ISSN 0289-842X

RIKEN
Accelerator
Progress Report
vol.

21

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

RIKEN Accelerator Progress Report 11 (Q)(6)71
January-December U'71 (Q)1/

.'

' './

.!

:

'!:

JIit. ~.Jiff ~ fiJT

the Inslifute of Physical and Chemical ReseDrcb
Wako-shi, Saitama, 35 '-0 J JAPANEditors
S. AmbeK. Asahi

Y. AwayaY. Chiba

T. Inamura

S. Kitayama

1. Shimamura. I. Tanihata

E. Vagi

Y. YanoThis volume contains recent infonnation of the accelerators at RIKEN (IPCR), informal
reports and abstracts of papers which will be published at scientific meetings or in publications
by staff members, guests, and visitors.
All rights reserved. This report or any part thereof may not be reproduced in any form (including photostatic or microfilm form) without written permission from the publisher.

CON T E N·T S
Page

I.

INTRODUCTIONII.

OPERATION OF ACCELERATORS
1.

RIKEN Ring Cyclotron Operation

2

2.

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

3

3.

Cyclotron Operation ............................................... ~ . . . . . . . . .

5

4.

T ANDETRON-Operation

6

"J

III.
1.

1

RESEARCH ' ACTIVITIES
Nuclear Physics
L

The Intruder "Deformed Band in 11lSn ...................................... ..

7

2.

High Energy r-Rays Observed in the 181Ta+ 4 0Ar Reaction
at 21 MeV/Nucleon ..................................................... . ..

8

Angular Distribution of Fission Fragments Coincident
with Projectile Fragments ....................................................

9

3.

"

2.

"

"

4.

Spin Alignment in Projectile Fragmentation at
Intermediate Energies ....................................................... 11

5.

Tensor Analyzing Powers of (d,2He) Reactions on IH and 12C ................ . . 13

6.

Rotational Perturbation to the Natural Parity Rotational
Band of 163Dy ...... ".. .......... ". ". ...........................................

15

7.

Study of Neutron-Rich Nuclei with Radio-Isotope Beams ....................... 17

8.

Development of a ~article-Identification Technique andSearch for New Isotopes . .........................................

......... 19

9.

Total Reaction Cross Section Measurement of Unstable Nuclei ......... . ........ 21

10.

Effect of Final State Interactions on (1r, 1)) Reactions .................... .. .... 23

11.

Level Densities with Fixed Exciton Number for Pre-Equilibrium
Nuclear Reaction ........................................................... 25

12.

A High-Energy Scattering Approximation ................ . ..................... 27

13.

Microscopic Analysis of the Hexadecapole Strength to ther-Vibrational Bands ................. . ...................................... 29

14.

Derivation of the Global Equation of Motion for theCollective Variable ........ . ................................................. 31

Atomic and Solid-State Physics
1.

Gauge Property for the Radiative Processes Induced by
Ion-Atom Collision ......................................................... 32

Page
2.

Photon Angular Distributions of the Ultrarelativistic K-Shell
Radiative Electron Capture Induced by Heavy-Ion Collision ..................... 35

3.

Angular Distribution and Linear-Polarization of X Rays Induced
by Radiative Electron Capture Process .................. ,...................... 37

4.

Calculation of Electron-Stripping Cross Sections of Ne Ionsin Proton Impact ........................................".................. 39

5.

Charge-Exchange Cross Sections and Equilibrium Charge States of
Incident Uranium Ions with Relativistic Velocity .............................. 41

6.

Electron Capture between Arbitrary Excited States in
the Continuum Distorted Wave Approximation ............................... 43

7.

Charge Transfer Collision between a Low Energy Ion anda Solid Surface ............................................................ 45

9.

The Born Approximation to the Reactance Matrix in
Low-Energy Electron-Molecule Collisions ...................................... 49

10.

Rotational Stopping Cross Sections for Collisions of Subexcitation
Electrons with Dipolar 'Molecules: Dependence on the Temperatureof the Molecular Gas ...................................................... 51

11.

Doubly Excited Rydberg Series of Molecular Repulsive
States: H2 ................................................................ 53

12.

Continuum Multiple Scattering Method for Molecules ......................... 55

13.

Hyper-Radial Adiabatic Expansion for a Muonic Molecule dtp .................. 57

14.

Deformed Atoms and Collective Rotational Motionof Electrons ................................................................ 59

15.

Identification of Al X 2p3d-2p4f Transition of Beam-Foil
Spectra .................................................................... 62

16.

Tilted-Foil Method Using Extremely Thin Foils ............................. 63

17.

Observation of Radiative Photons in the p- Transfer Process
for Liquid D2 with He Impurity ............................................. 64

18.

REC X-Rays from Collision System of 20.5 MeV lu Ar
Ions on Be . . .............................................................. 67

19.

Momentum Distribution of Be 2 s Electron Measured by a
Radiative Electron Capture Process ........................................... 69

20.

Resonant Transfer and Excitation (RTE) in Ge 2 9- on H2 Collisions ............. 71

21.

Charge Equilibration Process of 50 MeV Ar Ions in C Foils ..................... 73

22.

Broadening of Ar Projectile Ka X-Ray Satellite Lines in Cu andNi Target Foils ............................................................ 76

23.

A Systematic Study of KLn ~lultiple Vacancy Production for Ca
Bombarded by 0.25-1.5 MeV I uN e and Ar Ions ............................... 78

Page
24.

Impact Parameter Dependent Probabilities of Au L-Shell Ionization
by Ar -Ions ...................................' .......' ..•.. '. :................ 80

25.

Charge-State Distribution Measurements of Ar Ions ..........' . . . . . . . . . . . . . . . .. 82

26.

Coincidence Measurements of Electron Capture and Target
Ionization in 1.05 MeV /amu Ar12+ + Ne Collision ............................. 8427.

High Charge Effects on Electron Excitations in Metal Targets forAr12+ Impact Compared with Those for He;:!+ Impact ........................... 87

28.

Energy Spectra of AI-L VV Auger Electrons Induced by Grazing
Angle Incident Fast Heavy-Ion Impact ....................................... 8929.

A Piezoefectric Bimorph Transducer for the Coulomb-Excitation
M6ssbauer Spectroscopy .............. :...................................... 92

30.

57Fe M6ssbauer Study on YBa2Cua-xFex07-V ................................... 93

31.

Emission M6ssbauer Study of 119Sb Ions Adsorbed on Ferrimagnetic
Fea04 Surfaces ............................................................. 96

32.

TDPAC Study of Hyperfine Interactions at ll1Cd( ~ 111ln) in
Lio.5Fe2.504 Single Crystal ................................................... 98

33.

Surface Structure of Krypton-Implanted Aluminum ............................ 101

34.

Lattice Location Study on Krypton Atoms in Aluminum by
Means of a Channeling Method ............................................. 103

35.

RBS Investigation of AIN$ Deposited on Glassy Carbon (I) ..................... 105

36.

Lattice Location of Eu Ion in Eu-Implanted CaF 2 Observed by
Channeling Experiments ..................................................... 106

37.

Lattice Disorder arid the Behavior of Implanted Atoms in InImplanted Ti0 2 (Rutile) .. : ................................................. 107

38.

Hydrogen Trapping by Substitutional Impurities in Nb-3at %Mo
Alloys as Observed by the Channeling Method ................................ 109

39.

Evaluation of Structural Perfection by Rutherford Backscattering
Spectroscopy (RBS) of 6H-SiC Single Crystal Grown with a Vapor
Transport Method ...................... -. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

40.

Erosion of Graphite by Low Energy Atomic Hydrogen .......... '...... ' .......... 114

41.

The Channeling Analysis of Ge Epitaxial Growth on Si Substrate ................ 116

42.

Production of Fast Switching Power Thyristors by Proton
Irradiation

43.
3.

118

Background in PIXE Spectra ................................................ 120

Radiochemistry and Nuclear Chemistry1.

A New Nuclear Reaction Analysis of Nitrogen in Solids:
Utilization , of 15N ,as an Activable Trace,r ..................................... 123

2.

Study on Carbon and Boron in' Gallium Arsenide ............................ . 124

Page

4.

5.

3.

Analysis of Hydrogen in Plasma CVD SiOx Films by an Elastic
Recoil Detection Method . . .................................................. 125

4.

Heavy-Ion Rutherford 2tr-Scattering Analysis Applied to theDevelopment of a Monitoring Detector for the Measurementof Water Reactivity ........ . ................ . ............................... 126

5.

Application of PIXE to Medical and Environmental Science (II) .. . ............ 127, 6.

Application of PIXE and Diffraction Analysis to Ancient
Remains (II) ............................. . ................................ 129

7.

In Situ Emission Mossbauer Studies of Solid/Solution Interface:
119Sb5+ and 57C02+ Ions Adsorbed on r-Fe203 ................................... 131

8.

Mossbauer Spectroscopic Studies of Ruthenium Trichlorides ................. . ... 133

9.

Adsorption of No-Carrier-Added 119Sb(V) Ions onto Metal Oxide
Surfaces from Aqueous Solutions ............................... . ............. 135

Radiation Chemistry and Radiation Biology
1.

High-Density Excitation by Htavy Ions: Measurement of TrackDepth Resolved Emission Spectra ......................................... .. . 137

2.

Proton Irradiation Effects of Aliphatic Polymers ........ " ...................... 139

3.

Dosimetry with a Cellulose-Triacetate Film for Proton Irradiation ................ 141

4.

Position Detennination by Laser Marks of B. subtilis Spores Placedon a Plactic Track Detector and Inactivation of the Spores by aSingle Heavy Ion . ........................ . ................................. 143

5.

Mammalian Cell Inactivation and DNA Lesion Caused by Charged
Particle Beams ...................................... . ...................... 145

6.

Oncogenic Cell Transfonnation of Golden Hamster Embryo Cells
by Heavy Ions .............................. . . .. .......... ... .............. 147

Instrumentation

1.

Data Acquisition System at RIKEN Ring Cyclotron Facility ................... 149

2.

Cyclotron Calibration Test of Position Sensitive Detectors for Heavy
Cosmic Ray Telescope in Space .............................................. 152

3.

Design of an Isotope Separator On-Line System at RIKEN Ring
Cyclotron . . ... .. ........................................................... 155

4.

An Ion-Guide Technique for On-Line Isotope Separation Coupledwith a Gas-Filled Recoil Isotope Separator .................................... 158

5.

Counter Development for Rotating Catcher System ............................. 161

6.

Facilities for Studies on Nuclear Chemistry and Radiochemistry at
RIKEN Ring Cyclotron ..................................................... 163

7.

Further Study of Experimental Facilities for Light and LightHeavy Ion Induced Reactions ............................................... 164

Page

IV.

V.

8.

Ray-Tracing Calculation of the Variable-Angle Beam Rotator ................... 166

9.

Design of the RIKEN Projectile-Fragment Separator RIPS ..................... 168

10.

Design of a New Type of Low-Energy Radioisotope-Beam Channel"SLOW" for Surface Studies ................................................ 170

11.

Design of a Superconducting Secondary Beam Transport Systemwith a Large Solid Angle (SLQ) .............................................. 172

12.

Apparatus for Resonance Ionization Spectroscopy of Atomic
Nuclides ................................................................... 174

13.

Resonance Ionization Spectroscopy of Neutral Atoms by a Laser
Ablation Method ........................................................... 176

14.

Observation of Two-Step Photoionization of a Na Atomic Beam
Using cw and Pulsed Lasers ................................................. 178

15.

Development of the Parallel Plate Avalanche Counter for theTime-of-Flight Measurement ................................................. 180

16.

Pileup Rejecter for a Position-Sensitive Parallel-Plate Avalanche
Counter ...................................... .' .' ... ~ ...... , . . . . . . .. . . . . . . . . 183

NUCLEAR DATA
1.

Status Report of the Nuclear Data Group ..................................... 185

2.

Present Status of 63CU(p, n)63Z n and G5CU(p, n)65Z n Monitor
Reactions .................................................................. 186

3.

Present Status of a Monitor Reaction Al (p, x) 24Na ............................. 190

4.

On the Cross Sections for 77Br Production Reactions ............................ 191

5.

On the Cross Sections for 1271 (p, 5n) 123Xe ..................................... 195

DEVELOPMENT OF ACCELERATOR FACILITIES
1.

Status of RIKEN Ring Cyclotron Project in 1987 .................. '........... 196

2.

Field Stability of the Sector Magnets ........................................ 198

3.

Applications of CIM-DIM in the Beam Diagnostic System of
RIKEN Ring Cyclotron ..................................................... 201

4.

Improvement of RF Amplifier of RIKEN Ring Cyclotron ........ ~ .... " ........ 203

5.

Effects of Magnetic Fields on a Turbomolecular Pump of 5,000 l / s ............... 205

6.

Communication System for RIKEN Ring Cyclotron ............................ 207

7.

Injector AVF Cyclotron for RIKEN Ring Cyclotron ........................... 210

8.

ECR Ion Source for an Injector AVF Cyclotron ............................... 212

9.

RF Amplifier System of the Injector Cyclotron for RIKEN Ring
Cyclotron .................................................................. 214

10.

Production of Multicharged Heavy Ions by PIG Source of RILAC ............. 216

Page

VI.

11.

Developmerit of an LCE Ion-Source .................. .. ..... '.. : ..... ".......... 218

12.

6 GeV SOR Project

13.

Design of the Booster Synchrotron Lattice ... ; .. : .. ' ..... ~ ..................... 223

14.

Lattice Design for a 6 GeV Storage Ring .................... , ........ , ....... 225

15,

Chromaticity Correction in the Low-Emittance Chasm an-Green
Lattice , ................ , ........... , ........................ , ............. 228

16.

Design Stu.dyof the Magnets for a Storage Ring ... ,", .. ,", ....... , .... "., 230

17,

The .O verall Beam Flow ' of the 6 GeV SOR ................ , ....... , .. , ...... 233

18.

RF System for the 6 GeV SOR ................... '......... '. '................. 235

19.

Design of the RF Test Cavity for the 6 GeV SOR Ring .............. , .... ,.,' 237

20.

Vacuum Chamber for the 6 GeV Storage Ring " ...... : "' ...... " ... """ .. 239

21.

Pumping System for the 6 GeV SOR ....... , ... ,' ,' , .... , .. ,', ......... ,"'" 241

22.

Vacuum Test Device for Preliminary Experiments on the
6 GeV ,SOR , '.. , ,'.......... ,., .. , ... ,", ... ,'.,.,', ...... ,", ... ,., .. , .. " .. 243

23.

Synchrotron Radiation Power Distribution at the 6 GeV SOR " . . , ... , ... " .. ". 245

24,

Crotch Design for the 6 GeV SOR .,', ... ,',.,'.,., .. ,"' .......... . .... " .. 247

25.

Design of the Front End 'of the Beam Line at the KEK ' Photon
Factory .. ', ... , ...................................,., ...... ,., ........ . ... , .. 249

26.

Construction of a Multipole '¥iggler, BI3MPW, at KEK-PF ................... 252.... , .... , .......................................... , ... 220

RADIATION MONITORINGI,

Leakage-Radiation Measurements in the Cyclotron Building ..................... 254

2.

Routine Monitoring . of the Cyclotron, RILAC, and TANDETRON ............. , 256

3.

Radiation Monitoring at RIKEN Ring Cyclotron Facility ................ . ...... 258

VII.

LIST OF , PUBLICATIONS ...................' .. . ................... , .... . ........ 260

VIII.

LIST OF OUTSIDE USERS AND THEIR THEMES ............... , ....... . ...... 272

IX.

LIST OF SEMINARS ............ '...................... : ........................ 273

X,

LIST OF PERSONNEL
AUTHOR INDEX.......................... , .................. . . , .......... 275

1

I.

INTRODUCTION' H. Kainitsubo

During the past year the collaborative research
work using heavy-ion beams has been carried out
in the fields of atomic and nuclear physics, nuclear
and radiation chemistry, material engineering, andradiation biology at the Institute of Physical andChemical Research (RIKEN)." The main facilities
dedicated to the research work are a 160 em cyclotron,a variable-frequency heavy-ion linac (RILAC), a
1 MV electrostatic accelerator (Tandetron), and a
newly constructed separated sector cyclotron (RIKEN
Ring Cyclotron, RRC).
The first beam was extracted successfully from
RRC in December of 1986 and the inauguration washeld on January 23, 1987, under the attendance ofMinistry of State (Director of the Science andTechnology Agency). From April RRC has beenin routine operation, and test experiments on nuclear and atomic physics have been carried out. ' In
1987 we accelerated ions of 12C, 14N, 180, 4°Ar, and
65CU in the energy range of 20 to 44 MeV / u.
Currently, only one experimental hall was available
in this period. The construction of the second injector, an AVF cyclotron, and beam transport lines
to other experimental halls started this year.
RRC is open equally to outside users and thecollaboration with research groups of other institutions has been promoted in this period. International collaboration with IN2P3 of France, Academia
Sinica of China, and other foreign institutions werealso continued.
Studies on nuclear physics have been carried out
using RRC. In addition to the ' usual heavy-ion
experiments, new projects have started this year on
the measurements of high energy
rays and subthreshold pion production cross sections, reaction
cross sections by radio-active nuclei, and studies ofnuclei far from the stability line.
Theoretical studies of heavy-ion reactions andfission process were performed on the basis of transport calculations. Nuclear structure studies of largely
deformed nuclei were extensively performed, too.
Theoretical research on atomic collision processes
hav~ , been pursued in connection with various prob-rlems such as radiative electron capture at highenergy, ionization processes in collision of highly
stripped ions with atoms in gas and solid, and charge
exchange collisions on solid su#ace. Structure ofmuonie ~olecular ions was also studied theoretically.
Experimental studies were carried out on atomic
collision processes and on beam foil spectroscopy bymeasuring energy spectra of photons and Auger
electrons, charge state distributions of colliding ions,and angular distributions X rays 'and electrons aswell as scattered ions. Various kinds of ions accelerated at RILAC and RRC were used for thesestudies. ' The subnanosecond measurement of thelight emission along the heavy-ion trajectory ingaseous materials has been continued in this year.
Mossbauer spectroscopy and perturbed angularcorrelation techniques have been applied to thestudies on the properties of condensed matter andchemical processes on the surface of solid materials
in liquid, by using r rays emitted from Coulomb
excIted nuclei as well as from short-lived radioisotopes.
The analysis of the distributions of implanted ordisolved ' impurities in various materials has been
continued by using a Rutherford back-scattering
method, a Rutherford forward recoil detection
method, and a nuclear reaction method. The activation analysis of light-element impurities in highpurity materials was continued as before. PIXE
analysis was applied to the composition analysis of
medical, environmental, and geological samples.
The construction of exPerimental equipments anddevices has been continued. The design and fabrication of an on-line isotope separator (GARISIGISOL), a projectile fragment separator (RIPS),
a BAF 2 2rr spectrometer, a large scattering chamber,a ' large acceptance pion separator, and so on havebeen done in this period.
The R&D work on a high brilliance synchrotron
light source started this year and the design studyof a 6 GeV storage ring has pursued. The model
study of a RF cavity and the R&D work on a'vacuum chamber are in progress.

2

RIKEN Acce1. Prog. Rep. 21 (1987)

II. ,OPERATION OF ACCELERATORS
' :

,/

, J

1.

RIKEN Ring Cyclotron Oper~tion

Y. Yano, K. Hatanaka, M. Kase, A. Goto, H. Takebe, H. Nonaka, H. Isshiki,*
R. Abe,* S. Otsuka,· H. Akagi,· and T. Ishikawa*

The routine operation of RRC (RIKEN Ring
Cyclotron) began in April 1987. It has been madeevery other week: one week for the experiments andthe other for the maintenance and improvements.
April and May were devoted to the machine studies,and the beams were used to nuclear-physics andatomic-physics experiments since the end of May.
The extensive overhauls were done this winter(January-March) and summer (August-September).
Until the summer overhaul, RRC was operated witha harmonic number of 10 instead of 9 (normaloperation). The use of this harmonic number came froma five-resonator operation of RILAC. The RF amplifier of its last (sixth) resonator was disassembled
for the improvements. Since October, RILAC worked
with six acceleration tanks, and accordingly RRC
with normal harmonic number.
The following machine studies were performed tofacilitate the operation of RRC and its beam transfer
line: (1) automatic measurement of a charge-state
distribution, (2) automatic beam alignment on the
beam line, (3) optimization of the voltage and thephase of the RF buncher, (4) phase-setting optimization of the RF systerp, (5) beam injection and extraction procedures, (6) isochronization of sector fields,(7) transverse phase-space matching of RILAC beamwith RRC acceptance, and (8) well-centered orbit
acceleration ..- These items were successfully achievedby using our sophisticated computer control systemand beam diagnostic system. Our original methodwith three long-stroke -radial differential probes
creates well-centered orbits inside RRC. In the
beam-service runs, however, this operation is not performed, but off-centering acceleration is made tosave the beam preparation time and to expand theturn separation in the extraction region as shown in
Fig. 1. In this way, the single-turn extraction isestablished.
In this-year runs, five kinds of Ion species were

* Sumijyu Accelerator service. Ltd.

used for experiments. The main characteristics ofthese beams are summarized in Table 1. A great
number of improvements have been made .in addition to above machine-operation techniques to startup the machine quickly, to keep the stable beam
for a long time, and to provide high-quality beams
for the users. It takes approximately a half day toprepare a beam. High-quality beams with transverse~mmittances less than 31r nun ' mrad, the energy resolution less than 0.1 % and the time resolution lessthan 500 ps were used for experiments.

3000

31 00

3200

3300

3400

3500

Fig. 1. Tum pattern measured with a radial differential
probe in case of off-centering acceleration. Bottom figures
represent radial distances from the machine center (mmin units) .
Table 1. Characteristics of RRC beams in April-December.
1987.
~OAr

RF frequency

MHz

RILAC
Charge state
Beam energy MeV/u
Num. of tanks

28

28

l~.lSN

6SCu

180

35

25

35

5+
4+
3+
4+
1.28 1.58 2.00 1.01
5
6
5
5

RRC
6+
12+ 13+Charge state
R.F harmonic number 10910Beam energy MeV/u 21.0 26.0 33.7
IntensityenA
200 600 200(typical)

18+
10
16.7
10

4+
2.48
6
7+
9

42.0
20

3
RI;KEN ,,~cceL Prog. Rep. 21 ~1987)" I. ,.

11-2. ,RILAC Qperation. f, ",'.

Y. Miyazawa, M. Hemmi, T. Inoue, M. ya~~kura, · M: Kase,
E. Ikezawa, T. Aihara,* T. Ohki,* H. Hasebe,* and Y. Chiba

RILAC continues to supply various kinds of ion
beams for many fields of research. Total beam time
was reduced compared with the last year operation
because of long-term shutdown to improve the RF
oscillator and cooling system. Three days of thescheduled beam time were cancelled owing to accident
in the RF cavities. A percentage of the beam timefor RRC was about 42 0/0; ions, UN, 15N, 180, 4°Ar,
and 65CU accelerated by RILAC were injected to
RRC. Most of the users preferred Ar ions, and 75%of the total beam time was devoted to this ion.
The RILAC RF cavities had accident three times
in this period with silver strips of 0.2 mm in thickness, which were inserted to make good RF -contact
along a seam between the base block, supporting
drift-tube, and the top of inner conductor of a
coaxial resonator. Partially insufficient contact pressure caused RF -heating and protruding out of theposition of the strips. The damaged contact strips
in the cavities No.5 and No.6 were replaced withberyllium copper strips. A quadrupole doublet set
in the injection beam line had an electric disconnection in its tape coil terminal; it was replaced.
Several improvements were put into six rf-powersources of RILAC. The virtual value of a grid
damping registor of the final amplifier was reduced
to improve its stability in the high operating frequency region. Their alteration consequently required
an additional driving power, which was achieved bymodifying coupling elements between the final (vacuum tube RCA 4648) and the driving (EIMAC
3CX3000A7) stages and by providing a new plate

Table 2.

Percentage of beam time for research activities.
Days%

Atomic physics
36
Solid-state physics
15
Nuclear physics
1
Radiochemistry and nuclear chemistry
17
Radiation chemistry and radiation biology 8
Accelerator research
11
Beam transportation to RIKEN Ring
63
Cyclotron

23.8

Total

Table 3.

9.9

0.7
11.3

5.3
7.3
41.7
100

lSI

Statistics of ion used in this period.

SymbolMass

Charge state

C
N
N
0
Ne
Si
Ar
Cu
Mo
Xe

12
14
15
18
20
28
40
65
92
132

2
2

Days

2
10
3

3

4
2
3
4
4
7
9

6
9
113
4
2

Beam
signalI PulsesignalTable 1. Statistics of operation for the period of Jan. IDee. 31, 1987.

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

* Sumijyu Accelerator Service, Ltd.

Days

%

lSI

6
77
24
3
104

41.4
1.6
21.1
6.6
0.8
28.5

365

100

~-f.J.-S--1
Fig. 1. A pulsed beam obtained by a repetition frequencyof 5 kHz. Beam width is 100 /lS.

power supply of 10kW for the driving stage. A
newly developed screen grid bypass capacitor of the
final tube, having compact size but large capacitance(11 nF) , replaced old one and contributed to stabilityof the amplifier also. Two-phase lock circuits tosuppress fluctuation in phase of the accelerating

4

Y. Miyazawa, et al.

voltages were set for No.1 and No.2 resonators. The
beam extracted from RILAC became stable by thisimprovement.
The main cooling tower operating for ten years
was replaced with a new one. All water pumps andheat exchangers are overhauled this summer.

A beam chopper was instaUed at the injection beamline between bending magnets BM1 and BM2. This
device has a rising time of beam pulsing of 10 fl-s
and varies its pulse width from 20 fl-S to continuation. Figure 1 shows a pulsed beam obtained bythis device at a repetitio.n frequency of 5 kHz.

5
RIKEN Accel. Prog. Rep. 21 (1987)

11-3. Cyclotron Operation ·1. Kohno, K. Ogiwara, T. Kageyama, s. Kohara,
S. Fujita, K. Ikegami, and H.Takebe

The 160 cm cyclotron was operated on the 24 h a
day basis during the period XXII from Jan. 1, 1987
to Dec. 31, 1987. The statistics of the machine operation time is shown in Table 1. The total net beamtime in this period decreased compared with that of
the last period because of a long scheduled shutdown.
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 XXII.
Oscillator

Ion source

BeamReading of the time
meter on93,985.8 ..
Jan. 06 1987 (h)99,050.2

59,334. 9

Reading of the time
meter on95,270.1
Jan. 06 1988 (h)100,416.4

59,837.6

1,366.2

502.7

Difference (h)1,284.3

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

111 d
30
28
183
13

Table 2. Scheduled beam-time and research SUbjects
in the period ' XXII.
Subject
RI production
for nuclear physics
Nuclear chemistry
Radiation biology
Radiation chemistry
Radiation damageof polymer
Radiation damageof semiconductor
Test of radiation detector

Heavy ion Light ion

Total

Oh
0
50
482

35 h
222
62
45

35h
222
112
527

0

68

68

0
120

7
54

7
174

0

89

89

0
85

77
0

77
85

Outside users
Radiochemical analyses
Radiation damageof device for satte1ite
Test of single event upset
Proton irradiationon thyristor
Total
Percentage in total

0

86

86

737 h
49.7%

745h
50.3%

1,482 h100%

Table 3. Distribution of beam-time among particles
accelerated.
Particle

(h)

(%)

p
d
3He2+
'He2+

452
0
89
204
12
651
50
24

30.5
0
6.0
13.8
0.8
43.8
3.4
1.6

12CH
l'NH
l~N~+

2°Ne6 +
Total

1,482

6
RIKEN Accel. Prog. Rep. 21 (1987)

11-4. 'TANDETRON-Operation
T. Kobayashi~ H. Sakairi, E. Yagi, and T. ,Urai

The machine was operated for 182 days for one
year from November, 1986. The :species of accelerated
ions were lH, aHe, 4He, and llB.
The exchanger, developed last year, of ion charge
fr~m positive , to negative with lithium vapor, hasbeen operating satisfactorily. The outline of this exchanger is described under another item of thisreport ' (p. 218).
No serious trouble occurred in the last period, but
a time-worn ~ :thultichannel pulse-height analyzer was
replaced with new one controlled by a p~rsonal
computer.
Experimental studies were carried out on following subjects:(a) State of hydrogen in metals (Metal Phys. Lab.
and Beam Analysis Center) ;(b) Behavior of solid krypton in aluminum (Cyclotron Lab. and Metal Phys. Lab.); " ,(c) Solubility of D in.si (Nuclear Chern. Lab.) ;(d) Lattice location of E u in CaF 2 ,( Semiconductors Lab. and Beam Analysis Center) ;( e) Characterization of epitaxial Ge on Si surface(Cyclotron Lab. and Metal Phys. Lab.);(f) Lattice disorder , and behavior of implanted
impurities in ceramics (Metal Phys. Lab.) ;(g) Evaluation of crystalinity of ceramics (Friction and Lubrication Lab. and Beam Analysis
Center) ;(h)' Composition of AINz
(Beam Analysis
Center) ;(i) Surface composition of Ar-implanted Kapton(Beam Analysis Center) ; and ,(j) Basic , study of PIXE and its application to
medical, environmental, and archeological materials'(Solid State Chem. Lab;). '1
RIKEN Aced. Prog. Rep. 21 (1987)

III.

RESEARC" lACTIVITIES

1. Nuclear Physics
1. The Intruder Deformed Band in ,lllSn
H. Harada, T. Murakami, K. Yoshida, J. Kasagi, T. Kubo, and T. Inamuraj

NUCLEAR REACTION 98Mo(160, 3n) l11Sn, E= 76 MeV ;[ measured r-r coincidence, deduced levels.
.
Spherical-deformed shape coexistence in Sn isotopes has been recognized since Bron et al. havediscovered intruder bands in 112-118Sn .l) However, no
experimental evidence for existence of the intruder
bands in odd-mass Sn isotopes has been shown,mainly because the states investigated so far were
only low-spin states. An investigation of the intruder
bands in odd-mass Sn isotopes is desirable to examine
a quasiparticle-core coupling scheme, which has been
pointed out to be sensitive to the nature of the core. 2 )The high spin states of 111Sn were excited by the98Mo(160, 3n) l1~Sn re~ction with a beam energy of
76 MeV. The 'target used · was a 98 % enriched 98Mo
foil, 0.95 mg/cm2 in thickness, and backed with athin lead layer. Five sets of BGOACS were used for~, ------~---~
Js..L:l--J--- -

-

-

+

"",,",--_7.J-8_ _ _ _ _ _ _ _ 3SI2-t.4><--J-_ _ _ _ _ _ _ _--_.r.>jL..<.....L-.--_

~
922

1257

a' r,

1084

!,!

1112-4978 keY

112Sn
Fig. 1. Level scheme of l11Sn of the present study. Inclusionof 112Sn (from Ref. 3), is done for comparison as discussed
in the text. Note that th~' /2-, state in l11Sn is set at thesame level as the 0+ state in 112Sn.

.u

r-r coincidence measurements. Experimental details
were reported in Ref. 3.
The level scheme obtained in the present work isshown in Fig. 1, together with the relevant levelsof 112Sn (Ref. 3). The spin assignments are basedon the r-r angular correlations. All transitions shown
are of quadrupole character. As can be seen from
Fig. 1, a distinct band structure is observed for the
first time above the 23/2- state. The band c'a n be
understood as originating from the coupling of theh l l / 2 neutron to the deformed even core.
Transition energy ratio
E r(27/2- - 23/2-; ll1Sn)/ Er(8+- 6+; 112Sn) = 1.21
is obtained. The theoretical value for this ratio is
1.0 for a rotation aligned coupling scheme and 1. 73
for a strong coupling scheme. Thus, the present result favors the rotation aligned coupling rather than
the strong coupling. The present value is also close
to the results 2 , 4 ) for Xe isotopes;
E r(27/2- - 23/2-; l17Xe)/ Er(8+ - 6+; 116Xe) = 1.21
andE r (27/2- - 23/2-; 117Xe)/Er(8+ - 6+; 118Xe) = 1.21.
This striking accordance on the energy ratio gives
an another evidence for the similarity (Ref. 5) between the intruder bands in Sn isotopes and the g.s.'bands in Xe isotopes.
References
1) J. Bron, W. H. A. Hesselink, A. van Poelgeest, J. J. A.
Zalmsrta, M. J. Uitzinger, H. Verheul, K. Heyde, M ~vVaroquier, H. Vincx, and P. van !sacker: Nucl. Phys.
A, 318, 335 (1979).
2) P. Chowdhury, U. Garg, T. P. Sjoreen, and D. B. Fossan:
Phys. Rev. C, 23, 733 (1981) .
3) H. Harada, T. Murakami, H. Tachibanaki, K. Yoshida,
J. Kasagi, T. Kubo, and T. Inamura: RIKEN Accel.
Prog. Rep., 19, 18 (1985).
4) V. P. Janzen, J. A. Cameron, A. J. Larabee, D. Rajnauth,and J. C. Waddington: McMaster Ace. Lab. Annu. Rep.,
p. 54 (1984) .
5) H . Harada, T. Murakami, K. Yoshida, J . Kasagi, T.
Kubo. and T. Inamura: Phys. Lett. (in press) .

8
RIKEN Accel. Prog. Rep. 21 (1987)

High Energy r-Rays Observed in the 181Ta+40Ar ·Reaction at 21 MeV/Nucleon

111-1-2.

K. Yoshida, H. Hama, H. Harada, H. Takeuchi, M. Sakurai,
J. Kasagi, K. Ieki, T. Kilbo, and M. Ishiharal

NUCLEAR REACTION 181Ta+ 4°Ar, 21 Mev/nucleOn;)·
measured r-ray spectrum, statistical model calculation.

Recently, high energy r-rays with energies up to
100 MeV have been observed in heavy-ion collisions
at bombarding energies above 20 MeV/nucleon. The
reported r-ray spectra exhibit following features:
ray yields fall exponentially with energies for Er <10 MeV and Er > 30 MeV and the yields enhance inthe region between 10 MeV and 30 MeV. It is suggested the high energy (E r >30 MeV) exponentiallyfalling component arises from the nucleon-nucleon or
nucleus-nucleus bremsstrahlung emitted at an earlyrays below 30 MeVstage of the collision. 1, 2 ) The
have been described as the statistical GDR decay ofhighly excited reaction residues. In order to study
rays, we measured inclusive r-ray spectrum
thesein 181Ta+ 4°Ar reaction at 21 MeV/nucleon.
The experiment was performed at RIKEN Ring
Cyclotron. A foil of 181T a, 12 mg/cm 2 in thickness,
was bombarded with 4°Ar beams of 21 MeV/nucleon.
The high energy r-rays were detected with a large
BaF 2 detector, which consists of seven opticallyisolated elements(hexagonal, diameter = 7 cm,
length = 20 cm). The detector was positioned at
15 cm from the target and at 90 with respect to thebeam axis. Cosmic rays were rejected by the information of the ratio of the energy deposit between
in the center element and in total. Gamma rays,
light charged particles, and neutrons were identified
by pulse-shape analysis 3 ) and time of flight withrespect to the RF signal of the cyclotron. The detector response was calculated using a M onte Carlosimulation code. 4 )Observed r-ray spectrum is shown in Fig. 1. For
Er ~ 30 MeV the spectrum can be fitted by an expo~ential function exp ( - Er / Eo) ~ The deduced
slope parameter Eo = 7.0 ± 1.1 MeV is somewhat smaller than the systematics for bremsstrahlung spectra
obtained from reactions at higher energies. On theother hand, the obtained cross section 670+200 pb
for E r >30 MeV is rather large.
For the energies below 30 MeV, we attempt todescribe the spectrum as the statistical decay ofhighly excited residues dominated by the giant-dipoleresonance strength function. The
rays from pro-r->~:::t. 10 2

c: 10
W

-,j

N'b 10 °
-,j

10-1

r

r

0

r

1

-,j

10

20

30

40

50

Er (Me V)

Fig. 1. r-Ray spectrum observed for the reaction 181Ta +40Ar
at 21 MeV/ nucleon . The smooth line indicates statisticalmodel calculation added a bremsstrahlung component.
The dotted line indicates a bremsstrahlung component.

jectile-like fragments, target-like fragments, andfusion-fission fragments contribute to these r rays.
In calculation, only the r rays from fusion-fission
fragments were considered. The statistical model
calculation using the code CASCADE was performed,
and the results were folded by detector response tocompare with the experimental spectrum. The excitation energies of the fission fragments (--170 MeV)
are estimated by using the Viola systematics. 5 ) A
Lorentzian shape was assumed as the GDR strength
function. The experimental spectrum was reproducedwith the resonance energy EG = 13 MeV, width r G =15 MeV, and 100 % sum rule strength. The resonanceenergy was rather small compared with the groundstate systematics. To characterize these r rays, measurements in coincidence with reaction residues are
now in progress.
References
1) E. Grosse et al.: Europhys. Lett., 2, 9 (1986).
2) J. Stevenson et al.: Phys. Rev. Lett., 57, 555 (1986).
3) T. Murakami et al.: Nucl . Instrum. Methods A, 235, 163(1986) .
4) T . Tachibanaki, T. Murakami, and J. Kasagi: RIKEN
Accel. Prog. Rep., 19, 156 (1985).
5) V. E., Viola, K. Kwiatkowski, and M. Walker: Phys. Rev.
C, 31 , 1550 (1985).
'

9

RIKEN Accel. Prog. Rep. 21 (1987)

111-1-3. Angular Distribution of Fission Fragments Coincident
with Projectile Fragments
K. Ieki, Y. Ando, H. Fujiwara, M. Ishihara, N. Iwasa, S. C. Jeong,
S. M. Lee, T. Motobayashi, T. Mizota, H. Murakami, T. Murayama, Y. Nagashima,
M. Ogiwara, S. Okumura, Y. H. Pu, Jian-zhi Ruan (Gen) , S. Shibuya, and S. Shirato

NUCLEAR REACTION 209Bi+ 40Ar, E(40Ar) /A=26MeV/u; Jmeasured fission fragment angular distribution, projectile frag[ mentation, angular momentum transfer, spin alignment.

For studies of heavy-ion reaction mechanisms,
measurements of transferred angular momenta to theresidual nuclei and their spin alignment have given
important information. So far little is known about
the angular momentum transfer for intermediate
energy heavy-ion reactions. Therefore, we studied
the angular momentum transfer and the spin alignment by measuring angular distribution of fission
fragments coincident with projectile fragments forthe 209Bi + 40Ar reaction at E / A = 26 MeV / u. Thismethod has been successfully applied for the studiesof lower energy heavy-ion reactions. 1 ,2)A self-supporting 209Bi foil of about 1 mg/cm 2in thickness was bombarded with a 4°Ar beam fromRIKEN Ring Cyclotron. Projectile fragments weredetected with two sets of counter telescopes locatedat 12° from the beam axis and at 40 cm from thetarget as shown in Fig. 1. The telescopes consist of
45 mmX45mm Si LlE(300 /tm)-E(2mm)-E(2mm)detectors. With these signals, particle identification(PI) was performed using a simple formula. 3 ) A
sample PI spectrum is shown in Fig. 2. At this detection angle, a particles are mainly observed, and theyields for other particles become smaller as theparticle mass increases. Coincident fission fragments
were detected with 9 thin (30 or 50 /tm) Si detectors located at 10 cm from the target on the opposite
side of the beam to the telescopes. The detection

fission counterstargetPLF
telescopes
Fig. 1.

Schematic view of the detector system.

500

1000
1500
Channe 1 Number

2000

Fig. 2. Sample particle identification spectrum measured
with the telescopes.

angles are r./>= -70°, -105°, -125°, -145°,-165° for inplane measurements and {I = 0°, 15°,45 0 , 60°, r./> = - 70° for out of plane measurements,
where () and if> denote polar and azimuthal angles,
respectively. The z axis and the x axis are definedby the reaction plane normal and the beam axis,
respectively.
Typical fission-fragment spectra coincident with aparticles in the laboratory frame are displayed inFig. 3. The out of plane spectra (left-hand side)
show a decrease in yield towards small polar angles.
This large asymmetry of out-of-plane angular distribution suggests large angular momentum transfer
and large spin alignment with respect to the reaction
plane normal. The inplane spectra (right-hand side)
show small variation in the yield. The spectra, however, differ from each other in shape, i.e., the peak
position moves as the detection angle changes.
Assuming that fission-fragment energy spectra are thesame in the rest frame of the fissile nucleus, we canestimate the momenta of the fissile nuclei, the direction of which is found to be about -44° from thebeam axis. On the other hand, the recoil angle ofthe fissile nucleus in the a particles obtained from

10

K. Ieki, et ai.

out of plane

inplanethe 2-body kinematics is much smaller. With these
two facts combined, we can suppose that large missing momentum Pm exists in this reaction. Evaluating
Pm from the momenta of the beam, a particle andfissile nucleus (A""""200), we found that the directionof Pm (¢-6°) is near the grazing angle and thesize of Pm corresponds to the projectile-like fragments(A """"32) emission at the beam velocity. Thus theobserved large angular momentum transfer andthe large spin alignment can be explained byperipheral collisions accompanied by sequential decaysof the projectile-like fragments. Further analyses are
now in progress.
References
1) P. Dyer, R. J. Puigh, R. Vandenbosch, T. D. Thomas,
M. S. Zisman, and L. Nunnelley: Nucl. Phys., A322,
205 (1979).
2) H. Utsunomiya, T. Nomura, M. Ishihara, T. Sugitate,
K. Ieki, and S. Kohmoto: Phys. Lett. B, 105, 135 (1981) .
3) T. Nomura: [PCR Cyclotron Prog. Rep., 11, 81 (1977).

Fig. 3. Typical fission-fragment spectra coincident with aparticles in the laboratory frame. On the left-hand side
are shown the out-of-plane spectra with polar angles denoted; the azimuthal angle for them is 70°. The imp lane
spectra are shown on the right-hand side with azimuthal
angles denoted.

11
RIKEN' Aceel. Prog. Rep. 21 (1987)

111-1-4.

Spin Alignment in Projectile Fragmentation at
Intermediate Energies

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

NUCLEAR REACTION 180+9Be, E(180) IA=60 MeV/u;,B-delayed r rays from 14B, measured W r (()); deduced spin
[ alignment of 14B products, compared with theory.

Recent progress in studies of nuclei far fromstability, prompted by the advent of intermediateenergy heavy-ion accelerators, has proven that projectile fragmentation is a powerful tool for isotope
production. The effectiveness of this method motivates further interest in whether these product nuclei
are spin-oriented or not. In fact, more detailed
spectroscopic investigations become possible if spinoriented nuclei are available by this method. The
measurement of the spin orientation in projectile
fragmentation is also interesting, providing uniqueinformation on the reaction mechanisms. We thus
performed a measurement of the spin alignment ofprojectile fragments using a LISE spectrometer at
GANIL. Earlier part of this study has .been reported.1)

1

The spin alignment of 14B nuclei produced in a
J80+9Be reaction at E( 18 0) IA =60 MeV lu wasmeasured. The experimental setup is shown in Fig. 1.
The spectrometer LISE was used for the isotope
separation of the reaction products. A wedge-shaped
energy degrader for a momentum-loss technique 2 )was installed in the momentum-dispersive focal 'p lane
between the two dipole magnets of LISE. Produced
14B was collected in a stopper foil (Pt) pla~ed at
the achromatic focal point. The static magnetic
field Bo = 310 mT parallel to the two dipole fields of
LISE was applied to the stopper. r Rays emitted
after ,B decay of 14B were detected with two NaI (TI)
detectors placed at 0° and 90° to the direction of
Bo. The ratio R = N r (0°) INr (90° ) of the r ray
yields was measured both with Bo on (i.e." with thepr:::/~;::~target

r.y

Dl

I.

I

~

DegraderD2~, 'I \I F.P.

'-_/

* Grand Accelerateur National d'Ions Lourds (GANIL),** Institut de Physique Nudeaire, Orsay, France.
*** Physikalisehes Institut, UniversWit Gottingen, Gottingen, Fed. Rep. of Germany.

) / \y(900)~\

stopper (Pt)

Fig. 1. Experimental setup.

Caen, France.

y-counters

0

~11))
BO

~,
LISE

. 8
1'(0

K. Asahi, et al.

12alignment preserved) and off (with the alignment
destroyed) .
The spin alignment A produced by the reactionin the beam axis is expressed in terms of the population probability am for the magnetic sublevel m as
A = (2a+2 - a+1 - 2ao- a_1 +2a_2)/2

As a result of the spin precession in the dipole fields
I

~

+10

180 (60 MeV/u) + gBe

c

<L>

E

-I-

14B + X

-

I

+-'

c

I

I

0

~

Ol

.......

........
c:(

-10
I
I

I
I

~I
I
I
I

--...

-

+-' 1000.......
C:::J

IIp(target)

-

..Cl
L-

a

-

500
""0

........
<l>.......
>-

2.8

·3.0

Bp

3.2

n'm)

Fig. 2. Result for spin alignment A of HB produced in thereaction 180 (60 MeV lu) +9Be; the observed momentum distribution for HB is also shown. Value of A shown is theone averaged over the momentum bin which is indicatedby horizontal bars.

of LISE and in Eo, a new alignment A'= - (lj2)A
in the axis parallel to Eo is established3 ) after ashort period of time characterized by the transverse
spin relaxation time. Thus the initial alignment A
was deduced from the change in R between the two
conditions throughA=( -8/3)(RoN/ ROFF-I)

where ON and OFF refer to the measurement with
Eo on and off, respectively.
In Fig. 2 the result for the spin alignment isshown together with the momentum distribution
measured for the 14B particles. An interesting feature was observed: The alignment A is small in the
momentum region corresponding to the peak in theyield, whereas A takes a large negative value forthe high-momentum tail. The observed momentum
variation in the alignment seems to agree with theprediction from a simple model of projectile fragmentation. 4 )References
1) K. Asahi, M. Ishihara, T. Ichihara, Y. Gono, A. C.
Mueller, R. Anne, D. Bazin, D. Guillemaud-MuelIer,
R. Bimbot, W. D. Schmidt-Ott, and J. Kasagi: RIKEN
Accel. Prog. Rep., 20, 19 (1986) .
2) D. Guillemaud-Mueller, R. Anne, D. Bazin, C. Detraz,
J. Galin, D. Guerreau, A. C. Mueller, E. Roeckl, M. G.
Saint-Laurent, M. Bernas, V. Borrel, J. C. Jacmart, M.
Langevin, F. Naulin, F. Pougheon, and E. Quiniou:
Proc. 5th Int. Conf. Nuclei Far from Stability (Rosseau
Lake, Canada, 1987), p.757.
3) H. Morinaga and T. Yamazaki: In-Beam Gamma-Ray
Spectroscopy, North-Holland, Amsterdam, Chap. 9(1976) .
4) K. Asahi and M. Ishihara: RIKEN Accel. Prog. Rep.,
20, 21 (1986).

13
RIKEN Accel. Prog. Rep. 21 (1987)

111-1-5. Tensor Analyzing Powers of (d,2He) Reactions on lH and 12C
T. Motobayashi, M. Ishihara, H. Murakami, S. Satoh,* H. Sakai,** N. Matsuoka,**
T. Saito,** T. Noro,** K. Hosono,** A. Okihana,*** H. Okamura,**** and S. Hatori****NUCLEAR REACTIONS 1H, 12C(polarized d, 2He), E= 70 MeV;
[ measured Ayy ( 0) PWIA and DWBA analysis.

The (d, 2He) reaction, where 2He denotes the two
proton system in the relative S-state, is useful instudying spin-isospin excitation of nuclei. The importance of the measurements with a tensor polarized
deuteron has been recently stressed by Wilkin and
Bugg. 1) We measured the tensor analyzing power
Ayy for the targets of 1H and 12C using 70 MeV tensor
polarized deuterons provided by the cyclotron of the
Research Center for Nuclear Physics, Osaka University. Outgoing 2He particles were detected by a silicon
telescope array2) or a magnetic spectrograph
DUMAS,a) the letter of which was used only forthe measurements at forward angles. The results
are shown in Figs. 1 and 2.
For the 1H(d,2He)n reaction the PWIA (Plane
Wave Impulse Approximation) calculations were
performed. The solid and dot-dashed curves in Fig.
1 represent the results using the N-N amplitudes of
the Arndt's phase shift solution4 ) with and without
the D-state component of the deuteron wave function, respectively. The dashed curve shows the PWIA
prediction including the deuteron D-state with the
N-N amplitudes calculated from the Paris potential. 5 )

· 30

60

Fig. 1. Angular distribution of the tensor analyzing power
Ayy of the IH (d, 2He) reaction at E d =70 MeV. The solidand dashed curves show the PWIA predictions with Arndt's
phase shift solution and the Paris potential, respectively.
The result without including the deuteron D-state is shownby the dot-dashed curve.

* Department of Physics, Rikkyo University.

** Research Center for Nuclear Physics, Osaka University.
*** Kyoto University of Education.
**** Department of Physics, Kyoto University.

Ayy

1

12C(d,2He)12S

Ed =70MeV

0.5

o
-0.5
"--"--"-0-0.5

Ex =4.4MeVo----.-( f t~ +-0.5 . //~,,~,______ -- 2-

'.

"1-

-1

o

20

40

8cM

60

Fig. 2.

Angular distributions of the tensor analyzing power
for the (d,2He) reaction on 12C. The results of thefirst- and second-order DWBA calculations are shown by
the dashed and solid curves, respectively. For the .Jl=1transition to the 2- state of 12B, the DWBA predictions
assuming different spin values of 1- and 0- are also shownby the dot-dashed and double dot-dashed curves, respectively.

Ayy

At forward angles, the calculations, especially thatwith the Paris potential, reproduce the tendency ofthe experimental data. This is inconsistent with thediscrepancy between experimental data and PWIA
predictions reported for the KHOO) of the 2H(p, n)2He reaction in the same energy range. 6 ) At backward angles the PWIA predictions deviate far fromthe data, suggesting the important contribution of amultiple scattering process in the high momentum
transfer region.
The curves in Fig. 2 show the results of the oneand two-step DWBA (Distorted Wave Born Approximation) analysis for the 12C (d, 2He) 12B reaction. The
parameters used in the calculation are taken to be
the same as those described in Ref. 7. The fits tothe data for the ground state transition are good andthe two-step effect is not so large as for the crosssection.7) For the ill = 1 transition to the 2- excitedstate of 12B, the fits are poor, but the theoretical

14

T. Motobayashi, et al.

curve is closer to the data than the ones for theL1l = 1 transitions to the different spin states, 0and 1-.
References
1) C. Wilkin and D. V. Bugg: Phys. Lett. B, 154,243 (1986) .
2) T. Motobayashi, S. Satoh, H. Murakami, H. Sakai, and
M. Ishihara: RIKEN Accel. Prog. Rep., 20, 125 (1986) .
3) T. Noro, T. Takayama, H. Ikegami, M. Nakamura, H.
Sakaguchi, H. Sakamoto, H. Ogata, M. Yosoi, T. Ichihara, N. Isshiki, M. Ieiri, Y. Takeuchi, H. Togawa, T.
Tsutsumi, and S. Kobayashi: J. Phys. Soc. lpn., 55, Suppl.,
470 (1986) .
4) R. A. Arndt and L. D. Roper: Scattering analysis interac-

tive dial-in (SAID) program, Phase shift solution SP86,
Verginia Polytechnic Institute and State University (unpublished) .
, 5) M. Lacomb, B. Loiseau, J. M. Richard, R. V. Mau, J.
Cote, P. Pires, and R. de Joureil: Phys. Rev. C, 21, 861(1980) .
6) H. Sakai, N. Matsuoka, T. Saito, A. Shimizu, M. Tosaki,
M. Ieiri, K. Imai, A. Sakaguchi, and T. Motobayashi:
Phys; Lett. B, 177, 155 (1986).
7) T. Motobayashi, M. Ishihara, H. Sakai, N. Matsuoka, K.
Hosono, T. Saito, A. Okihana, S. Shimoura, and A. Sakaguchi: RIKEN Accel. Prog. Rep., 20, 29 (1986) ; T. Motobayashi, H. Sakai, N. Matsuoka, T. Saito, K. Hosono, A.
Okihana, M. Ishihara, S. Shimoura, and A. Sakaguchi:
Phys. Rev. C, 34, 2365 (1986).

15
RIKEN AcceI. Prog. Rep. 21 (1987)

111-1-6. Rotational Perturbation to the Natural Parity Rotational
Band of 163Dy
T. Inamuta, A. Hashizume, M. Oshima, * E. Minehara, * S. Kikuchi, *M. Matsuzaki, ** and H. Kusakari

NUCLEAR STRUCTURE 163Dy, energy levels, reduced transition[ probabilities, signature dependence, rotating shell model.

As we reported previously,!) there is quite a strong
signature dependent staggering of B(Ml) values in
163Dy. This is an unexpected result because theground-state rotational band of 163Dy is based on theneutron 5/2[523] Nilsson orbital whose main components are low spin orbitals such as h9/2 or f7/2 andits energy levels show no signature dependence.
The rotational perturbation effect which causes
signature dependent level energies and transition
moments has been well established theoretically andexperimentally for the case of high spin orbitals suchas i13/2.2-5) This is because the Coriolis force strongly
acts on high spin orbitals. However, no model calculations have ever suggested that there might besignature dependence in the nuclear structure of
deformed nuclei with low spin orbitals. A newtheoretical framework is needed to study such a
nucleus as 163Dy in question.
A rotating shell model with the r degrees of freedom6) seems to provide such a new framework.
According to this model, we have calculated reduced
transition probabilities and level energies. It turns
out that one can neglect a static r deformation,leaving the effect of a dynamical r deformation (rvibrations) significant; the static r deformation isvery small, being restricted to the region such that

20'

-IN

-0:>

r

r

* Tokai Research Establishment, Japan Atomic Energy
Research Institute.
** Department of Physics, Kyoto University.

o
0.05

0.10

0.15

0.20

0.25

1iWrOf { MeV I

Fig. 1. Quasineutron energy splitting e- 1/2-e,+1/2 plotted asa function of the rotational frequency nCl)rot. The boldline denotes the experimental data. The solid line denotes
the calculation with the r vibrations, and the dotted one
the calculation without the r degrees of freedom.

and the calculation has significantly been improved bytaking the r vibrations into account. (Note that thequasineutron energy splitting, for instance in 167Er,
which is a typical nucleus with a high j orbital (i13/2)'
are about ten times larger than that in 163Dy.) It
should also be pointed out that the improvement
has been made without causing signature dependence
in level energies, i.e., quasiparticle energy splitting.
Figure 2 shows the signature dependence of the
reduced Ml transition probabilities B(Ml) as a00<r<5°.
Figure 1 shows quasineutron energy splitting e'-1/2e'+1/2 as a function of the rotational frequency nWrot,
where e' a are quasineutron energies for the stateswith the signature a = + 1/2. (The plot starts at the
2nd excited state 9/2- at 167.3 keV.) Experimental
splitting is shown by a bold line; and the splitting
calculated with thevibrations are shown by asolid line, and the one without thedegrees of
freedom by a dotted line. Although there seems to
be a room to study further for higher rotationalfrequencies, the agreement between the experimental

1x16,3---'~---r------.---.----...,...,
6

~

4

!
I-.

I

t
2

o 0.05

1\

',,/\
'-\

I

/'

1\
\

\v/

I

\,'
y

,\
\

\
\

I !
0.10

0.15

0.20

0.25

llwrot {MeV}
Fig. 2. B (MI; I~I -I) values for the ground-state rotationalband of 163Dy. The solid and dotted lines are the sameas in Fig. 1.

16

T. Inamura, et al.

function of the rotational frequency nWrot. It isclearly seen that the signature dependent staggering
is well reproduced in the present calculation. The
calculation is a kind of cranked shell-model calculation. In general, the cranked shell model gets worsein the region of low rotational frequencies. Thistendency appears in the present calculation, but thisdoes not matter in the present study of signaturedependence since only higher rotational frequencies
concern the present study.
At present, it is hard to single out which is themain component, h9/2 or f7/2' but the h9/2 orbital
should be predominant in the 5/2[523] Nilsson orbitalat the deformation parameter ,B = 0.285 ;7) the ,Bvalue was estimated from the E2 transition probabilities between low spin members of the ground-state
rotational band of 163Dy. If the simple rule forsignature dependence is applied to this case,6) thephase of the staggering is different from the observed
one: The experimental data appear as if the main
component were the f7/2 orbital. The signaturedependent staggering has nothing to do with the rdegrees of freedom; but the absolute values of B (M 1 )do have.
In the case of natural parity orbitals such as f7/2
or h9/2' one has to take into account j mixing,

which is automatically accommodated in the present
calculation: The single particle space taken in thecalculation is the Nose = 4,5,6 shells for neutrons;
and the Nose = 3, 4, 5 for protons. Therefore, we
conclude that the signature dependence of B (Ml)values in the natural-parity rotational band is sensitive to the j mixing effect.
In contrast, B(E2; I~I-2) and B(E2; I~I-l)values have no significant signature dependence.
References
1) E. Minehara, M. Oshima, S. Kikuchi, T. Inamura, A.
Hashizume, and H. Kumahora: Phys. Rev. C, 35, 855(1987) .
2) J. Kownacki, J. D. Garrett, J. J. Gaardhoje, G. B. Hagemann, B. Herskind, S. Jonsson, N. Roy, and W. Walus:
Nucl. Phys. A, 394, 269 (1983) .
3) G. B. Hagemann, J. D. Garrett, B. Herskind, J. Kownacki,
B. M. Nyako, P. L. Nolan, and J. F. Sharpey-Schafer:
Nucl. Phys. A, 424, 365 (1984).
4) M. Oshima, E. Minehara, M. Ishii, T. Inamura, and A.
Hashizume: Nucl. Phys. A, 436, 518 (1985).
5) I. Hamamoto and B. R. Mottelson: Phys. Lett. B, 132,
7 (1983).
6) M. Matsuzaki, Y. R. Shimizu, and K. Matsuyanagi: Prog.
Theor. Phys., 77, 1302 (1987).
7) A. Bohr and B. R. Mottelson: Nuclear Structure, Benjamin, Inc., New York, Vol. II, p.229 (1975) .

17
RIKEN Accel. Prog. Rep. 21 (1987).' 111-1-7. Study of Neutron-Rich Nuclei with Radio-Isotope' Beams. I. Tariihata, T. Kobayashi,* s. Shimoura,* K. Ekuni,**
K. Sugimoto, *** and H. Sato****l

Heavy-ion collision, Radioactive beam, High-energy .collisions, )Interaction. cross section, Nuclear radii, Isobaric dependence~,.

It was shown that nuclear radii can be determinedfrom the interaction cross sections of high-energy
heavy-ion collisions. 1 ,2) In particular, the use of
beams of radioactive nuclei provides a unique methodfor determining matter radii of unstable nuclei andenables us to make a direct comparison of radii between isobars. The isospin dependence of radii wasdifficult to study because, in most cases, only one
stable isobar of the same mass number exists. In
this report was present the isospin dependence of
nuclear matter radii for isobars of mass numbers
from 6 to 12.
The root-mean-square (rms) radii of nucleon distribution were deduced by a Glauber-type calculation.
Details of the method are described in Ref. 2. The
rms radii of nucleon distribution are plotted forisobars of mass number A = 6, 7, 8, 9, 11, and 12 inFig. 1. A pair of nuclei with the same isospin (T)but different T z , such as 7Li- 7Be or 8Li_ 8B, show
equal radii. It suggests that the Coulomb effect on
the radii is negligible for these light nuclei. On theother hand, a nucleus with a larger isospin shows alarger radius except for A = 9 isobars. The isospin
dependence of isobar radii thus obtained is comparedwith theoretical predictions as follows.
First, predictions from the droplet modelS) wereshown by the dotted lines in Fig. 1. The predictedvalues are almost independent of isospin and fail toreproduce the experimental trend, i.e. the strong
isospin dependence. The droplet model allows protonand neutron density distribution to vary so as tominimize the total nuclear energy, but it assumes
constant surface diffuseness. The disagreement withthe present data suggests that those changes are notenough to explain the observed isospin dependence.
Next, comparisons with the predictions from a
Hartree-Fock(HF) calculation using the Skyrme
potential 4 ) were made as shown in Fig. 1. Two
different sets of potential parameters, SIll and SV,* National Laboratory for High-Energy Physics.
** Faculty of Science, Kyoto University.
*** Faculty of Science, Osaka University.
'I::!'*';'

Institute for Nuclear Study, The University of Tokyo.

.. .. ......... Droplet- _ .- SIll

2.5
2.2

------- SV

----1

2.5

/

L:::'::~
Be Li:~.-:,.-:' .~ ..,..

+/ / .. .

2.2

Li

He

.... ..-- -' - "':...~:...' :. :-... - -- ---.~-'~--.
Be

Li

t
+
--- -. ~~~~)j ........

IA = 121
2.5/LiBe ;" .. ,2.5-;:~~~:;;;i>·~f

.

2.2

C

B

Be

1

2

- - ./"

5/2

Tz

-1

0

Tz

Fig. 1. Isospin dependence of the root-mean-square radii ofnucleon distributions_ Experimental values are shown by
the solid circle. Dotted lines show results of the droplet
model calculations. Results of the Hartree-Fock calculations with Skyrme potentials are shown by the dash-dottedline (for SIll potential) and by the dashed line (for SV) _were used. 5 } These sets of parameters are basicallydifferent in the density dependence of effective interactions: SIll includes a strong density-dependentinteraction, but SV does not. Both calculations arein fair agreement with the data to within 0.2 fm formost of the nuclei. The radii calculated with the
SV potential, however, have the isospin dependence
much weaker than that of observed. On the other
hand, the radii obtained with the SIll potential agree
well with the observed isospin dependence, except for
A = 9 isobars. The comparison of the data with the
HF calculation, therefore, indicates the importanceof the density dependent interaction in understanding
the radii of exotic nuclei in the present framework.
However, the other nuclear structure effects, suchas deformation and clustering, have to be taken intoacount before obtaining the conclusive statement.
Isobars of A = 9 show abnormal behavior in the

18

I. Tanihata, et ai.

data, namely the isobar with smaller isospin (9Be)
has a radius larger than the isobar with a larger
isospin (9Li). It is known that the 9Be nucleus has
a broad charge distribution because of the strong
configuration of two a clusters weakly bound by aneutron. This anomalous structure was not taken
into account for the present HF calculation, therefore
it is understandable that the calcultion gave different
isospin dependence of nuclear radii.
References
I) I. Tanihata, H. Hamagaki. O. Hashimoto, S. Nagamiya,

2)

8)
4)
5)

Y. Shida, N. Yoshikaiv~~ O. yain:akawa, ·K. S~gi~oto: 'T.
Kobayashi, D. E. Greiner, N. Takahashi, and Y. Nojiri:
Phys. Lett. B, 160, 380 (1985) .
I. Tanihata, H. Hainagaki,0. Hashimoto, Y. Shida, N.
Yoshikawa, K. Sugimoto, O. Yamakawa, T. Kobayashi,
and N. Takahashi: Phys. Rev. Lett., 55, 2675 (1985);
I. Tanihata, T. Kobayashi. O. Yamakawa, S. Shimoura,
K. Ekuni, K. Sugimoto. N. Takahashi, T. Shimoda, and
H. Sato: Phys. Lett. B, 206, 592 (1988).
W. D. Myers and K.-H. Schmidt: Nucl. Phys., ADO, 61(1983) .
H. Sato and Y. Okuhara: Phys. Rev. C, 34, 2171 (1986).
M. Beiner, H. Flocard, Nguyen Van Giai, and P. Quentin:
Nucl. Phys., A238, 29 (1975) .

19
RIKEN Accel. Prog. Rep. 21 (1987)

111-1-8. Development of a Particle~ldentification Techniqueand Search for New Isotopes
W. P. Liu,* I. Tanihata, T. Kubo, T. Suzuki, M. Yanokura,
H. Kumagai, H. Murakami, T. Yanagimachi, T. Doke, N. Hasebe,
T. Nakagawa, J. Kikuchi, H. Yamaguchi, and T. Ito**

NUCLEAR REACTIONS 9Be (65CU, 4°Ar, 40Ca, x), E= 16.7, 25.75,
26.0 MeV / A; measured time of flight, energy loss, total energy andmagnetic rigidity; deduced mass number, atomic number, charge[
state and yield of fragments. Natural target.
A problem of primary importance for all studies
of nuclei far off stability is obviously to find suitablemeans to produce them in la!ge quantities. As highintensity heavy ions are now ' available at intermediate energies (GANIL, LBL, SARA, CERN;
RIKEN), the -projectile fragmentation mechanism
can be used to produce the exotic nuclei and thesecondary beams of _these nuclei can be produced bymagnetic separation.
For this reason we have planned a set of experiments: G5 Cu (16.7 MeV/A) +Be, 4°Ar (25.75 MeV/
A) + Be, and 40Ca (26.0 MeV/A) + Be to establish
an isotope identification technique and search for
new isotopes:
The experimental setup is shown in Fig. 1. In
RRC (Riken Ring Cyclotron) experiment room El,
the D (dipole) magnet bends the fragments of interest
to 20 degree, and two Q (quadrupole) magnets focus
them. In a focal plane, PPAC (parallel-plate avalanche counter) , PSSD (position-sensitive slicon1

detector) and slicon detectors constitute a JE-E-TOF(time of flight) isotope identification system. Thestart signal of TOF was given by an RF (radio frequency) signal of RRC. The probe inside the D
magnet gave a reference for the selection of a Bp
(magnetic rigidity) value. This system is rather
simple compared with that of other laboratories,
such as ' LISE (projectile fragments separator) in
GANIL, but gave satisfactory results.
We present the results of these three experiments
and the ideas evolved during the experiments.
65CU + Be run: A neutron-rich beam was chosen
RUN -OOll STARr·· 09:10:10 ST0P·· 10:23:30

Pnnt·· 19:02:05 24-0€C-97

Co.
K

Ar
Cl

S
P

SILICON
DETECTORS

Si

Tz

o

+ 1/2

+ 1 +3/2 +2 + 5/2

Tz=(NPRIMARY BEAM

Fig. 1.

Experiment setup.

(See text for details.)* Permanent Address: Institute of Atomic Energy, P.O.
Box 275 (60), Beijing, China.

** Science and Engineering Research Laboratory, Waseda
University.

!

-z )/2"Proton number

Neutron number

Fig. 2. TOF (time of flight) -PI (particle identification function) contour plot in Bp (magnetic rigidity) setting for
AjZ=2.0 isotopes in an 4°Ar+Be run. The isospin T z ofeach TOF branch and the element name of each PI line
are indicated.

20

w. P. Liu, et al.

for searching 54SC. PSSD and PPAC were not used.
Because of the momentum spread along the horizontal
direction from the reaction mechanism, it was impossible to separate the mass with silicon detectors
which have rather wide sensitive area (900 mm2).
Charge separation was achieved by using a PI function defined by PI= (E+11E)1.45-E1.45, where LIE
is the energy loss in the first slicon detector and E
is the residual energy in the second one.
40Ar + Be run: PPAC and PSSD were used. Isotope identification was achieved. By using the position
signal of PSSD, all data without losing the time
resolution were analyzed. Large cross sections for the
production of K isotopes were observed. This results
prompted us to use a · 40Ca beam to search for a newisotope 39SC and measure the cross sections of (40Ca,
40SC) and (40Ca, 4°K) , which provide useful data forthe transfer-reaction mechanism in this energy
domain. Figure 2 gives a TOF-PI contour plot in a
Bp setting appropriate for A / Z = 2.0 isotopes. (Theisospin T z of each TOF branch and the eleinent nameof each PI line is indicated.)
40Ca + Be run: A proton-rich 40Ca beam waschosen for searching for 39S C. By meaiuring the beam
intensity through the secondary electron emission fromthe target, the absolute cross section can be deduced.

.llHIIXll S1'ARr ••Ca-_~.

SllP-

Pnttt··1J~14

-+

_ _~

'" .. ,_. ' JstIJ

K

Lt

-K

-- - 0
..

...

. '.

Ar

5

P
Si
I

TOF

Tz +3/2 +1 +1/2

o - 1/2-1

Fig. 3. The same plot as Fig. 2 in a tOea + Be run; B psetting for proton-rich isotopes.

40SC was observed on-line. Figure 3 shows a TOF- PI
contour· plot in a proton-rich Bpsetting of the 40Carun.
The existence of 39SC and other results of thesethree runs are under analysis.

21
RIKEN Accel. Prog. Rep. 21 (1987)

111-1-9. Total Reaction Cross Section Measurement of Unstable Nuclei
M. Fukuda, M. Ishihara, I. Tanihata, K. Asahi, T. Ichihara,
T. Kubo, M. Adachi, M. Koguchi, and H. Kumagai

Heavy-ion ~ollis~~~~" Ra?ioactive beam, Projectile fragmentation,[ Total reactIOn cross sectIOn, 180.

1

pared with those in the lower or higher ene~gy
region.
Recently, Mittig et al. at GANIL reported themeasurement of lTR of unstable"nuclei (Z = 5-12) bydetecting r ray. They "interpreted a detection of r
ray as a sign of an occurrence of a reaction. We
also planned to measure lTR in a different waybeam attenuation method-using Si-detectors andcarried out a test experiment. One point of ours
different from M,i ttig et al. is that as the method
is' different, and then the definition of 'lTR' is different,
the physical meanings of measured value may also
be different. Another point is a thin secondary target.
The region of energy integration, therefore, becomesnarrower (40-20 MeV / u) than theirs (60-0 MeV / u) .
Figure 1 shows a schematic drawing of the setup. A

A total reaction cross section (lTR) includes avariety of information on the properties of nuclei
such as a nuclear size, reaction mechanism, or nuclear
structure. However, it had not been possible tomeasure lTR of unstable nuclei, until a projectile
fragmentation reaction in the high or intermediate
energy region provided a powerful tool to produce
unstable nuclei as a beam. By using the projectile
fragmentation, we can extend the field of the lTR
study to a broad unstable region. Another interest
is in a point that in the intermediate energy region
available at RIKEN Ring Cyclotron, a heavy-ion
reaction mechanism may have a transitional feature
between a low energy limit (collective aspect) and ahigh energy limit (nucleon-nucleon aspect). In addition, data on lTR in this energy region is poor com-

Primary Beam

SW-magnet

Slit-2

PPAC·lDetector
Chamber

Q2

Ql

Slit-!

PPAC·2

L'lEOl

L'lE 02

SecondaryTarget

L'lEl

.6E2

E

E·vetoD

Fragments

150 J,lm
I

100 ~lIn

300 1111112100 mm2

250 J,l111

300 J,l111

300 ml112 200 mm22000 J,l111

2000 J,l111

200 mm2

200 ml112----------_ .... ----------_ ...... -----_ .. _--_ .. ----------------------------- --- ------ ... -Detector Chamber

Fig. 1. Setup for <Tn measurement by a beam attenuation method in the test
experiment. The production target was Be of 46 mg/cm 2 in thickness. The,lower part shows a , detec,tor setup in the detector chamber. Six Si·detectors
supplied qom ORTEC were used. Figures under the Si-detectors are their thickness and active area. Secondary target was Be of 301 mg/cm 2 in thickness.

M. Fukuda, et al.

22beam hitting a production target produces various
kinds of nuclide coming out of the target with almost
the same velocity as the beam. They are roughly
separated by A / Z 'a fter passing through a switching(SW) -magnet. The beam is stopped at the exit of
the SW-magnet, and only the projectile fragments
are focussed on a detector position in the chamber.
The detector setup is devided into two parts: 'o ne
is for a first particle identification (PI) and thesecond is for PI after the secondary target. As
the transported projectile fragments contain several
kinds of nuclide, PI is needed at the first stage.
The first PI consists of magnetic rigidity (Bp) ,TOF, and LIE measurements. Bp of a particle which
cf'.n reach t<;> the detector c4aml:>er is selected by the
SW-magnet. The momentum dispersion at the second
parallel plate avalanche counter (PPAC-2) is
Bmm/%. TOF and LIE are measured with PPAC-l,
PPAC-2 and LlE01, 02. In order to reduce wrong
identification, we use two LlEO counters to checktheir consistency. PPACs are position sensitive and
PPAC-2 also plays a role as an active slit for Sidetectors.
The sec<;>nd PI is achieved by a LlE-E counter
telescope which consists of four Si-detectors. The
second PI is for checking whether or not an incident

particle changes in the secondary target. 'Two kinds of secondary target configurations,target-in-runs and target-o'4t,;,r~ns, are needed. The
target-out-run is for the corrett:ion for the missingof events by reaction in Si-detectors or pulse heightdefect. In the target-out-run, we put the secondary
target just after the production target to adapt theenergy at the entrance of the counter telescope tothe one in the target-in-run and also to identify
particles correctly.
The total reaction cross section is represented by
OR = (l/N t ) • In (Ro/R)
where Rand Ro are the ratios (the number of unchanged events/the number of incident particle) for
the target-in-run and the target-out-run, respectively,
and Ntis the number of target, nuclei p,e r unit area.
A test measurement was carried out with an 180
primary beam. (Fig. 2) The energy of the beam was
41.4 MeV /u, which was determined by an absolute
TOF measurement with PPACs. The beam current
was 0.1-1 enA. The production target was Be of
46 mg/cm 2 in thickness. At first, we measured OR of
the primary beam itself as a test. The secondary
target for the measurement was Be of 301 mg/cm 2 •The probability of a reaction in the secondary target
was about 2.5 %. The preliminary result is O"R(180_9Be) = 1,470 (80) mb. The main part of theerror co~es from the aml:>iguity , in distinguishingunchanged events from reaction products due to thetailing peak in the energy spectra of L1E counters.
The production of unstable nuclei was also checked.
Figure 3 shows several products identified by the
first part of PI with SW- and Q-magnets adjusted to
16C.

OED- T0F(2 PP,f\C)
2

l5

30

RWE:r1

2 40r.1E
(b)

240

180

...

: ...:., . .:''':..
lL.

IS:!

f-

6 0-

O~O-------R~~O~' ----~1+2r~j--~--'1~J=O------~2~~IC~
1

OE-O
Fig. 2. 11E-E plot of target-in-run (a), and target-out-run(b) for 180 primary beam. 11E is a sum of 11El and 11£2;
E is an output of an E detector.

Fig. 3. iJEO-TOF spectrum taken with a Bp condition adjected to 16C. ' The Bp resolution in this run was 1.9% ~JEO is a sum of iJEOI and and ' iJE02.

23
RIKEN ,Aced: frog. Rep;' 21 · (1987)'111-1,-10.

Effect of F.inal State Interactions on (n,1J) Reactions 'Y. Ohkubo and L. C. Liu*r NUCLEAR REACTION 12C ( 7r+, 7) ),' T = 555 MeV; DWIA 11<

l calculation with the eikonal approximation.

The study of eta mesons is of fundamental interest
because the 'so-called U ( 1) problem concerning eta
mesons is still not fully understood. The simple
SU(6) quark model cannot account for the mass difference between 7) and 7)' mesons. Studies of etanucleon interactions are expected to provide useful
information that might shed light on the structuresof eta mesons. Because it is nearly impossible toprod{,.ce an eta beam, the' nucleus i,s the only laboratory aV<l:ilable for such studies. R~cent1y, it 'has beenshown by ' Liu and his , collaborators · that' , the ' lowenergy Sti '7)N interaction is attractive I ) and that
this attraction can ,bind the ' 7J ~nto nuclear ' <;>rb~tals2)
in nuclei :with a mass. number :4.> 10. The 'eXistenceof a mesic nu<:le~~can,n9t be :readily investigated withother mesons such as pions or kaons. As for pions,
there is a strong cancellation between the isospin 1/2
and 3/2 rrN s-wave scattering amplitudes such thatthe resultant low-energy s-wave pion-nucleus interaction is weak and even repulsive. The p-wave pionnucleus interaction is attractive, but it turns out tobe very small owing to the critical dependence of
its strength on the local pion momentum. As forkaons, K+N interaction is repulsive at low energies.
Although the low-energy K-N interaction is attractive,
K- preferentially forms mesic atoms because of strong
Coulomb interactions. Liu and Haider 3 ,4) calculated
and identified the signature for the formation of
eta-mesic nuclei in the 160 (7r+, pHilO and HC (7r+,
7r-) l4O(double isobaric analog state) reactions with
the incident pion energy for the former case being
about 610 MeV and that for the latter about
420 MeV.
We are planning to calculate the differential crosssections d 2 a / dE."dQ." for the A ( rr, 7)) reaction with
A = 12C, 40Ca, 208Pb, taking into account the attractive r;-nucleus final state interaction. It is expectedthat this final state interaction enhances the cross sections at low energies of the outgoing 7) particle. 5 ) It
is much of interest to know how significant theattractivene~s in the 7)-nucleus final state interaction
is. In this period, using the DWIA formalism with

* Isotope and Nuclear Chemistry Division, Los Alamos
National Laboratory, New Mexico, USA.

the eikonal approximation6) for the incident pion
and with the plane wav~ approximation for the outgoing 7), we calculated the differential cross section
for the 12C(7r\ 7)) reaction at T1<=554.6MeV tocompare with its preliminary experimental data. 7)
As we know, the eikonal approximation is ,simple andgood for a high energy particle such as the incident
pion in the present reaction, but is not considered as
being good for a low energy particle such as the outgQing low energy 7). 'F or the r; particle, as its.
momentum , approaches zero, the optical potential
approaches a nonzero value. 1) Thus, the damping
factor due to , the distortion calculated by the eikonal
approximation is e~pecteddQ be unrealistitally larg~
for the low energy 7). Moreover, the eikonal approximation cannot reflect the attractiveness in the 7)nucleus interaction. It always diminishes the nuclear
t matrix. We show in this work that we needseriously take into account the 7)-nucleus final-stateinteraction. Incidentally, we calculated using theeikonal approximation also for the outgoing 7) tosee how the result due to this approximation looks
like. We used the off-shell rrN~7)N t matrix for thebasic scattering and the on-shell 7rN~ rrN and 7)N~r;N t matrices for the initial and final state interactions, all of which were obtained by Bhalerao and
Liu I ) in a single calculation based on their coupledchannels formalism. In Ref. 1 there are given two
sets of numbers for coupling constants, range parameters, and bare masses, based on two sets of rr N
phase shift data. We used the values based on therrN phase shift given by Arndt et ai. We calculated
the invariant mass for the off-shell rrN~r;N t matrix
in terms of kinematics for the outgoing particles. As
nucleon wave functions for 12C, we employed those
based on a harmonic oscillator potential. S ) In calculating the inclusive differential cross sections, wetook into account the 1s ,and 1p separation energy
difference and thus represented the final state either
as a system of an 7), a proton, and a ground stateof He or that of an r;, a proton, and an excitedstate of 11C. The excitation energy of HC was calculated using harmonic oscillator parameters and is
15.1 MeV. Since the Is neutron separation energy

Y. Ohkubo, et al.

24

20

-=VI

15

:$
Q)
~

!
c
-c
w

r1-f-- !

10

~

~

tt

HfHLr~nl 11\ I

5.--;'----,.--" "!

"/'\,! ;,;,/'--

-.-'

0

0

25

50

I'f

'\~
I

75

100

\

\\, f !

125

150

1'] Energy (MeV)

Fig. I. Differential cross sections d2u/dE7)d[J7)(O«hab<300)
for the 12C (7T+, 7]) reaction at T lr= 554.6 MeV. Solid circles
with bars: preliminary experimental results;7> solid curve:
present calculation using the eikonal approxima~ion for
the incident pion , the outgoing 7] being treated as a pIane
wave; dashed curve: present calculation using the eikonal
approximation for the incident pion and the outgoing 7].

is larger than the 1p one, a phase space for the process with a Is neutron off is smaller than that forthe process with alp neutron off. We performed
numerically 6-fold integrations with the help of theGauss method. Figure 1 shows the preliminary experimental data obtained .by Peng et al. (solid circles
with error bars), our calculated results using theeikonal approximation only for the incident pion,
the outgoing 1) being treated as a plane wave (solid
curve) and for the incident pion and the outgoing1) (dashed curve). Our calculation wi til the eikonal
approximation for the incident pion and outgoing 1),
as we expected, underestimated the differential crosssections at all 1) energies. Our calculation with theeikonal approximation for the incident pion andplane wave approximation for the outgoing 1) reproduces the cross sections at high 1) energies. However, even it underestimated the cross sections at
low 1) energies. We speculate that the attractives-wave 1)N interaction enhances the cross sections
very much at low 1) energies. This stimulates us tocalculate reliable distorted 1) state functions. This
program is undertaken.
References
I) R. S. Bhalerao and L. C. Liu: Phys. Rev. Lett. , 54, 865(1985) .
2) Q. Haider and L. C. Liu: Phys. Lett. B, 172, 257 (1986) ;174, 465 (E) (1986).
3) L. C. Liu and Q. Haider: Phys. Rev. C., 34, 1845 (1986) .
4) Q. Haider and L. C. Liu: submitted to J. Phys. G.
5) J. R. Taylor: "Sca~tering Theory," . John Wiley & Sons,
Inc., New York, Chap. 21-b (1972) .
6) Y. Ohkubo and L. C. Liu: Phys. Rev. C., SO, 254 (1984) .
7) J. C. Peng: private communication.
8) L. C. Liu: Phys. Rev. C, 17, 1787 (1978).

25
RIKEN Accel. Prog. Rep. 21 (1987)

111-1-11.

Level Densities with Fixed Exciton Number for
Pre-Equilibrium Nuclear Reaction
K. Sato and S. Yoshida

Level density with exciton number, Pre-equilibrium reaction,[ Residual interaction.

To evaluate pre-equilibrium reaction cross sections
the level densities with fixed exciton numbers arenecessary, and those of a well-known Ericson-Williams
type have been widely used because of their simplicity.
Recently Jacquemin and Kataria1 ) estimated, within
the framework of an independent particle model,
exact level densities by a recursive method using
realistic single particle energies. However only a few
studies have been carried out on the realistic level
density which takes residual interaction explicitly
into account.
Nishioka et al. 2 ) suggested the possibility of strong
coupling between groups of the levels classified byexciton numbers. If such strong coupling is actually
the case, the modification would be necessary forlevel densities with fixed exciton numbers having so
far been used. 2,3) As for the total level density,
which is given by the sum of such level densities,
Jacquemin and Kataria anticipated the difficulty infitting the experimental data at the thermal neutron
resonances unless the residual interaction is taken
into account.
In the present work we explicitly take the residualinteraction in studying level densities classified by the
exciton number m. It is done on the basis of thetheory by Nishioka et al. 2 ) who introduced theGaussian Distributed Ensemble (GDE). The GDE
assumes many GOEs, which are specified with theexciton number m and have different centers h m andvariances Mmm and are coupled with one anotherby the off-diagonal GOE random interaction. Thenthe GDE is characterized by second moments Mmn.
First the nuclear second moments

The calculated result indicates that for such nuclei
the strong interclass coupling proposed by Nishioka
et al. 2 ) is nearly the actual case. Then level densities
with an exciton number of pm are obtained first bysolving the saddle point equations 3 ) in the strong
interclass coupling limit given by'm2 -(Ehm-'m )-1
Amusing second moments as the input, and secondly bytaking the imaginary part of the propagator as(3)

The partial level densities pm (m=2, 4,6, ... )calculated for 20SPb are shown in Fig. 1. Dashedcurves represent the semi-circle level densities obtained by switching off the interclass coupling. In
Fig. 2 the total level density p(E) = L,pm(E) ismshown by a solid curve and is compared with thesum of semi-circle level densities; the total level

208Pb (Np-90, Nh-76l

"5>ou

~

GGSI res. Int.
1020

>-

t;
C/)
z

w
0

...J
W

10 10

>

(1)

1

I

W
...J

I

•

,

m_-_'!i ______ l _______ 1. _: m-4 :

W

::>

c::

are calculated on the basis of the same simple modelas Ref. 3 by using realistic single particle states, but
by adopting more general residual interactions, for
40Ca and 20SPb as examples. In Eq. 1 N m is thenumber of states which belong to the class of theexciton number m and va is the residual interaction.

..

I-

I
I

10 0

o

I
I

10

20

30

E (MeV)

Fig. 1. Level densities with fixed exciton number for 2osPb.
Dashed curves are semi-circles with exciton numbers m.
In the weak interclass coupling limit level densities reduceto the values represented by semi-circles.

K. Sato, et al.

26

208Pb(Np=90,Nh=76)
I

>

~ 10
>-

GGS I res. int.

20

l-

t)
Z

W

o

G1 10 10
>

W
...J
...J

~

o

I-

100

~L-~~~o_ _ _ _L -_ _~_ _~_ _ _ _~_ _- U

10

20

30

E (MeV)

Fig. 2.

Sum of level densities shown in Fig. 1.

density shifts to coincide with the solid curve at thethreshold energy.
Essential results of the present study are (1) the
enhancement in the low energy region, which would
greatly improve the agreement with the experimental
total level density at the thermal neutron resonances;(2) the general trend in shape change of level
densities with fixed exciton number according to thestrength of the coupling; (3) Wigner-like repulsion

between semi-circle level densities; and (4) the occurrence of the multimodal distribution, which was firstfound by French et al. 4 ) in another simple system.
Our results for level densities should be regarded
as giving qualitative information concerning how theresidual interaction changes their behavior. Because
the present study includes unrealistic assumptions inherent in the pure GDE such as the degenerate
spectrum of the one-body part of the Hamiltonian
and the multi-body residual interaction. Actuallyunperturbed semi-circle partial level densities would
be replaced by the Gaussian ones at least for large
m if the two-body nature of the residual interaction
is explicitly simulated. It is expected, however, thatthese results would be common features of level
densities when the residual interaction is taken into
account.
References
1) C. Jacquemin and S. K. Kataria: Z. Phys. A, 324, 261(1986) .
2) H. Nishioka, J. J. M. Vervaarschot, H. A. Weidenmiiller,
and S. Yoshida: Ann. Phys., 172, 67 (1986).
3) K. Sato and S. Yoshida: Z. Phys. A, 327, 421 (1987).
4) J. B. French and V. K. B. Kota: Phys. Rev. Lett., 51,
2183 (1983).

27
RIKEN Accel. Prog. Rep. 21 (1987)

111-1-12. A High-Energy Scattering Approximation
Y. Nishida,* T. Takemasa, and M. Shimauchi*( High-energy, scattering, Glauber, amplitude, wave-function, J~ Born, Gaussian potential, correction term.

In previous work,1,2) an approximation method
was developed to describe the scattering of a highenergy Schrodinger particle from central potentials.
In Refs. 1 and 2, the scattering wave function withan incident wave number ko was approximated by

W(r)=exp [iko(soor)]+ JG(r ,r') U(r') exp [ik o(80 r') ] dr'0+ jG(r, r') U(r')G(r' ,r") U(r")c/Jt(r") dr'dr"(2)

W(r) = exp [iko(soor)]+ JG(r ,r') U(r')Wt(r') dr'

which is obtained by adopting Eq. 1 in an iterative
solution of the integral equation. The second andthird terms of Eq.2 can be transformed by meansof the procedure developed in Ref. 2 into the single
and double infinite series, respectively. The scattering
amplitude f (()) may correspondingly by written as(1)

where U(r) =2 mV(r) In 2 , So is a unit vector along
the incident direction, and lJ" t (r) the internal spherewave function. 1) Under the conditions that thestrength of a potential is much smaller than theincident energy and its range is greater than the
reduced wavelength, the method 2) can well give thescattering amplitude and the differential cross section
in weak and intermediate coupling cases far beyond
the angular validity criterion of the Glauber's formula. 3 ) However, the method includes a practicallyimportant problem of extending an allowed range ofthe coupling parameter.
In this note, an attempt is reported to improvethe method by introducing manageable correction.
The scattering wave function is taken here to be of
the form

Re (f)

1

1(0) =IB1(0) + f.s2(0) + 2J mn(O)
m,n

(3)

where f~2 ((J) represents the second Born amplitude
expressed as a single infinite series.
The main task is now to replace the infinite series
included in Eqs. 2 and 3 by suitable finite series.
Particulary in managing 2J imn(O), we adopt a prom, ncedure of choosing terms to be retained so as toapproximate f ((J) and d(J I d!J as good as possible
over a wide range of scattering angles.
Numerical calculations are carried out for theGaussian potential U (r) = -A 2exp[ - (r I b) 2]. The
ImU)

10 1

da/ dQ10 2~ = 1.830

60

8 (deg)

90

10°

10 1

lO- 1

10°

lO- 2

10- 1

lO- 3

0

30

60

8 (deg)

90

10- 2

0

30

60
8 (deg)Fig. 1. Quantities Re (I), 1m (I) and du / dQ with b = 1.0 (unit of length) at
ko=5.0 and g= 1.8. The solid, dotted, and dashed curves show the results ofthe exact method, our procedure, and the eikonal approximation, respectively.

* Department of Physics, Saga University.

90

Y. Nishida, et al.

28

quantity kob is taken to be 5.0, and the coupling
parameter ~ = A 2 b /2ko is changed from 0.1 up to
2.0. The amplitude 1B2 (()) can be written in aclosed form for this potential. By comparison thecorresponding infinite series proves to be well approximated by a sum of its first four terms, and thesecond term of Eq. 2 becomes thus manageable. By
retaining the leading five and four terms in ~ Jmn((})
m,nfor ~ = 1.0 and 1.8, respectively, we found that theresults obtained for the real and imaginary partsof f ( ()) as well as da / dQ can very well be approximated to those calculated by the exact method ofpartial waves. It is noteworthy that the results for
g= 1.0 are much better in giving the change ofsigns of f ( () ) than the corresponding ones in Fig. 1
of R ef. 2. F or clarification and comparison, theresults for ~ = 1.8 are shown in Fig. 1 together withthose of the exact method and the eikonal approximation. 4 ) The range b is taken here to be a unit oflength as in Refs. 2 and 4. Figure 1 confirms that

our method can markedly extend an allowed rangeof g. It also points out that the results of the eikonal
approximation are much worse than ours for large
scattering angles particularly on the change of signsof f( ()) .
In summary, a method is developed to approximate
the scattering wave function as a sum of the second
Born form and correction terms. The present methodvery well reproduces the exact results for the coupling
parameter larger as well as smaller than unity far
beyond the conventional angular range of validityof Glauber's formula.
References
1) Y. Nishida, M. Shimauchi, and H. Tanaka: Nucl. Phys.,
50, 403 (1964).
2) Y. Nishida and M. Shimauchi: Prog. Theor. Phys., 76,
143 (1986).
3) R. J. Glauber: Lectures in Theoretical Physics, Interscience, New York, Vol. I, p.315 (1959).
4) C. J. Joachain: Quantum Collision Theory, North-Holland, Amsterdam, Chap. 9 (1975).

29
RIKEN Accel. Prog. Rep. 21 (1987)

111-1-13.

Microscopic Analysis of the Hexadecapole Strength
to the r-Vibrational Bands
M. Matsuo

NUCLEAR STRUCTURE r-vibrational bands, hexadecapole)[ transition probability, random phase approximation.

The r-vibration has been regarded as collective
oscillation of a deformed nucleus with quadrupole
multipolarity. Recent inelastic hadron scattering experiments, however, revealed that the hexadecapoletransition strength to the r-vibratonal bands are
considerably enhanced in some even-even rareearth nuclej1,2) and that the strengths have strong
dependence on nuclear species. 4 )We theoretically investigate the origin of the observed features of the hexadecapole strength to ther-bands. Although the enhancement may suggest arole of the two-body correlation of the hexadecapole
type,3) one has to be careful to draw the conclusionfrom this aspect. Since low-lying collective vibrations
such as r-motion are characterized strongly by the
structure of the single-particle levels near the Fermi
surface, the observed (N, Z) -dependence is also a
key property in understanding the phenomena. One
should also note the consistency of the hexadecapole
correlation, while the authors of Ref. 3 do not.
We describe the r-vibration microscopically bymeans of the random phase approximation (RPA).
The Nilsson + BCS Hamiltonian hdef with quadrupole
equilibrium deformation is employed as a singleparticle basis. Two-body correlation we adopt consists of the doubly-stretched quadrupole-quadrupole(Q2"Q/') and doubly-stretched hexadecapole-hexadecapole (Q4" Q4") interactions: 4)(1)

where QLK" = (rLY1J1d x-+x" and the doubly-stretchedcoodinates x" are those scaled according to theequilibrium deformation.
The doubly-stretched
multipole-multipole interactions satisfy consistency
between the mean-field potential induced by theinteractions and the matter density for deformed
nuclei,4) when the selfconsistent force strengths /C2 =.1:2 (self) and /C4 = /C4 (self), 5) are used. Reduced isoscalartransition probabilities B (IS4, ~4r) from the groundstate to the 4+ state in the r-vibrational band are
calculated in a usual manner using microscopicallyderived RP A phonon xi = 2jPII {¢(plJ )a~a! +fjJ(PlJ )allap} ,where a~ is a quasiparticle operator for a single-

Er
0.0t.

I

Er

~

0.Q3

0.Q2

Exp.

+ Dy

Yb

Gd

I

Sm
0.01

I

Os

Iw

• +

w

o I-+-+-i--I--+--I-+--t-+---II-+-+--I-t--l:;- L.J2

Q'~ + Q~.Dw
a t-+-t=t'-+-+-+-+--t-+---I--;=::;:=O;:=S=;-j0,02~Q'~ only;.~./:- \'\
0.01

.Dy

//

,·······Gd
,
\Sm

\'"

Hf

\ .....
\ ....."

W

/ :~~
O

Yb\
\ I

S

V
90

100

110

Neutron Number

Fig.I. Observed and calculated reduced isoscalar hexadecapole transition probability B (IS4, ~4r). Experimental data are taken from Ref. I. The theoretical results
shown in the bottom figure is calculated without the hexadecapole interaction.

particle level p.
Figure 1 shows the hexadecapole transition probabilities, B(IS4, ~4r), evaluated from the (p, p')
experiment1 ) and the calculated ones. It is seen thatthe characteristic (N, Z) -dependence of the experimental data is reproduced in the calculation. In
order to see the effect of the hexadecapole correlation(Q/'Q/'), we show the result of calculation which
taeks into account only the quadrupole correlation(Q/'Q/'). The hexadecapole correlation is not foundto play relevant roles in generating the (N, Z) -dependence of the r-vibrations. On the other hand theabsolute magnitude is underestimated by a factor of
about two. It is hardly possible in our model to30

M. Matsuo

enhance it with keeping the proper (N, Z) -dependence by increasing the hexadecapole correlation.
The origin of this overestimation is unclear and should
be investigated further.
The (N, Z) -dependence of B (IS4 ) is due to theproperty of the hexadecapole operator and the subshell structure of the single-particle levels. We canestimate the hexadepapole transition amplitude as<OI[Xr ,Q42JIO>
'"

2Epv

pv

Pv -

(

ex::.::...J - E
2-E 2 UpVv+UvVp)

X

2

Referencesr< ,ulr2 Y221t; > < ,ulr4Y 42 1lJ >(2)by neglecting the hexadecapole correlation Q4" Q 4/t(E r : r-vibrational energy, Epv=Ep+Ev: energy ofquasipaticle pair, Up, Vfl: pairing factors). The contribution of quasiparticle pairs near the Fermi surface
to the summation in Eq.2 are influenced strongly by
the subshell structure of the Nilsson single-particle
levels. For dominant components satisfying the selection rule in the quadrupole matrix elements < pi
rZY22I lJ>, the matrix elements of the hexadecapole
operator are expressed approximately as<,ulr4Y42!lJ> ex:: (5ng- Nosc)< ,ulr2 Yzz1t; >,of these levels to Eq. 2, gives positive coherence withrespect to those of the core excitation. Thus B (IS4 )enhances in this region. On the other hand, thesituation is opposite for N~ 110. Single-particle levels
near the Fermi surface in this region belong to Nose =5 and n3 = 1, 0, and their contributions cancel theother contribution in Eq.2. The proton number
dependence can be explained in a similar way.
Detail of this work is reported in Ref. 6.

(3)

where [Nosen3AQ] is the asymptotic quantum number for a single-particle level p. Since neutron singleparticle levels with Nose = 5 and n3 = 2 dominate
around the Fermi surface for N~98, the contribution

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); T. Ichihara, H. Sakaguchi, M. Nakamura,
M. Yosoi, M. Ieiri, Y. Takeuchi, H. Togawa, T. Tsutsumi, and S. Kobayashi: Phys. Lett. B, 182, 301 (1986);
Phys. Rev., 36, 1754 (1987) .
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) V. O. Nesterenko, V. G. Soloviev, A. V. Sushkov, and N.
Yu. Shirikova: Sov. ]. Nucl. Phys., 44, 938 (1986) [Yad.
Fiz ., 44, 793 (1986)] .
4) T. Kishimoto, J. M. Moss, D. H. Youngblood, J. D.
Bronson, C. M. Rozsa, D. R. Brown, and A. D. Bacher:
Phys. Rev. Lett.~ 35, 552 (1975); T. Kishimoto: Proc. Int.
Symp. Highly Excited States in Nuclear Reactions,
RCNP, Osaka, p.145 (1980).
5) A. Bohr and B. R. Mottelson: Nuclear Structure, Benjamin, New York, Vol. 2 (1975) .
6) M. Matsuo: Prog. Th eor. Phys., 78, 609 (1987) .

31
RIKEN Acccl. Prog: Rep. 21 (1987)

111-1-14.

Derivation of the Global Equation of Motion for theCollective Variable
S. Yamaji, H. Hofmann,* and R. Samhammer*

CFISSION, linear response theory. J
We reported the calculation of selfconsistent transport coefficients. 1 ) They were evaluated from theequation of the global motion for the collective
variable Q (t) at time t

the following result:<F>'f= <F>Q-

1:00 dsX(t-s)(Q(s)-Q) (6)with the response function X(t-s) defined byaf(Q(t) , T) _ [too dsX(t-s)(Q(s)-Q(t»=O
aQ(t)

J-oo

(1)

X(t-s)=i8(t-s)<[FI(t), FI(S)]>where, t (Q, T) is a free energy of the temperature T, and i (t-s) is a response function.
Equation 1 was derived in Ref. 2 by introducing afixed Qo which represents Q at t = to. However, its
derivation must be improved since each term was
not treated consistently to order 1 in (Q (s) - Qo) in
Ref. 2. In Ref. 3, Eq. 1 was given in its zero temperature limit.
Therefore, in this report, we give an extention tofinite excitations, keeping terms of order 1 in (Q (s) Qo) consistently. For that we expand the Hamiltonian like:

The detailed derivation of Eq. 6 is given in Ref. 4.
Since the nucleus is an isolated system, its total energy
must be a constant of motion. Since our Hamiltonian
depends on the parameter Q (t), this condition leadsto(8)
In the equation of motion we must calculate < ail I
aQ> t. Within our perturbation approach, we obtainto the first order/ ail"", _ -"

(2)

ail

/'-.

oV=(Q-Qo) aQo =(Q-Qo)F(Qo)(3)

on <aH laQ>t to order 1 in (Q(s) -Qo). We startfrom<F>~=TrPeq(Q)F(t)a2fj '"- r:oo X(t-s)(Q(s)-Q)ds

t

_

Qo)

(9)

(10)

The first two terms represent static forces, which
can be expressed by the partial derivative withrespective to Q about the free energy t (Q, T) definedby(4)r ds[FI(t), FI(S)](Q(s)-Qo) (5)
J

Qo (Q

/ ail", _ /'-.
/ a2il",_'" aQ / t- <F>Q+"" aQo2 / Qo (Q Qo)ii(Q))

f(Q, T) = - T In Tr exp ( -----;y--where F( t) can be calculated to the first order as
F(t)=FI(t)-i/Inserting Eq.6 into Eq.9 yields

For the time interval at = t - to we then treat the
influence of the local coupling-"Q"'" aQ /t - <F>, + "" aQo2 /fi(~i,Pi,Q)::::::H(Qo)2ail I
2 a il+(Q-Qo) aQo +"2(Q-Qo) aQo2

(7)

(11)

Thus we finally obtain Eq. 1 in the non-static case.

towith the interaction representation FI (t) of F(Qo)and Peq ( Q) is a equilibrium density operator given
by exp( -fi(Q) IT) ITr exp( -il(Q) IT). We expand Eq. 4 to the first order in (Q - Qo) and obtain* Physik-Department der Technischen Universitat Miinchen .

References
S. Yamaji and H. Hofmann: RIKEN Accel. Prog. Rep.,
20, 33 (1986).
2) H. Hofmann: Phys. Lett. B, 61, 423 (1976).
3) P. J. Siemens: Nucl. Phys., A387, 247 (1982).
4) S. Yamaji, H. Hofmann, and R. Samhammer: Nucl.
Phys., A475, 487 (1987).
1)

32
RIKEN Accel. Prog. Rep . 21 (1987)

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

Gauge Property for the Radiative Processes Induced
by lon-Atom Collision
K. Hino and T. Watanabe

In order to solve the problem of inconsistency
which lies in the formulation for radiative processes
induced by three-particle collisions,1,2) we investigate
the property of gauge invariance of the formula for
a radiative process. As a preliminary discussion before
we treat the three-body system, we consider thegauge invariance property on the occasion of twobody collisions. The photon emission processes induced by the acceleration of an active electron in
two-body collisions are(1)

a+b-a+b+r(free-free transition, i.e., Bremsstrahlung; anucleus, b an electron, and r a photon) anda+b- (a, b)+rISawhere H'j =: 2M.
- ie A ·Pj' A'IS th e vector potential ofradiation field, ~nd Pi is the linear momentum ofparticle j. 1'fO and 1'fO of particles and photons areunperturbed wavefunctions (plane waves).
The property of gauge invariance is examined by
the following procedure. Let us consider the casewhere the initial state of a particle with no photon
1'i(Y) (Y: the four-component vector, i.e., three
dimensional position vector y and the time t) changes
into the final state of a particle with one photon
1'f (x) (x: the four-component vector) due to theinteraction Afl(z) .Qfl(Z; x, y) as shown in Fig. l.
The S matrix for a photon emission process between
these states can be written by(2)(free-bound transition, i.e., radiative recombination).
For two-body scattering, the problem of photon emission processes was already treated in 1930 and has
set from the theoretical point of view. 3 ) Because weknow the exact formulas of a scattering state as well
as a bound state, we can see that the gauge invarianceproperty of photon emission S matrix holds in theseprocesses as already known. 3 )When the initial and final scattering states of process 1 are expanded as<Pi = (/lio+G oV1'iO+G OVG oV1'iO+···(3)

1'f =1'ro+G oV1'fO+G oVG oV1'ro+···h.
-li2
w ere Go=(E-Ho+~ctl, Ho= ---172

(4)

2p.

is a re-where Afl = (A, <D), .Qfl = (0, .Qo), A is the vector potential of radiation fields, <D its scaler potential. .Q isthe vertex function (the current operator) of aparticle and is given byieO(z; X,Y ) = - 2M [o( )(x-z)l1 zo(4)(z-y)4--o(4)(x-z)'rzo(4)(z-y)](7)and .Qo is the charge of a particle and is given asx

duced mass of a and b, and V is the interaction
potential between a and b, and S matrix for theradiative process can be written as<1'il~ H/I1'f>PfyJ= <1'iOl4J H/I1'ro>pf+<1'iOl VGo2JH/jJ+ ~ H/G oVI1'fo>prJ+<1'iOl VGo VGo2;JH/+ VGo~H/Go V
J+4J H/G oVG oVI1'fo>pr+···
J

J

(5)

Fig. 1. Schematic diagramme for the photon emission process due to the acceleration of a charged particle with theinteraction of radiation fields.

K. Hino, et al.

(8)

No~ the S matrix is rewritten by a gauge transformation f~om A,u (z) to A,u' ( z) using a relation

33

Because l (z) is an arbitrary functi<i>n, in order toobtain L1S = 0, i.e., to hold the gauge' invariance ofS matrix, it is necessary that we have
(16)

(9)

where

namely, •A\z) = A(z)+l7l(z)(10) '

fP'(z) = fP(z)+i(z)

(11)

(17)

Namely, a current defined bywhere A (z) is an arbitrary function and i is thederivative with respect to time. Under this transformation, a new S matrix Sft' is written as

Sri' = Sfi + < ¢r(x) la / l(z),Q Il(z; x, yl ¢I(Y) >ie

J(z) = - 2m < ¢r(x)Io(4)(x - Z)J7 z0(4)(Z - y)
- O(4)(X - z)'p zO(4)(Z - y) !¢i(Y) >= e¢r*(Z)¢ I(Z)r

'J S = dx dy i dz ¢r*(x)(a pZl(z»,Q Il(z; x, Y)¢i(Y)(13)

Making use of Green's theorem, we can obtain L1S as

JS= idXdy[JdS/{¢f*(X)l(Z),QIl(Z; X,y)¢i(Y)}(14)

where dSIl is the surface aFea element in the
integration on the boundary. Because l (± 00 ) =on the boundary, the first term of the right-handside of Eq.3 can be deleted. We have°

JS= - JdxdYJdza/'{¢f*(X),QP(Z; X,Y)¢I(Y)P(Z)(15)
Table 1.

(19)

in the usual form, should be conserved before andafter the interaction. For various ¢t (y) and ¢r (x),we can examine the gauge invariance property" pn
the basis of Eq. 16, i.e., the current conversion
requirement.
In the case of Bremsstrahlung, we can see that thegauge invariance property holds in every order of
perturbation e:h'Pansions of the S matrix. However,
if we make a perturbation expansion according to
Eq.3, in the continuum wavefunction for the radiative recombination process and ,employ ¢ f an exact
bound-state wavefunction, the gauge invarianceproperty does not hold in every order of perturbation
expansion of the S matrix.
For photon emission by electron acceleration in
the three-body system, we also examine the gauge

Validity of gage invariance in various approximations.

Systems and processes

Approximation

Two-body + fields
a+b- a+b+r-(a, b)+r

Exact solution for Bremsstrahlung and forradiative recombination

Hold

Two-body + fields
a+b- a+b+r

Perturbation expansion in terms of Va.b

Hold

Two-body + fields
A+b-(a, b)+r-/1 -Does not holdThree-body + fields
a + (b, c)-a+(b, c)*+r
a+(b, c)*-a+(b, c)+r

Perturbation expansion in terms of Va.b+ V a .c

HoldThree-body + fields
REG process
a + (b, c)-(a, c)+b+r

Perturbation expansion in terms of V a .c or V b.c using
non-potential Green's function (Brinkman-Krammers
approximation)

Does not hold-1/-

Perturbation expansion in terms of V a .c + Va.b or
Vb.c + Va.b using non-potential Green's function(Born approximation)

Does not hold-

Perturbation expansion in terms of V a .c with Green's
function under V a •c potential (Impulse approximation)

Approximately
hold

Strong potential Born approximation application

ApproxilDately hold

1/ -

-1/-

(18)

Jo(z) =e<c/Jf(x)lo(4)(x- Z)O(4)(Z- y) l¢i(Y) >(12)

If we write L1S = Sfi' - Su, L1S is given by,-:.J dZ¢r*{a/,QIl(z; X,Y)}l(Z}¢i(Y)]->Gauge invarianceK. Hino,et al.

34

1I1Vanance property in the same way. The gaugemvanance holds, for radiative excitation and radiative de-excitation such asa+(b, c)~ a+(b, c)*+r(20)

a+(b, c)*~ a+(b, c)+r

(11)

and

if we expand the scattering state in terms only ofVa,c and not of Va,b (here we assume a and barebare nuclei and c is an electron). However, for REC
such asa+(b, c)~ (a, c)+b+r,(22)

the gauge invariance property does not necessarily
hold.
In the Brinkman-Kramers approximation (thatignores Va,b and expands the S matrix in terms ofVa,c or Vb,c with a no-potential Green's function)and , in the Born approximation (that expands the
S matrix in terms of Va,b + Vb,c or Va,b + Va,c with ano-potential Green's function), the gauge invariancedoes not hold. The impulse approximation and thestrong-potential Born approximation (that expands
the 'S 'm atrix in terms of Va,c with Green's function
under': Va,c without and with off-shell contribution,
respectively) satisfy the gauge invariance approximately in 'every order of perturbation expansions.

