel calculation,
deduced transition strength, RPA model calculation.

For the study of nuclear collective motion, it isinteresting to investigate the r-vibrational band in
the 152 ~ A ~ 192 region,t-4) where the nuclei are
well-deformed and the non-collective components aresuppressed up to the gap energy (2.d) owing to thesuperconductivity of the ground state. In particular,
the hexadecapole degree of freedom in the collective
motion is of renewed interest. The possible existence
16°G:l(P. P .)

10 5

J. a

Ef'= 65 MeV

0.5
10 '

o. a
10 3
-0.5
10 2

J.O
0.5

10 I

0.0
I-

10 2

(JJ

a:

-0.5

10 1

3:

J.o

10 1

:z:

'-

w

.0

E
Z
0

tU
W
(f)

0

t:)

N

10 0

0.5
0.0

>-

-1
<: -0.5

:z:

(f)
(f)

a:
u

0
0..

10 1

100

<:

1.0
0·5
0.0
-0.5
1.0
0. 5
0.0
-0.5

Fig. 1. Measured cross sections and analyzing powers for the 16°Gd (p, p') scattering at
65 MeV. The solid (dotted) curves show the best-fit result of the coupled-channel
calculation assuming the Y 22 and Y 4.2 (only Yd r-vibration.

* Department of Physics, Kyoto University.

T. Ichihara, et al.

of the hexadecapole (Y42) component in the rvibration was reported in early works on inelastic
scattering. 4-6) Experimentally, recent progress in highquality beams and high resolution spectrographs has
made it possible to measure the low-lying inelastic
scattering for deformed nuclei in the 152 ~ A ~ 192region. In this respect, we have recently studied theexcitation to r-vibrational states in 168Er(p, p') at
65 MeV and performed a precise measurement andanalysis on the cross sections and analyzing powers. 1)
The results have clearly shown the importance of thehexadecapole (Y 42 ) component. However, the systematic behavior of the Y 42 strength with mass
number, which will be the key to understanding ther-vibration, is still an open problem.
Here we have extended the investigation over thewhole range of deformed nuclei; inelastic scatteringof polarized protons at 65 MeV exciting the rvibrational states has been studied for 152,154Sm,
160Gd, 164Dy, 166,168Er, 176Yb, 182,184W, and 1920S.
The characteristic behavior of the hexadecapole(Y 42) strength with mass number has been revealed;
the behavior fits a simple theoretical picture
relating the strength with shell filling of valence
nucleons. 7)
The experiment has been performed with polarized
protons from the cyclotron at the Research Center
for Nuclear Physics (RCNP), Osaka University, andthe data have been obtained using a high resolution
spectrograph RAIDEN.8)
The overall energy
resolution was 20-26 keY (FWHM). Details of theexperimental method are described elsewhere. 9-11 )Coupled-channel analysis assuming the r-vibrational model has been performed with a modified
version of the code ECIS79/ 2) which includes theform factors of surface vibration in deformed nuclei.
The potential surface is assumed to be
R(Q')=Ro[l+2J(3;.oY;.o(Q');'=2,4,6

Y 22(Q') + Y 2 - 2(Q')}+ a42 { Y 42 (Q') + Y 4 - 2(Q')} ]

+a22{

(1 )

where a22 and a 42 are the collective coordinatescorresponding to the quadrupole (Y 22) and hexadecapole (Y 42 ) r-vibration. The spin-orbit deformation (full Thomas term) and Coulomb excitation
were included in the calculation. The deformation
parameters for each part of the optical potential
were set to be identical for simplicity.
Without the hexadecapole (Y 42 ) term, the 4+
state of the r-vibrational band cannot be reproduced
for all the nuclei measured. Excellent fits have beenobtained for all the states by introducing the hexadecapole (Y 42) r-vibration. The solid ( dashed)
curves in Fig. 1 show examples of the coupledchannel calculation for 16°Gd assuming the Y 22 andY 42 (only Y 22 ) r-vibration. The coupled-channel

31

Yn transit .i on strength to/K" = 2+ 'V-vibrational band

0.3
(RPA)

•

(P.P·)

65MeV

/
Os

~

/

/
Os

0 .2

i
o

+

N
tf)

co

0.1

o

150

160

Y4.2 transition strength to

0 .04

K"= 2+ 'V-vibrational band
(RPA X3. 5)+(p.p') 65 MeV
Os

+>-

t

~

:1'o 0.02....

~

CO 0.01

o

150

160

170

180

190

mass number

Fig. 2. The Y 22 and Y42 transition strength to the r-band
obtained from the present experiments (closed circles) andfrom the RPA calculations (various lines).

analysis assuming an asymmetric rotor model gives
similar results. 1)
The quadrupole (Y 22) and hexadecapole (Y 42)
transition strengths were calculated from the best-fit
optical potential parameters and they are plotted as
closed circles in Fig. 2. We also show RP A calculations 13 ) assuming the paring plus Q-Q force in the
doubly stretched coordinates in Fig. 2, where theresults of the Y 42 strength of the RPA calculations
were multiplied by 3.5.
The RP A calculation reproduces the Y 22 transition
strength quantitatively well. In the region of 166Er,
the proton sub-shell (N, n z ) = (4, 1) and the neutron
sub-shell (N, n z ) = (5,3) which satisfy the selection
rule of the r-phonon excitation are half-filled and
it is expected that the collectivity of the r-vibration
becomes large. This effect is known as the sub-shellstructure effect.H) The experimental Y 22 strength
has a broad local maximum near the 168Er region.
The RP A calculation successfully reproduces thistrend.
The RPA calculation reproduces the trend of theY 42 strength, but fails to reproduce the absolutevalues by about a factor of 3. Since this RPA calculation assumes only the Q-Q force, only the Y 22 mode r-vibration is induced. Therefore, it will be32

T. Ichihara, et al.

necessary to introduce the Y42 -mode in the r-vibration to explain the experimental Y 22 and Y 42 transition strengths consistently.
In conclusion, the present study has revealed theimportance of the hexadecapole (Y 42 ) degree of
freedom in the r-vibration for the whole range of
deformed nuclei. The quadrupole (Y 22) and thehexadecapole (Y 42 ) transition strengths to the rvibrational band show the strong mass-number
dependences. A microscopic calculation assuming
the random phase approximation (RPA) has been
compared with the present data; this indicates thenecessity of the hexadecapole degree of freedom in
the r-vibration.
References
1) T. Ichihara, H. Sakaguchi, M. Nakamura, T. Noro,
F. Ohtani, H. Sakamoto, H. Ogawa, M. Yosoi, M. Ieiri,
N. Isshiki, Y. Takeuchi, and S. Kobayashi: Phys. Lett. B,
149, 55 (1984) .
2) I. M. Govil, H. W. Fulbright, D. Cline, E. Wesolowski,
B. Kotlinski, A. Backlin, and K. Gridnev: Phys. Rev. C,
33, 793 (1986) .
3) P. O. Tj~m and B. Elbek: Nucl. Phys. A, 107, 385 (1968).

4) R. S. Mackintosh: Phys. Lett. B, 29, 629 (1969) .
5) L. Ray, G. S. Blanpied, and W. R. Coker: Phys. Rev. C,
20, 1326 (1979) .
6) K. Van der Borg, M. N. Harakeh, and B.S. Nilsson:
Nucl. Phys. A, 325, 31 (1979) .
7) T. Ichihara, H. Sakaguchi, M. Nakamura, M. Yosoi,
M. Ieiri, Y. Takeuchi, H. Togawa, T. Tsutsumi, andS. Kobayashi: Phys. Lett. B, 182, 301 (1986) .
8) H. Ikegami, S. Morinobu, I. Katayama, M. Fujiwara,
and K. Hosono: Nucl. Instrum. Methods, 175, 335 (1980) .
9) T. Ichihara, H. Sakaguchi, M. Nakamura, T. Noro,
F. Ohtani, H. Sakamoto, H. Ogawa, M. Yosoi, M. Ieiri,
N. Isshiki, and S. Kobayashi: Phys. Rev. C, 29, 1228
(1984) .
10) F. Ohtani, H. Sakaguchi, M. Nakamura, T. Noro,
H. Sakamoto, H. Ogawa, T. Ichihara, M. Yosoi, andS. Kobayashi: Phys Rev. C, 28, 120 (1983) .
II) H. Ogawa, H. Sakaguchi, M. Nakamura, T. Noro,
H. Sakamoto, T. Ichihara, M. Yosoi, M. Ieiri, N. Isshiki,
Y. Takeuchi, and S. Kobayashi: Phys. Rev. C, 33, 834(1986) .
12) J. Raynal: code ECIS79 (unpublished).
13) M. Matsuo: private communications, submitted to Prog.
Theor. Phys.
14) A. Bohr and B. R. Mottelson: Nuclear Structure, Vol. II,
Benjamin, New York (1975).

33
RIKEN Accel. Prog. Rep. 20 (1986)

111-1-15. Transport Coefficients for Fission at High Excitations
S. Yamaji and H. Hofmann*r FISSION transport equation, linear response theory, two-centerl shell model.

The dynamics of fission can be viewed as a diffusion process in a phase space of collective degrees
of freedom. This picture was introduced by
Kramers,l) who assumed forces local in time, andthe diffusion coefficient was given by the famous
Einstein relation. Such a Markoffian behavior isquestionable since the timer scales for collective andintrinsic degrees of freedom, although different fromeach other, are not separated widely enough.
In Ref. 2 it was argued that Krammers' picture
can still be retained in its essential features whosetransport coefficients are calculated at a finite local
frequency. The transport coefficients are determinedby the response of the intrinsic system, and this
response depends on the frequency of perturbation(flo) , however, the perturbation must be given bycollective motion itself. Hence, this frequency has
to be calculated by solving locally a dispersion
relation (secular equation) for the collective motion.
The details of the theory will be published elsewhere. 3 )An aim of this report is to study how importantsuch a non-Markoffian effect is. We reported a
microscopic computation of the transport coefficientsfor inertia M, friction r, and local stiffness C bothin the present self-consistent version (no~O) as wellas in a zero frequency limit.4)
Our computation is similar to the one of Ref. 2
where the fission dynamic was followed up to asaddle. It is necessary to go beyond that point. But
then the microscopic picture has to be based on a
two-center shell modeP) This is a new feature here.
In this first computation within a two-center shellmodel, we restrict ourselves to a one dimensionalcase and take the center-separation Z as a collective
coordinate.
Actual microscopic calculations were carried out forfission of 212PO at temperature of about 2 MeV andabove. We plot stiffness C, inertia M, and frictionr as a function of Z in Figs. 1 to 3. In each case, weshow a self-consistent value as well as a zero frequency limit. We observed that this zero frequency* Physik·Department der Technischen Universitat Munchen.

1

limit is a very good approximation to the selfconsistent case. The stiffness coefficient C(O) in
Fig. 1 is a basic ingredient in our theory. We
approximate this by the second derivative of the

212pO- - c(n o)-51

E= 0.35---- C(O)

;;
~
u
- 10

- 15L-L-5L-~~~~~lLO-L-L~~~15~--L-~z (fm)

Fig. 1. The local stiffness as a function of center·separation Z. The local stiffness from the liquid drop energy
is shown by the dashed curve and the self-consistent
approach by fully drawn curve.

100

C

212pO

- .-

M(Werner- Wheeler)€= O.35
T= 2MeV

::l
til
til

E
c

.3 50

E

..8
:!;

Fig. 2. The inertia M as a function of Z. We show the selfconsistent value (fully drawn curve), the zero frequency
limit (dashed curve) as well as the liquid drop value(dotted·dashed curve).

S. Yamaji, et al.

34

2 12 pOr(n o)

300

E= 0.35
T= 2MeVr(O)0.27r".11

~

7 200
~

100

z (frn )Fig. 3. The friction coefficient r as a function of Z. The
self-consistent value is given by the full curve, the zerofrequency limit by the dashed one. The dotted-dashedcurve represents Nix's modified formula.

liquid drop energy with respect to Z. In Fig. 2 wecompare our result for inertia to a liquid drop model.
We find a usual situation that the irrotational flow
value underestimates 't he inertia. It is only in thescission region where the situation is reversed. As
for friction, in Fig. 3 we have added a plot of Nix's
modified version of the wall formula. 6 )Finally, we wish to draw attention to temperaturedependence. We plot in Fig. 4 inertia and friction
computed within the zero frequency limit as a function of T. As the most striking feature we observestrong temperature dependence of r. This is inremarkable contrast to the wall formula. 6 ) As thewall formula depends on T only slightly, the agreement between the dashed curve and the dotteddashed one in Fig. 3 is accidental to some extent
and just true for T = 2 MeV.
From our observations we deduce the following
statements:a) for a region of temperature higher than 1.5
to 2 MeV, the zero frequency limit appears to be agood approximation to the self-consistent calculation;b) friction increases with T until a plateau isreached at about 4 MeV.

300,---,---.----r---,----.---~
212 POz = 15.5frn

E = 0.35

200

100

Fig. 4.

The temperature dependence of friction and inertia.

References
1) H. A. Kramers: Physica, VII, No. 4, 284 (1940) .
2) H. Hofmann and A. S. Jensen: Nucl. Ph ys. A, 428, lc(1984) .
3) H. Hofmann, R. Samhammer, and S. Yamaji: Unpublished.
4) H. Hofmann and P. J. Siemens: Nucl. Phys. A , 257 , 156(1976) .
5) A. Iwamoto, S. Yamaji, S. Suekane, and K. Harada:
Prog. Theor. Phys., 55, 1I5 (1976) .
6) J. R. Nix and A. J. Sierk: Preprint LA-UR-86-698 (1986).

35
RIKEN Accel. Prog. Rep. 20 (1986)

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

Cross Sections of the Relativistic Radiative Electron Capture
by Use of the Strong-Potential Born Calculation
K. Hino and T. Watanabe

The relativistically extented strong-potential Born
(SPB) formalism is applied to the radiative electron
capture (REC) process caused by the bombardmentof a heavy and highly stripped charged particle witha relativistically high velocity.1) The results arecompared with those obtained from the non-relativistic SPB calculations 2 ) and with those from the

10

1

.

/'

/

...

!

i

i

I

~

/

.0

-10 0

/

197 MeV/amu
xe

54

+_

Be

relativistic Born calculation (Sauter's formula) ;3,4)
the latter includes no distortion effects between aheavy projectile ion and an active electron. Even
if the strong distortion effects are taken into considenltion in the SPB approximation, the shapes ofphoton angular distributions in the laboratory frame
still behave nearly as sin 2 0L (OL is the angle of theemitted photon) in the vicinity of the angle of 90°.
This behavior is the same as the results calculatedby Sauter's formula. The higher the charge of a
projectile ion becomes, however, the greater the discrepancy between the angular shape of our results
and that of Sauter's becomes at both angles smaller
and larger than 90° (Figs. 1 and 2). As is expected,
the magnitudes of the differential and the total crosssections are drastically influenced by the distortionV

10 31.~0.8

0.4

0.6

10-2 ~--~--~~--~--~

o

45

90

135

180

e L (degrees)Fig. 1. Angular distributions of REC photons for 197 MeV I
amu Xe 54+-Be collisions. Solid lines, the present calculations; Dotted chain curve, the relativistic Born calculations of Sauter (Ref. 2). Experimental results are quoted
from Ref. 5.

-...

\

I

I

.0

..J

.

1 0-1 L.....-~_'---'---1---..J-'---'

0.6

0.8

1.0

vic

/

-10 0
.......

1

0.4

/

f/)

"0

b

/

10 1

.......

c:

.0

-10 -

422 MeV/amu
U92 +_ Be.g 10- 1 .

10-2L-__- L_ _ _ _L -_ _~_ _~90
135 18045oe L (degrees)Fig. 2. The same as Fig. 3 for 422 MeV lamu U 92 +-Be
collisions.

Fig. 3. Total cross sections for Xe 54 +-Be collisions versus theincident velocity vic and the Coulomb parameter between
an active electron and the projectile ion lJ . Solid lines(---), the present calculations (RSPB-I); Chain lines(- - -), the relativistic SPB calculations without theLorentz contraction factor based on the motion of a target nucleus in the moving hame (RSPB-II); Dotted-chainlines (-.-), the relativistic Born calculations of Sauter(RB); Broken lines (- - - -), the non-relativistic SPB calculation of Ref. 2 (NRSPB); Dotted lines (.....), therelativistic impulse calculations (RIA); Experimental results are quoted from Ref. 5.

K. Hino, et aI.

36

V

1.00.90.8 0.7

10 3 ",,-,-,-"'----;'""1~

92+\~ !:l"

, \
'\

-

10

2

'

- Be

""
'- "-

, \
\, \

1 \ \

.0

\ .
\ \
\.

b
10 1

'.

\ \

\ .
\
\

\.

0

10 0 .6

mation are too underestimated to explain the experimental ones (Figs. 3 and 4). The Coulomb off-shellfactor represents the radiative transitions from theRydberg states of the electron-projectile bound system into the final state of the K-shell. The SPB
wave function includes the contributions from intermediate bound states as well as from the continuum
states. The former contributions are absent in theimpulse wave function.

0.8

1.0

vic
Fig. 4. The same as Fig. 5 for U 92 +-Be collisions.
The experimental result is quoted from Ref. 5.

effects ascribable to a large charge of a heavy projectile ion such as U 92 +. Our results are in good
agreement with recent experiments. 5 ) In addition,
the Coulomb off-shell factor introduced by the SPB
theory is found playing important roles in the caseof the relativistic REC process because the results
calculated by using the relativistic impulse approxi-

References
1) K. Hino and T. Watanabe: Phys. Rev. A (in press).
2) M. Gorriz, J. S. Briggs, and S. Alston: J. Phys. B, 16,
L665 (1983) .
3) F. Sauter: Ann. Phys. (Leipzig), 9, 217 (1931); 11, 454(1931) .
4) E. Spindler, H.-D. Betz, and F. Bell: Phys. Rev. Lett.,
42, 832 (1979) .
5) R. Anholt, S. A. Andriamonje, E. Morenzoni, Ch. Stoller,
J. D. Molitoris, W. E. Meyerhof, H. Bowman, ].·S. Xu,
Z.-Z. Xu, J. O. Rasmussen, and D. H. H. Hoffmann:
Phys Rev. Lett., 53, 234 (1984); W. E. Meyerhof, R.
Anholt, J. Eichler, H. Gould, Ch. Munger, J. Alonso, P.
Thieberger, and H. E. Wegner: Phys. Rev. A, 32, 3291
(1985); R. Anholt, Ch. Stoller, J. D. Molitoris, D. W.
Spooner, E. Morenzoni, S. A. Andriamonje, W. E. Meyerhof, H. Bowmann, ].-S. Xu, X.-Z. Xu, J. O. Rasmussen,
and D. H. H. Hoffmann: Phys. Rev. A, 33, 2270 (1986) .

37
RIKEN Accel. Prog. Rep. 20 (1986)

111 ..2..2.

Charge Exchange Call is ions on the Sol id Surface
K. Fujima and H. Adachi *Recently, Ion-Neutralization-Spectroscopy (INS)
has attracted a much interest as an effective toolfor investigating electronic properties of the solid
surface. 1 ) Four mechanisms i.e., resonant chargetransfer, Auger neutralization, inner-shell resonant
charge transfer and radiative neutralization, havebeen proposed in which an electron is transferredfrom the solid surface to an ion. 2 ) The latter two
are thought to be less important for low energy
collisions.
In this report we concentrate attention on thefirst mechanism. When an ion comes to a certain
distance from the solid surface, the orbital of ion
mixes with that of solid surface. An electron canmove from the solid to the ion or vice versa bytunneling. This mechanism is often called 'resonant
charge transfer.' The possibility of charge exchangeby this mechanism has so far been discussed basedon the comparison between the work function of
the solid and the ionization potential of the ion.
So, we feel an urgent need of a quantitative studyof charge exchange cross section from the first principle and plan to apply to this process a semi-classicaltreatment, which is now commonly used for chargetransfer collisions of ion-ion and ion-atom charge(namely diatomic system). There are three difficulties in extending this method to the collision of an
ion with a solid surface. First, we have to calculate
the wave function of the system composed of a solidand an ion and compute the coupling matrix elements. I t is hard to do this even for a di-atomic
system when many states are involved in the calculation. Second, we can reduce the dimension of
coupled equation by introducing a polar coordinate
and rotational and radial coupling between channels
for the diatomic system. But, for the system of ion
and solid surface, we must compute matrix elements
for the operators a/ax, a/ay, and a/az in the
Cartesian coords. because we can not use the rotational and the radial coupling operators i.e., iL y anda/ aR. Third, the potential between an ion and asolid is not so easily obtained which is necessary to
get a classical trajectory of the ion.
To this end, we have developed a new computercode which calculates the coupling matrix elements* The Hyogo University of Teacher Education.

In the Cartesian coord. using the wavefunction
obtained by the DV-Xa cluster calculation. We
applied this program to Si + He+-?> Si+ + He chargetransfer collision which the most simplified model ofneutralization of He on the Si surface. The energy
diagram for Si + He+ is shown in Fig. 1. Figure 2
shows the impact parameter dependence of charge

-20.0

-70.0
0.02

0.07

0.1

0.2

0.7 1

ATOMIC DISTANCE (a.u.)

Fig. 1. Energy diagram for Si + He+ system. Orbitals belong
to U', 71". and a irreducible representation are marked withT, •• and ... respectively.

0.6
0.5
0.4
.D

a..

0.3

0.2
0.1
0.0
2
3
4
IMPACT PARAMETER (a.u.)

Fig. 2. Charge exchange probabilities versus impact parameter. Chain - ' - ' - , solid - - . and dushed - - curves
correspond to the cases of incident energy 0.5, 1, and2 keY, respectively.

38

K. Fujima, et ai.

exchange cross sections at the incident energies 0.5,
1, and 2 keY. The integration of the coupled equation in orthogonal coordinate and computation of
the charge transfer cross section in ion-surface collision are in progress.

References
1) R. Souda and M. Aono: Butsuri, 41,633 (1986) (in Japa·
nese) .
2) H. Hangstrum: Phys. Rev., 96, 336 (1954) .

39
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-3.

Calculation of Ionization Cross Sections of Multi-Charged
Ions in Proton Impact by TFD Method Using BEAt
S. Zhou, * X. Zhang, * Q. Ma, * J. Cheng, * Y. Liu, * and T. Watanabe

Using the binary encounter approximation (BEA),
we have calculated the ionization cross sections by
the Thomas-Fermi-Dirac model for the reaction(1)

where Z is the atomic number of A and Z = 18 and
36 are taken in the present calculation, q = 1-5, andzA (q+l) (2J) stands for all possible electronic states of
the ion. In the present approach, we aim to obtainthe cross sections for relatively high Z values bytaking into account the exchange effect for mnershell electrons of the target ion.
These processes are characterized by a large
magnitude of momentum transferred to the electrons
in the ions zA (q+1)+ by colliding with incident protons.
Such collision can be treated by the classical description and this feature supports the use of BEA.1)
In this treatment an electron in the target ion isassumed to be ejected into the continuous states
when the energy transferred to the electron exceeds
its binding energy.
Both the momentum distribution f (p) dp for anelectron having momentum between p and p + dp
and the probability 1,,. (p) dp for finding an electron
at a distance r from the nucleus of the target ion
whose momentum is in this range are obtained fromthe TFD modeJ.2)
They arefor p(r)~Pmax(r) (2)</J" = x[c+(¢/X)1/2J3¢lx=c 2X/16
x¢'(x)lx = -q/ Z+¢lx, ¢(O) = 1(4)

Here we define a cross section (l(i) (v, w) in thelaboratory frame, where the nucleus of zA q+ is stationary, for ionization in the collision between an
electron with velocity w in zAq+ and a proton withvelocity v. The cross section (lAV(i) (v) for theelectron ejected from zA q+by collision with the proton
is defined as 4 )axt(v)= f~ aCi)(v, w)f(w)dw(5)

where f (w) denotes the velocity distribution functionof an electron of the ion zA q+ determined in Eq. (3).
(l( i ) (v, w)
for projectile proton is explicitly derived
from the Vriens theory/)(1) 2mv 2 > U i.

rV - Ul/2mv

a~~(v)= Jo

aA+Bf(w) dw+ roo

Jv- Ul/2mv

aB-f(w) dw(6)10-16 . - - - - - - - - - - - - - ,11, = 110 - 17for p(r»Pmax(r)andf(p)dp= {32rc2p2r3(p)dP/3(Z - q)h3 for p"2. p(R)32rc 2p 2R 3dp/3(Z - q)h3
for p< peR) ,(3)

where Pmax (r) = (2me 2Z/u)1/ 2[c+ (l/J/ x ) 1/2]. r(p )is determined from the relations P = (2me 2 Z / u) 1/2.
[c+(l/J/X)1/2J, x=r(p)ju, and u=(3j32rc 2)2/3h2j
2me 2 Z 1 / 3 , where R is the radius of zAq+, X=R/u, c=(3/32rc 2 Z 2 )1/3, and l/J is the TFD function which
satisfies the following equation and conditions: 3)
t Presented at the Xth International Conference on Atomic
Physics, 25-29th August, 1986, Tokyo.
* Dept. of Modern Physics, Univ. of Science and Technology of China (USTC) , Hefei, Anhui, China.

10 - 20 L-----L..,..--.L..,---L-;:--~~L_:__~:__:_':_;:~
7
6
5
10- 1 100 10 1 102 10 3 10 4 10 10 10
E (kev/amu)
Fig. 1. Cross sections for lsArq++H+~ lSAr(q+l)++H++e by
the binary encounter theory with the Thomas-Fermi-Diracapproximation as a function of impact energy per nucleon.

S. Zhou, et al.

40

10 - 16,--_ _ _ _ _ _ _ _ _ _ _----,(2)

2mv 2 < U i

GX~(v)= r=GB./(w)dw

JUi/ 2mv-v

(7)

where
GA+B=2rre'[1/ Ui+mw 2/3U12-l/2m(v 2- w 2)J/mv 2
GB= rre'{1/2mw(v+w)+ l/Ui

+ m[2v S +w s - (2 UII m + W2)S/2J/3w U12} / mv 2;;;' 10 - 18E

and
U i is the ionization energy of zAq+.
Figures 1 and 2 show the results we have obtainedof aAV(i) (v) for lsArq+ + Hand S6KrQ+ + H. They
are comparable to the results of another article 5 )which used the TF model instead of the TFD model.

~b

10 - 19

10 - 20

References
10 - 21 ~-..L._;:____L....:_-L_:_---L.._;:__....L...,--'_:_---L.._::____'
10- 1 100 101 lOZ 103 104 105 106 107
E (kev/ amu)

Fig. 2. Cross sections for 36Krq++ H +~ 3sKr(q+1l+ + H ++ e by
the binary encounter theory with the Thomas-Fermi-Diracapproximation as a function of impact energy per nucleon.

1) L. Vriens: in Case Studies in Atomic Collision Physics I(eds. E. W. McDaniel and M. R. S. McDowell), NorthHolland, Amsterdam, Chap. 6, p.335 (1969).
2) C. A. Coulson and N. H. March: Proc. Phys. Soc. A,3) P. Gombas: Die statistische Theorie des Atoms und ihre
Anwendungen, Springer, Vienna (1948); Ann. Phys., 18,
1 (1956) .
4) L. Vriens: Proc. Phys. Soc., 90, 935 (1967) .
5) X. Fang: Electron Stripping Cross Sections of Charged
Ions by H+ Impact, USTC thesis (1985).

41
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-4.

Extended Bethe Surface: Behavior of the General ized
Oscillator Strength along Isoelectronic Sequence
M. Iwai, I. Shimamura, and T. Watanabe

The generalized oscillator strength (GOS), whichis the generalization of the optical oscillator strength,
is directly related to the differential cross section for
inelastic collision of the fast charged particle withatoms and molecules. 1 ,2) This atomic or molecularproperty is important, since it reflects the detailed
electronic structure of target atoms or molecules, andrepresents the response of the system to a suddenchange of momentum of its electron.
In this report we investigate the behavior of GOS's
along isoelectronic sequence using the configurationmixing wave functions. An isoelectronic sequence
consists of a neutral atom and many ions. Eachmember of a sequence has the same number ofelectrons. Effects of electron correlation are negligible for ions with sufficiently large Z due to thestrong nuclear attraction potential. As Z decreases,
however, the configuration~mixing effects become
appreciable. Behavior of optical oscillator strengths
along isoelectronic sequence has been investigated in
depth so far. 3 ) However, the behavior of GOS's has
been only partially analyzed. Such an analysis will
afford the systematic understanding of electronelectron correlation effects on GOS's. In principle
one has to apply the Coulomb-Born approximation
rather than the plane-wave Born approximation to
the scattering of a charged particle by an ion. If
the incident particle is not an electron but an ion,
however, the effect of Coulomb deflection must be
negligible except for slow collisions. Then GOS'sof ions still contain important information about inelastic scattering of a heavy particle.
In these analyses we propose to extend the Bethe
surface,1} which is a three-dimensional plot of a
GOS as a function of a momentum transferred andexcitation energy, by introducing an additional axis
for the inverse of the (effective) nuclear charge. We
shall call this new surface an "extended Bethe
surface" and show the usefulness of this surface tovisualize effects of electron correlation on GOS's.
The GOS for excitation of the target state fromI 0 > to In> is defined byl)Fon(K)= 2;~n I<nl ~eik'''jIO> 1 2(1)where Eon is the excitation energy and K denotes

the momentum transferred during the collision.
Here we define the scaled GOS as a function of
the scaled momentum transfer K=K/Z by

::l

:

16

8

Zeff=Z-1. 7

4o -~1-0----8----6----4--~~-0~2--~
In(K/Z eff ) (in a.u.)
Fig. I (a). Scaled GOS for ]s22s 2S-ls22p 2p transition in Lilike system.

5.0
::l

'"c
N

4.0

44Q)

N

X

w

.......

3.0-;2

Zeff=Z-l. 7-;:;:2.0

1.0
Li I
0.0t=====_......:::::~~~

-10

-8

-6

-4

-2

_ __

0

In(K/z eff )2 (in a.u.)
Fig. 1 (b). Scaled GOS for Is 22s 2S-ls23P 2p transition in Lilike system.

42

M. Iwai, et al.

(2)
If electron-electron interaction can be completely
neglected, Son (K) is universal for all atoms, being
independent of Z. Then we notice that the variationof the scaled GOS from the universal value is wholly
due to the electron-electron interaction.
Figure 1 (a) and Fig. 1 (b) show the GOS's forthe 2s-2p and 2s-3p transitions in the Li-like system,

=i

o
c
N

N

C1J

UJ

"-

s;;:

u:

20

10

-10

-8

-6

-4
l nCK/Z

-2
ef f

0

) 2 Cln o.u. J

Fig. 2 (a). Scaled COS for 2s 2 1S-2s22p 1p transition in Belike system.

4.0

r~spectively.

Note that the scaled GOS's are plotted
as functions of the scaled momentum transfer. At
sufficiently high Z, the shape of the scaled GOS
almost coincides with that in the hydrogenic model
for both transitions. We readily notice, by comparisonof Fig. 1 (a) and Fig. 1 (b), that the behavior of
the GOS's along the isoelectronic sequence is quite
different between these transitions. Variations of the
GOS's with Z can be almost scaled for the 2s-2ptransItIOn. However, the situation for the 2s-3ptransition is totally different: The optical oscillator
strength decreases rapidly with decreasing Z, andalmost complete cancellation occurs in the region
near Li I. As Z becomes small, the minima in the
GOS along the K -axis approach the optical plane(K = 0 plane) while the maxima become larger (Fig.
1(b) ) .
Next, we see the behavior of the GOS's for the
2s-2p and 2s-3p transitions in the Be-like system inFig. 2 (a) and Fig. 2 (b). We again find the characteristic behavior of the GOS's for these transitions
similar to those in the Li-like system. The twodimensional plot of Fig. 2 (b) is represented in theform of the "extended Bethe surface," i. e., threedimensional plot as a function of Z-l and K in Fig.
3. Effect of electron correlation on the GOS isclearly seen from Fig. 3. The minima in the GOS
look like a valley and smoothly move towards the
optical plane. Almost exact cancellation of the
optical oscillator strength is found at Z = 4.2 (Zeff =2.2). These phenomena are quite similar to Cooper
minima in the optical oscillator strength which occurs

C III

25+
Cu

3.0

F(K)/ E x Zen

2

,;
..0
c

Zeff=Z-2
N

.....
.....
NQJ

2.0
......

;;2
u..

B II

1.0

Be I

o-~10~--~8----~6~---~4~~-2~~0~--In ( K/ Z )2 (in .a .u.)eff

Fig. 2 (b). Scaled COS for 2s 2 1S-2s 23p 1p transition in Belike system.

Fig. 3. Extended Bethe surface for 2s 2 1S-2s23p 1p transition
in Be-like system.

M. Iwai, et al.

on the usual Bethe surface. 1 )It is well known that the level crossings frequently
occur along the 2-1 axis. It often happens that, near
the neutral end of a sequence, a state which is stableat large 2 lies high up in a spectrum. Such a state
will cross other states with which it can interact.
A typical example of this is the 2s2 p 2 2S state in the
B-like system, which has the same energy as theF(K)/ E x Zeff2

43

ground state at infinite Z and is embedded in the
Rydberg series of 2s 2ns in B I. This state crosses.2s 23s 2S in the region near G II .and the conspicuous
irregularity in the optical oscillator strength isfound. 3 ) We see the GOS for the transition 2s 22p
2P-2s 23s 2S in Fig. 4 as the "extended Bethe surface."
The drastic irregularity of the oscillator strength isfound in Fig. 4, reflecting the fact that the configuration-mixing and the change in K introduce
complicated interference effects on the matrix element.
Through these analyses, we found that the extension of the Bethe surface by introducing an additional
axis for 2- 1 gives n~w aspects of GOS's. We plan
to study the behavior of GOS's for molecules in the
future.
References'D
Fig. 4. Extended Bethe surface for 2S22p 2P-2s 23s 2S transition in B-like system.

1) M. Inokuti: Rev. Mod. Phys., 43, 297 (1971) .
2) M. Illokuti, Y. Itikawa, and J. E. Turner: Rev. Mod.
Phys., 50, 23 (1978) .
3) A. W. Weiss: Beam-Foil Spectroscopy, Vol. 1 (eds. Sellin
and Pegg) , Plenum Press, New York and London, p. 51(1976) .

44
RlKEN Accel. Prog. Rep. 20 (1986)

111-2-5. R-Matrix Method for Rearrangement Collisions:Dissociative Recombination e + (AB)+ ~ A + B
I. Shimamura

Recombination of an electron and an atomic ion
in a two-body collision occurs only through emissionof a photon. The rate of this process is usually
very low. Molecular ions, on the other hand, canefficiently recombine with electrons. This is due toanother much faster recombination called dissociative recombination, in which excess energy released
from the electron is absorbed by the relative motion
between dissociation fragments. For diatomic molecular ions AB+, for example, the process is expressedase + AB+~A+ B
~ A+

+ B-

The dissociative recombination (DR) is importantin either physics or chemistry when secondary electrons playa decisive role; DR controls the numberof charged particles in the medium. Radiation
physics and chemistry, physics of the earth's upper
atmosphere, and physics of gaseous discharge are
typical research fields where the knowledge of DR
is indispensable.
Theoretical treatment of the DR process is difficult. This is partly because of the rearrangementof the particles, which makes the final channel quite
different from the initial channel. Another sourceof the difficulty lies in an infinite number of Rydberg
states of the compound AB, which plays the roleof intermediate states in DR.
We have started application of the R-matrix
method to DR. The R-matrix method for nonrearrangement collisions divides the whole configuration space into two, namely, the inner region (r < a)and the outer region (r > a),t) ,2) where r is the
distance between the collision partners. They form
a complex in the inner region, and they are separate
and interact through a local potential (or a potential

matrix) in the outer region. The two regIOns aretreated independently in two different approximations appropriate in the two regions, and the wave
functions are smoothly connected at the boundary
between the regions.
There are two different arrangement channels in
DR. Therefore, each arrangement channel needs
to be divided into inner and outer regions. Because
the inner region of the initial arrangement channel
confines all electrons in a finite region, there are
no Rydberg states. We have to take into accountonly a finite (and hopefully, small) number of intermediate states. This simplifies the whole procedurefor detailed ab initio calculations.
As a first example we apply the R-matrix method
to DR
e + H2+~ H(n > 1) + H(n= 1)~H++H-The electron-molecule collision part of the calculation is nearly the same as the ordinary R-matrix
calculation. 1 ).2) The atom-atom (ion-ion) collisionpart is treated with a one-electron picture. In thispicture one of the two electrons in the system isalways sitting in the ground orbit of the hydrogenatom, and only the other electron is active.
Calculations are now in progress, and results will
be reported soon.
References
1) I. Shimamura: Electronic and Atomic Collisions, Invited Papers at Xth lnt. Conf. Phys. Elec. Atom. Call.,Paris, July 1977 (ed. G. Watel) , North-Holland, Amsterdam, p. 213 (1978) .
2) I. Shimamura: Electron-Molecule Collisions (eds. I.
Shimamura and K. Takayanagi), Plenum, New York,
Chap. 2 (1984) .

45
RIKEN Aceel. Prog. Rep. 20 (1986)

111-2-6.

Classical-Trajectory Monte Carlo Calculations for
Coulomb-Interacting Three-Body Systems t
K. Nakanishi, K. Iguchi, * A. Ohsaki, and T. Watanabe

Coulomb-interacting three-body problems in quantum mechanics are among the major research subjects
to be studied in contemporary physics. Many problems, such as charge transfer processes between an
ion and an atom, are solved in practical way bytaking an approximation that nuclear masses aremuch heavier than electron's mass. On the other
hand, three-body problems can always be solved
numerically by classical mechanics. Such an approximation of classical mechanics as the classical-trajectory Monte Carlo (CTMC) method has been successfully proved to give accurate cross sections for the
charge transfer process empirically. 1) In this paper,
we calculate the cross sections of the following
processes:,u-d+t~

N~
C
C

o

:.;:;

u
Q)

<Jl
<Jl
<Jl

U
10 - 72

3

Impact velocity in a.u.

(1)

Fig.!. Muon transfer and break-up cross sections, t+ (J.t-d)~ (J.t-t) +d~ J.t-+d+t, as a function of impact velocity.

(2),u- +(,u+e-)~ (,u+ ,u-)+e(3)

The CTMC method is based on classical Hamilton's canonical equations, which are given by

p= -oH/oq, q=oHlop

10 - 6oo

and,u++,u-+e

10 -5

~

,u-t+d~ ,u-+t+d
e- +(e+e-)singlet~ (e+e-)triplet+e~ e-+e++e-~

10 - -\(4)

where q and p are the generalized coordinate andits canonically conjugate variable (momentum) andH is the classical Hamiltonian of the three-bodysystem. The equation can be treated to 12 coupledequations. The montion of a three-particle system
can be solved numerically under the randomlyselected quantum-mechanical initial conditions. The
initial quantum state of the target atom is represented
by the microcanonical distribution of classical orbits;
the requirement of a fixed binding energy leads tothe uniform distribution of the square of the angularmomentum, while the initial quantum state of the
projectile is represented by an ensemble of classicaltrajectories distributed unifonnly on the square of

the impact parameter. Both unifonn distributions
can be generated by random sampling with respect
to the corresponding ensembles of trajectories. The
final states of the system can be classified according to the signs of the interaction energies between
the two particles having different-sign charges when
the distance between the particles having the samesigned charge becomes infinite. The cross section is
given bya = (NR/ N);rb ma x 2

where bm ax is the maximum value of the impact
parameter taken in the calculation, N Rand N are
the number of events occuring, and the total numberof trajectories, respectively,
The results for the- process (1) are given in Fig.
1. In the process (1), the lowest binding energy of(I[d) is not different greatly from that of (p-t):
E 1s =2,713eV for (p-t) and =2,652eV for (p-d)
and the difference E~61 eV. The cross section
for the inverse process of p --transfer, (,l.l-t) + d ~(p-d) + t, is almost the same except for the low
velocity impact « 0.5 a.u.) .

t Presented at the Xth International Conference on Atomic
Physics 25-29th August, 1986, Tokyo.

* Department of Chemistry, Waseda University.

Reference
1) R. E. Olson and A. Salop: Phys. Rev. A, 16, 531 (1977) .

46

RIKEN Accel. Prog. Rep. 20 (1986)

111-2-7. Total and D'ifferential Cross Sections for (p.+ p-) Formation by
Collisions of p+ with (u-p) in the Eikonal Approximation t
X. Liu,* Q. Ma,* J. Cheng,* X. Zhang,* Y. Liu,* and T. Watanabe

We have carried out the calculation for the process from the initial ground state Cu-p) to the final
ground state (f1+ f1-) using the eikonal approximation. 1 ) The differential cross section was also calculated.
We can write the total Hamiltonian in the initialcoordinate system Ii and -; or in the final coordinate

where Vi is the interaction Hamiltonian III theinitial state frame and is explicitly given bysystem it and (, where ii and ii' mean the coordi-

K i IS the wave vector of relative motion in theinitial state, and cf>i (r) is the wave function of
initial ground state Cu-p).
The eikonal scattering amplitude can be reduced
to a compact two-dimensional integral form

nates of the relative motion, and -; and ( the coordinates of the inner motion as shown in Fig. 1. The
reduced masses of the system in the initial state
frame, 1.1 for the inner motion and f1 for the relative
motion, are given by-+

Fif«()=i24-iIKl_1- P'(l.Ii/)3/ 2

Kl

mpm p
mp(mp+mp)
1.1=
, P=
mp+mp
mp+2mp(1)

X

and those in the final state frame are given by
,_ mp

1.1-

2

,

Joo dSS-iIK\-l0

J~dXX- l(lJ-x-1(1_X)8)

X (

d:

2

r

{C.B2+Q 2)iIKi-l (f'-iQ.Z)-iIKi}(2)

where mp and mp are the masses of f1 and p,
respectively.
The eikonal approximation to the post form of
the scattering wave function is given by

(4)
where

1'= [(1.I 2+Ki,2)X- (it' ·x+is(l-X)Z)2]1/ 2+1.I'
Q=Kr' -xKt'-is(l-x)Z
~
--+
--.
-+
1 --+
Kl'=Kr+r;Kl, Kr'= -2:Kr+Ki
-to

-+ -+

(-+ -+

i [Z¢(+)(R, r)=exp iKi·R - KI

J

-00

-+

-+

)

Ui(R, r)dz' fjJi(r)(3)

where Kr is the wave vector of relative motion III
the final state. The differential cross section in theeikonal approximation is given byd(]Kf
2dQ = 2r;Ki !Fif«()!

(5)

Table 1. Cross sections calculated for p+ + (p-p)-+ (p+p-)+p.
Eikonal
Impact energy
approximation(keV)(n-ao2)p

Fig. l.

Coordinate system of collision system.
(J.t+J.t-) +p.

J.t+p+J.t-~t Presented at the Xth International Conference on Atomic
Physics, 25-29th August, 1986, Tokyo.

* Department of Modern Physics, University of Scienceand Technology of China, Hefei, Anhui Province, China.

1. 20
1. 70
2.00
2.40
3.60
7.00
20.00

1. 22x 10-4
2. 36x 10-4
2. 29x 10- 4
2.01 X 10-4
1. 18x 10-4
2.62x 10-56.45x 10- 7

FBA(n-ao 2 )DWBA(n-ao2)2.44x 10-5
1. 62x 10- 4
1. 77x 10- 4
1. 67x 10-4
1. 05x 10-4
2. 54x 10-5
7.5IxlO- 7

4.80x 10- 5
1. 79x 10-4
1. 89x 10- 4
1. 75x 10-4
1.09x 10-4
2. 79x 10-5
9. 76x 10- 7

FBA, First-order Born approximation; DWBA, First-orderdistorted wave Born approximation.

X. Liu, et ai.

47

The total cross section is given by(J= ~ r IFif(O) 12dQ

(6)2r;Ki J

Table 1 shows the numerically calculated total
cross section. FBA2) and DWBA2) are also shown.
Figure 2 shows the results of present calculation for
the total cross section, which are compared with
10 -3 r-------r-----~------_r----~

10- 7

10 -

OL--2~O--4~O--~60~~8~O~10~O~1720~1~4~O-1~6~O~1780·

4

Scattering angle (DEG)

Fig. 3. (JL+JL-) formation d,ifferential cross sections by JL+
collision on (JL-p) as a function of scattering angle. Curve
CD, eikonal approximation (2.4 keV); Curve ®, FBA (2.4keV); Curve @, eikonal approximation (7.0 keV); Curve@ , FBA (7.0keV) .

c

o

glO-

5

Vl

CTMC

Vl
Vl

o

U

those by other calculations i.e. FBA,2) DWBA,2) and
CTMC.3) In Fig. 3, the differential cross sections
obtained by eikonal approximation are comparedwith those by the first-order Born approximation.

10- 6References
10 -7 L-----~------~------~--~

023

Impact velocity (a.u.)
Fig. 2. (/1'+,.,,-) formation cross sections by IL' collision on(IL-P) as a function of impact velocity. DWBA, First-orderdistorted wave Born approximation; FBA, First-order Born
approximation; CTMC, Classical trajectory Monte Carlocalculation; B.K., Brinkman-Kramers approximation.

1) F. T. Chan, M. Leiber, G. Foster, and W. Williamson:
Advances in Electronics and Electron Physics (eds. L.
Marton and C. Marton), Vol. 49, Academic Press, New
York, p . 134 (1979) .
2) Q. Ma, X. Zhang, Z. Liu, Y. Liu, and T. Watanabe:
Phys. Rev. A, 132, 2645 (1985) .
3) A. Ohsaki, T . Watanabe, K. Nakanishi, and K. Iguchi:
Phys. Rev. A, 132, 2460 (1985) .

48
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-8.

Bound States of the dtp System Formed in
the Muon-Catalyzed Fusion Cycle
1. Shimamura and M. Iwai

Muon-catalyzed fusion is a kind of nuclear fusionthat avoids heating plasma to very high temperature. 1 ) In this fusion two nuclei are brought close
to each other not by thermal motion but by Coulomb
binding just as in ordinary diatomic molecules.
Therefore, muon-catalyzed fusion may be called the"cold" nuclear fusion.
When driven into the mixture of deuterium andtritium, muons are slowed down and eventually
captured by deuterons or tritons to form muonicatoms dll or til. Because the binding energy ofthe ground state of tfl is larger than that of dfl,
the muons in the atoms dfl are transferred totritons, resulting in til atoms. The til atoms are thencaptured by deuterons to form muonic molecules
dtfl. This molecular system is similar to that of diatomic molecular ions, especially to H2 +, in the sensethat a negatively charged light particle orbits aroundtwo nuclei and forms a three-body bound state.
The two nuclei d and t in the muonic molecule
have a finite probability of being found at the same
position, this probability being proportional to thesquare of the vibrational wave function at R = O.
Then the nuclear fusion reaction
d + t + fl ~ 4He + n + 17.6 MeV + floccurs in the muonic molecule, and the muon isreleased.
The released muon is again captured by either dor t and goes over into another cycle. According
to experimental measurements of neutrons emitted
after the d-t fusion, muons experience more than150 cycles on the average before they decay. Thisis the muon-catalyzed fusion.
The muon emitted after nuclear fusion is sometimes bound by 4He and can no more participate in
the muon-catalyzed fusion cycle. The probabilityof this muon sticking to 4He, the rate of formationof the dtfl molecules, and the rate of the d-t fusionin the dtfl system are the three main factors that
determine the energy gain in the muon-catalyzed
fusion. Knowledge of the bound-state wave functions of the dtfl molecule is crucial in theoreticalunderstanding of the three main processes. Thishas motivated the present study.
Some accurate calculations of 'the dtfl boundstates including only Coulomb interaction have beenreported by other authors. It has been pointed out

recently, however, that the nuclear force acting between d and t can increase the d-t fusion rate byas much as two orders of magnitude. 2 ) To settle
this question one has to carry out detailed threebody calculations for the dtfl system taking both
Coulomb and nuclear interactions into consideration at the same time.
We plan to apply a kind of R-matrix-eigenchannel theory to the bound states of the dtfl
molecule. The whole configuration space of thethree-body coordinates is divided into two regions,
one for short distances between d and t where thenuclear force is predominant and the other for longd-t distances for which only Coulomb interaction
exists. Some computational procedures have beenformulated for smooth connection of bound-state
wave functions in the two regions.
Before application of these procedures to detailed
dtll calculations, we have carried out model calculations to determine the best computational procedure.
The model problem is a two-channel bound-state
problem in which each element of the potential
matrix consists of square wells and a square barrier.
The procedure that appears the best for our purposeis the following.
We carry out inner-region calculations using thevariational R-matrix theory to obtain the R matrix
at the boundary between the inner and outer regions. Then we diagonalize the R matrix to define
eigenchannels at the boundary. A trial function for
the variational calculation for the outer region isconstructed so that each eigenchannel function
satisfies the logarithmic derivative determined fromthe inner-region calculation. With a small size ofthe inner region taken into consideration, the outerregion calculation is replaced by the whole-region
calculation in which integrals are more easily obtained than in the outer region.
Success of this computational procedure for themodel problem has led us to proceed to the real dtll
system.
References
1) L. I. Ponomarev: Atomic Physics X (eds. H. Narumi
and Y. Shimamura) , North-Holland, Amsterdam, p. 197(1987) .
2) Y. Haga, H. Kazama, Y. Akaishi, and H. Tanaka:
Abstracts, Xth Int. Conf. Atom Phys., Tokyo, August
1986 (eds. H. Narumi and I. Shimamura) , p. 92.

49

RIKEN Accel. Prog. Rep. 20 (1986)

111-2-9.

Energy Levels of Muonic Molecular Ionss. HaraRecently, the energy levels for the bound statesof muonic molecular hydrogen ion (pp p) + and of
its isotopes attract much attention since they are related to muon-catalyzed fusion reaction. 1 )Carter2 ) and Bhatia and DrachmanS ) carried out
variational calculations using Hylleraas type wavefunctions to describe three-body systems. Frolov andEfros4 ,5) and Hu6 ) adopted basis functions including
exponential functions of the internuclear distanceR, and showed that this type of basis functions gave
rise to faster convergence. Vinitsky et al. 7 ) and
Gocheva et al. 8 ) solved a set of coupled equations in
the adiabatic representation of the three body problem, where the wavefunction for a muonic moleculeis expanded in terms of a complete set of solutionsof the adiabatic two center problem solved accurately
in the spheroidal coordinate system. The spheroidal
type wavefunction has once been used by Halpern 9 )in variational calculations for the ground states of
the homo-nuclear muonic molecules with total
angular momentum ] = l.
Here, we present the results of the variational
calculations adopting the same form of the trial
function as that used by Halpern9 ) for the ground(v = 0) and the first excited (v = 1) states of thehomo-nuclear muonic molecular hydrogen ions
(pp p) +, (ddp) +, and (ttp) + with total angularmomentum ] = 0 and 1. I t is shown that thespheroidal-type trial function works well and, infact, the best binding energies among those so far
reported are obtained for several states.
The muon coordinates are expressed by thespheroidal variables r(c;, 1), ¢»:~= (ra +rb)/ R, r;= (ra - rb)/ R,

where ra and rb are the distances between the muonand the two nuclei a and b, respectively, R the
distance between the nuclei, and ¢> the azimuthal
angle around the internuclear vector R(R, @, (0).
Our trial function for homo-nuclear molecules iswritten in the form 9 }Ir= {(~2 - 1)(1- r/)} ml/2 ~b£
I

X exp ( - f3iR~) 1jCi exp (im¢»(2)
DfnM represents the Wigner functions and Xim(R)the functions of internuclear distance R:(3)

Here ai, b i , and Ci are integers with Ci being evenfor the ug-state and odd for 1t'g-state; I i stands forthe summation over sets of parameters (ai, bi , Ci,ai, I'i).
The explicit form of the matrix elements for the
Hamiltonian operator of the three body system isgiven by Hunter et al. 10 )We have used following values for the physicalconstants; proton mass Mp= 1,836.151 me, deuteronmass Md = 3,670.481 me, triton mass M t = 5,496.899
me, and muon mass M J1. = 206.7686 me, where me isthe electron mass and 1 Ry= 13.605804 eV.
Two sets of orbital exponents (ai, I'i) are taken
for the ug-type basis function and one set for the
1r g -type basis function.
At first, these orbital exponents are optimized at a small number (~120)of the basis set, for each (j, v) state of each isotope,
by Powell's procedureY> The number of terms in
the trial functions are then increased while checking the convergence of the results. The maximum
number of terms is 380 for (ddp) + with ] = 1 andv = 1, and 300 for other cases. These results, compared with other recent variational calculations inTable 1, are satisfactory even for the weakly boundstate of (ddpr.

Table 1. Energy levels of muonic molecules in eV. A 380term trial function is used for (ddp,+ with J=l and v=l,
and a 300-term one for other cases. The binding energyof the former obtained by the 300-term trial function is1.944 eV. (a), present; (b), Bhatia and DrachmanS ); (c),Frolov and Efros4 ); (d), Frolov and Efros.5)
(J,1)

(0,0)

pp,u+ (a)(b)(c)-253.152-253.15-253.152

dd,u+ (a)-325.073-325.07-325.072-35.843-35.815-35.836-362.909-362.90-362.900-83.770-83.630-83.722

(b)

(c)
tt,u+
1r g

.,.type molecular

(a)

(b)
(c)

(1,0)

(1,1)

-107.203-107.26-107.266(d)(1)

where fiO and 1/1 are (/g- andfunctions, respectively;(0,1)-226.670-1.955-226.66-1.862-226.682-1. 781-226.690-1.971-289.137 -45.198-289.12-45.096-289.139 -45.194

50

S. HaraReferences
1) L. Bracci and G. Fiorentini: Phys. Rep., 86, 169 (1982) .
2) B. P. Carter: Phys. Rev., 165, 139 (1968) .
3) A. K. Bhatia and R. J. Drachman: Phys. Rev. A, 30, 2138
(1984) .
4) A. M. Frolov and V. D. Efros: Pis'rna Zh. Eksp. Teor.
Fiz., 39, 449 (1984) .
5) A. M. Frolov and V. D. Efros: J. Phys. B, 18, L265 (1985) .
6) Chi-Yu Hu: Phys. Rev. A, 32, 1245 (1985).
7) S. I. Vinitsky, V. S. Melezhik, L. I. Ponomarev, I. V.
Puzynin, T. P. Puzynina, L. N. Somov, and N. F.

Truskova: Sov. Phys. JETP, 52, 353 (1980) .
8) A. D. Gocheva, V. V. Gusev, V. S. Melezhik, L. I.
Ponomarev, I. V. Puzynin, T. P. Puzynina, L. N. Somov,
and S. I. Vinitsky: Phys. Lett. B, 153, 349 (1985) .
9) A. Halpern: Phys. Rev. Lett., 13, 660 (1964) .
10) G. Hunter, B. F. Gray, and H. O. Prichard: J. Chern.
Phys., 45, 3806 (1966) .
11) M. J. D. Powell: Numerical Analysis; An Introduction(ed. J. Walsh), Academic Press, London and New
York, p.143 (1966).

51
RIKEN Accel. Prog. Rep. 20 (1986)

Measurement of Lifetimes of Highly Ionized Aluminium Atoms

111-2-10.

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

We have been carrying on lifetime measurementsof AI-ions making use of RILAC.l) Here, we report
the preliminary results of lifetime measurements andanalysis of the first excited state 2s2p 1 P of Be-like
AI-ion. As shown in Fig. 1, there are some cascades
which feed directly this state. Taking account of theeffect of these direct cascades to the lifetime determination, we have measured and analyzed the decay
curves of the primary decay as well as the direct cascades. Measurements were performed at an incident
energy of 35.3 MeV. As for the details of the experimental procedure, see Ref. 1. Decay curves were measured for the following transitions: a) 2S2 lS-2s2p 1p(332.78A); b) 2s2p lp-2s3s lS (63.13A); c)
2s2p lP-2p2 lD (670.06 A) and d) 2s2p lP-2p2 lS(395.62 A). The last one has a wavelength, which
is very close to that (395.36 A) of the transition between triplet states (2s2p ap_2p2 ap), and was excluded from the final analysis. The wavelength of thetransition from 2s3d lD (59.11 A) is slightly too short
to measure with our monochromator.

Fig. 1.

Partial energy level diagram.
time (nsec)

1.0

0.0

2.0

3 .
x I0 6 \

~. :\
o

\

u

"\
2

Table 1. Time constants obtained from the multiexponential fit.
Transition

Time constant (ns- l )a) 2S2 IS- 2s2p Ipb) 2s2p IP-2s3s IS

O. 84±0. 04, 4.42±0.19
3. 43±0. 30, 42. 5±4. 2
O. 95±0. 06, 2. 5± 1. 6c)d)2s2p IP_2p2 ID
2s2p IP_2p2 IS(2s2p SP_2p2 SP)

0.65±0.16, 4. 43±0. 05

First, measured decay curves were analyzed individually by use of the multi-exponential-fitting
programme cord DISCRETE.2) Examples of measured and calculated decay curves are shown in Fig.
2. The resultant time constants are summarized inTable 1. The primary decay curve is decomposed
into three exponential terms; among them, thestrongest is that with a time constant 4.42 ns- 1 = 1/
(0.226 ns).
Secondly, these time constants and intensities, aswell as the experimental primary decay curve itself,
were used as input data to the programme code
CANDya) to extract the lifetime of the 2s2p 1 P state.
Excluding the decay curve d) from the analysis because of the reason mentioned above, we obtain
0.192 ± 0.015 ns as the lifetime of the primary state.
To see the effect of the cascades on the lifetime
determination, additional calculations were performed. If we take account of only the cascadingfrom 2s3s lS, resulting lifetime of the primary stateis larger than the quoted value by about 30 %. If
we consider only the cascading from 2p2 lD, calculated lifetime is also larger by the same amount. The
decay curve d) contains a strong term with a time
constant 4.43 ns-\ which is very close to that of themain component of the primary decay. Therefore,
if we include the decay curve d) in the calculation,
it gives an extremely short lifetime of about 0.05 ns.
More detailed analysis and comparison with theoretical works are now in progress.

y.

" ' .. ..
~f"OI •.., •• "-.......... "-••~ .... .

.-----.
a ~_ ,._~_~~_~_~~~
;

o

10

20
30
distance (mm)Fig. 2. Decay curves measured (dots) and calculated (line)
for the transition: 2s2 1S-2s2p lp (332.78A).

References
1) S. Kohmoto, K. Ando, Y. Awaya, H. Kumagai, K. Sato,T. Tonuma, and S. Tsurubuchi: RIKEN Accel. Prog.
Rep., 19, 65 (1985) .
2) S. W. Provencher: J. Chern. Phys., 64, 2772 (1976) .
3) L. Engstrom: Nucl. Instrurn. Methods, 202, 369 (1982) .

52
RIKEN Acce!. Prog. Rep. 20 (1986)

111-2-11.

Identification of AI X2p3d-2p4f Transition in
Beam-Foil Spectrum

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

In beam-foil spectra, spectral lines arising from thef levels are so strongly observed that the transition
from other unknown f levels would be expected toappear in the spectra. In a Be-like ion of aluminum,
the transitions from displaced levels of 2p4f to thoseof 2p3d have not yet been identified. A preliminary
calculation of atomic energy levels using the HartreeFock approximation predicts that the transition arrayof 2p3d-2p4f will appear near strong lines of 2s3d2s4f and a pattern of the array is also similar to theobserved line group near 2s3d-2s4f lines.
The strongest line in the transition array comesfrom 3G to 3F levels, but the energy values for the
lower states 3F of this line are unknown. Therefore,

energies of the 3F states are estimated from an
isoelectronic sequence.
Slater integrals for the upper levels of 2p4f configuration in the expressions of term energies areexperimentally determined from the observed level
energies by least-squares fit calculation. A patternof the transition array with the fitted values of
Slater integrals is shown in Fig. 1 together with thespectra obtained from the beam-foil experiment. The
strongest line in this calculated spectrum did not fit
to the experimental one, because the 3F of the lower
level is uncertain as mentioned before. Strong lines
can be identified in the spectrum, but weak lines are
not for lack of sufficient resolution.

Q)

::l

co

>

168.00172.00176.00180.00 184.00 188.00
Wavelength (A)192.00 196.00 200.00

Fig. 1. Comparison between the spectrum obtained by the beam-foil experiment(upper) and the theoretically generated one of 2p3d-2p4f transition of Al X
(lower) .

53
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-12. Dependence of the Effective K-Vacancy Production Cross
Section on the Target Thickness and Projectile Charge State
for Argon Ions Colliding with Carbon Foils
T. Mizogawa, Y. Awaya, T. Kambara, Y. Kanai, M. Kase,
H. Kumagai, P. H. Mokler, and K. Shima

Target-thickness dependent measurements of Xrays emitted in collisions between fast heavy ions andsolid targets have been recognized to be an important
technique for the study of the inner-shell processesof heavy ions in solids, where the relaxation times
of excited states are not short enough compared witha mean collision intervaU) Here we report our
high-resolution X-ray measurements as a function of
the target thickness and projectile charge state, andthe importance of the effect of L-shell configurationon K-vacancy formation.
Target-thickness dependence of Ar Ka satellite
intensities from Ar4+ ions colliding with thin C foils
whose thicknesses were 2-100 pgjcm2 was measured.
For Ar6+,12+,13+, the thickness dependence was measured over the region 2-20 pg/cm 2 where the Lshell nonequilibrium region is contained, and for
Arll+ only one (2.6 pg/cm 2) target was examined.
The experimental setup and methods have been
already reported. 2)
The results obtained with Ar4+ and Ar12+ are
shown in Fig. 1. The vertical scale, O'x (n), is themean X-ray production cross section for each satellite, i.e., the X-ray yield divided by integrated ion current and target thickness (in arbitrary units). In

the thickness region below
10 pg/cm 2 quite different thickness dependence is observed between the
results for A r 4+ and for Ar12+. This difference iscaused by the difference in the projectile L-shell
configuration and in the course of the equilibration
process of the L shell. Furthermore, we may conclude that the mean K-vacancy formation crosssection itself changes with the depth through thechange in Ar-ion distribution over the initial Lvacancy number as follows. For thin targets we may
neglect the collisional quenching of the K vacancy(or electron capture from a target atom into theprojectile K vacancy). Thus the K-vacancy formation cross section, averaged over the initial no Kvacancy, n L-vacancy states with the weights of their
populations in solid, can be estimated by,....J(for thin limit)

av=Ljax(n)/w(n)nwhere (j) (n) is the fluorescence yield for the n-thsatellite. The value of the left-hand side of theabove equation is calculated using a theoretical
fluorescence yield for each defect configuration3) and
our data, and plotted against the C thickness in
Fig. 2. If the collisional quenching is taken into
account, the change in av may be further enhanced.
I~

.4 -

.4"-

I

,

I

0_ _ _ _ _
0

o

(b)-

0

o~

n= 5

.3 -

-

.3 -

'2'c

'2'c
:::J

~ -."-

..ci

.ci

o

:::J

~

~.2-

.2-

r-°s-o~~

C

c
Ib><

4
.~ •

-

o

/b><
70 0 •--;~o -

:\

.1 I-

.1 -

0

1+2+3

o

1_---L...----1'_..I....-----1_..I....--I
L...-.....L

1

2

5

10 20

50 100C-foil thickness (fJ9/cm2)

o

I

1

2

5

.

10 20

C-foil thickness (pg/cm 2 )Fig. 1. (a), Mean Ar Ka X-ray production cross section for each satellite as a function of C-foil thickness. The projectile
is Ar4+. Solid lines are only for eye-guide; (b), Same as (a) except that the projectile is Ar12+.

T. Mizogawa, et ai.

54

1.5

'E
'c;
:J

41-

13 +
... 12 +

"V

\J

.e

••

~

... ."". ..
\J

T

C

'3 31- oc......"-><

~

•• ~.

0

0

0 ,,"

• 4+

••

2'
'c 1.0

...

0

:J

-e

it>
lo-.I

~

2
1

10 20

50 100C-foil thickness

2<iJ9/cm2)

5

Sa.........

S 0.5

Fig. 2. L:<1.x(n)/ro(n) as a function of C-foil thickness.
n
Closed circle, Ar4+; open circle, Ar6+; cross, Arll+; closed
triangle, Ar12+; open triangle, Ar13+.

/~
/'

I~

Number of L- holes

,./

-e

-:
tl

~

3

,/

1 -0 -

0""l-hole- - - - - - - "----.- - - Jl..-..l.-1-..L.....I--L......I-..l

o

2

4

6

Fig. 4. Estimated cross sections for simultaneous formationof a K vacancy and n L vacancies. Projectile: Ar4+ (closed
circle), Ar12+ (closed triangle), Ar13+ (open triangle).
Initial L-vacancy number for each projectile charge is indicated by an arrow. The lines are drawn for eye-guide.

2~----~1------_~1--__~

o

5

10

Projectile Charge

Fig. 3. Estimate for the K-vacancy production cross section.
Horizontal scale is projectile charge state. Initial L-vacancy
number is indicated at the bottom-right corner. Opencircle, thinnest target (__ 2.6 p,g/cm2); closed circle, extrapolated value to zero-thickness. Solid and dotted lines
are drawn only for eye-guide.
In Fig. 3 the value at a thickness of
2.6 p.g/ cm 2and that extrapolated to zero-thickness are plotted
as functions of the projectile charge state. The
values for A 4+ and Ar6+ are approximately equal,
whereas <1v for Arl l +, Ar12+, and Ar13+ seem to increase linearly with the ,c harge. The onset of theincrease is at 9+, where an L vacancy comes toexist. This increased part of <11) can be attributed to
the K-to-L excitation cross section, which is approximately 13 X (number of L vacancies) % of the
background part (attributed to ionization cross section) in the zero-thickness limit.
In Fig. 4 <1x(n) / (J) (n) extrapolated to the zerothickness limit for Ar4+, Ar12+, and Ar13 + are plotted.
This distribution is interpreted as the distribution
over the L-shell configuration resulting from a single
collision in which K and L electrons are ionizedsimultaneously, provided ( 1 ) the extrapolation iscorrect, ( 2 ) electron capture to L shell simultaneouswith a K-vacancy formation collision is negligible,and (3) excitation from the K to L shell is negligible,-...J

compared with K-shell ionization. In such a case itis curious, as seen in Fig. 4, that there are considerable intensities of <1 x( 3) / (J) (3) for Ar12+ and<1 x( 4) / (J) ( 4 ) for Ar lS +, of which the L-vacancy
numbers (3 and 4) are less than those of the projections (4 and 5) by one. This fact may be anotherindication of the significance of the K-to-L excitation, for the assumptions (1) and (2) are considered
to be not so bad.
for different projectile charge states diminishes, andmost of them tend to decrease with the thickness.
20 p.g/cm 2 the difference between <1.x(n)AboveThis decrease is caused by electron capture from atarget atom to K vacancy of a projectile and theenergy loss of the projectile. The data in this region
could possibly be analyzed by some generalized version of 2- or 3-component modeP> However, suchan analysis seems to need too many adjustable parameters and uncertain assumptions. To enable us
more straightforward approach, a series of subsidiarymeasurements are in progress.
,-...J

References
1) See for example, H.-D. Betz, F. Bell, H. Panke, G ..
Kalkoffen, M. Welz, and D. Evers: Phys. Rev. Lett.,.
33, 807 (1974) .
2)

T. Mizogawa, Y. Awaya, T. Kambara, Y. Kanai, M.
Kase, H. Kumagai, M. Mostafa Ismail, and K. Shima:

RIKEN Accel. Prog. Rep., 19, 68 (1985) .
3) C. P. Bhalla: Phys. Rev. A, 8, 2877 (1973) .

55
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-13.

Measurement of Impact parameter Dependent Probabilities
for K-Shell Ionization in Ar-Ca Collisions
R. Schuch,* Y. Awaya, T. Kambara, T. Mizogawa,
H. Kumagai, Y. Kanai, K. Shima, and H. Shibata

Impact parameter ( b) dependence of target andprojectile K-shell ionization probabilities (Pk ( b ) )were measured for collision system with Ar ions
incident on a Ca target.
The measurement system was described previously.l )An Ar beam of 40.6 MeV from the linac was collimated to 1 mm X 1 mm with a divergence of 0.02°.
The target material of Ca was evaporated on a
2.5 pgjcm2 C foil and positioned at 45° relative tothe beam axis. The chickness of Ca ranged from
2 to 30 pgjcm2. The characteristic X-rays from the
projectile and target were detected by a 25.6 mm 2
Si (Li) detector placed at 90° to the beam direction
at a distance of 16.5 mm. In the forward scattering
direction scattered particles are counted by a parallel
plate avalanche counter (PPAC) which covered thelaboratory angles from 0.13 0 to 1.40 • The anodeof the PPAC was devided into 16 rings for different
scattering angles with an angular resolution of
11 () / () = 0.05. A coincidence circui t between the
PPAC and Si (Li) allowed to measure K X-rays coincident with scattered particles. The total numberof particles per ring of the PPAC was also measured
and served as normalization for getting absolute
K X-ray production probability PK (b). The purposeof the experiment was the investigation of solid effects on the PK (b) .2) For this, the absolute K-shellionizaiton cross section was determined simultaneously by measuring Ar ions from elastic scattering
at 20 0 to the beam with a surface barrier detector
covered by a slit aperture.
The K-shell ionization probabilities for the target
and projectile were obtained from the K X-ray pro-* Department of Physics, Heidelberg University.

1.0

~

x

:.0
co

.D
0

x

6.
c

co

N

• Ca
x
x

0

:.;:;

x Ar
x x

l'(

*

x
x

0.5

...

'c
.~

Q)

x

x x

x x

. . . ...

..c
Ul
I

~

0

500

1000

I

I

2 000

5000

Impact parameter (fm )Fig.!. Impact parameter dependence of the K·vacancy production probability (Prr. (b» for a 30 fJ-g / cm2 Ca target on
a 2.5 fJ-g/cm2 carbon foil.

duction probability using fluorescence yields forneutral atoms and efficiency of the Si (Li) detector.
The impact parameter b was obtained from thescattering angle calculated using a Bohr screened
Coulomb potential.
In Fig. 1 the values of P K (b) are shown for a
Ca target with a thickness of 30 pg/cm2. The error
bars are from statistical errors only and the effectof the carbon backing is not corrected.
References
1) R. Schuch, Y. Awaya, T. Kambara, T. Mizogawa, Y.
Kanai, H. Shibata, and K. Shima: Z. Phys. D At. Mol.
Clusters, 4, 339 (1987) .
2) R . Schuch, G. Nolte, and H. Schmidt-Backing: Phys.
Rev. A, 22, 1447 (1980) .

56
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-14. Charge-State Distribution of Cr-Ions after Passage
through a Carbon Foil
Y. Kanai, Y. Awaya, T. Kambara, M. Kase,
H. Kumagai, T. Mizogawa, and K. Shima

We started the present study on the charge-state
distribution of heavy ions after collisions to investigate the heavy ions-target atom violent collisions.
At the first stage, we measured the charge-state distributions of Cr-ions after passage through carbon
foils with various thicknesses and at various scattering angles. The Cr 5 +-ions were accelerated withRILAC to 1.23 MeV / amu and the charge state wasanalyzed with a beam analyzing magnet. The experimental setup is shown in Fig. 1. A projectile
beam was collimated with two sets of four jaws slits.
Scattering angles were determined by use of a movable aperture (1 mm in diameter) in front of a magnetic charge analyzer (AM magnet) .1) The distance
between the target and the movable aperture was
870 mm. The charge-state distribution was measured
with a parallel plate avalanche counter (PPAC) at
the rear of the AM magnet.
Typical experimental results are shown in Fig. 2.
With relatively thin targets (0.5 pgjcm2 and 4 p.gj
cm 2 ) , the charge state of the 0.33° scattered Cr-ions(broken lines in Fig. 2) is higher than that of the
0° scattered Cr-ions (solid lines). This result is consistent with an idea that a single violent collision(or a small impact-parameter collision, in which an
impact parameter is as small as the K-shell radiusof projectile ions) with a target atom increases
the mean charge state of the ions almost to its
equilibrium value in a thick target foi1. 2 ) With athick target (40 p.gj cm2 )', the charge state of the
0.33° scattered Cr-ions was determined from multiple
large impact-parameter collisions after a single violent

q
0.5

-

16.0

--- 16.1

z

~0.5

-

u

--- 15.5

~

«
0:

14.7

1I...

w
<!l

~O~~---..J"'=";:..::..:t:~--'---L--'--'--=~~-'----'--I

I

u

0.5

13.5

I

I
I

\

--- 14.7\\\"
o ~==~~--'-~--'-~~~~~~~~--'-~
15
CHARGE STATE (q)20

Fig. 2. Typical charge state distributions of Cr after passage
through several thickness carbon foils. Solid lines are forthe scattering angle OO±O.06°, broken lines for the scattered angle O.33°±O.06°. Mean charge (ij) of each condition is shown.

collision and the mean charge value of the 0.33°
scattered Cr-ions was equal to that of the 0° scatteredOr-ions.
In a single violent collision, the probability of Kshell vacancy production accompanied with simultaneous multiple L-shall vacancy production mustbe large. For the study of the single violent collision,an experiment is necessary to be carried out by
using a gas target, which is in preparation.
References

2175mm)(640m~

870mm)(

Fig. 1.

Experimental setup.

1) Y. Awaya, M. Kase, T. Kambara, H. Kumagai, Y. Kanai,
T. Mizogawa, K. Shima, and T. Chiba: p.132 in thisreport.
2) D. Maar, P. H. Mokler, D. Schull, and Z. Stachura:
Nucl. Instrum. Methods, 194, 377 (1982) .

57

RIKEN Accel. Prog. Rep. 20 (1986)

111-2-15.

Multiply-Charged Ions from SF6 Produced by
1.05 MeV/amu Ar12 +-lon Impact

H. Shibata, T. Tonuma, K. Baba, * S. H. Be, H. Kumagai,
M. Kase, T. Kambara, I. Kohno, and H. Tawara

In previous Progress Reports, we presented someresults on the observation of multiply-charged
secondary ions produced from molecular gas targets,
such as N 2, CH 4 , and C 2H 2, by energetic Ar12+-ion
impact. 1,2) In these experiments, we found that themultiple ionization of target atoms is enhanced significantly and the peak positions in the mass-charge
spectra of multiply-charged atomic ions resulting frommolecular targets shift toward the high-energy side
except for CH 4 • This energy shift was attributed to
the Coulomb potential of the multiply-charged molecular ions which were produced initially via
charge transfer and inner-shell ionization and dissociated immediately into multiply-charged atomic
ions. In this report, we present the result of theinvestigation for a much more complex moleculartarget, SF 6, in the collision with energetic Ar12+-ions.
In order to understand the production mechanismsof multiply-charged atomic and molecular ions frommolecular targets, we have used a mass-spectroscopic
technique to separate various ions produced fromSFs molecules with 1.05 MeV jamu Ar12+-ions obtained from the linear accelerator (RILAC). The
secondary ions produced are extracted under the
influence of a relatively weak electric field (40 V jcm), accelerated up to 1,000 V, and then masscharge analyzed with a double focusing magnet. A
typical mass-charge spectrum of the ions from theSF 6 molecular target is shown in Fig. 1, which indicates the formation of singly- and multiply-charged
sulfur (Si\ up to i = 8) and fluorine (Fi+, up to i =5) ions, in addition to dominant singly- (SF n +, n =1-6)' and doubly-charged molecular ions (SFn 2 +,n = 1-6). In Table 1 is shown a comparison ofrelative intensities of these atomic and molecularions resulting from SF 6 molecules by Ar12+ impact
with those by 500 eV electron impact obtained by
Stanski and Adamczyk. 3)
From Fig. 1 and Table 1, we find the following
features.
1) The relative production ratios of dissociatedmolecular and atomic ions are found to be enhanced
in energetic heavy-ion impact, compared with those* ULVAC Corporation.

256
CHANNEL NUMBER

Fig. 1. A typical mass-charge spectrum of ions produced
from SFs molecules in 1.05 MeV /amu Ar12+-ion impact.
Table I. Relative production ratios for various ions fromSFs molecules in different charged-particle impacts.
Ion
SF6+
SFs+
SF.+
SF 3 +SF z+
SF+
SF6 2+
SFS2+
SF.z+
SFS2+
SF22+
SF2+

Present 500 eV e- 3)study
2.9 (-2)
small
1.0
8.1 (-2)
2.1 (-I)
6.0 (-2)
9.0 (-2)

1.0
1.1(-1)
3.4 (-1)
7.3(-2)
1.4 (-1)?