The same results are f.ound in the relativistic theory.
Table 1 summarizes the gauge invariance propertyof "the S matrices for radiative processes in various
theories.
Inferring from the gauge properties of two-bodyradiative processes the Bremsstrahlung and the radiation recombination, we would expect that the gaugein,:ariant S matrix given by using a certain approximation method does not depend on the reference
frame employed for the three-body radiative' proce~s. Furthermore, by taking the degree of accuracyof ,the gauge invariance into consideration, we canm~ke a judgement of 'the coordinate-dependence of
the S matrix obtained ;'by a certain perturbation expansion for scattering states.
In the case of the REC S matrix by the perturbation expansion, for instanc~, the gauge invarianceholds more exactly in th~ projectile frame than in
the laboratory one.
References
1)

J. S. Briggs and K. Dettmann: Phys. Rev. Lett., 33, 1123

(1974) .
2) R. Shakeshaft and L. Spruch: Phys. Rev. Lett., 38, 175(1977) .
3) H. Bethe and E. E. Salpeter: Quantum Mechanics ofOne- and Two-Electron Atoms, Springer, Heidelberg,
p.320 (1957); Plenum, New York (1977) .

35
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-2. Photon Angular Distributions of the Ultrarelativistic K-Shell
Radiative :Electron Capture Induced by Heavy-Ion Collision
K. Hino and T. Watanabe

In 1979, Spindler et aU) observed that the radiation pattern of the radiative electron capture (REC;hereafter, we refer to REC into the projectile K
shell merely as REC) exhibits the forward-backward
symmetry. This feature is mainly due to the cancellation between the retardation effect of the emitted
photon and the aberrat~on of the emis,sion angle .of
photons from moving light source, i.e., the relativistic
effect cancels with the Lorentz transformation effectfrom the moving frame into the laboratory frame.
Here, the moving frame and the laboratory framemean th<;tt the origin of the coordinates are centeredon the incident projectile ion and on the center ofmass of ' the target atom, respectively. The cancellation effect of the REC photon angular distributions
can be shown using the first Born approximation as
follows. The angular distribution of the REC photon
estimated in the moving frame(1)

is Lorentz-transformed into the laboratory frame toprovide the form:(da/dfh) ex: sin2 {h(2)where OM and () L represent the emISSIOn angles ofphotons measured from the direction of the incident
velocity in the moving frame and in the laboratory
frame, respectively, Q M and QL stand for the associatedsolid angles, and {3 = v I c where v and c are therelative velocity and the velocity of light, respectively. Equation 1 includes the photon retardation
effect in the second term in parentheses; however,this effect is cancelled by the aberration effect given
by Eq.2.
Anholt et al. 2 ) experimentally justified the sin 2 () L
dependence of REC photons in bombardment of Be
atoms with 197 MeV lu Xe 54+ ions (,8 = 0.56). Recently, Pacher et ai. 3 ) theoretically confirmed such
behavior of the REC photon angular distribution byusing the non-relativistic impulse approximation (IA)method with retardation corrections. Furthermore,
Hino and Watanabe4 ) calculated the REC angular
distribution by virtue of the relativistically extended
strong-potential-Born (SPB) approximation and verified the experimental results of Anholt et ai. In
addition, they indicated that the sin 2 () L dependence

is deviated to some extent in the backward angle
region in ' the case of bombardment of Be atoms with
422 MeV lu U 92 + ions ({3 = 0.72) because of thestrong distortion effects between the incident projectile ion and the active electron. But there are no
experimental studies of REC photon angular distributions in the mass and energy region above
197 MeV lu Xe ions.
We are concerned with the ultrarelativistic behaviorof REC photon angular distributions, where {3 .isnearly equal to or above 0.9. , Recently, we 5 ) evaluatedthe radiation pattern of REC angular distributions
induced by U92+ colliding on a Be atom at several
ultrarelativistic incident velocities as depicted in Fig.
1. For calculations, two types of Feynman diagrams
are taken into consideration to explain the uItrarelativistic behavior of the REC process as shown in
Fig. 2. The first diagram is the conventional one andthe other involves an internal conversion process, thatis, the e+e- pair creation and the successive e+e- pairannihilation. In the ultrarelativistic energy region,
the contributions of the second diagram to the REC
process become comparable to that of the first one.
In Fig. 1, it is found that the peak positions of the
REC angular distributions are shifting to the forward
angle region, and their shapes deviate significantly
from the sin2 (} L dependence as the incident velocity
approaches the velocity of light. In the high energy

Fig. 1. Angular dependence of REC photon intensity for
U 92 + ions on Be systems. The intensity of photons isnormalized to the maximum value. Incident energy ofions are indicated in the figure. (}L denotes the angle in
the laboratory system.

K. Hino, et al.

36e-

to ion-atom collisions. .When the incident energy of
projectiles is more than 2 GeV lu, that is, the REC
photon energy exceeds 2 mc 2 a pair of e- and e+ is
produced. Since pair creation occurs in the moving
frame, the emitted e- and e+ are concentrated in theforward angle in the laboratory system. A permanent
magnet will be used to extract e- or e+ to detect
them with surface barrier detectors. When the paircreation is carried out by the radiative electron
capture to continuum, an additional electron will be
detected at the forward angle in coincidence witha pair or e- and e+. This ultrarelativistic effect of
REC angular distribution will be detected by coincidence measure~ents of simultaneously emitted twoelectrons and one positrons.
J

p

p

e-

T

(2 )

(1 )

Fig. 2. Feynman diagrams for the relativistic radiative electron capture process. P, a projectile ion; T, a target
nucleus; e-, an active electron; e, a positron; r' an emitted
photon. A black bold block represents the Coulomb interactions.

limit (f3 = 1 ), the REC photon angular distribution
is deduced to(3)2which is very different from the sin () L dependence
given by Eq. 2. The behavior represented by Eq.3
is due mainly to the higher-order photon retardation corrections.
We investigate the possibility of experimental
measurement along the line of radiative process due

References
1) E. Spindler, H.-D. Betz, and F. Bell: Phys. Rev. Lett.,
42, 832 (1979) .
2) R. Anholt, S. A. Andriamonje, E. Morenzoni, Ch. Stoller,
J. D. Molitoris, W. E. Meyerhof, H. Bowman, J.-S. Xu,
Z.-Z. Xu, J. O. Rasmussen, and D. H. H. Hoffmann:
Phys . Rev. Lett., 53, 234 (1984).
3) M. C. Pacher, A. D. Gonzalez, and J. E. Miraglia: Phys.
Rev. A , 35, 4108 (1987).
4) K. Hino and T. Watanabe: Phys. Rev. A, 36, 581 (1987).
5) K. Hino and T. Watanabe: unpublished.

37.

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-3.

Angular Distribution and Linear Polarization of X Rays Induced
by Radiative Electron Capture Process
K. Hino and T. Watanabe

Calculations using the Born approximation are
made for X-ray emission process on the ion-atomcollisions. The physical quaritities treated here are
the angular, distribution of the X-ray intensity due
to radiative electron . cc:l.pture (REC) into L-shells
and the linear polarization correlation of · photons
induced by REC to the K shell in the range ofrelativistic incident velocities.
Spindler, Betz, and Bell1 ) found for the first timeby measuring the REC spectra caused by light-ion
atom collisions that the radiation pattern of REC
to the K shell capture (K-REC) exhibits the forwardbackward symmetry independent of the projectile
velocity. They ,attributed this effect to the cancellation between electron retardation effects and theLorentz transformatio~ from the projectile frame tothe laboratory frame.
Recently, it has become possible experimentally tomeasure the angular distribution for photons induced
by REC to the L shell (L-REC) with the increaseof beam intensities of high-energy, heavy-ion accelerators. As far as we know, however, from theoreticalpoint of view, there ' is not even a simple prediction
for the angular distribution so far. It is expectedthat the measurements of the polarization effects of
the REC photons shed light on the REC process fromother viewpoints. In the present report, we discuss
the angular distributions for L-REC photons 2 ) andfurther for the linear polarization effects for K-REC
photons 2 ) by using the simple formulae for the photoelectric effect (PE) given by the Born approximation 3 ) and by Lorentz-transforming the formulae tothe laboratory frame. Hereafter, by the projectile
frame, the origin of ,the coordinate system is centeredon an incident projectile ion, and by the laboratory
frame, the origin is chosen at the center of mass ofan initial target atom.
Recently we investigated the validity of thequantum mechanical theory on REC from the viewpoint of the gauge invariance property.4) For theheavy projectile ion impact on a light target, theprojectile ,coordinate system is found to be mostproper or, in other words, call least errors under thecondition of electro-magnetic current conversion.
Thus, the coordinate system for PE is always definedin the projectile frame. Herein, we use L-REC for

the radiative electron capture to the 2p state of a
final projectile atom unless otherwise stated. We
have little interest in the radiation pattern for REC
to the 2s state because the pattern is almost thesame as that for K-REC. Furthermore, REC isassumed nothing but the inverse process of PE,
namely, the (two-body) radiative recombination
process. 3 )Firstly, we consider the shapes of the angular distributions for L-REC. By Lorentz-transforming to
the laboratory frame the angular distribution for PE
from the 2p states (L PE) given by using the Born
approximation including the lowest-order retardation
corrections,5,G) this can be obtained as(daU+Iu/dQ) = (au +III/ 47r )' [1-21' cos 0 sin2 OJ(I)

where subscript I stands for 2s state and II + III for
2p P 1/2 as well as 2p P 3/2 states, f3 = v / c (v and carevelocities of an ejected electron and light, respectively), (j and Q denote the emission angle of aphoton and the associated solid angle in the laboratory frame, respectively, and UIl+III represents the total
L(II + III) cross section for L-REC. If the retardation is negligible, i.e., if the second term in thesquare brackets of Eq. 1 can be dropped, the angular
distributions for L-REC become isotropic as shownby Bethe and Salpeter. 3 ) It is easily found from Eq. 1
that the retardation effects of L-REC are not completely cancelled by the Lorentz-transformation, while
those of K-REC are done. 1 )The observed photon spectra are given as thesummation of both contributions of REC into 2s states
and 2p states.7) The. photon angular shape of REC
into a projectile 2s state (L (I) -REC) is essentiallythe same as for K-REC. Further, we use L(II + III)REC to mean the capture into the projectile 2p states.
On the assumption that the REC process is theinverse one of corresponding photoionization, theangular distributions of X rays for L (II + III) -REC
must be isotropic as pointed out by Bethe andSalpeter. 3 ) However, we know the fact that theangular distributions of an ejected electron for thephotoionization deviate from the isotropic behavior
with the increase in the importance of the photon
retardation effect.

K. Hino, et al.

38

By Lorentz-transforming the angular distributions
for the photoionizations from the 2s and the 2p statefrom the projectile (moving) frame into the laboratory frame, we can obtain the photon angular distributions in the relativistic velocity region of L (I) and L(II+III)-REC as:(do"I/do"L) = (3/Bn-)o"I sin2 fh

§o
a..

N

(2)

where aI and aII+1II represent the total cross sections
for REC into the projectile 2s and 2p states, respectively and are given by(3)() (degrees)Fig. 2. Linear polarization correlation P (8) for radiativeelectron capture to the K-shell for several velocities. I, f3=
0.6 (235 MeV/amu); II, 0.7 (376 MeV /amu); III, 0.8 (626
MeV /amu); and IV, 0.9 (1.22 MeV /amu) .

and

(4)
Here,
F(IJp) = (21°n-ro2/3a)· 4n-

X IJp[l- exp (- 4n- IJp)J- 1 exp (- BIJp cot-1IJp)(5)
with r ° the classical electron radius where IJ p =Z pa/nj3, Zp is the charge of projectile ion in unitsof electronic charge, a is the fine structure constant,and n is a principal quantum number (n = 2).
In fact, one observes the L-REC angular distributions as the summation of the contributions from both
L(I)-REC (Eq.3) and L(II+III)-REC (Eq.4).
Thus, it is important to know the ratios of aI to
O"II+III with respect to the only one parameter Vp, They
are given in Table 1. It is expected that deviationsof the L-REC angular distributions from sin2 0Ldependence can be measured clearly in the large IJ p
regions. In Fig. 2, we depict some normalized LREC angular distributions for the projectile charges
Zp = 54 and the incident velocities v / c = 0.2 and
9.4, respectively.

L- REC>- 1.0

,..

I-

enz

,- ."

w

/

I~

/

~ 0.5
a:

/

/

«

w

/

,- /

i=
...J

/

/

/

/

- - /3=0.2----- /3=0.4

//

--'"

Fig. 1. Normalized photon angular distributions of L-REC(L (I) + L (II + III» for the projectile charge Zp= 54.
Table 1. Ratios of 0'1 to O'II+III
eters I.Ip.

IJp
O"r/O"II+I1I

O. I

V8.

the Coulomb param-

0.2 0.3 0.4 0.5 0.6 O. 7 0.8 0.9 1. 0

32.0 8.8 4.1

2.5

1.7

1.3

1.10.90.8 7.0

Next, the linear polarization correlations for the
K-REC photon are taken into consideration. The
differential cross section for PE from the K shell(K PE) is of the form S,9)(dO"PEK/dQ') =2- 1(do-PE K d/Q') unpol(l +P'(O') cos 21»(6)where f)' and QI stand for the emission angle andthe solid angle in the projectile frame, respectively,(dapEK / dQ') unpol means the K PE angular distribution for the unpolarized photon, P' (0') represents
the linear polarization correlation for K PE, if> isthe angle between the scattering plane and thepolarization plane constructed by k and e.
We can obtain the linear polarization correlation
for K-REC, P( 0) :P(O) = [ - (r- l )+2r(l- f3 cos O)J/[(r - l)(r - 2)+2r(l- f3 cos O)J(7)

where r- 1 = (1- 13 2 )1/2, P ( 0) represents the polarization correlation for the linear polarized K-REC
photon in the laboratory frame, average over initial
target electron spin states and summed over final
projectile electron spin states. P ( 0) is depicted inFig. 2.
References
1) E. Spindler, H.-D. Betz, and F. Bell: Phys. Rev. Lett.,
42, 832 (1979).
2) K. Hino and T. Watanabe: Phys. Rev. A, 36, 5862
(1987) .
3) H. A. Bethe and E. E. Salpeter: Quantum Mechanics ofOne- and Two-Electron Atoms, Springer-Verlag, Heidelberg (1957); Plenum, New York (1977).
4) K. Hino and T. Watanabe: unpublished.
5) G. Schur: Ann. Phys. (Leipz.) , 5 Folge, 4, 433 (1930).
6) H. K. Tseng, R. H'. P. Simon Yu, and ' A. Ron: Phys.
Rev. A, 17, 1061 (1978).
7) Y. Awaya, K. Hino, A. Hitachi, K. Kanai, K. Kawatsura,
K. Kuroki, H. Vogt, Y. Yamazaki, and T. Watanabe:High-Energy Ion-Atom Collisions, Lecture in Physics,
No.294 (eds. D. Berenyi and G. Hock) , Springer-Verlag,
Heidelberg, p.185 (1988) .
8) B. C. H. Nagel: Ark. Fys., 18, 1 (1960).
9) R. H. Pratt, R. D. Levee, R. L. Pexton, and W. Aron:
Phys. Rev., 134, A898 and A916 (1964).

39
RIKEN Accel: Prog. Rep. 21 (1987)

11I-2~4.

Calculation of Electron-Stripping Cross Sections
of..:Ne Ions in Proton Impact.X. Fang,* x. Zhang,* Q. Ma,* and Y. Liu,* and T. Watanabe
Inelastic collision pr9c~sses involving multi-charged
ions and atomic hydrogen are of considerable interest, not only from theoretical viewpoints but also
in relation to the practical aspects of electron stripping processes of accelerated projectile ions by accelerator~~ Among them, the processes of charge
stripping (ionization) and charge exchange (electron
capture) have Iieceived .a: great deal of attention 'in
the study of ' tharge balancing mechanism.
In this work, we treat the ·' problem of electron
stripping processes:
Aq+ +p- A(q+l)+ +e+p, q= 1,2,3, . . .

O'BEA(W,V, U)~. ~:: [~+ ~~: . '2m(V:-W

2 )]

(1)

"\Ie use a binary encounter approximation (BEA)
to describe collisions between an incident proton andelectrons of a target ion and use the RoothaanHartree-Fock method to obtain velocity distributions
for the elections.
Theoretical work on the electron stripping processof a multicharged ion was reported recently by
Karashima et al. l ) They calculated the electron stripping cross sections of C and N e ions in proton impact
based on BEA and velocity distributions of theThomas-Fermi model. The main purpose for theircalculation is to obtain the cross section for electron
stripping of a multicharged incident ion by a hydrogentarget atom. In some cases, the theory can be replaced by that for the ionization processes by proton
impact.
A main advantage of the binary encounter theory2)
is that it gives, in a direct and simple way, reasonableestimates of cross sections for a wide variety ofphysical processes. In general it is most satisfactory
to apply the binary encounter theory to the ionization process in comparison with charge exchange andexcitation processes. The Hartree-Fock method generally involves a great deal of calculations and gives
numerical results for atomic orbitals and energy levels.
Analytic fitting to numerical solutions of the HartreeFock equations is very useful for practical purposes.
The Roothaan-Hartree-Fock method 3 ) can be used
to obtain analytic orbitals for atomic systems. According to the Roothaan-Hartree-Fock formalism,
Clementi and Roetti 4 ) calculated and tabulated theparameters to determine analytic orbitals for a series* Department of Modern Physics, University of Science andTechnology of China, Hefei, Anhui, China.

of atoms and ions in the ground and some excitedstates. We "Yill use relevant data given by Cleme~ti
et al. 4 ) to calculate the electron velocity distributionsof target ions. 5 )The BEA cross section for the ejection of ane'ectron with :the velocity U? and binding energy U
by an incidellt proton of the vel~city v was derived 2)
as follows:

for

U
2mv

W~V----

U
for w;;::::v---

-

2mv

U

=0 for W~---V
-2mv

(2)

'f
()

; 10- 17oi=

frl 10-18

(J)

-20

10

10

2

10

4

6

10

ENERGY (keV)

Fig. 1. Electron stripping cross sections of Ne ions in proton
impact, calculated by the BEA and RHF velocity distributions. The comparisons are made for q=O and q=8 withexperimental as well as other calculated data. For q=O(p+ Ne) , experiments are from many authors6 - 10 > and calculation is using the Born approximation by Peach.11> For
q = 8, comparison is made by the scaled cross sections forK-shell ionization by proton impact on neutral target, notfor Ne8 + target. Particularly the K-shell ionization crosssection for neutral atomic target can generally be reduced
from the scaled cross sections.

X. Fang, et al.

40

where m is the mass of the electron.
The average cross section for process (1) is givenbyJr

U(V) =~ UBEA(W,V, UuJfaCw)dw
il(3)= ~ Wa rUBEA(W, V, Ua )w2 2.J Ca. kF)'k(W)2dw
il

J

k

(4)
where we have identified the binding energies of theelectron shell (i), U i with the magnitude of theorbital energy given by Clementi et ai. 4 )According to expression 3, we performed calculation for collisions between proton and Ne q + (q =0, 1, 2, ... , 8) In the ground state. Figure 1 shows
the results.
References
1) S. Karashima, T. Watanabe, Y. Awaya, and Y. Liu: Nucl.
Instmm. Methods A , 240, 505 (1985)., .

2) L. Vriens: Case Studies in Atomic Collisions Physics,(eds. E. W. McDaniel and M. R. C. McDowell) NorthHolland, Amsterdam, Vol. I, Chap. 6 (1967) .
3) C. c. J. Roothaan: Rev. Mod. Phys., 23, 69 (1951); J.
Hinze and C. C. J. Roothaan: Prog. Theor. Phys. Suppl. ,40, 37 (1967).
4) E. Clementi and C. Roetti: At. Data Nucl. Data Tables,
14, 177 (1974).
5) X. Fang: ' M. S. Thesis, USTC, Hefei, Anhui, China(1986) .
6) J. W. Hooper, D. S. Harmer, D. W. Martin, and E. W.
McDaniel: Phys. Rev., 125, 2000 (1962).
7) F. J. de Heer, J. Schutten, and H. Moustafa: Physica
32, 1766 (1966).
8) H . B. Gilbody and J. B. Hasted: Proc. R. Soc. A, 240,
382 (1957); H. B. Gilbody and A. R. Lee: Proc. R. Soc.
A, 274, 365 (1963).
9) L. 1. Pivovar and Yu. Z. Levchenko: Zh. Eksp. Teor.
Fiz., 52, 42 (1962) [Sov. Phys. ]ETP, 25, 27 (1967)].
10) E. S. Solov'ev, R. N. Il'in, V. A. Oparin, and N. Y. Fedorenko: Zh. Eksp. Teor. Fiz., 52, 42 (1962) [Sov. Phys.
]ETP, 15, 459 (1962)].
11) G. Peach: Proc. Phys. Soc., 85, 709 (1965); G . Peach: ].
Phys. B , 1, 1088 (1968).

41
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-5. Charge-Exchange Cross Sections and Equilibrium Charge
States of Incident Uranium Ions with Relativistic Velocity
S. Karashima, K. Hino, and T. Watanabe

Knowledge of the charge states of relativistic heavy
ions and of their charge-exchange processes in low
and high atomic-number (ZT) materials is of great
theoretical and experimental interest from the viewpoint of fundamental science and the applications
such as to the fields of heavy-ion beam inertial confinement fusion and of accelerator science.
The equilibrium charge states and linear energy
transfer, LET, of Ne and Ar ions in hydrogen gas
were calculated 1 ) in non-relativistic velocity region.
In this paper, the charge-exchange processes andcharge-state distributions of uranium ions with arelativistic velocity impacted in mylar, AI, Cu, Ag,
and Ta are treated by the relativistic formalism,
and the calculations are compared with experimental
values.
The fundamental processes in charge exchange areelectron loss from a projectile ion and electron capture
from a target atom into a projectile atomic level.
We develop a relativistic Born approximation for the
calculation of electron-loss cross sections. For electron
capture processes, radiative electron capture (REC)dominates rather than non-radiative electron capture(non-REC) in the high impact velocity range. The
REC cross sections into a projectile K-shell fall off
as v- 5 with increasing relative velocity, while the
non-REC decays as V- 12 • The non-REC and the REC
cross sections are calculated by the relativistically extended eikonal and strong-potential Born approximation.
On the occasion where a projectile ion with acharge q collides with atoms in a target, the ion may
capture or lose one or more electrons at each encounter. From now on, for simplicity, single-chargeexchange processes are assumed to be dominant for
relativistic heavy-ion impacts. The equilibrium charge
state distributions of the ion with an atomic number
Z are determined from the ratios 2 ) of the electron
capture and loss cross sections. The average equilibrium charge q is obtained from a fraction F q ofcharge state q:z
q = LJ qFq ,
f

with

z

LJ Fq = I(1)q

We consider two processes for electron capture in
relativistic velocity range: REC process and non-REC

process. REC is the inverse of a photoelectric process. A bound target-electron is captured into avacant state of the projectile and can directly radiate
the energy gained by this transition as an X-ray
photon. Charge exchange in matter for sufficiently
high incident energies is due predominantly to the
REC process.
The non-REC cross sections are calculated using
Eichler's formula 3 ) based on a relativistic eikonal
approach. The eikonal approach is an asymmetrictheory with respect to projectile and target. Whenthe active-electron-projectile and the active-electrontarget interaction are treated nonperturbatively, one
obtains different results. This is inherent in theeikonal theory and is called the post-prior discrepancy.
Concerning these two theoretical versions on the treatment of non-REC process, we properly use the priorform if ZP~ZT' and the post form if Zp>ZT' where
Zp is the projectile atomic number.
For the REC, Hino and Watan~be4) developed astrong-potential Born approximation 5 ) relativisticallyfor the process depicted in the Feynman diagram
shown in Fig. 1 (a). Projectile (P), target (T), andactive electron (e-) move along arrows through P-eand e--T interactions. In addition to this usualphoton emission process, the present calculation includes the contribution from the internal conversion
process shown in Fig. 1 (b) ; that is, in the first place,

P

e(a)

T

P

T

Fig.!. (a) Feynman diagram for the usual REC photon
emission process. P denotes a projectile ion, e- an active
electron, and T a target atom. e-· T makes an initial boundstate and P-e- a final bound state. Photon (r) is emitted
through an electron capture process from a target into theprojecile. (b) Feynman diagram including the internalconversion process for the REC. e+ denotes a positron, thedirection of particles are indicated by arrows and a blackbold block represents Coulomb interactions.

S. Karashima, et al.

42

the final electron and the virtual positron are produced at the same time when the photon emission
occurs and then the positron is pair-annihilated with
the initial electron under the Coulomb potential
between the electron (e-) and the projectile (P).
When the relative velocity v is higher than 0.5 nu(nu: natural units, n= c = 1), the internal conversion
contributions take an important part in the REC
process. This effect becomes remarkable particularly
for collision of highly charged ions such as U+ ion.
The electron-loss cross sections from projectile
atomic states are formulated by the Born approximation with some relativistic modifications. The modifications to the formalism include the considerationof the bi-spinor contribution of respective particles
as well as the full employment of the relativistic
kinematics. The Coulomb distortion effect between
a projectile and an active electron as well as the
Coulomb interaction between a projectile electron
and a target nucleus is taken into account, whereas
the loss cross sections due to the Bethe theory 6 ) usedby Gould et ai. 7 ,S) only include the latter contribution.
We can write the total electron loss cross section in
the form:

We calculated the charge state fractions Fq under
the condition of local charge equilibrium by
(3)

with

F q/ F q _ 1 =O'q_l, q/O'q, q-l = Pj
where (J q,q' is the capture (or loss) cross section fromcharge state q to q'.
For comparison with the experimental data obtained by Gould et ai., we calculated the value of theequilibrium charge state distributions for 200 MeV /nucleon (v=O.57 nu), 437 MeV/nucleon (v=O.73
nu) and 962 MeV/nucleon (v=0.87nu) uranium
ions and found that the overall tendency is explainedon the basis of our calculation, although small discrepancies could be found. For accounting for thetarget ZT-dependence of cross sections more precisely,
it is necessary to accumulate the cross section values
as a function of the target atomic number. In highZT targets, the non-REC process into excited statesof the projectile would be dominant, although notconsidered in the present calculations.
References

Xl k dk f~ (1+;.-')
X[l- MTrmTk + m2rk2_q2](2MTr)'l2

X

I<q)~;)(k, rleiq'-;'¢pe(r) >

r

(2)

C;)

where q)pe
and q)~-;)(k,;) are the initial boundstage wave function of an electron in the projectile
nucleus and the continuum-state Coulomb wave function of an ejected electron with a momentum k,respectively, MT and m are the masses of a target
atom and an electron, rk = (1 + (k/m) 2) 1 / 2, r =1/ (1 - v 2 )1/2 andof a target atom.

q denotes the momentum change

1) S. Karashima and T. Watanabe: Radiat. Res., 99, 476(1984) .
2) S. Karashima and T. Watanabe: lpn. I. Phys., 22, 895(1 983) .
3) J. Eichler: Phys. R ev. A, 32, 112 (1985) .
4) K. Hino and T. Watanabe : Phys. R ev. A , 36, 581 (1987).
5) J. Macek a nd R. Shakeshaft: Phys. R ev. A, 22, 1441
(1980); J. Macek and S. Alston: Phys. Rev. A, 26, 250(1982); S. Alston : Phys. R ev. A, 27 , 2342 (1983).
6) H. A. Bethe: Ann. Phys. (Leipzig), 5, 325 (1930).
7) H. Gould, D. Greiner, P. Lindsrom, T. J. M. Symon, M.
Grawford, P. Thieberger, and H. Wegner: Phys. Rev.
L ett., 52, 180 (1984); Errata: Phys. Rev. Lett., 52, 654(1984) .
8) H. Gould, D. Greiner, P. Lindstrom, T. J. M. Symons,
M. Grawford, P. Thieberger, and H. Wegner: Nucl.
Instrum. Methods B, 10/11, 32 (1985) .

43

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-6. Electron Capture between Arbitrary Excited Statesin the Continuum Distorted Wave Approximation
S. C. Mukherjee* and T. Watanabe
The cross sections for electron capture between
arbitrary excited states of a target and a projectile
have been calculated by Omidvar1 ) in the Oppenheimer-Brinkman-Kramers (OBK) approximation.
The 'Full Born approximation' has been used by
Toshima 2 ) for the calculation of a few selected
tranSItions between high-lying states of atomic hydrogen. The charge exchange calculations between
arbitrary excited hydrogenic states, nl and n'l' of atarget and a projectile in the high energy region havebeen reported by Eichler 3) in the eikonal approximation. Ho et al. 4 ) extended the eikonal calculations
to cover nlm contributions.
In the study of charge exchange process, at highincident velocities the classical capture occurs througha two-step process and thus the inclusion of thesecond-order term is necessary in the quantum mechanical calculation. 5 ) The continuum distorted wave
approximation (CDW) is known as an adequate
second-order method for the calculation of charge
exchange cross sections. 6 ) In the present paper, westudy the charge-transfer cross sections from arbitrary
initial excited states to final excited states in the
CDW approximation. The procedure we follow here
has been developed in a recent publication. 7 ) The
Coulomb integrals involved in the CDW approximation are evaluated in a closed form in terms of aterminating Gauss-Hyper Geometric function. Thisapproach is found to be (quite) suitable for application to any arbitrary excited states and also appears
to be of much convenience for numerical computation.

Table 1. Charge transfer cross-sections, O'nlm-n'l'm'X 10-16 in cm2, calculated for the reactions
H++H(2l)-+ H(3l' )+H+ as a function of energy. The numbers in parenthesis denote thepowers of ten, by which the numbers are multiplied.
Lab. energyof H+(keV)

0'2s-8s

0'2S-8p

0'2s-8d

0'2p-8S

0'2p-8p

0'2p-8d

25
50
100
250
500
800
1,000

1.30(-1)
1. 56( -2)
9. 74( -4)
1.23( -5)
3.28( -7)
2.56( -8)
7.49( -9)

1.55( -1)
1.26( -2)
5.03( -4)
3.47( -6)
6.01( -8)
3.63( -9)9.58( -10)

5.09( -2)
2.63( -3)
6.62( -5)
2.88( -7)
4.43( -9)
2. 73( -10)
7.68( -11)

1.41( -1)
6.12( -3)
1. 86( -4)
1.20( -6)
2.15( -8)
1. 33( -9)3.65( -10)

3.51( -1)
1.31(-2)
3. 57( -4)
2.46( -6)
5. 71( -8)4.42( -9)
1. 32( -9)2.05( -1)
a.1O( -3)
2.23( -4)
1.65( -6)
3.82( -8)
2.95( -9)
6.90( -10)

Table 2. Charge transfer cross-sections, O'nlm-n'l'm' X 10-16 in cm2, calculated for the reactions
H++H(2l)-+ H(4l' )+H+ as a function of energy. The numbers in parenthesis denote thepowers of ten, by which the numbers are multiplied.
Lab. energyof H+(keV)
25
50
100
250
500
800
1,000

0'2S-48

0'2S-4p

0'2S-4d0'2S-4f

0'2P-4S

0'2P-4p

0'2P-4d

0'2P-4f

5.69
(-2)
7.00
(-3)
4.29
(-4)
5.30
(-6)
1.40
(-7)
1.08
(-8)
3.18
(-9)

6.63
( -2)
5.80
( -3)
2.31
( -4)
1.58
( -6)
2. 74
( -8)
1. 67
( -9)
4.40
(-10)

2.62
( -2)
1.54
( -3)
4.01
( -5)
1. 74
( -7)
2.97
( -9)
1.90
(-10)
5.46
( -II)

8.12
( -3)
2.80
( -4)
5.57
( -6)
2.32
( -8)
4.12
( -10)
2.44( -II)
6.76( -12)

7.6
( -2)
3.03
( -3)
8.50
( -5)
5.26
( -7)
9.24
( -9)
6.3
(-10)
1.68
(-10)

1. 90
( -1)
6.48
( -3)
1.63
( -4)
1.08
( -6)
2.46
( -8)
1.84
( -9)
5.58
(-10)

1. 50
( -1)
4.41
( -3)
1.06
( -4)
7.21
( -7)
6.16
( -9)
1.23
( -9)
3.50
(-10)

1.09
( -1)
3.44
( -3)
9.20
( -5)
6.72
( -7)
1.01
( -8)
7.90
(-10)
3.63
(-10)

* Permanent address: Indian Association for the Cultivation of &ience ]adavpur, Calcutta-700032, India.

S. C. Mukherjee, et al.

44

10- 16 X 10- 4

10- 211

10- 16 X 10- 5

10 22

10 2 1

10- 16 X 10- 5

10- 16 X 10- 6s::

10- 16 X lO- G

2

.~

CfJ

10 - 16 X 10- 4

10- 2310- 16 X 10- 7

Vl
Vl

s::

.~

10- 231O- 1G X lO-1

<IJ

0

U

CfJ

5'"

0

Vl
Vl

0- 10- 21

10- 16 X 10- 8

U

U 10~

21

10 - 16 X 10- 8

::l

0-

25 - 35

10- 2'

1O- 21iJ
10 16 X 10- 9

10- 2510- 16 X 10- 10

10" 26

10- 16 X 10- 11

1O-2~0L-0-2.J.00-30L...0-4..l.0050L...0-6.J.00-70L...0-8.L0090L.::>0~10.L0-O_ _ _ _ _...J 10 16 X 10- 11

10- 16 X 10- 9

2s - 3d10-21
100 200 300 400 500 600 700 800 900 1000

Proton ~nergy(KeV)

P roton E nergy in Ke V

Fig.!. Cross sections for charge transfer between the n=2
and n'=3 level of hydrogen atom as a function of proton
laboratory energy. - - present CDW results for initial 2s
states, - - - present CDW results for initial 2p states.

Fig. 2. Cross sections for charge transfer between the n=2
and n' =4 level of hydrogen atom as a function of proton
laboratory energy. - - present CDW results for initial 2s
states - - - present CDW results for initial 2p states.

References

Chan: Phys. R ev. A , 24, 705 (1981).
5) Dz. Belkic: l. Phys. B, 10, 3491 (1977).
6) Dz. Belkic and R. McCaroll: l. Phys. B, 10, 1933 (1977).
7) G. C. Saha, S. Datta, and S. C. Mukherjee: Phys. R ev. A,
36, 1656 (1987) .

1) K. Omidvar: Phys. Rev., 153, 121 (1967).
2) N. Toshima : ]. Phys. Soc. lpn., 46, 927 (1979) ; 46, 1295
(1979) .
3) J. K. M. Eichler: Phys. Rev. A, 23, 498 (1981) .
4) T. S. Ho, D. Umberger, R. L. Day, M. Leiber, and F. T.

45

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-7. Charge Transfer Collision between a Low Energy Ion
and a Solid Surface
K. Fujima, H. Adachi,* and M. Kimura

In a previous reportl ) we calculated the chargetransfer coss section between He+ and Si to simulate
Ion Neutralization Spectra. This model calculation
in a diatomic model is the simplest, but it is desirable
to extend our calculation into a more realistic case.
To investigate the charge-transfer cross section
between a low energy ion and a solid surface, wetake a simple but still realistic cluster model.
We selected the Si (1 0 0) surface as a target andtook a cluster shown in Fig. 1 to represent thesurface. This cluster is made of seven silicon atoms
including the central and second nearest neighboratoms. A He+ ion approaches along the Z-axis andcaptures an electron from the target cluster. We
employed a basis set consisting of 1 s for the He+
ion and 1 s to 3 d for the Si cluster for most calculations. Selected calculations were performed for larger
basis sets including additional 2 sand 2 p orbitals for
the He+ ion to examine the issue of convergence.
Figure 2 illustrates the level diagram of the system
of He+ + Si 7 • In the united atom limit, this system
becomes a SiaS cluster. The orbital energies of thisneutral cluster are shown on the left-hand side ofFig. 2. Shown on the right-hand side of the figure
are the orbital energies in the separated atom limit,
i.e., an isolated Si surface plus a free He+ ion. Since
the 2 sand 2 p of the Si atoms are inner shell orbitals,
these orbitals do not mix with each other except forthe central Si atom. The 3 sand 3 p orbitals makean sp valence band. The 3 d orbitals of the Si atom
are not occupied and therefore make an unoccupied
band, which is not indicated in Fig. 2. The 1 s levelof He+ is located in the middle of the Land M

shell levels of the Si atoms, as in the diatomic casein the separated atom limit. When a He+ ion
approaches the surface at distances larger than 1 a.u.,

-0.1

-0.2

-0.5

>.

eo
H

He

Q)

+

(15)_10

~

f.il

~

.~

~

o

-20

-::::===-========Si( 2p) ~-5

S i (;;:.2,="p~)_ _ _ _Si(2s)_____-~~

Si(25)

Sili,~

25

-10

S(25)

0.2

0.5

5
2
atomic distance

10

20(a.u.)

Fig. 2. Energy diagram of the He++Si7 system. The 1 s
orbital energies of the Si atoms are not plotted. Only the
top and bottom of the Si 3 s-3 p band are indicated.

-0. 01

-0.03
-0.07
-1.0
T--

.,.-"'-"'''"''9"'--",-.,.-''' . .
4 a-y-", -. T - , . _ T -"If

-0.3
-7.0
-10.0

10""

r - - j T'-"'0.03 0.070.1
Fig. 1. A target cluster of Si atoms (solid circles) used in
the calculations.

* Hyogo University of Teacher Education.

T_.,_ ..-T-T-,"-"':" T-T-T-"
0.3

I

I

I

0.71

3

7

-70.0

ATOMIC DISTANCE (a.u.)
Fig. 3. Energy diagram of the He++Si system. Orbitals be·longing to CT, 7T, and 8 irreducible representations areplotted with ... , ., and A, respectively.

46

K. Fujima, et al.

the orbital energies of the cluster do not change
drastically. When the He+ comes closer to the surface,the 2 sand 2 p levels of the central Si atom start
to lower because of the attractive core potential of
the He+ ion. Owing to this lowering of the innershell levels, the 3 sand 3 p orbitals of the central
Si atom make molecular orbitals with the 1 s orbitalof the He+ ion. The bottom of the 3 s-3 p bandrises in energy. The energy of the 1 s orbital of the
He+ ion increases. The energy difference between
the bottom of the 3 s-3 p valence band of the Si
surface and the 1 s level of He+ becomes smaller.
In fact, the 1 s level is known to merge into the3 s-3 p band in the united atom limit, though thepresent calculations are too inaccurate close to thislimit to be included in Fig. 2.
This feature is quite similar to that of the He++
Si system previously reported 1 ) and indicates the large
amplitude of picking up an electron from the bottomof the Si 3 s-3 p band. The energy diagram of theHe++ Si system is shown in Fig. 3. Since the generaltrend of the energy diagram of the He+ + Si7 system
is very similar to that of the He+ + Si system, thecharge-transfer cross sections of both systems arethought to be of the same order of magnitude.
However, our calculation suggests that if the 2 s
and 2 p vacant orbitals of He+ are taken into account,these orbitals will mix with the 3 sand 3 p orbitalsof the central Si atom. These orbitals will also mix
with those of neighboring silicon atoms making aband. This would result in a quite different chargetransfer cross section from the 3 s-3 p band of the
Si surface to the L shell orbitals of the He+ ion ascompared with the case of the diatomic model.
Reference
1) K. Fujima and H. Adachi: RIKEN Accel. Prog. Rep.,
20, 37 (1986).

47
RIKEN Accel. Prog. Rep. 21 (1987)

Q. Ma,* X. Zhang,* Y. Liu,* and T. Watanabe
The lifetime of positronium is influenced greatly
by its spin state. The singlet spin state (para-positronium) decays radiatively emitting two r-rays with alifetime of 1.25 X 10-10 S1) and the triplet spin states(ortho-positronium) decays emitting three r-rays
with a lifetime of 1.41 X 10-7 S.2) The conversion crosssection is important in · measuring the lifetimes ofthe positronium. In this paper we calculated andobtained an analytical formula for the para-ortho
conversion cross section using the first Born approximation (FBA). Difficulty appears in evaluating thematrix element by using the Jacobi coordinate system
which has been treated in a p+ + (p-p) scattering
problem. 3 ) The numerical results are compared withthe classical trajectory Monte Carlo (CTMC) calculation. 4 )Let us consider the case where electron 1 collides
with a positronium composed of electron 2 andpositron 3 to result in a new positronium composedof electron 1 and positron 3, as shown in Fig. 1.
We use two-state approximation(2)

where kr a is vector of kr with k r2 = ~~ (E - sr),
-+
.- ->
-+ •
•
2P
F1(R)=e1kj"R and k i IS a vector of kJ WIth k i2 = ~-+-+X (E-ed, () is the angle .between Rr. and kI, Hi' is

the interaction potential in the initial state, and Si
and Sf are the initial and the final spin-state wavefunctions, respectively. The differential cross section
is obtained as
da

_ kr

dQ (0, ¢)-Tr!U(O)!

2(3)

and the total cross section is given by
in

v

a .u.

o

2

3

r-rT"T"1\r-T""T""r-r"T""T"""T""!""-r-rr"""""'-rnrrrrrr~ 10 2

-+

-+

-+-+

W=FJ(R)¢i(r)Si(l ,2, 3) + F r(R')¢f(r')Sr(2, 1,3)

\
\

(1)

\

\

where ¢i(;) and ¢r(-;') are the eigenfunctions ofI-.1_\"-+

bound states in the initial and the final states, Fi (R)-+and Fr(R') are the wavefunctions for the travellingstates of e- + (e-e+) in the initial and final states,
respectively, and Si (1,2,3) and Sf(2, 1,3) are theinitial and the final spin-state wavefunctions, respectively.
The scattering amplitude for the process III thefirst Born approximation is written as\ I, \/ / CTMC

\

\L
'i

\1
\

.!:

i
1:5" 10-4

10- 6

10- 8

10- 4

o
v

Fig. 1.

Schematic colliding system and its coordinates.

* Department of Modern Physics, University of Science andT echnology of China, Hefei, Anhui, China.

in

a.u.

Fig. 2. Total cross section for e-+ (e-e+) (1IS1)-+ (e-e+) (1180)+e- (ortho-para conversion) as a function of relative
impact velocity in atomic units. FBA, the present FBA
calculation; CTMC, the classical trajectory Monte Carlocalculation (Ref. 4); - - - - -, poor approximation region in
FBA.

48

Q. Ma, et al.

kr r= 27rTC;
J0 IU(8) 12 sin 8 d8
lr

(J

(4)

The total cross sections for the para-ortho conversion process as a function of an incident relative
velocity are given in Fig. 2. These data are compared with the results by CTMC.4)
Comparison with the CTMC calculations for the
total cross section (TCS) shows that TCS by FBA
has the same velocity dependence and is somewhat
smaller than that by CTMC above 1.5 a.u., contrary
to the cases of p.+ on (p.-p) and of positron on H
scattering. It is evident that the first-order calculation overestimates TCS at low velocities particularly
in a particle transfer process.
Differential cross sections (DCS's) have a quite
different tendency of the scattering-angle dependence

from those of p.+ on (p.-p) and e+ on H by FBA.
This is due to the same mass of the particles concerned. In the high velocity limit, the cross section
for the break-up channel e- + (e-e+) ' ~e++e-+e­will dominate. The exchange channel is limited tothe cases where the final momenta of the projectile
e- and e+ are confined to a small three-dimensional
domain, making a new positronium possible. Thisis the reason why DCS in the high velocity limit isconcentrated on 180 0 whereas DCS for p.++ (p.-p)and for e+ + H is concentrated on 00.
References
1) S. DeBenedetti and H. C. Corben: Ann. Rev. Nucl. Sci.,
4, 191 (1954).
2) A. Ore and J. L. Powell: Phys. Rev., 75, 1696 (1949).
3) Q.·C. Ma. X.-X. Zhang (Cheng), Z.-H. Liu, Y.-Y. Liu,and T. Watanabe: Phys. Rev. A, 32, 2645 (1985).
4) K. Nakanishi, K. Iguchi, A. Ohsaki, and T. Watanabe:
submitted to Phys. Rev. A.

49
RIKEN Acce1. Prog. Rep. 21 (1987)

111-2-9. The Born Approximation to the Reactance Matrix in
Low-Energy Electron-Molecu Ie Call isions
c. T. Whelan and I. Shimamura

The calculation of accurate collisional parameters
for electron-impact excitation of the rotational levelsof polar molecules is greatly complicated by the large
number of angular-momentum values (that correspond to impact parameters) that must be included.
It has been suggested that by using the Born
approximation to the reactance matrix1 ,2) and retaining the full unitarity of the S matrix (i.e. , the BornII approximation) the contribution from intermediate
to large values of the angular momentum may be
estimated accurately.
This approach parallels quite closely the use of
the Bethe approximation to the reactance matrix inthe study of the intermediate-energy scattering ofelectrons from neutral atoms. 3)
In this note we remark on how the mathematicaland computational methods developed for the neutralatom problem may be applied to advantage in themolecular case.
We will be concerned with rotational excitation ofmolecules and will work in a space-fixed frame ofreference. We will assume that the multipole expansion of the electron-molecule electrostatic potential
has its asymptotic form
(1)

where V I, V 2, • • • , are the dipole, quadrupole, ... ,moments of the charge distribution. PA is a Legendre
function of the cosine of the angle between the molecular axis and the position vector of the electron.
In these circumstances the Born reactance matrix
for the transition from an initial rotational state j toa final rotational state j' is given b y4 )respectively, the wave number and the angular momentum of the scattered electron before and after thecollision, and ] is the vectorial sum of the twoangular momenta j and l. 10 is an integral3)
loCk b l, kj' , l'; p)=J (kjkjl) J~jll(kj'r)jl(kjr)r-p.+ldr(3)with iz and j l' spherical Bessel functions.
All scattering cross sections may be written in termsof the transition matrix. For example, the total crosssection is given by
q(j' ,j) = 71:/ {kl(2j + I)} ~ (2J+ 1)1 TJjljlll \2
Jll'

(4)

We distinguish two approximations
T J(Bom II) = - 2iRJ(B) / {1- iRJ(B)}(5)

TJ(Born I)= -2iRJ(B)

(6)

and

The strong-coupling approximation, Born II, conservesprobability current and preserves the unitarity of the
S matrix, while the weak-coupling approximation,
Born I , does not. When summed over] the Bom-I
approximation is identical to the first-Born approximation as derived from standard perturbation theory.
It should be emphasized that the Born-II approximation follows from the variational principle forelectron scattering, and is not merely a "unitarized"
form of the first-order perturbation theory.3,5) In
Padial et al. 2 ) the utility of the Born-II approximation for high ] was demonstrated, but their calculations were carried out in the body-fixed framewith the fixed-nuclei approximation, i.e., kj = k jl. In
this case the Born matrix element is easy to compute,since, as is well known,where fp. is defined in Ref. 1, (k j, l) and (k jl' l') are,
71:k A- 1r(J..)r( {l+l'- p+2} /2)
loCk, l, k', l'; p) = 2P+1rc {l-l' + p+ I} /2)rc {l'-l+ p+ I} /2)rc {l+l' + p+2} /2)

In the general case kr'l=kjl' however, the numericalevaluation of lo(k h l, kj', l'; p) is more difficult.
In Ref. 3 it is shown that, for kj'=I=kjl'(7)

10 (k;, l, kil' 1'; fl.)= ~~ JlLCkhl,kj',l')QLC'X.)~ C71:/k j k/)/2p.r(p+ ~)
(8)

50

C. T. Whelan, et al.

where the sum over L is finite, Qlldk j , I, kjl' 1') is
given in Ref. 1, and QL(X) is a Legendre functionof the second kind with
(9)

In this form 10 can be computed to arbitrary accuracy at only a small cost in computer time. S)
We will shortly make available a molecular versionof the computer program BETRTS) that has beendeveloped based on Egs. 7 and 8 and used forelectron scattering by neutral atoms.
The basic philosophy of the approximation adopted
is to assume that, because of the centrifugal barrier,
we may take progressively simpler approximations
for the transition matrix as l (and hence]) increases.
So we might, for example, take a sophisticatedstatic-exchange calculation, e.g., R-matrix or closecoupling, for the first few j, and then, when

Now, just as in Ref. 3, we may sum this over J suchthata~?[n I(j', j) = (16/3) V 12 j>b Io2(k ,l ,k' ,l'; 1),(12)where j>=maxCi,j'), b=max(l,l'), and l'=l±l.
It can be shown, however, that 4 )00

1]1] blo2(k" l, kj',l'; 1)

1=lol'=l±1=:= (lo/4)(kj/kjl){Q210-I(X) - Q210(X)}(13)

and hence, we know

and can deduce
00

(10)

1] 1] a~~y l(j', j)/=/0 ll'

we could use the Born-I approximation for jo to
infinity. In the particular case of dipolar molecules,
however, a very large number of terms of the Born-I
form may be needed, because of the long-range
nature of the interaction, if we are to sum to convergence. It is therefore useful to be able to sum
for J'2: Join a closed analytic form.
When /l = 1 we have the I'IJ contributionS)

References
1) M.J. Seaton: Proc. Phys. Soc., 7'7, 174 (1961).
2) N. T. Padi~l, D. W. Norcross, and L. A. Collins: J. Phys.
B, 14, 2901 (1981).
3) C. T. Whelan: J. Phys. B, 19, 2343 (1986).
4) N. Chandra: Phys. Rev. A, 16, 80 (1977).
5) C. T. Whelan, A. Burgess, and M. A. Hayes: submitted
for publication.
6) A. Burgess and C. T. Whelan: Comput. Phys. Commun.,47, 295 (1987).

51
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-10. Rotational Stopping Cross Sections for Collisions ofSubexcitation Electrons with Dipolar Molecules:
Dependence on the Temperature of the Molecular Gas
1. Shimamura

Secondary electrons produced by high-energy
charged particles or by ionizing radiations lose theirenergies, as they penetrate matter, by exciting atoms
or molecules. When the energies E of the secondary
electrons become lower than a few electron volts andbelow the threshold for electronic excitation, the mainenergy-loss mechanism is vibrational and rotational
excitation in electron-molecule collisions. We referto such low-energy electrons as subexcitation electrons.
The cross section a (vJ~v'I'; E) for electronimpact excitation of a molecule from a well-defined
vib-rotational state vI to a well-defined vib-rotational
state v'I' at a collision energy E is difficult to measure
directly. This is due to the small rotational levelspacings; an electron spectrometer with extremely
good energy resolution is required for resolving rotational lines in electron energy-loss spectra. On theother hand, reliable theoretical calculations of the
vib-rotational-excitation cross sections are usually
cumbersome.
Molecules in a gas at thermal equilibrium arenormally distributed among many high rotational
states because of the small rotational energies. Therefore, transitions from many different I to manydifferent I' are taking place in the gas as subexcitation electrons penetrate it. Calculations of the crosssections for all of these transitions are almost
impossible.
The mean energy loss by subexcitation electrons
due to a particular vibrational transition v~v' isdetermined by the stopping cross section S (E) defined by an average of the quantity'2j (Ev'JI- EVJ)a(vJ----+ v' JI; E)
JI(1)over the degenerate initial states, where EVJ is theenergy level of the state v/. For application to a realgas, 8 (E) is to be further averaged over the rotational
distribution that depends on the gas temperature T;
the stopping cross section of the gas against electrons
may be written as 8 (E, T) .
Because S (E) depends on the initial rotational
state in general, S (E, T) is a function of both E and
T. I proved a theorem some years ago, however, that
S (E) is independent of the initial rotational state if

E is much higher than the rotational-excitationenergy.1-3) In other words SJ(E) for any value ofthe magnitude .I of the initial I is equal to SJ=o (E).
This leads to an important theorem that S (E, T) is
independent of T (so that 8(E, T) =S(E, 0) =8 J =0 (E) ), if E is much higher than the thermal energy kBT corresponding to the temperature T. I used acommutation relation involving the rotational Hamiltonian to prove this theorem for linear, symmetrictop, and asymmetric-top rotators. 1) Later, different
proofs by use of some relations between ClebschGordan coefficients were shown for linear andsymmetric-top rotators/,5) but not for asymmetrictop rotators.
In fact this theorem was proved on the assumption that the collision time is much shorter than therotational period of the molecule. This assumption
is valid for nonpolar molecules if E is much higher
than the rotational-excitation energy. For polar
molecules, however, this assumption is invalid forsmall-angle scattering even at high E, because of thelong effective collision time for distant collisions that
correspond to small-angle scattering.
In distant collisions the interaction between an
electron and a polar molecule is weak, and a perturbation theory is applicable. Furthermore, only thelong-range charge-dipole interaction survives at large
distances between an electron and a molecule. Therefore, we may safely apply the first-Born approximation
to scattering at angles below, say, () c, assuming only
the charge-dipole interaction. Then, we may use aknown formula for the differential cross section for
rotational excitation. At angles higher than ()c we
may assume that the collision time is much shorter
than the rotational period, and may apply thetheorem of Ref. 1 mentioned above. By summing
the contributions from the two angular regions, we
obtain the following results.
For molecules that may be regarded as linear
rotators it follows thatSAE)=SJ=0(E)-2Barn Ba(J)for small B/E(2)

where B is the rotational constant of the molecule,52

I. Shimamuraa (J) is defined by
~=o

~

and
a(J) = [(J+ 1)2 In (J+ 1)-J2In JJ/(2J+ I)

for J=I=O(3b)

and O"rnB is the momentum-transfer cross section m
the Born approximation and is expressible as

47rD2
(4)
a.u.
3E
in terms of the dipole moment D.
The rotational energy of a symmetric-top rotator
depends not only on the magnitude] of the rotational angular momentum J but also on its projection
I<. onto the symmetry axis. For such a molecule we
haveO"m B = - -SJ, K(E)=SJ=K=O(E)-2BO"m B b(J,K)

for small B/ E

(5)

where
b(O,O)=O(6a)andb(J, K)=a(J)- [K 2 /(2J+ I)J In [(J+ 1)/JJ

for J=I=O(6b)

Note that both Eqs.2 and 5 are independent of
the choice of the critical angle ()c' From these equations it follows for both linear and symmetric-top
rotators that
SeE, T)=S(E,O)-BO"m B In (kBT/B)

for small B/kBT(7)

In conclusion I have extended a theorem on thegas-temperature dependence of the rotational stopping cross section for collisions of dipolar moleculeswith electrons. For gas temperatures much higher
than the rotational excitation energy, the way the
stopping cross section depends weakly on the temperature is explicitly expressible in a simple form.
References
I) I. Shimamura: Phys. Rev. A, 23, 3350 (1981) .
2) I. Shimamura: Electron-Molecule Collision (eds. I.
Shimamura and K. Takayanagi) , Plenum, New York,
Chap. 2 (1984) .
3) I. Shimamura: Electronic and Atomic Collisions, Invited
Papers, XIVth Int. Conf. the Physics Electronic andAtomic Collisions, Stanford, July 1985 (eds. D. C. Lorents
et al.) , North-Holland, Amsterdam, p.93 (1986).
4) I. Shimamura: J. Phys. B: At. Mol. Phys., 15, 93 (1982) .
5) D. W. Norcross: Phys. Rev. A, 25, 764 (1982).

53
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-11.

Do~bly Excited

Rydberg Series of rVlolecular
Repulsive States: H2

I. Shimamura, c. J. Noble,* and P. G. Burke**

Most doubly excited states lie energetically above
the threshold of ionization, and they ionize when asufficient energy is transferred from one to the otherof the two excited electrons through the electronelectron interaction. The lifetime of a doubly excitedstate is inversely proportional to the energy widthof the profile that appears in a spectrum due tothis state. A doubly excited molecule may dissociate,
if a sufficient energy is transferred to the vibrationalmotion before it ionizes. Thus, ionization and dissociation are competing processes for a doubly excitedmolecule to break up.
Doubly excited states of molecules play an important role in many . kinds of dynamic processes,
such as dissociative attachment and recombination,
associative detachment, and competing photoionization and photo dissociation.
Doubly excited molecules may be formed in collisions of neutral molecules with photons, electrons,
or ions. Alternatively, they may be formed in collisions of molecular ions with electrons as compound
resonance states. Therefore, doubly excited states ofmolecules may be studied by calculating electron-ion
collisions at varying collision energies and by observing structures in the cross section. We havecarried out such calculations using the R-matrix
method.
The R-matrix method, proposed by Wigner andEisenbud to study nuclear reactions, was introduced
into the field of atomic collisions by Burke and others.
We generalized the method for dealing with electronmolecule collisions. 1) The successful applications of
this method to a wide variety of atomic and molecular
processes were reviewed in Refs. 2, 3, and 4.
In the R-matrix method we pay particular attention to the difference in the physics prevailing in
two different regions of the configuration space. The
inner region is where the scattered electron is inside
the molecular electron cloud. Here, all electrons in
the collision system interact strongly, and both theexchange and correlation effects are important. The* Daresbury Laboratory, SERe, England.
** Department of Applied Mathematics and Theoretical
Physics, the Queen's University of Belfast, Northern ireland.

whole system is treated by the configuration-mixing
method. The outer region, where the scattered electron is outside the molecular electron cloud, is infinitely large. Here, the scattered electron is distinguishable from the molecular electrons. There is
no exchange potential that the scattered electron
feels. Thus the Schrodinger equation reduces tosecond-order coupled ordinary differential equations.
Fast and stable numerical methods for solving theseequations exist in the literature. The whole scattering
problem is solved, if the wave functions in bothregions are connected smoothly across the boundary.
The essential physics of the doubly excited resonance states lies in the strong electron correlationin the inner region. The configuration-mixing method
is appropriate for describing this effect. The mosttime-consuming part of the inner-region calculations
need be carried out only once for all collision energies.
The outer-region calculations must be carried out
separately at each energy, but they are simple andshort in terms of the computer time. Thus the Rmatrix method is suitable for calculations at manyenergy points and for detection of narrow resonancestructures in the cross section as a function of theenergy.
We have applied the R-matrix method to electron
scattering by the hydrogen molecular ion to study
doubly excited states of the hydrogen molecule in the
14 g + symmetry.
In the adiabatic-nuclei approximation, in which
the internuclear distance is fixed, we have calculated
the eigenphase sum by taking into account six channels (lag) (Elg) and (Iau ) (Etu) with tg= 0, 2, 4
and tu = 1, 3, 5, and configurations representing thecorrelation effect in the inner region. Whenever a
structure is found in the eigenphase sum, we fit itto the Wigner resonance formula to determine theenergy level and the width of the doubly excitedstate corresponding to the structure.
Although only three resonances of this symmetry
are reported in the literature, we have found morethan fifteen resonances at each internuclear distance.
These resonances may be classified into two groups,(tau) (npa) and (la u ) (nfa) Rydberg series, thepreviously known resonances being the first three

I. Shimamura, et al.

64

Table 1. Doubly excited Rydberg states of the hydrogen molecule in the , II/}+ symmetry at
an internuclear distance of 2 a.u. E: Resonance energy in Rydberg units.
Energy width
in Rydberg units. n: Principal quantum number. f.l: Quantum defect. 1. O( -2) = 1. Ox 10- 2•r:(1(1u)(nf 0')(lO'u)(np (1)

n

E

r

f.l

n

E

r

2
3
4
5
6
7
8
9
10

0.408360.73093
0.796210.82382
0.838160.84657
0.85192
0.855540.858101.0(-1)1.0( -2)
3.8( -3)
1.8( -3)
1.0( -3)
6.4( -4)
4.2( -4)
2.9(-4)2.1( -4)

0.526
0.305
0.285
0.278
0.274
0.272
0.271
0.270
0.270

4
5
6
7
8
9
10

0.80635
0.828770.84095
0.848290.853070.85634
0.85868

2.4( -5)
1.8( -5)
1.2( -5)
8.5( -6)
6.0( -6)
4.4( -6)
3.3( -6)

members of the former series. The former series
couples strongly with the continuum, and is broader
and has a larger quantum defect than the latter.
Table 1 shows the calculated parameters for the
doubly excited Rydberg states at a representativeinternuclear distance.
In conclusion this work presents the first ab-initio
calculations of doubly excited molecular Rydberg
series, and proves the power of the R-matrix method
for such studies.

-0.006-0.006-0.007-0.007-0.007-0.007-0.007

References
1) P. G. Burke, I. Mackey, and I. Shimamura: ]. Phys. B:
At. Mol. Phys., 10, 2497 (1977).
2) I. Shimamura: Invited Papers, Xth Int. Conf. thePhysics of Electronic and Atomic Collisions, Paris, July
1977 (ed. G. Wate!) , North-Holland, Amsterdam, p.213(1 978) .

3) I. Shimamura: Electron-Molecule Collisions (eds. I.
Shimamura and K. Takayanagi), Plenum, New York,
Chap. 2 (1984).
4) P . G. Burke: Atomic Physics 10 (eds. H. Narumi and
I. Shimamura), North-Holland, Amsterdam, p.243(1987) .

55

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-12.

Continuum Multiple Scattering ' Method for Molecules
H. Sato, M. Kimura, * and K. Fujima

Continuum wavefunctions of molecules play animportant role in studies of electron scattering,
photoionization and others. A continuum multiple
scattering CMS) methodl ,2) is a very useful , method
for calculation of continuum states.
In the CMS method the coordinate space ispartitioned into three- types of regions (see Fig. 1):
I atomic: the inner regions of atomic spheres;
II molecular: the region between atomic spheres
and an outer sphere; andill outer: the outer region of outer sphere.
The atomic spheres are centered at the constituent
atoms and do not overlap each other. The outersphere includes all the atomic spheres and is selectedso as to minimize a ~ize of the sphere. A molecularfield regulating motion of a continuum electron isassumed to be spherically symmetric in the regions I
and ill and to be constant in the region II.
When a continuum electron having kinetic energy
E is in the i-th atomic sphere, a wavefunction isexpressed aswhere r i, 8 i , and ifJ i are spherical coordinates of aposition vector ri having an origin on the i-th nucleus.
The function fl Ii (r) is a solution of the one-electron
Schrodinger equation
Region III~)+ l(l+I)+ VIt(r)-E](/Jl(r) =0[ --I-~(r22r2 drdr2r2
and is finite at r = O. Atomic units are used unlessotherwise stated.
Since the potential in the region II is constant,
the wavefunction is expanded in terms of the spherical Bessel and Neumann functions jz and kz,

K=[2(E- Vn)] 1/2

where r o is a position vector originated at the centerof the outer sphere and VII the value of the constantpotential.
If the electron is in the region III, we can write
the wavefunction as+ LJ
a~~I g:n(ro) Ylm(8 o,</>o)1mHere the functions hIII(r) and gzIII(r) are solutionsof the equation[__
I ~ (r2~) + l(l+ 1)

2r2 drdr

2r2+ VmCr) - E J(;::::~~) =0
and have the following asymptotic forms
flm(r)--t _1_ sin (kr- .!.lrr+w)
kr

2.!.lrr+w)

glIII(r)--t - _1_ cos (krkr2

Fig. 1.

Partition of the coordinate space.

* Argonne National Laboratory, Argonne, Illinois 60439,
USA and Rice University, Department of Physics, Houston, Texas 77251, USA.

where (J) is the phase due to long-range behaviorof the potential VIII (r) .
F or a given set of b 1mII! we can determine thecoefficients aiZmI, az mII , ailmI!, and az m III by connecting these functions smoothly at the boundaries of
the regions. l , 2 ) Therefore, we can construct a continuum wavefunction of a molecule which has agiven asymptotic form at r ~ 00.
Electron elastic scattering by H 2 0S) and several
organic molecules have been investigated by applying
the CMS method. The potentials for continuum
electrons are generated by using the discrete variable

H. Sato, et al.

56

180

100
Angle (deg.)

Fig. 2. Differential cross section for electron elastic scattering by H 2 0 at E=20 eV. Theory: solid line, Ref. 3; broken
line, Ref. 7. Experiment: circle, Ref. 5.

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

1

100

1000

Collision energy (eV)Fig. 3. Total momentum transfer cross section for electron
elastic scattering by H 2 0. Theory: solid line, Ref. 3; broken
line, Ref. 7. Experiment: circle, Ref. 5; cross, Ref. 6; triangle, Ref. 8.

Xa method. 4 ) The Hartree-Fock-Slater approximation is adopted for the exchange interaction in thismethod.
The total and differential cross sections for electron
scattering by H 2 0 were calculated for collisionenergies E from 2 to 200 eV. The overall trend of
the present results is in good agreement with recent
measurements. 5 ,6) The differential cross section at
E= 20 eV3) is shown in Fig. 2, and the total momentum transfer cross section in Fig. 3. Results fororganic molecules will be published soon.

References
1) K. H. Johnson: Adv. Quantum Chem., 7, 143 (1973).
2) J. L. Dehmer and D. Dill: Argonne Natl. Lab. Radiol.
Environ. Res. Div. Ann. Rep., July 1972-June 1973,
ANL-8060, part I, p. 119 (1973).
3) H. Sato, M. Kimura, and K. Fujima: Chem. Phys. Lett.,
145, 21 (1988).
4) F. W. Averill and D. E. Ellis: J. Chem. Phys., 59, 6412
(1973) .
5) A. Danjo and H. Nishimura: J. Phys. Soc. Jpn., 54, 1224
(1985) .
6) T. W. Shyn and S. Y. Cho: Phys. Rev. A, 36, 5138 (1987) .
7) L. M. Brescansin, M. A. P. Lima, T. L. Gibson, V. McKoy,
and W. M. Huo: J. Chem. Phys., 85, 1854 (1986).
8) A. Katase, K. Ishibashi, Y. Matsumoto, T. Sakae, S. Maezono, E. Murakami, K. Watanabe, and H. Maki: J. Phys.
B, 19, 2715 (1986).

57

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-13.

Hyper-Radial Adiabatic Expansion for a Muonic
Molecule dtp
S. Hara, H. Fukuda, * T. Ishihara, * and A. V. Matveenko* *It is well known that the wave function expanded
in terms of basis functions which are adiabatic in
hyper-radius satisfies correct boundary conditions fora general three body problem. In practical application of such approach, five coordinates other thanhyper-radius can be chosen in many ways. Macek1 )and Lin 2 ) have successfully used hyper-spherical coordinates to treat atomic three body problems where
one particle is heavy and two are light. Recently
Matveenk03 ) and Matveenko and Abe 4 ) proposed touse hyperspheroidal coordinates for more generalcases. In this report we calculate, with sufficientaccuracy, the adiabatic potential curves and nonadiabatic interactions for low lying states of dtp
system using these two sets of coordinates. We also
calculated the bound states with total angular momentum I = 0 by solving the three-state coupled equations.
The hyper-radius R for the system of a triton t, a
deuteron d and a negative muon p is defined by(1)

where M and m are reduced masses of systems (t, d)and (t + d, p),1/ M= I/mt+l/md
I/m= I/(mt+md)+l/mp

(2)
(3)

X is the position vector of d relative to t, and x isthat of p with respect to the centre of mass of (t +d) . M 0 is an arbitrary mass constant; we choose
N!0 = M in the following.
The Hamiltonian for our system is given by using
the hyper-radius byl, 3)
I
I
a 5 a
H= - 2M R5 aR R aR +h( Q;R)

(4)where h is the adiabatic Hamiltonian operator which
includes R as a parameter and Q represents fivedimensionless variables. The eigenfunctions rpn (R ;Q) and eigenvalues en (R) of the operator h for agiven R are obtained by solving the Schrodinger
equation(5)

In hyper-spherical coordinates, a set of variables* Institute of Applied Physics, University of Tsukuba.
** Joint Institute for Nuclear Research, Moscow.

xX, x), where X and are polar
and azimuthal angles of vectors X and x, respectively, andQ is chosen to (a,a=arctan (..jM X/..jm x)(6)

The explicit form of the h is given In these coordinates 1 )
(7)

where

A2= -

I

sin a cos a. ~.(sinaaacos a~)aa+_I_(_iXX _ a_ )2
cos2 aax
1 (-~xX-.
a)
+-5m
.-2
a
ax

(8)

and V is the Coulomb interaction between threeparticles(9)

where Tt and rd are the positions of t and d relative
to the muon.
In hyper-spheroidal coordinates, !J is a set ofvariables (~, 'fj, cp, X), where(10)

and cp, the azimuthal angle for x around X axis,
are the spheroidal coordinates for x. In this coordinates system, h is given explicitly b y3)

h= - : : V r2+ 2~R2(J2_B-Jz2)+ V+ ;~2(11)where J is the angular momentum of the system,
and l z its component along X,(12)

S. Hara, et al.

58

The operator B is the Coriolis interaction operator
given in the paper of Matveenko and Abe. 4 ) In theabove expressions, the units e = n= m = 1 are used.
We have calculated en(R) and ifJn(R; SJ) for the
dtp system with ] = 0 by variational method. The
form of the trial function adopted in hyper-shericalcoordina tes is

9'i=(COS a)l,; (sin a)ZiF (ni' 2li+2+ni'

li + ~ , sin2 a ) P Ii (x' X)(16)

where €Pi is an eigen-function 5 ) of A2, F the hypergeometric function, and P z the Legendre polynomial.
In hyper-spheroidal coordinates, we adopt

qJn = ~ bin ifJi

(15')

ifJi=..jP ~n. e-f3tR~ Pzl,;)

(17)

i

(18)

for large R.
For the trial function in hyper-spheroidal coordinates, we use 77 basis functions. We obtained cn(R)for the lowest three states (n=l, 2, and 3) with
sufficient accuracy in the region R>0.3. Inaccuracy
for small R region is caused partly by the numericalintegration carried out over g and 1). If we use thetrial function in hyper-spherical coordinates, convergence is very slow except for small R. Using 91term trial functions, we have obtained satisfactory
results only for R<O.Ol. This is because our (dtp)system is more like a molecule rather than an atom.
For 0.01 <R<0.3 the results are unsatisfactory, butbetter than the hyper-spheroidal results. In the following we use hyperspheroidal results for R > 0.3 andhyper-spherical results for R<0.3.
The total wave-function 'If! is expanded by en(19)nThus the radial wave-function Xn satisfies a set of
coupled equations

(20)
where

15
Vn(R)=sn(R)+ 8MR2 - Wnn(R)
Wnm(R) = 2~ ( qJn0;2 qJm )Unm(R) = 2~ ( qJn (j~ qJm)

n

v=O

,v=l

2
3

-317.75-317.80-318.7-31. 99-33.46-34.4-319.14-34.83

Variation7-9)

and E is the total energy.
The coupling terms U nm are calculated by numerical differentiation of 'ifln and by using the Hellmann
and Feynman theorem. Both results agree at least
3 digits in the calculation in hyper-spheroidal coordinates. W nm are obtained by numerical differentiation. It is confirmed that the numerical calculationin hyper-spheroidal coordinates well reproduces thecorrect asymptotic forms of V n 6)

V 1(R) = -2.4190/MR4

for small Rand

7Jf = R-5/2 L] qJn(Q; R) Xn(R)

Table 1. Bound state energies (in e V) of the dt.u
molecule with J=O.

(21)

(22)
(23)

V 2(R) =0.0087 - 2.6454/ MR4

(24)
(25)

where 0.0087 is the difference in the binding energies
between the dp and tp atoms in the Is-state in ourenergy units. Energy is measured relative to theground state of tfl. In the potential curve C2 (R),there is a shallow minimum of about 5 eV at R = 7.0.
This causes the peak in U 12 in that region of R.
This dip almost disappears when the coupling term
W 22 is added to e2 (R).
We have solved Eq.20 and obtained the boundstate energies of dtp molecule with] = O. Calculations are carried out both variationally and by solving
coupled differential equations numerically6) for one
and two state cases and variationally for the threesta te case. I n the varia tional calculation, 12 X n (n =1 2 3 are numbers of states) basis functions areado~t~d. The results are shown in Table 1. By thethree-state calculation, we have obtained - 318.7 eV
and - 34.4 eV, for vibrational quantum numbers
v = 0, and 1, respectively. These values are comparedwith -319.14eV and -34.83 eV obtained by fullvariational calculations 7 - 9 ) using several hundred tomore than one thousand trial functions.
References
1) J. Macek: ]. Phys. B: At. Mol. Phys., 1, 831 (1968).
2) C. D. Lin: Phys. Rev. A, 10, 1986 (1974).
3) A. V. Matveenko: Phys. Lett., 129, 11 (1983).
4) A. V. Matveenko and Y. Abe: Few-Body Systems, 2, 127(1987) .
5) P. M. Morse and H. Feschbach: Methods in Theoretical
Physics, McGraw-Hill Book Co., New York, p.1730(1954) .
6) H. Fukuda, S. Hara, and T. Ishihara: to be published.
7) S. Hara, T. Ishihara, and N. Toshima: ]. Phys. Soc. ]pn.,
55, 3229 (1986) .
S. Hara, T. Ishihara, and N. Toshima: Muon Catalyzed
Fusion, 1, 277 (1987) .
8) L. I. Ponomarev: At. Phys., 10, 197 (1987) .
9) M. Kamimura: Muon Catalyzed Fusion, 2, in press.

59

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-14.

Deformed Atoms and Collective Rotational
Motion of Electrons
M. Iwai

Recently, there has been considerable interest incollective motion of atomic electrons. Many theoretical models have been proposed to analyze the joint
motions of electrons. The group theoretical method 1 }which leads to a molecular model and the adiabatic
hyperspherical coordinate approach 2 ) are the mosttypical ones. In the present paper we present a newinterpretation of collective rotational motion of electrons. Using the symmetry-violating mean field approach 3) and the Peierls-Yoccoz projection method,4)developed in nuclear many-body problem, we shallanalyze the collective rotational motions of electrons
in Be-like ions.
Let us first consider the possibility of deformationin the atomic Hartree-Fock fields in comparison with
the quadrupole deformation of nuclei. 3) An important feature of the nuclear shell structure is that
the S U (3) multiple structure of single-particle levels,
inherent in a three dimensional isotropic harmonic
oscillator, is realized to a good approximation.
That is, single-particle levels with the same parity
form a quasi-degenerate manifold. The 'quadrupole' deformation of nuclei with a half-filled shelloriginates from this symmetry property.3) The expectation value of the quadrupole tensorial operator
is regarded as an order parameter of the deformation. Our question is how this picture of nuclear
deformation is modified in the case of atomic systems.
The high degeneracy in hydrogen atom, which reflects the 0 (4) symmetry, is broken in many-electron
atoms. However, even in many-electron atoms thequasi-degeneracy among the Hartree-Fock levels withthe same principal quantum number n still remains.
With increasing azimuthal quantwn nwnber l, theorbital energy usually becomes higher. Let us focus
on a system with a closed subshell and with theground state of the lSe symmetry, such as alkaline
earth atoms. In such a system, the lowest singleparticle excitation occurs between the orbitals whose
azimuthal quantum numbers differ only by unity.
This suggests a 'dipole' deformation of atoms. Sinceelectron-electron interaction is repulsive, it is energetically more ,favorable to break a singlet electron pairin the same orbital. This is the origin of the wellknown fact that the lowest excited state of an alkalineeach atom has the 3p O symmetry. With increasing

strength of electron correlation, or equivalently, withdecreasing nuclear charge Z, the RPA3,5) frequency
from the ground to the lowest 3pO state could be
negative. In such a case, we obtain, in analogy tonucleus, a deformed Hartree-Fock ground state withthe energy lower than the spherical solution. In this
3pO_type deformation, one notices that the orderparameter is given by the expectation value of theoperator T;~~ce O~~?n whose spatial and spin parts
behave as a rank one tensor under spatial rotation.
We have carried out the ground state HartreeFock calculations for · Be-like ions, employing thediscrete cartesian Gaussian-type functions contracted
to 21 basis orbitals. First we obtain a solution under
the restriction that the ground state has the lSe
symmetry. By using the single-particle states generated
by this calculation, stability ' of the lSe ground state
was investigated by the RPA method. Negative excitation energy to the 3pO excited state is observedfor ions with Z<4.4. We next try to find the moststable non spherical Hartree-Fock solution for Be and
Lt. An effective method to do this is the linear
constraint method 3) explained below. First the following mean field calculation is performed in thepresence of the symmetry-violating operator T;~~ceO~~?n:where Ap); is the Lagrange multiplier corresponding
to a condition,< 1P"(l) IHI1P"(l) > =qp.v(2)

The value of qpJJ plays a role of the order parameter.
The Hellmann-Feynman theorem gives(3)This means that the symmetry breaks down spontaneously without help of the symmetry-violating operator
at extrema of the energy hypersurface spanned by
the order parameters, q,.w. Such symmetry violating
Hartree-Fock solutions were found for Lt. The moststable such a state is realized when qoo = 0 and allother qp.)) = O.
Figure 1 shows the energy difference between the
Hartree-Fock state of the lse symmetry and that ofM.Iwai60

qoox Z
12 (a. u.)-12

Fig. 1. The ground state Hartree-Fock energy change due
to deformation as function of order parameter.

this broken symmetry as a function of the orderparameter,qoo = <1JT(l)\~ z(j)szCj)\1JT(l) >(4)jwhere z (j) and Sz (j) are the z components of theposition vector and the spin angular momentum
vector of the j-th electron, respectively. The z axis
is chosen to coincide with the quantization axis ofelectron spin. The 'second-order phase transition' tosymmetry-violating state is seen at around Be. The
ISe solution becomes a saddle point in this case.
Electron density is plotted in Fig. 2 for HartreeFock state of Lt. From this figure, the deformation
seems to be like the ordinary quadrupole deformationx__--lH-l-t--I-I-:--H-+--7Z

Fig. 2. Total density of two valence electrons of the moststable deformed state of Li-.

Fig. 3. One valence electron density of the most stable deformed state of Li-. Electron distribution of the otherelectron is just a mirror-reflection of this with respect to
x-y plane.

of nucleus. 3 ) However, this is not true, because eachelectron orbital experiences the 'dipole' deformation
as is seen from Fig. 3. Two electrons with opposite
spin angular momenta repel each other, keeping thereflection symmetry with respect to the x-y plane.
Since each electron is localized separately in space,its kinetic energy increases, but the mutual coulombic
repulsion energy is reduced.
This deformed state violates the rotational symmetry, except for the rotation about the z-axis. Timereversal symmetry and parity are also broken. Thus
the deformed ground state includes the componentsof states with symmetry, different from ISe. Take,for instance, the restricted case of n = 2. Then, thedeformed ground state can be given approximatelyas\\(2s+e2po)X+l/2, (2s- e2po)X-l/2\\_(\2g21se> - e2 /./3\2p21se»-J2 e\2s2 p8 po> -./6 /3e 2 \2p21De>(5)

where X±1/2 is the spin function. Here one sees thatthe states of the 3pO and IDe symmetries mix into theground state wave function. Then the projection of
the deformed ground state onto the eigenfunction of
the total 'orbital' angular momentum is sufficient torestore the spin and parity symmetries.
Collective rotational motions are clearly extracted
through the angular momentum projection, as is explained below. 3 , 4 ) An energy expectation value ofthe deformed state is independent of its orientation
relative to the space-fixed frame. Superposing thewave functions of states deformed in all orientations
Q and variationally determining the corresponding.weight function f (Q), we can obtain more accurate
wave function and restore the broken symmetry. 4)
In the present case, the deformed state is axiallysymmetric and is the eigenstate with the eigen value
K = 0, where K is the projection of the angularmomentum on this symmetric axis. Then f(Q) is
determined only by the symmetry requirement, andwe have(6)

where I ([) > is the wave function of the state deformed in an arbitrarily chosen orientation. Land
M are the total orbital angular momentum and its z
component, respectively. R (Q) is the rotation operator acting on the spatial part of wave function.
Dto is the rotation matrix. It should be noted that
this procedure is just the angular momentum projection operation. If we assume that the deformation is
sufficiently large, the energy spectrum has the rotorlike series with the cut-off: E L """ L (L + 1) .3)
Figure 4 shows the energy levels calculated by theconfiguration interaction (CI) method and the pro-M.lwaiE(a. uJ

93.8%

7.35

lOe-

7.40

3 O__

96.3%

p

7.45

l e_S rigid
rotor

94.6%
CI

projection

Fig. 4. Energy levels of ground and low-lying excited statesof L 1- calculated by the configuration interaction (CI)method and projection method. The numbers attached to
the level of projection method indicate the overlap between
the two wave functions obtained by CI and the projection method. The first and second level of rigid rotor
are adjusted to the 1Se and the 3pO states of the CI method.

jection metho~l. The figures attached to the projectedlevels in Fig. 4 represent the percentage contributionof the 01 wave function to the corresponding projected one. We notice that their overlaps are fairly

61

large. The rigid rotor levels are also presented inFig. 4 for comparison. It is seen from this figurethat the following picture holds quite well: the strong
correlation between electrons brings about the symmetry violation in the mean field and then thecollective rotational motion of electrons restore thebroken symmetry.
The dipole character of the deformation and repulsive nature of the interaction which leads to thebreaking of singlet electron pair are reflected in therotational series Ise, apo, IDe, ....
References
1) D. R. Herrick and M. E. Kellman: Phys Rev. A, 21, 418(1980) .
2) C. D. Lin: Phys. Rev. A, 29, 1019 (1984).
3) P. Ring and P. Schuck: The Nuclear Many-Body Problem, Springer-Verlag (1980).
4) R. E. Peierls and J. Yoccoz: Proc. Phys. Soc. (London),A70, 381 (1957).
5) D. J. Thouless: Nucl. Phys., 21, 225 (1960); 22, 78(1961) .

62

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-15.

Identification of AI X 2p3d-2p4f Transition of Beam-Foil Spectra
K. Ando, S. Kohmoto, Y. Awaya, H. Kumagai, T. Tonuma, and S. Tsurubuchi

The transition array of 2p3d-2p4f has been observed
only for carbon, nitrogen, and oxygen ions, but notfor other ions. We have newly identified that of
2p3d-2p4f for Al X.
The identification of the AI X 2p3d-2p4f transition
array was carried out as the following procedure.
The average energy, Slater direct- and exchangeradial integrals, and spin-orbit interactions were
estimated by the Hartree-Fock program code of
MCHF77 1 ) for the 2p3d and 2p4f configurations.
The above values and configuration interactions of
the 2p3d are determined as parameters from theobserved energy levels by means of the least-squares
fits. 2) Using these parameters for the 2p3d and 2p4f
configurations and configuration interactions of 2p3d,
we calculated a theoretical spectrum of this transition
array by the program code of Cowan. 2-4 ) The parameters for the 2p4f configuration were determinedby comparing the experimental spectrum with thetheoretically calculated one. In this procedure, theuncertainty of the energy values of the lower levelsof 2p3d 3F was found to affect the position of thecalculated spectral lines, especially of the strongest
line. Therefore, the energy value of the lower level
2p3d 3F4 was adjusted so as to fit the position of thecalculated line to the experimental one.
The theoretically calculated spectra fits almost
completely with the experimental spectrum as shownin Fig. 1. The identification and classification of spec-

Fig. 1. Observed spectrum (upper) and theoretically calculated one (lower) of the Al X 2p3d-2p4f transition
array.

trallines are given in Table 1, in which the coupling
scheme of 2p3d is the LS-coupling, and that of 2p4f
is the jj-coupling because the purity of the jj-couplingis higher than the LS-coupling.
References
1) C. F. Fischer: Comput. Phys. Commun., 14, 145 (1978).
2) R. D. Cowan: The Theory of Atomic Structure andAtomic Spectra, Univ. of California Press, California(1981) .
3) R . D. Cowan: P hys. Rev., 163, 54 (1967).
4) R. D. Cowan and D. C. Griffin: ]. Opt. Soc. Am., 66,
1010 (1976) .

Table 1. Identification of lines of the 2p3d-2p4f transition array in Al X. Level designation is given in the LS-coupling scheme for 2p3d and in the jj-coupling for 2p4f.
Observed

Calculated

O-C

Classsification

No.
(A)

I

(A)

gf

(A)

lower

upper

2
3

174.86
175.77176.35

98
148
400

4
5
6
7
8

177.06177.82*183.02183.56184.33

165
84
121
287

9
10
11
12

184.86
185.67193.08
195.79

178
177
159
39

175.09175.64176.24176.30176.35176.95
177.68183.04
183.48184.15184.47184.91
185.65193.15195. 76

1.10
1.82
4.28
8.13
2.60
3.44
1. 34
1. 32
3.39
2.52
2.87
2.16
3.26
5.01
2.19

- 0.23
0.13
0.11
0.05
0
0.11
0.14
-0.02
0.08
0.18
-0.14
-0.05
0.02
-0.07
0.03

sFs
sFs
sF2
SF.
ID2
3Fs
ID2
3D 2
sDs
3D!
3D2
sDs
sP 2
IFs
IP 1

(3/2, 5/2).
(3/2, 7/2).
(1/2, 5/2)s(3/2, 7/2)5(3/2, 5/2)s(1/2, 7/2).
(l/2, 7/2)3(3/2, 5/2)8(3/2, 7/2).
(l/2, 5/2)2(1/2, 7/2)3(1/2, 7/2).
(3/2, 7/2)8(3/2, 5/2).
(3/2, 7/2h

rms deviation=O. llA*blended with Al X 2s3d sD-2s4f SF 177. 80A

63
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-16.

Tilted-Foil Method Using Extremely Thin Foils
S. Kohmoto, K. Ando, and M. Ishihara

The generation mechanism of atomic polarizationof an ion beam passing through tilted foil is not
fully clarified. We carried out tilted-foil experiments
to see whether there exists any influence of the earlystage of passage in a tilted-foil, i.e. a charge-nonequilibrium stage, on the atomic polarization state ofions which emerge from the foil. For this purpose,
we used carbon foils of 0.7 pgj cm2 in thickness. The
experiments were performed at the RILAC with a
14N3+ beam of a 29 MeV incident energy. The tilt
angle was 45 0 • Photons which are emitted from thebeam ions excited by the tilted foil successively passa phase plate, a polarizer, and a monochromator andare detected finally with a photomultiplier. The
photon intensity is measured as a function of theo ~~~~~~--~~~~~~--~~~~

o

27T

4 7T

67T

rotation angle (-B)

Fig. 1. Light intensities measured (dots) and calculated(continuous line) as a function of phase plate angle. The
absolute values of the relative Stokes parameters extracted
from the fitting are M/I= (-16.9±12.9) '% , C/I= (-6.2±
13.0) % and S/l= (2.2±3.2) %.

rotation angle (f3) of the phase plate. This angle
was advanced by 50 for each ion currents of 6 pC
accumulated in the Faraday cup. Figure 1 shows anexample of the intensity curve for NV A = 493 nm
line. On the whole, the intensity decreases graduallyas f3 increases or the irradiation time of the foil increases. This is probably because the charge state ofions after passing through a carbon foil changes fromthe non-equilibrium one to equilibrium one due tothe foil thickening under the bombardment of ionsowing to the insufficient vacuum. The continuousline in Fig. 1 was calculated by assuming a functional form l' (f3; I, M, C, S) exp ( -a(3), where function l' (f3; ... ) is usually used one1 ) to express thephoton intensity in charge-equilibrium state with the
Stokes parameters I, M, C, and C. Although theexponential term is introduced to simulate the foil
thickening effect, the fitting is not good in the small
f3 region. It should be reminded that, the incidentbeam ions being N3+, the charge fraction <P 4 of 4+ions is 0 at the zero foil-thickness. It seems that ourstarting foil-thickness (--0. 7y'2 pgjcm 2 ) is not far
from the maximum of <P 4' F or the N IV A = 341 nm
line,l) where also an ion beam of N3+ was used, one
exponential term was sufficient to simulate the foilthickening effect and a set of relative Stokes parameters seems to be common both in charge-nonequilibrium and equilibrium stages. Further analysis
is in progress.
Reference
1) S. Kohmoto, K. Ando, and M. Ishihara: RIKEN Accel.
Prog. Rep., 19, 64 (1985).

64
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-17. Observation of Radiative Photons in the pTransfer Process for Liquid D2 with He Impurity
T. Matsuzaki, K. Ishida, Y. Hirata, * R. Kadono, ** and K . Nagamine

The recent experiments on the muon catalyzed
fusion (MCF) in a DdT2 mixture carried out at
muon facilities are focussing to measure the muon
sticking probability, which is defined to be a muon
loss by the muon sticking to 4He nucleus, where 4He
is a fusion product of the MCF process. Under apractical experimental condition, we should take into
account the other possibility of the muon loss. The
one of other serious muon loss processes is considered
to be an effect of 3He in the D IT target which isa decay product of the tritium. As is experimentally
known, the muon easily transfers from muonic hydrogen atoms to helium nuclei to terminate the MCF
cycle. Therefore, it is very important to investigate
the f1. - transfer process from muonic hydrogen atoms
to helium nuclei (3,4He). In the first stage, we studied
the muon transfer mechanism from muonic hydrogens
to 4He. We will then extend our experiment to 3He
in order to compare both results.
From the theoretical point of view, a Leningrad
theoretical group has proposed a picture of the f1.transfer mechanism via the formation of the intermediate mesomolecule. 1 ) They calculated energy
levels and the formation rate of mesomolecules whichis the order of 10 8 Is. On the other hand, according
to the earlier theoretical calculation, the rate of thedirect charge exchange process (1) is of the orderof 10 6 /s. 2 )[(pd'He)*e-Y -+ [(pd'Het+ e-Y +r(3)[(pd'He)*e-Y -+ (pd'He)++ +e-(4)where the contribution of the Auger process to thedeexcitation was calculated to be less than 15 %.
Since there exists no bound ground-state of themesornolecule, it will dissociate into a muonic helium
atom and a deuteron.
(5)

The whole molecular charge exchange process does
imitate the direct charge exchange process (1). The
schematic picture of the energy levels for the proposedmodel is shown in Fig. 1. There appears the excitedE

OH-~--~-.--~-----

Fig. 1. Schematic picture for the radiative decay photons
in the proposed ,.,.- transfer mechanism.!>(1)

But the recent experimental transfer rates support
the prediction assuming the molecular charge exchange process.
In the present system, we can consider the molecular charge exchange reaction as follows.

Calculated Photon Energy 6.8 keVSpectrumI(2)

where the excited state of mesomolecule IS formed
as an intermediate state, accompanying a conversion
electron emission. The excited state can decay to
the ground state of the mesomolecule through radiative transition or Auger electron emission from themolecular ion.

* Nuclear Engineering Research Laboratory, Universityof Tokyo.

** Meson Science Laboratory, University of Tokyo.

Ey (keY)
Fig. 2. Photon energy spectra accompanying the ,.,.- transfer
processed from muonic hydrogen isotope atoms to 4He
nuclei. 2l

T. MatsU:~, . et fl.l.

bound state for the (fl-d4He) mesomolecule. This
excited bound state is very interesting';from ' the viewpoint of the three body system bound by the Coulomb
force. The radiative transition occurs from the excited state to th~ uribound gr:~~'nd'~state. :kra~tsov
et al. 3 ) also calculated the photon energy spectra
accompanying the muon transfer process from themuonic hydrogen atom to 4He nucleus; their results
are shown in Fig. 2. For the (fld 4He) system, thecentral energy and the width of expected photons
were calculated to be 6.8 ke V and 0.8 ke V, respectively. The predicted photon line-shape is not a
Gaussian but asymmetric with a low energy tail.
In order to observe an evidence of the predictedtransfer mechanism and obtain an accurate transferrate, we measured an energy and a time distributionof the emitted photons from a liquid deuterium
target containing a small amount of 4He impurity
after injection of fl- beams. So far, no one has evermeasured the photon spectrum accompanying thedeexcitation of mesomolecule. The delayed photon
observation will be direct evidence for the mesomolecular formation.
The present experiment was performed at thesuperconducting muon channel of the pulsed muon
facility of the Meson Science Laboratory, the University of Tokyo, located at KEK.4) This facility
produces a sharply pulsed muon beam (50 ns widthand 50 ms interval) and enable us to carry out a
low background measurement of the delayed phenomena associated with muon pulses. The 60 MeV / cbackward negative muon beam was injected into theliquid deuterium target (20 K) with a 4He concentration of 430 ppm. The liquid deuterium target wasplaced in the gap of Superconducting Helmholtz Coilsetup (SHe). We used a Si(Li) detector to observea low-energy photon; a Si (Li ) detector was also
placed in the gap of SHC. The photon energy signal
and the timing signal relative to the muon beam
arrival were recorded onto magnetic tapes event by
event. The whole experimental setup is similar to thatutilized in the 11CF experimentS) and is described
elsewhere. 6 )The delayed events in a time range between 0.28
and 7.5,us were analyzed. In the delayed photon
energy spectrum, we clearly observed a broad photon
peak around 6.85 keV. In order to examine a detailed structure of the photon peak, backgrounds due
to a pure deuterium target was subtracted; the results
are shown in Fig. 3. The observed line-shape is not
a Gaussian but asymmetric with a low energy tail.
The experimental photon energy and the line shapeitself show fairly good agreement with the predicted
spectrum as shown in Fig. 2. The time distributionof the 6.86 ke V photon was also analyzed and isshown in Fig. 4. The decay rate was deduced to

65

.200

...

(f)

~ 100

...

=>

o<..)

o 4

6

8

PHOTON1012ENERGY (keV)

Fig. 3. Observed delayed photon energy spectrum. The delayed photon background was subtracted. The base line
is shown by a fine solid line.

Photon Time Spectrum
Liquid O2 t 4He (430 ppm)
(f)

:z

2100
o

:I:

t t

0...

T = 0.98 p.sec'

lL

o

a::
lLJ
en

::;E

=>
:z

1~--~--~--~--~--~--~~~o234567
TIME (p.sec)

Fig. 4. Time spectrum of the delayed 6.85 keV photon peak.
The contribution of delayed photon background was
subtracted.

be 0.98 + / - 0.05 flS and the fl- transfer rate at
20 K from (fl-d) to 4He was determined to be
13.1 + / -1.2 X 108 / s, where the contribution of Auger
process is not taken into account.
Recently, the transfer rates have been calculated
for the muonic hydrogen atoms with helium nuclei
by means of various theoretical methods.7} The rates
were calculated as a function of the energy of relative
motion which depends on the temperature of thesystem. We compare the obtained experimental ratewith these theoretical predictions and found they
are in good agreement. The detailed comparison was
described in Ref. 6.
References
I) Yu. A. Aristov, et al.: Yad. Fiz., 33, 1066 (1981).
2) S. S. Gershtein: Zh. Eksp. Teor. Fiz., 43, 706 (1962) [Sov.

T. Mats'tfzaki, et al.

Phys. ]ETP, 16, 501 (1963)].
3) A. V. Kravtsov, et al.: Phys. Lett. A, 83, 379 (1984).
4) K. Nagamine: Hyperfine Interact., 8, 787 (1981); UTMSL Newsletter No. 1-6 (1981-1986) (eds. K. Naga~ine and T. Yamazaki) (unpublished).
5) K. Nagamine, et al.: Muon Catalyzed Fusion, 1, 137(1987) .
6) T. Matsuzaki, et al.: Muon Catalyzed · Fusion,~ 2, 217(1988) .
7) A. V. Kravtsov, A. I. Mikhailov, and N. P. Popov: J~
Phys. B: At. ~~l. Phys.,. 19, 2579 (1986).

, ,.

67
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-18.

REC X-Rays from Collision System of ·20.5 MeV/u Ar Ions on 'Be
Y. Awaya, A. Hitachi, Y. Kanai, K. Kawatsura,
K. Kuroki, H. Vogt, and Y. Yamazaki

When an energetic highly charged heavy ion
directly captures a bound electron of a target atom
to its inner shell orbit and the excess energy isemitted as a photon, this process is called radiativeelectron capture (REC) .1) The photon thus emitted
is called as REC X-rays. When one wants to describe
the process more precisely, expressions of K REC, L
REG and so forth are used according to the innershell of the projectile by which the electron is
captured.
We have measured the REG X-rays emitted fromthe 20.5 MeV ju Ar ions colliding with Be target
atoms at newly constructed RIKEN Ring Cyclotron(RRC) in the course of testing the experimental
conditions, such as the background caused by nuclear
reactions in this energy range and the setup at thisaccelerator. The final purpose is to obtain the angulardependence of the L REG because the relativistic
effects appear more clearly than the K REG.2,3) We
report here the preliminary results of this work.
Ar12 + ions accelerated by RRC were led to atarget chamber/) which was installed on a so-called
El-b test experiment beam line to which beams comestraight from RRC. The energies of Ar ions were
estimated from the acceleration conditions and also
from the amount of the Doppler shift of REG K Xrays as a function of the detection angle with respect
to the beam direction. The values of energy estimatedby both methods agreed well with each other within
the limits of error.
Since the thickness of a Be target foil was 25 pm(4.6mgjcm 2 ), the charge of about 90% of Ar ionsturns to 18 + after passing through about 1 mgjcm 2of the target. The target foil was placed at thecenter of the target chamber. The ports for themeasurement of X rays were covered with 50 pm
Be foils. Two Si (Li) detectors were used; one forthe measurement of angular dependence of X rays
and the other as a monitor set at 90° with respect
to the beam direction. The measurements of X rays
were made at 45°, 90°, 135°, and 155 0 with respect
to the beam direction. The size of the beam spot on
the target was about 3 mm X 3 mm. The diameterof the Si (Li ) was 6 mm and the distance between
the target and the detector was about 20 cm.
X-ray spectra are shown in Fig. 1. Main con-

ENERGY( keV)
20

1030

20. II Mev/u Ar on Be
u

UJ

c::::
I

""

.c
'-

o

CHANNEL NUMBER

Fig. 1. Angular dependence of X rays emitted on collisionof 20.5 MeV lu Ar ions on a Be target. The detection
angles with respect to the beam direction are shown. A
25 pm aluminum absorber was used for the measurement
at 155°.

tributions to the spectrwn are attributed to K REC,
L REC, secondary electron bremsstrahlung (SEB),
and primary breamsstrahlung (PB) . Peaks corresponding to the characteristic X rays of Ar ions, tothose of some elements contaminating the Be foil,
and to those of material of target holder induced by
the stray beams are also observed in the spectra.
The energy of X rays from the projectile is changed
according to the Doppler shift as is seen in Fig. 1.
The SEB and PB contributions evaluated by the
Born approximation are shown in Fig. 1 for the
spectrum taken at 45 0 •4 )The component of SEB is subtracted from thespectra by assuming that the pattern of SEB is anexponential function and by normalizing to the experimental data at energies higher than the K REC
peak. I t was found that the K REG peak consistsof two components: one comes from the capture of

A. Awaya, et al.

68

K- REC

1.0
~
en

:z::
w

~

w
~

0.5

f-

~

0

)

I

30

60

90
ANGLE

120

150

180

(deg. )

Fig. 2. Angular dependence of K REC X-ray yields as afunction of the detection angle with respect to the beam.
The solid curve shows the pattern of sin2 0L and is normalized to the experimental data at OL = 90°, where OL is thephoton emission angle in the laboratory frame.

the K REC peak. Iii this case, the K REC peak
was fit to a single Gaussian curve, because that L
REC peak is difficult to resolve into two components
corresponding to the captures of 2 sand 1 s electronsof the Be target. The result obtained in the present
preliminary experiments agrees with theoretical prediction 2 , 3) within experimental uncertainties, thoughinsufficient for further discussion. We plan an experiment with the larger value of Bohr's criterion,l)p = Z p a/n{3, where the contribution of REC by the
2 p shell relative to the 2 s shell becomes larger thanthe present experimental condition, where, Zp is theelectric charge of the projectile, a is the fine-structure
constant, n is the principal quantum number of the
projectile atomic orbit by which an electron is captured, and {3 is the velocity of a projectile in unitsof the light velocity.
Referencesa 2 s Be electron and the other from that of a 1 s Be
electron. This will be discussed precisely in the
succeeding report. 5) The angular dependence of K
REC X-ray yield is shown in Fig. 2. The experimental results fit to the curve of sin 2 0L predicted by
the theory; OL is the photon emission angle in thelaboratory frame.
The shape of the L REC peak is evaluated byusing the Gaussian curve with the same width as1) K. W. Schnopper, H. D. Betz, J. P. Delvaille, K. Kalata,
A. R. Sohval, K. W. Jones, and H. E. Wegner: Phys. Rev.
Lett. , 29, 898 (1972).
2) Y. Awaya, K. Hino, A. Hitachi, Y. Kanai, K. Kawatsura,
K. Kuroki, H. Vogt, Y. Yamazaki, and T. Watanabe:
Lecture Note on High-Energy Ion-Atom Collision Process, Springer-Verlag, p. 185 (1988).
3) K. Hino and T. Watanabe: p.37 in this report.
4) K. Ishii: private communication, 1987.
5) Y. Awaya, K. Hino, Y. Kanai, A. Hitachi , H. Vogt, K.
Kuroki, and Y. Yamazaki: p.69 in this report.

69
RIKEN Accel. · ;f,J;og. Rep ... ~l (1987)

111-2-19.

.

Momentum Distribution of Be 2s Electron Measured bya Radiative Electron Capture Process
Y. Awaya, K. Hino, Y. Kanai, A. Hitachi,
H. Vogt, K. Kuroki, and Y. Yamazaki" The radiative electron capture (REC) is the process in which a highly ionized projectile ion directly
captures an orbital electron of a target atom andthe excess energy is emitted as a photon. The photon
is called the REC X-ray and has energy of (1/2) mvp 2+ Un - Un, where m is the electron mass, Vp thevelocity of a projectile, Un the binding energy of then orbital of projectile ions that capture an electronand Un is the binding energy of the n orbital electron
to be captured in the target atoms. The width of
the REC X-ray peak is roughly proportional tomVpvn, where U n = (1/2)mv n2 •Since Schnopper et al. observed REC X-rays/l it
has been urged that one can determine the momentum
distribution of a captured electron in a target atomfrom the peak width of the REC X-rays; however,
only a few experimental studies have been reported.
Kambara et ai. 2l compared the width of the K REC
X-rays emitted on collision of Ne ions and various
gas targets with that calculated by assuming theh ydrogenic wave functions for outermost electrons of
the gas targets. In this calculation, the effect of theinner-shell electrons of the target atoms were neglected
for the elements with Z>2. They found relatively
good agreement for the target of Z = 1 to 10, butsome ambiguity was left concerning the absolutevalue.
The contribution of capturing core-electrons of thetarget atoms has been discussed by Betz et ai. 3 ) andSpindler et al. 4 ) for the target elements heavier thancarbon. They have pointed out that the width ofthe momentum distribution of an outermost shellelectron obtained from the K REC X-ray peak islarger than that obtained by the Compton scattering
method.
We will report for the first time that the momentum
distribution of the outermost shell electron obtained
from the REC X-rays agrees well with that obtainedby the Compton scattering method. We have measured the REC X-rays from the 20.5 MeV lu Ar ionscolliding with target Be atoms. The details of theexperiments and the X-rays spectra are given separately in this volume. 5 ) Since a Be atom has only
2s and 1s electrons, we could separate the contribution of the outermost shell electrons (2s ) and thecore-shell electrons (1 s ) .
The component of secondary electron bremsstrahlung (SEB) is subtracted from the spectra by assuming that the pattern of SEB is an exponential function and by normalizing to the experimental data inthe energy region of spectra higher than the K REC
peak. It is considered that the K REC peak consistsof two main components: one owing to the captureof a 2s electron of Be and the other the capture of
a 1s electron of Be.
The full width half maximum (FWHM), Ll, of
the REC X-rays estimated by the relativistic Born
approximation is given b y6l(1)

in natural units (Ii = c = 1) , where A = mZTa, m isthe electron mass, ZT is the screened nuclear charge
which is felt by an orbital electron captured by the
projectile, a is the fine structure constant, v is thevelocity of projectile, and 0 L is the angle in thelaboratory system where the REC X-rays are measured. The shape of the K REC X-rays emitted by
10qr---~------------~------------~:: 103
c

::J

-e0
(I)

I-

~

8

10 2

10 1 L -_ _~_ _ _ _ _ _ _ _ _ _ _ _~_ _ _ _ _ _ _ _ _ _~~1015
ENERGY

20(keV)

Fig. 1. Contributions of SEB (solid line), K REC (brokenline) and L REC (dot-dashed line) to the experimentallyobtained spectrum. Is and 2s denote the contribution
from Ar18+ ion capturing Is and 2s electrons of the Be
target. The spectrum was obtained at 90° with respect tothe beam.
J

70

Y. Awaya, et al.

capturing a 1s electron of Be is assumed to be
Gaussian with L1, where ZT is taken as 3.7 according
to Slater. The Gaussian curve thus obtained was
subtracted from the spectrum by fitting the low andthe high energy region of the K REC peak. The
remainder is considered to be the component due tothe capture of the Be 2s electron. Small contributionof Ar 17 + ions is neglected in this analysis. The resolved spectrum obtained at 90° with respect to thebeam is shown in Fig. 1. L1 of the K (2s) REC at
90° was estimated to be 1.14 keY.
On the other hand, the momentum distribution oforbital electrons was studied precisely by the Compton
scattering of photons. To check whether the momentum distribution obtained for Be 2s electron in thiswork agrees with the values obtained by the Compton
scattering, we compared our result with that obtained
by Currant et al.7) They measured the Compton profile of Be by Compton scattering of Mo Ka X-rays.
By subtracting the contribution of the 1s electron,
the value of 315 eV is obtained for the FWHM of
the Compton profile, D , for the 2s electron at Compton
shift of 850 ev.
In order to compare these two values, we should
consider the definition of the FWHM of a peak ineach case. In REC '21 is nearly equal to A.( V I c,
whereas in Compton scattering D is nearly equal toA.( (2m (0) 1m) 1/2, where A is a constant, V = vc,
w (0) is the Compton shift, and m is the electronmass in keY. Then the A A values of 5.4 and 5.5
were obtained for the REC peak and the Compton
scattering, respectively; that is, the width of the REC
X-ray peak gives truly the momentum distribution ofoutermost shell electrons.
References
1) H. W. Schnopper, H.-D. Betz, J. P. Delvaille, K. Kalata,
A. R. Sohval, K. W. Jones, and H. E. Wegner: Phys. Rev.
Lett., 29, 898 (1972).
2) T. Kambara, Y. Awaya, A. Hitachi, M. Kase, I. Kohno,
and T. Tonuma: J. Phys. B: At. Mol. Phys., 15, 3759
(1982) .
3) H.-D. Betz, M. Kleber, E. Spindler, F. Bell, H. Panke,
and w. Stehling: Proc. Xth Int. Conf. Physics ofElectronic and Atomic Collisions, p.520 (1977) .
4) E. Spindler, H.-D. Betz, and F. Bell: J. Phys. B: At.
Mol. Phys., 10, L561 (1977).
5) Y. Awaya, A. Hitachi, Y. Kanai, K. Kawatsura, K.
Kuroki, H. Vogt, and Y. Yamazaki: p.67 in this report.
6) This equation is obtained by one of authors, K. Hino.
7) R. Currant, P. D. DeCicco, and R. Kaplow: Phys. Rev.
B , 3, 243 (1971).

71
RIKEN ,Accel. Prog. Rep. 21 (1987) ,111-2-20.

Resonant Transfer and. ,Excitation (RTE) ,.in. Ge29 +on H2 Collisions
S. Reusch,* Y. Awaya, T. Kambara, D. J. ~c~aughlin,**P. H. Mokler,* A. Miiller,*** R. Schuch, and M. Schulz****In ion-atom collisions, 'it is possible that an excitation of 'an ' elect~on in " th~ 'projectile' ion and· a transfer
of an electron from the target atom to the projectile
occur simultaneously in one process induced by anelectron-electron interation. This process which iscalled as resonant transfer and excitation (RTE)
can be active if the total energy gained by the target
electron during the capture to the projectile coincides
with the excitation energy of the bound electron in
the projectile. As a consequence of the R TE, theprojectile ion is in a doubly-excited state with the
charge state smaller by one than the initial state.
This state can decay via photon emission or autoionization.
Figure 1 shows the R TE mechanism in the case of
Li-like germanium ion (Ge 29 +) incident on a hydrogentarget at energy of 13 MeV jamu. The resonancecondition shown here is marked as a KLL process
which corresponds to K-to-L excitation and targetto-L capture. If the target electron is free and monoenergetic, this process is called dielectronic recombination (DR) which is described as the inverse
process of Auger-electron emission. The width of
the resonances in DR is expected to be ~ 1 eV.
However, the target electron to be captured is not

;;
~

>0)
L-

Q)

C

5

0)

;:---

---0--0----- 1I2mv2-5

Excitation Function.Compton-Protae H2

1000

0

W

the' velocity distribution of the target electron(Compton profile) makes the width of the observed
resonance broader. In the example shown here, theobserved width of R TE is in the order of keV by
the effect of the Compton profile, which is also
indicated in Fig. 1.
We have investigated the KLn ( n > 2) resonancesof the R TE process in collisions between Ge 29 + ionsand a H 2 target. We worked with a beam of Ge 2~+ions from the UNILAC facility at GSI in Darmstadt
in the energy range between 12 and 18.5 MeV j amu.
In order to get a reasonable narrow Compton profile
for the target electrons to be captured, we should use
a target with a small electron momentum distribution,in other word, a small electron binding energy. In
the experiment, we used a differentially-pumped gas
target of H 2 • We measured characteristic K X raysof Ge-ions from the target region in coincidence withcharge-analyzed Ge 28 + projectiles after a magnet
downstream of the target. The primary beam wasmonitored by a Faraday cup for normalization. A
single-collision condition in the target was checkedby varying the target gas pressure.
The cross sections for R TE which are obtained
from the experiment are shown in Fig. 2. The data
show three clearly separated structures. The peak at

RTE on ~~Ge29+-Ions

10

Q)

fre~ hut bound iJ? a hyd~ogen atom and in .motion,

e-

M
L

«J

::9

c
i5
c -10

w
l500
e:::

iii

-15 t:.....L_ _---L_ _---1.._

CL-

K

_

"0

---1.._ _--'-_---::I

Fig. 1. Schematic description of the KLL-RTE process inthe case of 13 MeV /amu Ge 29+ and H2 collision.