5.6 (-3)
8.4 (-2)
5.4 (-2)
9.7(-3)4.4 (-2) .~ 5.3 (-2)
1. 3 (-2)

Ion

Present 500 eVe- 8)
study

S+
S2+
S3+
SH

2.1(-1) 1. 5 (-1)
5.4 (-2)
1.4 (-2)
5.9(-3)S5++P+ 3.2 (-3)
S6+
6.2 (-4)
S7+
S8+
F+
p2+
FH
p5+

small
small
1.4(-1) 2.1 (-1)
1.9 (-2)
6.2 (-4)

small

in electron impact. In particular, parent molecularIons (SF6+) are observed in heavy-ion impact,
whereas their intensity was neglibibly small in electron
impact. This singly-charged parent ion, therefore,
is regarded as a metastable-state one.
2) In the case of singly-charged molecular ions
(SFn+), the intensities of ions having odd numbersof n are stronger than those having even numbers.
On the other hand, for doubly-charged molecularions (SFn2+) the situation is opposite. This result

58

H. Shibata, et al.

is the same as that in the electron impact and seems
to be due to the electronic structure of molecularions. Further analysis is in progress.
References
1) H. Tawara, T. Tonuma, S. H. Be, H. Shibata, H. Kuma-

gai, M. Kase, T. Kambara, and I. Kohno: RIKEN
Aeeel. Prog. Rep., 18, 82 (1984) .
2) H. Shibata, T. Tonuma, K. Baba, S. H. Be, H. Kumagai, M. Kase, T. Kambara, I. Kohno, and H. Tawara:
RIKEN Aeeel. Prog. Rep., 19, 77 (1985) .
3) T. Stanski and B. Adamczyk: Int. J. Mass Speetrom. Ion
Phys., 46, 31 (1983) .

59

RIKEN Accel. Prog. Rep. 20 (1986)

111-2-16.

Production of Multiple-Charged Ions from CO and CO 2
Molecules in Energetic Heavy-Ion Impact
T. Matsuo, T. Tonuma, M. Kase, T. Kambara,
H. Kumagai, 1. Kohno, and H. Tawara

We have conducted systematic investigations on
the production of multiple-charged ions from molecular gas targets by energetic heavy-ion impact.
In a previous measurement for an N2 target, it was
found that the peak positions of multiple-charged
Ni+-ions in mass/charge (m/q) spectra shift towarda high-energy side, compared with corresponding
Ari+ peak positions from an Ar target, and additionally, this peak shift increases with increasing

10'

,,>

jIJI~ut~ql

C2~

;c;:+

2
0

+;

10 '

charge state of ions produced. 1) These findings
strongly suggest that such initial kinetic energies ofrecoil ions are provided through the Coulomb potential of multiple-charged molecular ions produced
first in collision. Peak shifts in m / q spectra havealso been observed for other molecular targets suchas NO, N 20, and N0 2.
To obtain further insight into the mechanisms andsystematics of the production of multiple-charged
ions from molecular targets, we have used a massspectroscopic technique to separate various ions fromCO and CO 2 molecules produced in Ar12+ impact.
The projectile Ar12+-ions were accelerated to
1.05 MeV /amu by the linear accelerator (RILAC).
Figure 1 shows m / q spectra of multiple-charged
atomic ions produced from CO and CO 2 targets,
together with those from Ar and CH4 targets forcomparison. It should be noted that the peaks observed with CO and CO2 targets are shifted in position and broadened, compared with those with Ar
and CH 4 targets. As reported previously,2) the peaksof Ci+ -ions from CH4 show neither shift in position
nor broadening compared with those of corresponding Ari+-ions which gain only a small amount ofrecoil energy.
In Fig. 2 are shown the observed energy shifts

10'

Ci+

/

100

10'

>
~
+"

..c

Ul

>,

tlO

~ 10
UJ

/

I

•

100

• co
o CO 2

•

I

0

00

10

256
CH~NNELNUMBER

Fig. 1. Mass/charge (m/q) spectra of recoil ions produced
from molecular targets CO and CO2 by 1.05 MeV /amu
Ar12+ ion impact. Vertical dashed-lines are drawn to show
the shift of peak positions of the multiple-charged ionsfrom CO and CO2 targets with respect to those from Ar
and CH4 targets.

2 3456

2 3456Charge state ( i-I-)

Fig. 2. The observed energy shift of the peak as a functionof the charge state of recoil ions produced.

60

T. Matsuo, et al.

of multiple-charged atomic ions produced from CO
and CO 2 targets. It is to be noted that the energy
shift of Ci+_ and Oi+-ions increases roughly as thesquare of the charge of ions in both CO and CO 2
molecules. This suggests that such kinetic energies
are provided through the Coulomb explosion ofhighly ionized molecular ions produced first in theimpact. With a CO molecule, the intensities of
Oi+_ and Ci+-ions (i= 1-3) are nearly equal, andthe energy shift are also roughly equal for Ci+- andOi+-ions with the same charge within the limits ofthe present energy resolution. These results are well
explained from the consideration that the dissociationof multiple-charged COi+ molecular ions plays adominant role in production of multiple-charged
atomic ions. With a CO 2 molecule, the energy shift
and peak broadening of Ci+-ion are very small; thoseof O i+-ions are considerably greater than with a CO
molecule. These results can also be explained byassuming that the multiple-charged atomic ionsoriginate in multiple-charged molecular ions COzi+
which dissociate immediately after their production
through the process:(1)

In this dissociation, the oxygen ions receive strong
Coulomb repulsion, whereas the carbon ion, locatedat the center of two dissociating oxygen ions, canobtain practically no kinetic energy. Thus, the present results show the importance of the atomic configuration of parent molecules in the dissociationof multiple-charged molecular ions produced byenergetic heavy-ion impact. This finding is expectedfrom the dynamic property of collisions; the collision time (,...., 10-17 s) and electron rearrangement
time (,...., 10-16-10- 17 s) are much shorter than the dissociation time of molecules (,...., 10-14 s) .
The recoiled molecular ion spectroscopy (REMIS)
in heavy-ion impact is found powerful in studying
the dynamic and structure of highly charged molecular ions.
References
1) H. Tawara, T. Tonuma, H. Shibata, M. Kase, T. Kambara, S. H. Be, H. Kumagai, and 1. Kohno: Phys. Rev.
A, 33, 1385 (1986) .
2) H. Tawara, T. Tonuma, H. Shibata, S. H. Be, H. Kumagai, M. Kase, T. Kambara, and 1. Kohno: Z. Phys. D,
At. Mol. Clus., 2, 239 (1986) .

61
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-17.

Energy Spectra of Secondary Electrons Emitted
from AI by Heavy-Ion Impact
A. Koyama, O. Benka, Y. Sasa, and M. Uda

Energy distributions of secondary electrons (SEs)emitted backward from thick Al target were measured in the SE energy region below 170 eV for
the impact of He 2+, N6+, Ne8 +, and Ar12+ which wereselected with a magnetic analyser. These ions
had the same velocities corresponding to 1.1 MeV /amu. The experimental setout was the same as
described in a previous report. I )The ratios of SE yields for these heavy-ion impacts to those fOr He 2+ impacts, R (E), are shownin Fig. 1, which indicates that 1) above the energyof the Al L-VV Auger electrons, 65 eV, the SE
yields for the N6+, N e 8 +, and Ar12+ impacts are given
by q2-scaling, 2) the SE yields decrease from thevalues given by the q2-scaling to those given by the
stopping power scaling in the energy region from 20(/)

V,Ar2.(E)/VHe2{E)"'0,........••.. ··.:.....~.:.:.....·.··~._·:..40:··:..'·v....~~.".;-....,."'..,.,......••__:

W

..'t

(j)

'0 10
~

VNe'l'(EVVHe 2'(E);"'~"'~":~~4·""\. .A;t-..; ............V ..~\~~..,.:• r~,-'---·/ ....:;~.~;"•.."'..../ ...................."'..,...'$\.:.,.,"':~;' -,... -.-~.-.,
VN s{EVVHe 2,E;'

~

r

1 0

20

40

60

80

100

120

140

160

Secondary Electron Energy (eV)Fig. 1. Ratios of yields of secondary electrons emitted from
Al by heavy-ion impacts to those induced by He 2 + impacts,= Y Ar12 +(E)/YHe 2+(E); R Ne , He (E) = Y Ne 8+(E)/Y He2+(E); R N. He(E) = Y N6+(E)/YHe 2+(E).

RAr,He (E)to 60 eV, and 3) the SE yields become much smaller
than those expected from the stopping power scaling
in the energy region below 20 eV, where such a decrease is more pronounced when SE energies become
lower and electric charges of projectiles becomes
higher; for example, R Ar , He(E) :::::: 5, R Ne , He(E) ~ 4,
and R N , He(E) ~ 2.4 at low energies near 0 eV. The
ratios of these values, 5 : 4 : 2.4, are nearly equal tothose of the respective charges of these projectiles,
12 : 8 : 6. Thus at low energies, the yields of SEs
for heavy projectiles with equilibrium charges areapproximately given by qI-scaling.
The electric charges selected here are nearly equal
to the respective equilibrium ones at this velocity.
Therefore, their charges after having penetrated athin surface layer whose thickness is comparable to
the SE escaping depth (....-50 A) will be the same astheir original charges. Thus, such pronounced decrease in the yields of low energy SEs for projectiles
with high charges compared with those expectedfrom q2-scaling is not considered to be due to thedecrease in their charges after penetrating a target.
The decrease can be explained in terms that for
distant collisions the screening of the charge of projectiles due to the polarization of target electrons
becomes effective. 2)
References
1) A. Koyama, Y. Sasa, and M. Uda: RIKEN Accel. Prog.
Rep., 18, 86 (1984) .
2) A. Koyama, O. Benka, Y. Sasa, and M. Uda: Phys. Rev.
B, 34, 8150 (1986) .

62
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-18.

Z2-Dependence of Energy of Loss-Electrons Backscatteredfrom Metal Targets
A. Koyama, O. Benka, H. Ishikawa, Y. Sasa, and M. Uda

I t is known that for gas targets, the energy ofloss-electrons is equal to that of electrons having avelocity the same as that of projectiles from which
the loss-electrons are stripped. Therefore, the energyof the peak of loss-electrons is independent of elements of gas targets.

2~OO~---~~--~~~--~OOO~--~l0c0·
Electron Energy (eV)Fig. 1. Spectra of backscattered loss-electrons stripped from
He+-ions. Energy of He+-ions is 4.4 MeV. The incident
angle of the beam is 53° relative to the normal to thesurface of a target. Only electrons emitted normal to thesurface were energy-analyzed and detected.

On the contrary, for metal targets, target dependence was found for the energy of backscatteredloss-electrons. The apparatus was described elsewhere. I ) He+-ion beam was incident on a target
with an angle of 53° relative to the normal to thetarget. Only those electrons backscattered normal
to the surface of the target were energy analyzed anddetected. Figure 1 shows the energy spectra of 10sselectrons for the targets of Au, Ag, eu, and AI.
The energy of the He+-ions was kept to be 4.4 MeV
throughout the measurements. From this energy
spectra it is concluded that the shorter the mean
free-path for electron-loss, the higher the energy ofloss-electrons. This implies that the Z2-dependenceof the energy of loss-electrons backscattered frommetal targets comes from the Z2-dependence ofenergy loss of these electrons inside the target before their escape from the surface.
Reference
1) A. Koyama, O. Benka, Y. Sasa, and M. Uda: Nucl.
Instrum. Methods B, 13, 637 (1986) .

63
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-19. Towards Production of Low Energy Pions and Muons Using
Heavy-Ion Reactions
K. Ishida, T. Matsuzaki, and K. Nagamine

It has been known that nucleus-nucleus collisions

can produce pions with the energy per nucleon significantly lower than the nucleon-nucleon threshold(280 MeV).
Pions and muons are very useful for the materials
research. Positive pions and muons are considered
to be light isotopes of hydrogen. Using pSR (muonspin rotation, relaxation and resonance) and channeling techniques, their states in matters, their diffusion properties, and the local magnetic field at themuon site have been extensively studied. Negative
pions and muons can be considered to be heavy
electrons which form mesonic atoms and molecules.
Negative pions and muons are used for the hyperfine studies of the mesonic atoms, and their energy
shifts have been used to determine nuclear charge
radii. The negative muon also behaves as a catalyst
for d-t fusion by forming a (dtp) mesonic molecule.
Here, we are going to estimate the production rateof low-energy pions and muons using the heavy-ion
beams available at RIKEN Ring Cyclotron and their
possible applications to material sciences.
In the pion/muon experiments mentioned above,
the requirement of low energy muons has increased
for the study of small samples and low density gases.
For this purpose, positive surface muons have been
extensively used so far. The surface muons are produced as follows. At first, positive pions are producedby nuclear collisions; some of the pions lose theirenergy and stop in the target and decay into muons
with an energy of 4.12 MeV. The muons lose theirenergy in the target, but some fraction of them canemerge from the surface of the target.
Much lower-energy muons are required for the
study of surface physics, and for the study of elementary particle physics in which muons or muoniums
are stopped in vacuum. Recently, one of us and his
collaborators succeeded in producing thermal energy
muoniums by stopping muons in a hot tungsten
foil; 1) they are now trying to ionize the muoniums
by a three-photon laser resonance to produce thermal muons. In this report, we propose an alternative
method to obtain low-energy muon beams directly
by using heavy-ion reactions.
There are several meson factories in the world,which can produce very intense beams of pions ormuons (typically 10 7 muons / s). All the factories use
proton beams of high intensities (more than 100 pA)
and energies above 500 MeV. Those high yields ofpions and muons cannot be usually exceeded byusing accelerators that deliver relatively low-current
and low-energy heavy-ions.
Let us compare the case of a heavy-ion beam of
135 MeV/nucleon with that of a proton beam of590 MeV on a carbon target.
Range(gjcm2)135 MeV ju 12C
6
590 MeV p
200

Cross section Typical intensity(particle pA)
(ph)

0.2
10

<1
100

The cross sections were estimated from the literature. 2 - 4 ) Since the range of the proton is muchlarger than that of the heavy ion, the total pion
production rate for a thick target becomes very large.
A total yield is not essential, however, for the production of low-energy particles, since the pions andmuons produced mainly near the surface can contribute to the low-energy component. An importantfactor is the yield of pion and muon per unit length,
which is determined by the product of a cross section and a beam intensity. Even so the high intensity
proton beam remains advantageous by three to fourorders.
We will mention two points where the heavy-ion
collisions may have an advantage over the protonnucleus reactions. First, the negative pion production
is enhanced by n-n interaction. Secondly, the yieldof pions and muons is large at low energy; the pionenergy distribution obtained by the heavy-ion reaction shows a peak around 10 MeV/) while theproton-induced reaction has a peak around 50 MeV.
The low-energy pions produced are stopped moreeasily in a target than high-energy pions and decay
near the surface to produce surface muons. Thus
the conversion efficiency from pion to surface muon
may be increased.
We show the Monte-Carlo calculation on the
135 MeV /u carbon nucleus injected into a carbon
target of 1,000 mg/cm 2 in thickness. The normalof the target was 60° to the incident beam. The
parameters used were:K. Ishida, et al.

64

1,105

O.8E1.77
610 (E/50)6.~ p.balmost isotropic in
C.M. system
Pion energy distribution (C. M. system)(l2C)
P(Err)=O.04exp(-Err/25)(proton, 0-50 Me V)
P(E,,)=E,,/2,500
Energy range relation for pion R= 12E:r1. 77
Range energy relation for muon R= 15Ei· 77

Range energy relation for 12C
Total pion cro.ss section
Pion angular distribution

0.0
10

1,

1, 1ifwhere energies are expressed in MeV or MeV /u,and the ranges are in mg/cm2 • The efficiency ofeach step washIT

5X 10-·
0.09
0.04

Figure 1 shows the depth distribution of the position calculated for the pion production and the pion
stopping. The pion production decreases with depth
owing to the energy loss of the projectile. The distribution of pion stopping positions is a little inhomogeneous, indicating the effect of low-energy pions withshort ranges, but not so large as to compensate thelow cross section. Thus, we might say that we cannot match the meson factories by a usual way. In
Fig. 2 are shown the calculated position, angle, andenergy distribution of muons emerging the target.
The number of the muons increases almost linearlywith muon's energy as expected from almost homogeneous pion stopping.
We have two choices in collecting and transporting a muon beam to a sample. One is a conventional magnetic beam transport line which can deliver
both surface muons and pions. If the angular acceptance of 10- 3 and momentum acceptance of± 5 % are assumed, the number of muons will be
100/s, which surely depends on the beam intensity.
Another is an electric beam transport, which can

5'I:L~=:::::1

b

-1000

Z (mg/cm2)

0

6
lXl:

~ooo

Z (mg/cm 2 )aFig. 1. Calculated depth distribution of the position forpion production (a) and pion stopping (b) for 135 MeV lu
12C in a carbon target. The fraction of pions producing
surface muons are also shown with a lower line in Fig.
(b). Vertical scales are in pions I s per bin for a primarylILA beam.

E (MeV)

5.0~y(deg)90o~~r9

ProtonPion production
1. 0 X 10- 5
Pion stops in the target
0.39
Muon come out from the target 0.04

L
to~.
r

o~ . rA:hl~r_~o-1000

X (mgkm2)

1000

Fig. 2. Calculated position (X, Y) , angle (0." 01/) , and energy distribution of the muons emerging the target. Verticalscales are in muons/s per bin for a primary lILA beam.

handle muon beams with energies up to 100 ke V
with high efficiency. No one has tried so far to produce such a low-energy muon beam by this method.
Since the fraction of muons below 10 ke V will be
6 X 10- 6 ., the muon yield is calculated to be 1/ s if
we assume the angular acceptance of 0.1. This yield
is not too low, since 104 muons would be enough todeteITIline the muon polarization in a sample to astatistical level of 5 %. The muons with these energy
ranges may be useful for the studies of the layers
near the surface. By selecting the energy of muons
with a step of 10 keV, we can probe the surface
layers with a resolution of 0.01 mg/cm z.
The latter beam transport system may also be used
to transport the secondary radioactive nuclei produced in heavy-ion reactions. We may have achance to study a sample using both the muonprobes and the other nuclear probes by hyperfine
interaction techniques.
References
1) A. P. Mills, Jr., J . Imazato, S. Saitoh, A . Uedono, Y.
Kawashima, and K. Nagamine: Phys. Rev. Lett., 56,
1463 (1986); K. Nagamine and A. P. Mills, Jr.: Sci. Papers I.P.C.R ., SO, 67 (1986) .
2) J. Stachel, P. Braun-Munzinger, R . H. Freifelder, P.
Paul, S. Sen, P. DeYoung, P. H . Zhang, T. C. Awes,
F. E. Obenshain, F. Plasil, G. R. Young, P. Fox, and
R. Ronningen: Phys. Rev. C, 33, 1420 (1986) .
3) C. Guet and M. Prakash: Nucl. Phys. A, 428, 119c(1984) .
4) J. F. Crawford, M. Daum, G. H. Eaton, R. Forsch, J.
Garzon, H. Hirschmann, P.-R. Kettle, 1- W. McCulloch,
and E. Steiner: Helv. Phys. Acta, 53, 497 (1980) .

65
RIKEN Accel. Prog. Rep. 20 (1986)

Coulomb-Excitation 73Ge Mossbauer Study Usinga New-Type Piezoelectric Transducer

111-2-20.

N. Sakai, F. Ambe, and K. AsaiThis note reports the preliminary result on a
Coulomb-excitation M6ssbauer spectrum studied withthe 40Ar 4+ beam of RILAC.
The 73Ge nucleus is one of the less-used M6ssbauer nuclei because of the following reasons:(1) The 13.3keV first excited state has a large
internal conversion coefficient in the order of 1,000,
and a long lifetime (2.95 f1s) which results in an
extremely narrow M6ssbauer line. (2) As shownin Fig. 1, the M6ssbauer transition between the66.7 keV state and the ground state does not occur
because of the long lifetime (0.5 s) of this excitedstate. (3) The 68.7 keV state is not populated in
the electron capture of 73As, and only populated toa small extent in the {3- decay of 73Ga. Thus, it isadvantageous to study the 73Ge M6ssbauer effect byusing the Coulomb-excitation method which can
excite the 68.7 keV state.
A fixed natural Ge-metal target was exposed toa beam of 50 MeV 40Ar 4+ ions with a beam currentof around 150 nA. The Coulomb-excited Ge nuclei
were scattered and stopped in the Ge-metal target
itself. The absorber used was powdered Ge02 witha hexagonal structure. Both target and absorber
4.S7h

SO.3d
------~

47'/,
~-

keY

~;,As

364.0

(3/2)-

EC

44 'I.

68.75 (1.6 ns)
66.7 (0.55)(7/2)+
1/2 -100'/.

5xl0
5,4 0 . - - - - - - - --

..

..

~

Z
::l

85,35

-10

----.

I·
-5

0
VELOCITY (mm/s)

10Fig. 2. Mossbauer spectrum of an Ge0 2 absorber with aGe-metal target. Both are cooled with liquid N 2 •were cooled with liquid N 2. A NaI (Tl) scintillation
counter was used to detect 68.7 keV r-rays.
The M6ssbauer transducer employed was composed of a pair of piezoelectric bimorph actuators.
This new-type transducer was proposed previouslyl)
and developed by one of the authors (N.S.). It
was found that the actuators were useful not only
at room temperature but also below 80 K.
The observed M6ssbauer spectrum is shown in
Fig. 2. A single absorption dip was observed. The
full-width at half maximum is about 5 mm/s, andthe depth of the absorption peak is only about 0.5 %of the counts of off-resonance. These observations
are consistent with the values reported in Ref. 2. Amuch better M6ssbauer spectrum will be obtainedby using a target of enriched 73Ge on Cr-metal andan absorber of Ge02 with a tetragonal structure.
These materials are known2 ) to induce a larger
recoil-free fraction than the present case. Such improvements are now in progress together with anapplication of the piezoelectric actuators at liquid
He temperature.

YoM

5/2 +
9/2+

Fig.!.

!

13.3(2.95 jJs)o

Energy level scheme for the 73Ge nucleus.

References
1) N. Sakai, F. Ambe, and K. Asai: RIKEN Accel. Prog.
Rep., 19, 159 (1985) .
2) G. Czjzek, J. L. C. Ford, Jr., J. C. Love, F. E. Obenshain, and H. H. F. Wegener: Phys. Rev., 174, 331(1968) .

66
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-21. rDPAC Study on (lllln~) lllCd Ions in Silver Phosphate
S. Ambe, K. Asai, T. Okada, and F. Ambe

In non-conducting materials, the after-effects
associated with the EC decay of ll1In are usually
so large that the amplitudes of the time differential
perturbed angular correlation (TDPAC) of l11Cd
r-rays are attenuated strongly at low temperature.
':Ve showed that such spectra can be interpreted,m some cases, on the basis of after-effects-free
spectra obtained at high temperature. I - 3 ) This report describes a study on the after-effects of theIl1In -7 1IlCd decay in silver phosphate (Ag3 P0 4 ).
Silver phosphate was prepared by neutralizationof a dilute nitric acid solution of silver nitratesodium dihydrogen phosphate with sodium hydroxide.
The X-ray powder pattern of the product showedno additional peaks due to impurities or otherphases. About 65 mg of silver phosphate powder
was developed over an area of 2 cm2 on an aluminum
plate and covered with an aluminum foil of 80 pm
in thickness. The target assembly was irradiatedwith 30 MeV a-particles accelerated by the cyclotron,
the back of the aluminum plate being cooled withwater. The silver phosphate sample was blackened
during irradiation due to radiation effects of thea-particles. Annealing at 800°C for 1.5 h in air
recovered the intrinsic orange-yellow color of thecompound. The TDPAC spectra of the annealed
sample were recorded at various temperatures with
NaI scintillation counters connected to a conventional fast-slow coincidence circuit.
Typical TDPAC spectra obtained are shown in
Fig. 1. The spectra above 510°C showed little
attenuation, indicating that l11Cd ions are in nearly
cubic environments in this temperature region.
Between 300 and 450°C, no reproducible results
were obtained. In some cases, TDPAC patterns
characteristic of relaxation were recorded. In another, a periodic oscillation due to an electric
quadrupolar interaction was observed superposed ona relaxation pattern. The results obtained at room
temperature and at liquid nitrogen temperature suggest distributed static quadrupolar interactions as
is usual for l11In in insulators.
The crystal structure of silver phosphate at room
temperature is cubic; each silver atom has fouroxygen atoms as nearest neighbors and two silver
atoms form a pair in the structure. The site symmetry of silver atoms is not cubic; silver phosphate

0.1

0.05
0.0
0
I J.
530 C.
I'
J', 1\ (" I!!ll Ihj
0.1 5 ,;""'i....'>i;'/o.,~'7/N{itNV~'trM1:.'dli'Viii;~/1r~rifir';\·J·

n

OJ :
ODS .
0.0 -

-

-

-

- - - - - --0.0 - ---

- - --~ 0.1 5~ 0.1
~ 0.05- --undergoes phase transition at 520°C. The hightemperature form is also cubic, but its structure has
not yet been determined.
It is interesting to note that the l11Cd ionsarising from 111 In in silver phosphate are in nearly
cubic envirorunents at 510°C, though the site symmetry of silver atoms in the matrix is not cubic
at this temperature. The observation indicates thatthe (1l1In -7) 111Cd atoms do not simply occupy the2sites of silver atoms. One possibility is that l11Cd +ions replace pair of Ag+ ions in the structure. The
poor reproducibility of the TDPAC spectra in thetemperature region 300-450°C suggests that diluted
impurities or imperfections produced in the samples
during TDPAC measurement play an important role
in relaxation process. Further work is in progress
to improve the reproducibility of the TDPAC spectra.
References
1) K. Asai, F. Ambe, S. Ambe, and H. Sekizawa: I. Phys.
Soc. lpn., 53, 4109 (1984) .
2) F. Ambe, K. Asai, S. Ambe, T. Okada, and H. Sekizawa: Hyp. Int., 29, 1197 (1986) .
3) K. Asai, F. Ambe, S. Ambe, T. Okada , and H. Sekizawa: Hyp. Int. , 34, in press.

67
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-22. An Investigation on the After-Effects of 1111 n (~ 111Cd)
EC Decay in a-Fe 2 03
K. Asai, F. Ambe, S. Ambe, T. Okada, and H. Sekizawa

In our previous papers,1,2) we reported studies on
the after-effects of 111 In (~ l11Cd) EC decay in aFe20S above room temperature. This year, wemeasured the time differential perturbed angularcorrelation (TDPAC) in the same system far below
room temperature, intending to deduce the hyperfine parameters for the electronic excited states
produced by EC decay and their lifetimes. Sample
preparation and experimental set-up were the sameas described in Refs. 1 and 2.
The TDPAC spectrum A 22 -G 22 (t) observed at
85 K is shown in Fig. 1. If there were no disturbance around 111Cd such as the after-effects of theEC decay, it would be reasonably assumed on thebasis of the crystal and magnetic structure of aFe 2 0S 3 ) that the hyperfine interaction is unique, theEFG is axially symmetric, and the angle () between
the directions of H hf and the principal axis of EFG
is 0°.
First, we analyzed the spectrum on these assumptions. The values of the Larmor angular frequency(J) L and the quadrupolar angular frequency (J) Q wereobtained by the least-squares fitting of the experimental data with a semi-empirical formula'"Cd(-"'In) in o:-Fez03 at 85K

a100

TDPAC coefficient A22 - G2dt) of the lllCd (~lllIn)
correlation in a-Fe20S at 85 K. The solid curves
represent the fitted values of C1 X G 22 (t) Uni'l+ C2 (a): withthe assumption of axially symmetric EFG with theprincipal axis parallel to the direction of H hf , and (b):without the assumption in (a).

Fig. 1.

r-r

parameters and the X2 -factors are tabulated in Table
1, and the fitted curves are shown in Fig. 1 (a).
As can be seen from Table 1 and in Fig. 1 (a), thespectrum is reproduced rather well in the regiont > 50 ns, but the absolute value of the amplitude,
C 1 , of G 22 (t) uniq is considerably smaller than thatof A22 ( :::;: -0.15), and the spectrum is not reproduced
well in the region with small t.
Next, we analyzed the spectrum by the sameprocedure without restrictions on the angle () andthe asymmetry parameter, '1), of EFG. The results
are shown in Table 1 and Fig. 1 (b). Compared withthe analysis described above (Fig_ 1 (a) ), the fitting
for t > 50 ns is improved to some extent. On thein the region t;;:::-: 50 ns, where C1 and C 2 were adjustable parameters and G22 (t) uniq is the perturbation factor for an ensemble of randomly oriented
microcrystals with a unique static interaction. 4 ) If
the above assumptions hold exactly, C 1 is equal to
A 22 , C 2 vanishes, and the observed spectrum is reproduced in the whole time-range. The best fitted
Table 1.

50

Fitted parameters obtained on the assumptions described in the text.

The parameters at

293 Ka) are tabulated for comparison.
Temperature
(K)

85
85
293
293

WL X

10- 7

WQ X 10- 7(rad/s)(rad/s)

1)

10.0
9.9
10. 7
10.7

2.52
2.54
2. 54c)
2.54

0.0
0.05
0.0
0.0

0
(deg.)

O.
6.
90.
90.

-C1

-C2

X2 b)

Assumption

0.051
0.064
0.134
0.111

0.024
0.020
0.002
0.009

1. 63
1. 35
1. 39
1. 32

A
B

C
D

a) taken from /1/. b) in a time-region t ~ 50 ns. c) value of wQo,
A, a unique static interaction with an axially symmetric EFG along < 111 >; B, a unique static interaction
without the restriction in A; C, a Gaussian distribution of wQ with a width LlwQ/wQo=8%; D, a Gaussian distribution of 0 with a width LlO=6°.

68

K. Asai, et ai.

contrary, the misfit for t < 50 ns is not improved
essentially. The value of WL is a little smaller thanthe one above the Morin temperature T 1\1, due tothe difference in the contributions of the dipolar
magnetic fields between the temperatures below andabove T 1\1. On the other hand, the value of WQ
agrees well with those at temperatures above T 1\1.
In the previous works,1,2) we were able to reproduce the spectra at and above room temperaturein the whole time-range by assuming a Gaussian
distribution in one of the hyperfine parameters: (Jaround 90°, or WQ around WQO' We tried to analyze
the present spectrum below T M by the same procedure, but were unable to obtain any satisfactory
results.
The present results of analyses show that the
TDPAC spectrum at 85 K has two distinctive features ascribed to the after-effects of 111 In (--7 111Cd)
EC decay. (1) A strong decay is observed in theamplitude of the perturbation factor G 22 (t) in an
initial period of about 50 ns. (2) The perturbation
factor G 22 (t) could be analyzed fairly well by
assuming a unique static interaction after that
period, though the hyperfine parameters are slightly
but definitely different from those expected fromthe crystal symmetry.
The 111Cd ions arising from 111 In are in highly

excited electronic states as a result of the Auger
process following the EC decay. The excited states
relax to the ground states through many electronicintermediate states with lifetimes spreading over awide time range. It is proposed that there are twodominant groups in the intermediate states affecting
the TDPAC spectrum, corresponding to the two
features mentioned above. One group is the states
populated in an early stage of the electronic relaxation with relatively high energy. The othergroup is some low-lying electronic excited states
populated in the last stage of the electronic relaxation. A more detailed discussion and a likely
model for ions in these low-lying excited states will
be described elsewhere. 5 )References
1) K. Asai, F. Ambe, S. Ambe, and H. Sekizawa: I. Phys.
Soc. lpn., 53, 4109 (1984) .
2) F. Ambe, K. Asai, S. Ambe, T. Okada, and H . Seki zawa: Hyp. Int., 29, 1197 (1986) .
3) R. Lefever: Landolt-Bornstein New Series III, Vol. 12b,
Springer-Verlag, Berlin-Heidelberg-New York, p . 7 (1 980) .
4) H. Frauenfe1der and R . M. Steffen: A1pha -, Beta- andGamma-Ray Spectroscopy (ed. K. Siegbahn) , Vol. 2,
North-Holland, Amsterdam, p. 1111 (1964) .
5) K. Asai, F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: H yp. Int. , 34, in press.

69
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-23. Supertransferred Hyperfine Magnetic Fields at l11Cd (~l11ln)
in Ferrimagnetic Oxides with Spinel Structure
K. Asai, T. Okada, and H. Sekizawa

We have been systematically investigating HSTHF
at Cd2+ in ferrimagnetic oxides with the spinel structure by means of the time differential perturbed
angular correlation (TDPAC) of 171-245 keY
cascade r-rays emitted from l11Cd ( ~ 111 In) . In
spinel oxides, the parent nuclei 111 In occupy the A(tetrahedral) sites (denoted by 111 In (A)) and thedaughter 111Cd (A) feel H STHF transferred from themagnetic ions on the nearest neighbor B (octahedral) sites. In a previous study on Fe304/) we
obtained an average of the contributions of Fe 3+(B)and Fe 2+(B) ions to HSTHF at 111Cd (A), but could
not separate out each contribution. This year, wemeasured H STHF at 111Cd (A) in solid solutions
Fe3-xM x04 (M = Ni or Co), where M2+ ions occupy
the B sites. The purpose of this study is to elucidate
the contributions of individual B site magnetic ionsto the observed H STHF.
Sample preparation, experimental set-up, and thedefinition of the directional anisotropy, R (t), of
the angular correlation were the same as described
previously.l) Representative spectra of the anisotropies, R ( t) , for the specimens F e3-xNixO 4 areshown in Fig. 1. The frequency spectra of theseR (t) give the distribution of 2WL including its sign.
From the sign of W L, the direction of H.l was foundto be parallel to the externally applied magnetic
field H ext . The distributions of H STHF, correctedfor H ext (small compared with H STHF) , are shownin Fig. 2.
In magnetic oxides with the spinel structure, H STHF

o

50

laO
Time

150

200

(ns)

Fig. 1. Directional anisotropies, R (t), of the coincident
counts in Fe 3 __",Ni",04 at room temperature. The solid
curves are fitted ones with the distributions of HSTHF
shown in Fig. 2.

4(a) x =0.1

3

2

§ 2
1)

3 1

1
O~Lru~~~~~~~~

oFig. 2. Distributions of HSTRF at lllCd2 + (A) in Fe a_",Ni",04'

at a nucleus on the A site can be regarded as thesum of the contributions of twelve magnetic ionson the nearest neighbor B sites. In the present
paper, we denote the field from the j-th ion N j (B)by h ( ~ N j ). The composition dependence of H STHF
shown in Fig. 2 indicates that the field h ( ~ Ni 2+)
is fairly smaller than h ( ~Fe2+). The overall shapesof the distributions of H STHF were reproduced successfully by assuming binomial distributions of Ni andFe ions on the nearest neighbor B sites, i.e.,
12

P(HSTHF ; x) ex: 2J 12C~(1- X/2)12-~(x/2)~~= l'O(HSTHF- H~)
H~= (12- ~)·h(-Fe)+~. h(-Ni 2 +)where, ~ is the occupation number of Ni 2+ ions on
the nearest neighbor B sites, 12Ce the binomial coefficient, xj2 the ratio of Ni 2 + ions to the totalmagnetic ions on the B sites, and He the hyperfine
magnetic field at l1lCd when the occupation numberof Ni 2+ is ~. The field h ( ~ Fe) is an average ofh ( ~ Fe 2+) and h ( ~ Fe3+) and will be a functionof Ni 2 + content, x. Similar analyses were performed
also on the data in the system Fe3-xCox04'
Figure 3 (a) shows the h ( ~ Fe) in both the systems, and Fig. 3 (b) shows h ( ~ Ni 2+) and h ( ~C0 2+ ) ,as functions of the composition. The abscissa of
Fig. 3 (a) is scaled linear in the ratio, P.., of
Fe 3+(B) to the total Fe ions on the B sites. The ratio

K. Asai, et al.

70

QJ

11

0

'Q) 6 - (b)'::::10.
'Q)

~4

~5

LL

I£'3
2

AM = Co

~ 9

..c

L
0.0.

I

I

0..2

0..4

0..6
R

I

J'

0..8

1.0.

a

0.0.

"""(

-

..c 1 1--8AA M = Coo M = Ni

~2 1--oM = Ni-~?
A A-~-g

1

1

0..2

0..4

-

0..6

0..8

La

M content x

Fig. 3. Composition dependence of the hyperfine magnetic
fields, h (~NJ) , at Cd2 + (A) transferred from the individual
magnetic ions, N J (B), in Fes_",M",04 with M = Co or Ni:(a) NJ=Fe. The quantity fR. is the ratio of P+(B) ionsto the total Fe ions on the B sites, (b) N j =Co, and=Ni.

fR. is related to the Ni content, x, as fR.= Ij(2-x).
It can be seen in Fig. 3(a) that h( ~Fe) increases
linearly with fR. ; this means that h ( .r Fe) is theweighted average of h ( ~ Fe 2+) and h ( ~ Fe 3+), i.e.,

The derived values of h ( ~ Fe 2+) , h ( ~ Fe 3+) ,h (~Ni2+), and h (~C02+) are 8, 11, 4, and 4 kOe,
respectively; it should be noted that they are almost
independent of the composition.
The above analyses are allowed only when F e2+
and Fe 3+ ions are undistinguishable due to the fastelectron hopping among them as realized in thecases with small x. Even if the above condition
does not hold, these analyses are justified as an
approximation because the difference betweenh (~Fe2+) and h (~Fe3+) is considerably smaller
than that between h ( ~ Fe) and h ( ~ M2+) .
Detailed discussion on the values of h's obtainedin the present study will be given elsewhere. Twobrief comments are given on these values in comparison with previous works. 2,3)

The HSTHF at Cd 2+( ~ l11mCd) in rocksalt-typeoxides, CoO and NiO, were measured at 4.2 K.2)
The values of h ( ~ C02+) and h ( ~ Ni2 +) in theseoxides calculated from their data are 29 and 32 kOe,
respectively, which are 7 or 8 times as large as thepresent values in spinel-type oxides. These differences suggest a strong dependence of H STHF on
the angles of Cd2 +-O-M2+ (M=Co or Ni) bonds;
they are ='=7120 0 in spinels and ='=7180 0 in rocksalts.
The angle 120 0 is not favorable as compared with
180 0 for the spin transfer from the magnetic ionsto the Cd ions via the 2p (/ orbitals of the oxygenions. This transfer is one of the dominant mechanisms to produce H STHF.
The second comment is about the comparison of2
HSTHF at Cd + and at In 3 +.
Both ions nominallyhave the same electronic configuration. From NMR
results on HSTHF at Ins+(A) in NiFe 204, the valuesof h (In 3+ ~ Fe 3+) and h (In 3+ ~ Ni2 +) were estimated to be 16 and 7.3 kOe, respectively.3) These
values are a few tens of percents larger than thepresent ones of h (Cd2 + ~ Fe 3+) or h (Cd 2+ ~ Ni 2+).
This fact shows that I n 3+-02- bond is more covalentthan Cd 2+-0 2- bond in this oxide, i.e., the amountof the transfer of oxygen valence electrons, which
are partially polarized by the B site magnetic ions,is larger in the former than in the latter. The sametendency that the covalency increases with thevalence states of the cations is also observed between Sn4+-02- and Cd 2+-0 2- bonds in a-Fe203.4)
References
1) K. Asai, T. Okada, and H. Sekizawa: l. Phys. Soc. lpn.,
54, 4325 (1985) .
2) H. H. Rinneberg and D. A. Shirley: Phys. R ev. B , 13,2138 (1976) .
3) Y. Miyahara and S. Iida: l. Phys. Soc. lpn. , 37, 1248
(1974) .
4) F. Ambe, K. Asai, S. Ambe, T. Okada, and H. Sekizawa: Hyp. Int., 29, 1197 (1986) .

71
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-24.

Simulation Experiment on Carbon Coating of the First
Wall of a Fusion Machine
Y. Sakamoto, H. Amemiya, Y. Ishibe, S. Kato, K. Okazaki,
H. Oyama, K. Yano, K. Akaishi,* N. Noda,* S. Amemiya,**
H. Minagawa,*** T. Hino,*** T. Yamashina, and S. Matsumoto****Metal impurities in Tokamak plasma have satisfactorily been decreased by first wall carbon coating
which the TEXTOR group has systematically developed. 1 - 4 } The carbon coating is carried out by
glow (FR-glow) discharge in hydrocarbon/hydrogengas mixture. This needs a complicated treatment todecrease hydrogen recycling and change over hydrogen isotopes.
We constructed a plasma device (RIKEN ECR-2),
which enable us to simulate a carbon coating process in fusion machines or to develop new methods
for producing carbon films by creating various coating conditions on the base of ECR plasma.
Figure 1 shows a schematic diagram of the ECR-2
device. 5} A stainless steel tube with a diameter of
10 cm and a length of 1 m is placed in electromagnetic coils (EM) which provide an ECR magnetic field corresponding to 2.45 GHz microwave
supplied from a magnetron source (MS). Threeturbomolecular pumping systems (TMP + RP)
evacuate a discharge tube, an Auger electron spectroanalysing system (AES ) and a quadrupole mass
analyzer with an orifice (QMA). We use a mixed
gas of CH4 and H 2, which are introduced throughmass flow controllers. In most cases samples are
fixed on a sample holder (SH) isolated electricallyfrom the discharge chamber and can be applied
direct current (DC) or radiofrequency (RF) voltage. The sample temperature can be raised with aheater (H) and is monitored with a thermocouple(TC). IG is an ionization gauge. The AES is used
when in situ observation is necessary.
Plasma electrons with temperature of several eVcollide with and dissociate gas molecules, for example,
2CH 4 +e--+ 2CH a + H2 +e
We can observe by use of the QMA system anincrease in hydrogen partial pressure and a decreasein that of methane due to plasma. An example isgiven in Fig. 2, where the initial partial pressures
are set identical (2 X 10-2 Pa) for hydrogen andmethane. As we know each gas flow rate, simple
calculations based on the mass conservation law giveus the average H/C ratio in a deposited film. Thisestimation on the average H/C ratio is useful, because we can know the in situ dependence of the
H/C ratio on the parameters of discharge. As an
example we show the dependence of the Hie ratioon the microwave power in Fig. 3, where the total
gas pressure is 6 X 10-2 Pa and the methane concentration is 25 %.
Important characteristics obtained are shown in
Table 1. We obtained the accurate H/C value fromanalysis using nuclear reactions
H (15N, ar )l2C)
and (12C ( d, p) l3C) .

e

N
I

o
x

ttl

0..

~

::l

3

~

Fig. 1. Schematic diagram of RIKEN ECR-2: Carbon coating simulation device.

* PPL, Kyoto University.
** Faculty of Engineering, Nagoya University.
*** Faculty of Engineering, Hokkaido University.
**** National Institute for Research in Inorganic Materials.

ECR on

t:r:

0..

Vl
Vl

0.

C

2

f---.4-----~-- ----.::I-

:r:
u

0..

~

o coating time (orbit.)
Fig. 2. Typical change in partial pressures of CH4 and H2
due to plasma production.

Y. Sakamoto, et al.

72

n
0.5

.~

100r-------------------------------~

0.4

e 0.3

:::c

6 X 10- 1 Po

'E

:§ 50
E
til

0' 0.2,gu0

as received
after carboniza ti on
after decarbonization

C

~
I

0.1
1200

0

100

200

300

400

500

600 W

Fig. 3. An example of dependence of the mean H IC ratio
in carbon film obtained from CH4 and H2 partial pressure measuremen ts.

Item

500

A
input power of p-wove

Table 1.

400

Characteristics of carbon films.
Condition

Estimation

Structure

CH 4/H 2 = 1/1
RHEED amorphous
Ptotal =0.01-0.1 Pa FTIR amorphous
P micro = 200 W
Vbias =0-100 V

Hardness

Vbias =0 V

870kg/mm2

Specific weight

3.0 g/cm 3

Hydrogen
Concentration

Vbias=O V(Vspace= +30 V) NRA 0.26
Vbias= -100Vdc
NRA 0.22
Vbias= -150Vdc
NRA 0.19
Vbias= 175 Vrf (amplitude) NRA O. 16

Microwave
Launcher/'

References

2)

3)

!

EIt?ctromagnets
Magnets

4)
5)

SampleFig. 4. Creation of local cleaning ECR plasma in a magnetic
field by permanent magnets.

800

films, for example, on observation windows, rf heating windows or high-voltage insulators. We succeeded in removing a carbon film (a~orphours, ona substrate of quartz) by pure hydrogen ECR plasma
produced locally in a magnetic field by the use ofpermanent magnets. 6 ) Figure 4 shows the local
plasma production in a branch of the discharge tube
shown in Fig. 1. Figure 5 shows the results of lighttransmittance measurements on quartz samples "asreceived," "after carbonization" and "after decarbonization." The data show that we can utilize a local
pure hydrogen plasma to remove a local harmfulcarbon film.

Gas Inlet~\

700

Fig. 5. Change in light transmittance of a quartz plate bycarbonization and decarbonization.

I)

Summarizing the items in Table 1, we can say (1)carbon films formed are high density, amorphous,and comparatively hard ones and (2), to decrease
the hydrogen concentration, high energy ion bombardment is effective. By the way, a typical valueof HIC in TEXTOR RG carbonization is about
0.4. 1 )Carbonization has a possibility to deposit harmful

600
in nm

6)

J. Winter: Invited paper presented at the 7th Int. Conf.
PSI, May 5-9, 1986, Princeton, USA, l. Nucl. Mater.,
145/147 (1987) (in press) .
N. Noda, Y. Ogawa, K. Masai, I. Ogawa, R. Ando, S.
Hirokura, E. Kato, Y. Taniguchi, T. Akiyama, Y. Kawasumi, K. Kawahata, K. Toi, T. Watari, S. Tanahashi,
K. Matsuoka, and Y. Hamada: lpn. l. Appl. Phys., 25,
L397 (1986) .
W. P. Poschenrieder, G. FuBmann, G. v. Gierke, F. Mast,
H. Niedermeyer, J. Roth, F. Soldner, K. Steinmetz, H.
Verbeek, F. Wagner, G. Becker, H. S. Bosch, H . Brocken,
K. BUchel, A. Eberhagen, D. Eckhartt, O. Gehre, J. Gemhardt, E. Glock, O. Gruber, G. Haas, J. Hofmann, A.
Izvozchikov, G. Janeschitz, M. Kaufmann, F. Karger, M .
KeiIhacker, O. KIUber, M. Komherr, K. Lackner, R. S.
Lang, M. Lenoci, F. Leuterer, G. Lisitano, H. M. Mayer,
K. McCormick, D. Meisel, V. Mertens, H. Murmann,
J. N. Noterdaeme, A. Pietrzyk, H. Rapp, H. Riedler, H.
Rohr, F. Ryter, W. Sandmann, F. Schneider, C. Setzensack, G. Siller, P. Smeulders, E. Speth, K.-H. Steuer, O.
Vollmer, F. Wesner, and D. Zasche: Proc. 13th Eur.
Con£. Controlled Fusion and Plasma Heating, Schliersec,
April 14-18 (1986).
J. P. Coad, K. Behringer, and K. J. Dietz: l. Nucl. Mater .,145/147 (1987) (in press).
Y. Ishibe, H. Ogawa, K. Okazaki, K. Yano, Y. Sakamoto,
N. Noda, and Y. Hori: Shinku, 29, 385 (1986) (in Japanese) .
Y. Sakamoto, Y. Ishibe, K. Okazaki, and H. Oyama:
lpn. l. Appl. Phys., 25, 764 (1986) .

73

RIKEN AcceI. Prog. Rep. 20 (1986)

111-2-25.

Measurement of Hydrogen Isotope in Carbon
Films Produced by ECR Plasmas
K. Yano, H. Oyama, Y. Sakamoto, M. Yanokura,
1. Kohno, and K. Sugiyama

In thermonuclear fusion carbon coating of thefirst wall, which is in contact with high temperatureplasmas, has attracted special interest, because metal
impurities in plasmas are drastically decreased bythis technique. Since a low content of hydrogen in
the carbon film is required, we carried out carbonization experiments using an ECR plasma device(RIKEN ECR-2)11 to simulate in-situ carbon coating of large fusion devices. The amount of hydrogenisotope in carbon films deposited was investigatedmainly by an ERD (elastic recoil detection) method.
A gas mixture (CH4 + H2 or D 2) was used as asource gas. A microwave power of 200 W was usu-

ally launched through a helical antenna for production of plasmas. The electron density and electron
temperature of a typical plasma were ,-11010 cm 3 and,-15 eV, respectively.
The amount of hydrogen isotope was measured by
the ERD method using an Ar4+ beam of 50 MeV
obtained from RILAC facilities. 2) The thickness
1.5 •P = 5 X 10-4 Torr
PM =200 W
no bias (Subs. Si)
Temp. ·····no control
1.0

Q
I

0.6

.Q

-e

0.4

u

'E

~ •

0.2

200

0

~

P =5 x 10-' Torr (500J0CH,+500J0H 2 )R.4=200 W .
Subs. Si
Temp.··· ·· no control

u

•

•

0.5

•

•

A
A

•

•

.•

0

-200 -400 -600 -BOO -1000 -1200

A

0.5

1.0

PCIi ,/(PCH4 + P02 )Bias voltage (V)Fig. 1. Dependence of impinging hydrocarbon ions on theatomic ratio H / C.

Fig. 2. Atomic ratios, H/C and D/ C in carbon films deposited in CH4 + D2 plasmas.

RIK0181.10001.0000

~,~

UJ

u
z

<
IX>

0.9000

0::

0

<I}

IX>

-< 0.8000

0.70000.6000
4000

3500

3200

2800

2400

2000

1600

1200

800

400

WAVENUHBERS (eM-I)
lD-NO

POSITIONHEIGHT

ID-NO

POSITIONHEIGHT

ID-NO

POSITION

HElGHT00

2925.52

1.0~10012204 . 26

0.8613022175.34

0.8729Fig. 3. Infrared absorption spectrum of carbon films deposited in CH4 + D2 plasmas(PD2/ PCH, = 1.0).

74

K. Yano, et al.

of the films was also estimated by this technique.
The atomic ratios of HIC and D IC were measured instead of absolute measurements of theamount of H , D, and C atoms. Figure 1 shows theatomic ratio, HIC, against bias voltage, which isapplied to the substrates of a Si wafer (see Fig. 1 ofa preceding paper). In this case, the gas mixture
was composed of 50 % CH4 and 50% H 2 • It becomes evident that the H/C is independent of theenergies of impinging hydrocarbon ions and keeps
the value of ,-10.2. On the other hand, hydrocarbon ions are reflected and only neutral species takepart in forming carbon films, when bias voltage is200V.
To examine the effect of H 2 added to the gas
mixture, D2 was used instead of H 2 • The atomic
ratios, H/C and D IC, are plotted as a function of
R= PCHj(PCH.+Po z ) in Fig. 2. When R=O.5, thecarbon films were 200 nm in thickness. For R = 0.05
it was found from their ERD spectra that the car-bon films were too thin to permit us to estimate
the films thickness ; therefore, it is still open to question whether or not D is contained in the carbon
film. Figure 3 shows an infrared absorption spectrum
for the carbon film (R = 0.5). This spectrum closely
resembles that of a dense amorphous carbon film. 3)
The peak 00 is ascribed to a C-H bond; the peaks
01 and 02 are to a C-D bond. The result leads tothe conclusion that the added D2 are dissociated inplasmas and then D atoms combine with C atoms.
References
1) Y. Sakamoto, H. Amemiya, Y. Ishibe, S. Kato, K. Okazaki, H. Oyama, K. Yano, K. Akaishi, N. Noda, S. Amemiya, H. Minagawa, T. Hino, T. Yamashina , and S.
Matsumoto: p. 7I in this report.
2) Y. Sakamoto, Y. Ishibe, K. Okazaki, H. Oyama, K. Yano,
M. Yanokura, and I. Kohno: RIKEN Aeeel. Pwg. R et).,19, 98 (1985) .
3) E. Vietzke: private communication.

75
RIKEN Acce1. Prog. Rep. 20 (1986)

111-2-26.

Hydrogen Trapping by Substitutional Impurity in

NbMo o.03 Alloys
E. Vagi, T. Kobayashi, F. Kano, S. Nakamura,
K. Watanabe,* Y. Fukai,* and T. Matsumoto**

It has been known that the addition of Mo to
Nb increases the tenninal solubility of hydrogen III
an a-phase of the Nb-H system. For elucidation ofits mechanism, the lattice location of hydrogen in
Nb-Mo alloys was investigated by the channelingmethod utilizing a nuclear reaction 1H(llB, a)-aa. 1 )
Specimens were single crystals of NbMoo.o3Ho.o2
and NbMoo.o3Ho.o5, which were in the a-phase atroom temperature. Hydrogen was doped in the gas
phase. Channeling experiments were carried out
with a 2.03 MeV llB2+ beam, which had 1.0 mm indiameter with a current of 1 nA. The collimation of
the beam was better than 0.076°. The specimen was
mounted on a holder of a three axis goniometer, withwhich the crystal orientation was set within the accuracy of ± 0.004°. Backscattered llB and emitted
a-particles were detected with two solid state detectors at a scattering angle of 150° and 90° , respectively. In front of the detector for a-particles, a 4 pm
Mylar foil was placed in order to stop scattered llB_particles. The vacuum in the scattering chamber
produced by a turbomolecular pump was 4 X 10- 7
Torr and a cold trap was equipped so as to surround the specimen and the detectors. More detailsof the exprimental setup have been described in previous papers. 1-5) In the present experiments, the channeling angular scans were made for < 1 0 0> and< 110> axes, and a {I OO} plane.
Figure 1 shows our example of the angular profilesof back scattered llB and emitted a-particles for the{1 OO} planar channel in NbMoo.o3Ho.o2 ((a)) andNbMOO.03Ho.05 ((b) and (c)). Figure 1 (a ) and (b)were obtained at room temperature, and ( c ) at
100°C on the same specimen used in (b). The aangular profile exhibited a narrow dip in NbMoo.osH O• 02, whereas the dip became broader and a small
central peak came to be observed in NbMoo.03H o.05
at room temperature. By heating the specimen up to
100°C, this profile changed drastically to a dip superposed with a central peak. In a previous paper2) weconcluded that hydrogen atoms in an a-phase of the
Nb-H system are located at tetrahedral sites. For* Faculty of Science, Chuo University.
*::: Na tional Research Institute for Metals.

{lOO!
Nb
• H

o

( b)

(C)

12

l1.0f-~o
" J-

.

'0

'. ,.

'"

.~

~ 08

o

z

06
O.G '-----'~~-.l-~-(,_____L_
-1

o

-1

__ I

_

0

L.. -4--'----J'---~

I-1

Angl€' (deg)Fig. 1. Angular profiles of HE- and a-yields in (a)NbMoo .oaHo.02 at room temperature, (b) NbMoo.03Ho.05
at room temperature, and (c) NbMoo.oaHo.o5 at 100°C.
The inset indicates the projection of T-sites onto theplane perpendicular to the {I OO} planar channel. Thelines represent the projections of atomic planes, and thesquares the projected positions of T-sites.

tetrahedral site occupancy, the {1 0 O} angular profile gives a dip superposed with a small central peak
as shown in Fig. 1 (c).
These results are interpreted to be that hydrogenatoms are located at sites different from the tetrahedral sites in NbMoo.o3Ho.o2 and, at 100°C, they
are located at the tetrahedral sites: at room temperature hydrogen atoms are trapped by Mo atoms andat 100°C they are detrapped. This interpretation is
also supported by the results on the < 1 0 0> and< 1 1 0> channels. The a-angular profile in Fig. 1(b), where the hydrogen concentration is higher tha~that of Mo, has both features of 1 (a) and (c). ThIS
result indicates that some fraction of hydrogen atoms
are located at the trapped sites and the remainder at
the tetrahedral sites. The trapping efficiency wasestimated from the comparison of a-angular profiles
in NbMOO.03Ho.05 observed at room temperature withthose calculated by assuming that all hydrogen atoms
are located at the trapped sites in NbMoo.o3Ho. o2 andat the tetrahedral sites in NbMoo.osH o.05 at 100° .
According to this estimation, each Mo atom trapps
aproximately one hydrogen atom. Therefore, in
NbMoo.osHo.o5 about 60% of hydrogen atoms arelocated at the trapped sites and 40 % at the tetra-

76

hedral sites at room temperature.
trapped sites in progress.

E. Vagi, et at.

Analysis on the

References
E. Vagi, T. Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe: I. Phys. Soc. lpn., 52, 3441 (1983) .
2) E. Vagi, S. Nakamura, T . Kobayashi, K. Watanabe, andY. Fukai: I. Phys. Soc. lpn., 54, 1855 (1985) .
1)

3) E. Vagi, T. Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe: Phys. R ev. B, 31, 1640 (1985) .
4) E. Vagi, T. Kobayashi, S. Nakamura, F. Kano, K. Watanabe, Y. Fukai, and S. Koike: Phys. Rev. B, 33, 5121
(1986) .
5) E. Vagi, S. Nakamura, T. Kobayashi, F. Kano, K. Watanabe, Y. Fukai, and T. Osaka: I. Phys . Soc. lpn ., 55 ,2671 (1986) .

77
RIKEN Accel. Prog. Rep. 20 (1986)

111-2-27.

Study of Krypton Bubbles in Kr-Implanted AI by Means ofElectron Diffraction
I. Hashimoto,* H. Yamaguchi,* E. Yagi, and M. Iwaki

In a previous work, the experiments on the thermal extraction of Kr atoms from Kr-implanted Al
specimens have been carried out by using a mass spectrometer and diffusion coefficients were estimated to
be of the order of 10-19-10-18 m 2 Is in the temperature range from 713 to 813 K.1) These values areabout seven orders of magnitude smaller than thoseobtained in the tracer diffusion experiment using
85Kr.2) With the help of electron microscopic observation, such a large difference was attributed tothat, in the Kr-implanted specimens, Kr atoms exist
in the form of Kr bubbles, whereas, in the specimens
used in the tracer diffusion experiments, Kr atoms
exist probably as isolated atoms; such small diffusion
coefficients were considered to be those for the Kr
bubbles.1) Furthermore, we also found that theamount of extraction increased rapidly above 540 K
with increasing temperature. 1) This fact suggeststhat the structure change takes place above 540 K.
If such a structure change would be caused by thechange in the state of Kr bubbles near the specimen
surface, some changes would be reflected in electron
diffraction patterns. Up to the present, however, ananomalous contrast of the diffraction pattern has notbeen observed. In the present work, the behavior
of Kr bubbles in Kr-implanted Al for thermal annealing was studied in detail by means of electron
diffraction and transmission electron microscopy(TEM).
Thin Al specimens (99.99% in purity) suitable forelectron microscopy were prepared by conventional
chemical- and electrolytical-polishing. Kr atoms were
implanted at 50 keY to a dose of 10 2°/m 2 • The
implanted specimens were examined with an H-800
electron microscope with a heating stage operating
at 100 kV.
The electron diffraction patterns indicated thepresence of double diffraction spots. It is known
that a double diffraction effect is prominent when
two crystalline phases coexist in a specimen. 3 ) Figure
1 (a) shows an example of the selected area 110 electron diffraction pattern taken at room temperatureon as-implanted specimens from the region in which
Kr bubbles and Al matrix coexist. The illustration* Faculty of Science, Science University of Tokyo.

(b)(1 1 0)•• 0.0 ••
o

o

o

o

o

0

0

o

Fig. l. An electron diffraction pattern taken at room temperature on a Kr-implanted specimen. (a), 110 selectedarea diffraction pattern from Al containing Kr bubbles;(b), Illustration of the diffraction pattern. Large spots
represent reflections from an Al matrix, small spots arethose from a solid Kr and open circles are due to double
reflections.

in Fig. 1 (b) was made up of only the relatively
strong double diffraction spots. Most of the spots
were observed experimentally. This result suggeststhat the Kr bubbles are in the solid phase. To reveal
the origin of the double diffraction spots, we carriedout the observation using the electron microscope inthe same area as shown in Fig. 1. The results areshown in Fig. 2 (a) , (b), and (c); (a) shows a brightfield image, (b) is a dark field one taken by the 200
reflection of AI, and (c) is a dark field one withthe 200 reflection of Kr. The image of Kr bubbles
in Fig. 2 (c) are isolated better than those in Fig. 2(a) and (b). Therefore, the double diffraction isconsidered to be due to the presence of both phasesof the well-isolated solid Kr bubbles and the Al matrix. From the diffraction patterns, the lattice pa-

Fig. 2" Transmission electron micrographs of the same area
taken under different diffraction conditions at room temperature. (a), the bright field image; (b), the dark field
one taken by a 200 reflection of AI; (c), the dark field one
taken by a 200 reflection of Kr.

78

1. Hashimoto, et ai.

rameter, the packing density, and the molar volume
of solid Kr were estimated to be 0.534 ± 0.003 nm,
2.63 X 10 2 8 atoms / m 3 , and 22.92 cm 3 / mol, respectively. The mean diameter of the Kr bubbles andthe number in unit area were estimated to be 1.6 nm
and 5.9 X 1016 /m 2 , respectively.
Figure 3 shows examples of diffraction patternduring annealing ; (a) , (b), (c), and (d) represent
those observed at 483, 618, 668, and 743 K using
the heating stage, respectively. T he double diffraction disappeared below 483 K , while diffraction reflections from the solid Kr remained up to 618 K.
When the annealing temperature was 618 K, a diffuse
ring corresponding to the "amorphous" Kr was observed as shown in Fig. 3 (b ) . The diameter of thering coincided with that of the 111 reflection ofsolid Kr and the intensity became maximum around618 K. The ring disappeared just above 618 K ; thisindicates that the melting of Kr bubbles occurs
through the "amorphous" state at temperatures
about 620 K.
Furthennore, streaks were observed above 618 K
as shown in Fig. 3 (b), (c), and (d ) . To reveal their
origin, we carried out TEM observation at room
temperature on the same specimen after annealingat 823 K for 10 min. In this case, the streaks also
remained in the diffraction pattern. From Fig. 4, it
is to be noted that the mean diameter of the bubbles is 6.7 nm and the number of the bubbles inunit area is 7.5 X 101 5 /m 2 • The former is about fourtimes and the latter is about 1/8 of those observedin as-implanted specimens as described above. Thismeans that the bubbles grow by coalescence during
annealing. In addition, a large and irregular shaped
white contrast indicated with a circle in Fig. 4
observed in the micrograph is considered to be a
micro crack formed during annealing. The mean
diameter of the microcracks was 69 nm and their
number in unit area was 1.3 X 101 5 /m 2 • From theseresults, the streaks are considered to be closely related to the existence of microcracks. The experi-

Fig. 4. Typical electron m icrograph of the same specimen
as shown in Fig. 3 a fter annealing at 823 K for 10 min.
The irregular shaped white contrast is indicated by acircle.

0.8....--- - - - - - - - - - ,Ec~ 0 .71-

Qj

5t r E'Oks~ 0 .61o
a
0..

~

Kr
I-<_...............~--~..a.--- -. -0.5-

0.3 '--3=---'-4--':-----'6----'-----'8
Annealing

Temperature (xl00K)

Fig. 5. Lattice parameter changes for solid Kr and Al during annealing.

ments with a scanning electron microscope IS III
progress.
The changes in the lattice parameters of Al and Kr
during annealing obtained by the microdensitometrictraces of diffraction spots are shown in Fig. 5. The
apparent linear thermal expansion coefficients were
estimated to be 2.7 X 10- 5 / deg for Al and 3.5 X 10-:'/deg for Kr. The value for Al is coincident with thatgiven III a handbook. 4 } The detailed description is
given in Ref. 5.
References

Fig. 3. Selected area diffraction patterns during annealing
for the (1 10) orientation at (a) 483 K, (b) 61 8 K, (c)668 K, and (d) 743 K.

1) K. Takaishi, T. Kikuchi, K. Furuya, I. Hashimoto,H. Yamaguchi, E. Yagi, and M. Iwaki: Phys. Status
Solidi, 95, 135 (1986) .
2) M. E. Gurevich, L. N. Larikov, V. M. T yshkevich, andV. M. Falchenko: Uhr. Fiz. Zh. , T24, 658 (1979) .
3) P. B. Hirsch, A. Howie, R. B. Nicholson, D. W. Pashley,
and M. J. Whelan: Electron Microscopy of Thin Crystals, Butterworths, London, p.148 (1965).
4) E. W. Washburn: International Critical Tables, Vol. 1,
McGraw-Hill, New York and London, p . 103 (1926).
5) I. Hashimoto, H. Yorikawa, H. Mitsuya, H. Yamaguchi ,K. Takaishi, T. Kikuchi, K. Furuya, E. Yagi, and M.
Iwaki: J. Nucl. Mat er. , 149 (1987) (in press) .

79
RIKEN Accel. Prog. R ep. 20 (1986)

111-2-28.

Eu-Ion Implantation in CaF2 (II)K. Aono, M. Iwaki, and S. Namba

In our previous report/) we have described theradiation damage and depth profiles of Eu in
Eu-implanted CaF z investigated by means of a
He" backscattering-channeling technique using the
TANDETRON.
A study is carried out on the technique using the
CaF 2 during Eu-implantation. Calcium fluoride specimens are colorless, transparent single crystal wafers
grown by the Bridgman-technique. Their largest
faces are parallel to the (1 1 1) cleavage plane. All
wafers were mechanically mirror-polished and chemically etched. The Eu-implantation in CaF z was performed at room temperature to doses of 101 3- 101 6
cm- z at 100 keY in a random direction at a low
dose rate of about 0.2 pAcm- 2 •By implantation the surface was significantly darkened owing to dense lattice damage as GaP. However, no coloration of CaF z owing to the damage
by 100 keY Eu-implantation was observed in thevisible region. A < 1 1 1> channeling measurement
was carried out by using 1.5 MeV. He+, and backscattered particles were detected at an angle of 150 0 •Figure 1 shows a random and a < 1 1 1> aligned
spectra observed for CaF z implanted with 1 X 10 1 6
and 1 X 1014 Eu+cm- z. The Eu depth profiles in the
random and the < 1 1 1 > aligned spectra of a specimen implanted with 1 X 1016 cm- z are of a Gaussiantype. A difference is exhibited between the random
and the aligned Eu-spectra for the as-implanted
specimen: for the implantation with 1 X 1016 cm- z
the scattering yield of the aligned Eu-spectrum showsa strong reduction in comparison with that of therandom spectrum. These results suggest that most of
Eu atoms will occupy substitutional lattice sites. The
random spectra obtained from CaF 2 give the same

-;;
+-

c

S

~ 1500

o

...J
W

>=
(!) 1000

Co

z

~

w

....

~ 500

o

(/)
~

o
~

100 KeV COF2
15 MeV He·

0L-~0.~5-------------'lO~~--~--~~t~5

ENERGY (MeV)
Fig. 1. Random and <1 11> aligned spectra observed for
CaF2 and Eu for Eu-implantation.

shape by implantation with 101 6 and 1014 Eu+cm- 2 ,indicating that no outdiffusion of Ca and F atoms
occurs through the surface. In general, the random
spectra for CaF 2 have two shQulders, which correspond to the energies of backscattered particles
from Ca and F atoms on the surface. The radiation
damage in Eu-implanted layers was investigated withthe spectra obtained from Ca in CaF z, because thespectra for Ca showed no overlap with those for
F in the high energy region. The aligned spectrum
for the specimen implanted with 1016 Eu+cm- 2 showsa little damage near the surface. The dose for the
implantation with 1 X 1016 Eu+cm- z is in good agreement with about 0.9 X 1016 Eu+cm- z calculated fromthe spectra of Eu shown in Fig. 1.
The result shows that CaF z was implanted by ion
at 100 keY without producing radiation damage.
Reference
1) K. Aono, M. Iwaki, and S. Namba: RIKEN Accel. Prog.
Rep., 19, 93 (1985) .

80
RIKEN Accel. Prog. R ep. 20 (1986)

111-2-29.

Defect-Impurity Interaction in Ni-Implanted Aluminum
E. Yagi, F. Kano, S. Nakamura, M. Iwaki, and T. Osaka*< 1 1 1> axes at room temperature by means ofbackscattering with 1.5 MeV He+ ions. The beam
was collimated to give a divergence of less than
0.076° . The specimen was mounted on a three-axis
goniometer whose angles were set to an accuracy of± 0.004°. The irradiated area was 0.78 mm 2 andthe beam current was 0.7-1.5 nA. The back scatteredHe+ ions were detected with a surface-barrier solidstate detector at a scattering angle of about 150°.
Transmission electron microscopic observation wasmade on polycrystalline Al specimens with a 200 kVelectron microscope.
The channeling angular profiles on a 5 X 1014 Nij
cm 2 implanted specimen (an average concentration:~0.06 at% ) are shown in Fig. 1. The angular profile of He ions backscattered by Ni atoms (Ni-profile)
exhibits a shallow dip with a depth of about 500/0of that of an AI-profile in all cases of < 1 00> ,< 1 1 0>, and < 1 1 1> channels. These Ni-dips
are composed of two components: a narrow dip anda broad dip. No large peaks were observed in theregion of a small incident angle t/J with respect tothe channel axis. These results suggest that about
a half of Ni atoms implanted are located at randomsites (R-sites), and the remaining half are at slightly

The ion-implantation is a useful technique of introducing impurity atoms to modify the surface layerof materials. This method, however, introduces not
only impurity atoms but also lattice defects simultaneously, and the behavior of implanted atoms isaffected by such defects. Therefore, in order to elucidate the mechanism for material modification, we
have to study the impurity-defect interaction. In
the present paper, the lattice locations of the Ni
atoms implanted in Al crystals are studied by using
a channeling method, and the results are discussed
from the view point of the impurity-defect interaction in comparison with the results of Sn atoms
implanted in AI; analysis of channeling angularprofiles on Sn atoms was described in a previous
paper.I)
Slices of about 1 mm in thickness were spark-cut
from a single crystal rod of 99.999 % purity. After
chemical polishing, the slices were annealed in a
vacuum of 10- 6 Torr at 823 K for 7 h. The Ni+ implantation was carried out at room temperature at
180 kV to three different doses 5 X 1013 jcm2, 5 X
1014 jcm2, and 5 X 1015 jcm2. The axial channeling
effect was investigated on the specimens implanted
to latter two doses for < 1 00> , < 1 1 0>, and

(100)

(110)

o Al

<111)

• Ni
1.0

U
I!J
.~

(ij

E

0 0.5
z

-3 -2 -1

0

2

3

-3 -2 -1

0

1

2

3

-3 -2 -1

0

1

2

3

Angle Cdeg)

Fig. 1. Channeling angular profiles on the 5 X 1014Ni j cm2 implanted AI. Dottedcurves represent the calculated profiles.
- --- - -- - - -* The School of Science and Engineering, W'aseda University.

81

E. Yagi, et al.

displaced interstitial positions (I-sites), or at both
I-sites and substitutional sites (S-sites). The location of Ni atoms can be examined in more detailby comparing the observed Ni-angular profiles withcalculated ones. The calculation was performed
using a multi-string model by assuming that the Ni
atoms located at sites shadowed by the host Al atoms
under the channeling conditions give the sameangular profile as an AI-profile.
The observed profiles fitted well within the experimental error with the calculated ones for the
distribution with 49 % of the Ni atoms at the Rsites and 51 % at the I-sites displaced in the < 1 1 0>
direction by 0.24 A from a lattice point. The calculated results are shown in Fig. 1 by dotted curves.
When the magnitude of displacement is small, otherpossibilities on the direction of displacement cannot
be ruled out; however, the magnitude is not sosensitive to the direction. With increasing implantation dose to 5 X 1015/cm 2 , the Ni-profiles showedno drastical change as observed for Sn, as will be
described below, but only became shallower. This
indicates that the Ni atoms do not drastically change
their location.
The electron micrographs are shown in Fig. 2. A
number of dislocation loops and black dotts wereobserved. With increasing dose, the dislocation
loops tangled to each other; no extra diffraction
spots were observed.
For comparison, the distribution of Sn atoms overvarious sites, obtained from similar experiments on
Sn-implanted Al/) is shown in Fig. 3. Most of the
Sn atoms were located at the R-sites. In the 1 X
1014 Sn/cm 2 implantation, the remainder were locatedat the S-sites and the I-sites displaced in the < 1 1 2 >or < 1 1 4> direction by 0.68 A. As the dose wasincreased to 4 X 1014 Sn/cm2 , the fraction of the Sand I-site occupancies decreased, whereas the tetrahedral (T) and octahedral (0) site occupancies
came to be observed. The T - and O-site occupancies
were also observed in the channeling experiments by
Swanson et al., after annealing of low-temperatureirradiated AI-0.03 at %Sn alloys above 220 K.2) Sev-

(a)

(b)

(c)

Fig. 2. Electron micrographs of Al specimens implantedwith (a) 5XlO13Ni/cm 2 , (b) 5XlO14Ni/cm 2 , and (c) 5X
l015Ni / cm 2 •100~---------------------------,~ 50 -

R

.~

U

~

~--::9~!~~:~~-=-~::::=:-:::::c:~.,.,_

lL.

o

0

o

I.,

6

8

10

• lOlL.

Dose (cm- 2)

Fig. 3. Dose dependence of distribution of 8n atoms overvarious sites. A result on Ni is also plotted.

eral experiments have suggested that the Sn atoms
in Al strongly interact with vacancies. 3 - 5 ) Therefore,
the occupancies of Sn atoms at various sites are interpreted as follows by taking account of such interaction. 1 ) (1) The R-site occupancy results from the
Sn atoms which are in the form of precipitates.
Actually the precipitates were observed by electron
microscopy. (2) The occupancy of the < 1 1 2>or < 1 1 4>-displaced I-sites is due to the relaxationof an Sn atom induced by trapping a divacancy.
The displacement of 0.68 A is about 17 % of thelattice constant. (3) The T - and O-site occupancies
result from trapping more than two vacancies by
an Sn atom. An Sn atom is displaced to the T -siteby trapping three vacancies to take a configuration
similar to a trivacancy or to the O-site by trapping
five vacancies to take a configuration similar to apentavacancy. These results indicate that with increasing dose much more vacancies are introduced
during implantation, and they are trapped by Sn
atoms to form larger clusters.
For Ni, the behavior is different. For 5 X 1014
Ni/cm 2 implantation, most of the Ni atoms arelocated at the R-sites. The R-site occupancy is also
considered to result from the Ni atoms in the precipitates because the solubility of Ni in Al is small,less than 0.03 at % at 640°C.6) The remainder areat the < 1 1 O>-displaced I-sites. But the magnitudeof displacement is much smaller than that of Sn
atoms in spite of nearly the same dose as in the Snimplantation, 0.24 A, which is about 6 % of thelattice constant. From the comparison with the calculation on relaxation around a vacancy/) the< 1 1 O>-displaced I-site occupancy is considered tobe due to the relaxation of an Ni atom induced bytrapping a single vacancy. On increasing the implantation dose by a factor 10, no T- or O-site occupancy was observed; therefore, no multiple trapping of vacancies occurs. From these results, weconclude that the interaction of Ni atoms with vacan-

82

E. Vagi, et ai.

cies in Al is not so strong as that of Sn atoms. Moredetailed description is given in Ref. 8.
References
1) E. Yagi, A. Koyama, S. Nakamura, H. Sakairi, and R. R.
Hasiguti: lpn. l. Appl. Phys., 24, 137 (1985) .
2) M. L. Swanson, L. M. Howe, and A. F. Quenneville:
Phys. Rev. B, 22, 2213 (1980) .
3) H. Kimura and R. R. Hasiguti: l. Phys. Soc. lPn., 18,
Suppl., 73 (1963) .

4) A. J. Perry and K. M. Entwistle: l. Inst. Met., 96, 344(1968) .
5) S. Ceresara and T. Federighi: Philos. Mag., 10, 893(1964) .
6) M. Hansen: Constitution of Binary Alloys, McGraw-Hill,
New York (1958).
7) M. Doyama and R. M. J. Cotterill: Lattice Defects andTheir Interactions (ed., R. R. Hasiguti), Gorden andBreach, New York, p.79 (1967).
8) E. Yagi, F. Kano, S. Nakamura, M. Iwaki, and T. Osaka:
Mater. Forum, 15·18, 605 (1987) .

83

RIKEN Accel. Prog. R ep . 20 (1986)

111-2-30.

Isochronal Annealing of Proton- or a-Irradiated Cu 3 Au
at Low Temperatures
E. Vagi, H. Sakairi, A. Koyama, and R. R. Hasiguti*

17.8 MeV a-particles below 30 K under the condition that incident ions penetrate the specimens.
After irradiation, an isochronal annealing experimentof electrical resistivity was performed up to 100 K
in 5 min pulse. Resistivity was measured at liquidhelium temperature. Irradiation was carried out tothe doses which gave approximately the same increase in resistivity for both proton and a-particle
irradiations.
Figure 1 shows the results on Cu irradiated with
4.8 MeV protons and 17.7 MeV a-particles below
15 K. As in the case of stage I recovery in electron
irradiation, five substages l a to I e were observed
below 60 K.
Figure 2 shows the results for the ordered CUgAu.
For the specimens irradiated with protons or with
low-dose a-particles (specimens #7-1, #7-4, #6-22,
and # 7-5 ), several substages were observed below
90 K: a small resistivity increase below 40 K andfive substages between 40 and 90 K. These five
substages are tentatively labeled lA, I B , Ie, I D , and
IE in order of increasing temperature. Although acentral temperature of each recovery stage seems tobe slightly different between proton and a-irradiations, they are as follows. lA, -"'-45 K; h , '~50 K ;The investigation of irradiation effects in CUgAu
has long been made since the beginning of radiation
effects research. Such an ordered alloy is a mostappropriate system to study replacement collision indamage production and migration of vacancies, because their effects are observed as a large change
in the ordered state. Therefore, the detailed study
on ordered alloys will give important informationon the damage production process and the behavior
of defects. For understanding of damage structuresand of behavior of irradiation induced defects, theannealing experiments at low temperatures are required. In the present study isochronal annealing
experiments have been made up to 100 K by electrical resistivity measurement on Cu, ordered anddisordered CugAu irradiated with protons or aparticles below 30 K.
The CugAu alloys were prepared by melting Cu
and Au both of 99.999% purity in a quartz capsule.
The Au concentration in this alloy was 25.8 at 910.
They were processed to foils of 30 pm in thickness.
The electrical resistivities of ordered and disordered
CugAu were 2.3-2.8 pO cm and 12 pO cm at liquidhelium temperature, respectively. Irradiation was
carried out with about 4.7 MeV protons or about

Cu
•

1.0

a - 17.7MeVUl6-5)"'P.= 8.3 nohm·cm

p - 4 ,BMeV(~6'4)o11.0 nohm,cm'b::;;,.___..........-...-.___'<>- --0- -0---0---0----<>- __ -0 __ -0-_-<>- ___ - 0 _ __ --0-o L -__- L____L -_ _- L_ _ _ _L -_ _

o

10

20

30

40

~

_ _ _ _L -_ __ L_ _ _ _

50

60

70

~

BO

__

~

__

90

~

100

T(K)

Fig. 1. Isochronal recovery curves of the electrical resistivity for p-4.8 MeV
or a-I7.7MeV irradiated Cu. Resistivity increases L1po are 11.0nncm forspecimen #6-4 and 8.3 nn cm for specimen #6-5.

* Faculty of Engineering, Science University of Tokyo.

E. Yagi , et ai.

84

1.0

::

:l--- '~--

p-irrad.
L..7MeV#7-1- - - - - " 'Po=S1.3(nohmcm)ip
u 7-[.

~- :~-:-

1.°r

-~

I

-

92.2

-- -~

I

I

I
I

I
I

cP 0.8 -

:

~
A

I

1.0 ~ --

p

:
I
-:
I --:
I - - - --U 6-22

- --

133

0.8

1.:~

n -s

56.S

a
11 6-21

0.81

101

Ci

1.0

o

10

20

30

40

50
i(K)

60

70

80

90

100

Fig. 2. Isochronal recovery curves of the electrical resistivity for p-4.7 MeV
or a-17.S MeV irradiated ordered CUaAu. Fraction not-annealed Jp / Jpo
is obtained by normalizing the resistivity increase J p to the irradiationinduced resistivity increase Jpo (O-CuaAu) .

I e, --58 K; I D, ~65 K , and IE, > 70 K. From thetemperature derivatives obtained from the recovery
curves shown in Fig. 2, it can be said that the peaktemperatures of stages lA, I B , Ie, and ID are independent of irradiation dose, and that of stage IE
is dependent on dose and shifts to lower temperatureswith increasing dose. This behavior is similar tothat of stages Ia to Ie in Cu. In Fig. 2, the fractional
resistivity recovery (fraction not-annealed Api Apo)
is normalized to the irradiation-induced resistivity
increase Apo ( O-Cu3Au ), which is composed of twocontributions: a resistivity increase due to decreasein long-range ordering originating in the replacement
between Cu and Au atoms and that due to Frenkel
pairs. The latter component ApO.FP(O-CU3Au) was
estimated to be ApO( O-CU3Au) 13.84 from previous
papers. 1 , 2) Therefore, the fraction of the recovery
of Frenkel pairs can be estimated by renormalizing
the recovered resistivity to ApO.FP(O-CU3Au) mstead of Apo(O-Cu3Au) . The result is shown in
Fig. 3. There is a close similarity between substages
below 90 K in ordered CU3Au and those of stage I
in Cu in (1) the dose dependence of central temperatures of recovery stages and (2) the total fractionof recovery of Frenkel pairs.
It has been considered that the migration ofinterstitials produce no ordering in CU3Au. 3,4) Alarge resistivity recovery has been observed around240 K in electron irradiated ordered CU3Au and theresistivity decreased to a value lower than the pre-irradiation ones. 5 ) This suggests the occurrence ofthe recovery of ordering. The recovery of this stage
is attributed to the long-range migration of vacancies.
Therefore, the recovery stages below 90 K are considered to be related to the interstitial migration.
It seems to be very difficult for Au interstitials to
make long-range migration retaining their configuration, because in ordered CU3Au all 12 nearest
neighbor sites of an Au atom are occupied by Cu
atoms, whereas it is possible for Cu interstitials to
make long-range migration, because a half of {100}planes are occupied by only Cu atoms. Therefore,
the stages I A to IE are assigned to those associatedwith Cu interstitials similarly to stages Ia to I e inirradiated Cu. The stage IE recovery is attributed
to the long-range migration of Cu interstitials.
The small recovery of disordered CU3Au, different
from the recovery of Cu and ordered CUaAu, may
result from the suppressed long-range migration ofinterstitials below 90 K as seen from Fig. 3.
Large reverse annealing was observed above 30 K
only in the a-irradiation (specimens #6-21 and# 6-19) and is peculiar to the ordered state. It
became more conspicuous with increasing dose.
These results suggest that the spatial distribution of
defects is different between proton and a-irradiations.
The temperature range of the reverse annealing corresponds to that of IA to Ie. Therefore, this reverse
annealing is closely related to such spatial distribution, especially, to the interaction of closely locatedE. Vagi, et ai.

85

a-i rrad .

1.0
17.5MeV

D-CuJAu(p 7- 15)

ID +IE~1 7. 7~1ev~-( U~~5)~ 17.8MeV
O-Cu3Auo L-__ ____ ____
o
10
20
30
~

~

L __ _(117-5)~_ _ _ _ _ L_ _ _ _

L.O

50

~

60

_ _ _ _L __ _

70

~

____

~

90

__

~

100

T(K)

Fig. 3. Isochronal recovery curves of the electrical resistivity for a-irradiateddisordered CUaAu , ordered CUaAu, and Cu. The fraction not-annealed isrenormalized to the resistivity increase due to Frenkel pairs .d (Jo,lI'P'

defects.

Phys. Soc. lpn., 50, 3023 (1981) .
J. A. Brinkman, C. E. Dixon, and C. J. Meechan: Acta
Met., 2, 38 (1954) .
4) S. Takamura and S. Okuda: Rad. EfJ., 17, 151 (1973) .
5) J. Gilbert, H. H erman, and A. C. Damask: Rad. EfJ.,
20, 37 (1973) .
3)

References
1) H. Sakairi, E. Yagi, A. Koyama, T. Karasawa, and R. R.
Hasiguti: I. Phys. Soc. lpn. , 43, 999 (1977) .
2) H. Sakairi, E. Yagi, A. Koyama, and R. R. Hasiguti: I.

86
RIKEN Accel. Prog. Rep. 20 (1986)

111-3.

Radiochemistry and Nuclear Chemistry1.

Production of Radioisotopes and Preparation ofLabeled Compounds
T. Nozaki, M. Iwamoto, Y. Ohkubo, M. Suehiro,
F. Yokoi, and M. K. Kubo

In this period the following studies were undertaken: (1) production of 57Ni as nickel tracer forthe study of adsorption on silicon surface from analkaline solution containing H 20 2 and of absorption
by plants; (2) synthesis of radiobromine-Iabeledbromoperidol and bromospiperone for neuro-receptor
study; and (3) synthesis of llCH 3 CH 2 CO:-H (propionic acid) by the malonic ester synthesis.
Very clean washing of silicon wafers is indispensable in the production of silicon semiconductor
devices. In this washing ultra-minute amounst of
impurities are sometimes adsorbed on the siliconwafer to result in the deterioration of the device
property. For the measurement of the adsorptionof nickel, there are no suitable reactor-made radiotracer nuclides; they are of limited specific activity.
Nickel-57 (36.0 h) was produced by the 56Fe(3He,2n) 57Ni reaction and used for this purpose and forthe investigation of the absorption of a minuteamount of nickel by plants. In order to obtain 57Ni
in high specific activity, the target iron should bemade free from nickel. Nickel was removed fromiron by the following process: ether extraction ofiron from 8 N HCI solution, washing of the extract
with 8 N HCI, back-extraction of iron into water,
and precipitation of ferric hydroxide. The precipitate was collected, dried, and reduced into metal
powder by heating to 700°C in H2 stream.
The iron powder was pressed into a disk andbombarded with 35 MeV 3He particles. The target
was dissolved in cone. HCI with occasional additionof Br 2 • Iron was extracted twice into isopropyl ether
from the solution, which was then passed throughan ion exchange resin column (Dowex 1 X 8) for
the removal of radio-cobalt and radio-manganese
formed as by-products. The effluent was found tocontain no radionuclides other than 57Ni and aweak activity of 56Ni (6.1 d).
Nickel was proved to be scarcely adsorbable on
silicon from alkaline solutions containing H 20 2 andammonia or choline. The measurement of 57Ni
absorption by cucumber plants from the root gave

results suggesting that nickel, different from titanium
and germanium,l) is absorbed by an active transport.
The study of 77,76,75Br-Iabeled bromoperidol andbromospiperone has been continued in order to makethem useful in practical diagnosis. 2) The safety intheir intravenous injection was proved by the
pyrogen test and by repeated injection of nonradioactive replica into volunteers. In the preparation of labeled bromoperidol by the Sandmeyer reaction, the product was found to be accompaniedwith a notable amount of haloperidol, which behaved competitively with bromoperidol in vivo. The
reason for this was examined by neutron activation
analysis of the reagents used in this synthesis, andwas found to be the presence of a noticeable amountof chlorine in aminoperidol, the starting reagent,probably as hydrochloride. By purification of aminoperidol, the contamination to the radioactive bromoperidol was reduced significantly. For bromospiperone the contaimantion with chlorine "vasfound to be much less notable, when the bromination was carried out under controlled conditions. By
the PET (positron emission tomography) measurement of 76,75Br-bromospiperone injected into amonkey (about 10 kg in weight), the striatum which
is rich in dopamine receptor was clearly visualized.
The striatum visualization was also possible by
76,75Br-bromoperidol, for which nonspecific binding
in the brain was of considerable degree.
By the use of llCH3I obtained from the automaticsynthesizer, propionic acid labeled with llC at thef3-site (llCH 3CH 2C0 2 H) was prepared by themalonic-ester synthesis:
C0 2EtI]\;aOEt
CH 2 ~
I
C0 2Et
C0 2EtI
HCH 3 CHI
C02 EtThis compoundIS

expected to show different zn-

T. Nozaki, et al.

vivo behavior from that of CHsCH 2 11C0 2 H and isprobably useful for some diagnostic purposes. By
the malonic ester synthesis with llCHsl, the preparation of various a-ltC-methyl fatty acids is under way,
and the examination of their various possible uses,
e.g., the use of for heart diagnosis, is planned.

87

References
1) M. K. Kubo, Y. Minai, T. Nozaki, and T . Tominaga:
RIKEN Accel. Prog. Rep., 19, 110 (1985) .
2) T. Nozaki, S. Ambe, M. Iwamoto, E. Gotoh, T. Kitsu·
nai, H. Nakatani, Z. Huang, Y. Minai, I. Arai, M. K.
Kubo, M. Suehiro, and F. Yokoi: RIKEN Accel. Prog.
Rep., 19, 106 (1985) .

88
RIKEN Accel. Prog. Rep. 20 (1986)

Charged Particle Activation Analysis

111-3-2.

T. Nozaki, Y. Itoh, M. Iwamoto, Y. Ohkubo,
T. Kimura, and H. Fukushima
In this period we have undertaken the following
studies, most of which are of continuation from thelast period: 1) (1) determination of the calibration
curve for IR spectrophotometry of carbon in semiconductor silicon, (2) measurement of surface oxygen under various ambient air pressure, (3) analysis
of carbon in aluminium and magnesium, (4) carbon
in gallium arsenide, and (5) in-diffusion of nitrogenin silicon by the use of 15N as activable tracer. Also,
various samples, about 240 in all, were analyzed forcarbon or oxygen in the trust analysis system by theJapan Chemical Analysis Center. 2 ) Details of thestudies (3 ) , (4 ) , and (5) are described in succeeding
pages of this volume.
The provisional calibration curve for IR spectrophotometry of C in Si given in the last volume has
been elaborated by the correction for the differencein counting efficiency between the separated Li 2 11 C0 3
and the graphite activation standard and for theinterference of oxygen by way of the ]60 (~He,2a) llC
reaction.1) Various careful measurements were carried out in order for the determination of the correction factors. The final result is shown in Fig. 1,
together with the results of SIMS (secondary ion
mass spectrometry) measured by a member laboratoryof the committee organized for the determination of
the calibration curve in JEIDA (Japan Electronic
Industry Development Association) . The SIMS
workers have drawn a straight line parallel to theactivation analysis line, regarding the difference between the two lines as the background in SIMS.

M

I

E

3

o
.....

2

u

c:

2c:
o

~'

c:

-e

III

()

."

~'

u

o

,fr.~

""

"

""

"

.•

.1."

.te'
.'"

0~----~----~2~--~3~----4L-

IR Absorption coefficientFig. 1. Calibration curve for IR spectrophotometry of C in
Si (605 cm-l, at room temperature). Solid line, before correction for C in IR reference; Si (C concentration, 4.3 X
1015 at. cm- 3 ) ; broken line, after the correction; 1::,., resultsof SIMS.

20
} Pb

10
"
E
'-!

5

tlIJ
......

2

AI

£

+-'

c:

III
::J

0 .5

0C
<l>

boO

0.2

>.

x

0

0.1
0.05
0.02

'f - 5 - 4 - 3 - 2 - 1 0234

5log p ( p : Pa )Fig. 2. Surface oxygen quantity at various ambient air pressures. Error bar indicates standard deviations for repeatedruns.

The present result is expressed as[C concentration] = 8.2 X 10 16 at. cm- 3 [IR absorption coefficient at the 607 cm- 1 absorption
peak (at room temperature)].
This calibration factor agrees very closely with ourprevious value,3) and we are highly confident of it.
We continued the measurement of surface oxygenfor many years and have finished the determinationof oxygen on Si, AI, and Pb for various surface clea ning and for various pressures of ambient air. Our
method is characterized by the sample arrangementin the charged particle bombardment. 4) Under thisarrangement, oxygen on the surface can be determined under any atmospheric conditions. The results are summarized in Fig. 2, where oxygen quantity
in an air gap of 10 p.m is also given in relation to
air pressure.
References
1) T. Nozaki, Y. Itoh, M. Iwamoto, Y. Ohkubo, T. Kimura,and H. Fukushima: RIKEN Accel. Prog. Rep., 19, 112(1985) .
2) T. Nozaki, Y. Itoh, M. Iwamoto, H. Shinyashiki, K.
Nomura, T. Kimura, and H. Fukushima: RIKEN Accel.
Prog. Rep., 17, 96 (1983) .
3) Y. Endo, Y. Yatsurugi, N. Akiyama, and T. Nozaki:
Anal. Chem., 44, 2258 (1972) .
4) T. Nozaki and M. Iwamoto: IPCR Cyclotron Prog.
Rep., 11, 116 (1977) .

89
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-3. Analysis of Carbon in Aluminium and Magnesium by
Deuteron Activation
T. Nozaki, K. Sato, I. Izumi, H. Yoshikawa, and H. Nakahara

Precise determination of impurItIes, especiallyhydrogen, carbon and oxygen, in various high-purity
metals are becoming more and more important withthe progress of their fine uses. Aluminum belongs
to these metals. It is produced by electrolytic reduction from fused salts by the use of graphite electrodes
and is thus suspected to contain a notable amountof carbon. A highly reliable method of analysis isthus required for carbon in aluminium in order tomake clear its behavior in the industrial production
processes and its effect on the properties of aluminium. Usually the carbon is analyzed by conversion
into CH4, but the reliability of this method needs tobe further ascertained by some more reliable andsensitive method.
We intend to first establish reliable procedure fordetermining trace amounts of carbon in aluminiumby charged particle activation with the I:!C ( d, n ) I3N
reaction and to then analyze aluminium of various
post-treatments. We already reported the outline of
the analytical procedure in the last volume. l ) Here
we describe in more detail the procedure which wehave established for routine use: ( 1) Sample plate(2 cm X 2 cm X 1 mm) is bombarded with deuterons(8.5 MeV, 3 pA, 10 min) and taken out immediatelyby the use of a target holder assembly specially designed for a quick operation under the supressionof the worker's radiation exposure; (2) the surfaceof the bombarded sample (20 pm in thickness) wasremoved by etching with a diluted NaOH solution
for elimination of surface contamination; (3) the
sample is dissolved in concentrated HCI (15 ml)
containing NH 4 CI (1.0 mmol ) as carrier and CuSO.j(1.5 g); (4) the solution is transferred to a small
separatory funnel and dripped onto solid NaOH
(10 g) in a distillation flask, which is then heated to
distill I3NH 3 into a solution of sodium tetraphenylboron, NaB ( CsH5) 4 (0.05 mol / l, 30 ml); and (5 )the precipitate of NH4B(CsH5)4 thus formed is collected by filtration and its positron activity is measured by a well-type Nal scintillator or a pair of
BGO scintillators operated in coincidence. The
carrier recovery is determined by weighing. Graphite
plates are used as the activation monitor.
The I3N in the bombarded aluminium is thought
to be converted quantitatively into I3NH 4CI in Step

3 from analogy with the behavior of nitrogen in the
Kjeldahl method which has been used popularly fora century: The above entire process is completed
within 30 min, and the radiochemical purity of the
I3NH4B(C sH 5) 4 has proved completely satisfactory.
Down to several ppb of carbon in aluminium canthus be determined reliably. The results of activation analysis in general have shown fairly good
agreement with those of the conventional analysis
by way of CH4 generation.
We have analyzed aluminium samples preparedby the following methods for the following purposes:(1) rapid solidification of melts presumably saturated
with carbon at several temperatures in order toobtain the solubility-temperature curve for carbon inliquid aluminium; (2) very slow solidification of themelt saturated with carbon in order to obtain the solubility of carbon in solid aluminium at the melting
poin t (660 0 C) ; ( 3 ) mixing of the melt with AIF 3 inorder to prove the reduction of carbon content by
this treatment; and (4) remelting in order to examine
its effect on carbon content.
Some results are shown in Fig. 1 and Table l.
From Fig. 1 the heat (AH) and entropy (AS) of

J

o

10

5.0

o

0

8______ B-~poin ts--------I).

§

2point?'-- ____

2 .0

9.0

Re ciproca l

10 . 0t emperature

Fig. 1. Carbon content of aluminium solidified rapidly fromthe melt presumably saturated with carbon at various
temperatures.

T. Nozaki , et al.

90

Table 1. Change of carbon content of aluminium by
AIF 3 treatment of the melt.
SampleBefore treatment
After treatment
After repeated treatment

Results of analysis (ppm wt)
5.13, 5.64
1. 76, 2.24
1. 12, 2.95, 1. 07, 1. 34

solution for carbon in liquid aluminium seem to beobtained. However, L1H thus obtained is only
18 kJ Imol, which is unreasonably small. The aluminium melts are thus suspected not to have beensaturated with carbon. We are preparing samples
for more reliable measurement of the L1H and L1S.
The solid solubility of carbon in aluminium was
obtained to be about 0.2 ppm at the melting point.
As is seen in Table 1, the AIF 3 treatment has been
proved to lower the carbon content, but its repetition seems not to have any notable further effect.
As for the effect of remelting, aluminium containing
4.3 ppm of carbon was remelted and sampled at
748°C to give the carbon content of 0.97, 0.99, and1.03 ppm for three repetition of the analysis. Samples
taken from the same melt at 719°C gave results of
0.88, 0.87, and 0.85 ppm. The remelting is thus
shown to reduce the carbon content.

Carbon in magnesium can also be determined by
the same procedure. In the 14C dating, accelerator
mass spectrometry is much superior to radioactivity
measurement for the lowering of the detection limitof 14C for a limited amount of carbon sample. As
the sample for the mass spectrometry, carbon in CO 2
is usually reduced to elemental carbon by the reaction with magnesium at about 950°C to be set in
an ionization chamber. Impurity carbon in thismagnesium is modem carbon and causes underestimation in the dating. High purity magnesium
samples of two different origins were analyzed andhave been shown to contain considerable quantities
of carbon (over 10 ppm). These carbon levels gave
serious errors in the dating for samples older than
10 4 y. Most part of the carbon is guessed to bepresent on the surface, with the quantity being
reduced by suitable washing. More detailed study
is needed concerning the origin of carbon in magnesium and especially for the reduction of its content.
Reference
1) T. Nozaki, Y. Hoh, M. Iwamoto, Y. Ohkubo, T. Kimura, and H. Fukushima: RIKEN Aeee!. Prog. R ep .,19, 113 (1985) .

91
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-4.

Studies on Carbon in Gall ium Arsenide
Y. Itoh, T. Nozaki, Y. Ohkubo, T. Kimura,
H. Fukushima, Y. Kadota,* and K. Sakai*

Carbo nin gallium arsenide is an electronically
active impurity. The carbon concentration has beenobtained mostly by infrared spectrophotometry at the
local vibrational mode (LVM) between 582.25 cm-l
and 582.74 cm- l • l ) This method is simple and nondestructive, but requires a calibration curve or areference sample to determine absolute carbon contents. We have examined the method 2 ) for simultaneous determination of carbon and boron in gallium
arsenide for its further improvement by activation
with the 12C (d,n) 13N and natB ( d,xn) llC reactions.
In our previous method, Molecular Sieve SA cooledwith liquid nitrogen was used to trap 13N. However,some migration of 13N in the Molecular Sieve trap
often caused a serious problem in the activity measurement; counting efficiency changed during themeasurement. We tried to use titanium sponge withwhich 13N readily combines at an elevated temperature. For quantitative separation of 13N and llC inpure states, we examined the recovery under different experimental conditions. First we changed aflow rate of hellium gas, which carried 13N and llC.
Since the recovery was found to be constant at flow
rates between 40 and 200 ml min-I, we fixed the flowrate to be 100 ml min-l in the present experiments.
The fusion temperature has been set at 1500°C,
because a constant recovery was obtained at 9001500°C. The length and diameter of a titaniumsponge column have been chosen to be 1.S cm and0.6 cm, respectively, because no difference was observed in the recovery for the column length between
1 and 6.5 cm. The temperature of the titanium
sponge has been decided to be 830°C, the mostsuitable after testing in a range from 600 to 830°C.
At a still higher temperature, the sponge is likely tobind to the inner surface of the quartz tube.

* Central Research Laboratory, Sumitomo Metal Mining
Co., Ltd.

X1015

3
e'C?'
0'

.- E
""'u
co (()•
....
2

cE
C1)

o

0

u""'
ern

0""

U
e
0

-ern

0
0

U

°0

1.0

LVM

2.0

3.0

4.0

Ab$orption (cm- 2 )Fig. l. Infrared absorption vs. carbon .concentration. For_~solid line, a proportionality constant IS 7 X 1015 atoms· cm
percm- 2 •Liquid-encapsulated (LEC) semi-insulating GaAs
with different carbon levels were used for the determination of the calibration curve in IR spectrophotometry. Figure 1 shows a relat.ionship b~tween
IR absorption (area of the absorptIon peak Ill. theIR absorption spectrum) and carbon concentr~tlOns
determined by actiavtion analysis. We can see hnear
dependence of the IR absorption on carbon concentration from 3 X 1014 to 3 X 1016 atoms·cm- 3. The
proportionality constant is (7 ± 1) X 1015 atoms'
cm-3 for the absorption of 1 cm- 2 • This value isabout one third of the value of Brozel et al. (2.4 X
1016 atoms' cm- 3 for cm- 2 •1)
References

1) M. R. Brozel, J. B. Clegg, and R. C. Newman: J. Phys.
D, 53, 5771 (1978) .
2) T. Nozaki, Y. Itoh, Y. Ohkubo, T. Kimura, and F. Fukushima: lpn. I. Appl. Phys., 24, L801 (1985) .

92
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-5.

Diffusion of Nitrogen into Silicon

Y. Itoh, T. Nozaki, Y. Ohkubo, and Y. Mochizuki

Nitrogen is often suspected as one of the mostinteresting residual impurities in semiconductor materials. However, the determination of a trace
amount of nitrogen in high-purity substances andthe study of its behavior are difficult owing to thesurface contamination and to the lack of a suitable
nitrogen radio-tracer. We previously reported thepossibility of using 15N as an activable tracer forthis study.1) In order toi'neasure the diffusion of
nitrogen into silicon, we employed a 15N tracer
together with the method of activating it by the
15N (a, n) 18F reaction (E = 20 MeV) with an equal
probability along the depth by rotating a set ofaluminium absorbers of suitably selected thicknesses
and widths in the a-particle beam path. 2 )The depth profile of nitrogen diffused into silicon
at various temperatures was obtained by this activation and repeated fine etching with HF-HNO s.
The 15N in-diffused samples were prepared at Hitachi, Ltd. Silicon wafers were covered with 15N_
nitride films formed by epitaxy from 15NHs andSiH4 and · heated in argon containing 1.5 % of 15N 2
at 1275, 1300, or 1350°C for 73 to 163 h. Silicon

31 _

~ r

C

A

·

\

\

---."

c:

o

---8

~ 1

,,
\

,
\

\

>

o

<

\

\
\

\

-- -

\
-\~

.........
100

(Y)

IE
u

c
o

"@

c

Q;

u

C

o
u
c

Q;

Ci'l

2

z

Depth (}Jm )Fig. 2. In-diffusion profile of 15N in silicon treated at1350 0 C for 73 h (0) and at 1275°C for 163 h (.) . The
solid lines represent the curve calculated from Pavlov's data.

without nitride film was also heated for the same
periods. Films of Na15N0 2 (30% enrichment)
were used as an activation standard for 15N. They
were precipitated on a 13-l1m Al foil to 4-13 mg·cm-2
in thickness from a suspension in ace ton. Kapton
films (2 % nitrogen) were used to check the uniformity of activation along the depth. Figure 1
shows the activation probability along the depth
under the experimental conditions. The depth profiles of 15N in silicon treated at two different temperatures are shown in Fig. 2. Pavlov's group
estimated the diffusion constant of nitrogen in siliconusing an indirect method on some assumptions. S )The curves calculated from their results are also
given in Fig. 2 for comparison. We continue thestudy for more reliable diffusion constant andsolubility of nitrogen in silicon using the direct
method described in this report.

200

Depth ( pm )in Si

Fig. l. Activation with an equal probability along thedepth. Solid line (A), calculated relative activation yieldconsisting of three components (dashed lines) corresponding to the thickness of the aluminium absorber
through which the 20 lv.feV a-particle passes; Solid line (B) ,relative activation yield.

References
1) T. Nozaki, Y. Itoh, and Q. Qiu: Collected Papers for
7th MTAA, Ris, Nat!. Lab., Copenhagen, p. 47 (1986) .
2) Y. Itoh and T. Nozaki: ]. Radioanal. Chern., 70, 329(1982) .
3) P. V. Pavlov, E. 1. Zorin, D.1. Tetelbaum , and A. F.
Khokhlov: Phys. Status Solidi, 35, 11 (1976) .

93
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-6.

Util ization of the D(3He, p)4He Reaction for High-S.ensitivity
Quantitative Analysis of Deuterium in Solids
Q. Qiu, T. Kobayashi, M. Yanokura, T. Nozaki,
M. Imai, and Y. Yatsurugi

Deuterium is used as an activable tracer freefrom the interference with environmental contamination which usually occurs in measurement of hydrogen in solids. We have already reported a quantitative analysis of deuterium using measurement of
the solubility of hydrogen in single crystal silicon. l )Samples for this measurement were prepared in
Komatsu Electronic Metals Co., Ltd. by the following methods: ( 1) heating of high purity silicon inD2 (100%) gas at 400, 700, 1,000, and 1,200°C
for 10, 10, 8, and 5 h, respectively; (2) float zonemelting (FZ) of silicon in a slow stream of D 2-Ar
in various mixing ratios ( 1, 10, 20, and 40 % D 2)
followed by sudden cut off of the heating power for
rapid solidification of liquid silicon saturated with
D2 under a given partial pressure; and (3) pretreatment of the samples in heated · trichloro-ethylene
gas or by covering them with evaporated films oftitanium or palladium and succeeding heating in D2
gas at 1,200°C for 5 h. The pretreatment in (3) was
expected to suppress the effect of surface oxide layer.
Deuterium contents in these samples were thenmeasured. Often after measurement, the sample
surface was washed with hydrofluoric acid or etchedwith HF-HN0 3 (5 to 200 p.m etching) and themeasurement was repeated. All silicon samples
heated in 100 % D2 gas were found to contain
about 2 X 101G atmjcm 3 deuterium in the depth over
0.2 p.m, regardless of the heating conditions. Thisvalue of deuterium concentration is nearly the· detection limit of this method. Float zone-melting in 1 %and 10% D2 gas gave 2 X 101G and 4.5 X 1016 atmj
cm 3 D contents, respectively; but the zone-melting
in 20% and 40% D2 resulted in gas bubble formation in the silicon. The depth profile are shownin Fig. 1 for samples covered with surface layer of

a

50

100

150

180

Depth (fJm)
Fig. I . Depth profile of deuterium in silicon heated in
D z gas at 1,200oC for 5 h after various pretreatments.
. : Trichloro-ethylene treatment (heavy deposition of carbon), 0 : Trichloro-ethylene treatment (light depositionof carbon), 0: 'Without any pretreatment, Do: Titanium
evaporated film covering, X: Palladium evaporated film
covering.

a-SiC, Ti, Pd, and Si0 2. The depth profile variedwith the surface conditions of the samples. Surface
oxide layer seems to suppress the in-diffusion rate
noticeably. In order to obtain reliable solid solubilityof hydrogen in silicon, we are making further efforts
for preparing meaningful samples. Measurement forother materials are also under planning.
Reference
1) Q. Qiu, T. Kobayashi, M. Yanokura, M. Imai, Y.
Yatsurugi, and T. Nozaki: RIKEN Accel. Prog. Rep.,
19, 129 (1985) .

94

RIKEN Accel. Prog. Rep. 20 (1986)

111-3-7. Application of PIXE to Medical and Environmental Science
K. Maeda, Y. Sasa, H. Kusuyama, M. Maeda, *H. Ishikawa, Y. Yokode, and M. Uda
PIXE (particle induced X-ray emission) spectroscopy is one of the most advanced, extremely sensitive and multielemental analyses. We have continued
a study on the application of PIXE to medical andenvironmental science. 1 - 3 ) We report here the experiments recently made on human calculi andsuspended particulates in sea water.
( 1 ) Urinary stones
The study of calculus compositions is of pnme
importance to elucidate the mechanism of stone
formation in human body. We have applied PIXE
to the analysis of human urinary stones. Samples
were surgically taken from patients of vesical(bladder, 3 cases), ureteral (8 cases), and renal(kidney, 1 case) stone diseases. Preliminary dataobtained with some of these samples were reported
previously.4) The samples were irradiated with an
8 MeV He+ beam of 0.5 mm in diameter. X-rays
generated from the targets were detected with aSi(Li) detector through an X-ray absorber made of
1 p.m polypropylene or 1.B mm polyethylene film.
The details of the data processing procedure were
described elsewhere. 5 )Results of PIXE analysis are summarized in Table
1, where integrated peak intensities of La (for Pb)'
and Ka (for other elements) were normalized byuse of Ka peak intensities of Ca which is a mamcomponent common to all of the samples. The
stone types were detennined by the X-ray diffraction
method and/or IR spectrometry. The phosphateand oxalate stones coexist with each other but notwith the urate stones. Magnesium is a main component of the phosphate stones and contained asmuch as Ca; whereas, much less amount of Mg isincluded in the oxalate and urate stones. The phosphate stones are characterized with high K and Srcontents in comparison to other stones. The Zn content changes drastically from sample to other andis extremely low in the urate stones (KI and TN).
The vesical (bladder) stones seem to have a Naconcentration higher than the others.
(2) Distribution of elements in calculus
To investigate the elemental distribution in calculi,
scanning analysis of PIXE was carried out for large
urinary stones. A crosssectional view of a vesicalstone (KY in Table 1) is illustrated in Fig. 1. The
stone is composed of layered outer shells (A) likean annual ring, a porous middle part (B), and adense center part (C) including nuclei. The positions analyzed with PIXE are shown in Fig. 1 with
6., 0, and. for A, B, and C, respectively. Meanvalues of integrated intensities of Ka for each ele-

Table 1. Results of PIXE analyses on urinary stones: peak intensities of La (for Pb) and Ka (for other elements)
normalized to CaKa= 100.
Absorber: 1.8 mm polyethylene

Absorber: 1 p.m polypropylene
Organ

Stone typePatient

nl nz

Mg

P

S

Cl

K

Ca

Fe

12 0.74 41
4 1.29 22
1. 16 24

182
146
144

<0.1
<0.1
0.9

0.41
0.61
1.9

1.3
2.3
1.8

100
100
100

0.16 <0.28
0.43 <0.19
1.5 <0.14

7.8 0.90 <0.13
2.4 0.61 <0.17
15.8 0.66 <0.07

Bladder

Phosphate

KY
KS
SO

UreterPhosphate

TK
TO

Phosphate+Oxalate

ES
YS
MU

3

Oxalate

CN

2

0

Urate

KI
TN

2

Kidney

TH

12
5

Na

Cu

Zn

Sr

Pb

0.22
0.67

17
8.9

143
104

0.4
0.5

0.28
0.48

2.4
1.2

100 0.80 <0.11
0.19
100 <0.15

2.2 0.95 <0.07
4.1 0.48 <0.08

0.45
0.32
0.07

0.6
1.0
0.4

39
58
31

1.3
0.4
2.8

0.80
0.40
1.03

0.55
0.63
0.73

100
100
100

0.31
1.8
0.12
0.57
2. 5 <0.17

4.8
9.1
12 . 9

0.19

0.2

9.3

0.5

0.42

0.42

100

2 0.22 <0.1
0.34
0.2

0.4
0.6

0.3
0.6

0.61
0.72

0.43
0.18

100
100

3.4
0.8

0.16
<0.17

0.5 0.13 <0.10
0.5 0.12 <0.09

2 0.1018.6 0.3

1.09

0.58

100

0.96

0.09

11.0 0.15 <0.08

0.2

0.30
0.23
0.26

0.26
0.12
0.11

nl and nz are number of analyzed points with a 1 p.m polypropylene absorber and a 1.8mm polyethylene absorber,
respectively. M ean values are adopted for the targets of n> 1.

* Tokyo University of Fisheries.

K. Maeda, et al.

95

Table 2. Elemental distribution in a vesical stone (KY): peak intensities of Ka normalized to CaKa= 100.
SD: standard deviation.

1.8 mm polyethylene

Absorber: I pm polypropylene,...,

Position
Na

Mg

P

CI

K

Ca

Fe

Zn

Sr

Outside (outermost shell)
Inside (outermost shell)

0.60
0.55

40
34

179
172

1.3
0.5

1.7
0.5

100
100

1.4
<0.2

5.2
5. I

0.83
0.73

Outer part0.80
(0.30)

27
( 8)

151
( 19)

0.5
(0.2)

1.0
(0.4)

100

<0.2

(SD, n=4)

9.3
(1.6)

0.77
(0.06)

0.79(0.18)

41
(22)

177
( 55)

0.3
(0.2)

1.2
(0.4)

100

<0.3

(SD, n=4)

8.8(1. 5)

0.97(0.13)

0.62(0.07)

57
( 5)

219
9)

0.4

(

to. 1)

1.6
(0.2)

100

(SD, n=4)

0.3
(0.1)

5.3
(1. 1)

0.96(0.08)

Middle partCenter point

Fig. 1.

Cross section of a vesical stone (KY in Table 1).

ment normalized to those of CaKa are given in
Table 2, together with standard deviations (SD).
High concentrations of CI and Fe found outside
the outermost shell may come from fluid surrounding
the stone. Sodium and strontium seem to distributealmost homogeneously. Difference in Zn contents
at the center part, and the middle and outer parts
are beyond the standard deviations.
(3) Suspended particulates in water of the
Antarctic Ocean
Suspended particulates act as main transport
media for chemical species in hydrosphere. We havealready reported the result of PIXE analysis on
suspended particulates in the urban river water. 3 ,6 )This year we have used PIXE to analyze suspended
particulates in the water of the Antarctic Ocean
where pollution caused by human activities is not
so serious. Samplings were made in January andFebruary 1984 at the stations located at (65°04'S,
116°09'E) and (60 0 56'S, 149°47'E). The sample
waters were collected at the depths of 0, 100, 300,
500, 1,000, and 1,500 m at each station and filteredthrough 1 mgjcm2 thick nuclepore filters of 0.80 11m
in pore size. The filters loaded with the suspended
particulates were washed with an ammonium carbonate solution and kept frozen until analysis. The
concentration of Ca was rather high in the deep
regions; however, some of the samples collected in
the upper regions contained Ca in high concentration. In these samples the concentration of P was
also high. Iron was enriched in the particulates
collected in the deep regions. Aluminum seems tomove in company with Fe.
References
1) K. Maeda, Y. Yokode, Y. Sasa, H. Kusuyama, and M.
Uda: Nucl. Instrum. Methods B, 22, 188 (1987) .
2) M. Uda, K. Maeda, Y. Sasa, H. Kusuyama, and Y. Yokode: Nucl. Instrum. Methods B, 22, 184 (1987) .
3) K. Maeda, Y. Sasa, M. Maeda, and M. Uda: Nucl. Instrum. Methods B, 22, 456 (1987) .
4) K. Maeda, H. Kusuyama, Y. Sasa, Y. Yokode, and M.
Uda: RIKEN Aeeel. Prog. Rep., 19, ll8 (1985) .
5) Y. Sasa, K. Maeda, and M. Uda: Nucl. Instrum. Methods B, 22, 426 (1987) .
6) K. Maeda, Y. Sasa, M. Maeda, S. Noriki, and M. Uda:
RIKEN Aeee!. Prog. Rep., 18, 126 (1984) .

96
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-8. Appl ication of PIXE and Diffraction Analysis toAncient Remains
Y. Sasa, K. Maeda, and M. U dafor the case without or with an X-ray absorber.
X-rays generated from the targets were detected witha Si (Li) detector through a 7.5 pm Be window.
Measurements of trace amounts of elements whichemit high energy X-rays were made through a thickpolyethylene absorber (93 mg/cm 2 ) inserted between
the target and the detector in order to depress thepile-up phenomenon in the detector. An electron
shower was applied to the targets to reduce thecharging effect. X-ray diffraction data were takenwith use of an automated X-ray diffractometerequipped with a Cu radiation source, a graphite
monochromator, and a NaI scintillation counter. ACgoniometer was scanned at a speed of (20 /min) =2 and with time constant = 1 s.
Results of the PIXE analyses of the Chinese potsherds are summarized in Table 1, where integrated
peak intensities for Ka were normalized by use of
Si Ka peak intensities. The sherds have been painted
with brown color agents for making simple andold fashioned patterns. PIXE analyses were carriedout on both areas characterized with colored andnon-colored. Mn, Fe, and S were concentrated on
the brown colored parts for every Yanshao sample,
suggesting that the color originated in compounds
made from, at least, these three elements. The
Yanshao-2 sherd had a high Al content on bothcolored and non-colored parts. This means that the
sherd was produced by use of a type of raw material
different from those of the other two sherds. X-ray
diffraction analyses showed that a-quartz and orthoclase were main constituents in the three kinds ofYanshao samples. Mn 304 or (Mn, Fe) 304 was also
detected from the colored parts. However, we founda muscovite, i.e., a clay mineral including OR radi-

For the analysis of ancient remains, non-destructive and highly sensitive measuring methods areindispensable. PIXE is one of the most effective
methods to gain our ends in view of elemental
analyses. PIXE has advantages over other methods,i.e., high sensitivity, simultaneous multielemental
analysis, short data acquisition time, easy sample
handling without pretreatment, limited amounts ofsamples and so on. Then several PIXE data havebeen reported on ancient potsherd. 1 - 6 ) Crystallographic analyses also bring us highly reliable information
on structures and chemical constituents of archaeological samples.
In this report we will describe chemical andcrystallographic surveys of ceramic products of different districts and ages. Concentrations of minor
constituent elements in these ancient remains will
give us keys to understand exchange or diffusion ofcultures. These data will also contribute to elucidate
technological backgrounds in ancient periods.
The samples analysed in this study were potsherdsof different districts and ages: 1) three pieces of
Majiayao category (B.C. 3000--4000) potsherds at
the Yanshao stage of China from Qin' an Gansu
China (referred to as Yanshao-l, 2, and 3, respectively), 2) three glazed sherds with brown-yellow,
green, and blue color obtained from the Banbohr
ruin in Pakistan dated back to 0-7th centuries (referred to as Banbohr-Brown-yellow, -Green, and-Blue), 3) three types of Japanese glazed porcelains
named Kakiemon, Tsutsue, and UFSSll (17thcentury) . Target materials were irradiated with
8 MeV He+ ions. The size of an ion beam focusedon the target was 0.5 X 0.5 mm 2 and the beam
intensity was selected as 0.2 or 20 nA on the targets
Table 1.

Yanshao-l N*
Yanshao-lB*
Yanshao-2N
Yanshao-2B
Yanshao-3N
Yanshao-3B

Na

Mg

1.1
0.68
1.0
0.96
0.87
0.76

4.3
3.0
4.6
4.2
3.8
2.5

Results of PIXE Analyses on Chinese potsherds.
Si

P

S

CI

K

Ca

Ti

Cr

Mn

Fe

28.9 100.0
24.9 100.0
33.8 100.0
36.2 100.0
26.4 100.0
25.8 100.0

4.2
4.5
3. 7
3.9
3.6
4.4

0.73
2.1
0.40
0.79
1.2
4.1

0.73
0.51
0.37
0.20
0.48
0.98

13. 1
13.3
11. 6
12.9
8.8
11. 7

22.8
12.0
17.9
19.4
15.7
18.2

0.47
1.1
0.74
0.92
0.61
0.89

0.07
0.11
0.06
0.05
0.03
0.07

0.11
7.70
0.14
5.1
0.18
7.4

2.1
4.7
3.7
5.9
2. 7
7.9

Al

* Nand B represent non-colored and brown colored parts, respectively.
Each Ka intensity is normalized to Si Ka= 100. O.

Y. Sasa, et al.

cals, from the X-ray pattern only for the Yanshao2 sample. This suggests that the sherd was fired atlower temperature than those for the Yanshao-1 andYanshao-3. Combining the results from PIXE anddiffraction analyses we imagine that the Yanshao-2
sherd was produced at a place different from theother two or in earlier age than that for the others,
and j or both. This assumption is also supported, atleast in part, by the fact that the sound from tapping the sherd is characterized by a low-pitchedtone for the Yanshao-2 but by a high-pitched one
for the other two.
Surfaces of the Pakistan potsherds have beenglazed and showed diffraction patterns characteristicof amorphous materials for all the samples examinedin this study. However, the back and side faces ofthe potsherd were free from glazed materials andcomposed mainly of a-quartz and orthoclase together with small amounts of aluminosilicates. Crystallographically these main components are the sameas those for Yanshao potsherds. It was confirmed
from the PIXE analyses that the colors of the glazes
are characterized by Pb and Fe (Pb La j Si Ka"=--0.03 and Fe KajSi Ka = --0.05) for the brownyellow sherd as shown in Fig. 1, by Cu and Fe(Cu KajSi Ka=--0.006 and Fe KajSi Ka=--0.006) for the green one, and Fe and Co (FeKajSi Ka= ...... 0.004 and Co KajSi Ka=--0.002)
for blue one. In the latter two sherds high contents

100000~----~--~~---.-----.-----n

Banbohr potsherd(Brown-yellow)

Si

10000

Pb

Q)

c:
c:

~

Fe

AI

o

1000 Mg

I II

Ti

II

100

(/)

c:
~
c:

10

l.
o

100

200

Japanese Porcelain

~

10000

(Kakiemon)

0

"5

~:3

1000

~

100

Ul

c:
Q)

~

c:

10

o

100

200

300

400

500

Channel Number

Fig. 2. PIXE spectrum from the Japanese porcelain, Kakiemon dated back to 17th century: a 1,000 p,m polyethylene
absorber was used.

of Na and K were found, which might make theglazes glassy.
Three kinds of Japanese green-blue procelains
were also analyzed by PIXE. Impurities detectedfrom glazed surfaces of Kakiemon were very low
in contents, as shown in Fig. 2, compared withthose from the ancient Chinese and Pakistan potsherds. Pale color was given by a small amount of
Fe together with very small amounts of Ti, Mn, Cu,
Zn, Au, and Pb. Such a tendency is, more or less,the same for the other two. This indicates that clay
minerals and agents as raw materials were carefully
chosen for porcelain production and glazing. The
X-ray diffraction data also supported these results,
i.e., a-quartz was only one main constituent forthe matrices.
References

::>

:3

~

100000

Pb

n

So

97

300

400

500

Channel Number

Fig. l. PIXE spectrum from the Banbohr-Brown-yellow
Potsherd dated back to 0-7th centuries.

1) G. Lagarde, I. Brissaud, J. Cailleret, P. Fontes, and
Ch. Heitz: Nucl. Instrum. Methods B, 1, 45 (1984) .
2) Proc. PIXE Conf., in Nucl. Instrum. Methods, Heidelberg, Vol. 3 (1984).
3) I. Brissaud, A. Houdayer, C. Jehanno, and A. Sabir:J. Radioanal. Nucl. Chern. Articles, 89, 473 (1985) .
4) S. R. Ryan, H. J. Fischbeck, and K. Chesnut: Nucl. Instrum. Methods B, 10-11, 645 (1985) .
5) Proc. Int. Workshop on IBA in the Arts and Archaeology, in Nucl. Instrum. Methods, Pont-:i-Mouson, Vol.
B14 (1986) .
6) Y. Sasa, K. Maeda, and M. Uda: Nucl. Instrum. Methods B, 22, 426 (1987) .

98
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-9.

Behavior of Light Elements in Hydrothermal Treatment ofGlass Surface as Studied by Heavy-Ion Rutherford
Forward Recoil Measurement
M. Aratani, Yanokura, Q. Qiu,* K. Sato, B. G. Yu,* and T. Nozaki

Weathering of minerals are regarded as fundamental recations on the surface of the earth. In thepresent study, a hydrothermal reaction of soda-lime
glass was taken for a simple model of the early stageof the weathering, and its surface hydrothermallytreated under various conditions are subjected to the
Rutherford forward recoil measurement1 ) with heavy
ions from RILAC.
Pieces (9 mm X 19 mm) of S-1214 microslide
glass (Matsunami Glass Ind., Ltd.) were boiled inwater in a flask equipped with a reflux condenser
for a few hours to several tens of hours. The samples were mounted on a target holder capable ofsupporting nine samples, and the target holder wasplaced at the center of a scattering chamber (1 min diameter). Quantities and depth profiles of hydrogen in the surface layers of the samples were
examined by using 50 MeV Ar 4+ ion beam (2 mm X2 mm), which was restricted around 25 nA after trial
bombardment with high-intensity current, carried out
to see irradiation effects on obtained spectra. The
samples were slanted by an angle of 30° to the incident Ar 4+ ion beam, and surface-barrier silicondetectors at the angles of 37° and 47° to measure
recoiled light elements and to monitor argon scattered from the samples, respectively. In front of the
37° detector was located an aluminum foil of 20 pm,
13 f.1m, or 10 f.1m in thicknesses as an absorber forheavy recoils. Si0 2 films of 200 A, 500 A, and
1,000 A in thicknesses on high-purity crystalline silicon and films of oxygen-containing amorphous silicon
were employed for reference samples.
The energy spectra of forward recoil hydrogenare shown in Fig. 1. The spectrum for the untreatedsample is regarded as being due to background hydrogen on the surface. The spectrum for the sample
treated for 28 h is shown in Fig. 2 in comparison
with the background hydrogen. The backgroundhydrogen level is around 5 X 1015 atoms / cm2 in everycase. This value is the same as those for the surfaces of various kinds of substances observed by using
this method. 2 ) Peak widths at half height of hydro-* ResearchLaboratory for
Institute of Technology.

Nuclear

Reactors,Tokyo

gen were almost constant for all the samples independent of their treating times. The peak heightincreased with the treatment time and appeared toreach a saturated value in ten hours or so; this may
be attributed to depth resolution estimated to be
500 A under the present experimental conditions.
*10 2
1.28.------r-----r----,--...------,----y---,------,H 20 (at b.p.) 2h

1.12 - -Surface hydrogen

0.96
(j)

AI abs. 20/-1~ 0.80..cu:? 0 .64c::l(5 0.48
0.32

0.1 6

Channel number

Fig. 1. Energy spectra of forward recoil hydrogen for the
sample treated for 2 h and that without treatment.

10 2

2.56 r::---.,---.,-----,--..,.-----,----y---,----,
2.24-

H 20 (at b.p.) 28 h

- - Surface hydrogen

1.92
Q)

AI abs. 20/-1§ 1.60ro..cu:?c 1.28::l<3 0.96

t\

0.64
I

0.32 !

-o B..~. ,,,- ._,"''/"".::. .,.,"';~-.&"W~~~It_Wl\J,.~v,..~'" i'r;;~.
o256
Channel number

Fig. 2. Energy spectra of forward recoil hydrogen for the
sample treated for 28 h and that without treatment.

M. Aratani, et al.

10 7 c---.---,----.---,---.--~----r_~- - AI abs. l0.um

10 6

-

c

~

AI abs. 20.u m

l

a;
..c
u

-

H

10 5
104 -

o
~

'-..

~ 103
:::l

o

102

U

101

512
Channel number

Fig. 3. Spectra with oxygen continuum through 10 J-Lm Al
foil and without it through 20J-Lm Al foil (Oxygen containing a-Si) .

106

105
a>

E 10 4- - H20 (at b.p.)H

9 h

H20 (at b.p.) 9 h- - { + CsCI 0.15N (at b.p.) 9h

I

AI abs. 10.u

('IJ

..c

99

Time required to obtain above spectra was a quarterhour or so. The irradiation effect on the heavy-ion
bombardment was negligibly small under this condition, because slight tailing of hydrogen peak due
to diffusion was recognized 4 h after irradiation.
These spectra were obtained by using a 20 pm Al
absorber.
The spectrum demonstrating oxygen continuum
through 10 pm Al foil is shown in Fig. 3, in whicha shift of the hydrogen peak is observed because of
the difference in thicknesses between two foils. The
spectrum for the sample boiled with a 0.15 M CsCI
solution for 9 h after hydrothermal treatment for 9 h
is shown in Fig. 4, in comparison with that for the
sample treated only hydrothermally for 9 h. I t isseen that decrease in surface oxygen and increasein surface carbon resulted from the CsCI treatment;
this may be attributed to C0 3 2- or HC0 3 2- covering the fresh Cs glass surface.
Very recently, the hydrothermal reaction of glasscame to attract attention in view not only of thefundamental processes in the hydrosphere but alsoof urgent problems related to disposal of radioactive
waste. Rutherford scattering analysis comes to show
its general usefulness for various problems.

u

?10 3
c

:::l

810 2

C

!

10 1

Channel number

Fig. 4. Spectra for the samples with and without 0.15 M
esCl treatment for 9 h after hydrothermal treatment for 9 h.

References
1) H. Nagai, M. Aratani, T. Nozaki, M. Yanokura, I. Kohno, O. Kuboi, and Y. Yatsurugi: RIKEN Accel. Prog.
Rep., 16, 125 (1982); H. Nagai, M. Aratani, S. Hayashi,
T. Nozaki, M. Yanokura, I. Kohno, O. Kuboi, and Y.
Yatsurugi: RIKEN Accel. Prog. Rep., 17, 102 (1983) .
2) M. Aratani, H. Nagai, S. Hayashi, M. Yanokura, O.
Kuboi, Y. Yatsurugi, I. Kohno, and T. Nozaki: RIKEN
Accel. Prog. Rep., 17, 104 (1983) .

100
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-10.

Substitution of Positive Ions in Glass Surface Layer Studied
by Heavy-Ion Rutherford Scattering Analysis
B. G. Yu, M. Aratani, M. Yanokura, T. Nozaki, and E. Arai*

The ERDA (Elastic recoil detection analysis)
technique in conjunction with RBS (Rutherford
back scattering ) has been used successfully in theanalysis of positive ion substitution near the surface
of soda-lime glass.1} Soda-lime glass was boiled with
H 2 0 for 24 h and then boiled with CsBr or BaBr 2
solution (0.1 N) for 3, 6, and 46 h. We expected
the substitution of H+ for Na+ in the H 2 0 treatment and that of Cs+ or Ba++ for H+ in the succeeding treatment. The experiments were carried out
using with 25 nA 49.65 MeV 40Ar 4 + from RILAC.
The detector angles were 35 0 for detection of hydrogen by ERDA, 45 0 for the detection of Cs or Ba
by RFS, and 165 0 for the detection of Cs or Ba
by RBS. The target angle was 30 0 to the incident
beam, and the beam spot was 1.5 X 1.5 mm2 on thetarget.
The ERDA spectra are shown in Fig. 1 and RBS
spectra in Fig. 3. Figure 2 shows spectra of RFS(Rutherford forward scattering) from Cs and of
ERDA for light elements. The ERDA spectra in
Fig. 1 obtained for the sample treated for 46 h in
the CsBr solution show much less hydrogen thanfor the samples treated for 6 or 3 h. For thesesamples, an increase in Cs amount was observed

CHANNEL NUMBER

Fig. 2. ERDA spectra of H, 0, and Si recoiled b y Ar ions,and RFS spectra of Cs obtained with Ar ions.

RBS (153°) 24 h(H)'10'

5. 12r---r--_---r------;--.,..-----,------.--~

10'

ERDA (35°)

C

O.lN

3 h(CsB r )20 lJm,AI Absorber
H

CHANNEL NUMBER

Fig. 3. RBS spectra of Cs obtained with Ar ions. S indicates a Cs peak area.

A

O. lN 45 h(CsB r )CHANNEL NUMBER

Fig. 1. ERDA spectra of H recoiled b y Ar ions from thesoda-lime glass boiled with water (24 h) followed by boiling with 0.1 N CsBr solution. Time of CsBr .solution
treatment: A, 46 h; B, 6 h; C, 3 h; D, no treatment. S indicates a hydrogen peak area.

* Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology.

with decreasing H amount in the RFS spectra in
Fig. 2 and RBS spectra in Fig. 3. For the sample
treated for 46 h, the peak in the spectrum indicatesthat Cs is not located on the surface but inside
the surface. The ERDA technique in conjunction
with RBS has proved to be highly useful in tracing
the movement of light and heavy elements simultaneously as exemplified by the substitution of positive ions in the glass surface layer.
Reference
1) B. G. Yu, M. Aratani, M. Yanokura, T. Nozaki, andE. Arai: Extended Abstracts, 47th Fall Meeting Jpn.
Soc. App!. Phys., p. 356 (1986) .

101
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-11. Elastic Recoil Analysis of Implanted H2 + Ions in Magnetic
Bubble Garnets
R. Imura, R. Suzuki, M. Aratani, M. Yanokura, and T. Nozaki

Ion-implanted magnetic bubble memory devices
are capable of very high-density storage. 1 ) These
devices use the change in magnetic anisotropy ofmagnetic garnet films caused by internal stress due
to ion implantation. High dose H2 + ions are usually
implanted into the garnets to induce large anisotropy
field changes. In the development of these devices,precise depth-profile analysis of the implanted H2 +ions has been requested to investigate the implantation and annealing effects of the H2 +-implanted layer.
We studied these effects by measuring the depth
profiles of H2+ ions and the strain induced by Implantation in bubble garnet films.
Elastic recoil detection analysis (ERDA) wasused successfully for the depth-profile analysis of H2 +ions implanted in garnets. Using 50 MeV Ar++
ions generated by RILAC, we detected forward recoiled H+ ions at a total scattering angle of 43 0
for the sample tilted at 33 ° with respect to thebeam axis. Strain depth profiles were determined
precisely from the X-ray rocking curve analysis
based on the dynamical theory of X-ray diffraction. 2)
Along with these measurements, H2 + ions bonding
state was also investigated by means of Fouriertransformed-infrared spectroscopy (FT-IR) analysis
with attenuated total reflection method. 3 )Accuracy of the H2 + depth-profile analysis and thedetection limit of H2 + ions in garnets in elastic recoil
detection analysis method were checked by changing
acceleration energy and ion dose in H2+ implantation. Figure 1 shows typical energy spectra for H2+implanted garnet samples. The depth of the main
peak in the H2 + ions profile became deep with increasing energy for implantation. A small peakwhich is found at the surface is attributed toabsorbed hydrogen. The depth of the main peakagreed with the value calculated from the LSS(Lindhard, Scharff, and Schiott) theory. This depthprofile analysis indicates that the H2 + ions implanted-----in garnets can be measured with accuracy of 0.06
to 0.08 p.m in depth resolution. The total H2 +ions content which is obtained from the integrationof the profile is proportional to the implantation
dose. The accuracy of H2 + ions content is within
10% . Considering the error of measurements andthe background energy spectrum, detection limit of.10 2
1.28.----.---,-----,,-----,---,-----,r----,-----,

2 x 1016o

Hi Icm 2

(0)

oJ.

0
2

266
CHANNELNUMBER

.'0
5.12

( b)

80 keV I Hi
-.J

w

z
z

3.84

DOSE

«
:r:

17

U

~

If)

1 x 10
2.56

I-

Z

=>

0
U

4 x 1016
1.28
2 x 10

16

0

133

0
CHANNELNUMBER

Fig. 1. Energy spectra for H2 + ions implanted in bubble
garnets. (a), Dependence of H 2+ implantation energy;(b), Dependence of H 2 + implantation dose.

the H2 + ions implanted in garnets is found to beapproximately 1 X 1016 /cm2.
Depth profiles of H2+ ions and strain are shownin Fig. 2 for an as-implanted sample (180 ke V, 4 X
101 6 /cm 2) and the samples annealed at 150 and
200°C. As expected from the LSS theory, the depthof the main peak in the H2 + ions profile immediately
after implantation is found deeper than that of themain peak in the strain profile. It should be notedthat H2+ ions diffuse toward the surface by annealing
and their distribution overlapped with the strain
distribution after annealing at 150°C.
Figure 3 shows FT-IR spectra observed in thesame samples as those shown in Fig. 2. There is
no absorption related to the implanted H2 + ions inthe spectrum before annealing; however, a strong
absorption occurs at a wavenumbers of about
3,400 cm-1 in the spectrum of the sample annealed

R. Imura, et al.

102

0.15

180 keYHiz

4 x 10 '6 /cm 2

180 keYHi

4 x 10 '6 'cm 2

without SiOZ

I
I

w

u
Z
<t
(I)

0:

o

2
c

<Il
10

<t

,,,,-0-,, ,

::J

,,,'"

o

U

-0"

, 0-

,,0::~-~o ~-~..::....------....::::::;~--~
0~0.05L..-.---L._

2

ZOO°C

After

4000

o

Annealing_...I....-_--L_ _...l----==::::I:::::::=--....L_

3000
WAVENUMBERS

-'

2000

_ L-_
1000

.< cm- 1 )Fig. 3. FT-IR spectra observed for the same samples as
those in Fig. 2.
...-0-o L--_....L._---1._ _ _
0.2
0.4
0.6
o
~

Depth

_'_..:=.......L._ _.I....._I

0.8

1.0

0

1.2

(pm)

Fig. 2. Depth profiles of H 2+ ions and strain for an asimplanted sample (180 keY, 4 X 1016 / cm2) and samples
after annealing at 150 and 200 o C.

at 150°C. This strong absorption indicates the existence of OH-bonding. It should be noticed thatthe H2+ ions implanted in garnets are combined withoxygen by annealing and the OH absorption becomes strong when the H2+ ions distribution overlapped with the strain distribution. Since the annealing temperature which gives the overlapping of
distribution in H2 + ions and distribution in strain
corresponds to temperature which induces the OHbonding, the formation of the OH-bonding is con-sidered to be due to the combination of diffused Hz +ions and free oxygen which are present in the region
damaged by implantation.
Using elastic recoil detection analysis, X-ray
analysis, and FT -IR spectroscopy, we examined theformation process of the OH-bonding in Hz+-implanted garnets. Elastic recoil detection analysis isvery useful method for the study of annealing behavior of H2+ ions implanted in bubble garnets.
References
1) Y. Sugita, R. Suzuki, T. Ikeda, T. Takeuchi, N. Kodama,
M. Takeshita, R. Imura, T. Satoh, H. Umezaki, andN. Koyama: IEEE Trans. Magn., MAG-22, 239 (1986).
2) T. Takeuchi, N. Ohta, Y. Sugita, and A. Fukuhara: J.
Appl. Phys., 54, 715 (1983) .
3) R. Imura and Y. Sugita: J. Appl. Phys., 60, 3269 (1986) .

103
RIKEN Acce!. Prog. Rep. 20 (1986)

111-3-12.

Behavior of Releasing Agents Coated on Heated Substrates
as Studied by Heavy-Ion Rutherford Scattering
1. Sugai, H. Kato, M. Aratani, M. Yanokura, and T. Nozaki

Heavy-ion Rutherford scattering was used for the
study of the behavior of NiCI 2 , which is used as areleasing agent in the preparation of a self-supporting carbon foil and is known to improve the lifetimesof the foils deposited on a substrate at high temperatures. 1 ,2) The releasing agent coated between
the substrate and deposited layer plays importantroles when the layer is separated in liquids, for example, water. Three kinds of measurements were
performed: 1 ) dependence of the substrate temperature on the lifetime of the carbon foil; 2) substrate temperature effects on the behavior of NiCI 2 ;and 3) characterization on NiCl 2 coated on a heatedsubstrate.
The samples were prepared by coating NiCl 2 toabout 20 pg/cm 2 on a slide-glass plate pre-cleaned(Matsunami glass) and outgassed by heating themat 250°C for 15 min. The temperature of the substrates was controlled by a thermo-meter to within± 5°C. The heating system for the radiation heating is composed of Kantal tantalum alloy heaterwires, which was set inside the double stainless-steel
roof for thermal shielding. The substrates coatedwith a releasing agent was kept at various temperatures from 25 to about 500°C during the DC
arc-discharge deposition, and the effect of the temperature on the lifetime of the foils was investigated.
The results obtained are shown in Fig. 1. No clear
improvement of the lifetime was observed. No measurement was carried out above 430°C, at which thesubstrate did not release the deposited carbon layer
by immersion in water; the carbon layer could not
be removed from the substrate by rubbing with afinger. In order to study the reason for this in releasing, we carried out following experiment. The
substrate coated with NiCl2 to about 100 pg/cm2 atroom temperature was heated to 460°C, and theweight changes of NiCl 2 was determined; the results are listed in Table 1.
During the heating at 400°C, the glass substratechanged its color to pale brown, and the surface
was removed with a finger more easily than thatwithout heating treatment. This result suggests that
the NiCl 2 deposited at 460°C.
The results listed in Table 1 shows that most of
NiCl 2 sublimated above 460°C. The glass substrates~~.~----------------------~

DC-55(A)
Carbon Rods ' 5 mm ¢
1000

10

IL-~

o

__

100

~

__

200

~

__

300

~

__

~

400

__

500

'I'eIllj?erature of substrate

~~

600

700

( °el

Fig. 1. Dependence of the substrate temperature on the lifetime of carbon foils.
Table 1. Effect of heat treatment on the decrease in the
thickness of the NiCl 2 releasing agent.
SampleNo.

2

3
4

Thickness of
NiOl z before
heating(pg/cm2)

Thickness after
heating at(pg/cm2)

Decreasedamount(pg/cm2)

100
90
100
100

10
7

83

8

92

30

70

460°0

90

Samples #1, 2, and 3 coated on slide glasses and #4
coated on 4 pm Al thin foil.

heated to temperatures lower than about 350°C weretransparent. However, when the substrates heatedat 350°C were exposed to the atmosphere, their surfaces changed to opaque due to the deliquescenceof NiCI 2 • The carbon layer deposited on the deliquescent NiCl 2 can not be lifted off from the substrate in water. Hence carbon should be depositedon the NiCl 2 later in the vacuum; the carbon layer
thus prepared can be easily removed in water.
We applied the heavy-ion Rutherford scattering
method both to backward (so-called Rutherford
backscattering; RBS) and to forward angles to study

I. Sugai, et al.

104

X10 2
5.12,--,----,----,----,---.--r--,----j

*10 2
2.56
2.24

Ni

!

1.60

£

§ 3.20

0

•

j

j

ro

£

C
:J

:J

o

o

0.96
Si

0.64

Surface
H

~

c

0

OJ

~

? 1.28
0

H

3.84

1.92
OJ
c
c
ro

- - Unheated sample- - Heated sample

4.48- - Unheated sample- - Heated sample

j

CI

j

0.32

Channel number

Channel number

Fig. 2. Spectra of particles observed at backward angle(165°) for unheated and heated samples.

Fig. 3. Spectra of recoiled particles at forward angles (35°)
for unheated and heated samples.

the behavior of NiCl2 in the heating treatment. An
ion beam of 50 MeV Ar 4 + with 20 nA delivered fromRILAC was used. Spectra of argon particles at backward angles and recoiled particles at forward angles
are shown in Figs. 2 and 3, respectively, where aheated and unheated samples are compared.
Figure 2 clearly shows that the amount of the Ni
layer on the substrate was decreased more pronouncedly than that on the unheated substrate.
Figure 3 shows the spectra of light elements oxygen,carbon, and hydrogen. The amounts of hydrogen in
the internal layer and on the surface were significantly reduced by heat treatment as well as those ofcarbon.
Oxygen, on the other hand, was increased by heat
treatment, indicating that a chemical reaction occurred in the slide-glass substrate in the heating
treatment. Further experiments are in progress.
References
1) S. Takeuchi, C. Kobayashi, Y. Satoh, T. Yoshida, E.
Takekoshi, and M. Maruyama: Nucl. Instrum. Methods,
158, 333 (1979) .
2) J. Jaklovsky, ed.: Preparation of Nuclear Target for Particle Accelerators, Plenum Press, New York and London,
pp.17, 65 (1981).

105
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-13.

Eva Iuation of W/ GaAs Interface Diffusion by the Rutherford
Back Scattering (RBS)K. Saito, K. Suzuki, * M. Yanokura, M. Aratani,
K. Sato, and T. Nozaki

A tungsten film is a promising gate electrode for a
GaAs field effect transistor (FET). Since the electrical properties of FET is affected by the reaction or the
diffusion at the interface of the tungsten film andthe GaAs substrate, evaluation of these phenomena
is indispensable for development of FET. The interface diffusion or reaction has been generally evaluatedby Auger Electron Spectrometry (AES) or Secondary
Ion Mass Spectrometry (SIMS) in which elemental
depth profiles are obtained by sputtering the specimen with accelerated ions. In the W jGaAs systems,
however, the depth resolution of an elemental profile
is lowered by non-uniform sputtering and an accurate profile of a very thin interface layer can not be
obtained in these methods. The RBS method is expected to be suitable this for purpose comparedwith other methods.
In order to obtain the high resolution for elemental depth profiles, high-energy heavy ions (Ar4+,
50 MeV) from RIKEN RILAC were used andthe analytical conditions were investigated. As apreliminary experiment, RBS measurements were
performed with the most commonly used geometricalarrangement and an incident beam angle of 90°.
Back scattered ions were measured at high angles.
The measured samples were non-annealed andannealed W (1,000 A) j GaAs system. The RBS spec10 7

tra, obtained by setting the angle of back scatteredions to be 157°, are shown in Fig. 1. Peaks in thehigh energy part of the profiles represent tungsten
films and in the low energy part, a GaAs substrate.
The separation between the peaks for the tungsten
film and the GaAs substrate is fairly well, but thedepth resolution, i.e. the sharpness of the shoulderof these peaks, is not satisfactory. A lower energy
parts of the tungsten profile for the annealed sample
is somewhat deformed. This deformation is considered to indicate the formation of a tungsten compound at the surface by annealing, though it cannot
be identified in this experiment. In order to improve

Fig. 2. Geometrical arrangement for high resolution depth
analysis. Depth resolution is improved by tilting the sample and setting the detector at a smaller scattering angle.

10 6
-.J
W

Z
Z

10 7

10 5

10 6

<!
:r: 10 4

-.J
W

u

"(f)
~

Z

=>

0

Z
Z
<!

10 3
10

2

10

1

5

:r:
u

10 4

"-

10 3

(f)
~

U

10

Z

=>

0

10 2

U

512

10 1

CHANNEL NUMBER

Fig. l. RBS spectra of W (I,OOOA) jGaAs system with andwithout annealing at 800°C for 30 min in nitrogen atmosphere. The depth resolution is 150A.

* R&D Center, Toshiba Corp.

512

CHANNEL NUMBER

Fig. 3. RBS spectra for W (I,OOOA) jGaAs systems obtainedwith the geometrical arrangement shown in Fig. 2. Depth
resolution was improved remarkably to be less than 100A.

106

K. Saito, et ai.

the depth resolution, measurements were performed
with a lower incident-beam angle (30°) and a lower
detection angle (47°) as shown in Fig. 2. The results of the RBS measurements with the same samples are shown in Fig. 3. The depth resolution was
improved remarkably and was estimated to be lessthan 100 A from the sharpness of the shoulder of
the tungsten profile in the non-annealed sample.
Interface diffusion of tungsten and gallium or arsenide, which is not clear in Fig. 1, was clearly observed in the annealed sample. Substrate atoms were
found to diffuse deeply into tungsten films. Anothermerit of this geometry is to permit detection of recoiled atoms. The peak at a channel number 300
appearing on the profile of the GaAs substrate was
identified with oxygen on tungsten film surface, whichsuggested the formation to tungsten oxide by annealing. In Fig. 4, the RBS spectra of annealed W /GaAs and WNIC / GaAs systems are shown.
Interface diffusion is not observed in the WN a,/

10 4
85;47 •
--l
W

10

3

Z
Z

<l:
I
U

"'-

10 2

(f)

I-

Z

~

0

,U

10 1

10°

0

5 12

CHANNEL NUMBER
Fig. 4. RBS spectra for W (l,OOOA) jGaAs and WN", (l,OOOA) j
GaAs systems after annealing at 800°C for 30 min in nitrogen. No diffusion was observed at the interface in WN ", j
GaAs system as compared with W jGaAs system, in whicha large number of substrate atmos diffuse into a W-film.

GaAs system. The addition of nitrogen was foundto improve the heat resistance of tungsten films.

107
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-14. In Situ Emission Mossbauer Study on 119Sb5+ (~119Sn) and
57C02 + (~57Fe) Ions at a-Fe 2 0 3-Aqueous Sol ution Interface
S. Ambe, T. Okada, and F. Ambe

We previously reported M6ssbauer spectroscopic
investigations on the chemical states of no-carrieradded 119Sb 5+ and 57C02+ adsorbed on a-Fe203Y4 )In this period, in situ emission M6ssbauer measurement was made on 119Sb 5 + ions adsorbed on a-Fe 2 0 3
together with non-radioactive Sb 5+ carrier ions. The
effect of Sb 5+ ions on the adsorption state of 57C02+
on a-Fe203 was also studied.
The 119Sb 5+ ions were adsorbed on 30 mg a-F 20 3
powder from a 10 cm3 0.25 mol/dm3 KCI solution
containing about 1 mg Sb 5+. About 0.3 mg Sb 5+ wasadsorbed at pH 2.5 and 4.0. The amounts of Sb
adsorbed are less than that required to cover all thea-Fe203 surfaces monomolecularly. The experimental
set up of the in situ emission M6ssbauer measurement
was described elsewhere. 2)
The emission M6ssbauer spectra obtained areshown in Fig. 1. It is seen from Fig. 1 that thewidth of the emission M6ssbauer spectrum at pH
2.5 is much smaller than that of the no-carrier-added
119Sb5+ ions/,5) while essentially no effect of carrier
Sb 5+ ions is observed at pH 4.0. The observation at
pH 2.5 is indicative of high energy bonding at low
coverages, i.e., in the absence of carrier Sb, the sites
forming strong chemical bonds are occupied preferentially by 119Sb 5+. These interactions of 119Sb 5+
with strong bonding site are diluted out in the presence of carrier Sb leading to the small line widthand weak average bonding.

>-

10 0

f-

C/1

Z

W
f-

z

98

w 100
>
f-

a:

99

--1

w

c::

-1 6

-8

0

8

16

RE LATIVE VEL OCITY
eMM/S VS BARIUM STA NNATE)

Fig. 1. In situ emission Mossbauer spectra of 119Sb 5 +(~ lt9Sn) ions adsorbed on a-Fe203 with Sb 5 + carrier from0.25 mol/dm 3 KCI solution: (A) pH 4.0 and (B) 2.5.

>-

99

I-

-16

-8

a

8

16

RELATIVE VELOCITY
CMM/S VS METALLIC IRON)

Fig. 2. In situ emission Mossbauer spectra of 57C02+(~ 57Fe) ions absorbed on a -Fe203 with Sb 5+ ions from
0.1 mol/dm 3 KCI solution at pH (A) 5.5 and (B) 9.2
and from (C) 0.3 M KOH.
When bivalent 57C02+ ions were adsorbed on aFe 203 together with Sb 5 + ions, an increase in adsorption in the weakly acidic region was observed. For
example, when 30 mg a-Fe203 was shaken with
10 cm 3 0.1 mol dm 3- KCl solution at pH 5.5 containing no-carrier-added 57C02+ and about 1 mg Sb 5 +ions, 95 % of 57C02+ and about 30 % of Sb ions wereadsorbed. The [Sb(OH) 6l anions are considered tofacilitate adsorption of bivalent 57C02+ ions on thepositively charged surfaces of a-Fe203'
The emission spectra of the bivalent 57C02+ ionsadsorbed under these conditions are shown in Fig. 2
along with the results obtained under different conditions. The in situ spectra of bivalent 57C02+ coadsorbed with Sb 5+ ions are very different fromthose of 57C02+ adsorbed alone,5) showing a marked
effect of the coadsorbed Sb 5+ ions on the chemical
structure of adsorbed 57C02+. The emission M6ssbauer spectra are complex and their analysis is unfinished. It is evidents from the spectra, however,that the 57Fe ions produced by EC decay of 57C02+
interact magnetically with the ordered ferric ions of
the substrate ; this means that 57C02+ are not adsorbedon the surface Sb 5+ ions, but directly on the surfaceof a-Fe 20 3.

108

S. Ambe, et a f.

References
1) T. Okada, S. Ambe, F. Ambe, and H. Sekizawa: J. Phys.
Chern., 86, 4726 (1982) .
2) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: RIKEN
Accel. Prog. Rep., 17, 109 (1983) .
3) F. Ambe, T. Okada, S. Ambe, and H. Sekizawa: J. Phys.
Chern ., 88, 3015 (1984) .

4) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: RIKEN
Accel. Prog. Rep., 18, 141 (1984) .
5) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: Geochemical Processes at Mineral Surfaces (eds. J. A. Davisand K. F. Hayes), Arner. Chern. Soc., Washington, DC,
p. 403 (1986).

109
RIKEN Accel. Prog. Rep. 20 (1986)

111-3-15.