* GSI, D6100 Darmstadt, F. R. Germany.
** Physics Department, University of Hartford, Hartford CT06117, USA.
*** Strahlenzentrum, Universitat GieSen, D6300 GieSen,
F. R. Germany.
**** Physikalisches Institut, Universitat Heidelberg, D6900
Heidelberg, F. R. Germany.

12

14

16

18

20

Energy (Mev/u)
Fig. 2. R TE cross sections. Dots show experimental data.
The error bars are of statistical origins only. Vertical bars
at the bottom show the position and relative cross sectionof DR resonances. Solid curve shows the DR cross sections
folded with the Compton profile of H 2 • The experimental
data are normalized to the maximum of the curve.

72

S. Reusch, et al.

13 MeV / amu is due to the KLL processes, where
the target electron is captured to the L-shell of the
projectile, predominantly resulting to the Is2s2p 2
state. This doubly-excited state can stabilize via anemission of a Ka X-ray photon. The second maximum at around 16.2 MeV / amu corresponds to KLM
processes with final states of Ge 28 + which have one
electron in the M shell. _The third one at around17 .5 MeV / amu corresponds to KLn (n > 3) processes.
This is the first measurement of RTE where aseparation between KLM and higher resonances wasobservable.
The data points are compared with ab-initio calculated DR cross sections which are indicated asvertical bars at the bottom 'of -Fig. 2. The positionsof the resonances are deduced using the multiconfiguration code of Grant et aU) Folding thecontributions of different DR resonances with theCompton profile of H 2 , one yields the solid curve ofFig. 2. The data points are adjusted in absoluteheight to this curve in the maximum of the KLL
reson~ce.
The general agreement between thetheory and the experiment is quite fair.
Reference
1) I. P. Grant, B. J. McKenzie, P. H. Norrington, D. F.
Mayers, and N. C. Pyper: Comput. Phys. Commun., 21,
207 (1980).

73
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-21.

Charge Equilibration Process of 50 MeV Ar Ions in C Foils
T. Mizogawa, Y. Awaya, T. Kambara, Y. Kanai,
M. Kase, H. Kumagai, and K. Shima

It is well known that an effective projectile K xray emission cross section, i.e. the K X-ray yield perion divided by the target thickness, depends on thetarget thickness in collisions between heavy ions andsolid targets. 1 ) This occurs when the mean intervalof relevant collisions and the lifetime of K-hole bearing states are of the same order of magnitude. On
the other hand, when the target thickness becomesthin enough, another thickness dependence of the K
X-ray cross section appears owing to the variation of
the L-shell configuration, affecting the K-hole formation cross section. In both cases the experiment on
target-thickness dependence of K X-ray yield is useful to obtain the information about the collision
processes concerning projectile inner shells in solid.
In the latter case, however, the analysis based solely
on the data of X-ray measurements may be unsuccessful because of the complication owing to the large
number of concerning states of projectiles.
We have performed the experiments on the targetthickness dependence of 50 MeV Ar ion charge-state
distribution (CSD) after passing the ions throughthin carbon foils. With the aid of these data, ananalysis of our previous results on K X-ray measurements in the L-shell nonequilibrium region for thesame collision system 2 ) can be made. In this paper
the description is restricted to this analysis, and thepresent data of CSD measurements will be fully
discussed elsewhere.
In the K X-ray measurements 2 ) we found that the
projectile K-hole formation cross section depends on
the number of the L-holes in the initial state of a
projectile. The effective K-hole formation cross section can be approximated as(1)

where ar is the ionization cross section and aE is theK-L excitation cross section per one L-hole, and(2)where nL is the average number of L-holes at thedepth x. If the value TiL is known from the CSD
data, the ratio (JEf ar can be deduced from the experimental data of av.
Carbon foil target (2-20 p.gfcm 2 ) were bombarded

CHANNEL NUMBER

Fig. 1. T ypical charge spectrum of Ar ions after passing
through C foils.

with 50 MeV Ar 4 +,12+ from the RIKEN linear accelerator (RILAC). The CSD was measured with amagnetic charge analyzer and a position-sensitive
parallel-plate avalanche counter. The target thicknesses were measured after the CSD measurements
by a recoil-detection method described in Ref. 2. The
beam intensity during each CSD measurement was
low enough and caused no deterioration of the target.
A typical charge spectrum is shown in Fig. 1. The
charge-state fractions determined from such spectra
are shown as a function of target thickness in Figs.
2 (a) and (b).
The target-thickness dependence of CSD for gaseous targets can be analyzed by a parameter-fitting
technique using coupled rate equations containing asuitable number of adjustable charge-changing crosssections. 3 ) For solid targets, however, such an approach is hardly applicable, mainly because of the
difficulty in preparing the target thin enough to74

T. Mizogawa, et al.

100

100
12+

<=~
10

.?2

~

1=1

1=1

~

~
''""'

~

~

~

~

~

~

U)
CL>

~

<:

10

16+

rn'"

8+

~

'"

- 9+

..Q

0

.01

_16+

~ - 8+

.1

'"

..Q

0

11+

: - - 14+
10+

~_15+

CL>

.1

:~ 13+.01~.

7+. 0-7+

.001
10

15

5

0

Target Thickness (jJg/ cm 2 ) .

10

15

Target Thickness (jJg/cm2)w~
Fig. 2. Target thickness dependence of Ar-ion charge-state fractions after passing
through C foils. (a), Ar4 + impact; (b), Ar12+ impact.

extract the meaningful information. A more simplified
model is desirable for solids. In this paper we assume firstly that the distribution of ions over thenumber of M-holes immediately reaches an equilibrium after passing the entrance surface of the target
regardless of L- and K-shell configurations. Secondly,
we assume that the fraction of K-hole bearing ionsis negligibly small. Then our problem reduces to thedevelopment of L-holes in solid. The problem canbe described by 9-component rate equations,d-d Y i = 2j aij Y j - (2j a ji) Y i
X

j

j

(3)

where Y i denote the fractions of ions having i Lholes (O~i~8) at the depth x, and O'ij are the crosssections for changing the L-hole number from j to i.
The value O'ij can be approximated asf

aij = Piib) (2n-b) db(4)

The average increase in L-holes after the collision
for the initial state j is(6)

After integrating over the impact parameter,(7)2j(i- j)aij=(8- j)al- jae
i

where

J

al = Pl(b)(2n-b) db,

ac=f

Pc(b)(2n-b)db(8)

Using Eq. 7 we obtain a differential equation for the
average L-hole number nL as a function of thedepth,
ddx nL = al(8 - nL) - acnL

(9)

where
(10)

where P ij (b) is the impact-parameter dependent
probability for changing the L-hole number from j
to i. Here we adopt further approximations that(a ) each orbital in the L-shell occupied by anelectron has a constant probability PI to lose theelectron regardless of the other orbitals and(b) each unoccupied orbital in the L-shell has
also a constant probability Pc to capture a target
electron regardless of the other orbitals.
Assumption (b) may not be unrealistic if theaverage number of captured electrons in a single
collision is small enough compared with the Z number of the target atom. Then

The parameters 0'1 and O'c can be deduced by aleast-square fitting of the solution of Eq.9 to theexperimental average L-hole number. To analyze
the full CSD data, however, we need the knowledgeof the impact-parameter dependence of PI and Pc,
but it is out of the range of this report.
In Fig. 3 the thickness dependence of the averagecharge q computed from the CSD data is shown.
According to the Eq.9, the data can be fitted by
the form

Pij = ~(8; j) P1k(1- Pl)B-j-kC~ k)PcJ-i+k(1- Pc)i- k

where nL (eq) and nM(e q ) are the equilibrium numbersof the L- and M-holes, and(5)

q=nL(eq)+nM(eq)+(nL(O)- nL(eq») exp (- AX) (11)

T. Mizogawa, et al.

75

13~----~------~------~-----,(14)

In Fig. 4 nL is plotted. Interpolating the nL data
and the given zero-thickness value by straight lines,
integration was performed. Resulted nL is also plottedin Fig. 4. With the aid of these nL and Eq. 1, (lEI(l.,can be evaluated.

CD

~ 12
cu
.r:

o

CD

C)

cu
G; 11

• Ar4+-C... Ar12+-c~

Solid line: least-square fit
by the form

iTv[12+ J = ar+aE1k[12+ J

q~A-Bexp(-Cx)

iTv[4+ ] = ar+aE1k[4+ J

10

5

15

Then

20

Target Thickness (lJg/cm2)

Fig. 3.

Average charge as a function of the target thickness.

(12)

To evaluate the values in Eq. 2, we tentatively
adopt the nM(e q ) obtained by the fitting to Ar12+ data,
because the value evaluated from A r 4+ data is too
sensitive to the experimental errors. Then average
L-hole number nL is(13)
The equilibrium M-hole number IS(15)

iTv[12+J-iTv[4+J(16)aE/ ar= nL[ 12+ J iT v[4 + J - rk[4+ JiTv[12+ J

From the data for the thinnest target of the K X-ray
measurements,
aE/ ar = 0.23 per one L-hole

The most serious error source in above evaluation
would be the equilibrium number of M-holes. However +0.5 error in nM(e q ) causes only 10% error inabove ratio. Another error source is Uv itself, which
we deduced from K X-ray emission cross sections byneglecting the electron capture to K-hole. 2 } For thintarget this effect is small and tends to cancel in theratio iTv[12+ JiTv[4+ J. In conclusion, the contributionof K-L excitation to the total K-hole formation crosssection is approximately given by
0.23 X (L-hole number)
1+0.23 X (L-hole number)

1/1

CD

(5

J:

I
...I

This means that about 50% of the K-hole formation
cross section for the charge-equilibrated Ar beam (ofwhich average L-hole number is at least 4.3) is dueto the K-L excitation .

3

'0
1
I
1
1
1
1

G;
.Q

E
::l

Z

References:
Thinnest target
1 - - In K X-ray
1
measurements

I
I

I

Assumption

I

I
O~~~~----

oFig. 4.

n~r) =7.4__~____-...I

5

10

Depth

(J.lg/cm2)

15

Average L-hole number. See Text.

I) 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, P. H. Mokler, and K. Shima: Nucl.
Instrum. Methods Phys. Res. A, 262, HI (1987).
3) S. Datz, H. O. Lutz, L. B. Bridwell, C. D. Moak, H. D.
Betz, and L. D. Ellsworth: Phys. Rev. A, 2, ~30 (1970).

76
RIKEN Accel. Prog. Rep. 21 (1987)

11-2-22.

Broadening of Ar Projectile Ka X-Ray Satellite Lines in
Cu and Ni Target Foils
H. Vogt, Y. Awaya, Y. Kanai, M. Kase, and T. Mizogawa

We have investigated the widths of Ka satellite
X -ray lines of 33 MeV Argon projectiles induced in
Cu and Ni foils of various thicknesses. Previous
measurements/,2} where thick target foils have been
used, have shown a strong dependence of the projectile satellite line widths on the atomic number Zof the target foil material. For target materials likee.g. Cu, Ni, and Fe the satellite line widths areseverely broader than in cases where C or Al targets
have been used. In Ref. 2 it was shown that thisbroadening of the satellites lines may be correlated
to the electron density Zna of the target material,
where na is the atomic density. The line width can
not be explained fully by Doppler broadening due tomultiple scattering of the projectiles and due to thespectrometer resolution. In targets of higher electron
density the rate of interactions of the projectile withthe target electrons is higher and may lead to a lifetime shortening effect of the excited projectile similar
to pressure broadening in optical spectra. Here different types of interaction are however possible. The
highly ionized Ar projectile (mean charge statehere~ 11 +) can capture or lose K, L, and M shellelectrons or may scatter elastically. The influence of
these processes on the satellite line widths is not wellunderstood.
The aim of these measurements is to determine if
the line broadening is still present in very thin targets,where the projectile X-rays are emitted mainly outside the target. For typical K-hole lifetimes of about

10-14 s a target thickness of much less than 0.1 pm
is required to obtain X-rays from projectiles decaying
outside the target. Measurements using gas targets ofthe same atomic number would be very interesting,however, in this case technical problems to get a gas
target of sufficient intensity and small target length
arise. We carried out measurements of the Ar Ka
X-ray spectra using target foils of Cu and Ni withthicknesses ranging from 0.03 pm up to 1 pm (27890 pg/cm 2 ). The Ar Ka X-rays were measured
using a broad range crystal spectrometer (Ge crystal,
2() = 74 deg) 3} at an observation angle of 90 deg.
The experimental setup is shown in Fig. 1.
In order to have a definite mean charge-state eveninside the thinnest targets, an Ar 4 + beam of the
RIKEN linear accelerator was passed through a C
foil of 10 pg/cm 2 in thickness located about 10 cm infront of the target. The target thickness was estimated by measuring the Rutherford scattered projectiles and recoil atoms with a surface barrier
detector at 45 deg. The satellite line widths are

3000

(a)

2000
1000
0
2

2c

PSPC

G."y".1

3

4

5

6

7

;::I

~

0

C)

/!------

1000

I
I

II
I
T,I

I I\

/" I I \c

~SBD

I

500

JAr beam

OSiLiFig. 1. Experimental setup. PSPC, position sensitlve proportional counter; T, target; C, carbon foil; SBD, surface
barrier detector. Distances, target-Ge crystal: 315 mm, Ge
crystal-PSPC: 187 mm.

o~~~~~~~~~~~~~

350

1234567
channel number

540

Fig. 2. Measured Ar Ka X-ray spectra in a) Al foil 0.8 f.Lm
and in b) Ni foil 0.5 f.LID in thickness. Solid line: Resultof the Gaussian line fits.

H. Vogt, et al.

estimated by fitting Gaussian curves to the observed
satellite spectra.
The fitting procedure was carried out under theassumption that each satellite component KV" hassame line width. Figure 2 shows results of the Ka
spectra and the Gaussian line fit obtained with an
Al foil and with a Ni foil. The measured line widths
as a function of the target thickness are shown in
Fig. 3 for Cu targets and in Fig. 4 for Ni targets. In
Figs. 3 and 4 are shown error bars of the line width
calculated by the fitting program. Not shown are
the errors of the target thickness measurements which
are up to 50 ero because of the small distance of 4 cm
between the SBD, which was used to count the
Rutherford scattered particles, and the target. For a
direct comparison of the results, which were obtainedin different beam times and thus with slightly different Ar beam profiles, measurements using Al target
foils, where the line broadening is much smaller,

,

I

I

Cu

,

+

20

~
..c.:

.:0

I

~

19

I

I

+ +f
-

•+

.~
Q)

~
18 I-

~
17
I

t
I

,

I

I

I

10- 1

I

I

77

,

,

I

I

Ni

~

20

I

I

~~

;
+
I

-

~

~
..c.:
...,

I

191-

-

+

"0
.~
Q)

I=l

;.:::;

18

17
I

10- 2

I

I

I

I

I

I

I

,

10- 1

target thickness [JLm]
Fig. 4. As Fig. 3 for Ni target foils. . , selfsupported Ni foil;b,., Ni foil on 4 p.g/cm 2 e foil; \l, Ni foil on 3 pg/cm2 e
foil.

were carried out at the beginning and end of eachbeam time. (The line width here with Al foil 0.8 pm
is 18.0 eV, with C foil 3 pgjcm2 is 15.3 eV).
Figures 3 and 4 show that the satellite line widths
are small at very low target thicknesses up to 0.05 pm
and increase in the thickness range of 0.05 to 0.1 pm
to a constant value. During the K-hole lifetime the33 MeV Ar ion travels roughly a length of 0.1 pm.
Therefore, these measurements support the conclusionthat the line broadening arises only if the projectile
ion decays inside the target.
ReferencesI1target thickness [JLm1
Fig. 3. Line width (FWHM) of the Gaussian line fits of
the KL" satellite components as function of the Cu target
foil thickness. . , selfsupported Cu foil; b,., Cu foil on
3 p.g/cm2 e foil; \l, eu foil on 1 p.g/cm2 e foil.

1) Y. Awaya, T. Kambara, M. Kase, H. Shibata, H. Kumagai, K. Kujima, J. Urakawa, T. Matsuo, and J. Takahashi: Nucl. Instrum. Methods B, 10/11, 53 (1985).
2) R. L. Watson, J. R. White, A. Langenberg, R. A. Kene·fick, and e. C. Bahr: Phys. Rev. A, 22, 582 (1980).
3) A. Hitachi, H. Kumagai, and Y. Awaya: Nucl. Instrum.
Methods, 195, 631 (1982).

78
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-23.

A Systematic Study of KLn Multiple Vacancy Production for
Ca Bombarded by 0.25-1.5 MeV / u Ne and Ar Ions
B. Sulik, Y. Awaya, T. Kambara, Y. Kanai, and T. Mizogawa

We studied the KLn multiple vacancy productionof Ca target atoms by measuring the relative K
satellite X-ray yields. For an Ar projectile the colliding system is almost symmetric (Z1 = 18, Z2 = 20),
whereas for a Ne projectile it is asymmetric. The
scaled projectile velocity, i.e., the projectile velocity
divided by the characteristic velocity of the target
L-shell electrons, is less than unity in the whole projectile energy region.
Experiments were carried out on the beams of
RILAC. Energies of the Ne 2 + projectiles were 0.54,
0.83, 1.03, 1.31, and 1.54 MeV /u and those of Ar 4+
projectiles were 0.25, 0.54, 0.80, 1.04, 1.30, and1.57 MeV lu. The target was 70+ 10 p.g/cm 2 Ca
exaporated to a 10 p.g/cm 2 carbon backing. Ka
satellites, Ka hypersatellites, and a part of Kf3 satellites were measured by using a broad-range crystal
spectrometer1 ) consisting of a flat crystal and a position sensitive proportional counter. The beam was
focused and collimated to a 1 mm size spot on thetarget surface. The target was placed at 60 0 withrespect to the beam. The carbon backing of thetarget was faced to the beam in order to ensure thealmost equilibrium charge state distribution of the
projectile ions inside the Ca part. A Ge ( 111) crystal
was placed at 90 0 with respect to the beam and withinclination of 2 () = 58.8 0 at the center of the crystal,

where () is the Bragg angle. Simultaneously a Si(Li)detector was used partly for monitoring the beam andthe target, partly for measuring an X-ray spectrum
in a wide energy range.
A typical Ca K spectrum is given in Fig. 1. A
preliminary evaluation of the intensities of the Ka
diagram and satellite lines was carried out. The experimental values of the L-shell ionization probabilities per electron, P L , are plotted as a function of thescaled projectile energy E / AU in Figs. 2 and 3 forN e ions on a Ca target and Ar ions on a Ca target,
respectively, where E is the projectile energy, ,t is
the ratio of the projectile rest mass to the rest massof the electron, and U is the binding energy of the
L-shell electron of the target. In these figures, calculated curves are also shown for comparison; the dottedline and dashed one show the prediction of thebinary encounter approximation (BEA) 2,3) and thesolid line shows that of the geometrical model(GM) . 4) For the BEA calculations no accepted
method is available in the literature to determine aneffective projectile charge Zeff; therefore, we presented the predictions of this theory using both the(Xl03)
4.10

Ne~Ca

2

3.58
3.07
~

0.4

':J

.I:l..

::.::\\/ BEA(Z.~,)

22.56

'"

...c::

(Il

~2.05
2r:::

']

u

'"

g 1.54

~

1
,

~

4i

1.02
0.51

0.

>.

...c::

Fig. 1. Typical Ca K X-ray spectrum. KL" denotes the initial vacancy configuration. The projectile is 1.30 MeV lu
Ar ions.

0

0

::2

0
325

,

~GM
__ ~BEA(Zi on)

(Il

0

0

0

0
0

1

2

3

Ef)..uFig. 2. Energy dependence of P L for Ne-ion bombardment.
Open circles, experiment (present work) ; dotted line, BEA
with Z e tf=Znucl ell r; dashed line, BEA with Zett=Zlonlc;
solid line, GM.

B. Sulik, et al.

""'- ... . . ,,
I

Ar-Ca

'

I
I

"

,/

,

\\

,
I

\
\

,I

\ \/

I

\

2

BEA (Znucl)

I
I

\

II
I

"\

,
I

I

I
I

i

: /
I

/

j

0

/-----,,(BEA (Zion)

.

~

GM

~

____

~

____

tion. The equilibrium ionic charges were determinedby the scaling formula of Ref. 5. In the process of
the GM calculations the determination of Zeff isincluded. Both theories are given in their simplest
forms: binding correction, charge transfer and rearrangement process prior to the K-vacancy decay
are not taken into account. In comparison with theexperimental data, both theories overestimate the PL
values, but among them, the GM prediction seems
to fit the experimental data better than the BEA one
and also reproduce the experimental tendencies. A
more detailed analysis is under work.
References0I

OL-____

79

~

_____

0 2 3

E/ t..u
Fig. 3. Energy dependence of P L for Ar-ion bombardment.
For details, see the caption of Fig. 2.

nuclear charge (dotted line) and the average (equilibrium) ionic charges (dashed line) of the projectiles
as possible upper and lower limits of the BEA de scrip-

1) A. Hitachi, H. Kumagai and Y. Awaya: Nucl. Instrum.
Methods, 195, 631 (1982).
2) J. H. McGuire and P. Richard: Phys. Rev., AS, 1374
(1973) .
3) Y. Awaya: Proc. XI-th Int. Conf. on Physics of Electronic and Atomic Collisions, Kyoto, 1979 (eds. N. Oda
and K. Takayanagi) , North Holland, p.325 (1980).
4) B. Sulik, 1. Kadar, S. Ritz, D. Varga, J. Vegh, G. Hock,and D. Berenyi: Nucl. Instrum. Methods B , 28, 509(1987) .
5) K. Shima, T. Mikumo and H. Tawara: At. Data Nucl.
Data Tables, 34, 357 (1986).

80
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-24.

Impact Parameter Dependent Probabilities of Au L-Shell
Ionization by Ar Ions
T. Kambara, T. Mizogawa, Y. Awaya, Y. Kanai,
K. Shima, and R. Schuch

The ionization processes in asymmetric ion-atomcollisions have often been compared with perturbation
theoretical descriptions. In these cases, a so-calledbinding effect is often introduced to the first-order
perturbation theories like a plane-wave Born approximation (PWBA) and a semi-classical approximation(SCA). When the two nuclei of the projectile andthe target approach closer than the radius of theelectron orbit, the initial state wavefunction of thebound electron in the target is changed by the influence of the field of the projectile. This is calleda binding effect.
To investigate the binding effect in a heavy ionatom collision, the target Lm-shell ionization probability as a function of impact parameter was measured in a collision system of 1 MeV jamu Ar on Au.
The result is compared with calculations of a semiclassical approximation (SCA) with relativistic electronic wavefunctions.
The measurement was performed at RILAC byusing almost the same experimental setup as thatreported previously.l) An Ar beam with energy of
40.6 MeV was collimated to 1 mm X 1 mm anddivergence of 0.02 deg by a double slit system andwas led to a target. The target was Au with thickness of about 30 f1g/cm 2 evaporated on a thin C foil.
The characteristic L X-rays of Au were detected witha Si (Li) detector placed at 90 deg to the beamat 16.5 mm of distance. Scattered projectiles weredetected with a parallel-plate avalanche detector(PPAD) placed at 193.5 cm from the target to theforward direction. The anode of the PPAD isdivided into 16 rings corresponding to 16 different
scattering angles ranging from 0.14 to 1.4 deg. The
coincidence events between the X rays and thescattered projectiles at different scattering angles arerecorded in event mode by a computer. At the sametime the total number of scattered particles at eachring of the PPAD was counted with scalers and wasused for the normalization to obtain the probabilityof the target L X-ray emission at each scattering
angle.
The Lm-ionization probability was estimated fromthe measurement of the La X-ray which emits fromthe transition of an M electron to an Lm hole. The

345 6
Impact parameter (b)7 8(x l03fm)

Fig. 1. Impact parameter dependence of the ionization
probability of Au Lm shell. Dots show the experimental
data and lines show the SeA calculation results; SA is forseparated atom wave function for the initial state of theionized electron and VA is for the united atom one. r B
shows the Bohr radius of Au L shell.

obtained La X-ray emission probabilities were corrected for the fluorescence yield of the neutral atom
to obtain the Lm-vacancy production probability
P LIII (b). The effect of the Coster-Kronig transition
was not considered. The results are shown in Fig. 1.
The impact parameter b was calculated from thescattering angle by a screened Coulomb potential.
The Bohr radius of the Au L shell is about 2,800 fm.
The lines in Fig. 1 represent the probabilities predicted by SCA calculation. 2 ) In the calculations, relativistic wavefunctions were used for the Lm electrons of the target Au and the recoil effect wasconsidered. To see the contribution of the binding
effect, we compared the results of calculations fordifferent effective nuclear charges which determines
the initial electron wavefunction in the target: oneis the target nuclear charge (SA) and the other isthe sum of the projectile and the target (UA) nuclear
charge. The screening by the inner shell electrons
was taken into account according to Slater. The fullline shows the result of the calculation with the SA

T. Kambara, et ai.

assumption and the dashed lines show that with VA.
At impact parameter larger than the Bohr radiusof the Au L shell, the experimental P LIII ( b ) has
values clos~ to or larger than the SA calculation. At
smaller impact parameter, it becomes considerably
smaller than the SA calculation and tends to be close
to the V A values. We have observed the same effectin the P ( b) of the target K-shell ionization of He-Ca
collision system. 1 ) It supports the applicability of the
SeA calculation with the binding effect for ionization in different collision systems.
The effect of multi-scattering in the solid target
may affect , the shape of the PLIn (b) especially at
smaller scattering angles. According to 'a table given

81

by Sigmund and Winterbon, S) the half width of theangular distribution of the multiple scattering IS
estimated to be smaller than 0.06 deg in our case. It
may cause the flattening of the shape of PLIn (b) atlarge impact parameters. Detailed analysis is m
progress.
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) D. Trautmann: Private communication.
3) P. Sigmund and K. B. Winterbon: Nucl. Instrum. Methods, 119, 541 (1974).

82

RIKEN Aced. Prog. Rep. 21 (1987)

111-2-25.

Charge-State Distribution Measurements ' of Ar Ions ·Y. Kanai, Y. Awaya, T. Kambara, M. Kase,
H. Kumagai, T. Mizogawa, and K. Shima ,We measured the charge-state distributions of projectile Ar ions after single close . collisions with gas
targets to investigate the heavy· ions-atom violent
collisions. We used Ar ions (1.27 MeV lu) fromRILAC. Our experimental setup is as same as shownin previous papers.l,Z) A gas cell was set at thetarget position and was differentially pumped tomaintain the beam line in good vacuum. The pressure of the target gas was monitored with a capacitance manometer (MKS Baratron). Though difficult
to measure from the value indicated with the Baratron
gauge, the gas pressure at the beam position wasconsidered proportional to the value of the gauge.
The target gas pressure dependence of the chargestate fractions of Ar ions after collisions was measured in the pressure range between 10- z and 10- a
Torr (at the Baratron gauge), since the singlecollision condition is maintained in this range asshown in Fig. 1. Typical charge-state distributions of
Ar ions in the Ar 4+ + Ar collisions are shown in Fig.
2, in which open and closed circles are for the scattering angle of 0°-+-0.066° and 0.13°-+-0.066°, respectively.
The mean charge states ql (Z2) measured for Ar
ions (1.27 MeV lu) are shown as a function of thetarget atomic number (Z2) in Fig. 3. The valuesplotted in this figure are for Ar ions with almost thesame impact parameter: 0.6±g:~ X 10-9 cm for a Ne
target, 0.8± g:~ X 10-9 cm for an Ar target and 1.0-+~} X 10-9 cm for a Kr target. The results for Arlz+
are also plotted. Our results seem to show that thevalue of the mean charge state converges to a certain

164L-~-7~~~-L~__L-~
4

6

8

10 12 14 ·16 18

CHARGE STATE

Fig. 2. Charge-state distributions of Ar ions after the Ar4 ++Ar collision. Energy of Ar'+ is 1.27 MeVlu. Open andclosed circles are for charge-state distributions of Ar ionsscattered into 0° ± 0.066° and 0.13° ± 0.066°, respectively.
Target Ar gas pressure is 5.9 mTorr.

10~~------~------~----~
Ar4+ + Ar
~12
NN

0

Itr

W

I-

t

0

~11
If)

•

~
~

0 10

8+

9+

~

•

~

10+
11+/

•

z

/

12+/

105L-------~------~----~
103
1(iPRESSURE ( Tor r)

Fig. 1. Pressure dependence of the charge-state fraction ofargon ions after the Ar4 ++ Ar collisions.

9
0

I

10

I

I

I

20
30
40
TARGET ATOMIC NUvlBER(Z2)50

Fig. 3. Target atomic number (Z2) dependence of the mean
charge state of Ar ions after single close collisions. The
impact parameter is O.6X 10-9 em for the Ne target, O.8X
10-9 em for the Ar target, and l.OX 10-9 em for the Kr
target. The energy of Ar ions is 1.27 MeV lu. Closed circles
are for Ar 4 + impact; open circles for Ar12 + impact.

Y. Kanai, et al.

value as Z2 becomes large. Rosner and his groupreported similar results as ours. 3 ,4) In their cases, theK-shell vacancies have influe~ce on the mean charge
values of ions, since the impact parameter (b) is muchsmaller than the K-shell radius (rk) of the projectileions. In our case, the impact parameter is larger
than the K-shell radius of Ar, i.e., 0.45 X 10-9 cm.
Considering the impact-parameter dependence of theK-shell-vacancy production probability Pk (b) for
1 MeV lu S ions on Kr and Xe by Maor et al. 5 ):( 1) the values of Pk (b) for b > rk are smaller thanthose for b<rk, (2) the values of Pk (b) for S on
Kr are smaller than those for S on Xe, we may saythat the values of Pk (b) for the Ar ( 1.27 MeV lu)Ne, Ar Kr collisions are so small that the effect of83

production of K-shell vacancies is negligible. The Z2
dependence of the mean charge state of Ar (1.27
MeV lu) after single close collisions, shown in Fig. 3,
would be determined by the behavior of the L-shell(and outershell) electrons.
References
1) Y. Kanai, Y. Awaya, T. Kambara, M. Kase, H. Kumagai,
T. Mizogawa, and K. Shima: RIKEN Accel. Prog. Rep.,
20, 56 (1986).
2) Y. Kanai, Y. Awaya, T. Kambara, M. Kase, H. Kumagai,
T. Mizogawa, and K. Shima: Nucl. Instrum. Methods A,
262, 128 (1987) .
3) B. Rosner and D. Gur: Phys. Rev. A, 15, 70 (1977) .
4) B. Rosner and W. Brandt: Phys. Lett. A, 61, 97 (1977).
5) D. Maor, B. Rosner, M. Meron, H. Schmidt-Bocking, and
R. Schuch: ]. Phys. B, 14, 693 (1981).

84
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-26. Coincidence Measurements of Electron Capture andTarget Ionization in 1.05 MeV / amu Ar12+ + Ne Collision
T. Tonuma, T. Matsuo, H. Kumagai, S. H. Be, and H. Tawara

We report experimental studies of target ionizationand projectile electron capture processes, studies
which were carried outtp.rough coincidence measurements between a charge-analyzed projectile andtarget ion for 1.05 MeV I amu Ar12+ projectiles colliding with N e targets.
A 1.05 MeV / amu Ar4 + beam was provided by
RILAC. Ar12+ beams were selected with a switchingmagnet by passing through a carbon foil and directed
into a target cell. A target-gas cell and a recoil ion
detection system are shown in Fig. 1. Ionized recoiltarget ions were charge-analyzed on a time-of-flight(TOF) spectrometer. This spectrometer separates
recoil ions with respect to their flight times, which
determine their charge state. The bottom plate (ionrepeller) and the grid inside the target cell were on
a positive potential of + 700 V and +300 V, repectively. An Einzel lens plate was on a negative
potential of -300 V, and a channeltron-detector cone
was to -2.5 kV. The distance between the interaction region and the channeltron detector was about
14 cm. After allowed to pass the target cell, the projectile ions were charge-analyzed with an electrostatic
analyzer and detected with a position-sensitive parallel
SignalChanneltron

1---+- - 2.5kV

Deflect.,

I 0V

L ens ____ __ _ .l. __ :____

-IOOV

!

----~-1~ + 300V~

! + 700V

Gas Target Chamber (grounded)

Fig. 1. Target gas cell with a time-of-flight spectrometer.

1.05 MeV/amu ~r12+ on Ne

-1

W

:z:

~ 10 4

:r:

11+

u

"-

~ 10

3

13+

:z:
:J

8 10

2

Fig. 2. Charge distribution spectrum of the projectile in
Ar 12++ Ne collision.

plate avalanche counter (PPAC) (see Fig. 2 whichshows a typical charge distribution spectrum of the
projectile in Ar12 + + Ne collision).
The experimental setup is shown schematically in
Fig. 3. The energy signal from the PPAC was used
as a stop signal to a time-to-pulse height converter,and the signal from the channeltron counting recoil
ions was used as a start signal, with which a TOF
spectrum (i.e., a recoil-ion charge-state spectrum)
was obtained. The projectile charge-state spectrum
was recorded via the position information from the
PPAC. On the basis of a list mode option,t> thespectra, which represent coincidences with a given
gate in other spectrum (for example, a particular
projectile charge shown in Fig. 2), could later beobtained. I t should be noted from PPAC spectra(see Fig. 2) that the relative cross sections of electron
capture for the projectile are much larger than thoseof electron loss in the present collision system.
Figure 4 shows typical coincidence spectra for Ar12+
on Ne. Figure 4(a) shows the TOF spectrum taken
in coincidence with beam particles which do notchange their charge (pure ionization). On the other
hand, Fig. 4 (b) shows the spectrum taken in coincidence with beam particles which have captured twoelectrons. A little shift of peak positions at the sameT. :ronuma, etal.

',j.

85

'.,'

Start

r-----=-=~

Time to pulse
heightconverter

Stop
EnergysignalPositionsignalChanneltron
Recoilions~+ l-----------~---------q

Projectileions----------q-=-l

L_.1+ ------------Electrostatic
chargeanalyzer

Interaction
regionParallelplate
avalanchecounterFig. 3. Schematic diagrams of the coincidence experiment.

10'
(a )
Ne i + i= 1

10J

1 . 05 Me V/amu Ar 1 2+ on Ne

10 2

Ar1 2+ ......

-1~ 1 0' Z.

<:
I

U 100
.......
(J)
I-

(b)

z

~ 10

2

U

10'
10°
0 0

r

~+-

Ar 1O +512

CHANNE L NUMBE R
Fig. 4. Time-of-flight spectra for 1.05 MeV/amu Ar12++Ne
collision. (a), Spectrum was taken in coincidence withbeam particles which do not change their charge (pureionization spectrum); (b), Spectrum was taken in coincidence with beam particles which captured two electrons(transfer-ionization spectrum).

charge state between (a) and (b) spectra was causedby the electric circuit system. As can be seen fromthese spectra, for a given incident-projectile charge
state, the charge-state distribution of the recoil ions isstrongly correlated to the final charge state of the
projectiles. The double-electron capture events by theincident ions during collision are found to causesignificant shifts in recoil ion charge-state distribution
toward high charge states. We concluded from theseobservations that the direct multiple ionization is adominant process for the production of low chargestate recoil ions, whereas the production of highcharge-state recoil ions is accompanied by electron
capture into projectile ions from target atoms (transfer ionization) .

The observed charge-state distribution of recoil Nei +ions summed over single- and double-electron capture
events of projectiles is compared with the compoundatom modeF> whose main assumption is that duringclose collision some electrons of both projectile andtarget atoms, whose electrons are not altogether
thrown out of the system, create a common structureless electron cloud. The electrons in this electron
cloud are later redistributed between both ions depending upon their nuclear charge, which in turn
determines the final charge-state distribution of recoil
ions produced in close collision as well as that ofprojectile ions. The results are shown in Fig. 5 where
both the experimental and theoretical values at recoilion charge state i = 5 are normalized to unity. Figure
5 indicates that the compound atom model well
reproduces the observed (relative) charge distribution of recoil ions with i> 5 whereas the model underestimates those for i<4. It is not clear why the observed values for low charge recoil ions, which are.~ 10°
u

Q)
C/)
C/)
C/)

o
s..

u

Q)

>

.~ 10 1
Qi

ex::

23456
Recoil - ion charge stat e

Fig. 5. Charge-state distribution of recoil Ne ions in collision of 1.05 MeV /amu Ar12+ with a Ne target as a functionof the recoil-ion charge state i. Solid points represent theexperimental data summed over single- and double-electron
capture events. Solid line represents the distribution calculated by the compound atom model. Both values arenormalized to unity at i=5.

86

T. Tonuma, et al.

related with single- and double-electron capture, are
far larger than the calculation. This might be due
in part to electron capture of recoil ions before acceleration. It should be also noted that intense projectile beams were used when spectrum shown in
Fig. 4 (b) was taken, while the main incident projectile beams without change in charge were stopped
in a Faraday cup. As discussed in a previous paper,3)
the contribution of direct ionization to low charge

recoil ions is two or three orders of magnitude larger
than the values estimated from the compound model.
References
1) H. Kumagai. M. Sasagase. and T. Wada: RIKEN Rep.,
62, 114 (1986) (in Japanese) .
2) M. Meron and B. Rosner: Phys. Rev. A, 30, 132 (1984).
3) T. Tonuma, T. Matsuo, M. Kase, T. Kambara, H. Kumagai, S. H. Be, I. Kohno, and H. Tawara: Phys. Rev. A,
36, 1941 (1987).

87
RIKEN Accel. Prog. Rep. 21 (1987)

0111-2-27.

High~Charge

Effects on Electron Excitations in Metal Targets
for Arl~+ Impact as Compared with Those for He2 + Impact
0

A. Koyama, H. Ishikawa, Y. Sasa, O. Benka,* and M. Uda**

In the present paper, energy spectra of low energy
Auger electrons (AE) from AI, and eu metals induced by Ar12+ are . compared with those for He2+
in ord~r to examine the excitation of inner-shellelectrons with binding energies lower than 100 e V
by high-charge projectiles. Experimental results wereobtained which suggest that the screening of projectile's charge by other target electrons is importantalso in the . excitation of those inner-sheIl-electrons.
The apparatus and experimental conditions are
the same as those described in a previous paper. 1)
Velocities of Ar12+ and He 2+ are equal and correspondto 1.1 MeV / amu. Al and Cu targets are vacuumevaporated in-situ on polished stainless-steel substrates. Targets are set at the earth potential. The
beam .is incident on a target at an angle of 39°
relative to the surface.
Figure 1 shows the angular resolved energy spectra,
E·N(E), of LVV-AE from Al on the background ofcontinuous SE; (a) is for Ar12+ and (b) for He 2+.
Hyper-satellite peaks, L*VV and L**VV, are seenin (a) ,2) but only L*VV is seen in (b).
Figure 2 shows the ra~o of the yields of electrons(AE plus SE) for Ar12+ to those for He 2+. At 70 eV,
the ratio decreases stepwise from 33 to 25. In theenergy ranges below 30 eV and above 80 eV, the
o

8

40

AI Targetwt.: 80~IIa:20~~--~--~--~~

20

40

60

Electron

80

100

120

Energy (eV)Fig. 2. Ratios of the yields of electrons (Auger plus secondary electrons) for Ar l2+ impact to those for He2+ impact.
The arrow indicates the energy at which the Auger peaktakes its maximum. The dotted line shows the values of
the ratios only for the yields of secondary electrons, inthe energy range below 30eV or above 100 eV. In theintermediate region, the dotted line shows the values of
the ratios only for continuous SE as estimated from interpolation.

ratios are relevant only to SE. In the energy region
30--100 eV, the ratio for background SE were estimated from interpolation and shown by the dottedcurve in Fig. 2. At the energy of the AE peak(marked by an arrow), the value of the ratio of theyields of electrons (AE plus AE) is 25, fairly small
compared with the estimated value of the ratio for
SE, 32. From these values for the ratios, it follows
that
YAE(Ar)/YsE(Ar)=O.8YAE(He)/ YSE(He)

. .

·
r
~
.; 4

.oo~

320

40
60
80
100 120
Electron Energy (eV)3~~--~--~~--~

20

40

QO

Electron(a)

80 100 120
Energy (eV)(b)}'ig. 1. Energy spectra of AI-LVV Auger electrons on the
background of continuous secondary electrons induced by
Ar l2+ impact (a), and by HeI+ impact (b). Energy ofthe projectiles correspond to 1.1 MeV /amu.

* Universitat Linz, A-4040 Linz, Austria.

** Present address:

Department ofWaseda University, Tokyo.

Materials

Science,(1)where Y AE and Y SE are the yields of AE and SE,
respectivel y.
Figure 3 shows similar energy spectra of MVV-AE
from Cu on continuous SE. Hyper-satellite peaks
are not distinguished even for Ar12+. Figure 4 shows
the similar ratio for the yields of electrons (AE plusSE) induced by Ar12+ to those induced by He 2 +. A
pronounced dip can be seen around the energy of
the AE peak. In the energy regions below 50 eV
and above 70 eV, the ratios are relevant only to SE.
In the energy region 50-70 eV, the dotted line shows
the ratio only for SE as estimated by interpolation.
At the energy of the Auger peak,
YAE(Ar)/YsE(Ar)=O.88YAE(He)/YsE(He)(2)

A. Koyama, et ai.

88

12

13

11

12
? 11

C

=:l

~ 10

~

1¥ 9
_ No,

:c
>- 8

6
5L-~--~--~--~~

30

60
70
Energy (eV)4050Electron80

6~~--~--~--~~

30

40
50
Electron

60
70
Energy (eV)

80

(b)
(a)
Fig. 3. Energy spectra of Cu-MVV Auger electrons on the
background of continuous secondary electrons induced by
Ar12+ impact (a), and by Hes+ impact (b).

19

will

PII(Ar) -0 85 PII(He)
Pv(Ar).
Pv(He)(3)

where Pli is the ionization probability of ).J-shell, and

Pv is the excitation probability of valence electrons

18

into continuous states with corresponding energies.
Such depression of the ionization probability of
inner-shell electrons relative to the excitation ofvalence electrons for Ar12 + compared with that for
He 2+ can be tentatively explained in terms of thescreening of the Coulomb force of high-charge projectiles by other target electrons. In the case of He 2+,w';t i 7

J.

§16

&

.;.

" 15

0::

are proportional to the ionization cross-sections of
the respective inner-shells. By the correction for thecontribution from the hyper-satellite peaks, the ratio
for Al in Fig. 2 increases from- 25 to 27 at the peakenergy of the AE. This correction is small and will
be small also for the case of a Cu target. Then it
is said that the ratio of the ionization cross-sectionof the inner-shells, L:-shell of AI, or M-shell of Cutargets, by Ar12+ impact to that by He 2+ impact issmaller than the ratio of the production probabilityof continuous SE with corresponding energies by
Ar12+ impact to that by He 2+ impact. Continuous SE
be . main~y contributed from valence electrons.
The following equation can therefore be obtained
from Eqs. 1 and 2,

.,.
14 )'

1k~~
40~~
50~~ro~~7~0--~80
Electron

Energy (eV)Fig. 4. Ratio of the yields of electrons (Auger plus secondary electrons) for Ar12+ impact to those for He 2 + impact.
The dotted line is obtained by the same procedure as inFig. 2.

Fluorescence yields are usually negligibly small,when the binding energy of ' the concerned innershell is low, and when there are not too many holes
in the outer-shells. In metal targets, holes in outershells are refilled by outer electrons of surrounding
atoms in a very short time compared with the lifetime of the hole in the inner-shell. In fact, nosatellite peaks have been observed in the spectraof low energy AE from lattice atoms. 3 ) Thus it isreasonable to consider that the peak heights of these
AE with the contribution from hyper-satellite peaks

the impact parameter is small, and only very few
electrons are present between the projectile and anelectron concerned; thus screening will be ignored.
However, in the case of Ar12 +, the impact parameteris large; and more electrons will be present between
the projectile and the target electron in an innershell than in an outer-shell. This will result in more
effective screening for inner-shell electrons than forouter-ones.
References
1) A. Koyama, O. Benka, Y. Sasa, and M. Uda: Nucl.
Instrum. Methods Phys. Res. B, 13, 637 (1986).
2) W. Schmidt, P. Muller, V. Brucker, F. Loffier, G. Saemann-Ishenko, and W. Schukert: Phys. Rev. A , 24, 2420
(1981) .
3) G. Saemann-Ishenko and W. Schmidt: Nucl. Instrum.
Methods Phys. Res., 218, 757 (1983).

89
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-28.

Energy Spectra of AI-LW Auger Electrons Induced by
Grazing Angle Incident Fast Heavy-Ion Impact
A. Koyama, H. Ishikawa, and Y. Sasa

In the present experiment, projectile dependenceof the AL-L 2,3 VV Auger line is precisely examined
for incident energies corresponding to about 1 MeV /amu, and for incident angles of 39° and 4° relative
to the surface of a target. Although projectile dependence is negligible for 39° incidence, clear projectile-dependence was observed for 4° incidence;the peak energy of the L 2,3 VV Auger electrons decreases as the atomic number of projectiles increases.
This paper reports these new observations.
An Al target was in-situ vacuum deposited on apolished stainless-steel substrate with a 1 cm Xl cm
area at a pressure lower than 10-8 Torr. The pressureof the target chamber was kept below 2 X 10-10 Torrwhen a beam was incident on a target. The beam
diameter was 1.5 mm, and beam current was lessthan 5 nA. Incident energies for N6+, Ar4+, andAr12+ correspond to 1.3 MeV / amu, and that forXe 9 + 0.98 MeV / amu. Only electrons emitted back39'

ward from the target are concerned here. The
apparatus was described previously.l) The angle
resolution of the parallel plate analyzer was 1°.
Furthermore, only electrons emitted from a fine spot
(0.5 mm X 0.5 mm) on the target are energy-analyzed
and detected. Contamination by secondary electrons
emitted from the edge of the target or other places
outside the target can thereby be ignored, and spectra
are energy- and angle-resolved ones. The reproducibility of the data was confirmed by independentmeasurements.
Figure 1 shows energy spectra of electrons emitted
at an angle of 90° relative to the surface of thetarget induced by the various projectiles in theenergy range from 54 to 69 eV. Figure 1 ( 1) is forlarge incident angles: (a) for 1 keV e- with anincident angle of 24° relative to the surface, (b) for
N6+, (c) for Ar12+, and (d) for Xe 9 +. The incident
angles for N6+, Ar 12 +, and Xe 9 + are all 39° rel-

1nc j dent

Grazing

(1)
.j.)

Angle

Incident

(1)
.j.)

c

:J

C
:J

.0

.0

'(\1

'(\1

w

W

z

z

W

W

56.0

60.0

64.0

ELECTRON ENERGY (eV)
(1 )

68.0

56.0

60.0

64. 0

68.0

ELECTRON ENERGY (eV)(2)

Fig. 1. Energy spectra of electrons emitted at an angle of 90° relative to the surfaceof the Al target induced by various projectiles. Spectra are normalized to givethe same peak height. (1), for large angle incidence: (a), for 1 keV e- incident
at 24° relative to the surface; (b), for N6+; (c), for Ar12+; and (d), for Xe 9+.
Incident angles for N6+, Ar12+, and Xe9+ are all incident at 39° relative to thesurface. (2), for grazing angle (4°) incidence: (a), for e-; (b), for N6+;(c) , for Ar12+; and (d) for Xe 2 +.

A. Koyama, et ai.

90

Ar'2+

IMPACTAr 4 +

IMPACT(0)...,01...,O'l

::J

c

C
::J

.0l-

.0I-

(tI

(tI

w

z

!:::!
z

w

w

56.0

60.0

64 . 0

68.0

ELECTRON ENERGY (eVl

56.0

60.0

64 . 0

68.0

ELECTRON ENERGY (eVl(1)(2)
Fig. 2. Emission angle dependence of the Auger spectra induced by the grazing
angle (4°) incidence of Ar ions. Spectra are normalized to give the same peakheight. (1), for Arl 2+ impact: (a), for an emission angle at 129°, and (b), for94°, relative to the beam. (2), for Ari+ impact: (a) for an emission angle of 34°,
and (b) for 94°, relative to the beam.

ative to the surface. Figure 1 (2) is for the grazing
angle incidence of 4° relative to the surface: (a) fore-, (b) for N6+, (c) for Ar12 +, and (d) for Xe 9 +.
The spectra are nonnalized to give the same height
for all the projectiles. When incident angles arelarge, the projectile-dependence of the peak energy
is almost negligible. On the other hand, for thegrazing angle incidence the peak energy of the
AI-L2,3 VV Auger electrons shows clear projectiledependence: the peak energy is shifted to a lower
value, as the atomic number of the projectile increases; this is the first observation to authors'knowledge. The amount of the energy decrease forXe 9 + is as large as 3-4 eV compared with for e-. : Itshould also be noted that, in Figs. 1 ( 1) and 1 (2) ,the widths of the Auger peaks are independent : ofthe projectiles.
Figure 2 shows the emission-angle dependence ofthe peak energy for grazing angle (4°) incidence of
Ar ions. Figure 2 ( 1) is for Ar12+ impact: (a) is foran emission angle of 129°, and (b) for an emission
angle of 94°, relative to the beam direction. The
peak energies for (a) and (b) are almost the same.
Figure 2 (2) is for Ar 4+ impact: (a) is for an emission angle of 34°, and (b) for an emissio;n angle of94°, relative to the beam direction. The peakenergies are also the same for (a) and (b). It isthus concluded that there is no emission-angle dependence in the energy of the Auger electrons.
For grazing angle incidence of heavy projectiles,
a frequent hard collisions will occur in a thin surface
region compared with for a larger angle incidence.

Sputtered atoms in flight will play an important role
for Auger emission, consequently. An Auger line of
Al atoms in flight will show atom-like features,2) andalso show emission-angle dependence or peak broadening due to the Doppler effect. The Auger peaks forthe grazing angle incidence obtained here, however,show neither atom-like features, emission angle dependence, nor peak broadening, as shown in Figs. 1
and 2. Thus the peak shift observed here is not due
to the Doppler effect.
When outer-shell electrons are excited together
with an inner-shell electron, the energy level of theouter-shell is lowered, and it is well known that theenergy of the satellite Auger line is lower than thatof the diagonal line. Then, if the lifetime of theelectron holes in the outer-shell is longer than thatof the electron hole in the inner-shell, such decreasein the energy of the Auger line will be observed evenfor metal targets.
According to Saemann-Ishenko and Schmidt, theNi-M2,3 VV Auger peak shows projectile dependence
even for a large-angle incidence of 50° relative tothe surface. 3) They suggested that the projectile dependence of the Auger line is due to the long lifetime of electron holes in the d-band of Ni produced
in multiple excitation of target electrons by heavy
projectiles. They also suggested that the projectile
independence of the AI-L2,3VV Auger line is due tothe short lifetime of electron holes in the valenceband of AI targets. In the case of grazing angle
incidence of heavy projectiles with incident energies
concerned here, the lifetime of electron holes is

A. Koyama, et al.

suspected to be prolonged owing to a kind of asurface effect even for the Al valence band. A great
number of low energy ele~trons are excited by projectiles and emitted almost perpendicularly to thebeam direction. In the case of large angle incidence,
however, excited electrons are only "replaced" fromthe path region of the projectiles: most of excitedelectrons will be inside the target. Thus, the electron
density averaged in time for the projectile's pathregion will be nearly equal to that in the otherregion. In the case of grazing angle incidence, how-91

ever, excited electrons will be directly emitted fromthe surface, and the electron density averaged in time
for the path region will be really lower, causing alonger lifetime of electron holes.
R eferences
1) A. Koyama, O. Benka, Y. Sasa, and M. Uda: Nucl.
Instrum. Methods Phys. Res. B, 13, 637 (1986).
2) C. Benazeth, N. Benazeth, and L. Viel: Surf. Sci., 78,
625 (1978).
3) G. Saemann-Ishenko and W. Schmidt: Nucl. Instrum.
Methods Phys. Res., 218, 757 (1983).

92
RIKEN Accel . Prog. Rep. 21 (1987)

111-2-29.

A Piezoelectric Bimorph Transducer for the CoulombExcitation Mossbauer Spectroscopy
N. Sakai, F. Ambe, and K. Asai

Previously, we have verified 1 ,2) that a Mossbauertransducer composed of piezoelectric bimorph (PB)
actuators is very useful for the Coulomb-excitation
Mossbauer spectroscopy. We have further developed
the transducer which can be applied not only toordinary measurements but also to in-beam experiments. The improved driving unit is illustrated
schematically in Fig. 1. The size of the PB plate(purchased from NGK Spark Plug Co., Ltd. inJapan) is 40 mm in length, 15 rnm in width, and
0.5 mm in thickness. Two PB plates are connected
to a holder for an absorber or a source with Vshaped metallic plates, which are necessary to release
the slight change in the horizontal length of the PB

7

@
o

5cm

Fig. 1. Schematic drawing of the piezoelectric bimorphtransducer: 1, piezoelectric bimorph actuator plates; 2,holder; 3, V·shaped eu-metal connectors; 4, base.

~ 50

"'

..

z

::>

o

u

plates during their vibration. The reason for usinga pair of PB plates instead of one is to achieve uniformity in velocity over the entire holder. The
actuators are activated by sinusoidal voltage from a
digital function generator at 97.65 Hz which corresponded to 10- f1 s dwell time per channel of a 1,024
channel MCA. For the room-temperature operation,
the applied peak voltage was about ±0.9 V for avelocity of ± 15 mm/s. Slightly different voltages butwith the same phase were applied to the two actuators
to make their mechanical amplitudes identical. Goodstability of the motion of the transducer was foundwithout any negative feedback sensor on the source
holder. The observed FWHM of the absorption
peaks (±1/2~+1/2) of natural Fe metal accumulated for 16 hours was 0.256 ± 0.005 mm/s, which
was comparable to the value obtained with a conventional electromechanical transducer. The observed
symmetry of the Fe-metal spectrum indicates that
there is no hysteresis effect of the piezoelectricity,
because of the small amplitude of displacement (about
0.1 mm) of the PB plate. The Mossbauer spectrumof Fe304 at room temperature, shown in Fig. 2,
demonstrates good velocity resolution in the highvelocity region. Clear separation of the two peaks
around - 8 mm/s shows that the PB driving unit isreliable in the measurement up to 10 mm/s. It iseasy to increase the maximum velocity of this driving
system up to several hundreds of millimeters per
second by applying higher voltage with a higher
frequency to the actuators.
Contrary to a usual electromechanical driving unit,
this PB plate has the advantage of operation at low
temperatures down to the liquid-He temperature. The
construction of a liquid-He cryostat for this purpose
is now in progress.

45
-10

-5

o

5

10

VELOCITY (mm 15)

Fig. 2. Test spectrum of magnetite Fe304 at room temperature.

References
1) N. Sakai, F. Ambe, and K. Asai: RIKEN Accel. Prog.
Rep., 19, 159 (1985).
2) N. Sakai, F. Ambe, and K. Asai: RIKEN Accel. Prog.
Rep., 20, 65 (1986).

93
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-30. 57Fe M6ssbauer Study on YBa2Cu3-xFex07-Y
T. Okada, N. Sakai, K. Asai, Y. Toba, and T. Yamadaya

Since Bednorz and Muller found a clue to a highT c copper oxide superconductor,l) many studies havebeen intensively performed seeking a new material
having a high T c' The oxide YBa2CuS07-Y is atypical superconductor with T c = 90 K found among
these oxides. 2 ) The high T c of this material is far
beyond the upper limit predicted by the BCS theory,and the mechanism of the superconductivity of thismaterial is yet unrevealed. Some crystallographic,
electric, and magnetic studies have been made, but
only a few microscopic studies on the electronic structures of this material using hyperfine techniques havebeen reported to our knowledge and thus are highly
desired. In the present study, we report the 57Fe
Mossbauer study on the system YBa2Cus-xFex07-Y
with the Fe content x between 0.03 and 1.0.
Specimens were prepared by calcination of Y 20S,
BaCOs, CuO, and 57Fe20s powders at 950°C in theoxygen-gas flow. By means X-ray analysis, we verified
that they were of an orthorhombic (x>0.03) or atetragonal (0.1::;; x < 1. 0) phase. The lattice constantc decreased slightly with an increase in the Fe content x, but the lattice constant a in the tetragonalphase remained almost unchanged. Detailed resultsof the crystallographic, electric, and magnetic studies
on this system will be reported elsewhere. Mossbauer
spectra were taken at temperatures between 1.7 K androom temperature with a conventional or a newly
developed driving system. S)
Figure 1 shows the typical Mossbauer spectra of
57Fe in this system at room temperature. The
spectrum changes drastically with the Fe content x,
and each spectrum consists of several broad lines.
After a number of trials, we found that all the
spectra can be analyzed with three slightly asymmetricdoublets, which means that the sites occupied by Feions can be classified into three groups: the isomer
shifts and the quadrupole splittings of 57Fe on thesites in the same group resemble each other, but are
distributed to some extent. The isomer shifts relative to Fe metal, the quadrupole splittings, andthe relative intensities of the doublets for these threegroups are listed in Table 1. We call these groups
I, II, and III, according to the magnitude of thequadrupole splitting. The quadrupole splittings forthe groups I and II are considerably large, and theirisomer shifts are nearly zero. On the other hand, the

_

100

~ 95

-;---Yrr:r~;3W-W

Z 100 r·--.......=--...-~""""'"--:"""""__ I

§

51r:n
Z

87

o2
.

~ 100 '~::::~w" , ' . ,"1. °

E-<

99

, -

-2

0"

0

2

VELOCITY (mm/s)
Fig. 1. Typical Mossbauer spectra of lS'Te in YBaZCu3_ .. Fe.. 0 7 _ v (O,03~x~l.O) at room temperature, The bottom
one (d) shows the spectrum of a specimen (x=O.2) heattreated at 550°C in vacuum for 20 h.

quadrupole splitting for the group III is small, andits isomer shift is near the one for Fes+ on the octahedral sites in highly covalent oxides. 4 ) Apparently,
these hyperfine parameters for these groups change
little, but their relative intensities change systematically with the Fe content x. The population of Fe
ions of each group per one chemical formula can be
determined from the product of its relative intensities
and the total Fe content x under the assumption thatthe recoilless fractions for these three groups areequal; the populations of the Fe ions of each groupare shown in Fig. 2 as a function of x. In a small
x region (x~0.1), the populations of these groups
increases with an increase in x. On the other hand,in the larger x region (x>0.1), only the populationof the group II increases with an increase in x, andthe populations in the groups I and III remain nearly

T. Okada, et ai.

94

Table 1.

Mossbauer parameters for the three groups in YBa2Cu3_xFex07_Y at room temperature.

The isomer shift is relative to Fe metal.
Relative area

QS (mm/s)

IS (mm/ s)

II

III

I

II

III

Other
phase

1. 22
1. 17
1.12
1.09
1.05
0.96
0.85

0.60
0.44
0.37
0.28
0.27
0.21
0.24
0. 21

0.50
0.52
0. 30
0.21
0.17
0.11
0.03
0. 70

0.42
0.38
0.56
0.67
0.70
0.79
0.65
0

0.08
0.10
0.14
0.12
0.13
0.10
0.04
0.04

0.28
0.26

X

0.03
0. 1
0.2
0.3
0.4
0.5
1.0
0.2*

+ 0.04+0.05+ 0.04+0.04+0.04+ 0.05+0.12+ 0.11

II

III

-0.03
+0.01
+ 0 . 02
+0. 03+0.04+0.05+ 0.12+ 0. 34+ 0.22+0.24+0.17+ 0.23+ 0.20+ 0.23+ 0.21

1. 91
1.92
1. 93
1.95
1.96
1.88
1.85
1. 95

* Heat-treated at 550°C in vauum.

cr.J

.:s0
E-<

Y Ba 2CU3-xFex07-Y
0.6

<l:;

site s

Z

II

0

~

>-<

r:-.

III

0 .4

0

Z

0

E-<

<:t;

0.2

...:i

0

p..
0
p..

.
!

!

0

0.1

0 . 2 0 .3

0.4

0.5

CONCENTRATION

1.0

(x )

Fig. 2. Populations of the three Fe groups per one chemical
formula as a fu nction of the total Fe content X .

II!

~ 1 00
z
o
Vi
tf)
~

z
«

95

II

0::
I-

1 1

I a nd II

- 10

o

10

VELOCITY (mm/s)
Fig. 3. Mossbauer spectra of 57Fe in YBa2Cuz.sFeo.207_v at
1.7 K. S1 is the difference between the first peak position
and the second one, S2 between the fifth and the sixth.

constant. Figure 3 shows the Mossbauer spectrum
for the specimen with x = 0.2 at 1.7 K. This spectrum
can be ascribed to the superposition of two magnetically split sextets: The major one (~80%) has a
distributed hyperfine magnetic field around 240 kOe,a quadrupole splitting parameter, SCS2 (for thedefinition, see Fig. 3) , of about 1.48 mm/s and theisomer shift of 0.04 mm/s, and the minor one( ~20 %) has a hyperfine field of 442 kOe and theisomer shift of 0.26 mm/s. The quadrupole splittingof the latter is found to be small. From the valuesof the isomer shifts and the relative populations,the major sextet can be attributed to the 57Fe of thegroups I and II, and the minor sextet to that of thegroup III. Figure 1 (d) shows the Mossbauer spectrum of the specimen with x = 0.2 at room temperature obtained after a heat treatment at 550°C in
vacuum for 20 h. The doublet for the group I remains almost unchanged. On the other hand, theintensities of the doublets for the other groups,
especially for the group III, diminish drastically, anda magnetically split sextet (Hh f = 270 kOe) appears
in the spectrum.
The Fe ions are considered to occupy the Cu sites
substitutionally. Thus, the chemical formula of thissystem can be written as YBa2 (CU1-eFee) [Cul-7JFe7J]207-Y' The ions denoted in () are on the la sitewhich is the center of a plane formed by four 0 2ions, and those in [ ] are on the 2q site which isthe center of the basal plane of a 0 2- pyramid. In
the present paper, we refer to the former sites as
the planar sites and the latter as the pyramidal ones.
It has been reported that the 0 2- ions on the 1b sites
neighboring the planar (la) sites are partially removed by the above-mentioned heat-treatment invacuum, but the 0 2- ions neighboring the pyramidal(2q) sites are not affected. 5)
Our explanation of the present results is as follows:
Iron ions belonging to the group I, remaining after
the heat treatment in vacuum, occupy the pyramidalsites, and those belonging to the group II occupy theplanar sites, and those belonging to the group III,
minor in population for any concentration x, occupy
some octahedral sites.
There are two points to be noted. One relates tothe hyperfine parameters for the groups I and II.

T. Okada, et al.

The isomer shifts and the hyperfine magnetic fields
for these groups are remarkably smaller than Fe s+ or
Fe 4 + found in other oxides. This result means thatthe electronic states of the Fe ions of I and of II
in this oxide are much different from those ordinarily
realized in other oxides. We propose that the valence
states of the Fe ions of these groups are the Fe 5 +.
The hyperfine parameters for the Fe 5 + found in (Sr,Ca)FeOs-x (IS =:::.0 mmls, and H hf =:::.280 kOe at low
temperatures) 6) are relatively close to those in thepresent study. Another point is the occurrence ofthe magnetic order of the Fe ions occupying the Cusites in this superconductor. In magnetic susceptibility
measurements, the present specimen with x = 0.2
shows a fairly sharp transition at T c = 53 K. Whether
the coexistance of magnetic order and superconduc-95

tivity shown in the present study is intrinsic or due
to an inhomogeneity of the specimen is not clear
at present.
References
1)
2)

3)
4)
5)

6)

J. G. Bednorz and K. A. Muller: Z. Phys. B, 64, 189(1986) .
M. K. Wu , J. R. Ashburn, C. J. Torng, P. H. Hor, R. L.
Meng, L. Gao, Z. L. Huang, Y. Q. Wang, and C. W.
Chu: Phys. Rev. Lett., 58, 908 (1987).
N. Sakai: Hyperfine Interact., 42, 1165 (1988).
K. Asai and H. Sekizawa: I. Phys. Soc. lpn., 49, 90(1980) .
S. Izumi, H. Asano, T. Ishigaki, E. Takayama-Muromachi, Y. Uchida, N. Watanabe, and T. Nishikawa: lpn.
I. Appl. Phys., 26, L649 (1987) .
M. Takano, N. Nakanishi, Y. Takeda, S. Naka, and T.
Takeda: Mater. Res. Bull., 12, 923 (1977).

96
RIKEN Accel. Prog. Rep. 21 (1987)

11-2-31.

Emission Mossbauer Study of 119Sb Ions Adsorbed on
Ferrimagnetic Fe304 Surfaces
T. Okada, S. Ambe, F. Ambe, and H. Sekizawa*

Application of emission Mossbauer spectroscopy to
the study of the chemical states of ions adsorbed on
the surfaces of ferrites has been proved to be very
usefuP-3) In these studies the so-called "no-carrieradded" parent nuclide ions are hydrolytically adsorbed
onto the surfaces of powdered magnetic oxides, andthe r-rays emitted by the daughter Mossbauer nuclide
ions are collected to be analyzed. The ionic statesof the ions are reflected in the resulting Mossbauer
spectrum through the hyperfine magnetic and electricfields acting on the corresponding nuclei of the ions.
We have been studying the ionic states of 119Sb5+
ions hydrolytically adsorbed on the surfaces of various
ferrimagnetic spinel type oxides such as r-Fe Z03,
NiFe z0 4, and CuFeZ04' In this paper we report thetemperature dependence of the "as adsorbed" ionicstates of 119Sb ions hydrolytically adsorbed on thesurfaces of Fe30 4 by means of emission Mossbauer
analysis of the daughter nuclide.
Experimental procedures were described in previous
reports. 1 - 3) The source nuclide 119Sb was producedby the cyclotron. No-carrier-added 119Sb5+ ions werehydrolytic ally adsorbed on the surfaces of the ferrimagnetic spinel oxide powders of Fe30 4, the Neeltemperature of which is about 575°C. The powders
were filtered out and dried in vacuum over P Z0 5.
Emission Mossbauer analysis was applied to thedaughter nuclide 119mSn arising from 119Sb5+ by meansof a conventional spectrometer in absorber-drive modewith a BaSn03 absorber at room temperature.
The Mossbauer spectra of 119Sb 5+ (~11 9 Sn) ionshydrolytic ally adsorbed on the surfaces of the ferrimagnetic oxide powders of Fe30 4 measured at room
temperature and liquid nitrogen temperature areshown in Figs. 1 (B) and (C), respectively, alongwith the computer-fitted curves. The upper reference
spectrum shown in Fig. 1 (A) is that of CrZ03 taken
at room temperature, which is characteristic of diamagnetic Sn ions on a material with a negligibly
small hyperfine magnetic field and also a negligibly
small electric field gradient. It is noteworthy that no
sharp central peak due to 119Sn in the absence of amagnetic field (the so-called "para- or diamagnetic
peak" with a width of about 1.0 mm/s) was observedin the spectra of Fig. 1 (B) and (C). From the* Chiba Institute of Technology.

100

95

Fe 3 0c 1l9 Sb ;;.:.
(As adsorbed)

B

at ro om temperat ur e

100lA'~

.r~'

'V"
.

91

.

.'

"

C

a t liquid ni trogen temperature-100
VELOCITY (mm/s)

10Fig. 1. (A) Mossbauer spectrum of Cr20S-1l9Sb at room
temperature. (B) Mossbauer spectrum of "as adsorbed"
Fes04-1l9Sb at room temperature, and (C) at liquidnitrogen temperature.

values of the isomer shift (0.0±O.3 mm/s relative
to BaSn03), it is certain that the 119Sn ions resulting
from the adsorbed 119Sb ions are tetravalent. As canbe seen from Fig. 1, even in the "as adsorbed" specimen the emission line is considerably broadened compared with that of diamagnetic 119Sn4+ ions. We
attribute the origin of the broadening to the STHF
magnetic interactions of the 119Sn4+(~119Sb5+) ionswith the magnetically ordered Fe 3+ and Fe 2 + ions in
the Fe30 4 substrates. The distribution of the hyperfine magnetic field (Rbf) was computed by analyzing
the spectra by means of Hesse-Riibartsch method,4}and the obtained distribution function P (R) of thehyperfine magnetic field Rhf is shown in Fig. 2.
In ferrimagnetic Fe304 with a spinel structure, thetetrahedral (A) sites are occupied by the Fe 3+ ions,and the octahedral (B) sites by Fe 3+, Fe 2 +, and Sb 5 +ions. There are the Fe 3+(A) -O-Sb 5+(B) pathways inthis structure, where 0 is an oxygen anion. The

T. Okada, et al.

z. ... ;'., ~·i~!·. .

o ",

~.

Cf.l

i

97

at room temperature'

Cf.l

Z

<t:

o

~

,

100

200

~

HYPERFINE "MAGNETIC FIELD (KOe)Fig. 2. (A) Distribution function ', P (H) of the hyperfine
magnetic . fields of "as adsorbed" Fes04-u9Sb at room
temperature and (B) at liquid-nitrogen temperature.

96

at 1 iquid ni trogen t e mperaturemagnetic hyperfine fields observed at diamagnetic
nuclei, 119Sn 4+( ~119Sb5+) in Fea04 and other spinel
ferrites, are supertransferred hyperfine fields, whicharise as a result of the transfer of electronic spin
density from the magnetic nearest neighbors (the Feions). This STHF interaction between Fe a+(A) andSb 5+(B) ions can be divided into two processes. The
first is the polarization of the ligand electrons of 0 2 ions, by the 3d electrons 'of th~ Fe 3 +(A) ions" and thes~cond , is , the polarization ~f ~electtons of the' Sb 5+(B)ions .,by 't hese ligand , el~ctrons. These two processes
are caused by the overlap, and the transfer mechanisms in the relevant chemical bonds (Fea+(A) _0 2for the, first process, 0 2- -Sb 5+(B) for the second),~nd ' it is :known that the' m~gnitude of the total
STHF interaction increases with an increase' in thecovalency of either bond.
Indices of dominant free crystal surfaces ofpowdered', Fe 3 0 4 is unsettled yet, but ' (111) seems
to be the ' most phmsible one. Thus, the description~f t,he ' spinel type crystal structure based on an imageof alternative stacking of (1 1 1) oxygen layers andmetal ' hiyers given by Iida5) seems ' suitable ' for our
purpose. According to this model, various types ofad~orbed 1l9Sb5+ ions can be discriminated. The distributi0I?-. of the hyper~~e ,m~gnetie ." fields at the
119Sb5+ ' ions . is' being ' analyzed' on the basis of thismodel. Establishment of a: conclusive model which
can explain ail the experimental findings for Fe a04('tnd ,other various ferrites is in progress.

- 10

10

VELOCITY (pll;n/s)

Fig. 3. (A) , Mossbauer $pectra of Fea04-119Sp : heaHreated at
1,100°C for 2 h in soft vacuum and measured at rQolll
temperature, and (B) at liquid-nitrogen temperature.

The Mossba:uer spectra of a Fea04-119Sb specir~enheat-treated at 1,100°C for 2 h in soft vacuUm 'aret~ken at room ' temperature and 'liquid nitrogentemperature; the results are shown in Fig. 3. The
spectra consist of a ' singlet, and a doublet. " Thesinglet has' a large positive value 6f isomer shift. The
doublet has a large quadrupole splitting, and a 'large
positive value of isomer shift. : From ,isomer : shift(+ 2.8 nun/s) determined by analyzing the spectra,
the valence state of the Sn ions in heat-treated Fe a0 4
is concluded to be divalent.
The full accounts of the results on a group ofsimilar materials such as r-Fe20a, NiFe204, andCuFe204, along with the ,results on the effect 'of heattreatment after adsorption, will be published.
References
1) T. Okada, S. Ambe, F. Ambe, and H. Sekizawa: ·}.
Phys.Chern., 86, 4726 (1982).
2) F. Ambe, T. Okada, S. Ambe, and H. Sekizawa: J. Phys.
.
,
Chern., 88, 3015 (1984).
3) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: ACS
Sy~p. Ser., 86, 403 (1986). ,4) J. Hesse and A. Riibartsch: J. Phys. E, 7, 526 (1974) .
5) S. Iida: . J. Phys. ,Soc. Jpn .• 12, 222 (1957).

.1:

98
RIKEN Accel. Prog. Rep. 21 (1987) ," 1nteractions at l11Cd( ~1111 n)
111-2-32. rDPAC Study 0 f Hype rfInein Lio.5Fe2.504 Single Crystal
K. Asai, T. Okada, T. Yamadaya, and H. Sekizawa

We have been systematically investigating thesupertransferred hyperfine (STHF) magnetic field,
H STHF, at 111Cd2 + in ferrimagnetic oxides with thespinel 's tructure by means of the time differential
perturbed angular correlation (TDPAC) of 171245 keY cascade r-rays emitted from 111Cd( ~111In) .1,2) In the spinel oxides, the parent nuclei
111 In occupy the A (tetrahedral) sites [denoted by
11lIn(A)], and the daughter nuclei ll1Cd(A) feel
H StHF transferred from the magnetic ions' on thenearest neighbor B (octahedral) sites. In previous
study on the system M xFe3-X04 (M = Ni or Co;
O.O:S;;x :S;; 1.0),2) we clarified the contributions ofindividual B site ions to the H STHF'S. Their magnitudes
are 11.0 and 8.0 kOe for Fe 3 +(B) and Fe 2+(B) ions,
respectively, and about 4 kOe both for Co2+(B) andfor Ni 2 +(B) ions at room temperature.
,2, This year, we studied HSTHF at ll1Cd +(A) in
lIthium ferrite. This ferrite is a completely inversed
l +Fe3 +]BO", in which Li 1+(B) andspinel (Fe8 +)A[Li0.5
1.5
3
Fe +( B) ions form an ionic order in the B sites. a ) It
sh9uld be noted that this ferrite has the highest Curie
temperature (T c = 943 K) among all the spinel
ferrites 3) although one fourth of the B sites areoccupi~d by diamagnetic ions -Li1+(B). An aim of
the present study is to. clarify the mechanism produc-,
ing the high T c of this ferrite.
The probe nuclei 111Cd 2+(A) in this ferrite feel anaxially-symmetric electric field gradient (EFG) in
addition to H STHF because of the. trigonal symmetryof the A sites of this ferrite. When EFG coexists
with the hyperfine magnetic field H hyp , there are,generally, unavoidable ambiguities in the analysis of
the TDPAC spectra for polycrystalline samples. (Thefield H hyP includes both the field HSTHF and theexternal field H ext ) 'Thus, we measured theTDPAC
spectra of l11Cd in the single crystals.
We carried out measurements at room temperature
in a magnetic field, Hext, of 10 kOe applied perpendicularly to the detectors plane in order to polarize
the magnetization of the specimens completely in thisdirection. We define the nonnalized anisotropy, R(t),of the angular correlation N(@, t) by-0.Q5~

o,J:l.: , .

I

.1.

50

100

150
200
Time (ns)

250

300

(b)

a

R(t) = [N( - 31r/4, t)- N( + 31r/4, t)]/[N( -31r/4, t)+N( + 31r/4, t)]I
2
3
Angular Frequency (rad/s)

Fig. 1. (a) Normalized anisotropy R (t) of the .angularcorrelation of r-rays emitted from 11lCd (+-lllIn) In , po~y­crystalline Lio.:;Feu04 at room temperature. Th~ solid
curve is the fitted one with the Fourier spectrum shownin ·(b). (b) The Fourier spectrum of R (t) .

where @ and t are the angle ' and the time interval
between the cascade r-rays. The Fourier c~~ponentof R ( t ) corresponds to the twice of the ~annor
frequency unless EFG exists.
The anisotropy R (t) for polycrystalline Li o.5Fe2,50 4 and its Fourier spectrum are shown in Figs.
1 (a) and 1 (b), respecti~ely, in which the Fourier
spectrum has a considerably broad intensity distribution around 3.5 X 108 rad/s. However, we could not
determine whether this distribution is caused by a
distribution of H hyp, or otherwise caused by an EFG
coexisting with H hypo
The anisotropies R (t) for single crystalline Lio.5Fe2.l;0 4 measured in two different geometries areshown in Figs. 2 (a) and 2 (b): (a) in the one
geometry with [11 1] J Hext and [11 ~] in 'the' x-z .
plane, and (b) in ' the other geometry with [1 0 0] J
H ext and [1 1 1] in the x-z plane. Here, the x- andZ-axes are defined by the directions of the first rray (171 keV) and H ext, respectively. A remarkablediffernce between these two spectra indicates that anappreciable magnitude of EFG acts on 111Cd2 +(A)in addition to the hyperfine magnetic field H hyp •We derived an explicit expression of R (t) for theintennediate state (5/2+) of ll1Cd under H hyP (J z),
combined with an axially-symmetric EFG, and thenK. Alai. et 01.

~nalyzeq .the .observed spectra in Figs. 2.( a) and 2 (b)uSIng , thi~ expression. ' Both spectra~re reproduced
well with' a common set of the Lannor frequency
a:Qd th~ quadrupolar frequency, and with the orientations of the principal axes of EFG expected fromthe cryst.allin~ geometries. , The fitted curves andtheir F.()urier spectra are shown in Figs. 2 and 3,
respec,tively, The derived H hYP is 122 kOe parallel to
H e~t' and the magnitude of EFG is 90 X 1013 esu. The
fairly large widths of the Fourier components are

2-.0 Ii '
(a)

.R
Jy
.1

~I::'(A) .

",

' '

Lt(B) ,
3
Fe ·(B).Fe3'(B)(c)(b)

Fig. 4. ,L opll ionic configurations of Lio,5Fe~l.l~O.: (a) osions around CdS+ (A). The trigonal axis lies along CdS+ (A).012- bond. (b) Cations around 0 12- ions. (c) Cations
around On2- ions.
'

of

o

50

100

150
Time

200

250

(ns)

300

Fig. 2. Normalized anisotropies, R (t), of the angular correlations of r rays emitted from lllCd (+-111In) in a single
crystalline Li0.5FeuO. at room temperature. The solid
curves are the fitted ones with the Fourier spectra shownin Fig. 3. Geometries of the single crystal, detectors, andthe externally applied magnetic field are shown in theinsets: (a) [11 1] ~ Hext and [11 IJ in the :x;-z plane;(b) [100] ~ H ext and [11 1] in the x-z plane.

3

1l1Cd in Li o,S Fe2,S0L,

single crystal(a) OIlJ II Hex!

2
c

::II
.d

~

~O~--~--~--~~~~~~bc--~~3
1Il(b) (100) If Hex!

c

C1>

c2

4
3
Angular Frequency (rad Is)

5

xlO

86

Fig. 3. Fourier spectra of R (t) for a single crystalline
LiuFeuO. at room temperature. Dotted lines represent
individual Fourier components and solid lines the total ofthem: (a) [1 1 1] ~ Hext and [11 f] in the x-z plane; (b)[1 0 0] ~ H ext and [1 1 1] in the x-z plane.

ascribed to th~ after-effects of the'BC decay ' ll1In~
111Cd. 4 )..
The field H ~THF then de;ived' is 1t2 kOe. Figure
4 shows the ionic configurations in Lio.5Fe2.50.. The
probe ion ll1Cd2 +(A) is surrounded by four 0 2- ionsof two kinds denoted by 0 1 2- and On z-; through0 1 2- ion, three Fe3+(B) ions are linked to the Cd 2+(A) ;on the contrary through On z- ion, two Fe 3 +(B) and
one Li1+(B) ions are linked. Thus, the magnitude of
the field from one Fe 3+(B) ion through 0 1 2- or On2[denoted by h (~Fe3+)] is 12.4 kOe on average.
The value of 12.4 kOe for Lio.5Fe2.504 is morethan 10% larger than the one (11.0 kOe) reported
for M xFe3-x04 (M=Ni or Co) system. 2) By comparing crystallographic parameters of Lio.5Fe 2 . 50. and
MxFe3-X04, it is concluded that this large value ofh (~Fe3+) in the fonner as compared with that in
the latter system cannot be explained by the differenceof either the lattice constants or the oxygen (u)parameters between them,3,5) but should be attributed
to the presence of Lj1+(B) in the former. Then, we
consider the influence of Li1+(B) to the STHF
interactions between Cd 2+(A) and Fes+(B) in Li o.5Fe 2 . 5 0 4 •The electronegativities of Li 1+ and 3d transition
metal ions are listed in Table 1. 6 ) The electronegativity of Lj1 + ions is markedly smaller than those of
3d transition metal ions. In Lio.5Fe2.504, it will
occur as a result of this smaller electronegativity of
Table 1. Electronegativities of Li and some 3d transition
metal ions.S)
Ion
Electronegativity

0.95

1. 7

1.8

1.7

1.7

100

Li 1 +(B) that the ligand electrons of On 2- are polarized
towards the Cd 2+ (A) and the two F e3+(B) ions tosome extent since the el~tfrons are less attracted
towards the Li 1 +(B). ThereJore, the covalencies of
the chemical bonds Cd ~ + (A) -On 2- and F e3+(B) On 2- are expected to be larger than the corresponding
bonds with no adjacent Li 1 +(B) in Lio.sFe2.504 orin other ferrites. This influence of the LP+(B) ion on
the neighboring bonds is expected also from theextended electrostatic valence principle.7) It holds
generally in ionic crystals that the STHF interaction
between the cations increases with an increase in thecovalency of the chemical bond connecting thesecations through the intervening oxygen ion. Thus,
we conclude h (~Fe3+) through On 2 - is enhanced by
the neighboring LP+(B). If we assume that h( ~Fe3+)
through 0 1 2- is 11.0 kOe as in MzFe3-Z04, h (~Fe3+)
through On 2.., ,; must be ' 13'.3 kOe, ab:6 ut 20 % Hlrg~~
than the 'fortner. '' ,.
' The markedly large axially-symmetric EFG observed at Cd 2+(A) in Lio.sFe2.504 is explained as aresult of the difference in the covalency between one
Cd 2 +(A) -Ol- and three Cd 2+( A) -On 2 - bonds aroundCd 2 +(A) in this crystal [see Fig. 4 (a)].

.

;

.

~

.. !.

: . . i· \-'c.i':. "(~The STHF" and superexchange Interactions havenoticeable similarity: Both increase with' an ihcreaseiIi the co~alency of the relevant ' chemIcal bbnd': , The
superexchange ' interactions between Fe3+(A) ' andFe 3+(B) through On 2- must be enhanced by thepresence of the neighboring Lil'l- (B) "'ions: " Thisenhance~enf of, thesuperexchange ' interactions by
Lil+(B) is considered "to be an origin of the highT~ of Lio .5Fe2.50~ . ' ;',References
1) K. Asai, T. Okada, and H. Sekizawa: l. Phys. Soc. lpn.,
54, 4325 (1985) .
2) K. Asai, T. Okada, and H. Sekizawa: Hyperfine Interact.,
84. 435 ,(1987).
3) J. Smit and H. P. J. Wijn: Ferrites, John Wiley & Sons,
New York, Chap. 8, pp. 136-175 (1959) .
4) K. Asai, F. Ambe, S. Ambe, T. Okada, and H. Sekizawa:
Hyperfine Interact., 34, 277 (1987).
5) The oxygen positions are described well by the oxygenparameter u even in Lio.5Fe2.504'
6) W. Gordy and W. ].0. Thomas: l. Chern. Phys., 24, 439(1956) .
7) I. D. Brown and R. D. Shannon: Acta Crystallogr. Sect.
A, 29, 266 (1973) .

iOi
RIKEN A.ccel.:Pi:og.R:ep~ 21 (1987) .

jU~2-33. 'S'urface Structure "of Krypton-Implante~ Aluminum
I. Hashimoto, * H. Yamaguchi, * E. Vagi, and M. I waki

Extensive experimental information on the' evolu~tion of surface structure' of me't:ils :due fo implantation of gas: ions ' has been ' accumulated in the last
decade. Especially, a great number "of data havebeen obtained On implantation of light ions (H 'andHe) in solids and sununarized, for example, in areview paper by Scherzer.1) The study on implantation of ' heavy ions has been made also for neon,.
argon, krypton, and xenon iIi 'various metals. 2 - 8 )We have studied recently the thermal extractionof krypton atoms from krypton-implanted aluminumby a constant rate heating method and shown thatkrypt.o n ·a:t~ms, ~'r~ e~tr~ct~d in the .temperature rf\.nge
from 540' to 1,100 K.9) ' It is to be noted that nodetectable. amount of krypton atoms was extracted
below 540 K. We have also" determined . tliat. thediffusion: coefficiehts ofkryptoIi in aluminuin' obtain~dby the ' extr~ction experiment are between 10-15 and1.0-14 cm2/s . j~ the temperature range from 713 to813 K9) Furthermore, as already pointed out in aprevious' .papet,10) the implanted krypton atoms form
solid bubbles. These bubbles are stable at temperahIres ' 16wei ' ih~n 6'i8 K 'and melt at about 620 K.
These ,results .indicqte that the str:uctural changes of
impl~n'ted sp~cimen would have occurred during
aimealing. ··.It is thll-s·iriteresting -toobserve ·the change
ofa'n implanted surface during annealing.
In the, present ~tudy, we examined the surfacestruct~e. 'change of krypto~-implanted aluminum by~ea~s ofscanni.qg. dec:tr<;m microscopy (SEM).
'.The . material ; ~sed ,:was' single .crystal aluminum
foils of 99.9'9%' purity, :gtown by a' strain ~nnealing
procedure. Specimens suitable for electron microscopy were prepared by conventional chemical- andelectrolytical-polishing and implanted at an energyof 50 ke V with a dose of 1016 ions / cm 2 •To examine the effect of annealing on the implanted surface, we carried out SEM observation
after annealing at various temperatures for 10 min
outside the electron microscope. The results areshown in Figs. 1 (a)-(f) and the features observed
after each annealing are as follows.
Some circular fractures on the surface are observed
at 723 K (Fig. 1 (a) ). In addition, small irregularshaped swface pits are observed as shown by small* Department of Physics, Faculty of Science, Science University of Toyko.

Fig. 1. Surfa~e features after annealing at ,various temp<;ra"tures for lO min oU,tside an ele<;tro~ microscope. (a). 723 K;(b) , 748 K; (c), 773 K; (d), 873 K; (e), 923 K; (f), 933 K.
Small and large arrows in «9 show surface pits and bl~st,ercraterS, respectively'. ' .
,arrows, and larger and deeper holes ' (blister craters)
are shown by large' 'arrows. - Between 723 and 823 K ·; ,the change of the surfa.ce· structure occurs abruptly.
The number of blister craters (observed as images
with a large black contrast in. Fig; l ·. (b)) increases
rapidly at 748 K, and the whole area is covered
with spongy structures (observed as a white contrast
containing small black spots). Blister craters andsome flakes are observed at 773 K (Fig. 1 (c) ). Size
distributions of spongy structures and blister craters
at several annealing temperatures are shown in Figs.
2 (a), 2 (b), and 3, respectively. Here, although thespongy structures and the blister craters have irregularshape, their diameters are estimated by assuming thatthey are equal to those of circles having the same
area. On the basis of the difference between Figs.
2(a) and 2(b), it can be concluded that sma~er
sponges disappear more rapidly than larger ones WIth
increasing temperature. From Fig. 3, the size distributions of the blister craters change markedly be-

I. Hashimoto, et al.

102(a) 773K(b) 823K

In this case, the driving force fqr the fracture formation would be given by bubbles having very highpressure owing . to the hig!). temperature, annealing.
'Ie'r".
"' .
''., After ' annealing at 923 K, the same tyPes of defects
shown in Figs. 1 (a), (b), and (c) are observed
again together with new fine blisters and needle'<shaped structureS' as shown in Fig. 1 (e ). The formation of the needles is considered to occur by the
curling of remaining flakes or by remaining blisterboundaries.
Fjnally; after annealing at 933 K, the specimen
which was partially melting was e~amined. Largefractures are al~ost elimina~ed, while ,there remainsome . small blisters (~jg. , 1 (f)). This result showsthat evenal?ove the melting point ;of alwninum someof krypton atoms remain in an aluminum matrix;
this result is consistent with the r~sult reported ina previous paper. 9 ) More detailed d~scriptions onthese phenomena are given in Ref.. 11.
F

til

" , '

'.

! ':

Z

Diameter of Spongy Structure (JJm) ,Fig. 2. Size distributions of. spongy structures. N s shows thenumber of the spongy structure in a unit area. It is tobe ,noted that the smaller ones disappear more rapidly
than the larger ones,,d 2r - - - -- - - - - - - --.
0748 K4773K
c 823 K

References
1) B. M. U. Scherzer: Top. A.ppl. Phys.,~2. 271 , (1983).
2) N. Marachov and P. J. Goodhew: Radiat. Elf. Lett., 85,
61 (1984).
3) R.J. Cox, P.]. Goodhew. and J.H. Evans:]. Nucl.
Mater•• 126i i1l7 . (1984) •" . ,!
4) A. vom Felde, J. Fink, Th. Miiller-Heinzerling, J.
PflUger, . B. Scheerer, G:. Li~kerJ~nd, .p .. Kc~.letta: Phys.
Rev. Lett" 53, 922 (1984)' . "5) D. J.Mazey ' artd ' J. H; jEvans: 'J.
Mater .• ISS. 16
.
..
.
. .
;' (1986). ': J~

co

z

>

:.

•

"

'

.

Nucl.

2.5
Diameter of Blister Crater (jJm)

Fig. 3. Size distributions of blister craters. NB in logarithmic
scale shows the numb'e r of the blister ' craters in a unit 'area. The number .of small ones decreases rapidly during
annealing, while that of ,l arge ones increases.

tweeri 748 ';and ' 773 K, '~ and '; ~ma1Ier , dn'e,s decrease
with increasing temperature, while larger ones increase. It is to be noted that the surface covered with
the :spongy,' structures and .' with the blister cratets
peel offftom the, -specimen . at 823 K and a .flattersurface ' appears ,at 873 K (Fig. 1 (d)).
When temperature rises above 873 ,K~ . .a marked
structural ohange occurs again on th speCimen surface.,

P . .Lukac and V. Jesenak: Phys. StatUs Solidi A.. 55., 647(1979) .
.
,7) R. C. Birtcher. an«;l W. Jager:. N~l. lnstrum. Met~ods
Phys. Res. B, 15, 435 (1986) .
'.
.
8) R.O; Birtcher and W . .Jager: ]. Nucl. " Mater .• 185, 274. (1985). '.
·9) r:',X; " Takaishi. T. Kikuchi" K; Furuya, I.. Has4imoto, H.
Yamaguchi, E,' )"agi, and" ~ .. Iw<t.lcl; P~1,5. St4t tlS ~lidi
4 / 95, 135 (1~86) ' .
,' . ' .... '. '10). '1. HashImoto, H. 'yorikawa, If Mhsuya, Ii~ ' Yama~chi,
K Takaishi. T. 'Kikuchi, K. 'Furuya. E. "Yagi; ·and ·'M.
Iw'aki:: j. Nucl; 'Mater," '149;69" (198t)~ :: , .
';~1) .l. ,Hashimoto, a. Yorikaw~;H. Mit$uya. H. Yamagiichi,, .i ;K. Furuya, E. Vagi" and M .. Iwalti: ]. lYuel. Mater .• 150;'
6)>", 100(1987). : .'.'' .' '. .: '•~ .".1 j ',...

J

.

"'

~ ' 1-~'

,

: "

,t:

. ,. I••~ .'.~• I•. i, . , '

.

, '.

. .'

• t,

~.~.'

, l '
",, 1

"

, -:

, ' r;

.
. .(

,

~

.,
~

.

~

,

RIKEN, Accel. PrQg., Rep. ~1 In~87)

:.f
:

'. I

~

111-2-34~ ' Lattic'e Location StUqy on ,Kryptorl ,Atoms in 'Alum'in'um by :Means of a Channeling Method
'"i:'

I

•

r.

. i

E.Yagi, K. Tanaka, ,and M. Iwaki

•

-:'

r· !

- ~.

:' ~

.

Recently it ,ha~ p~~n' demml$t~ated that the heavier
i~ert ga~es ' (Ar, Kr" an~ Xe) pre~ipitate in bubbles
at ambient temperature into a solid phase epitaxiallywith .. a host ' 'matrix. 1,2) Such behavior of inert gas
atoms ' has' ',been " in~~tigated mostly by electron
microscopy. In the present study, this effect wasinvestigated more microscopically on Kr-implanted Al
by use of an ion channeling method.
The specimens used were AI single-crystal slice of
99.999% purity. They were chemically and electrolytically polished and then annealed at 10-6 Torr at
823 K for 7 h. The Kr+-implantation was carried out
at room temperature and at 50 ke V at a dose rateof 3.2 X 1012 /cm 2 s to two different doses, 1 X 1015 /cm 2 and 1 X 1016 /cm 2 • To study the lattice locationof implanted Kr atoms, we investigated the axial
channeling effect at room temperature with respectto < 1 0 0> , < 1 1 0>, and < 1 1 1 > axes by meansof backscattering with a 1 MeV He+ beam accelerated
by a tandem accelerator. Channeling angular profiles
for the as-implanted specimens are shown in Fig. 1.
j ,'

(b)

,

(100)

(111)

+

1.0 '

Kr

a Al

f

9

!:!:! 0,5>oUJ

lxl015Krlcm2
as- implanted

N

:::i

3«

o

O~~~~~~~~~-L~~~~~~~~~

Vv

(a)

Z

1.0

0,5

-2

0

-2

0

2

'V
lx1016 Krlcm 2
as-implanted-20

ANGLE (deg)Fig. 1. Channeling angular profiles of backscattering yields
of He ions from Al and implanted Kr atoms on the asimplanted specimens for (a) lXl()1IKrjcmll and (b) IX
1()11> Krjcm2 implantations. The dotted curves are calculated
ones for the distribution with (a) 100% of Kr atoms at
random sites and (b) 57% of Kr atoms at random sites,
23% at substitutional sites, 3% at tetrahedral sites, and
17% at octahedral sites.

2
IX I 0'5 Kr/cm
annealed
593K 30min

0

---J

,~ , 1.0 0

UJ
N

:J
<!

2:

a:

2 0,5

0

(100)

{11O>

(11 1)

II~' 'v v'\-0/'j\"-oJ'.... '

I

-2

0

I

A

-2

0

oKr
.Al

I

2

-2

0

ANGlE(deg)Fig. 2. Channeling angular profiles for a specimen implanted with a dose of 1 X lOll> Krjcm2 and annealed at
593 K for 30 min. The dotted curves are calculated ones
for the distribution with 80% of Kr atoms at randomsites and 20 % at substitutional sites.

For the 1 X 1015 Kr/cm 2 implantation, post-implantation annealing was carried out at 593 K for 30 min;the result is shown in Fig. 2.
For the 1 X 1016 Kr/cm 2 implantation, the normalized scattering yields from Kr atoms (Kr-yields)
were the same independent of the incident angle forthe < 100>, < 110>, and < 111> channels, indicating that most of the Kr atoms are located at
random (R) sites, i.e. in the form of precipitates.
Studies by electron microscopy revealed that the
precipitates are in the solid phase epitaxial with ahost Al crystal to have an fcc structure with alattice constant of 0.534 nm, which is larger by 30 %than that of the Al crystal. 3 )F or the 1 X 1015 Kr / cm 2 implantation, the < 1 0 0 >and < 1 1 1> channeling angular profiles of Kr-yieldon the as-implanted specimen exhibited a shallow
dip with a half width approximately the same asthat of the corresponding AI-profile. On the < 1 00>
Kr-profile a small central peak was superposed. The< 1 1 0> Kr-profile consisted of a large central peak
and a wide shallow dip. The fractions of Kr atoms
at various sites were estimated by fitting the calculated angular profiles to the observed ones. The
observed profiles were well fitted by a distribution
with 55-57% of the Kr atoms at R-sites, 23-25 %at substitutional (S) sites, 3-5 % at tetrahedral (T}E. Vagi, et al.

sites, and 15-17% at octahedral (0) sites. Examples
of calculated profiles are indicated by dotted curves
in Fig. 1. Figure 2 .shows that, upon annealing,
the fine struct~~es in the Kr-profiles disappear :,anda simple shallow dip with the same half-widtp as
the corresponding AI-dip is observed for the < 1 00>,
< 1 1 0>, and < 1 1 1> channels. This result indicates that the T- and O-site occupapcieshave
disappeared and that the Kr atoms are located at
R- and S-sites. The observed profiles were well fittedwith calculated ones for the distribution with 80%
of Kr atoms at R-sites and 20 % at S-sites (dottedcurves in Fig. 2 ) . Therefore, the T - and O-site
occupancies are interpreted as a result of the strong
interaction of Kr atoms with vacancies introduced
by Kr implantation to form Kr-vacancy complexes

having configurations < ~imilar' tcfthoseof a trivacancy
and a pentavacancy.
More detailed descriptions" are gi".er in Refs. 4
and 5 . .
References
1) A. vom Felde, J. Fink, Th. Miiller-Herzering, J. Pfliiger,
B. Scheerer, G. Linker, and D. Kaletta: Phys. Rev. Lett.,
53, 922 '(1984) .
2) C. Templier, C. Jaouen, J.-P. Riviere, J. Delafond, andJ. Grilhe: C. R. Acad. Sci. Paris, 299, 613 (1984).
3) I. Hashimoto, H. Yorikawa, H. Mitsuya, H. Yamaguchi,
K. Takaishi, T. Kikuchi, K. Furuya; E. Vagi, and M.
. Iwaki: 1. Nucl. Mater., 149, 69 (1987).
4) E. Vagi: Phys. Status Solidi A, 104, K13 (1987).
5) E. Vagi, M. Iwaki",. K,.: T',maka, ~. Hashimoto, and, H.
Yamaguchi: Nucl. Instrum. Methods Phys.Res. B , inpress.

\'" '!\ '.

105
RIKEN Acce1. Prog. Rep. 21 (1987)

111-2-35.

RBS Investigation of AIN x Deposited on Glassy Carbon (I)K. Kobayashi, S. Namba, T. Fujihana, Y. Dai,
T. Kobayashi, and M. Iwaki

Recently aluminium nitride (AlN) is of particularinterest because it has a large energy gap, goodthermal conductivity, and stability up to very hightemperature, as well as chemical inertness. 1 )We investigated the composition of AINx films deposited by the activated reactive evaporation (ARE)by Rutherford back scattering (RBS).
The AINx films were deposited on glassy carbon
by means of ARE in a nitrogen atmosphere. Thebase pressure was 2 X 10- 6 Torr and the partial pressure of the nitrogen during deposition was 1 X 10- 4
Torr by N z gas feeding into a chamber. Substrates
were water-cooled and a bias voltage was not supplied between the substrates and the evaporation
source. The power of the electron shower for ionizing
the nitrogen was about 3.6 W. Two kinds of films
were obtained by two deposition rates: at about
70 A/min and at about 7 A/min. The thickness ofthe former film was about 750 A and that of thelatter was about 1,250 A. The composition of the

AIN

x on Glassy Carbon

In~ 3000
:J

o

u

Al

2000

1

c

1

o
...J 1000·
w
>-

o

O. 2

O. 4

O. 6

ENERGY

~

O. 8

1. 0

(MeV)

Fig. 1. Rutherford backscattering (RBS) spectrum for an
AIN", film deposited on the glassy carbon by the activatedreactive evaporation (ARE) at a deposition rate of about
70 A/min. The arrows indicate the edges of AI, 0, andN on the AIN", film.

AINxonGlassy Carbon

In

AI

1
o

~ 1000>-o

0.20.40 .60.81 . 0
ENERGY(MeV)

Fig. 2. Rutherford backscattering (RBS) spectrum for an
AIN", film deposited on the glassy carbon by the activatedreactive evaporation (ARE) at a deposition rate of about
7 A/min. The arrows indicate the edges of AI, 0, and N
on the AIN", film.

film deposited on the glassy carbon was evaluatedfrom RBS with 1.5 MeV He+ beams.
Figures 1 and 2 show the spectra of RBS. The
arrows indicate the edges of AI, 0, and N on the
AINx film surface. A small amount of O-atoms foundin the film were not identified whether they had
migrated from the glassy carbon or had been absorbed
from the nitrogen atmosphere. On the basis of thefirst order approximation of the RBS analysis, theratio, AI/N, for the film at a deposition rate ofabout 70 A/min was about 1.3 and that at a rateof about 7 A/min was about 0.6. These results
indicate that the stoichiometric AIN films on glassy
carbon would be gained at a deposition rate of about
43 A/min.
ReferenceI) A. Fathimulla and A. Lakhani: ]. Appl. Phys., 54, 4586
(1983) .

106
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-36. Lattice Location of Eu Ion in Eu-Implanted CaF2
Observed by Channeling Experiments
K. Aono, M. Iwaki, and S. Namba

A study has been carried out of luminescence from
CaF 2 during ion-implantation with Eu, Cr, or Fe
ions as a function of the implantation-dose. In thisreport, the radiation damage caused in Eu-implanted
CaF 2 was studied from the transmission changes in
the optical density and by a He+ backscatteringchanneling technique using the TANDETRON.
Specimens used were colorless, transparent single
CaF 2 crystals with the surface parallel to the (1 1 1)
cleavage plane. The Eu+-implantation was performed
to the doses from 1012 to 1016 ionsjcm2 at room
temperature at a relatively low dose rate of about
0.2 flA/cm 2 in a direction misoriented by a few
degrees from crystal axis with ions having an energyof 100 keY. The ion implantation caused no change
in color of CaF 2; this result differs from that of
implantation into any other insulators. In general,
we could see coloring of the specimens in the visible
region due to radiation damage caused by 100 keY
ion-implantation. The optical transmittance was--94.7% and --95.5 % for CaF 2 implanted with
1 X 1016 ionsjcm2 and un-implanted, respectively, overa wide visible wavelength range. These results indicate that 100 keY-ion implantation hardly resultsin radiation damage.
Channeling measurements were carried out using
1.5 MeV He ions with a fluence of 10 flC. Backscattered particles were detected at an angle of 1500 ,and random and < 1 1 1 > or < 1 1 0> aligned
spectra were determined for estimation of compositions, damage, and Eu-Iattice sites in the implanted
layers. As reported elsewhere,1> no out-diffusion of
Ca and F atoms occurs through the surface. These
spectra also show no out-diffusion of Eu atoms implanted in CaF 2, and the aligned spectrum for the

-1

0

-1

0

ANGLE

-1

0

(deg)

Fig. 1. Close-encounter probability (normalized yield) as afunction of angle from <11 1> axis for Ca- (0) and Eu(e) atoms in Eu-implanted <11 1> CaF2 • a, un-implanted; b, 1 X 1015 Eujcm2; and c, 1 X I()16 Eujcm2.

implanted specimen with 1 X 1016 ionsjcm 2 shows
little damage near the surface. For implantation with
1 X 1015 and 1 X 1016 ionsjcm 2 the scattering yield of
the aligned Eu-spectrum decreased markedly in comparison with that of the random spectrum. This
result suggests that implanted Eu-atoms occupied thelattice sites of CaF 2. The results of angular scans
for the host Ca and impurity Eu yields near the< 11 1> direction are shown in Fig. 1. For a
relatively low dose of 1 X 1015 ionsjcm2 , Eu has
the same angular profile as Ca; we also obtained
the same results for an angular scan near the< 1 1 0> direction.
In conclusion Eu-atoms implanted in CaF 2 mainly
occupy the Ca substitutional sites.
Reference
1) K. Aono, M. Iwaki, and S. Namba: Nucl. Instrum.
Methods Phys. Res. B, in press.

107
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-37.

Lattice Disorder and the Behavior of Implanted Atoms
in In-Implanted Ti02 (Rutile)
S. Nakamura, E. Vagi, T. Osaka,* and M. Iwaki

Rutile (Ti0 2 ) is an insulator; upon reduction anddoping impurities it becomes a semiconductor.
Although ion implantation is a useful technique forsuch doping, the interaction of implanted atoms withdefects during implantation plays an important rolein determining the properties of implanted materials.
Studies of such interactions are required, therefore,
for elucidation of the mechanism by which thematerial is modified.
In the present study of Ti0 2 implanted with In
atoms, which act as acceptors, the lattice disorderand lattice location of implanted atoms were investigated by an RBS-channeling method.
In+-implantation was carried out for Ti0 2 (rutile)
single crystal slices of 99.99% purity at room temperature at 100 kV to various doses from 1014 to
101 5 / cm2 • Channeling measurements were performed
with a 1.5 MeV 4He+ beam collimated to give adivergence of less than 0.07°. The area irradiatedat a beam current of 1-2 nA was 0.78 mm 2 • The
backscattered He+ ions were detected with an SSD
at a scattering angle of 155°.
Typical aligned spectra for the [0 0 1] and [1 0 0]channels are shown in Fig. 1. The maximum disorder in both Ti and 0 sublattices saturated at adose of around 2 X 101 5 In/cm2 , below which the[0 0 1] Ti disorder peak consisted of two subpeaks,
i.e., peak A around the depth of 150 A from thesurface and peak B around 300 A. The depth ofpeak B coincides within the experimental error withthe measured implantation depth of the In atoms
4000[001 )(a)(b) [100)

III

§

3000

0

Ti

1----1t-----i

2000
0

In

...J

w

>-

1000

0.5

0.6

0.7

0.8

0.9

1.0

ENER GY

1.1

12

1.3

10

1.1

(MeV)

Fig. 1. Aligned [0 0 1] and [1 0 0] spectra of backscattered
H e+ ions in Ti0 2 crystal implanted with 100 keV In.

* The School of Science and Engineering, Waseda University.

(Rp = 270 A) , therefore, peak B is attributed to thedisorder caused by the presence of the In atoms.
Since the depth of peak A is shallower than R p ,peak A is considered to be due to the damage caused
by In-irradiation. The presence of two peaks has
also been observed in In-implanted AI 2 0 g .1) On theother hand, in the [1 0 0] spectra, no separate peaks
were observed, because peak B is much higher thanthat in the [0 0 1] case, and the height of peak A
is not very different between the two cases. Thus
peak A has small anisotropy and peak B large
anisotropy at low doses. The anisotropy disappeared
at a dose of saturation.
The recovery of lattice disorder in the Ti sublattice proceeded through two annealing stages ataround 650 K and at above 1,000 K. In the 650 K
stage, the recovery was a little at the depth of thepeak B; in the second stage, the recovery was extensive and the disorder peak shifted towards the surface.
Simultaneously, In atoms diffused towards the surface.
After qnnealing at 1,173 K , about 15% of the implanted In atoms diffused out. Such out-diffusion of
implanted impurity atoms after the recovery of latticedisorder has been observed in Pb- or Xe-implanted
AI 2 0 g . 2-4 )In order to investigate the lattice location of In
atoms, we performed channeling angular scansthrough the [1 0 0] and [0 0 1] axes, and a (0 0 1)
plane on the specimens implanted with 5 X 101 \ 1 X
1015 and 5 X 1015 In/cm 2 • Figure 2 shows the [100]and [0 0 1] angular profiles for the 5 X 1014 In / cm2
implantation. The [0 0 1] angular profile of In-yields(In-profile) exhibited the same dip as the Ti-profile,which was wider than the a-dip. T he [1 0 0] In-dip
had approximately the same half-width, but was
about 12 % shallower than the Ti-dip. Therefore,
in the 5 X 1014 In/cm 2 case, most of the In atoms
substitute Ti sites but some of them are located atinterstitial sites along the c-axis of a Ti sublattice.
In the 1 X 101 5 In/cm 2 implantation (angular profiles are not shown), the In profile coincided with
the Ti-dip for the [0 0 1] channel, but was about
25 <fo shallower than the Ti-dip for the [1 0 0] channel.
Further, this [1 00] In profile clearly exhibited afine structure with double peaks at about +0.15°.

S. Nakamura, et at.

108

9
n

>-

Ti

o
W
N

05

-'

«

(0)

2:
0:

o
Z

V •

. __- _TI .

0 ~~~~~~-7--~~~~-L--L-~--~~
-2
-1
0
1
2
-2
-1
0
A NGLE( d eg r e e 5 )Fig. 2. Channeling angular profiles on the 5 X 1014. Injcm2
implanted TiO.2' Broken lines represent the calculated
profiles.

From these results, some fraction of the In atoms
are anticipated to be located at OO! sites. The results on the (00 1) channel agreed with this site
occupation.
The distribution of In atoms at various kinds ofsites can be examined by comparing the observed
I n-angular profiles with calculated ones. The calculation was performed using a multi-string model byconsidering three kinds of site occupancy: Ti substitutional (S) sites, 00 ! interstitial sites, and random(R) sites. The distributions of In atoms were estimated as follows: 88 % at S-sites, 11 % at 0 0 !
sites, and 1 % at R-sites for the 5 X 101 4 In/cm2 implantation, as shown by the broken curves in Fig. 2,
and 72 % at S-sites, 24 % at 0 O! sites, and 4 % at
R-sites for the 1 X 101 5 In/cm 2 implantation.
With increasing dose to 5 X 10 1 5 In/cm 2 , the minimum yield of In-dip increased drastically to 1-0.9,
suggesting that most of the In atoms precipitated as
In clusters or some other type of second phase.
Nevertheless, the OO! site occupancy was still observed. Annealing at 973 K eliminated the OO! site
occupancy and increased the fraction of substitutionalsite occupancy.
The increase in the OO! site occupancy withincreasing dose, and its disappearance after annealing
at 973 K suggest that the OO! site occupancy of In
atoms results from the interaction of In atoms withdefects formed during implantation, i.e., In-defectcomplexes. Considering the symmetry around the caxis of the OO! site and the close-packing of the
Ti atoms along the c-axis, an In-Ti vacancy pair
and an In-Schottky trio complex are proposed as
the In-defect complex. These configurations areshown in Fig. 3.

Fig. 3. The In atom-defect complex models in which an In
occupies 001- site; (a) In-Ti vacancy pair, and (b) InSchottky trio complex.

When a larger In atom replaces a Ti atom, or
when an In atom is located at the 0 0 1- site bytrapping a Ti vacancy or a Schottky trio, the Ti
atoms neighboring the In atom, or the Ti vacancy,
respectively would relax. The magnitude of relaxation is larger in the [0 0 1] direction than in the[1 00] direction, because the separation of neighboring Ti atoms in the [1 0 0] direction is 1.5 times
larger than that in the [0 0 1] direction. The latticedisorder in a Ti sublattice due to this effect would beobserved more conspicuously in the [1 0 0] channelingthan in the [0 0 1] channeling. The anisotropy ofpeak B is thus explained qualitatively.
The In-implantation produces a large number ofpoint defects. At low doses, mainly Ti interstitials
and their clusters would be responsible for peak A
in the aligned Ti spectra. Ti interstitials are considered to be located at 0 i! or 0 i i sites. 5 , 6 ) Thesesites produce flux peaks in both [1 00] and [00 1]
channeling angular profiles. Therefore, Ti interstitials produce no large anisotropy in the latticedisorder as observed for peak A. More detailed
descriptions are given in Ref. 7.
References
1) A. P. A. Mouritz, D. K. Sood, D. H. St. John, M. V.
Swain, and J. S. Williams: Nucl. Instrum. Methods Phys.
Res. B, 19/20, 805 (1987).
2) A. V. Drigo, S. Lo Russo and P. Mazzoldi, P. D. Goode,and N. E. W. Hartley: Radiat. EfJ., 33, 161 (1977).
3) Hj. Matzke and J. L. Whitton: Canad. J. Phys., 44, 995(1966) .
4) A. Turos, Hj. Matzke, and P. Rabette: Phys. Status
Solidi A, 64, 565 (19Rl).
5) J. B. Wachtman, J r. and L. R. Doyle: Phys. Rev. A,
135, 276 (1964) .
6) E. Vagi, A. Koyama, H. Sakairi, and R. R. Hasiguti:l. Phys. Soc. l pn., 42, 939 (1977) .
7) S. Nakamura, E. Vagi, T. Osaka, and M. Iwaki: Nucl.
I nstrum. M ethods Phys. Res., in press.

109
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-38.

Hydrogen Trapping by Substitutional Impurities in Nb-3at% Mo
Alloys as Observed by the Channeling Method
E. Vagi, T. Kobayashi, S. Nakamura, F. Kano,
K. Watanabe, * Y. Fukai, * and T. Matsumoto**

The effect of alloying on the terminal solubility
for hydrogen (TSH) in group Va metals (V, Nb andTa) has been investigated for various alloying elements. It has been known that for undersized metal
solutes the TSH increases rapidly with metal soluteconcentration. For the enhancement of TSH atrapping model has been proposed: 1) a strong attractive interaction between substitutional solute atoms
and hydrogen. If such a strong interaction is effective, it might result in the change of the lattice
location of hydrogen. Hence, the observation of lattice
location of hydrogen will give the useful informationon the existence of the attractive interaction, and,
therefore, the mechanism of the enhancement of
TSH.
In the present study the lattice location of hydrogen was investigated in Nb-3at % Mo alloys, where
Mo atoms are undersized solutes, by means of achanneling method utilizing the nuclear reaction
IH(llB, a) aa, a method which is effective for thedetection of lattice location change as reported inprevious papers. 2 ,3)Experiments were performed with a 2.03 MeV l1B 2+
beam, and channeling angular profiles of backscattered llB and emitted a-particles were obtainedfor < 1 0 0>, < 1 1 0>, and {I 0 O} channels.
The angular profiles obtained at room temperatureon the specimens Nb-3atroMo-2at%H and Nb3atroMo-5at%H are shown in Fig. 1 as a functionof an incident angle 1/J with respect to the channeling
direction. When the hydrogen concentration is lower
than that of Mo (Nb-3at%Mo-2at%H, Fig. 1 (a)),
the angular profiles of a particle yields (a-angularprofiles) are very different from those for the tetrahedral (T) site occupancy as observed in the Nb-H
system. 4) In the a phase of the Nb-H system thea-angular profiles exhibited a large central peak at"" = 0° for the < 1 0 0> channel, a large central
peak consisting of three subpeaks at 1/J = 0 0 and+0.35° for the < 11 0> channel, and a shallow
dip superposed with a small central peak for the* Faculty of Science and Engineering, Chuo University.

** National Research Institute for Metals.

{I OO} channeJ.4) In the Nb-3at%Mo-2at%H alloy
the a-angular · profiles exhibited no peak at "" = 0°
for all the three channels, but a small peak at 1/J~0.1 °for the < 1 0 0> channel, much smaller peak around"" = +0.2° and - 0.6 0 for the < 1 1 0> channel,
and a shallow dip for the {I OO} channel.
When the hydrogen concentration becomes higher
than that of Mo (Nb-3at % Mo-Sat H, Fig. 1 (b) ) ,the a-angular profiles change significantly. The< 1 00> a-angular profile exhibited a higher central
peak at 1/J =0°. In the <110> channel, muchhigher subpeaks appeared at 1/J = 0° and about+0.35°, the small peak around -0.6° being stillobserved. The {I 0 O} a dip became deeper and asmall central peak appeared, being superposed on thedip. These newly observed subpeaks are located at
the same angular positions as observed in the a phaseof the Nb-H system. 4) These results suggest that somefraction of H atoms are located at T -sites in the
Nb-3at%Mo-5atroH alloy.
The angular profiles obtained at 373 K on thespecimen Nb-3at % Mo-Sat H are shown in Fig. 2.
The a-angular profiles exhibited a much higher
central peak at 1/J = 0° for the < 1 00> channel, anda shallow dip superposed with a central peak for the{I 0 O} channel. They are characteristic of the T site occupancy.4) This result indicates that H atoms
are located at T-sites at 373 K.
These results can be interpreted as follows. In
the Nb-3atrolvfo-2at%H alloy most of the H atoms
are trapped by Mo atoms and located at sites different from T -sites (trapped sites) at room temperature. In the Nb-3at %Mo-5at % H alloy some fractionof H atoms are located at trapped sites and the remaining H atoms are at T -sites at room temperature,
while at 373 K the trapped H atoms are detrapped
to be located at T -sites.
The lattice location of the trapped site was determined by fitting the calculated angular profiles tothe observed ones. The calculation was made on thebasis of the multi-string model by using the Erginsoy
formula for a continuum potential. From this analysis
it is concluded that in the Nb-3at % Mo-2at H alloy

ro

ro

ro

E. Yagi, et al.

110

1.5

Nb-3%Mo-2%H

(a)

{100}

(110)

(100)

R.T.
• H
Nb
Q

'...,..... ....

~~.

;

9W

~

_-- -

1.0

,.

\

V

>=
0

w

~

-'
<{

2:

a:
0

z

0.5

0

-2

0

-2

2

-1

0

0

ANGLE(deg)1.5

Nb-3%Mo-5%H

(b)
(110)

{lOO>

9
w
>=

{100}

~._

1.0

R.T.
• H
o Nb

.r

~

0

W

N

:::;
<{

Fig. 1. Channeling angular profilesof lIB_ and a-yields obtained atroom temperature for (a) the
Nb-3at%Mo-2at%H
alloy, and(b) the Nb-3at%Mo-5at%H alloy.
The full curves and the dashedcurves were drawn to guide the
eye.

2:

a:

0

z

0.5

o

-2

o

-2

-1

o

ANGLE(deg)Nb-3%Mo-5%H

1.5 -

{100}

373K
• H
o Nb

9 1.0
w

>=
o

W

N

:::::;
<{

2:

a:

o
z

0.5

-2

o

-1

ANGLE(deg)oFig. 2. Channeling angular profiles of lIB_ and a-yields
obtained at 373 K for the Nb-3at%Mo-5at%H alloy. The
full curves and the dashed curves were drawn to guidethe eye.

E. Yagi, et al.

all H atoms are trapped by Mo atoms to be locatedat sites displaced from T -sites by about 0.6 A towards
the nearest neighbor Mo atoms and at 373 K they
are detrapped to be located at T -sites. The present
results give the direct evidence for the existence of
attractive interaction between substitutional soluteatoms and hydrogen in the Nb-3at %Mo alloys.

111

References
1) T. Matsumoto, Y. Sasaki, and M. Hihara: J. Phys. Chem.
SoUdis, 36, 215 (1975.).
2) E. Yagi, T. Kobayashi, S. Nakamura, Y. Fukai, and K.
Watanabe: J. Phys. Soc. Jpn., 52, 3441 (1983).
3) E. Yagi, T. Kobayashi, S. Nakamura, F. Kano, K. Watanabe, Y. Fukai, and S. Koike: Phys. Rev. B, 83, 5121
(1986) .
4) E. Yagi, S. Nakamura, T. Kobayashi, K. Watanabe, andY. Fukai: J. Phys. Soc. Jpn., 54, 1855 (1985).

112
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-39. Evaluation of Structural Perfection by Rutherford
Backscattering Spectroscopy (RBS) of 6 H-SiC Single
Crystal Grown with a Vapor Transport Method
T. Kobayashi, M. Iwaki, H. Sakairi, and M. Aono

Single crystal of 6H-SiC of 3 mm X 3 mm X 4 p.m
was prepared by the vapor transport method in whichsilicon vapor from molten silicon is transported to a
growth cavity made of graphite at the National Institute for Research in Inorganic Materials. l ) X-ray
diffraction revealed that the largest face of the crystal
is parallel to the (0 0 0 1) plane. The crystal was
chemically polished at room temperature with HF
and HN0 3 mixed at a volume ratio of 1: 1.
The RBS experiments were carried out with a beamof 4He+ accelerated to 1.5 :MeV with a CockcroftWalton-type tandem accelerator (Tandetron) andcollimated to a 1 mm diameter; the intensity was
0.7 nA in total. The specimen was mounted on athree-axis goniometer, with which the orientation of
the specimen could be set with +0.004°. The energyof back scattered 4He particles was analyzed with asurface-barrier solid-state detector placed at a scattering angle of 150° connected with a 1,024-channel
pulse-height analyzer. The energy resolution and thesolid angle of the solid state detector were 20 keV(FWHM) and 0.03 sr, respectively. During the RBS
experiments, the temperature of the specimen was
kept at room temperature.
Figure 1 shows typical RBS spectra of 6H-SiC
measured with a 1.5 MeV 4He+ beam. The energies

of scattered 4He particles are plotted vs. the channel
numbers. The lower and upper spectra were measured for the incidence parallel to the < 0 0 0 1 >axis and to a random direction, respectively. Bothspectra are ascribed only to silicon and carbon andshow no impurity present within the detection limitsof the present technique. In the lower spectrum acarbon-surface peak is clearly observed at an energy
corresponding to a channel number of 196. The
width of the carbon-surface peak, 22 keY in FWHM,
is close to the energy resolution of the detector(20 ke V). Although a silicon-surface peak is also
observed at a channel number of 437, its intensity
is much smaller than that of the carbon-surface peakdespite the fact that the Rutherford scattering crosssection of silicon is larger than that of carbon by afactor of 6.5. This indicates that the (000 1) surface
is mostly terminated with carbon atoms or that, although the surface is more or less terminated withsilicon atoms, they are covered with carbon orhydrogen atoms which give no spectral features because of their smaller mass than that of 4He+ but
shadow the silicon atoms.
Figure 2 shows the angular dependence of the1 • 5 ~-----------,WINO();l 1

s I -S U,,~~:
o

~

>-

Fig. 1. Typical RBS spectra of 6H-SiC crystal measured witha 1.5 MeV 4He+ beam. Energies of scattered 4He particles
are plotted vs. channel numbers. The lower and upper
spectra were measured in the [0 0 0 1] channeling axis andin a random direction, respectively.

Fig. 2. Angular dependence of the intensity of 'He particles
scattered from silicon atoms in 6H-SiC crystal. The dependence was measured by changing the direction of theincident 4He+ beam around the [0001] channeling axis.

T. Kobayashi, et al.

intensity of 4He particles scattered from silicon atoms;
the dependence was measured by changing the direction of the incident 4He+ beam around the <000 1 >channeling axis normal to the surface. The energy
window used in this measurement is shown in Fig. 1
as 'window 1.' This considerably wide energy window
was used to reduce the statistical error in the intensityof scattered 4He particles and to measure the axial
half-angle with high accuracy. The axial half-angle,
1fJ1/2, is defined to the half angle of the channeling
dip observed in the angular dependence of the intensity of scattered 4He particles as indicated in Fig.
2, and is estimated to be 0.64° -+- 0.07°. Theoretically, 1fJ1/2 is given by2)
1fJ1/2 = 0.246FRS (g) (ZlZ2/ Ed) 1/2 (indegrees)(1 )where Zl and Z2 are the atomic numbers of projectile ion and target atom, respectively, E the incident energy of projctile ion (in MeV), d the atomic
spacing along the axial direction (in A) , FRs proportional to the square root of the continuum
Moliere potential, and g= 1.2U1/ aTF ( U1 and aTF
are the one-dimensional rms vibration amplitude
and the Thomas-Fermi screening radius, respectively) .
The values of FRS us. g are given in Ref. 2.
In the present case, 1fJ1/2 is calculated and foundto be 0.61° from Eq. 1. This theoretical value,
which is estimated by assuming that the 6H-SiC
crystal has a perfect structure, is close to the experi-113

mental value mentioned above, 0.64° -+- 0.07°.
An experiment similar to that of Fig. 2 was carriedout by using another energy window just below thesilicon surface peak indicated in Fig. 1, as 'window 2.'
From the result of the measurement (not shown),
we estimated the value called the minimum yield
Xmin • The value of Xmin for the 6H-SiC specimen
determined in this way is 0.040 -+- 0.001. Theoretically, Xmin is given b y2)(2)where N is the atomic density and the meanings ofother notations were the same as above. In thepresent case, where N = 0.0861 atoms/ A3, Xmin is
obtained to be 0.040 from Eq.2. This theoreticalvalue for the perfect structure is again in agreementwith the corresponding experimental value mentioned
above, 0.040 -+- 0.001.
Thus, both 1fJ1/2 and Xmin determined by the RBS
experiments for the 6H-SiC specimen are found toagree with the corresponding theoretical values estimated by assuming that the crystal has a perfectstructure. The vapor transport method is considered
promising in preparing a good crystal of 6H-SiC.
References
1) Y. Inomata: J. Cryst. Growth, 12, 57 (1972).
2) J. W. Mayer and E. Rimini: "Ion Beam Handbook forMaterial Analysis," Academic Press Inc., New York(1977) .

114
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-40.

Erosion of Graphite by Low Energy Atomic Hydrogen
K. Yano, H. Oyama, Y. Sakamoto, and M. Yanokura

M aterials covered with graphite tiles or coatedwith carbon film are promising for first wall of fusion
devices, because carbon has the low atomic number
and is heat-resistant. In fusion devices, a cold plasmaof electron temperature of ......,10 eV is present near
the first wall, surrounding a hot core plasma. FranckCondon hydrogen neutral atoms are produced mostly
in this region by a dissociative excitation process.
These chemically active atoms with energies of ......,5 eV
react with carbon atoms on the surface and cause
erosion of the wall. Therefore, we need data concerning the erosion of carbon wall, especially ofgraphites, because the practical wall is composed
essentially of graphite tiles. An ECR (Electron Cyclotron Resonance) plasma forms considerably high fluxof Franck-Condon :neutrals in simulation experiments
and neutrals impinge on graphite surfaces without
collision with molecules, because the resonant energy
absorp.t ion by electrons allows low pressure (......, 10- 2 Pa)
operation.
Figure 1 shows the experimental setup describedin detail elsewhere. 1 ) A graphite sample (SA) issituated 13 cm apart from the discharge tube axis
to assure elimination of influx of energetic ions which
intensify erosion. Before erosion experiments, dis-

MFC:
MG
LA
LP
DT

mass flow controller
magnetron(2.45 ~Hz,800 w max.)
launcher with helical antenna
Langmuir probe
discharge tube
(94 ¢ x 1300)

Fig. 1. Schematic arrangement of the ECR plasma irradiation apparatus.

charge cleaning with hydrogen plasmas was carriedout carefully to reduce impurity contamination,
especially oxygen and / or water having very large
erosion rates.
Three kinds of graphite samples (40 X 40 X 0.5 mm)
were used:I) I sotropic graphite
1)
2)
II)
3)

ISO-880U apparent density p= 1.90 g cm - 3
IG-llOU
p=1.77
Molded graphite
YPD-K
p=2.00

Irradiation plasma was produced under the following conditions.
1) H2 flow rate
2 SCCM
pressure in the discharge tube 4 X 10- 2 Pa
2) microwave power
200 W cw
The plasma had the electron density of 2.7 X 1010 cm-3and the temperature of 10 eV. From these plasma
parameters, the Franck-Condon neutral flux was
estimated 2 ) and found to be 2.3 X 101 5 cm- 2 S-l. We
irradiated the samples with the above neutral flux
for 100 h at 50°C. We determined the erosion rates
from weight loss measurements using a microbalance:
1) ISO-BBOU 3.0x 10- 3 C atoms/Ho2) IG-llOU
4.2x 10- 3
3) YPD-K
2.6x 10-8
From these results, the erosion rate was found to
decrease with increase in the apparent density. Since
these values lie in between those for energetic ions(,-10- 2 CjH+) and thermal atomic hydrogens (......,10-4
CjHO), our results are probably reasonable. It is
well known that the erosion rate depends on thesurface concentration of hydrogen; accordingly, an
ERD method by using RILAC was employed formeasuring the near-surface concentration. Graphite
samples for the ERD measurement were irradiatedwith D2 plasmas, because graphites contain hydrogenby nature. The depth profiles of H and D nearsurfaces at different sample temperatures are shownin Figs. 2 (a) and (b). Figure 2 shows that the concentration of D in the surface heated at 385°C is
low compared with that at 50°C. This result indicatesthat the erosion rate increases with increasing surface
temperature, because recombination of near-surface
atoms with incident atoms decreases with increasing
temperature. 3 )K. Yano, et al.

115

• J02

0.80

ISO - 880U (Temp.; ca.50°C)

4.48

ISO - 880U(Temp.;385 ~C)'Fluence; 2.6 x 10 20 D Cm- 2 (24hrs irradiation)
0.64,

Fluence; 3.3 X l019 D cm- 2(3hrs irradiatlon~...J~ 3.20:z....Iw o· 48
:z

<

:z
<:
:r:
'-'
.......

:J:

u 2.56"C/)l-

S 1.92

(j)

r-

o

0 .32

:z

u

::>

a

1.28

'-'
0.16

0.64
0~0--~~--~----~--~1~28~~~~~--~---­CHANNEL NUMBER
Fig. 2.

o0

CHANNEL NUMBER

128

(b)
(a)
Depth profiles of Hand D near graphite surfaces irradiated with D atoms at (a) 50°C and (b) 385°C.

References
1) Y. Sakamoto, Y. Ishibe, K. Okazaki, H. Oyama, K. Yano,
M. Yanokura, and I. Kohno: RIKEN Accel. Prog. Rep.,
19, 98 '(1985) .

2) K. Yano, H. Oyama, Y. Sakamoto, K. Okazaki, and Y.
Ishibe: lpn. I. Appl. Phys., 20, 1765 (1981).
3) J. Roth: I. Nucl. Mater., 145-147, 87 (1987).

116

RIKEN Accel. Prog. Rep. 21 (1987)

111-2-41.

The Channeling Analysis of Ge Epitaxial Growth on
S i Su bstrate
K. Tanaka, E. Vagi, and H. Kamitsubo

The heteroepitaxial layer of Ge on a Si substr~te
can be applied to an infrared sensor or a suitablebuffer layer for the subsequent growth of GaAs. For
these purposes, a Ge epitaxial layer of high crystalline
quality is required. Cross-sectional transmission electron microscopy (TEM) and an X-ray diffraction
method have been used to investigate the crystalline
quality of deposited layers. However, for crosssectional TEM observation a skilful technique is indispensable for preparation of thin foils from thesamples without introducing defects. The informationon the crystalline quality as a function of depth cannot be obtained from the X-ray diffraction method.
An Rutherford back scattering (RBS) ion channelingmethod nondestructively provides quantitative information on surface layers as a function of depth. In
the present study, therefore, we used the RBS method
to investigate the crystalline quality of the Ge epitaxial
layers on Si substrates.
Ge layers were grown on Si (1 0 0) substrates byusing a molecular beam epitaxy method. As shownin Fig. 1, Ge was grown by a two-step procedure: 1 )the first Ge layer was grown at lower temperaturethan that for the second layer formation in order toform an interlayer to reduce the lattice mismatch
between Ge and Si. In this work the growth temperature of the second layer was kept constant at
600°C and that of the first layer was changed.
Table 1 shows growth conditions of Ge layers.
Characterization of the Ge epitaxial layers was
carried out by RBS with a 1.5 MeV 4He beam. 2 )The beam diameter was 1 mm and the beam divergence was less than 0.076°; the current was approximately 1 nA. The backscattered 4He ions weredetected with a surface barrier solid state detector ata scattering angle of ~55°. The sample was mounted
on a three-axis goniometer and the < 1 0 0> axis of
the sample was aligned in the direction of a beam
Table 1. Growth conditions of Ge layers on Si (1 00) substrates by a two-step procedure growth method. The
growth temperature of the second layer was kept constantat 600°C and the thickness of the second layer was 5,000 A.
Sample 7 was prepared by a one-step procedure.
Sample number
1st layer thieknetil

1st layer growth

I

I

200

135

310

480

2,000

I

400

500 600

300

temperature (0C)

x Rand om• [ 100l alignedo Ge crystal

Si /G e ! ~V He-yDelee lor

6 ,0

III

C

5 4 .0u.uog-r-,,"",,~"T7'1..,.-r:,..,..,..~.,..,..,/...,..,-

.<t
o
o
o
If)

layer

-

-

-

- -

-

- ---

{;
o

lD
I

;. :S:/G'/la;/~~~:::~~~~toSi(100) substrate

Growth temperature
Energy of scattered particles

Fig. 1. Schematic illustration of the growth method of a Ge
epitaxial layer on Si (I 00) by a two-step procedure.

Fig. 2. Rutherford backscattering spectra of a Ge epitaxial
layer on Si (Sample 2 in Table I).

K. Tanaka, et al.

incidence. Figure 2 shows typical energy spectra of
the backscattered 4He ions for < 1 00> aligned andrandom incidenc~s: . 1.'he < 1 00> aligned spectrum .
for a Ge single · crystal was also shown in Fig. 2.
The dechanneling from the Ge epitaxial layer was
greater than that in the Ge single crystal and an
additional peak was observed at the Ge/Si interface.
As crystallinity degrades the dechanneling increases.
As a measure for the perfection of the Ge epitaxial
layer, the value A was defined as:

8.0
1 0\

7.0

0200 .6.

\\

1st layer thickness\

0 2000 .6.

\

6.0

\
\

\

5.0
I>l
"0

"~\

~4.0

\

\

\

3.0

\

2"-

2.0

A = Xs-Xr.

( 1)

l-Xr

1.0

where Xs is the backscattering yield from the Ge
epitaxial layer for the < 1 00> aligned incidence
normalized to that for the random incidence; Xr isthe backscattering yield from a Ge single crystal forthe < 1 00> aligned incidence normalized to thatfor the random incidence. S )

10.0

117

Ge

Si

8.0

0

-- - -3-/~
05

~,,6

0

200

400

600

Growth temperature of 1st layer(OC)Fig. 4. Plot of A versus growth temperature of the 1st Ge
layer.

Figure 3 shows an example of the plot of A us.
depth (z) in the Ge layer. The depth (z) was
derived from the energies of backscattered 4He ions.
The integrated values of A over the thickness of
the Ge epitaxial layer are plotted as a function of
the growth temperature in Fig. 4. We concluded
that the best crystalline quality of heteroepitaxiallygrown Ge/Si is obtained when the first layer isgrown at 400-500 0 C, and the second layer is grown
subsequently at 600°C.
References
1) Y. Fukuda and Y. Kohama: l. Cryst. Growth, 81, 451

Fig. 3. Plot · of A versus depth in a Ge epitaxial layer on a
Si substrate (Sample 2 in Table 1). A is defined by Eq. 1
and is directly proportional to the dislocation density.

(1987) .

2) E. Yagi, F. Kana, S. Nakamura, M. Iwaki, and T. Osaka:
RIKEN Accel. Prog. Rep., 20, 80 (1986) .
3) A. Kyoshima: l. Phys. Soc. lpn., 50, 2395 (1981).

118
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-42.

Production of Fast Switching Power Thyristors
by Proton Irradiation
I. Kohno

The thyristor features quick switching. When used
for a high-frequency power source, it can exert its
full advantages. Even thyristors with short turn-on
and turn-off times, a tail current is generated when
it is used for a high-frequency power source. The
tail loss due to this tail current detennines the upper
limit of the working frequency of the devices. Therefore, how to minimize the tail current is an essential
problem for thyristors when used for high-frequency
power source. For thyristors, it is necessary to control
the life time of carriers in the base layer to reduce
the tail current. In order to control the life timeof carriers we used defects produced by proton
irradiation.
Figure 1 shows various ways of proton irradiationon thyristors. When (1) the surface of thyristor was

K G

w w w

ww w
1 l 1
\EV't"-V1 1 1\£Vt+\£V
n

-

n-

n

p+

p+

(I)
Fig. 1. Various ways of proton irradiation on the thyristor,
A, K and G stand for an anode, cathode, and gate of thethyristor, respectively.

E = 5.0 MeV

E = 5.0 MeVpp

Al absorber thickness 60 pm

Al absorber thickness 52 pm

143.16151.01

:'. 1
.1
,-.,.

~
tJ

Q)

~ 10

tJ

7

~

10

7

.;;:
til

~
Q)

Q)

p:;

p:;

bO

bO

~

I'.. :

~

'M

'M
'"tl

Q)

Q)

101
0.

101
0.

""<lI
e

e

p:;

p:;

til

.. .....

....

".

"

<lI

"

"

...

~..

1
I·

... . .
.,:

til

105 ~--L---L---~__~__~__- L_ _-L-,~__~

o

40

120

80

Depth/Dist ance<rm)

105 ~~__~__~__~__~__L-~~~__~__~

o

40

80

Depth/Distance

<rm)

(b)

(a)

Fig. 2.

120

Rs (spreading resistance) profile. Ordinate is arbitrary.

160

I. Kohno

irradiated with protons at the energy to produce
vacancies in the n- region. When (2) the back surface
was irradiated with proton, and when (3) the both
surfaces was irradiated with proton.
Figure 2 ( a) shows an example of the depth profileof the R s (spreading resistance) of silicon irradiatedwith 5 MeV protons with fluence 5 X l012cm-2 througha 52 pm thick Al absorber (case (1)). An Rs crest
created by the defect production appeared at 151 pm
from the silicon surface with an extensive width ofabout 27 pm. This Rs profile indicates that the
proton irradiation produces defects at a narrow depth
region in the n- layers. Figure 2 (b) shows a depth
profile of the P s of silicon irradiated with 5 MeV
protons through a 60 pm thick Al absorber.
Figure 3 shows the relationships between a proton
fluence (j) and T OFF (turn-off time) which stands forthe time during which anode current decreases from90 % value of peak to 10%. When (j) is increased
to above 0.5 X l012cm- 2 , TOFF can be decreased drastically, On the other hand, when (j) is increased theelectric resistance between the anode A and thecathode K was increased.

119

30 ..

<:
I.t)

,....;

II~-:0 20.-._----__

O~~o~~~_L_ _~~_ _~

234
(/J

5

6

(Fluence) [ x 1012 cm - 2]

Fig. 3. Relationship of (j) (proton fluence) vs. T OFF (turnoff time).

From these experimental results we can find thatthe proton irradiation of proper fluences for the production of vacancies in the n- layer is effective to
reduce turn off time of the thyristor when used fora high-frequency power source.

120
RIKEN Accel. Prog. Rep. 21 (1987)

111-2-43.

Background in PIXE Spectra

K. Maeda, Y. Sasa, and M. Uda*

For quantitative elemental analysis by PIXE (particle induced X-ray emission), the exact evaluationof background is indispensable. Most of the background in PIXE spectra comes from continuous X
rays emitted from the target itself. The intensities
of continuous X rays decrease rapidly with increasing
X-ray energy. Thus, appropriate X-ray absorbers areoften used to attenuate low energy X rays for achieving sufficient sensitivity. To investigate the influenceof absorbers on the profiles of background in PIXE
spectra, we measured continuous X-ray spectra
emitted from a Kapton ((HlOC22N205)n) film
through different kinds of absorbers. We chose
Kapton as a target material because it emits nohigh-energy characteristic X rays that complicate theanalysis of background.
X-ray spectra emitted from a 7.5 pm Kapton film
were measured through five different absorbers:
3.9 mgjcm2 aluminum, 6.0 mgjcm2 titanium, 9.9 mgj
cm 2 vanadium, 5.2 mg/cm 2 silver, and 94 mg/cm2
polyethylene films. X rays were detected with an
ECON-2 Si(Li) detector with a 7.5 pm-thick beryllium window. An 8 MeV helium ion beam of 3 mm
in diameter was used for excitation. The details of
the spectrometer geometry were described elsewhere. l )Wi thout absorber::: 103A thin (1 pm) polypropylene film was placed toprotect the detector window from the attack of
scattered ions when absorbers were not used. The
spectrum observed through this thin film may bepresumed to be the spectrum without an absorber,because the absorption of X rays by the film is not
so significant (less than 10 % at the energies higher
than 1.25 keV) .
Figure 1 shows PIXE spectra obtained from a
Kapton film with and without X-ray absorbers. The
spectra detected through the AI, Ti, V, and Ag
absorbers seem as if they have broad peaks at thelow energy sides of the absorption edges of theabsorbers. A similar peak was also seen in a spectrum
obtained with a polyethylene absorber. Appearanceof such broad peaks is due mainly to the presence of
low-energy signals, the intensities of which were not
reduced to the extent that expected from the absorption effects of the absorbers. If only the absorption
effects are taken into accounts, the spectra measured
through absorbers should have sharp curvatures suchas those represented by dashed lines in Fig. 1.
r rays must contribute at least in part to the lowenergy background, since the main component ofhigh-energy background is caused by the Compton~~

3.9 mg/em2 Al (b)(a)

Q = 2.4 ue

Q =6.0 mg/em2 Ti (e)--(1Jf
I lii~Mm
Q = 65 UC

15 ~C

Q)

c:
c:

-§ 102.

•

I........

(/)

+oJ

C

8 10'

d

d

~

~

Q)

::J

~100~----~~L-~--~-L__~ ~~__~~~~~~==~IU.W~

r-~--~----~----~---,

Q)

:s

103

:>.

Q = 80 lIC~>!: 102
10'

15

o

10

X-ray energy (keY)

Fig. 1. PIXE spectra obtained from a Kapton film with and without X-ray
absorbers: dashed lines were estimated by multiplying the spectrum withoutabsorber (a) by the transmissivities 2l of the absorbers.

* Present address:

Department
Waseda University, Tokyo.

ofMaterials

Science,15

K. Maeda, et al.

rscattering of nuclear
rays, and the r-ray background increases slowly with decreasing pulse-heightenergy.3) This component should be almost unaffected by absorption in the typical X-ray energy
region. However, as it can be seen from Fig. 1,
counts of low-energy signals are essentially different
from a spectrum to another. To account for entire
profile of the spectra, other effects which give rise
to low energy signals should be taken into consideration.
It is known that when monochromatic X rays aredetected with a Si(Li) detector, many kinds of signals
modified by the internal processes in the detector (e.g.,
Si Ka escape and incomplete charge collection) arefound in the resulting pulse-height spectrum. The
major contributors to the low-energy signals are the
Si Ka escape peak, the truncated flat continuum,
and the truncated exponential tail on the low energy
side of the full energy peak. 4 ) For continuous X-ray~

104~.~~~.----'----.----.----r---'r-~

Q)

::.:

§

~ 10

3

~

121

spectra, the contributions from these modified signals
to the background are to be determined by integration of the intensity distributions of incident (i.e.,
original) spectra operated with the response functionof the detector for X rays of each energy. We haveattempted here to evaluate how much the modified
signals contribute to the measured continuous spectraby complementary use of the known data concerning
the response functions of Si (Li ) detectors. 5 -7) The
profile of the continuous X-ray spectrum was numerically estimated for each absorber used in this experiment, based on an assumption that the spectrum iscomposed of real continuous X rays, low-energy
signals modified from these X rays by the internal
processes in the detector, and the r-ray background.
The spectrum of the Kapton film measured withoutabsorber (Fig. 1 (a)) was used as an original one,after subtraction of small amounts of the r-ray background and multiplication by the transmissivity of the~a:;

3.9 mg/cm2 Alc:c:

Q : 15 UC"5~

5.2 mg/cm 2 Ag
Q = 80 uC

0

§

§

8

.§ 10 2

b
U)

c:
~
c:

10 1

>-

>-

~

0

';- 10°

I

X

><

4

3

6

4

7

5

7

6.0 mg/cm 2 Ti
Q: 65 . IJC

:g

c:

5

X-roy energy (keV)X-roy energy (keV)

10 3

-;;;
c:

',.

::J

8
b
U)

c:
~
c:

10 1

>.

~
I

10°

X

7

I

a:;

5 103
~c:

8 10

3

4

6

7

I

9.9 mg/cm 2 V

c:
c:

2

X-ray energy (keV)

X-ray energy (keV)

d

::.:

.&)

>

::.:

Q : 82

lIC

I >

2

b
~ 10 1

~
c:

>-

~
I

10°

X

6
X-roy energy (keV)

Fig. 2. Observed and estimated PIXE spectra of a Kapton film.
e, observed; - - , estimatedtotal signals; ----, full energy component; --- - ---, escape component; - ' - '-, flat continuum
component; --------, low-energy exponential tail component; - .. '-, r-ray component.

122

K. Maeda,et al.

absorber.
The escape fraction was obtained from · Eq. 2 inRef. 5. The energy dependency of the tail fraction
was reported by Shima et al. 6 ) The tail fraction
depends on detectors used. Therefore, we measured
the tail fractions at S Ka and Ti Ka for our detector
and used them to estimate the tail fractions at otherenergies by assuming that the energy dependency is
the same as that given by Shima et al. The flat
continuum fraction was reported to be 1 to 5 % in
the energy range of 1.5-5.9 keV,7) but its energy
dependency was not clear. Thus, we adopted theaverage value of 3 % for the flat continuum fraction
The contribution from the r-ray background Sr (s)was estimated by using a modelS) given by Sr(s) =a[exp(-bs)+c], where a, b, and c are the fitting
parameters, and c the pulse height energy. We usedas the parameters, band c, those deduced from thepulse-height spectrum of Dotite (its main component
is carbon) detected through a very thick absorber( 170 mg I cm 2 , polyethylene), assuming that the shapeof the r-ray: background for Kapton is similar tothat for Dotite. The parameter, a, was determinedfor each spe~trum using the average of signals in

the high energy region (15-I8·keV).
The spectra thus estimated are shown in Fig.. 2
together with their. components and observed data.
The profiles of the observed spectra are well interpreted on the basis of the effects , of the absorption
factors of the absorber, the response function of thedetector, and the ,nuclear r-ray background. The
components produced by the internal processes in thedetector were not too small to be neglected in theevaluation of background in PIXE analysis, .especiallyin the low energy region.
References ..
1) K. Maeda, Y. Yokode, Y. Sasa, H. Kusuyama, andM. Uda: Nucl. Instrum. Methods B, 22, 188 (1987).
2) VM. J. Veigele: At. Data Tables, 5, 51 (1973).
3) H. C. Kaufmann, K. R. Akselsson and W. J. Courtney:Adv. X-Ray. Anal., 19, 355 (1976).
4) R. P. Gardner and J. M. Doster: Nucl. Instrum~ Methods,
198, 381 (1982).
5) P. J. Staham: ]. Phys. E, 9, 1023 (1976).
6) K. Shima, S. Nagai, T. Mikumo, and S. Yasumi: Nucl.
Instrum. Methods 217, 515 (1983).
7) W. Maenhaut and H. Raemdonck: Nucl. Instrum.
Methods B, 1, 123 (1984).

123
RIKEN Accel. Prog. Rep. 21 (1987)

111·3.

Radiochemistry'· and Nuclear Chemistry
1. A New Nuclear Reactiofl Analysis of Nitrogen in Solids:
Utilization of 15N as an Activable Tracer
Y. Itoh, H. Fukushima, T. Nozaki, Y. Mochizuki, and E. Arai*

Determination of a trace amount of nitrogen contained in metals and semiconductors is one of themost important subjects in solid state sciences. Nitrogen is abundant in nature, and the determination of
its trace contents is likely to be interfered with contaminations on the surface and from environment;
thus, the use of 15N is meaningful as an activable
tracer. We reported the determination of nitrogenin bulk silicon (130 pm depth from the surface; theinsident energy of 20 MeV) by activation with the
15N (a, n) I8F reaction. l ) This method is sensitive
over deeper portions; shallower parts of a sample
can be ' analyzed by the following d-induced reaction.
We used the 15N (d, p) 16N reaction to determine
nitrogen on and near the solid surface. Our ultimate

~ ~

~

~~

~

S13 NLj:E::E: , :E:

J rrm( J5N not.}....:interest is to examine whether any enhanced solubility
and diffusion be observed in the portion near thesurface as compared with the deeper portion.
We used 'silicon wafers covered with 15N nitride
films formed by epitaxy from 15NH g (15N 50 ro) andSiH4 and SiaN4 (15N 0.365 ro) plate. The analysis
was carried out by cyclic activation. Each bombardment used a deuteron beam of <5 nA for 15 s. Afterthe beam was cut off pneumatically, the high energy
r-rays from the excited states of the 160 (E r = 6.13,
7.12 MeV) were measured for 15 s with a BGO
scintillator placed close to the sample. The cycle of
15 s bombardment- IS s measurement was repeatedautomatically for 500-1,000 s.
The spectra of typical samples are shown in Fig. 1
together with a normal background spectrum ofnitrogen-free silicon. The region integrated forquantitative detenriination is also shown. Since theser rays are of so high energies, the interferen:ces withall lower energy r rays can be removed by discrimination. The thick target yield of this reaction is shownin Fig. 2. This method indicates the sensitivity of1018 at. em-a. Further studies are in progress.

LPCVD flim-

800A(lSN 52%)

cal.

c
:J

-e«
c
0

uOJ 0.1(f)

FZ SI (Blank)

III
III

0

U

2

100~'-----r---;=-=-=-'=-~- '-='="=' !:;===~=-F~~~

2000
chonne J numberrFig. 1. Typical energy spectra forrays in silicon nitride
samples induced by )5N (d , p) ION with a background ofsilicon.

* Nuclear Reactor Research Laboratory, Tokyo Institute ofTechnology.

3

Energy ( MeV)

Fig. 2.

Thick target yields of the IoN (d, p) ION reaction .

Reference
1) Y. Itob, T. Nozaki, Y. Ohkubo, and Y. Mochizuki:
RIKEN Aeeel. Prog. Rep. , 20, 92 (1986) .

124
RIKEN Accel. Prog. Rep. 21 (1987)

111-3-2.

Study on Carbon and Boron in Gallium Arsenide
Y. Itoh, T. Nozaki, H. Fukushima, and Y. Kadota*

Accurate determination of ultra trace carbon inhigh purity gallium arsenide is required to clarify theeffect of carbon on the semi-insulated matrix. We
reported on the determination of carbon by meansof the deuteron activation analysis with the 12C (d,n) lSN reaction. 1) The relationship between the infrared (IR) absorption coefficient and the carbon
concentration obtained by this method was also reported. 2) Since IR spectrophotometry is used for theroutine analysis of carbon in gallium arsenide in semiconductor ind~stries, it is urgently required to determine the calibration curve as reliably as possible forgeneral use. Japan Electronic Industry Development
Association organized a committee for the determination of the calibration curve. As a member laboratoryof the committee, we have continued the charged
particle activation analysis of carbon in samples
prepared by the committee. These samples werealready submitted to round robin IR measurementby 16 laboratories belonging to the committee. The
results are under treatment by the committee.
To prove the reliability of the analysis, we analyzed
many sample wafers cut from a presumably uniform
portion of a single ingot before the committee's work.

GaAs
melt

Table 1. Concen trations of carbon and boron in GaAs
crystals grown in different ambiences.
SampleNo.

Atmosphere

Solid
Boron
Carbonfraction (x 101S cm - 8) (x 1018cm -S)
(%)

A

Ar

0.17 (top)0.64 (tail)

0.93
0.51

2.5
1.9

B

Ar+l% O 2

0.14
0.76

16
18

3.6
3.4

C

Ar+l% CO

0.1

O. 77

6.4
6.4

1.7
1.5

D

Ar+l% CO(long duration)

0.17
0.78

6.0
6.1

2.8
1.9

Graphite plates were used as the activation comparator. In this method boron can be analyzed
simultaneously with carbon by the lOB(d, n)llC
reaction. The reproducibility of analysis is shownby the following results; for 30 graphite plates,(3.68 + 0.044) X 108 cpm as saturation activity for
1 pC min-1 bombardment; for 18 samples 24.6 +2.62 ppb.wt of carbon and 48.8 + 4.2 ppb.wt ofboron, where the sign + indicates standard errors.
Since the ingot was grown from GaAs melt covered
with B2 0 S encapsulant in a pyrolytic boron nitride
crucible, as shown in Fig. 1, the crystal is thought
to inevitably contain a noticeable concentration ofboron. These samples actually were found to contain1016 to 101 8 atoms cm-S boron. Table 1 shows theconcentrations of carbon and boron in 8 samples cut
from top and tail positions of 4 ingots grown in different ambiences. Further experiments are planned
to get more information about correlation among theconcentrations of carbon, oxygen and boron.
References

Fig. 1.

Crucible for growing LEC GaAs ingots.

* Electronics Materials Laboratory, Sumitomo Metal Mining Co., Ltd.

1) Y. Itoh, T. Nozaki, Y. Ohkubo, T. Kimura, H. Fukushima, Y. Kadota, and K. Sakai: RIKEN Accel. Prog.
R ep. , 20, 91 (1986).
2) Y. Kadota, K. Sakai, T. Nozaki, Y. Itoh, and Y. Ohkubo:
Semi-Insulating III-V Materials, Ohmusha, Ltd., Tokyo,
p.201 (1986).

125
RIKEN Accel. Prog. Rep. 21 (1987)

111.-3-3.

Analysis of Hydrogen in Plasma CVD SiOx Films by
an Elastic Recoil Detection Method
K. Saito, H. Yamaguchi, * M. Aratani, and M. Yanokura

A plasma CVD (chemical vapour deposition) SiOz
film is a promising insulation material for surface
passivation or isolation of multilayer metallization on
integrated circuit (IC). Since the electrical propertyof IC is affected by the composition of the SiOz film,
it is indispensable to find the relationship between
the value of film growth conditions and the film
composition on IC production process. Especiallyhydrogen remaining in the SiOz films after CVD
growth using SiH4 gas for the reactant material affects
physical strength or electrical leakage of films. In
the present study, the hydrogen contents in the SiOz
filins grown under different conditions were measured
by an ERD (elastic recoil detection) method using
an Ar-ion beam from RILAC. SiOz films weregrown to 1 p.m in thickness on single silicon substrates under various conditions:(1) Flow rate of reactant gasses (SiH4/N 2 0):
flow rate of SiH4 was changed from 110 sccm to
160 seem, while that of N 2 0 was kept constant.
(2) Plasma power: 1 A to 3 A.
(3) Substrate temperature: 250°C to 350°C.
Geometrical arrangement of the ERD measurement
is shown in Fig. 1 with an example of hydrogen
peak profiles. The sample surface was bombarded
with a 50 MeV Ar 4 +-ion beam at an incident angleof 30°, and recoiled hydrogen ions were measured
at a detection angle of 33°. Scattered silicon ions or*10I!150- .,OG"".600",,";oi

2.56nr-~-~~-~-..-~-""'--'"

/

°

0/°

100

'--...:..I=----!::---:-l::-I-:~r_L-I-L-.l6
8
10 12 14 16
H Concentration (atm"lo)Fig. 2. Relation between the hydrogen content and the SiH4
flow rate.

H Concentration (atm"lo)

10

15
400

4

o

2

I

'--~

o

__

L-~_ _'--~_ _L-~

10

20

30

H Concentration (olm"lo).

Fig. 3. Relation between the hydrogen content and the substrate temperature and RF (radio frequency) power.

0.32°O~~~~~-1~28-~~~~~CHANNEL NUMBER
Fig. 1. Geometrical arrangement of ERD measurement and
ERD spectra of hydrogen in SiO", films.

* R&D Center, Toshiba Corporation.

oxygen ions, which form a background at the hydrogen peak, were absorbed with a 20 p.m thick aluminum film placed in front of the detector.
The results of analysis are shown in Figs. 2 and3, which indicate that the hydrogen content increases
in proportion to the SiH 4 flow rate and decreases
in inverse proportion to the substrate temperatureand the plasma power. From these results, the hydrogen content of a CVD SiOz film was found sensitive
to film growth conditions.

126
RIKEN Aced. Prog. Rep. 21 (1987)

111-3+4. Heavy-Ion Rutherfo'rd 22f,.Scattering Analysis Appl ied to
the Development of a Monitoring Detector for the Measurementof Water Reactivity
T. Nozaki,* M . Aratani, M. Yanokura, and B. G. Yu

Heavy-ion Rutherford 21r-scattering (HIR21rS)
analysis was used to develop a monitoring detector
for the water reactivity. The principle is as follows.
Soda-lime-silica glass plates are treated with a CsCI
solution 1 ) or D zO for the replacement of cations
near the surface (up to a few micrometer depth)with Cs+ or D+, and then exposed to the environment. The extent of Cs-to-H or D-to-H exchangewith environmental water is measured by heavy-ion
Rutherford 2 1r-scattering analysis. Information is
also obtained on salts contained in the water
simultaneously.
Soda-lime-silica glass plates treated with a boiling
CsCI solution, or sealed with D zO or D zO-H2 0 inquartz ampules and heated to lOO°C for 4 to 5 days,
were kept in contact with sand containing water, or
exposed to air or water for various times. Table 1
shows some preliminary results on the D /H ratio of
the total area covered by a D Peak to that by a H
peak in HIR21rS spectra2 , S ) which were obtained
under the same geometrical arrangement. The total
area covered by a H peak of as-obtained glass samples, which is regarded as due to background surfacehydrogen, was subtracted from every measurement
Table 1. . D-for-Na substitution and D -by-H replacement
for glass plate under various conditions.
Sample PretreatNo.
ment

n

None

6
5 )
7
8
9

DzO
lOO °C,
120h

Dj H
Ratio

Treatment

D,0-H,o(IO: I)}{~
D zO-HzO(3 : I)r

DzO-HzO(I: I)
md

Sand+ 15% H 2O

lOO°C, 120h

0.266

lOO °C, 98h

0.294
0.195

26°C; 216 h

Sand + 7% H 2O } 60 °C {24 h, 72hRoom Air

0.279
0.190
0.181
0.091

(26 °C), 216 h 0.214~~--* Present address: School of Hygienic Sciences, Kitasato
University, Kitasato, Sagamihara, 228, Japan .

o:H

..~

t::.: Cs

";n

E

~L,()
z
o

o

~

H

a::

I-

~ 20
u
z

o
0

0

o
u

0
L!.

t::.
A

o

t::.

6

Cs

L!.

12
1B
24
Cs8r solution treatment time(ll).
46Fig. 1. Preparation of Cs-substituted glass plates for amonitoring detector of water reactivity.

value. The background surface hydrogen was rather
constant in the order of 1015 H atoms/cm 2 among
various samples. Z ) The water content of sand is givenby the weight fraction of water added to the sandwhich had been dried at 100°C for several days.
Correlations seen in Table between the ease of
the D-to-H replacement and environmental condition
are thought to be reasonable, though qualitatively at
the present stage. The D /H ratio is always lessthan 1, mainly because H was not replaced by D in
the D 2 0 treatment at 100°C in the depth beneathmicrometer. The uncertainty in the value of D /Hwould be 10% due to statistical error.
Cs-substituted glass plates are also promising as amonitoring detector of water reactivity. We obtained
preliminary results on exposing experiments. The
results are shown in Fig. 1.
We intend to utilize this method for . the study onwater in, nature.
References
1) B. G. Yu, M. Aratani, M. Yanokura, T. Nozaki, and E.
Arai: RIKEN Accel. Prog. Rep., 20, 100 (1986) .
2) H. Nagai, S. Hayashi, M. Aratani, T. Nozaki, M. Yanokura: Nucl. Instrum. Methods B, 28, 59 (1987) .
3) M . Aratani: Radioisotopes, 37, 43 (1988) .

127
RIKEN Accel. P~og. Rep. 21 (1987),'

111-3-5. Application of PIXE to Medical and Environmental Science (II)K. Maeda, Y. Sasa, H. Kusuyama, K. Yoshida,*
M. Maeda,*:* and M. Uda***Growing interest has developed in a balance ofelement concentrations in biological organs andenvironmental materials affecting human health.
Rapid, sensitive mu~tieIemental analyses are requiredfor investigating this problem. PIXE is one of themost advanced meth~ds which meet such a requirement. We have continued a study on the applicationof PIXE to medical and environmental science. 1 - 4 )We report here the PIXE analysis made on ( 1 )human spermatozoa and seminal ' plasma and (2)seaweeds.
( 1 ) Spermatozoa and seminal plasma
Recently many papers have been presented oncorrelations between trace element concentrations insemen and human sperm quality relating infertility.
It is attractive to investigate element concentrations inspermatozoa themselves. PIXE is quite suitable forsuch 'small amounts of samples. We have analyzed
human spermatozoa and seminal plasma taken fromthree patients of infertility and a normal man.
Spermatozoa were separated from seminal plasma by
centrifugation. The samples were deposited on 1 pm
thick polypropylene film, dried in a vacuum desiccatorand then used as targets without any other pre-treatments. An 8 MeV He+ ion beam of 1 rom in diameter
was used as an exitation source. X rays generated(0)

from the targets were detected with a Si(Li) detector
through an X-ray absorber made of 1.5 pm thickpolypropylene or 1.0 mm thick polyethylene film.
Typical PIXE spectra obtained in this experimentare shown in Fig. 1. The elements, Na, Mg, P, S,
CI, K, Ca, Fe, Cu, Zn, and Br were detected in bothspermatozoa and seminal plasma. The K concentration in dried weight was almost the same in all
samples examined here. F or all of the sample pairs,
S and Fe are richer in spermatozoa than in seminal
plasma. The Fe content in spermatozoa taken fromthe normal man was higher than those from theinfertile men. Weare now searching for a techniquefor preparing spermatozoa samples which are notcontaminated with seminal plasma, without changing
their composition, in order to obtain more reliable
data.
(2) Seaweeds
Seaweeds, favorite healthy food for Japanese, areimportant sources of iodine and so-called mineralcomponents essential for living. Numerous analyses
have been made on concentrations of individual elements contained in marine organisms. 5 ) There are,however, few reports on simultaneous multielemental
analyses of seaweeds. We studied here the variations
in element compositions with species, growing dis-

104

(b)

Zn

n

100 1----,-WL.L..L.--1J........,.......
o10
X-ray energy (keV)

10
X-ray energy (keV)

15

Fig. 1. PIXE spectra of spermatozoa taken from a normalman. (a) with 1.5.um polypropylene and (b) with 1 mm
polyethylene absorbers.

* Saitama Medical Center, Saitama Medical School.
** Tokyo University of Fisheries.
*** Present address: Department of Materials Science,
Waseda University, Tokyo.

K. Maeda, et al.

128

tricts, and the distributions of elements in a specimen.
Commercially available edible seaweeds, a sea

Table 1. Ka peak intensitiesa ) of PIXE spectra for a freshsea tangle: 5.0 MeV H+ impact.
Cl
Outer region of
stick
Inner region of
stick
Leaf

(a) sea lettucea)i

Ca .. Zn

Br

Sr

200 2.9 1.2 0.028 0. 19 0.06 0.032
160 7.4 3.8 0.024 0.09 0.06 0.006
110 6.5 8.0 0.037 0.08 0.06 0.005

Peak. intensities are normalized by use of the background intensities at 3.0 keV.

lO2

~JOI

;.!::

,

K

100~---.-----.~~~-WWM~~L-~

o

[00

200
300
Cilallile [ Ilumbe r

400

500

[~ ~_ _- ._ _~~~~~~~~~-L~

o

100

200
300
Cll01lileI Ilumbe r

400

500

(c) I-Iakame, east

lettuce (Vlva sp., green algae) grown at the west
coast of Japan and two wakames ( U ndaria sp.,brown algae) from the east and the west coasts ofJapan, were analyzed. The sample materials werereconstituted from dried seaweeds with distilled water.
Figure 2 shows the PIXE spectra taken from thesesamples excited with 1.6 MeV H+ ions. The element
compositions of wakames obtained from different districts were almost the same. The wakames (brownalgae) contained a large amount of As, I, and Sr;
the sea lettuce (green algae) were rich in Cr, Ni,
and Cu. Brown algae are well known to accumulate
I and As in high concentrations. 5 ) PIXE is expected
to be a convenient and effective method to seek forsuch accumulator organisms because of its ability todetect fugacious elements together with other elements
simultaneously without any chemical pre-treatments.
Three parts of a fresh sea tangle (Laminaria sp.,brown algae), the leaf, and the outer and the inner
regions of stick, were analyzed with 5.0 MeV H+ ions.
The sample was washed with tap water and cut witha stainless steel knife. The results are shown in Table
1, where the Ka peak intensities are normalized withthe background at 3.0 keV. Iodine is concentrated
in the outer region of stick compared with the leaf
and the inner region of stick. The Ca level was
highest in the leaf.
References

Channe [ number

Fig. 2. PIXE spectra taken from dried seaweeds. (a) sea
lettuce obtained from Noto district at the west coast ofJapan; (b) wakame obtained from Noto district; and (c)wakame obtained from Sanriku district at the east coast ofJapan. 1.6 MeV H+ impact, 1 mm polyethylene absorber.

1) M. Uda, K. Maeda, Y. Sasa, H. Kusuyama, and Y.
Yokode: Nucl. Instrum. Methods B, 22, 184 (1987).
2) K. Maeda, Y. Yokode, Y. Sasa, H. Kusuyama, and H.
Uda: Nucl. Instrum. Methods B, 22, 188 (1987).
3) K. Maeda, Y. Sasa, M. Maeda, and M. Uda: Nucl.
I nstrum. Methods B, 22, 456 (1987).
4) K. Maeda, Y. Sasa, H. Kusuyama, M. Maeda, H. Ishikawa, Y. Yokode, and M. Uda: RIKEN Accel. Prog.
Rep., 20, 94 (1986).
5) R. Eisler: Trace Metal Concentrations in Marine
Organisms, Pergamon Press, New York (1981).

129
RIKEN Accel. Prog. Rep. 21 (1987)

111-3-6. Appl ication of PIXE and Diffraction Analysis
to Ancient Remains (II)Y. Sasa, K. Maeda, and M. U da *For the analysis of ancient remains, non-destructive
and highly sensitive measuring methods are indispensable. PIXE is one of the most effective methods togain our ends in view of elemental analyses. Several
PIXE data have been reported on ancient coins andjeweries. 1 - 9 ) Crystallographic analyses also bring ushighly reliable information on structures and chemical
constituents of archaeological samples. This paper reports chemical and crystallographic surveys of coinsfrom different districts and ages. Concentrations ofminor constituent elements in these ancient remains
might give us keys to understanding of exchange or
diffusion of cultures. These data will also contributeto the elucidation of technological backgrounds inancient priods.
The samples analyzed were coins made at different
districts and ages: 1) Pakistan coins and their darkgrey casting molds obtained from the Banbhor ruin
in Pakistan dated back to 0- 7th centuries; 2) ancient
Chinese coins casted at Tang and Song era, 7- 11th
centuries, of China (referred to as ancient Chinese
coins); 3) a coin minted at the Qing are (1841)
of China (referred to as a Qing coin). Target
materials were irradiated with 1.3-2.1 MeV jamu He+
ions obtained from the linear accelerator and 1.6 MeV
H+ ions from the RIKEN TANDETRON. X rays
generated from the targets were detected with aSi(Li) detector through a 7.5 pm Be window. Highenergy X-rays emitted from the trace amounts ofelements were measured through a thick polyethylene
absorber (1 mm) or thin Co absorber (8 pm) inserted between the target and the detector in orderto depress the pile-up phenomenon in the detector.
Signals from the detector were stored in a multichannel analyzer, and then processed on a microcomputer and transferred to magnetic discs. Background X-ray spectra were subtracted.
X-ray diffraction data were taken with an automated X-ray diffractometer equipped with a Cu
radiation source, a graphite monochromator, and a
NaI scintillation counter. Operation conditions ofgoniometer scanning speed (2()O jmin) = 2 and time
constant = 1 s were used, and diffraction data were

* Present address: Department of Materials Science, Waseda
University, Tokyo.

recorded on strip charts and magnetic floppy discs.
Figure 1 shows the PIXE spectrum obtained from
Banbhor coin. The cllemical compositions correspond to bronze including a relatively high contentsof iron and lead (Fe KajCu Ka = --0.08 and Pb
La j Cu Ka = --0.05). The X-ray diffraction analysis
also confirmed a bronze phase: From the coin c'a sting
mold with a dark grey color a-quartz, ferro-alumino10 5

Bonbllo r co i n

PbM

10Lj

</)
~

c:

10

3

::::l

8
102

10 1

100

a

100

200

300

LjOO

500

Channel Number

Fig. 1. PIXE spectrum from the Banbhor coin (dated 0-7th
century) bombarded with a 2.1 MeV /amu He+ beam.

10

5

10 4

~

Pb L
r-r-l

Ancient Ch i nese coin
(Sung T' ung coi n)(wi th 8 \Jill Co obs , )

10 3

10 2

10 1

10 0

0

100

200

300

Chonne I

Numbe rLjOO

500

Fig. 2. PIXE spectrum from the ancient Chinese coin
(Song Tang coin) bombarded with a 1.6 MeV proton
beam; on 8 Il-m Co absorber was used.

Y. Sasa, et al.

130

10 5
Ch'ingcoin(w.i t h 1 ITI1l P. E. obs. )

10 4

103

'"<:
;;:J

a

u

102

10 1

these coins are now in progress.
PIXE spectrum from Qing coin is seen in Fig. 3.
On the basis of the i>IXE analyses the coin was madeof brass (Zn Ka/Cu Ka = ....:,0.55). Lead was also
'found from this sharply grooved coin (Pb La/eu
Ka = 0.08- 0.18) , suggesting that the coin was casted
in a mold and then letters or figures on the coin
were finished ,u p by knife cutting. Ancient craftsmen
seem to have already known that Pb in brass is very
effective to improve machinability; modern metallurgy
uses Pb-brass for fine machinery.
References

100
100

200,

300

400

500 '

Channel Number

Fig. 3. PIXE spectrum from the Qing coin (1941)
bombarded with a 2.1 MeV/amu He+ beam; a l,ooo,um
polyethylene absorber was used.

silicates and calcite were detected by X-ray diffraction. The PIXE data shows that the main components of the mold are Si, Ca, and Al (Ca Ka/Si
Ka = 0.30 and Al Ka / Si Ka = 0.26), indicating that
results from PIXE are consistent with those from
X-ray diffraction.
A typical PIXE pattern of an ancient Chinese coinis displayed in Fig. 2. All coins studied were grouped
into bronze from elemental and structural analysis.
Detailed technological or archaeological analyses on1) H. Mommsen 'and T. Schmittinger : Archaeonometry , 23,
71 (1981).
2) G. P. Ferreira and F. B. Gil: Archaeonometry, 23, 189(1981) .
3) C. P. Swan: N ucl. Instrum. Methods, 197, 237 (1982).
4) G. Demortier, B. van Dystaeyer, and A. Boullor: Nucl.
Instrum. Methods B, 3, 339 (1984).
5) Z. Smit and P. Kos: Nucl. Instrum. Methods B, 3, 416(1984) .
6) S. J. Fleming and C. P. Swan: Nucl. Instrum . Methods
A , 242, 626 (1986) . .
7) Proc. Int. Workshop on IBA in the Arts and Archaeology,
Pont-a-Mouson, Nucl. Instrum. Methods B, 14 (1986) .
8) J. W. Palmer , M. G. Hollander, P. S. Z. Roger, C. J.
Duffy, and T. M. Benjamin: Nucl. Instrum. Methods B,
22, 419 (1987) .
9) Y. Sasa, K. Maeda, and M. Uda: Nucl. Instrum. Methods
B , 22, 426 (1987).

131
( ..

RIKEN Accel. Prog. Rep. 21 (1987)

111-3-7. In Situ Emission M6ssbauer Studies of Solid/Solution
Interface: 119Sb5+ and 57C02 + Ions Adsorbed on r-Fe203
F. Ambe, S. Ambe, and T. Okada

In spite of the development of physicochemical
techniques for surface analysis, spectroscopic methods
applicable to the study of chemical bonding at interfaces between solid and aqueous phases are limited.
We previously demonstrated that the ex and in situ
emission Mossbauer measurements are useful inclarifying the chemical environment of dilute metal
ions adsorbed on magnetic metal oxide surfaces. I - S )When l1!lSn or 57Fe ions arising from 119Sb5+ or
57C02+ are bonded through oxide ions to the orderedsurface metal ions of a magnetic oxide, the 119Sn or
57Fe nuclei feel the hyperfine magnetic fields induced
by interaction with the ordered magnetic metal ionsof the· substrate. The hyp~rfine ~agnetic fields areobserved as broadening or splitting in the emission
Mossbauer spectra. In this report, application of thistechnique to 119Sb5+ and 57C02+ ions at the interface
between r-Fe20S and aqueous solutions is described.
The source nuclide 119Sb was produced by thecyclotron.4 ) About 10 cm S of an aqueous solution
containing 119Sb 5 + or 57C02+ was put in a Teflon

100.:_,'.,'... fl:7
. . .. ,-. .

'~
" '"
,

...

,

•

I'

•

pH 7. 4,'"ft'

vessel equ,i pped with a 0.5 mm-thick Teflon windowat the bottom. About 30 mg of r-Fe20S powders
was added to the solution. The suspension was
shaken thoroughly at room temperature. 'T he amountsof antimony and cobalt coexisting with the nuclides
are estimated to have been less than 400 ng and
300 ng, respectively, i~e., to have bee~ much smaller
than that required fo~ mon~layer coverag~ of 30 mgof the r -F e 20s sample.
The r-Fe20S with adsorbed 119Sb5+ or 57C02+ alongwith the solution was subjected to the emission
Mossbauer measurement at 24 + 1°C. The absorbers
employed were 57Fe-enriched potassium ferrocyanide(0.5 mg 57Fe/cm2) and barium stannate (0.9 mg:- ,I , ' I.

~99.5
(f)

Z

~100 1-.:""~~....

:z

w99.5

>

>- 99.5

I-

I-

',~

(f)

~ ', . _,III""It,:z 10 0

w

t':'

I' :

f-

Z

~::.: ~pH 5 . 0

w 99.5>I-

5w 10 0100f---~. ....

...... .

99.5

a::

99.5

- 15

-10

-5

0

5

10

15

RELRTIVE VELDC I TY
CMM/S VS MET RLLIC IRe N)
- 16

-8

0

8

16

RE LRTIVE VE LD CITY
( MM/S VS BRR ruM STANNRTE)
Fig. 1. In situ emission Mossbauer spectra of 119Sn '+ arisingfrom lloSb5 + at the r-FezOs/0.25 mol dm- 3 LiCI solution
interface at pH 7.4, 5.0, and 2.6 (measurement at room
temperature). The isomer shift is given relative to barium
stannate at room temperature and the sign of relative
velocity is defined as in ordinary absorption spectra. The
curves arc the results of least-squares fitting with a
Lorentzian.

Fig. 2. In situ emission Mossbauer spectra of 57Fe3 + ansmg
from 57C02+ at the r-Fe20s/0.1 mol elm-a NaCI solution or
0.3 M NaOH interface for various pH values of the aqueous
phase (measurement at room temperature): (A) pH 5.9,
(B) pH 7.7, (C) pH 9.7, (D) pH 11.5, (E) 0.3 M NaOH.
The isomer shift is given relative to metallic iron at room
temperature and the sign of relative velocity is defined asin ordinary absorption spectra. The curves are constituted
based on the results of Hesse-Riibartsch analysis assuming
no relaxation.

132

F. Arnbe, et al.

119Sn / cm2)'. The Mossbauer r-rays of 57CO and 119Sb
were detected respectively with a Kr (+ 3 % carbon
dioxide) -filled proportional counter and with a 2 mmthick NaI (TI) scintillation counter through a 65 p.mthick Pd critical absorber for Sn K X-rays.
The in situ emission Mossbauer spectra of 119Sn 4+
arising from 119Sb 5 + ions adsorbed on r-Fe20S from0.25 mol/dm s LiCI solutions of different pH values
at room temperature are shown in Fig. 1. As seenfrom Fig. 1, the spectra are essentially symmetriclines centered at the zero relative velocity against abarium stannate absorber. This demonstrates that
119Sn at the interface is exclusively in the tetravalentstate. The width of the lines is much larger thanthat for 119Sn 4+ arising from 119Sb5+ on dia- or paramagnetic oxide surfaces (about 1.3 mm S-l). We
conclude, therefore, that most of the adsorbed 119Sb5+
ions on r-Fe20S particles have a certain magnetic
interaction with the ordered ferric ions of the substrate at the pH value. The pH dependence of theline width is, however, much less pronounced for
r-Fe20S than the case of 119Sb5+ on a-Fe20S'S). The emission Mossbauer spectra of 57Fe arisingfrom G7C02+ ions at the interface between r-Fe20S
particles and 0.1 mol/dm s NaCI solutions of different
pH as well as a 0.3 M NaOH solution at room
temperature are shown in Fig. 2. As can be seenfrom Fig. 2, the emISSIOn spectra show a marked
dependence on the pH of the aqueous phase incontrast to the case of 119Sb5+ described above. No
emission lines ascribable to paramagnetic iron species
are recognized in the spectra within the experimental
uncertainties. The isomer shift indicates that 57Fe
ions arising from 57C02+ at the interface are predominantly in the trivalent state. At pH 5.9 and
7.7, the spectra consist of a partly resolved sextet ofbroad lines. With increase in pH of the aqueous
phase the splitting of the sextet increases and simultaneously the width of each line diminishes. Theseobservations are essentially in parallel with those for
a-Fe20S reported previously. 3)
The results of detailed analysis of the experimental
data and discussion in terms of the surface structureof the oxides will be described elsewhere.
References
1) T. Okada, S. Arnbe, F. Ambe, and H. Sekizawa: ]. Phys.
Chern., 86, 4726 (1982) .
2) F. Arnbe, T. Okada, S. Arnbe, and H. Sekizawa: ]. Phys.
Chern., 88, 3015 (1984) .
3) F. Ambe, S. Arnbe, T. Okada, and H. Sekizawa: Geochemical Processes at Mineral Surface (eds. J. A. Davisand K. F. Hayes) , ACS Symp. Ser. 323; Am. Chern. Soc.,
Washington, D.C., p.403 (1986) .
4) S. Arnbe: J. Radioanal. Nucl. Chern. Artie., 81, 77 (1984).

133

RIKEN Accel. Prog. Rep. 21 (1987)

111-3-8.

Mossbauer Spectroscopic Studies of Ruthenium Trichlorides
Y. Kobayashi, M. Katada, H. Sano,* T. Okada
K. Asai, N. Sakai, S. Ambe, and F. Ambe 'We previously reported the 99Ru M6ssbauer spectroscopic investigation using the cyclotron-produced
9DRh in ruthenium powders as a source. 1 ) In thisperiod, the 99Ru Mossbauer effect and the magnetic
susceptibility were studied on anhydrous ruthenium
trichlorides. 2 )It is known that anhydrous ruthenium trichlorides
occur in two · fOnDs; black a-RuC1 3 with the P3 1 12
space group and brown ~-RuCI3 with the trigonal
P3cl. In both fOnDs, trivalent ruthenium ions havea low-spin 4d 5 configuration lying in a distorted
octahedra of chloride ions. It' was also re'p orted thata- and ~-RuCI3 became antiferromagnetic below 13 K
and about 870 K, respectively, on the basis of magnetic susceptibility data. 3) No Mossbauer spectrumof a-RuCI 3. has been published yet. The spectrumof ~-RuCI3 is reported to show only a quadrupole
splitting,4) in contradiction to the above magnetic
susceptibility result.
.
The method of source preparation was similar tothat previously reported,l) except that 97 %-enriched
99Ru metallic powders (83 mg cm- 2 ) were used for
proton irradiation to improve the SIN ratio of
Mossbauer r rays. Magnetic susceptibility measurement was carried out using a vibrating-sample
magnetometer (the Foner type) with a magnetic
field up to 20 kOe for a-RuC1 3 and 16 kOe for ~­RuCl 3 between 4 K and room temperature. The
sample of a-RuCl s was commercially obtained, ~­RuCl s was prepared by a new method developed by
us: by heating triruthenium dodecacarbonyl, Rus(CO) 12, in a chlorine stream at 360°C for 4 h. Our
method is more convenient and yields purer ~-RuCls
compared with the previous one. 5 ) Neither un reacted
carbonyl nor by-products (such as a-RuCI 3, otherchlorides and ruthenium metal) were detected fromthe X-ray diffraction pattern of the obtained product.
The typical Mossbauer spectra obtained with thesource and absorber, 1.02 g cm- 2 of a-RuCl s and0.34 g cm- 2 of ~-RuCI3, at 5 K are shown in Figs.
1 (a) and (b), respectively. The susceptibility of aRuCl 3 is essentially in agreement with the previous
result3) and follows the Curie-Weiss law in the temperature range 120-300 K. The magnetic susceptibility of ~-RuCls was found to obey the Curie law* Department of Chemistry, Tokyo Metropolitan University.

,..... 100·'!-,;u:·:--~r.:'~~:"'.
'.t{fti:::;;.~:~,<:'~);~~

11'<!

•

z:

::!

J .

f

~

......: . .ft~ .•~.......

~ 99.7
z:
.
a:
~

-4

.

~

...

• ~ '. ";

(a)

o

4

VELOCITY (MM/SEC)~ . 99.7

z

a:

(b)

a:

I-

-4

o

VELOCITY CMM/SEC)

Fig. 1. Mossbauer spectra at 5 K of (a) a-RuCls and (b){J-RuCls against the 99Rh-Ru metal source at the same
temperature «a) a total of 5.4 X 107 counts per channeland (b) a total of 1.1 X 107 counts per channel) .

over the temperature range studied.
In the analysis of the Mossbauer spectra, we
adopted Kistner's value of 2.7 for the E2/Ml mixing
ratio, 02 , together with the ratio of the quadrupole
moment of the nuclear excited state (Ie = 3 12) tothat of the ground state (Ig= 5/2), Qe/Qg= 2.89. 6 )Symmetric 18 lines appear in a spectrum under apure magnetic field, while an asymmetric doublet
appears in the presence of an electric field gradientof ordinary magnitude.
As seen from Fig. 1 (a), the Mossbauer spectrumof a-RuCl s has a hyperfine structure with little
asymmetry. This observation suggests the presence ofa considerably strong magnetic field and the absenceof a significant electric field gradient at the 99Ru
nuclei in this compound. In fact, the experimental
data can be analyzed with a reasonable X2-value
assuming no electric field gradient. The obtained
M6ssbauer parameters are summarized in Table 1.
The value of the isomer shift is in the range typicalfor trivalent ruthenium compounds. 7 ) The magnitudeof H hf , 209 kOe, is about 2/3 of those in trivalentY. Kobayashi, et ai.

134

Table 1. Mossbauer parameters for anhydrous ruthenium
trichlorides.
Compounda-RuClsfi-RuCls
fi-RuCls

e'-qf4/2 Hhf' (kOe)o(mm S-1)& (PlmS-:l)b

- 0.74
-0.71
-0.71

0
0.75
0.85

209
0

Ref..
this work
this work4a, relative to ruthenium metal; b, the quadrupole splitting for the excited state.

ruthenium oxides with the perovskite structure, inwhich Ru ions are also in the low-spin 4d 5 state.
Isomorphous iron trichloride, FeCIs, has a large hyperfine magnetic field of 495 kOe extrapolated to 0 K,
because Fe 3 + is in a high-spin 3d 5 state. On the basisof the present result of Mossbauer measurements, weconclude that a-RuCl s is in a magnetically orderedstate at 5 K. The temperature dependence of themagnetic susceptibility supports this conclusion. The
absence of an appreciable quadrupole interaction implies that the distortion of six Cl- octahedron aroundtrivalent Ru ions is small in the layer structure of
a-RuCI 3 •The Mossbauer spectrum of tS-RuC1 3 (Fig. 1 (b) )is a doublet with a small asymmetry. The spectrum
was analyzed satisfactorily on the assumptions of zeromagnetic field and an axially symmetric electric field
gradient expected from a crystallographic study.S)
The determined Mossbauer parameters of tS-RuCl s

are shown in Table 1(" Our re'fined data' are not so
different from those reported by Clausen et aU) The
occurrence qf th~ . ant!~e~~op1ag~e~j~ ord~,ring below
about '870 K' 'proposed ' by ' Fletcher et 'al. based on
their magnetic susceptibility measurement is obviously
inconsistent with the Mossbauer spectroscopic results.
On the other hand, our measurement shows that themagnetic susceptibility follows the Curie law down
to 4 K, indicating that tS-RuCls is paramagnetic at
5 K where the Mossbauer spectrum was obtained.
The electric field gradient is attributed to the distortion of RuCl 6 octahedron with a relatively close
Ru-Ru spacing in the chain structure of this compound. ~)References
1) Y: Kobayas'h i, M. Katada, H. Sano, T . Okada, K. Asai,
S. Ambe, and F. Ambe: RIKEN Accel. Prog. Rep., 20,
Ill. (1986) .
2) Y. Kobayashi, M. Katada, H. Sano, T. Okada, K. Asai,
N. Sakai, S. Ambe, and F. Ambe: Hyperfine Interact. ,41, 487 (1988).
3) J. M. Fletcher, W. E. Gardner, A. C. Fox, and G. Top' ping: J. Chem. Soc. (A), 1038 (1967).
4) C. A. Clausen, R. A. Prados, and M. L. Good: Chern.
Phys. L ett., 8, 565 (1971).
5) K. R . Hyde, E. W. Hooper, J. Waters, and J. M. Fletcher:
1. 'Less-Common Metals, 8, 428 (1965).
6) O. C. Kistner: Phys. Rev., 144, 1022 (1966).
7) D. C. Foyt, T. H. Siddall, C. J. Alexander, and M. L.
Good: Inorg. Chem., 13, 1793 (1974).

135
RIKEN Accel. Prog. Rep. 21 (1987)'111-3-9. Adsorption of No-Carrier-Added 119Sb (V) Ions onto
Metal Oxide Surfaces from Aqueous Solutions
S. Ambe 'We previously studied the adsorption kinetics of
cyclotron-produced n 9Sb (V) onto a-Fe203 surfaces
by a radiotracer method.1.) The adsorption was foundto proceed at pH 4, at the highest rate from asolution and with the second-order kinetics with respect to the concentration of antimony (V) and thesurface area of a-Fe203. These findings were discussed in connection with the chemical structure ofadsorbed 119Sb (V) investigated by emission Mossbauer spectroscopy.2,3) The results motivated us to
study the , adsorption of 119Sb (V) onto other metaloxides with different crystal structures. This report
describes the pH dependence of the adsorption of
no-carrier-added 119Sb (V) ions onto Cr203, a-AI 20 3,
r-Fe20 3, a-FeOOH, CoF 20 4, and NiFe204 as well
as respective adsorption kinetics.
The adsorbent waS added to a 0.25 mol dm-3 LiCI
solution containing no-carrier.:.added 119Sb (V) ions.
The suspension was shaken in a definite 8-shape
motion with a mechanical shaker at given temperature,_ An aliquot of the : suspension was taken at agiven intervals for determination of the fraction of
119Sb adsorbed. The adsorbent suspended in thealiquot was 'filtered out"with a glass fiber fiiter. 'The
23.9 ke V' r ~ays and S~ , KX rays of 119Sb in eachfiltrate were counted with an NaI scintillation
counter.
Adsorption of 119Sb (V) ions was analyzed on thebasis of a rate equation:

dx/dt=k(a-x)n(1)

where a is the initial radioactivities of 119Sb (V) inthe solutions, x the radioactivities of 119Sb (V) adsorbed, k the rate constant, and n the order of adsorption. The surface areas of the adsorbents used are
sufficiently large to assume that the areas are invariable on adsorption of Sb (V) ions.
The percentages of 119Sb (V) ions adsorbed on
Cr 2 0 3 are shown in Fig. 1. A part of the 119Sb ionswere adsorbed by Cr20 3 in the acid pH range after
60 min shaking at 60°C, though the yield was low.
In the alkaline pH range no adsorption was observed.
Marked increase in the adsorption was observed at
pH 2--4 after 170 min stirring at 100°C, the adsorbed
fraction amounting to 80- 90 % of the total 119Sb (V)

100

~

z

8

~

50

a::

~

0

<:(

0

2

4

8

10

12

pH

Fig. I. Percentage adsorption of no-carrier-added 119Sh (V)ions from 0.25 mol dm-3 LiCI solutions onto (0) CrZ0 3
after 60 min shaking at 60°C, ( .) CrzOa after 170 min
shaking at 100°C and (.) r-Fe20a after 30 min shaking
at 20°C.
1 00r-------------------~

O~~-----L--~----~~

o

100

200

TI ME (min)Fig. 2. Adsorption kinetics of no-carrier-added lloSb (V) ions
onto (e) CrzO a from a 0.25 mol dm.-3 LiCI solution of
pH 3.0 at 100°C, onto (0) a-AI.20s from the solution of
pH 2.0 at 100°C, and onto (.) CoFe204 from the solutionof pH 2.3 at 50°C.

ions. The kinetic plot obtained for a solution at pH
3.0 at 100°C is shown in Fig. 2. The adsorption
increased steadily with time of stirring. The resultof analysis of the data by an integral form of Eq. 1(n = 2) shows that the relation between 1/ (a-x)
and t is linear, indicating that the order of reaction
is 2.
About 30 % of 119Sb (V) was adsorbed by a-A1 20 3from solutions at pH 1- 3 and 10-207'0 at pH 6-10
after 60 min shaking at 50°C. At 100°C, 80-90%
of 119Sb was adsorbed at pH 2.0 in 80 min. An
adsorption kinetic study carried out with a solutionof pH 2.0 at lOO°C shows that the adsorption yield

S. Ambe

136

of 119Sb(V) increased with time (Fig. 2). The relation of 1/ (a-x) vs. t was represented as a linewith a bent on the .h~lf way, tqat is, a steep line
followed by a less steep one.
119Sb (V) ions were adsorbed rapidly by r-Fe203
in the acid pH range at 20 0e and the percentage
adsorption amounted to 90 % in 30 min as shown in
Fig. 1. The adsorption decreased abruptly at pH's
higher than 7. The kinetic data obtained from asolution of pH 4.0 at 50 0e are shown in Fig. 3.
The relation of 1/ (a-x) vs. t obtained from thedata is linear, suggesting that the adsorption is of
the second order.
The adsorption of 119Sb(V) onto a-FeOOH at
pH 4.0 proceeded rapidly, resulting in more than
90% of adsorption in 4 min at 50 0e (Fig. 3). The
data are analyzed in accordance with the third-orderkinetics.
The adsorption of 119Sb(V) onto eoFe204 powder
was found to be affected greatly by the pH of thesolutions. Maximum adsorption was observed around
100 ,----- - - -- -,100.---- - --

-

--,

z

8

~

50

0::

oV)
Cl

<C

•
•
OL-~_~_~i~_~~.
o

2

4

6

8

10

pH
Fig. 4. Percentage adsorption of no-carrier-added 119Sb (V)ions from 0.25 ml dm- a LiCI solutions onto (.) CoFe 2 0 4
and (0) NiFe204 at 50°C after 60 min shaking.

pH 2 as shown in Fig. 4. From a solution at pH 2.5,
about 80 % of 119Sb (V) was adsorbed in 1 h at
100°C. The amount of 119Sb(V) adsorbed at pH 2.3
and 50°C increased with time (Fig. 2). However,
the kinetic data failed to fit the integral form of
Eq. 1 with n = 1, 2, or 3. Adsorption of 119Sb (V)onto NiFe204 powder showed also pH dependence
similar to that for CoFe204 (Fig. 4). About 900/0
of 119Sb (V) was adsorbed at 1000e at pH 2.4 in

2 h.
The above findings suggest that not only the surface
structure of the oxides but also the kinds of chemicalelements involved are important in determining theorder of the adsorption rate.

z:

8

~
cr::
oV)

50

Cl

<C

References
O L-~L_~_~_~046

8

TmE (min)Fig. 3. Adsorption kinetics of no-carrier-added 118Sb (V) ions
onto (.) r-Fe203 and onto (0) a-FeOOH from 0.25
mol dm- 3 LiCI solutions of pH 4.0 at 50°C.

I) S. Ambe: Langmuir, 3, 489 (1987).
2) T. Okada, S. Ambe, F. Ambe, and H. Sekizawa: J. Phys.
Ch em., 86, 4726 (1982).
3) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa: Geochemical Processes at Mineral Surface (eds. J. A. Davisand ·K. F. Hayes), ACS Symp. Ser. 323; Am. Chern. Soc.,
Washington, D.C., p.403 (1986) .

137
RIKEN Accel. Prog. Rep. 21 (1987)

111-4.

Radiation ·Chemistry and Radiation Biology
1.

High-Density Excitation by Heavy Ions: Measurement ofTrack-Depth Resolved Emission Spectra
K. Kimura, T. Yoshida, S. Imai, T. Nakamura, and N. Hamada

One of the most characteristic irradiation effectsof heavy ions is, in condensed matter, the highdensity excitation of electrons in an outermost shell.
Most of the high-energy states such as ions andexcited states of inner-shell electrons can be converted
into lower excited states of the outermost shell.
Energy deposition of an ion varies along the path of
the ion, as illustrated by the curve of stoping powerdE I dx vs. range (x), and the maximum energydeposition for heavy ion possibly amounts to as large
as a few thousand electron volts per Angstrom. Sinceenergy deposition should be expressed by dEl (r 2 dx)(r stands for the track radius) rather than in dE I dx,
it should increases in much larger extent near its
maximum than that estimated from dE I dx, considering that a radius of the "core" -part is approximately
proportional to the ionic velocity, v, and the "halo"part, V 2 • 7 • Furthermore, dEl (r 2 dx) may be expressed
formally as 1 / v, since dE I dx in a vicinity of its
maximum can be approximated to v. The highdensity effect is, therefore, much larger than that
estimated by dE I dx especially near termination of
an ion and its maximum should be shifted to thetrack end. In addition, charge-exchange andCoulomb-explosion, which are not included explicitly
in stopping power calculation, become important in
the region mentioned above. What is actually caused
in matter by such high-density excitation is unknown
yet and is considered to be an important problem tobe resolved.
Previously, we measured the track depth-resolved
emission spectra and their decays along the path ofion track in dense helium gas to obtain detailed
information of specific emission dL I dx and its
efficiency dL I dE. Since rare gases give relatively
high emission yields under high-density excitation,
they are most appropriate to our aims. Previous
experimentsl - 3 ) on dense helium gas at 400 Torr and
5 K irradiated with 5 MeV /amu N-ions (track lengthof 11 mm) showed several interesting results. One ofthem is that dL / dE along the track continues increasing in the region of decreasing stopping power
after its maximum value. Is this result explicableby dE I (r 2 dx) or by increase in the probability of
direct excitation and charge exchange? Is this correlated with the new emission bands observed? They
all are essential problems in the initial physicochemical stage of radiation effects in matter. On theother hand, excited states may be quenched at muchhigher density of excitation than the above conditions.
We are also interested in such a quenching process.
The depth-resolution of the previous measurements
was, however, about 0.1 mm, which is too crude to
analyze the region near the maximum stopping power.
Then, we developed a new simple track-scope forthe precise observation of UV- and VUV-emission
intensities with much denser samples. The scope is

bllndlefiber

ions

C-foiI

Fig. 1. Experimental arrangement of a track-scope, an ion
detector, and the cold part of a cryostat.

o

256

512

CH

Fig. 2. Photosensitivities of the track scope along ion-tracks,
measured by sliding 2,537 A light of 0.3 X 10.0 mm.

138

K. Kimura, et al.

composed of a square bundle of 2 X 2 mm of 10,000
quartz fibers. The terminal of the array is coatedwith sodium salicylate to convert VUV light to UVwith a peak at 420 nm and was set close «0.1 mm)
laterally to the ion-tracks shaped with a cross sectionof 0.1 X 2 mm by collimation with a slit. Light fromanother terminal was focused on the photoplate ofan OMA (Optical Multichannel Analyzer byPrinceton Applied Research) for simultaneous counting of photons from each fiber. Thus, the UV or
VUV track-image has a resolution of 20 m and canbe integrated for time without disturbance due toinstability of ion current. To calibrate photosensitivityof the track scope along the direction of ions, 2,537 A
light (0.33 X 10 mm) was projected on different sections of a VUV-sensitive plane of the track-scope.
Figure 2 illustrates a superposition of typical 6 OMAspectra, showing nearly constant photosensitivity.
Experimental data are under analysis.
References
1) K. Kimura: J. Chern. Phys., 84, 2002 (1986).
2) K. Kimura: J. Chern. Phys., 84, 2010 (1986).
3) K. Kimura, M. Kataoka, K. Hara, and T. !ida: RIKEN
Accel. Prog. Rep., 19, 141 (1985).

RIKEN Accel. Prog. Rep. 21 (1987)

111-4-2.

Proton Irradiation Effects on Aliphatic Polymers
T. Sasuga, S. Kawanishi, T. Seguchi, * and 1. Kohno

Polymers used in space as the components andequipments of artificial satellites are subjected toirradiation of high-energy electrons, protons, andheavy ions. The radiation effects are presumed tobe different between ion beams and electron or rrays because of the difference in energy deposition.
Irradiation effects of electron and/or r rays onorganic polymers have been extensively studied at
the request of utilization around nuclear power
facilities, but those of heavy ions are a few, especiallyon mechanical properties. I - B) The main reason forsuch a few data would be due to the lack in irradiation techniques and equipments to evaluate themechanical properties of polymers.
The study was planned to measure the practicalproperties of organic polymers irradiated with highenergy protons in comparison with those irradiatedwith electron. A special chamber was constructed toallow a wide area of polymer films to irradiate
uniformly, and the radiation-induced changes inmechanical properties were studied by tensile tests.
Polyethylene, polypropylene, ethylene-vinyl acetate
copolymer, polyvinylidenefluoride, and tetrafluoroethylene-propylene copolymer, and Nylon 6 wereused in a form of film with 100 pm thickness. Proton
irradiation was performed with a beam of 8 MeV
from the cyclotron in the specially constructedchamber shown in Fig. 1. The specimen mounted
on an aluminum rotor of 50 mm in diameter was
rotated and moved repeatedly along the rotation axis.
By using this apparatus, the specimen can be irradiated uniformly over the area of 157 X 36 mm2 ,which is enough for the measurement of the tensile
properties.
Specimens were irradiated under vacuum with aproton beam adjusted to the size of 5 mm horizontal
and 15 mm vertical. Eight MeV for proton is enoughto pass through a polyer film of 100 pm thickness,because the range of 8.06 MeV proton was reported 4 )to be 1.353 mg/cm 2 • The current of the incident beam
was about 1 pA, and was monitored during irradiation. The total charge was obtained by integrating
the beam current passing through the specimen. The
average fluence rate was about 13 nC/cm 2 /s. The
temperature during irradiation was monitored by athermo-color indicator put on the rotor and thetemperature of specimen was confirmed to be below
60°C.
Electron irradiation was carried out under heliumgas flow with a 2 MeV electron beam from theaccelerator installed in JAERI Takasaki; the electron
fluence rate was 1.07 pC/cm2 /s. The radiation effects were measured by a tensile test under the testing
conditions of a cross head speed of 200 mm/min at
25°C for the specimens cutting into an ASTM 1822
type dumbbell.
For polyethylene the ultimate elongation is shown
as a function of the fluences of 8 MeV proton andpolyethy lene

Fluence giving 112 elongation

8.5,lLC/cm 2

protonelectron

185)LC/cm 2

800
50m1
1-36mm-1
Alminum rotor~.
SpecImen~--. 600tco=;;; 40001Co----<l-W 200
5x15 mmpro ton bea m •move repeatedly
36mm/minFig. 1.

Schematic drawing of the irradiation method.

* Takasaki Radiation Chemistry Research Establishment,
Japan Atomic Energy Research Institute.

o L---1.0- -,-l0-0--2-l0-0--3-'0-0--4----'0'-0--5-0'-0--60 0
L-(for electron)o10(for proton)

2030

Fluence(;.t C/cm 2 )Fig. 2. Ultimate elongation against fluence for polyethylene
films irradiated with electrons and protons.

T. Sasuga, et al.

140

2 MeV electron in Fig. 2. The ftuence gIvmg thehalf value of the initial elongation is 8.5 pC / cm 2for proton and 185 pC/cm 2 for electron, respectively,
indicating that the ratio of radiation effects per one
proton to that per electron is 26.
An absorbed dose D (kGy) of charged particles
for organic compounds is given:

D=8xQ

(1)

8=( - dE/dx) =k Z[ln (2moV2/ 1(1- [j) - [j2]

2
~

~-~

40

~

... 30
..III

oo<r

IfI

~

20

(t-IJ-or--+
~

III
I-

40~

c

...III

30 V;
'0

IfI
C

Q;
>-

10

o

L-~

o

__________~__________

1.0

~~

2.0

800
~

600

c

.~ 400
til
OJ

C

~ 200

w

o L-~0-----------lJ.0-----------2~.~0
Absorbed dose(MGy)(3)

where D c is the dose measured with aCTA (cellulosetriacetate ) film dosimeter. The stopping power forelectron was calculated by Seltzer and Berger method 5 )to be 1.77 MeV cm 2 /g for polyethylene.
The tensile strength, yield strength and elongation
are shown in Fig. 3 as a function of the dose calculated by Eqs. 1 and 3. The changes in the tensile
strength with dose is slightly different between protonand electron, but those of the yield strength andelongation are completely coincident. The otherpolymers used in this study showed no marked difference in the dose dependence of mechanical properties between proton and electron irradiation.
The changes in the mechanical properties of polymer are ascribed mainly to chemical reactions likechain scission and/or crosslinking through excitation,
ionization, free radical formation, and reactions ofactive species. It can be seen from the stopping
powers for protons and electrons that the linear
energy transfer (LET) of proton is about 30 times
higher than that of electron. Since difference in LET
causes the difference in the distribution of ionization

til

a.

~

OJ
C

(2)

where mo is the rest mass of electron, v and carethe velocities of an incident particle and light, f3 is
v / c, and Z and I are mean atomic number and mean
excitation energy of the target material, respectively.
I can be calculated by an additive rule from theexcitation energy of each element constituting themateria1. 5 ) 1 and S of polyethylene for 8 MeV proton
are 56.51 eV and 53.00 MeV cm 2 /g.
The absorbed dose (De) in electron irradiation was
calculated by:
De = Dc X (8 of polyethylene/ S of CT A)?{~ J~~

til

a.

~

where S ( MeV cm 2 / g) is the mass collision stopping
power of the incident particle and Q (pC / cm 2 ) is
the ftuence. The stopping power was calculated byusing Bethe's equation:lJi---t50

Fig. 3. Tensile properties as a function of dose for polyethylene films irradiated with electrons «(») and protons(0 ).

sites even though the total energy deposition is same,the mechanical properties are expected to be different
among the irradiation sources. In contrast with thisconsideration, the findings for several aliphatic polymers showed that there is little or no LET effects
observed in the changes of mechanical properties between proton and electron irradiation.
References
1) B. Santos and G. F. Sykes: Proc. 13th Nat!. SAMPE
Tech. Conf., p.256 (1981).
2) G. Wang, X. Li, Y. Zhu, Q. Liu, N. Hu, X. Gu, andQ. Wang: Nucl. Instrum. Methods Phys. Res. B, 7/8,
497 (1985) .
3) D. R. Coulter, Ma. V. Smith, F. Tsay, and A. V. Gupta:
J. A ppl. Polym. Sci., 30, 1753 (1985).
4) L. C. Northcliffe and R. F. Scilling: Nucl. Data Table,
A7, 255 (1970).
5) S. M. Seltzer and M. J. Berger: Int. J. Radiat. Isot. , 33,
1189 (1982).

141

RIKEN Accel. Prog. Rep. 21 (1987)

111-4-3.

Dosimetry with a Cellulose-Triacetate Filmfor Proton Irradiation

H. Sunaga, T. Agematsu,* R. Tanaka,* K. Yoshida,* and 1. Kohno

Recent application of ion-beam irradiation forstudies on material science and radiation chemistry
requires an ion-beam dosimetry for high doses andhigh dose-rates.
Ionization chambers have been used so far mainlyfor proton-beam dosimetry in the field of radiation
therapy, but are difficult to apply to the higher doserate region for studies of material science.
Film dosimeters widely used for radiation processing with electron beams ,and r rays are suitable forthis purpose because of the high spatial resolution
and simplicity of the measurement. We tried toapply a cellulose-triacetate (CT A) film dosimeterl )used mainly for electron-beam dosimetry to proton
irradiation and compared the basic dosimetriccharacteristics for proton beams with those for electron beams. 2 )A commercial CT A film dosimeter, FTR-125 ofFuji Photo Film Co., Ltd. of 125 pm in thickness,
was used. The dosimetry is based on the linear dose
response of radiation-induced optical densities at
280 nm. The dose response was measured mainly witha CTA film dose reader FDR-Ol, and two-dimensional dose distribution was measured with a doublescanning micro-spectrophotometer. CTA films were
irradiated in vacuum with protons of 5, 8, and
15 MeV from the cyclotron.
A rotation-type irradiation apparatus was attachedto the beam course No.2 for the uniform irradiation over a wide area to give the same dose. It
provides a cylindrical film holder made of aluminumof 50 rom in diameter, which is rotated 120 rpm andsimultaneously scanned mechanically between two
points separated by 36 rom at a speed of 36 rom/min
along the rotation axis perpendicular to the directionof the proton beam. The total charge impinging on
the sample holder is measured with a current
integrator.
The proton fluence was calculated from the total
charge and the effective irradiation area given by
the product of the circumference of the cylindricalholder and the scan width on the rotation axis. The
absorbed dose of the CTA sample exposed to the* Takasaki Radiation Chemistry Research Establishment,
Japan Atomic Energy R esearch Institute.

proton beam was given from the product of themass stopping power in CTA and the proton fluence
onto the sample. The stopping power was calculated
by using "OSCAR 84" developed by Rata. The
calculated values for 5, 8, and 15 MeV protons are ,75.0,51.8, and 31.3 (MeV·g-l·cm 2 ) , respectively.
Figure 1 shows the relationship between the absorbed dose and the radiation induced optical density(LlOD) in the CTA film (FTR-125) in comparison
with the result obtained with electron beams. The
radiation induced optical density for proton beams
increases lineary with dose up to 300 kGy. The valueof L10D per unit dose (K value) is 0.063 (10 kGyr l

III

2.0

Cl

C
!tI

-B 1.5
>-

~

.~

~ 1.0

o 15MeV protons• BMeV protons
A
5MeV protons
2MeV electrons

III
"C

~ 0.5
.~

~

0.

o

0~---.l-----.....L.--

o

100

200

Absorbed dose

_ _-.1..._ _
300

(kGy)

Fig. 1. Relation between the absorbed dose and the radiation induced optical density at 280 nm of a CTA dosimeter exposed to 5, 8, and 15 MeV protons.

.

"1\ ~~. ~~

I~

I\.
',rtr

\

'--

~

,,-v----'":2-:='I~

I ',-J ......-II~,.-----;::::. ~ (/,

.,
CI)

-4

o
o

15

X (mm)

0030

Fig. 2. An example of the two-dimensional dose distribution
in a CTA sheet exposed to 8 MeV protons.

142

H. Sunaga, et al.

for 8 and 15 MeV, which is the same as the value
for electron beams. The K value for 5 MeV issmaller than the value for 8 and 15 MeV by about
10%.
The above result suggests that there is no differencein LET effect between a high-energy proton beam
and an electron beam, but the LET dependence may
be appreciable in a CTA film dosimeter for protons
lower than 5 MeV. A similar LET dependence wasobserved in a Radiachromic film dosimeter. S)
Figure 2 shows a typical example of equi-dose
maps in the cross-section of proton beams obtainedwith a CTA film exposed to an 8 MeV proton beam
passed through a beam aperture (20 mm X 20 mm).
The result shows that it is necessary to uniformize
the lateral dose distribution in the film sample for a
dosimetric study.
Figure 3 shows the depth-dose distribution in astack of CTA films exposed to a 15 MeV protonbeam. Precision in determining the depth-dose profile
will be enhanced by using thinner CTA films.
From the results described above, the CTA film
dosimeter is found to be useful for dosimetry anddose mapping for proton irradiation in the high dose
range from 10 to 300 kGy. It will be necessary to
study the dosimetric characteristics on higher LET

250
200

15MeV proton{; 150
,:,t.

ClJ
til

100

o

o

50
100

200

300

Depth in eTA (mg/cm 2 )Fig. 3. An example of the depth-dose distribution in a stackof eTA sheets exposed to 15 MeV protons.

radiations, such as heavy ions and low energy
protons, with thinner CTA films.
References
1) R. Tanaka, S. Mitomo, H. Sunaga, K. Matsuda, and
N. Tamura: JAERI-M (in Japanese), 82-033, Japan
Atomic Energy Research Institute (1982).
2) H. Sunaga, T. Agematsu, R. Tanaka, K. Yoshida, and1. Kohno: Radioisotopes (in Japanese), 37 (2), 83-86(1988) .
3) J. W. Hansen and M. Wille: Radiat. Phys. Chem., 23,455 (1984).

143
RIKEN Accel. Prog. Rep. 21 (1987)

111-4-4.

Position Determination by Laser Marks of B. subtilis
Spores Placed on a Plactic Track Detector andInactivation of the Spores by a Single Heavy Ion
T. Takahashi, F. Yatagai, T. Katayama, S. Konno,
K. Izumo, 1. Kaneko, and T. Kasuya

F or better understanding of the mechanism of cell
inactivation induced by heavy ions, we carried out
experiments to characterize the microscopic structureof the radiation action nearby a single heavy ion.
This has been done by measuring the fraction of deadspores as a function of the distance between thecenter of the path of an ion and spores around it,
but the precise position of the spores in relation to an
ion track is very difficult to determine. Few years
ago we succeeded in marking scratches on a plastic
detector by using a micromanipulator. The technique
has been intensively employed by Bucker and his
group for the marking on cellulose nitrate (CN)track detectors. I ) Recently, a further improvement
has been made in laser marking on CR-39-type plastic
detectors, providing etch pits clearer than those of
CN detectors. The CR-39 track detectors were dyed
to be opaque to 355 nm, the third harmonics of a
YAG laser. B. subtilis spores were fixed with a 5 %polyvinyl alcohol solution on the plastic detector, andthen reference grid-like marks were printed with a
UV laser beam on the dyed detector. After irradiatedwith Ar ions from the RILAC, the spores werecovered with a nutrient agar film. A photograph
was taken to check the outgrowth for the spore after
incubation at 37°C. The detectors were immersed
in a 6 N-NaOH solution at 70°C. Etch pits were
found to be sufficiently developed in 30 min for--25 MeV Ar ions and in 2 h for --60 MeV N ions.
The position of the spores in relation to the track
etch pits was determined sometimes to better than
0.2 pm, but was estimated on the average to about
0.5 pm. For the constant accuracy to 0.2 pm, further
improvement is necessary. The present technique will
be applied to investigate the effects of high Z and
high-energy particles on living cells during the spaceflight (IML-1 mission) in 1991.
The fraction of dead spores is shown in Fig. 1 asa function of the distance from the particle track of
Ar ions and in Fig. 2 for N ions. To date, wecannot decide whether or not there is a statisticallymeaningful increase in the fraction of dead spores in
the range of 0.5- 1.0 pm compared with the control
level (see Fig. 1 (A) and (B)). If the fraction of

0.6~ 0.5 - : B

c&0.4 ::

<Il

"'0
ctI

:

o

0.3

~

.~ 0.2
()

ctI

~ 0.1
O~~

o

AJ

,,

,,

I" control__~__~__~__L-~___
2

3

4

5

6!J.m

Fig. 1. Fraction of dead spores as a function of the distancefrom the etch pit of an Ar ion. (A) Bold solid line,--25 MeV Ar observed by A; (B) Dotted line, --25 MeV
Ar observed by B corrected by T; (C) Thin solid line,--56 MeV Ar from Ref. 3.
<Il... 0.5
q)

0

0<Il

0.4

"'0
ctI
q)

"'0

~
~

0.3
0.2

·3 0.1-control

()

...

ctI

~

0
0

1

2

3

4

5

6

!J.m

Fig. 2. Fraction of dead spores as a function of the distancefrom the etch pit of an N ion. Scratched marks were used
for the determination of the position of spores.

dead spores really exceeds the control level, thermal
spikes or shock waves produced by a heavy ion 2 ) may
be responsible for the inactivation since the range ofa-electrons from --25 MeV Ar ions in the plastic isless than 0.2 pm. As shown in Fig. 1 (C), Schafer
et at. 3 ) observed a conspicuous increase in the fraction of dead spores at 2.5-4.0 pm for --56 MeV Arion irradiation, in contrast to our result; the discrepancy might be due to the different experimental
conditions. They 4) also claim that the inactivation
probability is considerably lower than unity at small
impact parameters. Here, the impact parametermeans the distance between the center of the spore
and the path of an ion and the present experimentis in accordance with their result. However, thesmall impact parameter does not always mean a direct

144

T. Takahashi, et ai.

hit. In case of direct hit, the amount of energy
deposited by an Ar-ion traversal corresponds to a dose
whereby at least 90 % of the spores will be inactivated. For distinguishing a direct hit from thehits at small impact parameters, the accuracy ofthe position must be less than 0.2 pm, because radiusof the spore core in which DNA is contained is considered to be about 0.25- 0.3 pm. Furthermore, it is
not always guaranteed that the spore core is locatedat the center of the spore coat whose shape is visible
under the microscope, whereas the spore core is not.
If yeast is used in such an experiment, it would
be easy to distinguish a direct hit, because yeast ismuch larger in size than the spore. A preliminary
test for yeast (Saccharomyses serevisiae) is now inprogress.
References
1) M. Schafer, R. Facius, K. Baltschkat, and H. Biicker:
7th Symp. on Microdosimetry (1980).
2) T. Takahashi, F. Yatagai, T. Katayama, Y. H. Kang,
S. Tamada, I . Kaneko, and S. Okada: RIKEN Accel.
Prog. Rep., 17, II" (1983).
3) M. Schafer, R. Facius, and H. Biicker: Proc. 10th Int.
Conf. Solid State Nuclear Track Detectors, p.l055(1980) .
4) M. Schafer, R. Facius, and H. Biicker: 8th Symp. on
Microdosimetry (1983).

"

145

RIKEN Accel. Prog. Rep. 21 (1987)

111-4-5.

Mammalian Cell Inactivation and DNA Lesion
Caused by Charged Particle Beams
K. Eguchi-Kasai, T. Kosaka, I. Kaneko, T. Takahashi,
A. Maruhashi, and K. Nakano

Mammalian cells are more sensItive to charged
particle beams than torays or X rays. The
absorbed dose required to reduce the cell survival
fraction to 37(Ds7) is in the range of 2-5 Gy in
60CO r rays and about 1 Gy in charged particles.
Moreover, the dose-survival curve (natural log ofsurviving fraction as a function of radiation dose)for charged particles is nearly linear whereas it isconvex for r rays. Ritter et al. insisted that nonrepairable DNA breaks resulted in cell death because
an excellent correlation was held between theefficiency of single-hit cell killing and the inductionof non-repairable DNA strand breaks over a linear
energy transfer (LET) range of 1-1,953 keY j p.m. 1 )The non-repairable DNA breaks assayed in theirwork, however, cannot be directly related to thecell death, because they used heavy ions of fairly
higher doses ( up to 450 Gy) than the dose to
examine survival (up to 15 Gy) to induce DNA
breaks. A recent study showed a similar relationshipof DNA breaks between LET and the relative
biological effectiveness (RBE) at low doses (20 Gy) .2)
These results did not explain the difference in the

Table 1. LET of radiations in water.

r

LET (keV/pm)
77

radiationa particles (HMV-I)(HA-l)
N ions60Co r-rays

ro

36
530

0.3

shape of dose-survival curves for low- and high-LET
radiations and did not show even the nature of
non-repairable DNA breaks. We have shown thata N-ion beam induces more single strand breaks andDNA-protein crosslinks than X rays.S) Here we examined the DNA double strand breaks (DSB) induced by a particles and N ions in comparison withthe cell killing in 2 mammalian cell lines whichshow a different radiosensitivity to 60CO r rays.
We used HMV-I cells derived from human melanoma (tumor cells) and HA-l cells derived fromchinese hamster cells ("normal" cells). Nitrogenions and a particles (0.8-2 Gy j min) from RIKEN
Cyclotron and 60CO r rays (1.4 Gy jmin) wereused. The irradiation procedure for particle beams
was previously described. 3 ) Beam currents were

Do 5 eo (Gy)
(B)

3
.n
Ul

'0
<II

fW-I~ Cl

V

:a
0.1

c

e

/1

'0

~ 2

0

I

u
0

o

I'

vi : '

C

....

lI..

o
c

v

>

c

....
:;,

v;' ,,/

QI

C'I

>>

; 0./

c

0.01

:g
0.001

U1

(ij

a:

0

/.'~'

I:>
/1:>

r;f/ I:> 7iF~./;"I:>/1:>./1:>/80-/./ • °°.
_.0 __ _---0

HW-I
Y-RAYS~o0.0001

,:/0
,?,,;

/.~/

o

-

_1)-

0

HA-l. Y-RAYS

50

100

Dose (Gy)Fig. 1. Dose-survival curves (A) and a relative number of non-repairable DNA
double strand breaks in mammalian cells (B). 0, HA-I cell after r-ray irradiation;. , HA-l a-particles; 1:::", HMV-I r-rays; 0, HMV-I N-ions; \l, HMV-I a-particles.
The lines in figures were fitted by least-squares method. One unit of the ordinate
in (B) corresponds to approximately 600 non-repairable DNA dsb per cell.