Emission Mossbauer Studies of No-Carrier-Added
Sb-119 Electrodeposited on Gold
S. Ambe, F. Ambe, T. Okada, I. Tanaka,'"S. Nasu,* and F. E. Fujita*

In electrolysis of small amounts of antimony, it has
been pointed out that the yield of electrodeposition
is low and that the electrodeposited material is partly
redissolved by washing with water. 1 ,2) The redissolution of electrodeposit by washing is a serious andgeneral problem in preparation of thin radioactive
sources. In relation to this problem it is nqt only
important but also interesting to clarify the chemical
states of deposits.
The present paper reports electrodeposition of nocarrier-added 119Sb(V) (Mossbauer source nuclideof 119Sn ) from a Li 2 S0 4 solution and the chemical
states of electrodeposited 119Sb on foil by in situ andex situ emission Mossbauer spectroscopy.
No-carrier-added 119Sb (V) was electrodeposited atabout 10 V on an Au foil cathod (10 p.m in thickness, 18 mm in diameter) from about 30-cm3 0.12mol dm- 3 Li 2 S0 4 solution at pH 1-12 using a spiral
Pt wire anode at 50-60°0.
Emission Mossbauer measurement on (11 9 Sb~) 119Sn
was performed on convensional Mossbauer spectrometers (Austin S-600 and Ranger 700 series) using
119Sb on Au foil as a source and BaSnOs (0.9 mg
119S n cm- 2 ) as a standard absorber. The isomer
shifts are presented relative to BaSn0 3 at room temperature.
Although no appreciable electrodeposition of 119Sb
was observed from weak alkaline and neutral solutions within 1 h, 119Sb was efficiently electrodepositedat pH 1-2. In the present study electrolysis was
carried out with a 0.12-mol dm- s Li 2 S0 4 solution at
pH 1.5. Typical yield curves of electrodeposition are
shown in Fig. 1. The dotted line shows that interruption of electrolysis for sampling an aliquot fromthe electrolyte resulted in redissolution of the deposited 119Sb. The other points in Fig. 1 were obtained by sampling aliquots under applied voltage.
Although the experimental conditions were essentiallythe same, the yield varied greatly from a run toanother.
A typical in situ emission Mossbauer spectrum of
119Sb on Au is shown in Fig. 2 (a). It consists of two
singlets with isomer shifts of 1.66 and 2.72 mm S- l.

* Faculty of Engineering Sciences, Osaka University.

100
~

o'P

'0
OJ

.j.J

'M
(/)

0

0,
OJ

50

•

'0
0
H

.j.J

U
OJ
...-I

ILl

O~--~--~----~---L--o60__L -_ _~120180240300

Time (min)Fig. 1. Yield of electrodeposition of 119Sb (V) on a gold foil.

w>- 100

I-

a:

-1

w

0::

-8

-4

o

4

8

RELRTIVE VE LOCITY
eMMIS VS BRRIUM STR NN RTE)
Fig. 2. In situ (a) and ex situ
spectra of 119Sb on gold foils.

(b)emission Mossbauer

We reported previously that the substitutional 119Sb
atoms in an Au matrix give a single line of an isomer
shift of 1.83 mm S-l at 78 K.3) The emission spectrumof 119Sb in antimony metal consists of a single linewith an isomer shift of 2.68 mm S-l at 78 K.4) We
ascribe the component in the in situ spectrum with
an isomer shift of 1.66 mm S-l to 119Sb atoms on thesurface of gold foil and the other with that of
2.72 mm S-l to 119Sb in antimony metal. The amount110

S. Ambe, et ai.

of antimony in the electrolyte «300 ng) is estimatedto have been smaller than the calculated value
for a monolayer deposition on the foil. The 119Sb
observed in antimony metal suggests that antimony
atoms form aggregates of metal instead of depositing
homogeneously.
A spectrum of 119Sb on the gold washed withethanol and dried after electrodeposition is shownin Fig. 2 (b). The spectrum also consists of two singlets having almost the same isomer shifts as thoseof the in situ spectrum. This result suggests thatwashing and drying cause no appreciable change In
the chemical states of electrodeposited 119Sb.
References
M. Bellemare and J. C. Roy: Nucl. Instrurn. Methods,
97, 131 (1971) .
2) W. Parker, M. Croes, and K. Sevier: Nucl. Instrurn.
Methods, 7, 22 (1960) .
3) I. Tanaka, S. Nasu, F. E. Fujita, F. Ambe, S. Ambe, andT. Okada: ]. Phys. F, 16, L151 (1986) .
4) F. Ambe, S. Ambe, H. Shoji, and N. Saito: J. Chern.
Phys., 60, 3773 (1974) .
1)

111
RIKEN Accel. Prog. Rep. 20 (1986)

Mossbauer Spectroscopic Studies of Ruthenium Compounds

111-3-16.

Y. Kobayashi, M. Katada, H. Sano,* T. Okada, K. Asai,
S. Ambe, and F. Ambe

Ruthenium belongs to the secondary transition elements and displays ten oxidation states from - 2, 0
to + 8. 1) Consequently, studies of the valence stateand electronic configuration in ruthenium compounds
have attracted much attention of many investigators.
However, chemical applications of the Mossbauer
effect in 99Ru and 101Ru have been limited by theexperimental difficulties: both the source and absorber must be kept at liquid-helium temperature,a thick absorber must be used because of a low
recoil-free fraction and both 99Ru and 101 Ru have
only short-lived source nuclides. In this period, aMossbauer absorption spectroscopic investigation wasstarted by using an absorber of ruthenium powder
metal, in order to obtain useful information on thechemical environment around the ruthenium nuclei
in ruthenium compounds.
The source nuclide 99Rh was produced by the
99Ru(p,n) 99Rh reaction (Fig. 1) on ruthenium metal
with 13 MeV protons in the cyclotron. This method
for source preparation was essentially similar to thatgiven by Kistner 2 ,3) and Mossbauer et al. 4 ) Naturalruthenium metal of purity 99.9% (216 mg/cm 2 ) was99

Tc

packed in a source holder (Fig. 2) made of aluminium and covered with aluminium foil; the diameterof the source holder was 30 mm. During bombardment, cooling water was circulated on the back sideof the holder. Three days after bombardment, ther-ray spectrum of the irradiated ruthenium metal in
the holder was measured with LEPS (Low-Energy
Photon Spectrometry) to determine produced nuclides. The results are shown in Fig. 3. Although
not only 90 keV Mossbauer transition r-rays of 99Rh
but r-rays of 100Rh (T 1/2 = 20.8 h) from 100Ru and101+101mRh (T1/2 = 4.3 d) from 101Ru were observed
because natural ruthenium metal was bombarded,
the radioactivities of non-Mossbauer nuclides decayed
more rapidly than 99Rh and the signal-to-noise ratio
was improved after 10 d. The source was used for the
Mossbauer spectroscopic measurements over 2 months
after preparation.
It is necessary to obtain a Mossbauer spectrum atvery low temperature because the Mossbauer transition energy is very high (Fig. 1) and the DebyeWaller factors for most ruthenium compounds are
significantly lower than that of ruthenium metal. A
Dewar bottle, Model HD-700 (Ranger Inc.), wasused after slight improvement for cooling both source
and absorber to liquid-helium temperature. The capacities for liquid helium and liquid nitrogen of the
Dewar were 5 and 2 dm 3 , respectively, with a helium
consumption rate of 0.11-0.12 dm 3 /h.
Absorption spectra were recorded on a multi-chan-

322.4

~M

mKEN Accel. ,'rog r. Rep,

89.8

Fig. 1. Energy level diagram for 99Ru.

100~~~~~~~~~~~~~~~~~~~-rFig. 2. Source holder made of aluminium.

* Department of Chemistry, Faculty of Sciences, Tokyo
Metropolitan University.

o500
Energy (keV)

1000

Fig. 3. r·Ray spectrum of proton-irradiated natural ruthenium metallic powder.

Y. Kobayashi, et ai.

112

~

100

NaI (TI) crystal. Velocity calibration for ruthenium
spectroscopy was accomplished by measuring thespectrum of 57Fe in pure iron foil.
A Mossbauer spectrum obtained with an absorberof ruthenium metallic powder is shown in Fig. 4.
The line width of the singlet line in our work was
0.25 ± 0.01 mIls, which was slightly narrower thanthose given in other reports. 2 - 4 ) The absorption was
1.56 ± 0.05 %, almost in good agreement with thereported results. 2 - 4 )-=?--j.:j~~;:?·!.·(:~,:.:;.\.;,...x. .:~s;~
-~

I

I

o

-2
Ve lo ci ty

2[mm / se c]

Fig. 4. Mossbauer spectrum of ruthenium metallic powder(223 mgjcm 2) at liquid helium temperature.

nel analyzer, Model ECON-2 (Northern Inc. ) , connected with a driving unit, Model VT -200 (Ranger
Inc.) , and a scintillation detector with a 2-mm thick

References
1) S. E. Livingstone: Comprehensive Inorganic Chemistry,
Vol. 3 (eds. J . C. Bailar, Jr., H. J . Emeleus, Sir R.
Nyholm, and A. F. Trotman-Dickenson), Pergamon
Press, Oxford, Chap. 43, p. 1190 (1975) .
2) O. C. Kistner, S. Monaro, and R. Segnan: Phys. L ett.,
5, 299 (1963) .
3) O. C. Kistner: Phys. Rev., 144, 1022 (1966) .
4) G. Kaindl, W. Potzel, F. Wagner, U. Zahn, and R. L.
Mossbauer: Z. Physik, 226, 103 (1969) .

113
RIKEN Accel. Prog. Rep. 20 (1986)

111-4.

Radiation Chemistry and Radiation Biology
1. High-Density Excitation by Heavy Ion: Techniques ofSubnanosec Measurement of Emission Decay and a
Track-Scope Using Optical Fibers
K. Kimura, A. Fundoh, T. ~ishina, K. Kanai,
T. U eno, and M. Kataoka

One of the most characteristic irradiation-effectsof heavy ion is the high-density excitation of electrons in an outermost shell. All high energy statessuch as ions, excited states of inner-shell electrons,
and high Rydberg states are converted into lower
excited states of an outermost shell through ionelectron recombination, Auger effects, and internalconversions.
We have been concerned with direct observationof the high-density effect using techniques of measuring emission spectra and its decay. This report
describes two new techniques to elucidate dynamics
of excited states formed at high density and to observe emission spectra along the path of ion-tracks,
in other words, track-depth-resolved emission spectra.
(1) Emission-decay measurement with 100 ps
resolution
Most of lower excited molecules decay in a few
ns in FWHM in the isolated system. In the highdensity excitation by heavy ion, excited states interact with each other to shorten their lifetimes orsometime to convert other excited states or to produce clusters of excited states as shown by our previous studies. 1 ,2}The observation of such processes requires ameasurement technique with a resolution shorter
than ns. If this is possible, one may expect to observe some of the second order processes such as thecase mentioned above. We have already reported atechnique with 1 ns time-resolution. 3 } In this system, a single-ion hitting and single-photon counting
technique was developed along with a coincidence
technique. A timing pulse to inform the timing ofion hitting was generated by a photomultiplier which
detects photons emitted from a thin scintillator foil
penetrated by an ion. The limiting step of this system is the time-resolution of photomultiplier and thelifetime of emission from the scintillator-film. Resultant resolution was therefore limited to about 1 ns.
This system is, however, characterized by the meritof an infinitesimally short pulse-width of ion becauseof single-ion hitting. Therefore, the faster detector

Fig. 1.

Block diagram of detectors and the circuit.

can be developed, the better time-resolution can beobtained. Now, we adopted an Map (micro channel
plate) to obtain a fast timing pulse of the ion hitting
and constructed a measuring system shown in Fig. 1.
An ion passes through an assembly of two coaxial
copper-cylinders before, hitting a target. These twocylinders are isolated electrically and have entrance
orifices of 1.5 mm in diameter and exit orifices of
2 mm in diameter. An Map (Hamamatsu Photonics,
a tandem of type FI551-21) is mounted behind acopper plate (with an orifices of 1 mm in diameter)
placed at the bottom of the inner cylinder. A thincarbon film of 50 p.g/cm2 is attached on the entrance
orifice of the outer cylinder. This assembly is placedin a static magnetic field which is adjustable in intensity. Secondary electrons emitted by penetration of
ion through the carbon film are accelerated to 2 keV
between the outer and inner cylinders and bended
by the magnetic field toward the copper plate at thebottom of the inner cylinder and eliminated by theorifice. Thus, only secondary electrons which have thesame kinetic energy and an orbit with a definite curvature and path length can attain Map; thus Map can
generate a precise fast timing pulse. One may expect
at least 100 ps time-resolution for the timing of ion
hitting, since the rise-time of Map is known to be below 100 ps. To amplify such a fast pulse, a fast preamp was developed, which was composed of micro

K. Kimura, et al.

114

2560,----.-----.----~----._----._--_,----~

r10nsec

)1

...J
W

z

Z1540
q:
:r:

u

"t-

CJ)

Z
::J

8 510
°22~0~--~--~~----~--~4~7=
6----~~~~---....l

CHANNEL NUMBER

Fig. 2. Resolution of the detector, measured using a system
shown Fig. 1 and 1.32 MeV /amu Ar4+ ions.

PC 1652G by NEC, resulting in a specification of
38 db at 1 GHz. The time-resolution of this assembly was measured by a coincidence technique shownin Fig. 1 using T AC whose start pulse was given
from the above assembly and whose stop pulse wasgiven by PPAC (Parallel Plate Avalanche Counter)
developed by one of present authors.4) The resolution of PP AC was ascertained using 1.3 Me V / amu
Ar ions from RILAC to be 199 ps in FWHM. Using
the same projectile, the time-resolution of the present assembly was estimated to be 481 ps from Fig. 2
which displays pulse counts us. channel number(44.2 ps I channel). Although this resolution is as low
as 1 /5 of the expected one, the time profile given
in Fig. 2 shows a fairly good symmetric structure;
this suggests that the · time-jitter is not due to thetime-retardation caused by miss matching of the detector system. The value of 481 ps is 1.9 of the flighttime of Ar ions from the carbon foil to PPAC. The
former may be considerably improved by narrowing beam slits and the latter can be reduced byusing a thinner foil (a few pg/cm 2 ). Actual
measurement of emission decay will be facilitated byusing a MCP-mounted photomultiplier (Hamamatsu,
R1564) whose lifetime is below 100 ps.
(2) Track-depth-resolved emission spectra
Excitation processes by ions, e.g. knock on collision, glancing collision, and charge exchange, aredependent on ion energy. The effect of secondary
electrons, sort and population of excited states, andcharge number of ions produced are also energydependent. In condensed matter, a large density
effect is added to the above ones, and also all eventsoccur in a microscopic range. If these events andtheir dynamics can be observed directly along thepath of ion track, this must be a goal of the subjectof eluciation of radiation effect. However, it is
too difficult to measure the track by separating it
into sections as small as sub pm. Then, we havemade measurements on high-density He gas, in whicha track length becomes 11 mm for 5 MeV / amu Nions; these experiments have been previously re-Fig. 3. Track-scope for measurement of track-depth-resolved
emission-intensity.

ported. 1 ,2) A result shows that emISSIon efficiencies
for most peaks, dL/ dE, increase with increasing
penetration depth, and the increase continues still tothe region where the stopping power tends to decrease from its maximum value. This was explained
to be caused by the decreasing of track-radius, increase in probability of direct excitation, and charge
exchange, based on another result that helium excimer-excimer collisions doesn't lead to nonradiative
processes, in contrast with usual scintilla tors andmolecular photochemical processes. Furthermore, existence of the pumping cycle from nonradiative statei.e., 3 a to higher radiative states seems to suggest an
increase in the lowest state, lA, the emission fromwhich is at 800 A and considered most intense. We
developed a new simple track-scope for precise observation of UV- and VUV-emission intensities particularly in a region of decreasing stopping power
after passing through its maximum value by using
samples at high-density. The scope is composedof a linear array of quartz fibers as shown in
Fig. 3. A terminal of the array was coated withsodium salicylate to convert VUV light to UV witha peak at 420 nrn and was set close and laterally tothe tracks. Light from another terminal was focusedon a photoplate of an OMA (Optical Multichannel
Analyzer by Princeton Applied Research) to countphotons from each fiber simultaneously. Thus, thisscope enable us simultaneously to measure the trackimage of UV- and VUV-emission with a resolutionof 50 pm. Namely, the measurement can be done
independently of instability of ion current. Calibration of photosensitivity having been finished, measurement will be made in the next beam time.
References
1) K. Kimura: ]. Chern. Phys., 84, 2002 (1986) .
2) K. Kimura: ]. Chern. Phys., 84, 2010 (1986) .
3) K. Kimura, K. Mochizuki, T. Fujisawa, and M. Imamura: Phys. Lett. A, 78, 108 (1980) .
4) H. Kumagai, S. H. Be, M. Ishihara, Y. Ikegami, M. Fuse,
and E. Gotoh: RIKEN Accel. Prog. Rep., 18, 164 (1984) .

115

RIKEN Accel. Prog. Rep. 20 (1986)

111-4-2. Modification of a-Particle-I nduced Cell Killing and
Non-Repairable D'NA Lesion by Hypertonic Treatment
T. Kosaka, 1. Kaneko, K. Eguchi-Kasai, K. Nakano, and A. Maruhashi

The cell killing effect by low linear-energy-transfer (LET) radiation is enhanced by exposing thecells to an anisotonic solution. 1 , 2 ) The hypertonic
treatment carried out immediately after r-radiation
inhibited the rejoining of DNA double strand breaks(dsb) ; this results suggested that the low LET radiation-induced cell damage sensitized by hypertonic
solution is closely related to non-repairable DNA
lesion. 3 )The present report describes that the hypertonic
treatment enhances the cell killing caused by aparticles ( 22 MeV) possibly owing to the inhibitionof the rejoining of DNA dsb induced by a-particles.
Chinese hamster HA-1 cells were used throughout
the experiment. Cell survival is assayed by a colony
formation technique, and DNA dsb by a neutral
filter elution technique. 4 )The survival curve of HA-1 cells irradiated withr-rays or a-particles are shown in Fig. 1. The cell
survival after irradiation with r-rays or a-particles
was reduced by the hypertonic treatment. The survival curve obtained with r-rays has two components: an initial shoulder region followed by a linearresponse region. The hypertonic treatment carried

0.001 L -_ _ _ _ _ _ _ _--'

Fig. 1. Dose survival curves for HA-l cells. Cells irradiatedwith r-rays (0 ) and a-particles (0), r-rays followed byhypertonic treatment (e) and a-particles followed by h ypertonic treatment (.).

0 .15

'0
C

~

til 0 .10
Q)

15
:J

o

'0

'0
Q;

E 0.05
::J

c

OJ

>

'0

a:i

0:

a

20

40

60

SO

Dose (Gy)Fig. 2. Dose-response curve for non-repairable DNA lesionin HA-l cells. Relative number of double strand breakin DNA of cells irradiated with r-rays ( 0 ). a-particles(0 ), r-rays followed by hypertonic treatment (e) anda-particles followed by hypertonic treatment (.).

out immediately after r-irradiation strongly reduced
survival. The survival curve with a-particles is foundto be linear against absorbed dose. The hypertonic
treatment followed by a-particles irradiation slightly
enhanced the cell killing.
The dose-response curve for non-repairable DNA
lesion caused by r-rays or a-particles after incubation
at 37°C for 14 h are shown in Fig. 2. The nonrepairable DNA lesions increase with an increasein absorbed dose of r-rays or a-particles. The dose
response curve of the non-repairable DNA lesion
caused by r-irradiation has also two components:
an initial shoulder region followed by a linear response region. The hypertonic treatment after rirradiation enhances the non-repairable DNA lesion
and affected the shape of the shoulder and thelinear-response region of the non-repairable DNA
lesion. The dose-response curve obtained by a-irradiation is found to be linear against absorbed doseas described. The hypertonic treatment after irrradiation slightly enhanced the non-repairable DNA
lesion. These dose-response curves were found to bea mirror image of the survival curves obtained witha-particles and r-rays. The relative number of dsb

116

T. Kosaka, et al.

(RN) was calculated from minus logarithm of thefraction retained on the filter at 15 ml of fraction.
The values of D37 are obtained from equivalentdoses of 37 % cell survivor. RNs at D37 for rirradiation alone, for r-irradiation followed by thehypertonic treatment, for a-irradiation alone, andfor a-irradiation followed by the hypertonic treatment are 0.0016, 0.0019, 0.0016, and 0.0024, respectively. These cell damage caused by a-particles aswell as that caused by r-rays, and cell killing caused

by ionizing radiation relates to the amount of the
non-repairable DNA lesion.
References
1) H. Utsumi and E. E. Elkind: Radiat. Res., 77, 346 (1979) .
2) G. Raaphorst and W. C. Dewey: Int. J. Radiat. Bioi.,
49, 383 (1979) .
3) T. Kosaka, I. Kaneko, and H. Koide: Unpublished data.
4) M. O. Bradley and K. W. Kohn: Nucleic Acids Res., 7,793 (1979) .

117

RIKEN Accel . Prog. Rep. 20 (1986)

111-4-3.

Oxygen Effect on DNA Double Strand Breaks in Human
Melanoma Cells Induced by a-Particle BeamK. Eguchi-Kasai, 1. Kaneko, A. Maruhashi, T. Kosaka,
T. Takahashi, and K. Nakano

Reduction in the oxygen enhancement ratio(OER) in cell inactivation is one of the major
features of high-LET radiation. 1 ) The reason forthe small OER value in comparison with those for
low-LET radiation has not been entirely understood. We have made a special apparatus to irradiate
cultured cells with an a-particle beam from thecyclotron under hypoxic conditions and have examined the OER effect on inactivation of humanmelanoma cells (NMV-I) .2) Here, we describe theoxygen effect on DNA double strand breaks (DNAdsb) induced by a-particles in HMV-1 cells.
Procedures for gas replacement and irradiation
have been described previously.2) Oxygen concentration in the culture medium surrounding cells wasless than 2.5 ppm. Linear energy transfer (LET)of a-particles in the cell was 77 keY / f.1.m. DNA
dsb was detected by a neutral elution method, bywhich DNA dsb can be sensitively detected witha low detection limit of 3 Gy.3) Relative number of
DNA dsb was shown on the ordinates in Figs. 1,a nd 2 in arbitrary units (minus log F). The curvesin these figures were fitted to a linear-quadratic
relationship by linear regression analysis.
Total DNA dsb induced by 60 00 r-rays increased
quadratically with dose under both hypoxic and
1.o,....-------,----r----,-10 l o g Fr------r---.---,.-----r----.-..,-----,r-----r-,-------,(al

Co-ldsb

18 -22 h
/

10
/

0

/
/
/0
/

Aer.

/

5

/

././

Hyp.

O~~~~~L-~--L-~-J-~~~~500

o

100

200

300

Dose (Gy)

I

I

(b) _

r- oc-particles
dsb.1S -20 h/

0.4 r-

./

-

LL

f--

01
I

0,2 r--

0

-

~"

~

.

1."I"~"!o"",......-

",".

-

/

/0
/0

/

-

f--

'J:/~ ;!...-:!O~_o
I

I

0

50

100

Dose (Gy)Fig. 2. Oxygen effect on non-repairable DNA dsb in humanmelanoma cells (HMV-I). a, 60CO r-ray; b, a -particle.

co-r
dsb .Oh

0 .8

0.6
LL

Aer.

Ol

o

0,4

0.2

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

°

50

100

150

Dose ( Gy )Fig. 1. Oxygen effect on DNA dsb induced by 60CO r-ray
in human melanoma cells (HMV -I) .

aerobic conditions (Fig. 1). Much enhanced DNA
dsb was induced under the aerobic conditions thanunder the hypoxic conditions. The OER value forthe DNA dsb was 1.6 at a 300-DNA dsb level.
Total DNA dsb can be divided into two classes:
repairable and non-repairable dsb. About 3/4 of thetotal DNA dsb induced with r-rays was rejoined
during post-irradiation-incubation at 37°0. The re,pairable DNA dsb might not playa important rolein the cell inactivation. The DNA dsb remaining
after incubation is considered to be non-repairable.
The non-repairable DNA dsb also quadraticallyincreased with dose and was much more induced
under the aerobic conditions than under the hypoxic
conditions (Fig. 2a). The OER value for the nonrepairable DNA dsb was 1.6 and the same as that

118

K. Eguchi-Kasai, et al.

for the total DNA dsb. This result suggests thatoxygen has no effects on the repair of DNA dsb
induced with r-rays. Thus, only non-repairable
DN A dsb was detected after irradiation with aparticles. Non-repairable DNA dsb induced by aparticles increased almost linearly with dose andwas induced much more under the aerobic conditions than under the hypoxic conditions (Fig. 2b).
The OER value for the non-repairable DNA dsb
was 1.9.
The OER value of a-particles cannot be directlycompared with those of r-rays, because of the difference in the shapes of the curves. Thus the numbers of non-repairable DNA dsb per cell at 37 %survivor were calculated from every fitting curve.
They were almost constant among 4 curves in spiteof the differences in radiation quality and irradiation
conditions. This result indicates that the non-repairable dsb closely relates to cell inactivation inducedby radiations.
References
1) E. A. Blakely, C. A. Tobias, T. C. H. Yang, K. C. Smith,and J. T. Lyman: Radiat. Res., 80, 122 (1979) .
2) K. Eguchi, I. Kaneko, T. Kosaka, T. Takahashi, and
K. Nakano: RIKEN Accel. Prog. Rep., 19, 136 (1985) .
3) M. O. Bladley and K. W. Kohn: Nucleic Acid Res., 7, 793(1979) .

119
RIKEN Accel. Prog. Rep. 20 (1986)

111-4-4. Calculation of Dose around the Path of an Ion andMicrodosimetric Considerations of the Effects of
Heavy Ions on Microorganisms
T. Takahashi, F. Yatagai, S. Konno, T. Katayama,
K. Izumo, and T. Tabata*

Reliable evaluation of the dose around the trajectory of an ion is essential for interpretation of theinactivation cross sections of microorganisms. Recently, Hansen and Olsenl ) reported that a modified
Katz's energy deposition formula, to which they
introduced a parameter a,2) successfully explains the
response of a radiochromic dye film dosimeter tohigh LET radiations when a was chosen to be 1.67.
This parameter appears in the range energy relationof electrons, R = kwn:, where Rand Ware the range
and energy of electrons, respectively, and k is aconstant. As to our data on inactivation cross sectionof E. coli, however, a lower value of a, very close
to unity, seems appropriate. To overcome suchdifficulty, we have calculated the dose around thepath of an ion by using Tabata and Ito's energy
deposition algorithm for electrons. 3) This algorithm
is an improved version of that used by Kobetich andKatz,4) and gives a better fit to data over a wider
range of electron energy.
( 1 ) Calculation of the dose DT around the pathof an ion
As a first step, secondary electrons were assumed
to be ejected perpendicular to the path of an ion. 5 )The number of the secondary electrons with energies
between Wi and Wi + (.dw) i generated per unit
path length of a heavy ion is given by(1)

Here, C is a constant ( C = 0.85 ke V /100 p.m forwater), the effective charge Z* e is given by Z* e =Ze [1-exp( -125,8Z-2/3) ] (Ze is the nuclear chargeof an ion,) and ,8 is the ratio of the velocity of theion to that of light.
Electrons are taken to be initially free 5 ) (thoughvery weakly bound to a water molecule) andsecondary electrons having energies more than 1 eVwere taken into account. Energy deposition D j wascalculated in the jth shell, which is located between
radii x = Xj and x = Xj + (.dx) j from the trajectoryof an ion:

* Radiation Center of Osaka Prefecture.

D j =4J, (Lln)iE iiL1x)j(2)

where Eij is the effective stopping power at x = Xj
for an electron with energy Wi and is given by
Tabata and Ito to be Eij=1f(Xj) and y'( x) =d- dx [1)(x) T(x)J. Here, 1)(x) is the . transmission
coefficient, i.e., the fraction of the number of incident electrons at the depths 2:::x and T (x) is theratio of the total kinetic energy deposited at thedepths ~x to the number of electrons deposited at
the same region of depth. T ( x ) and r; ( x) are
analytically given in Ref. 3 for a semi-infinite halfspace ~x, and the calculated values for r; (x) andT ( x) were assumed to be applicable approximately
to the present situation. The effective atomic number and atomic weight of water were calculated tobe 7.22 and 13, respectively, according to Ref. 3.
Since the range-energy relation of electrons plays animportant role in these calculations Tabata and
Ito's extrapolated range Rex is compa;ed below withthe ranges given by other authors. It is larger thanBooz and Smith's R95 for T. E. gas 6 ) or Rcsda inwater given in ICRU 16,7) but smaller than Butts
and Katz's range RBK for water below about 1.5 keY.
From about 3 ke V to about 10 keV, Rex is larger
than RBK but a little smaller than Rcsda given in
Ref. 7. The density of energy delivery (erg / cm 3 )DT (x j) at the distance x j from the trajectory of anion is easily found to beDT(Xj) = ~ (Lln)iEi /(2n:x j )(3),and is compared with Butts and Katz's dose D KZ ( x) /)where the constant a was taken to be unity and thetransmission coefficient was not taken into consideration (Fig. 1). DT(Xj) was calculated from 1 A to
Rex with appropriate intervals, and the results werestored as "tables" in a computer disk.
(2) Normalization of D KZ and DT to LET
Both D KZ (x) and DT (x) mentioned above are
essentially doses due to close collisions. In a previous
paper,2) D KZ added by D p , which includes dose due
to distant collisions, was denoted by D KA , and00

T. Takahashi, et al.

120

1.2

E.coli B S-I
Eo = 1.26 krad

N ion
x Cion• He ionA- - DK:-J----- DTN

1.0-'-'- D(a= 1.67);;;,_--------------N.. ;. . . . r....

,,;.~,#

N

~

-C

.2
u
<.J

r.f)

~ 0.6

c

U

c:
.S

ro

of

~ 0.4

..:;

0.2

lOlL:--:-S. - - - - - --:-'7--,;----710~--;~ --~10-3
10O
x (em)

Fig. 1. Comparison of Dxz (x) (solid line) and DT (x)(dotted line) for ions with 4 MeV lu. DKN (x) is equal toDxz (x) and DTN (x) is equal to DT (x) in the region x>
I A from the path of an ion.

27t'

Jr~lA XDKA(X) dx was found to be nearly equal to

LET

7

)
Therefore it seems reasonable to normalize
and DT to LET as in the case of Chatterjee
and Schaefer's dose. The normalization of the dosein water was made by the use of following equations:
00.

D KZ

00,

DKN(X)=D(Xl)

X~Xl

(4)

DKN(X)=DKZ(X)

X>Xl

(5)

Here, DKN is Butts and Katz's dose normalized to
LETIn the present paper, Xl was chosen to be
1 A and D ( Xl) was determined so as to fulfil thefollowing equation:
00 .

7t'X12D(Xl)+27t'

roo XDKZ(x)dx=LEToo

(6)

J.~1
No difference in the calculation of inactivation crosssections was found when Xl was chosen to be 10 A
or 20 A. Since the situation was the same for D T ,it was also normalized by Eq. (6) when D KZ wassubstituted by D T • The normalized DT is denotedby D TN , hereafter. The second term on the left-handside of Eq. (6) is about 80% of LET for D KZ andabout 85% for DT (for Xl = 1 A) in case of N, C,
and He ions of several MeV / u.
(3) Mean dose absorbed with a sensitive element
If a sensitive element is a short cylinder of radius
a whose axis is parallel to and at distance r fromthe path of an ion, the mean absorbed dose 15 (r) is
calculated from Eqs. (7) and (8) in Ref. 8 for DKN
and D TN • The core radius Xl is assumed to be 1 A
00

,-..J

Energy (MeV/u)

Fig. 2. Inactivation cross section S as a function of energyof ions for E. coli B s - 1 ' Solid lines are calculated using
DKN and dotted lines using D TN ; dot-dashed line is calculated by modified Katz's dose D (a = 1.67) .

as a constant but this rough approximation does notcause any erroneous effect on jj (r ) if Xl is chosen
to be sufficiently small.
(4) ' Analysis of inactivation cross section by DKN
and DTNThe inactivation cross section of E. coli BS-I was
analyzed by use of DKN and DTN by the same procedure as in Ref. 2. From least squares analysis, by
the use of D KN, the area of the sensitive element was
found to be 7t'a 2 = 0.50 flm 2 for E. coli Bs - 1 . The
experimental inactivation cross sections were also
well explained by use of D TN , as shown in Fig. 2,
but deviation is obvious for the modified Katz's dose(a = 1.67) 1) as mentioned above. When Hansen and
Olsen's constants a = 1.67 and k= 5.11 X 10-11 in theequation R = kwa are chosen, the range of electronsof energy 10 keY is close to that given in ICRU
37,7) but only about 60% of electrons are transmitted to the region X > R ex/ 2, according to thecalculation based on Ref. 3. Therefore the modified
Katz's dose (a= 1.67)/) in which the transmission
coefficient is not taken into account, seems to overestimate the dose at least at the region r> Rmax/2,
where Rmax is the range of a-electrons with maximum
kinetic energy. The authors have also analyzed inactivation cross sections for vegetative cells of E.
coli Blr and of B. subtilis spores to heavy ions with

T. Takahashi, et al.

the same procedure as in Ref. 2; details will be
published. 9 )References
1) J. W. Hansen and K. J. Olsen: Radiat. Res., 97, 1 (1984) .
2) T. Takahashi, F. Yatagai, K. Izumo, S. Konno, and
T. Katayama: RIKEN Accel. Prog. Rep., 19, 138 (1985) .
3) T. Tabata and R. Ito: Nucl. Sci. Eng., 53, 226 (1974) ;T. Tabata and R. Ito: Jpn. J. Appl. Phys., 20, 249(1981) .
4) E. J. Kobetich and R. Katz: Nucl. Instrum. Methods,
71, 226 (1969) .

121

5) J.J. Butts and R. Katz: Radiat. Res., 30, 855 (1967).
6) B. G. R. Smith and J. Booz: 6th Symp. Microdosimetry(eds. J. Booz and H. G. Ebert), Vol. 2, Harwood
Academic Publishers, Ltd., London, p. 759 (1978) .
7) ICRU Report 16, Linear energy transfer, International
Commission on Radiation Units and Measurements(1970); ICRU Report 37, Stopping power for electronsand positrons (1984).
8) T. Takahashi, F. Yatagai, and S. Kitayama: Adv. SpaceRes., 3, No.8, 95 (1983) .
9) T. Takahashi, F. Yatagai, S. Konno, T. Katayama, and
I. Kaneko: Adv. SPace Res., 5 (in press) .

122
RIKEN Accel. Prog. Rep. 20 (1986)

111-5. Instrumentation
1.

Calibration Test of Si-Detector Telescopes with Large Geometric
Factors for Isotope Identification in the Heavy Cosmic
Ray Particles
T. Doke, N. Hasebe,*l T. Imai, J. Kikuchi,*2 T. Kohno, K. Nagata,*3
A. Nakamoto,*4 H. Murakami,*4 S. Yanagita,*5 and T. Yanagimachi*4

In the GEOTALL mission/) which will belaunched in 1992, .dE-E silicon detector telescopeswith large geometric factors are planned to be used
for observing the isotopic abundance of heavy solar
flare or galactic cosmic ray particles. Recently, thefirst models of position sensitive .dE silicon detectors(.dE-PSDs) to be used in the .dE- E detector telescopes were made by the Hamamatsu Photonics Co.
and the thickness uniformity, the energy resolution,and the position resolution of them have been investigated by using heavy-ion beams from RIKEN
Ring cyclotron.
In the experiment, two JE-PSDs (No. 312 and313) of 26 mm X 26 mm in size and --30 pm inthickness and one .dE-PSD (No. 317) of 50 mm X
50 mm in size and --250 pm in thickness were tested
for helium ion beams of 10 MeV In and nitrogen ion
beams of 5.7 or 6.0 MeV In. The thin .dE-PSDs are
the models of .dE-detectors to be used in the HEPMI sensor in the GEOTALL mission and the thick.dE-PSD for the HEP-HI sensor.l) The thickness,the energy resolution, and the position resolution inthese detectors depend on the incident position of
the beam. To simultaneously measure them, a copper plate of 0.6 mm in thickness, in which 81 holesof 0.5 mm in diameter are drilled in the matrix of
9 X 9 with the equal interval of 5 mm, was placed
21 cm apart from a target, made of gold foil of
2.32 mg/cm 2 in thickness, at the angle of 30° tothe beam direction, and then a .dE-PSD to be investigated was set just behind the copper plate used
as a collimeter. If .dE-PSD has a linear responseon position, its output should show a pattern withsquare geometry.
*1 Faculty of General Education, Ehime University.
*2 Science and Engineering Research Laboratory, Waseda
University.
*3 Faculty of Engineering, Tamagawa University.
*4 Faculty of Science, Rikkyo University.
*5 Department of Earth Science, Ibaraki University.

Thus obtained 2-dimensional pattern in thick .dEPSD No. 317 is symmetric, but remarkably deformed
compared with the original pattern of square geometry as shown in Fig. 1 (a) and (b). Here, (a)was obtained for nitrogen ions of 6 MeV I nand (b)for helium ions of 10 MeV I n. In both cases, the central part is expanded and the side part compressed.
To remove such deformation, JE-PSD with a newreadout electrode system,2) which is expected to havea good linear response, is being developed. Nitrogenions bombarded stop inside the detector, while helium
ions penetrate the detector. The deposited energy
in the fonner, therefore, is remarkably large compared with that in the latter, an excellent position
resolution is expected for a nitrogen ion beam. Thus,. .. ....-:,_

.t .~

.! '

.-".- .- -'-

ta l

.

,.,

• J.

,

..j

• I'.1·., .i .,l• I.\ ..•.

Ii:; ':"

'

.
-1

- 1

.

'"

x

x

Fig. l. Two dimensional patterns obtained by thick L1EPSD (No. 317). (a), for nitrogen ion beam of 6 MeV / n;(b), for helium ion beam of 10 MeV In.

123

T. Doke, et al.

(a)
M: 17 . 17

F: 0 . 64
3.70%

H: ) 7 . 16

F;

0 . 774 . 48';

M: 17 . 79
F: 1 . 06
5.98X

H: 17. B4
0 , 854 . 75%F:

M: 17 . 65
0 . 653 . 70X

M: 18 . 71
I. 02
5 . 47:>:

M: 17 . 93
0 . 613 . 4UF:

F:F:

M: IB .3J
0 . 94

M: lB. 33
F: 0 . 74.1 . 62%

5 . 13X

4 . 03X

1 . 12
6.23%

O. B6
4 . 70X

M: 18. OB
F: O . B4

F'

d
I. 36

M: lB . 07
F: 1 . 2 4

7,73X

6, Bll;M: 17 . 58

F:q
M: 17 . 43
F: 0 , B8F:

5.06.1:

1.06
5 . 95%

M: 17 . 37

M; 17 . 54

F:F:

0 . 623 . 58X

0.96
5 . 45%F:

M: 17. B2
0 . 85
4.75X

A

F:

b

M: IB . 30
F: 0 . 8B

c)
LlE Spectra
(b)
M:

F:

8 . BO
0 . 434 . B9';11 :B . 79

M:
F:

F:

B. B3
0 . 51
5.7)%

H:
F:

B . B4
0 . 53

H:F:

B . BI
0 . 495. 55X

M: 8 . 81
F:' 0 . 49
5 5BX

M:

B.BI

F:

0 . 47
5.33:>:

c)
M:
F:

0.43
4 . 94Xft

F:

5 . 95:>:'B. 80
0 . 434 . 90 X

M:

B . BO
0 . 424 . 76.1:

M:F'

8 . B4

F: 0 . 52

H:F:

5.87:>:

B. 92
0.65
7 , 27X

M:

B, BO

H:

F:

0.50
5.74X

F:

B.B3
0 . 47M:

B . B8H:

0 . 647 . 19X

F:

B . 790 . 46H:

B . B20.42

4 . 76';F:

B , 8\

0 . 404 . 56%5 . 37Xc)
M:
F:

B . B4
0 . 4839X

M:F:

B . 96
0.51

M:

F:

5 21X

8 . 810 ,43
4 . BBX

M:
F:

B. 9 I
0 . 47M:

8 . 82
0 . 42
4 .74%

d
M:
F:

B.92
0 . 53

f1:

F:

B . BBM:

F:F:

5 .9 6"

F:

9 01
0 51
5 . 70XP
LlE Spectra
Fig. 2. Energy loss distribution obtained by using thin .JE·PSD (No. 312) andthick .JE-PSD (No. 317). (a) Data of No. 312 for nitrogen ion beam of 6 MeV In;(b) data of No.317 for helium ion beam of 10 MeV In. Each energy loss distribution in (a) or (b) corresponds to that obtained at each hole in the matrix
holes of 5 X 5 taken with the equal interval of 5 mm in the collimeter plate.

124

T. Doke, et al.

the pOSItIon resolution in (a) is simply limited by
the size of the collimeter holes. For the helium ion
beam, the position resolution roughly agrees withthat estimated from an electronic noise level. On
the other hand, the data obtained by thin L1E-PSDs
show non-symmetric patterns as well as the remarkable deformation as in that for thick L1E-PSD. The
reason why such non-symmetric patterns were obtained is under investigation.
Figures 2 (a) and (b) show the energy distributions measured at 25 holes (= 5 X 5 matrix) takenwith an equal interval of 5 mm in the collimeter
plate for thin L1E-PSD No. 312 and for thick L1EPSD No. 317, respectively. The energy distribution(a) was obtained for a nitrogen ion beam of 6 MeV In
and (b) for a helium ion beam of 10 MeV I n. In
both cases, the width of the energy loss distribution
at the central part is the worst. This may be explained by taking the so-called "channeling effect"
into consideration. For both cases, the time constant of
the amplifier was long enough to collect all the produced charges to the collector. In the thick L1E-PSD,
the FWHM of the energy loss distribution for helium
ions of 10 MeV In except for the central region
agrees roughly with that estimated theoretically(--4.6%). In thin L1E-PSDs, however, the FWHMsof the distributions range from 1.2 to 2.5 times
larger than the theoretical one (--3 %) except forthe central part. These worse resolutions are considered to be due mainly to the microscopic nonuniformity in detector thickness.
The local fluctuation of thickness in L1E-PSD wasinvestigated by measuring the mean values of theenergy loss distributions for charged particles passing
through collimeter holes except for the central region.
The fluctuation of thickness in thick L1E-PSD No. 317
was ± 0.6 %, which is uniform enough to identify
the adjacent isotopes around Fe. In thin L1E-PSDs,
on the other hand, the fluctuations are ± 2.4% forNo. 312 and ±4.5% for No. 313, which includes
the systematic variation of detector thickness. If sucha systematic variation can be removed, thin L1E-PSD
with non-uniformity of -- ±0.57'0 would be realized.
References
1) T. Doke, N. Hasebe, J. Kikuchi, T. Kohno, A. Nakamoto, A. Nishida, K. Maezawa, H. Murakami, T. Terasawa, B. Wilken, S. Yanagita, and T. Yanagimachi:
Report of Sci. and Eng. Res. Lab., Waseda University,
No. 85-4, 22 July (1985).
2) T. Doke: Report of Sci. and Eng. Res. Lab., Waseda
University No. 86-7, 22 September (1986).

125
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-2.2He Spectrometer
T. Motobayashi, S. Satoh, * H. Murakami, * H. Sakai, ** and M. Ishihara

The (d, 2He) reaction is a useful tool in investigating spin-flip isovector excitation of nuclei because of its selectivity of AS = 1, ATz = + 1. 1 ) It isdifficult, however, to obtain experimental data withhigh statistics because the product of the (d, 2He)
reaction is an unbound di-proton system, which mustbe identified by measuring two protons in coincidence. The beam intensity is restricted to maintainthe counting rate of each detector low enough sothat the ratio of accidental coincidence events tothe true events is reasonably small and the pulses
from the detectors are not deteriorated.
One means to obtain good counting statisticsof 2He is to use detectors with large solid angles.
It can be achieved by setting the detectors at asmall distance from a target. However this does
not work properly by using standard detectors ofthick casing. These two detectors should be set close
to each other because the two protons are emitted
at a small relative angle (around 10° for E 2He =60 MeV). To overcome this difficulty we developed
Si-solid-state-detectors (SSD's) specially designed forthe 2He detection. They have a large effective area
compared with the size of the casing.
Another way to improve counting efficiency is toset many counters around a target. This can increasea total solid angle without increasing the counting
rate for each detector. We developed an SSD counter
array with 4-telescopes in a geometry of 2 X 2 matrix.
In actual measurement we employed two arrays. This
makes an increase in detection efficiency by about
50 times compared with the case of using only twotelescopes consisting of commercially available SSD's.
We also developed compact pre-amplifiers andshaping amplifiers to treat many signals from thecounter array. The whole system was used in themeasurements of the 90Zr (d, 2He) reaction at E d=
70 MeV at Research Center for Nuclear Physics,
Osaka University.
Figure 1 shows a schematic view of the SSD
counter array for 2He detection. Each telescope consists of one AE- and two E-counters. The 11E counters are 150-400 p.m thick surface barrier detectors* Department of Physics, Rikkyo University.
** Research Center for Nuclear Physics, Osaka University.

Fig. l. Schematic view of the 2He spectrometer.

and E-counters are 4.7-5.5 mm thick Li-drifted Si
detectors. Each detector is mounted in a casing of
27 X 27 mm 2 made of plastic. The active area ofthe detectors are about 20 X 20 mm 2. Protons originating in 2He are detected by the 11E- and first Ecounters, and the second ones are used as vetocounters to reject unwanted events arrising fromhigh energy protons and deuterons. In actual measurement, the slits of 15 X 15 mm 2 are set in frontof the detectors. The distance of the counter arrayfrom the target is 130 mm. This geometry gives thesolid angle of 13 msr for each telescope. The detection angle of one telescope is 10° apart from thatof the neighboring telescope. The effective solid
angle for detecting 2He by a pair of telescope isabout 3 msr for 60 MeV 2He.
The pre-amplifier system, which consists of hybrid
amplifier tips as main components, is set inside a
detector housing. Six shaping amplifier tips are set
in a one-span standard NIM module. Four such
modules are necessary to treat 24 signals from thetwo counter arrays. They are set near a scatteringchamber. The pre-amplifier system and the shaping
amplifier are electrically connected with parallel
twist-pair cables through multi-connectors.
Reference
1) D. P. Stahel, R. Jahn, G. J. Wozniak, and J. Cerny:
Phys. Rev. C, 20, 1680 (1979) ; T. Motobayashi, H. Sakai,
N. Matsuoka, T . Saito, K. Hosono, A. Okihana, M. Ishihara, S. Shimoura, and A. Sakaguchi: Phys. R ev. C, 34,
2365 (1986) .

126
RIKEN Acce!. Prog. Rep. 20 (1986)

111-5-3.

Parallel Plate Avalanche Counter-Application in the Coulomb Excitation StudyH. Kumagai, M. Fuse, E. Gotoh, M. Ohshima, *A. Hashizume, and T. Inamura

Multiple Coulomb excitation by heavy ions provides a useful means to obtain accurate transition
moments for up to high spin states (]::::: 20h oreven larger) in atomic nuclei model-independently.l,2)
A standard method used is to detect deexcitingrays in coincidence with scattered particles recordedwith a large solid angle; particles have to be detectedwith a position sensitive counter array in order tomake a kinematical correction for observed r-rays.
Here we report a particle counter system designed
for this purpose.
The parallel plate avalanche counter (PPAC) 3)
affords a large-size position-sensitive area for heavyions, has an excellent time resolution and highcounting rate capability, and is thus best suited tothe present application. We have so far constructed
several different types of PPAC and investigatedtheir fundamental characteristics,4) aiming at establishing basic techniques required for use in experiments at the RIKEN Accelerators. Some of thesecounters have already been used in atomic physics
experiments. 5 )For application to Coulomb excitation experiments
we have recently started to construct a new system
consisting of a scattering chamber and four built-in
modules of PPAC, as shown in Fig. 1. The counters
are arranged to cover a large solid angle for theparticle detection. Thin walls (1 mm thick) of thescattering chamber facilitate the detection of r-rays
using Ge (Li) detectors placed outside the chamber.
The gas volume for the PPACs is separated fromthe vacuum region with four windows each of which
is made of an aluminized Mylar film (2.5 pm inthickness, 75 mm X 81 mm in area). Each PPAC
module consists of three planer electrodes; an Xposition sensitive cathode (cathode-X), an anode,
and a Y-position sensitive cathode (cathode-Y).
They are placed in parallel 3 mm apart from one
another. Cathode-X consists of 20 strips of a thin
(40 pgjcm 2 ) gold layer evaporated on 2 pm thick
Mylar film. The strips are 4.5 mm wide and 110 mmlong and are spaced 0.5 mm apart. The anode isa 2 pm thick Mylar film, on both sides of which ar-* Japan Atomic Energy Research Institute, Tokai.

BeamCathode-X

Iso-Butan
6 Torr

o
I

50m01
,I

100mm
t,

1

I

Fig. l. Schematic view of the PP AC system designed for
the Coulomb excitation study.

40 pgjcm2 gold layer (100 mmX 100 mm in area)

is evaporated. Cathode-Y, made from a printed
circuit board, has 20 strips of a copper layer 4.8 mm
wide and 110 mm long with 0.2 mm inter-strip
spacing. All the contiguous strips in the cathodes
are connected to each other with resisters of 25 n.
The position detection is accomplished by using thecharge division technique for the charges induced on
the cathode strips by avalanche.
In processing the cathode signals, we have adopted
a new method which uses no charge sensitive amplifier: Signals from the counters are amplified in
low-noise, wide-band amplifiers without any shapingof signal pulses, and then fed to a charge-to-digitalconverter (QDC). Position infonnation is derived
from the digitalized data using a computer. Since
the shape of the pulse from PPAC is sharp, a shortpulse (--60 ns duration) can be used to gate the
QDC input. This enables the position detection of
the incident particles even at counting rates as highas some hundreds of kilo counts per second. This is
in contrast to the conventional method involving
pulse shaping time of typically 0.5 ps, which suffersfrom the pile-up effect when the counting rate ex-

127

H. Kumagai, et al.

(FWHM) values for the peaks ranged from 2.5 mm
to 3.3 mm in position. The present values are about
three times larger than the values typical for theconventional method, but good enough for the present application in view of the required position
resolution of 5 mm to 10 mm. Normalized numbers

ceeds 104 counts per second.
Figure 2 shows the position spectrum obtained bydetecting alpha particles from a 241Am source passing
through 16 holes (2 mm in diameter, 25 mm apartfrom one another) made on a screen placed in
front of the counter. Full-width-at-half-maximum

3.oor-----------.-__________. -__________. -__________~----------~

PP,J1S.004

I

I

I

I

Alpha Particle(Am-24l)

(a)

-

25mm

L;j

-

1.80

:z
:z

<
~ ~

I-

-

1.50

a.. ......
(/)

2.5mm

(f)

l-

S 1.20~2. 8mm.., 2. 7mm

-

o

u

H

3. 3mm

0.90

-

0.60

-

O·:~0_____----L)~I-~~9_9-.7--~)~I-\~1-00-----J~I-~\1~0-0----)L-~I~~9_7._8____~~11000

CHANNEL NUMBER

3.00r-__________. -__________. -__________~----------~----------~

PPAtlS.003

I

I

I

I

-

2.70

(b)

25mm

2.\0

L;:l

-

1.80

z
z

<
~ ~

I-

-

1.50

a.. ......

(/)

f.J

(f)

2. 6mml-10-. 2. 5mm

iH

2. 5mm

S 1.20iH 3. Omm

o

u

-

0.90

-

0.60

-

0.30

99'.9

97.7

100

99.4

_

oo~---~J~I\~~)~I\~~)~I~~~)~I~\--~IJoo
CHANNEL NUMBER

Fig. 2. Position spectra obtained for (a) X-axis and (b) Y-axis, using wide-band
amplifiers and QDC. Figures appearing at the bottom of the p eaks represent
normalized total numbers of counts for the respective peaks.

128

H. Kumagai, et al.

of counts for respective peaks, given in the bottomof the peaks in Fig. 2, indicate that the uniformityof detection efficiency better than ± 1 % is obtained.
References
1) B. Katalinski, A. Baecklin, D. Cline, C. Y. Wu, R. M.
Diamond, A. Maccbiavalli, and M. A. Stephens: Proc.
of the 16tb Mikolajki Summer School on Nuclear Phys-

ics, Poland, p.2 (1984) .
2) D. Cline: Nuclear Structure 1985, Elsevier Science Publishers, B.V., Amsterdam, p. 313 (1985) .
3) H. Stelzer: Nucl. Instrum. Methods, 133, 409 (1976) .
4) H. Kumagai, S. Sasagase, and T. Wada: Reports I.P.C.R.,
62, 114 (1986) (in Japanese).
5) Y. Kanai, Y. !tob, T. Koizumi, H. Shibata, T. Matsuo,
H. Kumagai, T. Kambara, M. Kase, T. Mizogawa, andY. Awaya: RIKEN Accel. Prog. Rep., 19, 146 (1985) .

129
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-4. Construction of a Two-Dimensional Multiwire Drift Chamber
H. Shimizu, * J. Iimura, * H. Ohnuma, * and M. Ishihara

A two-dimensional Multiwire Drift Chamber(MWDC) has been developed as a multi-purpose
position detector to be used in the RIKEN Ring
Cyclotron facility. It is also a test chamber for a
focal plane detector in a magnetic spectrograph. 1 )In spite of very attractive properties of MWDC's,such as good position accuracy, a large detection
area, and simple operation,2) they have not been
extensively used in nuclear experiments, where theeffect of multiple scattering in the chambers isserious. This effect prevents one from using so calleda "double chamber method"3) to reduce left-rightambiguity when MWDC's are used in low energy
experiments. In RIKEN Ring Cyclotron energy
region, however, the effect is not serious unlessfurther position measurements are made far downstream. Thus the following requirements are taken
into consideration in the design of the RIKEN
MWDC:(1) The chamber should be as thin as possible.
(2) Left-right ambiguity should be resolved
without another chamber.
(3) The chamber should have simple structure(for simple operation and low cost).
We have constructed, bearing these conditions inmind two identical MWDC's. Each chamber consists ~f a 230 X 230 rnrn 2 duralumin frame, 16.8 rnrn
in thickness, for a wire plane and two 1.6 rnrn thickbrass frames for grounded cathode planes. The inner
windows of the cathode frames are covered with agold-evaporated Mylar foil, 6 pm in thickness (condition 1). One of the cathode planes can be replaced with a multi-strip cathode plane as an option
for two-dimensional read-out. The basic cell geometry is shown in Fig. 1. The square geometry has
been chosen so that the cathode planes need not to

S

F

S

f~b-.

a

I

F

S

\

/

C

Fig. 1. Geometry of drift cell. S, sense wires (+ HV); F,
field shaping wires (grounded); C, cathode planes(grounded); a=b=IO mm.

* Department of Physics, Tokyo Institute of Technology.

c

a

e

a

b

c

Fig. 2. Exploded view of MWDC assembly. A and B, wire
frames; a, cathode frames; b, cathode strips; c, Mylar
frames; d, alignment slots; e, gas inlet, outlet.

have graded fields (condition 3). The wire planeconsists of 8 sense wires and 8 field-shaping wires.
These wires are soldered to gold-plated brass pins
insulated with Delrin sheaths. The field-shaping wire
to sense wire distance (drift length) is 10.00 ±0.01 mm. The distance between the wire plane andthe cathode plane is 10 rnm. The sense wires andfield-shaping wires are gold-plated tungsten, 20 pm
in diameter and gold-plated molybdenum, 80 pm indiameter, respectively. The wire tension was measured to be 37.5 ± 2.5 g for sense wires and 182.1 ±4.0 g for field-shaping wires, respectively, by searching for resonance frequency of current put on theindividual wire in a magnetic field. The left-rightinformation can be obtained from induced signals
on neighboring field-shaping wires (condition 2).
Several units of the MWDC's can be combined tomake various kinds of chamber assemblies. An exploded view of a standard chamber-assembly is shownin Fig. 2. It consists of two MWDC's, A and B,
which are identical but with B staggered by one-halfwire spacing with respect to A. The alignment of
the two chambers is achieved by means of rectangular
metal pieces and the mating slots machined precisely with respect to the first wire of a given chamber. In this assembly left-right ambiguity can be
resolved by using sense wire signals from the twochambers.

130

H. Shimizu, et al.

As performance test of the MWDC's is underwaywith a l06Ru f3-source. Further tests will be conducted with a proton beam.
References
1) H. Ohnuma, T. Ichihara, K. Ieki, M. Ishihara, S. Kato,

T. Kubo, K. Maeda, T. Motobayashi, H. Orihara, and
H. Shimizu: p.134 in this report.
2) F. Sauli: CERN Rep., 77-09 (1977) .
3) J. Heintze and A. H. Walenta: Nucl. Instrum. Methods,
111, 461 (1973); D. C. Cheng, W. A. Kozanecki, R. L.
Piccioni, C. Rubbia, R. L. Sulak, H. J. Weedon, and J.
Wittaker: Nucl. Instrum. Methods, 117, 157 (1974) .

131
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-5.

Test of Electron-Ion Merging Beam ExperimentY. Kanai, Y. Away~ , Y. Itoh, T. Kambara, H. Kumagai, T. Koizumi, T. Mizogawa,S. Ohtam, K. Okuno, H. Shibata, S. Takagi, and S. Tsurubuchi

We rebuilt an EBIS apparatus, called "ProtoNICE," in order to study collisional processes ofelectrons and heavy ions by a merged electron-ion
beom method and reported the test data of theProto-NICE as an EBIS-type ion source. 1 , 2 )In the present stage, the Proto-NICE has been
set on a RILAC beam line (B1) and the tests ofthe ~lectron-ion merging beam experiment are being
carned out. The argon ions (Ar4 +, 1.24 MeV lu)
from RILAC enter the interaction region throughan axial, 2 mm-diameter hole in the cathode of theelectron gun of the Proto-NICE. The charge state
distribution of argon ions at the down stream of theProto-NICE are measured by a charge state analyzer
using a magnet and a Parallel Plate Avalanche
Counter (PP AC) . 3 ) Electron-ion collision energy ischanged by varying electron energy. The acceleration
voltage of electrons of the Proto-NICE is modulated
at 141 Hz as shown in Fig. 1. The data on the
charge state of the ions merged with electrons(abbreviated as "on state") and the data without
electrons ("off state") are measured and accumulated by using respective memories. These two setsof data normalized with integrated Ar 4+ ions beam
currents, which are measured with a Faraday cup
in front of the PPAC, can be compared with eachother. The ratio Ar3 +I Ar 4 + of "on state" is as sameas that of "off state," 3 X 10-6 , because this value isdetermined from A r 4 +- residual gas (10- 7 Torr X 6 m)collisions. The change in the ratio Ar 3+ I Ar 4+ by theelectron-ion collisions in the Proto-NICE, which is
expected to be of the order of 10-8 , is small comparedwith the overall ratio Ar3 +I Ar 4+. We have to make

z
o

j::~

~~
~<5

on

on

on

lj> off<I:

TIME
Fig. 1. Electron acceleration voltage modulation.

Table 1. Width of the Gaussian fitted to the data. Values
are normalized to the broadest width (condition (e».

ArH
Energy(a) 1. 24 MeVlu(b) 1. 24(c) 1. 24(d) 1. 24(e) 1. 24

Electron energy(Acceleration
voltage)

Electroncurrents

Width of
ArH

630eV
0
630*
0*
0**

16mA
0
0*
0*
0**

0.78
0.99
0.97
1.00
1.00

* Off the filament currents of the electron gun of theProto-NICE.
** Stop the operation of the Proto-NICE (used as a beamduct).

efforts to reduce the amount of residual gas (10-8Torr or less) in the beam ducts and charge analyzer
to measure this change.
We measured the profiles of Ar 4 + ion beams with
the PPAC at the down stream of the Proto-NICE.
The width, which is the width of the Gaussian fitted
to the data and normalized to the broadest case,and the conditions for each profile for typical cases
are listed in Table 1. The profile of Ar 4 + for "onstate" (Table 1 (a)) is narrower than that for "offstate" (Table 1 (b) ). The acceleration voltage modulation without electrons does not affect the width(Table 1 (c ) and (d) ). The existence of electrons
affects the width. This means that the argon ion
beam and the electron beam are merged in the
Photo-NICE and the interactions between them makethe ion beam focussed.
References
1) S. Ohtani, Y. Awaya, Y. Itoh, T. Kambara, Y. Kanai,
T. Koizumi, T. Mizogawa, K. Okuno, H. Shibata, S.
Takagi, and S. Tsurubuchi: RIKEN Accel. Prog. R ep.,
19, 144 (1985) .
2) T. Mizogawa, Y. Awaya, Y. Itoh, T. Kambara, Y. Kanai,
T. Koizumi, S. Ohtani, K. Okuno, H. Shibata, S. Takagi,
and S. Tsurubuchi: Mass Spectrosc., 35, 1 (1987) .
3) Y. Awaya, M. Kase, T. Kambara, H. Kumagai, Y. Kanai ,T. Mizogawa, K. Shima, and T. Chiba: p. 132 in thisreport.

132
RIKEN Acce!. Prog. Rep. 20 (1986)

111-5-6. A Broad-Range Magnetic Charge Analyzer
Y. Awaya, M. Kase, T. Kambara, H. Kumagai,
Y. Kanai, T. Mizogawa, K. Shima, and T. Chiba
A magnet for analyzing the charge state ofheavy ions with incident energies of up to about
1.5 MeV j amu has been constructed. This magnetic
analyzer has been designed to analyze and detectheavy ions with different charge states simultaneously
and to be capable of resolving ions with charge of qe
from those of (q + 1) e at q ~ 20 by adopting a
position sensitive parallel plate avalanche counter(PPAC) as a detector.
The specification of the magnet are as follows:
radius150cm
1.5 Wbjm2
maximum magnetic field
angle of deflection25°
gap of pole pieces
3cm
aperture of vacuum chamber
2.3 cmX 10 cm
total weightabout 3 tons

A plane figure of the magnet and the vacuum
chamber is shown in Fig. 1. A PPAC1) is placed at
the distance of about 5 em from the exit port of themagnet in order to detect the heavy ions with different charges in the range from qe to 0.6 qe. The
size of the entrance window of the PPAC is 10 em X

(a)

.• ..

CICI

(b)

Ar 4 +,12+

CI

e

•

4

8

12

4

12

(d)
.......

16

ClC>CICIC>

Ti 15+~ 10- 1

cu 4+,17+

C>

4-

~

o

10- 2

.......

o

C/l
Q)

10- 3

o

~
Cl

-5 10- 4

o

Q)

:

10- 5

Cl

~ LII

~

II

~rl ~ 1~~

10 0

Section at A- A

+

-S

~

1;.,
......

10 1

Xe 8 +,26+

•

•
o
o

N

10- 4
10- 5 L-.iL-....lL....lL....l--l.--I.--'---'-12
16
20
24

u

:::>

C> C> C>

+

",

c

20

C>

•

..c.

u

16

C>

~

~c 10 3

0

12

(f)

+

r-1

~ 10 2

. .

10- 1

+

;:!;

8

(el.··.

in units of mm

Fig. 1. A plane figure of the magnet and the vacuum chamber of the analyzer.

104

10- '-'--'-.L...-L......l'--L---'---'---'-_
20
8
12
16

A

o
channel number
Fig. 2. The charge spectrum of 1.3 MeV /amu Ti 15+ ionsafter passing through a 10 p.g/cm 2 C foil.

16

20

24

28

32

charge state q
Fig. 3. Relative charge state fractions of various heavy ionsafter passing through a 10 p.g/cm 2 C foil. (a), 0.83 MeV /amu A13+ ions; (b), 1.3 MeV /amu Ar 4 + and Ar12+ ions; (c),1.3 MeV /amu Ti15 + ions; (d), 0.83 MeV /amu Cu 4 + andCu17 + ions; (e), 0.83 MeV /amu Kr6+ ions; and (f), 0.83
MeV /amu Xe8 + and Xe 26 + ions. Dots show the values forlower charge ions, circles those for higher ones, and thehalf blackened circles mean the overlap of dots and circles.

Y. Awaya, et al.

2 cm and is covered with an aluminum-evaporated
2.5 pm Mylar foil. Isobuthane gas is flowed in the
PPAC at a pressure of about 6 Torr. The positionof incident ions is determined by the charge division
method using signals from the cathode. A timing
signal is obtained from the anode when required.
Measurements of charge distributions of somespecies of heavy ions after passing through a 10
pg/cm 2 carbon foil were carried out not only to test
the equipments but also to obtain new data in the region of the mass and energy of heavy ions where there
are scarce reports. Figure 2 shows an example ofthe charge distribution spectrum obtained at one
measurement with 1.3 MeV / amu Ti1 5+ ions passing
through the carbon foil.
The relative charge state fraction for 1.3 MeV /amu
Ar4+, Ar12+, and TP5+, 0.83 MeV / amu AP+, Cu 4 +,C U 17+, Kr 6+, Xes+, and Xe 26 + ions after passing
through the carbon foil are shown in Fig. 3 (a) - (f) .
The AP+, Ar4+, Cu4+, Kr6+, and Xes+ ions were obtained directly from RILAC and Ar12 +, Ti1 5+, C U 17+,and Xe 26 + ions were obtained by making the beams
pass through a charge stripper. The initial charge
state of Ti ions was 4+. The momentum of all the133

ions were analyzed by using a beam analyzing magnet.
There are no difference between the distributionof the charge fraction for A r 4+ and that for Ar12+
ions (Fig. 3 (b)), between Cu4+ and C U 17+ ions (Fig.
3 (d) ), and that between XeS+ and Xe 26+ ions. Thismeans the thickness of carbon foil of 10 pg/cm 2is enough to make 1.3 MeV / amu Ar ions, 0.83
MeV / amu Cu and Xe ions equilibrate in charge.
On the basis of this result, the charge fractions
obtained for Al and Kr indicate that these ions arein charge equilibrium and the charge fraction for Ti
indicates that it is in or nearly in equilibrium.
This magnetic analyzer, which is named "AMmagnet," will be used for the measurements ofcharge distribution of heavy ions scattered not only
at zero degree but also at small angles, coincidence
measurements between X-rays and scattered ions andmerging beam experiments between heavy ions andelectrons.
Reference
1) H. Kumagai, T. Kubo, M. Ishihara, M. Fuse, and E.
Gotoh: RIKEN Accel. Prog. Rep., 19, 148 (1985) .

134
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-7. Design Study of Experimental Facilities for Light andLight-Heavy lon-Induced Reactions
H. Ohnuma,* T. Ichihara, K. Ieki, M. Ishihara, S. Kato,**T. Kubo, K . Maeda,*** T. Motobayashi, H. Orihara,**** and H. Shimizu

Medium-energy light and light-heavy ion beams
will become available from RIKEN Ring Cyclotron
at the installation of an injector AVF cyclotron.l)
Design study of a detection system is in progress tofacilitate particle measurements in experiments withthose beams.
The basic idea of the layout of the system asshown in Fig. 1 is to use a beam swing@r magnet
along with a cascade-type magnetic spectrometer forcharged-particles and with a time-of-flight (TOF)
spectrometer for neutrons.
Since the incident beam direction will be rotatedby a swinger, there is no need to rotate the magnetic
spectrometer in angular distribution measurements.
This makes the design of a magnetic spectrometer
free from many restrictions imposed otherwise andmakes a construction of cascade-type spectrometer
possible. A proposed spectrometer consists of three

quadrupoles and two dipoles (QQDQD) with two
focal planes, one after the first dipole and the otherafter the second dipole. The first three elements(QQD) with the first focal plane will serve as a
low-resolution, large-solid-angle spectrometer. The
second focal plane will be used when higher resolution is required. The third quadrupole and the second
dipole magnifies the image on the first focal planein this latter case, hence the name of cascade-type
spectrometer. Design characteristics of the proposed
spectrometer are given in Table 1.
The beam swinger consists of a quadrupole triplet
and two dipoles, and similar in its basic form to thatat CYRIC.2) It is designed not only for beam direction rotation but also for momentum dispersion of
the incident beam. Dispersion matching is mucheasier to realize in the present system than in an
ordinary system without a swinger, since the beam

SCRLE ::: 1/100

IBt1

TWISTER

Fig. 1. Layout of the proposed system conslstmg of the beam swinger,magnetic spectrometer, and neutron flight path.

* Department of Physics, Tokyo Institute of Tech·
nology.

** Faculty of Liberal Arts, Yamagata University.
*** College of General Education, Tohoku University.
*':'** Cyclotron and Radioisotope Center, Tohoku University.

H. Ohnuma, et al.

Table 1.

135

Design characteristics of the spectrometer.

Configuration
Number of focal planes
First order resolving power
Momentum byte (Pcmax)/(P<mlnJ
Aperture
Maximum solid angle
Mean orbit radius
Maximum magnetic fieldGap of dipole magnets
Angular resolution
Angle of measurements

Q-Q-D (first stage)
Q-D(second stage)*2
5,000 (first stage)
13,000 (second stage)*
1. 41 (first stage)
1.04 (second stage)
200 mr (in the reaction plane)
100 mr (vertical to the reaction plane)*
20 msr*

2.4m
1.5T
20 em (DI)
10 em (D2)
3mr
-10 to + 10 deg. (zero deg. mode)+ 10 to +30 deg. (forward mode)+30 to + 140 deg. (backward mode)** Tentative

will be dispersed along the rotation axis of the spectrometer.
The flight path for the neutron TOF measurement will be 20-40 m at the beginning with future
extension expected. Large volume liquid scintillation
counters will be used for neutron detection.
The present system allows simultaneous measurements of charged particles and neutrons emitted in
the same direction. This and the large solid angle ofthe magnetic spectrometer should enable us to detectvarious kinds of unbound particles, such as d, 2He,a*, and 8Be, broadening hopefully the scope of thenuclear reaction and structure studies.
The production of a medium-energy neutron beamis also under discussion. Design studies of other related equipments, e.g. spin rotators and polarimeters,
are in progress. Construction of thin two-dimensional
multiwire drift chambers is also underway.
References
1) H. Kamitsubo: RIKEN Accel. Prog. Rep., 15, 149(1981) .
2) H. Orihara and T . Murakami: Nucl. Instrum. Methods,
188, 15 (1981) .

136
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-8.

Projectile Fragments Separator for RIKEN Ring Cyclotron
T. Kubo, K. Asahi, T. Ichihara, T. Matsuzaki, M. Fukuda,
K. Nagamine, 1. Tanihata, and M. Ishihara

Recently much attention is being paid to unstable
nuclides far from the stability line of the nuclear
chart. In order to perform research on such nuclides,
an on-line separator for projectile fragments, named
RIPS (RIken ~rojectile fragments Separator), hasbeen proposed at RIKEN Ring Cyclotron Facility.
The use of projectile fragmentation in heavy-ion reactions is of great advantage to provide the unstable
nuclides. A large number of nuclides far from thestability line are produced as projectile fragments.
The fragmentation yields are concentrated aroundzero degree with a small angular spread. Besides,
the fragmentation conserves a velocity of projectile
although fragments have small spreading of velocity.
These features enable efficient collection and separation.
The RIPS system is an achromatic spectrometerwith an intermediate focal plane. Figure 1 shows thelayout of the system. It consists of two dipole (D1and D2), seven quadrupole (Q1, Q2, Q3, Q4, Q5,
Q6, and Q7), and two sextupole (SX1 and SX2)
magnets. The intermediate focal plane (F1) after
the Q3 magnet is dispersive with respect to magnetic
rigidity (Bp). The Q3 magnet is used to adjust thedispersion at F 1 arising from the D 1 magnet. The
focusing at F1 is achieved by using the Q1 and Q2
magnets. The SX1 magnet corrects chromaticaberrations at F 1. The D 1 magnet has a curved
entrance boundary, by which a sextupole component
is introduced, to correct non-chromatic aberrations
at F1. The final focal plane (F2) at the end of
the system is achromatic with respect to Bp. The
Q4 and Q5 magnets are used to obtain theachromatism at the exit of D2 magnet. The focusing
at F2 is achieved by using the Q6 and Q7 magnets.
The roles of the SX2 magnet and a curved exit
boundary of the D2 magnet are similar to those ofQ1

F2

TARGET

Fig. l.

Layout of the RIPS system.

Table 1.

Design characteristics of the RIPS system.

Configuration
Number of focal planes
Aperture
Maximum solid angle
Maximum Bp
B P acceptanceFirst order resolution at
Fl (PI LlP)

Q - Q - D-SX- Q -Q-Q-SXD-Q-Q
2, dispersive and achromatic± 30 mr (horizontal)±40 mr (vertical)
4.8 msr
6T·m±3%...... 2,000

the sextupole components for F1.
The isotope separation with the RIPS system will
be made by using the following two methods simultaneously:
1) separation by selection of a Bp value,
2) separation by a thick Bp-degrader set at theF 1 focal plane.
The first method corresponds to the separation by
A I Z of fragments. The Bp values of fragments areproportional to their A I Z, because the projectile
fragmentation approximately conserves a projectile
velocity. The second method utilizes the isotope
dependence of the Bp loss in the degrader, which
can be expressed as J(Bp) IXa- (A3/Z2) (Bp)-3.
When the degrader is used, the focusing position
moves on the F2 plane according to A 3 I Z2 of fragments. The use of a slit enables the separation by
A 3 /Z 2 of fragments. A wedge-shaped degrader,! )which does not change the dispersion at F1, will be
used so as not to break the achromatism. The design goal of mass resolution (AI JA ) IS morethan 100.
The design characteristics of RIPS system aregiven in Table 1. The solid angle and the Bp acceptance are determined considering spreads of fragmentation spectra. The solid angle is about fivetimes large compared with the similar spectrometer
LISE2) at GANIL. Large part of fragmentation
yields can be collected with the RIPS system although
the collection efficiency depends on a projectile
energy and a combination of projectile and fragment. The maximum Bp is about 1.7 times larger
than that of RIKEN Ring Cyclotron. This is advantageous for the collection of neutron-rich nuclides
far from the stability line, because the use of a

T. Kubo, et al.

higher projectile energy becomes possible.
The RIPS system has a beam swinger just before a target to collect fragments produced at backward angles. This makes the production of polarized
nuclei possible.
The detailed design of the system is now inprogress.

137

References
1) J. P. Dufour, R. Del Moral, H. Emmermann, F. Hubert,
D. Jean, C. Poinot, M. S. Pravikoff, A. Fleury, H.
Delagrange, and K. H. Schmidt: Nucl. Instrum. Methods
A, 248, 267 (1986) .
2) R. Anne and C. Signarbieux: GANIL Report, RAjN]
278 (1982) .

138
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-9.

Beam Plasma Effects in Operating with an lon-Guide
Isotope Separator On-Line
K. Morita, T. Inamura, T. Nomura, J. Tanaka, H. Miyatake,
M. Fujioka, T. Shinozuka, M. Yoshii,* H. Hama,* K. Taguchi,*K. Sueki, Y. Hatsukawa, K. Furuno, and H. Kudo

An ion-guide isotope separator on-line (IGISOL )has been first constructed at University of Jyvaskyla.
The IGISOL has a prominent advantage that it
works almost independently of chemical and physicalproperties of elements and therefore can be applied
to all elements equally well. The IGISOL has beensuccessfully tested mainly using light-ion induced reactions and proven to work very stably for a long
period of time. 1)
We have constructed an IGISOL at INS (theInstitute for Nuclear Study) and have been testing
its performance. The present report is concernedwith an effort to extend the application of the
IGISOL to heavy-ion induced reactions. In doing
so, an important problem is the plasma effect whichshould be significant in such reactions: The dense
plasma formed by collision between beam particles
and helium atoms along a beam path may induce
quick neutralization of charged reaction products andtherefore reduce the fraction of useful 1+ ions.
This effect is probable since reaction products aremostly recoiled out in the beam direction. The
density of the plasma formed by heavy-ion beams is
proportional to the energy loss of the beam in gas,
the number of beam particles, and the gas pressure
inside a target chamber. We have detected theeffect of the plasma on the extraction efficiency ofreaction products by changing the density under theidentical experimental conditions.
Relative efficiencies were measured by using reactions 27Al(a, 2 pn) 28Al at 33 MeV, 19F (12C, 2 pn ) 28AI at 38 MeV, and 12C (19F, 2 pn) 28AI at 60 MeV
as a function of beam intensity. Incident energies
were chosen to give the same excitation energy of
the compound nucleus produced in these reactions.
A 6 pm Al foil was used for the target for the27Al(a, 2 pn) reaction, LiF of about 2 mg/cm 2 inthickness evaporated onto a thin Al foil was used forthe 19F(12C, 2 pn) reaction, and a 3 mg/cm 2 selfsupporting natural carbon foil was used for the 12C_
(19F, 2 pn) reaction. All the measurements were performed by detecting the 1. 78-MeV r-rays following* Faculty of Science, Tohoku University.

the ,a-decay (t1/2 = 2.2 min) of 28Al with a 80 cm 3
pure Ge counter at the tape transport position. The
pressure of the target chamber was set at 60 mbar.
Other parameters were fixed throughout the measurements.
The results are shown in Fig. 1. For the a-induced
reaction the efficiencies are nearly constant when theo 27At (ex ,2pn)28At• 19F (12 C, 2pn) 28At
o 12C( 19 F,2pn)28At

6~5""Vl 4

?

)!

f-

z

6 3

Pte =60 mbar

f9 ~

+

u

?

Q
¢

~ ¢ $ ¢.

¢

·0+ .

e ...

o •
0
10-2

10- 1
1
BEAM INTENSITY (ejJA)

10

Fig.!. Yields of 1.78 MeV r-rays normalized by the integrated beam current versus average beam intensities in
the 27AI (a, 2pn) 28AI, 19F (12C, 2pn) 28Al, and 12C (19F, 2pn) 28Al reactions.

o27Al (o, 2pn) 28Al•

19p (l 2c ,2pn ) 28Al ; IIlUl t ipl1ed by 1.45ol 2C(l9p ,2 pn)2S" 1 ; mul t iplied by 1. 23

u 10

~

"'Vl

00

o

0

0

f-

Z

::>
o
u

•o

Fig. 2. The same as in Fig. 2, but plotted against LlE, theproduct of beam intensity and estimated energy loss ofbeam particles in helium gas of 60 mbar under the present
experimental conditions. LlE=Energy loss in HeXnumberof beam particles.

K. Morita, et al.

beam intensity (Ib) is less than 1 p.A, but decrease
with the beam intensity in the range of Ib > 1 p.A.
This decrease in the efficiency becomes prominenteven at low intensities for the 12 0_ and 19F-induced
reactions. In Fig. 2, the same normalized yields areplotted as a function of the product of the beam
intensity and energy loss of beam particles in heliumgas of 60 mbar. It is clearly seen that all the experimental points lie on a smooth curve. This indicatesthat the observed change in the relative efficiency is
primarily due to the change in plasma density formed
along the path of a beam, which should be proportional to the quantity taken as the abscissa.
The present results provide the first clear evidence
that the efficiency of the IGISOL is strongly affected

139

by the plasma formed by beam particles in buffer
gas when the plasma density becomes high. This
indicates that the rate of the neutralization of recoil
ions is enhanced by the dense plasma. 2 )References
1)

J. Xrje, J. Xysto, H. Hyvonen, P. Taskinen, V. Koponen,
J. Honkanen, K. Valli, A. Hautojarvi, and K. Vierinen:

Nucl. Instrum. Methods ..4., 247, 431 (1986) .
2) K. Morita, T. Inamura, T. Nomura, J. Tanaka, H. Miyatake, M. Fujioka, T. Shinozuka, M. Yoshii, H. Hama,
K. Taguchi, K. Sueki, Y. Hatsukawa, K. Furuno, andH. Kudo: Proc. 11 th Int. Conf. Electromagnetic Isotope
Separators and Techniques Related to Their Applications (EMIS-ll), Los Alamos, Aug. (1986).

140
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-10.

INS Gas-Filled Recoi I Separator

H. Miyatake, T. Nomura, H. Kawakami,* J. Tanaka, M. Oyaizu,*
K. Morita, T. Shinozuka, H. Kudo, K. Sueki, and Y. Iwata**

A gas-filled recoil isotope separator (GARIS) has
been constructed at INS.1) The present GARIS
mainly aims at efficient collection of reaction products by separating them from beam particles for the
study of short-lived nuclei.
Reaction products recoiled otu of a target havebroad distributions both in charge and momentum.
When they enter a dipole magnetic field with gasof low pressure, they follow an average trajectory
corresponding to their momenta and average chargeseli) defined by their multiple collision with gas atoms.
Because the average charge is roughly proportional
to momentum, the average trajectory is almost independent of the initial distributions of momentum andcharge states, and depends only on their mass (A)and atomic number (Z) .2) Main characteristics ofthis kind of separator are relatively high efficiency(order of 10%) and its short separation time
(1 fls).
The present GARIS consists of Q-Q-D-Q-Q configuration as schematically shown in Fig. 1. The
maximum magnetic rigidity of the dipole magnet
and dispersion of this system are 2.4 T· m and7.14mm for 1% of ABpjBp, respectively. A region
filled by helium gas is separated from the vacuum

region by a , thin nickel foil of 1.77mgjcm 2 and
16 mm in diameter, located just before the target
position upstream. The pressure of helium gas ismeasured by a capacitance manometer at the detector chamber and is controlled remotely with asolenoid-type gas-inlet valve at the target chamber.
The vertical and horizontal acceptance angle areusually 70 mr and 50 mr, respectively.
The present GARIS has been tested first by using
16 0 and 40Ar beams which pass through the Ni-window and have thus significant momentum spread.
Later we have also tested it by using the reaction
58Ni(12C, pn) 68As at 44 MeV, in which the Ni-window is used as a target. The various experimental
parameters such as beam enegies and momentum
spreads are listed in Table 1.
The efficiency of the GARIS is defined as a ratioof the amount of radio-activity of interest collected
at the focal plane and that recoiled out of the target.
We obtained the efficiency for 68As from the measurement of the yields with 1,016 keV r-rays decaying
from this nucleus. This value slowly decreased from
12.3 to 8.0 % when the pressure of helium increased
from 0.27 to 1.01 Torr. We also measured the resolution, ABp/ Bp, for various beams to compare calcuSlit chamber

Detector chamber

Fig. 1. A schematic drawing of the present GARIS. QI, Q2, Q3, and Q4
are quadrupole magnets and D is a dipole magnet.

* Institute for Nuclear Study, University of Tokyo.
** Faculty of Science, Hiroshima University.

H. Miyatake, et al.

Table 1. Experimental parameters and results. E and JP
are the mean energy and the momentum spread, respectively, after passing through the Ni-foil. The vjvo is theaverage ionic velocity in unit of vo at the midpoint of thedipole magnet after correction of the energy loss by heliumgas. The given average charge is the one at the He pres.
sure (PRe) which corresponds to the minimum resolution.
Ion
Ni-foilE(Beamthickness 1M V)
energy) (mg/cm 2) \ e
160 (33 MeV)
160 (26 MeV)
fOAr(38MeV)
68As

2.21
2.21
1. 77
1. 77

-

vivo

A

141

20

10

/

up P PRe(%) (Torr)

22.89 6.81
3.87
15.06 5.53 6.50
17.,90 3.85 18.3
3.60
1. 35 111. 0

ij

(e)

13.0 6.61±0.52
6.0 5.67±0.41
3.0 6.11 ±O. 34
0.75 2. 72±0. 31

lated values with experimental ones. It is well known
that the resolution is mainly determined by statistics of charge-changing collision, multiple scattering,velocity dispersion, and beam optics. We estimatedthese effects in the same way as described in Ref. 2.
The effects of energy loss of ions in helium gas was
also taken into count. Figure 2 shows the pressure
dependence of the resolution for 4°Ar in which experimental values are measured by Faraday cup set
at the focal plane. The calculated values are shownby solid curve in Fig. 2. It is noted that a value ofan effective charge-changing cross section, which isneeded to estimate the contribution from the chargechanging collision, is chosen to be 7.7 % of that calculated by using a unified empirical formula for asingle electron capture 3 ) in order to obtain the best
fit. The above values is consistent with the one
given in Ref. 2. We also fitted calculated values toexperimental ones for 68As and 16 0.

15

Fig. 3. The measured average charges obtained in heliumgas of low pressure as a function of atomic numbers.
Experimental values of 160, 40Ar, 68As, 84J{r, 90Mo, 103Ag,
llOSn, 132Xe, 125CS, and 149Tb are plotted. The values
from 84Kr to 149Tb are taken from Ref. 4. All the experi·mental points are normalized to those of the ionic velocity
of v=4vo (vo=cjI37). A solid line shows ij ex: ZO . 57
dependence.

The minimum resolution was obtained to be 50/0
for 40Ar at the He pressure of 3 Torr in this test experiment.
Finally we measured average charge ((1) at thehelium pressure corresponding to the minimum resolution as shown in the last column of Table 1.
Petrov et aU) have shown that iJ. of ion moving inhelium gas with relatively low velocities of v / Vo = 4,
in which Vo is the Bohr velocity (vo = c /137), is proportional to ZO.57 for 36"':::::: Z === 54. In order to see
whether this holds for smaller Z values, the present
data are plotted together with the results of Ref. 4
in Fig. 3. It is clear that the ZO.57 dependence of q
holds well down to Z = 8.
At present a study of a-decays from unknown
nuclei, whose half-lives are expected to be the orderof ps, is in progress with the GARIS.
References

J. Tanaka,
M. Oyaizu, K. Morita, T. Shinozuka, H. Kudo, K. Sueki,
and Y. Iwata: Proc. 11 th Int. Con£. Electromagnetic
Isotope Separators and Techniques Related to Their Applications (EMIS-ll), Los Alamos National Laboratory,
USA, Aug. 18-20 (1986); Nucl. Instrum. Methods B, 26,1) H. Miyatake, T. Nomura, H. Kawakami,

40

Ar

5

17.90 MeV

309 (1987) .
2)
OL-----~~------~~----~~

0.1

PCtard

10100

The measured dependence of the resolution LlBP/
BP on helium pressure for 4°Ar ions at 17.9 MeV. The
other experimental parameters are given in Table 1. The
experimental errors are about 10% for all points. A solid
curve shows the calculated values explained in the text.

Fig. 2.

P. Armbruster, J. Eidens, J. W. Cruter, H. Lawin, E.
Rockl, and K. Sistemich: Nucl. Instrum. Methods, 91,

499 (1971) .
3) H . Knudsen, H. K. Haugen, and P. Hvelplund: Phys.
Rev. A, 23, 597 (1981) .
4) L. A. Petrov, V. A. Karnaukov, and D. D. Bogdanov:Sov. Phys. jETP, 32, 1042 (1971) .

142
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-11. The Experimental Beamline for the First Beam fromRIKEN Ring Cyclotron
M. Fukuda, T. Kubo, 1. Tanihata, K. Asahi,
M. Ishihara, and H. Taketani*

An experimental beamline named "20-degrees
course" has been designed for the experiments using
first beams from RIKEN Ring Cyclotron (Fig. 1).
A main purpose of this line is to perform the experiments easily on exotic nuclei produced by projectile
fragmentation. l ,2) Figure 1 shows that a primarybeam and reaction products coming out from a target are separated by making them pass through adipole magnet of 350 mmcf> in radius. In this situation, the radius of curvature of the central ray p
is -'2 m and maximum Bp is about 3 T·m.
As the central ray is bent by 20°, the dispersion
becomes 0.342·[ cm per 100% rigidity difference (l:the distance from the center of the magnet). Because the typical interval between the primary beam
Beam

Table I. Counting rates of objective nuclide and most frequent contaminants at Counter-I.
180 beam

4°Ar beam

Object: l4Be
7Li
8Li
llBe
12Be
13Be

15 cpsObject: 83AI

110 cps

2°F
21F
23Ne
25Na
27Mg

4. 8x 105
5.1 X 105
6.5x105
5.9X10 5
4. 7x 105

49
2,600
450
1,100
350

and the central ray becomes several cm at Slit-2, theprimary beam can be stopped here.
It is not possible, however, to separate a specificnuclide completely from a large number of nuclides
produced by fragmentation by use of such a simple
magnet. In Table 1, we exemplified the counting
rates of each nuclide after Slit-2, assuming that ob10 8

650

I~o_

TargetCi)-Slit-1

~

10 7

2CII
a:

10 6

a.

D-magnet(700mm ¢ )

en

.:
'E
~

10 5

0
()

"iii

;§

10 4
10 3

10 2
0

100

200

Target ThIckness

300(mgfcm2)

1000

(b)

Ci)

ft

I

...I..

I

33AI
Q)

ro

100

T8C'

a:
Cl

-'

.!:

'E

~

0
()

./

10

"'

~

V

~

v
./

"

148e::

V
1

10

Fig. 1. Schematic drawing of H20-degrees course." Lengthin cm.

* Department of Applied Physics, Tokyo Institute ofTechnology.

100

Targe! Thickness

1000(mgfcm2)

Fig. 2. (a) Total counting rates at Counter-I and (b)counting rates of objective nuclides. The target is 9Be.
The better SIN, the thinner the target.

143

M. Fukuda, et al.

Table 2. Transmission from the target to Counter-2 forthree combinations of a beam and a fragment.
Fragment (Beam)TransmissionaBe (180)
18C (22Ne)
38AI (40Ar)

1.0%
2.0%
3.9%

owing to a distributed production depth in the target
and the difference in energy loss between the beamand the fragments. In comparison with this effect,
multiple scattering contributes little to the decreasein the yields. The mean scattering angle jOse inthese situation is --,10- 3 rad, which is --,10 times as
small as the above effect.
In order to investigate the transmission of the system and the distribution of objective fragments at
the focal point, we carried out Monte-Carlo simulation. Some of the results are shown in Table 2 andFig. 3. From this calculation, we found that, at
Counter-2, S IN becomes a few times better thanthat at Counter-l.
At this line, experiments on neutron rich exotic
nuclei, e.g., the search for new isotopes or lifetime
measurements using the rotating catcher,3) are being
planned.

jective fragments are 14Be and 33AI from 18 0 and
4°Ar beams, and targets are 100 and 60 mg/cm 2 9Be.
In this calculation, the angular and momentum
spreading of fragments by reaction and the energy
distribution by energy loss in the target were taken
into account. The values of cross sections for projectile fragmentation were taken from GANIL's
data. 2 ) Slit-1 and -2 were set to improve SIN. The
width of the slits were assumed to be 3 mm (Sl) and2 cm (S2). The above estimates indicate that theseslits improve S IN at Counter-1 by 20-300 times.
Spreading of fragments after passing through themagnet is very sensitive to the target thickness.
Figure 2 (a) and (b) shows counting rates calculated for whole nuclides and an objective after Slit-2
as a function of target thickness for a few combinations of a beam and an object. The yields of theobjects become maximum around 100 mg/cm 2 • The
decrease in yields for thicker target is ascribed tothe broadening of energy distribution of fragments

References
I) M. Langevin, E. Quiniou, M. Bernas, J. Galin, J. C.
Jacmart, F. Naulin, F. Pougheon, R. Anne, C. Detraz,
D. Guerreau, D. Guillemaud-Mueller, and A. C. Mueller:
Phys. Lett. B, 150, 7I (1985) .
2) D. Guerreau: Proc. Int. Conf. Heavy Ion Nuclear Collisions in the Fermi Energy Domain, C4-155 (1986) .
3) M. Fukuda, T . Kubo, K. Asahi, 1. Tanihata, M. Ishihara, H. Kumagai, Y. Oikawa, T. Abe, and H. Taketani: p. 146 in this report.

25~-----------------------.

20

33AI from 40Ar; 30 MeV/A

12

12

8

8

4

4

0

o

o

-5

-4

-4

-8

-8

-12

-12

15
10
5

."

.:.-:W~~\~:.-

-10
-15
-20
-25

-20

-10

0

-20

10

-12

20

-4

0

4

12

-12

12

12

8

s

4

4

o

o

-4

-4

-8

-8

-12

-12
-12

Slit-2

-8

-8

-4

0

4

8

Counter-2 (a)

12

-8

-4

0

4

8

12

4

8

12

· ...-::.t).

-12

-8

-4

0

Counter-2 (b)Fig. 3. Position distributions of objective nuclide at Slit-2 and Counter-2 by Monte-Carlo simulation.
Two cases for different combinations of a beam and an object are shown (upper and lower). The
targets are 60 and 100 mg/cm 2 9Be. Counter-2 (a) and (b) indicate the cases without and with theslits, respectively. The unit is cm.

144
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-12.

Sensitivity Test of Resonance Ionization Spectroscopy

H. Katsuragawa, T. Minowa, M. Shimazu, K. Nishiyama,* and T. Inamura

We have tested the sensitivity of resonance ionization spectroscopy (RIS) using an apparatus constructed last year. 1 )Figure 1 shows the block diagram of the experimental setup. The TI atoms are excited and photoionized by a single frequency two-step resonant process with a tunable dye laser (peak power 10 kW)
pumped by a nitrogen laser (peak power 200 kW,
repetition rate 10Hz). The wavelength of the output beam of the dye laser was tuned to 377.6 nm
which corresponded to that of the 72S1 / 2-6 2 Pl/2
transition of thallium. Pairs of ion and electron
generated by resonance ionization were detected witha pair of CERATRON detectors (ceramic electron+H.V.

multiplier, MURATA EMW-6081B). They were
set opposite to each other and the distance between
the two was 5 cm. The observed time-of-flight(TOF) of a thallium ion was 1.3 fls. This agrees
well with the estimated value of 1 f1S from the electric field (4.5 kV applied) and geometrical arrangement of the CERATRON detectors. The FWHM
of the TI peak on the TOF spectrum was about
100 ns. The time resolution of the detecting systemitself was 17 ns. The signal-to-noise ratio has been
improved by the order of 10 2 compared with thesingle detection of electrons or ions. The TOF
spectrum is presented in Fig. 2. A small peak on
the right-hand side is considered due to diffusionpump oil molecules.
We measured average counts per laser pulse atvarious temperatures of the thallium sample. Figure
3 presents the experimental results. The averagecounts (1) per laser pulse are plotted against 1IT,
where T is the temperature of the TI sample in
Kelvin. We assumed that the intensity of a TI beam
was proportional to the saturated vapor pressure at
the surface of the TI sample. The solid line in Fig.
3 was obtained from the least-squares fit of the data
to the formlog ] = -Fig. 1. A block. diagram of experimental system. The meanings of the abbreviations in the figure are as follows: TFA,
timing filter amplifier; CFD, constant fraction discriminator; TAC, time-to-amI,>litude converter. MCA, multichannel analyzer; SCA, single-channel analyzer; H.V., highvoltage.

AIT + B

where A=12,300 (15) and B=20.5 (3).

WJh-----~_)~,~l~~~A~--~
o

0.5

1.0

1.3

1.5

1.9

Tim e of Fl ight ()Js)

Fig. 2. A TOF spectrum. The peak at 1.3 f.Ls is due to
TI and the small peak at 1.9 f.Ls is considered due tomolecules of the diffusion-pump oil.

* Faculty of Science, Toho University.

1.7

1.9 x 10-3 K-1

1.8

lIT
Fig. 3. Average counts per laser pulse are plotted against
1/ T, where T is the temperature of the TI sample in
Kelvin.

H. Katsuragawa, et al.

In the present work, it is assumed that almost
100% resonance ionization of TI atoms took placein the irradiation area, based on experimental resultsof RIS of TI atoms using the same dye laser of thesame power in a previous work. 2) From the averagecounts per laser pulse in the irradiation area
(10- 4 cm- 3 ) at 592 K, it is concluded that the sensitivity of this method reached the thallium densityof 20 atoms/cm 3 , which is by the order of 104 better
than the proportional counter cell method. 3 ) The
sensitivity will be further improved when an Einzel

145

lens system is used to converge ions.
References
1) T. Inamura l K. Morita, K. Ando, H. Katsuragawa, T.
Minowa, and M. Shimazu: RIKEN Aceel. Prog. Rep.,
19, 157 (1985) .
2) T. Minowa, H. Katsuragawa, A. Kawamura, and M.
Shimazu: Opt. Commun., 60, 37 (1986) .
3) H. Katsuragawa, T. Minowa, M. Shimazu, and T. Inamura: Contributed to the EMIS-ll Conference, Los
Alamos, N.M., 18-22 August (1986), and to be published in Nucl. Instrum. Methods.

146
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-13. A Rotating Catcher System for Projectile Fragments
M. Fukuda, T. Kubo, K. Asahi, I. Tanihata, M. Ishihara,
H. Kwnagai, Y. Oikawa, T. Abe, and H. Taketani*

A rotating catcher system has been disigned forlifetime measurements of exotic nuclei produced byprojectile fragmentation with a beam from RIKEN
Ring Cyclotron. A schematic drawing of the rotatingcatcher system is shown in Fig. 1. On the first stage,
secondary particles separated from the primary beam
are particle-identified by a combination of time-offlight and dE / dX measurements. Two silicon .tiEcounters are set in front of the catcher with anenergy absorber between them. The absorber is forparticle identification. The last .tiE-counter is position sensitive to record the landing position on thecatcher. The catcher is a rotating Al plate of about
1 mm in thickness (peripheral part) and 350 mm inradius. The angular velocity of the catcher is variable in the range of 0.1-10 rps in order to match therotating velocity to the life of an objective nuclide.
Emitted f3-rays from fragments on the rotatingcatcher are detected by position sensitive plastic strip
counters and E.a-counters placed behind the strip
counters. Each strip is a plastic scintillator of 1 mm

in thickness, 2 mm in width, and 27 mm in length.
One hundred chips of the strip are set along thepass of rotation. The minimum distance between
the catcher plate and them is about 1 mm. Epcounters are consisted of six plastic scintillators of
about 80 X 80 X 150 mm in size and set at a distance of 10-15 cm from the catcher.
Position information is used to connect a f3-ray
and a particle identification signals via angularvelocity of the catcher. Therefore, energy and timeinfonnation of f3-rays can be recorded on a magnetic
tape with information on the corresponding parent
nuclide.
The width of the strip counter and the distance
between the counters and the rotating catcher havea large influence on the position resolution .tix. If
there is an isotropic point source at a distance d fromthe counters, position distribution becomes a Lorentzian type of FWHM = 2d. The width of the strip
counter, therefore, is desirable to be 2d. The condition of suppressing the probability that there are
more than two stopped fragments in a width .tix on
the catcher is given by
Llx .N<lprojectile fragmentsv-

where v is the velocity of rotation and N is the
stopping rate of fragments on the catcher. From
this equation, the maximwn counting rate becomesN m ax = V / .ti X = 10 2-10 4 cpS depending on the life ofan objective nuclide, when .tix = 2 mm.
This system will be used at 20-degree course1) as
one of the first experiments at RIKEN Ring
Cyclotron.
Reference
Fig. 1.

A schematic drawing of the rotating catcher system.

* Department of Applied Physics, Tokyo Institute ofTechnology.

1) M. Fukuda, T. Kubo, I . Tanihata, K. Asahi, M. Ishihara, and H. Taketani: p.142 in this report.

147
RIKEN Accel. Prog. Rep. 20 (1986)

111-5-14.

Radiation-Detected NMR Measuring System for Short-Lived
Radioactive Isotopes
H. Kumagai, K. Asahi, and M. Ishihara

Projectile fragmentations at intermediate energies
provide a means to produce a wide variety of unstable nuclei which have been difficult to access sofar. Spin-polarized unstable nuclei become available
if these reactions are combined with a polarizing
method such as those using laser optical pumping,tilted-foil, or ultra-low temperature techniques. Furthermore a simple model consideration of the fragmentation process1 ) suggests that these product nuclei
are spin-oriented even without any polarizing technique. These expectations motivate a number ofinteresting experiment 2 , 3 ) involving the nuclear magnetic resonance (NMR) detected through a change
in the angular distribution of nuclear radiations. We
here report a system we have recently developed forsuch measurements.
Block diagram of the system is shown in Fig. 1.
The essential part of the present system consists offive electronics modules designed for the present purpose. A programmed sequence generator (PSG)
t o Accelerator

provides signals to control the procedures of themeasurement including beam bombardment, detection of radiations emitted from product nuclei, andapplication of the radio frequency (RF) field, according to the prearranged sequence stored in thememory. Figure 2 illustrates the procedures taken
in a typical experiment. More detailed descriptionof PSG is given elsewhere. 4 ) A two-channel digitalto-analog converter (DAC) feeds analog voltages toan RF oscillator to control the frequency and amplitude of the RF field. Any functional form can bechosen for the time variation in the frequency andamplitude, by loading properly programmed voltage
steps to the PSG memory. At every event, the signal
from the counter electronics, non-stop time-to-digitalconverter (TDC) registers the time elapsed after theend of beam bombardment. The clock in non-stop
TDC starts at the end of beam bombardment andcontinues to run upon accepting an event signal.
This feature is very useful when f3 decay process is(Beam Interrupt)

r----J 11 Aux iIi a ry

Counter

Crate Controller(CES 2180)

Electronics

to Microcomputer

L ___________ _Fig. 1. Block diagram of the control system for radiation-detected NMR m easurement. Shaded boxes
represent the modules developed in this study.

H . Kumagai, et al.

148

and input register are processed in auxiliary crate
controller, and the resulting multi-dimensional histograms are constructed in two modules of 16 bit X
256 kword histogramming memory (HM). Sixteen
chips of 256 kbit memory are installed in each HM
module. They are backed up with batteries so thatthe data may hold at an accidental power failure.
The presently developed modules constitute a compact and flexible system, for which a small-size microcomputer can be employed for on-line monitoring
and final recording of the data on a floppy disk.

beam
RF ampI i tude
RF f r equency
cou nt gate

TDC rese t

o

40

80 ms

Fig. 2. Typical time chart for the procedures taken in theexperiment.

involved, since more than one events per beam-intervening period (usually chosen to be of the sameorder as the decay lifetime) are needed to attain arequired statistics in a limited length of the beamtime. The data obtained from non-stop TDC, PSG,
and other CAMAC standard modules such as ADC

References
1) K. Asahi and M. Ishihara: p.21 in this report.
2) K. H. Tanaka, Y. Nojiri, T. Minamisono, K. Asahi, and
N. Takahashi: Phys. Rev. C, 34, 580 (1986) .
3) K. Asahi, M. Ishihara, T. Shimoda, T. Fukuda, N. Takahashi, K. Katori, S. Shimoura, N. Ikeda, C. Konno, K.
Hanakawa, A. Nakamura, T . Itahashi, Y. Nojiri, andT. Minamisono: J. Phys. Soc. Jpn., 55, Suppl., 1032
(1986) .
4) H. Kumagai, K. Asahi, and M. Ishihara: p.1 49 in thisreport.

149

RIKEN Accel. Prog. Rep. 20 (1986)

111-5-15.

Programed Sequence Generator

H. Kumagai, K. Asahi, and M. Ishihara

Measurement of the decay of short-lived isotopes
produced with medium-energy heavy-ion beams obtained from RIKEN Ring Cyclotron will provide
useful information for the studies of f3 decay, nuclear
structures, and solid-state physics. Such studies essentially use a periodically repeated sequence ofprocedures, such as target bombardment with apulsed beam and subsequent manipulation of external
conditions followed by detection of decay as a function of time ;1) therefore, a versatile control system
for these procedures is needed for the experiment
to be carried out efficiently. We have made a smallsize electronics module which provides several control signals to the experimental devices following aprearranged sequence stored in memory. Use of sucha dedicated module facilitates accurate timing control and largely simplifies software consideration forthe data acquisition system, compared with relying
Read LAM status regi.

~

24/
~
Go

,..------, G,-=yW" Memory48(8 k>, 43 \ I~

24

24 24

G
'-3.-r--f---'

Start
Reset

Tr iggerFig. 1. Block diagram of the programmed sequence generator. Circuits for the CAMAC function decoder are notshown.

n

n+ I

CNTL
( #8) = I :" END "TIME

N = I - 15;
N=

Fig. 2.

0:"PAUSE"n > 10:

LI t = ..

n= 1- 9Format of 48 bit data stored in the memory.

on the help of a computer which concurrently
handles the data acquisition.
The block diagram of the module is shown in
Fig. 1. A 48 bit, 8 kword static random accessmemory (SRAM) contains a programed sequenceof operation loaded from a computer. Each wordcorresponds to an individual step of the sequence,and has a structure illustrated in Fig. 2. It consistsof a 40 bit code (composed of 16 bit DAC-R, 16 bit
DAC-L, and 8 bit CNTL) representing the output .
states of the control signals, and an 8 bit code
(TIME) specifying the time duration for these output states to be maintained. At the end of theduration the address counter is incremented to initiate a subsequent step of the sequence. The datastored in DAC-L and DAC-R are fed through adifferential line driver to two 52-pin connectors on
the front panel. These signals are normally used as
inputs for a 2-channel 16 bit digital-to-analog converter (DAC ) , which provides the analog signals tocontrol the experimental conditions such as the frequency of the radio frequency (RF) field for NMR.
The 8 bit ~ata in CNTL are buffered by 50 n line
drivers and fed to output coaxial terminals. These
logic signals are typically used to start and stop abeam, to gate counter signals, and to trigger external
devices. The address counter is cleared when END
code (represented by "1" state in CNTL#8) is encountered, thus enabling the repetition of the sequence by restarting at address O. PAUSE code is150

H. Kumagai, et al.

also available, which stops the sequence and brings
the module into the waiting state for an input signal
to restart. The module accepts eight external signals
which interrupt or modify the operation.
The present functions are installed in a doublewidth CAMAC standard module and controlled uta
the CAMAC data bus.

Reference
1) K. Asahi, M. Ishihara, T. Shimoda, T. Fukuda, N. Takahashi, K. Katori, S. Shimoura, N. Ikeda, C. Konno,
K. Hanakawa, A. Nakamura, T. Itahashi, Y. Nojiri,
and T. Minamisono: l. Phys. Soc. lpn., 55, Suppl. 1032
(1986) .

151

RIKEN Accel. Prog. Rep. 20 (1986)

111-5-16. Test-Bench System for On-Line Data Acquisitions System
of RIKEN Ring Cyclotron Facility
T. Ichihara, T. Inamura, K. Asahi, and M. Ishihara

A prototype data acqUIsItIOn system based on
Micro VAX-II for the test and development of the
new data-acquisition system for RIKEN Ring Cyclotron facility was installed last year. We have developed software of this system for special-purpose
experiments such as the experiments at the GANIL(under Japan-France collaboration program) carriedout successfully in May 1986.
This year we have improved the system as follows:( 1) Main memory size of the Micro VAX-II
computer was increased from 2 MB to 6 MB.
( 2) 1600 BPI, a 75 IPS magnetic tape driver
was installed. ·( 3) A new 270 MB Disk driver was installed.
( 4) A laser beam graphic printer (CANON
LBP-8/ A2) was installed.
( 5) A Tektronix 4205 intelligent color graphic
display and a 4696 color hard copy (ink jetmethods) unit were installed.
( 6) Serial terminal lines (RS-232C) were increased from 5-lines to 9-lines.
( 7) The maximum user number of the Micro
VMS system (software license) was increased
from 2 to 8.
( 8) A 9600 bps 4-ch optical modem was mstalled.
( 9) Three 9600 bps base line 2-wire modems
were installed.
(10) Connection to the NTT DDX-P and KDD
VENUS-P public network system (X.25) at
9600 bps is in progress.
(11) A local area network (LAN) system basedon the Ethernet hardware (10 Mbps) and the
Decnet software is in progress.

/ICC : CES 2180 (Jl1
CC

Micro VAX II: Kinetic 3320~

f------.---i A

5MB

RS-232C

VT-220Fig. 1. A block diagram of the Micro VAX-II and CES
2180 ACC (J-ll) data acquisition system for the GANIL
experiments and for test and development of RIKEN
Ring Cyclotron data acquisition system.

The new configuration is shown in Fig. 1. We
have developed the device driver software for the
Kinetic 2920-3920 crate controller which is capableof block-mode DMA data transfer. The maximum
data transfer rate is 500 kB / s. We are now preparing to connect our computer system to a public
network system (NTT DDX-P and KDD VENUSP) with X.25 protocols.
The experiments with RIKEN Ring Cyclotron
will be started in April 1987. To match this schedule we are preparing the final design of the whole
data acquisition system for RIKEN Ring Cyclotron.
In 1987, some part of this new data acquisition
system will be installed in RIKEN Ring Cyclotron
facility.

152
RIKEN Accel. Prog. Rep. 20 (1986)

IV. NUCLEAR DATA
1.

Status Report of the Nuclear Data GroupA. Hashizume, Y. Tendow, Y. Ohkubo, T. Nozaki, and K. Kitao

In this period efforts were focused on the threefollowing items. The first is related to the operation
and application of programs related to EXFOR systems. The second is the compilation of new EXFOR,
files of nuclear reaction cross sections. The third is
the mass-chain evaluation work of nuclear structure
for the implement of Evaluated Nuclear Structure
Data File (ENSDF) and compilation of reference
files originated in Japan.
(1) The programs presented by the courtesy of
IAEA were implemented and have been operated
successfully. They are Check Entry Run, Extractfrom Master Run, Prepare Edited Exfor Listing Run,and Prep air Author Proof Listing Run. The functions of these programs were explained in Ref. 1. As
the Check Entry Run is very usefull for the error
check of first edited files, this program has been distributed to the EXFOR compilers. The center hostcomputer M-380 has been replaced with M-780; a
microcomputer of PC9801 has been effectively used.
By utilizing a graphic display (No. 084) and its
supporting program, a flexible graph describing
program has been completed. This program canmake graphs using the data filed in EXFOR. Whenmany experimental results are expressed in a graphic
form, it is very convenient to know the present
status of the results. We are now editing thesegraphs of excitation curves.
(2) The reactions in which we mainly interested
are those whose products are utilized in mediobiological applications. The cross sections of the reactions
which produce the following isotopes have been compiled in the EXFOR file. The isotopes are llC, l3N,
15 0, 18F, 28Mg, 52Fe, 67Ge, HAs, 77Br, 82Br, 77Kr, 81Rb,
82mRb, ll1In, 123Xe, 127Xe, 123 1, 1241, and 125 1 nuclei. 1)
We have also compiled the reaction cross sections
for various combinations of incident particles andtarget nuclei described in the same reports.
Furthermore, since the last meeting of the nuclear
data center held in October 1985/> we begun compilation of the integrated nuclear reaction cross section data originated in Japan in the EXFOR files.
The main sources of recent data are annual reports
published by universities and institutes having accelerator facilities.

In collecting the excitation functions of reactions
which produce the radioisotopes for medical use, wehave found some discrepancies between the experimental results. 3,4) In view of these discrepancies, werealized the importance of the standard or monitor
reactions. In the foil activation method by which
the cross sections are measured, a target consists ofa stack of two kinds of foils, one is for investigationand the other for monitoring. The 12C (p, pn) llC
reaction can be used as a primary standard for
proton-induced reactions. In particular, the absolute
cross sections of this reaction have been measured
in a wide range of incident energies. For other than
12C (p, pn) reaction, 27 Al (p, 3np) 24Na, 63CU(p, 2n)62Zn , 65CU (p, n) 65Zn , and 65CU (p, pn) 64CU reactions
are used for monitoring. For deuteron, the 27 Al (d, x) UNa reaction is used. For alpha induced reactions, anan aluminum target is also used to induce 27Al ( a, x) 24Na. Typical errors of measured cross sections of
the 12C (p, pn) llC reaction are within 3 to 5 % in theenergy range between 20 MeV and 28 GeV. The
data of these reaction cross sections were compiled
and compaired. The errors of these monitor reactions
are scattered between 3 to about 10%, dependingon the kind of reactions and incident energies.
(3) The recent reference files published periodically by Brookhaven National Laboratory (BNL)should cover all references in the field of nuclear
physics, but the reports published in Japan were
not completely filed. Upon the request, the references of annual reports and quartary reports published in Japan were compiled and were sent to the
BNL Data Center. In connection with this work,
all reference files of Nuclear Data Sheets were received from the Japan Atomic Energy Research Institute. In these files, BNL uses an extended EBCDIC
code and, for the printing out, the change of thecode was required. The code change program fromthe extended EBCDIC code to the ATF (Advanced
Text Formation for science) system in FACOM anda search program of intended references were made.
By applying these program, a reference book of r-ray
induced reactions is nearly completed. This reference book is motivated by the evaluation of activities
induced by r-ray irradiation of foods.

A. Hashizume, et ai.

(4) For the mass chain evaluation of nuclear
structure data, we have started to evaluate thenuclear structure of the A = 177 mass chain. This
mass chain is different from the mass region in which
our Japanese group owes, but this evaluation work
is started in advance the schedule of evaluation on
nuclear structure data in world-wide network.

153

References
1) A. Hashizume, Y. Tendow, Y. Ohkubo, and T. Nozaki:
RIKEN Accel. Prog. Rep., 19, 162 (1985) .
2) Report on the 8th IAEA Consultants' Meeting of the
Nuclear Reaction Data Centers, INDC (NDS) ·178 Oct.
(1985) .
3) A. Hashizume and Y. Tendow: RIKEN Accel. Prog.
Rep., 19, 163 (1985) .
4) K. Kitao, A. Hashizume, Y. Tendow, · and Y. Ohkubo:
p. 156 in this report.

154

RIKEN Accel. Prog. Rep. 20 (1986)

IV-2.

Nuclear Reaction Data for 52Fe Production
Y. Tendow, A. Hashizume, Y. Ohkubo, and K. Kitao

As a part of the compilation of nuclear reaction
data concerning radioisotope production for medical
applications, the excitation functions and production
yields for 52Fe appeared so far in publications werereviewed.
The positron-emitting 52Fe (Tl /2 8.3 h) has beenrecognized as a useful agent for bone marrow imaging in studying the erythropoietic tissue or othermetabolic processes. Other iron isotopes such as 55Fe
and 59Fe are not suitable for this purpose because
their half-lives are too long and the energies of accompanying r-rays are too high or low. They act as
harmful or interfering impurities for patients as well
as for measurements. It is, therefore, necessary toestablish a 52Fe production method which IS freefrom other iron impurities as less as possible.
112Fe is also used as the parent nuclide for a 52Fe52mMn generator system which separates 52mMn (Tl /2
21.1 m). Radiomanganese has shown its usefulness
as an imaging agent in myocardial diagnosis. 52Fe
containing other radioiron impurities can be used forthe generator system because the iron impurities result in no interfering manganese daughters. In thiscase, 52Fe producing reactions which would be accompanied with significant production of other radioiron become usable.
Experimental excitation functions for the 52Fe
producing reactions, fundamental data to evaluate
production yields, have not sufficiently been accumulated. It appears that we are not in the stage tomake an evaluation of 52Fe production cross sections
for recommendation. Table 1 shows the experimental excitation functions, and Table 2 the production
yields measured both appeared in publications to date.
Table 1. Excitation functions for 52Fe.
Reaction

Energy {peak}
(MeV)

(Jmax

(mb)

TargetRef.

55Mn(p,4n)54Fe(p, p2n)54Fe(p, t)
54Fe(p, dn)
59CO(p, spall)
58Ni(p, ap2n)52Cr(3He, 3n)59Co(a, 3p8n)54Fe(a, a2n)54Fe(6Li, X)

40- 73 {54}33- 44 {45}
18-23
33- 60 {45}59-98{77}42-56
23- 44 {35}113- 170
38- 4055- 94

1.4
1.4
0.3
4
0.44
1.8
5
0.26
0.34
4.8

Mn metal
Fe metal
Fe metal
Fe metal
Co metal
Ni metal
Cr metal
Co metal
Fe metal
54Fe

1
2
3
4
5
6
7
8
9
10

Table 2.
Reaction
55Mn(p,4n)55Mn(p,4n)55Mn(p,4n)55Mn(p,4n)55Mn(p,4n)58Ni(p, spall)Cu(p, spall)Fe(p, spall)Cu(p, spall)Fe(p, spall)Ni(p, spall)Ni(p: spall)Ni(p, spall)Ni(p, spall)
52Cr(3He, 3n)52Cr(3He, 3n)5ZCr(SHe, 3n)52Cr(8He, 3n)5ZCr(SHe, 3n)50Gr(a,2n)
50Cr(a,2n)
50Cr(a,2n)
Cu(1zC, spall)

Production yields for 52Fe.

Energy(MeV)
65
70- 5070
73-39
60- 39
70
193.0
590
590
590
590
588
200
800
800
45.5
23
40
33
45- 30
65
30
30
1,032

Production
yield

TargetRef.

MnOz
Mn metal
Mn metal
Mn metal

1213(p.Ci/ p.Ah)

160
200
98
670
380
110
50
0.25mb0.80mb0.27mb
0.675mb
700
67
3,300
138
50
0.7
50
20
22.5
8jgm

3.3
0.5
0.35mbMn metal
Ni metal
Cu metal
Fe metal
Cu metal
Fe metal
Ni metal
Ni metal
Ni metal
Ni metal
Cr metal
Cr metal
Cr metal
Cr metal
Cr metal
Cr metal
Cr metal
Ce metal
Cu metal

11

14
13
15
16
17
14
14
18
7
19
20
21
22
23
24
25
26

Although there are a variety of production methods available, a rather limited number of schemes
have been conveniently utilized in practices fornuclear medical applications so far. In practicalpoint of view, noticeable reactions among those are(3He,3n), (a, 2n), (p, 4n), and (p, spallation).
The natCr(3He, 3n) 52Fe reaction seems the mostsuitable to produce the 52Fe almost free from impurities. The reaction is feasible with a relatively
low energy cyclotron.
The natCr(a, 2n) 52Fe reaction also produces asmall amount of 55Fe impurities. Though not a pure
52Fe, the product is adequately usable for a generator
system.
The natMn(p, 4n) 52Fe reaction provides 52Fe in
relatively high yields, but produces also iron impurities as in the (a,2n) reaction. This reaction
seems to be convenient when proton beams of about
60 MeV are available.
The (p, spallation) reaction which requires a highenergy facility of larger scale has been reported toY. Tendow, et al.

give the highest yields for 52Fe. This reaction isconsidered advantageous for the carrier free separation of 52mMn in the Fe-Mn generator system because
the reaction employs targets other than manganese.
Generally speaking, the data for 52Fe production
reactions are still insufficient and further experiments
are needed.
References
1) K. Suzuki: Radioisotopes, 34, 537 (1985) (in Japanese).
2) R. Michel, G. Brinkmann, H. Weigel, and W. Herr:
Nucl. Phys. A, 322, 40 (1979) .
3) B. L. Cohen and T. H Handley: Phys. Rev., 93, 514(1954) .
4) I. R. Williams and C. B. Fulmer: Phys. Rev., 162, 1055
(1967) .
5) R. A. Sharp, R. M. Diamond, and G. Wilkinson: Phys.
Rev., 101, 1943 (1956) .
6) S. Tanaka, M. Furukawa, and M. Chiba: J. Inorg. Nucl.
Chem., 34, 2419 (1972) .
7) M. W. Greene, E. Lebowitz, P. Richards, and M. Hillman: Int. I. Appl. Radiat. Isot., 21, 719 (1970) .
8) R. Michel and G. Brinkmann: Nucl. Phys. A, 338, 167(1980) .
9) S. Tanaka, M. Furukawa, S. Iwata, M. Vagi, H. Amano,
and T. Mikumo: J. Phys. Soc. lpn., 15, 1547 (1960) .
10) J. Jastrzebski: Phys. Rev. C, 19, 724 (1979) .
11) G. B. Saha and P. A. Farrer: Int. J. Appl. Radiat. Isot.,
22, 495 (1971) .
12) T. H. Ku, P. Richards, L. G. Stang, Jr., and T. Prach:Radiology, 132, 475 (1979) .

155

13) L. Mausner, T. Prach, and P. Richards: Am. Chem.
Soc. Symp. Ser., No. 241, 77 (1984) .
14) R. W. Atcher, A. M. Friedman, and J. R. Huizenga:
Int. J. Nucl. Med. Bioi., 7, 75 (1980) .
15) J. E. Cline and E. B. Nieschmidt: Nucl. Phys. A, 169,
437 (1971) .
16) C. J. Orth, H. A. O'Brien, Jr., M. E. Schillaci, B. J.
Dropesky, J. E. Cline, E. B. Nieschmidt, and R. L.
Brodzinski: I. Inorg. Nucl. Chem., 38, 13 (1976) .
17) V.J. Sodd, K. L. Scholz, and J. W. Blue: Med. Phys.,
1, 25 (1974) .
18) F. J. Steinkruger, G. E. Bentley, H. A. O'Brien, Jr., M. A.
Ott, F. H. Seurer, W. A. Taylor, and J. W. Barnes: Am.
Chem. Soc. Symp. Ser., No. 241, 179 (1984).
19) J. R. Dahl and R. S. Tilbury: Int. I. Appl. Radiat. Isoto.,
23, 431 (1972) .
20) Y. Murakami, F. Akiba, and O. Ezawa: Proc. Symp. New
Development in Radiopharmaceuticals and Labelled
Compounds, IAEA, Vienna, Vol. I, p. 257 (1973) .
21) G. V. S. Rayudu, S. P. H. Shirazi, E. W. Fordham, andA. M. Friedman: Int. J. Appl. Radiat. Isot., 24, 451 (1973) .
22) R. Bett, J. G. Cuninghame, J. A. B. Goodall, J. I. S. Hill,
H. E. Sims, H. H. Willis, and A. L. Nichols: U.K. At.
Energy Auth., AERE-R 9453 (1979).
23) Y. Yano and H. O. Anger: Int. J. Appl. Radiat. Isot.,
16, 153 (1965) .
24) M. L. Thakur, A. D. Nunn, and S. L. Waters: Int. J.
Appl. Radiat. Isot., 22, 481 (1971) .
25) D. J. Silvester and J. Sugden: Nature, 210, 1282 (1966) .
26) T. Lund, D. Molzahn, B. Bergersen, E. Hagebo, I. R.
Haldorsen, and C. Richard-Serre: Z. Phys. A, 304, 43(1982) .

156
RIKEN Accel. Prog. Rep. 20 (1986)

IV-3.

On Nuclear Data for Production of 77Br

K. Kitao, A. Hashizume, Y. Tendow, and Y. Ohkubo

A survey on the published nuclear reaction data
for the production of 77Br by charged particles andthe entry work of these data to a data library, maintained by Nuclear Data Section, International Atomic
Energy Agency, was performed, and the compilationof these data including thick target yields has been
also continued.
Radioactive isotopes of bromine have been considered to be suitable agents to prepare labeled radiopharmaceuticals. Because the compounds labeledwith bromine are more stable than those with otherelements owing to the stronger bond to carbon ascompared with that to iodine. Among radioisotopesof bromine, 77Br is most favorable because of its
rather longer half-life (Tl/ 2= 57 h) and lower-energy
r-rays of 239 keV (abundance 23.9%) and 521 keV(23.6%).
77Br is produced directly with charged-particle
reactions or is obtained as decay products of 77Kr
(Tl/2 = 77.4 min). Since the method of productionof 77Br with the a-particle-induced reaction onarsenic was developed by Helus,1) following reactions
have been proposed, and the cross sections or the
thick-target yields were measured:
E= 14.2 MeV
75As(a,2n)
77Se (p, n)+
E= 2.2 MeV
78Se (p,2nV
E= 12.8 MeV
79Br(p, p2n) +E= 19.2 MeV
81Br(p, p4n) +E= 29.3 MeV
79Br(d, p3n)E= 21.7 MeV
81Br(d, pSn)
E= 35.4 MeV
79Br(p, 3n) 77Kr
E= 23.0 MeV
81Br(p, Sn) 77Kr
E=41.3 MeV
79Br(d, 4n) 77Kr
E= 2S.6 MeV
81Br(d,6n)77Kr
E=36.2 MeV
76S e (3He, 2n) 77Kr+
E = 6.S MeV
77S e (3He,3n)17Kr+
E= 14.2 MeV
78Se (3He, 4n) 77Kr
E = 2S.1 MeV
76Se (a, 3n) 77Kr
E = 28.2 MeV
Mo(p, spallation) 77Br

E:

threshold energy
enriched target was used
As mentioned above, few data have been obtainedwith the enriched target, while practical data suchas thick-target yields have been given in almost published papers. It is reported that the errors in themeasurement of cross sections were estimated to be+•1000 ~----~------~------.------,.,(.~.'.'.

",

,/

j)

.§
I:

o

~

"
,'/

"

"

"-

""

/.·;l'". . . . .... . .~.~~.',_,

100

:g

0,

...

" .,
I

Q)

C/')

.'

fJ

.:

:

"

I. ! I:

CI)
Cf)

o

f /:,

l

(3

;

I

:

I

:

Q)

I

!

.~

u~

.... --/-......

,

f "

:

10

I

:

iii

Lundqvist et al 1979

; ,
f :

Nozaki et al 1979::

Diksic et al 1979Ij :De Jong et al 1979:.
,

Weinreich and Knieper 1983

I

I

I

1

20

30

40

50

Incident Proton Energy (MeV)

Fig. 1. Cross sections measured for the proton-induced reaction with bromine of the natural isotopic composition.

10-25%. Figure 1 shows large discrepancies between
excitation functions measured for Br + p reactions.
Diksit et al. 2 ) compared the experimental excitation
function with the theoretical prediction by intranuclear cascade and two pre-equilibrium models
followed by equilibrium evaporation on the 79Br (p,3n) and (p, p2n), and 81Br(p, 5n) and (p, p4n) reactions (Fig. 2).
The 77As(a, 2n) 77Br (15As has 100% naturalabundance) is most widely used for production of
77Br with bombarding energy of 28-30 MeV. Selenium consists of many isotopes. Both 77Se (p, n)
and 78Se (p, 2n) 77Br reactions are also used practically, but enriched targets should be used to prevent
contamination with other isotopes. The productionof 17Br by the spallation process allows the preparation of a batch with larger activities. The crosssections for the spallation of Mo with 800 MeV
protons were measured. The Se (3He, xn) 77Kr reactions have resulted in considerably lower yield.
Measurements of cross sections and thick-target
yields were carried out by using stacked foil techniques, with following reactions as monitor: 27 Al (p,3pn) 24Na, 63CU(p, p2n) B1CU, 63CU (p, 2n) 62Zn , 63CU_

157

K. Kitao, et aI.

,'~-

l

10 2 1-

-

"'"

/ ;'

,","

I !/.f'f
t ~
I ;f
"
"'I Y
". I
fA
" .. "I If

:8
()

(I)

en

l-

(;
10'1ll-

-

~''''

If

.sc
0

'"

!~"'\..

~

II)
II)

......... ,

"

I ff

-

II

-

I

I

40

50

60

70

80

90

Ep (MeV)Fig. 2. Comparison of theoretical and experimental cross sections for 79Br (p,3n). Experimental values are from Diksic
et al.2 > ---, Internudeon cascade-evaporation model; - ' -,Gadioli's excitation model; - - , pre-equilibrium geometrydependent hybrid model.

(p, n) 63Z n , 27 Al (d, 3p2n) 24N a, 63eu (3He, p3n) 62Zn,
and 65eu (3He, 2n) 66Ga.
For the cross sections of 27AI(p, 3pn) 24Na reaction,
the values of 6-8 % were cited as errors. It is reported that the results of integrated beam currentsmoni tored by using the 6Seu (SHe, p3n) 62Zn and
65eu (3He, 2n) 66Ga reactions agreed within 10% .
The errors in the cross sections for the 63eu (p, n) 63Zn reaction with proton of higher than 30 MeV
and the 63eu (p, 2n) 62Zn reaction with proton ofhigher than 40 MeV were estimated to be 15
fora natural copper target owing to the contributions
from the 65eu (p, 3n) 63Zn and the 63eu (p, 4n) 62Zn
reactions, respectively. Generally speaking, however,definite information on the reliability of these monitor
reactions is still lacking. Thus, the critical evaluation
for these monitoring reactions is essential in thecompilation of cross sections for the production
reactions.

ro

References
1) F. Helus: Radiochem. Radioanal. Lett., 3, 45 (1970) .
2) M. DiksiC, J.-L. Galinier, H. Marshall, and L. Yaffe:
Phys. Rev. C, 19, 1753 (1979) .

158
RIKEN Accel. Prog. Rep. 20 (1986)

On 1241 Production Cross Section

IV-4.

A. Hashizume, Y. Tendow, K. Kitao, and Y. Ohkubo

1241 is often produced as a by-product of 123 1 which
is one of the most useful radionuclides for nuclear
medical studies using computed tomography. Because
1241 has a half-life (4.8 d) longer than that of 123 1(13.2 h) and emits many higher energy r-rays, theformer becomes undesirable impurity in vivo studies.
It is important, therefore, to learn the production
yield of 1241 relative to that of 1231.
The excitation functions obtained for the 1271 (p,5n) 1231 reaction were compiled previously in Ref. 1.
The 1271 (p, x, y) type reactions have been studied by
Diksic and Yaffe 2} in the energy range from 20 to
85 MeV. Though the starting point of excitation
function as well as the cross sections of 1271 (p, p3n)1241 show a small difference from those of 1271 (p, 5n),the peak of excitation function of the (p, p3n) reaction is more broad than that of the (p,5n) reaction as shown in Fig. 1. In the region of higher
incident energies, Kuznetsova et al. 3 ) investigated thecross sections between 100 and 680 MeV and Landenbauer et aU) studied the cross sections in theenergy range from 250 MeV to 1 Ge V where thecross sections decrease to 1.8 mb.
Above authors also compared the experimental
cross sections with calculated ones based on a Monte
1000~~---'---'---'---'--'---'--':0 100

S
c

o

:;:;

u

Q)
If)
If)
If)

o

o 10

1~

20

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

30

40

50

60

70

80

90 100Ep( MeV)Fig. 1. Excitation functions of 1271 (p, p3n) 1241 and 1271 (p,5n) 123Xe.

!

I":0 100

E

c

II
I

u

:~

If)

:'

0
0';::;
Q). _ -I-

1-1
/
~-:_:

l:

/

10

- - __ _ -----calculated(precompound)calculated(cascade evaporation).10experiment-1-"_1_1_1_<::-.:::- ~ -

If)
If)

0

'I

J

11

lL-__~__~__~__- L_ _~_ _~_ _ _ _~~

20

30

40

50

60

70

80

90 100Ep (MeV)Fig. 2. Comparison of experimental and calculated excitation functions for 1271 (p, p3n) 1241 reaction.

Carlo internuclear cascade evaporation model andalso based on a preequilibrium model. However, theagreement is not satisfactory. The experimental
values are larger than calculated ones by a factor
of about 2 (Fig. 2).
Reuland and Carett05} investigated the cross sections of (p, n) and (p,2n) reactions for several
targets at an incident energy of 400 MeV. They
revealed that the 124Te (p, n) 1241 reaction has a crosssection of 1.3 mb and 124Te (p, 2n) 3.6 mb. If one
compares the ratio of these cross sections to thoseof other targets such as 52Cr, 63CU, the high (p, 2n) /(p, n) ratio is obtained for the 124Te target. These
differences were attributed by these authors to thedifferences in the ratios of excitation energy andneutron separation energy.
Though the excitation curves for (p,5n) and(p, 3np) are close to each other in the same energy
region, 123Xe, a rare gas, can be easily purified bychemical methods. If an appropriate purification
method is employed, one hardly finds 1241 in 123Xe.
Thus, the importance of chemical separation techniques should be stressed.
The practical yields of 1241 and 123 1 in the Te + p

A. Hashizume, et al.

0.5r---.---.---.---.---~--~--.---.-~

0.4......

~0.3>........

~0.2
>0.1

Fig. 3. The yield ratios of 1241 and 1231 for thick targets asa function of incident particle energies.

reaction have been investigated by Dmitriev et al. 6 )On the basis of their experimental data, the yieldratios of 1241 to 123 1 are shown in Fig. 3 as a function of proton energy, where the yield ratios for otherreaction types were also shown. In these reactions,the ratios of 1241 to 1231 of induced reactions witha Te or an Sb target show low minimum values
compared with those of proton or deuteron induced
reactions.
Yu et al. 7l examined the Xe isotope yields by bombarding 23SU with 11.5 GeV protons. The independent yields of Xe isotopes show mass dependency, and,in the neutron deficient sides, 124Xe and 135Xe show
maximum yields of 3.0 and 3.1 mb, respectively. The
recoil ranges of Xe isotopes in this reaction werealso measured and, for the neutron-deficient products, their ranges were by a factor of more than159

2 shorter than those of neutron-richer ones, suggesting some different mechanism is involved for theneutron-deficient productions.
Fissions of the 209Bi + 12C system were investigatedby Branquinho and Robinson 8) at Manchester University. When the compound nucleus' excitationenergy was 66 MeV, the fission yields were 1.63 X
10-3, 3.73 X 10-3, 3.84 X 10-3, and 0.706 X 10- 4 for
124 1, 126 1, 128 1, and 131 1, respectively. Iodine fission
yields were also examined in the 40Ar + 238U system by de Saint-Simon et al. 9 ) The independent
yield cross sections for 1241 were 0.683 mb for
240 MeV of 40Ar and 2.64 mb for 340 MeV. The
fission yields are discussed from the view point ofcomplete fusion and quasielastic-transfer-induced
fission.
References
1) A. Hashizume and Y. Tendow: RIKEN Accel. Prog.
Rep., 19, 163 (1985) .
2) M. Diksic and L. Yaffe: J. lnorg. Nucl. Chern., 39, 1299
(1977) .
3) M. la. Kuznetsova, V. N. Mekhedov, and V. A. Khalkin:
Sov. Phys. JETP, 34 (7), 759 (1958) .
4) l.-M. Landenbauer and L. Winsberg: Phys. Rev., 119,1306 (1960) .
5) D. J. Reuland and A. A. Caretto, Jr: J. lnorg. Chern.,
31, 1915 (1969) .
6) P. P. Dmitriev, M. V. Panarin, and Z. P. Dmitrieva: At.
Energy, 49, 329 (1978) .
7) Y. W. Yu, N. T. Porile, R. Warasila, and O. A. Schaeffer:Phys. Rev. C, 8, 1091 (1973) .
8) C. L. Branquinho and V. J. Robinson: J. lnorg. Nucl.
Chern., 39, 921 (1977) .
9) M. de Saint-Simon, R. J. Otto, and G. T. Seaborg: Phys.
Rev. C, 18, 1651 (1978) .

160
RIKEN Accel. Prog. Rep. 20 (1986)

V. ACCELERATOR DEVELOPMENT
1. Status of RIKEN Ring Cyclotron Project in 1986
-Commissioning of RIKEN Ring CyclotronH. Kamitsubo

An Ar12+ beam accelerated to 21 MeV lu was
successfully extracted from RIKEN Ring Cyclotron(RRC) at 15: 34 on December 16. A beam accelerated at RILAC up to 1.28 MeV lu was injected
into RRC. The frequency of the RF systems was
28 MHz for both accelerators. As the oscillator of
the 6th RF amplifier of RILAC was disassembled
for improvement, we were obliged to accelerate ionswith other five acceleration resonators, therefore, thefinal energy was lower than the expected value. For
this reason a harmonic number of 10 was adopted
instead of the designed number of 9.
We started coupled operation of RILAC and RRC
on November 28. It took several days to adjust thebeam diagnostic devices and the buncher installedin the beam transport line from RILAC to RRC byusing the beam and to bring the beam to the first injection bending magnet of RRC.
We succeeded in injection of the beam to thefirst acceleration orbit of RRC on December 3, andthe beam reached the outermost radius on December 10. Then we succeeded in making a complete
isochronous field with a help of the radial phaseprobe on December 16 to extract the beam withease. On December 20 the beam was transported
to the E 1 experimental hall.
The assembly of magnet vacuum chambers wasstarted in January and completed in April. They
were assembled one by one and examined carefully
that air leakage was less than the specified value foreach chamber. Beam diagnostic devices such asradial probes were built in the chambers and tested
in August and September.
The first resonator of the RF system was assembled
in July and the second one in August. After careful
vacuum tests, measurements of the static characteristics of the resonators were pursued in Augustand September. At the same time the assembly of
an amplifier system was continued.
The beam transport line between RILAC and
RRC was installed in July and August. Field distributions were measured for all the bending magnets and the Q-magnets before they were installed

Fig. 1.

Photograph of RIKEN Ring Cyclotron.

in the beam line. Pipes and chambers for the beamdiagnostic devices are made of aluminum. The injection elements such as bending magnets in thecentral region, magnetic inflection channels, and anelectric inflection channel were built in the positions
in July and August. Extraction elements and a beamtransport line to the E 1 experimental hall was installed in September. The vacuum test and stability
measurements of the power supplies were performed
after their installation.
Soft-ware development for the control system wascontinued throughout 1986. Those for CAMAC
modules named CIM and DIM, which locally control the power supplies and the beam diagnostic
devices, were mainly written in assembler languageand developed by ourselves. All the programs forthe main control computers are written in UNIX andFORTRAN and developed also by us.
The construction of RRC was completed in September, 1986. Figure 1 shows a photograph of RRC
taken from the south-east corner of the cyclotron
vault. The beam is injected to the other side of RRC
and extracted at this side. Two bending magnets andthe beam transport line to the experimental halls areshown in the foreground.
We continued power tests of the RF systems dur-

H. Kamitsubo

161

RIKEN ACCELERATOR RESEARCH FACILITY( March 1989 )EI: IGISOL(Ion Guided Isotope Separator On line)
E2: Multi':'Particle Correlation Spectrometer
Highly-Ionized Atom Spectrometer
E3: Pion Spectrometer
Irradiation Syste'm for Short-lived Isotope Production
E4: High- Resolution Charged- Particle Spectrometerwith Neutron TOF System
E5: Biomedical Irradiation System
E6: RIPS(RIKEN Projectile Fragment Separator)
E7: Material Irradiation System

Fig. 2.

Plan view of the RIKEN Accelerator Research Facilities.

mg October and November. The vacuum of thewhole system was very good and pressure inside ' thechambers reached 2 X 10- 6 Pa. After the first acceleration trial, the vacuum in the resonators became poor; small leakages were found at weldedparts of the cooling pipes inside the resonators. The
first overhaul of RRC is scheduled in February,
when they will be repaired. Some other repairs andimprovements will also be made. RRC will be open
to the test experiments from April in 1987.
The construction of the second injector, an AVF

cyclotron with K = 70 MeV, and the beam transportlines to the experimental halls will be started. Extension of the building to the west will also start innext year and will be completed in 1988. Threeexperimental halls, which will be used for studies
of nuclear reactions and structure and for biologicalstudies, will be available by the end of 1988. Figure
2 shows a full layout of the building together withthe accelerators, the beam transport lines, and themain research facilities.

162
RIKEN Accel. Prog. Rep. 20 (1986)

V-2.

First Trial of Beam Acceleration In RRC

S. Motonaga, Y. Yano, A. Goto, M. Kase, K. Hatanaka,
T. Wada, H. Takebe, and H . Kamitsubo

At 15 : 34 on December 16, 1986, we succeededin extraction of a 21 MeV I u 12+ argon beam fromRIKEN Ring Cyclotron (RRC). An argon beamof 1.28 MeV lu from RILAC was injected into RRC.
Acceleration was performed with a harmonic numberof 10 instead of 9 (normal operation). This number
was adopted because RILAC was operated with fiveresonators except the last one (sixth), the amplifierof which had been disassembled for improvement.
The whole components were assembled during
the period from January to September, 1986. In
the vacuum chamber equipped with ten 10,000 Z/ s
cryopumps and four 5,000 lis cryopanels, a pressureof 3 X 10-8 Torr was achieved at early October. The
resonators were operated at a dee voltage of 140 k V,
which exceeds the dee voltage required for acceleration of an argon beam at 28 MHz. The isochronous
field of the sector magnets could be arranged withan accuracy of few parts in 10- 4 by the field setting
program. The progress in the first operational trials

for RRC is as follows.
Sept. '86 The whole components were assembled.
The vacuum system was tested and found tobe satisfactory. Transportation of a beam fromRILAC to RRC was tried.
19 Sept. ' 86 All of work related to radioactive
isotopes and accelerators had to be stopped intermittently until the end of November because of aradiation hazard accident outbroken in another section of the institute.
Oct. '86 The RF system was tested. (The 11th
Cyclotron conference, '86-Tokyo, was held.)
28 Nov.-3 Dec. The beam injection system wasadjusted.
29 Nov. The first trial of beam injection was made.
3 Dec. The beam injection to RRC was achieved.
The beam was accelerated up to the radius R =2.87 m. (Note: the extraction radius R = 3.45 m)
5 Dec.-l0 Dec. Adjustment of beam injection,
initial acceleration, beam centering and beam

f-

55

g3

ORBIT PATTERN MEASURED BY MDP2 (December 20, 1986)

Cl

Injected beam
Extracted beam

t.Ll

f-

fZ

t.Ll

e:::
e:::

~

U

U

t.Ll

Ar12+ 1.28 MeV/u from RILAC (Ar 4+)
21 MeV/u

RF fequency 28 MHz
Harmonic number
Dee voltage

~
t.Ll

:r:

10
90kV (inj.) - 120kV (ext.)

f-

~

<

t.Ll
III

1000

1500

2000
f-

55

e:::

o

Cl
t.Ll

f-

U

t.Ll

...J

u..

W

Cl

/~fRADlUS(mm)

2500

3000

3500

Fig. 1. Beam patterns in RRC measured with the radial probe. The abscissa isthe distance in mm from the machine center. The ordinate is the measured beam
current in arbitrary units. The peak around the radius of 3,470 mm is the AI'
beam accelerated to 21 MeV lu.

S. Motonaga, et al.

acceleration were tested. The beam was accelerated up to the extraction radius, but could
not be extracted.
11 Dec.-16 Dec. The trial for beam extraction was
carried out, and we succeeded in extracting thebeam at 15: 34 on December 16. During thisperiod, the beam phase probes installed in the
S-valley chamber were completed, and beamphase was measured using them.
20 Dec. The beam was accelerated successfully andtransferred to the experimental hall E 1 for aninspection according to the radiation-safety

163

regulation by the government.
Thus, the first injection of a beam took only 6 d
and its first extraction 15 d, after the first operationof the whole system of RRC. During this trial
RRC operated with enough reliability and good
reproducibility. Figure 1 shows an orbit patternmeasured with the radial probe MDPI.
After these initial operations, we have carried out
repair of the vacuum system of the RF resonatorfrom the end of January, 1987. The period isscheduled until the end of March, and we will start
the operation again at the beginning of April.

164
RIKEN Accel. Prog. Rep. 20 (1986)

V-3.

Present Status of RF Resonator for RIKEN Ring Cyclotron
K. Ogiwara, T. Fujisawa, S. Kohara, Y. Oikawa, and I. Takeshita

The design of radio-frequency (RF) system for
RIKEN Ring Cyclotron (K = 540) has been alreadydescribed. I}
Two RF resonators have been installed at the sitein September 1986; Fig. 1 is their picture. Theirelectrical characteristics are measured on low-levelsignals from a frequency synthesizer. The results
are compared with the calculation based on a
one-dimensional transmission line approximation. 2 )Measured resonant frequencies of the fundamental
mode and the higher-order ones are shown by dots
in Fig. 2. The solid line shows the calculated
frequency of the fundamental mode and the brokenlines show the multiples of measured ones. The
broken lines cross the higher-order mode frequencies
at several points, where an undesirable mode ispossibly excited by a higher harmonic component
in the RF power. In such a case, the relation between the undesirable mode and the fundamental
mode has to be changed by moving a capacitive
tuner and movable boxes.
In Fig. 3, the shunt impedances (Rs) defined at
the extraction radius and Q-values (Q) are shown together with calculations. The Q-value was deduced
from the width of the resonance curve which wasmeasured by two capacitive coupler coupled very
weakly to the resonator. The shunt impedance wasmeasured by perturbation method using a dielectric
ceramic ball to avoid the effect of RF magnetic
field. The fundamental frequency in Fig. 2 and

Fl*4
/

150

/

/
/

..

/
/

/

o

FI*)

/

/
/

/

~~.~

1/

.",
I

•

~I

"It

Ie.

100
I
N

/

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I

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~

.0
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•

.,. •

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I

;>.

I

(,l

I

C

<11

C1'
~

""'

/ /
50

"

• ..

"

•

.....

.

/

.....

~ •• ;/d"<11•..... /

I

;:s

•••

/ / / /f • " 0 0 .. eo . . . . . . __• - - Fl*2
/ 1). on dee (radial) ,.I..... /
1/2). on dee0~... ......
(azimuthal)...... 0;)0.

/'

1/2 A on dee (radial)//.~ _ ... _I--0----.. .

I~d~entalomode!Fl)

o
100

300

400

500

600

700 ( mm

Distance of movable box to median plane.
Fig. 2. Resonant frequencies of fundamental and higherorder modes.

saoo •• ; No.1 Resonator
O. L:,; No.2 Resonator

c:

XI0

0

3

~

'-' 400

IS

Vl

~

OJ
tJ

300

10 OJ
:J

C
t1l

...-I

'0

~
6
'n
.u

200

::l

100

c

~

4

I

CY

<55

a

Fig. 1. Picture of the RF resonator. A, Dee; B, Movablebox; C, Stem; D, Capacitive tuner.

t1l

t.

<9 \

5

/(s

0

Calculated value X 2/3

20

25 30
35
40 45
Frequency (MHz)Fig. 3. Q-values and shunt impedance.
calculations.

The lines show

K. Ogiwara, et al.

frequency dependences of Q and Rs are well reproduced by the calculations, while measured Q isabout 4/5 of the calculated one, and measured Rs
is about 2/3. Such disagreement is due to the factthat the structure of the resonator is too complex
for one-dimensional transmission line approximation
and resistances of many contacts are not taken into
account.
Relative distributions of RF electric field along
the dee gap were measured in the same way for the

Frequency
(MHz)

4

44.6
QJ

00

~

rl

0

:>

165

shunt impedance. The results are shown in Fig. 4,
where the dee voltages a:re normalized near the beam
injection radius. The radially increasing voltage distribution are obtained. The dee voltages at the
injection and extraction radii for the input power of
220 k Ware calculated from the shunt impedances
and the radial voltage distributions; these are shownin Fig. 5. The input power of 220 kW is enough togenerate the dee voltage required for beam acceleration. Although designed mechanically in up-down
symmetry, the resonator has asymmetry due tofabrication errors to cause the RF electric field inside the dee. This field is undesirable for beam
acceleration. Furthermore, it might disturb beamdiagnostic systems or give rise to local heating of
the structure. The field (vertical component) was
measured with the pickup in the dee as shown in
Fig. 6 (b). Figure 6 (a) shows the ratio of the electric

42.8

QJ
QJ

A

41.5

QJ

:>

...,

-ri

Frequency-20MHz

<0
rl
QJ

38.4

p::

2

34.5
lower dee
Voltage pick-up in the dee

29.1
20.1

'1000

~x

2000

3000

-1

Position along the accelerating gap(mm)Fig. 4. Relative distributions of RF electric field along thedee gap.

+2+4 (cun)Difference between upper and lower
movable box positions.

(b)

(a)

Fig. 6. (a) , Ratio of RF electric field inside the dee to thatof the accelerating gap. The lines are drawn to guide theeye; (b), Dee voltage pickups for low-level test.

500
400

;-

Input power=220kW

300

I

C
QJ

00

...,<0VY

V ,__f-'"
Vin

200

rl

0

:>

V

I

p

100 r-",~_/ // /_,co':>",'"x/- -",~

/

/

kV
QJ

QJ

"0
0

/

+'

/

$..

/

QJ

.....",

x/",4;-'" xI- co - ","'-

'"

0..
~

//

0

tJ

.....

bd

cl'
~i:..,v"'~~ / "'~
20

100

rl

_",+0/ V / /50 f--~

I

200

a
e

/ ~ ~( \

QJ
QJ

0

/

/

V

~

0

QJ

tJ

....... 1

~

30

40

45

Frequency (MHz)Fig. 5. Dee voltage estimated by low-level test for the input power of 220kW. Vex and Vill are voltages at theextraction and injection radii, respectively. The voltage
at the extraction radius required to accelerate various ionsare also shown.

CIl
+'
til

.,..; '
Q

15

30
Frequency

40

45

MHz )

Fig. 7. Position of the coupler for good impedance matching.

K. Ogiwara, et al.

166

0
-1

~

-2

0

....

........

-3

<I

39

-4

32

100

200

Distance of capacitive frequency tuner toFig. 8.

300

dee

330

(mm)

Dependence of the resonant frequency on the capacitive tuner.

field inside the dee to the accelerating field against
difference between positions of the movable boxes.
As we can see, the inner field can be canceled by
setting the boxes in asymmetry.
The RF power is fed into the resonator througha 50 n coaxial feeder line which is coupled with theresonator by a capacitive coupler. Its positions satisfying the impedance matching are realized within
its stroke of 20 cm through the frequency range asshown in Fig. 7.
Fine tuning of the resonant frequency is made bymoving a capacitive tuner. Dependence of the resonant frequency on the capacitive tuner was measured and shown in Fig. 8. The region between two

broken lines shows practically useful position of thetuner.
At the first power test in 28 MHz, a multipactoringarose at the dee voltage of about 300 V and waseasily overridden after pulse excitation with input
power of about 60 kW. We obtained the dee voltage of 140 kV with the input power of 55 k W; it IS
consistent with the shunt impedance measured.
References
1) H. Kamitsubo: Proc. 10th Int. Conf. Cyclotron Appl.,
East Lansing, USA, pp. 257-262 (1984) .
2) K. Ogiwara, M. Hara, and T. Fujisawa: Reports I.P.C.R. ,57, 222 (1981) (in Japanese) .

167
RIKEN Accel. Prog. Rep. 20 (1986)

V-4.

Performance of Power Amplifier of RIKEN Ring Cyclotron
T. Fujisawa, K. Ogiwara, S. Kohara, I. Yokoyama,
M. Nagase, Y. Chiba, and Y. Kumata *The radio-frequency system of RIKEN Ring Cyclotron has been described. 1 ) The main parts of theamplifier were fabricated last year 2 ) and have beentested and improved this year. Figure 1 shows thelatest scheme of the final and driver amplifiers, inwhich the pair of all-pass networks in previous
design 1 ) is replaced with a cascade of a transformer
and an all-pass network, and several electrical constants of the components are changed. The wholesystem was installed in the cyclotron vault in August
1986 and its performance was studied. 3 ) Figure 2
shows tuning characteristics of the plate circuit andFig. 3 matching condition of the output capacitor.
The measurement was carried out on low levelsignals from a synthesizer where the output port was
terminated by a dummy load of 500 as shown in
the inset of Fig. 3 and the plate load resistance was
kept at 180 O. In Fig. 4, the input impedance andtuning characteristics of the cathode circuit are
shown. The parameters are cathode resistances
simulating driving powers for the tube. Figure 5
shows the voltage gain and the input impedance of
the all-pass network. The performance of each element is cohsistent with the design.
In a power test, a parasitic oscillation with a

Ca thode tuning
capacitor 23-450 pF

100

~
6
0

..:I

c
0

50

.....

....
.....
en

0
0.

.0
:J

...,

Cf.l

o
20

Screen by passcapacitor 0.09 pF
Grid by passcapacitor 0.115 pF

I 'bypass
Screen~capacitor

CgL);+CgLg2::200pF* Sumitomo Heavy Industries, Ltd.

45

(MHz)

Fig. 2. Tuning characteristics of the plate circuit of the
final amplifier.

All pass net work

Fig. 1.

40

30Frequency

Schematic drawing of the final and driver amplifiers .

T. Fujisawa, et al.

168

frequency of 650 MHz was detected at the output
port independently of tuning frequency. This parasitic mode was suppressed, by mounting dumping
resistors on the plate tuning circuit as shown in Fig.
6. Table 1 shows typical operating conditions of theamplifier system. The performance is satisfactoryfor most of frequencies, but maximum output powersof the final amplifier are reduced to 160 kW at thecapacitor

frequency around 40 MHz and to 225 k W around
27 MHz. These reductions of the output power arecaused by the 80 MHz resonance between screen andcontrol grids, as explained in Fig. 7 (a), which is
excited by higher harmonic component of tuning
frequencies of 40 or 27 MHz. In order to avoid
the effect of this resonance, we will shift the resonant frequency higher than 90 MHz by improving

13

Phase

..<::
0

150

60

/)

_ -0·_

20

..

""

"0

10
50 ohmc..
"-

RS2042SK

.,

50
-10

(J

..

<:

.,'"

'0

(J

~ 100

40

...,

"
-2 0 ..<::a-

IlDpedance

"-

~

,.

(J

""-

IT
20

"
0

40

30
Frequency

'"::>

45

MH z

"-

'"::>

1.0

50

0

CalculaLed value

C
'M

:>

"-tJI

•

2:

z

c 0.5

'M

o

30

20

'"

Vin

tJI

45

40

tJI

(MHz

B-x
p
9:4

Matching

Q)

Frequency-'"

tran~.

+>.-(

Fig. 3.

Matching condition of the o utput ClP:lcit , 1'.

300 t - - --

vg

40

30
Frequency

c..

f-'m4

:>

20

RS2042SKJ".

01 of' RS20l2CJ

45

(MUz)

Fig. 5. Voltage gain and input impedance of the all-pass
network.

\-----a.
PLATE STUB

.

o

c::

IMPEDANCE
MATCHING

Tuning capacitora;S~ 200~--------~-------------------------o

CAPACITOR

oJ

a.
C!I
o
tJ'I
C

-ri

C

:::I

100r-----------------~~----------­

E-<

o
8

~

'"
o

1500

1000

c::

c:

"t1

N

a;S

~

',--

7.7 ohm><--- )(

15 ohm"""..........

J<.~ .'-..~

o---<r- - - _'0... --~""~---~---.~-<;l~~=-=--~®~:--..:;-::...---,j(~

---

41

a.

.~

500

5.1 ohlll

2030Frequency

40

45

(MUz)

Fig. 4. Input impedance and tuning characteristics of thecathode circuit.

Fig. 6. Resistors
650 MHz.

for suppressing parasitic oscillationatT. Fujisawa, et at.

Table 1.

(W)
17
20
25
27
30
35

-40

450
350
600
660
480
640
640
BOO

40
45

/

Typical operating condition of final and driver amplifier.