150

146

K. Eguchi-Kasai, et al.

monitored with a Faraday cup and transmission
ionizing chambers during irradiation. The LET
values in water were listed in Table 1. Cells were
irradiated at room temperature in most cases except
for the test on DSB induced immediately after
irradiation where cells were irradiated on ice. DSB
was detected by a neutral elution technique,4> which
detects DNA breaks very sensitively. The relative
numbers of DSB are plotted against the absorbed
dose and the curves were fitted to a linear-quadratic
relationship by a least-squares method.
The number of DSB induced by r ray was compared between 2 cell lines which have different r ray
sensitivities; HMV-I cells were more sensitive to r rays
than HA-l cells. The number of DSB was found independent from the radiation sensitivity of cell, because DSB was induced as much as or slightly more
in HA -1 cells than in HMV-I cells (data not shown) .
However, about 60-90 % of the total DSB was
rejoined during post-irradiation incubation at 37°C.
Remainder can be considered to be non-repairable.
It was shown that more number of non-repairable
DSB was induced in HWV-I cells than in HA-lcells by r rays (Fig. 1 (B) ). Number of non-repair-able DSB in both cells increased quadratically withthe dose of r rays, whereas it increased linearlywith the dose of charged particle radiation. These
results correspond to data of cell survival curves(Fig. 1 (A)) and also indicate that a non-repairable
DSB is induced by a single hit of a charged particle,
whereas two hits on duplex DNA at the same or a'quite near' point are necessary for r rays.
We found that the amounts of non-repairable DSB
in the two cell lines at the same survival levels arealmost same without regard to cell lines and to thequality of radiation. These results show a close relationship between the cell inactivation and thenon-repairable DNA DSB.
References
1) M. A. Rittel", J. E. Cleaver, and C. A. Tobias: Nature,
266, 653 (1977).
2) R. Roots, T. C. Yang, L. Craise, E. A. Blakely, and
C. A. Tobias: Radiat. Res., 78, 38 (1979).
3) K. Eguchi, T. Inada, M. Yaguchi, S. Satoh, and I. Kaneko: Int. J. Radiat. Biol., 52, 115 (1987).
4) M. O. Bladely and K. W. Kohn: Nucl. Acid Res., 7, 793(1979) .

147
RIKEN Accel. Prog. Rep. 21 (1987)

111-4-6.

Oncogenic Cell Transformation of Golden Hamster Embryo
Cells by Heavy Ions
M. Watanabe, M. Suzuki, K. Suzuki, and J. Kaneko

The major objective of the present study is tounderstand the potential carcinogenic effects of cosmic
rays and the mechanisms of radiation-induced celltransformation. During the past several years, wehave studied the induction of oncogenic transformations by X rays in primary cultures of golden hamster
embryo (GHE) cells and established the relationshipbetween absorbed dose and the frequency of transformation over the dose range from 0.01 to 6 Gy.l)
This study is designed to examine the efficiency ofradiations by heavy ions in producing oncogenic celltransformations.
We used diploid GHE cells cultured for 13 to 14
day-old embryos. The tissue culture techniques for
obtaining GHE cells was modified from that previously described. 1 ) Cells were grown in Eagle's
minimum essential medium supplemented with 10%
fetal bovine serum. The transformation assay used inthis study was reported previously. 1-3) Briefly, after
irradiation, about 60 viable cells per dish of 60 mm
in diameter were inoculated into dishes containing
feeder cells and were grown for 10-12 days, before
being fixed and stained with a Giemsa solution.
Although a heterogeneous population of colonies wasobserved in this system, the end point used for
determining the transformational change was theappearance of morphologically altered colonies, whichwere observed only a very low frequency in control(< 5 X 10-4 ). Transformed colonies were readily distinguished by their morphological change according
to the criteria that the cells in the transformed colony
piled up to from densely stained colonies with acharacteristic criss-cross pattern at the periphery (typeB colonies) .1) Cells derived from type B colonies
were tumorigenic. In parallel to the transformation
study, a survival study was carried out by using
the colony-forming method. The transformation
frequency was determined by dividing the number oftransformed colonies by the number of survivingcolonies.
The survival curves for cells exposed to various
kinds of radiations are shown in Fig. 1, whichindicates that N ion (95 MeV) and a particles(22 MeV) give curves exponential to the dose overthe entire dose range examined (0-6 Gy). In contrast the survival curves for X rays and r rays from

137CS have broad shoulders at low doses, but approximate to exponential functions of dose at high doses.
Figure 2 shows RBE for cell killing of various radiations relative to X rays (182 kVp). RBE for heavy
ions apparently vary with the cell killing level atwhich the comparison is made. RBE for heavy ionsdecrease with increasing cell killing. However, theRBE of r rays from 60CO and 137CS to X rays are
not greatly different in cell killing. The data forcell transformation as a function of dose following
exposure to X rays or r rays from 137CS are presented

DOSE(GY)
01234567
1~~~~~--~~~--~

0.5

z

oi=

0.1

~ 0.05LL

G
Z:> 0.01:>
a: 0.00
::l

U)

0.001
Fig. 1. Dose-response curves for GHE cells irradiated withvarious radiations. The data points plotted are the meansof replicate experiments.

4
3

w
£02
a:
1
o~----~----~-----.----,

1.0

0.5
0.2
0.1
0.05
SURVIVING FRACTION

Fig. 2. RBE relative to X rays for cell killing of GHE cellsby various radiation.

148

M. Watanabe, et al.

(xlO- 3 )

4

ci
w

a:
lL.3

z

o

fi

::a: 2
a:

f2en

Zl

«
a:
~

o
02468
DOSE(GY)
Fig. 3. Dose-response curves for cell transformation by X
rays and r rays from 137CS. The data points plotted are
the means of replicate experiments.

in Fig. 3. The general shapes of induction curvesof transform ants were almost the same for X rays
and r rays from 137CS. At shoulder doses «2 Gy),

the transformation frequencies increased steeply withincreasing dose. At doses higher than 2 Gy the frequencies of transformants increased only slightly.
When the transformation frequency per survivor
induced by an X rays dose that gives a 50 % lethality
is taken at the reference point, the RBE for r raysfrom 137CS was found to be about 0.78 (2.3 X 10-3 /2.0 X 10- 3 ). This value is about same for both cellkilling and oncogenic transformation for X rays.
We continue to investigate the oncogenic transformation effects of heavy ions. An understanding of
the carcinogenic potential at low doses of a variety
of radiations is of great help in assessing the cancer
risk to environmental and occupational exposures.
References
I) M. Watanabe, M. Horikawa, and O. Nikaido: Radiat.
Res., 98, 274 (1984).
2) M. Watanabe, O. Nikaido, and T. Sugahara: Int. ].
Cancer, 33, 483 (1984).
3) M. Watanabe, N. Suzuki, S. Sawada, and O. Nikaido:
Carcinogenesis, 5 1293 (1984).

149
RIKEN Acce1. Prog. Rep. 21 (1987)

111-5.

Instrumentation
1.

Data Acquisition System at RIKEN Ring Cyclotron Facility
T. Ichihara, T. Wada, and T. Inamura

The project of the construction of the data acquisition system at RIKEN Ring Cyclotron Facility started
in spring 1985. In the beginning of 1986, we prepareda test bench system consisting of a DEC Micro VAX
II computer and aCES 2180 Auxiliary Crate Controller. The basic design was settled also during thesame period. In August 1987, the half part of thesystem was installed (VAX computers), and in
January 1988 the remaining part of the system(FACOM M-380 computer) was installed. The
overall turning of the system is now in progress.
Figure 1 shows the configuration of the dataacquisition system. This system is a hierarchical multiprocessor system: CAMAC interface, fast front-end
processors (CES 2180 ACC), local processors (VAX),
and a host processor (FACOM M-380). Each datafrom the counters is digitalized by the CAMAC
modules. Data from the CAMAC module are readby the front-end processor event by event andbuffered. When the buffer is full, the buffered data
are transferred to the local processor by the Direct
Memory Access (DMA). At the local processor,
data are monitored and analyzed in real time and

CCP: Communication control Processor
BMC: Block Multiplexer (3MB/s)
SCL: Serial Channel Link
DACU: Device Attachment Control Unit..........- - - , ....... ACC: Auxiliary Crate Controller (111 CPU)

recorded in magnetic tapes. Furthermore, the data
are transferred to host processor.
(1) Front end processor-CES 2180 Auxiliary
Crate Controller (ACC)
CES 2180 ACC is a single-span CAMAC module.
This module reads data from CAMAC modules eventby event, triggered by the interrupt signal. Typical
CAMAC read time is about 2 f1.S for 16 bit data
including the software. When the buffer is full, thismodule sends an interrupt signal (LAM) to the local
processor and changes the buffer and continues thedata acquisition. The data is then transferred to the
local processor by D MA.
Figure 2 shows a block-diagram of CES 2180 ACC.
This module consists of DEC J11 CPU (one chip
PDP-ll micro processor), 128 kB static RAM, andsome interface circuits to CAMAC bus and external
Q22 bus. The overhead of the interrupt service
routine is very small (about 10 f1.S including saving
all the resisters) to minimize the dead time.
In order to extract the maximum performance,
the data acquisition program on this front-end processor is written in PDP-ll Macro Assembler. The
development of the program on this processor andassemble and link is carried out on the local processor(VAX/Micro VAX) using VAX/RSX (PDP11
emulator) software. The task image is on-line downline loaded from the VAX computer to the memoryof the 2180 ACC via the CAMAC data way. This

to Local Processor(MAX 7 crates) I(MAX 8 crates) I(MAX8crates).

Fig. 1. Data acquisition system at RIKEN Ring Cyclotron.
5 February 1988.

Fig. 2.

Block diagram of CES 2180 ACC.

T. Ichihara, et al.

150

4692 Colour HC

Fig. 3. Configuration of the Micro VAX II based local
processor system.

on-line down-loading mechanism enlarges the flexibility of the data acquisition.
(2) Local processor-DEC Micro VAX II/VAX
8350 computer
Buffered data from the front end processor aretransferred to the local processor in DMA via the
CAMAC crate controller; the data transfer rate isabout 1 MB/s. We prepared three local-processor
systems (two Micro VAX II system and one VAX
8350 system) to enable two experiments and program

development or experimental preparation simultaneously.
On-line data monitoring and data recording are
carried out in the local processor. Finally, raw data
are recorded in 6250 BPI magnetic tapes. Data canbe also transferred to the host processor in DMA via
the DR (V) -11 W interface, a Device Attachment
Control Unit (DACU), and Block Multiplexer(BMC).
Raw data are analyzed and displayed on a color
graphic display (Tektronix 4125K, 4207) , and color
hard copies are available (Tektronix 4692 and 4696).
Many personal computers (Macintosh and PC9801)
are also used as graphic terminals.
The operating system on the local processor is
VAX/VMS which supports the real-time and time
sharping system simultaneously. Most of the programs
are written in FORTRAN. The on-line data taking
and analyzing tasks are consisted of(1) DMA control (data transfer) task;(2) Command interpretation and execution task;(3) On-line data analyzing task; and(4) Data display tasks.
These are running in a real-time multi-task environment with proper priorities. Figure 3 shows a typicalconfiguration of the Micro VAX II.
(3) Host processor- F ACOM M-380 Mainframe computer
A host processor is used for the on-line very com-

X, 2 5(48kbps.

SHA-GATEWAY(48kbps ,RS - 232C
x 16(- I 9 20 0 bps

F624JXX : F62UNIJ

PS2UMSIF6H2YV : P6242KB2
FS242AIIfS242JS
F62WIC

6, 8 G B

F6242ZZ : F6242KB2
F6242A II
F6242JS~~

Fig. 4.

Configuration of the host processor (FACOM M-380).

A V R

T. Ichihara, et al.

plicated data analysis as well as for the off-line data
analysis. The speed of this CPU is about 23 million
instructions per second (MIPS). Figure 4 shows theconfiguration of this system. During experiments, raw
data from the local processor (VAX/Micro VAX)
are transferred to the channel adapter (BMC) of
the host processor via Device Attachment Control
Unit (DACU) , which is a standard interface between
VAX and an IBM main frame computer. The effective data transfer rate is 400 kB / s.
This computer has a hierarchical mass storage:
24 MB main memory, 6.8 GB disk system, 48 GB
cartridge library system (CLS) , and three 6250-BPI

151

200-IPS magnetic tape drivers. The data transferredfrom the local processor are stored in a disk andanalized in real time. The CLS are used as thesecondly disk system. The file transfer between thestandard disk and CLS are carried out automatically.
DECnet-SNA gateway enables the network connection between host and local processors via ethernet.
File transfer using the remote job entry (RJE) andremote login using a 3270 tenninal emulator areavailable. Packet switching data network link using
an X.25 protocol (NTT DDX-P, KDD VENUS-P)
is also available at 48 kbps.

152
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-2. Cyclotron Cal ibration Test of Position Sensitive Detectorsfor Heavy Cosmic Ray Telescope in Space
T. Kohno, T. Imai, K. Munakata, T. Doke, J. Kikuchi,* T. Kashiwagi,
H. Murakami, T. Motobayashi, A. Nakamoto, T. Yanagimachi, N. Hasebe, and K. Nagata

Techniques of a .dE-E telescope of silicon solidstate detectors are useful for the observations ofelemental and isotopic compositions of cosmic ray
heavy particles. A large geometric factor of thetelescope plays an essential role in the observations
In space.
A wide acceptance angle, as well as a large detection area, is necessary to realize a large geometricfactor of the telescope. Slant incidences in a telescope
having a wide acceptance angle, however, smear the.dE information by broad pathlength distribution. In
order to have a large acceptance angle without
smearing the .dE information, we need to know theparticle incident angle by getting the positions atappropriately separated two detectors. Recently newlarge position sensitive detectors (we call PSD hereafter) with good linearity became available from
Hamamatsu Photonics Company, and its characteristics are examined with cyclotron beams.
The PSD is of an ion-implanted type with asensitive area of 45 rom X 45 mm, thickness of 400 pm

and junction capacitance of 500 pF; the shape isshown in Fig. 1. The position signals are taken out
from the electrodes at the four corners of an ionimplanted anode side, where the surface resistivity
and the line resistivities of the strips at the foursides are formed. 1 ) The position of the incident
particle can be expressed by

X= (A+B)-(C+D) .~A+B+C+D2(1)

y= (B+C)-(A+D).~

A+B+C+D(2)

2

where A, B, C, and D are the charge signals fromelectrode and L is the length of one side. The originof the coordinate (0,0) is set at the center of the512.----------------------------.
a

BB Me V N ions , .=3 j.L s

b a
I--<H

UJ

I-

Z
:J

o

U

o

o
OL---~------~~~--~~~---J
o
50
100

t ' i + - - - - 45 nun -----t-+tl

ENERGYo(MeV)

512.------------------------------.
b

95 MeV N ion s,.=11.5 j.L s .

UJ

IZ

o

:J

o
U

s ide strip

o

o
o

A

50

ENERGY

Fig. 1. Schematic view of the PSD. The surface resistivityof 18 kO is surrounded by side strips of 1.5 k n each resistivity. Four signals can be taken out from the four
corners while the energy signal can be taken from rearside. The effective area is 45 mmX45 mm and the thickness is 400 /lm.

* Science and Engineering Research Laboratory, Waseda
University.

100

(MeV)

Fig. 2. Energy spectra in N ion experiments. a, Accumulated data of four position signals for 88 MeV. The pulse
shaping time is 3/ls; b, Energy signals from rear the sidefor 95 MeV beam. Shaping time is 11.5/ls. The pulse
height ranges indicated by two horizontal bars named aand b correspond to the data groups used in a and b ofFig, 3, respectively. All N ions with these energies will be
stopped in PSD.

153

T. Kohno, et aI.

detector. We used a He beam with energy of 40 MeV
and N beams with 88 MeV and 95 MeV. While N
ions of both energies will be stopped in PSD, Heions can penetrate it, therefore, we used a Si(Li)detector of 1 rom in thickness and 3" in diameter as
an energy detector behind PSD. In front of PSD,
we put a multi-slit collimator consisting of 9 X 9 holesof 0.5 rom~ disposed in a ckeckered pattern having
a 5 mm adjacent distance. The material of the collimator is 0.6 mm thick phosphor bronze.
A main beam was scattered with a 4 flm Au foil
target, and the detector system was set at a 30°
scattering angle and at 30 cm apart the target. Eachsignal was recorded on a micro computer througha CAMAC system. Four different pulse shaping time
constants of 1.8 fls, 3 fls, 5 flS and 11.5 fls were
tested.
Figure 2 shows the energy spectra of N ions in the
PSD for two shaping time constants of 3 fls and11.5 fls. The spectrum with 3 fls shaping time iscomplicated and shows a broad distribution, but thatwith 11.5 flS shaping time shows a narrow single peakwith FWHM of 2.3 MeV. With such a large detector,
the time necessary to collect the whole charge varies
with the incident position of particles. That is tosay, the closer the ion position to the side strip orthe electrode itself, the faster the charge collection
to the electrode. If the pulse shaping time constantis smaller than the time scale which we need tocollect the whole charge, the obtained pulse height

will be lower than that from the larger shaping time
constant. We can obviously see this effect in Fig. 3,
where the pulse heights from nearest particles to theeach side strips or each electrode itself are clearlyhigher than those from the other positions. The
reason why the spectrum has a two distinct peaks
instead of broad distribution may be attributed tothe difference in the distance from the side strip to
the first row and the second row is discrete.
Two examples of the position data for He ions
are shown in Fig. 4, which also shows the position
resolution dependence on the shaping time constant.
Since we used Si(Li) detector behind PSD in the
He-beam experimen t, the da ta taking system was
triggered with a pulse from the Si(Li) detector. The
detector size of 3" in diameter cannot cover thewhole PSD, and this effect can be seen in Fig. 4 as
the data absence at each corner of the PSD.
We obtained the quantitative position resolutionof each measurement from the average of FWHM of
Gaussian fitting of each slit data. The resultant position resolutions of all measurement are listed inTable l.
The position non-linearity (deformation of themulti-slit image on the position data plots) is also
important for our final purpose of cosmic-ray observation. Here we define the position non-linearity as. ~•'!i'.' •

.)l:

' :'"

".:':.

.... " •••••.•••.......'.....
., .
.'
.
•
.
..... .
• .• • *"•••a. ... ."

...

..

'l'.~

. .

~ ·" ;~.: 4

,*.

"'~.

.", .. • • • ~ :+ • •

.-

.,

-1

-1

~

.~

'

'.~

~

~.

..,.
".

x

x

... .

. '.. .. . . . ..
--.. . .

).

. .. .. . .

•

-1

'"

tI

•

•

•

•

•

•

..

•

•

"t

x

Fig. 3. Positions calculated by Eqs. I and 2 for the two datagroups indicated by the horizontal bars in Fig. 2a. The L
of Eqs. I and 2 is assumed tentatively to be 2.

-1

x
Fig. 4. Position data (same as Fig. 3) for He ions. Pulse
shaping time is 1.8 p,s for a and 5.6 P.s for b. The energy
deposition of the ions in the PSD is 15 MeV. The datataking system is triggered with a pulse from a Si (Li)detector located behind the PSD. The size of the Si (Li)detector of 3" in diameter cannot cover the whole PSD;
hence there are no data at the corners.

T. Kohno, et al.

154

Table 1. Summary of position resolutions and nonlinearities.
Ion

Energy(MeV)

Shaping
time
(ps)

N
N
He
He
He

88
95
15*
15*
15*

3.0
11.5
1.8
5.6
11.5

NonPosition res.
linearity(FWHMinmm) (rmsin mm)
0.42±0.12
0.71 ±0.13
1.03±0.55
1.97±0.71
3. 35± 1.01

0.097
0.054
0.109
0.086
0.134

the root mean squares of the distances from the realslit position to the measured position plotted in Fig. 4,
for example. Above defined non-linearities obtained
from all measurements are also shown in Table 1.
From a series of cyclotron experiments, we reachthe first conclusion that the newly developed PSDs
have good enough characteristics for our final purposeof cosmic-ray observation in space.
Reference* Energy deposited in the detector by He ions with an
initial energy of 40 MeV.

1) T. Doke, J. Kikuchi, H. Yamaguchi, S. Yamaguchi, andK. Yamamura: Nucl. Instrum. Methods A, 261,605 (1987) .

155
RIKEN Aceel. Prog. Rep . 21 (1987)

111-5-3.

Design of an Isotope Separator On-Line System at
RIKEN Ring Cyclotron

K. Morita, T. Inamura, K. Valli,t T. Nomura, J. Tanaka, H. Miyatake,
K. Sueki, Y. Hatsukawa,* M. Fujioka, T . Shinozuka, K. Taguchi,** H. Kudo,
Y. Nagai, T. Toriyama,*** H. Hama, M. Yoshii,**** and K. Furuno
An ~otope ~eparator ~n-~ne (ISOL) system is
now under construction at the E 1 experimental hallat ~IKEN ~ng Cyclotron (RRC) facility. The aimsof constructing this ISOL system are to search for
new isotopes which will be produced with highenergy heavy-ion beams from RRC and to get new
structural information of such unstable nuclei. We
report here the characteristics of RIKEN ISOL
system.
This ISOL consists of two parts. One is a gasfilled Eecoil ~otope ~eparator (GARIS) and the otheris an ion-~uide isotope ~eparator .~m-Ene (IGISOL).
The main role of GARIS is to separate reaction
products from beam particles and to transmit themto IGISOL with a high efficiency. GARIS can also
be used by itself as an isotope separator with amoderate resolving power. The principle of GARIS
is as follows. Reaction products recoiled out of atarget have broad distributions both in charge andin momentum. When they enter a dipole magnet
filled with low pressure gas, they follow average
trajectories corresponding to their momenta and an
average charge (q) defined by their multiple collision
with gas atoms. Because q is roughly proportional tothe velocity, the average trajectory is almost independent of the initial distributions of momentum
and charge states, but depends only on their mass(A) and atomic number (Z). That isq- oc -v x Z avo(1)

which V is the velocity of a recoiled atom and
Vo is the Bohr velocity (vo = c /137). The value of
a is 1/3 according to the theoretical consideration
by Bohr, but Miyatake et al. 1 ) give the value of 0.57
from their experimental study. The magnetic rigidity(Bp) can be written as
IIIt On leave from Jyvaskyra University, Finland.

* Institute for Nuclear Study, University of Tokyo.
** Cyclotron and Radio-Isotope Center, Tohoku University.

*** Photon Factory, KEK.
**** Tandem Accelerator Center, University of Tsukuba.

A

Bp=O.084x ZO.S7 (T·m)(2)

The IGISOL technique was developed by Arjeet at. 2 ) as a new method of ISOL for the light-ion
induced reactions, and then developed to apply tothe heavy-ion induced reactions by Morita et ai. 3 )A prominent advantage of IGISOL is that its operation is almost independent of the chemical andphysical properties of elements and, therefore, it canbe applied to study all elements equally well. A
principle of IGISOL is as follows: the reaction
products recoiled out of a target are stopped in achamber (thermalization chamber) filled with heliumgas (,-100 Torr) and go out through a small exit
hole of the chamber. Atoms of the reaction productare singly chargedf for some time even after they
are thermalized in the helium gas. These singly
charged atoms are extracted through the exit holeby a gas flow and transported to an accelera tingregion where the pressure is low enough (,-1 X 10-4
'forr) through a skimmer having a negative potentialof several hundreds of volts relative to the thermalization chamber.
The effect of the plasma formed along the pathof the incident beam in the thermalization chamber
was studied by Morita et at. 3 ) and found that theefficiency decreases with the increase in the densityof the plasma. Therefore we decide to couple
GARIS to IGISOL in order to eliminate the incident beam and to get a high collection efficiency
for the study of rare events. This combination,GARIS + IGISOL, was tested by Nomura et al. 4 )and proved to work well even when large (,-40 cm 3 )thermalization chambers are used. From this result
it can be deduced that the lifetime of singly charged
28Al ions in helium gas is more than 50 ms.
1) GARISGARIS consists of a D-Q-Q configuration asshown in Fig. 1; the characteristics are listed inTable 1 together with those of the dipole magnet of
IGISOL. We have two target positions in GARIS.
One is placed at the input pole boundary of thedipole magnet and the other is placed at 0.7 m infront of the boundary. Experimentalists can choose

K. Morita, et ai.

156

RlKEN lSOL SYSTEM
El

o
Q!

IGISOLbooste r
pump

Fig. 1.
Table 1.

Schematic view of the RIKEN ISOL system.

Characteristics of magnets.
IGISOLGARISDTable 2.

D

Ql,Q2

Deflecting angle (degree)
45
Maximum field (T)1.5
Maximum field gradient (T /m)
Pole length (mm)942.5Pole gap or bore radius (mm)150
Radius of central ray (mm)1,200Pole tilt angle (degree) input
45
Pole tilt angle (degree) output-45
Radius of pole boundary (mm)
input
-400
Radius of pole boundary (mm)output1,200
Maximum ampere-turn/pole
115,000(A-turns)
Number of turn/pole (turns)
210
Maximum current (A)548
Total residence of coil at 20°C<'Q.) 0.231
Maximum power dissipation (kW) 79
Flowing rate of cooling water
47.6(l/min)

68
0.75
5.2
500
150

1,186.8
55
1,000

°
°
57,00018,300

179
319
0.47
53.9
40

60
309
0.053
5.4
9.8

the target position according to their aims of theexperiments. Differences of the characteristics between these two modes are listed in Table 2.
The region where the gas is filled is separated
from the vacuum region by thin metal foils.
2) IGISOL
The total IGISOL system is also shown in Fig. 1
schematically. The central parts of an ion-guidechamber and an extraction chamber are shown in
Fig. 2. The ion-guide chamber is evacuated with amechanical booster pump having a large pumping
speed (6,000 m 3 / h). The extraction chambers are
separated by a skimmer with a 1.5 mm.p hole andevacuated by two oil diffusion pumps of a 1,500 l/ s
pumping speed. The ion-guide chamber, the extraction chamber, and the pumps mentioned above areelectrically insulated from the ground potential toapply 80 kV potential for acceleration.

Comparison between two modes.

Distance from the target to poleboundary (mm)Angular acceptance (mr), horizontal
Angular acceptance tmr), vertical
Solid angle (msr)
Dispersion (cm/ %)Total length (mm)Magnification, horizontal
Magnification, vertical

MODE I

MODE II

°

700

±85
±80
13.6
0.20
4,070
-0.57
-1.47

±80
±70
11. 2
0.78
4,770
-0.74
-1.51

Fig. 2. Central part of IGISOL. The ion-guide chamber
and the extraction chamber.

K. Morita, et ai.

Table 3.

Characteristics of the electrostatic analyzer.

Form of electrodes
Radius of central ray (mm)Focal length (mm)Gap between electrodes (mm)Height of the electrodes (mm)Deflecting angle (degree)

Spherical condenser

SOO
1,000

40
60
90

We have one einzel lens and electrostatic Q-Iens( doublet) before the analyzer magnet, one einzel lens
after the magnet, and four sets of electrostatic deflectors (both horizontal and vertical) for successful
beam transportation. The characteristics of theanalyzer magnet are listed in Table 1. We have threelines for a momentum analyzed beam. The straightline leads the beam to the next experimental hall
E2. The 90° -bent line has an electrostatic mass

157

~nalyzer (ESMA) to get better mass resolution. The
characteristics of the ESMA are listed in Table 3.
All the equipments will be set by the end ofJune, 1988.

References
1) H. Miyatake, T. Nomura, H. Kawakami, J. Tanaka, M.
Oyaizu, K. Morita, T. Shinozuka, H. Kudo, K. Sueki,
and Y. Iwata: Nucl. Instrum. Methods B, 26,309 (1987).
2) J. Arje, J. Aysto, H. Hyvonen, P. Taskinen, V. Koponen,
J. Honkanen, K. Valli, A. Hautojarvi, and K. Vierinen:
Nucl. Instrum. Methods A, 247, 431 (1986).
3) 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: Nucl. Instrum. Methods B, 26, 406 (1987).
4) T. Nomura, J. Tanaka, M. Oyaizu, Y. Iwata, N. Ikeda,
K. Valli, K. Morita, Y. Nagai, T. Toriyama, Y. Murakami, Y. Yorii, and S. Harada: submitted for publicationin Nucl. Instrum. Methods.

158
RIKEN Acce1. Prog. Rep. 21 (1987)

111-5-4.

An lon-Guide Technique for On-Line Isotope Separation
Coupled with a Gas-Filled Recoil Isotope Separator
K. Morita, K. Valli,t T. Nomura, J. Tanaka, M. Oyaizu, N. Ikeda,*
Y. Nagai, T. Toriyama,** Y. Murakami,** Y. Torii,** and S. Harada**

The ion-guide technique for on-line isotope separation is based on the fact that nuclear reaction
products recoiled out of a target and stopped inhelium gas are still singly-charged sometimes withhigh probabilities. Those ions are quickly transported
to a low-pressure region with a gas-jet through asmall exit hole of a gas chamber and accelerated in
the same way as in an usual isotope separator on-line(ISOL). The ion-guide ISOL (IGISOL) has advantages that it works very stable for all elements
because no ion source is used, and that it can beapplied to radio-activities with half-lives as short as
0.1 ms.
IGISOL has been successfully applied to the
products in light-ion induced reactions. However, it
is still questionable whether IGISOL works sufficiently
well in heavy-ion induced reactions because of afollowing reason: The velocity of the reaction products formed in heavy-ion reactions is generally larger
than that in light-ion reactions, so that higher gas
pressure is needed to stop the products in the heliumgas chamber. Thus, dense plasma must be formedin the gas along a beam path due to collisions ofbeam particles with helium atoms and may resultin quick neutralization of charged reaction products
since they are mostly recoiled out in the same direction. Note that the plasma density is proportional tothe energy loss of beam particles, gas pressure, andbeam intensity. In fact, we have recently observed
a considerable decrease of the IGISOL efficiency due
to the plasma effect in heavy-ion reactions when the
beam intensity becomes high.l)
The difficulty mentioned above can be avoided bypermitting only the reaction products separated fromthe beam particles to the gas chamber. This will be
realized when we put the gas chamber of IGISOL
at the focal point of the recoil isotope separator witha high collection efficiency. A purpose of this work
is to study characteristics of such hybrid type IG ISOL,
especially ionic-state probability of reaction products
thermalized in helium gas.
The present experiment has been carried out usingt On leave from Jyvaskyra University, Finland.

* Institute for Nuclear Study, University of Tokyo.
** Faculty of Science, Tokyo Institute of Technology.

o

0.5

I (m)

Slit chamber
Beam

o

10

~

20 (cm) Mechanical Booster pump'---'---'--'---'

Fig. 1. A schematic view of the present experimental set-up.

radioactive 28Al produced in the 27AI (a, 2pn) reaction at Ea = 38 MeV. The experimental setup is
shown in Fig. 1. A gas-filled recoil isotope separator(GARIS) 2) set at the cyclotron laboratory at theInstitute for Nuclear Study, University of Tokyo, wasused to transport 28AI recoiled out of a target foil
(1 mg/ cm 2 AI) from the target position to the focal
plane of GARIS. The entire region of GARIS was
filled with helium gas of about 1.7 mbar. The collection efficiency of the system was about 20 %.
The kinetic energy ER of 28Al ions ejected fromthe target ranged from 160 keY /u to zero, since thethick target was used. 28AI lost its energy throughsuccessive collisions with helium atoms, its maximum
ER at the focal plane being estimated by use of therange-energy relation given in Ref. 3. Polyester foils
of various thicknesses could be placed 1 cm before thefocal plane to degrade ER when necessary. In orderto obtain a rough estimate of a distribution of ER
values at the focal plane, we measured the yield of
28Al as a function of the degrader thickness. For
this purpose a round catcher foil of 35 mm in diameter was set at the focal plane to collect 28Al. The
1. 78 MeV r-ray yield following the f3 decay of
28AI(tl/ 2 =2.2 min) was measured off-beam by useof a 120 emS Ge(Li) detector after the target wasirradiated for 5 min with a 1 pA a beam; the resultis shown in Fig. 2. It turned out that the yield at
a 1.5 pm degrader foil was equal to that without
the degrader, indicating that there was the minimum

K. Morita, et al.

159( p'm )

o
I

I

2

3

4

I

I

I

200

1000r-

-eo
100

I

o

200

Thickness

-100

600

400
(

,ug/cm 2 )Fig. 2. Measured yields of the 1.78 MeV r rays following
the {J decay of 28AI at various degrader thickness. The
measurement started 2.25 min after the 5 min irradiationof the target with a 1 /-LA a beam as explained in text andcontinued for 5 min.

roCollector Voltage

50100( Volts)

Fig. 3. Measured yields of 1.78 MeV r rays versus the applied voltage of the catcher foil placed I em behind theexit hole of conical shape gas chamber taken in the similar
way to Fig. 2.

Runvalue of ER in 28Al reaching the focal plane. The
range of 28Al in polyester was found to be about
530 pg/cm2 at ER = 160 keV lu. Assuming that therange-energy curve of 28Al in polyester is similar tothat of 21Al in mylar given in Ref. 3, we estimatedthe minimum value of ER of 23 keV.
The efficiency of IGISOL was measured by setting
a gas chamber of a conical shape at the focal planeof GARIS (see Fig. 1). A window of the gas chamber consists of 1.5 pm polyester foil attached ontoa stainless mesh, which is round in shape and 35 mm
in diameter. The transmission of the mesh is 85 %.
The 28Al activity transported from the target enters
the gas chamber filled with helium of 200- 300 mbar
and is extracted through an exit hole of 1.1 mm
in diameter. The gas chamber was placed in a larger
cubic vacuum chamber, which was pumped with amechanical booster pump of a 2,070 m 3 /h pumping
speed. An aluminum catcher foil was set about 1 cm
behind the exit hole to collect the 28Al radioactivity
extracted through the hole. In order to distinguish
posItIve ions of 28Al from neutral ones, we applied
positive or negative voltage onto the catcher foil
relative to the gas chamber. An example of theyield of the 1.78 MeV
ray as a function of theapplied voltage (V) is shown in Fig. 3. The measured yield decreases drastically by changing the signof V, indicating that there is a considerable amountof positive 28AI ions. The yield of positive ions (n+)
is deduced from n+=N_-N+, where N_ and N+ are
the yields at negative and positive voltages, respectively. We assume here that the yield of negativeions is negligibly small. Since the yield is almost
independent of the absolute values of the applied
voltage, we usually apply -+- 50 volts to obtain N±.
The efficiency measurements were made for various conditions summarized in Fig. 4. For I, we-50

Heliumpressure

Degraderthickness(mm)[ 200mbar. 2.5 ~m,

80%

300mbar, 2.0 ~m.

80%

300mbar, 2.0 ~m,

100%

(I)

(II)

[ 200mb", 2.0 11m,

80%

(liD
300mbar,2.0~m,

100%--t==nr:::;;:]. 40--==r~

~=

t

co

"eo

~.~~~
~6ci'~--'- ~~._1~

Fig. 4. Schematic presentation of the present experimental
conditions of the gas chamber of IGISOL. The maximum
range of 28AI in helium under the given conditions isindicated by arrows. The degrader thickness, helium pressure, and fraction of 28AI which can be stopped in helium
relative to 28AI entering the gas chamber are given.

used an original conical gas chamber to stop reaction
products 8AI) in helium. For II, we changed theopening of the window of the gas chamber by settinga thick slit of 18 mm in diameter on the window,
so that 28Al could enter only the central part of thechamber. In this case, a proportion of 28AI entering
the chamber was measured to be about 36 % ascompared with the case r. For III, the gas chamber
was enlarged in length by putting a 2 cm cylindricalextension behind the window. The maximum rangeof 28Al corresponding to the maximum kinetic energyof 28AI after the 1.5 pm polyester foil was estimatedby use of the range-energy relation given in Ref. 3.
Assuming that the distribution in kinetic energy of
28Al is uniform, we estimated a fraction of 28 Al
stopped in helium for each case. This fraction (I)is also indicated in Fig. 4.
The measurements were carried out in the following way. The target was irradiated for 5 min with
2 pA a beam ; the catcher foil was then taken outeK. Morita, et al.

160

Table I. Results of present experiment. n+=N_-N+ and
ntot=N_. nstop is the yield of r ray corresponding to thenumber of 28AI atoms stopped in helium (see text andfigure caption for Fig. 2).
Helium Degrader
n+/ntot n+/nstopn+Run pressure thickness nstop(counts)(counts)(%)(%)(mbar)
(pm)
I
I
II
III
III

200
300
300
200
300

2.5
2
2
2
2

666
884
411
884
1,105

49±9
78±8
33±4
45±7
72±8

48±9
63±7
57±8
44±7
52±5

7.2±1.4
8.8±0.98.0± 1.0
5.1±0.8
6.5±0.7

from the vacuum chamber and was put just in frontof the surface of a Ge (Li) counter, which was placedin a low background room.
The results are summarized in Table 1. Note thatthe absolute values of 28AI (denoted by nstop in thetable) were estimated by use of the results shown in
Fig. 2 and the fractions f indicated in Fig. 4. It
turned out that about 12-16% of 28AI stopped inhelium were extracted, and that about a half ofthem remained charged.
References
1) 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: Nucl. Instrum. Methods B,26, 406 (1987).
2) H. Miyatake, T. Nomura, H. Kawakami, J. Tanaka, M.
Oyaizu, K. Morita, T. Shinozuka, H. Kudo, K. Sueki,
and Y. Iwata: Nucl. Instrum. Methods B, 26,309 (1987) .
3) L. C. Northcliffe and R. F. Schilling: Nucl. Data Tables
A, 7, 4 (1970).

161

RIKEN AcceI. Prog. Rep. 21 (1987)

111-5-5.

Counter Development for Rotating Catcher System
M. Koguchi, M. Fukuda, K. Asahi, H. Kumagai,
M. Adachi, and M. Ishihara

We previously reported the design of a rotatingcatcher system (CAROT) for studies of f3 decay of
nuclei far from stability.l) Briefly, CAROT aims at
observation of decay particles (including f3 rays andf3-delayed particles) from identified mother nuclides
produced in projectile fragmentation reactions. Because of the general slowness of f3 transitions (halflives known so far are longer than several milliseconds
for f3 decays) a conventionally employed coincidence
technique is not applicable to correlating of detecteddecay particles with the isotope identification signals
obtained from an SSD telescope. CAROT employs
a novel method using a rotating disc in which reaction products are implanted after passing throughthe SSD telescope. f3 Rays from the disc are detectedby position-sensitive detectors. Details and the geometry of the system are presented in Ref. 1.
The mechanical part of the system and a control
unit with a microprocessor have been constructed in
the Technology Division. A catcher disc made ofaluminum (80 cm in diameter and 0.10 cm in thickness) was installed, and the maximum rotating speedof 10 roundsjs was attained.
Below in this report we describe the developmentof a f3 counters for CAROT. A position-sensitive
detector consisting of 100 strips of a plastic scintillator (each 1 mm thick, 2 mm wide, and 27 mmlong) has been developed. Both ends of each strip
are optically coupled to plastic lightguides of 1 mm
in diameter which transport scintillation light separately to two photomultipliers. Twenty photomultipliers, each accepting the light from ten scintillator
strips, constitute a 10 X 10 matrix and thus provide
the position information of detected f3 ray. Pulseheight spectra obtained for f3 rays from a 90Sr source
indicated that the f3-ray signals are large enough to
be discriminated from noise, as shown typically in
Fig. 1. This transmission type detector is placed close
to the rotating disc, and is used for determinationof the position in the disc from which f3 ray isemitted.
A sector-shaped plastic scintillation counter wasassembled for measurement of the f3-ray energies.
This counter consists of six segments, each being a
trapezoid of 8 cm in thickness, 15 cm in length and7 cm in average width. A photomultiplier of 5 cm

( x 10 3 )90 sr source

8
~

w

z:
z:
:c
<::(

u

te

6
CZi

0::::

C/)

f-

4

z:

0

u

2

0

0

/~~

W
CL

:::>

-

•

~
200

400

800

600

1000

PULSE HEIGHT (CH)
Fig. 1. Typical pulse-height spectrum obtained from aplastic scintillator strip of the position-sensitive f3-ray
detector. A f3-ray source of 90S r was placed at a distanceof 2 mm from the strip.

pl ast i c scintlll otor

~I

__

miL]
f source-----I..-[:.-!-'-PM-T--llight guide1,~:x(~m)
104~------------------------------------,

102
100
98

~

-0-

. -u- #6

.g, 94

'ill
r.

#1

..... #3

96

92

~

R 104

~

.~ 102§ 100

e-0- #2..... #4

98
96
94
92+-~---r--~-.--~--.-~--.-~--~

0 .0

3.5

7.0
10.5
X(cm)

14.0

17.5

Fig. 2. Measured position dependence of the signal pulse
height from each segment of a p-ray energy counter.
Abscissa represents the position of the source as illustrated
in the upper part of the figure.

162

M. Koguchi, et al.

in diameter is attached to each segment of thecounter. In order to make the position dependenceof the signal pulse heights as small as possible,
several methods for wrapping the scintillators (forlight reflection) were carefully examined. Afterseveral trials we chose Teflon film as a wrapping
material. In Fig. 2 the position dependence observedfor each scintillator segment is shown.

Development of a computer software for dataprocessing and control will be started shortly.
Reference
1) M. Fukuda, T. Kubo, K. Asahi, I. Tanihata, M. Ishihara, H. Kumagai, Y. Oikawa, T. Abe, and H. Taketani:
RIKEN Accel. Prog. Rep., 20, 146 (1986).

163
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-6.

Facilities for Studies on Nuclear . Chemistry andRadiochemistry at RIKEN Ring Cyclotron
M. Yanokura, Y. Ohkubo, S. Ambe, and F. Ambe

F or a variety of chemical studies making use of
RIKEN Ring Cyclotron, a unique irradiation system
and laboratory equipment for chemical handling ofradioisotopes have been designed and are to be constructed in the near future.
The main part of the "Falling-ball Irradiation
System" will be installed in the E3 irradiation room.
The system has been selected, because the transportation with a conventional pneumatic tube is not suitable for targets irradiated in vacuum and has therisk of bringing contaminated air with targets. Our
system assures safe and rapid transportation of theirradiated targets to the hot laboratory. This system
also has an advantage, because the laboratory lies
downstairs just beneath the irradiation room.
Targets are mounted in hollow metallic balls,
which are set in a standby tube connected to theirradiation chamber. They are sent to an irradiation
position one by one. After irradiation, the target is
moved down to a monitering site under the chamber,where its radioactivity is measured with an ionizationchamber. If the radiation level of the target is suitable for safe handling in the hot laboratory, the ballis rolled down to a hood installed in the laboratory
through a stainless steel tube. In the midway of thetube, a deceleration device is installed to avoid aviolent collision of the ball against the end of the
tube. After closing a gate valve near the end of thetube, the terminal lid of the tube is open and thetarget is taken out from the ball for chemical studies.
In the hot laboratory are to be installed hoods,
sinks, workbenches, and glove boxes. The details of
the facilities and the results of test experiments will
be reported.

164
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-7.

Further Study of Experimental Facilities for Light andLight-Heavy Ion Induced Reactions

H. Ohnuma, K. Hatanaka, S. Hayakawa, * T. Ichihara, K. Ieki, M. Ishihara,
S. Kato, T. Kubo, S. Kubono, K. Maeda,** T. Motobayashi, T. Nakamura,***H. Orihara, H. Shimizu, H. Toyokawa,**** M. Yasue, and H. Yoshida****Further study of a particle detection system to be
used in experiments with light- and light-heavy ion
beams from RIKEN Ring Cyclotron is in progress.
Continuous efforts have been made to optimize
the whole system reported in the RRC Annual Report
last year. I ) Figure 1 shows an example of the resultsof the first-order beam optics calculation for thetwister-beam swinger system. General discussion of
the optics of beam twisters is given elsewhere. 2)

Extensive ray tracing calculations for the proposedcascade-type magnetic spectrometer have been carriedout. A typical result is shown in Fig. 2. It is intended
that the combined system can be used in dispersion
matching mode.
The structural design of magnets is also under way.
Figure 3 shows an example of the field calculationof a split-type quadrupole magnet for the spectrometer. Such a quadrupole magnet is needed to' BEAM T WIS T ER ' SI,Il NGER X I'
BE/\ M ENVEL0 PE
X= 1.50MM . DX= 2. 00'1R .

Y= 1. 50M M, Y=

1.13 MR , DP = O. 05:g

L
U
<.D

/
/

....-:/--------_... --

c:5

...

-----

r-j

0
:..;

~

t?

,

.={ . ~

0:::

0:::
0

o

Fig. 1.

Beam optics for the twister-swinger system.

* Ashikaga Institute of Technology.
** College of General Education, Tohoku University.
*** Cyclotron and Radioisotope Center, Tohoku Univer·sity.

**** Department of Physics, Tokyo Institute of Technology.

-'-

O:::::JO::: ::JO:::<OGO GOL

0:::

o

x
w

H. Ohnuma, et al.

r-- -- - ---------------------------- I

Q1-5

165

600 A/cm**2//

Fig. 2. Sample ray-tracing calculation for a cascade-type
spectrometer.

facilitate small angle measurements with the present
large solid-angle (20 msr) spectrometer.
In addition, two types of neutron detectors of arectangular type (5 cm X 10 cm X 100 cm) and acylindrical type (5 cm thick and 20 cm in diameter),
were designed. They are to be used in neutron TOF
measurements as well as in the detection of emitted
neutrons in heavy-ion induced reactions.
Estimates of radiation doses due to the beam andFig. 3. Magnetic field calculation of a split-type quadrupole
magnet.

to residual activities have been obtained, and used tocarry out shield calculations under various experimental conditions.
References
1) H. Ohnuma, T. Ichihara, K. Ieki, M. Ishihara, S. Kato,
T. Kubo, K. Maeda, T. Motobayashi, H. Orihara, and
H. Shimizu: RIKEN Accel. Prog. Rep., 20, 134 (1986).
2) s. Kato: Nucl. Instrum. Methods A, 254, 487 (1987);
p.166 in this report.

166
RIKEN Aced. Prog. Rep. 21 (1987)

111-5-8.

Ray-Tracing Calculation of the Variable-Angle Beam Rotator
S. KatoThe high resolution magnetic spectrometer to beconstructed will not be rotated even for measurementsof angular distribution. 1) Instead, the beam will betransported through a rotate-type beam swinger2- 4 )to the target from various incident angles. The reaction plane becomes perpendicular. The medianplane of the swinger magnet is not in coincidence withthat of the upstream transport system. There aremany merits in such a spectrometer. But we mustovercome a serious demerit of it. The symmetry withrespect to the horizontal plane which has been conserved by the upstream beam transport system will
be destroyed by the rotated swinger. Without thesymmetry, the beam character at the target will nolonger possess the condition of the dispersion matching between the beam transport system and thespectrometer.
In order to retain the symmetry, we must rotate
the beam image around the beam direction by any
angle before the swinger so that a new symmetry
plane of the beam coincides with the median planeof the rotated swinger magnet. A detailed analytical
discussion how to rotate the beam images has been
described in Ref. 5 by use of the first order transfer
matrices. In the present report we briefly survey how
we can rotate the beam image and illustrate theresults of ray-tracing calculations.
In the point-to-point transportation, an ordinary
triplet of quadrupole magnets, whose geometricalarrangement possesses a symmetry with respect to thedirection of the motion of the beam, transfers beams
with unit magnifications in both the transverse directions. One of the signs of these magnifications is
positive and the other is negative. The signs can beinterchanged by changing the polarity of the current.
The triplet plays a role of an inverter of the beam
images with respect to the plane which corresponds
to the negative magnification.
If we rotate the symmetry plane around the axis,
which is defined by the direction of the beam, thebeam image will be inverted with respect to therotated symmetry plane. The result can be regarded
as the inversion with respect to the original symmetry
plane and the rotation by twice the rotated angleof the magnets. The inversion of the beam images
dose not matter because the system in the upstream
is symmetric with respect to the median plane. Thus