Driver amplifier(Vp =6. BkV, V g1 = -125 V, V g2 = BOO V)
Electrode current
RF amplitude
Gl
G2
Plate
Eg(peak) Ep(peak)
(kV)
(rnA)
(A)
(V)
(rnA)

Pre-Amp.
Frequency output
(MHz)
power

200
200
100
50
60
60
50
80

-30
-70
-50
-130
-IBO
-BO
-10

~

'

VOLTAGE DISTRIBUTION'\CONTROL GRI DTERMINAL

/

\,

.

135
160
150
150
160
160
140
150

3. I
3
3.6
3.0
3.9
4.6
3
3.4

CONTROL GRID

C,I,,2'448",i---------I~ 8,,,ss

CAPACITORl'

SCREEN GRID /169

SCREEN GRIDTERMINA L

RS2042sK

5.2
5.B
5
4.7
3.B
4
3. 7
4. 7

Final amplifier(Vp =12.5kV, Vg1 =-340 V, Vg2 = 1,100 V)
Electrode current
RF amplitude
OutputGI
G2
Plate
Ep(peak)
power
(A)
(A)
(kV)
(kW)
(A)
-0.74
-0.6
-0.7
-1.2
-0.6
-1.0
-1.2
-1.0

1.2
1.2
1.2
1.2
1.5
1.3
0.6
1.0

36
39
40
30
37
40
24
35

9.6
10
II
B.6
IO.B
10.7
7.0
7.B

300
300
300
225
324
300
160
290

the connection of the tube as shown in Fig. 7 (b) .
We started beam acceleration test using Ar12+
ions at the frequency of 28 MHz in November 1986.
The resonators were powered at the vacuum pressureof about 1 X 10- 6 Torr. Multipactoring arose at thedee voltage of about 300 V, but it was easily overcome after pulse excitation with input power of about
60 kW. We obtained the dee voltage of 140 kV with
the input power of 55 kW. The automatic frequency
tuning system, the dee voltage stabilizer, and thephase stabilizer were working well. The dee voltage
stability is within ±1.5 X 10-4 and the phase stability
is better than ± O.2°. In the near future we will
make power test of the RF system throughout thefrequency range designed.

CONTROL GR ID TERNI NAL

References
SCREEN GR I D TE RM INAL

TERf'll NA L

FI LAM ENT\' KAPTON SHEETGROUND\TERMINAL;R ID~­

l'CONTROLBYPASS CAPAC ITOR

~i(------- 100 M~1(b)Fig. 7. Equivalent circuit between screen and contwl grids(a) and improvement of connections of control and screen
grids (b) .

1) T. Fujisawa, K. Ogiwara, S. Kohara, Y. Oikawa, 1. Yokoyama, M. Hara, 1. Takeshita, and Y. Chiba: Proc. 10th
Int. Conf. Cyclotron and Appl., East Lansing, USA,p. 311 (1984); T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, 1. Yokoyama, I. Takeshita, Y. Chiba, and Y.
Kumata: Sci. Papers l.P.C.R., 79, 12 (1985); T. Fujisawa, K. Ogiwara, S. Kohara, Y. Oikawa, I. Yokoyama,
1. Takeshita, Y. Chiba, and Y. Kumata: Proc. 1985
Particle Accelerator Conf., Vancouver, Canada, p.2897(1985) .
2) T. Fujisawa, S. Kohara, K. Ogiwal-a, I. Yokoyama, M.
Nagase, and Y. Chiba: RlKEN Aced. Prog. Rep., 19,
170 (1985) .
3) T. Fujisawa, K. Ogiwara, S. Kohara, Y. Oikawa, 1. Yokoyama, M. Nagase, 1. Takeshita, Y. Chiba, and Y. Kumata: Proc. 11 th Int. ConL Cyclotron and Appl., Tokyo,
Japan (1986).

170
RIKEN Accel. Prog. Rep. 20 (1986)

V-5.

Control System of RIKEN Ring Cyclotron

T. Wada, H. Takebe, J. Fujita, T. Kambara, and H. Kamitsubo

RIKEN Ring Cyclotron system is controlled bymeans of three mini-computers, which are linked
with one another through optical fiber 100ps.1) Figure
1 shows a block diagram of the control system.
Computer 1 stores the field mapping data of magnets.
At a request from any control computer (computer
2 or 3) , time consuming tasks such as orbit calculations and transport calculations are performed bycomputer 1 using these mapping data, and the results are sent back to the control computer. Computer 1 is equipped with a CAMAC SHD and canbe used as a back-up computer for the control computers. Computer 1 is also linked with the centralcomputer of the institute (FACOM M-780). Computer 2 controles RILAC through GP-IB using
optical fiber links. Computer 3 controls the ring
cyclotron through the CAMAC bit serial loop. The
console devices are linked with computer 3 withouta CAMAC system. This computer is also linked witha computer (MITSUBISHI MX-3000) of the radiation safety control system. 2 ) For radiation safety,
MX-3000 has the highest priority in accelerator
operation. Before starting operation, an operator

should ask MX-3000 for permission. If any erratic
conditions occur in the safety system during operation, MX-3000 sends back a beam-stop command.
Six CAMAC crates are distributed in four power
supply rooms. One is installed in an operators' console. These CAMAC crates are linked by a bit serial
CAMAC loop of optical fiber cables. A disadvantageof this optical loop is that it has no bypass function
when any crate is powered off.
Two types of intelligent module are used for theinterface between controlled devices and the CAMAC
system. 3 ) CIM is a CAMAC module and DIM isan interface module to each controlled device andinstalled closely to the device. CIM executes message transfer between the control computer and DIM.
Information is transferred between elM and DIM
through plastic optical fiber cables. The maximum
length of this cable is limited to 30 m. DIM executes local sequence control, local surveillance, function generation, and testing. Each DIM has several
digital input/output (DI/DO ) ports and sixteen
analog input (AI ) ports. The DI/DO ports of DIM
for power supply are of a 12 V opto-coupled type.

~~O~P~T~IC~A~L~D~A~TA~WA~Y~16~M~bP~S===1--~~~~~L-~====={=C=ON~TROLSYSTEM}- 200 m

RADIATION SAFETY CONTROL- 200 mLOCAL AREA NETWORK IOMbps~__________________________________~~-=~__________________________~{~CAMACSYSTEM}{ACCELERATon
SYSTEM}

SEC TOR MAGNETINJECTION TRANSPORTI

nr

INJ EC TION/EXTRACTION
TnANSPOR T
DIAGNOS TIC SVACUUM
COO LING{ TSS TERMINA L) C==================================:::================~=================:!J

Fig. 1. Block diagram of control system. SHD, serial highway driver; UP A, U ·Port Adapter; CCL2. Serial crate
controller.

T. vVada, et ai.

Left

Right

Center

L!d

osc

171

ITV

OJ

Fig. 2.

Operators' console.

DIM for beam diagnostics has TTL level DI/DO
ports in order to carryon such high speed exchangeof data as that from a beam profile monitor or anemittance measuring system. For control of maindifferential probes (MDP), DIM are linked to a
dedicated microprocessor. Since high speed control
is performed for the RF system by programable controllers (PC), the main jobs of DIM are start/stopand monitoring. Status and analog values are sent
to the control computer. A vacuum control system
also uses PC. Almost all interlocks and sequencecontrol are performed by PC. Vacuum gauges andthe temperatures of cryopumps are read by DIM. A
residual gas analyzer (QMA) is controlled by a
dedicated microcomputer, and the data are transferred directly to the control computer throughoptical RS232C line. For a cooling system, DIM
only reads the status. The total numbers of ClM
and DIM are 30 and 170, respectively.
Diagnostics of controlled devices is carried out
conveniently by verifying the response of the devices.
For this local diagnostics, an local area network(Ethernet 4 ») with a transmission rate of 10 Mbps isused. Four interface terminals (TIA) are prepared;
two are placed closely to computer 1 and 3, and theother two are closely to the CAMAC stations.
Diagnosis is carried out by plugging a TSS terminal
unit into a port of a nearest TIA. These ports arealso used for displaying machine status in an operator
room or counting rooms by selecting a desired partof the machine on a keyboard. Since this network
links two computers (computer 1 and 3), an operator
is accessible to each computer.
Figure 2 shows an operators' console, which consists of three parts (center, left, and right parts);
the left and right parts are made equivalent to eachother. The console devices are linked directly tocomputer 3 without CAMAC interface. The center
part is prepared for devices such as a lTV, a scope,and error message output CRT. CRT's, #1-#7,

are model VT241 of DEC with touch pannels (TP)on the screens. CRT #8 is VT241 without TP.
CRT's #9 and #14 are low-speed full graphic displays, # 10 and # 13 are high-speed full graphic
CRT's, and #11 and #12 are character displays.
Almost all man-machine interactions are performedby TP's and information is displayed on CRT's, #9# 13. The first assignment of the role to each TP
is done at the center TP (#4).
The operating system OS60 /UMX is a combinationof a real time and UNIX system. The application
programs are first developed in the UNIX system
and later executed in the real time system for highspeed response. The application programs are written
in FORTRAN 77 language. These programs arecomposed of several tens of thousands of steps. The
data base about accelerator devices are almost completed. The required memory is about 20 kB. In
our computer, different tasks occupy independent
logical memory space in order to avoid addressing
overlaps. These tasks exchange information throughthe common area, to which other computers areaccessible through a data way.
Many kinds of programs have been developed forthe man-machine interface with TP. We can use TP
conveniently and flexibly, and layout various types
and colors of push buttons on it. The programs for
DIM of power supply are extensively improved tocarryon high-speed execution.
References
1) T. Wada, H. Takebe, J. Fujita, T. Kambal'a, and
H. Kamitsubo: lIth Int. Conf. Cyclotron and Their
Applications, Tokyo, Japan, Oct. (1986) .
2) I. Sakamoto, S. Fujita, T. Wada, and H. Takebe:p. 206 in this report.
3) N. Nagase, H. Takebe, T. Wada, and K. Shimizu: 11th
Int. Conf. Cyclotron and Their Applications, Tokyo,
Japan, Oct. (1986) .
4) Digital Equipment Corporation: Introduction to Local
Area Network, USA (1982) .

172
RIKE N Accel. Prog. R ep. 20 (1986)

V-6.

Sector Magnet

H. T akebe, T . Wad a, M. Nagase, S. Motonaga, a nd A. Goto
A fi nal field measurement was made in July 1986
along the hill center line cof the sector magnet installed with a vacuum chamber. The cyclingl) process of the sector magnet excitation was slightly

changed, as can be seen from Fig. 1, because themultiple (DACs) current set routine was possible bymeans of a CIM-DIM*,2) micro-program. Figure 2
shows the effects of the excitation histories preceding* elM-DIM: Communication Interface Module and Device
Interface Module .

MAIN & TRIM HAX.
'i"//;//MAI N - 520A (10 kG) BASE FIELD REPROD UCIBILITY

TRIM COILS EXCITED~r-l_'0_0_ _...J;V ';//J2/'>;~

(eM)

0. 99

-5

MAIN COIL EXCITED

Fig. 2. Reproducibility of the magnetic field distributions
measured at field level of lOkG (main coil=520 A, thetrim coils excited), after the cycling process. The fieldlevel before the cycling were a: 0 A; 6 kG (3 h) , b: 300 A;
6 kG (12 h) , c: 520 A; 10 kG (3 h), d: 520 A; 10 kG (3 h ) ,and Ref: 520 A; 10 kG (3 h). The trim coils were excitedat all the level except the case 'a.'

FACTORS x OBJECT CURRENT
I

I

90

60

30

TIME

120

( Min.

Fig. 1. Time chart of the cycling process for the sector
magnet .

MULTI CURRENT-SET CONTROL ON DIM MICRO PROGRAM
Current
End Value ---Example Parameteron Trim Coil Power Supply.

InitialValue -DAC No.

Step time = 100 mSec
Step Current = 1.0 A(St e p Value = Different on
Max.current ofeach DAC No. )Ma x.Current
50 A - 400 An

InitialValue -

Max.DAC Da t a65535 (FFFF

Max . ADC Da t a

409 5

End Value(FFF

DAC No.6

End Value
DAC No.2
Initial _ '"""-_ __ _ __ _ _ _ _ _ _ _ _ _ _--'--_ _ __Value
End Value

InitialI~
DAC No.1
I
Value - -===---------- --------:---......,..." Ti

I

l.<.

I

Start Command

End Me ssag efrom M60

to M60me

Fig. 3. Time chart of a multip le current set co ntrol by th e DIM micro task.

.)
hex
.)
hex

173

H. Takebe, et al.
Po wer Supply R OO lIl

COlllrul R(Xlill

~
I

----~

Comrol Room

Cycling & Pre·set

program

M agncts_ - -"7'--_ _ _ _ _r--'

2. Inj-E xL. Mn g nc ts
3. Tr anspo rt - I
4. T ra ns port -2
5. Tran s po rt-3 . ..

TSS+.--==-----=---,

Preset curren I data
data fi Ie

1. Scc tor

I

Ethernetread

copy.• •••_ -7- .read· -Data · base Ta bl e
( M60 Me mory)

Current se tpr,-o-'g_c,_·\m
_ _

---f,

Multi-c urr. set - - - - - - ,Adress Da t a
BranchCrate
elM No .
DIM No .
DAC No .

-read -- __Current ValueDAC Data
ADe Data. __- -- \vl'll~

Micro - program

POWER
SUPPLY
Fig. 4.

Flow diagram of the magnets power suppli es control sequence.

the cycling on the field distributions along the sector
center line at the same excitation currents (520 A,
10 kG). The reproducibility of the field distributions
was less than 1 G when the excitation level, justbefore the cycling process, was the same as that of
the case c and d, and less than 3 G even when the
excitation levels before the cycling process were different between the case a (0 G), b (6 kG) and thereference (10 kG). Magnetic field stability measured
by an NMR gaussmeter, whose probe is located near
the back side gap spacer (outer radius) of the sector
magnet, is less than 1 G in 5 h after the cycling.
Because of a small drift appeared in one or twodays, a magnetic field feed back loop program wascreated in the M-60 software using the NMR gaussmeter and an M2 power supply.
At this time, magnet current control programs
were modified using a new CIM-DIM micro tasks.
The current set process of the DIM micro task issimilar to the M-60 FORTRAN program at thelast field measurement.!) Figure 3 shows a time
chart of this multiple set process in one DIM. The
maximum DAC number is 15, the step time 100 ms,
and the step current 1.0 A in the case of the sector
magnet power supply. The M-60 computer only
sends parameter data to all DACs of each power

supply using a CAMAC block transfer routine, anda start command to the DIM, so that, a start up
routine of the huge number of trim and main coils
becomes faster. 2) This program is also used for the
beam transport system's and injection/extraction
system's power supplies.
Since the maximum current values against the full
bit of the DAC and ADC, step current value,
CAMAC crate number, station number, DIM number, and the coil name are stored in an M-60's
memory and a table file, the user application(touch panel controling, etc.) program calls a semibasic subroutine with only a power supply nameand current values. The current preset program(FORTRAN) and those data files for the beam
accelerations are stored and developed in an UNIX
operating system. And some of control programs aretransferred and run on a real time operating system(Fig. 4). A power supply check and a program testare performed by using local TSS terminals througha Local Area Network (Ethernet).
References
H. Takebe, S. Motonaga, and T. Wada: RIKEN Aceel.
Prog. Rep., 19, 174 (1985) .
2) M. Nagase, H. Takebe, T. Wada, and K. Shimizu: Proc.
10th Int. Conf. Cyclotrons and Their Application (1986) .
1)

174
RIKEN Accel. Prog. Rep. 20 (1986)

V-7.

Beam Transport System for RIKEN Ring Cyclotron

K. Hatanaka, T. Inamura, Y. Yano, A. Goto, M. Kase, and H . Kamitsubo

The beam transport system for RIKEN Ring
Cyclotron consists of lines from injectors to thecyclotron and those from the cyclotron to experimental halls. One of the injectors is the heavy-ion
linac (RILAC) which was completed in 1980, andthe other an AVF cyclotron which will be constructed in two years. We have installed a beamtransfer line from RILAC and a beam channel
to an experimental hall. The remaining lines will
be constructed in two years. The beam transfer linefrom RILAC is about 64 m long. The installed line
to the experimental hall is a straight one with four
quadrupole triplets.
Figure 1 shows the perspective view of the linefrom RILAC. The beam transfer line consists ofeight dipole magnets, fourteen quadrupole doublets,
thirteen quadrupole singlets, and thirteen steering
magnets in both the horizontal and the vertical directions. The beam from RILAC passes a charge
stripper (a thin carbon foil) and is deflected with adipole magnet DALO by an angle of 100 mrad. Thismagnet, made of laminations of 0.35 mm thick siliconsteel, can be excited by pulsed current to make possible time-sharing of the beam between RIKEN Ring
Cyclotron and RILAC experimental halls.
The spatial dispersion at the slit SLL10 after themagnet DML1 is calculated to be 0.46 m. In taking
account of the beam size at this position, themomentum resolving power is about 20 and a single
charge state is selected with the slit for light ions.
The system from DALO to DML2 is a beam shifting
section, where an achromatic beam from RILAC isagain achromatic at the exit of DML2. Four quadrupole singlets QSJ24-QSJ27 are introduced toobtain the erect ellipses at SLJ27 in the transverse
phase space. The slit position SLJ27 is the object
point for the succeeding momentum analyzing system from QDJ28 to QSJ31. The line after the slit
SLJ27 is described in detail in Ref. 1.
The magnetic field was measured in the midplane for all the dipole magnets except for DALO
by means of a carriage of three hall probes driven

t rom

AVF
CyClotron

D : Dipole Ivl agnet
QS : Quadrupole S inglet
GD: Quadrupole Dou b lf~
SL: Sl it

Fig. 1. Perspective view of the beam transfer line from RILAC. The verticaldistance between DMJ3 and DMJ4 is 7.8 m and that be tween DMS7 to BM2
is 4.0 m.

K. Hatanaka, et ai.

175

DMS?

",B/BoX 10 3
1. 0

t
T
T

T

r--~~-<It-;-___..-,,~=>;,;--<'~;

y/
/

/

__1_

--"" '\,~\ ;o mm

/

l

,

\

I
/
I

I

I
I

I

I

\,

\

I
I

I
I

\

(, : Bo = 6
0 :k~Bo = 17.5 kG\

I
I

d

\

6

Fig. 2. Cross sectional view of the pole of dipole magnets and the radial
distributions of the magnetic field.

Table 1.

Parameters of the quadrupole magnets.

Type

Q170

Q220

Q420

Aperture(mm)Max. gradient(Tim)
Max. current(A)
Max. voltage(V)
Length(mm)
Effective length
(mm)

70.0

70.0

70.0

15.0

15.0

15.0

260.0

260.0

260.0

15.5

18.0

28.0

170.0

220 . 0

420.0

200.0
±0.3

249.7
±0.5

450.7
±0.5

by a step motor. Examples of the measured radial
distributions of the magnetic field are shown in Fig.
2. The deviation of the field JB / B is less than
1 '10-3 for DMS7 in the required region which isestimated to be less than 20 mm in full width froman ion-optical calculation; for other magnets thedeviation is less than 2 '10- 4 in a much wider region.
The deviation of the effective field length at different
excitations is less than 1 mm for all the magnets.
Quadrupole magnets are of three types. Theirparameters are summarized in Table 1. The magnetsof the type Q170 are used in the beam transfer linefrom RILAC. A quadrupole triplet in the line tothe experimental hall consists of two Q220 and one
Q420 magnets. The pole of hyperbolic profile has a
70 mm base width. A yoke has a square structure.
In order to obtain the wide flat region of the effective length, the optimum end-cut shape was determined by referring the experimental results obtainedat KEK and INS. 2) The field distributions in the
midplane were measured for two magnets of eachtype at three exciting currents of 100, 200, and 260 A.
The deviation of the effective length is less than
1 mm for all magnets and for all excitations within
the radial region of + 30 mm. Azimuthal distributions of the field were measured at the center ofthe magnets and at a radius of 30 mm. The measured data were analyzed to give the strength ofmultipole components. The values of the multipole
components relative to the quadrupole one are 7 '10-4,
2 '10-a, and 3 '10- 4 for the 3rd, 5th, and 7th multipoles, respectively.
References
1) N. Kishida and Y. Yano: Sci. Papers l.P.C.R., 75, 214(1981) .
2) M. Kumada, H. Someya, I. Sakai, and H. Sasaki: Proc.
2nd Symp. Accel. Sci. Tech., 75 (1978) .

176
RIKEN Accel. Prog. Rep. 20 (1986)

V-B.

Beam Buncher for RIKEN Ring Cyclotron
A. Goto, T. Fujisawa, I. Takeshita, T. Urai,
Y. Ikegami, and Y. Yamada

A beam buncher has been completed and set up
in the course of the beam transport line from theinjector RILAC to RIKEN Ring Cyclotron. It
worked successfully during the first operation of
RIKEN Ring Cyclotron, and the beam bunching was
obtained at the entrance of the cyclotron. Specifications of the beam buncher and its model study
were reported elsewhere. 1 ,::!)
Figure 1 shows a cut-away view of the buncher.
The vacuum chamber which contains the drift tubes
is made of alminum alloy. The parting disk between
this vacuum chamber and the coaxial stub at atmospheric pressure is made of ceramics ( AI 20:~) . Figure
2 gives the results of measurement of resonant
frequencies, Q values, and shunt impedances together with the calculations based on the transmission line approximation. The resonant frequencies

cal

meas

Frequency
Q value

Shunt
Impedance

100

d = 85 mm ( max)
N

s:

80

I

~
>,

u

<ll

C
<ll

~
>
a

B- 60
~

lJ..

40
o

0

__~___ L_ _~_ _L -_ _~
200
500

20L-~

S (mm)

(a)

meas

cal
FrequencyCQ value

~
c

<ll

::>

cr
~

lJ..

Shorting plate

c

~0.
<ll

60 r-

0

Coaxial Tube<ll0

S =595 mm

N

>,

:.:

Shunt
Impedance80------._--,.
~

2
<0
>

a

5X1d

E

C
::>

.c
<f)

500

401x

x
o

Xx

2O~~~_L~1~~_L~~~

100

50

0

d (mm)(b)

Fig. 2. (a) Measurements of resonant frequencies, Q values,
and shunt impedances against the position of the movable
shorting plate (s) for the distance between the frequency
tuner and the drift tubes being maximum (d=85 m111) .
The calculations using the transmission line approximation
are also shown for comparison. (b) The same as Fig. 2(a) against the position of the frequency tuner (d) for s
being nearly maximum (s=595 mm) .

Chamber (AI alloy )Fig. 1.

Cut-away view of the beam buncher.

cover the required frequency range (40-90 MHz ) .
The Q values and shunt impedances were found to
be about a third of the design values. This resultsfrom the fact that the dielectric loss of the ceramics

A. Goto, et al.

disk is larger than expected. vVe will replace thisceramics disk with a thinner one having smaller
dielectric loss. The beam buncher, however, could
produce enough voltage for the first beam (the injection energy of Ar12+ is 1.28 MeV lu; the voltage
required is about 7 kV at RF frequency of 56 MHz) .
In Fig. 3 is shown a photograph of the buncher atthe due place. Figure 4 shows a block diagram of
the RF amplifier system. The RF signal is fed fromthe signal generator of RILAC. The frequency ofthis signal is doubled with a frequency doubler. The

177

drift-tube voltage and its phase are automaticallystabilized by comparing the pickup signal from theresonator with a reference signal. The resonant
frequency of the resonator is automatically tuned bymonitoring the incident and reflected power on thefeeder line. The system can be remotely operated
with the help of a computer control system. The
bunch signal of the beam obtained just before theentrance of the cyclotron is shown in Fig. 5.
References
1) A. Goto, T. Fujisawa, and I. Takeshita: RIKEN Aeeel.
Prog. Rep., 18, 184 (1984) .
2) A. Goto, T. Fujisawa, I . Takeshita, and K. Ogiwara:
RIKEN Aeeel. Prog. Rep., 19, 184 (1985) .

Fig. 3. Photograph of the beam bundler.

Fig. 5. Bunch signal picked up just before the entrance ofthe cyclotron.

Resonator<I>

Signal fromthe injElctor

>

:;:
'0

c
a.

2

o

I--

From drift-tube vol toge pickup

Fig. 4. Block diagram of the RF amplifier system.

178
RIKEN Accel. Prog. Rep. 20 (1986)

V-g.

Beam Diagnostic Equipment in the Beam Transport Linebetween RILAC and RIKEN Ring Cyclotron
M. Kase, I. Takeshita, 1. Yokoyama, Y. Oikawa, and M. Saito

Figureillustrates the layout of the beamdiagnostic equipment along the beam transport line
between RILAC (RIKEN linac) and RIKEN Ring
Cyclotron. Since the beam line is as long as 65 m,
beam handling along the beam line requires a number of beam diagnostic probes such as beam profile
monitors (denoted as PF in Fig. 1), Faraday cups
(FC) , capacitive phase probes (PP), emittancemonitors (EM), and slit systems (SL) , some of which
are shown in Fig. 2.
Every diagnostic probe and its actuator have been
built on a stainless-steel flange (NWIOO type for anemittance monitor, and CF152 for other probes).
They are normally mounted on a diagnostic chamber. Several types of diagnostic chambers, having
different numbers of ports, have been installed ateach position depending on local requirements.
These chambers as well as beam pipes were madeof aluminum alloy, because of its low out-gassing
rate and low cost.
A beam profile monitor is used for the measurement of beam intensity distribution in three directions on the plane perpendicular to the beam axis.
The principle of the measurement is the wire scanning

method. 1) In addition to two cross wires diagonal
to the driving axis, the third wire has been strung
perpendicular to it. A pneumatic driver moves theprobe head in linear action by a stroke of 75 mm
at a rate of around 75 mm/s. The sensitive region
is inside a circle of 50 mm in diameter around thebeam axis. The positions of the probe head are
detected precisely by two photo switches near theboth ends of the stroke. The relative position fromthese absolute positions is detected by a rotary encoder which is rotated by a probe shaft via rack andpinion gears; the position resolution is 0.08 mm.
When the profile monitor is mounted on the diagnostic chamber at 45 0 to the vertical axis, thebeam intensity distributions in the horizontal, verticaland 45 0 directions can be obtained. These data permit a tomographical display of a beam on a computer CRT.
As shown in Fig. 1, in every straight beam line,
there is at least one Faraday cup, which will aid toestimate beam transmission along the beam line.
Some of them also works as a beam stopper undercontrols of the radiation safety system for men andthe protection system for instruments. A rough but
Ring Cyclotron\. . . Dipole magnet.... Qudmpole magnet-+ Steering magnet

Fig. 1. Layout of the beam diagnostic system in the beam transport line between RILAC and
RIKEN Ring Cyclotron. Open rectangles on the line indicate the diagnostic chambers. The
devices mounted there are shown nearby using symbols. First two letters of them show thedevice name. PF, profile monitor; SL, slit system; FC, Faraday cup; PP, phase probe; EM,emittance monitor; CS, charge stripper; AT, beam attenuator; BP, bunch probe (coaxial
Faraday cup) .

179

M. Kase, et al.

Fig. 2. Photograph of diagnostic equipment used in the
beam transport line. The upper one is a profile monitor,
the middle a Faraday cup, and the lower a slit system.

easy estimation of the beam transmission along thebeam transport lines can be made with a nondestructive intensity monitor. It is using the ioniza-tion of residual gas in a beam pipe. 2 )Beam phases with respect to an RF accelerating
system are measured with five capacitive phaseprobes. PP-L21, PP-X21a, and PP-J27 are used for
precise measurement of the energy of a beam fromRILAC, while PP-S71 and PP-J41b are for tuningof the buncher RF voltage and phase. The time
structure of beam bunch can be measured with acoaxial Faraday cups (BP-L21 and BP-J41b in Fig.
1 ). I t also works as a phase probe, when a beam
is as weak as less than 10 nA. Signals from theseprobes are transferred via coaxial cables to the control console of RIKEN Ring Cyclotron and displayedon an oscilloscope.
Electronics for the beam diagnostic equipment
are shown in Fig. 3. The beam diagnostic devices,like other devices such as magnet power supplys,
are connected through DIM-CIM modules 3 ) to a
CAMAC loop under the control of computers in
RIKEN Ring Cyclotron control system. 4 ) In the

VACUUMSTATION
DIM

I

r--'
I I

OPTICALFIBERIn:

I s: I

CIM

If:;

I

I
I

I

BDA-PF

L _J

1

MONITORCONTROL
CI RCU IT

n
J;>
~
n
r

0

BDA - SL

~

SLIT
DI~'

CONTROL
CIRCU ITBOA-EM

DIM

Fig. 3.

EMITTANCEMONITORCONTROL
CIRCUIT

Block diagram of the circuits for the beam diagnostic system.

180

M. Kase, et al.

beam diagnostic system, however, additional circuits
connecting the diagnostic equipment and DIM
modules are needed. These circuits can be divided
into two groups, BDI and BDA.
The BDI-circuits, which are built in the plug-in
modules (according with DIN 41494), use DIM digital input/output as a common bus line. A varietyof circuits (up to 64) can be connected to one DIM
module via the bus; they include a pneumatic drivercontroller, a bias supply, a vacuum system controller,
and an interlock circuit. Analog signals as beam
currents from a Faraday cup or slit system are fed
into a log-amplifier and converted into digital signals
in one of the BDI-circuits.
A beam profile monitor, a slit system, and an emittance monitor are controlled with the BDA-circuits.
These circuits have two boards inside. One is a
DIM board and the other a control circuit for eachdevice. The latter board has a counter for rotary

encoder, a driver for stepping motors, and so on.
The circuits enclosed by dash-dot lines in Fig. 3
are mounted inside a 19" rack called as a beamdiagnostic station (BDS). There are six BDS's along
the beam transport line. Every diagnostic equipment is connected with the circuits in nearby BDS
via hard cables of shorter than 10m.
References
1) O. B. van Dyck, A. Harvey, H. H. Howard, and D. I.
Roeder: IEEE Trans. Nucl. Sci., NS-22, 1570 (1975) ;M. Hemmi and I. Yokoyama: RIKEN Aeee!. Pmg. Rep .,15, 146 (1981) .
2) M. Kase and E. Ikezawa: RIKEN Aeee!. Pmg. Rep.,
19, 210 (1985) .
3) K. Shimizu, T. Wada, J. Fujita, and I. Yokoyama: 10th
Int. Conf. Cyclotron and Their Applications, East Lansing, Michigan, USA, April (1984) .
4) T. Wada, J. Fujita, I. Yokoyama, T. Kal11bara, and
H. Kamitsubo: Sci. Pape1's I.P.C.R. , 79, 28 (1985) .

181
RIKEN Accel. Prog. Rep. 20 (1986)

V-lO.

Replacement of Computer for the Control System of RILAC
T. Kambara, E. Ikezawa, and T. Wada

A new computer network system has been introduced to control the accelerator complex (RILAC
and RIKEN Ring Cyclotron) .1) The network con-sists of three MELCOM 350-60/500 computers of
Mitsubishi Electric Corp. (M-60). One of them isdedicated to control RILAC in place of a HP-1000
for Ring Cyclotron
MDWS-60<E--Optical Fiber(Duplex)for Ring Cyclotron

UUCP<c--Optical Fiber

FXD

SEL

~

HP-IB

Injection
Une

RF#1-3DT Magnet

RF#4-6DT Magnet

Beam
Transport
SystemFig. 1. Block diagram of the new computer system. LCP, loop coupler; DWA,
dataway adapter; IFA, intergrated file adapter; SEL, selector channel; MPX,
multiplexer channel, CLA-H, computer linkage adapter-high speed type; SHD,CAMAC bit serial highway driver; MDWS, Mitsubishi Dataway System; UUCP,
UNIX-UNIX Copy network; ISC, intelligent system console; C / M , control andmeasurement; FTP, fine tuning panel; TB , track bowl.

T. Kambara, et ai.

182
Table 1.

Configuration of the computer.

Computer
MemoryFixed disc
Magnetic tape
Floppy discLine printerPlotter
20" Color character display
20" Color graphic display
Touch panel (VT24 1)
Fine tuning panel

HP-IB
CAMAC SHDMELCOM 350-60/500

3MB
202MB
1 (1,600/800 bpi)
2 (8")
1 (390Ipm)
1 (10 pens)
1

1
2 (575 kB/s)
1 (5 MB/s)

computer of Yokogawa-Hewlett-Packard Ltd. (YHP) ,which had been used since November 1979. 2 ) The
computer system with mass storage and peripheraldevices were totally replaced, but control and measurement processors (HP2240A/2241A supplied by
YHP) were preserved to be used for signal input/
output with RILAC devices in the old system. These
processors are interfaced to the new system with
HP-IB. The new devices are listed in Table 1. A
block diagram of the new system is shown in Fig. 1.
There are four devices on the operator console in
the new system: a color character CRT terminal(M4398) , a color graphic CRT terminal (M4328), afine tuning panel, and a VT241 CRT terminal. The
M4398 CRT displays the status and parameters ofthe devices in selectable tables and also can receive
the commands from operators via a keyboard. The
M4328 CRT displays the general status of RILAC
in graphic form. The fine tuning panel has a plasma
display, 4 rotary encoders, and 16 push buttons withlamps and is used for the fine tuning of magnet
currents. The VT241 CRT has a touch panel andis used for the fine tuning of RF voltages.
Eight-inch floppy discs are used for storage of
RILAC parameters during operation in place ofcasette tapes in the old system. A CAMAC system
is used for beam diagnostic devices installed newly in
RILAC beam lines. The operating status of RIKEN
Ring Cyclotron can be transferred through the computer network (MDWS-60) and displayed on theM4328 CRT. The source programs and messages
are transferred through the UNIX-UNIX Copy network (UUCP).
The new computer was installed in November
1985 in the computer room of RILAC building.
After installation and initial adjustments, the development of application programs was continued till July
1986. The programs which had been developed on
the HP-1000 computer were transferred to the M-60.
In the transfer, FORTRAN source files on the HP1000 disc were written on magnetic tapes in ASCII
format and copied to the M-60 UNIX file. They
were then modified to involve the real time anddisplay functions specific to the new computer. Some
programs have been newly developed for the newconsole devices like the touch panel and the rotary
encoders. During the program development, RILAC
was operated with the HP-IOOO computer. In August
1986, the operator console was modified for new
console devices. The new computer has been used
for operation SInce September without critical
troubles.
References
1)

T. Wada, J. Fujita, K. Shimizu , I. Yokoyama, T. K am ·bara, and H. Kamitsubo: IEEE Tmns. Nucl. Sci. , NS·32 ,2095 (1985) .
2) T. Kambara: R eports I.P.C.R. , 62, 88 (1986) (in Japanese) .

183
RIKEN Accel. Prog. Rep. 20 (1986)

V-II. Present Status of the Vacuum System for RIKEN Ring Cyclotron
K. Ikegami, S. Nakajima, and S. H. Be

The vacuum chamberl) for RIKEN Ring Cyclotron consisting of four magnet vacuum chambers,
two valley vacuum chambers, and two RF resonator
chambers was completed at the end of September,
1986, and evacuated with ten cryopumps of pumping
speed of 1 X 104 [/s and four panel-type cryopumpsof 5 X 10s1/s. Early October, we achieved a pressure less than 5 X 10-6 Pa, which is sufficiently low
for heavy-ion acceleration.
After each chamber was fabricated at a factory,
we applied chemical cleaning to the inner surfaceof the chamber. The chemical cleaning was carriedout as follows:
1) Machine oil was removed with a Freon(DIFLON SOLVENT-Ss) jet.
2) Animal and vegetable oils were removed withan alkali solution (NEOS-K) jet.
3) Welding scales and oxided layers were removed with a water jet (at room temperature) 1 h
after suffusing on the surface with an acid solvent(NEOS-CM 305FA) including a surfactant and an
inhibitor. The acid solvent was simultaneously washedout with a water jet.
4) Acid residues were removed with a neutralizer(NEOS-CM 308).
5) Finally, the surface was sprayed with awater jet.
After chemical cleaning, leak detection was performed with a helium detector connected with theforepump side of a turbomolecular pump, and mass
spectrum of residual gases was monitored on aquadrupole mass analyzer. To estimate the leakrate of a chamber indirectly, we also used a pressure build-up method occasionally. The total leakrate of the chamber was suppressed to less than
10-7 Pa· m 3 /s.
From February to May in 1986, four magnet
vacuum chambers brought in our institute wereassembled between the magnet poles and subjected
separately to leakage check. Figure 1 shows a photograph of the magnet vacuum chamber after chemicalcleaning. The N-sector magnet vacuum chamber
under assembling is shown in Fig. 2.
The RF resonator chamber has an intricate structure with a large volume, and a dee, a stems, amoving boxes, etc. are inserted into the chamber.
After checking leakage of the chamber, we assembled

Fig. 1. Photograph of a sector magnet vacuum chamber
after chemical cleaning.

Fig. 2. Photograph of N-sector magnet vacuum chamber
under assembling between the magnet poles in thecyclotron vault. Trim coils covered a flash-coated thinceramic insulator is shown under the chamber.

the insertion parts and checked leakage again. From
July to August, two RF resonators and two valley
chambers were set in the cyclotron vault.
Early September, we carried out preliminary experiments for the discharge cleaning with the 3/8
sections (two magnet chambers and one valley chamber) of the whole chamber to reduce has gas loadfrom inner surfaces of the chamber. Electron cyclotron resonance discharge cleaning (ECR-DC) 2) wasapplied to the magnet chambers, and radio frequency
assisted glow discharge cleaning (RF AG-DC) wasapplied to the valley chamber. Dominant contaminations of the inner surface, namely hydrocarbon which

184

K. Ikegami, et al.

was left from the manufacturing process, were removed by the discharge cleaning. The detail for
the RFAG-DC will be reported by us in this report. 3 )After integrating eight chambers into one, we
checked leakage. Then ten cryopumps and four
panel type cryopumps4) were installed at the chamber, because charcoal in a cryopump becomes asource of outgassing even at room temperature anda small leakage is very difficult to detect. A photograph of RIKEN Ring Cyclotron installed with thevacuum chamber is shown in Fig. 3, which also shows
the cryopumps installed with the valley chamber.
Figure 4 is a photograph of seven compressors ofcryopumps.
The pumping system is controlled by a program-

Fig. 5. Photograph of the graphic local control panel set
in the cyclotron vault.

Fig. 3. Photograph of RIKEN Ring Cyclotron assembled
with the vacuum chamber. Three cryopumps installed atthe valley chamber is shown.

ming controller 5 ) set in the cyclotron vault, and its
graphic panel for local operation is shown in Fig. 5.
Remote operation is conducted with a computer control system of RIKEN Ring Cyclotron through the
CIM-DIM interface. 6 ) At the end of September,the pumping system was completed and evacuationof the chamber was started. The pump down timefrom atmospheric pressure to 10 Pa by using mechanical booster pumps of 2,600 m 3 /h with a rotary
pump of 4,700 l/min was about 13 min. Afterevacuation to 10- 3 Pa with four turbomolecular pumpsof 5 X 10 3 l / s, the chamber was evacuated with ten
cryopumps of 10 4 [ / s and four panel type of cryopumps of 5 X 10 3 [/s. After continued evacuationfor one week, we achieved the pressure of the orderof 10-6 Pa that is sufficient to accelerate heavy ions.
References
1) K. Ikegami, S. Nakajima, S. H. Be, I. Takeshita, Y. Oikawa, and S. Motonaga: RIKEN Accel. Prog. Rep., 18,
172 (1984) .
2) K. Ikegami, S. Nakajima, Y. Oikawa, Y. Ishibe, H. Ohyama, Y. Sakamoto, S. Motonaga, and H. Kamitsubo:
Sci. Papers I.P.C.R., 77, 78 (1982) .
3) K. Ikegami, S. Nakajima, and S. H. Be: p. 185 in thisreport.
4) N. Ohsako, K. Morimoto, T. Kikuchi, K. Ikegami, S.
Nakajima, Y. Oikawa, and S. H. Be: RIKEN Aeeel.
Prog. Rep., 19, 191 (1985) .
5) K. Ikegami, S. Nakajima, Y. Oikawa, and S. H. Be:
RIKEN Accel. Prog. Rep., 18, 189 (1984) .
6) T. Wada, J. Fujita, K. Shimizu, I. Yokoyama, and T.
Kambara: RIKEN Aceel. Prog. Rep. , 17, 138 (1983) .

Fig. 4.

Photograph of seven compressors of cryopumps.

185
RIKEN Accel. Prog. Rep. 20 (1986)

V-12.

Application of the RF Assisted DC Glow Discharge Cleaning
to the Valley Chamber for RIKEN Ring Cyclotron
K. Ikegami, S. Nakajima, and S. H. Be

The vacuum chamber1) of RIKEN Ring Cyclotron has a large volume and a large inner surface
area; moreover, baking is impossible because of the
intricate structure. We applied a radio-frequency
assisted glow-discharge cleaning (RFA-GDC) to its
valley-chamber to reduce the gas load from theinner wall surface. Preliminary experiments were
performed to investigate the discharge cleaning
effect.
The volume of the valley chamber is 1.5 m 3 withan inner surface area of 25 m 2 • A turbomolecularpump of 5,000 lis was used to evacuate the chamber.
For detection of residual gases during the dischargecleaning, a quadrupole mass analyzer was set at
another chamber separated from the valley chamberwith an oriffice of 10 lis for N2 gas and evacuatedwith a turbomolecular pump of 300 lis.
The RFA-GDC head inserted near the center ofthe chamber supplies RF and DC voltages simultaneously. It consists of a central tube for introducing
hydrogen gas to the chamber and an anode coil madeof a hollow stainless-steel tube of 6 rnrn in diameterallowing water cooling. The coil (1.2 pH) has 6
windings of 50 mm in diameter and 100 rnrn inlength. The RF voltage was supplied with a
13.56 MHz RF generator with a maximum powerof 300 W. This RF electrode system was coupled
to a DC power supply (0-1 kV, 5 A at maximum)
through an LC network. Figure 1 shows a schematic
diagram of the RF and DC coupling network for theanode coil; the gas puffing tube is also indicated.

To measure the pressure PI at which the discharge
ignites and the pressure PQ at which the discharge
is quenched, we applied a constant DC voltage of
900 V to the chamber for introducing hydrogen gas.
Figure 2 shows variation in the pressures PI and PQ
as a function of the RF power. The minimum pressures, PI and P Q , were 3.5 X 10-1 Pa and 1.5 X 10- 2 Pa,
respectively. A small RF power of 15 W, which will
be described later, suffices to maintain the discharge
at pressures as low as 10-2 Pa in the chamber. The
quenching pressure PQ of the RF -assisted glow discharge was a factor of 10 lower than that of a conventional glow discharge. The discharge at pressures
as low as 10- 2 Pa decreases read sorption of gases
released by the discharge. Ignition of the discharge
was easily achieved by gas-puffing near the RF antenna. To estimate the ion-current arriving at thechamber wall, we set two ion-current probes having
the surface area of 3 cm2 • One was set near the RF
antenna anode and the other at 1 m separated fromthe antenna anode. The current density per unit
wall surface area as a function of discharge current
is shown in Fig. 3. The average ion-current density
at the discharge current of 1.0 A was approximately
12 pA/cm 2 , which corresponds to the ion-flux densityof 7.2 X 1013 ions/cm 2 • s. Figure 4 shows a photograph of the RF glow discharge cleaning. The discharge voltage and current were 330 V . and 1.0 A,
respectively.
Figure 5 shows a typical discharge voltage as afunction of the discharge current under the condi-

Variable vacuum capacitor
4 '" 250 pF
13.56 MHz

300 W maxHydrogen 'gas ~ =::C:===~4====::=J========::::::==l

0.01

F

5 kV
DC 1 kV, 5 A max

1
Fig. 1.

Vacuum_

15000

20 IJHpF

Schematic diagram of the RF and DC coupling network for RFA-GDC head.

<p50

K. Ikegami, et ai.

186

tions of a constant DC voltage of 900 V and constant RF power as the working pressures decrease
from the igniting pressure PI to the quenching pressure P Q • Figure 5 shows that the discharge voltage
decreased with an increase in the discharge current,
and that the operating points at relatively stable
discharge for any working pressure and RF power
fall nicely on a straight line. A discharge voltage
as a function of discharge current at two operating

Applied base voltage: 900 V

Fig. 4. Photograph of a glow discharge when discharge
voltage and current are 330 V and 1.0 A, respectively.

PI: Igniting pressure
P : Quenching pre ss ure
Q

o

100 0

10- 1

900

Applied DC voltage: 900 V

800o Supplied RF power: 40 W
• Supplied RF power: 100 W

700

-;;;

S-

!:!
(J)
(J)

(j)
~

o

0

(j)
~
~

>

\

600

(j)

10- 2

til
<I!
+J
.-t

p..

0

500

:>
(j)

til
~

<I!

..c:

400

U

(J)

'M

0

300

o

20
40
60
80 100
Supplied RF power (W)

120
200

Fig. 2. Variation in ignition (PI) and quenching (PQ ) pres·sures for discharges as a function of the RF power.
100a

Effective input· RF power: 15 W

N

13

~ 30

Operating pressure: 3.6 x 10- 2 Pa

N
H

0.2

0.3

0.4

Discharge current ID

0.5

(~)

Fig. 5. Discharge voltage curve as a function of discharge
current when constant voltage of 900 V was applied.

o

'"

0.1

]
.-< 20.f'oo.....'OJ"

....
.j.J

Vl
C
OJ

..,'"c 10
~

"

u

0.5

1.0

1.5

2.0

Dischar g e Current ID (A)Fig. 3. Current density measured by two ion current probes
as a function of the discharge current.

pressures is shown in Fig. 6, from which we can findthat the discharge voltage V D increases rapidly witha slight increase in the ID to 0.5 A, and that in theregion of more than 0.5 A, V D keeps a constant value
with increasing discharge current V D. This constantregion of V D corresponds to a normal glow discharge
region. Thus we can maintain the normal glow
discharge ignited at a lower pressure. The ignitionat the lower pressure makes the evacuation after theK. Ikegami, et ai.

187

Effe cti v e input RF power : 15 W
400

Gas: Hyd r ogen-------------.

After discharge cleaning of 16 hrs
Pressure : 7.8 x 10- 5 Pao-------------~

350

300

~

..... 7.4 x 10- 2

>

<ll

K

...o

Opera ting p r e s sure-0- 3 . 6 x 1 0- 2 Pa

250

0

~ 10-10 i-f--- - --

pa

200

~

150

~ 10-

0

>
<ll

"o

8'

- -- - - - - - - ---- ----'

11"' 100~10-12 '--'--''-1'-,'---,-'-,-'-,-'-L' -L' -,' -,-'-,' -,' -,' '; -i,-,I'-1I,--,,---,-,---,--,---,---,--,, -,-'-'-.'..L€..L' -,-' -'- '--'-''--'-'-'---'----'--'---'--'---'-'--''
161718
28 30
40
45

0

50

M/ q Mass spectrum

1. 5

0 .5

2.5

2 .0

Di s c harg e Cur ren t 1D (A)Fig. 6. Discharge voltage curve as a function of discharge
current at two operating pressures.
10 - 9l-<Effective i nput RF power : 1 5 W;>,

2Operating pres sure : 3 . 6 x 10- p

~

r-I

cU
C
cU
til
til

r1l

E

~

1 0- 10

0

0.
::l
l-<
'0
cU
::l
0'

m/q

18

---

-?

.L.

....
0

..:
.jJ

c:

29

Q)

l-<
l-<
::l

u

c:
~

10- 110'"E

Fig. 8. Mass spectrum of residual gases after discharge cleaning for 16 h. The operating pressure was 3.5 X 10-2 Pa.
The discharge voltage and current were 330 V and 1.0 A,
respectively.

discharge cleaning easier.
Partial pressures (as the ion current of QMA) of
gaseous impurities released by the RF -assisted glow
discharge are shown in Fig. 7 as a function of thedischarge current, which shows that the release of
the impurities except water of m / q = 18 increases
rapidly with an increase in the discharge current.
Further, the amount of the impurity released fromthe surface decreased with discharge cleaning time,
though not shown. Figure 8 shows a mass spectrumof residual gases after the discharge cleaning for 16 h
at the discharge voltage of 330 V and current of
1.0 A. Figure 8 also shows that the dominant contaminants of the inner surface, i.e.~ hydrocarbons
resulting from manufacturing processes, were removed by glow discharge. Thus we conclude that
the RF glow discharge cleaning is effective in removing the contaminants from the inner surface ofthe chamber.
Reference

0. 5

1.0

1.5

2.0

2. 5

3.0

Dis c h a r ge c urre nt ID (A)Fig. 7. Variation in partial pressures as a function of discharge current.

I) K. Ikegami, S. Nakajima, S. H. Be,!. Takeshita, Y. Oikawa, and S. Motonaga: RIKEN Accel. Prog. Rep.,
18,172(1984) .

188
RIKEN Accel. Prog. Rep. 20 (1986)

V-13.

Injection System for an Injector Cyclotron
N. Nakanishi and T . K ageyama

An A VF cyclotron as an injector for RIKEN
Ring Cyclotron has been designed. 1 ) In order toaccelerate va rious types of ions, the cyclotron must
be adaptable for external ion sources. An ECRsource, by which we can obtained highly charged
ions, is scheduled to be equipped with a cyclotron.
Other. kinds of ion sources will be also equippedfrom now on. For this purpose, beam transport lines
between ion sources to the cyclotron and a beam inflection system to the median plane of the cyclotron
have been designed. The brief description will begiven here on the beam line and the inflection system. T he beam line must have functions not only to
guide beams to the cyclotron but also to be capableof adjusting optical properties of the beam.

A preliminary beam line, as shown in Fig. 1, consists of 4 sections. A quadrupole triplet immediately
after the source focuses the beam to a double waist
at the object point of the following charge state
analysing section. I t is also considered to use electric quadrupoles in place of the magnetic ones forthis purpose. The charge state analysing section isof mirror symmetry having the configuration of atelescopic cell of quadrupole doublet + dipole +quadrupole doublet in the half system. In this case
we can achieve the cha rge resolution of dQ/ Q =1/40. A phase space matching section composed of
4 quadrupoles is installed subsequently. The system
makes the beam which the focusing conditions at
the exit of an inflector. In the axial hole of the

ECR - SOURCE

SB 1-- - ' -r.ledia~.pl" "e

QB,QI,Q - quadrupole magnets
BM- bending magne ts
S- steererI- inflector

SW

C
B

SB
Fig. 1.

- switching magne t- cylindrical lenses- buncher- slit bo x

A p relim inary b eam line from an ECR source to the cyclo tron.

N. Nakanishi, et al.

189

cyclotron, the beam receives focusing and rotating
actions due to the stray field. In order to correct
the unwanted rotation of the optical axis, a beam

(a)
60 MM

YIRM
1.5

2.1

1.0

1.5

X/RM

1.3

(b)

i 60 MI1

0.9

Fig. 2. Beam orbits projected on the median plane, anq
the rotation centers at the exit of the spiral inflector. The
coordinates are normalized by the magnetic radius of R ill '2 .0(a) HO R I ZONTRL DI STRNCE FRO M ENTRRNCE

~

1.5

w
u

z

:::en

EXIT

;::; 1.00.5

y0.0 - I - i - t - + - - \ - t - t - I - i 1 1

1

1

1

1 1

1

I

1

1 I

I

1

I

1

(c)
30 MM

2.0

(b) RRD I RL GRRD lENT RT EX IT
30 MM+---t---t--,,6j<-m.~-+----I---+XCla::: 1. 0
Cl

a:

a::

t!>
I

a::

o. 0

I-l-t----+---t-I-t,-I-I-t-I-!-I-tl-tl'--+--+-'~-+-t---i-l--t---1--t--+-1-::*

0.5

1.0

-1.0

Fig. 3. K dependence of the distances from the entrance of
the inflector to its exit and the rotation center at theexit (top) , and the radial gradient of the beam at the exit
versus K (bottom).

Fig. 4. Typical beam orbits in the central region of thecyclotron. Broken lines show the central lines of accelerating gaps, and a thick line a front of the puller. (a), 0+
beam is injected with 20.4 keV and accelerated up to
7 MeV/u in a mode of h=2; (b), Proton beam is injectedwith 6.4 keV and accelerated up to 50 MeV in a mode of
h = 1; (c), Behavior of the instantaneous rotation centerfor the case of the C4+ beam.

190

N. Nakanishi, et al.

rotating system has to be provided. For the matching and rotating sections, we have not yet examined
their specifications for the lack of magnetic field datain this area.
It is well known that there are three types of beam
inflectors from the axial beam line to the magnet
median plane: an electrostatic mirror, a hyperboloid
inflector, and a spiral inflector. Because of its
flexibility, small volume, and low electric power, we
employ the spiral inflector. Its shape projected on
the median plane is determined from a value of K =Re/2Rm, where Re and Rm are the electric and magnetic radii at the exit of the inflector, respectively.2)
In Fig. 2 are shown beam orbits projected on the
median plane, and rotation centers corresponding toeach beam orbit. Figure 3 (a) also shows the K
dependences of the distances from the entrance of
the inflector to its exit and the rotation center atthe exit, and Fig. 3 (b) the radial gradient of thebeam at the exist us. K. Calculation has been per-formed for on-axis beams in an assumed magnetic
field in order to optimize the inflector parametersand examine optical properties of beams in the central region of the cyclotron. Particles will be accelerated on constant orbits for harmonic numbers of
h = 1, 2, and the orbit center must converge to themachine center after a certain number of rotation.
Typical examples are shown in Figs. 4 (a), (b), (c)for the each acceleration mode. A tentative result has
been obtained of K = 1.38, Re = 2.3 cm, and Rm =0.83 cm. For different acceleration modes, optimization of the acceleration condition has to be madeby movement of the puller and the rotation of theinflector with respect to the machine axis.
References
1) N. Nakanishi and T. Kageyama: RIKEN Accel. Prog.
Rep., 19, 197 (1985) .
2) J. L. Belmont and J. L. Pabot: IEEE Trans. Nucl. Sci.,
NS·IS, 191 (1966) .

191
RIKEN Accel. Prog. Rep. 20 (1986)

V-14.: Focusing Magnetic Channel of the Baby Cyclotron
T. Karasawa

An electrostatic deflector pulls ion beams out of
their circulating orbits, and then the beams passthrough the fringing field of the main magnet. The
gradient of this field gives radial defocusing effects
to the beams. A magnetic channel that has a fieldof inverse radial gradient against the fringing field
reduces radial divergence of the beam at an extraction window on an acceleration chamber.
On the Baby Cyclotron, an entrance of the magnetic channel is positioned 75 degrees downstream
from an exit of the deflector; its expanding in angle
is 26 degrees. A beam probe follows near an exit of
the magnetic channel. In Fig. 1, a layout of thedeflector and the magnetic channel with the acceleration chamber is shown.
The magnetic channel consists of three iron bars,
the cross section of which is shown in Fig. 2A. This
type of the magnetic channel was invented by Odera
et at.!) In a uniform external field, the magnetic
induction inside an iron bar is twice as much as theexternal field induction. Magnetic induction outsideof the iron bar is represented by

5

[

mm

]

I I I I I I I-----;;;i 2R 4-C~)"""""""':<'

50 - · ···· ·· ·-.(~'~ ...... :. .... _.. . . _.
\.. __J

.

2L

r'~"

,1,

( + I .. ·.... ······.. ·..
'-._- ./

2L ----'"
Fig. 2A. Cross section of magnetic channel.

z
,

Bz

Bz = R2 {(Z2 - y2)/ (Z2 + y2)} Bo
For notations see Fig. 2B. This equation means thatthe outer field is proportional to external field as longas the iron is not magnetically saturated. When theiron is saturated, the outer induction is nearly constant independently of the external field.
In the magnetic channel of the BC-1710 type
cyclotron, the iron bars of cross sectional radius of
2.5 mm are placed with an aperture of 18 mm. The
carbon content of the iron bars is below 0.01 %.
When the induction inside the iron is below theFig. 2B.

Notation of coordinate.

saturation, a relative magnetic field gradient on the
median plane is calculated and the results at thecenter (the middle point between the inner bar andthe outer bars) are shown in Fig. 3, as a functionof the gap between the iron bars.
High magnetic fields are used in the Baby Cyclo-

Exi t Wi ndo....

~~(. Coo t"
--_

i

of

: ~.

H"",,

O. 6~

S 0. 4-=- j '~ --"0:, _ _ _

•

~

_
'J

___

~

':' --- 0-....._ 0" O. 2 ~
N '

:

o:l

O. '1 ~ L.. L.L.L.L. .. J...J. .. L.. L.L.L.l
15
Ma'gnet i c Channe l~'==_ _ ~
~-

16

17

2x L . [

18

mm )

19

20

a p er tur e of b ar
Acce lera t ion Chamber

Fig. 1. A layout of deflector, magnetic channel, beam probe
and exit window on acceleration chamber.

Fig. 3. Field gradient of the magnetic channel vs. aperture
between iron bars (at the middle point between the ironbars on the median plane) .

192

T. Karasawa# 7

p+6pnl1.4=0: reference ray. X #4

x·

P
1.3

p-6P

n3 x ·
R-b.R. >< #.6
R

R+b.R

b.R=lmm b.P·=lmr a d
1. 2

Fig. 5. Phase space at the entrance of the deflector (startpoint) .

1.1
1 15

120

( deg ) 125

130

135

azimuthal angle at ' center of iron bars
along magnetic channel

Fig. 4. Field by main magnet along the center of the magnetic channel.

E
E

"t

-2:
E

~

40

20

CI)

tron, and the magnitude of the main field at theposition where the magnetic channel is placed ishigher than 1.0 T. The magnetic fields along thecenter line of the magnetic channel for proton acceleration are shown in Fig. 4. In this case, the ironbars of the magnetic channel are fully saturated.
We suppose that the field gradient produced by themagnetic channel is constant along the beam path
independently of the main field. The gradients arecalculated to be 0.31 and 0.34 T / cm for saturationinductions of 2.2 and 2.4 T in the iron, respectively.
We have studied an effect of the magnetic channel on the deflected beam by numerical calculationsof radial orbits. Firstly, a reference ray is determinedso that a reference particle arrives at the center ofthe exit window on the acceleration chamber without the magnetic channel. Secondly, the magnetic
channel is so placed that the reference ray is notaffected by the magnetic channel field. The calculation starts at the entrance of the deflector. Seven
particles on a phase space around the reference ray(two different radius and two different radial momentum) are calculated. These seven particles havethe same total momentum. In Fig. 5, the phasespace at the entrance of the deflector is shown.
Trajectories of the radial motions are calculated as
far as the exit window on the acceleration chamber
and a radial spacing of a pair of particles are discussed. The # 2 and # 5 particles are parallel
beams with respect to the reference ray at theentrance of the deflector. As the field gradient of
the channel increases from zero, the radial spacingof #5-#2 reduces at the exit window. When thegradient is zero, the radial spacing is 62 mm, andwhen the gradient is about 0.23 T / cm, the radial

C)

c

~

.VI

"0

- 20

-;
"0
<11

- 40

!-o

e
e

.o J
-2:
0.15

I

I

I

0.2

0.25

0.3

gradient of channel

0.3 5

0.4

(T/cmJ

Fig. 6. A: Radial distance of #2 and #5 particles, B: Radial distance of #3 and #4 particles, C: Radial distance of# 1 and #6 particles (at the exit window on the acceleration chamber) .

spacing is nearly zero, which means focused beam.
When the gradient increases furthermore, the radialspacing increases, which means over focused beam.
The displacements of #2 and #5 particles from thereference ray at the exit window versus the gradient
are shown in Fig. 6A. The displacements of #2
and #5 particles are nearly the same except its sign,arid we have so selected a pair of particles as tosatisfy this condition: # 1 with #6 and #3 with #4.
The #3 and #4 particles are diverging beams,
but the # 1 and #6 particles are converging beams
at the entrance of the deflector. At the entranceof the magnetic channel, the radius of # 1 particles
is already larger than that of #6 particles. The
displacements of the pair of # 3 and #4 particles
and the pair of # 1 and #6 particles from the reference ray versus the gradient are shown in Fig. 6B
and 6C, respectively. In Table 1, the focusing gradient for each pair are shown. For parallel beams,

T. Karasawa

193

Table 1. Focusing gradient.
Pair of particles

Focusing gradient

#2-#5
#3-#4
#1 - #6

0.23
0.24
0.27

(Tjcm)

E
E

-2

.= :~
Q)

u
C

~
I

,

E

Each pair of the particles is focused at the exit win·
dow on the acceleration chamber

I

_\ ~

I

1

til

0

'0

-1

-;; -2
'0
ell
\.0

~

-3
-~

~~

~2~

0.2

0. 2 5

0.3

gradient of channel

0 . 35[T fern}Fig. 8. A: Radial distance of #2 and #5 particles, B: Radial distance of #3 and #4 particles, C: Radial distance of#1 and #6 particles (at the beam probe).
Fig. 7. Radial spread vs. the gradient of magnetic channel(at the exit window on the acceleration chamber).

Table 3.

Limiting gradients for reversed beam profile.
Focusing gradient

Table 2. Radial spread for zero gradient, upper and lower
gradient for narrow radial spread at the exit window.
Pair ofparticles

#2-#5
#3-#4
#1-#6

Radial spread* Upper gradient Lower gradient(T jem)(T jem)
(cm)

6.2
19.5
7.4

0.29
0.31
0.31

0.18
0.19
0.20

* for zero gradient at the exit window
it is weekest. When a source point may be assigned
for each pair, the source point gets nearer to themagnetic channel and the gradient becomes stronger.
For each pair, we define the radial spread at theexit window as the distance between the inner andouter particles. In Fig. 7, the radial spread versus
the gradient of the channel is shown. At a given
gradient, the radial spreads vary according to theinitial condition of the pair, but the focusing gradients are not so widely changed.
Beams, which we practically handle are a mixture of particles having different radii and radial
momentums within a some extent. For practical useof the magnetic channel, the radial spread of thedeflected beam must be reduced below the widthof the extraction window on the acceleration chamber. In rough estimation, we try to reduce the radial
spread for each pair to less than 1/5 of the spreadat zero gradient. For each pair, the spread at zero
gradient and the gradient at which the spread is
reduced to 1/5 are shown in Table 2. The gradi-

Pair of particles

At beam probe(T/cm)At exit window(T/cm)

#2-#5
#3-#4
#1-#6

0.26
0.27
0.30

0.23
0.24
0.27

ents have two values: the upper gradient is above
focusing gradient and the lower is below it. For
practical use, we are able to fix the gradient ,of thechannel at a value between the lower and the upper
values.
During the beam test at the factory, reversed
beam profiles between the beam probe and the exit
window on the acceleration chamber have been observed. When the beam focuses between them, thisphenomenon may occur. The displacement from thereference ray to the particles of each pair at thebeam probe near the focusing gradient are shown in
Fig. 8A, B, and C. By comparing Fig. 8 with Fig. 6,
we can estimate the gradient for the reversed beamfor each pair. These are listed in Table 3. If we
can determine a phase plot representing the realbeam, we can estimate the gradient of the channel
within narrow values; however we have no experimental results to determine which pair among threepairs described above is good approximation to thereal beam. Hence the gradient of the channel isestimated within relatively wide values above 0.23
and below 0.30 T / cm. When the effective crosssectional radius of the iron bar is reduced from

194

T. Karasawa

2.5 mm to 2.25 mm, the calculated value of thegradient is 0.25 T / ern for saturation induction of
2.2 T inside the iron.
We have made an interpretation about the effectof the magnetic channel in high field from the experimental observation of the reversed beam andcomputation of particle trajectory on aassumption of the phase plot.

simpleReference
1) M. Odera, Y. Miyazawa, T. Tonuma,. M. Henmi, andO. Terajima: Nucl. Instrum. Methods, 65, 247 (1968) .

195
RIKEN Accel. Prog. Rep. 20 (1986)

V-I5. Sputter PIG Source for RILAC
Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase

A new sputter PIG source of indirectly-heatedcathode type has been developed for RILAC. The
production of multicharged ions of solid elements
have been measured on its test bench. 1 } Figure 1
shows a cross sectional view of the sputter PIG
source. The anode consists of three parts, and the

middle part of them having the ion exit slit and two
anode holders is built interchangeably. Such construction allowed easy mechanical fitting of the anodegeometry. This middle part is made of stainless steel
and milled away by a section of 16 X 26 mm 2 fromthe rear-side of the anode. We made a sputtering

I2ITJ Insulator
Filament

c?oling ~~~~~~li~~~~~~~~~~~
Anode
coolingCathodecooling~o

50 (mm )A-

1 ::::::1:::;:= = = =:::;111::::Fig. 1. Cross sectional view of the sputter PIG source. 1, electron shield (Mo) ;2, filament (0.8, W); 3, cathode (W); 4, cathode heat shield (Mo); 5, anodeholder (copper) ; 6, anode (stainless steel) ; 7, anode holder; 8, anti-cathode (W) ;9, beam slit (Mo) ; lO, sputtering electrode; 11, clamp of the sputtering electrode(copper); 12, shield of the clamp (stainless steel).

Mag. field 4kG
Gas = 0.2cc/ min
Arc = 300V/ 2.7 A
Mg (Xe)Sputter = 20V/ 105mA
10 ¢x 141

1005040302018161412

10 9 87

6 m / q,100504030 20181614 12100~~~~~~-,~~~~~~--~;t;

Sputter = 105V/ 50mA
Gas = 0.3cc/ min-3

Nal (Xe)+Cu P1mm

+oJ

:::l

.e

oro

:::l

~

o

Q)

~

:::l

o

Cf)

0.1HfI---- - - - t - ---'-f+P71-o7

6 m/q,o~ Arc = 270V/ 2.2A::i 1010 9 8100~~~--~~~~~~+~-J.-~---.

Mag. field 4kG~[~
LJ~
5 ~..,.

coz

5Extraction voltage

Fig. 2. M/q spectrum of NaI sputtered in a xenon discharge.

~ 10

-3
+oJ

:::l

.e
:::l

0
Q)

~
:::l

0

Cf)

0.1

o

5

10
15
Extraction voltage (kV)20

Fig. 3. M/q spectrum of Mg sputtered in a xenon discharge.

Y. Miyazawa, et ai.

196electrode with a surface area of 80 to 140 mm 2 • To
prevent the electrode from melting, it was supportedwith a water-cooled clamp fitted into the shield of
the clamp with a gap of 1 mm. Typical sizes of the
sputtering materials were a 5 X 18 X 14 mm 3 blockand a cpl0X 14mm3 column. An observed Mjq

100504030 20181614 12 10 9 8
100

t

7

spectrum of ions of solid elements are shown in
Figs. 2-11. For operation of this source Ar or Xe
gas was used to support the arc discharge. Table 1
gives the output currents obtained by the ion source.
Ions of solid elements, Na 4+, Mg4+, AI4+, Si 5 +, Ti 6 +,Cr 7 +, Fe 6 +, Ni 7 +, Cu 7 +, and Ge 8 + have been obtained.

6 mill100;l; Mag. field 4kG~ Arc=370V/2.7A

10050403020181614 12 10 9 8!

Sputter =40v/300 mA-W>''I---+---r;+- Gas = 0.25 ccl min

<' 10
.3
....