we can rotate the beam images by rotating an
inverter.
The remaining problem is that the symmetric
triplet of quadrupole magnets is not the ideal inverter
because the triplet transfers only the coordinate components, leaving the angular ones transferred improperly. The matrix elements (x'i x) and (y' I y)which should be equal to 0 do not vanish.
In order to eliminate these two elements, we must
add two degree of freedom. The simplest symmetric
set of quadrupole magnets with additional two parameters is a symmetric septet of quadrupole magnets.
We can obtain the full inverter of the beam imagesby the symmetric septet of quadrupole magnets. It
will rotate the beam image by twice the geometricallyrotated angle with accompanying beam inversion
which is not the aim of the system.
The difference between the full inverter and theordinary triplet is difficult to understand from thediscussion of the elements of transfer matrices. We
illustrate the difference between them by the raytracing calculations. We traced the motion of beams
in the fields of triplet and the septet of quadrupole
magnets. The lengths of the quadrupole magnets
were assumed . to be 0.20 m. The length of the freespaces were set as 0.30 m with the exceptions of
0.40 m at the both ends. The strengths of thequadrupole magnets of the triplet were searched sothat (x I x') and (y I y') vanished and the numbersof intermediate nodes became 0 and 1 for the horizontal and the vertical directions, respectively. Thenthe conditions of (x I x) = (x'l x') = 1 and (y I y) =~~_o.:..,.. ...
~~~.-;.,:,, ~J"_.,,,.
~

Fig. 1. Beam images for the triplet of quadrupole magnets.
Upper five figures are images at and near the starting
point with 0.04 m (tenth of the length of the free space)intervals . The lower ones show those near and at thefocus point.

167

S. Katoj~_ '~"'.""""""'""''''..t~:i:}'I_. . ..~ .

f::Fig. 2. Beam images for the septet of quadrupole magnets.
The other conditions are same as those of the Fig. 1.

(111 y') = -1 were automatically fulfilled. Those of
the septet were searched so that the additional conditions of (X' I X) = (11 I y) = 0 were also satisfied.
In Figs. 1 and 2, we show the beam images atseveral spots near the starting point and the focusing
point of 0.04 m steps for the triplet and for theseptet, respectively. The systems were rotated by 10
degrees. We can expect the beam images to berotated by 20 degrees and inverted. Although there
is no remarkable difference between the images of
the triplet and the septet at the focusing point, thedifference between them off the focusing point isremarkable. This means that although the beam
image can be transferred by both the triplet and theseptet, the angle of incidence cannot be properlytransferred by the triplet. In order to rotate thebeam images with the full phase space unchanged,
we must use a symmetric septet of quadrupole
magnets.
References
1) H. Ohnuma, K. Hatanaka, S. Hayakawa, T. Ichihara,
K. Ieki, M. Ishihara, S. Kato, T. Kubo, S. Kubono,
K. Maeda, T. Motobayashi, T. Nakamura, H. Orihara,
H. Shimizu, H. Toyokawa, M. Yasue, and H. Yoshida:p. 164 in this report.
2) D. A. Lind, R. F. Bentley, J. D. Carlson, S. D. Schery,
and C. D. Zafiratos: Nucl. Instrum. Methods, 130, 93(1975) .
3) R. K. Bhowmik, R. R. Deoring, L. E. Young, S. M.
Austin , A. Galonsky, and S. D. Schery: Nucl. Instrum.
M ethods, 143, 63 (1977).
4) H. Orihara and T. Murakami: Nucl. Instrum. Methods,
188, 15 (1981) .
5) S. Kato: Nucl. Instrum. Methods Phys. Res. A, 254, 487(1987) .

168
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-9.

Design of the RIKEN Projectile-Fragment Separator RIPS
T . Kubo, M. Ishihara, K. Asahi, and 1. Tanihata

Experimental studies of nuclei far from stability
are one of the most interesting subjects pursued byusing heavy-ion beams from RIKEN Ring Cyclotron.
The construction of the projectile-fragment separator
RIPS (RIKEN Projectile-fragment Separator) has
been proposed1 ) in order to facilitate the experiments
on such exotic nuclei.
The ion-optical design of RIPS has been completed. The layout is schematically shown in Fig. 1,
and the basic characteristics are given in Table 1.
The ion optics of RIPS has been designed to havea high collection efficiency compared with a similar
separator LISE at GANIL.2) The solid angle of
RIPS is about 25 times larger than that of LISE.
This large acceptance should enable us to collect
more than half of fragmentation yields.
The separator RIPS forms an achromatic beamtransport line, which can be divided by focal planes

01 02 03 S X1

01

02
45deg.
p=3. 6m

Q8

010
0 11

0 12

F3

Fig. 1. Layout of the separator RIPS.

Table 1. Design characteristics of RIPS.
Configuration

Aperture
Solid angle
Bp acceptance
Maximum Bp
Focal planes

Isotope separation
Energy degrader(FI)
Goal of mass
resolution (F2)
Correction for
aberration

Q-Q-Q-SX-D-SX-Q (first stage)
Q-Q-SX-D-SX-Q-Q-Q (second
stage)'Q-Q-Q (third stage)± 40 mr, circle
5msr

±3%
5. 76 Tm
FI , dispersive, end of first stage
F2, achromatic, end of second stage
F3, achromatic, end of third stage
AIZ and energy loss selection
wedge-shaped (achromatic degrader)

AILI A -I 00 for full acceptanceby four sextupole magnets

into three stages. The first stage consists of a Q-QQ-SX-D-SX-Q configuration, where Q, D, and SX
represent quadrupole, dipole, and sextupole magnets,
respectively. The momentum-dispersive focusing at
the first focal plane (Fl) is obtained by quadrupole
magnets on this stage. An energy degrader foil, which
permits isotopes to be separated, is set at F1. The
second stage consists of a Q-Q-SX-D-SX-Q-Q-Q
configuration, by which the achromatic focusing at
the second focal plane (F2) is achieved. The roleof sextupole magnets on these two stages is tominimize optical aberration.
The principle of isotope separation is the sameas that of LISE. The first stage allows coarse
separation according to A / Z of fragments, because
projectile fragmentation approximately conserves abeam velocity. Fine separation by the energy degrader is made on the second stage. The isotope
dependence of energy loss, expressed as dE / dx ex:
A 2 . 5 / Z 1.5, generates isotope dispersion at F2, whichenables us to select a specific isotope. The wedgeshaped degrader 2 ) will be used, which does not affectthe first-order optics on the second stage.
The final stage, which consists of triplet quadrupole
magnets, transports a selected isotope to experimental
devices at the final focal plane (F3).
In the ion-optical design, the minimization ofaberration is necessary especially for F2 where theisotope separation is made. This is because RIPS

T. Kubo, et al.

10000,10oo,
J

m=+2% m=+1/otm=O % t=m=-1%t=m=-2%
1.,0\
I ~
~ I I 111\1
~

~

II'

(/)
~

z

:>
0

100

1\

\

•

1 _. !~

•

,

"I.

111

Jl~lrln.

lu~! I till I

10

I ! I I I ! I-50 -40 -30 -20 -10

0

10

20

30

40

50

X(mm)

fig. 2. ~y~ical mass sp«:;ctrum at F2 simulated using opticalparameters obtained by ORBIT2. Full acceptance anddegrader thickness of dIR2)=O.5 are assumed. Each peak
; corresponds to isotopes whose fractional mass differences(m= (A-Ao) lAo) are -2, -I, 0, +1, and +2 %,respectively.

is requjred to have large acceptance. Effects ofdegrader on optics have been also taken into accountbecause the presence of degrader is found to affectaberration. We have used the code ORBIT2 3 ) developed for this purpose. The code ORBIT2 allows
the ion-optical treatment of degrader4) and calculates aberration coefficients up to the third order.

169

By using ORBIT2, we have made" the ion-opticaldesign as follows: 1 ) the first-order optics is designed $0, that it may , produce small ab~rration;2) then; each strength': of four sextupole magnets is
searched for so as to minimize major aberration suchas (x/()o), (x/()m), (X/02) , (X/()2), and (X/()3).
Figure 2 shows an example of the mass spectra at
F2 simulated using optical parameters thus obtained.
This figure shows that a mass resolution greater thanthe design goal (A / 11 A ~ 100) is achieved.
The detailed design of magnets, vacuum chambers, and beam monitoring system is now in progress
toward the completion in the spring of 1,989.
References
I) T. Kubo, K. Asahi, T. Ichihara, T. Matsuzaki, M.
Fukuda, K. Nagamine, I. Tanihata, and M. Ishihara:
RIKEN Aeeel. Prog. Rep., 20, 136 (1986).
'
2) 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).
3) By S. Morinobu at RCNP, Osaka University:' private
communication.
4) S. Morinobu: Proc. RIKEN-IN2P3 Symp. Heavy-Ion
Collisions, Shimoda, Oct. (1987), p.91.

170
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-10.

Design of a New Type of Low-Energy Radioisotope-BeamChannel "SLOW" for Surface Studies
T. Matsuzaki, K. Ishida, and K. Nagamine

We are constructing a low-energy radioisotopebeam channel "SLOW" in the E7 experimental areaof RIKEN Ring Cyclotron (RRC). "SLOW" isused for the study of emission mechanisms of various
slow radioactive atoms from characterized metal surf~ces treat~d carefully and is also for the extractionof useful radioisotopic ions for solid-state physics
studies .
. High-energy heavy-ion beams available at RRC
will be injected into a metal target, whose temperature could each 2,000 K. By a nuclear reaction, manykinds of radioisotopes are produced and moderated in
the target. The moderated · atoms reach the metal
surface by diffusion · arid could evaporate into a
vacuum outside the target surface. In particular, theatoms of alkaline, alkali earth, and rare earth metals
evaporate from the surface with a thermal energy
and autoionize partly by a surface ionization effect.
The surface ionization occurs only when the evaporating atom has the ionization potential smaller than
the work function of the target metal surface. The
other atoms with higher ionization potentials are
emitted from the target surface and will be ionizedby an ionizing device separately prepared near thetarget surface. Thus, around the target surface, thelow-energy radioisotopic ions are generated with auniform kinetic energy. By means of "SLOW" beam
channel, these ions are extracted, accelerated, energetically analyzed, and transported to focussing points.
In Fig. 1, a proposed design of the "SLOW" beam

channel is shown. All beam lines are composed ofelectrostatic lenses with no magnetic field. Thus, theions with an · equal charge state can be transported
and fOGussed u~~er the same beam-line conditions.
The masses will be . identified by means of a TOF(Time Of Flight) method. The ions are thenextracted and accelerated « 10 kV) by SOA electric
aperture / tube lenses located in a ultra-high vacuum
chamber and are focussed at the first focussing point(F1) with a pair of electric quadrupole lenses (EQ).
The ions starting from F 1 are transported with 4 setsof EQ's and bent in an electric bend (EB) by 90
degrees. Finally, the ion beams are focussed again
at the second focusing point (F2). The electrode of
EB is troidal-shaped. The troidal electrode is capableof focussing ion beams not only horizontally but also
vertically relative to the transporting plane. The EQ
has 4 spherical shaped electrodes, and the bore diameter for the beam is 80 mm. The "SLOW" beamline has also an adjustable slit (SXY and SX) andan electrostatic X-Y deflector (ED.) All electricallenses are designed to be insulated up to + / - 10 kV.
Prior to experiment, an electron source will be
used to tune a beam line and to examine the opticalproperties of the "SLOW" beam line, when thepolarity of all electric lenses are reversed. The highvoltage supplied from a main high-voltage power
supply (10 kV, 10 rnA) is applied to each terminal
through a voltage divider. The radioisotopic ionsare detected at F 1 and F2 with a micro channel

sx
EQ
EQ
F2
Fig. 1.

Proposed design of a "SLOW" beam channel.

T. Matsuzaki, et al.

plate and a Si(Li) particle detector. To define thetime zero of radioisotopic beams, the applying voltage
for the second electrode of an SOA lense is rectangular-pulsed. . The TO:F is measured ' as a ti~e 'difference between the time zero and the stop pulse
obtained by particle detectors. In addition to the
TOF analysis, the lifetime and energy for (3- orrays from stopped ions at F2 are measured for nuclear
assignment.
For a high vacuum (10-s Torr) of the beam line
to be kept, the whole beam line is designed to be
bakable up to 150°C. The vacuum space of thebeam line is evacuated with two sets of turbo moleculer pumps (TMP, 300 lis). At the head of the"SLOW" beam line, there is a large ultra-highvacuum (URV) chamber evacuated with a cryopump (1,500 l/ s). The inside vacuum of the URV
chamber is aimed to reach as high as 10-10 Torr after
outgasing by elaborate baking. In addition to a
vacuum gauge, an electric quadrupole mass analyzer
is equipped to .analyze a . residual gas component in a
vacuum. The residual gas is known to affect themetal surface; therefore, its analysis is essential tocontrole the metal surface. Above the URV chamber, we put an additional vacuum chamber, withwhich we can treat and characterize the metal surfaceof targets. The 5 kV argon-ion gun is equipped tocarry out an ion etching on the metal surface. A
LEED / AUGER spectrometer installed in the chamber is used for crystallographic measurements and

r-

171

analysis of the components on ' the metal surface. 'In order to investigate the emission mechanisms of. \,,~rious ions f;rom the characterized m,e~al surface, weshould obseive a variety' of the emitt~d radioisotopic
ions and their yields unde~ various conditions (surface
treatment, coating materials, crystallographic axis,
surface temperature, target thickness, target mate. rials, incoming heavy-ion beams, and incident energy) .
The present method is superior to an ion-scatteringor an ion-implantation method, because various ions
are generate inside the metal and will be emitted
from the surface aft.er thermal diffusion . .By selecting
a combination of an incoming heavy-ion beam, an
incident energy and a target material, we can chooseradioisotopic atoms produced inside the target metals
through various nuclear reactions.
The second goal of this work, in addition to thestudy of emission mechanism, is to. obtain radioactive
6Re and SRe beams. They are very usefull to study
microscopic diffusion properties of helium atoms in
metals, because they are f3-ray emitters with lifetimesof 808 and 122 ms, respectively. We can trace thediffusion of helium atoms in / on metals by observing
the f3 rays from them with an aid of a multi wire
proportional counter array. The properties of heliumin metals have not yet been well investigated; therefore the radioactive helium beams will be of a great
importance for the study on the behavior in metals.
The detailed optical calculations and design work
are now in progress ..
i ~ ,

172
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-11. Design of a Super-conducting Secondary Beam Transport ,System with a Large Solid Angle' (SL!J)K. Ishida, T. Matsuzaki, and K. Nagamine

A new type of beam transport system for lightcharged particles (Superconducting Large .Q) has
been designed and is under construction at E 7 portof RIKEN Ring Cyclotron. It makes use of the
focusing properties of an axially symmetric magnetic
field of 0.8 T (at maximum value) produced bythree superconducting coils. The main purpose of
the beam channel is to collect the secondary particles
as much as possible with a moderate momentum andmass separation.
In an axially symmetric magnetic field, a charged
particle emitted from a point source on the axis is
refocussed onto the axis after one Larmor period ofa helical orbit. In order to gain a high flux, it isdesirable for the rays of a number of trajectories tointersect at the same point along the same axis. The
rays should be characterized by a large spread inemission angle a and a small spread in momentum
p. It is well known that a suitably shaped concave
magnetic field ( d 2 B / dz 2 > 0) has this property due
to the following reasons: 1,2) the concave field produces intermediate ring focus; by means of an annularslit situated at this intermediate image the momentum
spread can be selected for the particles collected at
the focus; moreover, only a small spherical aberation
is produced at the focus.
A schematic diagram of the proposed system isshown in Fig. 1. The system makes use of two Larmor
periods in an axisymmetric field. The basic concept
is as follows: the first part from T to F 1 selects themomentum to a resolution of ± 2 %; the second partfrom Fl to F2 separates the particles according to. the energy loss at the degrader.
F2

B

a.....
'

50cm~~-..'

Fig. 1. Schematic diagram of the large Q beam course: T,
production target; FI, energy degrader at first focus; F2,experimental target and detectors at second focus; A,annular slits; B, vacuum chamber; C, superconducting coils.

Calculations were performed by using an M780
computer at RIKEN. The field calculating program
and the ray tracing program calculate the ray tracks
in the magnetic field. In determining the coil parameters, we placed the following requirements: thespherical aberation at F2 should be small; the rays
should be nearly parallel at F2; the solid angle
should be as large as possible; the momentum resolution should be below 2 %; the magnification should
be so small that the size or the position of the primarybeam at the target is not essential; the stray field at
F2 should be small.
In Tables 1 and 2 we present the optical properties
Table 1.

Optical properties of large Q.

Production target location T
First focus location (Fl)Second focus location (F2)Angular acceptanceSolid angle
Maximum momentum
Resolution of momentum
Maximum distance of the raysfrom the axis

z= Ocmz= 100 cm
z=255 cm
35 0 _47 0
860 msr
30 MeV/c±2%
27cm

Table 2. Technical characteristics of large Q (designed
values) .
Coil parameters

Coil 1

Coil 2

Coil 3

74.1
74.1
74.1
Inner diameter (cm)
85.9
85.9
85.9
Outer diameter (cm)
4.8
7.3
4.8
Coil length (cm)Location of
180.0
20.0
100.0
coil centers (cm)
200
143
143
Coil weight (kg)
1,980
1,980
3,036
Number of turns
6.1
6.1
13.5
Inductance (H)
0.36
0.36
Mutual inductance (H)
83
159
152
Current per wire (A)
164
484
300
Current/coil (kAT)
58
112
106
Current density (A/mm 2)
8.7
59.5
25.5
Hoop force (t)Attractive force
1. 32
2.33
between coils (t)Cryostat parameters
Total weightStored energy
Inner bore diameter
Outer diameter

2.0 t
260kj
60cm
102cm

K. Ishida, et al.

173

and coil parameters thus determined. The axial field
produced by this coil configuration is presented inFig. 2 (a). The ray tracks for a point source on
the axis at z = cm are presented in Figs. 2 (b) and2 (c) for various angles and momenta, respectively.
One of the main purposes of the beam course is
to collect surface muons obtained as products of positive pions decay at the skin of the production target,
where the pions were produced by high energy heavyions. Figure 3 shows the trajectory of muons, positrons and pions emitted from the axis at z = cm
for various angles and momenta. Annular slits arelocated at z = 10, 20, ... , 230, and 240 cm. An energy
degrader of 50mg/cm 2 in thickness is placed at z=
100 cm. We can expect the angular acceptance of
800 msr and momentum acceptance of + 2 % with afull separation of muons from positrons and pions.
The system can be also applied to collect slow heavyions. For a particle with mass number A and charge
state q, the maximum accepted momentum is 30 q
Me V / c and the maximum accepted energy is 0.48 q2/
A MeV.
The field produced by this superconducting coilsystem is moderate. Instead, it has the following
characters. The cryostat has a large room temperature access to the central region. The current of
the three coils can be changed independently withthe use of six current leads to guarantee the flexibility
needed for various types of application of thiscelebrated system.

°

F2

30

E
g

°

0:::

Fig. 2. (a) The axial field produced by the set of coils in
Table 2. (b) Trajectories with P=30 MeV Ic and emission
angles ao=35, 38, 41, 44, and 47° with respect to thesystem axis. (c) Rays with emission angle ao=41 ° andmomenta p=28.8, 29.4, 30.0, 30.6, and 31.2 MeV Ie.

E 30

Positron
I I

J

Fig. 3. Trajectories of muons, positrons, and pions for all
combinations of emission angles ao=32, 35, 38, 41, 44, 47,
and 50° and momenta P=28.8, 29.4, 30.0, 30.6, and31.2 MeV Ic. The currents of coil 2 and coil 3 are reduced
compared with that of Fig. 2 (a) to match the reduced
momenta of muons after the degrader.

References
1) K. Siegbahn: Alpha-, Beta- and Gamma-Ray Spectroscopy, North-Holland, Amsterdam, Vol. 1, p.145 (1965) .
2) I. Lindgren and W. Schneider: Nucl. lnstrum. Methods,
22, 48 (1963) .

174
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-12.

Apparatus for Resonance Ionization Spectroscopy ofAtomic Nuclides
T. Murayama, M. Takami, Y. Matsumoto, and T. Inamura

A resonance ionization technique is one of the mostpowerful methods of spectroscopy of elements in trace
amounts. Its high selectivity and sensitivity for allof the elements (except He and N e) have well been
:r:ecogIlized in the last decade. 1) Recently, a methodof high sensitive detection of pairs of ions and electrons has been developed for resonance ionization
spectroscopy (RIS) .2) To make use of this novel
technique for nuclear spectrosc~py, lasers were installed and an interaction chamb~r was constructed;
the chamber is equipped with an ion gun to produce
neutral atoms.
Figure 1 shows an arrangement of the lasers, theinteraction chamber, and optics. The specificationsof the lasers are listed in Table 1. Two laser systems
are used for the multistep excitation in RIS: One isa ring dye laser pumped by an Ar-ion laser, which
is important especially for the first step excitation to
give the selectivity of elements; and the other is adye laser pumped by a copper-vapor laser. Laserbeams are guided along with each other by using

I
OJ

He -1
APPl'

Table 1.
(1)

(2)

Specifications of the lasers for nuclear spectroscopy.

Ring Dye Laser ' System
High Resolution Dye Laser:· Ring Dye Laser (Coherent
699-29),Wavelength 400-600 rim
Pumping Laser: Ar-Ion Laser (Spectra" Physics 171-19)
Output 18 W, CW
Copper Vapor Laser System
High Power Dye Laser: Lambda Physik FL3002E
Copper Vapor Laser: Plasma Kinetics 351-HR
Frequency 6-10 kHz
Output Power average 24 W
peak 180 W at 8 kHz(pulse width 17 ns)
Wavelength 511 nm (60%), 578 nm (40%)

mirrors and interact with atomic beams in the chamber. A frequency doubler BBO (,B-BaB 2 0 4 ) crystal
is useful to expand the region of elements available
for RIS; its conversion efficiency is expected to be
more than 6070.
In Fig. 2 is present~d a .photograph qf the chamber.

DD
Dye Circulator

.J

1

c

: Molecular Beam :1 TOF apparatus
1

oS

<:

1

I

:-----------~
Atomic Beam
RIS chamber

Laser Nuclear-SpectroscopyDB

Layout of Test Experiments
Fig. 1.

Schematic arrangement of the apparatus.

T. Murayama, et al.

Figure 3 shows the schematic presentation of the RIS
experiment using the apparatus. Atomic beams are

Fig. 2. Photograph of the interaction chamber for RIS.
Lasers come into the resonance cell through a long guide.
Ar beams from the ion gun bombard the target at thebottom of the chamber, producing neutralized target atoms.

AtomicBeam

175

produced by sputtering a target material by Ar-ion
beams from an ion gun (ANEL VA 5 kV Ion Gun).
Sputtering has the following advantages in producing
atomic beams: i) The sputtering process occurs
almost independently of the chemical properties of
elements; ii) Sputtering has nothing to do withvolatility; and iii) most of the sputtered particles
are neutral atoms (more than 990/0). Ar beams
bombard the surface of the target with an angle of
65 0 to the normal so as to obtain maximum yields.
Test experiments off-line are now in progress. First
we make spectroscopy of stable nuclei of rare earth
elements. Our method also enables. us easily to make
spectroscopy of elements Ta and W whose melting
points are prohibitively high to vaporize. Next we
proceed to spectroscopy of radioactive isotopes. Radioactive atomic beams can be generated by sputtering
the target onto which they are implanted: Radioactive species are produced in the heavy-ion induced
nuclear reactions such as target fragmentation. In
the end we aim to measure hyperfine structure to
determine spins and moments of nuclei far from thestability line and also to measure isotope shifts todeduce the change in charge radius as a function of
the number of neutrons or protons.
We will extend the present method for the on-line
spe~troscopy with a hybrid isotope separator, GARIS3)
and IGISOL/) and a projectile isotope separator
RIPS. 5) Lastly, mention should be made that thedevices will shortly be installed for RADOP (radiation detect optical pumping).
References

TargetFig. 3.

Schematic presentation of our method.

1) C. S. Hurst: Resonance Ionization Spectroscopy 1984
(eds. G . S. Hurst and M. G:; Payne), The Institute ofPhysics, Bristol and Boston, p.7 (1984) .
2) T. Minowa, H . Katsuragawa, K. Nishiyama, M. Shimazu ,and T . Inamura: J. Appl. Phys. , 61, 436 (1987) .
3) H. Miyatake, et al.: Nucl. Instrum. Methods B, 26, 309.
4) K. Morita, et al.: Nucl. Instrum. Methods B, 26, 406(1987) .
5) T. Kubo, H. Ishihara, K. Asahi, and I. Tanihata: p . 168
in this report.

176
RIKEN Accel. Prog. Rep. 21 (1987)

111-:5-13 . . Resonance Ionization Spectroscopy of Neutral Atoms .~ya Laser Ablation Method ' .
M. Otsuki,* T. Mlnowa, H. Katsuragawa, M. Shimazu,*, arid T. Imimura ·,. We have employed ·a laser ablation method t6 carryout resonance ionization spectroscopy (RIS) of AI,
Sr, N a, and Cu because this method is capable ofgenerating neutral atoms from ·almost all the matter.
The laser ablation method is based on nonlinear
phenomena caused by a · laser with a high output
power. A laser beam with an extremely strong field
intensity generates plasma on the surfaces of me'tal
samples to produce large amount of neutral atoms
as well as ions.
The schematic diagram of the experimental setup
is shown in Fig. 1. The half of the output energy(60 m] per laser pulse) ofaXeCI excimer laser wasused to generate neutral atoms. The laser beam was
focused on the surface of a metal sample (AI, Sr, Na,or Cu) placed in a proportional counter filled witha pure Ar gas (1 atm) to multiply ionization signals
and to prevent neutral atoms from chemical reactions.
Neutral atoms generated were ionized resonantly byirradiation of single or two pulses of a · dye laser
according to the ionization scheme of atoms concerned. A chopper cut off the output beam of the
XeCI laser every two shots. Photoionization signals
were detected with a proportional counter when the
XeCI laser beam was not in the counter. The output

signals from the proportional counter were amplified
and averaged by using a boxcar integrator. The
intensity of the averaged signal' was· recorded against
the output wavelength of the dye-laser pulse (1 m] /pulse).
,
Spectra observed are shown in Fig. 2.
( 1 ) Aluminum
Peaks I and II are due to the coincidence of thelaser frequency with the 4S 1 / 2 -3P 3/2 and 4S 1 / 2 -3P1 /2
transition frequencies of AI, respectively. Dependenceof the intensity of peak II on the output energy ofthe dye-laser pulse was measured. From this measurement almost all the Al atoms in the ionization area
are ionized at output energies above 0.1 m]. The
intensity ratio of peak I to peak II is 0.6 and agreed
with the population ratio of the 3P3 / 2 state to the
3P1 / 2 state at room temperature.
(2) Strontium
Peak III is due to the coincidence of the laser
frequency with that of the SP1 -SS 0 transition of Sr.
(3) Sodium
Peaks IV and V are due to the coincidence of thelaser frequency with the 3P 1 / 2 -3S 1 / 2 and the 3P3 / 2 3S 1 / 2 transition frequencies of Na, respectively. The
intensity of peak IV is not equal to that of peak V.

H.V.
r----------I

Dye
Laser

Trigger

XeCl Laser

BoxcarIntegrater

Counter'-------1

Dye
Las e rTriggerFig. 1.

Schematic diagram of an experimental setup.

* Department of Physics, Faculty of Science, Toho University.

Frequency
Divider (1/2)

M. Otsuki, et al.

(a) AlThis result suggests that the output power of thepulsed dye-laser was not enough for almost complete
ionization of Na atoms in the ionization area.
(4) Copper
Peak VI is due to the coincidence of two times
the laser frequency with the 6S 1 / 2-4S 1 / 2 transition
frequency of Cu. Two-photon absorption takes place.
Using the sensitivity of the proportional counter,
we estimated the densities of neutral atoms at
1010 cm- 3 •(b) Sr
II

III

I

~

r-:\O """"

0'10'1

0'1

MM

M

M

~
M

(e) Na

co

r-.

N
\0

00
\0 \0

""

"" ""

(d)

~

Cu

V

a
'""": ~ ~0'1 0'1
en co co
lJ")

""

lJ")

Lf)

r-.
\0
<Xl
lJ")

a

r-:
00

M

0

;Q

177

""

co

r-.
M

Fig. 2. Observed spectra for AI, Sr, Na, and eu atoms.

178
RIKEN Acce1. Prog. Rep. 21 (1987)

111-5-14.

Observation of Two-Step Photoionization of a Na Atomic
Beam Using cw and Pulsed Lasers
T. Minowa, H. Katsuragawa, and M. Shimazu *Recently we have carried out highly sensitive resonance ionization spectroscopy (RIS) of a TI atomic
beam by a time-of-flight (TOF) method1) and wereable to detect TI atoms of a density of 20 cm-S • As
next step we observed two-step photo ionization of a
Na atomic beam to demonstrate the applicability ofthe technique used in RI8 of a TI atomic beam andthe possibility to construct high-resolution laser
spectrometers with high sensitivity.
The schematic diagram of an experimental setup
is shown in Fig. 1. The output beam of a cw dyelaser was admitted into a vacuum chamber containing a Na atomic beam source, the two beams
being collinear. The cw dye-laser had an output
power of 10mWand the width of the output wavelength of 0.1 nm at 590 nm and was used to excite
Na atoms from the ground electronic state (3S 1/ 2)
to the 3P 3/2 state; emission due to the 3P 3/2-381/2
transition is well known as the D2 line (589.0 nm) .
Na atoms were evaporated from a Na sample byheating and collimated through two baffles having
holes (3 mm in diameter) at centers.
The output beam of a pulsed dye-laser pumped
by a XeCI excimer laser was focused on the Na
atomic beam in a crossed way. Because the wavelength of the output beam of the pulsed dye-laser
is 390 nm (3.18 eV) and the ionization potential of
Na is 5.14 eV, Na atoms in the ground electronic
state were ionized by two-photon absorption. The

VACUUM
CHAM BE R

ATOMIC BEAM
SOURC E

Fig. l. Schematic diagram of an experimental setup. T AC,
time to amplitude converter; MCA, multichannel analyzer.

* Department of Physics, Faculty of Science, Toho University.

a

>-

I-

~ 0

w

~1

IV

b

--l

<!
Z

t')

Vi

o
o

0.5

1.0

TIME OF FLIGHT (us)Fig. 2. Time-of-Hight spectra, (a) Na atomic beam source
is not heated. (b) Na atomic beam source is heated.

Na atoms populated in the 3P3/ 2 level with theresonant cw dye-laser beam can be ionized by single
photon (390 nm) absorption.
Na ions and electrons generated by irradiationof the pulsed dye-laser beam were detected with apair of CERATRON detectors (MURATA EMW6081B). The arrangement of electronic devices for
detecting ions and electrons were described in detailin Ref. 1. Electron signals were used as the time
origin for the TOF measurement because the TOFof electrons was negligibly short compared with thetime resolution of the electronic devices. Only ion
signals having the TOF corresponding to Na ionswere recorded in order to reduce the backgroundnoise.
The TOF spectra obtained are shown in Fig. 2;(a) the Na atomic beam source is not heated and(b) the source is heated. Peaks I, II, and I'll in(a) appear to correspond to C, C 2 , and C 3 ions,
respectively. These ions would be generated by dissociation and ionization of molecules of diffusion
pump oil. When the Na atomic beam source reaches
a temperature enough for Na to be evaporated, TOF
signals due to N a ions appear on the TOF spectrum(peak IV in (b)). Signal intensities due to Na ion
were recorded against output energies of the pulsed
dye-laser. This result suggests that the saturation
condition is fulfiled at energies above 1 mJ per pulse.
The peak power density at the ionization area isestimated at 109 W jcm2 at the output energy of

T. Minowa, et aI.

1 m] per pulse.
Intensities of Na ion signals under both conditions,where (a) the outp:ut, be9-~ of the cw laser· is tuned
to the 3P3/2-3S1/2 transition of Na (on resonance)and (b) it is detuned (off resonance), were recorded. 'The signal intensity under the condition (a) was
larger than that under the condition (b) by a factor
of about 3. The output energy of the p~sed qye- :laser was kept at about 0.4 m] per pul~ein , ;:these,:measurements. The increase in Na ion signal intensity

is due to excitation oLNa atoms by the resonant cw
dye-laser beam. This result means that a highly
sensitive las~r spectrometer with high resolution canbe . constructed by using the combination of a highresolution cw las.e r and a high power pulsed laser.
Reference, 1) H. Katsuragawa, T. Minowa, M. Shimazu, and T. Ina... mura: ' Nucl. Instrum. Methods B, 26, 440 (1987).

.,'.' I ~ . ; :

.

' f

'

. ,' " .. . . I

•.

179

180
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-15.

Development of the Parallel Plate Avalanche Counterfor the Time-of-Flight Measurement
H. Kumagai, M. Fuse, E. Gotoh, M. Fukuda,
K. Asahi, and M. Ishihara

We have been investigating for these three years
the characteristics of a parallel plate avalanche
counter (PPACP) and constructed several different
types of PPAC. Taking advantage of the highcounting rate capability and the high resistanceagainst radiation damages, these counters have provento be very useful as heavy-ion detectors. Several
counters designed for the angular distribution measurements have been successfully used in the atomic
physics 2 ,3) and nuclear physics4 ) experiments. Here
we report a recent application of the PPAC to thetime-of-flight (TOF) measurement for heavy ions.
PPAC is a low pressure gas detector with small thickness, it can be used for timing measurements withoutcausing substantial change in the energy of detectedparticles.
The structure of the PPAC currently constructed
for the TOF measurement is shown in Fig. 1. The
counter has an effective area of 50 mm X 50 mm andcomprises an anode and two cathodes. The anodeis made of a 2 pm thick Mylar film, on both sidesof which 40 pgjcm2 thick gold layers are deposited.
Each of the two cathodes, one providing the position
sensitivity for the x-direction and the other for the
Y-direction, consists of ten strips of a gold layer of
4.5 mm wide and 40 pgjcm2 thick with 0.5 mm interstrip spacing, which are fonned by evaporating gold
on a 2 pm thick Mylar film. The anode and thetwo cathodes are aligned parallel to one another with
3 mm spacing, as shown in Fig. 1. They are installed
in a chamber filled with the isobutane ( 10 Torr).
Each strip in the cathodes is electrically connected tothe two neighboring strips through 2 ns delay lines.
Signals from the strips are read out from both endsof the strip chain, and thus the time difference between the two pulses propogating through the different paths is used to identify the strip in which theparticle is detected.
Figure 2 shows the position spectrum obtained witha particles from an 241Am source. In this measurement a shielding plate with holes of 1 mm in diameter
was placed in front of the detector. The a particles
were collimated with these holes so that they wereincident at the central part of each strip. The full

X2
CathodeFig. 1. Structure of the PPAC developed for the TOF
measurement.
10 7

448
10 6

1 o~
...J
UJ

.:z
~ 10 4:x:Q"-~ 10 J
:z:

=>
0

U 102

10 1

512

CHANNEL NUMBER
Fig. 2. Position spectrum obtained with a particles froman 2UAm source. The a particles are collimated so as to
be incident at the central part of each cathode strip.

width at half maximum (FWHM) of about 1 mm
was obtained, showing that the timing property wasgood enough for the identification of the strip.
A TOF measurement using two PPACs of thistype was performed in December 1987 during anexperiment4 ) on the total reaction cross sections forunstable nuclei. Arrangement of the counters and atarget is schematically shown in Fig. 3. Use of theH. Kumagai, et al.

181

Primary Beam
Production Target
SW-magnet

Slit-2

PP AC -I

Ql

Detector
Chamber

Q2

Slit·l-;- - - ...... - ............ ............... ...... ......
:

PPAC-2--............ . . ............ ...... ...... . . . . ...... .................. ............... . . ...... ................. ...... ...... - -... ...... ...... . . ............ ... _... _,

tlEOI

tlE02

Second a ry
Target

tiE l

t. E2

E

E- ve t o :D

Fra gments

150 11m

100 11m

250 11m

300 11m

300 mm2 200 mm2

300 01012100 01012

2000 11m

2000 11m

200 mm2

200 mm2

Detector Chamber

Fig. 3. Schematic view of the arrangement for the target, PPACI, PPAC2,and solid state detectors (SSD) used in the experiment on total reaction
cross section for unstable nuclei. Particles from the target are defiectedwith a dipole magnet, pass through a slit, and are focused at the focal
point inside a detector chamber, in which PPAC2 and the six SSDs are
installed.

position sensitive counters not only provided a means
to monitor the beam profile, but also gready reduced
the uncertainty in flight time determination due tothe position dependence of the propagation delay forthe anode signal. In fact, without position detection
the uncertainty would amount to +0.13 ns (taking
the value 5 ) of 19 cm/ns for the signal propagating
speed along the electrode), corresponding to +2.5 cm
uncertainty in . the propagation path (determined by
the size of the anode). By simply detecting the position to +0.25 cm uncertainty (the cathode strip size) ,this ambiguity was reduced by a factor of 10.
A simplified block diagram of the electronics used
for the TOF measurement is shown in Fig. 4. The
trigger signal for the data acquisition was obtained
from the 3-fold coincidence among the anode signalof PPAC2 and timing signals of two solid state
detectors (LIE 1 and JE2). Pulse durations of the
LlEl and LlE2 signals fed to the coincidence circuit
were chosen to be so long that the leading edge ofthe trigger signal was solely given by that of the
PPAC2 signal. Cathode signals of PPAC 1 andPPAC2 were fed into an 8-ch Time-to-Digital Converter (TDC), thus providing the position information in the way described above. The TOF measurement for detected particles was made by using aTime-to-Amplitude Converter (TAC). The start andstop signals were obtained from the anode signals of
PPAC2 and PPAC 1, respectively. T AC was care-

Fa s tDela yCFD

CPO : Constant Fraction Discriniinator~ : TiJre to Allplitude COnverter'ltX: : TiJre to Digi tal convertet

Fig. 4. Block diagram of the electronics used for the TOF
measurement.

fully calibrated by using an ORTEC 462 Time
Calibrator. Furthermore, in order to minimize theerror originating from possible non-linearity of theTAC, a reference peak in the TAC spectrum wasrecorded by replacing the PPAC 1 and PPAC2 signals
with a standard pulser signal and by inserting astandard delay line whose delay time was accurately
known (to ±0.03-ns accuracy) before the stop input.

H ; Kumagai, et al.

for the 180 particles was deduced to be 85.56 +0.06 ns. This value includ~s a correction for thedifference (measured to be 0.06 ns) between thesignal propagation 'times in the anodes of the two
PPACs. Combined with the measured length of739. 7 + 0.2 em for the flight path from PPACl to
PPAC2, the kinetic energy of the 1 8 0 particles·10·

6 . SSr---~--~----~~~____~__~____~__~

.-I
re
co M
.

' 0

U)

co 0

- +1
H

<I)

U1

..J

W

:z: -1.10
:z:
<:
:z:
~ 3.28O"I.re

~U)

·0
U)

CO O

~+I

£ El\l! .,,0

EjA=41.32 ± 0.08 MeVju

(f)

l-

S 2.<\6was obtained. Taking into account the energy loss
'in PPACl (0.08 MeV ju), the EjA value thus obtained indeed agrees very well with that calculated
from the employed values of parameters for the beam
acceleration. The excellent accuracy (0.2 %) obtainedin the energy determination demonstrates the usefulness of the position-sensitive PPAC in heavy-ion TOF
measurements.

o

<.)

1.64

0.82

O. 0237nS /ch°1 38 8

H52

CHANNEL 'NUMBER

Fig. 5. Time spectru~ obtained for the 18 0 beam fromRIKEN Ring Cyclotron. Reference peak recorded by replacing the PPAC signals for TAC inputs with a pulser
signal and by inserting the standard delay line befor,e t~e, References
stop signal is also shown.
.f.', ,..
,. . ~
1) H. Kumagai, S. Sasagase, and T. Wada: Reports I.P.C.R. ,62, 114 (1986) . (in Japanese) .
2) Y. Kanai, Y. Awaya, T. Kambara, M. Kase, H. KumaThe absolute value for the 'TOF was obtained bygai, T. Mizogawa, and K. Shima: Nucl. Instrum. Meth comparing the observed peak for the particles withods A, 262, 128 (1987).
the reference peak.
3) T. Tonuma, T . Matsuo, H. Kumagai, S. H. Be, and
H. Tawara: p. 84 in this report.
Figure 5 shows the time spectrum obtained for the184) M. Fukuda, M. Ishihara, 1. Tanihata, K. Asahi, T.
0 beam from RIKEN Ring Cyclotron. From the
Ichihara, T. Kubo, M. Adachi, M. Koguchi, and H.
observed difference in peak position between the deKumagai: p.21 in this report.
tected particles and the reference signals, the TOF
5) H. Stelzer: ,Nucl. instrum. Methods, 133, 409 (1976).
c

\

183
RIKEN Accel. Prog. Rep. 21 (1987)

111-5-16.

Pileup Rejecter for a Position-Sensitive Parallel-Plate
Avalanche Counter
H. Kumagai

We have constructed1) a parallel-plate avalanche
counter (PPAC) capable of 9ne-djmensionalposition 'detection. This counter has been extensively used in
the studies of atomic physics. 2) The position analysis3 )was made by using an ORTEC Model 464 positionsensitive detector analyzer (PSDA). In these measurements, however, the obtained position spectra exhibited a broad 'peak presumably ascribed to an improper oper~tion of analyzing circuits. Although thesignals contributing to this spurious peak appearedwith only small probabilities (1 % or less in typical),it turned out to become a severe difficulty in certain
experimental situations.
The position analysis in PSDA involves peaksensitive detection of a pulse height" and thus the
spuri~us peak above can ' arise from two sources: i)the pileup due to the overlap of two successive pulses
and ii) the misassignment of the peak which occurs
when the peak part of a pulse is g~ted off during
processing time needed for a preceding ,pulse. The
probability for these events to occur increases withincreasing counting rate, and this spoils the advantage of the high-counting capability4) of PPAC.
To cope with this problem we developed a pileup
rejecter. The essential function of this , module is toblock the signals which are preceded or followed byother pulses with time intervals of 3 fls* or less.
The electric circuit for the pileup rejecter shownin Fig. 1 consists of three basic sections. The firstsection, shown in lower part of Fig. 1, includes six
integrated circuits (IC 1 to lC 6 ), and monitors a timeinterval between two successive pulses. A gate pulse
is generated when intervals of longer than 3 fls aredetected. The minimum separable interval between
two successive pulses is 20 ns. Actually this limitation introduces no difficulty in applying this circuit
to experiments at RIKEN Ring Cyclotron or RILAC,
since the beams from these accelerators are bunchedwith the intervals longer than 20 ns. The second
section (shown in the middle part of Fig. 1) consisting of IC 9 to IC ll generates a gate pulse with
3 flS duration. This pulse opens a linear gate (IC 13 )* This value is chosen so as to make the pileup effect benegligible for the pulse shaping time of 0.5 f.Ls as recommended in the PSDA instruction manual.

+15

-15

output-A"'-_-'-" Output-B

+12

+5

ADC

Fig. L

Circuit diagram of the pileup rejecter.

of the last section shown in the upper part. The
last section also includes an output driver stage withunit gain (IC 14 and IC 15 ).
Figure 2 shows the block diagram of the electronics
used for the measurement of position by using thepileup rejecter and PSDA. A timing signal for the
pileup rejecter was extracted from the anode. In
order to remove the events classified above as ii), thepileup rejecter was gated by BUSY signals fromPSDA and from ADC.
In Fig. 3 a position spectrum obtained with pileup
rejection is compared with that without rejection.
Two collimated a sources (241Am) with different
intensities were placed near the right- and left-handends of the detector window. The total counting

H. Kumagai

184

Anode
AIr. Busy In.

r

PPAC
----1

I
I
I
I
I

~
l-

t-

I
I

l-

I

lI-

I

I-

I

~
I-

I
I

l-

I
I

ll-

I

PSDA Busy

I

200ll I A

Position In.

~

«

x

c:

Q

0

Ul

t= ~

PositionOutIn.

I-I-~IN'-<>-=:"'-'~~ ___ _2QO.£l1

I

PSDA : Position Sensitive Detector Analyzer
Shap. Amp. : Shaping Amplifier
C.S. Amp. : Charge Sensitive AmplifierFig. 2.

Block diagram of the electronics used in the position measurement.

107·r---~----~----~--~----~----r---~----,

1 O~
-l

W
Z

~10i

without Pileup Rejecter

:J:
(.)

.......

~ 10J

::z::
o

::>

rate was 42.2 kcount/s. A peak ongmating from aweaker source is identified much clearly in the pileuprejected spectrum (lower) compared with the spectrum without pileup rejection, thus demonstrating
the effectiveness of the present pileup rejecter for
observation of weak contributions. A narrow peakon the right-hand side in the upper spectrum
originates from the saturated signals due to puleup
and is completely absent in a pileup rejected
spectrum.

(.) 1 O~

References

Count Rate
42,200 cps

512

CHANNEL NUMBER
Fig. 3. Position spectra obtained with (lower curve)
without (upper curve) using a pileup rejecter.

and1) H. Kumagai, T. Kubo, M. Ishihara, M. Fuse, and
E. Gotoh: RIKEN Accel. Prog. Rep., 19, 148 (1985).
2) Y. Awaya, M. Kase, T. Kambara, H. Kumagai, Y. Kanai,
T. Mizogawa, K. Shima, and T. Chiba: RIKEN Accel.
Prog. Rep., 20, 132 (1986).
3) H. Kumagai, S. H. Be, M. Ishihara, Y. Ikegami, M. Fuse,
and E. Gotoh: RIKEN Accel. Prog. Rep., 18, 164 (1984).
4) H. Stelzer: Nucl. Instrum. Methods, 133, 409 (1976).

J85
RIKEN Accel. Prog. Rep. 21 (1987)

IV.

NUCLEAR DATA
1. Status Report of the Nuclear Data GroupA. Hashizume, Y. Tendow, Y. Ohkubo, K. Kitao, K. Sueki, and T . Nozaki

In this period efforts were continued on the twoitems. The first is related to the nuclear data activity
concerning with the charged particle induced reactions. In this connection we cooperated with
Nuclear Data Section in International Atomic Agency( IAEA) and the Consultants' Meeting and 'Data Requirements for Medical Radioisotope Production' washeld at Kyoiku Kaikan in Tokyo from 20 to 24 inApril 1987. The objectives of the meeting are: tomake a survey of the medical radioisotopes in use andtheir production methods, to optimize the production
methods, to list reliable and generally available computer codes suitable for the calculation of excitation
functions of radioisotopes, to develop guidelines andpriorities for the compilation of available excitation
functions, to prepare an outline of the planned IAEA
Handbook Computer File, to consider the standard
monitor reactions, and to enquire into the availabilityof the appropriate target material.
The second is the mass-chain evaluation work of
nuclear structure for the implement of EvaluatedNuclear Structure Data File (ENSDF) and compilation of reference files originated in Japan.
(1) The work for the compilation of new EXFOR(Exchange Format for Experimental Data) files ofnuclear reaction cross sections has been continued.
The reactions which we mainly interested in are those
whose products are utilized for mediobiological applications. The cross sections of the reactions producing the following isotopes have been compiled in
the EXFOR file. The isotopes are 11C, 13N, 150,
18F, 28Mg, 52Fe, 67Ga, 68Ge, 68Ga, HAs, 17Br, 82Br,
17Kr, 81Rb, 82mRb, 111 In, 123Xe, 127Xe, 1231, 1241, and
125 1 nuclei. 1) We have also compiled the reaction
cross-sections for various combinations of which theabove primary interested reactions were investigated.
The compilation of the integrated nuclear reaction
cross-section data originated in Japan in the EXFOR
files is also continued. The main sources of recent
data are annual reports published by universities andinstitutes having accelerator facilities.
We are planning to publish a Data Book of excitation functions for the reaction which produce radioisotopes above mentioned. For this purpose, we are
now collecting complete cross section data fromEXFOR Files and/or from original reports. For thelisting of excitation functions, the use of flexible graphdescribing program completed last year is previewed.
As explained in the status report of the last year,2)
it is important to make clear the present status of thecross sections of standard monitor reactions. There
are more than 17 reactions which have been used
for this purpose. We collected the data on the
12C(p,pn)l1C, 27AI(p, 3pn) 24Na, 63Cu(p,2n)62Zn,
and 65CU(p, n)65Z n reactions. 3,4)
The computer code ALICE to calculate nuclear
reaction cross sections in compound and precompoundprocesses can be now used. This code will be served
for the evaluation of experimental data. The parameter search of the code has been done for thereaction 1271 (p, 5n)1231 and other reactions. 5,6)
The center host computer M-780/10s has been replaced with an M-780j10 which economize about
10% for cpu time. We have also used a microcomputer PC9801.
(2) F or the mass chain evaluation of nuclear
structure data, the proofreading on the mass 120 had
been made, compiled in the ENSDF (EvaluatedNuclear Structure Data File) of NDC at Brookhaven National Laboratory and published in the
Nuclear Data Sheets from Academic Press. The
evaluation work on the nuclear structure of theA = 177 mass chain has been continued.
The recent reference files published periodically by
Brookhaven National Laboratory should cover allreferences in the field of nuclear physics, but thereports in Japan were not completely filed. The
references of annual reports and quartery 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 Japan Atomic Energy Research Institute.
References
1) A. Hashizume, Y. Tendow, Y. Ohkubo, T. Nozaki, andK. Kitao: RIKEN Accel. Prog. Rep., 20, 152 (1986).
2) "Report on the 8th IAEA Consultants' Meeting of the
Nuclear Reaction Data Centers," Oct. 1985, INDC
(NDS) -178.
3) A. Hashizume, Y. Tendow, Y. Ohkubo, and K. Kitao:
p.186 in this report.
4) A. Hashizume, Y. Tendow, Y. Ohkubo, and K. Kitao:
p. 190 in this report.
5) K. Kitao, A. Hashizume, Y. Tendow, Y. Ohkubo, andK. Sueki: p.191 in this report.
6) K. Sueki and A. Hashizume: p . 195 in this report.

186
RIKEN Accel. Prog. Rep. 21 (1987)

IV-2.

Present Status of 63CU(p, n) 63 Zn and 65CU(p, n)65Zn
Monitor Reactions
A. Hashizume, Y. Tendow, Y. Ohkubo, and K. Kitao

The 63CU (p, u) 63Zn and 65CU (p, n) 65Zn reactions
have been frequently used for monitor reactions to
obtain integral reaction cross sections in activation
method. The threshold energies of these reactions
are 4.21 and 2.17 MeV for 63CU(p, n) and 65CU(p, n)reactions, respectively. Since these values are lower
than that of the llC(p, n) or Al(p, x) 24Na, a copper
target can be used as the monitor in the low energy
region. Copper with a natural isotopic abundance
can be used as the target, because the half-life of
Table 1.
First author

Place

Ref.

63Zn is relatively short (38.1 m) and that of 65Zn islong (244.1 d) and that their r rays which are usedas determinations of activities can be separated in a
r-ray spectrum. Many studies have been made on
excitation functions comparing . other kinds of reactions.
63CU (p, n) 63Zn reaction: This reaction has been
investigated since 1950.1 ) The range of incident
proton energies used for bombardment lies from thethreshold to 11.5 Ge V; however, the data are scarce

Reaction list of 68CU (p, n)68Cu.

Target Beam energy Detector(mg/cm2)*(MeV)

S.N. Ghoshal (Berkeley)

1)J.-P. Blaser (Zurich)
J. W. Meadows (Massachusetts)

8.3, 0.85 6.45±0.03
100, 70±10.01"
40
20±0.401O±0.535±0.94

GM
GM
NaIx2

n longcounterppc,
NaIx2

3.2-26GM

H.A. Howe(California)

2)
3)
4)

R.D. Albert(California)

5)

1.5

J. Wing(Argonne)6)

H. Taketani(Rochester)7)

L.F. Hansen(California)

8)10.5-4.5
1O±0.155±0.5
4.1- 6.5
69.09% :
0.1
4.26, 5.03
99%: 4.43
1.5-8
5. 2- 11

K. Chackett(Birmingham)

9)0.001 in.

R.M. Humes (Ohio)10)

not given

6.75

G.F. Dell
J.E. Cline(Ohio)(Idaho)11)

12)

2.5 pm50-1000

6.75
590

M. Hille(Mlinchen)

13)

Wpm

8.7-168.7±0.2

Ge(Li)

E. P. Steinberg (Argonne)

14)

several

1. 5-11. 5
GeV
2.86-25
0.10

ppc,
chem. sep.
Ge(Li)

25-50

GM

9.85

5

R. Colle

(BNL)

15)

5-15

Y. Yoshizawa(Hiroshima)

16)

Wpm

Errors and comment
typical error: 9%, Tl/ 2 =38 m,
Ip+=93%, IEcK=7%.
not reported, Tl/2= 38 m
relative to 27Al(p,3pn)2·Na
3% (uncertainty of EC correction
is not included), (det. eff.: < 1%,
stand. source: 2%), Tl/2= 38. 3 m
I p+=89.3%
7% (the detail is not reported)<10%, Tl/2=38.3m, Ip+=93%

NaIx2

6% (T*** thick: 3%, I beam : <3%,det. eff.: 3%), Ip+=89.8%

n longcounter9.3±0.3** NaIx2

7% (A long counter was calibrated
by MnSO,)
4.2% (stand. source: 2%,
beam integrator: 1%)

ppc,
NaIx2
NaIx2
Ge(Li)

5.4% (the detail is not reported)

5.4%, T 1I2 =38 m, Ip+=90%
13% (det. eff.: 5%)
relative to 27 Al(p, 3pn)2fNa
6% (det. eff: 3%, statistical: < 1%,
photo peak area: 3%, T thick.: 3%
I beam : 2%, Tl/ 2 : 1- 3%)
5-10%, monitor 27Al(p,3pn)2'Na
7-12% (Ibeam: 1%,
number of T atoms: 1-1. 5%,
T thick.: 1-1. 5 %, statistical: < 3 %T 1I2 : 3%, det. eff.: 5-10%,
IT: 1-4%)
10% (detail is not reported)
Isotope Separator on Line was used.

A. Hashizume, ~t al.

Table 1.
First author

Place

187

(Continued)

Target Beam energy
Ref. (mg/cJll2)*(MeV)

Detector
Ge(Li)A. Grutter(Wurenlingen)

17)

0.1
0.05

M.E. Sevior(Melbourne)

18)

99.89%

16.1-69.8
70±0.5316±1.6
4.21 - 4.86

BFa inparaf.

Errors and comment
3-5%, relative to 65Cu(p,n)65Zn
T l/2 =38.47 m,
I r {669. 6)=8. 40%
11% (Ibeam: 2%, number of
T atoms: 2%, n detection: 10%)* If unit is not given, the thickness is represented by mg/cm 2•** Energy spread due to target is included.
*** T: target
Table 2.

Reaction list of 65CU(p, n)65Zn .

TargetBeam energy(MeV)(mg/cm2)*

Detector

8.3, 0.85 6. 5±0. 25
0.01/15-100
70±1
uniform.
1O±O.535±O.94
<0.5%

GM
GM

not reported, Tl12 = 250 d
relative to 27 AI(p, 3pn)2'Na

NaI

3% (uncertainty of EC correction
is not included), (det. eff.: < 1%,
stand. source: 2%), Tl/ 2= 38. 3 m,
1,8+=0.893
7% (the detail is not reported)

First author

Place

Ref.

J .-P. Blaser(Zurich)

J.VV.Meado~s (Harvard)

2)
3)

H . A. Ho~e(California)

4)

R.D. Albert(California)

5)

1.5

9.85

B. VV. Shore(Massachusetts)

19)0.25 mil

7.5

K . F. Chackett (Birmingham)

9)

0. 001//

6)

5

R.M. Humes (Ohio)
G.F. Dell(Ohio)

10)
11)

2.5 p.m

9. 3± 0. 3** NaI, ppc
chem. sep.
1O.5 ± 0.15 Nalx2
5±0.5
6.75
NaI,ppc
6. 75
NaI,ppc

I. R. VVilliams

20)

J. VVing(Argonne)

M. VV. Greene (BNL)

21)

0.005- 0.02/1 60±0.35
40±0.55
7
16-32.8

R. Colle

(BNL)

15)

' 5":'15

E. Gadioli(Milano)22)

30.91%
42.52 mg

(Oakridge)

2.86- 25
0.10

n longcounter
NaI, CsI

Ge(Li)

G~(Li)'

Ge(Li)

10.2- 44.3 Ge(Li)18±0.25
1O±0.35
2.15-4.0 BFa ~ith
Z. E. S~itko~ski(Melbourne)
23)
paraf.
(Wurenlingen)17)16.1- 70
A. Grutter
0.1 , 0.05
Ge(Li)
70 ± 0.53
16±1.6 '2.2- 3.2
M.E. Sevior (Melbourne)
18)
5keVatBFa in2.2MeV
paraf.
P. Kopecky
22.8
4.42- 32.4 Ge(Li)(Rez, Czeck.)24)
32.7±0.2
14. 5±0.45
13.0±0.2
4.42±0.4* If unit is not given, the thickness is represented by mg/cm 2.
** Energy spread due to target is included.
*** T: target

Errors and comment

3. 7% (~eighing: 1%, statistical: 1%,
coin.: 3%, h eam: 1%,
beam integrator:<I%, Tl/ 2 : 0.5%)
3.9% (calib. source: 2%, heam : 1%)
IEc=98. 3+0.1 %<10 %, T 1I2 =245 d,
Ir (1120)=0.49
6.5% (the detail is not reported)
5% (the detail is not reported)
Tl/2= 248.5 d, Ir (1114)=0.49
30%, I beam : 1%
Tl/ 2=245 d, Ir (1114)=0.45
10%, (T*** thick.: 1%,
statistics: 3%, det. eff. : 3%)
9% agreement to l2C(p,n)l1C
7- 12% (Ibeam: 1%, T: 1-1.5%,
T thick: 1-4%, statistics: <3%
Decay: 3%, det. eff.: 5-10%)
Ir (1114) = 0. 506±0.004.
<10%, Tl/ 2= 246d, I r (I115)=0.49

normalized to 73Coool data
3- 5% (errors caused by decay data
are not included), I r(I115)=0.5075
11 % (det. for n: 10% , det. forI beam : 2%, T: 5%, IT: 2.5%)

5-8% (beam integrator: 0.5%,
T thick.: 1%, det. eff.: 4%,
statistics: <2 %,peak area= 1. 9 - 6.8%)

r

r :9%

A. Hashizume, et al.

188

above 70 MeV. Authors, target thicknesses, incident
beam energies, detectors employed, errors, and others
are listed in Table 1. In 1950s, activities were determined by counting positions with GM counters basedon an emitting probability of 89.3 or 90 %, which
is lower than the commonly adopted value of 93 %by Auble. 25 ) Therefore, a correction of about 3 %should be made for the difference. The data of 14
experiments up to 70 MeV of incident energies areplotted in Fig. 1. In the figure the plots were notcorrected to show the differences. The results of
Meadows 3 ) deviate toward high values. The dataof Albert5) and Chackett9) is also about 35 %higher than Colle's15) data at 9.3 MeV. The
agreement between Colle's15) and Grutter's17) results,
which were obtained from the most recent precise

measurements, is good. Yoshizawa's results obtainedby using ISOL were interpreted tentatively as 63CU_(p, n) and not nlltcu(p, n), because by this interpretation, the data are reasonably normalized toMedows' results at 25 MeV as explained by theauthors. However the disagreement between Grutter'sand Y oshizawa's results are apparent; a precise
measurement above 22 MeV is needed.
65CU(p, n)65Zn : All experiments done for thisreaction are shown in Table 2, and 17 experimental
results were plotted in Fig. 2. One observes the deviation toward high values for the results obtained
during 1950 and the beginning of 1960 (Howe/)
Chackett,9) Humes,lO) Williams. 20 ) The agreements
among the data of Colle/ 5) Kopecky24) and Grutter17 )are good, though there is a systematic trend that1000 : rnnr I I I I i I I I i i i j I i i I I I I I i i i I I I I I i I [ I I I I I j I I I i i I I -I Ii I I I I ( i I I I i I I i i i I I i I

63 Cu (p,n)63 Zn

Vl

c 100 o

L

.D

E

8

j

0

€I

o

0

~

10

~

,,,,I,,,,,,,,,I,,,,,," ,I,,,,,,,,,I,,',," ,,I,,,,,,,,

0 .0

2 0.0

60 .0

40.0

,j
80 .0

ENERG Y (Me V )Fig. 1. Compiled cross sections for the eacu (p, n) oaZn reaction .

..

o

o

o

10
-

8

o

0

0

o

- ~
o

0.0

20.0

40.0

60.0

ENERGY (MeV)
Fig. 2. Compiled cross sections for the ·Cu (p, n) OISZ n reaction.

8 0. 0A. Hashizume, et al.

Grutter's results are smaller than Kopecky's. The
data of Greene21 ) and Gadioli22 } are larger than thoseof Colle's or Grutter's results. Reinvestigation above
20 MeV are required.
References
1) S. N. Ghoshal: Phys. Rev., 80, 939 (1950).
2) J.-P. Blaser, F. Boehm, P. Marmier, and D. C. Peaslee:

Helv. Phys. Acta, 24, 3 (1951).
3) J. W. Meadows: Phys. Rev., 91, 885 (1953).
4) H. A. Howe: Phys. Rev., 109, 2083 (1958).
5) R. D. Albert and L. F. Hansen: Phys. Rev. Lett., 6, 13(1961) .
6) J. Wing and J. R. Huizenga: Phys. Rev., 128, 280 (1962).
7) H. Taketani and W. P. Alford: Phys. Rev., 125, 291(1962) .
8) L. F. Hansen and R. D. Albert: Phys. Rev., 128, 291(1962) .
9) K. F. Chackett, G. A. Chackett, and L. Ismail: Proc.
Phys. Soc., SO, 738 (1962).
10) R. M. Humes, G. F. Deli, Jr., W. D. Ploughe, and H. J.
Hansen: Phys. Rev., 130, 1522 (1963).
11) G. F. Dell, W. D. Ploughe, and H. J. Hausman: Nucl.
Phys., 64, 513 (1965).
12) J. E. Cline and E. B. Nieschmidt: Nucl. Phys., Al65,189

437 (1971).
13) M. Hille, P. Hille, M. Uhl, and W. Weisz: Nucl. Phys.,A198, 625 (1972).
14) E. P. Steinberg and L. Winsberg: Phys. Rev. C, 7, 1410
(1973) .
15) R. Colle, R. Kishore, and J. B. Cumming: Phys. Rev. C,
9, 1819 (1974).
16) Y. Yoshizawa, H. Noma, T. Horiguchi, T. Katoh, S.
Amemiya, M. Itoh, K. Hisatake, M. Sekikawa, and K.
Chida: Nucl. Instrum. Methods, 134, 93 (1976).
17) A. Grutter: Nucl. Phys., ASS3, 98 (1982).
18) M. E. Sevior, L. W. Mitchell, M. R. Anderson, C. I. W.
Tingwell, and D. G. Sargood: Aust. J. Phys., 86, 463(1982) .
19) B. W. Shore, N. S. Wall, and J . W. Irvine, Jr.: Phys.
Rev., 123, 276 (1961).
20) I. R. Williams and C. B. Fulmer: Phys. Rev., 162, 1055
(1967) .
21) M. W. Greene and E. Lebowitz: Int. J. Appl. Radiat.
Isotopes, 23, 342 (1972).
22) E. Gadioli, A. M. G. Strini, G. Lo Blanco, G. Strini, and
G. Tagliafferri: Nuovo Cimento A, 22, 547 (1974).
23) Z. E. Switkowski, J. C. P. Heggie, and F. M. Mann: Aust~
J. Phys., 31, 253 (1978).
24) P. Kopecky: Int. J. Appl. Radiat. Isot., 36, 657 (1985).
25) R. L. Auble: Nucl. Data Sheets, 28, 559 (1979).

190
RIKEN Accel. Prog. Rep. 21 (1987)

IV-3.

Present Status of a Monitor Reaction AI(p, x)24 Na
A. Hashizume, Y. Tendow, Y. Ohkubo, and K. Kitao

In obtaining integral cross-sections from experiments, there are many sources which cause errors.
An important systematic error comes from the estimation of a beam flux. The beam flux is usually
measured from the electric currents of an incident
beam in a Faraday cup. However, without sufficient
precaution, the measurement would be accompanied
by an unexpected error. Part of the charge collectedin the Faraday cup would be changed because
secondary electrons, ions and electrons produced by
the secondary electrons and / or by ionization of gas
remaining in a vacuum would escape from the
Faraday cup.
Instead of the absolute measurements of beamenergies and currents, the cross sections are obtainable
relatively to known cross sections of monitor reactions. The use of a monitor reactions also hasan advantage when a Faraday cup cannot be usedin such a case as for internal beams of high energy
accelerators.
F or the production of radioisotopes protons aremost extensively used, and the monitor reaction,
12C(p, pn)l1C, has been studied since 1950 to increase the accuracy of the cross sections in a wide
range of incident proton energies.1) This reaction
has the threshold of 18.5 MeV.
Because of its relatively high threshold, otherreactions are often used as monitor reactions for thereactions of which products are useful for medical
applications; another reason is that aluminum or
copper is a very accessible material for the target andoften used as energy degrader in the stack foil
method. The monitor reactions other than 12C (p,pn) 11C include AI(p, x) 24Na, 63CU(p, n) 63Zn , 65CU(p,n) 65Zn, and about 13 kinds of other reactions. 2 )However, since no evaluated values of cross sections
are available for these reactions, it is needed tocompile and evaluate these values of cross sections.
As the first step we compiled the integral cross sections measured by the 27AI(p, x) 24Na reaction.
The cross sections available for the 27AI(p, x) 24Na
reactions are plotted in Fig. 1, which shows large
discrepancies from the threshold to about 70 MeV
among different experiments. The disagreement still
exists over the cited errors even at 80 MeV. One
reason for these discrepancies could be attributed
to the estimation of energies which were degradedby targets and absorbers from incident values. The~?i ! ~ ~~ ~ ~ o-~-9'0 -9-. -9- -,. -9-. -9- -9i-9- -9--9- -9-.-9- - -10tS .r,,<r

~o _·

Vl

c

~-

tk'

.D
• .!.

'E

;

•
...

b

0.1
<;>

0 . 0130

70

cumming ref 1
Hicks

ref 3

Wiliams ref 4+

Miyano

ref 5
ref 6

~

Holub

q

Hogan

ref 7

9

Michelref 8

110
ENERGY ( Me V)

150

190

Fig. 1. Cross sections for the Al (p, x) !UN a reaction as afunction of energy.

recent values obtained by Michel et aZ. S ) are determined relatively to the cross sections of 27Al (p,x) 22Na. Above 100 MeV, the agreement between
Michel's and Hicks' results is good, though Hicks'
values3) are systematically smaller than Michel'svalues. The results of Holub show a pronounced
sharp peak at 65 MeV. 6) It is not clear whether
or not the energy resolution in the experiments ofHolub is better than the other experiments, because
neither the beam condition nor target thickness is
explicitly given.
References
1) J. B. Cumming: Nucl. Phys., 49, 417 (1963).
2) A. Hashizume: INDC (NDS) -196/GZ, 37 (1988).
3) H. G. Hicks, P. C. Stevenson, and W. E. Nervik: Phys.
Rev., 102, 1390 (1956).
4) I. R. Williams and C. B. Fulmer: Phys. Rev., 162, 1055
(1967) .
5) K. Miyano: l. Phys. Soc. lPn., 34, 853 (1973).
6) R. Holub, M. Fowler, L. Yaffe, and A. Zeller: Nucl.
Phys., A288, 291 (1977).
7) J. J. Hogan and E. Gadioli: Nuovo Cimento A, 45, 341(1978) .
8) R. Michel, F. Peiffer, and R. Stuck: Nucl. Phys., A441,
617 (1985).

191
RIKEN Accel. Prog. Rep. 21 (1987)

IV-4.

On the Cross Sections for 77Br Production Reactions
K. Kitao, A. Hashizume, Y. Tendow, Y. Ohkubo, and K. Sueki

One of the roles of the evaluation of nuclear
reaction data is to provide the best reference forthe bench mark test of computer codes on thecalculation of excitation functions and to provide
the basic data for estimating the optimum irradiation conditions for the cyclotron production ofradionuclides. From this point of view, the statusof the experimental excitation functions for the production reactions of 77Br (T1/2 = 56.0 h) were discussed.
Radioactive isotopes of bromine have been considered suitable to prepare labelled radiopharmaceuticals. At present some comprehensive reviews
exist on productions and applications of the isotopes.
These are:1) G. Stocklin: Int. J. Appl. Radiat. Isot., 28,
131-147 (1977)
2) S. M. Qaim and G. Stocklin: Radiochim.
Acta, 34, 25-40 (1983)
3) M. J. Welch and K. D. McElvancy: Radiochim. Acta, 34, 41-46 (1986)
4) S. M. Qaim: Appl. Radiat. Isot. (Int. J.
Appl. Radiat. Isot. part A) , 37, 803-810 (1986)
5) B. Maziere and C. Loc'h: Appl. Radiat. Isot.
(Int. J. Appl. Radiat. Isot. part A), 37, 703713 (1986).
However, radiobromine compounds have been rarely
used in hospitals and clinics in Japan.
Our first object is to prepare a complete data
file for reaction cross sections concerning certain
radionuclide productions. The second object is toevaluate these cross sections so as to facilitate theproduction maker to use them for the estimation of
the yield of radionuclides concern. I t is also important to find out a reaction type and an energy
range to minimize the impurities. 77Br is one ofthese radionuclides selected, and we reexamined thepresent status of data and compared with the results
calculated by a code ALICE.
Bromine-77 can be produced directly by chargedparticle reactions with arsenic, selenium or bromine,
and also be obtained indirectly as the decay productof 77Kr (Tl/2 = 77.4 min) or the decay chain of
77Rb (T 1/2 = 3.7 min) - 77Kr. The spallation reactions with high-energy protons on molybdenum arealso used to produce 77Br. Since a method of
production of carrier-free 77Br by bombarding aparticles on arsenic was developed by Helus,!) various types of reactions and the target assemblies havebeen proposed to produce 77Br and 77Kr. Thicktarget yields and cross sections for the production ofthese nuclides were measured under various bombarding conditions and for target systems. 2-23 ) See
Table 1.
(1) Excitation functions
The 75As (a, 2n) 77Br reaction (75As has 100%
natural abundance) is most widely used for the
production of 77Br with bombarding energies of
28-30 MeV. The excitation functions were given
by Waters et ai.,S) Nozaki et al.,!3) Alfassi et al.,17)
and Qaim et ai. 28 ) Figure 1 shows these data to
be in good agreement in the energy range of 25
to 28 MeV, except for those Nozakj et al. 1S ) But
these data would become more reliable if Alfassi
had measured cross sections at energy of 20 MeV,or if Waters or Qaim had measured with energies
higher than 30 MeV. Qaim et al. 23 ) pointed
out the discrepancy to be ascribed partially to theuse of different target materials. In Fig. 1, theoretical cross sections calculated by using the code
ALICE/Livermore/82 are also included. Qaim etal. 2 3 ) have also measured cross sections of the reaction 75As (a, 2n) 77mBr and cross section ratios forthe isomeric pair.
The excitation function for the reaction 79Br (p,p2n) 77Br are difficult to measure, because, as shownin Fig. 2, the 79Br nuclide is also produced fromthe decay of 77Kr by the reaction 79Br (p, 3n) occurring simultaneously in the bombarding process.
Moreover, in proton energies higher than the threshold of the 81Br (p, p4n) reaction, when natural
bromine is used as target materials, the 77Br nuclide
is also produced from this reaction. For the reaction 81Br (p, p4n) 77Br, there is a similar situation.
These data were measured by Diksic et al. l l ) using
the isotopically 95.060/0 enriched 79Br and 97.81 %for 18Br. Diksic et al. l l ) also compared cross secrions
for the (p, xn) and (p, pxn) reactions on 79Br and81Br with some theoretical predictions by intranuclear
cascade and two pre-equilibrium models followed byequilibrium evaporation. He concluded, however,that none of the three computer codes was able
to reproduce all excitation functions satisfactorily.
The excitation function for the 79Br (p, 3n) 77Kr

192

K. Kitao, et al.

Table 1.

Production reactions and measured quantities.
Measured quantities

ReactionThick target yield
75 As (a, 2n) 77Br--

Excitation function

D

Waters et al. S)
Nozaki et al. IS )Qaim et ai.2S)

Helus
Nunn::et al. 5 )Nozaki et al. 18 )Alfassi et al.17)
Blessing et al. 18 )Dmitriev et al. 19 )Qaim e(al. 28 )~--75 As(a ,2n)17mBr- - - - - ---- -- -- -- -- ---Qaim et al. 28 )Qaim et ai. 28 )77S e (p, n)77Br

Norton et al. 8 )*Janssen et al. 15 )*Janssen et al. 15

7BSe (p,2n)17Br

Madhusudhan et ai. w*
Janssen et al. t5 )*Janssen et al. 15 )*79Br(p, p2n)77Br

Dikliic et ai. 6 )*Diksic et ai. 6 )*81Br(p, p4n)17Br

Diksic et ai. 6'*

Diksic et ai. 6 )*Br(d,pxn)77Br

Qaim et al.7)

76Se(SHe, pn)17Br

He Youfeng et ai. )*He Youfeng et al. 20 )*He Youfeng et ai.2O>

He Youfeng et ai. 20 )*--- -- - --'*Qaim et aU)
20

77Se(SHe,p2n)77Br---- - - - - - -----------Se(p,xn)77Br

Dmitriev et al.
Nozaki et al.l3)

Nozaki et ai.13)

Se(d,xn)17Br

Dmitriev et al. 19 )Se(a, xn)77Br

Dmitriev et ai. 19 )Mo(p, spallation)77Br

Grant et al. 16 )79Br(p,3n)77Kr

Diksic et al. 6)*
Nozaki et al.l8)
de Jong et al. 9 )de Jong et al. 10 )Weimeich et ai.'}.1)

Lundqvist et al. 12 )Nozaki et al. mde Jong et al. 9 )Diksic et al.11)*
Weinreich et ai.21)

81Br(p, 5n) 77Kr

Lundqvist et ai. 12 )Nozaki et al.13)
de Jong et al. 9)

Lundqvist et ai.12)
Nozaki et ai. tS )de Jong et ai. 9 )Dik"Sic et al. 6 )*Br(d,xn)77Kr

Qaim et al. 7 )Qaim et ai. 7 )76Se (SHe,2n)77Kr

de Jong et ai. tO )He Youfeng et al. 20

19 )- - - - -- -- - - - - -- - - - - - - -,*de Jong et ai. tO )He Youfeng et al. 20 )*He Youfeng et al. 20 )*He Youfeng et al. 20 )*de Jong et al. 10 )Se(8He, xn)77Kr

He Youfeng et al. 20 )76S e(a,3n)17Kr

Blue et al. 2 )*t

Br(a, xn)77Rb

Helus et al. 4 )t

* enriched targets were used.
t no data given by authors.

reaction with the 79Br enriched target was obtained
only Diksic. l l ) If bombarding energies are below
the threshold of the SlBr{p, 5n) 77Kr reaction, theexcitation function on natural bromine can be used
for the evaluation. Comparisons of experimental

excitation functions of this reaction are shown in
Figs. 3 and 4: there are considerable disagreement
between these data. In all these experiments, sodium
bromide (NaBr) was used as target materials.
77Se (p, n) 77Br and 7SS e (p, 2n) 77Br reactions areK. Kitao, et al.

193

2

2

10

:a

10

$

c

:a

.Q

U

S

<11
C/l

c
o

C/l

(f)

u

0

<11

~ 10
C/l

0 ld

1

o

o
•

De Jong (1979a)

1f }Diksic (1979)
1~ ~~--~--~~~~__~__~~~
10

20

30

ECl

40

50

(MeV)

Fig. 1. A comparison of excitation functions for the reaction 75As (a, 2n) 77Br. Included is that calculated bycode ALICE/Livermore/82.

Fig. 3. A comparison of excitation functions for the 79Br (p,3n) 77Kr and the 8l.Br (p, 5n) 77Kr reactions.

1~r------'~-----,-------.------~

2

10

::;;-

100

:0

$

-5

c

.Q

c

U

.~
~

<I>

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C/l
C/l

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010

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U

1

10

- - - ALICE_.- 0-.-De Jong (19790)-t- Diksic(1979)
Nozoki (1979)---C>--- Weinreich(1983).- ..-

from DikSic (1979)1

10~~--~~----~------~----~90

EpFig. 2.

Excitation functions for 79,81.Br+proton reaction.

also used practically to produce 77Br. Selenium consists of many isotopes. The enriched target prevents
cross contamination with other isotopes. Only one
data has been reported by Janssen et al. 15 )In the Se+ 3 He reactions enriched targets should
also be used. Excitation functions for these reactions
were given by He Youfeng et al. 20 ) on enrichedtargets. Although the values of cross sections forSe (3He, xn) 77Kr reactions are comparable to thoseof other 77Kr production reactions, de Jong et ai. 1 0 )reported that thick target yields were lower thano102L.0--~--3...l.0-~-4L..
O-~--5-'-::0~

Ep

(MeV)

Fig. 4. A comparison of excitation functions for the reaction 79Br (p, 3n) 77Kr. Including is that calculated bycode ALICE/Livermore/82.

other reactions as figures of one to two order. Thismay be due to the kind of target materials. Thissuggests that the kind of target materials andbombarding conditions strongly affect measurementsof the cross section.
The production of 77Br by the spallation process
allows the preparation of a batch with larger activities. The cross sections for the spallation of molybdenum with 800-MeV proton were measured.

K. Kitao, et al.

194

Table 2.

Target materials used in some references.

Authors
Waters et ai.

Materials
3)

Nozaki et at. tS )Alfassi et at.m
Qaim et at. 23 )As deposited by electric discharge on
Al foil in arsenie gas.
Stacked Mg2A~07 foils.
Metallic As suspended in a selfsuporting polystyrene film.
Electrolytic deposition of arsenic on
eu-baking.

(2) Decay data
There were confusing differences among decay
data used in activity measurements. The half-lifeof 56 h for the nuclide HBr has been widely used,while Blue and Benjamin 2 ) used 59 h and Blessing
et aU 8 ) used 57 h. As for the r-rays abundance of
77Br, Diksic.': et al.l1) used 26.0% for the 239-keVrays, but other authors used 22.8 or 23.1 or
23.8%. Weinreich and Knieper21) used 82.2% for
the 130-keV r ray and 39.3% for 147-keV r ray of
the nuclide 77Kr, but all other authors used values of
87.3 % and 40.9 %, respectively.
(3) Conclusions
At present, the excitation functions for the production of 77Br or 77Kr are difficult to evaluate,
because published excitation functions depend upon
conditions of experiments. Because of this reason,
discrepancies still exist among these values in some
type of reactions. As for the decay parameters of
the nuclides 77Br or 77Kr and those of monitor
reaction products, different values are used in
actIvIty measurements in some cases. More precise
measurements are necessary for those reactions.

rReferences
1) F. Helus: Radiochem. Radioanal. Lett., 3, 45 (1970).
2) J. W. Blue and P. P. Benjamin: J. Nucl. Med., 12, 417(1971) .

3) S. L. Waters, A. D. Nunn, and M. L. Thakur: J. Inorg.
Nucl. Chem., 35, 3413 (1973).
4) F. HeIus, W. Maier-Borst, R. M. Lambrecht, and A. P.
Wolf: Proc. 7th Int. Conf. Cyclotrons and Their Applications, Experimentia, Suppl., 24, 474 (1975).
5) A. D. Nunn and S. L. Waters: Int. J. Appl. Radiat. Isot.,
26, 731 (1975).
6) M. Diksic, J.-L. Galinier, H. Marshall, and L. Yaffe:Int. J. Appl. Radiat. 1sot., 28, 885 (1977) .
7) S. M. Qaim, G. Stocklin, and R. Weinreich: Int. J. Appl.
Radiat. Isot., 28, 947 (1977).
8) E. F. Norton, K. Kondo, K. Karls trom , R. M. Lambrecht,
A. P. Wolf, and S. Treves: J. Radioanal. Chem., 44, 207(1978) .
9) D. de long, G. A. Brinkman, and L. Lindner: Int. J.
Appl. Radiat. Isot., 30, 188 (1979).
10) D. de Jong, H. Kooiman, and J. Th. Veenboer: Int. J.
Appl. Radiat. Isot., 30, 786 (1979).
11) M. Diksic, J.-L. Galinier, H. Marshall, and L. Yaffe:
Phys. Rev. C, 19, 1753 (1979).
12) H. Lundqvist, P. Malmborg, B. Langstrom, and S. N.
Chiengami: Int. J. Appl. Radiat. Isot., 30, 39 (1979).
13) T. Nozaki, M. Iwamoto, and Y. Itoh: Int. J. Appl.
Radiat. Isot., 30, 79 (1979) .
14) C. P. Madhusudhan, S. Treves, A. P. Wolf, and R. M.
Lambrecht: J. Radioanal. Chem., 53, 299 (1979) .
15) A.G.M. Janssen, R.L.P. van den Bosch, J . J.M. deGoeij, and H. M.J. Theelen: Int. J. Appl. Radiat. Isot.,
31, 405 (1980) .
16) P. M. Grant, R. E. Whipple, J. W. Barnes, G. E. Bentley,
P. M. Wanek, and H. A. O'brien, Jr.: J. Inorg. Nucl.
Chem., 43, 2217 (1981) .
17) Z. B. Alfassi and R. Weinreich: Radiochim. Acta, 30,
67 (1982) .
18) G. Blessing, R. Weinreich, S. M. Qaim, and G. Stocklin:
Int. J. Appl. Radiat. Isot., 33, 333 (1982).
19) P. P. Dmitriev, M. V. Panarin, and Z. P. Dmitrieva: At.
Energ., 52, 72 (1982) .
20) He Youfeng, S. M. Qaim, and G. Stocklin: Int. J. Appl.
Radiat. Isot., 33, 13 (1982) .
21) R. Weinreich and J. Knieper: Int. J. Appl. Radiat.
Isot., 34, 1335 (1983).
22) G. Blessing and S. M. Qaim: Int. J. Appl. Radiat. Isot.,
35, 917 (1984).
23) S.M. Qaim, G. Blessing, and Ollig: Radiochim. Acta,39, 57 (1986).

195
RIKEN Acce1. Prog. Rep. 21 (1987)

IV-5.

On the Cross Sections for 127I(p,5n)123Xe
K. Sueki and A. Hashizume

In the production of radioactive nuclides for medical use, it is necessary to select the type of reaction
and to find the best condition of bombardment suchas beam energy, target material, and its thickness.
This is because the ratio of the activity of theinterested radioactive nuclide to those of impurities
is related to this bombarding conditions. If the excitation functions of these reactions were calculated,
it would be of a great help to find the best conditionof bombardment, in particular when all the excitation
functions related to impurities were not studied experimentally. And this is often the case.
Many excitation functions have been studied experimentally and theoretically so far. However, theparameters of a computer codes have not yet been
examined systematically to fit the excitation functionsof the reactions which related to a wide range ofelements and / or masses.
For the production of radioisotopes by using a
cyclotron, the nuclear reactions of type (a, xn) arefrequently employed, where a is an incident particle
and x is the number of neutrons emitted. In thisreaction, the particles are considered to be emitted
by evaporation after passing through a compoundand pre-compound process. The cross sections of thisreaction type can be calculated by codes such as
ALICE, STAPRE. We used the ALICE1) to calculate the cross sections for the 1271 (p, 5n) 123Xe reaction and compared with experimental excitation
functions. In the code ALICE, the binding energies
of related nucleus are calculated by the mass formulaof Myers and Swiatecki. 2 ) The optical potential iscalculated by giving certain fixed optical potential
parameters. 3) Evaporation of particles and fission
from compound nuclei are calculated by a statisticalmodel. In this processes pre-equilibrium processes
are treated by a hybrid model 4 ) where the intermediate state densities are calculated by excitonmodel and their average intermediate state lifetime

!c:

100

o

•.-1

.j.I

o

Q)

til

~

o

10

! Syme et al.

+
I

~

u

+

I Diksic et al.
~ Paans et al.
I Wilkins et al.
Lagnus-Solaret al.

+

k~Om=~~4~O=mili=~6~O~Wm~80~~~IO~O~~~1~2~OmW~I~40
ENERGY (MeV)

Fig. 1. Calculated (ALICE) and experimental excitation
functions for proton induced reaction on 1271 target. The
dot-dashed line represents compound-nucleus formation
theory, and the dashed and solid lines the hybrid model.

was combined to the nucleon-nucleon scattering data.
The level density parameter, the upper limit ofangular momentum concerned, initial exciton number and some parameters of optical potential werevaried to find optimum fit for the experimental excitation function. The results are shown in Fig. 1.
Although many parameters have been adjusted
systematically, the absolute experimental values ofcross sections in the high incident bombarding energy
region, which is related mainly to the precompoundprocess, could not be fitted very satisfactory in our
first survey. Further parameter search and examination of the code related to this processes are necessary.
References
1) M. Blann: COO- 3493- 29.
2) W. D. Myers and W. J. Swiatecki: Nucl. Phys., 81,(1966) .
3) P. E. Hodgson: Ann. Rev. Nucl. Sci., 17, 1 (1967).
4) M. Blann: Phys. Rev. Lett., 27, 337 (1971); M. Blann
and A. Mignerey: Nucl. Phys., A186, 245 (1972); M.
Blann: Nucl. Phys., A21S, 570 (1973).

196
RIKEN Accel. Prog. Rep. 21 (1987)

V.

DEVELOPMENT OF ACCELERATOR FACILITIES

1. Status of RIKEN Ring Cyclotron Project in 1987
H. Kamitsubo

After successful extraction of an Ar beam fromRIKEN Ring Cyclotron (RRC) on December 16,
1986, it was officially permitted on January 13, 1987,
to operate the machine routinely and use it forexperiments. The inauguration ceremony was heldon January 23, and then RRC was shut down for
two months for regular inspection. Routine operationof the facility started in April, and after acceleration
test and beam study of two months, preliminary experiments have been carried out. Species and energies
per nucleon of ions accelerated in this period are:4°Ar I2+ (21 MeV /u), 4°ArI3 + (26 MeV /u), 14,15N6+(33.7 MeV/u), 65CU 18 + (16.7 MeV/u) , 180 7 + (41.5
MeV lu), and 12C5+ (42 MeV lu). The beam intensity
ranges from several hundreds nA down to 1 nA. Theenergy resolution and beam bunch width were measured as LJE/E<0.16% and 7:"<400 ps in the experimental hall E 1.
At the moment only two beam lines are temporarily installed for the experiments in the experimental hall El (Fig. 1) where all the preliminary
experiments were performed. They were classified
into three groups, the first one is projectile fragmentation in the reactions 15N +9Be, 40Ar + 27AI, and
65CU + 9Be, the second is fusion-like reaction 40Ar+
181Ta, and the last is atomic physics measuring X raysfrom the 40Ar + 9Be reaction. In the first experiments,
projectile fragments have successfully been identified
from lithium to nuclei neighbouring the projectile byapplying a TOF, a charge analyzing magnet, and
LJE-E counter telescopes. In the second one, energetic
r rays up to 100 MeV were observed with BaF 2
detectors. The atomic physics group measured X rays
associated with radiative electron capture at several
angles with respect to the beam direction. All thesemeasurements show that the backgrounds and noises
in the experimental area are very small.
The construction of the second injector, an AVF
cyclotron with K= 70 MeV, started in April, 1987.
We decided to adopt a Model 715 of SUMITOMO
Heavy Industries, Ltd. (SHI) as a prototype for thedesign of the injector cyclotron and modified it to beequipped with external ion sources which are an ECR
source for heavy ions and a duoplasmatron for

protons and deuterons. The detailed design has been
finished in RIKEN and the order was placed to SHI.
I t is expected to be completed in March, 1988.
The design of the ECR source was carried out
based on the source developed in Berkeley. Assemblyof the source will begin in February, 1988.
The construction of beam transport lines to experimental halls El, E2, E3, and E7 is under way andwill be finished in March, 1988. The beam line goingto the RIPS (RIKEN Projectile Fragment Separator)
and to E 7 branches from the main beam line at theexit of the cyclotron vault. Those going to E4,
E5, and E6 will be installed after the building iscompleted.
This year we have started construction of thefollowing facilities: An ion-guided isotope separator
on line (IG ISOL) combined with a gas-filled recoil
isotope separator (GARIS) will be installed in E 1
by June, 1988. Laser spectroscopy experiments areplanned to measure spins, moments, and mean squarecharge radii of those nuclei as are separated at the
IGISOL. A large scattering chamber with a ' multiparticle correlation spectrometer is under construction
and will be installed in E2.
The beam line for the study of atomic physics is
installed in ' E2, too. A highly-ionized-atom spectrometer, a general purpose scattering chamber, andan X-ray goniometer will be built along this beamline.
A pion spectrometer which is now set up in E 1 will
be moved to E3 and the study of subthreshold pion
production by measuring charged pions with thisspectrometer will be continued there. An irradiation
system for short-lived isotope production is also installed in E3.
A slow ' pion and muon spectrometer with a largesolid angle is under construction. This is a superconducting solenoid and will be used to measure theproduction rate of the low energy charged pions
and muons, providing a possibility to apply RRC
for very low energy muon spectroscopy. A spectrometer to measure the ion emission from metallic
surface is also under construction. These two spectrometers will be installed in the room E 7.

H. Kamitsubo

197

RlKEN Accelerator Research Facility(March 1989)
EI: IGISOL (Ion Guided Isotope Separator On Line). E2: Multi-Particle Correlation Spectrometer
Highly-Ionhed Atom Spectrometer
E3~ Pion Spectrometer
Irradiation ~ystem for Short-Lived Isotope Production
E4: High-Resolution Charged-Particle Spectrometervith Neutron TOr System .
E5 Biomedi,c al Irradiation System
E6 RIPS (RIKEN Projectile Fragment Separator)
E7 Material Irradiation System

Fig. 1.

Plan view of RIKEN Accelerator Research Facility.

Projectile fragmentation in heavy ion reactions is
a very promising process to produce nuclei far fromthe stability line and also to get a "radioisotope
beam." The RIPS is designed to separate the projectile fragments from an incident beam and to collectthe produced isotopes having a broad spectrum of
kinetic energy onto the focussing point in the room
E6. It will be completed by the beginning of 1989.
A horizontal irradiation system with a wobbler
magnet is installed for biomedical studies in E5. Because the room E5 will be completed in March, 1989,
the system will be tentatively installed in El.
The data acquisition system is a hierarchic multiprocessor system with CAMAC interfaces. The local

processor consists of three DEC Micro V AXIl's anda V AX8350. The host computor is a FACOM M380 whose processing speed is 23 MIPS. The CAMAC
crate is equipped with an auxiliary crate controller,
CES2180, which works as a front-end processor ofthe data-taking system. The whole system is used
for on-line data acquisition as well as off-line data
reduction and analysis.
The design of the particle spectrograph and thebeam swinger is in progress. They will be installedin E4 in 1989.
The phase III part of the building is under construction; it includes experimental rooms E4, E5, andE6, and the offices for the staffs and visitors.

198
RIKEN Accel. Prog. Rep. 21 (1987)

V-2.

Field Stability of the Sector Magnets

H. Takebe, T. Wada, M. Nagase, J. Fujita, and S. Motonaga

Figure 4 shows a sector magnets control system.
As the NMR scanning data should be used simultaneously for three programs (a logging and graphic
program, an NMR feedback (stabilizing) program,and a touch panel program), a global common
memory on the M350 / 60 host computer was used
(Fig. 4 (a) ). If the difference in the sector field was
between +2j.tT and +100 j.tT and dB/dt was positive, the bypass current of the M2 power supply wasincreased. When it exceeds 100 j.tT, or dB/dt was
negative, this program was only waiting the next data
(Fig. 4(b)). Thus the four sector stabilizing system
was achieved independently.
The reproducibility of the sector magnet fields wasmeasured using the CYCLING method. 1 } Figure 5
shows a time chart of the sector magnets operation
during the machine time. At the end of the machine

The first overhaul of sector magnet power supplies
was done from Sept. 26 to Oct. 10, 1987. After
adjustment of the power supplies by the company
engineers, the current stability of a main coil power
supply was checked. Stabilities of the main coil
power supplies* were found within -+-5 X 10- 6 , andthe temperature of a shunt resistance was 29 -+- 0.2°C(Fig. 1). Nevertheless, the magnetic field of the sector
magnet drifted by a few tens of parts per million(Fig. 2) with a temperature drift (5°C) of the cooling water for the magnets. To reduce the field drift,
an NMR ** feedback system was operated by using
an NMR probe and a host computer (M350 / 60) .
Figure 3 shows the field deviation measured during
the machine time on November 9-11; it was within-+-2 or 3 ppm at 1 Tesla when the NMR feedback
loop was turned on.
JJfJ-t--l'+4~t== _ AC.41·SV Input Voltage Change of the P.s.
F~-

I-- .

___ ~

. - ----1-- - -- ,:=1=t=I::=:-= c-:::: ~ .,:~'--- - - -.: =l:F.i;:t.=-- ~=,' .,... 1---,0--+-I- --t---.- -::-=t-

-

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1--- .-

-II--

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30 0

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Temp. of Cooling Water for Magnet Coil.

I---- 1'-::=

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(Hour)

Fig_ L Twenty-four-hour record of the shunt resistance voltage of the main coil power supply (Ml) , AC415 V input
voltage, and a temperature for the magnets cooling water.

* DC

Hi-precision power supply; IDX Corporation,
Tokyo.
** NMR Magnetometer (type 1000); SENTEC Co., Ltd.,
Switzerland.

H. Takebe, et al.

NMV187NMR.

VAC-PRES.

22: 18:03. 89 87-11-02 SI I f I.

CONTI NUE MJ. M2.

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23

TIME

a~

H

Fig. 2. Magnetic field drift of the E-sector magnet, water temperature for the magnets,
and vacuum pressures of the RF chambers.

Sector Magnet Field Stability during Machine Time
PRESS.

0.25

11 -Nov-1987

0 . 20NMR Feedback Loop: ON(mBar.)

0. 15
0.10
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1.0£ -05-0 .25

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F=== == = = = d " " " ' = = = = = = = = == == = = = = = = = f 1.0£'07-0 . 30
0

,

2

3

4

5

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9

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13

14

15

16

17

18

19

20

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22

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TIME ( H )Fig. 3. Magnetic field stability of the sector magnets, which wasmeasured duril!g the machine time on November 9-11; it waswithin ±2 ppm at 1 Tesla.

time, all the magnet currents were logged and thesectors were turned off. Next day and the day after
the next, the sector magnets were excited again byusing CYCLING as exited to the logged data. The

difference in the magnetic field from those of theprevious days, measured by the NMRs, are shown inparentheses in Fig. 5; they were within +70 pT.

H. Takebe, et al.

200

NMRStabi·Wind

Reproducibility of the Sector M agnet Field Level

Sector Magnet Control Programs ( M60 )I Nj4RD I.

Date 9/Nov

READ

Write

109270.. - --- -------------,
L -_ _ _...... - . . :~Bs(4), Bm(4), Code:
(GCA Memory))/{:~~ - - -I NMRLOG I(O.OG)..----=----,

Logging to File(lday). 4
Graphic Plot(lday)"Ar28H9" Calculate Data(a)

NMR4SB; Sector field stabilizing Sequence(+0.70)1091 0.59G

10909.93G

Machine TimeAr 13+ 28M Hz----- - - --

13

12

11

10
E-Sector NMR

~
:::;
0

G

(.0.60)10909.34G' (!J.

Test

z '

:::;

~
:<;:.

Test

Curr.Data
Logging

Fig. 5. Reproducibility of the sector magnet fields measured
by using the CYCLING method.

Reference
1) H. Takebe, T. Wada, M. Nagase, S. Motonaga, and
A. Goto: RIKEN Accel. Prog. Rep., 20, 172 (1986).

1 Min. Interval

NMR WINDOW for Stabilize
+1.0

0
0

.a:I

+0.02
-0.02

t:6

M2 Bipass
Current =f ,.. dB /0.27

-1.0

(b)
Fig. 4. Sector magnets control programs (a) and NMR
feedback system for stabilizing the sector magnetic field (b) .

201
RIKEN Accel. Prog. Rep. 21 (1987)

V-3. Applications of CIM-DIM in the Beam Diagnostic System
of RIKEN Ring Cyclotron
M. Kase and 1. Yokoyama

All measurements concerning the beam diagnosis
at RIKEN . Ring Cyclotron, except for the observation of fast signals from a probe, are made througha CIM-DIM (Communication Interface Moduleand Device Interface Module) 1) data transfer
system under control of a Mitsubishi M60 computer.
The applications of DIM, in the beam diagnostic
system, are divided into two groups, BDA (Beamdiagnostic DIM Application) and BDI (Beam Diagnostic Interface).
A BDA circuit has been developed for a fixedpurpose. Every BDA circuit is composed of a DIM
board and other circuits and has its own way how
to use the DIM digital I/O. Three kinds of BDA
circuits are used: a profile monitor controller, a slit
system controller and an emittance monitor controller.
A block diagram of the profile monitor controller(BDA-PF) is shown in Fig. 1. For the measurementof a beam profile in a beam line, the three-wire sensor
is scanned on the beam area with an air cylinder. 2 }The wire position relative to the beam axis is detectedby using position sensors at the both ends of stroke
and a rotary encoder. The total counter (16 bits)
is reset at one of the position sensors and counts
pulses from the rotary encoder. A preset counter (8bits) provides a . trigger for sample holding and datataking. After receiving a measurement command, theDIM actuates the air cylinder, takes the position
and three analog data, and stores them in a memory.
The DIM transmits these data to CIM by othercommand.
The other application of DIM (the BDI circuit)has a large flexibility compared to the BDA circuit.
In the beam diagn<?stic system, some probes may be
added or moved from one place to other dependingon situations, and some new devices will be developedin the future. In these cases, electronics in the BDI
application can easily be modified according to thechanges.
The BDI circuit, which is built in a plug-in
module (according with DIN 41494), uses DIM
digital input/output as a common bus (BDI bus).
The bus has 48 digital signals (6 bits for the highaddress, 8 bits for low address, 8 bits for input andoutput data, 8 bits for LAM (Look At Me) , 8 bits
for unit number, and 2 bits for read/write strobes).

Four power lines (+5 V, + 15 V, -15 V, and+ 24 V) are also contained in the BDI bus. The
BDI circuit has two connectors at the rear end ofits board: the lower one (64 pin) connected to the
BDI bus and the upper ,o ne used for connection withprobes or other circuits. The circuit is readily change-

BDA-PF
1' -------

DIM---- ---,

1 ~--------~~~~----------~A~NA~L~O~GI'Nmprr,U~T~ 1 r-*-~--~4---+.-+r----~1T-------T---'
z

0

,

~I

o..J .

I

I z~
,

z
«

:I:
()

PROFILE, MONITOR
BEAM

Fig. 1.
tem.

Block diagram of a beam profile measurement sys-

M. Kase, et al.

202

able if necessary, since there is no cable connection
on its front panel.
There are two types of BDI circuits, a BDI moduleand a BDI unit. BDI module has a passive function
under control of DIM. A maximum of 64 BDI
modules can be connected to one DIM and each BDI
module can be operated on 256 functions. Several
kinds of BDI modules are used, such as a pneumatic
driver controller, a bias supply, a vacuum system
controller, an interlock circuit, and a beam current
amplifier.
The circuit called the BDI unit has a micro processor in it and executes more intelligent functions
than those of BDI modules. A Maximum of eight
BDI units can be connected to one DIM. An example of the BDI units, BDI-RP IC (radial probe
control unit), is shown in Fig. 2. The radial probes

in RIKEN Ring Cyclotron is actuated by the combination of a stepping motor and ball screw and aprobe position is detected by the combination of six
position sensors and a rotary encoder. After receiving
a command from a DIM via the BDI bus, a processoron the BDI-RP IC starts a measurement. It actuates
the probe, takes data, and stores them on one of its
2 kB memories. When one of the memories is full,
BD I -RP I C makes a LAM flag to the DIM andcontinues the measurement using another memory.
The DIM can read, at any time, the data in the
fully-stored memory directly without disturbing themeasurement going on. The radial probe data can,therefore, be taken step by step without waiting forthe end of whole measurement.
The program in DIM and CIM is directly written
into an 8 kB ROM in them. The CIM program is
identical for any DIM's used in the beam diagnostic
system. A main function of the CIM program is toconvert the data transfer format between 8-bit serial
one (CIM-DIM) and 24-bit parallel one (CIMCAMAC).
Every DIM has a common program for the. communication with CIM. Whenever a command from
CIM reaches one DIM, the DIM is interrupted andthis program starts. ' In this routine DIM checks thepriority of the command, verifies it on a command
list of its own, and finally sends a three-byte responseback to CIM, which waits for the response for 30 ms
after sending the command. The response has information about whether or not the command isacceptable, and also some message, when the command is rejected. After sending the response, theD 1M start performing the command.
The other area of ROM in DIM is used for a
specified program for each DIM. Four kinds ofprograms have been developed for the DIM used
for a BDI circuits and for three types of BDA circuits.
References

Fig. 2.

Block diagram of a radial probe system.

1) T. Wada, J. Fujita, I. Yokoyama, T. Kambara, and
H. Kamitsubo: Sci. Papers I.P.C.R., 79, 28 (1935);
K. Shimizu, T. Wada, J. Fujita, and I. Yokoyama: 10th
Int. Conf. on Cyclotron and Their Applications, East
Lansing, Michigan, USA, April (1984).
2) M. Kase, I. Yokoyama, I. Takeshita, Y. Oikawa, M. Saito,
and Y. Yano: 11th Int. Conf. on Cyclotron and Their
Applications, Tokyo, Japan, Oct. (1986).

203

RIKEN Accel. Prog. Rep. 21 (1987)

V-4.

Improvement of RF Amplifier of RIKEN Ring Cyclotron
T. Fujisawa, S. Kohara, M. Saito, and Y. Chiba

The radio-frequency system of RIKEN Ring
Cyclotron was installed in the cyclotron vault inAugust 1986 and have been working weIU,2) Its
performance is satisfactory for most of the frequencies,
20-45 MHz, but the maximum output power of the
final amplifier is limited to be 160 kW at the frequency around 40 MHz.2) This reduction in the output power is caused by the 80 MHz resonance (GlG2 resonance) between the screen and control gridsof the final tube SIEMENS RS2042SK, which is
excited by a higher harmonic component of tuning
frequency of 40 MHz. In order to avoid the effectof this resonance, we are trying to shift the resonanceat a frequency higher than 90 MHz by improving
the screen and control grid bypass capacitors. We
studied performance of a few models of capacitors
mounted on RS2042SK by ' measuring the voltage
transmission ratios from the plate terminal to thescreen and control grid bypass capacitors.
Figure 1 shows the cross-sectional view ofRS2042SK with the bypass capacitors finally designed.
T he cylindrical bypass capacitors (Cgl = C g 2 = 8,700
pF ) are made of 125 p.m Kapton film coated withsilver paint. A pair of the capacitors is mounted in
the space between the screen grid and cathodeterminals in order to reduce inductance which lowers
the resonant frequency. Calculation showed that thisreduction of inductance (70, 4.5 cm) moves the res-of4\ 9 .2 Q .

antral gridPlatee'r:~rthCa!
" ''-.....w-.=-o,Fig. 1. Cross sectional view of the RS2042SK tetrode andimproved screen and control grid bypass capacitors.

14

10. 6 Q0Q

6.5 em23 . 7Q

6. 5 em

V p, g2

Sc r ee n\

C p, g2

Gr id~g~~~nGND2Screen grid
bypass copoc i ta r

~ 2.5 e m

~ 2 emPlate

Sc reen grid

83 pF

VA

/

C p , g1
6 pF~

V g 1, ,2~

C g 1, g2
390 pFG2 bypassVC)' - - - - ' -_ _- - 4

Contr.o l

Gr i d

_ \,

VB

8 Q
2 em

o

11. 0 Q
11 em

CD

12 .0 Q

5 em

G1 bypass(j) 12 . 4 nH

Capacitor

Fig. 2. Equivalent circuit of the pla te, screen grid, and control grid of RS2042SK withbypass capacitors.

tGNDl

204

T. Fujisawa, et al.

onance at a frequency higher than 100 MHz. A
copper cylindrical earth surrounds the tube to keep
the circuit a coaxial geometry and to reduce theinductance of the feeder line for a signal. An RF
signal was fed to four positions between A and
GND1, which are set in axial symmetry, and thevoltage transmission ratios were measured at positions Band C.
Figure 2 shows an equivalent circuit for the plate,screen grid, and control grid of RE2042SK and thebypass capacitors. The numbers correspond to thepositions shown in Fig. 1 and the positions A, B, andC are also shown.
Figure 3 shows the measured voltage transmlSSlonratios together with the result calculated with theequivalent circuit. The voltages V A, VB, and V careobtained at the positions A, B, and C, respectively.
The calculations are in fairly good agreement withthe measurements. The resonant frequency becomes
about 100 MHz, and the voltage transmission ratios
are 0.012-0.014 for the screen grid bypass capacitor
and 0.0014-0.002 for the control grid bypass capacitor

I'

Cgl = 115000 pF
N
01

>

0.

10- 1

Cg2 = 90000 pF-...........
~<'il

>

N

0.:
0;
>

10- 2

-g
0
N

01
0.

>
-...........
N

01

>

01

10- 3

10-4 L - -_ _ _.L..-_-'--_-'-_-L-_-'-_-l-_~_~_
20
30
LID
50
60
70
80
90
100
frequ ency (MHz)Fig. 4. Calculated ratios of Vg 1 , g2 to Vp ,g2 and of
VB) to Vp ,g2'

(Vgl,gS-

2...... ~c eo::
o ~
U-'
-00

c

.::

c

.~

!:3~
c Cl)
Q)
Q)

'-~

4--

o

U)

·0
+-'

0

~

Q

8'-

4--

U)

'--

E: .~
c
0

U)

Cg1 = Cg2 = 8700 pF......

0 ,1

g
g

(f)

.~ n

if)
if)

0

+-'
Q)

0 1

E
D

.~

'-

.8 01 0 ,01

au>

in the frequency range of 20 to 45 MHz. The voltage
transmission ratios obtained, however, are not theratios at the active area inside the tube. In order toestimate the ratios at the active area, we calculated
the ratios of V g1 ,g2 to Vp,gZ, and of (Vg1,gZ-VB) toVp,gz (See Fig. 2).
. In Fig. 4, the result is shown together with aresult of the bypass capacitors (Cg1 = 115,000 pF and
C g2 = 90,000 pF) used in the actual amplifier. It isclear that the G1-G2 resonance is moved at around
100 MHz. In the present study calculation was
carried out with the computer FACOM 380 at
RIKEN.

~

References

0.0011-"""
0 --3..1.0----L40----l5L
O--6L.- -7..L.0- -S..J..0---:-L
90:-----I1O'00
2Frequency (MHz)Fig. 3. Voltage-transmission ratios from the plate terminalof RS2042SK to the screen and control grid bypass capacitors. The line shows the calculation with the equivalentcircuit.

1) T. Fujisawa, K. Ogiwara, S. Kohara, Y. Oikawa, I. Yokoyama, I. Takeshita, Y. Chiba, and Y. Kumata: Sci.
Papers I.P.C.R., 79, 12 (1985); T. Fujisawa, K. Ogiwara,
S. Kohara, Y. Oikawa, I. Yokoyama, M. Nagase, I. Takeshita, Y. Chiba, and Y. Kumata: Proc. 11th Int. Con£.
Cyclotron and Their Applications, Tokyo, Japan (1986).
2) T. Fujisawa, S. Kohara, K. Ogiwara, I. Yokoyama,
M. Nagase, and Y. Chiba: RIKEN Aceel. Prog. Rep.,
19, 170 (1985); 20, 167 (1986).

205
RIKEN Accel. Prog. Rep. 21 (1987)

V-5.

Effects of Magnetic Fields on a Turbomolecular Pump of 5,0001/5
A. Nishide and S. H. Be

We investigated effects of magnetic fields on aturbomolecular pump of 5,000 lis (TMP; OSAKA
Vacuum, Ltd., TH5000), which is used in RIKEN
Ring Cyclotron. We estimated: 1) a temperaturerise of the TMP rotor installed in magnetic field
distributions as shown in Fig. 1; 2) a decrease in therevolutions per second; and 3) an increase in loss on
the power supply for driving TMP. Figure 1 showsthat magnetic field distributions as a function of a
distance from the presumptive center of TMP before
installation. The distributions as shown in Fig. 1
were produced at a maximum base field, Bmax of
15.4 kGauss for sector magnets of the cyclotron, but
the magnetic fields can be varied by adjusting. theexciting current of main coils for the sector magnets.
In this experiments, the magnetic fields were continuously applied throughout an operation of TMP.
For estimation of the effects of the magnetic fields on
TMP, only the magnetic fields in the direction verticalto a revolution axis of TMP were considered because
the magnetic fields in the direction parallel to arevolution axis caused no temperature rise of therotor and · no decrease in revolutions per second.

Actually, we need to consider the effects of themagnetic fields ·in the parallel direction since magnetic
materials are present in TMP; however, at B2 ~200
Gaus:; (at B = Bmax) no problem occurred.
The rotor temperature rise in the magnetic fields
is indirectly estimated from an eddy current loss,
Ploss, in blades to be proportional to the square of
the magnetic field. The Ploss is evaluated from thedifference of dissipation powers in the blades for
B = 0 and B¥=O at revolution frequency decay curves
measured, not shown here, after TMP is stopped.
When the revolution frequency decreases from (J) to((J)-Ll (J)) during a short time Llt, the dissipation
power P is given by I ( (J) Ll (J) ) I Llt. Here I is themoment of inertia. The rotor temperature rise canbe obtained using both the Ploss, which is shown in
Fig. 2, and a relation between the rotor temperature200~'--'150
<J)
en

~

80
U)

-0-<>--0-

:

x, Bx

- x- x- x-

:

y, By

<J)

~ 60

S

o

20

40

60

80

100

Magnetic flux density (Gauss)

Fig. 2.
30

10'~~~~,~>x 10

Cyclotron center' x.....' x

20'"I ITMr l~.
z=5O L.J

y, B,

20

Magn--=y .. : \ Magnet

40- 50 ¢(unit in em):c, Bx

TMP

20

Eddy current loss vs. magnetic flux density.

30

100

x, y (em)

T~~t::~"'-~'-' 50.~ •"-. z = O

60

280
~

r-.

;::l

~ 60
r-.
~

P..

~ 40
r-.

o

80
Fig. 1. Magnetic field distributions as a function of a distance from the presumptive center of TMP before TMP
is installed. z=o and 50 em correspond to positions ofan uppermost part (inlet port) and lowermost one (exhaustport) of TMP, respectively.

~ 20

o

20

40

60

80

100

Magnetic flux density (Gauss)

Fig. 3. Rotor temperature as a function of the magnetic
flux density.

206

A. Nishide, et al.

and the Plos s . This relation has been given by otherexperimental results. Figure 3 shows that the rotor
temperature increases with an increase in themagnetic fields and reaches ~100°C at -80 Gauss.
The rotor temperature which can be allowed for
TMP is ,.....,120°C.
The decrease in revolutions per second is indirectly 'evaluated from a difference between accelerating
torques of the motor with and without the magnetic
fields. In this evaluation we used a retarding torquein the magnetic fields, as shown in Fig. ' 4, and theaccelerating torque without the magnetic field. The
evaluated result, i.e., the decrease in the revolutions
per second is shown in Fig. 5 as a function of themagnetic field. As seen from Fig. 5, the revolutions
per second decrease slightly with an increase in themagnetic fields, because the retarding force due toan eddy current induced by the magnetic fields breaks
a constant torque condition under which a highfrequency power of the pump motor is supplied.
The results of the rotor temperature rise and thedecrease in the revolutions per second for TMP
immersed in the non-unifor magnetic fields indicate,as shown in Fig. 1, that the magnetic field allowed
for TMP is -80 Gauss. This value corresponds tothat at the position of the TMP when the maximum
base field for the sector magnets is 15.4 kGauss.
A relationship between the output current of thepower supply and the magnetic field, not shown here,
shows that the output current increases slightly withan increase in the magnetic field up to B = (2/3) Bmax,
but the output current at B> (2/3) Bmax increases

i' 0.15e~ 0.10

r:3'

2'"'
bIl

.5 0.05

'"'"'
!

~

~

00

20

40

60

80

100

Magnetic flux density (Gauss)

Fig. 4. Relation between retarding torque of the motor andmagnetic flux density.
~240~~--------~--~

o

"

20

I

40

60

80

100
Magnetic flux density (Gauss)

Fig. 5. Revolutions per second as a function of the magnetic
flux density.

rapidly with increasing magnetic field, where B is
the base field for the sector magnets. From theseresults, we conclude that the magnetic fiel~ allowed
for the continuous operation of the TMP is --30
Gauss, which corresponds to , B= (2/3)Bmax • The
continuous operation of the TMP at B = Bmax for ashort time of about 1 h will cause no damage.

207

RIKEN Accel. Prog. Rep. 21 (1987)

V-6.

Communication System for RIKEN Ring Cyclotron
H. Takebe, S. Fujita, R. Abe,* H. Akagi,* T. Wada, and T. Inamura

The RIKEN Accelerator Research Facility(RARF) consists of two injectors, a heavy ion linacAVF cyclotron and a K540 ring cyclotron.!) RIKEN
Ring Cyclotron (RRC) was completed in November
1986 and the first beam was, accelerated in December.
At present, the heavy ion linac (RILAC) is used
as an injector for RRC. The construction of anotherinjector, a K70 AVF cyclotron, has been started andwill be completed at the end of 1989 FY. Total areaof the facilities exceeds 12,000 m 2 and the number ofthe rooms will be about 80.
The communication (audio and video) system for
the RARF consists of interphones/speakers, a bidirectional transceiver, a video monitors network(CA TV), and a computerized voice warning system.
Figure 1 shows a schematic diagram of the wholesystem. Some of them are installed and tested thisyear. Fifteen sets of small hand-free transceivers (bidirectional, headphone-mic type wireless telephones;
Shinwa Comm. Co., Ltd., 410 MHz-up/450 MHzdown band) and the interphone / speakers system(AIHON Electr. Co., Ltd.) were installed in 1986.
Antennas (400 MHz) for this transceivers are installed in all experiment halls, RRC vault, the control
room, and the counting room. The linear accelerators
vault and their control room will be installed withantennas in 1988. In-house broadcast speakers will
be connected with a paging system of a new Digital
PBX2) system this fiscal year. A four-camera autoscan 3 ) system and CCD color video cameras (highresolution, low price; family use) were installed andtested this year. In 1988, ten to sixteen video cameras
for power supply rooms and experiment devices will
be installed and connected to video/audio remotescanning switches. Some of the selected signals aretransferred to the control room, and displayed andconverted to a CATV's RF frequency (Ch. 1-12) to* Sumijyu Accelerator Service, Ltd.

be broadcasted in the facility. This system is controlled by a CIMjDIM4) system or a personal computer (PC9801 or mz-X1) with a touch panel.
Figure 2 shows a computerized voice warning
system for RRC control system and a radiation
safety control system. Message signals of the control(or surveilance) programs of RRC's M350j60 minicomputerS) should give notice to operators andother staffs using voice synthesizer sounds. A hard
wired interlock or warning signals of the RF system
and a vacuum system are also connected to the voicesynthesizer boards to give notice. There are two typesof synthesizer boards, which are of a 6 kHz sampling
ROM type and of an 8 or 16 kHz sampling RAM
type. 6 ) These audio signals will also be connetced to
the CATV and interphone sp'eakers (Fig. 2 (a) ) .
The entrance to and exit from a radiation-controlled area are checked very strictly by using apersonal card.7) Users, especially unfamiliar with ourfacility, need some information of checking procedure
to pass over a radiation safety check point (handfoot-clothe monitors are especially difficult to use forgeneral users) smoothly. For this purpose, a voice
guide system using a voice synthesizer is adopted(Fig. 2 (b) ).
References
1) H. Kamitsubo: RIKEN Accel. Prog. Rep., 20, 160 (1986).
2) Digital Private Branch t"changer: FIJITSU, FETEX3700.
3) Mitsubishi Electr. Co., Ltd.: /MELOOK-8.
4) Communication Interface Module and Device Interface
Module.
5) T . Wada, H. Takebe, J . Fujita, T . Kambara, and
H. Kamitsubo: RIKEN Accel. Prog. Rep., 20, 170 (1986).
6) Sankyo Electr. Co., Ltd.: ICR500Z/A, VS400A, VS800A.
7) 1. Sakamoto, S. Fujita, T. Wada, and H. Takebe:
RIKEN Aceel. Prog. Rep., 20, 206 (1986).

AVF

B2

~

AVF

B2-Eaot::E

B2-W •• t

,

,,
,,

'.

.,
"

................... _----

o

X

&

.g
o
=r

... ,.<11",,;'lch-12ch

,

I

I

I

I

-_._--

'.
,,
,,,
,,
,,

,,

~
"
"
"
1,\

"
"
"
"

:',

,:

~~-;~;-'. .. -_ .... -_._. --------_ .......... -----

,,,

,
,
,

,,

I
I
I

----- .... ',,,,".---.-.. -------f--------------. -.--."~',

Optical Fiber

,

,

..

I

I
I

'- ... - -

,
,,

RF ,

PS :

,
,

/

"

Stripper'

,

~PS:

-

---_ .... - _... _..... - .... -_ ................... --~'

LINAC CONTROL DESKv

CI)

CameraCamera--------_. -_. --.-.- -..... \IF Entrance

2F Entranc.

.. '

,
,,

(~~ con~,,/ .....

'.

II IMOnitortI..
.. ----_ ............ '.~COUNTING ROOM~---------------+------------------~-------------7-----------

C1? ../

tl

::E

)..l

·ri

'-

'
IMonitor
\ _
:

'\

..

Fig. 1. Schematic diagram of the information system for RIKEN Accelerator Research Facility (ring cyclotron and linac). It consistsof interphone / speakers, bidirectional transceiver, video monitors network (CATV), and computerized voice warning system.

I ",, "'O"'U.
............ _-- -_ .. --- --- -_ ... ----- .. -------_ .....

~

IIRC

'''''-''-- - - --- ----.-

I

)..l

,

+J
fll

-rl

,

~I~
~X

\...J-

,

,,

~

(/)

Monitors

)..l

..

+J
fll
r--I

Speakers""

ratoIS console

Camera,"""\,~ r-400 MHz

Ant e nna""

II.·········· -----------. --. --------RR-C- -C~~ t-;~ 1- R~~~-- ---........... ,....,',

CameraCamera,,,,---Wireless
Telephones

:B2~

:

: E1

IIRC
,,

,,
,,,
,,,
,,,
,,
,,
,, '

RRC B2-Bl//----- ----------------- ------

RRC-Communication/CATV system

88-2-4, CATV-4

j:.

~

~

~

r:

;:t

co

C>

~

.

,

-------- -----.

Center

Mon itoring

InsitituteFib erOplical

~

( a)

3kH z

~--- -- ---------- - --------- - ---,

Antenna

Experiment Room's

4 ch x 2

Radiation
Monitor's

H.F.C.
MonitorRadiation Controled Aria(b)

H.F.C : Hand-Foot-C lothe Monitor

Gate
Bar's

VS400A - l
ROM 64Kb 3KHz

Mini Computer

MX3000Computerized voice warning system for RRC control system (a) and for a radiation safety control system (b).

BroadcaSI (1ch-l 2ch )Fig. 2.

4ch

Video &
Audio
MalrixSwilchRRC Voice Warning System Ver.3

~
cc

:--

\:)

~

~C'lI

r:::1'

~

~

;:t=

210
RIKEN Accel. Prog. Rep. 21 (1987)

V-7.

Injector AVF Cyclotron for RIKEN Ring Cyclotron
A. Goto, K. Hatanaka, K. Ikegami, T. Kageyama,
M. Kase, S. Kohara, N. Nakanishi, H. Nonaka,
M. Saito, H. Takebe, and Y. Yano

An AVF cyclotron is used as an injector to gethigher energies for light and light heavy ions. In
coupled use with RRC, the final energies designed
are 210 MeV for protons, 135 MeV lu for 12C, 14N,
160, 95 MeV lu for 4°Ar and so on. A conceptual
design of the AVF cyclotron was reported elsewhere.1}
At that stage the cyclotron was designed to be used
not only as the injector for RRC but also as a standalone machine which can accelerate, for example,
protons up to 60 MeV, by taking the acceleration
harmonic number to be 2 and 1, respectively.
Recently, however, the harmonic number of 1 wasabandoned because otherwise the central region of
the cyclotron will be very complicated. A model
750 PV2) of Sumitomo Heavy Industries, Ltd. (SHI)
was decided to be purchased and to be modified tomeet the requirements for the injector as well as
for external injection.
Table 1 gives the characteristics of the AVF cyclo-tron; its layout is shown in Fig. 1 and its performancein Fig. 2. The K70 AVF cyclotron has four spiralsectors and two RF dees with an angle of 85 0 •The extraction radius is 714 mm. Ions from external ion sources consisting of a duoplasmatron
and an ECR source are axially injected into thecyclotron and led onto the median plane with aspiral inflector. This cyclotron can accelerate ionswhose mlq values are up to 4.
Construction of the AVF cyclotron started in April
1987. After magnetic field measurement, all parts

Cryo-Pump

Gradient

Q)

Pro e

.0

o

Table 1. Characteristics of the AVF cyclotron.

~=;;;;;;;;:;;;;;;;;;;:;;;;~~F~?

p.,

Number of sector
4
Sector gap
127 mmPole gap
300mm
Pole diameter
1,730 mm
Extraction radius
714 mmMaximum magnetic field
1.7T
Maximum main coil current
1,000 A
Maximum power
150kW
Number of trim coils
9
Number of harmonic coils
4
Magnet size
2.1 m (H)x 1.9 m (W)x3.9 m (L)Magnet weight
110 t
Number of dees
Dee angle
Frequency
Maximum dee voltage
Maximum RF power2
85 deg12-24 MHz50kV
30x2kW

Inflector
Main evacuation system
Pressurespiral type4,000, 6,500 lis cryopumps
1,500 lis turbomolecular pump
2 X 10-5 Pa

Control system
Acceleration harmonic number

Computer network and
CAMAC interfaces
2

C
'M
C'C!

:z

Phase
Beam

o

1 00
0
!

!

Cryo-Pump

Fig. 1. Layout of the A VF cyclotron.

2

3

4

6

8

10 V / MlQ (kV)r------,-;:'---...:;---;----r---r--:,.::....... (injection
voltage)
2.0

1.0

E 0.8
co 0.60.4............ -..... -.-... -.~ ..... -..... ..... ..

0.2 ......................................-,,........... ~ ................. .
i h=2
5
6
·7
8 ~o
1,,2 114 F orbit (MHz).

2

Fig. 2.

3

4

5

6

8

10

~

15

20 E (MeV/u)

Performance of the AVF cyclotron.

A. Goto, et ai.

of the cyclotron will be assembled at the factory of
SRI by the autumn of 1988 and various tests suchas a leak test, a moving test, and an RF test will
be made there before the installation into the cyclotron vault of RIKEN. The installation and assemblyof the cyclotron at RIKEN is scheduled to be completed by the end of March 1989.

211

References
1) N. Nakanishi and T. Kageyama: RIKEN Accel. Prog.
Rep., 19, 197 (1985).
2) K. Fujii, M. Maruyama, T. Satoh, M. Ishikawa, and
S. Kadota: Proc. 11 th Int. Conf. Cyclotrons and Their
Applications, p.626 (1986).

212
RIKEN Accel. Prog. Rep. 21 (1987)

V-B.

ECR Ion Source for an Injector AVF Cyclotron
K. Hatanaka and H. Nonaka

An ECR ion source for an AVF-Ring Cyclotron
complex is now under construction. The source will
be used to produce highly-charged relatively lightheavy ions (up to Ar). The first beam is scheduled
in April 1988. Through further one-year development, the beam from this source will be axially injected into the AVF cyclotron. The mlq value ofions which the AVF cyclotron can accept is less than
4. In the case of Ar ions, for example, the charge
state must be higher than 10. If an 40Ar13+ ion isaccelerated with this cyclotron, the final beam energy
from RRC reaches 95 MeV lu.
Main parameters of the source are listed in Table
1; its schematic view is shown in Fig. 1. The source
Table l.

Main parameters of the ECR source.

1st stage
magnetic confinement
chamber diameterchamber length

RFpump
2nd stage
magnetic confinement
mirror ratio
chamber diameterchamber lengthRF
pump
extraction
acceleration voltage
suppression voltage
extraction gap

Fig. l.

solenoidal field
60mm
20 mm (quartz tube)
250mm
10 GHz CW 1 kW max
520l/sTMP
mirror + hexapole field
1.4 to 1. 8 (variable)
l00mm
520mm
IOGHz CW 2.5kWmax
500l/sTMP
3 to 25 kVo to -lOkV
5 to 45 mm (variable)

Schematic drawing of the ECR source.

consists of two stages: the first stage is used forplasma filamentation and the second for productionof highly charged ions. The source is provided withthree gas feeding lines: two lines at the first stage
and the other line at the second for gas mixing.
Principal design of our ECR source is based on the
LBL ECR source,l) but the higher frequency (10GHz) microwave is used for both the first and second
stages, and stronger magnetic confinement is adopted
in plasma stages.
An axial magnetic field is produced by solenoid
coils, which are divided into eight sections. The
currents in all eight axial field coils can independently
be varied to find the optimum axial magnetic field
profile. A return yoke reduces the power consumption of coils and shields X ray from the plasmachamber. In the second stage, an open S m 2 Co 17(B res = 10 kG) hexapole magnet is set to produce aradial magnetic field. The inner diameter of thehexapole is 11 cm. Each pole is 4 em wide, 5 emhigh, and 45 cm long. The hexapole is placed inside
the vacuum chamber, and each pole is enclosed in ajacket and cooled with a non-dielectric coolant. The
magnetic field at the exit of the first stage is well
above the resonance field for 10 GHz. This field
profile gives better second stage confinement. A
surface position of the ECR zone near the gas feedis easily changed by varying currents of the first two
axial coils. The second stage works in the usual
minimum B mode. The mirror ratio and the minimum value of the magnetic field are easily controlled
by varying currents for six axial coils. The minimum
field can be high enough to test the tangential field
effect. 2 ) But from the magnetic pressure point ofview, the B2 I flo value at the extraction hole is required to be lower than that of the hexapole chamber
wall: if not, the diffusion of the plasma is caused
mainly to the hexapole walls and the extraction current may be reduced. The optimum mirror field may
be lower for getting high extraction current thanthat to test the tangential field effect. The second
stage plasma chamber is 10 em in diameter and 52 em
in length. The long plasma region can reduce themagnetic field gradient at an ECR surface to about
100 G/cm, which is better for the electron accelaration by the ECR and increases the electron temperature. 3)

K. Hatanaka, et ai.

10 GHz mIcrowaves are fed into both first andsecond stages through circular wave guides of 27 mm
in inner diameter. In the first stage, an RF power is
injected radially from the high magnetic field region.
By the beach effect, an RF reflection will be reduced.
On the other hand, a microwave is axially fed into
the second stage. For the efficient absorption of an
RF power in a plasma, a plasma chamber must bea multimode cavity. It is pointed out that thechamber diameter D is more than twice as large as
the RF wavelength A .4,5) In our case, D I A is 2 in
the first stage and 3.3 in the second stage. The RF
signal is sent from a Gunn oscillator source, amplified
with a GaAs FET amplifier, divided into two lines,
and amplified with two klystron amplifiers (Thomson
TV851 ). The RF power fed to each stage can bevaried independently by using a variable attenuator.
The maximum RF power is 1 kW for the first stageand 2.5 kW for the second stage. A DC cut is performed up to 25 kV with a two-fold insulation of
2-mm thick Teflon sheets. A vacuum window ismade of BeO.
The pressure is expected to be about 10-4 Torr in
the first stage cavity, and in the second stage it mustbe less than 10- 6 Torr to reduce charge exchange

213

collisions with neutral atoms. A 500 lis TMP is set
at the first stage, and two 1,500 lis TMP's at thesecond stage and in the extraction region. To avoid
the diffusion of the fed gas into the wave guide, aquartz tube of 20 mm in inner diameter is used in
the first stage.
The extraction voltage is varied from 3 to 25 kV
according to the injection condition to the AVF
cyclotron. The extraction hole is 10 mm in diameter,
and the gap between the extraction hole and theextraction electrode can be changed from 5 mm to
45 mm. To reduce secondary electrons from thegrounded electrode, the extraction electrode is biased
at the negative suppression voltage.
References
1) C. M. Lyneis: Proc. 7th Workshop ECR Ion Source,
p . l (1986).
2) T. A. Antaya and Z. Q. Xie: Proc. 7th Workshop ECRIon Source, p.72 (1986) .
3) Y. Jongen: Proc. 6th Workshop ECR Ion Source, p.238(1985) .
4) F. Bourg, J. Debernardi, R . Geller, B. Jacquot, R.
Pauthenet, M. Pontonnier, and P. Sortais: Proc. 6thWorkshop ECR Ion Source, p . 1 (1985).
5) C. M. Lyneis: Private communication.

214
RIKEN Accel. Prog. Rep. 21 (1987)

V-g.

RF Amplifier System of the Injector Cyclotron for
RIKEN Ring Cyclotron
S. Kohara, M. Nagase, M. Saito, T. Kageyama,
A. Goto, and T. Fujisawa

Design parameters of the RF system of the injector
AVF cyclotron 1 ) (K = 70) for RIKEN Ring Cyclotron 2 ) (RRC) are summarized in Table l.
A block diagram of the amplifier system is shownin Fig. 1. A master oscillator and power amplifier(MOPA) system is employed to keep synchronous
operation through the whole RF system including
RRC and beam bunchers. A phase adjustment system consists of two modulators: one is used so as tokeep the phase difference between the two resonators
zero and the other to adjust the phase of the deevoltage to the reference. The dee voltage is regulatedwith an amplitude modulator. A pulse modulator isemployed to overcome the multipactoring phenomenon in the resonator and also helps vacuum aging.
Table I.

The resonator is tuned automatically with a capacitive frequency tuner by comparing phases between
a plate and a control grid voltage of the final amplifier.
A power amplifier system consists of a solid-state
wide-band amplifier (500 W) and a groundedcathode tetrode amplifier (EIMAC 4CW50,000E).
A schematic diagram of the power amplifier system
is shown in Fig. 2. An all-pass networkS) is
adopted in the input circuit of 4CW50,000E; atransformer is used to match the input impedanceof the all-pass network, 250, to the output imShortingplate

Resonator

Design parameters of the RF system.

Numbel' of resonators
RF frequency
Harmonic number
RF peak voltage
Frequency stability
Voltage stability
Phase stability
Extraction l'adius
Dee angle
Output power of
RF amplifier2
12-23 MHz2
50kV
1 X 10- 8
1 X 10- 3
0.5 0
7l.4 em83

All pass
networkz--

0

9,OOOpF

20kW
Fig. 2.

Schematic diagram of the power amplifier.

RRC andbunchers

from No.1 Resonatorfrom No.2 ResonatorNo.2 Amplitude
modulator
Fig. 1 Block diagram of the amplifier system.

S. Kohara, et al.

~60~
N

(a)

215

20

1

Angle
o

•

~

o

i

1.6

lO C

0

•

Q:)

"

::>

"-

~

v

5or---. .------------------~0
~
0
~

2:

~

.0<

.(;

-10

v

~

c

.~
40
«:S

0

0

0

0

•

•

•

o

0

' 0

o

1.2
1.0

o

0.8

~

;2;

Magnitude

12

c

~

(b)

1.4

15

20

~

-20

"0

:>

23

12

Frequency (MHz)

15

20

23

Frequency (MHz)Fig. 3. (a) Input impedance CZ= IZ l sjO) and (b) voltage gain (Vg/V 1n) measured for the all-pass
network combined with the impedance matching transformer. The solid line in (b) is thecalculation.

pedance of the wide-band amplifier, 50 o. The
RF control grid voltage is estimated to be 200 V
for the dee voltage required. The measured
input capacitance of the tube is 340 pF. The model
study of several types of all-pass networks was
carried out; voltage gain (Vg/V in ) and input impedance (Z = I Z I ejf)) were measured for several
values of circuit parameters for each type. The results for the optimum circuit type and parameters
are shown in Fig. 3. The impedance varies from 39
to 540; the voltage standing wave ratio (VSWR)

is less than 1.3. Construction of the amplifier IS inprogress.
References
1) N. Nakanishi and T. Kageyama: RIKEN Accel. Prog.
Rep., 19, 197 (1985).
2) H. Kamitsubo: Proc. II th Int. Conf. Cyclotrons andTheir Applications, Tokyo, p.17 (1987) .
3) T. Fujisawa, K. Ogiwara, S. Kohara, Y. Oikawa, I. Yokoyama, I. Takeshita, Y. Chiba, and Y. Kumata: Sci. Pa~
pers I.P.C.R., 79, 12 (1987).

216
RIKEN Accel. Prog. Rep. 21 (1987)

V-lO.

Production of Multicharged Heavy Ions by
PIG Source of RILAC
Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase

The production of multicharged heavy-ions ofelements having mass numbers from 40 (calcium)
to 208 (lead) has been examined on a test bench
by using sputter PIG sources of an indirectly-heatedcathode type. We reported last year the productionof multicharged heavy ions with mass numbers below

74.

+

...

-.3

100 100 504030~:018l!:4 12 :0 9
u

u

U

6

c-+~1
<N
+

+>

~

;t;N

::s

~
1
o

1)

The M / q spectra observed for Ca, Zn, Zr, Ag,
Sn, Ta, W, and Pb are shown in Figs. 1-8. Argon
or xenon was used as a support and sputter gas forarc discharge of the sputter PIG source. The sputter
electrodes had different shapes for respective elements
as shown in Figs. 1-8. For prevention of melting
good thermal contact was essential between a sputter
electrode and its clamp for low melting-point metals,.;t~..;: \~

;!;

<:

~ 10

7 MI q,100504030 20181614 12 10 9 8

100

+

U

N

J-.

::s

~

u'"

+ .....

Q,)

~

~0.1

~~
j;

~ fl
~

V

A~

I

j;

~ / f\

9OZdAr)

u

V

5
10
15
Extraction voltage (kV)Fig. 3.

~IdJZr:: t(~'\ ;t;+

Mag. field=4KG
Arc=280V/3.3A
Sputter=300V 10.36 A

TO~74"/m;'i

+

~o

J~

20

Mjq spectrum of Zr sputtered in argon discharge.

7 MI l[;100504030 20181614 12 10 9
100 ,......---'-'---'-:~-\-J--T-:-'--""*"-'-.....L....;:-'-,------,

M/ q,

Mag. field=4 KG
Arc =290 V13.8A
Sputter= lOV10.14 A
Gas=O.38cclmin
4OCa(Xe)
+>

::s

fr
::s
o

(I)
(J

(I)

I-<

::s
o

en

U

J-.

::s

~ 0.11--t--lW---

O.ll--Ht---+---+--I----rJI%I------..:Ji1---::;::-- - I
+

+~

0.01

::;::

0

'0
5

O.ot

20

10

O

Extaction voltage

Fig. 1.

Mjq spectrum of Ca sputtered in xenon discharge.

Fig. 4.

100 100 504030 20181614 12 10 9 8 7 Ml q,j;+Mag. field=4KG~ ;!;~ ~Arc=360/ 2.9A
+ c
Sputter=60V10.24A;t~ + N t ~ +Gas = 0.3cclmin_r---N-~..,
~ -~c
64
•
><:
N
Zn (Xe).;t ;';
j;
~I
Zn
XX
c
;t;
.fr
N
o ·
g 1 +c ~20

15
Extraction voltage (k V)

Mjq spectrum of Ag sputtered in argon discharge.

MI q,100504030 20181614 12 10 9100~~~~~~-.~~-~--~
+

~o

~

~

=

~V

N

Q,)

1\

U

J-.

::s

o
CIJ 0.1
+

ITJ.

~

II

~~

~

~-

~

=
o

(I)

U
1-0

::s

~ 0.1 t--1SM--

X

~

5

10

I

15

20

20

Extraction voltage (kV)Fig. 2.

Mjq spectrum of Zn sputtered in xenon discharge.

Extraction voltage

Fig. 5.

M/q spectrum of Sn sputtered in argon discharge.

Y. Miyazawa, et al.

Table 1.

217

Output currents of RILAC source (in epA).
Charge state

Element

Gas

2

Xe

Ca

"

"
"Ar
"
"
"
"
"
"

Zn
Zr
Ag
Sn

"
"
W

0.17
0.18
0.02

1/

Ta

Pb

2+

1+

0.02
0.1
0.02

3+

4+

5+

6+

7+

8+

Arc

9+

i 40

50
22
0.14
10
7
0.06
2
0.7
I.··TO-------!
20
13
5
0.2
1.5 ------3:-8--- 14
13
4
10
14
8
3.4 i 91.2
0.6~------~:-:----------i:-;---l
;
0.3
0. 1
1
0.3
~. 25
;------~-.-~-----J ~. 3
0.1
0.02
4
4
3.5 i 2
0.5
1
3
0.3
0.1
3. 6 ~ ----4:-8-----L_~:_~

DC
pulse

DC

"
"
"
pulse
DC
pulse

DC

____._....~_:_~.___.__

pulse* Gases used to support arc-discharge.

100

200100 5040 30 25

20

Mlq,

15

200100 50 40 30
20 Mlq,
1OOl~~~~--~~~----r_----~
Mag. fjeld=5.95KG
Arc =430V/8.1 A1l
Sputter =75VO.07 A;_-!-¥---\- Gas=0.6cclmin<" 101---D.f of pulse 30%-.3
208Pb(Ar)

.....
::l

fr

g 1~-"+~~~~~~+-~----~----~~?'!

Mag. field==5.5KG~IillTag
Arc=410V/2.7 A
00 O.ll---H-++I-+--SpuUer =60V/0.21A+-_ _~Gas=0.73cc/min
181Ta(Ar)

Fig. 6.

t\.b.

10
15
20
5
Extraction voltage (kV)M/q spectrum of Ta sputtered in argon discharge.
100 200 100 50 40 30 25

20 18 1614 MI q,::s+rZ 0.1 ::;:.-1'4+-+--1-----0.01 0

5

10

g 1
4)

()

'g"'

000.1

CU

~I~J]~,~.fL__I--=--_+_--_+-Pb

O.OI·~O...A..l'4L-~5------,.I~O---1~5:----~20

Extraction voltage (kV)Fig. 8. M/q spectrum of Pb sputtered in argon discharge.
Arc discharge was operated at pulse with a duty factorof 0.3.

such as Zn, Sn, and Ph. The sputter electrodes weremachined to final dimensions except for Ph, which
was prepared by molding.
Table 1 lists the output currents obtained with theion sources. In the present experiment, we succeeded
in detecting Ca7+, Zn7+, Zr6 +, Ag 7+, Sn8 +, TaB+, W 8 +,Pb9 +. The dashed line in table shows the lower limitof the charge to mass ratios of ions which can heaccepted hy RILAC.

4)
~

s..

[

15

20

Extraction voltage (kV)Fig. 7. M/q spectrum of W sputtered in argon discharge.

ReferenceI) Y. Miyazawa, M. Hemmi, T. Chiba, and M. Kase:
RIKEN Accel. Prog. Rep., 20, 195 (1986).

218
RIREN Accel. Prog. Rep. 21 (1987)

V-II. Development of an LeE lon-Source
T. Kobayashi, T. Urai, and H. Sakairi

Figure 1 shows the LeE (lithium charge exchange)ion-source equipped originally to our T ANDETRON.
This ion source comprises a duoplasmatron ion
source, an einzel lens, and a lithium-vapor cell. The
positive ions produced by arc discharge in the
duoplasmatron were converted to negative ions bydouble charge exchange in the lithium-vapor cellshown in Fig. 2.
In this cell the heater wires of the furnace being
installed in a vacuum chamber, the loaded lithium
is rapidly contaminated or oxidized by degassing theheaters. The heaters, on the other hand, arecorroded by the lithium vapor faster than in agood vacuum. Such interference resulted in shorten-

ing of the lifetimes of the loaded lithium and heaters.
Moreover, use of the heaters in a vacuum requires a
special terminal structure, expensive in preparation.
In a new cell developed in our laboratory shown in
Fig. 3, these problems were settled by winding heaterwires outside the vacuum chamber to separate lithiumfrom the heaters.
Another disadvantage occurs on the former cell'i.Je in zel Duop laim~tron
lenslithium charge
exchange c e ll

1011Fig. 1.

12
13
14

Original LeE ion-source.

li t hium15boil er
16
canal
17
co upling (KF 25 ) 18
gate valve
19

23
O-ringhea t erwater .cooling
slit
clamp

20

21
22
23
24

O- r i ng
clamp
beam line
thermo couple
heater coverFig. 3. New (outer heating) LCE cell.

r~j-J· :~==:z:Z:J\

1L!::z:==·f\\r---'::::;

!

I

I

I
I

~

I

:

I

I

I

I
I

I

i

I

I

I
I

I

I

I

,

i===\:~:l77i==r==u

33
32
31

Fig. 2.

I(\(;t==:z::;P="i77I_t;===;
-t./
31
32
33
34
35
36

Original, inner
heating type

dL:<j

I

!

Table 1. Comparison of the original charge exchange cellwith the new one.

chamberboilerhea t erc ana lbeam line
end hea t er

Original (inner heating) LCE cell.

Difficulty inmaintenanceWork for lithium
loadingDifficulty in operation
Start-up time
Interval of lithium
loading
Stability
Intesity of HeAverage
Maximum

large

New, outerheating typesmall

2 persons X 1 h

I personxO. 5 h

large
greater than 3 h
1 weeksmall
about 1 habout 5 weeks

not so good

improved

200nA
1.5,uA

500nA
2.6 pAT. Kobayashi, et al.

when it is reassembled to the beam line after reloadedwith lithium in argon atmosphere in a glove box.
As the cell is equipped no gate valves it requires
the greatest care not to expose the lithium to airin bringing the cell from the glove box to the beamline. The new cell, however, has a compact structure
and is allowed to be set gate valves at both ends of219

canal without any alteration of beam optics. This
improvement makes easy in reassembling the cell.
The performances of the original and new cells
are compared in Table 1. The beam intensity andthe interval of lithium loading increased evidently
and the maintenance became easier; the beamstability was also improved.

220
RIKEN Accel. Prog. Rep. 21 (1987)

V-12. 6 GeV SOR Project
M. Rara and R. Kamitsubo
In the fiscal year 1987, RIKEN was given funds
for technical research for the construction of a large
synchrotron radiation facility and started researchand development for a next-generation synchrotron
radiation source.
The goals of this facility should:(1) be composed of a great number of longstraight sections for undulators and wigglers;(2) provide high-brilliance photon beams ( 1017
photons/s rnA nun 2 mrad 2 0.1 <yo b.w.); and(3) have long beam lines and ample space forexperiments.
In designing the facility, future expansion is also
taken into consideration. This facility is composedof a main storage ring, a booster synchrotron, a
1.5 GeV pre-injector linac, positron production linacs
and others.
This year we have started the basic design, in
which main efforts are laid on the lattice design. The
main parameters of the ring should be determinedfrom the requirements of users. Although user groups
have not been fully organized yet, the energy istentatively determined to be 6 GeV. The main photon
sources are expected to be insertion devices as shownin Fig. 1. For stable photon beams, positron beams
are to be stored and a full-energy injection systemshould be adopted. The storage ring is designed to
ldS'Y---~~~------__' -____. -____r -__~c BENDING fv1AGNET(c)1017 - 'Il MPW.10cm.40
1016 _ : 3cm.n:l
4cm.N:l1015,- • 6cm.N:!
+ Scm.N:!
1014'i------r____-r---:(b::;;;)nn9'lD.......
I:t!::I.;s.
__r:dl+-IlDQ__~__aofn::,--___1

la31-----~~I.......
~aT~~'~~~--'~t-~~$m~r_~~~~

la2~-----~~-'~·--~w(pa)~,~~~. ~' 4~P-.[~-'-·~-'-'4_-··-'~''~·.C~.~D~'D~
lalt-____~~~I~-,-,~-,-Ja+'~-··-··--_+----_+----_Fc~--~satisfy the following conditions:( 1 ) low emittance operation with ez less than
10 nm·rad;(2) a great number of long straight sections (7 m)for insertion devices;(3) a large dynamic aperture sufficient for injection;(4 ) having flexibility in the lattice configuration;and(5 ) being easy to construct.
For the 6 GeV storage ring, we have intensively
investigated the double bend achromatic (ChasmanGreen type) lattice which consists of two bending
magnets, ten quadrupole magnets, and seven sextupole
magnets per unit cell. 1 ) The characteristics of accelerators, a storage ring, and a radiation source arelisted in Tables 1-3. A low-emittance ring with many
Table 1. Accelerators.
Positron production linacs
Electron (positron) linac
Synchrotron
Source ring
Table 2.

200 MeV+250 MeV
1.5 GeV
6GeV
6GeV

Source ring characteristics.

Particle
EnergyCurrents
Bending magnet
Bending radius
Circumference
Periodicity
Energy width
Emittance horizontal
VerticalHarmonic number
rf Frequency
Bunchelectron, positron
6GeV
lOOmA
0.8T
25m
1,069.2m
36
0.001
8.2 nm rad
0.8 nm rad (10% coupling)
1,800
504.7 MHz
single bunch, 25 n

Table 3. Light source.

c

1dOl-----t-----1------i------+-----~u~~!09i-----+-----1-----+-----+---__+-~--r
106i- -----r----+-----·r-----+---__+-__~
1'07-t-r....-rrrn..f-..-.-,.......,.+_~~+_..-.-,rTTTT..\__~.......,..l_.__r_o~
.001

.01

.1

10

100

1000

photon energy (kev)Fig. 1. Spectral brilliance of the 6 GeV synchrotron radiaction source (a), Bo=0.8 T, dipole magnet; (b), Bo=
1.5 T, Au = 10 em, total length 4 m multi-pole wiggler; (c),Undurator radiation, total length 4 m, fundamental mode,
Br = 1.25 T, minimum gap = 12 mm. Fundamental modes
for Au=3 cm, 4 cm, 6 em, 8 em are shown.

Insertion devices
Number of sources
Length of straight sections
Beam size horizontal
VerticalBeam divergence horizontal
VerticalBending magnet source
Number of source
Beam size horizontal
VerticalBeam divergence horizontal
Vertical

307m
0.43mm0.09mm
0.02 mrad0.01 mrad(30)
0.15 mm
O.14mm
0.005 mrad

M. Hara, et al.

long dispersion-free straight sections can be obtained
only by using strong quadrupole fields, thus resulting
in high tune values and large natural chromaticities.
The chromaticity should be corrected with sextupole
magnets in the dispersive sections. The use of sextupole magnets, however, produces amplitude-dependent
tuneshifts, which make a beam unstable by driving
harmful resonances and make a dynamic aperturesmall. In order to get rid of these harmful effects,
additional sextupole magnets (harmonic sextupoles)
are introduced. We analyzed the modified betatronmotion with the sextupole magnets by a canonicalperturbation theory. Using a tracking code, we intensively surveyed the electron behavior in the DFA
lattice configuration, and found the lattice with asufficiendy large dynamic aperture. The betatronfunctions and the dispersion function of one of thelattice candidates are shown in Fig. 2, and the calculated dynamic aperture is shown in Fig. 3.
The synchrotron lattice was also investigated. A
booster synchrotron was used to raise energy from 1.5
to 6 GeV for full energy injection to the storage ring.
A simple FODO-type lattice!) with four dispersion-

Emittance: 8.2 X10-9

CHR- X : - 67.9
CHR-Y : -28.8

30A

Xp : 0.48.. . . \,

c
o

\
\
\

.e 20

1 ' (jj
I-.
<1)

<1)

!Xl

/3y

10 __ _- --' , I

0-

:

Vl

:

is

OL-__- L_ _~L_o5

_ _~--~~--~~~O

10

25

Path length
RIKEN2-F (High /3 Solution)

Fig. 2. Betatron functions and dispersion function for oneof the lattice candidates (RIKEN 2-F high f3) .

80
70

RIKEN2-F DYNAMIC APERTURE WITH ERRORSI I I I I IIAO"x=4.3x10- 4
III v: I.U"

~!

I~

•

GO

t---..
I

50

E

.s

I

Ii

r'

.. ' w ~~( ts

1\
l

f-

-..-

I

\

/

~"

c.

c

II,

20

-100

I

/

30

10

'.I '"

~

I

>-

'. U
'.U

I

40

v:

"" ' \.
\

'"

- 80

-GO

[? I!I

- 40

- 20

0

X (mmJ

20

40

GO

80

100

(12110187)

Fig. 3. An example of the calculated dynamic apertures(RIKEN 2-F).

221
Table 4. Booster synchrotron characteristics.

EnergyLattice typeCircumference
Double rf system
Number of cells
Number of straight sections
Emittance E. ", at 6 GeV

1.5-6 GeV
FODO
342.145 m
504.7 MHz, 28.02 MHz
36
4
2.7 X 10-7 mrad

free sections was adopted. The dispersion is suppressed by removing a dipole magnet. Injection elements extraction elements and RF cavities are arranged in these dispersi~n-free straight sections.
Although vertical tune can be adjusted in a wide
range, horizontal tune can be changed only withina narrow range. This can be improved by allowing
slight dispersion at the straight section. Chromaticity
can be corrected using two families of sextupoles. A
large dynamic aperture was obtained even with magnetic field and misalignment errors. For efficient injection, two RF system is under investigation. The
main parameters are listed in Table 4. A beam flowis also investigated for two types of operations (eand e+). Details are presented in this report. 2 )The design of the RF system, the magnet system,and the vacuum system is also in progress. The RFparameters of the storage ring and the synchrotron
are specified. The type of a cavity resonator has notbeen determined yet. We have many technical problems remaining unsolved. A test cavity was fabricatedand subjected to investigation. Storage ring magnets
were designed by using a computer code TRIM. The
design of proto-types for dipole and quadrupole magnets was almost completed.
The design study of the vacuum system of the
6 GeV source ring was also performed. Very highsynchrotron radiation power and its density make thevacuum system design difficult. In order to protect
the vacuum system from high radiation power,
crotches and absorbers are adopted, and basicallythe surface of the vacuum chamber is not directly
exposed to the radiation. The crotch is located justdownstream near the bending magnet and is equippedwith three pumps (NEG, SIP, TSP) to trap photoinduced outgasses. Analysis to simulate the heat flow
within the crotch was made by using finite-element
models and was presented in this report. 3 ) The
vacuum chamber of the main ring was investigated.
For the materials of the chamber, stainless steel andaluminum are the candidates and are under investigation. As for the cross sectional shapes of the chamber,
we are considering an antechamber type adopted at
Argonne (APS). The pumping system is based on
the NEG strips in the antechamber, a titanium sublimation pump, and a sputtering ion pump. Since
we must use many vacuum components for thesystem, their reliability is very important. In orderM. Hara, et al.

222

a

~

I

(1) Electron Line ar Accelerator (200Me V)(2) Electrical Machine Room
(3) Electron / Positron Linear Accelerator (l.SGeV)(4) Electrical Machine Room
(5) Synchrotron (6GeV)(6) Electrical Machine Room
(7) Storage Ring
(8) Electrical Machine Room
(9) Control Room(10) Expe r i ment Building

Fig. 4. An example of facility arrangements.

to investigate the performance characteristics of various vacuum components, a test device consisting of
extruded aluminum alloy chambers were constructed.
In parallel with the design work, we have been
granted the Special Coordination Funds for Promoting Science and Technology to construct a multipole
wiggler at the Photon Factory of National Laboratoryfor High Energy Physics (KEK-PF) in cooperation
with the KEK-PF group. This year we designed a
27-poles wiggler and the front end of the beam line,
which were installed at the straight section between
the bending magnets, B12 and B13, of the 2.5 GeVelectron storage ring of KEK-PF. 4) The design wascompleted and are under construction.
At present, construction site has not been decided
yet. The configuration of the facilities depends muchon the site. The site will be selected within 1988.
In order to grasp an image, an example of thearrangement is shown in Fig. 4.
We have many research and development problems
in constructing the synchrotron radiation source andwill need three years for research and developmentfrom 1987 followed by five years for construction.
References
1) H. Tanaka, R. Nagaoka, and M. Hara: p.225 in thisreport.
2) H. Miyade, K. Yoshida, K. Tsumaki, and M. Hara:p. 233 in this report.
3) Y. Morimoto, S. Yokouchi, H. Sakamoto, and S. H. Be:
p. 247 in this report.
4) S. Anami, H. Kitamura, Y. Kamiya, and T. Nakajima:
Photon Factory Activity Report 1984/85, p . 6.

223
RIKEN Accel. Prog. Rep. 21 (1987)

V-13.

Design of the Booster Synchrotron Lattice

K. Tsumaki, K. Yoshida, H. Tanaka, R. Nagaoka, and M. Hara

The booster synchrotron was designed under the
specifications shown in Table 1. The synchrotron
lattice has four super periodicity, and the lattice ofa super period consists of normal cells and a straightsection where a dispersion function is suppressed bya missing dipole (Fig. 1). The straight section isused for setting injection, extraction elements, and rf
cavities.
Only two families of quadrupole magnets QF and
QD are used to make the system simple. In this case,the stability region of betatron oscillation is represented by a necktie diagram, but the condition thatthe straight section must be a dispersion free section
restricts the operational region and the possible regionis only on the solid line as shown in Fig. 2. Whenthe operating point moves on the solid line, the tunechanges as shown in Fig. 3, from which one can seethat the horizontal tune can be changed only from
10.2 to 10.45, while the vertical tune can be changed
from 3.4 to 12.1. However, if a small value of dispersion function at the straight section is permitted,
the horizontal fractional tune is easily changed to theupper half region (0.5-1.0). When the maximum
value of the dispersion function at the straight section

is 0.1 m, the solution is represented by the dottedline in Fig. 2, and the fractional tune moves to theupper half as shown by the dotted line in Fig. 3.
For simplicity, a operating point is so chosen thatthe quadrupole magnets QF and QD have the same
strength. The betatron function and the energy dispersion function are shown in Fig. 4, and the major
parameters are shown in Table 2.

1

2

KF·L

Fig. 2. Operational region on the necktie diagram. X,
Operating point: KF=B'.Zq/B p ; lq, Length of quadrupole
magnet; L, Distance between the two adjacent quadrupole
magnet.

Table 1. Specifications of the booster synchrotron.
Item

Specification

Acceleration energy
Magnet lattice
Number of straight section
Number of cellI

1.5-6GeV
FODO
4
36

9.5

,

r§HD~
QD

B

QF

B

QD

(a)

42.8

/:

:1

EJ:

SD1

Fig. 1. (a) Normal FODO cell (B, bending magnet; QF
and QD, quadrupole magnets). (b) Lattice configurationof 1/2 superperiod (SF and SD, sextupole magnet).

ll",

ll"

Fig. 3. Possible operating region on the tune diagram.
- - , l1=Om; ---, 11=0.1 m.

K. Tsumaki, et al.

224

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

20

Vacuum chamber
aperture

5

:§
~

~

E

$Ot------f'I&:-----+---I--t----i---=J----l

10

~

of

-5
-10 .~~~__L_~~
0-20 -15 -10 -5

Path length (m)

__

5

~-L~

10 15 20X (em)

Fig. 4. Betatron and energy dispersion function.
Fig. 5. Dynamic aperture. ---, no error; - - -, with errors;
Table 2.

Major parameters of the booster synchrotron.

Energy E (Ge V)
Maximum bending field B (T)Strength of quadrupole magnet KF (m)KD(m)
Tune ])x])z

Momentum compaction a
Circumference C (m)Natural chromaticity

'x
'z

6
0.8
0.343
0.343
10.232
10.4190.015
342.145
-14.2
-14.3
4.59
3.0
3.0

Energy loss UO(Me V /rev)Damping time 1: x (ms)1:z (ms)
1: e (ms)
1.5
2. 7x 10- 7
Emittance c (tr mrad)
576
Harmonic number h
9R.F. voltage Vrf (MV)
R.F. frequency Irf (MHz)504.7-----------------

To avoid the head-tail instability, the chromaticity
correction is applied by means of two families of
sextupoles SF and SD, and the resulting dynamic
aperture was calculated by the particle tracking forthe following three cases: (1) no error, (2) witherrors, and (3) with momentum deviation. In caseof errors, the tracking was done under the conditions
shown in Table 3. The results are shown in Fig. 5.
The dynamic apertures of all three cases were larger
than the aperture of a vacuum chamber, and no
problems were found.
When the strength of dipole magnet fields ischanged, the sextupole fields are induced due to the-.-, 8PIP=I%.
Table 3. Tracking condition for the case of errors.

BendingmagnetQuadrupole
magnetError

Strength

Field uniformity oB/B
Rotation error o{} (mrad)
Setting error OX,(mm)
Field gradient error oK/K
Skew o{} (mrad)±1 X 10-8
0.5
0.1
1 X 10-3oz

1

0.4 .-----------------------,

0.3

0.2

O.l':":----''------''------I.__----L_ _---'-_ _---'-0.06 -0.04 -0.02

Fig. 6.

0.00

0.02

0.04

0.06

dP/P
Momentum dependence of tune.

eddy currents in the vacuum chamber. However, thechromaticity generated by this effect is of the acceptable order of 1 at most for the slow change in themagnetic field of a bending magnet.
The momentum dependence of tune is shown in
Fig. 6. For the particles, the energy deviation ofwhich is within +2 0/0, the tune variations were lessthan 0.005; this is quite acceptable.

225
RIKEN Accel. Prog. Rep. 21 (1987)

V-14.

Lattice Design for a 6 GeV Storage Ring
H. Tanaka, R. Nagaoka, and M. Hara

The lattice design for a 6 GeV storage-ring wasstudied. Following performance conditions are required for this lattice.
a) a dispersion-free long straight section (about
6-7m)b) low emittance (:::;; 10 nmrad)c) tunability of f3 configuration at the straightsectiond) a large dynamic aperture even with practicalerrorse) operation flexibility
CHASMAN GREEN (Double Bend Achromat)

TBA(Tripie Bend Achromat)

FOCO--~·-·-l·-~~·-----·--t·J)-·+---·-·-·I -·~-·E-7.--._ _\L _Bending Magnet()

Focusing Quadrupole Magnet

11' Defocusing Quadrupole Magnet
Fig. l.

Lattice types for a low-emittance ring.

Most efforts are concentrated in optImIzmg theserequests which frequently conflict with each other.
There are three typical lattice types (Fig. !) fora low-emittance ring. The most suitable type oflattice must be sellected as a 6 GeV low-emittancelattice among these candidates after careful investigation and comparison. As a first step to make comparison among three lattice types, a Chasman Green(CG) lattice was studied in detail along a following
design flow.
CG Lattice design flow
Step-! According to the doubly achromat conditions, a dispersive area structure (drift arrangement and quadrupole magnets strength) isdecided.
Step-2 Based on constraints t for drift arrangement, a dispersion free area structure is decided.
Step-3 Twiss parameter matching is made withthe computer code SYNCH on many different
conditions of f3x and f3y at the straight section
remarking a location of the crossing point of f3x
and f3y at a dispersive area and emittance. (Fromthe viewpoint of chromaticity correction, it isbetter that the crossing point of f3it and f3y is
located between two chromaticity correction
sextupoles) .
Step-4 Tune and emittance are adjusted. Concerning tune, a workpoint is selected carefully to
avoid first- and third-order resonances driven by
sextupoles.
Step-5 Coefficients of amplitude dependent tuneshift are checked. If coefficients are bigger thancriteria, go back to Step-2.
Step-6 Harmonic sextupoles and chromaticity
correction sextupoles are optimized to suppress
the resonance driving term.
Step-7 Dynamic aperture is calculated in both
ideal case (no error) and practical case (including errors) with a computer code RACETRACK, and behavior of dynamic aperture isanalyzed.
t Constraints of drift arrangement in our casea) long drift sections (about I m) are obtained at bothside of bending magnet for crotch and bumper magnet
of injection;b) 0.2 m is taken as a minimum drift section between
two magnets; andc) a dispersion free straigh t section = 7.0 m

H. Tanaka, et al.

226

RIKEN tentative CG lattice candidates for highEmittance: 8.2 X 10- 9
CHR- X: -67.9 Xp : 0.48
CHR- Y: -28.8

30{3, low {3, and middle {3 designed along the CGAlattice design flow described above and lattice
parameter are shown in Figs. 2 and 3 and Table l.
The number of cells is determined from the viewpoint of request of emittance ( ::;: 10 nmrad) . The
length of a unit cell and circwnference are 29.7 m and1,069.2 m respectively. Quadrupole doublet in thedispersive area is adopted to adjust a dispersion value
and also a quadrupole triplet in a dispersion free area
is adopted to adjust {3 configuration at the straightsection and tune per cell.
The tune diagram is shown in Fig. 4, from which
fetal resonance lines driven by sextupoles (1J1C = 36 N,
31J1C = 36 N, lJ x ± 21J y = 36 N) are found to be far fromworking points.
The dynamic aperture corresponding to each latticecandidate is shown in Figs. 5 and 6 with other ones
which were presented by ESRF and APS. Tracking
condition for dynamic aperture calculation is shownin Table 2. In spite that RIKEN tentative lattice0# "" \
\
\

! 20

\

v

D:l

I

Py

,:

10 ___ -- -'.1o.~--~--~~--~----~--~----~o

o

5

10

15

20

25

Path length (m)RIKEN2-F (High P Solution)
Emittance: 8.4 X 10 - 9
CHR-X : -101.49
30'
CHR- Y: - 33.84

B: 0.48

10

Table 1. Ring parameters of RIKEN tentative
CG lattice candidates.

OL-~-L--~L---~----~--~----~O

o

5

10

15

20

25

Path length (m)Low P Solution

Beam energy
Beam current
Natural emittance
Circumference
Cell No.
Length of cell
Length ofstraight section
Damping time
(Horizontal)(Energy)
Bending radiusFig. 2. RIKEN tentative CG lattice candidates (1). CHR·
X and Y represent horizontal and vertical chromaticity,respectively; and Xp represents horizontal dispersion.

40

2
Emittance: 8.4 XlO - 9
CHR- X: - 88.8
CHR-Y: - 23.15
Xp: 0.48

30

]:

C

:§
r::

1 .~

! 20

r-.

v

6.0GeV
1~100 rnA
8,2 X IO- L 8. 4 X 10- 9
1,069.2m
36
29.7m
7.0m
9.3ms
4.7ms
25.0m

v

j:Q

r;:l.
Ul

10
0
0

20

x2

x1

Q

0

25

Path length (m)yMiddle /3 Solution

Emittance: 8.4 Xl0- 9
CHR- X : -64.6
30 CHR- Y : - 25.2
Xp
: 0.42D

X : Horizontal Tune

10

Y : Vertical Tune

D.: High 13 Solution( A )OL----L----~--

o

5

10

__
15

L __ _~~_ __ L_ _~O

20

25

Path length (m)RIKEN3-A (Middle /3 Solution)
Fig. 3. RIKEN tentative CG lattice candidates (2). CHRX and Y represent horizontal and vertical chromaticity,respectively; and Xp represents horizontal dispersion.

(x1,x2) = (32,33), (y1,y2) = (11 ,12), X= 32.2, Y = 11.16
Low 13 Solution( B)(x1,x2) = (44,45) , (y1,y2) = (17,18), X = 44.2, Y = 17.16
Middle 13 So lution( C)(x1.x2) = (32,33), (y1,y2) = (11,12), X = 32.25, Y = 11 .16
Middle 13 S9lution( D)(x1,x2) = (33,34), (y1,y2) = (1 1,12), X = 33.2, Y = 11.15

e:
0:
X:
Fig. 4.

RIKEN tentative lattice tune diagram.

H. Tanaka, et al.

80i-

RIKEN2-F DYNAMIC APERTURE WITH ERRORSI I I I I I
II

70 '1(Jx=4.3x10· 4
i60 1-"-.'.s.

r--.IO""'" .....

/

20

~

I

i\

•

\

•

I,{ _

20+-------;----A~~-------r-------1i-'- I-~ ~ ~~~ -; I-.- 1-'- 1--'~\.......

~.

..

- -

a'"

-100

i

."

a
•

·80

-60

·40

20

-20

X (mm)

o· C i"

i

40

60

C

10

-10
80

100

X (mm)GO

RIKEN3-A DYNAMIC APERTURE WITH ERRORS_ I. ! ! , j ! I !

i-,..... (Jx=3.2x10- 4

50 I-

I-

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

E

r

30

I

""

,.e- ....

20

r

- 100

I ,.~

·60

~

:d

-20

...

C"S.(
' - - -&.=50
[]
C,,50

a
E

.s.

20

40

60

80

~

"a. 1
=5.

\

-60

·40

\

Gi!I~

o

f-,.,l...._.l . . . .I,...... l". . . L..LI-LW-l--WI---l--I=l=::t=t=i=11..f-l

D

1 ~

-;,

J"

........
-80(Jx=4.3x10- 4~ ~ fI

a

100

I

~

/

ESRF UW DYNAMIC APERTURE WITH ERRORS

I-!

(Jx=3.6x10-4 -

/
-20

20

X (mm)

60.-,-.-.-.--.-.-.-.-.-.-.~~~~-.~~~~

50 1- 1---

"

/

/

10

(10127/87)//...,n 0, "20IaX (mm)

/

>-

-

b

-'"'D' --C=s:t:

o

-

I

i

~

-40

5,

30

..... 0, 1

--

i

~

•

1

00-

"'tv.
ao

..

·80

'1il...

C-o. 1
C,,0.(1B

5. 0,.. "0!

' I ..

~

---

C

-a-

I

~

IDEAL
.... am-- " --""

,,"-

40

I

_.,

40

(12121/87)(12/10/87)

APS DYNAMIC APERTURE WITH ERRORS

10RIKENW_1.1X10-4

I

a

§.
>-

." c

10+------~-------r----~~------_;-\ +--J-.1 '

10

O"x:

.j-------+----=---ho---..---~------l ESRF~O.73Xl0-4

I

\.

/

ESRF(H.S.)
RIKENW(H.S.)

C

1M

-...
11.

~

II

30

8

c· 1,0'
l,;.

/

- f--

>-

DYNAMIC APERTURE AT lOW BETA SECTIN
30~------~------~-------r-------;,L- t · 'v ' :v,U'

I

40

c

I

/
I/

'5 0 1-

E

A

227

\
A

40

(12114/87)

Fig. 6. Dynamic aperture of RIKEN tentative CG latticecandidates.

1-140'-4-4--r-+-r-r-r-r-+-+-+-4-4-~HL~-;~~~+r~:_1- -r-+-t'-f---l---l--ll-l'"•20,-------------~~------------~"s.b

I 30+-;-4-;-~-r-r-r-r-+~'-~~~r4-+-+~~~m=ns~-0~+r~
~

~

~

III

1\

•

.,

I

~-r-+-+-~~~~~Jr~~IHI~I~~,\4-+-+-+-+-+-~~i10-r-~~~~~~I/_r_r~I.~·T+l_·~+_+-4-~~~~~

O-r-4-4-4-4-~~~~~-~~~~~..~A-+-4-4~-4~~
-100

-80

-60

-40

-20

0
X (mm)

Fig. 5.

20

40

60

80

100

(5)

(6)

e- 10 -t--~a.:-----_f'\~-----___1.g.
>(11/2/87)

Comparison of dynamic aperture among three lattice.

Table 2. Tracking condition for dynamic aperture
calculation.
(1)
(2)
(3)
(4)

a

CASE-1
CASE-2
CASE-3

Tracking code
RACETRACK
Tum No.
500 turn
Tracking initial condition
X'=O, Y'=O
Tracking particle No.
1 particle
Error condition(a) Error input stylerandom(b) Kind of error
Misalignment at Q magnet 5x 10- 5 m
2.5xlO-4
Bending field error (dB/B)
2.5 X 10- 4 rad
Bending tilt error
Gradient error(d(DB/DX)/(DB/DX»)
Q magnet tilt error
5. 0 X 10- 4 rad
In the case that errors are distributedin the ring, tracking is done
without COD correction

candidates have emittance of lower than 10 nmrad,they have a large dynamic aperture (> about 500"x)
even in both ideal case (no error) and practical case(including errors). I t will be studied whether the
dynamic aperture is sufficient for beam injection andO;-------T-----~~----~------~

o

10

20

X (mm)
CASE-1 : C.S + H.S + ERRORS+ COD CORRECTION
CASE-2 : C.S + H.S ( NO ERROR)
CASE-3 : ONLY C.S ( NO ERROR)

Fig. 7. An example of dynamic ,aperture recovery by COD
correction.

for the ring installed many insertion devices anddistributed multipole magnet errors and other different conditions.
In a real ring, COD is corrected with a monitor
and corrector system, so the dynamic aperture is
expected to have a certain value between ideal andpractical case according to the level of COD correction. The COD correction is simulated by RACETRACK and its result is shown in Fig. 7. With
COD correction, the dynamic aperture is almost
recovered. It is ascertained from the 'present resultsthat COD correction by a monitor and corrector
system is very important for a low emittance ring.

228
RIKEN Accel. Prog. Rep. 21 (1987)

V-I5. Chromaticity Correction in the Low-Emittance
Chasman ..Green Lattice
R. Nagaoka, H. Tanaka, and M. Hara

The "dedicated" storage rings should be able toaccumulate, in general, a low-emittance beam for along period of the operation time. Due to the following relation, however, the low-emittance and thelarge stability of the motion cannot be simply met
simultaneously: The low-emittance condition necessarily demands a large value of the horizontal
betatron tune v x , since the emittance is roughly proportional to third power of the inverse tune. Thisimplies the presence of strong quadrupole magnets,
which in turn calls for stronger sextupole magnets
to correct the larger linear chromaticity. In Fig. 1
is shown the momentum dependence of the betatrontunes in the absence of the linear chromaticity correction. With the sextupole magnets, the large amplitude betatron motions of the particles are greatly
influenced by their non-linear fields and in manycases become quite unstable due to harmful resonances driven by these elements.
To recover the stability of the betatron motion,
analysis must be made of the motion under sextupole
fields. Since sextupole fields enter the equation of
motion as quadratic, one can no longer rely on theusual linear optics theory. Here, we follow what iscalled the "canonical perturbation theory" to describe the modified betatron motion perturbed by
the sextupoles. 1 ,2)When the sextupole potential enters as a perturbation to the Hamiltonian system, the action variable2'-~·1~~--~--~--~
1 --~
I •

1 ---

L1v xc =Cll·2Jx+C12·2Jy(1)

L1Vyc = C21 · 2Jx +C22 · 2Jy(2)where V'n e (u = x, y) is the tune per cell, LJvu c is thecorresponding shift, and Ju denotes the action variable. Coefficients C ij (i, j= 1, 2) can be expressed
analytically. Using the harmonic expansion, the expression for C l l reads, for example/)

Cll = -18·

IJ ( 3vAam- 2m + V3Alm2
)
- m

m=-cc

xc

(3)

xc

I t is worth noting that coefficients A j m (j = 1 or 3)
depend on the sum of strength and location of the
sextupole magnets. Remaining C i j have similar expressions. One finds that- the larger the Cif, thegreater will be the tune shifts. leading to ,unstablebetatron motions. Amplitude dependent tube shifts
are sensitive ' to the resonances induced by the sextupoles as seen in Eq. 3.
Figure 2 illustrates the configuration of the Chasman-Green (CG) ' type lattice which is under consideration. Important point is that, as suspected fromthe shape of {3x, horizontal tune per cell comes close

d~ux

•

L

becomes no longer an invariant. The spirit of thecanonical perturbation theory is to perform systematic transformation of the canonical variables sothat the action becomes approximately an invariant.
Within the first-order formulation, one then finds
the following "amplitude-dependent tune shift formulate."

dbuy--~I ~.- -~-- ~-__l_
D

l ee
I
~
o --------r---'''''''''''-'' ,-"""'''--,,-'''' '"'''0 ''-''''''' "" ,,- -"-"--+-"
[J

D

•

:

c

D

J

Ie

-1 ",,---,,--- --,,-""- -- - , - r----",,,,,,,,,t,,,:I11 --.,,,,f,,,,,,,,,,--,,,,,,

Ir-2~~-r~~~~~~~--~4-~~

-3

-2

-1

o

2

3

dpJp(%)

Fig. 1. Momentum dependence of the betatron tunes with"out cl1romaticity correction.

Fig. 2. Beta and dispersion functions for Chasman-Greencell. Dark triangles indicate chromaticity correcting sex"
tupoles, and white ones the harmonic sextupoles.

229

R. Nagaoka, et al.

Px

25

Px

20
15

!

10

v. ~

"'-""". \"'-1-.........._ ....

\,

.f
5

o

-30

\

x

- .-

1\

o

10

~

:/
-20

-10

(a)

20

x (mm)

Fig. 3. Comparison of the theory and tracking in the dynamic aperture calculations. No harmonic sextupoles areincluded.
80~--~--~--.---.----.--~--~--~

I - - -.-- j.....---+--+~.--+--.....j....-- ----..
60 t--+---+-;;::=.....j.:;;:::--~.--~- --+......-.-....

I

----~

1/:

40

• "\

~~--f --·--~ .' t
20f--"--iJ...
/ _- -r~. .._.. . _. ...
hI1••••••••••-.

---.. . .

j - ---

or-~-·4--+--~~\~~~~

-100

-50

o

'I"

50

100

x (mm)

Fig. 4. Dynamic aperture obtained from tracking a particle
over 500 turns. Outer and inner curve represent resultswith and without the harmonic sextupoles, respectively.
Dark squares are those including random errors.

to unity which results from achieving the low-emittance. Under such circumstances, we can expect
tune shifts to be dominated by the resonances LJ xc =1, and 3LJ xc = 3, which are of the order one andthree, respectively. In fact, this was verified from thenumerical analysis. Dominance of the above twocomponents can also be realized from Fig. 3 wherecomparison of the dynamic aperture is made between the theory and tracking. Prediction of thetheory is based on the simplified Hamiltonian which
only takes account of the contributions of the above
resonances.
Knowing the origin of the instability and that they
are much localized, it may be possible to recover
the stability by adding few families of sextupoles in
the lattice so as to cancel the harmful effect. Twofamilies of "harmonic sextupoles" as they are called
are tried in our case (see Fig. 2). Although thelocations of these magnets are another freedom, they(b)Fig. 5. Phase space of the horizontal betatron motion calculated at the straight section. (a) : without harmonic sextupoles, (b): with harmonic sextupoles.

were fixed in our present case study and theirstrengths were numerically searched to minimize themagnitudes of the coefficients C i j (i, j= 1, 2). In
most cases, the strengths converged at moderatevalues~ whereby the resultant magnitudes of C i j werereduced roughly by the order of two. We show in
Fig. 4 the dynamic aperture obtained after optimizing
the harmonic sextupoles. One observes a drastic improvement of the stability. Also demonstrated is the
tracking result for five machines including random
errors. (Field error of 0.025%, and as much as
0.05 mm of quadrupole magnet misalignment are
taken into account.) In the result shown, thedynamic aperture is still adequately large even witherrors. According to our analysis, however, the behavior of the ring against errors has a deep connection with the properties of the ideal lattice and iscertai~ly a subtle problem. We believe further study
is required on this subject. Typical changes of thephase space vehavior before and after the correction
are displayed in Fig. 5. Characteristic shapes of thecurves indicate that before correction, the horizontal
motion is ruled by the first-order resonance, while
it disappears after correction and the motion isaffected by resonances of the third-order.
To sum up, we have been able to restore thestability of the betatron motion by the aid of two
families of harmonic sextupoles. Routine for optimization relied greatly on the specific situation met withthe low-emittance CG lattice. We have interest to
extend the analysis to other type of lattices and wehope to do so in future.
References
1) H. Wiedemann: PEP-220, 1976.
2) E. A. Crosbie: ANL-HEP-CP-87-21.

230
RIKEN Accel. Prog. Rep. 21 (1987)

V-16.

Design Study of the Magnets for a Storage Ring
S. Motonaga, T. Kasahara, and Y. Yamagishi

A storage ring is designed with a Double Bend
Achromat Chasm an Green Lattice. 1 ) It is aimed at
the storage of electrons with an energy of 6 GeV
injected from a synchrotron. 2 ) The magnet latticeconsists of 36 unit cells, each composed of 2 dipole
magnets and 10 quadrupole magnets in the principal,
and 7 sextupole magnets used for the chromaticity
correction; thus total amount of the magnets constituting the magnet lattice is 72 dipole magnets, 360
quadrupole magnets, and 252 sextupole magnets.
The orbit characteristics of the storage ring are given
elsewhere in this progress report. 1 ) The aperture of
the magnet. required for a good fiat field is 70 mm
in the horizontal (X) and 30 mm in the vertical direction. The requirement for field quality of thedipole and quadrupole magnets is serious to get agood beam. 1 ) Guidelines of the required field quality
are given in Table 1.
In order to design these magnets, we carried out
numerical calculations of magnetic fields by using
the program code TRIM. Figure 1 shows the crosssectional views of the dipole and quadrupole magnets
designed to be optimum. The parameters used inthese calculations are given in Fig. 1. Ten quadrupole

Table 1. Required field quality of the dipole and quadrupole magnets.
MagnetDipole magnet

Quadrupole magnet

Field strength
0.8T
Gap distanceor bore radius
0.062mBending radius
24.98mBending angle
5
Uniformity
Field strength ilB(X)/Bex=o)or gradient<1.5x 10-·
X=±37mm
Y=±14mm
Effective length ilBlex)/Blex=o)of field<2x 10-·15T/m, 14T/m, lOT/m
O.04m

X=±35mm
Y=±14mmilGl ex )/Gl ex=0)<2.5X 10-8

ilB(X)/B(x=o), JGeX)/G(x=O) indicate variations in fieldstrength and field gradient, respectively, JBl(X)/Bl(x=Oh
ilGl<x)/Gl(x=O) also indicate variations in integrated fieldstrength (effective field length)
gradient, respectively.

andintegrated fieldmagnets in a unit cell were divided into three groups
according to their field strength and core length.
The cross sections of these magnets are identical.
For the dipole magnet we calculated various polewidths, shim geometries, and the optimum geometry
Quadrupole magnet

Dipole magnet(A)

Gap distance

62mm

Amper turns
Pole width
Pole length

4.04 x 104 A.T
236 mm
124 mmBore diameter

80mm

Amperturns

1.0 x 104 A.T

9.5 x 10 3 A.T
6.Sx 103 A.T

Pole width
Pole length

90 mm
124mm

90 mm
124mm

526
210

236

80

0
H
N

lI"\

'"

I

:'L...-

~

C")

~
\.0

Radial ed e shim

Fig. 1.

(B),(e)80mm

Cross sectional views of the dipole and quadrupole magnets for the calculation.

s~Motonaga, et ai.

which gives a desired field distribution. The magnet
is of the C-shaped rectangular type as shown in
Fig. 1. The pole is flat over the horizontal range of-+-104.3 mm and has radial shims of 1.5 mm in thickness at both ends. The ratio of cross-sectional areaof the yoke to that of the pole base is 0.89. The
ampere-factor, which indicates the degree of saturation of the iron core, is 1.25 percent at = 0.81 T.
Calculated radial field distributions normalized at
the center of the dipole magnet are shown in Fig. 2.
The flat field region within a radial variation
L1 BIB = 1.0 X 10-4 is expected over an aperture of
X= ±60mm and Y=-+-15 mm.
As the first step for choosing the optimum pole
profile, the calculation carried out on the quadrupole
magnet having a completely four-fold symmetry as
shown in Fig. 1.
In order to enlarge a flat field gradient region andto suppress higher multipole fields, the pole profileis shaped along a hyperbola. Radial field distributions calculated for the quadrupole magnets areshown in Fig. 3a. The field gradient of 15 T 1m isachieved at a magnetomotive force of 1.0 X 10 4ampere turns per pole; this magnetomotive force
is 5% higher than the value calculated by assuming infinite permeability. This difference shows thatthe effect of saturation in the iron core is large
at this field gradient; therefore, a yoke width will
be wider by more than 10% of this design. The
magnetomotive force of 1.0 X 10 4 A. T is adequate
at the real magnet. Figure 3b shows the variationin field gradient in the radial direction for two polewidths of 80 mm and 90 mm. The distributions of
the field gradient are normalized at a radius of
25 mm, because the calculation introduces a field

231

,
9000

!

Y.1.00(cm)----;-

L _. _----, - -

I

In

"

::c

r--

L-

I

I

i

~ 5000~IIi--+----+-:-;./--+--I--+-+--+--I~ 4000~I

1~·····_·Vc..+·---.. _j.. -·-1····-····-·+·_...··-1·--- --L---

i

7

3000

. . . . . . . .....-.. . .- . .-....

/Lt.... - .+_.-.......+ .. -+ .............+ ......_+ .............. j··-j···············..;.-············I

2000

/

~17'

1000
0

!/

17
o

2

4

3
X(cm)

6

5

Fig. 3a. Calculated radial field distribution of the quadrupole magnet.

1.040
G( X)=lS Tim.1.020_ . ::--===:::=:;"-----~=="""-

1.000

0.980

___---\90~--\\-1·80mm

0.960

\"
I

~

3 .0

4.0

5.0

6.0 .

Fig. 3b. Variation of calculated field gradient of the quadrupole magnet for the pole widths of 80 mm and 90 mm.

Y=1.50(cm)0.0004

2 .0

X(cm)

O.OOOE?

I'C'[ 0.0002~~~
rf .........

r§'
0.0000'P--

I-0.0002~ Y=O.OO(cm)-0.0004

'- I

I

-6

·4

1110000

f

-V

J..

~.

1-

'\:

Y.0.50(cm).

-0.0006-0.0008

-8

-2

2

10

X(cm)

Fig. 2. Calculated radial field distribution of the dipole
magnet. Field distribution is normalized at the center(x=O) .

I

I/,

8000 -~ ~~t:O~+~?j:=t-j~t=~~6()()0 --- --"'F.!h)l-~'m_£ - - - .--I
u;-7000 ----- -_ Y=O.625cm - - - - --_.

1. 0
0.0008-0.0010
-10

I
!

T

0.0010E+

10000'--'--'-~---'--'--'--~-'--~--~~~

error at the central region caused by mesh plots of
the TRIM.3) Difference in the field quality can not
be distinguished in both cases of the pole width considering the accuracy of the calculation. The flat
region of the field gradient is wide enough. The
radial variation in the field gradient at 15 Tim isshown in Fig. 4. The pole has a hyperbolic shapeand a width of 90 mm. The flat region of the field
gradient within 1.0 X 10-3 is expected over an elliptical area of X = ± 35 mm and Y = ± 12.5 mm.
As described above, the geometry of the quadrupole magnet used in the calculation is completely fourfold symmetry. In the real quadrupole and sextupole
magnets, however, a vacuum chamber having anantechamber will be installed as shown in Fig. 5a.

S. Motonaga, et al.

232

The top and bottom halves of the quadrupole magnet
are jointed through a non-magnetic metal as shownin Fig. 5a. Therefore, the structure is not completely
four-hold symmetric, magnetic flux does not crossthe median plane of return yoke, and unwanted
dipole and higher multipole fields will increase in
the quadrupole and sextupole fields. However, fromthe calculation carried out by assuming the structure as shown in Fig. 5b, the variation in the field
gradient was found almost the same as that for thecompletely symmetric structure. The detailed design

I

1.010

i

1.008
1.006

-.L

] 1.002'r'""
8 0 .99 8"

0 .99 6I

1/1000

1.004'"
C" 1 . 000

Y=1.25cm/,/

Fig. 5b. Cross sectional view of the quadrupole magnet forcalculation. The yoke core at the median plane is removed.

I

Y=0 . 65cm

I

~/

>~ --

-

\

y.o.oo m

0 . 994
0 . 992
0 . 990

T

o

1.0

2 .0

3.0

4.0

5 .0

X( cm)

Fig. 4. Variation of calculated field gradient of the quadrupole magnet at 15 Tim.

Table 2. Specifications of the prototypes of dipole andquadrupole magnets.
Dipole magnet

Quadrupole magnet
865mm
OOmm
l24mm
90mm

Core length
Gap distancePole length
Pole width
Magnet height
Magnet width

2,114mm
62mm
l24mm
236mm
730mm
526mm

Amper turns
Conductor
Redistance
Max current
Max. voltage
Consumption
power

4.04X 10' A. T
1 X 10' A.T
11.5x 17.5 mm,5m~ 6X6mm,3mm
0.018 ohm at 40°C
0.4 ohm at 45°C
140A
900 A
16.3V
55V
7.5kW
15kW

500~m

610mm

and calculation are now in progress to achieve a required field with various asymmetric constructions.
Precise estimation of the effective length of a field,
necessary for beam dynamics, should take the end
effect of the magnet into account. Effective lengths
at various radii are different due to the end effect.
Their variation will be corrected based on the results obtained from iterative measurements of the
field with various end shims.
The design of prototypes for dipole and quadrupole
magnets has been almost finished. Investigation of
the field property and development of the techniques for the field correction will be carried out
on these magnets. The main specifications of thesemagnets are given in Table 2. The magnetic field
will be measured by using flip and rotating coils forfast and accurate measurement. The design of themeasurement system is now in progress.
References

520

Fig. 5a. Cross sectional view of the quadrupole magnet inwhich a vacuum chamber with an antechamber is installed.

1) H. Tanaka, R . Nagaoka, and M. Hara: p.225 in thisreport.
2) M. Hara and H. Kamitsubo: p.220 in this report.
3) K. Egawa: Proc. Semin. High Energy Accelerator,
OHO'85, 2-1 (1985).

233

RIKEN Accel. Prog. Rep. 21 (1987)

V-I7.

The Overall Beam Flow of the 6 GeV SOR
H. Miyade, K. Yoshida, K. Tsumaki, and M. Hara

The overall beam flow of the 6 GeV SOR wasinvestigated. Two types of operations are expected.
One is the case in which electrons are used (e--mode),and the other, positrons are used (e+ -mode) . Table 1
shows main specifications of the 6 Ge V SOR.
Eight electron pulses are produced with an electron gun at 60 Hz. Each pulse is 15 ns long. The
current is 170 rnA for the e--mode and 3.5 A forthe e+-mode. It is expected that the efficiency fromthe electron gun to the electron linac is 60% .1,2)
In the e--mode electrons are accelerated with anelectron linac up to 1.5 GeV, injected into a synTable 1.

Main specifications of the 6 GeV SOR.

Electron gun
EnergyPulse length
Pulses/ cycle
Current
Pulse rate
Linac
EnergyCurrent
Frequency
Synchrotron
Injection energy
Extraction energy
Current
Circumference
RF frequency
Low
High
Har-monic No.
Low
High
Acceleration cycle
Duration time ofkicker magnet
Bunches/ cycle
Storage ring
EnergyCurrent
Circumference
RF frequency
Harmonic No.
No. of bunches
Accumulation time

150keV
15 ns
8
170 rnA (e--mode)
3.5 A (e+-mode)
60Hz

1. 5 GeV
100 rnA (e- -mode)
10 rnA (e+-mode)
2.856GHz
1. 5 GeV
6GeV
10 rnA (e--mode)l.OmA (e+-mode)
342.144 m

chrotron through a septum magnet during the 1/6 sflat bottom, accelerated up to 6 GeV in 1/3 s at theconstant rate of 13.5 GeV /s (15.4 keY per turn) , andextracted during the 1/6 s flat top; the cycle is
1 Hz. Since the injection method is of one-turn,a kicker magnet with a duration time of less than
120 ns is used.
In the e+-mode, electrons from the gun are accelerated up to an appropriate energy and hit apositron converter, where positron pulses are ' produced. The conversion efficiency is . assumed to be
0.5%.1,2) The positrons are accelerated with a positron linac up to 1.5 GeV and injected into the synchrotron. The scheme of injection, acceleration, andextraction is the same as in the e--mode.
To avoid radioactivation due to high energy
beams from the linac both in the e--mode and in
the e+-mode, the beam loss at the injection into
the synchrotron is desired to be as low as possible.
In the e+-mode the beam current from the linac islower than in the e--mode. Therefore, the synchrotron has two RF systems. One is a high frequency
system (504.7 MHz) and the other is a low one. The
low one makes a bucket wide so that it is possible
to inject the beam with good efficiency.1,3) With
this method the efficiency of the injection into thesynchrotron is expected to be 95 % .1) The low frequency will be either 28.04 MHz or 42.06 MHz.
Figure 1 shows the longitudinal separatrices for the

2.-------~--------~--------~------~

28.04 or 42.06 MHz
504.7 MHz
32 or 48
576
1 Hz

~

lli'i 0< 120 ns
8
6GeV
100 rnA
1,.069.2 m
504.7 MHz
1,800
1, 25xN
1 min (e--mode)
10 min (e+-mode)

-1

-2

-20

- 10

0

10

20

Width (ns)Fig. 1. Separatrices of the low frequency system at EB=
l.5 GeV with various q. The frequency is 28.04 MHz. At
q=2.5 the bucket width is 22.5 ns and the height (tJE / E B )is 0.58%.

M. Miyade, et al.

234

During acceleration the bunch length is decreasedby radiation damping. Its behavior is shown in
Fig. 2. In this calculation, q = 2.5 at the injection(EB = 1.5 GeV) and the constant increasing rate of
the peak voltage (1 ,950 kV / s) were assumed. Whenthe bunch length is short enough to fit the bucketof the high one, the high frequency system is turnedon and the low one is turned off. The bucket widthof the high one is about 2 ns. From Fig. 2 it isfound that the bunch length is less than 2 ns at

3025ii) 20..s

Bucket Width

-S

~

<I)

~ 15
u

~

EB~2.3GeV.

10

5

0
1. 5

Bunch Length

2 .0Energy (GeV)

2.5

3.0

Fig. 2. Decrease in the bunch length by radiation damping.
The behavior of bucket width is also shown. This bucket
is of the 28.04 MHz frequency system. In the area of thisfigure the bunch length decreases faster than the decreasein the bucket width.

28.04 MHz frequency system at EB = 1.5 GeV (EB is
the beam energy). On the basis that the relative
deviation of beam energy ( 11 E / E B ) is 0.6 %/) the
overvoltage (q) at injection should exceed 2.5.

After acceleration, the electron (or positron)bunches are extracted from the synchrotron andinjected into a storage ring ; the efficiency of theinjection is expected to be 50% .1,2) The numberof bunches in the storage ring is a multiple of 25.
In order to accumulate the beam up to 100 rnA,
it takes about 1 min for the e--rnode and 10 min
for the e+-mode.
References
1) 7 GeV Advanced Photon Sources: Conceptual Design
Report, ANL-87-15, April (1987) .
2) European Synchrotron Radiation Facility: Foundation
Phase Report, Feb. (1987) .
3) A. Febel and G. Hemmie: Proc. 11th Int. Conf. HighEnergy Accelerators, Geneva, Switzerland, July 7-11,
1980, p.43 (1980).

235
RIKEN Accel. Prog. Rep. 21 (1987)

V-lB. RF System for the 6 GeV SOR
T. Yoshiyuki, T. Kusaka, and M. Hara

The RF (radio frequency) systems designated forthe 6 Ge V SOR are classified into RF systems of astorage ring, a booster synchrotron, and linacs. In
this report we represent the RF systems of the storage
ring and the booster synchrotron.
( 1) Storage ring RF system
The RF system of the storage ring provides
adequate accelerating voltage to compensate for theenergy loss due to synchrotron radiation from thedipole magnets and insertion devices. There will bean additional loss due to the excitation of parasitic
modes by the beam. The peak RF voltage must be
in excess of the amount needed to make up theselosses and to provide overvoltage for an adequate
beam lifetime. The RF system is also the major
factor in determining the bunch length.
The RF parameters are listed in Table 1. The
nominal frequency of operation for the storage ring
RF system is 504.7 MHz. At 6 GeV beam energy,
the energy loss per tum due to synchrotron radiation
emission from the dipoles amounts to 4.6 MeV. The
additional loss component due to the insertion devices
depends on the exact distribution of undulators or
wigglers and their characteristics finally applied. Here,the estimation for the maximum loss component due
to insertion devices is based on one example of theTable 1. RF parameters of the storage ring.
Beam energy
Cir cumference
Bending radius
Momentum compaction factor
Radio frequency
Harmonic number
Synchrotron radiation loss per turn
Energy loss for insertion devices
Parasitic energy loss per 100 rnA
Nominal RF voltage
Maximum RF voltage
Shunt impedance
Quantum lifetime
Number of cells
Synchrotron frequency
Radiation damping time
Synchrotron phase angle
Beam current
Beam power
Cavity power
Klystron power
Number of klystrons

6GeV
1,069.2m
25m
1.86 X 1()-4
504.7 MHz
1,800
4.6 MeV
2.1 MeV
0.3 MeV
7MV
lOMV
23.5 Mn/m
1.6 X 1()6 h20
2.48 kHz
4.66 X 10- 3 s
44.4 deg
100mA
700kW
710kW
IMW

2

Table 2. Characteristics of the cavities for the representative storage ring.
Cell length Shunt impedanceCavity power(m)(Mil/m) (Mil per cell) (kW per cell)APS*
ESRF**PETRA**
PF*
RIKEN

0.425
0.426
0.4
0.3
0.3

26.4
26.6
22
29
23.5

11.23
11. 31
8
8
7.05

36
25
25
30
36

* single·ceU cavity, ** 5-cell cavity
design for a set of undulators and wigglers. The
total energy loss is estimated at 2.1 MeV. This energy
loss can be compared with other similar facilities;
ESRF1) in which a total loss per turn due to a fulloperational set of insertion devices is 1.5 MeV and
APS2) in which this loss is 1.2 MeV. Other energy
losses due to cavities and vacuum chambers are evaluated to be 0.3 MeV. These would make the total loss
7 MeV per turn. The operation RF voltage required
would then be 7 MV. The peak voltage would be
10 MV to get a sufficiently long quantum lifetime.
The overvoltage factor of 1.43 gives a relative energy
acceptance l1Err/Eo of +2.40/'0. When a beam energy
spread ae/Eo is 3 X 10- 3 , a relative "bucket" size
l1E r r/ae ' is 8.0, from which a quantum lifetime isevaluated at 10 6 h.
The RF power is calculated from the shunt impedance of the cavities, the cell number, and thebeam current. The shunt impedance of the cavities is23.5 Ma/m, which can be compared with otherrepresentative facilities in the world. Table 2 shows
the characteristics of the cavities for the representative storage rings. In this RF system cavities have
20 cells. The RF power dissipation per cell is 36 kW
and the total cavity power is 710 kW. The beam
power at the nominal storage ring current of 100 rnA
is 700 kW. The total power consumed in the storage
ring is 1.41 MW. The RF generator should supply
the sum of the beam power, the cavity power, andreflected power which depends on the cavity coupling
coefficient. The generator power, therefore, needs atleast about 2 MW. Klystrons rated for 1 MW output at 504.7 MHz are available. In total two 1 MW
klystrons are required for 20 cells.
In the structure of RF cavity we examine two
types: one is a single-cell cavity which is used on

236

T. Yoshiyuki, et ai.

the Photon Factory and SRS (Daresbury) and is
proposed to use on APS, and another is a multi-cellcavity which is used on PEP (Stanford), PETRA,(Hamburg), and LEP (CERN) and is proposed touse on ESRF. To select the type of cavity we arepresently testing the model cavity used as both singlecell cavity and multi-cell cavity.3)
Besides the fundamental RF system a higher
harmonic RF system may be combined with it andused to provide additional Landau damping or tolengthen the bunches if required for added stability.
From now on, we will further. investigate this RF
system about the RF parameters and the structure ofcavities.
(2) Booster synchrotronRF system
The booster synchrotron has two accelerating systems. The first, a low frequency system, is used tocapture electron or positron bunches from the linac
and accelerate electrons or positrons from 1.5 GeV,
accelerating energy of the linac, to more than 2 GeV.
After that, a high frequency system is used toTable 3. Parameters of 504.7 MHz RF system in the booster
synchrotron.
Beam energy
Circumference
Bending radiusRadio frequency
Harmonic number
Synchrotron radiation loss per turn
Nominal RF voltage
Maximum RF voltage
Shunt impedance
Quantum lifetime
Number of cells
Cavity power
Beam power
Klystron power
Number of klystrons

6GeV
342.144 m
25m
504.7 MHz
576
4.6 MeV
5MV
9MV
23.5 MU/m
>600s
15
770kW
<50kW
IMW

accelerate them to 6 GeV,' beam energy in the storagering.
A list of parame~ers for the high frequency system
is given in Table 3. The frequency is the 576th
harmonic of the revolution frequency. Since this RF
system will also make use of 504.7 MHz, it would
be favorable if the same RF cavities would be usedas those for the storage ring. The maximum RF
voltage required for acceleration, synchrotron radiation loss, and adequate longitudinal bucket size isgiven as 9 MV. At the maximum voltage of 9 MV
a quantum lifetime is calculated at 10 min and theovervoltage factor at 1.8. The shunt impedance ofthe cavities is the same value, 23.5 Majm, as thestorage ring, so more than 15 cells in the cavities
needed in this case is about 770 kW. Consequently,
the use of one 1 MW klystron identical to the ones
used for the storage ring is expected. The RF power
the use of one 1 MW klystron identical to the ones
used for the storage ring is expected. The RF powerfrom the klystron is divided equally among the 15
cells.
The subharmonic frequency of the low frequency
RF system is 28.0 or 42.1 MHz. The exact dynamics
and maximum RF voltage required for this low
frequency system have not been determined at thisreport. Nevertheless, the harmonic number of bothrings and their circumferences have been adjusted
for such a subharmonic system. The harmonic number of the low frequency system is, therefore, fixedat 32 or 48.
References
1) European Synchrotron Radiation Facility: Foundation
Phase Report, Feb. (1987) .
2) 7 GeV Advanced Photon Source: Conceptual Design
Report, ANL-87-15, April (1987) .
3) T. Kusaka, T. Yoshiyuki, N. Kawasaki, and M. Hara:
p.237 in this report.

RIKEN Accel. Prog. Rep. 21 (1987)
i

V_19.

Design of the RF Test Cavity .for the 6 GeV SOR Ring
;1'-•

T. Kusaka, T. Yoshiyuki~ N. Kawasaki,* and M. Hara

In the 6 GeV SOR ring, it is desired for accelerating cavities to make a stable and efficient acceleration.
For this purpose, it is important to study the characteristics of the cavities at resonant frequencies.
Computer programs are available to design the
structure of cavities. However, they are limited in
the cavity structure and the resonant modes which
can be calculated. Therefore, it is ' necessary tofabricate a test cavity and evaluate its electromagnetic properties. In this report, the design ofthe model cavity for low power tests by using
numerical programs is de,scribed.
In Advanced Photon Source, single-cell cavities areproposed for the storage ring, while multi-cell cavities
are designed in European Synchrotron Radiation
Facility.l,2) In order to compare them, a model cavity
has been designed to operate in both single-cell modeand multi-cell mode. Figure 1 shows the structure of
the cavity in a 3-cell 'mode. ' The single-cell cavity,on the other hand, is 'assembled by using a center
cell and two end plates. Each cell has the re-entrant
structure and the noses help concentrate the electricfield in the beam 'axis:, The cell lengths are of ahalf ,wavelength long. In '~' multi-cell mode, cells arecoupled together magnetically with off-axis slots. The
cavity is excited through the coupling loop locatedin the center cell. Three other ports are prepared fora frequency tuner and damping couplers which suppress higher-order modes.
The cross section of the half cell is shown in Fig. 2.
The gap length g, the nose angle 8, the nose radiusr, and the disk thickness t are chosen as design pa-

1020

Fig. 1. Structure of the test cavity in a 3-cell mode,* College of Humanities and Sciences, Nihon University.

t12

Fig. 2.

Design parameters.

9~----------------------~

8

-<ll'

a
(J

:2:

~

7

N

12

14

16

18

20

22

24

26

gap length (em)Fig. 3. Variation in shunt impedance as a function of the
gap length.

rameters. The accelerating frequency is set to
500 MHz, and the cavity diameter d is adjusted. The
beam aperture a, which is decided by injection conditions, is now set to 10 cm¢>. The characteristics ofthe cavity are calculated by a program, SUPERFISH.
Figure 3 shows the shunt impedance ZTT as afunction of the gap length when the values of theremaining parameters are fixed. The shunt impedanceshould be increased for efficient acceleration as far
as the beam stability is kept. The optimum shunt
impedance exists for the gap length of about 20.6 cm.
The reason why the optimum value exists is that the
Q value increases with the gap length, but the transit
time factor decreases. Similarly, the dependences ofthe shunt impedance upon the other parameters
are calculated. The optimum nose angle and the
optimum disk thickness are searched under the condition that the values of the other parameters are

T. Kusaka, et ai.

238
Table 1.
Operating frequency
Number of cells
Material
Cell diameter
Gap length
Q (single cell)
ZTT (single cell)

Specification of test cavity.

500 MHz3
Aluminium
437mm
200mm
32,000
7.4Mn

constant. The best disk thickness is thought to givethe maximum ratio of the cavity volume to the surface
area. The smaller nose radius produces the larger
shunt impedance, but it should be designed to avoid
voltage breakdown because of a higher value ofelectrical field gradient.
Table 1 shows the specification of the test cavity
based on the above calculations. The cavity is madeof alminium because of high electric conductivity
and handling convenience. Overall machining accuracy should be better than 0.1 mm for the purposeof tuning the resonant frequency. The Q value andthe shunt impedance are given for the single-cellcavity in the accelerating mode. Higher-order modes
with axially-symmetric fields can be calculated aswell as the fundamental mode. Several patterns ofelectric field, which are calculated by a computercode HAX, are shown in Fig. 4 (a) through (d) .
Higher-order modes cause the beam energy loss andthe bunched beam instabilities. The longitudinal andtransverse impedances of higher-order modes should
be suppressed to avoid the bunched beam instabilities. 3 )The following items will be studied by using thetest cavity.
( 1) the comparison between the single-cell cavity
and the multi-cell cavity;(2) the optimization of the cavity structure;( 3 ) the measurement of the characteristics of the(a) FREQUENCY = 499.8 MHz(b) FREQUENCY = 728.8 MHz(e) FREQUENCY", 1.225 GHz(d) FREQUENCY = 1.425GHz

Fig. 4. Plots of electric field at several resonant frequencies.

cavity in resonant modes; and( 4) the test of the input coupler, the frequency
tuner and the damping coupler.
References
1) 7 GeV Advanced Photon Source: Conceptual Design Report, ANL 87-15, April (1987).
2) European Synchrotron Radiation Facility: Foundation
Phase Report, Feb. (1987) .
3) Y. Yamasaki, K. Takata, and S. Tokumoto: KEK 80-8,
August (1980) .

239

RIKEN Accel. Prog. Rep. 21 (1987)

V-20.

Vacuum Chamber for the 6 GeV Storage Ring
S. H. Be, Y. Morimoto, H. Sakamoto, and S. Yokouchi

The vacuum chamber, a ring of about 340 m indiameter, consists of two chambers with different
shapes and two types of absorbers. To minimize
synchrotron radiation (SR) -induced desorption as
well as thermal outgassing, we are considering touse new aluminum-alloy chamber extrusions (A6063
T6) with a slot-isolated antechamber.
In the slot-isolated antechamber, the feature of
the slot is to prevent the circulating electron beamfrom coupling to the lower-frequency modes of theantechamber. However, higher-frequency electromagnetic fields in the range above 15.9 GHZl) of
the cutoff frequency for the 1 cm-slot penetrate into
the antechamber and their power is stored there. At
present the power is not estimated quantitatively,
but in the operation of TRISTAN (e+ e- collider),it was found that (1) the wires of electric connection
present in the chamber of sputter ion pump, which
is separated from beam chambers by the slits of
10 mm X 50 mm, are cut by melting,2) and (2) inhigher-frequency electromagnetic fields, conductors
discharge even when they are ceramic-insulated,
ultimately leading to breakdown. 3 ) These findings
indicate that the thermal loading to non-evaporable
getter (NEG) strips due to the power of higher
frequency modes gives rise to an increase in bulk
NEG temperature. In the storage ring this temperature change occurs repeatedly because of repetitive operation of th~ storage ring and would give adeleterious effect4 ) to the NEG strips by causing
thermal fatigue.
The development of the thermal fatigue effects

causes the peel-off of gettering powder; the peel-off
strongly depends on temperature and duration of
NEG activation. Consequently, the lifetime of the
NEG strips will be limited, becoming short. To
avoid this deleterious ~ffec~ on the NEG strips anddischarge between the NEG strips and ceramics forsupporting the NEG strips, a new vacuum chamberis proposed for use in the straight sections.
( 1) Vacuum chamber for the straight sections
The vacuum chamber consists of an electron beamchamber and an antechamber and cross-sectionalview of it is shown in Fig. 1. The antechamber
structure with a slit-isolated pump chamber differsfrom that planned for the Advanced light sourceby Lawrence Berkeley Laboratory, or for the Advanced photon source by Argonne National Laboratory, and consists of two portions: a. portion for
inserting NEG strip pumps and the other for thepassage of synchrotron radiation. The former isseparated from the latter by a wall with slits forpumping. The important feature of our new vacuum
chamber prevents a deleterious effect on the NEG
strips due to thermal fatigue.
At present effects of photons and their associatedphoto-electrons on the NEG performance are notclear; no one knows whether or not photons andtheir associated photo-electrons are injurious to thegetter performance. At least our antechamber structure with a slit-isolated pump chamber can reduce
interaction of the NEG strips with photons andtheir associated photo-electrons.
(2) Bending magnet vacuum chamber
Slit-- - ----Slot-- - - --Cooling chan"nel--Ceramic insulator

o

2

4

6

8

10

em

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

Scale
Fig. I.

Cross-sectional view of the vacuum chamber for the straight sections.

S. H. Be, et al.

240

Sheath healer

Cooling channel .

Antechamber

o
I

2

4

6

I

I

Ceramic insulator

10
, em

8

Scale

Fig. 2.

Cross-sectional view of the bending magnet vacuum chamber.

The cross-sectional view of the vacuum chamberis shown in Fig. 2.
Much of the gas produced by the localized SRinduced desorption as well as thermal desorption at
the absorbers placed downstream and upstream ofthe bending magnet is pumped out with lumped
pumps, but part of the gas is suspected to diffuse
into the bending chamber throughout the antechamber.
We therefore install a distributed ion pump (DIP)
and a NEG strip pump on opposite sides of theelectron beam chamber as shown in Fig. 2. These
pumps evacuate not only gases desorbed from thebending magnet chamber but also assure efficient
removal of gases which permeates from the crotch
and absorber loca tions and results in low operatingpressure in the electron beam chamber.
The same antechamber structure with slit-isolated
pump chamber as in the straight chambers cannot
be used in the bending magnet chambers, becauseof the narrow gap between bending magnet poles.
DIP is to be the main pumping source for thebending magnet vacuum chambers.
.Since the discussions on the chambers describedabove are qualitatively, quantitative studies areneeded to determine which type antechamber ismore appropriate for the storage ring from the pointof view of higher-frequency modes and photons.
(3) Bakeout of the chamber and its coolingThe vacuum chambers shown in Figs. 1 and 2
contain a cooling and a baking channels. In our
vacuum chambers part (~1 kW) of SR light thatpasses out through the slot, without being interceptedat the crotch (C) as shown in Fig. 3 and absorber(SA) , intercepts a part (----3 m) of the back side of
the slot, but only in the dispersion region of thelattice between the two bending magnets (BM1 ,BM2). The corresponding power deposition a t theback side of the slot is ~300 W 1m. Besides thispower deposition, the power due to NEG activationmust also be taken into consideration. To achievetemperature sufficient for the NEG activation, a100.-------------------------______~

E

~
:;::

10

t:
en

z

LU
Cl

.1

a:

LU

::
o

.01

0.

.001 +-.-...-....-~.............
4.0

•

~

From BMl RADIATION

r:::a From BM2 RADIATION

0:
LU

3 .0

0Cl
LU

2.0

::
o
m

E=6(GeV)
1=100(mA)

a:

o
(f)

m

~

5

10

15

20

25

30

LENGTH(m)Electron bea~ ,Mit I

IIMII

II

II

l iM trCl

SAl C2

SA2

SA3

SA4 C lFig. 3. Absorbed power and power density.

heating current of 110 A is required and the corresponding power dissipation is 4 X 990 W 1m larger
than 300 W I m. These thermal loads can easily beremoved by a cooling water system, which is designed for loads up to 5 kW 1m. This can be achievedby flowing water at .-..2 mls in two channels of
10 mm-diameter.
The chamber is baked out by inserting flexible
sheathed heaters into baking channels, which bringthe chamber temperature up to 150°C. The chamberis thermally insulated with kapton films.
References
1) R. L. Kustom, G. L. Nicholls, S. L. Kramer, T. K. Khoe ,and J. M. Cook: ANL-HEP-CP-87-19.
2) H. Mizuno: private communications.
3) H. Ishimaru: private communications.
4) J. L. Cecchi, S. A. Cohen, and J. J. Sredniawsky: ]. Vac.
Sci. Technol. , 17, 294 (1980) .

241
RIKEN Accel. Prog. Rep. 21 (1987)

V-21.

Pumping System for the 6 GeV SOR

S. Y okouchi, Y. Morimoto, H. Sakamoto, and S. H. Be

The pumping system of the 6 GeV SOR storage
ring must maintain a pressure of the order of 10-10
Torr to achieve a beam lifetime of about 20 h. The
gas load in the vacuum system depends on the SRinduced gas desorption and thermal desorption. The
gas load due to this SR-induced gas desorption decreases with an increasing in an integrated photon
flux, which is directly related to the circulating
electron beam: 1) The gas load, Q, decreases with the
integrated electron beam current, D (Ah), i.e., Q =1.9 X 10- 4 D - 2/3 Torr lis for 0.1 A at 6 GeV. Thismeans that at the start of ring operation a larger
pumping system is needed because of the very highSR-induced desorption, but a smaller pumping systemis enough after depleting the chamber wall withincreasing the D. We consider 10 Ah as the D in thefollowing discussions. In the planned 6 GeV ring, theSR-induced total gas load after 10 Ah dose is 4.1 X
10- 5 Torr lis, and the total thermal gas load is 3.1 X
10-5 Torr lis. In estimating the thermal gas load, we
consider an extruded aluminum alloy as the chambermaterial and assumed that its outgassing rate is 5 X
10-12 Torr lis cm 2 • In our case, the inner surface areaof the chamber is 6.1 X 10 6 cm2 ; thus, the total gas
load in our ring is 7.2 X 10- 5 Torr lis.
Figure 1 shows the pumping system per cell of thering. For this total gas load, the total pumping speed
necessary to achieve a pressure of 1 X 10-10 Torr at thebeam chamber is 29,100 lis per cell. In this estimation, for the case of the antechamber the slot conductance was considered of course. The actual total
pumping speed of our pumping system, which consists of non-evaporable getter (NEG) strips, a sputterion pump (SIP), and a titanium sublimation pump(TSP) installed in the chambers, is 30,900 lis per cell(see Fig. 1).
The NEG material is a 84%Zr-16%AI alloy,
which is suitable for pumping active gases, but not
for methane or noble gases. The alloy reacts withthe active gases such as CO, CO 2 , N 2, O 2 , H 2 0, fo~­ing stable chemical compounds, while hydrogen IS
sorbed reversibly. NEG needs a heat treatment called"activation", which makes a thin surface layer, formed.
on the surface by explosing to air or by ventmg toatmospheric pressure, diffuse into the bulk. The
temperature for this activation depends on a kindof NEG, and the activation for NEG (St 101) to be
used in the 6 GeV ring is performed at 700°C.
After the activation NEG develops its pumping
characteristics, which 'depends on the amounts andmolecular species of the gases and also on the temperature of NEG. The pumping speed of NEG
decreases gradually with pump down time because ofsaturation of the getter surfaces. Therefore, NEG
must be heated repeatedly to recover the pumping
speed. For this purpose, the CERN Laboratory madeexperiments and found that a few ~inutes of heat~ng
at 400°C is sufficient for recoverIng the pumpmg
speed. 2 ) This operation is referred to as "conditioning." Distributed NEG strips are installed in theantechamber, as shown in Fig. 2, and thereby all of
the SR-induced gas molecules are pumped before
they have a chance to bounce into the beam chamber,and the thermally desorbed gas molecules are pumped
uniformaly in the chamber. The pumping speed of
the NEG strips at an operating temperature of 25°C
is 900 lis m for H2 and CO. The sorption capacityfor H2 is sufficient to keep practical "conditioning"intervals of about 5 months in the ring operation at~m~rmu}?!

B eam --~ Q ~UlQ,e.
"'"
aUla

a

ill

~ ~

Q
Ul a Ul Q
aUla
a

~

ill

Ceramic insulator

Q
aUl~(/)Q
a

NEG

a

strip

- - Distributed NEG strips~ SIP ( lOO LIsee )rn

0 TSP (400 Li see )i3] TSP (lOOO l/see) ·SIP (400 l/see)Slot

E.j Lumped NEG pump (2500 Li see )~ Crotch• Absorber~ TMP

1><1 All metal valve

Fig. 1.
cell.

Pumping system of the 6 GeV SOR storage ring per

Beamchamber

Antechamber

Fig. 2. Cross section of the vacuum chamber with NEG
strips. SR from beam strikes surface of the antechamber
and induces gas molecules.

242

S. Yokouchi, et al.

1 X 10-9 Torr. Since sorption of H2 gas is reversible,
the lifetime of the NEG strips is estimated at morethan 20 y. On the other hand, since CO gas is notsorbed revesibly but also forms stable chemical compounds, the lifetime for CO is estimated at two or
three years even if conditioning is repeated several
hundred times. Therefore, additional titanium sublimation pumps (TSP) are required for pumping
reactive gases such as CO and CO 2 except H2 gas.
TSP can pump active gases by sorbing into thesublimated fresh titanium film on the chamber surface,
but not methane or noble gases. As consumed, thegetter material must be exchanged every 1 or 2 y.
The NEG strip and TSP are limited to only reactive
gases, and noble gases and CH 4 are not pumped.
Therefore, additional sputter-ion pumps (SIP) areto be installed.
SIP has ability to pump out both active and noble
gases, and the pump current can be used as anindication of local pressure.
By locating lumped NEG pumps, SIP and TSP
near the crotch and absorber (details of which will
be described in this progress report by Y. Morimoto
et al.) , almost all the SR-induced gas molecules are
pumped out before they have a chance to bounce
around in the beam chamber. At the section of an
insertion device, which will be constructed in the
future, only beamchamber instead of the antechamberis planned to be used, and SIP and TSP are installed.
Our main pumping system is based on the NEG

strip and a feature of the pumping system is a mixed
pumping one which consists of NEG strip, SIP, andTSP.
As a roughing pump, turbo molecular pumps areunder consideration and will be used for pumping
the chambers before the SIP, TSP, and NEG pumpstart up. Further, TMP's are also used for bakeoutof the chambers and the activation and conditioningof NEG.
All metal gate valves with an RF contact are
mounted for isolating the chambers at each end of
the cell. By closing them each cell can be pumped
independently after venting to atmospheric pressure
and subjected to leak check.
Bellows with RF fingers are used for compensating
misalignments during installation of the chambers,
valves, etc. and thennal expansion during ring operation and bakeout.
The all metal gate valves and bellows are to be
specially designed to minimize the RF impedance;development of valves and bellows with smoother,simpler, and more conductive wall is strongly required.
Aluminum gaskets are used for connection of theflanges.
References
1) ESRF, Foundation Phase Report, Chap. II (1987).
2) H. P. Reinhard: "The Vacuum System of LEP," Proc.
IX IVC-V ICSS, Madrid (1983).

243

RIKEN Accel. Prog. Rep. 21 (1987)

V-22.

Vacuum Test Device for Preliminary Experimentson the 6 GeV SOR
S. Yokouchi, Y. Morimoto, H. Sakamoto, and S. H. Be

We constructed an experimental device consistingof extruded aluminum alloy chambers as shown in
Fig. 1 to investigate characteristics of various vacuum
components and materials, which will be used in the
6 GeV ring; they include characteristics of pumps,
outgassing rates from chamber materials and othermaterials in the vacuum, and reliabilities of components such as valves, bellows, and gauges. A photograph of the device is shown in Fig. 2.
The device consists of three cylindrical chambers,
and vacuum seals between flanges of the chambers are
made by using aluminum gaskets. The individual
chambers can be isolated with two gate valves, andan orifice of 5 mm in diameter was mounted between
the chambers 1 and 2. On each outside surface ofthe chambers, sheath heaters were welded for baking
the chambers at 150°C, and chromel-almel thermo-

Fig. 1.

Fig. 2.

Photograph of the device with test instruments.

couples were also attached for measuring temperatureof the chambers.
Figure 3 shows a schematic diagram of the device
with test instruments. As seen from Fig. 3, in thechamber 1, a Bayard-Alpert (BA) nude gauge(BAG1), a BA normal gauge (BAG2), and a variableleak valve (VLV) for introducing gases were installed. In the chamber 2, a BA nude gauge (BAG3),a spinning rotor gauge (SRG) for calibration of ionization gauges and a quadrupole mass analyzer(QMA) for analyzing residual gases were installed.
In the chamber 3, a sputter ion pump (SIP), atitanium sublimation pump (TSP), and non-evaporable getter (NEG) strips, all of which will be usedin the 6 GeV ring, are installed. Thus we can in-

Outline of the device.

TSP

M
V4~M u@'L§A~~·
I,Gf Gf11~ ~ t\l/lXJ
NEG BAG4

Vent

V2

BAG! BAG2 BAG3QMA

VV2 l PEG

LJ

Ch•• b" I

Chamber 2V\J

VL~~ VVl~ (S)rI

Chamber 3~\t SRG V3~-' 1)
I_I
I-I
I-I

SIP

Fig. 3.

Bellows Elbow I

PG

~J

I

l~rTMPlto Fore pump

Schematic diagram of the device with test instruments.

S. Yokouchi, et al.

244

vestigate the pumping characteristics of each pump
and a mixed pwnping system consisting of two
pwnps or three by opening or closing the gate valves
V3 and V4.
At the present time, the chambers have been
evacuated for about 470 h with only 300 l / s turbo
molecular pump without baking the chambers, andthe outgassing rate of the chamber 1 as a functionof pumpdown time is shown in Fig. 4. Fluctuationof data after about 40 h in this figure is due to thevariation in the pressure caused by the change inambient temperature. The pressure after about 40 h
1~R~______~________

10~______

100

~

1000

PUMPDOWN TIME [hourI

Fig. 4. Outgassing rate of the extruded aluminum alloychamber.

was about 1 X 10-7 Torr. The outgassing rate Q was
obtained from Q = C X (P 1 - P 2 ) / A Torr lis cm 2 ,where C is the conductance (2.28l/5) of the orifice,P 1 the pressure in the chamber 1, P 2 that in thechamber 2, and A the inner surface area (1,715 cm 2 )of the chamber 1. Further, the pressures in thechamber 1 and chamber 2 after 470 h pumping are
5.5 X 10-8 Torr and 3.0 X 10-8 Torr, respectively. From
this figure, we can find that the outgassing rate after
470 h pumping is 3.3 X 10-11 Torr lis cm 2 , and thisis a reasonable value as the outgassing rate of the
extruded aluminum alloy chamber without bakeout.
We plan to carry out following investigations using
the test device described above:1) Thermal outgassing rate of various materials
which will be used in the 6 GeV ring2) Surface treatment for reducing the outgassing
rates from the various materials3) Outgassing rate of a model chamber for the
6 GeV ring4) Outgassing rates of the materials bombarded
with electron beams
5) Pumpa) Characteristics of the NEG strip (or pump) ,SIP, and TSPb) Vacuum performance of the mixed pumping
systemc) Practical pumping characteristics after pumps
are installed in the model chamber of the
6 GeV ring

245

RIKEN Accel. Prog. Rep. 21 (1987)

V-23.

Synchrotron Radiation Power Distribution at the 6 GeV SOR
Y. Morimoto, H. Sakamoto, S. Yokouchi, and S. H. Be

Synchrotron radiation (SR) power distributions
along the 6 GeV SOR storage ring are calculated toestimate thermal problems of a vacuum chamber andits outgassing rates. The dominant outgassing ratein the storage ring is due to an SR-induced desorption
rather than a thermal one. In general, the rate of
SR-induced desorption is 10 to 100 times larger than
the thermal outgassing rate at the initial operation.
The SR power distribution is determined by a shapeof the vacuum chamber or its size, and positions of
the crotch and strip absorber where most of the
SR power produced in bending magnets (BM) is
deposited. The SR power, Pr in kW, is given by
Pr = 26.6E3BI, where E is the electron energy in
GeV, B the magnetic field in T, and 1 the electron
current in A. In the design parameters of E = 6 GeV,
B=0.8 T, and 1=0.1 A, the total SR power from72 BM in our storage ring corresponds to about
460 kW. Thus the SR power emitted from each BM
becomes approximately 6.4 kW.
As shown in Fig. 1, to prevent vacuum chambers
from receiving such a high SR power, crotches, C1
and C2, are positioned just down stream of BM1 andBM2, respectively, and strip absorbers, SAl, SA2, andSA3, in front of BM2, an insertion device (ID), andBMl, respectively. The crotches and absorbers areused for the same purpose, but their structures aredifferent. The structure of the crotch is more complicated than that of the absorber because of its
heigher power absorption.
The calculated SR power distributions including
power densities along the storage ring are shown in
Fig. 2. In Table 1, numerical values of those shownin Fig. 2 are given. The crotches, C1 and C2,intercept the greater part of SR except that to theexperimental facility and the electron beam passageway. The crotch consists of a water-cooled copper

r

~

VCI
Photon beam

unit which absorbs thermal load from SR, and highly
concentrated pumps for evacuating gases desorbedwith SR in this region. Detailes of the crotches aredescribed in this progress report by Morimoto et al.
Approximately 50% (3.4 kW) of each SR powerfrom BM1 and BM2 is absorbed at the C1 and C2,
respectively.
SR power absorbed at SA3 depends on a shape
20 .-------------------------------------~

o+-------------~----------------------~~

4• BMI RADIATION
~
~

c::
w

re BM2 RADIATIO N

3

~

o

c...

Cl

w
CD
c::

2

o
(J)
CD

~1

5

10

20

15

25

30

LENGTH (M)

~
Cl

[§ill
SAl

C2

II
SA2

I 0

[E!IJ
SA3

C1

Fig. 2. Absorbed power and power density in the chamber
for ID.

tr-

Photon beam

Cl
Fig. 1. Schematic of the cell of the 6 GeV storage ring.

Y. Morimoto, et al.

246

Table 1. Absorbed power and power density. The values inparentheses are for the chamber without ID.
Area% AbsorbedAbsorbed power(kW)

Power density(kW/cm2)a) BMI Radiation
Cl
52.7
16.6
VCI
SAl
25.2
C2
5.5
Total
100.0

3.4
1.1
1.6
0.3
6.4

18.0
0.05
0.6
0.3

b) BM2 Radiation
C2
52.7
SA2
37.7
0.0 (5.6)VC2
SA3
6.8 (1. 2)
Cl
2.8
Total
100.0

3.4
2.4
0.0 (0.3)
0.4 (0.1)
0.2
6.4

18.0
1.7
0.0 (0.05)
0.2 (0.2)
0.1

and size of the chamber mounted in a straight section(VC2). In the chamber for ID, the percentage ofthe power absorbed at SA3 is 6.80/0 (0.4 kW) of the
SR power from BM2 and that in the chamber without
ID is 1.2% (0.1 kW). The difference in thesepercentages comes from that in the latter a part of
SR is intercepted with the chamber before SR
reaches SA3, but in the former not so. A part of
SR from BMI also strikes the vacuum chamber infront of SAl (VC 1), and a small percentage of the
SR power from BMI and BM2 is catched up by thefollowing crotch.
The power density of less than 2 kW j cm2 can beabsorbed by the normal absorber such as a watercooled copper plate or cylinder, or cooling channels
mounted in the vacuum chamber, but for the highpower density of 18 kW jcm2 as in our cases, a specially designed absorber is required for the crotch.
The design of the crotch which absorbes high power
density and evacuates large SR-induced gas load is
one of most severe and urgent problems in thevacuum system of the 6 GeV SOR.

247
RIKEN Accel. Prog. Rep. 21 (1987)

V-24.

Crotch Design for the 6 GeV SOR

Y. Morimoto, S. Yokouchi, H. Sakamoto, and S. H. Be

We made conceptual design of a new type crotch
having a structure in which photo-electrons producedby photons and reflected photons are trapped. Synchrotron Radiation (SR) -induced outgasses from thecrotch are pumped locally with three different pumps:
a lumped non-evaporable getter (NEG) pump, asputter-ion pump (SIP), and a titanium-sublimation
pump (TSP). A bird's eye view of the crotch isshown in Fig.!. The main chamber made of copper
consists of two rooms: one is for an electron beam
passageway, which is fabricated so that it matchesa cross section of an electron beam chamber, andthe other is for trapping of photo-electrons, photons,
and SR-induced outgas. A slit in front of the trapping room is for the SR beam pass. The pumps, i.e.,a NEG pump, a SIP, and a TSP are mounted tothe trapping room. Thus, almost all the SR-induced
outgasses are pumped before they have a chance tobounce around in the electron beam chamber. Cooling
IS achieved by flowing water through four channels

TSP

Cooling Channel

Fig. 1. Bird's eye view of the crotch.

Fig. 2.

provided in the main chamber.
The crotch is a component used for intercepting
the SR beam from the bending magnet except thatto an experimental facility and evacuating gases
desorbed with SR in this region as described before.
The positions which the crotches are ·considered to
be located in the 6 GeV storage ring are shown in
Fig. 2. The crotches are located just down stream ofthe bending magnets, and photon beam lines are
separated from the electron beam chamber behindthe crotches. A distance between the crotch andthe end of the bending magnet is approximately
50cm.
The SR power from the bending magnet is concentrated into a smaller vertical angle (--1/ r), thus
resulting in significantly great power densities at theimpinged surfaces; here r is the ratio of an electron
beam energy to the electron rest mass energy. For
the design parameters of 6 GeV and 100 mA, theSR power and. its power density for the crotch are
3.4 kW and 18.0 kW /cm 2 , respectively. The absorption of such high power density is a severe technological problem.
For a detailed study and analysis to optimize configuration of the crotch and for assessment of its
vacuum benefits, we are developing computer programs to analyze temperature and stress distributions
due to specific power input. The results of computer
simulation is to be confirmed by tests for actual
configurations using an electron and an SR beam.
As a first step, for simulation of the heat flow
within the crotch thermal analysis was made using
a finite element method .program MARK-CDC on
the same configurations and conditions as CESR(Cornell Electron Storage Ring) .1) The simulation
model and conditions are shown in Fig. 3. Thismodel consists of beryllium and copper, and a beryl-·

Schematic of the cell of a 6 GeV storage ring.

Y. Morimoto, et al.

248

Depth (em)

o

Z

,

!

10

1\ ;36°C

Cu

Mirror plane

t--

Be
L Q=O

h= eonst. (Tw< 15)
h= f( Tw) (TIr > Ts)
Tw = 30°C

Fig. 3. Simulation model and conditions for heat flow computation.

lium piece is used to diffuse heat load. Heat input
of 6.5 kW is uniformly distributed over a strip of 1 cm
wide and 6.5 cm long and is deposited just on thesurface (power density = 1 kW Icm 2 ). Boundary conditions are set to allow heat transfer to occur onlyat the back side, along which cooling-water flows,
and insulate the other surface. The heat flux per
unit area, Q in W 1m 2 , at the water-cooled back side
IS given by
Q=h(Tw- Tc)(1)

Q = 1,970 exp (2P/8.69 X 106)(Tw- TS)2(2)

where h is the heat transfer coefficient in W Icm2K,
T w the wall temperature in K, Tc the water temperature in K, P the water pressure in N 1m2 absolute,
and Ts the boiling point in K at pressure P. Equation
1 can be applied only to the forced convection heattransfer condition. When the wall temperature ishigher than the water boiling temperature, Eq. 2 f~r
the fully developed nucleate boiling is used in addItion to Eq. 1. The nucleate boiling causes heat-transfer
extremely greater than that of the forced convection;
but we must pay attention to the reduction of heattransfer properties due to the film boiling, which is
caused by excessive heat flux through the wall-waterinterface. Figure 4 shows the calculations for themodel illustrated in Fig. 3, assuming h = 1.2 W Icm 2 •K and T c = 30°C. The results are in good agreement with Cornell's one.
Since this simulation model is the one for theexperiments using a electron beam welder, the power
density is not so high. No calculations for SR of ahigh power density was carried, because heat input
conditions are not clear. ,The difference between the

1'\

E.
beam

o 475°C-

:~

4500C
400°C
350°C

"V
~

oo°C
50°C

162°C
ZOO°C
250°C
300°C

Fig. 4. Computed temperature distribution by an electron
beam.

power deposition with an electron beam and thatwith SR is that, in the former, heat is deposited on
the surface, while in the latter, SR penetrates con.
siderably into the materials, especially low atOmIC
number materials such as beryllium and thereby theheat power is distributed in a large volume. Therefore
we must determine the distributions of input heatload in the materials to simulate the model for SR.
The study of the heat input conditions for SR isunder way.
The total gas load in the crotch is 3.5 X 10-1 Torr lis(SR-induced gas load = 3.3 X 10-1 Torr lis after 10 A.
hr beam condition, and thennal gas load = 2.3 X 10-8
Torr lis at 120°C). Thus, the overall effective
pumping speed required for an operational pressureof 1 X 10-10 Torr is 3,500 lis. In the crotch, a 2,500 lis
NEG p~mp, a 400 lis SIP, and a 1,000 lis TSP will
be installed. This total pumping speed is high enoughto achieve a required pressure.
The detailed design of the new crotch is scheduled
to be completed by the end of April, 1988, and aheating test using an electron beam will be performed
with a prototype model.
Reference
1) D. M. Mills, D. H. Bilderback, and B. W. Batterman:
IEEE Trans. Nucl. Sci. , NS-26 , 3854 (1979).

249

RIKEN Aced. Prog. Rep. 21 (1987)

V-2S.

Design of the Front End of the ,Beam Line at the KEK
Photon Factory
Y. Morimoto, S. H. Be, M. Hara, and S. Sato·

The project for the analysis and estimation technology of high performance material by a new beamtechnique was started in April, 1986. This project isfinanced out of the Special Coordination Funds for
Promoting Science and Technology, which is provided by Science and Technology Agency. A new
beam line BL-13 is constructed at the KEK Photon
Factory as a part of this project. RIKEN takes
charge of the construction of a multi-pole wiggler(MPW) and the front end of a beam line. Detailesof MPW are described by Sasaki et ai. in thisvolume.
Two major considerations must be taken into account in the design of the front end of the beamline: ( 1) vacuum protection of the components ofthe storage ring against vacuum failure in the experimental area and (2) power absorption of synchrotron