--t

""*-----JI-(,.)-

7

6 millMag. field 4kG
Arc=340V/ 3A~~~~e~.;j ~~I~i~90 mA

AI (Xe)Cr(Xe)r!¥ ~.s- 1~+*----+---~~+-~r---~~
2
~
:::J

:::J

o

~~~l~Iov,tk?

.....:::J.s:::J

o

o

Q)

5

~

;!;

:::J

+Q)

o

u

en 0.1 X++;-----+------~--H~-+f·- + ---/-t---i

~

o

5

~ ~z

o

10
Extraction voltage

Fig. 4. M / q spectrum of Al sputtered in a xenon discharge.

5
1015Extraction voltage (kV)20

Fig. 7. M / q spectrum of Cr sputtered in a xenon discharge.

710050403020181614 12 10 9 8

6 mill100~-W~~~~-L~~~--+---L-~~j; + ;!;

Mag. field 4kGQ) .- Q)
Arc=380/ 3.3A~lt ~Sputter=220V/ 130mA~x ~l,-t+ - Gas=0.29cc/ min+x..... ! ~ +
Fi
' (X)
~
:;; ~ ~~ + """ + e e ~cu
<0

t 1

10
----<C

.3

....

.s-

~ 1~~

o

:::J

:::J
:::J

~

~ ~ i + ~-roT Fe

U)

~

-t.,

t

0

~l

~-

;,;

7

~
x 0
Z
~0.1~+~-----+------~~~~-rr

o

o

5

5

Fig. 5. M/q spectrum of Si sputtered in a xenon discharge.

7

6 mill100 504030 20181614 12 10 9 8<' 10i Il--l-ll---j--+~-+~~ ii(}I~
~

~

+

~

5

=:w

~

(~

5 ~

en o.ll-tt4------f-----L--+---,~,-IJt~ r---='tt-----i

7

6 mill100~-u~-+~~~-r~~~.-~---.

Mag. field 4kG
Arc = 360V/2.5A
Sputter = 180V1130mA
Gas=0.22cc/min

E

20

Fig. 8. M / q spectrum of Fe sputtered in a xenon discharge.

100~-w~-T~~~-r~~~~~--~

;!;

10

Extraction voltage

Extraction voltage

100 504030 20181614 12 10 9 8

'1.

;t

Mag. field 4kG
Arc = 490v/2.8 A
Sputter=200Vl,130mA!z:tj;;!:Q)xQ)Q)+;!;x~.....:::J

.s-

~

xx~

+ + -Gas=0.23cc/mm~ t~

Ni(Xe)z:-------+-

:::J

i~

~

Ni

o

Q)

7 '1.

~

:::J

o
en 0.1 H+-I----+---+~-

t~Z

o

5

o

Extraction voltage

510Extraction voltage

Fig. 6. M / q spectrum of Ti sputtered in a xenon discharge.

Fig. 9. M/q spectrum of Ni sputtered in a xenon discharge.

197

Y. Miyazawa, et al.

Mag. field 4kG
Gas=0.6cc/min
Arc=300V/3.7 A
Ge(Ar)
Sputter=70V/140mA7

100 504030 20181614 12 10 9 8

100~-LLl~tLL~~~r-~~~~~---.

x

6 mill7100504030 20181614 12 10 9 8

100~-U-L~~~~T!~~--~--~-'

{~

« 10

3

.....::lc..

g<' 101---- - --+l-1--+--\

II--Ht-----~7'-'~:

<

+ ~
5

3

~

...::l

t:I

%
1
o
(I)

::l

o

o

t

t

<0

CD
OQ(!l

+
+ +
+
an
r-

~

en 0. 11---+....=....---t-----~1---------'1--->.,""""____jt

510Extraction voltage
Fig. 10. M I q spectrum of Cu sputtered in a xenon discharge.

+
C't)

o

20

5
10
15
Extraction voltage (kV)Fig. 11. M I q spectrum of Ge in an argon discharge.

Table 1.

2+

1+

3+

The output currents of RILAC ion source.
4+

5+

6+

7+

8+

9+

10+

11+

12+

Sputtering materials
Na (Ar)(Xe)
Mg (Ar)(Xe)
Al (Ar)(Xe)
Si (Ar)(Xe)
Ti (Ar)(Xe)
Cr (Ar)(Xe)
Fe (Ar)(Xe)
Ni (Ar)(Xe)
Cu (Ar)(Xe)
Ge (Ar)
(Xe)

5.5
4

4.3
17
23
60

8
8

0.6
1.1
5
7
70
30
12
7
8

9

15

13
30
2.5

1.2 :
1. 5 :
2
2.8 i

i 10

~!

NaI crystal

0.02
0.25
0.2
2.8
2.5
0. 02
11

7

0.8

27

11

4.5

5.5
3

10

0.9

" "
" block"Al" crystal"Si" "Ti block" block"Cr" blockFe

Mg block

12
8.5
2

2
1.4
0.8
1.2

1.8

0.3

4
6

1.3
6

-i

Ions, M g 3+, AP+, Si3+, Ti 5 +, Ni G+, and Cu6 +, wereaccelerated by RILAC and delivered to various
target stations. Gases indicated in the parentheses
were used to support arc discharge. The dashed line
shows the lower limit of the charge-to-mass ratios of

0. 1

0.03

0.02
0.3
0.25
5
0.05

/I

/I

/I

Ni

block

" "
" crystal"Ge
Cu block

2
0.07

/I

/I

ions which can be accelerated by RILAC.
Reference
1) Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase:
RIKEN Accel. Prog. Rep., 19, 184 (1985) .

198
RIKEN Accel. Prog. Rep. 20 (1986)

V-16.

Performance of ECR2

M. Yanokura, S. Ishii, and H. N onaka

The performance of ECR2 1 ) (RIKEN Electron
Cyclotron Resonance type-ion source) has been improved since January 1986. An extracted beam
current of Ar 1+ ion was about 1 /-LA when reported
last year. This value is not satisfactory for RILAC.
The purpose of the present improvement is to increase beam currents.
Improvements were made on a few points. One
is a reform of the 1st cavity. A quartz tube of
400 mm in length and 21 mm in diameter was inserted into the 1st cavity, and gas was admitted byusing a slow leak valve into the quartz tube. Since
conductance of the tube was very small, a pressure
difference arose between inner and outer sides of thequartz tube; the calculated pressure difference wasof about 2 order of magnitude. During operation of
the ion source, ECR plasma was formed only inside
the tube. The pressure in the quartz tube wasaround 10- 4 Torr. Produced ions collide the innerwall of the quartz tube, but ion loss is rather small
because the charge exchange cross section at thesurface of the quartz tube is smaller than those atother materials. Thus, the pressure at the RF injection port was reduced, and no RF discharge took
place at this position.
The second improvement is made on an extraction
system. Before improvement, the bore diameter ofthe first electrode faced to the plasma surface was
10 mm. The bore diameter of acceleration electrodewas equal to that of the first electrode; the acceleration gap was about 4 mm. The extraction system
was improved by referring to a LBL ECR ion
source. 2 ) The parameters of the new extraction
system are as follows:
1 ) the bore diameter of the 1st electrode is
8mm;2) the bore diameter of the acceleration electrodeis 10 mm; and3) the acceleration gap width is 21 mm.
The beam-current loss at the extraction system wasdecreased by this improvement. The load of an
extraction power supply was also decreased.
Figure 1 shows two types of charge distribution ofan extracted Ar beam after improvement. The
vacuum pressure under each condition is also shown

100.----_ _ _,

10

«

::l,

:;

a.

:;
0
<l1

u

:;
0

(f)

123456ChargE' statE'

Fig. 1.

Charge distribution of the extracted Ar beam.

in Fig. 1. Open circles show high-intensity but poor
charge distribution data; triangles show low-intensity
but better charge distribution data. Matching between microwave and plasma for high-pressure operation is better than that for low-pressure operation.
Beam currents of both data are higher than those of
the last year anti Ar 1+ current are 20 times larger
than those reported last year; however, we need more
intense beams of high charge-states for RILAC.
We now plan further modifications; they are1) installation of an additional coil to decrease
an axial magnetic field gradient at the ECR point;2) increase in pumping speed, which lowers theoperating pressure at the 2nd stage to lower than
10- 6 Torr;3) modifications for increasing the RF electricfield in the cavity; and
4) installation of an electrode ad just mechanism
and a beam converging element such as a solenoid
coil.
References
1) M. Yanokura, S. Ishii, and Y. Sakamoto: RIKEN Aceel.
Prog. Rep., 19, 214 (1985) .
2) C. M. Lyneis: Proc. 7th Int. ECR Ion Source Workshop,
Jiilich Nuclear Centre Publ., p. 1 (1986) .

199
RIKEN Accel. Prog. Rep. 20 (1986)

V-I7.

Three Dimensional Analysis of RF Electromagnetic Fieldby the Finite Element Method
M. Hara, T. Wada, K. Mitomori, and F. Kikuchi

Calculation of an electromagnetic field is very important in designing accelerators. We have alreadydeveloped some computer codes 1 ,2) to calculate anelectromagnetic field in cavity resonators, based on
the finite element method. Everything goes quite
well in, a two-dimensional or axi-symmetric case.
Three-dimensional calculation, however, had difficultyin imposing a divergence free condition. We have
tried a finite element formulation where divergence
free condition is treated by a penalty method; however, the results were not fully satisfactory.
We have developed special finite element models
with "exotic" nodal configurations for two and three
dimensional elements. 3 ) In these models, the tangential component of the electric field at each side ofeach element is taken to be an unknown variablewhich is constant on the side and continuous along
the interelement boundaries. Some mixed finite element models are presented with numerical results
for two- and three-dimensional problems. Satisfactory
results have been obtained for simple problems.
1) Basic Equations
We deal with a time-harmonic electric field In
vacuum of bounded region surrounded by a perfectconductor. It is described by Maxwell's equations,which are reduced to
div E=O(1)

rot rot E= AE

(2)

and

where A = {J)2 / c 2 •The boundary condition isn X E=°

on the surface

sides of the element. We call these models exotic
models. Detailed formulation of these models arepresented in Ref. 4 and here we only summarize
the results. In Ref. 4 weak formulations for Maxwell'sequations are presented based on the mixed andpenalty methods. Mixed formulation is based on
the Lagrange multiplier.
Characteristics of these models are:(1) Tangential components of the electric fieldon the sides of the element are adopted as unknown
variables, which are constant on the sides;(2) The divergence-free condition is fully satisfied in each element;(3) The electric field is not strictly continuous,
but only tangential component is continuous along
the interelement boundaries;(4 ) The handling of the boundary condition iseasy;(5) Only five types of elements are in practicaluse.
In Fig. 1, five types of mixed finite element models
with exotic nodal configurations are shown. In theseelements, the triangular element for the two-dimensional and axi-symmetric case and tetrahedral element for the three dimensional case are importantfor practical use.
In the finite element model of the two dimensionalcase, we take the following approximation of E inan element:( 1) linear polynomial approximation;(2) rot E=constant;- - : SIDES(3)

where n is a unit vector normal to the surface.
In Eq. (2),for A=FO, div E= 1/ A div (rot rot E) = 0, and
A =0, rot E=O, but not div E=O.
We must treat an eigenvalue problem for a real
vector-valued function. A difficulty of this problem
is in dealing with the divergence-free condition (1).
2) New Type of Finite Element Models
These models have quite different node configurations from usual finite element ones because unknown
variables are taken not on nodal points but on the

NODES

[

o

: VERTICES

6D~§cfJ

DD~tEJl~-2-DIMENSIONAL ---.

- - 3 - DIMENSIONAL----..-

Fig. I. Types of exotic element models. Only these five
types can be used for our new types of finite element
models. Upper and lower rows show the sides and nodesof the clements, respectively.

M. Hara, et al.

200(3) div E=O;
(4) The tangential component IS constant oneach side of the element;
The electric field E = (Eq;, E z ), in this element, iswritten as
Erc=a l +azY
Ey=as-azx

In these equations, the coefficient of Y in Eq; andthat of x in Ey have the same absolute value andopposite signs due to the above condition (4).
Then,rot E= aEy _ aEx = -2a2axayEq;=a l +azY+ asz
Ey=a 4 -azx+ a5 z
E Z =a6- a Sx - a5Y

anddiv E= aEx + aEy = 0axshapes can be divided into tetrahedral elements withquite good approximation. In the same manner as
the two-dimensional triangular element, following
conditions are required for this finite element model.
( 1) linear polynomial approximation;(2) rot E=constant;(3) div E= 0;(4) Tangential components are constant on eachside of the element.
The electric field E = (Eq;, E y, E z ), in this element
IS written asay

In this element model, shape functions are givenasThe element stiffness and mass matrices for the
tetrahedral case are also given through the procedure as the case of two dimensional, but the explicit
expression is too complicate to write down.
2x2A

2x2B

5 x 5A

5x5B

andwhere s indicates the side of i + 3 in Fig. 2, Ii isthe length of the side of i + 3, and Si indicates thesign of li.
From this expressions, the element stiffness matrix
M s and element mass matrix M m are given byMs(i, j) = (11 A) [liljSiSj]
andMm(i, j)=(l/4AZ)[SiSjlilj

ff

Fig. 3 (a).

Two-dimensional mesh.

{(X-Xi)(X-Xj)+(Y-Yi)(Y-Yi)} dxdy
= (11 A) [S$jlilj {Xi*X/+Yi*Y/

3.0

A,t

- (1/6)(xl *xz * +xz *xs * + Xs *Xl *1+Yl*Y2*+Y2*YS*+YS*Yl*)} ]2.5

where A is the area of the element and Xl * = XI-X M
with XM being the center of gravity.
In the finite element model of the three-dimensional case, regions of arbitrary three-dimensional

2.0

3
1.5

o

-

(10XIOB): EXOTIC: CONVENTIONAL (14xI4B)

1.0

1 "------6-----1 2
0.4

Fig. 2. Triangular element. Figures 1-3 indicate nodal
points and Figs. 4-6 indicate sides. The tangential component of electric field on each side is constant and continuous, but oormal component is not continuous at theinterface of elements.

0.6

0.8

1.0

1.2

1.4

1.6

1.8

-Q

Fig. 3 (b). Calculated eigenvalue. Notch depth dependenceon eigenvalue is shown. The results show good agreementwith the calculation with a conventional finite element
model.

201

M. Hara, et al.

•

".

~

•

..

Joo

I>

..

....

•

•

~

Jo,

..It.

...

4
~

...

..,

......
..

..

.....

~
~

~

..

..

-to

..I.

"

..oil

....

. . - ..... .., ,., ... .., "" .. ..
~

-

~

~

as such. This kind of errors is inherent in thismethod.
For a three-dimensional problem, we calculated a
deformed parallelepiped cavity. Figure 4 shows thelowest eigenvalues with deformation x. This variation of the eigenvalue consists with the perturbation
theory. That is, when the volume where electric

a=O.3
10xl0A

Fig. 3 (c). Electric fields calculated at the center of massof each triangular element.

0

1.03
0

w

1.02
0

:::>
..J

<
>

z

0

1.01

0

w

"w

0
0

1.00
0

0.99

0

3
0.98 .

DIVISION 8X3X8Fig. 3 (d). Electric fields in two triangular elements at theedge indicated by the circle in Fig. 3 (c) . In these figures,
eigenvalue and eigenvectors are calculated on the sides of
elements and, from these values, the electric fields atarbitrary points are calculated.

TETRAHEDRAL ELEI1ENT

0.97

0

-0.4

3) Numerical Results
We made some calculations for several simple
problems to check the validity of our approach.
Figure 3 shows the calculations of a two-dimensional problem. We calculated the field in arectangular domain with a notch of depth a. Figure
3 (a) shows two types of meshes. We calculated thelowest eigenvalue using a triangular element. Usingsymmetric properties of the fields, only an upper
half area is divided and calculated. The notch dependence(a) of the lowest eigenvalue for 10 X lOB
meshes is shown in Fig. 3 (b), in which the solid line
indicates the results obtained with the conventional
method. 1 ) The calculated eigenvalues show good
agreement with a conventional method and theeigenvalue dependence on a is consistent with theperturbation theory. Figure 3 (c) shows the field
distribution calculated at the center of mass of eachtriangular element. In Fig. 3 ( d), the field in two
triangular elements at the edge are shown. Bars
indicate the magnitude and direction of the electricfields. The electric fields at element interfaces havedifferent values which depend on the element. In
this model, only tangential components are continuous. F or the same reason, the exact electric fields
should have no normal component on the symmetry
plane, but the calculated ones have a small amount

-0.2

0.0

0.2

DEFORMATION

Fig. 4.

0.4
X

Variation in eigenvalue with deformation.

I

P
I
I

/)

-;; 10 5

I

'C

()

0

I

10 ~

(;

!

/~

>
a:

o
~ lOq

:::

o
w
a:

,I' 0

:)

a

~ 10 3

5

N

I
I

"

o

2

4

6

DIVISION

Fig. 5.

8 10

20

30

N

Required memory vs division N.

4 050

202

M . Hara, et al.

field is strong is reduced, the eigenvalue should be
reduced. It is well known that in the three-dimensional calculations a large size of computer memory
is required. Figure 5 shows the required memory
size estimated vs division number N that the required
memory has N 5 dependence. It is because the skyline scheme is adopted for the solver. When thedivision is N , the order of matrix is nearly proportional to N 3. In the skyline scheme, the bandwidthis nearly proportional to N2 and the required memory
size is approximately proportional to N 5. According
to our mesh generator program, the maximum nonzero components of one column or row is expected
to be 19 considering the symmetry of the matrix;
therefore, the minimum size of memory to store thematrix is about 19 X N 3, which line is also indicatedin this figure. At present, we are developing a computer code based on some iteration methods which
can take advantage of this storage property.5)
References
1) M. Hara, T. Wada, A. Toyama, and F. Kikuchi: Sci.
Papers I.P.C.R. , 75, 143 (1981) .
2) M. Hara, T. Wada, T. Fukasawa, and F. Kikuchi: IEEE
Trans . Mag., 19, 2417 (1983) .
3) M. Hara, T. Wada, K. Mitomori, and F. Kikuchi: Proc.
11th Int. Conf. Cyclotrons and Their Applications, Tokyo , Oct. (1986) .
4) F. Kikuchi: "A finite element method for 3-D analysis
of cavity resonators," in preparation.
5) Y. Iwashita: private communications.

203

RIKEN Acce1. Prog. Rep. 20 (1986)

VI.

RADIATION MONITORING
1.

Calculation of Neutron Skyshine over the Area around
RIKEN Ring Cyclotron Facility
T. Shikata, N. Nakanishi, S. Fujita, H. Kamitsubo, and T. Kosako*

We have previously estimated the dose rate due toskyshine. 1 ,2 ) Recently, importance functions for neutron skyshine have been calculated by Hayashi andNakamura3l and Alsmiller 4 ) for a point source location at 15 m in height and by Hayashi and Nakamura5 ) at 0 m in height, for energies up to 400 MeV
and various source-to-field point distances. In thesecalculations the importance functions are presented
for several cos Os intervals in the upper hemisphere;
the emission angle, Os, is shown in Fig. 1, and thesource is assumed to be independent of the azimuthal
angle. This report describes more precise recalculation using the importance functions of the neutron
dose due to the skyshine over the area around
RIKEN Ring Cyclotron facilities. We calculated thesource neutron fluxes traversing through a roof using
the one-dimensional discrete ordinate code ANISN
a nd the neutronphoton multigroup cross section
library DLC87/HILO for neutron energies fromthermal to 400 MeV and photon energies from
10 keY to 14 MeV.
RIKEN Ring Cyclotron facilities are built on theslope: the level of the air-ground interface lies above
the roof of the experimental hall at one side of thevault and below the roof at the other side. Thus,

we have calculated the dose rates for both source
locations at 15 m and 0 m in height. Neutrons
emitted by reactions l:'!C ( 135 MeV I u , 6· 101 ::! pps )and ]2C(75 MeV lu, 6·10] 2 pps ) on a 5GFe thicktarget were selected as sources ; the spectrum of theformer is given in Ref. 1, and that of the latter isin Ref. 6. Energies of carbon ions of 135 MeV lu
and 75 Me V I u correspond to the highest ones, whencarbon ions are accelerated with the future A VF
cyclotron and with RILAC as injectors, respectively.
These spectra show many energetic neutrons not onlyin the forward direction to the beam direction but
in the sideward direction compared with other available spectra calculated in nuclear reactions with light
projectiles. 7,8)
In the calculation, neutrons ejected from the target
into a cone having a half apex angle of 60 degree
were taken as an original source, and a given effective thickness of the roof was assumed . Next wemade following simplifications in calculating thedose rate: the neutrons escaped from the wholesurface of the roof were replaced by those emitted
isotropically from a point source giving an equivalent
integral flux; importance functions for any Os were
substituted by those for a cosine interval, 0.2 <cos Os < 0.4. According to the calculated results(b)lR ON 3E Ai-l J Ui-iP

Fig·. 1. Geomctry used to calculate the neutron dose due to the skyshine.
(b) thc cyclotron vault.

* Reseal·ch Center for Nuclear Science and Technology,
The University of Tokyo.

(a) experimental hall;

T. Shikata, et al.

204

12

C<135r'1EV/u,6'10(b)

EXPERI~lENTI\L HALL

Ex PER Ir1ENTAL HALL
12

12C<75r'1EV/u,6'10

pps)

12

pps)

ON
56 FE THICK TIIRGETON
56 FE THICK TARGET~ 10- 2
a::
w

w

.....
~

(f)

o

<=>
:z
o
a::

UJ

o

<=>
:z

.....
~ 10- 3

o

a::

.....
:::>

U1

z:

- - - REF ,5 SOURCE IiEIGHTC(}.,)

10- 4- - REF,3 SOJRCE liEIGHT05Ml- - - - REF ,4 SOORCE I-£IGHTCJ5.1)

DISTANCE FROM SOURCE CM)

DI STANCE FROM SOURCE (M)Fig. 2. Dose rate due to the neutron skyshine over the area around an
experimental hall. (a) 12C (135 MeV lu, 6.1012 pps) on a 56Fe thick target;(b) 12C (75 MeV lu, 6.1012 pps) on a 56Fe thick target.

, """ICYCLOTRON VAULT
12C<13:fEV/u,6·10

CYCLOTRON VAlLT
12

12C<7S"EV/u,6'10

pps)

12

pps)

ON
56FE TIiICK TARGET

0.2(cos 8s (0.4
A: WIll~.IT BEAM DUt1P
B: IRON BEAM JJJMP c5Ck:M)- - REF.3 SOUKE HEIGHTCJ5.1)
-- -

10 1

10 2

REF,4 SOURCE HEIGHTClSM)

10 3

DI STANCE FROM SOURCE (M)D I STANCE FROM SOURCE (M)Fig. 3. Dose rate due to the neutron skyshine over the area around thecyclotron vault. (a) 12C (135 MeV lu, 6.1012 pps) on a 56Fe thick target;(b) 12C (75 MeV lu, 6.1012 pps) on a 56Fe thick target.

given in Refs. 3, 4, and 5, the importance functions
at a given distance not very far from the source increases with 8 5 , The functions for the above interval
are somewhat larger than those averaged over all

cosine intervals. Thus the dose rates obtained will
be of safety side. The geometry for the calculationand the results are shown in Figs. 1, 2, and 3.
Figures 2 and 3 indicate that the source height

T. Shikata, et al.

dependency of the calculated doses is rather small
and may be applied to other vertical source locations
not markedly different from those used here. Finally,it should be emphasized that the beam loss in thecyclotron vault will be about one tenth of the totalbeam, and ions will not always be accelerated withfull power of the accelerators.
References
1) S. Fujita, S. Yamaji, and T. Shikata: I .P.C.R. Cyclotron
Prog. Rep., 14, 203 (1980) .

205

2) T. Shikata, T. Kosako, S. Fujita, S. Yamaji, and H.
Kamitsubo: Sci. Papers I.P.C.R. , 77, 99 (1983) .
3) K. Hayashi and T. Nakamura: Nucl. Sci. Eng., 91, 332(1~85) .
4) R. G. Alsmiller, Jr., J. Barish, and R. L. Childs: ORNL/
TM-7512 (1980) .
5) K. Hayashi and T. Nakamura: Private communication.
6) T. Nakamura: INS-NUMA-5 (1977) .
7) T. A. Gabriel, R. T. Santro, H. W. Bertini, and N. M.
Larson: ORNL-TM-4334 (1973) .
8) R. G. Alsmiller: Cited in the report of H. A. Smith, Jr.
(IUCF Internal Rep., No. 74-6) .

206
RIKEN Accel. Prog. Rep. 20 (1986)

VI-2.

Radiation Safety Control System for RIKEN Ring Cyclotron
I. Sakamoto, S. Fujita, T. Wada, and H. Takebe

A Radiation Safety Control System (RSCS) consists of a radiation monitoring system and a radiation
protection control system. Figure 1 shows a block
diagram of the RSCS. A large number of devices for
the RSCS are distributed in RIKEN Ring Cyclotronbuilding. Since there are more than two hundredparameters and intricated control sequences for
operating the RSCS, a computer control system is
introduced; the host computer is a MITSUBISHI
MX-3000.
( 1 ) Radiation monitoring system
Four monitoring posts at the boundary of the
Accelerator Facility and one in the control room
have been installed to measure the leakage-radiation
during operation of RIKEN Ring Cyclotron. A
NaI (TI) scintillation detector and a helium-3
counter are placed in each post to detect environmental r-rays and neutrons, respectively, besides,
eleven ionization chambers and eight BFa counters
are used to measure the radiation level at RIKEN
Ring Cyclotron vault and the experimental rooms.
In order to measure the radioactivity in drainwater and in the air of the experimental rooms andat the exit of the exhaust duct, three activity monitoring stations have been built in RIKEN Ring Cyclotron building. The radioactivity in the drain water
is measured with a NaI (TI) and plastic scintillation<MACHINE CONTROL>
M-60 SYSTEM

detector. The radioactivity in the aIr (gases andairborne dust) is measured with aNaI(TI) , ZnS(Ag),and plastic scintillation detector. All the data
coming from monitors are logged periodically by the
MX-3000 and stored in diskfiles; the MX-3000 candraw a graph by using those data.
VI/ e succeeded in extracting a 21 MeV / u 12-'argon beam from RIKEN Ring Cyclotron on December 16, 1986, and transported the beam on thetarget at the E1 experimental room on December
20. The beam intensity was 30-100 nA.
Leakage-radiation during operation of RIKEN
Ring Cyclotron has been measured inside and outside RIKEN Ring Cyclotron building. Figure 2
shows an example of the intensity increase whenthe Ar beam was accelerated. No leakage r-rays
and neu trons from RIKEN Ring Cyclotron building
was detected.
(2) Radiation protection control system
The radiation protection control system consists ofcard-operated gate-bars, safety keys, operation status
lamps, radiation level indicators, shield doors, handfoot-clothes monitors, and rotary shutters.
The entrance to and exit from the controlled area
are checked very strictly by a personal card. At
the entrance of each experimental room the radiationlevel inside the room is displayed on the radiation<RADIATION SAFETY>
MITSUBISHI SUPER MINI COMPUTER MELCOM70 MX3000 SYSTEM

WORKSTATION

x3

U
CONTROL SYSTEMRADIATION MONITORING SYSTEMGATEENVIRONMENTAL

VENTlLATlNG DAMPER

KEY BOXROOM AIRDRAINING ElEMENTS

OPERATION STATUS LAMPLABORATORY AREAS

RADIATION LEVEL INDICATORVENTILATIONSHIELD DOORDRAINS

HAND·FooT.cLOTHES MONITOR

ALARM LAMPSROTARY SHUTTERI

RADIAT10N HYGIENE CONTROL

Fig. 1. Block diagram of the Radiation safety control system for RIKEN Ring
Cyclotron.

I. Sakamoto, et al.

207

(a )

I

A ( Y- rays)nrj~A ( Y- rays),i I'i\/ 8 ( y- rays )r H'if:,'1 '1,::: :::: ~::; :c,:~ :(Neutrons),:; : I• •II

10- 12/ 15 12/ 16 12/ 17 12/ 18 12/ 19 12/ 20 12/ 21
Date (1986)
Fig. 2. Comparison of day variations of the radiation levelmeasured with radiation monitors in RIKEN Ring Cyclotron vault and the El experimental room. A, an ionizationchamber in the ring cyclotron vault; B, an ionizationchamber in the EI experimental room; and C, a BF 3
counter in the EI experimental room.

level indicators, by indicating each level with Green,
Yellow, or Red. The operation conditions of RILAC,
the AVF cyclotron, and RIKEN Ring Cyclotron are
also displayed on the operation status lamps.
RIKEN Ring Cyclotron is controlled with acomputer system/ l consisting of a MITSUBISHI
M-60, which is linked with the MX-3000 of the
RSCS. For radiation safety, the MX-3000 has thehighest priority in accelerator operation. Before
starting operation, an operator should ask the MX3000 for permission. If any erratic conditions occur
in the RSCS during operation, the MX-3000 sends
a beam-stop command.
The MX-3000 permits RIKEN Ring Cyclotron
operation, when

No person is in RIKEN Ring Cyclotron
vault and experimental room where beams will
be used;(b) The shield doors are closed in RIKEN Ring
Cyclotron vault and in the experimental room
where beams will be used;(c) The rotary shutters are open in the beamcourse where the beam will be used ; But otherrotary shutters are closed .
Persons are not permitted to enter the relevant
vault or rooms, when(d) RIKEN Ring Cyclotron is in operation;(e) Beams are being handled in the experimental
room;(f) The radiation level of the experimental room
is Red level, or the radioactivity in the air of
the room is at high level.
(3) Display on CRT terminal
The radiation level of each experimental room isalso indicated with color, Green, Yellow, or Red,
which is displayed on three Cathode Ray Tube
(CRT) terminals together with the number of
persons working in this area. The status of safety
keys, RILAC operation, AVF cyclotron operation,
RIKEN Ring Cyclotron operation, shield doors,rotary shutters, and ventilating damper are also displayed on these CRT terminals, which are placedon the RSCS control desk, RIKEN Ring Cyclotron
operation desk, and the underground passage.
ReferenceI) T. Wada, H. Takebe, J. Fujita, T. Kambara, and H.
Kamitsubo: p. 170 in this report.

208
RIKEN Accel. Prog. R ep. 20 (1986)

VI-3.

Routine Monitoring of RIKEN Accelerators

I. Sakamoto, S. Fujita, M. Yanokura, T. Kobayashi, O. Kurihara, and 1. Kohno

65Z n and 5SCO in the cyclotron vault and the experimental areas, and 137CS and 210Pb in the hot laboratory and chemical laboratories. The contamination
was wiped off twice a year and immediately after
this decontamination; thus, the activities on the floorof the most of above places were reduced below
10- 7 flCi/cm 2.
When radioactive substances were handled in the
hot laboratory and chemical laboratories, the air inthe draft chamber was activated. The air in thedraft chamber was exhausted; the radioactivity inthe exit was below 10-]2 flCi/cm 3 .
(3) Drainage
The radioactivities in drain water from the cyclotron and the linac building were found to be of theorder of 10-8-10- 5 flCi/cm 3 . The total activity inaqueous effluents was about 200 flCi, and the nuclides
found by r-ray spectrometry were 75S e, 7jBr, and137CS.
( 4 ) Radiation monitoring for RILAC andTANDETRON
The leakage radiation during operation of the
RILAC was measured in the circumference of thelinac building every month. No leakage of r-rays
and neutrons from the linac building was detected.
No contamination of the surface and air due toresidual activities was found in the control area in

The present report describes the results of routine
radiation monitoring carried out for the cyclotron,
RILAC, and TANDETRON from April 1985 toMarch 1986. Aspects of the leakage radiation fromthe cyclotron are described in a succeeding report.
(1) Residual activities of the cyclotron
In January 1986 the dose rates due to residual
activities of the machine were measured 17 days after
shutdown. The results are shown in Table 1.
The external exposure doses for two workers during replacement of the septum were 6 and 10 mrem.
(2) Surface and air contaminations in the cyclotron building
The surface contamination has been kept below
10-5 flCi/cm 2 on the floors of the cyclotron vault,
the underground passage, and the experimental areas,
and below 10- 4 flCi/cm2 on the floors of the hotlaboratory and chemical laboratories. The radioactive nuclides found by r-ray spectrometry wereTable 1.

Dose rates of residual activities.

Location

Dose rate (mR/h)ca. 25 em apart from septum(before replacement of septum)
ca. 20 em apart from septum holder(after replacement of septum)

100
100

Table 2. Annual exposure doses received by RIKEN accelerator workers from April 1985
to March 1986.
Number 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
Average annual dose per p erson:
Maximum individual annual dose:Collective
dose

Dose
undetectable

10-100(mrem)>100(mrem)

Total

8

0

0

8

0

10
9

0

0
0
0
0

10
10

6

1

9

0

0
0
0
0

6
9
6

0
10
50
100
780
0
10
0
0

99

950

11

26
2
2
5
9
6
88
9.6mrem
370 mrem

1

0
0
10

12
27
2

(man-mrem)

I. Sakamoto, et al.

the linac building.
X-ray monitoring was carried out for the T ANDETRON when boron ions were accelerated. When avanadium target was bombarded with 2.0 MeV B2+ions at 1 nA, the maximum irradiation dose rates
measured around TANDETRON was 0.7mR/h.
No leakage X-rays was detected around the target
chamber and outside the TANDETRON room.
(5) Personnel monitoring
The external exposure doses to personnel were
measured by using r-ray and neutron film badges.

-"7___ .

209

The doses received by accelerator workers during
the present period are shown in Table 2. The collective r-rays dose to all workers was 950 manmrem, while the collective dose owing to thermal
and fast neutron exposures was too small to be detected. The collective dose to the workers was about
52 % of the value in the preceding period.
In this period the average annual dose per person
was 9.6 mrem, and the maximum individual annual
dose was 370 mrem.

210

RIKEN Accel. Prog. Rep. 20 (1986)

VI-4.

Leakage-Radiation Measurement in the Cyclotron Building
I. Sakamoto, S. Fujita, and 1. Kohno

In May 1985 the leakage radiation was measured
at various points in the cyclotron building, when atin target placed in the beam course No.2 was bombarded with helium ions at a beam intensity of
12-14 flA.
The r-ray dose rate was measured with an ionization chamber survey meter, and the dose equivalent
rate for fast neutron and slow neutron was measured
with a "rem meter." * The results are shown in Fig. 1.
The leakage dose measured from April 1985 toMarch 1986 with r-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.
Of the dose values at point A measured every
month, the maximum total dose of 1,120 mrem wasobserved in May, when the values for r-rays andthermal neutron and fast neutrons were 580, 70, and
470 mrem, respectively.
The fast neutron doses observed at point A in
May and June, 470 mrem and 310 mrem, werelarger than those in other months. These results
let us to conclude that the increase in the neutron
dose was mainly due to activation analysis and radioisotope production.

0.02

o

!

!

11

,

!

012345'm,,Experimental area (L) :0.3:-0.4., x

Undergroundpassage

Underground passage~

6.2: xAX1212-10 ,'

1.0: x2.0: t

,

l

I

,WT

o
Hand foot cloth monitor

Control room
Basement

Ground plan

Fig. 1. Leakage-radiation (neutrons and r-rays) in the cyclotron building.
Operating conditions

40 MeV
Beam course: No.2
Target: Sn

Dose unit
r-ray
Neutron:mRjhmrem/h(under line)

Those data include 0.02 mRjh background radiation ; Measured on May 1985.

* A Neutron Dose Rate Meter 2202, manufactured b y
AB Atomenergi, Sweden.

I. Sakamoto, et al.

211

Table 1. Leakage-radiation dose (in mrem) in the underground passage of the cyclotronbuilding from April 1985 to March 1986.
Point B*

Point A*

(mrem)

Thermalneutrons(mrem)

Fast
neutrons(mrem)

4,85'
5
6
7
8
9
10
11
12
1,86'
2
3

380
580
540
110
0
60
190
250
120
0
200
210

30
70
70
10
0
10
10
30
10
0
30
20

140
470
310
20
0
20
70
150
70
0

Total

2,640

290

Month

*

r-RaysSee Fig. 1.

(mrem)

Thermalneutrons(mrem)

Fast
neutrons(mrem)(mrem)

160

550
1,120
920
140
0
90
270
430
200
0
310
390

10
10
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0

20
30
10
0
0
10
0
20
10
0
20
0

30
40
10
0
0
10
0
20
10
0
20
0

1,490

4,420

20

0

120

140

80

Total

r-Rays(mrem)Total

212
RIKEN Accel. Prog. Rep. 20 (1986)

VI-5.

Calculation for the Design of an Iron Beam Dump for
Shielding of Neutrons
N. Nakanishi, T. Shikata, S. Fujita, and T. Kosako*

Among radiations produced by the accelerator ina few hundreds of million electron volts per nucleon
energy range, the most penetrating component is thehigh-energy neutron flux. In this energy range, theeffect of capture-r-rays generated in the shield on
the dose equivalent is relatively small. Therefore,
we have primarily focused our study on the neutron
shielding.
We have previously obtained a design chart for
determination of the thickness of shielding materials
based on a two-layer slab modeP) This chart enables us to determine the thicknesses of a concrete
wall of the building and a local shield simultaneously
and easily, at any arbitrary thickness ratio.
In the present report, similar charts for designing
an iron beam dump obtained by using a concentric
spherical shell model are given. In the calculationof the neutron dose at a point on the surface of aconcrete wall, say, point B shown in Fig. 1 (a), thisconfiguration was represented by a model consisting'.... .
a:..

~'"Fig. 1.

Model for the calculation of doses.

of concentric spheres radii of which were taken to
be the distances from the point neutron source tothe interfaces of media in a specified direction(point B) as illustrated in Fig. 1 (b). The dose rates
on the outer surface (point B) were then calculated
as a function of the thickness of a concrete shell,
with a radius of an iron sphere taken as a parameter.
7

10'

10

6

10

lOS

1

10

uJ

10

6

lOs

.....>:>:
>:

>:

4

10

fIT"l

6

or
4

-'
-'

lOs
4

10

>:

'"
I-

10

]

10

10

'"

3

I-

0

10

10

3
0

0

"" 10

u

2

3

<:

2

~

""~ 10"" 10'"" 10'

10

2

0

«

10'

a:
0

10°

0

>-

0

10°

a

i5 10- 1

i5

~

.
I-

l-

«

0

10°

>-

>-

0

0

0

T H I ~ KNE SS OF A CONCRE TE SHEll (M)TH IC KNESS OF A CONCR ETE SHCll (M)THI CKNCSS OF A CO liCRETE SHEll (M)Fig. 2. Design charts. Dose rates on the outer surface of a concrete wall as a function of RON, with Rr taken
as a parameter; (J stands for a specified angular interval of interest.

* Research Center for Nuclear Science and Technology,
The University of Tokyo.

N. Nakanishi, et al.

213

3

~

~ 10 0
<>:
I-

<>:

UI
I-

7? 10- 1
UI
tI)

o

<>: 1
u.

Cl

0.1

o

10- 2

en

en
lJJ
z:

(p+Ad 00 -30°

0.6

""u
;:

1

1-0

1

o

2

Fig. 3.

0.5

1

The corrected Fig. 2 in Ref. 2.

The computer code and the cross section libraryused in the calculation are the one-dimensional discrete ordinate code ANISN and DLC-87 jHILO,
respectively. Neutrons were assumed to be emitted
by a reaction of 12C(135 MeVju,6·1012 pps) on a
56Fe thick target. 2) In the transport calculation using
the ANISN code of the spherical geometry having
the source neutron at the center, the source should
be isotropic. In the present case, however, we applied the ANISN code to a source having angulardependence and, in order to calculate the approximate dose rate in ., () direction to the incident ion
beam, we used an isotropic source, which intensity
per unit solid angle per a given energy interval was
equal to that of the assumed source in the same ()direction. Results of the calculation for average dose
rates on given () intervals are shown in Fig. 2. We
can simultaneously determine RON and R 1, whichyield a tolerance dose rate at the surface of a concrete wall in a specified direction () to the ion beam,at any arbitrary ratio (RCNjRI) at a given R from
Fig. 2.
When the thickness of a wall is given, a similar
chart can be obtained easily for a composit beam
dump; for instance, an iron-heavy concrete one. In
a previous report,3) the design charts for this casewere given; however, we J ound errors in Fig. 2 inRef. 3 and gave the corrected .p~e .iIL 9~~ pr~.~~nt report as Fig. 3.
."
References
1) T. Shikata, N. Nakanishi, S. }iujita, and T. Kosako:
RIKEN Accel. Prog. Rep., 19: 218"(1-985) .
-2) S. Fujita, S. Yamaji, and T. Shikata:' IPGR Cyclotron
Prog. Rep., 14, 203 (1980) .
3) N. Nakanishi, T. Shikata, S. Fujita, and T. Kosako:
RIKEN Accel. Prog. Rep., 18, 194 (1984) .

214

VII.

LIST OF PUBLICATIONS

1. Accelerator development and accelerator physics
1) S. Ishii, H. Amemiya, and M. Yanokura:"An Optimum Condition of Multipole Field
for an ECR-Type Ion Source," lpn. J. Appl.
Phys. , 25, 712 (1986).
2) F. Kikuchi: "An Isomorphic Property of two
Hilbert Spaces Appearing in Electromagnetism: Analysis by the Mixed Formulation,"
lpn. l. Appl. Math., 3, 53 (1986).
3) S. Kaizu and F. Kikuchi: "An Imbedding
Theorem for a Hilbert Space Appearing inElectromagnetics," Sci. Pap. Coll. Arts Sci.
Univ. Tokyo, 36, 81 (1986) .

2. Nuclear physics and nuclear instrumentation
1) N. Yoshinaga : "In trinsic Sta tes in the sdg
Interacting Boson Model," Nucl. Phys. A,
456, 21 (1986).
2) S. Kubono, K. Morita, M. H. Tanaka, A.
Sakaguchi, and M. Sugitani: "Highly Excited High Spin States in 28Si Populated
through the 12C (2°Ne) Reaction," N ucl. P hys.
A, 457, 461 (1986).
3) Y. Gono, T. Kohno, M. Sugawara, Y. Ishikawa, and M. Fukuda: "Collective Vibrationsin 218Ra," Nucl. Phys. A , 459, 427 (1986).
4) S. Suzuki, T . Doke, A. Hitachi, A. Yunoki,
K. Masuda, and T. Takahashi: "Photoionization Effect in Liquid Xenon Doped with
Triethylamine (TEA) or Trimethylamine(TMA) ," Nucl. Instrum. Methods A, 245,
78 (1986).
5) S. Kubono, M. H. Tanaka, H. Kawakami,
K. Sueki, H. Miyatake, T. Nomura, K.
Morita, M. Ishihara, S. Kato, C. Konno, and
A. Sakaguchi: "High-Energy Gamma Ray
Spectrometer for Heavy-Ion Induced Experiments," Nucl. Instrum. Methods A , 251, 74(1986) .
6) T. Murakami, J. Kasagi, H. Tachibanaki, K.
Yoshida, Y. Shibata, T. Nakagawa, M. Ogihara, S. M. Lee, T. Kubo, and T. Motobayashi: "Properties of BaF 2 Scintillators in
Charged Particle Detection," Nucl. Instrum.
Methods A, 253, 163 (1986).
7) T. Otsuka and N. Yoshinaga: "FermionBoson Mapping for Deformed Nuclei," Phys.
Lett. B, 168, 1 (1986).
8 ) A. Akiyama, K. Heyde, A. Arima, and N.
Yoshinaga : "The Structure of the 168Er
Nucleus and the 166Er (t, p) 168Er Reaction inTerms of the sdg Interacting Boson Model,"Phys. Lett. B, 173, 1 (1986).
J. Kasagi, H. Harada, T . Murakami, K.
Yoshida, H. Tachibanaki, and T. Inamura:"Enhanced E2 transitions between 9- and 8States in llOSn and 112S n ," Phys. Lett. B, 176,
307 (1986).
10) H. Sakai, N. Matsuoka, T. Saito, A. Shimizu,
M. Tosaki, M. Ieiri, K. Imai, A. Sakaguchi,
and T. Motobayashi: "Measurements of K1J1J
at 0° for the 2H (15, ii)2p Reaction at 50, 65,
and 80 MeV," Phys. Lett. B, 177, 155(1986) .
11) Y. Nagashima, J. Schimizu, T. Nakagawa, Y.
Fukuchi, W. Yokota, K. Furuno, M. Yamanouchi, S. M. Lee, N. X. Dai, T. Mikumo,
and T. Motobayashi: "Effects of Entrance
Channel and Compound Nucleus in the
Fusion Cross Sections for 28Si + 28Si, 16 0 +40Ca, 32S+ 30Si, and 12C+50Cr," Phys. Rev.
C, 33, 176 (1986).
12) T. Kohno, M. Adachi, S. Fukuda, M. Taya,
M. Fukuda, H. Taketani, Y. Gono, M. Sugawara, and Y. Ishikawa: "Level Structure andElectromagnetic Properties in 212Ra," Phys.
Rev. C, 33, 392 (1986).
13) S. Kubono, K. Morita, M. H. Tanaka, A.
Sakaguchi, and M. Sugitani: "g9/2 Single
Particle State in 28Si," Phys. Rev. C, 33, 1524
(1986) .
14) K. H. Tanaka, Y. Nojiri, T. Minamisono, K.
Asahi, and N. Takahashi: "Polarization of
12B Produced in 14N-Induced Reactions,"
Phys. Rev. C, 34, 580 (1986).
15) T. Motobayashi, H. Sakai, N. Matsuoka, T.
Saito, K. Hosono, A. Okihana, M. Ishihara,
S. Shimoura, and A. Sakaguchi: "Analyzing
Power Measurements of (d, 2He) Reactions
on Light Nuclei," Phys. Rev. C, 34, 2365
(1986) .
16) A. Sakaguchi, K. Nagatani, M. Torikoshi,
S. I. Hayakawa, T. Motobayashi, O. Satoh,T. Yamaya, M. Fujiwara, N. Matsuoka, and
H. Sakai: "Spectroscopy with the SingletDeuteron Reaction 12C (a, ds=o) 14N at 50
MeV," Phys. Rev. Lett., 56, 1112 (1986).
17) N. Yoshinaga, A. Akiyama, and A. Arima:"The sdg Interacting Boson Model Applied
to 168Er," Phys. Rev. Lett., 56, 1116 (1986).
18) S. Kubota, T. Motobayashi, J. Ruan, F.
Shiraishi, and Y. Takami: "A New BariumFluoride Plastic Scintillator," IEEE Trans.
Nucl. Sci., 33, 370 (1986).
9)

215

19) K. Ikeda, S. Yoshida, and S. Yamaji: "Application of Time-Dependent Mean-Field
Theory to Heavy Ion Collisions: Simple
Example of an S-Matrix Calculation for
Elastic Scattering," Z. Phys. A-Atomic Nuclei,
323, 285 (1986).
20) Y. Nojiri, K. Takeyama, K. Matsuta, K.
Asahi, and T. Minamisono: "Nuclear Polarization Production by the Tilted Foil Techniqueand Its Application," j. Phys. Soc. jpn., 55,
Supp!., 391 (1986).
21) K. H. Tanaka, Y. Nojiri, T. Minamisono, K.
Asahi, and N. Takahashi: "Study of 12B
Polarization in 14N-Induced Reactions," J.
Phys. Soc. j pn., 55, Supp!., 790 (1986).
22) K. Asahi, M. Ishihara, T. Shimoda, T. Fukuda, N. Takahashi, K. Katori, S. Shimoura,
N. Ikeda, C. Konno, H. Hanakawa, A. Nakamura, T. Itahashi, Y. Nojiri, and T. Minamisono: "Beta Decay of Polarized Nucleus 15C
Produced in Heavy-Ion Reaction," j. Phys.
Soc. j pn., 55, Supp!., 1032 (1986).
23) Y. Nojiri, K. Takeyama, K. Matsuta, K.
Asahi, and T. Minamisono : "Nuclear Polarization of Short-Lived f3 Emitters 8Li, 12B, and27Si Created by the Tilted Foil Technique,"J. Phys. Soc. jpn., 55, Supp!., 1086 (1986).
24) H. Ohsumi, M. Ishihara, S. Kohmoto, K.
Asahi, K. Sugimoto, T. Tanabe, T. Hattori,
and K. Haga: "Nuclear Spin Polarization of
27 Al Produced by Tilted-Foil Method andDetermination of the Polarization by Coulomb
Excitation," j. Phy. Soc. jpn., 55, Supp!.,1088 (1986).
25) T. Inamura: "Massive Transfer in Heavy
Ion Reactions," Heavy Ions in Nuclear
Physics, Hardwood Academic Publishers, New
York, p. 1 (1986).
26) Y. Ishibe, H. Oyama, K. Okazaki, K. Yano,
Y. Sakamoto, N. Noda, and Y. Hori: "Carbon
Coating by ECR Plasma," j. Vac. Soc. jpn.
(in Japanese), 29, 385 (1986).
27) A. Yunoki, K. Masuda, J. Kikuchi, T. Takahashi, and T. Doke: "Measurement of a-f3
Ratio in Scintillation from Liquid Argon,"
Bull. Sci. Eng. Lab. Waseda Univ., 113, 54(1986) .
28) H. Kumagai, T. Takahashi, T. Kubo, and
M. Ishihara: "Parallel Plate Avalanche
Counter for Heavy-Ion Dosimetry," H oshasen(in Japanese), 12,38 (1986).
29) H. Kumagai, M. Sasagase, and T. Wada:"An On-Line Data Acquisition System at
RILAC," Reports I.P.C.R. (in Japanese), 62,
114 (1986).
30) K. Asahi: "On-Line Isotope Separator Projectat RIKEN," Genshikaku Kenkyu (in Japanese), 31, 69 (1986).
3. Atomic and solid-state physics
1) S. Hara, H. Sato, S. Ogata, and N. Tamba:"Vibrationally and Rotationally Resolved
Cross Sections and Angular Distributions of
Photoelectrons from H 2," J. Phys. B: At. Mol.
Phys., 19, 1177 (1986).
2) S. H. Be, T. Tonuma, H. Kumagai, H. Shibata, M. Kase, T. Kambara, 1. Kohno, and
H. Tawara: "Net Ionization Cross Sectionsof Rare Gases by Collisions of Fast Highly
Charged Heavy Particles," j. Phys. B: At. Mol.
Phys., 19, 1771 (1986).
3) H. Sato and S. Hara: "Theoretical Study ofAutoionizing States of Molecules: II The
1!/ and 1II g States of H 2," J. Phys. B: At.
Mol. Phys., 19, 2611 (1986).
4) S. Hara and M. Nakamura: "Determinationof the Photo-Ionization Asymmetry Parameter," j. Phys. B: At. Mol. Phys., 19, L467
(1986) .
5) 1. Tanaka, S. Nasu, F. E. Fujita, F. Ambe, S.
Ambe, and T. Okada: "119Sb Mossbauer
Study on Quenched-in Vacancies in Gold,"
J. Phys. F: Met. Phys., 16, L151 (1986).
6) E. Yagi, S. Nakamura, T. Kobayashi, F. Kano,
K. Watanabe, Y. Fukai, and T. Osaka:"Lattice Location Study on H in Ta by the
Channeling Method," J. Phys. Soc. jpn., 55,
2671 (1986).
7) S. Hara, T. Ishihara, and N. Toshima:"Variational Calculation for Muonic Molecules," j. Phys. Soc. j pn., 55, 3293 (1986).
8) K. Nagamine: "Recent Topics in Muon Spin
Polarization Phenomena and pSR Experiments," j. Phys. Soc. jpn., 55, Supp!., 402(1986) .
9) M. Uda, A. Koyama, Y. Sasa, and O. Benka:"Chemical Effects on Augar Spectra Induced
by Fast Ions," Nucl. lnstrum. Methods B,
13, 196 (1986).
10) A. Koyama, O. Benka, Y. Sasa, and M. Uda:
"Energy Spectra of Secondary Electrons fromAl Induced by High Speed He 2+ and Ar12+
Impact," Nucl. lnstrum. Methods B, 13, 637(1986) .
11) K. Nakanishi, K. Iguchi, A. Ohsaki, and T.
Watanabe: "Classical-Trajectory Monte Carlo
Calculations for Coulomb-Interacting ThreeBody Systems," Atomic Collision Res. in Japan-Prog. Rep., No. 12, p.6 (1986).
12) Q. Ma, X. Zhang, Y. Liu, and T. Watanabe:"T otal and Differential Cross Sections for(p+ p-) Formation by Collisions of p+ with

216(p-p) including Excited States in First Born
Approximation," Atomic Collision Res. inJapan-Prog. Rep., No. 12, p.8 (1986).
13) M. Iwai, 1. Shimamura, and T. Watanabe:"Extended Bethe Surface: Behavior of theGeneralized Oscillator Strength along Isoelectronic Sequence," Atomic Collision Res. m
Japan-Prog. Rep., No. 12, p. 17 (1986).
14) S. Karashima, T. Watanabe, X. Zhang, Q.
Ma, and Y. Liu: "Electron Stripping Cross
Section of Multiply Charged Ions by Neutral
Atoms," Atomic Collision Res. in Japan-Prog.
Rep., No. 12, p.32 (1986).
15) T. Mizogawa, Y. Awaya, T. Kambara, Y.
Kanai, M. Kase, H. Kumagai, P. H. Mokler,
and K. Shima: "Effect of L-Hole Populationon K-Hole Formation Cross Section for Argon
Ion Passing through thin Carbon Foil," Atomic
Collision Res. in Japan-Prog. Rep., No. 12,
p.45 (1986).
16) Y. Awaya, T. Kambara, M. Kase, H. Kumagai, T. Mizogawa, Y. Kanai, and K. Shima:"A Broad Range Magnetic Charge Analyzer,"
Atomic Collision Res. in Japan-Prog. Rep.,
No. 12, p.57 (1986).
17) K. Fujima, T. Watanabe, and K. Mirna: "XRay Spectra Emitted from High Density andHigh Temperature Si," Atomic Collision
Res. in Japan-Prog. Rep., No. 12, p. 126(1986) .
18) 1. Shimamura and M. Iwai: "An R-Matrix
Method for Wave Functions That Are Accurate Close to the Coordinate Origin," Atomic
Collision Res. in Japan-Prog. Rep., No. 12,,p. 151 (19B6). ·19) F. Ambe, "K. Asai, S. Ambe, T. Okada, and
H. Sekizawa: "Comparative Mossbauer and
TDPAC Studies on the After-Effects of the
EC Decays of 119Sb and 111In in a-Fe20g,"
Hyperfine Interact., 29, 1197 (1986).
20) N. Sakai and H. Sekizawa: Observation of
Mossbauer Spectrum without Utilizing Doppler Motion," Hyperfine Interact., 29, 1521
(1986) .
21) M. Schmolz, K.-P. Doring, K. Fiirderer, M.
Gladisch, N. Haas, D. Herlach, G. Majer, J.
Rosenkranz, W. Schafer, L. Schimmele, W.
Schwarz, A. Seeger, and E. Vagi: "Positive
Muons in Iron: Dipolar Fields at Tetrahedral
Sites and Jump Frequencies at Low Temperatures," Hyperfine Interact., 31, 199(1986).
22) K. Nagamine and K. Ishida: "pSR in Polyacetylenes," Hyperfine Interact., 32, 535(1986) .
23) K. Nishiyama, K. Ishida, K. Nagamine, T.

Matsuzaki, Y. Kuno, H. Shirakawa, R. Kieft,
and J. H. Brewer: "Precise Measurement of
HFS Constant of the Muonium Substituted
Radical in cis-Polyacetylene," Hyperfine
Interact., 32, 551 (1986).
24) N. Toshima and T. Watanabe: "Simplified
Distorted-Wave Treatment for AsymmetricElectron-Capture Processes," Phys. Rev. A,
33, 1382 (1986).
25) H. Tawara, T. Tonuma, H. Shibata, M. Kase,
T. Kambara, S. H. Be, H. Kumagai, and 1.
Kohno: "Production of Multiply Charged
Molecular Ions (Nl2+-N 214+) and Multiply
Charged Atomic Ions (N6+, N7+) in Energetic,
Heavy-Ion Impact on N2 Molecu'tes,~' Phys.
Rev. A, 33, 1385 (1986).
26) T. Tonuma, H. Shibata, S. H. Be, H. Kumagai, M. Kase, T. Kambara, 1. Kohno, A.
Ohsaki, and H. Tawara: "Production ofHighly Charged Slow Ar Ions Recoiled in
1.05 MeVjamu Ne q + (q=2, 7-10) and Arq +(q=4, 6, 10-14)-Ion Bombardment," Phys.
Rev. A, 33, 3047 (1986).
27) J. Kasagi, K. Yoshida, T. Murakami, and
H. Harada: "Measurements of Ka 2 to Ka1Intensity Ratios for 62 ~ Z ~ 82 by 3.5 MeV
Proton Bombardment," Phys. Rev. A, 34,
2480 (1986).
28) A. Koyama, O. Benka, Y. Sasa, and M. Uda:
"Energy Spectra of Secondary Electrons fromAl Induced by Heavy Ion Impact," Phys. Rev.
B, 34, 8150 (1986).
29) E. Vagi, T. Kobayashi, S. Nakamura, F.
Kano, K. Watanabe, Y. Fukai, and S. Koike:"Direct Evidence of Stress-Induced Site
Change of H in V Observed by the Channeling Method," Phys. Rev. B, 33, 5121 (1986).
30) O. Benka and M. Uda: "Molecular-Orbital
Model for the Chemical Effect on the K-XRay Spectrum of Fluorine," Phys. Rev. Lett.,
56, 54 (1986).
31) A. P. Mills, Jr., J. Imazato, S. Saitoh, A.
Uedono, Y. Kawashima, and K. Nagamine:"Generation of Thermal Muonium in Vacuum," Phys. Rev. Lett., 56, 1463 (1986).
32) O. Benka and M. Uda: "Resonant ElectronTransfer Relaxation Observed in Fluoring K
Auger Spectra," Phys. Rev. Lett., 56, 1667
(1986) .
33) Y. Awaya: "X-Ray Production in Heavy IonAtom Collisions," Proc. Symp. Region ofHybrid Studies and Nuclear Physics-RCNPP-86, p. 126 (1986).
34) M. Uda: "Chemical Effects in Characteristic
X-Rays Emitted from Multiply IonizedStates," Atomic and Nuclear Heavy Ion Inter-217

actions Brasov Int. School 1984, Central Institute of Physics Bucharest Romania, p. 293(1986) .
35) T. Minowa, H. Katsuragawa, A. Kawamura,and M. Shimazu: "Highly Sensitive Detection of Thallium Atoms Using Resonance
Ionization," Opt. Commun., 60, 37 (1986).
36) H. Tawara, T. Tonuma, H. Shibata, S. H.
Be, H. Kumagai, M. Kase, T. Kambara, and1. Kohno: "Multiply Charged Ions Produced
from C 2 H 2 and CH 4 Molecules in Energetic,
Heavy Ion Impact," Z. Phys. D, Atoms,
Molecules and Clusters, 2, 239 (1986) .
37) K. Takaishi, T. Kikuchi, K. Furuya, 1. Hashimoto, H. Yamaguchi, E. Vagi, and M. I vvaki:"Thermal Extraction of Krypton in Aluminum
Using Mass Spectrometer," Phys. Status Solidi
A, 95, 135 (1986).
38) T. Mizogawa, Y. Awaya, T. Kambara, Y.
Kanai, M. Kase, H. Kumagai, P. H. Mokler,
and K. Shima: "Target Thickness Dependence of Ka Satellite Intensities of Argon Ions
Colliding with Thin Carbon Foils," Proc. Int.
Semin. Dynamic Processes of Highly Charged
Ions, p.55 (1986).
39) A. Koyama: "Ion Induced Auger Electron
Spectroscopy," Kotai Hyomen Biryo Bunseki(in Japanese), Keiei-Kaihatsu Center, Tokyo,
p.153 (1986).
40) 11. Uda: "Fast Ion Induced X-Ray Spectroscopy," Kotai Hyomen Biryo Bunseki (inJapanese), Keiei Kaihatsu Center, Tokyo,
p.141 (1986).
41) K. Maeda: "PIXE (Ion Induced X-Ray
Spectroscopy) ," Kotai Hyomen Biryo Bunseki(in Japanese), Keiei Kaihatsu Center, Tokyo,
p. 166 (1986).
42) A. Awaya: "Multiple Inner-Shell Ionizationof Heavy Ions Passing through Foils," Atomic
and Nuclear Heavy Ion Interactions (eds. AI.
Berinde, 1. A. Orobantu, and V. Zoran),
Central Inst. Phys., Bucharest, Romania, Vol.
1,p.241 (1986).
43) T. Watanabe: "Photo-Excitation, PhotoIonization and Photo-Chemical Processes ofAtoms and Molecules," Synchrotron Radiation ( in Japanese) , (ed. Phys. Soc. J pn. ) ,Baifu-kan Publish., Co., Tokyo, p. 183 (1986).
44) K. Nagamine: "New Movement of Solid
State Physics Research Using Muons-Pulsed,uSR-," Kotaibuturi (in Japanese), 21, 125(1986) .
45) K. Nagamine and A. P. Mills, Jr.: "Thermal
Muonium in Vacuum: Its Birth and Future,"
Sci. Papers I.P.C.R., 80, 67 (1986).
46 ) K. Nagamine and K. Ishida: "Material Syn-thesis and Nuclear/Muon Probes," Sci. Papers
I.P.C.R., 80, 77 (1986).
47) A. Koyama, Y. Sasa, Y. Ishibe, A. Shiraishi,
T. Shiga, H. Ohmori, M. Fuse, and M. Uda :"Construction of a UHV Apparatus forSpectroscopy of Ion-Induced Electrons from
Solids," Reports I.P.C.R. (in Japanese), 62,
218 (1986).
48) S. Karashima and T. Watanabe: "Stopping
Power for Energetic Heavy Ions in a High
Temperature Material," Proc. 2nd Int. Topical
Symp. Inertial-Confinement Fusion Research
by High Power Beams (ed. K. Yasui), Technol. Univ. Nagaoka, Nagaoka, p. 377 (1986).
4. Radiochemistry, radiation chemistry and radiation biology
1) K. Kimura: "Spectral Measurements along
the Path of N Ions Impinged into Dense He
Gas (400 Torr, 5.2 K). 1. Emission Spectra
and Decay Measurements," J. Chern. Phys.,
84, 2002 (1986).
2) K. Kimura: "Spectral Measurements along
the Path of N Ions Impinged into Dense
Helium Gas (400 Torr and 5.2 K). II. Excimer Reactions Dependent on Stopping
Power and Large Emission Yields near theTermination of the Track," J. Chern. Phys. ,84, 2010 (1986).
3) K. Kimura: "Electronic Excitation at HighDensity by Heavy-Ion Irradiation," Radiat.
Chern. (in Japanese), 42, 2 ( 1986) .
4) T. Takahashi and S. Konno: : "W-Values andFano Factors in Liquids and Gases-Mainly
on Liquefied Rare Gases-," Radiat. Chern.
(in Japanese) , 42, 21 (1986).
5) K. Kimura: "Clustering of Helium-Excimer
under the High-Density Electronic Excitation
by Heavy Ion Irradiation," loniz. Radiat. (inJapanese), 12, No.3, 32 (1986).
6) 1. Kohno, M. Yanokura, S. Motonaga, H.
Kamitsubo, M. Yatsuhashi, T. Suematsu, andH. Kobayashi: "Effects on the Fast Neutron
Irradiation on Cable Materials," IEEE Trans.
Nucl. Sci., NS-33, Vol. 1, 77 (1986).
7) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: "In Situ Mossbauer Studies of Metal
Oxide/ Aqueous Solution Interfaces with Adsorbed Co-57 and Sb-119 Ions," Geochemical
Processes at Mineral Surfaces, Am. Chern.
Soc., Washington, D.C., p.403 (1986).
8) T. Nozaki, Y. Itoh, T. Masui, and T. Abe:
"Behavior of Oxygen in the Crystal Formation and Heat Treatment of Silicon Heavily
Doped with Antimony," Appl. Phys., 59, 2562
(1986) .

218(Papers Presented at Meetings)
1. Accelerator development and accelerator physics
1) F. Kikuchi: "Mixed and Penalty Formulation
for an Eigenvalue Problem III Electromagnetics," Annu. Meeting Math. Soc. Jpn.,
Kyoto, Apr. (1986).
2) F. Kikuchi: "Formulations and Finite Element Approximations for an Eigenvalue Problem III Electromagnetics," 15th Numerical
Analysis Symp., Karuizawa, May (1986).
3 ) S. Ishii, H. Amemiya, and M. Yanokura:"An Optimum Condition of Multipole Field
for an ECR-Type Ion Source," 7th Workshop
on ECR Ion Sources, Jiilich, E. Germany,
May (1986).
4) F. Kikuchi, M. Hara, and T . Wada: "WeakFormulation for Finite Element Analysis ofan Eigenvalue Problem in Electromagnetism,"
10th Symp. Computational Methods in Structural Engineering and Related Fields, Tokyo,
July (1986).
5) F. Kikuchi: "Saddle Point Type Variational
Principle and an Finite Element Approximations," Symp. Real Functions and Functional
Analysis, Naruto, July (1986).
6 ) F. Kikuchi, M. Hara, and T. Wada: "Mixed
Finite Element Analysis of an Eigenvalue
Problem III Electromagnetism," 7th Symp.
Finite Element Methods in Flow Problems,Tokyo, Aug. (1986).
7) M. Hara: "Principle of Synchrotron Radiation," Symp. Application of Synchrotron
Radiation to Biology, Wako, Sept. (1980).
8) F. Kikuchi: "Mixed and Penalty Formulations for Finite Element Analysis of an Eigenvalue Problem III Electromagnetism," 1stWorld Congr. Computational Mechanics,
Austin, USA, Sept. (1986).
9) T. Inamura: "RIKEN Accelerators and Their
Experimental Programme," Int. School-Seminar on Nucl. Phys., Dubna, USSR, Sept.
(1986) .
10 ) T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, 1. Yokoyama, M. Nagase, 1. Takeshita, Y. Chiba, and Y. Kumata: "Radio
Frequency System of the RIKEN Ring Cyclotron," 11th Int. Con£. Cyclotron and Their
Applications, Tokyo, Oct. (1986).
11 ) 1. Kohno, K. Ogiwara, S. Fujita, K. Ikegami,
T. Kageyama, S. Kohara, and H. Takebe,"RIKEN 160 cm Cyclotron," 11th Int. Conf.
Cyclotron and Their Applications, Tokyo, Oct.
(1986 ) .
12) N. Nakanishi, T. Kageyama, and H. Kamitsubo: "AVF -Cyclotron as an Injector for the

RIKEN Ring Cyclotron," 11 th Int. Con£.
Cyclotron and Their Applications, Tokyo,
Oct. (1986).
13 ) T. Wad a : "Control System of the RIKEN
Ring Cyclotron," 11th Int. Conf. Cyclotron
and Their Applications Tokyo, Oct. (1986).
14) M. Kase, 1. Yokoyama, 1. Takeshita, Y. Oikawa, M. Saito, and Y. Yano: "Beam Diagnostic Equipments for RIKEN Ring Cyclotron
and its Beam Lines," 11th Int. Con£. Cyclotron and Their Applications, Tokyo, Oct.
( 1986) .
15) A. Goto, H. Takebe, S. Motonaga, K. Hatanaka, Y. Yano, T. Wada, and N. Nakanishi:"Isochronous Fields for RIKEN Ring Cyclotron," 11th Int. Conf. Cyclotron and Their
Applications, Tokyo, Oct. (1986).
16 ) R. Kamitsubo: "Progress III RIKEN Ring
Cyclotron Projects," 11 th Int. Con£. Cyclotron
and Their Applications, Tokyo, Oct. (1986).
17 ) M. Rara, T. Wada, K. Mitomori, and F.
Kikuchi: "Three Dimensional Analysis of
RF Electromagnetic Field by the Finite Element Method," 11th Int. Conf. Cyclotron and
Their Applications, Tokyo, Oct. (1986).
18) M. Rara, T. Wada, K. Mitomori, and F.
Kikuchi: "Three Dimensional Analysis of RF
Electromagnetic Field by the Finite Element
Method IV (Exotic Model) ," Autumn Meeting Phys. Soc. Jpn., Kobe, Oct. (1986).
19) F. Kikuchi: "Numerical Analysis of an Eigenvalue Problem III Electromagnetics by the
Mixed Method," Applied Mathematics Symp.,
Kyoto, Dec. (1986).
2. Nuclear physics and nuclear instrumentation
1) H. Hofmann and S. Yama ji : "Large Scale
Nuclear Collective Motion," Int. Con£. on
Quantum Chaos (Fourth International Colloquium on Statistical Nuclear Physics) ,Cuernavaca, Mexico, Jan. ( 1986) .
2) S. Yamaji and H. Hofmann: "Study ofTransport Equation Based on Locally Harmonic Approximation," J AERI Symp. Heavy
Ion Nuclear Physics and Chemistry III
Tandem-Energy Region II, Tokai, Ibaraki,
Jan. (1986).
3) H. Kumagai, T. Takahashi, T. Kubo, and
M. Ishihara: "Parallel Plate Avalanche
Counter for Heavy-Ion Dosimetry," Radiation Detector and Dosimetry, Tsukuba, Jan.
(1980) .
4) N. Yoshinaga and S. Yamaji: "Dipole Moment of 22°Ra (I) ," 41 th Annu. Meeting
Phys. Soc. Jpn., Tokyo, Mar. (1986).
5) K. Asahi: "On-Line Isotope Separator Project

219

at RIKEN," 41th Annu. Meeting Phys. Soc.
Jpn., Tokyo, Mar. (1986).
6) T. Murakami, J. Kasagi, H. Harada, T.
Tachibanaki, K. Yoshida, S. Kubono, M.
Yasue, M. H. Tanaka, M. S. Lie, M. Ogiwara,
H. Fujiwara, and S. C. Jeong: "High Energy
r Rays Emitted from Highly Excited Statesin the Continuum," 41th Annu. Meeting Phys.
Soc. Jpn., Tokyo, Apr. (1986).
7) J. Kasagi, H. Harada, T. Murakami, K.
Yoshida, H. Tachibanaki, and T. Inamura:"Large B (E2) Values Observed for 9- ~ 8Transitions in llO-112S n ," 41st Annu. Meeting
Phys. Soc. lpn., Tokyo, Apr. (1986).
8) H. Harada, T. Murakami, H. Tachibanaki,
K. Yoshida, Y. Shibata, J. Kasagi, T. Kubo,
and T. Inamura: "Shape Change Observedfor Yrast High-Spin States in llO-112Sn," 41st
Annu. Meeting Phys. Soc. lpn., Tokyo, Apr.
(1986) .
9) Y. Shibata, K. Yoshida, H. Harada, T. Murakami, and l. Kasagi: "Radiation Damage
Test of BaF 2 Scintillator," 41 th Annu. Meeting Phys. Soc. lpn., Tokyo, Apr. (1986).
10) A. Hitachi, S. Suzuki, A. Yunoki, J. Kikuchi,
T. Doke, K. Masuda, and T. Takahashi:"Photoionization Phenomena in Liquid Argon
Admixed with Impurities," 41 th Annu. Meeting Phys. Soc. lpn., Tokyo, Apr. (1986).
11) S. Suzuki, T. Sano, A. Yunoki, A. Hitachi,
T. Takahashi, K. Masuda, and T. Doke:"Photoionization Phenomena in Liquid Xenon
Admixed with TEA or TMA," 41th Annu.
Meeting Phys. Soc. lpn., Tokyo, Apr. (1986).
12) M. Fukuda, Y. Gono, T. Kohno, and M.
Sugawara: "r-Ray Spectroscopy of 22°Ac with
BGOACS System," 41th Annu. Meeting Phys.
Soc. lpn., Tokyo, Apr. (1986).
13) K. Okazaki, H. Oyama, Y. Ishibe, S. Kato,
Y. Sakamoto, S. Amemiya, T. Tsurita, Y.
Hori, K. Akaishi, K. Kawahata, and N. Noda:"Influence of in situ Carbon Coating on
Window Materials in Fusion Experimental
Devices," 7th Int. Conf. Plasma Surface
Interactions in Controlled Fusion Devices,
Princeton, USA, May (1986).
14) S. Y ama ji and N. Yoshinaga: "Dipole Moment of Ra Nuclei in the Two-MolecularConfigulation," RCNP Symp. Nuclear Physics
in High Spin States, Osaka, July (1986).
15) K. Morita, T. Inamura, T. Nomura, J.
Tanaka, H. Miyatake, M. Fujioka, T. Shinozuka, M. Y oshii, H. Hama, K. Taguchi, K.
Sueki, Y. Hatsukawa, K. FUTUno, and H.
Kudo: "An Ion-Guide Isotope Separator OnLine at INS," EMIS-l1 ( 11 th Int. Conf.

Electromagnetic Isotope Separators and Techniques Related to Their Applications ), Los
Alamos, USA, Aug. (1986).
16) H. Miyatake, T. Nomura, H. Kawakami, J.
Tanaka, M. Oyaizu, K. Morita, T. Shinozuka,
H. Kudo, K. Sueki, and Y. Iwata: "INSGas-Filled Recoil Isotope Separator," EMIS11 ( 11 th Int. Conf. Electromagnetic Isotope
Separators and Techniques Related to Their
Applications), Los Alamos, USA, Aug. (1986).
17) H. Harada, J. Kasagi, T. Murakami, K.
Yoshida, T . Inamura, and T. Kubo: "Spherical and Deformed States in High-Spin Yrast
Region of llOSn and 112Sn," Int. Nucl. Phys.
Conf., Harrogate, U.K., Aug. (1986).
18) Y. Sakamoto, H. Amemiya, Y. Ishibe, S.
Kato, K. Okazaki, H. Oyama, K. Yano, K.
Akaishi, N. Noda, S. Amemiya, H. Minagawa, T. Hino, T. Yamashina, and S. Matsumoto: "Simulation Experiment on Carbon
Coating of First Wall of Fusion Machines,"
14th Symp. Fusion Technology, Avignon,
France, Sept. (1986).
19) K. Yano, H. Amemiya, Y. Ishibe, K. Okazaki, S. Kato, and Y. Sakamoto: "Productionof Carbon Films by Means of ECR Plasma,"
47th Meeting lpn. Soc. Appl. Phys., Sapporo,
Sept. (1986).
20) K. Asahi, M. Ishihara, T. Shimoda, T. Fukuda, N. Takahashi, K. Katori, S. Shimoura,
N. Ikeda, A. Nakamura, K. Hanakawa, T.
Itahashi, Y. Nojiri, and T. Minamisono: "Beta
Decay of Polarized Nucleus 15C and Magnetic
Moment of the 1/2+ Ground State," 1986
Fall Meeting Phys. Soc. lpn., Kobe, Oct.
(1986) .
21) K. Asahi, M. Ishihara, T. Ichihara, Y. Gono,
J. Kasagi, A. C. Mueller, R. Anne, D. Bazin,
D. G. Mueller, R. Bimbot, and W. D. Sch;midtOtt: "Spin Alignment in Projectile Fragmentation at Intermediate Energies," 1986 Fall
Meeting Phys. Soc. lpn., Kobe, Oct. (1986).
22) N. Yoshinaga and S. Yamaji: "Dipole Moment of 22°Ra (II) ," 1986 Fall Meeting Phys.
Soc. lpn., Kobe, Oct. (1986).
23) K. Sueki, H. Nakahara, I. Kohno, and T.
Matsuse, "Mass Division by Equilibrium Process and Nonequilibrium Process at Heavy
Ion Nuclear Reaction," 1986 Fall Meeting
Phys. Soc. lpn., Kobe, Oct. (1986).
24) Y. Gono, T. Kohno, Ch. Briancon, F. A. Beck,and Chateau de Cristal Collaboration: "Studyof 222Th with BGOACS and 41C Crystal Ball,"1986 Fall Meeting Phys. Soc. lpn., Kobe, Oct.
(1986) .
25) H. Harada, T. Murakami, K. Yoshida, K.

220

Takeuchi, M. Sakurai, J. Kasagi, T. Inamura,and T. Kubo: "B (E2) Values of the Rotational Band in 112Sn," 1986 Fall Meeting
Phys. Soc. Jpn., Kobe, Oct. (1986).
26 ) K. Yoshida, J. Kasagi, T. Murakami, H.
Harada, T. Inamura, and T. Kubo: "HighlyExcited High-Spin States in 110,112S n ," 1986
Fall Meeting Phys. Soc. Jpn. , Kobe, Oct.
( 1986).
27 ) H. Miyatake, T. Nomura, H. Kawakami, J.
Tanaka, M. Oyaizu, K. Morita, K. Sueki,
H. Kudo, T. Shinozuka, and Y. Iwata: "INSGas-Filled Recoil Isotope Separator," 1986
Fall Meeting Phys. Soc. Jpn., Kobe, Oct.
(1986) .
28 ) Y. Sakamoto, H. Amemiya, Y. Ishibe, S.
Kato, K. Okazaki, H. Oyama, K. Yano, S.
Amemiya, H. Minagawa, T. Hino, and T.
Yamashina:"Simulation Experiment on
Carbon Coating: RIKEN ECR-2," 3rd Fall
Meeting J pn. Soc. of Plasma Physics andNuclear Fusion, Tokyo, Oct. (1986).
29 ) T. Yanagimachi: "Test of PSD's Resolutions
with He and N Beams at the Cyclotron,"
RIKEN Symp. Heavy Ion Observation Techniques in Space and Laboratory, Wako, Nov.
(1986 ) .
30 ) T . Doke: "Improvement of 2-Dimensional
Position Sensitive Silicon Detector," RIKEN
Symp. Heavy Ion Observation Techniques inSpace and Laboratory, Wako, Nov. (1986 ) .
31 ) Y. Ishibe, H. Amemiya, S. Kato, K. Okazaki,
H. Oyama, Y. Sakamoto, K. Yano, S. Amemiya, S. Matsumoto, H. Minagawa, T. Hino,
and T. Yamashina: "Carbon Coating by ECR
Plasma (II) ," 27th Joint Meeting Vacuum,
Osaka, Nov. (1986).
32 ) Y. Ishibe: "Evaluation of Carbon Films
Coated by the RIKEN ECR-2 Device,"
RIKEN Symp. Plasma Vapour Deposition
and Estimation of the Deposited Films, Wako,
Nov. (1986).
33 ) S. Yamaji and H. Hofmann: "Transport
Coefficients for Fission at High Excitations,"
RIKEN Symp. Non-Equilibrium Process in
Fission and Fusion, Wako, Nov. (1986).
34) K. Asahi: "Beta Decay of Nuclei Far off theStability Line," RIKEN Symp. Nuclear Structures and Nuclear Interactions in the Regions
Far from the Stability Line, Wako, Dec.
(1986) .
35 ) K. Asahi: "Radioactive Beam Course at
RIKEN and Future Experiments," RCNP
Workshop on Physics Using Secondary Beams,
O saka, Dec. (1986 ) .

3. Atomic and solid-state physics
1) E. Yagi: "Lattice Location Study on Hydrogen in Metals by Using Ion Beam," 2nd
Meeting Interaction between Ion Beams andSolids, Yugawara, Jan. (1986).
2) T. Kambara, Y. Awaya, T. Watanabe, K.
Ando, M. Kase, H. Kumagai, Y. Kanai, andK. Shima: "Studies of Charge State Distribution of Swift Heavy Ions Passing throughSolid Target," 2nd Meeting Interaction between Ion Beams and Solids, Yugawara, Jan.
(1986) .
3) Y. Awaya: "X-Ray Production in Heavy IonAtom Collisions," Symp. Region of Hybrid
Studies and Nuclear Physics, Osaka, Jan.
(1986) .
4 ) Y. Kanai, Y. Awaya, T. Watanabe, K. Ando,
T. Kambara, M. Kase, H. Kumagai, and K.
Shima: "Studies of Charge State Distributionof Swift Heavy Ions Passing through Solid
Target," Symp. Interaction between Ion
Beams and Solids, Tokyo, Feb. (1986).
5) T. Mizogawa, Y. Awaya, T. Kambara, Y.
K anai, and M. Kase: "Carbon-Foil Thickness Dependence of Ar K Satellite Lines in
Ar Ion-C Foil Collisions," RIKEN Symp. 7th
Meeting Atomic Collisions by Using Accelerators, Wako, Feb. (1986).
6) P. H. Mokler: "Experiments with Decelarated
Highly Charged Heavy Ions," RIKEN Symp.
7th Meeting Atomic Collisions by Using Accelerators, Wako, Feb. (1986).
7) K. Asai, T. Okada, and H. Sekizawa:"TDPAC of r-Rays Emitted from 111Cd( ~111 In) in Magnetic Oxides," Applicationof Perturbed Angular Correlation Techniqueto Solid State Physics, Kumatori, Feb. (1986).
8) E. Yagi : "Researches in Materials Science
Using Ion Beam in RIKEN Institute," Symp.
Fundamental Problems and Application of
Heavy Ions, Univ. Tokyo, Feb. (1986).
9) M. Iwai, I. Shimamura, and T. Watanabe:"Dependence of Minima in Generalized Oscillator Stren ~ths on Excitation Cross Sections,"+lth Annu. Meeting Phys. Soc. Jpn. , Tokyo,
M ar. (1986).
10 ) K . Fujima, K. Mirna, and T. Watanabe:"X-Ray Spectrum Analysis of High Density
Laser Plasma by DV-Xa Method," 41th Annu.
Meeting Phys. Soc. Jpn., Tokyo, Mar. (1986).
11) S. Karashima, I. Kawada, T. Sato, and T.
Watanabe: "Estimation of Stopping Powerof High Temperature and High Density Substances for Heavy Ions," 41th Annu. Meeting
Phys. Soc. Jpn., Tokyo, Mar. (1986).
12) F. Ambe, K. Asai, S. Ambe, and H. Seki-221zawa: "TDPAC of r-Rays Emitted from
11ICd ( ~111 In) in In20s," 41 th Annu. Meeting Phys. Soc. Jpn., Tokyo, Mar. (1986).
13) H. Sekizawa, K. Asai, and T. Okada: "AnTDP AC Study on Ferrites with the Spinel
Structure," 41th Annu. Meeting Phys. Soc.
Jpn., Tokyo, Mar. (1986).
14) T. Mizogawa, Y. Awaya, T. Kambara, M.
Kase, H. Kumagai, Y. Kanai, M. M. Ismail,and K. Shima: "Dependence of Ka Satellite
Spectra of 50 MeV Ar Beams on the Thickness of Target Foils," 41 th Annu. Meeting
Phys. Soc. Jpn., Tokyo, Mar. (1986).
15 ) K. Shima, K. Umetani, Y. Awaya, T . Kambara, Y. Kanai, H. Kumagai, M. Kase, T.
Mizogawa, and M. M. Ismail: "Excitation
Process of Ions in Heavy Ion-Foil Collisions,"
4 1th Annu. Meeting Phys. Soc. Jpn., Tokyo,
Mar. (1986.)
16) E. Vagi, S. Nakamura, T. Kobayashi, F.
Kano, K. Watanabe, Y. Fukai, and T. Osaka:"Lattice Location of Hydrogen in Tantalum,"4 1th Annu. Meeting Phys. Soc. Jpn., Tokyo,
Mar. (1986).
17) K. Nishiyama, T . Matsuzaki, K. Nagamine,
K. Ishida, and H. Shirakawa: "Measurement
on Muonium Substituted Radical in cis-Polyacetylene," 41 th Annu. Meeting Phys. Soc.
Jpn., Tokyo, Apr. (1986).
18 ) K. Ishida, K. Nagamine, and H. Shirakawa :"Muon Spin Resonance Studies on Polyacetylene III," 41 th Annu. Meeting Phys.
Soc. Jpn., Tokyo, Apr. (1986 ).
19) I. Furutate, T. Kokubu, S. Satoh, Y. Ando,
T . Motobayashi, and S. Shirato: "DWBA
Analysis of Neutron Induced Reactions on
GLi and 7Li at 14 MeV," 4 1th Annu. Meeting
Phys. Soc. Jpn., Tokyo, Apr. (1986).
20) H. Ohsumi, K . Hanakawa, M. Ishihara, Y.
Nagai, T. Motobayashi, K. Katori, and H.
Gotoh: "Strength of Highly Excited OneParticle States in 209Bi Excited by 20SPb (a, t)
Reaction Studied by t-r Coincidence Method,"
41th Annu. Meeting Phys. Soc. Jpn., Tokyo,
Apr. (1986).
21) P. H. Mokler: "Atomic Physics with Heavy
Ions- The Past Ten Years at GSI and Future
Developments," 41 th Annu. Meeting Phys.
Soc. Jpn., Tokyo, Apr. (1986 ) .
22) I. Hashimoto, H. Yorikawa, H. Mitsuya, H.
Yamaguchi, K. Takaishi, T. Kikuchi, K.
Furuya, E. Yagi, and M. I waki : "Behavior
of Kr Bubbles in Kr-Implanted Aluminum,"
41th Annu. Meeting Phys. Soc. Jpn., Tokyo,
Apr. (1986).
23) H. Kusuyama, T . Watanabe, K. Yoshida, M.

Tomita, M. Hobo, S. Sakamoto, Y. Uchijima,
K. Okada, K. Maeda, Y. Sasa, and M. Uda:
"E1emental Analysis by Particle Induced xRay Emission (I) Urinary Stone Diseases,"
74th Annu. Meeting Jpn. Urological Association, Hiroshima, Apr. (1986).
24) H. K atsuragawa, T. Minowa, K. Nishiyama,
and T. Inamura: "Resonance Ionization
Spectroscopy of TI by Atomic Beam," 33rd
Spring Meeting Jpn., Soc. Appl. Phys. andRelated Societies, Funabashi, Apr. (1986 ) .
25) Y. Fukai, K. Watanabe, and E. Vagi: "Natureand Some Consequences of Stress-Induced
States of Hydrogen III BCC Metals," Int.
Con£. Properties and Applications of Metal
Hydrides, Maubuisson, May (1986).
26 ) E . Vagi, S. Nakamura, T. Kobayashi, F. Kano,
K. Watanabe, Y. Fukai, and T. Osaka:"Lattice Location Study of H III Ta by
Channeling Method," Int. Con£. Properties
andApplicationsof
Metal
Hydrides,Maubuisson, May (1986).
27 ) S. K arashima and T . Watanabe: "Stopping
Power for Energetic Heavy Ions in a Finite
Temperature Material," 2nd Int. Topical
Symp. ICF Research by High-Power Particle
Beams, N agaoka, June (1986).
28 ) ~1 . Schmolz, K .-P. Doring, K. Fiirderer, M.
Gladisch, N. H aas, D. Herlach, G. Majer, J.
Rosenkranz, W. Schafer, L. Schimmele, W.
Schwarz, A. Seeger, and E. Vagi: "Positive
Muons in Iron: Dipolar Field at Tetrahedral
Sites and Jump Frequencies at Low Temperatures," 4th Int. Conf. Muon Spin Rotation,
Relaxation, and Resonance, Uppsala, Sweden,
June (1986).
29) K. Nagamine: ",uSR in Polyacetylenes," 4thInt. Conf. Muon Spin Rotation, Relaxation,
and Resonance, Uppsala, Sweden, June
( 1986) .
30) K. Nishiyama, K. Ishida, K. N agamine, T.
Matsuzaki, Y. Kuno, H. Shirakawa, R. Kiefl,
and J. H. Brewer: "Precise Measurement of
HFS Constant of the Muonium Substituted
R adical in cis-Polyacetylene," 4th Int. Con£.
Muon Spin Rotation, Relaxation, andResonance, U ppsala, Sweden, June (1986).
31 ) M . Uda, O. Benka, K. Fuwa, K. Maeda, and
Y. Sasa : "Chemical Effects in PIXE," 4thInt. Con£. PIXE and Its Application to
Analytical Chemistry, Tallahassee, USA, June
( 1986).
32) M. Uda, K. M aeda, Y. Sasa, H. Kusuyama,
and Y. Yokode: "Trial of Cancer Diagnosis
by PIX E," 4th Int. Con£. PIXE and Its
Application to Analytical Chemistry, Talla-

222

hassee, USA, June (1986).
33) Y. Sasa, K. Maeda, and M. Uda: "Application of PIXE and Diffraction Analysis toAncient Remains," 4th Int. Conf. PIXE and
Its Application to Analytical Chemistry,
Tallahassee, USA, June (1986).
34) K. Maeda, Y. Yokode, Y. Sasa, H. Kusuyama, and M. Uda: "Multielemental Analysis
of Human Thyroid Glands Using Particle
Induced X-Ray Emission (PIXE) ," 4th Int.
Conf. PIXE and Its Application to Analytical
Chemistry, Tallahassee, USA, June (1986).
35) K. Maeda, Y. Sasa, M. Maeda, and M. Uda:
"Diagnosis of River Pollution by PIXE," 4thInt. Conf. PIXE and Its Application to
Analytical Chemistry, Tallahassee, USA, June
(1986) .
36) K. Ishida, K. N agamine, and H. Shirakawa:"Muon Spin Rotation and Relaxation Studies
of Undoped and Iodine-doped Polyacetylene,"Int. Conf. Science and Technology of Synthetic Metals (ICSM '86), Kyoto, June (1986).
37) T. Watanabe: "Laser Spectroscopy in Atomic
Processes," Symp. Laser Spectroscopy inFundamental Science, Chofu, July (1986).
38) T. Watanabe: "Theory of Hydrogen Nucleus
Transfer Reaction," 4th Special Meeting flmeson Catalyzed Nuclear Fusion, The Research Society for Atomic Energy, Tokyo, July
(1986) .
39) T. Watanabe: "Specificity of Highly Charged
Ions," RIKEN Symp. Int. Semin. Dynamic
Processes of Highly Charged Ions, Susono,Aug. (1986).
40) N. Shimakura, H. Sato, M. Kimura, and T.
Watanabe: "Low Velocity Collision of 0 6 +with He by MO Base Treatment," RIKEN
Symp. Int. Semin. Dynamic Processes ofHighly Charged Ions, Susono, Aug. (1986).
41) M. Iwai, I. Shimamura, and T. Watanabe:"Manifestation of Minima in the Generalized
Oscillator Strengths as Minima in the Integrated Cross Sections for Ion-Atom Collisions,"
RIKEN Symp. Int. Semin. Dynamic Processesof Highly Charged Ions, Susono, Aug. (1986).
42) K. Nakanishi, K. Iguchi, A. Ohsaki, and T.
Watanabe: "Classical-Trajectory Monte Carlo
Calculations for Coulomb-Interacting Three
Body Systems," Int. Conf. Atom. Phys. and
Few Body Systems (ICAP-X and Few Body
XI), Tokyo, Aug. (1986).
43) S. Karashima, T. Watanabe, X. Zhang, Q.
Ma, and Y. Liu: "Electron Stripping Cross
Sections of Multiply Charged Ions by Neutral
Atoms," Int. Conf. Atom. Phys. and Few
Body Systems (ICAP-X and Few Body XI),Tokyo, Aug. (1986).
44) Q. Ma, X. Zhang, Y. Liu, and T. Watanabe:"T otal and Differential Cross Sections for(fl+ fl-) Formation by fl+ with (fl-P) including
Excited States in the First Born Approximation," Int. Conf. Atom. Phys. and Few Body
Systems (ICAP-X and Few Body XI), Tokyo,
Aug. (1986).
45) T. Tonuma, T. Matsuo, K. Baba, M. Kase,
T. Kambara, S. H. Be, H. Kumagai, I. Kohno,
and H. Tawara: "Multiply Charged Ci+ andOi+ Ions from Molecular Targets by 1.05 MeV I
amu Ar12+ Ion Impact," Int. Conf. Atom.
Phys. and Few Body Systems (ICAP-X and
Few Body XI), Tokyo, Aug. (1986).
46) K. Fujima, K. Mirna, and T. Watanabe: "XRay Spectra Emitted from High Density andHigh Temperature Si," Int. Conf. Atom. Phys.
and Few Body Systems (ICAP-X and Few
Body XI), Tokyo, Aug. (1986).
47) S.-M. Zhou, X.-X. Zhang, Q.-C. Ma, J.-F.
Cheng, Y.-Y. Liu, and T. Watanabe: "Calculation of Ionization Cross Sections for Multicharged Ions by Proton Impact with BEA andTFD Method," Int. Conf. Atom. Phys. and
Few Body Systems (ICAP-X and Few Body
XI), Tokyo, Aug. (1986).
48) X.-W. Liu, Q.-C. Ma, J.-F. Cheng, X.-X.
Zhang, Y.-Y. Liu, and T. Watanabe: "Total
and Differential Cross Sections for (fl+ fl-)Formation by Collisions of fl+ with (fl-P) in
the Eikonal Approximation," Int. Conf. Atom.
Phys. and Few Body Systems (ICAP-X and
Few Body XI), Tokyo, Aug. (1986).
49) N. Shimakura, H. Sato, M. Kimura, and T.
Watanabe: "Electron Capture in Pseudo-TwoElectron System 0 6 ++ He: Molecular Basis
Expansion Method," Int. Conf. Atom. Phys.
and Few Body Systems (ICAP-X and Few.
Body XI), Tokyo, Aug. (1986).
50) I. Shimamura and M. Iwai: "An R-matrix
Method for Wave Functions That Are Accurate Close to the Coordinate Origin," Int.
Conf. Atom. Phys. and Few Body Systems(ICAP-X and Few Body XI), Tokyo, Aug.
( 1986 ) .
51) M. Iwai, I. Shimamura, and T. Watanabe:"Extended Bethe Surface: Behavior of theGeneralized Oscillator Strength along Isoelectronic Sequence," Int. Conf. Atom. Phys. and
Few Body Systems (ICAP-X and Few Body
XI), Tokyo, Aug. (1986).
52) K. Shima, K. Umetani, S. Fujioka, M. Yamaguchi, Y. Awaya, T. Kambara, T. Mizogawa,and Y. Kanai: "Evolution of Fast Heavy Ion
Excitation in Solid Target-0.83-2.4 MeV lu

223

Br q +, Cu q + + C," Int. Conf. Atom. Phys. and
Few Body Systems (ICAP-X and Few Body
XI), Tokyo, Aug. (1986).
53) T. Mizogawa, Y. Awaya, T. Kambara, Y.
Kanai, M. Kase, H. Kumagai, P. H. Mokler,
and K. Shima: "Target Thickness Dependence of Ka Satellite Intensities of Ar Ions
Colliding with Thin Carbon Foils," Int. Conf.
Atom. Phys. and Few Body Systems (ICAP-X
and Few Body XI), Tokyo, Aug. (1986 ) .
54) K. Ando, Y. Awaya, S. Kohmoto, H. Kumagai, T. T onuma, S. Tsurubuchi, and K. Sato:"Identification of Highly Ionized Aluminum
III Beam-Foil Spectrum," Int. Conf. Atom.
Phys. and Few Body Systems (ICAP-X and
Few Body XI), Tokyo, Aug. (1986).
55 ) K. Nagamine: "Thermal Muonium and Muon
Catalyzed Fusion with Pulsed Muon Experiments," Int. Conf. Atom. Phys. and Few Body
Systems (ICAP-X and Few Body XI) , Tokyo
Aug. (1986 ) .
56) S. Hara and M. Nakamura: "Determinationof Photoionization Asymmetry Parameter,"Int. Conf. Atom. Phys. and Few Body Systems(ICAP-X and Few Body XI) , Tokyo, Aug.
(1986) .
57 ) T. Motobayashi: "Symmetries among theProton and Neutron Induced Transfer Reactions on 6Li and 7Li," Int. Workshop on
Few-Body Approach to Nuclear Reactions inTandem and Cyclotron Energy Region, Tokyo,
Aug. (1986).
58 ) H. K atsuragawa, T. Minowa, M . Shimazu,and T. Inamura: "Electron-Ion Coincidence
Method for Ultra-Sensitive Detection ofAtoms," 11th Int. Conf. Electromagnetic Isotope Separators and Techniques Related to
Their Applications, Los Alamos, USA, Aug.
(1986) .
59) A. Ohsaki, T. Watanabe, K. Nakanishi, andK. Iguchi: " fl- Transfer Cross Sections from(fl-d) or (fl-t) to and a in High Velocity
Region Using Classical Trajectory Monte
Carlo Method," Int. Symp. Muon-Catalyzed
Fusion fl-CF86, Tokyo, Sept. (1986) .
60) S. Hara, T. Ishihara, and N. Toshima: "Variational Calculation for Muonic Molecules,"Int. Symp. Muon-Catalyzed Fusion fl-CF86,
Tokyo, Sept. (1986).
61 ) K. Nagamine: "Muonic X-Ray Measurementon the fl - Sticking Probability III MuonCatalyzed Fusion of Liquid d-t Mixture," Int.
Symp. Muon-Catalyzed Fusion fl-CF86 , Tokyo, Sept. (1986).
62) E. Vagi, F. Kano, S. Nakamura, M. Iwaki,
and T. Osaka: "Defect-Impurity Interactionin Sn- or Ni-Implanted Aluminum," Int. Conf.
Vacancies and Interstitials III Metals, West
Berlin, F. R. Germany, Sept. (1986).
63 ) E. Vagi, A. Koyama, H. Sakairi, and R. R.
Hasiguti: "Isochronal Annealing of Protonand a-Irradiated CUaAu at Low Temperatures," Int. Conf. Vacancies and Interstitials
in Metals, West Berlin, F. R. Germany, Sept.
(1986 ) .
64) H. Mitsuya, 1. Hashimoto, H. Yorikawa, H.
Yamaguchi, E. Yagi, and M. I waki: "Behavior
of Kr Bubbles in Kr-Implanted Aluminum(II ) ," 1986 Fall Meeting Phys. Soc. lpn.,
Nlshinomiya, Sept. ( 1986).
65 ) E. Vagi, T. Kobayashi, S. Nakamura, F. Kano,
K. Watanabe, Y. Fukai, and T. Matsumoto:"Lattice Location of H ydrogen III NbMo
Alloys," 1986 Fall Meeting Phys. Soc. lpn.,
Nishinomiya, Sept. (1986 ) .
66 ) T . Okada, T. Yamadaya, and K. Asai: "111Cd
T DPAC Study on a Single Crystal Lio.5Fe2.5O -!," 1986 Fall Meeting Phys. Soc. lpn.,
Nishinomiya, Sept. (1986).
67 ) K. Asai, F. Ambe, S. Ambe, T. Okada, and
H. Sekizawa: "An Investigation on the MterEffects of 111 In ( ~1 11 Cd) EC Decay in aFe 20 S ," 1986 Fall Meeting Phys. Soc. lpn.,
Nishinomiya, Sept. (1986).
68 ) K. N agamine: "International Conference Report : International Symposium on MuonCatalyzed Nuclear Fusion," 1986 Fall Meeting Phys. Soc. lpn., Nishinomiya, Sept. (1986) .
69 ) K . Ishida, T. Matsuzaki, Y. Hirata, and K.
N agamine : "Muon Transfer Reaction to
Helium Impurity in Liquid Hydrogen," 1986
Fall Meeting Phys. Soc. lpn., Nishinomiya,
Sept. (1986).
70) A. Uedono, T. Emado, S. Tanigawa, and H.
Sakairi: "The Study of Agglomeration andRelease Process of Helium Implanted in
Metals by Slow Position Beam," 1986 Fall
Meeting Phys. Soc. lpn. , Nishinomiya, Sept.
( 1986) .
71 ) K. Asai, S. Ambe, T. Okada, and F. Ambe:"TDPAC Study on (111In~ )tllCd Ions inSilver Phosphate," 7th Int. Conf. Hyperfine
Interactions, Bangalore, India, Sept. (1986).
72 ) K. Asai, F. Ambe, S. Ambe, T. Okada, and
H. Sekizawa: "An Investigation on the AfterEffects of 111In(~111Cd) EC Decay III aFe20 a," 7th Int. Conf. Hyperfine Interactions,Bangalore, India, Sept. (1986).
73) K. Asai, T. Okada, and H. Sekizawa: "Supertransferred Hyperfine Magnetic Fields at
lllCd ( ~ll l In) in Ferrimagnetic Oxides with
the Spinal Structure," 7th Int. Conf. Hyper-

224

fine Interactions, Bangalore, India, Sept.
(1986) .
74 ) K. Ishida, K. Nagamine, and H. Shirakawa:"pSR Studies on Polyacetylenes," 7th Int.
Conf. Hyperfine Interactions, Bangalore, India,
Sept. (1986).
75) K. Yano, H. Amemiya, Y. Ishibe, K. Okazaki, H. Oyama, S. Kato, and Y. Sakamoto:"Production of Carbon Film by ECR Plasma,"
47th Fall Meeting Jpn. Soc. App!. Phys.,
Sapporo, Sept. (1986).
76) M. Shimazu, T. Minowa, and H. Katsuragawa: "Monochromatic Image Observationsof Flames of an Internal-Combustion Engine," 47th Fall Meeting Jpn. Soc. App!.
Phys., Sapporo, Sept. (1986).
77) T. Mizogawa: "Electron Configuration of Ar
Ions Passing through Carbon Foils," Symp.
Ion Excitation and Scattering, Tsukuba,
Sept. (1986).
78 ) T. \'Vatanabe: "New Fields by Using Extreme
Intensive and High Bright Light SourcesFrom the View Point of Atomic and Molecular
Physics," Symp. Overview on New Research
Fields Using Extreme Intensive and High
Bright Light Source in VUV and Soft X-Ray
Region, Omachi, Oct. (1986).
79) A. Koyama, O. Benka, H. Ishikawa, Y. Sasa,
and M. Uda: "Z2-Dependence of the Energyof Backscattered Electrons Stripped from
He+," 1986 Fall Meeting Phys. Soc. Jpn.,
Kobe, Oct. ( 1986) .
80) A. Koyama, O. Benka, H. Ishikawa, Y. Sasa,
and M. Uda: "Secondary Electrons from
Metal Surfaces Induced by Heavy Ion Impact," 1986 Fall Meeting Phys. Soc. Jpn.,
Kobe, Oct. (1986).
81 ) T. Motobayashi, S. Satoh, H. Sakai, N.
Matsuoka, T. Saito, K. Hosono, M. Ishihara,
S. Shimoura, S. Hatori, and A. Okihana:"90Zr (d,2He) Reaction," 1986 Fall Meeting
Phys. Soc. Jpn., Kobe, Oct. (1986).
82) S. Kubota, S. Shirato, T. Motobayashi, H.
Murakami, Y. Ando, S. Satoh, T. Murakami,
and J. Kasagi: "Neutron Detection by
Plastic-BaF 2 Scintillator," 1986 Fall Meeting
Phys. Soc. Jpn., Kobe, Oct. (1986).
83) H. Murakami, S. Kubota, S. Shirato, K. Gen,and T. Motobayashi: "n- r Discrimination
Circuit for Plastic-BaF 2 Scintillator," 1986 Fall
Meeting Phys. Soc. Jpn., Kobe, Oct. (1986).
84) S. Satoh and T. Motobayashi: "SSD Spectrometer for 2He Detection," 1986 Fall Meeting Phys. Soc. Jpn., Kobe, Oct. (1986).
85) T. Matsuzaki, K. Ishida, Y. Hirata, K. N agamine, S. E. Jones, M. A. Paciotti, A. J. Caffrey,and H. R. Maltrud: "Basic Experiment on
Muon Catalyzed Fusion I," 1986 Fall Meeting Phys. Soc. Jpn., Kobe, Oct. (1986).
86) T. Watanabe: "Problems in X-Ray Lasers
Using Highly Charged Ions," Symp. PhysicalProcesses in X-Ray Lasers, Nagoya, Nov.
(1986) .
87) K. Muraoka, S. Sasaki, I. Kohno, and J.
Nishizawa: "Proton Irradiation into the SI
Thyristor," 5th Symp. Ion Beam Technology,
Hosei Univ., Tokyo, Dec. (1986).
4. Radiochemistry, radiation chemistry, and radiation biology
1) Q. Qiu, T. Kobayashi, M. Yanokura, M.
Iwai, Y. Yatsurugi, and T. Nozaki: "Utilization of the D (3He, p) 4He Reaction in HighSensitivity Analysis of Deuterium in Solids,"
4th Symp. Ion Beam Technology, Hosei
Univ., Tokyo, Dec. (1985).
2) T. Takahashi, Y. Kameda, C. Shimakawa,Y. H. Kang, K. Eguchi, K. Nakano, T.
Katayama, and I. Kaneko: "Application ofSolid State Plastic Detector to Heavy Ion
Dosimetry and Microdosimetry," 33rd Spring
Meeting Jpn. Soc. App!. Phys. and RelatedSocieties, Funabashi, Apr. ( 1986) .
3) K. Kimura : "Dynamics of Helium-Excimer
Clusters," 41 th Annu. Meeting Phys. Soc.
Jpn., Tokyo, Apr. ( 1986).
4) Y. Kadota, K. Sakai, T. Nozaki, Y. Itoh, and
Y. Ohkubo: "Determination of Carbon Concentration in the LEC GaAs Crystal," 4thInt. Conf. III-V Semi-Insulating Materials,
Hakone, May (1986).
5) I. Kaneko: "DNA Strand Breaks in Mammalian Cells by Heavy Ion Particles," Symp.
Prospects on Tritium Radiation Genetics,
Mishima, June (1986).
6 ) Q. Qiu, T. Kobayashi, M. Yanokura, M.
Iwai, Y. Yatsurugi, and T. Nozaki: "Utilization of the D (3He, p) 4He Reaction in HighSensitivity Analysis of Deuterium in Solids,"
10th Symp. Ion Sources and Ion-Assisted
Technology, Tokyo, June (1986).
7) T. Nozaki, Y. Itoh, S. Hayashi, and Q. Qiu:
"U tilization of Deuterium and 15N as Activable Tracers in Solid State Sciences," 7thInt. Conf. Modern Trends in Act. Anal.,
Copenhagen, Denmark, June (1986).
8) H. Fukushima, T. Kimura, H. Hamaguchi, T.
Nozaki, Y. Itoh, and Y. Ohkubo: "Routine
Determination of Light Elements by Charged
Particle Activation Analysis," 7th Int. Conf.
Modern Trends in Act. Anal., Copenhagen,Denmark, June (1986).

2259) H. Sunaga, T. Uematsu, R. Tanaka, and I.
Kohno: "Measurement of Distribution ofProton Beam Radiation Dose Using Cyclotron," 23rd Meeting Isotope Research III
Science and Technology, Tokyo, July (1986).
10) T. Takahashi, S. Konno, and F. Yatagai:"Calculation of Dose around the Path of a
Heavy Ion and Its Application," RIKEN
Symp. Mechanism of Biological Effect ofHigh LET Radiation, Tokyo, July (1986).
11) K. Eguchi-Kasai and I. Kaneko: "DNA LeSIOn III Mammalian Cells by Heavy Ion
Particles," RIKEN Symp. Mechanisms ofBiological Effects by High LET Radiation,
Tokyo, July (1986).
12) T. Takahashi, T. Katayama, K. Takahashi,
Y. Takayanagi, and I. Kaneko: "Inactivationof B. Subtilis Spores by a Single Heavy Ion,"
3rd Spore Seminar, Tokyo, July (1986).
13) T. Takahashi, F. Yatagai, S. Konno, T. Katayama, and I. Kaneko: "Microdosimetric Considerations of Effects of Heavy Ions on Microorganisms," 26th Plenary Meeting Committeeon Space Research, Toulouse, France, July
(1986) .
14 ) K. Kimura: "Possibility of Dimer and Clusters between Helium-Excimers Produced at
High-Density by Irradiation of Heavy-Ion at
Low Temperature," Int. Conf. Atom. Phys.
and Few Body Systems (ICAP-X and Few
Body XI), Tokyo, Aug. (1986).
15) T. Nozaki ': "Accelerator Production of Radioisotopes and Their Utilization in Other Fields
than Nuclear Medicine," Int. Conf. Nuclear
and Radiochemistry, Beijing, China, Sept.
(1986) .
16) M. Iwamoto and T. Nozaki: "Charged Particle Activation Analysis for Surface Oxygen
under Various Ambient Pressure," Int. Conf.
Nuclear and Radiochemistry, Beijing, China,
Sept. (1986).
17 ) K . Kimura and M. Kataoka: "An Ion-Track
Scope Using Optical Fibers," 1986 Fall Meeting Phys. Soc. Jpn., Nishinomiya, Sept. (1986).
18) T. Takahashi, S. Konno, T . Tabata, and R.
I to: "Calculation of Dose around the Tra jectory of an Heavy Ion and Its Application,"
47th Fall Meeting Jpn. Soc. Appl. Phys.,
Sapporo, Sept. (1986).
19) Q. Qiu, T. Kobayashi, M. Yanokura, T.
Nozaki, M. Iwai, and Y. Yatsurugi: "Utilization of the D (SHe, p) 4He Reaction in HighSensitivity Analysis of Deuterium in Solids,"
47th Fall Meeting Jpn. Soc. App!. Phys.,
Sapporo, Sept. (1986).
20 ) Y. Itoh, T. Nozaki, Y. Ohkubo, T. Miura,

Y. Kadota, K. Sakai, T . Kimura, and H.
Fukushima: "Simultaneous Charged Particle
Activation Analysis of Carbon and Boron in
GaAs," 47th Fall Meeting Jpn. Soc. Appl.
Phys., Sapporo, Sept. (1986).
21) B. G. Yu, M. Aratani, M. Yanokura, T.
Nozaki, and E. Arai: "Substitution of Positive Ions III Glass Surface Layer Studied
by Heavy-Ion Rutherford Scattering Analysis,"
47th Meeting Jpn. Soc. App!. Phys., Sapporo,
Sept. (1986).
22) K. Asai, S. Ambe, T. Okada, and F. Ambe:"TDPAC of (1l1ln~) ll1Cd in Silver Phosphate," 30th Symp. Radiochemistry, Sendai,
Oct. (1986).
23) K. Asai, F. Ambe, S. Ambe, T. Okada, and
H. Sekizawa : "Chemical Effects of the EC
Decay of l11 In in a-Fe203 by TDPAC," 30th
Symp. Radiochemistry, Sendai, Oct. ( 1986).
24) S. Ambe, F. Ambe, T. Okada, I. Tanaka, S.
Nasu, and F. E. Fujita: "Emission 1vIossbauer
Spectra of 119Sb Electroplated on Au Surface,"
30th Symp. Radiochemistry, Sendai, Oct.
(1986) .
25) M. Yanokura, K. Sato, M. Aratani, M.
Nozaki, and K. Saito: "Study on Phase
Transition III Heat Treatment of W /GaAs
by Heavy Ion Scattering," 30th Symp. Radiochemistry, Send ai, Oct. (1986).
26) K. Sato, T. Nozaki, and I. Izumi: "Determination Carbon III Aluminium by Charged
Particle Activation Analysis," 30th Symp.
Radiochemistry, Sendai, Oct. (1986).
27) M . Aratani, M. Yanokura, Q. Qiu, K. Sato,
B. G. Yu, and T. Nozaki: "HydrogenatedSurface Layers of Soda-Lime Glass Studied
by the Forward Recoil Measurement with
Heavy-Ions," 30th Symp. Radiochemistry,
Sendai, Oct. (1986).
28) Y. Itoh, T. Nozaki, Y. Ohkubo, and T.
Miura: "Diffusion of Nitrogen III Silicon
Using 15N as an Activable Tracer," 30th
Symp. Radiochemistry, Sendai, Oct. (1986 ) .
29 ) K. Kimura, M. Kataoka, and H. Kumagai:"A Technique for Sub nanosecond Decay
Measurement of Heavy-Ion Induced Photoemission," 29th Conf. Radiation Chemistry,
Kyoto, Oct. (1986).
30) T. N ozaki: "Charged Particle Activation
Analysis of Impurity Light Elements in Semiconductor Materials," 11th Int. Conf. Cyclotrons and Their Applications, Tokyo, Oct.
(1986) .
31) I. Kaneko, K. Eguchi-Kasai, T. Takahashi,
T. Kosaka, and K. Nakano: "Beam Portand Irradia tion Chamber of the RIKEN

226

Ring Cyclotron for Biological Samples," 11th
Int. Conf. Cyclotron and Their Applications,Tokyo, Oct. (1986).
32 ) K. Eguchi-Kasai, T. Kosaka, 1. Kaneko, A.
Maruhashi, and K. Nakano: "Cell Deathand DNA Lesions Caused by Accelerated
Charged Particles," 11th Int. Conf. Cyclotron
and Their Applications, Tokyo, Oct. (1986).
33 ) T. Takahashi, F. Yatagai, T. Katayama, S.
Konno, K. Takahashi, Y. Takayanagi, K.
Nakano, and 1. Kaneko: "Calculation of Dosearound the Trajectory of an Ion and Interpretation of Inactivation Cross Sections ofMicroorganisms," 29th Annu. Meeting lpn.
Radiat. Res. Soc., Kanazawa, Oct. (1986).
34) K. Eguchi-Kasai, T. Kosaka, K. Nakano, 1.

Kaneko, and A. Maruhashi: "Oxgen Effecton DNA Lesion in Mammalian Cells by aParticle Beam," 29th Annu. Meeting lpn.
Radiat. Res. Soc., Kanazawa, Oct. (1986).
35) M. Suehiro, F. Yokoi, T. Nozaki, and M.
Iwamoto: "Contamination from Nonradio. active Bromine and Chlorine in the Synthesisof Radiobromine-Labelled
Butylophenone
Derivatives for Neuro-Receptor Study," 26th
Meeting lpn. Soc. Nuclear Medicine, Kamogawa, Nov. (1986).
36) T. Takahashi, F. Yatagai, T. Katayama, T.
Doke, and H. Ohashi: "Inactivation of
Microorganisms by Different Heavy Ions,"
Int. Symp. Biological Science in Space, Nagoya, Nov. (1986).

227

VIII.

LIST OF OUTSIDE USERS AND THEIR THEMES(Jan.-Dec. 1986)
1)

S. Orito and S. Nakamura"Test of Sensibility of CR39 Track
Detector for High Energy Proton"

F acuIty of Science, U niv. Tokyo

2)

T. Kimura and H. Fukushima"Radiochemical Analysis of 160, 14N
and 12C in Si Crystal and GaAs"

Japan Chemical Analysis Center

3)

H. Homareda"Production of 43K"

Faculty of Medicine, Kyorin Univ.

4)

T. Hayashi and A. Ohnishi"Radiation Damage of Cover Glassfor a Solar Cell"

Institute of Span and Astronautical Science5)

K. Yamamoto and 1. Yoshii"Study of Single Event Upset in
Microprocessors by Bombarding
14N and 40Ar Particles"

Semiconductor R&D Lab., Toshiba Co., Ltd.

6)

M. Yatsuhashi and T. Suematsu"Effects of the Proton Irradiation
on Cable Materials"

Fujikura, Ltd.

7)

H. Tanaka and Y. Kitamura"Study of Latch-up in Microprocessors
by Bombarding 14N and 42Ar Particles"

NEC, Ltd.

8)

A. Mario"Study of Single Event Upset in
Microprocessors by Bombarding
14N and 2°N e Particles"

Japan Trust Center for Electronic Parts

9)

K. Muraoka and S. Sasaki"Improvement of Static Induction
Thyristors by Proton Irradiation"

Toyo Semicon Co., Ltd.

10)

M. Watanabe and K. Ueno
"Improvement of Thyristors by Proton
Irradiation"

Fuji Electric Corporate R&D, Ltd.

11)

T. Abe and K. Tomii"Improvement of Thyristors by Proton
Irradiation"

Semiconductor R&D Lab., Matsushita
Electric Work Co., Ltd.

228

IX.

LIST OF SEMINARS(Jan.-Dec. 1986)
1) M. Tohyama, Univ. Giessen (West Germany),
29 January"Two-Body Collision Effects on Fusion\Vindow"
2) T. Yukawa, KEK (Ibaraki), 12 February"Statistics of Level"3 ) Y. Mori, KEK (Ibaraki), 18 February"International Workshop on Polarized Sources
and Targets"
4) S. Midorikawa, INS (Tokyo), 26 February"Heavy Ion Reaction and Axion"5 ) T. Cheon, Michigan State Univ. (USA) , 9 April"Density Matrix Expansion for Optical
Potential"6 ) M.J.A. de Voigt KVI (Netherlands), 22 April"Super Deformed High Spin States"
7) Y. Koike, Univ. Tokyo (Tokyo), 7 May"Nucleon-Nucleon Interaction Based on the
Flip-Flop Model"
8) G. Graw, Univ. Munich (West Germany), 14
May"High Resolution Studies with Polarized
Deuterons near 20 MeV"
9) R. Nagaoka, Univ. Tokyo (Tokyo), 20 May"Pauli-Principle Effects in Pion Scatteringfrom the Light Nuclei"10 ) N. Takigawa, Tohoku Univ. (Miyagi), 26 May"Report on ANL Symposium and Some Other
Topics on Heavy Ion Collisions"11) T. Kobayashi, KEK (Ibaraki), 6 June
"Gas Chamber for the Detection of HeavyIons"
12 ) H. Sakamoto, Tsukuba Univ. (Ibaraki), 24 June
"Microscopic Analysis of Anharmonicities in
Nuclear Quadrupole Collective Motions by
Use of the Self-Consistent Effective Interaction"15 ) W. Galster, Tsukuba Univ. (Ibaraki), 15 July
"Central Heavy Ion Collision at Intermediate
Energy"16) S. Ohta, KEK (Ibaraki), 29 July
"Forces between Quark Clusters"17) R. J. Peterson, Univ. Colorado (USA), 9 September"New Results on Isoscalar Giant Resonances"18) Y. Iseri, Chiba-Keizai Junior College (Chiba) ,30 October"Break-up Effect of the Deuteron in the
Polarized Deuteron Elastic Scattering"19 ) R. C. Sethi, Bhabha Atomic Energy Institute(India ), 30 October"Design of Sectors for AVF Cyclotron"
20) R. K. Bhandari, Bhabha Atomic Energy Institute (India), 30 October"Variable Energy Cyclotron Facility at Culcutta"21) D. Heindy, RCNP (Osaka), 18 November"Pre-scission Neutron Multiplicities and Fission Dynamics"
22) R. Anne, GANIL (France), 1 December"LISE at GANIL Construction and Recent
Results"23) S. Nomachi, KEK (Ibaraki), 2 December"Measurement of Antiproton-Proton Cross
Sections at Low Antiproton Momenta"
24) T. Kamae, Univ. Tokyo (Tokyo), 9 December"New Detection Method of r-Ray and Its
Application to Medical CT-Spectroscopy"25) S. Takeuchi, Univ. Tokyo (Tokyo), 16 December"Pauli-Blocking Effect of Quarks in Nuclei"
26) Y. Haneishi, Nihon Univ. (Tokyo), 16 December"Backward Production of Proton in ProtonNucleus Collisions at Low and Intermediate
Energy"13 ) M. Odera, Sumitomo Heavy Industries, Ltd.
(Tokyo), 26 June
"ECR Ion Sources Meeting (Jiilich) and
Linac Meeting (Stanford)"27) M. Matsuo, Kyoto U niv. ( Kyoto), 16 December"Microscopic Description of Anharmonic
Gamma-Vibrations by Means of the SelfConsistent-Collective-Coordinate Method"

14) N. Tajima, Univ. Tokyo (Tokyo), 1 July
"The Unusual High Spin Isomer in 1 8 2 0 and
the Proton-Neutron Interaction"28) T. Uchiyama, Tohoku Univ.
December"EMC Effect"(Miyagi), 24

229

x.

LIST OF PERSONNEL

Members of the Board
AWAYA Yohko ~ ~ ~-=f
HASHIZUME Akira ~ JR AA
KAMITSUBO Hiromichi J::I5f ~ m
KATSUMATA Koichi ~ X. Mz= KOHNO Isao M my JiJ
MA TSUOKA Masaru if'1 ffijj~
NOZAKI Tadashi !f Ilfflj .IE
SAKAMOTO Yuichi :!&:;;$: Mt. UDA Masayuki

f EEl ~ Z

CHIBA Y oshiaki =f ~ Iff ~ISHIHARA Masayasu 13 J]t .IE ~KANEKO Ichiro ~ -=f - ~~KIRA Akira 5" ~~KURIHARA Osamu ~ @: {~NAGAMINE Kanetada :7k ~ Fj~ I~'
SAKAIRI Hideo :!& A !if Mt.
T ANIHAT A Isao :G 1m ~ ~WATANABE Tsutomu 7lt $1J** chairman

Cyclotron Operation and Maintenance Group
FUJIT A Shin iii EEl
ff
KAGEYAMA Tadashi J& ili
KOHNO Isao M!f rj]
T AKEBE Hideki il\ $ !if tM

iE

IKEGAMI Kumio @J:n=J3
KOHARA Shigeo /J\ J]t £ ~OGIW ARA Kiyoshi ~ J]tm-

Linac Operation and Maintenance GroupCHIBA Yosiaki =f ~ Iff ~IKEZAWA Eiji @ iR !if
KAMBARA Tadashi f$ @:iE
KUBO Toshiyuki 0... 1* fiiJ. =$Y ANOKURA Minoru ~!f~ ~-=HEMMI Masatake ~ ~ 1& il\
INOUE Toshihiko j:f: J: fiiJ. ~*KASE Masayuki 1ml§ Z
MIY AZAWAY oshitoshi g iR 1* fiiJ.

Scientific and Engineering Personnel

Cosmic Ray Laboratory
IMAI Takashi 4- j:f:

Cyclotron Laboratory~*

BE Suck Hee ~ 1iJi
FUjITA jiro iii EEl~~
HARA Masahiro @: lJl ~L.
INAMURA Takashi ff8;fj" -*KARASAWA Takashi ;g iR 1f::
MORIT A Kosuke ~ EEl ~ 11--=

KOHNO Tsuyoshi M ~FUjISAWA Takashi~

iii iR 7i1b ~GOTO Akira 1~ iii ~HATANAKA Kichiji m cp 5" ~KAMITSUBO Hiromichi J::I5f 1Z m
KOHNO Isao M!f rj]
MOTONAGA Shoshichi j[;:7k fIB t

230

NAGASE Makoto ~ ;U ~NAKANISHI Noriyoshi ¢ f!§ ~ g
SAKAMOTO Ichiro :!tZ;<$: - H~
SHIMIZU Kazuo
71<. ~ !J5
TOYAMA Mitsuru ~ ili
if.4J

m

Y AMAJI Shuhei III ~ {~ 3¥
YOKOYAMA Ichiro ~ ili - H~

NAKAJIMA Shunji*¢ ~ ~ -=SAITO Motozo
JJi #i .=:SHIKATA Takashi ~ 11 ~ ~T AKESHIT A Isao 'IT T ~ ~WADA Takeshi ~ E8t$.
Y ANO Yasushige fk!f '!i:. £YOSHINAGA Naotakatf(Visitors)
ANNE Remy (GANIL, France)
CHABER T Andre (GANIL, France)
DOKE Tadayoshi ;@:,~, ~* (Sci. Eng. Res. Lab., Waseda Univ.)
EGUCHI-KASAI Kiyomi iID-~ :1f m~ (Inst. Basic Med. Sci., Univ. Tsukuba)
EJIRI Hiroyasu II m 7i:. ~ (Dept. Phys., Osaka Univ.)
FUJIOKA Manabu JJi ffLj $ (Cyclotron Radioisot. Cent., Tohoku Univ.)*

FUKUMOTO Sadayoshi m ;<$: ~ ~ (KEK)
FURUNO Kohei ~ !f Jl! 3¥ (Inst. Phys. Tandem Accel. Cent., Univ. Tsukuba)* *=HIRAKI Akio 3¥
fIB
IEKI Kazuo *:!P~ fIJ ~(Fac. Eng., Osaka Univ.)(Dept. Phys., Tokyo Inst. Technol.)*

IKEGAMI Hidetsugu it!! 1:
M (RCNP, Osaka Univ.)
INOUE Makoto :1f 1: {"§ (RCNP, Osaka Univ.)
ISOYA Akira ~ *- ~ (Sch. Sci., Tokai Univ.)
IWASHITA Yoshihisa :E- T 7!f !A (Inst. Chern. Res., Kyoto Univ.)
KADOYA Shingo fl3 *- J{ -fr (japan Gasoline Co.)~-T- ~ j;:H~

KANEKO Kumetaro
KASAGI Jirota~ *ffl'H~ j;:-=(Inst. Nucl. Study, Univ. Tokyo)(Dept. Phys., Tokyo Inst. Technol.)

KAT OR I Kenji f& IN Frl(Dept. Phys., Osaka Univ.)
KATSURAGAWA Hidetsugu f! )II ~ /jJ (Dept. Phys., Toho Univ.)
KIKUCHI Fumio *i ±ili )(!J5 (ColI. Arts Sci., Univ. Tokyo)**

Ifj fF (Dept. Phys., Kyoto Univ.)
KOBAYASHI Shinsaku !j\
KOHMOTO Susumu M ;<$:~ (Univ. Electro-Commun.)
KONDO Michiya l[ Hi lEt -ill, (RCNP, Osaka Univ.)
KUDO Hisaaki I JJi !A IJE (Dept. Chern., Niigata Univ.)
MALLIK Chaturanan (V.E.G. Cent., B.A.R.C., India)

MATSUKI Seishi fl*{IE ~ (Inst. Chern. Res., K yoto Univ.)

MINOWA Tatsuya ~ f;fij i! ~ (Dept. Phys., Toho Univ.)
MIURA Iwao .=: 00 :E- (RCNP, Osaka Univ.)
MIYATAKE Hiroari '§ JEt f= ill, (Fac. Sci., Osaka Univ.)
MOTOBAYASHI Tohru ;$:~ (Fac. Sci., Rikkyo Univ.)
MURAKAMI Takeshi M 1: ~ (Dept. Phys., Tokyo Inst. Technol.)***

NAGAMIYA Shoji'§ 1£ ffl' (Dept. Phys., Univ. Tokyo)
NAKAHARA Hiromichi ¢ ~ 51. lEt (Dept. Chern., Tokyo Metropolitan Univ.)=

NAKAI Koji CP :1f f5(KEK)
NOMURA Toru !I!f M -'7* (Inst. Nucl. Study, Univ. Tokyo)
NONAKA Hideki !I!f ¢ ~ ~ (Sumitomo Heavy Ind. Ltd.)ODERA Masatoshi /J\ 9: 1£ {~* (Sci. Eng. Res. Lab. , Waseda Univ.)
ONISHI Naoki*- g§ it[ ~ (Dept. Phys., ColI. Gen. Educ. , Univ. Tokyo)

OT A Shigemi

j;: IB 1tt ~ (KEK)*

fJiJ ~

231

QIAO Qingwen (Inst. Mod. Phys., Academia Sinica, China)
SAKURADA Yuzo ~ B3 ~(ULVAC Co.)
SATO Kenichi f6: Hi ~ ~ (Div. Phys., Tohoku ColI. Pharm.)
SHIMAZU Mitsuyoshi !lb if: fJIf ~ (Dept. Phys., Toho Univ.)
SHINOZUKA Tsutomu ~:i% *1l (Cyclotron Radioisot. Cent., Tohoku Univ.)-=-

SHIRAISHI Haruki

8 E

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*W

(Natl. Res. Inst. Metals)

SUEKI Keisuke -*J@: 1r (Inst. Nucl. Study, Univ. Tokyo)
TAKEKOSHI Hidekuni ¥r HI ~(lnst. Chem. Res., Kyoto Univ.)
TAKEMASA Tadashi :ITt i!& 7'" ± (Dept. Phys., Saga Univ.)
TAKIGAWA Noboru ~ }If¥I- (Dept. Phys., Tohoku Univ.)
TAMAGAKI Ryozo .E:!:§.Bi!.
(Dept. Phys., Kyoto Univ.)
TANAKA Hitoshi B3 ¢tsj (Japan Gasoline Co.)

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TANAKA Jinichi B3 ¢ 1=
(lnst. Nucl. Study, Univ. Tokyo)
TANAKA Koki B3 ¢ $ ~ (Nippon Steel Corp.)
TORIZUKA Kanji ,~ ~ o/f(Fac. Med., Kyoto Univ.)
TSUNEMOTO Hiroshi I~~:JC~ (Natl. Inst. Radiol. Sci.)
WANG Zhen (Inst. Mod. Phys., Academia Sinica, China)
YAMAZAKI Takashi I-U rIfflj~ (RCNP, Osaka Univ.)m=-

YOSHIDA Nobuaki E B3 'if(Dept. Phys., Univ. Tokyo)
YOSHIDA Shiro E B3 ,FiI!, fl~ (Dept. Phys., Tohoku Univ.)
YOSHINAGA Naotaka E:7k iWI ~ (Comput. Cent., Univ. Tokyo)* Visiting Professor(Students)
HARADA Hideo JJi! B3 ~ fl~ (Dept. Phys., Tokyo Inst. Technol.)
HATSUKAWA Yuichi m)lf 1i#. ~ (Dept. Chem., Tokyo Metropolitan Univ.)
KOIKE Yuji ;j\ Wz ra Pj (Dept. Phys., Univ. Tokyo)
MITOMORI Kuniharu -=-p~~* (ColI. Hum. Sci., Nihon Univ.)
NAGAI Masahito 7k #A (Fac. Sci., Toho Univ.)
YAMAGUCHI Kazuhisa I-U IJ fI]!A (ColI. Hum. Sci., Nihon Univ.)
YOSHIDA Koichi E B3 J't ~ (Dept. Phys., Tokyo Inst. Technol.)m

Linac Laboratory
CHIBA Toshiya =f ~ flJ itIt
GONO Yasuyuki ~~. ijf Z
INOUE Toshihiko # J:: 1iP. ~KASE Masayuki 110 Ni :J§ Z
KUMAGAI Hidekazu .ff~:& ~ fO
MIZOGAWA Tatsumi 11ii: JlI JJZ CTONUMA Tadao P 11'1 1£ 1i#.

CHIBA Yoshiaki =f ~ fH- fij:IHEMMI Masatake ~ 5! i!& :ITt
KAMBARA Tadashi ~ JJi!
1£
KUBO Toshiyuki !A f* 1iP. $MIYAZAWAY oshitoshi E lR {* 1iP.
TANIHATA Isao :& ml ~ ~YANOKURA Minoru ~~~(Visitors)
FUJIWARA Ichiro Hi JJi! - fl~ (Inst. At. Energy, Kyoto Univ.)
ITO Noriaki -@t Hi '" IJH (Dept. Cryst. Mater., Nagoya Univ.)
NON AKA Hideki !f ¢ 5i:. (± (Sumitomo Heavy Ind., Ltd.)SUGAW ARA Masahiko

Wi JJi! :J§ ~ (Fund. Sci., Chiba Inst. Technol.)

5t

232

(Student)
FUKUDA Mitsunori

Wi EE ::it }11f4 (Fac. Sci., Tokyo Inst. ~Technol.)Radiation Laboratory
ASAHI Koichiro :it!! ~:- R~
HASHIZUME Akira ~ JR AA
ISHIHARA Masayasu n ®: 1£ ~KOHNO Toshiyuki ;fiiJ ~ {~ Z
OKANO Masaharu ~ ~ ~ ~TENDOW Y oshihiko ::R.:@: 7J ~(Visitors)

GONO Yasuyuki ~~ 11 ft~ Z
ICHIHARA Takashi rP ®:-$I
IZUMO Koichi ill ~ :J't KONNO Satoshi ~!f~
TAKAHASHI Tan ~ ~ II*

DOKE Tadayoshi :@:,'if, ~ (Sci. Eng. Res. Lab., Waseda Univ.)
FUJIOKA Manabu Jli ~~ (Dept. Phys., Tohoku Vniv.)
HASEGAWA Takeo ~:&Jllff\~ (Inst. Nucl. Study, Vniv. Tokyo)
HITACHI Akira jj ill~ (Sci. Eng. Res. Lab., Waseda Univ.)lIO Masahiro fi& ~ 1£ rt. (Fac. Med., Univ. Tokyo)
KITAO Kensuke *~~~WJ (Natl. lnst. Radiol. Sci.)
KOBA YASHI Hisanobu 1]\
fA. {~ (Fac. Eng., Saitama Univ.)
KUBOTA Shinzou ~ EE f~':::' (Fac. Sci., Rikkyo Univ.)
KUSAKARI Hideshige 1fi- XU ?Ji:. ~ (Fac. Educ., Chiba Univ.)
LEE Sang Mu
if§))t (Univ. Tsukuba)
MASUDA Kimiaki :It EE 0. ~ (Sch. Sci. Eng., Waseda Univ.)
MOTOBAYASHI Toru ;;$.:~ (Fac. Sci., Rikkyo Univ.)
MURAMATSU Hisakazu fl flfA. fQ (Nat. Lab. High Energy Phys.)
OHSUMI Hideaki *- Il~ ~ ~ (Fac. Sci., Osaka Univ.)
OHTSUKA Hideko *-:l% ~ T
ONAI Yoshio ,~F9 1*; ~ (Dept. Phys., Cancer lnst.)
SHIBAMURA Eido ~ fl ?Ji:.:@: (Saitama ColI. Health)
SHIMIZU Hajime ;W J}( ~ (Fac. Sci., Tokyo lnst. Technol.)

**

*

**

(Students)
lIMURA Jifo fi& *1 1!X. e~ (Dept. Phys., Tokyo Inst. Technol.)
ONO Yoichi /J\ ~ ~ (Fac. Educ., Chiba Univ.)
SHINOHARA Hideo 11M ®: ~.. (Fac. Educ., Chiba Vniv.)
SUZUKI Satoshi ii
IE't~ (Sch. Sci. Eng., Waseda Univ.)*

Atomic Processes Laboratory
ANDO Kozo Y!. Jli ~IJ =:IW AI Masahiro :6- 3f 1£ ~KANAI Yasuyuki ~ # 1* Z
SHIMAMURA Isao ~ *1 !f!{.{

AWAY A Y ohko ~ ~ ?J;. T
KAMBARA Tadashi 1$ ®: 1£
NISHIDA Masami g§ EE ~ ~W A TANABE Tsutomu mt {$ 11(Visitors)
FRITSH Wolfgang (Hahn-Meitner lnst. fUr Kernforschung)

233

FUJIMA Kazumi Hi FdI- ~ (Dept. Phys., Chuo Univ.)
HARA Shunsuke ®: ~ if- (Dept. Phys., Univ. Tsukuba)-=

HITACHI Akira A lB
(Inst. Sci. Technol., Waseda Univ.)
ISHII Keishi :6 # tfz (Dept. Eng. Sci., Kyoto Univ.)
ISMAIL M. Mostafa (Dept. Phys., Cairo Univ.)
ITOH Yoh {it ii~ (Fac. Sci., Josai Univ.)
KARASHIMA Shosuke ~ ~ Jffi if- (Dept. Electr. Eng., Tokyo Univ. Sci.)**{§" ~ (Dept. Phys., Tokyo Metropolitan Univ.)
KOBAYASHI Nobuo /J\
KOIKE Fumihiro Jj\ rtf! Y:. ri (Sch. Med., Kitasato Univ.)
KOIZUMI Tetsuo Jj\ JR :gr ~ (Dept. Phys., Rikkyo Univ.)
KOYAMA Naoto /J\ ili TI[ A (Dept. Eng. Phys., Univ. Electro-Commun.)***

LIN Chii-Dongj@:(Dept. Phys., Kansas State Univ.)
MATSUO Takashi f'1 jig(Dept. Pathol., Tokyo Med. Dent. Univ.)
MATSUZAWA Michio f'1 ~ ;im!±. (Dept. Eng. Phys., Univ. Electro-Commun.)
MIZOGAWA Tatsumi ~ JII JJZ B (Fac. Sci., Saitama Univ.)
MOKLER H. Paul (Gesellschaft fUr Schwerionenforschung)*"OHSAKI Akihiko *- ill®- ~ l!i (lnst. Mol. Sci.)
OHTANI Shunsuke *-:& {~if- (Inst. Plasma Phys., Nagoya Univ.)
OKUNO Kazuhiko ~!Y:ffi l!i (Dept. Phys., Tokyo Metropolitan Univ.)
SATO Hiroshi ~ ii r5.se. (Dept. Phys., Ochanomizu Univ.)
SATO Kuninori ~ Hi
(Inst. Plasma Phys., Nagoya Univ.)
SATO Yo ~ Hi
~ (Fac. Sci., Josai Univ.)
SCHUCH Reinhold (Dept. Phys., Heidelberg Univ.)
SHIBATA Hiromi !i1!§ EEl fa ~ (Res. Cent. Nucl. Sci. Technol., Univ. Tokyo)
SHIMA Kunihiro ~ri (Tandem Accel. Cent., Univ. Tsukuba)
SHIMAKURA Noriyuki ~ ~ ~ z (Gen. Educ. Dept., Niigata Univ.)

ffiI..
:m*

TAKAGI Shoji ~ff ~ (Dept. Phys., Toho Univ.)
TAWARA Hiroyuki ~ ri ~ (Inst. Plasma Phys., Nagoya Univ.)
TOSHIMA Nobuyuki ? ~~ {§" ¥ (lnst. Appl. Phys., Univ. Tsukuba)
TSURUBUCHI Seiji t~ V#I ~(Fac. Technol., Tokyo Univ. Agric. Technol.)
URAKAWA Junji 1m}ll jlJi rt1 (Natl. Lab. High Energy Phys.)-=(Students)
HINO Kenichi B!f M (Dept. Appl. Phys., Univ. Tokyo)
NAKANISHI Kiyotaka cp [!:§ m~ (Dept. Chern., Waseda Univ.)

Metal Physics Laboratory
ISHIDA Katsuhiko :6 EEl MJ l!i
MATSUZAKI Teiichiro f'1dffljtjHp~~
SHIOTANI Nobuhiro :l;¥[:& B 1J.b.

KOYAMA Akio /J\ ili HE 1i#
N AGAMINE Kanetada 7k ~ ~ ,~,Y AGI Eiichi(Students)
KANO Fumihisa ,/:&!f Y:. ~ (Sch. Sci. Eng., Waseda Univ.)
NAKAMURA Shiho cp tf ~ 1* (Sch. Sci. Eng ., Waseda Univ.)

j\

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234

Magnetic Materials Laboratory
ASAI Kichizo ~ # E ~SAKAI Nobuhiko ~ # f~ ~OKADA Takuya

fmj B3 .$: fu

Plasma Physics Laboratory
ISHIBE Yukio 1J $ fi ..
OKAZAKI Kiyohiko fmji/fflj rnltil

ISHII Shigeyuki 1J # m<: fi
OY AMA Hitoshi *- U-i~

SAKAMOTO Yuichi :#j

Y ANO Katsuki* Uf -~!f JWf -1=(Visitors)
SUGIYAMA Kazuo~ U-i ~ ~(Fac. Eng., Saitama Univ.)

U-i f31- 1~ fI~ (Fac. Eng., Hokkaido Univ.)

YAMASHINA Toshiro

Semiconductors Laboratory(Visitor)
AONO Keiko H!f;fi T(ColI. Lib. Arts, Kitasato Univ.)

Solid-State Chemistry Laboratory
KOBAYASHI Masayoshi /J\
SASA Y oshihiko ~ /:{ a ~** ~ ~

MAEDA Kuniko iW IE *13 T
UDA Masayuki ¥ B3 »G Z

(Visitors)
BENKA Oswald (Johannes Kepler-Univ. Linz, Austria)
ISHII Keizo 1J # II: ~ (Cyclotron Radioisot. Cent., Tohoku Univ.)
KUSUYAMA Hiroyuki *i U-i "51. Z (Saitama Medical School)
MUKOUYAMA Takashi n:u U-i ~ (Inst. Chem. Res., Kyoto Univ.)
YOKODE Yutaka ~ teis (Sch. Med., Nihon Univ.)(Student)
ISHIKAWA Hiroshi 1J}IIf5 (Dept. Phys., Sci. Univ. Tokyo)

Radiochemistry Laboratory
AM BE Fumitoshi 'i7!. $~ARAT ANI Michi m;fr ~ ~:x

AMBE Shizuko* T

ITOH Y oshiko f]I7f T
MIURA Taichi =: 00- 7::. OHKUBO Yoshitaka *-?\-f* a~

IW AMOTO Masako :!fi
NOZAKI Tadashi !f i/fflj

1£

1£(Visitors)
FUKUSHIMA Hiroto m ilI~ f5 A (Japan Chemical Analysis Cent.)
HUANG Ziwei •T ~ (lnst. BioI. Pedol. Psamol. Res., China)
IMAI Masato A, # 1£ A (Komatsu Electronic Metals Co., Ltd.)IMURA Ryo # t-t 'iG (Cent. Res. Lab., Hitachi, Ltd.)IZUMI Iwao ~~ (Nippon Light Metal Co., Ltd.)'i7!. $ D T

*

235

KATADA Motomi Jt 83 :7C B (Dept. Chern., Fac. Sci., Tokyo Metropolitan Univ.)
KATO Hajime 110 Hi ~ (Fac. Educ., Yamanashi Univ.)*:ft

KIMURA Toshimasa
fii9:.IE (Japan Chemical Analysis Cent.)
MINAI Yoshitaka ~ ~ 1* ~ (Fac. Sci., Univ. Tokyo)
MOCHIZUKI Yasuhiro ~ A ~~.l.. (Hitachi, Ltd.)NASU Saburo ~ ~ ~ *~ (Fac. Eng. Sci., Osaka Univ.)OOHIRA Shigeo
SjZ m 5'3 (Nikkei Techno Res. Co., Ltd.)**-SAITO Kazuo
Hi ~ hi (Toshiba Corp., R&D Cent.)
SUEHIRO Makiko
J1;. tf5I.: T (Tokyo Metropolitan Geriatric Hospital)
SUGAI Isao -g #~ (Inst. Nucl. Study, Univ. Tokyo)**

SUZUKI Ryo ~~ (Cent. Res. Lab., Hitachi, Ltd.)YATSURUGI Yoshifumi /\ §W -gr::st (Komatsu Electronic Metals Co., Ltd.)YOKOI Fuji tl # jJ. % (Ment. Muscular Disord., Natl. Cent. Nerv.)(Students)
ARAI Iwao ~#.lii/iffll~ (Fac. Pharm., Sci. Univ. Tokyo)
KOBAYASHI Yoshio ;j\~ 5'3 (Fac. Sci., Tokyo Metropolitan Univ.)
KUBO Kenya !A 1* ~ fjJ(; (Fac. Sci., Univ. Tokyo)**

QUI Qi £if):n: (Res. Lab., Nuc1. React. Tokyo Inst. Technol.)
SATO Kazuhiro ~ Hi ~ J1;. (Fac. Sci., Toho Univ.)
TANAKA Isao B3 r:pJj] (Fac. Eng. Sci., Osaka Univ.)
YOSHIKAWA Hideki -gr]l[ ~ W (Fac. Sci., Tokyo Metropolitan Univ.)
YU Byongon Wr m:l:$ (Res. Lab., Nucl. React., Tokyo lnst. Technol.)Radiation Chemistry Laboratory
KIMURA Kazuie*:ft ~ ~(Visitor)
ITO Yasuo

W Hi ~ ~ (Res. Cent. Nucl. Sci. Technol., Univ. Tokyo)(Students)
FUNDOH Atsushi ?t ~ W ~ (Dept. Phys., Chuo Univ.)
HARA Korehisa JJit ~!A (Dept. Phys., Chuo Univ.)
IIDA Tsuyoshi i& B3/lGJIJ(Dept. Phys., Chuo Univ.)
KANAI Koichi ~ # i* ~ (Dept. Phys., Chuo Univ.)
KATAOKA Masayoshi Jt flDj ~ 5l, (Dept. Phys., Chuo Univ.)
NISHINA Takuya t f4 ~ 1:11 (Dept. Phys., Chuo Univ.)
UENO Takao L!f" ~ (Dept. Phys., Chuo Univ.)

Radiobiology Laboratory
KANEKO Ichiro ~ T ~ *~NAKANO Kazushiro

r:p!f ~ :9JX

(Visitors)
EGUCHI-KASAI Kiyomi rrD-ll#m~ (Inst. Basic Med. Sci., Univ. Tsukuba)
MAJIMA Hideyuki ,~ ~~ ~ IT (Fac. Med., Univ. Tokyo)

236

MARUHASHI Akira jr,;fI ~ (Inst. Clin. Med., Univ. Tsukuba)
OKADA Gensaku Itfij EEl ~ fF (Tokyo Metropolitan Nurse Sch.)(Student)
KOSAKA Toshiyuki /J\:!1j ~ Z(Dept. Vet. Radio!., Nihon Univ.)

Safety Control Affairs Office
KAGAYA Satoru no~~ ,t:g:
KURIHARA Osamu ~ JJR {~MIY AGAW A Makoto g JfI • §SHINOHARA Shigemi 11M JJit
USURA Isao ~ ~ ~Beam Analysis Center*iE ~IW AKI Masaya :ESAKAIRI Hideo :!1j l\
W.

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KATOU Takeo
Iii tFt "hi
MA TSUZAWAYasuhide ;f~ ~ Y:. ~SAKAMOTO Ichiro ~T AKI Kenro ~ ~IJ M

KOBA Y ASHI Takane

*-

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ADACHI Hirohiko JE iL fa ~ 37
AIHARA Toshimitsu ~ JJjt ~1J:J't 5
AKAISHI Kenya !ffi E 11! -tI! 71
ALONSO Jose R. 27
AM BE Fumitoshi P!. $ )( ~ 65,66,67,107,109,111
AMBE Shizuko *- $ It T 66,67,107,109,111
AMEMIY A Hiroshi ffi '§71
AMEMIY A Susumu ffi '§ ~ 71
ANDO Kozo P!. ni ~IJ =: 51,52
ANNE R. 19
AONO Keiko T!t my *1 T 79

GOTOH Eiichiro 1&Hi*-fI~ 126
GUILLEMAUD-MUELLER D. 19
HAMA Hiroyuki ~ It ¥ 138
HAMAGAKI Hideki ~:@: ~ ~ 25
HANAKAWA Kazuyuki 1E}I[ fQ Z. 23
HARA Masahiro JJjt ~ 5J,. 199
HARA Shunsuke JJjt ~ 1t- 49
HARADA Hideo JJjt IE ~ fI~ 6,8
HASEBE Nobuyuki ~~${§IT 122

ARAI Eiichi ~ #100
ARA T ANI Michi m;& ~ ~ 98,100,101,103,105
ASAHI Koichiro fig fJt-fIll 19,21,23,136,142,146,

HASIGUTI Ryukiti R. 11 IJ ~ E 83
HATANAKA Kichiji ;m l:/J E ~ 162,174
HATSUKAWA Yuichi fJJ JI[ tt - 14,138
HEMMI Masatake ~ J! i!& ft\ 5, 195
HINO Ken-ichi B my • - 35
HINO Tomoaki B my 1Y.. ~ 71
HOFMANN Helmut 33
HOSONO Kazuhiko 1fflI my ;fO ~ 29
ICHIHARA Takashi m JJjt ¥ 19,30,134,136,151

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147,149,151

ASAI Kichizo ~ # E II 65,66,67,69,111
AWAYA Yohko ~ ~ ~ T 51,52,53,55,56,131,132
BABA Kei ,~~ xg 57
BAZIN D. 19
BE Suck Hee ~ .fiJi % 57,183,185
BECK Francis A. 17
BENKA Oswald 61, 62
BIMBOT R. 19
BRIANCON Ch. 17
CHENG Jia-Fu f.¥ ~ ~ 39,46
CHIBA Toshiya =f ~ ~IJ ~ 132,195
CHIBA Yoshiaki =f ~ P.f ~ 5,167
DOKE Tadayoshi itt,'it', ~ 122
EGUCHI-KASAI Kiyomi iIlJ-~#m~ 115,117
EKUNI Katsuaki iIlEMfIJ?:3 '2:l
FUJIMA Kazumi ni FJ1 - ~ 37
FUJIOKA Manabu ni p.Gj ~ 138
FUJISAWA Takashi nilR ~;E 164,167,176
FUJIT A Fransisco Eiichi ni B3 ~ - 109
FUJITA Jiro ni B3
fI~ 170
FUJITA Shin Hi B3~ 2, 203,. 206, 208, 210, 212*=

FUKAI Yuh ~ #~ 75
FUKUDA Mitsunori :fi B3 :J't JI~ 12,14,136,142,146
FUKUDA Tomokazu :fi B3 ;it;fO 23
FUKUSHIMA Hiroto :fi ~~ ?i5 A 88,91
FUNDOH Atsushi 7t ~ ~ ~ 113
FURUNO Kohei it my ~ ~ 138
FUSE Masaharu ;ffi" 1ifB ~ ~ 126
GONO Yasuyuki ~~. iiff Z. 12,14,17,19
GOTO Akira ~ Bi ~ 162,172,174,176*

HASHIMOTO Iwao 11
HASHIMOTO Osamu 11
HASHIZUME Akira 11 JT\

*

~

77
{~

25

AA 126, 152, 154, 156, 158*

IEIRI Masaharu
A 1£ ~ 30
IEKI Kazuo *:!m;fO ~ 134
IGUCHI Kaoru # IJ § 45
IIMURA Jiro i&;ft (X fI~ 129
IKEDA Nobuo itB B3 {$ ~ 23
IKEGAMI Kumio itB1:tL~:!l3 2,183,185
IKEGAMI Yuji itB 1: :tb 'j§'j 176
IKEZAWA Eiji itB lR ~5,181
IMAI Masato A, # IE A 93
IMAI Takashi A, #~ 122
IMURA Ryo #;ft 'iG 101
6,8,126,138,144,
INAMURA Takashi flli;ft ..$I 151,
174
INOUE Toshihiko # J: ~ ~ 5
ISHIBE Yukio E $ IT tit 71
ISHIDA Katsuhiko E B3 ,Igf ~ 63=

ISHIHARA Masayasu

EJJjtIE~

19, 21, 23, 29, 125,
129,134,136,142,
146,147,149,151

ISHII Shigeyuki E # mt IT 198
ISHIKAWA Hiroshi E JlI

?i5

62,94

IT AHASHI Takahisa t'i 11 ~!A. 23
ITOH Yoh W Bi ~ 131
ITOH Y oshiko {Jt
7!j T 88,91,92
IWAI Masahiro E # IE PJJ 41,48
IW AKI Masaya :¥:r
IE ~ 77,79,80**

IW AMOTO Masako E)$: 1£ -=f 86,88
IWATA Yosei E EEl # -tit 140
IZUMI Iwao 7'R• 89
IZUMO Koichi ill ~ jt - 119
KADOT A Y oshinori ft3 EEl ft *l 91
KAGEY AMA Tadashi f6 ili 1£ 2,188.

~

5,53,55,56,57,59,
131,132,170,181
cb w.160, 162, 170,
1::f5IZ /J:. m 174,203

KAMBARA Tadashl 1$ w:•

JL

KAMITSUBO Hiromichl
KANAI Koichi ~ # ~ - 113
KANAI Yasuyuki ~ # 1* Z 53,55,56,131,132
KANEKO Ichiro ~ -=f - f!~ 115,117
KANO Fumihisa 1m!f)t ~ 75,80
KARASAW A Takashi~
1j:. 191
KASAGI Jirota 1i:*~f!~* 6,8,19

m

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5,53,56,57,59,132,162,

KASE Masayukl 110 ~ El L 174,178,195
KAT ADA Motomi h EEl JC c. 111
KATAOKA Masayoshi h IM):p;J- % 113
KAT AY AMA Toshiko h ili 4iii -=f 119
KATO Hajime 110 Bi - 103

*
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KATO Seigo 110 Hi
if 134
KA TO Shigeki 110 Hi
w 71
KATORI Kenji J1g~
23
KATSURAGAWA Hidetsugu ;f1 }11 ~ Iffilij 144
KAWAKAMI Hirokane ]II 1: 7.t. ~ 140
KIKUCHI Fumio *1:1fu)t 14 199
KIKUCHI Jun *i?fu JiJft 122
KIMURA Kazuie
tt - ~ 113
KIMURA Toshimasa
tt ~ 1£ 88,91. KIT AO Kensuke ~ ~ J~J~M 152,154,156,158**** Jil fF 30**
4,75,93,208** 14 25,26,27** 5'5 111

KOBAYASHI Shinsaku /J\
KOBAYASHI Takane /J\
KOBA Y ASHI Toshio

/J\

~

~

KOBAYASHI Y oshio /J\~
KOHARA Shigeo /J\ w: ~ 'X. 2,164,167
KOHMOTO Susumu ¥PI)$: :Qg 51, 52
KOHNO Isao ¥PI!f :r:j; 2,57,59,73,208,210
KOHNO Toshiyuki ¥PI!f ~ Z 12,14,17
KOHNO Tsuyoshi ¥PI!f ~ 122
KOIZUMI Tetsuo 1]\ 7'R rg- 'X. 131
KONNO Satoshi ~!f ~ 119
KOSAKA Toshifumi /J\ ~ ~)t 115,117
KOSAKO Toshiso /J\f3:~4iiirf 203,212
KOYAMA Akio /J\ ili I3E 14 61, 62,83
KREBS Gary F. 27
KUBO M. Kenya !A 1* ~ ~ 86
KUBO Toshiyuki !A 1* 4iii =¥= 5,6,8,134,136,142,146
KUDO Hisaaki I Hi !A I3E 138,140

KUMAGAI Hidekazu ff~:e. ~;fQ

51,52,53,55,56,57,~~6~i~7~f~9132,

KUMATA Yukio ff~ EEl =¥= &: 167
KURIHARA Osamu ~ w: f~ 208
KUSUYAMA Hiroyuki ;l:1!-U sl Z 94
LID Xiawei ~U /J\ {1jt 46
LID Yaoyang ~U ~ ~ 39,46
MA Qiancheng ~~ 39,46
MAEDA Kazushige ~ EEl ;fQ
134
MAEDA Kuniko ~ EEl *~ -=f 94,96
MAEDA Masaru ~ EEl
Jm 94
MARUHASHI Akira 1L~ 115,117
MATSUMOTO Seiichiro *,~)$:~-f!~ 71
MA TSUMOTO Takehiko *,~)$::LEt ~ 75

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MA TSUO Takashi *'~ ~59
MATSUOKA Nobuyuki *'~ 1M:! {$ IT 29
MATSUT A Kensaku *'~ ~ @ ~ 27
MATSUZAKI Teiichiro *,~~1&mf!~ 63,136
MINAGAWA Hidenori ~}II ~ ~ 71
MINAMISONO Tadanori i¥.i ~ ,~, ItU 23,27
MINOWA Tatsuya ~ ~ :it ~ 144
MITOMORI Kuniharu =.? ~ 00* 199
MIYATAKE Hiroari g:LEt ~ t!1 138,140
MIYAZAWA Y oshitoshi g ~ ft 4iii 5,195
MIZOGAWA Tatsumi ~]l1 JJZ B 53,55,56,131,132
MOCHIZUKI Yasuhiro ~ JI m sl 92
MOKLER Paul H. 53
MORITA Kosuke ~ EEl ~:fr 138,140
MOTOBAYASHI Tohru )$::® 29,125,134
MOTONAGA Shoshichi JC 7k I3E t 162,172
MUELLER A.C. 19
MURAKAMI Hiroyuki tt 1: ~ Z 122,125
MURAKAMI Takeshi tt 1: @ 6,8
NAGAMINE Kanetada 7k ~ ~ ,~, 63,136
NAGAMIYA Shoji 7k g 1£ ~ 27
NAGASE Makoto ~ ~ ~ 167,172
NAGATA Katsuaki 7k EEl Jm ~ 122
NAKAHARA Hiromichi r:p w: sl m 89
NAKAJIMA Shunji r:p Nb ~183,185
NAKAMOTO Atsushi r:p)$: w: 122
NAKAMURA Akihiko r:p tt ~ ~ 23
NAKAMURA Masanobu r:p tt 1£ f~ 30
NAKAMURA Shiho r:p;ft ~ 1* 75,80
NAKANISHI Kiyotaka r:p gg m- ~ 45
NAKANISHI Noriyoshi r:p gg ~ & 188,203,212
NAKANO Kazushiro r:p!f;fQ ~ 115,117
NAMBA Susumu • 7J1t. Jig 79**-=

NASU Saburo~ ~=. f!~ 109

NISHINA Takuya t f4 lj[ 1:11 113
NISHIY AMA Koichi g§ ili J;b 144
NOD A Nobuaki my B3 {~~ 71
NOJIRI Yoichi my JJL i$ - 23,27
NOMURA Toru my M "7 138,140
NONAKA Hideki my tfJ ~ ~ 198
NOZAKI Tadashi !f ~ 1£ 86,88,89,91,92,93,98,
OGIWARA Kiyoshi ~ 1*
OHKI Tomonori~

100,101,103,105,152
2,164,167***!A-f*~~ ~~4~~5~\~~'* 1B m**~ J!IJOHKUBO Yoshitaka---------OHNUMA Hajime
OHSAKI Akihiko

5

152,

129,134

r!Jtff- ~ lfj

45

OHSHIMA Masumi~ ~ ~ 126
OHT ANI Shunsuke *:G ~ 1r 131
OIKAWA Yoshifumi ~ )11 ~ 1m 146,164,178
OKADA Takuya flijj B3 lj[ 1:11 66,67,69,107,109,111
OKAZAKI Kiyohiko flijj~m.l:t1l 71
OKIHANA Akira ytft 1E ~ 29
OKUNO Kazuhiko ~!f fO lfj 131
OMAT A Kazuo 1]\ 1~ fO::k 26, 27
ORIHARA Hikonojo ~)]t~zz1S 134
OSAKA Toshiaki~ ~ ~ 80OYAIZU Mitsuhiro IJ\;WP~:JcIt 140

*
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OYAMA Hitoshi~ 71,73QIU Qi Jii3
93,98
SAITO Kazuo 1f Hi fO ~ 105
SAITO Motozo 1f Hi M.:::: 178
SAITO Takane 1f Hi ~ mt 29
SAKAGUCHI Atsushi ~ D ~ ~ 29
SAKAGUCHI Harutaka ~ D 7#s ~ 30
SAKAI Hideyuki iW # ~ IT 29
SAKAI Kazuo :M - ~ 91
SAKAI N obuhiko ~ # {~~ 65
SAKAIRI Hideo ~ A ~ ut 4,83,125
SAKAMOTO Ichiro ~;;$: - Pl~ 206, 208, 210
SAKAMOTO Yuichi ~;;$: ut - 71,73
SANO Hirotoshi
my it ~ 111
SASA Y oshihiko~ ~ 61,62,94,96
SATO Kazuhiro ftc Hi fO It 89,98,105

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SATOH Shinichi~
SCHMIDT-OTT W.O. 19
SCHUCH Reinhold 55

125

SEKIZAW A Hisashi M ~rbJ 67,69*

SHIBATA Hiromi ~ B3
~ 55,57,131
SHIDA Y oshijiro ~ B3 ~(XfI~ 25,26,27
SHIKA T A Takashi gg 15 ~.se. 203,212
SHIMA Kunihiro ~ n it 53,55,56,132
SHIMAMURA Isao ~ M ~ 41,44,48

SHIMAZU Mitsuyoshi ~ ~ fml '~ 144
SHIMIZU Hajime
7l< ~ 129,134
SHIMODA Tadashi T B3
1£ 23,26
SHIMOURA Susumu T 1ffi $= 23,27,29
SHINOZUKA Tsutomu 1~:I% tlJ 138,140m*

SUEHIRO Makiko
rt. t& T 86
SUEKI Keisuke~ 1r 138,140
SUGAI Isao '§f #~ 103
SUGAW ARA Masahiko '§f 1* l§ lfj 12,14
SUGIMOTO Kenzo ~;;$: ~.:::: 25,26,27
SUGIYAMA Kazuo ~ ili fI]::k 73***-

SUZUKI Kazuo MJ
ut 105SUZUKI Ryo MJ~ 101
SYMONS T.J.M. 27
T ABAT A Tatsuo ~ iJ!i Ji::k 119
TAGUCHI Kazuhiro B3 D fO it 138
TAKAGI Shoji ~1$ ~ 131
TAKAHASHI Noriaki ~ ~ • ~ 23,25,26
TAKAHASHI Tan ~ ~ 1L 117,119
T AKEBE Hideki lEt $ ~ 1ti 2, 162, 170,172, 206
TAKESHITA Isao ¥r T ~::k 164,176,178
T AKET ANI Hiroshi lEt:G lfL 14,142,146
TAKEUCHI Youichiro ¥r~Wi-fI~ 30
TAKEYAMA Kunihiko lEt ili n ~ 27
TANAKA Isao B3 tfJJ)] 109
TANAKA Jin'ichi B3 tfJ t m 138,140
TANIHATA Isao :G mI jJ::k 5,25,26,27,136,142,146
TAWARA Hiroyuki ~ it Z 57,59
TENDOW Y oshihiko ;R.:@: 7f ~ 152,154,156,158
TOG AW A Hiroaki 7i- ]II r-Ji ~ 30
TONUMA Tadao ? 1B 1£ ut 51,52,57,59
TSURUBUCHI Seiji ll! i1#I ~51,52,131. TSUTSUMI Toshiaki tI It'~ ~ 30
UDA Masayuki
B3 1Z Z 61,62,94,96
UENO Takao J:!f. ~ 113
URAl Teruo 1ffi # ~::k 4,176
W ADA Takeshi fI] B3
ut 162,170,172,181,199,206
WATANABE Kenji at ill ~ (X 75
WATANABE Tsutomu at $h 35,39,41,45,46

*

*

-=

*

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YAGI Eiichi
4,75,77,80,83
YAMADA Yutaka ili B3
176
YAMAGUCHI Hiroyuki Ib IJ SA Z 77
YAMAJI Shuhei Ib ~ {~~ 10,33
Y AMAKAWA Osamu ili)ll {~25, 26
YAMASHINA Toshio Ib 14 ~ fI~ 71
YANAGIMACHI Tomoki ;Wp f1IJ Jill ~ 122
Y ANAGIT A Shohei ;Wp B3 lIB ~ 122
Y ANO Katsuki IF:.!f Jm
71,73

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*

YANO Yasushige ~!f 9!. ~ 162,174
YANOKURA Minoru ~!f~ ~ 5,73,93,98,100,101,
103,105,198,208

YATAGAI Fumio ~B3~)(*= 119
YATSURUGI Yoshifumi /\ ~U E)( 93
YOKODE Yutaka tt ill
94
YOKOI Fuji tt;lt 100. % 86
YOKOYAMA Ichiro tt Jli -.&~ 167,178
YOSHIDA Koichi E B3 ]It - 6,8m

YOSHII Masato E;It.IE A 138
YOSHIKAWA Hideki E)I[ ~ W 89
YOSHINAGA Naotaka E 7k fb1 ~ 10
YOSOI Masaru 4~;It f.f 30
YU Byong Gon ~ ~:f:ltt 98, 100
ZHANG Xixiang 5& ~ ff 39,46
ZHOU Su-Min mJ ~ fMJ 39

RIKEN Accelerator Progress Report
JI1t$if~ffl1JD&H~;1{.{$-Fn Miti~20*(1986)

U~fI] 62 if (1987) 81=125 B

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理化学研究所
埼玉県

和光市

広沢