radiation (SR) from MPW and the bending magnet(BM) except that to experimental area.
A layout of the various components of the BL-13
a beam line for MPW is shown in Fig. 1. All components are set along a line extended to the straightsection of the ring where MPW is located. Vacuum
protection is achieved with an acoustic delay line
(ADL) , a fast closing valve (FCV), and an isolation
valve. ADL is used to delay rapid propagation of apressure front caused by vacuum failure. FCV isclosed by a pneumatic actuator with a closing timeof less than 12 ms, but sealing performance of FCV
is not perfect. Therefore, the isolation valve is to be
successively closed within a few seconds after closing
FeV. A water cooled absorber is installed to preventthe valves and a beam shutter from overheating due
to SR. Three masks limit a SR beam to a size ofthe aperture which is necessary for transporting an
SR beam to the experimental area. The apertures

Crotch protection plate(located in : BM)
Horizontal

Vertical

I:

Imrad

L
Imrad

Fig. 2. SR beam from MPW.
Table 1. Absorbed power and power density. P ab is theabsorbed power in kW and Wab the power density in kW /cm2 • Power densities are the values at the surfaces perpendicular to SR.

Absorber
Mask 1
Mask 2
Mask 3from MPW

from BM

MPW+BM

P ab

Wab

P ab

Wab

P ab

Wab

7.0
1.4
0.0
0.0

3.5
3.8

0.2
0.5
0.1
0.1

0.9
1.1
0. 6
0.3

7.2
1.9
0.1
0.1

4.4
4.9
0.6
0.3

0.0
0.0

Absorber and pumps
ADLland pumps
FCV

MaSk

3~ ~

Position monitors
Pump/
Mask 2

Fig. 1.

Schematic layout of the front end of BL-13.

* Photon Factory, National Laboratory for High Energy
Physics.

Beam shutter and pump

Y. Morimoto, et al.

250

Mask 2SRo

50

Fig. 3. Schematic assembly of the front end of BL-13.

for a SR beam, and absorbed powers and power
densities deposited on a absorber and masks for thedesign parameters of 2.5 GeV and 350 rnA are shownin Fig. 2 and Table 1, respectively. A beam shutter
made of a stainless steel block of 16 cm in width,
8 cm in height, and 40 cm in thickness is operated
with a hydrostatic pressure cylinder and is installed
for personnel protection from radiation caused bybeam loss during injection. Final assembly of BL-13
is shown in Fig. 3. Vacuum chambers including main
components are made of stainless steel and evacuatedbelow 2 X 10-10 Torr after baking at 250°C using
three 110 lis sputter-ion pumps (SIP) and two
5,500 lis titanium-sublimation pumps (TSP). A
170 lis turbomolecular pump is ' used as a roughingpump.
On the base of the method given by Okano andTominaga,t) we made an analysis to simulate thetransit time in ADL. A simulation model is shown in
Fig. 4. Calculations were made on the assumptions
that the flow rate through an orifice is determinedby the pressures on both sides of the orifice and thatthe gas flow which blow straight through the orifice
is negligibly small. The pressure of each segment, Pi,
is given by
Vi(dPJ dt) = Ci - 1(Pi - 1 - Pi) - Ci(Pi - Pi + 1) - 8 i Pi
(1)
Vo(dPo/dt) = -CO(PO-Pi )

L

wx

H=A

Reservoir

Fig. 4. Simulation model of aN-segmented ADL.

The increasing rate of pressure for each segment
at a given time is calculated from Eqs. 1 and 2. The
pressure after considerably short time intervals, LIt
is determined by(3)

In this m,anner, the increases in pressure were numerically calculated. Gas molecules in each segment of
ADL were assumed to be in thermal equilibriumwith the wall, and the conductance of the orifice wascalculated all in air at 293 K.
40=20 ~M;;.3.Q ~M
A=40 ~M-- ~ J
-[l

30

0"
w
~
w

~ 20
en
z

I

<
a:

10

.VV"

J
v

,-

4

•.-

.,../

//

V

...

_- -

I

o
2

/

V
./

V / V7" ~ .,/
-V
~

t-

where C i is the conductance of the orifice, Vi thevolume of each segment, Si the pumping speed of an
auxiliary pump, Po and Vo the pressure and thevolume of a reservoir, respectively, and P N +1 andV N+1 the pressure and volume of the main vacuum
system of a storage ring. V N+1 is assumed to be
infinitely large and PN +1 is fixed at the initial pressureof the storage ring.

1/

en

t-

(2)

Main vacuum system

ADL

6

8

10

12

14

NUMBER OF SEGMENTS

Fig. 5. Relation between the transit time and number ofsegments.

Y. Morimoto, et aZ.

ga:

10· 5 _ ___

+-_ ,

w

a::

=>
<n
<n

w

a::
Q.

101~--~----r---~---4----+---~
o
5
10
15
TRANSIT TIME (MSEC)

Fig. 6.

Pressure increase in the last seWnent.

Figure 5 shows a relationship between the transit
time to reach 1 X 10-2 Torr in the last segment andthe number of the segments as parameter of theorifice area A. Initial conditions for calculation are:
Po=760 Torr at t=O, PI to PN 1 X 10-10 Torr, Vo=
60 1, L = 90 cm, and D = 28.9 cm. All segments havean equal volume. Pumps are applied only to the=251

N /2 'th and N 'th segment with the effective pumping
speeds of 5,300 lis and 1021/s, respectively. The. calculated transit times increase with increasing number of segments and/or decreasing orifice area.
Figure 6 shows the pressure increase in the last
segment of the finally designed ADL. In this calculation, the orifice area of 39 cm2 was used. Tensegments have irregular volumes owing to pumps
installed. The transit time to reach 1 X 10-3 Torr inth€! last segment ' is approximately 12 ms, which islong enough. In an actual beam line, since thetransit time in components other than ADL is further
added ' to that in ADL, the realistic one becomes
longer than 12 ms and thereby the pressUre in thelast segment is expected to be less than 1 X 10-3 Torr.
The calculated results show that theFCV can beclosed before ,the pressure front reaches the storage
ring.
The construction of BL-13 including a control
system is scheduled to be completed by the end of
August, 1988, and ' experiments using BL-13 will bestarted at the beginning of 1989.

Reference
1) T. Okano and G. Tominaga: lpn. I. Appl. Phys., 20,
1729 (1981).

252

RIKEN Accel. Prog. Rep. 21 (1987)

V-26.

Construction of a Multipole Wiggler, 813MPW, at KEK-PF
S. Sasaki, M. Hara, S. Yamamoto,* T. Shioya,* and H. Kitamura*

A multipole wiggler is under construction at the
Photon Factory of the National Laboratory for HighEnergy Physics, KEK-PF. This insertion device,
B13MPW, will be installed at the straight section
between the bending magnets, B12 and B13, of the
2.5 GeV electron storage ring of the PF. It will provide with highly intense synchrotron radiation in the
X-ray region for the diffraction and absorption experiments.
The maximum magnetic field, Bmax, of 1.5 T isrequired so that a sufficient flux of photon beam up
to 10 keY may be obtained. The critical photon
energy corresponding to the 1.5-T magnetic field is
6.2 keV. The hybrid configuration of magnetic andcore materials was adopted in order to realize sucha high field. As shown in Fig. 1, each magnetic poleis composed of a permendur core and Nd-Fe-B
permanent magnets having the residual magnetic fieldof 1.2 T, the coercive force of 17 kOe, and the maximum energy product of 35 MGOe.
The number of the magnetic poles was determined
to be 27 for the B 13 MPW from the conditions: ( 1 )the minimum gap width of 27 mm, (2) the period
length of the magnetic field of 180 mm, and (3) theavailable length of the straight section of about 3 m.
Therefore about thirty times higher flux of a photon
beam is expected around 5 keV photon energy compared with that of the bending magnet radiation.
The designed parameters are listed in Table 1. Figure
single pole
length of period: Au (1 unit)

Fig. I. Schematic structure of the hybrid configuration of
the multipole wiggler, BI3MPW.

* Photon Factory, National Laboratory for High Energy
Physics.

Table I.
Minimum gap
Period length of the magnetic field
Width of the magnetic pole
Number of poles
Maximum magnetic field
Maximum K-value
Maximum load

27mm
180mm
150mm
27
1.5T
25
13 tf

~~:i 1010!~~~~~~~!I~"~
.ci

l:?ei
~

~ IOI

E

Photon Energy I keY

Fig. 2. Spectrum of the multipole wiggler, B13MPW, calculated on the basis of the parameters listed in Table 1
and the beam parameters of the PF ring (<Tx= 1.7 mm, <Ty=
0.22 mm, <Tx '=O.l5 mrad, <Ty'=O.024 mrad) .

2 shows the spectrum calculated by using the parameters listed in Table 1 and the beam parametersof the PF ring.
Magnetic properties of a single pole was measured
using a mirror image method. The results show thatour design of the magnet yields the satisfactorymagnetic properties including maximum field strengthof 1.49 T at the gap of 27 mm'
Each magnetic pole is mounted on I-beams of the
supporting frame so as to generate an alternating
magnetic field of 1.5 T with the period length of
180 mm. Since an electron travels sinusoidally insuch a field, the geometrical conditions as well as
the performance of the magnetic poles are very important for the characteristics of the radiation fromthe device. The schematic view of the overall structure is shown in Fig. 3.

S. Sasaki, et al.

Driving system

820

2700

Fig. 3. Schematic view of the multipole wiggler, B13MPW.

In the design process of the support frame, theheavy load of 13 tf generated by the magnetic field
was considered. The required specifications were;( 1 ) the machining accuracy is high enough: thedegree of straightness of the I-beams should be within

50 pm/m and the parallelism of the two beams
should be at most 20 p.m over the full length of thebeams of 2,700 mm. (2) · The strain of each beam
should be less than 15 pm by the magnetic force andthe self weights. (3) The gap should be controlledwith the accuracy of 5 p.m over the moving range ofthe gap from 27 mm to 250 mm.
The gap width between upper and lower poles
can be adjusted by changing the inter I-beam distance by the driving system. The techniques used
for numerically controlled machines are applied tothe driving system. The operation of the device will
be controlled by a computer placed at the operating
room of the storage ring with a GPIB interface.
This project is being performed by the Insertion
Device Group of KEK-PF and the Design Group at
Synchrotron Radiation Facility Planning Section at
RIKEN under the auspices of the Special Coordination Funds for Promoting Science and Technology
by the Science and Technology Agency.

254
RIKEN Accel. Prog. Rep. ~1 (1987)

VI. RADIATION MONITORING
1.

Leakage-Radiation Meas'urements in the Cyclotron Building
I. Sakamoto, S. Fujita, and I. Kohno

In October 1987 leakage radiation was measured
at various points in the cyclotron building, when a 'target placed in the beam course No.2 was bombarded
with 40MeV helium ions at a beam intensity of
0.4 pA.
r-Ray dose rates were measured with an ionizationchamber survey meter, and dose-equivalent rates forfast neutrons and slow neutrons were measured witha "rem meter."* The results are shown in Fig~ 1.
The leakage doses measured from April 1986 to
December 1987 with
ray and neutron film badges
placed at two positions on the underground passage(point A and B in Fig. 1) are shown in Table 1.

r

The operation of the cyclotron was discontinued on
according to the scheduled from August 1986 to
January 1987.
. :,Of the dose values at point A measured every
month, the maximum total dose of 1,810 mrem wasobserved in June 1986, when the values for r rays
and thermal neutrons and fast neutrons ..were 1,280,
130, and 400 mrem, respectively.
The high fast-neutron doses observed at point A
in April, May, and June 1986 were 200, 100, and
400 mrem, respectively. These increases in neutron
dose were due mainly to activation analysis and radioisotope production carried out for these periods.

,

.

,

!

,

!

!

012345m. Experimental area (L) :I
I

0.02: x~--'"",,"""""''---...Jo-

Undergroundpassage

I

I

Underground passage}'

3.8: x3.0:
O.l6/ x0.25: t

[

I
I

iWT

ON

I
I

:0
: 11..

cI

r..t-o.........I.\,j,j,o.!l __ 'Hand foot cloth monitor

Control room
Basement

Ground plan

Fig. 1. Leakage-radiation (neutrons and r rays) in the cyclotron building.
Dose unit

Operating conditions

Ea: 40 MeV
Beam course: No.2
Target: Ir* A Neutron Dose Rate Meter 2202 manufactured by AB
Atomenergi, Sweden.

rray: mR/hNeutron : mrem/h (under line)

I. Sakamoto, et al.

255

Table 1. Leakage-radiation dose (in mrem) in the underground passage of the -cyclotron building from
April 1986 to December 1987.
Point A*r raysPoint B*

Fast
neutrons(mrem)

Total

r rays(mrem)

Thermalneutrons(mrem)(mrem)

2~ -

30

30

200 . 100

460
-340

400

1,810
0
0
0
0
0
0
0

12

210
1,280
0
0
0
0
0
0
0
30
·0
O.
310
550
220
0
280
320
70
0

-Total3,-500

Month

4.86'
5
6
7
8

9
10
11
12
1.87'
2
3

4
5
6
7
8
9

10
11.

. ' See Fig. 1.

:'; ,

130
0
0
0
0
0
0
0
0
0
0
40

0
20
0
10
10
10
0
280

(mrem)

Thermalneutrons(mrem)

Fast
neutrons(mrem)

0
0

0
0
350
560
260
0
310
370
80
0

10
0
30
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

50
10
100
0
0
0
0
0
0
0
10
0
0
10
0.
10
0
0
10
0
0

800

4,580

40

0

200

0
0
0
0
0
0
0
10
0
0
0
10
20

0
20
40

40

Total
(mrem)
60

"

10
130
0
0
0
0
0
0
0
10
0
0
10
0
10
0
0
10
0
0
240

256
RIKEN Accel. PrQg. Rep. 21 (1987)

VI-2.

Routine Monitoring of the Cyclotron, RILAC, and TANDETRON
I. Sakamoto, S. Fujita, M. Yanokura, T. Kobayashi, O. Kurihara,
T. Katou, M. Miyagawa, S. Kagaya, S. Shinohara, and 1. Kohno

The present report describes the results of routine
radiation monitoring carried out for the cyclotron,
RILAC, and T ANDETRON from April 1986 to
December 1987. Because of unexpected contaminations found in the hot laboratory and experimental
area in the cyclotron building in August 1986, thecyclotron and RILAC were stopped compulsorily
for three months. The radioactive nuclide found by
r-ray spectrometry was 21OPb. The decontamination
and repairs of the hot laboratory were perfonned
from August 1986 to January 1988. RILAC was put
back in operation in the middle of November, 1986.
The operation of the cyclotron was discontinued on
account of long scheduled shutdown from August
1986 to January 1987.
Aspects of the leakage radiation from the cyclotron
are described in a succeeding report. 1)( 1) Residual activities of the cyclotron
In August 1987, the dose rates due to residual
activities of the machine were measured 23 days after
the scheduled shutdown ; the result are shown in
Table 1. The external exposure doses for two workers
during replacement of the septum were 25 and28 mrem.
(2) Contamination in the cyclotron building
The surface contamination has been kept below
10-5 /lCi/cm2 on the floors of the cyclotron building.
The radioactive nuclides found by r-ray spectrometry
were 183Re, 65Z n , and 1850S in the cyclotron vault andthe experimental areas, and 77Br, 65Zn, and 137CS in
the hot laboratory and chemical laboratories. The
contamination was wiped off twice a year. Immediately after this decontamination, the activities
on the floor of most of the above places were reduced
below 10- 7 /lCi/cm2.
When radioactive substances were handled in the

Table 1. Dose rates of residual activities.
Locationca. 1 em apart from septum(wi th a cover (Pb 3 mm) , before
replacement of septum)
ca . 1 cm apart from septum holder(with a cover (Pb 3 mm) , before
replacement of septum)

Dose rate (mRjh)
100

80

hot laboratory and chemical laboratories, the air ina draft chamber was activated. The air in the draft
chamber was exhausted; and the radioactivity in theexit was found 10-12 /lei/cm3 •(3) Drainage
The radioactivities in drain water from the cyclotron and the linac buildings were found to be of theorder of 10-8- 10-5 /lCi/cm3. The total activity inaqueous efHuents was about 490 /lCi, in which themain radioactive nuclide was 77Br, the radioactivity
was about 470 /lCi, and the other nuclides found by
r-ray spectrometry were 75S e, 137CS, 51Cr, 56CO, and
57CO.
(4) Radiation monitoring for RILAC andTANDETRON
The leakage radiation during operation of RILAC
was measured in the outside the linac building every
three months. No leakage ofrays and neutrons
from the linac building was detected. No contamination due to residual activities was found on the floorof control area and conditioning air in the linac
building.
X-ray monitoring was carried out for T ANDETRON, when a rutile (Ti0 2) target was bombarded
with 2.1 MeV B2+ ions of 0.2 nA, the maximum irradiation dose rates measured around TANDETRON
was 1.2 mR/h. No leakage X-rays were detectedaround the target chamber and outside T ANDETRON room.
( 5) Personnel monitoring
The external exposure dose to personnel were
measured by using r ray and neutron film badges.
The dose received by accelerator workers from April
1986 to December 1987 are shown in Tables 2 and3. The collective r-ray doses to all workers from
April 1986 to March 1987 and from April to December 1987 were 1,160 and 180 man-mrem, respectively.
The collective dose owing to thennal and fast neutron
exposures was under the detection limit. The collective dose to the workers from April 1986 to March
1987 increased to 122 % of the value in the preceding
period.
In August 1986, 21°Pb intakes occurred to two
workers who checked up a contaminated substancewith a radioisotope in the hot laboratory. The
amount of intake in the operation was assessed byr

I. Sakamoto, et al.

257

Table 2. Annual external exposure doses received by RIKEN accelerator workers from April 1986
to March 1987.
Number of persons
Workers

Collective
dose(mrem)

Dose
undetectable

10-100(Plrem)>100(mrem)

Total(mrem)

Cyclotron operators
Linac operation and maintenance groups
Nuclear physicists
Accelerator physicists
Physicists in other fields
Nuclear chemists
Radiation chemists
Biological chemists
TANDETRON workers
Health physicists

9
7
16
9
25
4
6
9
11
6

0
3
1
3
3
4
0
0
0
0

0
0
0
0
0
3
0
0
0
0

9
10
17
12
28
11
6
9
11
6

0
30
50
90
60
930
0
0
0
0

Total

102

14

3

119

1,160

Average annual dose per preson, 9. 7 mrem; Maximum individual annual dose, 370 mrem.
Table 3.

External exposure doses received by RIKEN accelerator workers from April to December 1987.
Number of persons
Workers

Collective

Does
undetectable

10- 100(mrem)>100(mrem)

Total(mrem)

dose(mrem)

6

o

o

6

0

o
o
o

5
10
16
15
27
7
5
8
9
6

60
30
0
30
30
20
10
0
0
0

114

180

Ring cyclotron operation andmaintenance groups
Cyclotron operators
Linac operation and maintenance groups
Nuclear physicists
Accelerator physicists
Physicists in other fields
Nuclear chemists
Radiation chemists
Biological chemists
T ANDETRON workers
Health physicists

16
14
26
6

o

4

1

8
9
6

o

o
o
o

o

o

o

Total

108

6

o
o

4
9

o
o

Average dose per person, 1.6 mrem; Maximum individual dose, 60 mrem.

using the equation as recommended by ICRp2) for
the workers from the 210Pb concentration in feces.
The internal exposure dose of the workers were
4.2 rem and 0.3 rem. The workers were subjected toperiodic medical examination, but showed no abnormal signs.
Commissioning of RIKEN Ring Cyclotron started
in April 1987, and its operation and maintenancegroups were organized.
References
1) I. Sakamoto, S. Fujita, and I. Kohno: p.254 in thisreport.
2) R ecommendations of the International Commission on
Radiological Protection Report of Committee II on
Permissible Dose for Internal Radiation (1959); ICRP
Publication 2, Pergamon Press, · Oxford (1960).

258
RIKEN Accel. Prog. Rep. 21 (1987)

VI-~.

Radiation Monitoring at RIKEN Ring Cyclotron Facility

s. Fujita, I. Sakamoto, T. Inamura, and H. Kamitsubo
The Radiation Safety Control System (RSCS) has
been in steady operation since it was installed. 1 }Figure 1 shows the layout of RIKEN Ring Cyclotron facility and its indoor monitoring positions.
Commissioning of RIKEN Ring Cyclotron started in
April 1987; and radiation monitoring has been continuously and automatically performed by the RSCS.
The beam line available for experiments was in theexperimental vault E1 only. Here we shall present
a typical example recorded.
(1) Leakage radiation
In July, an experiment was carried out with a
65CU beam of 16. 7 MeV / u in the E 1 experimental
vault; the beam current was 100 neA. Figure 2 shows
day variations in dose rates recorded on radiation
monitors: (a) RIKEN Ring Cyclotron vault and (b)the experimental vault El. The dose rate recordedon July 20 shows that a beam was accelerated
rays and neutrons(Fig. 2 (a) ), but no leakage
were recorded in the E1 vault (Fig. 2 (b) ). The
dose rates on July 21-22 show that the beam was
guided into the E1 vault; accordingly, the radiation

r

~

~

"

"

~

E

::t.

Q)

4
10

!"nrTTTT1rTTTT1rTT..-nrTTTT1rT'TTT"rT'TTT"rn"TTrn""1'""Tf

G'lC~ ~ 10 2
C\l

...,

t..

:::l

l'-

Z

Q)

10

I

lJ....!rt.J.:.Ll.J...J,M,r4rW~W..J..L.~\r'-L~~..u..~~UJ;~
Date

(b)

(1987)

Fig. 2. Day variations in the radiation level measured in
RlKEN Ring Cyclotron facility. Detectors are: (a), an
ionization chamber in RIKEN Ring Cyclotron vault; (b),an ionization chamber and a BFs counter in the experimental vault El.

d o s eunit

m R /h; ;3(JJJFig. 1.

Layout of RIKEN Ring Cyclotron facility as of

1987. Monitoring positions are denoted by X .

Fig. 3. Detection points around RIKEN Ring Cyclotron.
EDC, an electrostatic deflection channel; MDC2, a magnetic deflection channel; MDPI, a main differential probe
1; MDP3, a main differential probe 3; and TMP, a turbomolecular pump.

S. Fujita, et al.

level in the cyclotron vault ( a ) suddenly decreased
and the neutron dose rate in the El vault sharply
increased (b).
No leakage r rays and no neutrons from RIKEN
Ring Cyclotron and E 1 vaults were detected sincecommissioning.
(2) Residual activities
On September 7-8, days after experiment, thedose rates due to residual activities of the machine259

were measured with aNal scintilation survey meter;
The results are shown in Fig. 3. The maximum dose
rate was observed to be 3.0 mRjh at EDC, anelectrostatic deflection channel of the beam extraction
region . .
ReferenceI) 1. Sakamoto, S. Fujita, T. Wada, and M. Takebe: RIKEN
Accel. Prog. Rep., 20, 206 (1986).

260

VII.

LIST OF PUBLICATIONS

1. Accelerator development and accelerator physics
1) H. Kamitsubo: "Progress in RIKEN Ring
Cyclotron Project," Proc. 11th Int. Conf.
Cyclotrons and Their Applications, Tokyo,
Oct. 1986, p. 17 (1987).
2) 1. Kohno, K. Ogiwara, S. Fujita, K. Ikegami,
T. Kageyama, S. Kohara, and H. Takebe:"RIKEN 160 cm Cyclotron," Proc. 11th Int.
Conf. Cyclotrons and Their Applications,Tokyo, Oct. 1986, p.46 (1987).
3) Y. Miyazawa, M. Hemmi, T. Inoue, T.
Kambara, M. Yanokura, M. Kase, T. Kubo,
E. Ikezawa, Y. Chiba, and 1. Tanihata:"Operation of RILAC at RIKEN," Proc.
11 th Int. Conf. Cyclotrons and Their Applications, Tokyo, Oct. 1986, p.50 (1987).
4) A. Goto, H. Takebe, S. Motonaga, K. Hatanaka, Y. Yano, T. Wada, and N. Nakanishi:"Isochronous Fields for RIKEN Ring Cyclotron," Proc. 11th Int. Conf. Cyclotrons andTheir Applications, Tokyo, Oct. 1986, p. 292(1987) .
5) 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," 11 th Int. Conf. Cyclotrons and Their
Applications, Tokyo, Oct. 1986, p. 329 (1987).
6) M. Hara, T. Wada, K. Mitomori, and F.
Kikuchi: "Three Dimensional Analysis of RF
Electromagnetic Field by the Finite Element
Method," Proc. 11 th Int. Conf. Cyclotrons
and Their Applications, Tokyo, Oct. 1986,
p.337 (1987).
7) K. Ikegami, S. Nakajima, Y. Oikawa, I.
Takeshita, S. Motonaga, and S. H. Be:"Vacuum System for the RIKEN Ring Cyclotron," Proc. 11th Int. Conf. Cyclotrons andTheir Applications, Tokyo, Oct. 1986, p.392(1987) .
8) T. Wad a, H. Takebe, J. Fujita, T. Kambara,and H. Kamitsubo: "Control System of the
RIKEN Ring Cyclotron," Proc. 11th Int.
Conf. Cyclotrons and Their Applications,Tokyo, Oct. 1986, p.407 (1987).
9) M. Nagase, H. Takebe, T. Wada, and K.
Shimizu: "Program for Controlling Magnet
Power Supplies of the RIKEN Ring Cyclotron," Proc. 11 th Int. Conf. Cyclotrons andTheir Applications, Tokyo, Oct. 1986, p.410(1987) .
10) M. Kase, 1. Yokoyama, 1. Takeshita, Y.

Oikawa, M. Saito, and Y. Yano: "BeamDiagnostic Equipments for RIKEN Ring
Cyclotron and Its Beam Lines," Proc. 11 th
Int. Conf. Cyclotrons and Their Applications,Tokyo, Oct. 1986, p . 443 (1987).
11) Y. Yano, A. Goto, K. Hatanaka, H. Takebe,and S. Motonaga: "Beam Injection and
Extraction System of RIKEN Ring Cyclotron," Proc. 11th Int. Conf. Cyclotrons andTheir Applications, Tokyo, Oct. 1986, p.470(1987) .
12) N. Nakanishi, T. Kageyama, and H. Kamitsubo: "AVF -Cyclotron as an Injector for
RIKEN Ring Cyclotron," Proc. 11 th Int.
Conf. Cyclotrons and Their Applications,Tokyo, Oct. 1986, p.511 (1987).
13) K. Hatanaka, T. Inamura, Y. Yano, A. Goto,
M. Kase, and H. Kamitsubo: "Beam Transport System for RIKEN Ring Cyclotron,"
Proc. 11 th Int. Conf. Cyclotrons and Their
Applications, Tokyo, Oct. 1986, p. 523 (1987).
14) T. Shikata, N. Nakanishi, S. Fujita, and T.
Kosako: "Shielding Calculation of Neutrons
for the RIKEN Ring Cyclotron Facility,"
Proc. 11th Int. Conf. Cyclotrons and Their
Applications, Tokyo, Oct. 1986, p. 538 (1987).
15) T. Kambara: "Control System of the RIKEN
Heavy-Ion Linear Accelerator," Reports
l.P.C.R. (in Japanese), 62, 88 (1986).
16) K. Ikegami, S. Nakajima, S. H. Be, N.
Ohsako, K. Morimoto, T. Kikuchi, and S.
Morishita: "Design and Performance Characteristics of Refrigerator-Cooled Cryopumps
for the RIKEN Ring Cyclotron," Vacuum,
38, 99 (1987).
2. Nuclear physics and nuclear instrumentation
1) E. Minehara, M. Oshima, S. Kikuchi, T.
Inamura, A. Hashizume, and H. Kumahora:"Signature Dependence Observed for M1
Transitions between Rotational Levels Basedon an f7/2 Single-Particle State in 163Dy,"
Phys. Rev. C, 35, 858 (1987).
2) T. Ichihara, H. Sakaguchi, M. Nakamura, T.
Noro, H. Sakamoto, H. Ogawa, M. Yosoi,
M. Ieiri, N. Isshiki, Y. Takeuchi, and S.
Kobayashi: "Effect of Inelastic Excitationon the Elastic Scattering of Alpha Particles
from 144,148,150,152,154Sm at 120 MeV," Phys.
Rev. C, 35, 931 (1987).
3) H. Sakai, N. Matsuoka, T. Saito, A. Shimizu,
M. Tosaki, M. Ieiri, K. Imai, A. Sakaguchi,

261

and T. Motobayashi: "Transverse Polarization Transfer DNN (0°) Measurements for the(p, n) Reactions on 58Ni and 90Zr at Ep =80 MeV," Phys. Rev. C, 35, 1280 (1987).
4) T. Ichihara, H. Sakaguchi, M. Nakamura,
M. Yosoi, M. Ieiri, Y. Takeuchi, H. Togawa,T. Tsutsumi, and S. Kobayashi: "Inelastic
Proton Scattering Exciting the r- Vibrational
Band in Deformed Nuclei (152~AS;192) at
65 MeV and the Systematics of the Hexadecapole (Y42) Strength of the r-Vibration,"
Phys. Rev. C, 36, 1754 (1987).
5) H. Sakai, N. Matsuoka, T. Noro, T. Saito,
A. Shimizu, M. Tosaki, M. Ieiri, K. Imai,
A. Sakaguchi, Y. Takeuchi, and T. Motobayashi: "A Neutron Polarimeter for the(p,n) Reaction at E p =50-80MeV," Nucl.
Instrum. Methods A, 257, 279 (1987).
6) K. Ieki, N. Hoshino, M. Iwase, H. Ohnuma,
Y. Takahashi, and H. Orihara: "A LiquidHelium Scintillator as a Fast-Neutron Polarimeter," Nucl. Instrum. Methods A, 262,
323 (1987).
7) 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 OnLine at INS," Nucl. Instrum. Methods B, 26,
406 (1987).
8) H. Katsuragawa, T. Minowa, M. Shimazu,and T. Inamura: "Electron-Ion Coincidence
Method for Ultrasensitive Detection ofAtoms," Nucl. Instrum. Methods B, 26, 440(1987) .
9) M. Matsuo and K. Matsuyanagi: "Microscopic Description of Anharmonic GammaVibrations by Means of the SelfconsistentCollective-Coordinate Method. III," Prog.
Theor. Phys., 78, 591 (1987).
10) M. Matsuo: "Microscopic Analysis of the
Hexadecapole Strengths to the GammaVibrational Bands," Prog. Theor. Phys., 78,
609 (1987).
11) H. Kawakami, K. Nisimura, T. Ohishima, S.
Sibata, Y. Shoji, I. Sugai, K. Ukai, T.
Yasuda, N. Morikawa, N. Nogawa, T. Nagafuchi, T. Suzuki, F. Naito, H. Taketani, M.
Iwahashi, K. Hisatake, M. Fujioka, Y. Fukusima, T. Matsuda, and T. Taniguchi: "AnUpper Limit for the Mass of Electron AntiNeutrino from the INS Experiment," Phys.
Lett. B, 51, 198 (1987).
12) S. Hirenzaki, T. Kajima, K.-I. Kubo, H.
Toki, and 1. Tanihata: "Pionic Atoms of
Unstable Nuclei," Phys. Lett. B, 194, 20(1987) .
13) H. Ohsumi, H. Ejiri, T. Shibata, K. Okada,Y. Nagai, and T. Motobayashi: "ContinuumSpectra of Neutrons Following the 90Zr (a, a')Reaction," Nucl. Phys. A, 469, 507 (1987).
14) S. Yamaji, H. Hofmann, and R. Samhammer:"Selfconsistent Transport Coefficients for
Average Collective Motion at Moderately
High Temperatures," Nucl. Phys. A, 475,
487 (1987).
15) K. Sato and S. Yoshida: "Studies of Nuclear
Second Moments for Pre-Equilibrium Nuclear
Reaction Theories," Z. Phys. A, 327, 421(1987).
16) S. Kubota, T. Motobayashi, J. Ruan (Gen) ,T. Murakami, J. Kasagi, and T. Shimizu:"Response of Barium-Fluoride Plastic Scintillator to Light Particles and Particle Identification," IEEE Trans. Nucl. Sci., NS-34, 438(1987).
17) Y. Nojiri, K. Matsuta, T. Minamisono, K.
Sugimoto, K. Takeyama, H. Hamagaki, S.
Nagamiya, K. Ornata, Y. Shida, 1. Tanihata,
T. Kobayashi, S. Matsuki, S. Shimoura, J. R.
Alonso, G. Krebs, and T. J. M. Symons: "Online Isotope Separation of Projectile Fragments Produced in Relativistic Heavy-Ion
Reactions," Hyperfine Interact. , 35, 1019
(1987) .
18) K. Asahi: "Physics Using Secondary Beams,"
Butsuri (in Japanese), 42, 799 (1987).
3. Atomic and solid-state physics
1) T . Watanabe and K. Hino: "Radiative Processes in High-Energy Ion-Atom Collisions,"
Nucl. Instrum. Methods A, 262, 29 (1987).
2) H. Iwai, I. Shimamura, and T. Watanabe:"Irregularities in the Differential and Integral
Cross Sections for Ion-Atom Collision in thePlane-Wave Born Approximation," Nucl.
Instrum. Methods A, 262, 37 (1987).
3) H. Tawara, T. Tonuma, T. Matsuo, M. Kase,
H. Kumagai, and 1. Kohno: "Multiply
Charged Atomic Ions Produced throughCoulomb Explosions in Heavy Ion Impact,"
Nucl. Instrum. Methods A, 262, 95 (1987).
4) M. Kimura, N. F. Lane, K. Fujima, and
H. Sato: "Theory of Ion-Surface Collisions;
Case Study of H e+ Projectile Ion," Nucl.
Instrum. Methods A, 262, 114 (1987).
5) Y. Kanai, Y. Awaya, T. Kambara, M. Kase,
H . Kumagai, T. Mizogawa, and K. Shima:"Charge-State Distribution Measurements of
Heavy Ions," Nucl. Instrum. Methods A, 262,
128 (1987).
6) T. Mizogawa, Y. Awaya, T. Kambara, Y.

262

Kanai, M. Kase, H. Kumagai, P. H. Mokler,
and K. Sima: "Target Thickness Dependenceof Projectile Ar K X-Rays L-shell Nonequilibrium," Nucl. Instrum. Methods A, 262,
141 (1987).
7) M. Uda, O. Benka, K. Fuwa, K. Maeda, and
Y. Sasa: "Chemical Effects in PIXE Spectra,"Nucl. Instrum. Methods B, 22, 5 (1987).
. 8) H. Tawara, T. Tonuma, K. Baba, T. Matsuo,
M. Kase, T. Kambara, H. Kumagai, and I.
Kohno: "Multiply Charged Ion Production
through Coulomb Explosion of MolecularIons in Heavy Ion-Molecule Collisions," Nucl.
Instrum. Methods B, 23, 203 (1987).
9) K. Hino and T. Watanabe: "Cross Sectionsof Relativistic Radiative Electron Capture by
the Use of Strong-Potential Born Calculation," Phys. Rev. A, 36, 581 (1987).
10) T. Tonuma, T. Matsuo, M. Kase, T.
Kambara, H. Kumagai, S. H. Be, and I.
Kohno: "Slow-Recoil Ne i + Ions Produced hy
1.05 MeV jamu Neq+-(q= 2, 6,8-10) and Arq+(q=4,10, 12, 14) Ion Impact: Evidence ofInner-Shell Electron Transfer in Highly
Charged Recoil-Ion Production," Phys. Rev.
A , 36, 1941 (1987).
11) N. Sakai and H. Sekizawa: "MagneticElectron Compton Profiles of Ferromagnetic
Fe and Ferrimagnetic Mn Ferrite," Phys.
Rev. B, 36, 2164 (1987).
12) A. Koyama, O. Benka, Y. Sasa, H. Ishikawa,and M. Uda: "Z2-Dependence of Peak
Energies of Loss Electrons Back-Scatteredfrom Target for He+ Impact," Phys. Rev. B,
36, 4535 (1987).
13) K. Hino and T. Watanabe: "Angular Distribution and Linear-Polarization Correlationof Photons Induced by the Relativistic Electron Capture Process," Phys. Rev. A, 36,
5862 (1987).
14) I. Hashimoto, H. Yorikawa, H. Mitsuya, H.
Yamaguchi, K. Takaishi, T. Kikuchi, K.
Furuya, E. Yagi, and M. Iwaki: "Annealing
Behavior of Krypton-Implanted Aluminum,
I. Diffraction Effects from Krypton Bubbles,"]. Nucl. Mater., 149, 69 (1987).
15) Y. Higashiguchi, Y. Suzuki, E. Yagi, M.
N arui, and H. Kayano: "Effect of Heliumon the Deformation Mode for Ti-7.5 Al
Alloy," J. Nucl. Mater., 149,328 (1987).
16) I. Hashimoto, H. Yorikawa, H. Mitsuya, H.
Yamaguchi, K. Furuya, E. Vagi, and M.
Iwaki: "Annealing Behavior of KryptonImplanted Aluminum, II. SEM Study on
Surface Structure during Emission of Krypton
Atoms," J. Nucl. Mater., 150, 100 (1987).

17) K. Asai, F. Ambe,: S.Ambe, T. Okada, and
H. Sekizawa: "An Investigation on the
After-Effects of l11In(~111Cd) EC Decay in
a-Fe203," Hyperfine Interact., 34,277 (1987).
18) K. Asai, T. Okada, and H. Sekizawa: "Supertransferred Hyperfine Magnetic Fields at
ll1Cd ( ~111 In) in F errimagnetic Oxides with
the Spinel Structure," Hyperfine Interact.,
34, 435 (1987) .
19) Y. Fukai, K. Watanabe, and E. Vagi: "Natureand Some Consequences of Stress-Induced
States of Hydrogen in h.c.c. Metals," J. LessCommon Metals, 130, 202 (1987), (Extended
Abstract) .
20) E. Vagi, S. Nakamura, T. Kobayashi, F.
Kano, K. Watanabe, Y. Fukai, and T. Osaka:"Lattice Location Study of H in Ta by the
Channeling Method," ]. Less-Common Metals,
130,207 (1987), (Extended Abstract).
21) T. Kambara, Y. Awaya, M. Kase, H. Kumagai, H. Shibata, and T. Tonuma: "RECX-Rays for 3He and 4He Targets," ]. Phys.
Soc. ]pn., 56,1907 (1987).
22) N. Sakai: "Simulation of Compton Double
Scatterings of Circularly Polarized ·r-Rays by
Magnetic Electrons,'" J. Phys. Soc. ]pn., 56,
2477 (1987).
23) Y. Awaya: "Recent Studies on Atomic
Physics at RIKEN Accelerators," ]AERI-M,
87-134,70 (1987).
24) K. Ando, Y. Awaya, S. Kohmoto, H. Kumagai, T. Tonuma, and S. Tsurubuchi: "Spectrum and Lifetime of Highly Ionized Aluminum," ]AERI-M, 87-134, 84 (1987).
25) R. Schuch, Y. Awaya, T. Kambara, T. Mizogawa, Y. Kanai, H. Shibata, and K. Shima:"Measurement of Impact Parameter Dependent Probabilities and Total Cross Sections
for Target K-Shell Ionization by He+ Ions,"
Z. Phys. D-At. Mol. Clusters, 4, 339 (1987).
26) K. Nagamine, T. Matsuzaki, K. Ishida, Y.
Hirata, Y. Watanabe, R. Kadono, Y. Miyake,
K. Nishiyama, S. E. Jones, and H. R. Maltrud:"Muonic X-Ray Measurement on the p,Sticking Probability for Muon Catalyzed
Fusion III Liquid d-t Mixture," Muon
Catalyzed Fusion, 1, 137 (1987).
27) A. Ohsaki, T. Watanabe, K. Nakanishi, andK. Iguchi: "p,- Transfer Cross Sections from(p,-d) of (p,-t) to t and a in High Velocity
Region U sing Classical Trajectory Monte
Carlo Method," Muon Catalyzed Fusion, 1,
245 (1987).
28) T. Mizogawa, Y. Awaya, Y. Itoh, T. Kambara, Y. Kanai, T. Koizumi, S. Ohtani, K.
Okuno, H. Shibata, S. Takagi, and S. Tsuru-

263

huchi: ' ''Charge State Distribution of Ions
Extracted f~om a Compact EBIS," Mass
Spectrosc., 35, , 1 (1987).
29) Y ..Awaya, K. Hino, A. Hitachi, Y. Kanai, K.
Kawatsura, K. Kuroki, H. Vogt, Y. Yamazaki, and T. Watanabe: "Photon Angular
Distribution of the Relativistic Electron
Capture," Lecture ' Notes of Third Workshop
on High-Energy lon-Atom Collision Process,Springer-Verlag, p. 185 (1987).
30) T. Nozaki, M. Uda, and E. Vagi: "Analysis
of Impurities in Metals by Particle Accelerators," Tetsu to Hagane (in Japanese), 73, 41(1987) .
31) E. Vagi: "Lattice Location Study on Kr in
Al by the Channelling Method," Phys. Status
Solidi A, 104, K13 (1987).
32) N. Shimakl,lra, N. Toshima, T. Watanabe,and H. Tawara: "Final (n, I) State-Resolved
Electron Capture by Multiply Charged Ions
from . Neutral Atoms," IPPJ-AM-Report,
IPPJ-AM-54, Inst. Plasma Phys., Nagoya
Univ., p.62 (1987).,
33) T. Watanabe: "Atomic and Molecular Research Using High Brightness and Strong
Intensity Radiation Sources," Proc. Workshop, ,Future Prospect of the Research Study Using
Intense and . Bright Synchrotron Radiation in
VUV and Soft X-Ray Region (National
Laboratory for High Energy Physics, Oho,
Ibaraki, Japan), . (in Japanese), p. 98 (1987).
34) , E. Vagi, F. Kano, S. Nakamura, M. Iwaki,
and T. Osaka: "Defect-Impurity Interactionin Sn- or. Ni-Implanted Aluminum," "Mater.
Sci. Forum, 1~18, 605 (1987).
35) T. Minowa, H. Katsuragawa, K. Nishiyama,
M. Shimazu, and T. Inamura: "Novel Highly
Sensitive Coincidence Detection Method for
Resonance Ionization Signals," ]. Appl. Phys.,61,, 436 ,(1987).
36) :N. Shimakura, H. Sato, M. Kimura, and T.
Watanabe: "Electron Capture Process in
Collisions of 0 6 + with He Using Travelling
Molecular Orbital Method," ]. Phys. B: At.
Mol. Phys., 20, 1801 (1987).
37) H. Kawakami, K. Nisimura, T. Ohishima, S.
Sibata, Y. Shoji, I. Sugai, K. Ukai, T. Yasuda,
N. Morikawa, N. , Nogawa, T. Nagafuchi, T.
Suzuki, F. Naito, H. Taketani, M. Iwahashi,
K. Hisatake, M., Fujioka, Y. Fukusima, T.
Matsuda, and T. Taniguchi: "Precise Measurement of Ag KLL Auger-Spectrum," Phys.
Lett. A, 121,. 414 ,(1987).
38) T. Watanabe: "Report on International Conference on Atomic' Physics and Few-Body Sys. terns; Emphasis ' on Atomic Physics," ]. At.
I

Energy Soc. lpn. (in Japanese), 29,34,(1987).
4. Radiochemistry, radiation chemistry and radiation
biology1) M. U da, K. Maeda, Y. Sasa, H. Kusuyama,
and Y. Yokode: "An Attempt to Diagnose
Cancer by- PIXE," Nucl. Instrum. Methods
B, 22, 184 (1987) '.
2) K. Maeda, Y. Yokode, Y. Sasa, H. Kusuyama, and M. Uda: "Multielemental Analysis
of Human Thyroid Glands Using Particle
Induced X-Ray Emission (PIXE) ," Nucl.
Instrum. Methods B, 22, 188 (1987).
3) Y. Sasa, K. Maeda, and M. Uda: "Application of PIXE and Diffraction Analysis toAncient Remains," Nucl. Instrum. Methods
B, 22, 426 (1987).
4) K. Maeda, Y. Sasa, M. Maeda, and M.
U da : "Diagnosis of River Pollution by
PIXE," Nucl. Instrum. Methods B, 22, 456(1987) .
5) H. Nagai, S. Hayashi, M. Aratani, T. Nozaki,
M. Yanokura, and I. Kohno: "Reliability,
Detection Limit and Depth Resolution of the
Elastic Recoil Measurement of Hydrogen,"Nucl. Instrum. Methods B, 28, 59 (1987).
6) T. Nozaki, Y. Itoh, S. Hayashi, and Q. Qiu:
"Utilization of Deuterium and 15N as Activable Tracers in Solid State Sciences," l.
Radioanal. Nucl. Chem., 112( 1), 47 (1987).
7) H. Fukushima, T. Kimura, H. Hamaguchi,
T. Nozaki, Y. Itoh, and Y. Ohkubo: "Routine
Determination of Light Elements by ChargedParticle Activation Analysis," ]. Radioanal.
Nucl. Chem., 112 (2), 415 (1987).
8) T. N ozaki: "Charged Particle Activation
Analysis of Light Impurity Elements in Semiconductor Materials," Proc. 11 th Int. Conf.
Cyclotrons and The~T Applications, Tokyo,.
Oct. 1986, p.579 (1987).
9) I. Kaneko, K. Eguchi-Kasai, T. Takahashi,
T. Kosaka; and K. Nakano: "Beamport and
Irradiation Chamber of the RIKEN Cyclotron for Biological Samples," 11th Int. Conf.
Cyclotrons and Their Applications, Tokyo,
Oct. 1986, p.633 (1987).
10) K. Eguchi-Kasai j T. Kosaka, I. Kaneko, T.
Takahashi, A. Maruhashi, and K. Nakano:"Cell Death and DNA Lesion Caused byAccelerated Charged Particles," 11th Int.
ConL Cyclotrons and Their Applications,Tokyo, Oct. 1986, p.667 (1987).
11) T. Seguchi, T. Sasuga, W. Kawakami, M.
Hagiwara, I. Kohno, and H. Kamitsubo:"Proton Irradiation Effects on Organic
Polymers," Proc. 11 th Int. Conf. Cyclotrons

264

and Their Applications, Tokyo, Oct. 1986,
p.669 (1987).
12) T. Takahashi, F. Yatagai, T. Katayama, S.
Konno, K. Takahashi, Y. Takayanagi, K.
Nakano, and I. Kaneko: "Calculation of
Dose around the Trajectory of an Ion andInterpretation of Inactivation Cross Sectionsof Microorganisms," ]. Radiat. Res., 28, 71(1987) .
13) K. Eguchi-Kasai, T. Kosaka, I. Kaneko,
T. Takahashi, A. Maruhashi, and K. Nakano: "Induction of Non-Repairable DNA
Strand Breaks by N-ion Beams," ]. Radiat.
Res. , 28, 213 (1987).
14) S. Ambe: "Adsorption Kinetics of Sb (V)Ions onto a-Fe 2 0 g Surfaces from an Aqueous
Solutions," Langmuir, 3, 489 (1987).
15) K. Kimura: "Roles of Electronic Excited
States in Irradiation Effect of Heavy Ion,"
Radiat. Chern. (in Japanese) , 44, 42 (1987).
16) K. Eguchi, T. Inada, M. Yaguchi, S. Satoh,and I. Kaneko: "Induction and Repair of
DNA Lesions in Cultured Human Melanoma
Cells Exposed to a Nitrogen-Ion Beam," Int.
J. Radiat. Bioi., 52, 115 (1987).
17) T. Takahashi, K. Eguchi, A. Hashizume,
and T. Inada: "Data Requirements in Heavy
Ion Radiotherapy - Considerations on Available Physical Quantities - ," Proc. Advisory
Group Meeting on Nuclear and Atomic Datafor Radiotherapy and Related Radiobiology,
IAEA Panel Proc. Ser. STI/PUB/741, p.367(1987) .
18) I. Kaneko: "Basic Researches for Cancer
Therapy with Heavy Charged ParticlesDNA Lesions and Their Repair in Human
Melanoma Cells," Rep. Mochida Mem.
Found. Med. Pharm. Res., 3, 241 (1987).
19) T. Takahashi, F. Yatagai, T. Katayama, T.
Doke, and H. Ohashi: "The Inactivation of
Microorganisms by Different Heavy Ions,"
Proc. 1986 Int. Symp. Biological Sciencesin Space (eds. S. Watanabe et ai.) , MYU
Research, Tokyo, p.365 (1987).

(Papers Presented at Meetings)
1. Accelerator development and accelerator physics
1) M. Nagase, H. Takebe, T. Wada, and K.
Shimizu: "Program for Controlling Magnet
Power Supplies of the RIKEN Ring Cyclotron," 11 th Int. Conf. Cyclotrons and Their
Applications, Tokyo, Oct. (1986).
2) Y. Yano, A. Goto, K. Hatanaka, H. Takebe,and S. Motonaga: "Beam Injection and

Extraction System of RIKEN Ring Cyclotron," 11th Int. Conf. Cyclotrons and Their
Applications, Tokyo, Oct. (1986).
3) K. Hatanaka, T. Inamura, Y. Yano, A. Goto,
M. Kase, and H. Kamitsubo: "Beam Transport System for RIKEN Ring Cyclotron,"
11 th Int. Con£. Cyclotrons and Their Applications, Tokyo, Oct. (1986).
4) Y. Miyazawa, M. Hemmi, T. Inoue, T.
Kambara, M. Yanokura, M. Kase, T. Kubo,
E. Ikezawa, Y. Chiba, and 1. Tanihata:"Operation of RILAC at RIKEN," 11th Int.
Conf. Cyclotrons and Their Applications,Tokyo, Oct. (1986).
5) K. Ikegami, S. Nakajima, Y. Oikawa, 1.
Takeshita, S. Motonaga, and S. H. Be:"Vacuum System for the RIKEN Ring
Cyclotron," 11th Int. Conf. Cyclotrons andTheir Applications, Tokyo, Oct. (1986).
6) T. Shikata, N. Nakanishi, S. Fujita, andT. Kosako: "Shielding Calculation of Neutrons for the RIKEN Ring Cyclotron Facility," 11th Int. Con£. Cyclotrons and Their
Applications, Tokyo, Oct. (1986).
7) K. Ikegami, S. Nakajima, Y. Oikawa, 1.
Takeshita, and S. H. Be: "Vacuum System
for the RIKEN Ring Cyclotron," 11th Int.
Conf. Cyclotrons and Their Applications,Tokyo, Oct. (1986).
8) F. Kikuchi, M. Hara, and T. Wada: "Development of a Finite Element Code for
3-D Analysis of Electromagnetic Waves,"
Workshop Fundamental Studies of Numerical
Computations of MHD Problems and Confinement of Plasmas by Tokamak Type Devices, Enoshima, Jan. (1987).
9) A. Goto, T. Fujisawa, I. Takeshita, T. Urai,
Y. Ikegami, and Y. Yamada: "BeamBuncher in the Injection Beam Transport
System of the RIKEN Ring Cyclotron,"42th Annu. Meeting Phys. Soc. ]pn., Nagoya,Mar. (1987).
10) S. Motonaga, Y. Yano, A. Goto, K. Hatanaka, M. Kase, T. Wada, H. Takabe, and H.
Kamitsubo: "Beam Acceleration Test of the
RIKEN Ring Cyclotron," 42th Annu. Meeting Phys. Soc. ]pn., Nagoya, Mar. (1987).
11) M. Kase and I. Yokoyama: "Beam Diagnostic Equipment in the RIKEN Ring Cyclotron," 24th Eur. Cyclotron Progress Meeting,Nice, May (1987).
12) Y. Yano: "Commissioning of the RIKEN
Ring Cyclotron," 24th Eur. Cyclotron Progress Meeting, Nice, May (1987).
13) M. Kase and 1. Yokoyama: "Beam Diagnostic System in the RIKEN Ring Cyclotron,"

265

6th Symp. Accelerator Science and Technology, Tokyo, Oct. (1987).
14) T. Inamura: "Ring Cyclotron Project at
RIKEN," RIKEN-IN2P3 Symp. Heavy-Ion
Collisions, Shimoda, Oct. (1987).
15) A. Goto: "Status of the RIKEN Ring
Cyclotron," 1987 Fall Meeting Phys. Soc.
Jpn., Utsunomiya, Oct. (1987).
16) F. Kikuchi, M. Hara, and T. Wada: "A
Finite Element Method for 3-D Analysis ofCavity Resonators," Int. Symp. Modeling and
Simulation of Distributed Parameter Systems,
Hiroshima, Oct. (1987).
17) T. Fujisawa, K. Ogiwara, S. Kohara, Y.
Oikawa, I. Yokoyama, M. Nagase, and Y.
Chiba: "Radio Frequency System of the
RIKEN Ring Cyclotron," 3rd Jpn.~China Jt.
Symp. Accelerators for Nuclear Science andTheir Applications, Wako, Nov. (1987).
18) Y. Yano: "Initial Operation of RIKEN Ring
Cyclotron," 3rd Jpn.-China Jt. Symp. Accelerators for Nuclear Science and Their
Applications, Wako, Nov. (1987).
19) H. Takebe, T. Wada, M. Kase, T. Kambara,and H. Kamitsubo: "Control System of the
RIKEN Ring Cyclotron," Control System
Workshop, Tsukuba, Nov. (1987).
2. Nuclear physics and nuclear instrumentation
1) K. Asahi: "Spectroscopy of Unstable Nuclei
with LISE and RIB," INS Symp. Clustering
Aspects in Nuclear Physics and Prospects inIntermediate- and High-Energy Heavy-Ion
Physics, Tokyo, Jan. (1987).
2) K. Asahi: "Summary of Experiments Using
Radioactive Beam Course," Workshop Experiments at RIKEN Ring Cyclotron, Tokyo,
Jan. (1987).
3) M. Oshima, E. Minehara, S. Ichikawa, H.
Iimura, T. Inamura, A. Hashizume, and H.
Kusakari: "E2 Transition Probabilities of
the Ground-State Rotational Band in
161,163Dy," 42th Annu. Meeting Phys. Soc.
Jpn., Nagoya, Mar. (1987).
4) K. Ornata, T. Kobayashi, T. Shimoura, K.
Sugimoto, 1. Tanihata, K. Takeyama, N.
Takahashi, Y. Nojiri, and O. Yamakawa:"Projectile Fragmentation of llLi, 8He, 6He
at 0.8 GeV / A," 42th Annu. Meeting Phys.
Soc. Jpn., Nagoya, Mar. (1987).
, 5) S. Yamaji and N. Yoshinaga: "Dipole
Moment of 222Ra as a System of Pb + HC
Molecular Configulation," 42th Annu. Meeting Phys. Soc. Jpn., Nagoya, Apr. (1987).
6) T. Suzuki: "Neutrino Mass Studied by
Measuring Tritium Beta-Decay with an Iron-

Free Beta-Ray Spectrometer," 11th Int. Conf.
Particle and NeUclei (PANIC '87), Kyoto,
Apr. (1987).
7) 1. Tanihata: "Nuclear Structure Studies
Using High-Energy Radioactive Beams," 11th
Int. Con£. Particle and Nuclei (PANIC '87),
Kyoto, Apr. (1987).
8) K. Nagamine, T. Matsuzaki, K. Ishida, Y.
Hirata, Y. Watanabe, R. Kadono, Y. Miyake,
K. Nishiyama, S. E. Jones, and H. R. Maltrud: "Direct Observation of a-Sticking
Probability in Muon Catalyzed (dtp) -Fusion
with X-Ray Method," Int. Symp. Muon
Catalyzed Fusion, Leningrad, U.S.S.R., May(1987) .
9) T. Sano, T. Doke, J. Kikuchi, K. Masuda,
and T. Takahashi: "Liquid Xenon Photoionization Detector," 1987 Fall Meeting Phys.
Soc. ]pn., Sendai, Sep. (1987).
10) I. Tanihata: "Nuclear Structure Studies
Using Beams of Radioactive Nuclei," 5th Int.
Conf. Nuclei Far from Stability, Rosseau
Lake, Canada, Sep. (1987).
11) K. Asahi, M. Ishihara, T. Shimoda, T.
Fukuda, N. Takahashi, K. Katori, K. Hanakawa, T. Itahashi, Y. Nojiri, T. Minamisono, N. Ikeda, S. Shimoura, and A. Nakamura: "Production of Spin Polarized 15C
in Heavy-Ion Reaction and Measurement ofg-Factor for the 1/2+ Ground State," 5thInt. Conf. Nuclei Far from Stability, Rosseau
Lake, Canada, Sep. (1987).
12) T. Inamura: "Progress in Research at
RIKEN Ring Cyclotron Facility," 1987 Fall
Meeting Phys. Soc. Jpn., Utsunomiya, Oct.
(1987) .
13) H. Harada, J. Kasagi, T. Murakami, K.
Yoshida, T. Inamura, and T. Kubo: "The
Rotational Band in Odd Mass 111Sn," 1987
Fall Meeting Phys. Soc. ]pn., Utsunomiya,Oct. (1987).
14) K. Yoshida, J. Kasagi, H. Hama, H. Harada,
H. Takeuchi, M. Sakurai, K. Ieki, T. Kubo,
and M. Ishihara: "High Energy r Rays
Observed in 181Ta + 40Ar Reaction at 21
MeV /nucleon," 1987 Fall Meeting Phys.
Soc. Jpn., Utsunomiya, Oct. (1987).
15) K. Asahi, M. Ishihara, T. Shimoda, T.
Fukuda, N. Takahashi, K. Katori, K. Hanakawa, T. Itahashi, Y. Nojiri, T. Minamisono,
N. Ikeda, S. Shimoura, and A. Nakamura:"Study of Spin Polarized Nuclei Using Heavy
Ion Reaction," RIKEN -IN2P3 Symp. HeavyIon Collisions, Shimoda, Oct. (1987).
16) I. Tanihata: "Nuclear Structure Studies
Using Beams of Radioactive Nuclei," RIKEN-

266

IN2P3 Symp. Heavy-Ion Collisions, Shimoda,
Oct. (1987).
17) T. Motobayashi: " (d, 2He) Reactions by
Polarized Deuteron," RIKEN-IN2P3 Symp.
Heavy-Ion Collisions, Shimoda, Oct. (1987).
18) A. Hitachi, A. Yunoki, T. Doke, and T.
Takahashi: "The Scintillation and Ionization
Yield in the Presence of Quenching in Liquid
Argon," 12th Int. Conf. Atomic Collisions
in Solids, Okayama, Oct. (1987).
19) . T. Kubo: "RIKEN Projectile-Fragment
Separator RIPS," 1987 Fall Meeting Phys.
Soc. Jpn., Utsunomiya, Oct. (1987).
20) T. Murayama': "Arrangements for RIS at
RIKEN Ring Cyclotron," Symp. Lasers in
Nuclear Physics, Osaka, Dec. (1987).
, 21) T. Inamura: "Lasers in Nuclear Physics,"
Symp. Lasers in Nuclear Physics, Osaka, Dec.
(1987) .
22) K. Asahi: "Beta Decays of High Isospin
Nuclei," INS Symp. Nuclear Physics III
Japan Hadron Project, Tokyo, Dec. (1987).
23) K. Asahi: "Recent Results from GANIL,"
Symp. Clustering Aspects in Nuclear Structures and Reactions, Osaka, Dec. (1987).
24) K. Asahi: "Spectroscopy of Neutron-Rich
Nuclei," INS Workshop Studies of Nuclear
Reactions at Intermediate Energies Using 4n' Spectrograph, Tokyo, Dec. (1987).
3. Atomic and solid-state physics
1) Y. Awaya, T. Watanabe, K. Ando, T. Kambara, M. Kase, H. Kumagai, Y. Kanai, andK. Shima: "The Charge Distribution of
Swift Heavy Ions Passing through Solids,"
Symp. Interactions between Ion-Beams andSolids, Tokyo, Jan. (1987).
2) T. Mizogawa, Y. Awaya, T. Kambara, M.
Kase, H :' Kumagai, Y. Kanai, and K. Shima:"Charge Distribution of High-Velocity Heavy
Ion after Passing through Solid Target,"Symp. Interaction between Ion-Beam andSolids, Tokyo, Jan. (1987).
3) E. Vagi: "Lattice Location Study on Hydrogen in Metals by Means of Heavy Ion Channeling Method," Symp. Interactions 'between
Ion Beam and Solids, Tokyo, Jan. (1987).
4) K. Fujima, T. Watanabe, and K. Mirna:"X-ray Emission Spectra of High and Dense
Si Plasma," Symp. Atomic Processes in Laser
Induced Implosion Plasma, Okayama, Jan.
(1987) .
5) T. Kambara: "Impact Parameter Dependenceof K-Shell Vacancy Production for Solid andGas Targets," Energetic Atomic Collisions,
Oberstdorf, W. Germany, Jan. (1987).

6) Y. Awaya, "Recent Studies on Atomic Physics
at RIKEN Accelerators," 2nd Jt. Semin.
Atomic Physics, Solid State Physics andMaterial Sciences in the Energy Region of
Tandem Accelerators, Tokai, Jan. (1987).
7) K. Hino and T. Watanabe: "Radiative Processes in Ion-Atom Collisions," US-Jpn. Jt.
Semin. Interactions of Highly Ionized Atoms
by Ion-Atom Collisions, Kobe, Mar. (1987).
8) I. Shimamura, M. I wai, and T. Watanabe:"Irregularities in the Cross Sections for Discrete Excitation in Ion-Atom Collisions Calculated in the Plane-Wave Born Approximation," US-Jpn. Jt. Semin. Interactions ofHighlyIonized Atoms by Ion-Atom Collisions,
Kobe, Mar. ' (1987).
9) H. Tawara, T. Tonuma, T. Matsuo, M. Kase,
T. Kambara, H. Kumagai, and I. Kohno:"Multiply Charge Atomic Ion Production
through Coulomb ' Explosions by Heavy Ion
Impact," US-Jpn. Jt. Semin. Interactions ofHighly Ionized Atoms by Ion-Atom Collisions,
Kobe, Mar. (1987).
10) Y. Kanai, Y. Awaya, T. Kambara, M. Kase,
H. Kumagai, T. Mizogawa, and K. Shima:"Charge State Distribution Measurements of
Heavy Ions at RIKEN," US-Jpn. Jt. Semin.
Interactions of Highly Ionized Atoms Produced by Ion-Atom Collisions, Kobe, Mar.
(1987) .
'11) T. Mizogawa, Y. Awaya, T. Kambara, Y.
Kanai, M. Kase, H. Kumagai, P. H. MokIer,
and K. Shima: "Target Thickness Dependence of 'Projectile Ar K X-Rays-L-Shell
Non-Equilibrium," US-Jpn. Jt. Semin. Interactions of Highly Ionized Atoms Produced by
Ion-Atom Collisions, Kobe, Mar. (1987).
12) K. Ishida, T. Matsuzaki, Y. Hirata, Y.
Miyake, ' Y. Watanabe, and K. Nagamine:"Muon Transfer Reaction to Helium Impurity in Liquid Hydrogen II," 42th Annu. Meeting Phys. Soc. lpn., Nagoya, Mar. (1987).
13) K. Nishiyama, H. Katsuragawa, T. Minowa,
M. Shimazu, and T. Inamura: "Resonance
Ionization Spectroscopy of Tl Atomic Beam,"
42th Annu. Meeting Phys. Soc. Jpn., Nagoya,Mar. (1987).
14) H. Katsuragawa, K. Nishiyama, T. Minowa,
M. Shimazu, and T. Inamura: "Resonance
Ionization Spectroscopy of Ta Atoms," 42th
Annu. Meeting Phys. Soc. Jpn., Nagoya, Mar.
(1987) .
15) Y. Kanai, Y. Awaya, T. Kambara, M. Kase,
H. Kumagai, T. Mizogawa, and K. Shima:"Charge-State Distribution of Heavy Ions after Single Close Collisions," 42th Annu. Meet-267

ingPhys. Soc. Jpn., Nagoya, Mar. (1987).
16) E. Vagi, H. Sakairi, A. Koyama, and R. R.
Hasiguti: "Isochronal Annealing of Protonor a-Irradiated CUsAu at Low Temperatures,"42th Annu. Meeting Phys. Soc. Jpn., Nagoya,Mar. (1987).
17) N. Sakai and T. Okada: "Mossbauer Spectrometer Using Piezoelectric Actuators," 42th
Annu. Meeting Phys. Soc. Jpn., Nagoya, Mar.
( 1987) .
18) T . Matsuzaki, K. Ishida, Y. Hirata, Y.
Watanabe, Y. Miyake, R. Kadono, K. Nagamine, H. R. Maltrud, and S. E. Jones:"Fundamental Experiment for Muon Catalyzed Fusion II," 42th Annu. Meeting Phys.
Soc. Jpn., Nagoya, Mar. (1987).
19) X .-W. Liu, Q.-C. Ma, J.-F. Cheng, X-X.
Zhang, Y.-Y. Liu, and T. Watanabe: "Calculation of Cross Section for fl+ + (.t[p) ~(p.+ fl-) + p," 42th Annu. Meeting Phys. Soc.
Jpn., Nagoya, Mar. (1987).
20) T. Watanabe: "Radiative Processes Induced
by Ion-Atom Collisions," Jt. Workshop
Atomic-Molecular Physics and Heavy-Ion
Nuclear Reaction, Tanashi, Mar. (1987).
21) K . Aono, M. I waki, and S. N amba: "Ion
Implantation in CaF 2 (II)," RIKEN Symp.
'18th Symp. Ion Implantation and Submicron
Fabrication,' Wako, Mar. (1987).
22) Y. Awaya, K. Hino, T. Kambara, Y. Kanai,
K. Komaki, K. Kuroki, I. Shimamura, andY. Yamazaki: "Study of Atomic Collisions
by Using Relativistic Heavy Ions," Workshop Experiments and Experimental Facilities at SIS jESR, Darmstadt, W. Germany,
Mar. (1987).
23) K. Nagamine: "Muon Catalyzed Fusion with
Pulsed Muons: Present and Future," Int. Sch.
Fusion Reactor Technology, Erice, Italy, Apr.
(1987) .
24) T. Matsuzaki, K. Ishida, Y. Hirata, R.
Kadono, and K . Nagamine: "Muonic X-ray
Measurement on the p.- Transfer Process in
Liquid D2 to 4He Impurity," Int. Symp.
Muon Catalyzed Fusion, Leningrad, U.S.S.R.,
May (1987).
25 ) E. Yagi: "Lattice Location Study of Impurities by Means of Channeling Method," 24th
Meeting Isotope Research in Science andTechnology, Tokyo, Jun. (1987).
26 ) S. Karashima and T. Watanabe: "Electron
Stripping Cross Sections from Multiply
Charged Ions by Neutral Atoms Using BEA
and Born Approximation Method," 15th Int.
Conf. Physics of Electronic and Atomic Colli. sions, Brighton, England, JuI. (1987).

27) T. Mizogawa, Y. Awaya, T. Kambara, Y.
Kanai, M . Kase, H. Kumagai, P. H. MokIer,
and K. Shima: "Study of K-, L- and MShell Equilibration Processes of 50 MeV
Argon Ions in Carbon Foils," 15th Int. Conf.
Physics of Electronic and Atomic Collisions,
Brighton, England, Jui. (1987).
28) T . Kambara, Y. Awaya, T. Mizogawa, H.
Kumagai, Y. Kanai, K. Shima, H. Shibata,and R. Schuch: "Measurement of Impact
Parameter Dependent Probabilities for KShell Ionization in Ar-Ca and Ar-Cu Collisions," 15th Int. Conf. Physics of Electronicand Atomic Collisions, . Brighton, England,
Jui. (1987).
29) S. Reusch, Y. Awaya, T. Kambara, P. H.
Mokler, D. J. McLaughlin, A. Miiller, R.
Schuch, and M. Schultz: "Resonant Transfer
and Excitation (RTE) in S 2Ge 29 +~ H 2 Collisions," 15th Int. Conf. Physics of Electronicand Atomic Collisions, Brighton, England,
JuI. (1987).
30) Y. Kanai, Y. Awaya, T. Kambara, M. Kase,
H. Kumagai, B. Liu, T. Mizogawa, and K.
Shima: "Charge State Measurements of
Heavy Ions Scattered by Gas and Solid
Targets," 15th Int. Conf. Physics of Electronicand Atomic Collisions, Brighton, England,
Jul. (1987).
31) H. Tawara, T. Tonuma, T . Matsuo, M.
Kase, H. Kumagai, and I. Kohno: "Multiply
Charged Atomic and Their Initial Kinetic
Energy through Coulomb Explosions of Multiply Molecular Ions Produced in Energetic,
Heavy Ion Collisions," 15th Int. Conf.
Physics of Electronic and Atomic Collisions,
Brighton, England, Jul. (1987) .
32) ·K. Hino and T. Watanabe: "Gauge Invariance on Radiative Process , Caused by
Ion-Atom Collisions," 15th Int. Conf. Physics
of Electronic and Atomic Collisions, Brighton,
England, JuI. (1987). '33) K. Hino and T . Watanabe: "Cross Sections
for Relativistic Radiative Electron Capture 'by
the Strong-Potential Born Calculation," 15th
Int. Conf. Physics of Electronic and Atomic
Collisions, Brighton, England, Jul. (1987).
34) Y. Awaya, H. Hino, T. Kambara, T. Watanabe, A. Hitachi, Y. Kanai, H. Vogt, K.
Kuroki, and Y. Yamazaki: "Radiative Electron Capture Process," 10th Int. Semin. IonAtom Collisions, Frankfurt, W. Germany, JuI.
(1987) .
35) K. Aono, M. Iwaki, and S. Namba: "Luminescence during Eu-Implantation into Calcium Fluoride," Radiation · Effects in In-

268

sulators-4, Lyon, France, Jul. (1987).
36) Y. Awaya, K. Hino, A. Hitachi, Y. Kanai,
K. Kawatsura, K. Kuroki, H. Vogt, Y.
Yamazaki, and T. Watanabe: "Angular
Distribution of REC X Rays," 3rd Workshop High-Energy Ion-Atom Collision Processes, Debrecen, Hungary, Aug. (1987).
37) T. Tonuma, T. Matsuo, M. Kase, T.
Kambara, H. Kumagai, S. H. Be, I. Kohno,
and H. Tawara: "Multiple Ionization by
Energetic Heavy Ion Collisions-An Evidenceof the Innershell Electron Transfer in Highly
Charged Recoil Ion Production," 3rd Workshop High-Energy Ion-Atom Collision Processes, Debrecen, Hungary, Aug. (1987).
38) H. Iwai, I. Shimamura, and T. Watanabe:"Anomalous Behavious of Cross Sections Appeared In Ion-Atom (Ion-Ion) Collisions,"
UK-Jpn. Semin. Theory of Atomic Collisions,
Egham, England, Aug. (1987).
39) K. Hino and T. Watanabe: "Photon Emission Processes Induced by Ion-Atom Collisions," UK-Jpn. Semin. Theory of Atomic
Collisions, Egham, England, Aug. (1987).
40) N. Sakai: "A New Mossbauer Transducer
Using Piezoelectric Bimorph Actuators," Int.
Conf. Appl. Mossbauer Effect, Melbourne,
Aug. (1987).
41) T. Okada, N. Sakai, K. Asai, Y. Toba, andT. Yamadaya: "57Fe Mossbauer Study on
YBa2Cu3-wFew07-1I," Int. Conf. Applicationsof the Mossbauer Effect, Melbourne, Australia, Aug. (1987).
42) Y. Sakamoto, H. Oyama, and K. Yano:"Erosion of Graphite by Very Low Energy
Hydrogen Atoms," 8th Int. Symp. Plasma
Chemistry, Tokyo, Aug. (1987).
43) T. Matsuzaki, K. Ishida, Y. Hirata, R.
Kadono, and K. Nagamine: "Photon Transition of the Excited Bound State in Cu-d 4He)
Mesomolecule Accompanied with (,u-d +4H~,u- 4He+d) Process," 1987 Fall Meeting Phys. Soc. Jpn., Utsunomiya, Sep. (1987).
44) K. Ishida, T. Matsuzaki, Y. Hirata, R.
Kadono, and K. N agamine: "Photon Emission from Excited Bound State of Muonic
Molecule dHe,u-," 1987 Fall Meeting Phys.
Soc. lpn., Sendai, Sep. (1987).
45) S. Karashima, K. Hino, and T. Watanabe:"Charge State of Relativistically High Velocity Heavy Ions in Matter," 1987 Fall Meeting of Phys. Soc. lpn., Sendai, Sep. (1987).
46) K. Nishiyama, H. Katsuragawa, T. Minowa,
S. Kawamura, H. Sonobe, M. Shimazu, andT. Inamura: "Resonance Ionization Spectroscopy of Neutral Atoms Produced by Lasers,"

1987 Fall Meeting Phys. Soc. lpn., Sendai,
Sep. (1987).
47) A. Koyama, H. Ishikawa, Y. Sasa, O. Benka,
and M. U da: "High Charge Effects on Electron Excitations in Metal Targets for Ar12+
Impact Compared with Those for He 2+ Impact," 1987 Fall Meeting Phys. Soc. lpn.,
Sendai, Sep. (1987).
48) A. Koyama, H. Ishikawa, and Y. Sasa:"Energy Spectra of AI-L VV Auger Electrons
Induced by Grazing Angle Incident Fast
Heavy Ion Impact," 1987 Fall Meeting Phys.
Soc. Jpn., Sendai, Sep. (1987).
49) E. Vagi: "Behavior of Kr Atoms in Aluminum," 1987 Fall Meeting Phys. Soc. Jpn.,
Sendai, Sep. (1987).
50) F. Itoh, Y. Sakurai, K. Suzuki, N. Shiotani,
N. Sakai, H. Kawata, Y. Amemiya, and M.
Ando: "High Resolution Compton Profilesof AI," 1987 Fall Meeting Phys. Soc. Jpn.,
Sendai, Sep. (1987).
51) E. Vagi: "Lattice Defects and ,uSR," 28th
Meeting Lattice Defects, Fukushima, Sep.
(1987) .
52) K. Ishida, T. Matsuzaki, and K. Nagamine:"Towards the Application of RIKEN Ring
Cyclotron to Solid State Physics with Nuclear
Methods," 28th Meeting Lattice Defects,
Fukushima, Sep. (1987).
53) S. M. Younger, A. K. Harrison, K. Fujima,and D. Griswold: "Computational Studies
of High Energy Density Plasmas," 6th APS
Top. Conf. Atomic Processes in High Temperature Plasmas and Int. Conf./Workshop
Radiative Properties on Hot Dense Matter,
Santa Fe, U.S.A., Sep. (1987).
54) K. Hino and T. Watanabe: "Instantaneous
X-Ray Emission Induced by Ion-Atom Collision," 14th Int. Conf. X-Ray and InnerShell Processes, Paris, France, Sep. ( 1987) .
55) K. Hino and T. Watanabe: "Angular Distribution and Linear Polarization of X-Rays
Induced by Radiative Electron Capture,"
12th Int. Conf. Atomic Collisions in Solids,
Okayama, Oct. (1987).
56) S. Karashima, K. Hino, and T. Watanabe:"Charge Equilibrium of Relativistic Heavy
Ions In Matter," 12th Int. Conf. Atomic
Collisions in Solids, Okayama, Oct. (1987).
57) K. Ando, S. Kohmoto, Y. Awaya, T. Tonuma,
H. Kumagai, and S. Tsurubuchi: "Beam-Foil
Experiments on Lifetime and Spectra ofHighly Ionized Aluminum Ions," 12th Int.
Conf. Atomic Collisions in Solids, Okayama,
Oct. (1987).
58) K. Fujima, H. Adachi, and M. Kimura:

269"The Charge Transfer Collision between a
Low Energy Ion and the Solid Surface,"
12th Int. Conf. Atomic Collisions in Solids,
Okayama, Oct. (1987).
59) K. Shima, T. Kakita, E. Nakagawa, M.
Yamanouchi, T. Momoi, Y. Awaya, T. Mizogawa, and Y. Kanai: "Projectile Atomic
Number Dependence of Equilibrium Charge
States for 1 and 2 MeV lu Ions Passing
through Carbon Foil," 12th Int. Conf. Atomic
Collisions in Solids, Okay am a, Oct. (1987).
60) T. Mizogawa, Y. Awaya, T. Kambara, Y.
Kanai, M. Kase, H. Kumagai, and K. Shima:"Charge Equilibrium Process of 50 MeV Ar
Ions in C Foils," 12th Int. Conf. Atomic
Collision in Solids, Okayama, Oct. (1987).
61) A. Koyama, H . . Ishikawa, and Y. Sasa:"Energy Spectra of AI-LVV Auger Electrons
Induced by Grazing Angle Incident Fast
Heavy Ion Impact," 12th Int. Conf. Atomic
Collisions in Solids, Okayama, Oct. (1987).
62) A. Koyama, H. Ishikawa, Y. Sasa, O. Benka,
and M. Uda: "Depression of Yields of Low
Energy Secondary Electrons Induced by Impact of Heavy Ions with High Electric
Charges," 12th Int. Conf. Atomic Collisions
in Solids, Okayama, .Oct. (1987).
63) A. Koyama, H. Ishikawa, Y. Sasa, O. Benka,
and M. Uda: "High Charge Effects on
Electron Excitations in Metal Targets forAr12+ Impact Compared with Those for He 2 +Impact," 12th Int. Conf. Atomic Collisions
in Solids, Okayama, Oct. (1987).
64) E. Vagi, M. Iwaki, K. Tanaka, I. Hashimoto,and H. Yamaguchi: "Behaviour of Krypton
Atoms in Aluminium," 12th Int. Conf. Atomic
Collisions in Solids, Okayama, Oct. (1987).
65) E. Vagi, T. Kobayashi, S. Nakamura, F.
Kano, K. Watanabe, Y. Fukai, and T. Matsumoto: "Hydrogen Trapping by Substitutional
Impurities in NbMoo•o3 Alloys as Observedby the Channeling Method," 12th Int. Conf.
Atomic Collisions in Solids, Okayama, Oct.
(1987) .
66) S. Nakamura, E. Vagi, T. Osaka, and M.
Iwaki: "Lattice Disorder and Behavior of
Implanted Atoms III In-Implanted Ti0 2(Rutile) ," 12th Int. Conf. Atomic Collisions
in Solids, Okayama, Oct. (1987).
67) K. Kobayashi: "N Ion Beam Induced Recrystallization of AINx Films," 12th Int. Conf.
Atomic Collisions in Solids, Okayama, Oct.
(1987) .
68) Y. Awaya: "Measurements of REG X-rays
for 20.4 MeV lu Ar Ions on Be Target,"
RIKEN Symp. '8th .Symp. Atomic Collisions

by Using Accelerators, Int. Symp. Dynamic
Interactions of Charged Particles with Solids,'
Wako, Oct. (1987).
69) B. Sulik: "Simple Projectile and Target
Scaling in the Description of Multiple Ionization," RIKEN Symp. '8th Symp. Atomic
Collisions by Using Accelerators, Int. Symp.
Dynamic Interactions of Charged Particles
with Solids,' Wako, Oct. (1987).
70) T. Kambara: "Measurement of Impact Parameter Dependent Probabilities for K-Shell
Ionization in Ar-Ca and Ar-Cu Collisions,"
RIKEN Symp. '8th Symp. Atomic Collisions
by Using Accelerators, Int. Symp. Dynamic
Interactions of Charged Particles with Solids,'
Wako, Oct. (1987).
71) A. Koyama: "Energy Spectra of AI-LVV
Auger Electrons Induced by Grazing Angle
Incident Fast Heavy Ion Impact," RIKEN
Symp. '8th Symp. Atomic Collisions by Using
Accelerators, Int. Symp. Dynamic Interactions of Charged Particles with Solids,' Wako,
Oct. (1987).
72) K. Hino: "Theory of Relativistic Radiative
Electron Capture," RIKEN Symp. '8th Symp.
Atomic Collisions by Using Accelerators, Int.
Symp. Dynamic Interactions of Charged
Particles with Solids,' Wako, Oct. (1987).
73) I. Kohno: "Application of RIKEN 160 cm
Cyclotron," Int. Symp. Applications of Ion
Beams Produced by Small Accelerators,
Jinan, China, Oct. (1987).
74) K. Aono, M. Iwaki, and S. Namba: "Luminescence during Ion-Implantation into CaF 2,"
1987 Fall Meeting Jpn. Soc. Appl. Phys.,
Nagoya, Oct. (1987).
75) Y. Awaya: "Introduction of Some Experimental Proposals for RRC," RIKEN Symp.
Studies of Solid State Physics and Materials,
Atomic Processes, Nuclear Chemistry, andBiology and Medical Science by Using Ring
Cyclotron, Wako, Nov. (1987).
76) Y. Awaya: "On the Organization of NonNuclear Study Group at RRC," RIKEN
Symp. Studies of Solid State Physics andMaterials, Atomic Processes, Nuclear Chemistry, and Biology and Medical Science byUsing Ring Cyclotron, Wako, Nov. (1987).
77) Y. Kanai: "Beam Line and Facilities for
Studies of Atomic Physics at RRC," .RIKEN
Symp. Studies of Solid State Physics andMaterials, Atomic Processes, Nuclear Chemistry, and Biology and Medical Science byUsing Ring Cyclotron, Wako, Nov. (1987).
78) Y. Awaya: "The Test Experiment made at
RRC," RIKEN Symp. Studies of Solid State

270

Physics and Materials, Atomic Processes,
Nuclear Chemistry, and Biology and Medical
Science by Using Ring Cyclotron, Wako,
Nov. (1987).
79) T. Kambara and K. Ando: "Experiments at
RRC Planed by Atomic Processes Laboratory," RIKEN Symp. Studies of Solid State
Physics and Materials, Atomic Processes,
Nuclear Chemistry, and Biology and Medical
Science by U sing Ring Cyclotron, Wako,
Nov. (1987).
80) K. Nishiyama, H. Katsuragawa, T. Minowa,
S. Kawamura, H. Sonobe, M. Shimazu, andT. Inamura: "Resonance Ionization Spectroscopy with Laser Ablation," 1987 Fall Meeting Spect. Soc. Jpn., Kyoto, Nov. (1987).
81 ) T . Watanabe and K. Hino: "Photon Emission Processes Induced by Ion-Atom Collisions," Natl. Symp. Scattering Theory and
Its Applications, Culcatta, India, Dec. (1987).
82) T. Watanabe, A. Ohsaki, K. Nakanishi,
and K. Iguchi: "Classical-Trajectory Monte
Carlo Calculation for Collision Processes of
Coulomb-Interacting Three-Body Systems,"
Natl. Symp. Scattering Theory and Its Applications, Culcatta, India, Dec. (1987).
83) T. Watanabe: "Atomic Processes in X-Ray
Laser Development Research," Symp. Atomic
Collisions, Kalyani, India, Dec. (1987).
4. Radiochemistry, radiation chemistry, and radiation biology
1) T. Seguchi, T. Sasuga, W. Kawakami, M.
Hagiwara, I. Kohno, and H. Kamitsubo:"Proton Irradiation Effects on Organic
Polymers," 11 th Int. Conf. Cyclotrons andTheir Applications, Tokyo, Oct. (1986).
2) T. Takahashi, S. Konno, F. Yatagai, K.
Takahashi, Y. Takayanagi, T. Tabata, and
R. Ito: "Calculation of Dose around the
Trajectory of an Ion and Its Application (2) ,"34th Spring Meeting Jpn. Soc. Appl. Phys.,
Tokyo, Mar. (1987).
3) S. Ambe, T. Okada, and F. Ambe: "In situ
Emission M6ssbauer Spectra of 119Sb 5+ and
57C02+ Adsorbed on a-Fe20g with a MacroAmount of Sb 5 +," 54th Natl. Meeting Chern.
Soc. Jpn. (Spring), Tokyo, Apr. (1987).
4) T. Takahashi, F. Yatagai, T. Katayama, and
T. Kasuya: "Inactivation of B. subtilis Sporesby Heavy Ions Using Solid State Nuclear
Track Detectors," 5th Meeting Solid State
Nuclear Track Detectors, Tokyo, Apr. (1987).
5) K. Kimura, T. U eno, K. Kanai, T. Nishina,
A. Fundo, and M. Kataoka: "Decay Mea' surement of Sub ns Resolution of Photo-

emission Induced by Heavy-Ion Irradiation,"
42th Annu. Meeting-Phys. Soc. Jpn., Nagoya,
Apr. (1987).
6) T. Nozaki, Y. Itoh, and Q. Qiu: "Dissolutionof Hydrogen and Nitrogen in Silicon,'" Int.
Conf. Methods and Applications of Radioanalytical Chemistry, Conna, Hawaii, Apr.
(1987) .
7) F. Ambe, S. Ambe, and T. Okada: "Chemical States of 57C02+ and ,119Sb5+ on r-Fe20g
and NiFe204 Surfaces," 13th Int~ Hot Atom
Chemistry Symp., Yamanaka, May (1987).
8) S. Ambe, F. Ambe, T . Okada, 1. Tanaka,
S. Nasu, and F. E. Fujita: "M6ssbauer Studyof the Chemical States of 119Sn ~ 119Sb Electrodeposited on Gold Surface," 13th Int. Hot
Atom Chemistry Symp., Yamanaka, May(1987) .
9) K. Asai, F. Ambe, S. Ambe, T. Okada, and
H. Sekizawa: "TDPAC Studies of the AfterEffects of IHln ~ lllCd EC Decay in a-Fe20g
and Other Inorganic Compounds," 13th Int.
Hot Atom Chemistry Symp., Yamanaka, May(1987) .
10) K. Kimura: "Roles of Electronic Excited
States in Radiation Effect of Heavy Ions,"
3rd Semin. Radiation Chemistry, Tokyo, May(1987) .
11) K. Kimura: "High-Density Excitation by
Heavy Ions: Track-Depth Resolved Emission
Spectra and Decays along the Path of Ions
Impinged into Helium at 400 Torr and 5 K,"
3rd China-Jpn. Bilateral Symp. Radiation
Chemistry, Changchun, China, Jun. (1987).
12) I. Kaneko, K. Eguchi-Kasai, and K. Nakano:"Oxygen Effect on DNA Double Strand
Breaks in Human Melanoma Cells Induced
by Alpha Particles," 3rd Workshop Heavy
Charged Particles in Biology and Medicine,
Darmstadt, W. Germany, Jul. (1987).
13) I. Kaneko, K. Eguchi-Kasai, T. Takahashi,
T. Kosaka, and K. Nakano: "Beam Portand Irradiation Chamber of the RIKEN Ring
Cyclotron for Biological Samples," 3rd Workshop Heavy Charged Particles in Biology andMedicine, Darmstadt, W. Germany, Jul.
(1987) .
14) I. Kaneko, K. Eguchi-Kasai, and T. Takahashi: "Cell Biology at RIKEN Accelerator,"
3rd Workshop Heavy Charged Particles in
Biology and _Medicine, Darmstadt, W. Germany, Jul. (1987).
15) T. Takahashi, F. Yatagai, T. Katayama, I.
Kaneko, and ' T. Tabata: "Effect of Heavy
Ions on Microorganisms-Track 'Structure
Theories and Single ' Particle Experiment-,"

271

3rd Workshop Heavy Charged Particles in
Biology and Medicine, Darmstadt, W. Germany, JuI. (1987).
16) K. Kimura: "The dE/dx Dependence ofHigh-Density Excitation by Heavy-Ion, Studied by Track-Depth Resolved Emission
Spectra and Decay on Rare Gas," 8th Int.
Congr. Radiation Research, Edinburgh, U.K.,
Jul. (1987).
17) T. Takahashi, F. Yatagai, S. Konno, T.
Tabata, and R. Ito: "Calculation of Dosearound the Trajectory of an Ion and Its
Application, 8th Int. Congr. Radiation Research, Edinburgh, U.K., J ul. ( 1987) .
18) H. Kusuyama, K. Okada, T. Kawai, K.
Maeda, Y. Sasa, and M. U da: "Elemental
Analysis of Thinly Sliced Renal Cancer by
PIXE," 16th Annu. Meeting Soc. Trace
Metal Metabolism Research of Jpn., Tokyo,
Jui. (1987).
19) S. Ambe and F. Ambe: "Mossbauer Emission
Study of Recoil 119Sb and 119mTe Atoms afterp- and Alpha-Reactions in SnS and SnSe,"
Int. Conf. Applications of the Mossbauer
Effect, Melbourne, Aug. (1987).
20) K. Maeda, Y. Sasa, M. Maeda, H. Kusuyama, and M. Uda: "Application of PlXE
to Biological Materials in a Daily Life," 12th
Int. Symp. Hosei Univ., Application of Ionsin Material Science, Tokyo, Sep. (1987).
21) K. Kimura, N. Hamada, F. Imai, T. Nakamura, and T . Yoshida: "Simultaneous Measurement of Ion-Track Scintillation Using a
Bundle Fiber and One-Dimensional Photodetector," 1987 Fall Meeting Phys. Soc. Jpn.,
Sendai, Sep. (1987).
22) Y. Itoh, T. Nozaki, H. Fukushima, Y. Mochizuki, T. Masui, and T. Abe: "Diffusion
Constant of Nitrogen in Silicon Measured by
15N Activable Tracer Method," 48th Fall
Meeting Jpn. Soc. Appl. Phys., Nagoya, Sep.
(1987) .
23) T. Takahashi: "Biological Effects of HZEParticles," 1st Annu. Meeting Jpn. Phys. Soc.
BioI. Sci. in Space, Tokyo, Sep. (1987).
24) 1. Kaneko, K. Eguchi-Kasai, T. Kosako, A.
Maruhashi, and K. Nakano: "Oxygen Effectof a-Particles on Human Melanoma Cells,"
46th Annu. Meeting Jpn. Cancer Assoc.,
Tokyo, Sep. (1987).
.
25) S. Ambe, F. Ambe, T. Okada, and H. Sekizawa: "Emission Mossbauer Spectra of 151Gd
Adsorbed on YIG Surface," 31st Symp.
Radiochemistry, Fukuoka, Oct. (1987).
26) F. Ambe, S. Ambe, and T. Okada: '''In situ

and Ex situ Emi~'sion Mossbauer Spectra of
57C02+ and 119Sb5+ Adsorbed on r-Fe20g and
NiFe 20 4 Surfaces," 31st Symp. Radiochemistry, Fukuoka, Oct. (1987).
27) M. Aratani, M. Yanokura, 1. Sugai, and H.
Kato: "Heavy-Ion Probe Backscattering
Analysis Applied to the Study for Preparationof Self-Supporting Carbon Film," 31st Symp.
Radiochemistry, Fukuoka, Oct. (1987).
28) Y. Kob<;tyashi, M. Katada, H. Sano, T.
Okada, K. Asai, N. Sakai, S. Ambe, and F.
Ambe: "Mossbauer Spectroscopic Studies of
Ruthenium Compounds (II) ," 31st Symp.
Radiochemistry, Fukuoka, Oct. (1987).
29) S. Ambe: "Adsorption of No-Carrier-Added
119Sb5+ onto Metal Oxide " Surfaces," 31st
Symp. Radiochemistry, Fukuoka, Oct. (1987).
30) H. Kumagai, K. Eguchi, Y. Hatanaka, T.
Takahashi, 1. Kaneko, and T. Kanai: "Dosimetry at the Biology Course of RIKEN Ring
Cyclotron," 1987 Fall Meeting Jpn. Soc. App!.
Phys., Nagoya, Oct. (1987).
31) K. Kimura, T. Yoshida, N. Hamada, F.
Imai, and T. Nakamura: "Simultaneous
One-Dimensional Photo-Counting of Ion
Track Using a Bundle Fiber," 30th Conf.
Radiation Chemistry, Nagoya, Oct. (1987).
32) T. Sako, K. Sasaki, S. Imai, Y. Ohmura, Y.
Noguchi, S. Tazawa, Y. Itoh, and T. Nozaki:"Determination of Carbon and Boron in
GaAs," Annu. Meeting Anal. Chern. Soc.
Jpn., Kumamoto, Oct. (1987).
33) T. Takahashi, F. Yatagai, T. Katayama, and
1. Kaneko: "Biological Effects of Heavy
Charged Particles in Cosmic Rays and Experimental Programme of our Group," 46th
Space Environmental Monitoring Group
Meeting, Wako, Oct. (1987).
34) T. Takahashi, T. Katayama, F. Yatagai, S.
Konno, 1. Kaneko, T . .:Kasuya, T. Doke, and
H: Ohashi: "The Inactivation of Bacterial
Spores by a Single Heavy Ion and Preparation for Experiments in the Spacecraft," 30th
Annu. Meeting Jpn. Radiat. Res. Soc., Tokyo,
Dec. (1987).
35) K. Eguchi-Kasai, 1. Kaneko, T. Kosaka, K.
Nakano, and A. Maruhashi: "Effects of
Heavy Charged Particles on DNA in Mammalian Cells," 30th Annu. Meeting Jpn.
Radiat. Res. Soc., Tokyo, Dec. (1987).
36) T. Kosaka, 1. Kaneko, and K : Eguchi-Kasai:"Potentially Lethal Damage Sensitive toHypotonic Solution and DNA Double Strand
Breaks," 30th Annu. Meeting Jpn. Radiat.
Res. Soc., Tokyo, Dec. (1987).
.

272

VIII.

LIST OF OUTSIDE USERS AND THEIR THEMES(Jan.-Dec. 1987)
1)

H. Fukushima"Radiochemical Analysis of 160, 14N,
and l~C in Si Crystal and GaAs"

2) T. Hayashi and A. Ohnishi

Japan Chemical Analysis Center

Institute of Space and Astronautical Science"Radiation Damage of Cover Glassfor a Solar Cell"
3)

S. Yoshida"Radia tion Damage of GaAs
Solar Cells"

Mitsubishi Electric Co., Ltd.

4)

H. Ueyama"Radiation Damage of Si. Crystal Solar Cells"

Sharp Co., Ltd.

5)

M. Watanabe and K. Ueno
"Improvement of Thyristors byProton Irradiation

Fuji Electric Corporate R&D, Ltd.

6)

H. Akiyama"Improvement of Thyristors
by Proton Irradiation"

LSI Lab., Mitsubishi Electric Co., Ltd.

7)

T. Abe and K. Tomii"Improvement of Thyristors
by Proton Irradiation"

Semiconductor R&D Lab.,
Matsushita Electric Work Co., Ltd.

8)

K. Toriyama"Study of Single Event Upset in
Microprocessors by Bombarding
14N and 12C Particles"

Mitsubishi Electric Co., Ltd.

9)

T. Kikuchi and K. Yamazaki"Study of Single Event Upset in
Microprocessors by Bombarding
14N and 12Ne Particles"

Nippon Electric Co., Ltd.

10)

K. Yamamoto and I. Yoshii"Study of Single Event Upset in
Microprocessors by Bombarding
14N and 4°Ar"

Semiconductor R&D Lab., Toshiba Co., Ltd.

11)

Y. Fujita"Calibration of Space Environment:Monitor Carried on a Satellitewith Proton and a Particles"

Meisei Electric Co., Ltd.

12)

T. Suematsu"Effects of the Proton Irradiation
on Cable Materials"

Fujikura Co., Ltd.

273

IX.

LIST OF SEMINARS(Jan.-Dec. 1987)
1) Y. R. Shimizu, Kyushu Univ. (Fukuoka), 16
January"Recent Topics on High Spin Nuclear Structure"2) F.P. Calaprice, Prinston Univ. (U.S.A.), 22
January"Narrow Resonance Optical Pumping NMR
and Possible Searches for Nuclear Elastic
Dipole Moments"
3) M. Ieiri, Kyoto Univ. (Kyoto), 22 January"Polarimeter and Porarization Transfer in
Deuteron Break-up Reaction"4) H. Utsunomiya, Texas A & M Univ. (U.S.A.),
5 February"Width of the Fragment Momentum Distribution in Peripheral Nucleus-Nucleus Collisions"5) Z. Yizhong, Institute for Atomic Energy (China),
10 February"Semimicroscopic Optical Potential Based onSome Effective Interactions from Non-Relativistic to Relativistic"6) M. Namiki, Waseda Univ. (Tokyo), 10 March"Measurements in the Quantum Mechanics"
7) K. Valli, Univ. JyvaskyHi (Finland), 17 March"Gas Flow in Ion Guide"8) H. J. Mang, Tech. Univ. Munich (W. Germany),
24 March"RPA Calculations for the Low-Lying Collective States of 164Er"

13) M. Blann, Univ. California (U.S.A.), 27 April"Nuclear De-Excitation Processes Following
Heavy-Ion Collisions"14) T. Shibata, CERN (Switzerland), 28 April"Low Energy Anti-Proton Experiments by
LEAR"
15) J. P. Schiffer, Argonne National Lab. (U.S.A.),
30 April"Crystalline Beams"16) M. Nishimura, RCNP, Osaka Univ. (Osaka),.14 May"M 1 Form Factor in the Region of Low
Momentum Transfer"17) T. Marumori, Univ. Tsukuba (Ibaraki), 19 May"Theory of Large-Amplitude Collective Motions"18) Y. Masuda, KEK (Ibaraki), 2 June
"P and T Invariance in Nuclei - Experiments
Using Polarized Low Energy Neutron-"19) S. Iwasaki, Univ. Chiba (Chiba), 9 June
"Rotational Bands of Sn"20) O. Yamakawa, KEK (Ibaraki), 25 June
"Data Acquisition System for TOPAZ Detector"21) K. Koyama, Inst. of Space and Astronautical
Science (Tokyo), 30 June
"Formation of Elements in Space"

9) M. Fujiwara, RCNP, Osaka Univ. (Osaka), 7
April"New Interest in Nuclear Discrete States"

22) D. C. Hoffman, Univ. California (U.S.A.), 3
July"The LEAD to Explore the Region of
Neutron-Rich Heavy Element Isotopes"

10) Y. Terrien, CEN Saclay (France), 14 April"Inelastic Process in Intermediate NucleonNucleon Scattering"23) H. Togawa, Kyoto Univ. (Kyoto), 10 July
"Development of Data Acquisition System
Using Some Front-End Processors"

11)

J. Gosset, CEN Saclay (France), 14 April"Correlation Measurements of Intermediate
Heavy Ion Reaction by 47r-TPC Counter"12) A. Gelberg, Univ. Koln (W. Germany), 14 April"F -Spin Symmetry and Ml Transitions"24) J. Tanaka, Hitachi, Ltd.
"RF Power Source"(Tokyo), 10 July25) H. Nishimura, LBL (U.S.A.), 13 July
"Introduction to Particle Tracking for a
Synchrotron Radiation Source in the Next

274

Generation"26) H. Nishimura, LBL (U.S.A.)' 14 July
"Introduction to the Theory and Practice ofParticle Tracking"27) K. Koshigiri, Osaka Kyoiku Univ. (Osaka), 14
July"Nuclear f3-Decay and Axial Charge"
28) P. J. Nacher, Laboratoire de Physique de l'ENS(France), 17 July
"Polarizing 3He Nuclei by Laser Optical
Pumping"29) H. Nishimura, LBL (U.S.A.), 20 July
"Advance Light Source Project at LBL"
30) Y. Hirata, Kitasato Univ. (Tokyo), 24 July

"Soliton-Antisoliton Pair Creation in Strong
External Fields"

31) S. Lunardi, Univ. Padova (Italy), 4 September"Shape Coexistence at High Spin in the N =78 Nuclei 140S m and 142Gd"
32) Y. Fujia, Fudan Univ. (China), 8 September"Scientific Activity at Fudan Univ. and Institute of Nuclear Research Shanghai"33) T. Kamei, Univ. Tsukuba (Ibaraki), 9 Sep-

tember"On the Accelerators"

Linear Accelelator"
36) P. G. Hansen, Aarhus Univ.

(Denmark), 21
September"Nuclei Far From Stability: Past, Present andFuture"37) H. Hofmann, Tech. Univ. Munich (W. Germany) , 22 October"On a Nucler Transport Theory for Slow
Collective Motion"38) M. Ichimura, Univ. Tokyo
October"Excitation of T-(}' Modes
Scattering"(Tokyo) ,In

27Quasi-Free

39) M. Matsuzaki, Kyoto Univ. (Kyoto), 5
November"Triaxial Deformation and Electromagnetic
Transitions at High Spin"40) K. Hirata, KEK (Ibaraki), 6 November"Introduction to Beam Tracking"41) K. Nomoto, Univ. Tokyo (Tokyo), 24 November"Supernova and Formation of Heavy Elements"42) H. Duohui, Univ. Sci. Tech. (Hefei China), 30
November"Status of HESYRL Project"34) Y. Yamazaki, KEK (Ibaraki), 9 September"RF System of KEK PF and TRISTAN"

43) T. Kobari, Hitachi, Ltd. (Ibaraki), 10 December"Photon-Stimulated Desorption from Vacuum
Chamber"35) K. Satoh, Tokyo Inst. Techno!. (Tokyo), 11
September"Electromagnetic Characteristics of I-H Type44 ) H. Aiba, Kyoto U niv. (Kyoto), 16 December"Microscopic Description of Large-Amplitude
Quadrupole Motions"

275

x.

LIST OF PERSONNEL

Members of the Board
AMBE Fumitoshi 1i. -$ )( ~CHIBA Yoshiaki =f ~ tff ~INAMURA Takashi W;fJ 1iI
KAMITSUBO Hiromichi 1: if ~ :Ill
KATSUMATA Koichi ·mJ R ~ KOHNO Isao . fiiJ my :c)jrJ

MATSUOKA Masaru~ . Mj
SAKURAI Akira 1k #IDG
T AKAMI Michio ~ J! :Ill !£WATANABE Tsutomu ~ -$ jJ

AWAYA Yohko ~ §[?j;. T
HASHIZUME Akira m J1\ M
ISHIHARA Masayasu :tl 1* iE ~*KANEKO Ichiro ~ T - R~
KIRA Akira 5" ~ ~KURIHARA Osamu ~ 1* f~
NAKAMINE Kanetada '71< ~ ~ J~
TABATA Yoshio EEl ~ am
TANIHATA Isao :& ~ ~x* Chairman

Cyclotron Operation and Maintenance GroupFU JIT A Shin Hi EEl
fT
KAGEYAMA Tadashi ~ rl!
KOHNO Isao fiiJ my :r:}j
T AKEBE Hideki lEt -$ ~ ut

iE

IKEGAMI Kumio ~1:fL,=:::!Jj
KOHARA Shigeo ;j\ 1* m: x
OGIWARA Kiyoshi ~ 1* m

Linac Operation and Maintenance GroupCHIBA Yoshiaki =f ~ tff ~IKEZAWA Eiji ~ ~ ~KAMBARA Tadashi :f$ 1*

iE

KUBO Toshiyuki 0...1* ~YANOKURA Minoru ~my~

~

=-

*

HEMMI Masatake ~ J% i:& lEt
INOUE Toshihiko # 1: ~ Jft
KASE Masa yuki tID mi I§ Z.
MIYAZAWAYoshitoshi '§ ~ 1* ~Scientific and Engineering Personnel

Cosmic Ray Laboratory
IMAI Takashi A, #MUNAKATA Kazuoki~* - lEa

KOHNO Tsuyoshi~(Visitors)
HASEBE Nobuyuki ~:B--${~rr (Fac. Gen. Educ., Ehime Univ.)
MURAKAMI Hiroyuki ;fJ J:. ~ Z. (Fac. Sci., Rikkyo Univ.)
NAGATA Katsuaki 71< EEl mJ ~ (Fac. Eng., Tamagawa Univ.)
NAKAMOTO Atsusi cP;$: i!jI (Fac. Sci., Rikkyo Univ.)
Y ANAGIMACHI Tomoki tpp oo:r M fM (Fac. Sci., Rikkyo Univ.)

fiiJ myfi276(Student)* flJ it-KASHIWAGI Toshisuke ~B

Cyclotron Laboratory
BE Suck Hee ~ m:j:-=

FU JITA Jiro Hi ffi
a~
GOTO Akira 1& Hi :It
HATANAKA Kichiji mr:p E r#1
INAMURA Takashi m M .$:.
KAMITSUBO Hiromichi 1::P/Z 7.t. :@:KOHARA Shigeo IJ\ N{
:;k:.

m:

MATSUO Masayuki rl ~ 1£ Z
MOT ONAGA Shoshichi jC 7k IlB -f:;
NAGASE Makoto ~ Mi ~NAKANISHI Noriyoshi r:p iffi ~ :j:
SAITO Motozo fir Hi M =:SHIKATA Takashi [9 1f ~ ~T AKEBE Hideki JEt $ 51: W
TOYAMA Mitsuru :Ill rb
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FU JISAWA Takashi Hi R ~ ;E
FU JIT A Shin Hi ffi~
HARA Masahiro N{
ME ']1IKEGAMI Kumio itH1:ft=:~
KAGEYAMA Tadashi ~ rb
KARASA W A Takashi n!f?R
KOHNO Isao iEJ!f ;rj]
MORITA Kosuke ~ ffi ;'i5- it-

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SHIMIZU Kazuo m- 7k ;m ~T AKESHIT A Isao 'It r ~ :;k:.
W ADA Takeshi ;ru ffifit
Y ANO Yasushige *!f *-m:

Y AMAJI Shuhei U-J ~ 1~ -¥YOKOYAMA Ichiro 1t U-J -a~(Visitors)
ANAYAMA Hiroshi /t rbj}l (Reliability Cent. for Electronic Components of Japan)
CHOE Byung-Ha 1m~ (KAIST, Korea)
EGUCHI-KASAI Kiyomi iI tJ (~it) 1W~ (Inst. Basic Med. Sci., Univ. Tsukuba)
EJIRI Hiroyasu IT JJL 7R ~ (Dep. Phys., Osaka Univ.)m*

FUKUMOTO Sadayoshi :m
Ji ~ (KEK)
FURUNO Kohei r5!f ~ ijZ (Inst. Phys. Tandem Accel. Cent., Univ. Tsukuba)*

GOKA Tateo l i~:;k:. (NASDA)
HARADA Kichinosuke N{ ffiaZM (Nippon Energy K.K.)
HARADA Minoru N{ ffi~ (Reliability Cent. for Electronic Components of Japan)
HA Y ASH I Nobuyuki
1$ 1'1 (Electro Tech. Lab.)HIRAKI Akio ijZ
1lB:;k:. (Fac. Eng., Osaka Univ.)
IKEGAMI Hidetsugu ifu 1:
Jm. (RCNP, Osaka Univ.)
INOUE Makoto it 1: 1~ (RCNP, Osaka Univ.)
ISOYA Akira ~ *. :It (Sch. Sci., Tokai Univ.)

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IWAMOTO Akira :6
IlB (Japan Atomic Energy Res. Inst.)
IWASHITA Yoshihisa :6 r 7f!A. (Inst. Chern. Res., Kyoto Univ.)
KADOYA Shingo %3 *. ~ tf (Japan Gasoline Co.)
KANEKO Kumetaro ~.:r~*a~ (Inst. Nucl. Study, Univ. Tokyo)
KASAl Shunichi iEJ iffi ~ - (Japan Atomic Energy Res. Inst.)
KATORI Kenji J.m ~ ~(Dep. Phys., Osaka Univ.)
KATSURAGAWA Hidetsugu f!]I[ ~ IffiiiJ (Dep. Phys., Toho Univ.)
KIKUCHI Fumio *i:lfu Jt:!15 (ColI. Arts Sci., Univ. Tokyo)
KOBAYASHI Shinsaku IJ\
Jfi fi: (Dep. Phys., Kyoto Univ.)
KOHMOTO Susumu 1ilJ
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277

KONDO Michiya ;cr Hi :@: {g (RCNP, Osaka Univ.)
KOSAKO Toshiso IJ\%:"i!ifiiT± (Atomic Energy Res. Cent., Univ. Tokyo)
KOWATA Mitsuyoshi /J\ *~:J't.:g: (Reliability Cent. for Electronic Components of Japan)
KUDO Hisaaki I Hi 0... liB (Dep. Chern., Niigata Univ.)
KUSAKA Takuya B r .$: {g (Kobe Steel, Ltd.)MALLIK Chaturanan (V.E.G. Cent., B.A.R.C., India)*

MATSUKI Seishi *'1
liE 5t: (Inst. Chern. Res., Kyoto Univ.)
MINOWA Tatsuya ~ ~ it ·~ (Dep. Phys., Toho Univ.)
MIURA Iwao .:::. 00 E (RCNP, Osaka Univ.)
MIYAOE Hiroki '§ ili
ife (Sumitomo Heavy Ind., Ltd.)MIYATAKE Hiroari g it f: {g (Fac. Sci., Osaka Univ.)**

MORIMOTO Yoshihide ~{t ~ (Kobe Steel, Ltd.)MORIO Atsuo ~ ~ ~:;R (Reliability Cent. for Electronic Components of Japan)
MURAYAMA Toshiyuki tt rlt flJ ¥ (Tokyo Univ. Mercantile Marine)
NAGAMIYA Shoji 7k g 1£ t€t (Oep. Phys., Univ. Tokyo)
NAKAHARA Hiromichi cp]Jj{ ~L:®: (Oep. Chern., Tokyo Metropolitan Univ.)=

NAKAI Koji tp # ~(KEK)
NAKAJIMA Kazuhisa cp ~ - 0... (KEK)
NAKAMURA Shinya cp tt I~ {g (Reliability Cent. for Electronic Components of Japan)
NAKAMURA Takashi cp tt f<!;] 'PJ (Cyclotron Radioisot. Cent., Tohoku Univ.)
NOMURA Toru mr tt 7* (lnst. Nucl. Study, Univ. Tokyo)
NONAKA Hideki mr cp ~ ~ (Sumitomo Heavy Ind., Ltd.)ODERA Masatoshi /J\ {f 1£ ~* (Sci. Eng. Res. Lab., Waseda Univ.)
ONISHI Naoki~ mr ~ (Dep. Phys., ColI. Gen. Educ., Univ. Tokyo)
OT A Shigemi ::k EEl~ (KEK)
SAKAMOTO Hiroyuki :liZ
i'* ¥ (Ishikawajima-Harima Heavy Ind., Co., Ltd.)SAKAMOTO Isao ~~ (Electro Tech. Lab.)SAKURADA Yuzo ~ EEl ~.:::. (ULV AC Co.)

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SASUGA T .suneo 1t't.g ~ (Japan Atomic Energy Res. Inst.)
SATO Kenichi %: Ji ~ - (Oiv. Phys., Tohoku ColI. Pharm.)
SHIMANO Yosuke ~ mr ¥¥= 1t- (NASOA)SHIMAZU Mitsuyoshi ~ &t V; ~ (Oep. Phys., Toho Univ.)
SHINOZUKA Tsutomu 1II:f% ~ (Cyclotron Radioisot. Cent., Tohoku Univ.)
SHIRAISHI Haruki B E ~ ~ (Natl. Res. Inst. Metals)**

SUEKI Keisuke
Ff§ 1t- (Inst. Nucl. Study, Univ. Tokyo)
SUNAGA Hiromi ~ 7k ~ ~ (Japan Atomic Energy Res. Inst.)
TAKEGOSHI Hidekuni ¥r J1f ~ n (lnst. Chern. Res., Kyoto Univ.)
TAKEMASA Tadashi it i& j't ± (Oep. Phys., Saga Univ.)*

TAKIGAWA Noboru nt]l[
COep. Phys., Tohnku Univ.)
TAMAGAKI Ryozo 3S.:@: ~.:::. (Oep. Phys., Kyoto Univ.)
TANAKA Hitoshi EEl cp
jSj (Japan Gasoline Co.)TANAKA Jinichi EEl cp t m (Inst. Nucl. Study, Univ. Tokyo)
TANAKA Koki EEl cp ¥ £ (Nippon Steel Corp.)
TASAKA Shigeki ffi ~ ~;W (Fac. Educ., Gifu Univ.)
TOMIMASU Takio ~Jt~.:g::;R (Electro Tech. Lab.)TORIZUKA Kanji ,~~ ~ ~ (Fac. Med., Kyoto Univ.)
TSUKIJI Masaru ~:Ifu 11 (NEC Corp.)
TSUMAKI Koji~

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278

TSUNEMOTO Hiroshi tg 5C Pi (Natl. Inst. Radiol. Sci.)
VALLI Kalevi (Oep. Phys., Jyvaskyla Univ., Finland)
WAKISHIMA Susumu ' .IMb &Ii~ (Reliability Cent. for Electronic Components of Japan)
WANG Zhen (Inst. Mod. Phys., Acad. Sin. , China)
WATANABE Hiroshi *~ ffrIJ Pi it (Electro Tech. Lab.)YAMASU Kazushige ~~ ~ fI] m: (Mitsubishi Heavy Ind., Ltd.)YAMAZAKI Takashi 0-J dfflJ l* (RCNP, Osaka Univ.)
YOKOUCHI Shigeru :tl Ji'ga (Osaka Vacuum, Ltd.)YOSHIOA Katsuhisa
EEl R: ~ (Mitsubishi Electric, Co.)YOSHIDA Nobuaki a EEl(Oep. Phys., Univ. Tokyo)

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YOSHIDA Shiro
EEl If[f}~ ~~ (Dep. Phys., Tohoku Univ.)
YOSHINAGA Naotaka B 7k j11;1 $ . (Comput. Cent., Univ. Tokyo)
YOSHlYUKI Takeshi
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* Visiting Professor(Students)'*

ARAI Toshiyuki ~:#- flj(Fac. Sci., Toho Univ.)
HARAOA Hideo JJR EEl ~ ~~ (Oep. Phys., Tokyo Inst. Technol.)
KASAHARA Tatsuya ~ JJR ~ fu (Fac. Sci. Eng., .Chuo Univ.)
KAWASAKI Noriko }II ~ *C -r (ColI. Hum. Sci., Nihon Univ.)
KOIKE Yuji /J\ 7m 1% J§j (Oep. Phys., Univ. Tokyo)
KOJIMA Toshiyuki /J\ &Ii ~ Z. (Fac. Sci. Eng., Chuo Univ.)
YAMAGISHI Yoshinori ili J¥ ~ qffJ.t (Fac. Sci. Eng., Chuo Univ.)
YOSHIDA Minoru a EEl~ (ColI. Hum. Sci., Nihon Univ.)

Linear Accelerator Laboratory
CIDBA Toshiya =f- ~ flj iilt
HEMMI Masatake ~ 5! i!& lit
KAMBARA Tadashi fiji JJR 1£'*

KUBO Toshiyuki ~ 1* fit;:
MIYAZAW A Yoshitoshi '§ iR. 1* fit;:*

SUZUKI Takeshi ~~TANIHATA Isao ~ m~ ~YANOKURA Minoru 9i;:!f~

CIDBA Yoshiaki =f- ~ ff ~INOUE Toshihiko if 1: fit;: ~KASE Masa yuki 110 llm l§ Z
KUMAGAI Hidekazu ff~ ~ ~ fI]
NAKAGAWA Takahide $}II $ ~'*TAKEUCHI Sachiko ¥r Pi-r
TONUMA Tadao ? 7f1 1£ 14~(Visitors)
FUJIWARA Ichiro Hi JJR - ~~ (Inst. Atomic Energy, Kyoto Univ.)
ITO Noriaki {Jt Hi ~ at3 (Oep. Cryst. Mater., Nagoya Univ.)
KIKUCHI Jun *i:l:fu JIJ: (Sci. Eng. Res. Lab., Waseda Univ.)
LIU Wei Ping l!lP .:z. ~ (Inst. Atomic Energy, China)
NONAKA Hideki !l!f tj::J ~ ~ (Sumitomo Heavy Ind., Ltd.)SUGAW ARA Masahiko 13' JJR l§ ~ (Fundam. Sci., Chiba Inst. Technol.)
YAMAGUCHI Hiromi 0-J IJ fa ~ (Sci. Eng. Res. Lab., Waseda Univ.)(Student)
FUKUDA Mitsunori fi EEl j1t JIJ: (Fac. Sci., Tokyo Inst. Technol.)
ITO Tatsuya {Jt Hi ~ fu (Sci. Eng. Res. Lab., Waseda Univ.)

279

Radiation Laboratory
ASAHI Koichiro M fJf~ ~~HASHIZUME Akira ~ JR M
ISHIHARA Masayasu E l* lE ~KONNO Satoshi ~!f . ~TENDO Y oshihiko 7( jE! =Jj jffj

GONO Yasuyuki ~R~" ~ Z
ICHIHARA Takashi rtf 1* ~IZUMO Koichi ill ~ Jlt ~TAKAHASHI Tan ~ ~ .§.

(Visitors)
ABE Yasuhisa IlPJ $ ~ 0... (Res. Inst. Fundam, Phys., Kyoto Univ.)
ADACHI Minoru JE 1L Jf (Dep. App!. Phys., Tokyo Inst. Technol.)
ANDO Yoshiaki Ji. Hi & ~ (Oep. Phys., Rikkyo Univ.)*

DOKE Tadayoshi jE!
J~ ~ (Sci. Eng. Res. Lab., Waseda Univ.)
ENDO Saburo ~:iii =: ~~ (Fac. Eng., Sci. Univ. Tokyo)
FUJIOKA Manabu Hi ~~ (Oep. Phys., Tohoku Univ.)
HAMA Hiroyuki ~ rt. $ (Dep. Phys., Tokyo Inst. Technol.)
HASEGAWA Takeo ~~JII:lit~ (Inst. Nucl. Study, Univ. Tokyo)
HITACHI Akira A ill~ (Sci. Eng. Res. Lab., Waseda Univ.)
ICHIMURA Munetake rtf M *:lit (ColI. Gen. Educ., Univ. Tokyo)
IEKI Kazuo~ fIJ ~ (Fac. Sci., Rikkyo Univ.)
KASAGI Jirota 12:*~ ~~-* (Fac. Sci., Tokyo Inst. Technol.)
KATO Norihisa
Hi tr 0... (Oep. Phys., Kyushu Univ.)
KATO Seigo
Hi D l§- (Fac. Lib. Arts, Yamagata Univ.)
KATORI Kenji 00 !IX ~(Fac. Sci., Osaka Univ.)
KAWAKAMI Hirokane }I[ 1: ~ ~ (lnst. Nucl. Study, Univ. Tokyo)
KITAO Kensuke *~ ~ l! M (Nat!. Inst. Radio!. Sci.)
0... 1~ (Fac. Eng., Saitama Univ.)
KOBAYASHI Hisanobu 1]\
KOHNO Toshiyuki %.f!f ~ Z (Nat!. Inst. Radiol. Sci.)
KUBONO Sigeru 0...i*!f J:t (Inst. Nucl. Study, Univ. Tokyo)
KUBOTA Shinzou ~ E8 1~ -=: (Fac. Sci., Rikkyo Univ.)
KUSAKARI Hideshige 1jt XU ~ ~ (Fac. Educ., Chiba Univ.)

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LEE Sang Mu
if§(Inst. Phys., Univ. Tsukuba)
MASUDA Kimiaki it E8 0- I!I:J (Sch. Sci. Eng., Waseda Univ.)
MOTOBAYASHI Tohru ;$:~ (Fac. Sci., Rikkyo Univ.)
MURAKAMI Takeshi M 1: {@ (Oep. Phys., Tokyo Inst. Technol.)NAGAI Yasuki 7J< it ~ W (Fac. Sci., Tokyo Inst. Technol.)**NAGASHIMA Yasuo ~ l¥b ~ ~ (Oep. Phys., Univ. Tsukuba)
NAKAYAMA Shintarou r:p 1.D1~-*~~ (ColI. Gen. Educ., Univ. Tokushima)*- rB Ii (Fac. Sci., Tokyo Inst. Technol.)
OHSUMI Hideaki *- ~I~ ~ ~ (Fac. Sci., Osaka Univ.)
OHNUMA Hajime

ORIHARA Hikonojo ~l*jffjZ]g (Cyclotron and Radioisot. Cent., Tohoku Univ.)
OYAIZU Mitsuhiro I]\WP~3trt. (Inst. Nucl. Study, Univ. Tokyo)
RUAN (GEN) Jian-zhi ~ j! ~ (Oep. Phys., Rikkyo Univ.)
SAKAGUCHI Harutaka iJj D ~ ~ (Oep. Phys., Kyoto Univ.)
SHIBAMURA Eido ~ M ~ jE! (Saitama ColI. Health)
SHIMIZU Hajime ~ 71< •(Fac. Sci., Tokyo Inst. Technol.)=

SHIRATO Shoji B ± i'}(Oep. Phys., Rikkyo Univ.)
SUGAWARA Masahiko ~ ~ l§ jffj (Fundam. Sci., Chiba Inst. Technol.)
TAKAHASHI Noriaki ~ ~ l! I!I:J (ColI. Gen. Educ., Osaka Univ.)

280

TAKIGAWA Noboru¥f (Oep. Phys., Tohoku Univ.)~}II

TOKI Hiroshi ± ~ -M (Oep. Phys., Tokyo Metropolitan Univ.)
YAMAYA Takashi ili ~~ (Oep. Phys., Tohoku Univ.)
YASUE Masaharu !i. i[ 1£ tti (Inst. Nucl. Study, Univ. Tokyo)
YOSHIZAWA Yasukazu E ~ Eft fIJ (Oep. Phys., Hiroshima Univ.)(Students)
ASHIKAGA Kinya JE flJ ffX ijJt (Sch. Sci. Eng., Waseda Univ.)
FUJIWARA Hideaki Bi @: ~ ~ (lnst. Phys., Univ. Tsukuba)
FUKUDA Mitsunori m ill .yc JINi (Fac. Sci., Tokyo Inst. Technol.)
FUNATSU Yoshinori Wc~ it ~ tw. (Fac. Sci., Kyushu Univ.)
HWANG Han YuH 1t ~ 'I:#. (Oep. Phys., Yonsei Univ., Korea)
ICHINOSE Hideo mz;U~;fi;: (Grad. Sch. Sci. Eng., Waseda Univ.)
ITO Tatsuya W jfi ~ ii1 (Grad. Sch. Sci. Eng., Waseda Univ.)*

IWASA Naohito E~ t(Oep. Phys., Rikkyo Univ.)
JEONG S. C. I) ~ Mt (Inst. Phys., Univ. Tsukuba)
KOGUCHI Masanari r,§ij Q Jt p.x (Oep. Appl. Phys., Tokyo Inst. Technol.)
MIZOTA Takeshi ~ ill ftt ~ (Inst. Phys., Univ. Tsukuba)
OGIWARA Masahiro @( @: 1£ j.f. (Oep. Phys., Rikkyo Uiv.)
OGIWARA Mitsuhiko @( @: .yc ~ (Inst. Phys., Univ. Tsukuba)
OKUMURA Susumu ~ N
j1g (Inst. Phys., Univ. Tsukuba)
OKUMURA Yasuaki ~ N ~ ~ (Sch. Sci. Eng., Waseda Univ.)
ONO Yoichi Ij\ Jf IWi (Fac. Educ., Chiba Univ.)
PU Y. H. rm~ m (Inst. Phys., Univ. Tsukuba)
SAKURAI Mikio ~ if # ~ (Oep. Phys., Tokyo Inst. Technol.)
SANO Toshio fie Jf ~ ~ (Grad. Sch. Sci. Eng., Waseda Univ.)
SHIBUYA Shinji ~:fr ~(Oep. Phys., Rikkyo Univ.)=*

TAKEUCHI Hiroki 'rT pEj 'it.
(Oep. Phys., Tokyo Inst. Technol.)
TAMURA Akitoshi ill;ft ~ if<: (Grad. Sch. O-okayama, Tokyo Inst. Technol.)
UTSUMI Motoharu pEj ifij !at 5C (Grad. Sch. Sci. Eng., Waseda Univ.)
YOSHIDA Koichi 15 ffi .yc - (Fac. Sci., Tokyo Inst. Techno!.)Atomic Processes Laboratory
ANOO Kozo !i. Iii )lGJIJ .=:HINO Kenichi B Jf ~ KANAI Yasuyuki ~ if 1* Z
SHIMAMURA Isao fib ift ~AWAYA Yohko ~ ~?&-=f
KAMBARA Tadashi :f$ @: 1£
NISHIDA Masami ~ ill Jt ~WATANABE Tsutomu ?1t $11(Visitors)
FUJIMA Kazumi Iii FdJ - ~ (Oep. Phys., Chuo Univ.)
HARA Shunsuke @:~ 1l- (Oep. Phys., Univ. Tsukuba)
HITACHI Akira jJ t/j•(lnst. Sci. Technol., Waseda Univ.)
ISHII Keishi -.:ci if It Z (Dep. Eng. Sci., Kyoto Univ.)
ISOZUMI Yasuhito .li+;f:t~A (Radioisot. Res. Cent., Kyoto Univ.)
ITO Shin W jfi •(Radioisot. Res. Cent., Kyoto Univ.)*

ITOH Yoh W~ (Fac. Sci., Josai Univ.)
IWAI Masahiro E # 1£ -M (Theor. Oiv., Inst. Mol. Sci.)

281

KARASHIMA Shosuke
KAWATSURA Kiyoshi
KIMURA Mineo
KOIKE Fumihiro
KOIZUMI Tetsuo
KOYAMA Naoto
KUROKI Kenro
LIU Bing ~ll~ Nb Jffi 1t-}II TIij* M *"

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(Oep. Electron. Eng., Tokyo Univ. Sci.)(japan Atomic Energy Res. Inst.)(Argonne Natl. Lab.)IJ\ jtg )( tf(Sch. Med., Kitasato Univ.)
IJ\ 7'R tf 7:.
(Oep. Phys., Rikkyo Univ.)
IJ\ U-t U[ A.
(Oep. Eng. Phys., Univ. Electro-Commun.)~(Natl. Res. Inst. Police Sci.)b:k (lnst. Mod. Phys., Acad. Sin., China)
MATSUO Takashi fl ~(Oep. Pathol., Tokyo Med. Oent. Univ.)
MATSUZAWA Michio fl ~ jj ~ (Oep. Eng. Phys., Univ. Electro-Commun.)*'

MIZOGAWA Tatsumi~}II ~ 8(Fac. Sci., Saitama Univ.)

MUKHERJEE Sunil Chandra (Oep. Theor. Phys., Indian Assoc. for Cultiv. Sci.)
OHSAKI Akihiko -)( dffij ~ jfg (Inst. Mol. Sci.)
OHTANI Shunsuke -}(:fr ~ 1r (Inst. Plasma Phys., Nagoya Univ.)
OKUNO Kazuhiko ~ If ;fIJ jfg (Oep. Phys., Tokyo Metropolitan Univ.)
SATO Hiroshi f&: Hi r-5.se. (Oep. Phys., Ochanomizu Univ.)
SATO Kupinori f&: Hi m ~ (Inst. Plasma Phys., Nagoya Univ.)
SCHUCH Reinhold (Oak Ridge Natl. Lab.)m

SHIBATA Hiromi ~ B3
~ (Res. Cent. Nucl. Sci. Technol., Univ. Tokyo)
SHIMA Kunihiro Nb
tf (Tandem Accel. Cent., Univ. Tsukuba)
SHIMAKURA Noriyuki Nb ~ *G Z (Gen. Educ. Oep., Niigata Univ.)
STOLTERFOHT Nikolaus (Hahn-Meitner-Inst. Kernforschung, Berlin)
SULIK Bela (Inst. Nuc!. Res., Hung. Acad. Sci. (A TOMKI):m~ AKAGI Shoji~* tf: 5f\

(Oep. Phys., Toho Univ.)
TAWARA Hiroyuki ~~ Z(Inst. Plasma Phys., Nagoya Univ.)
TSURUBUCHI Seiji b mfI ~(Fac. Technol., Tokyo Univ. Agric. Technol.)=

URAKAWA Junji 1m}ll JINt ~ (Natl. Lab. High Energy Phys.)
VOGT Hans G. (Phys. Inst., Univ. Heidelberg)
WHELAN Colm T. (Univ. ColI. London)
YAMAZAKI Yasunori U-t dffij ~(Res. Lab. Nucl. Reactor, Tokyo Inst. Technol.)m(Student)
NISHIMURA Hisashi g§ M

!A (Oep. Phys., Tokai Univ.)

Metal Physics Laboratory
ISHIOA Katsuhiko "E B3 Mf ~MATSUZAKI Teiichiro fldffijtJnlJH~
SHIOT ANI Nobuhiro ~ ~ Ef 5.b.

KOYAMA Akio Ij\ U-t lIB 14f
NAG AMINE Kanetada 7k ~ ~ ,1fB.
Y AGI Eiichi

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ISHIKAWA Hiroshi "E}II
r-5 (Fac. Sci., Sci. Univ. Tokyo)
KANO Fumihisa ~ If )( ~ (Sch. Sci. Eng., Waseda Univ.)
NAKAMURA Shiho cP M ~ 1* (Sch. Sci. Eng., Waseda Univ.)

Magnetic Materials Labora tory
ASAI Kichizo

13t it E ~OKAOA Takuya

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282

SAKAI Nobuhiko#j if f§" ~(Visitor)
IllEB~Mi~

YAMADAYA Tokio(Fac. Lit. Sci., Yokohama City Univ.)(Student)
TOBA Yoshikazu~ 3]:J .B! ~(Fac. Sci., Toho Univ.)

Plasma Physics Laboratory
ISHIBE Yukio -:& $ IT tit
OKAZAKI Kiyohiko fM:I~~.l:tit
SAKAMOTO Yuichi#j

ISHII Shigeyuki -:& if IDG IT*OYAMA Hitoshi
III ~Y ANO Katsuki *-!I!f JlJ §* tit-(Visitors)
SUGIYAMA Kazuo ~ III ~ ~ (Fac. Eng., Saitama Univ.)
YAMASHINA Toshiro III f4 ~ fl~ (Fac. Eng., Hokkaido Univ.)

Semiconductor Laboratory(Visitor)
AONO Keiko'Ff!f if! -:r (ColI. Lib. Arts, Kitasato Univ.)

Inorganic Chemistry Laboratory
DAI Yisheng it~!:E (Inst. Opt. Electron., Acad. Sin., China)

Solid-State Chemistry Laboratory
KOBA YASHI Masayoshi 1]\
SASA Yoshihiko {£ /.{ ~ ~

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MAEDA Kuniko ;ru EB n T
T AKAMI Michio ~ J! ~ ~(Visitors)
ISHII Keizo-:& if ~ ~ (Cyclotron Radioisot. Cent., Tohoku Univ.)
KUSUYAMA Hiroyuki ~ Ib s1,. Z (Saitama Med. Sch.)MUKOUYAMA Takashi n:u III ~ (In st. Chern. Res., Kyoto Univ.)
UDA Masayuki f= IE ~ Z. (Dep. Mater. Sci., Waseda Univ.)(Student)
MAEDA Haruka ;WEB,;t iO) (Dep. Eng., Tokyo Univ.)~

Radiochemistry Laboratory
AMBE Fumitoshi Ji. =$ )( ~ARATANI Michi
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IWAMOTO Masako
OHKUBO Yoshitaka:E-* lE -:r*0.f*~~AMBE Shizuko

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ITOH Yoshiko W J!j T
NOZAKI Tadashi !I!f ~ lE

283

(Visitors)
ENDO Kazutoyo :ii Hi ru ~ (Fac. Sci., Tokyo Metropolitan Univ.)
FUKUSHIMA Hiroto m~~ i* A (Japan Chemical Analysis Cent.)
IMAI Masato A, # 1£ A (Komatsu Electronic Metals Co., Ltd.)IMURA Ryo #;ft(Cent. Res. Lab., Hitachi, Ltd.)KATADA Motomi J='r IE :JG B (Fac. Sci., Tokyo Metropolitan Univ.)
KATO Hajime 110 Hi - (Fac. Educ., Yamanashi Univ.)
KIMURA Toshimasa *;ft ~ 1£ (Japan Chemical Analysis Cent.)
MOCHIZUKI Yasuhiro .i!)j51 (Hitachi, Ltd.)OOHIRA Shigeo *- ¥ !fi::!J3 (Nikkei Techno Res. Co., Ltd.)SAITO Kazuo
Hi ;fO ~ (Toshiba Corp., R&D Cent.)
SVEHIRO Makiko
rt. !&. -r (Tokyo Metropolitan Geriatric Hospital)
SUGAI Isao "1Jf #~ (Inst. Nucl. Study, Univ. Tokyo)
SUZUKI Ryo ~.5!. (Cent. Res. Lab., Hitachi, Ltd.)WATANABE Yasuo IN ill.
~ (Fac. Sci., Tokyo Metropolitan Univ.)YATSVRUGI Yoshifumi I\, 9W E X (Komatsu Electronic Metals Co., Ltd.)

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KOBAYASHI Yoshio /J\~:!J3 (Fac. Sci., Tokyo Metropolitan Univ.)
KUBO Kenya !A 1* ~ ~ (Fac. Sci., Univ. Tokyo)
QUI Qi 1i:~n (Res. Lab. Nucl. React., Tokyo Inst. Technol.)
YU Byon Gon 1f.r
1$ (Res. Lab. Nucl. React., Tokyo Inst. Technol.)m

Radiation Chemistory Laboratory
KIMURA Kazuie *;ft - ~(Visitor)
ITO Yasuo W Hi ~ ~(Res. Cent. Nuc1. Sci. Technol., Univ. Tokyo)(Students)
FUNDOH Atsushi 51 ~ i$ ~ (Dep. Phys., Chuo Univ.)
HAMADA Naoki ~ IE U[ ~ (Dep. Phys., Chuo Univ.)
HARA Korehisa JJi{ £!A (Dep. Phys., Chuo Univ.)
IIDA Tsuyoshi ~ E8
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IMAI Satoshi A, #Jf'~ (Dep. Phys., Chuo Univ.)
KANAI Koichi ~ # ~ - (Dep. Phys., Chuo Univ.)
KATAOKA Masayoshi J='r fj'ijj ~ £ (Dep. Phys., Chuo Univ.)
NAKAMURA Tetsuya r:j:I;ft:gr t!1 (Dep. Phys., Chuo Univ.)
NISHINA Takuya 1= f-I- ¥ t!1 (Dep. Phys., Chuo Univ.)
VENO Takao 1:!f" ~ (Dep. Phys., Chuo Univ.)
YOSHIDA Tatsuya E E8 ~ -ill. (Dep. Phys., Chuo Univ.)

Radiobiology Laboratory
KANEKO Ichiro ~ r- fi~

NAKANO Kazushiro

r:j:I!f fO ~

284

(Visitors)
BAVERSTOCK Keith F. (Radiobiol. Unit, Med. Res. Counc., U.K.)
EGUCHI-KASAI Kiyomi iI 0 (~#) m-~ (Inst. Basic Med. Sci., Univ. Tsukuba)
MARUHASHI Akira 1L fI~ (Inst. Clin. Med., Univ. Tsukuba)**

SUZUKI Keiji~ PJ eRI Cent., Fac. Med., Yokohama City Univ.)
WATANABE Masami ~ ill. iE c. (RI Cent., Fac. Med., Yokohama City Univ.)
Y AMASHIT A Shoji Wr ~ (X (Natl. Saitama Hospital)(Students)
KOSAK A Toshiyuki
SUZUKI Masao~Z/J\ ~ ~

* a tit(Oep. Vet. Radiol., Nihon Univ.)(Fac. Sci., Rikkyo Univ.)

Safety Control Affairs Office
KAGAYA Satoru tJDli~ 'r-g:
KURIHARA Osamu ~!* ~MIYAGAW A Makoto 13]11 ~ ~SAWA Hiroshi ~~USUBA Isao ~ ~ ~Beam Analysis Center*

IWAKI Masaya :!fiiE fjJ(;SAKAIRI Hideo :t& A ~ tt
(Visitor)
FUJIHANA Takanobu

Laser Science Research Group

l!Jl.

*-

~

'*

SAKAMOTO Ichiro ~a~
SHINOHARA Shigemi ~!* ~ c

KOBAYASHI Takane /J\;fit;::8i 1E ~ '§ (Advanced Technology Inc.)(Student)
KOBAYASHI Kenzo /J\;fit;:.

NAMBA Susumu •KA TOU Takeo 1m Hi :JEt tit
MA TSUZAWA Yasuhide :fl iR-= (Fac. Eng. Sci., Osaka Univ.)_~

AUTHOR INDEXABE R yo I5PJ $% 2, 207
ADACHI Hirohiko JE fl.:fa lB 45
ADACHI Minoru JE fl. • 21,161
AGEMA TSU Takashi J:. *'1 ~ 141
AIHARA Toshimitsu ml JJ.it ~IJ:J't 8
AKAGI Hiroyasu dft.
'it. 1X. 2,207
AMBE Fumitoshi 1X. $ :)( 1if( 92, 96, 131, 133, 168
AMBE Shizuko 1X. $96, 131, 188, 185, 168

*

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ANDO Kozo 1X. Xi /lijIJ.=:. 62, 68
ANDO Yoshiaki 1X. »i ~ iVi: 9
ANNE Rene 11*-

ARAI Eiichi ~ if:123
ARA T ANI Michi m;'G ~ ~ 125, 126
ASAHI Koichiro M. ~- ~~ 11, 21, 161, 168, 180
ASAI Kichizo ~ if ~ ~ 92,98, 98, 188
A WAY A Y ohko ~ ~ :g.:r 62, 67, 69, 71, 73, 76, 78, 80, 82:m:

1i1i!:=

84,205,289,241,243,245,247,
249

BENKA Oswald 87
BIMBOT Rene 11
BURKE Philip G. 58
CHIBA Toshiya =f ~ ~IJ 'iWi; 216
CHIBA Yoshiaki =f ~ !if IY3 8, 203
DAI Yisheng ~ ~ ~ 105
DOKE Tadayoshi

*

m

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HATANAKA Kichiji 1m tf::t ~ ~ 2,164,210,212
HA TORI Satoshi 3PJ ~Jf~ 13
HA TSUKAW A Yuichi
bt - 155
HAYAKAWA Shun-ichiro Jf!.)11~-~~ 164
HEMMI Masatake ~ J! &:JEt 3, 216
HINO Ken-ichi E Jf 11 - 32, 35,37,41, 69
HIRA T A Yoshihiro :lIZ EB ~ m 64
HITACHI Akira J3 t±1• 67, 69
HOFMANN Helmut 31
HOSONO Kazuhiko kiB!f;ru lB 13
ICHIHARA Takashi rP JJ.it ~ 11,21,149,164

:m]l[

*

x

-=

145

FU JIT A Jiro :Hi EB~~ 198
FUJIT A Shin :Hi EEl~ 5, 207, 254, 256, 258
FUJIW ARA Hideaki »i JJ.it ~ IY3 9
FUKAI Yuh ~ if ~ 109
FUKUDA Hiroshi :m EEl'it. 57FUKUDA Mitsunori 1M EEl :J't J~ 11,21,161,180
FUKUSHIMA Hiroto 1M~!; ~ A 128,124
FURUNO Kohei ti!f ~ 3¥ 155
FUSE Masaharu
1JfB Jl fr:!i 180
GONO Yasuyuki ~""Mt Z 11
GOTO Akira ~ Xi ~ 2,210, 214

285,287,249,252

HARA Shunsuke JJ.it ~ it- 57
HARADA Hideo JJ.it EEl 31§: ~~ 7, 8
HARADA Shigenobu JJ.it EEl ~ f~ 158
HASEBE Hiroo ~;'G$mbt 3
HASEBE Nobuyuki ~;'G$f~rr 19, 152
HASHIMOTO Iwao
~ 101
HASHIZUME Akira
JT\ M t~5185, 186, 190, 191,

IEKI Kazuo~ ;ru x 8,9, 164
IKEDA Nobuo tm EEl f~
158
IKEGAMI Kumio ltI!J:.1L'=:':!Jj 5,210

19,152

EGUCHI-KASAI Kiyomi IT D (~if) m~
EKUNI Katsuaki IT IE R: HE 17
FANG Xushan 15 i\It JIffi 89
FUJIHANA Takanobu Xi;{E. ~ '§' 105
FUJIM A Kazumi Xi ret! - ~ 45, 55
FUJIOKA Manabu »i ffnj
~ 155
FU JISAWA Takashi »i iR ~ ~ 203,214

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AONO Keiko ~!f ~.:r 106
AONO Masakazu ~!f iE;ru 112

BAZIN Daniel 11
BE Suck Hee ~GOTOH Eiichiro ~»i*- ~~ 180
GUILLEMAUD-MUELLER D. 11
HAMA Hiroyuki ~ Jb $ 8,155
HAMADA Naoki ~ EEl rnr
187
HARA Masahiro JJ.it Jt"51.. 220, 228, 225, 228, 283,

IKEZAW A Eiji ltI! iR ~8
IMAI Satoshi A, if lf~ 137
IMAI Takashi A, if ~ 152¥flli M

INAMURA Takashi

7,15,149,155,174,
176,207,258

INOUE Toshihiko if 1: 1if( lB 8
ISHIDA Katsuhiko E EB JWJ lB 64,110,172
ISHIHARA Masayasu E JJ.it iE ~ 8,9,11,18,21,68,,

161,164,168,180

ISHIHARA Takeshi E JJ.it lEt 57
ISHIKAWA Hiroshi E)II
~ 87,89
ISHIKAWA Toshiyuki E} II ~ rr 2
ISSHIKI Hiroshi - ~ ~ 2
ITO · Tatsuya 1fr »i ~ 1ft 19*

ITOH Yoshiko 1fr
1f T 123, 124
IW AI Masahiro :E- if: .IE ~ 59
IWAKI Masaya :EiE ~ 101,108,105,106,107,112
IW ASA Naohito ;fi 16: w: t: 9
IZUMO Koichi t±1 ~ :J't - 143
JEONG S. C. ~ ~ ill 9
KADONO R yosuke F~!f ~:$ 64*

*-KADOT A Yoshinori 1f3 83 11
124
KAGA YA Satoru tJD~~ '/tJ- 256
KAGEYAMA Tadashi ~ W .IE 5, 210, 214.IE 71,73,78,80,82
KAMBARA Tadashi 1$
KAMITSUBO Hiromichi J:. ~ <JR:@: 116, 196, 220, 258
KANAI Yasuyuki ~ #- i* Z 67,69,73,76,78,80,82
KANEKO Ichiro ~.:r - a~ 143, 145, 147'*

KANO Fumihisa J.m If )( ~ 109
KARASHIMA Shosuke ~ mjffi:fr 41
KASAGI Jirota ~*~ a~* 7,8,11
KASAHARA Tatsuya ~~ fu 230
KASE Masayuki 110. ~~i~' 73, 76, 82, 201, 210,

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KASHIWAGI Toshisuke m frJ:fr 152
KASUY A Takahiro *B:B- ~ <JR 143
KA T ADA Motomi Jt 83 :JC C. 133
KAT A Y AMA Toshiko Jt ili fii;:.:r 143

KUSUYAMA Hiroyuki*

M W ~.b. Z

ft.

127

LEE S. M.
f§ a; 9LIU Lon Chang flU
23
LIU Wei Ping ~p::L 5jZ 19
LIU Yaoyang flU • ~ 39,47
MA Qianchen ~ T ~ 39,47
MAEDA Kazushige IW 133 fQ a; 164
MAEDA Kuniko M 83 :m.:r 120, 127, 129
MAEDA Masaru M 83
1lJ 127
MARUHASHI Akira JL;fI~ 145 IJ "

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MA TSUMOTO Takehiko *'~lEt ~ '109
MA TSUMOTO Yoshiyasu *'~E ~ 174
MA TSUO Masayuki *'~ 1€ .IE Z 29
r ," .
'
J). ; \
MATSUO Takashi *'~84
MA TSUOKA Nobuyuki *'~ ~ f$ IT 13
MATSUZAKI Masayuki *'~ dItff ~ Z 15 '"": ;;KA TO Seigo 110!i ft if 164, 166
KA TOU Takeo 110!i lEt t4. 256
KA TSURAGAWA Hidetsugu ;It JII ~ RBiiJ 176,178
KAWANISHI Shunichi M g§ ~ 139

MATSUZAKI Teiichiro *'~dltff1Jn=paB 64, rro,i72 : ; ,MATVEENKO A. V. 57/ . " " (:,KAWASAKI N oriko JII 41- *2.:r 237
KAWA TSURA Kiyoshi JII iIi ~ 67
KIKUCHI Jun *'i:lfu J~ 19,152

MINOWA Tatsuya 3t ~ ~ ~ 176,178
MIYADE Hiroki '§ /:B ~ ~ 233
MIYAGAW A Makoto '§ JII ~ § 256. .: ' ."MIYAT AKE Hiroari 13 lEt ? fu 155
MIYAZAWA Yoshitoshi 13 1R 11 ~ 3,216
MIZOGAW A Tatsumi m]ll JJR B 73,76, 78, 80," 82 1
MIZOT A Takeshi i1i 83 lEt ~ 9
MOCHIZUKI Yasuhiro ~}j ~~.b. 123
MOKLER P. H. 71
MORIMOTO Y oshihide ~;,;$: 1* ~ 239,241,243,

KIKUCHI Shiro *i:lfu ± a~ 15

*

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** _ 256

KOBAYASHI Kenzo /J\{I.=. 105
KOBA Y ASHI Takane /J\
6, 105, 109, 112,218,
/J\

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McLAUGHLIN D. J. 71
MINEHARA Eisuke _ J]{~:fr 15

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KIMURA Kazuie
M - ? 137
KIMURA Mineo =*.tt~ 45,55
KIT AMURA Hideo ~t tt ~ ~ 252
KITAO Kensuke *~~7JWJ 185,186,190,191

KOBA YASHI Toshio

1** t4.
**~

17

MORIT A Kosuke~ 83 15 1[-* **245,247,249
155, 158

KOBA Y ASHI Yoshio /J\~ ~ 133
KOGUCHI Masanari rffl IJ
nX; 21,161
KOHARA Shigeo 1]\!I! *= 5,203,210,214
KOHMOTO Susumu M:i1f; 62, 63
KOHNO Isao M If Jj] 5,118, 139, 141, 254, 256

MOTOBAYASHI Tohru~ 9,13,152,164
MOT ONAGA Shoshichi :JC 7k BB -l:; 198,230
MUELLER Alex C. 11
MUKHERJEE Sunil Chandra 43
MULLER A. 71

KOHNO Tsuyoshi M!I!f ~ 152
KONNO Satoshi ~ If ~ 143
KOSAKA Toshifumi 1]\ #j ~)( 145
KOYAMA Akio /J\ ili aE Mt 87,89
KUBO Toshiyuki A i* fii;: ~ 7,8,11,19,21,164,168
KUBONO Shigeru Ai*1f a; 164

MUNAKATA Kazuoki
i l - ~ 152
MURAKAMI Hiroyuki tt 1: 15 Z 9, 13, 19,152
MURAKAMI Takeshi tt 1: {I 7
MURAKAMI Yoshio tt 1: ~ t4. 158
MURAYAM A Toshiyuki M ili frJ ~ 9,174
NAGAI Yasuki 7k #- ~ W 155,158
NAGAMINE Kanetada 7k W. ~ I~ 64,170,172
NAGAOKA Ryutaro ~~~*aB 223,225,228
NAGASE Makoto ~ ~ ~ 198,214
NAGASHIMA Yasuo ~~ *= 9NAGATA Katsuaki 7k 83 1lJ aE 152
NAKAGAWA Takahide cp}ll 1f- ~ 19

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K UOO Hisaaki I Hi A aE 155
KUMAGAI Hidekazu fil3 -'l\' *:f:n 19,21,62,73,82,'*' ' ' ' 1=f' 7'$ IJ'I-l

84, 161,180,183

KURIHARA Osamu ~f~ 256
KUROKI Kenro ~{I aB 67, 69*

KUSAKA Takuya

B T -&! fu

235,237

KUSAKARI Hideshige 11- XU ~ ~ 15*m.... ·'

NAKAMOTO Atsushi ,*,;;$: ~ 152
NAKAMURA Shiho# ~107,109
NAKAMURA Takashi ,*,;ft r¥I '§j 164
NAKAMURA Tetsuya ,*,;ft tf i:!1 137
NAKANISHI Noriyoshi
gg ~:g 210
NAKANO Kazutoshi ,*,!f fI]:!7J\G 145
NAMBA Susumu • 1Bt J:tg 105,106
NISHIDA Yoshihiko gg EEl ~ j'ffi 27
NISHIDE Akihiko g§ ill I3B j'ffi 205
NOBLE Cliff J. 53
NOMURA Toru my #7- 155, 158

'*'

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NONAKA Hideo !f~ ~ 2,210,212
NORO Tetsuo !f g ti":k 13
NOZAKI Tadashi !f Wtif iE 123,124,126,185
OGIWARA Kiyoshi ~ @: m 5
OGIW ARA Masahiro ~ @: iE 5.£ 9"* * ~ j{rJ 3

OHKI Tomonori
OHKUBO Yoshitaka"*0..1*~~ i~o~~~i185,186,
OHNUMA Hajime "* 7B 1N 164
OKADA Takuya IilJJ EEl .Ej[ i:!1 93,96,98,131,133
OKAMURA Hiroyuki IilJJ # 5.£ Z 13
OKIHANA Akira i$ 11: ~ 13
OKUMURA Susumu ~ #J:tg 9
ORIHARA Hikonojo ~@:j'ffiZE,g 164
OSAKA T oshiaki "*:!1X tljf ~ 107
OSHIMA Masumi
flb ~ ~ 15
OTSUKA Shozo "* ~ ~2
OTSUKI Masayoshil§ ~ 176OYAIZU Mitsuhiro ,J\:fgpitlCft 158
OYAMA Hitoshi "*!1J ~ 114
PU Y. H. 1i ~ m:. 9
RUAN (GEN) Jian-zhi IVC Y! l#s 9
REUSCH S. 71
SAITO Kazuo
Hi fO ~ 125
SAITO Motozo
Hi !J$
203,210,214
SAITO Takane
Hi ~ ~ 13
SAKAI Hideyuki mi # ~ IT 13
SAKAI N obuhiko :!1X it 1§" j'ffi 92, 93, 133
SAKAIRI Hideo :!1X J\ ~ -W 6, 112, 218
SAKAMOTO Hiroyuki :!1X;;$: ~~!~, 241, 243, 245,

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*
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SAKAMOTO Ichiro :!1X
fl~ 254,256,258
SAKAMOTO Yuichi :!1X;;$: -W - 114
SAKURAI Mikio ~ it ~:k 8
SAMHAMMER R. 31
SANO Hirotoshi *!f it tljf 133
SASA Yoshihiko~ j'ffi 87,89,120,127,129
SASAKI Shigeki
SASUGA Tsuneo

* /.{
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*Lit~

252

~

139

* ,t][****SATO Hiroshi
Hi "t-1i. 17
SATO Hiroshi
Hi ~ 5e. 55
SATO Kenichi
Hi ]I - 25
SA TO Sigeru
Hi ~ 249
SATOH Shinichi
Hi • - 13
SCHMIDT-OTT Wolf Dieter 11
SCHUCH Reinhold 71,80
SCHULZ M. 71
SEGUCHI Tadao llj D J~ ~ 139
SEKIZAWA Hisashi ~ ¥Rr¥I 96, 98*=

SHIBUYA Shinji ~:fr ~9
SHIMA Kunihiro flb n it 73,80,82
SHIMAMURA Isao flb #~ , 49,51,53 ' ,SHIMAU CHI Masaaki flb R iE I3B ·'27 r : .
SHIMAZU Mitsuyoshiflb it fml ~ 176,178
SHIMIZU Hajime m 71< If 164
SHIMOURA Susumu r 00- 7- 17
SHINOHARA Shigemi ~ @: Lit c 256
SHINOZUKA Tsutomu ~ ~ !@ 155
SHIOYA Tatsuro ~ ~ Ji fl~ 252=**=

SHIRATO Shoji B ±~}9
SUEKI Keisuke
J@: 1r 155,185,191,195
SUGIMOTO Kenzo ~;;$: @17
SULIK Bela 78
SUNAGA Hiromi ~ 7k it ~ 141
SUZUKI Keiji ~J@: '§j 147
SUZUKI Masao ~Jt -W 147SUZUKI Takeshi ~@ 19
TAGUCHI Kazuhiro EEl D fO it 155
TAKAHASHI Tan ~.E!. 143,145
TAKAMI Michio ~ J! m ~ 174
T AKEBE Hideki lEt $ ~ ~ 2,5,198,207,210
TAKEMASA Tadashi lEt ~ ~ ± 27
TAKEUCHI Hiroki ¥r R ;:e:g 8
TANAKA Hitoshi EEl:gg 223,225,228
TANAKA Jinichi EEl
1= m 155,158
TANAKA Koki EEl r:p£ 103, 116
TANAKA Ryuichi EEl r:p ~ - 141
T ANIHA T A Isao :fr 1m ~:k 17,19,21, 168
T AWARA Hiroyuki 1az it Z 84
TENDOW Yoshihiko 7(
7j j'ffi 185, 186, 190, 191

*
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TOBA Yoshikazu ~ ~ ~ fO 93
TONUMA Tadao pt iB iE -W 62,84
TORI! Yoshinari ~ % ~.IV(; 158
TORIY AMA Tamotsu ,~!1J 1* 155,158
TOYOKAWA Hidenori J! JII ~ [II] 164*

TSUMAKI Koji ~:¥: l#s 223,233
TSURUBUCHI Seiji tf§ vm IDiX
62=

UDA Masayuki ? IE JZ Z 87,120, 127,129
URAl Teruo tffl it
6, 218_;k.

VALLI Kalevi 155, 158
VOGT Hans 67,69,76
WAD A Takeshi ;fa IE 14 149,198,207
WATANABE Kenji ~ ill {@ (?{ 109
WATANABE Masami ;1l ill iE c. 147
WATANABE Tsutomu ;1l W jJ 32,35,37,39,41.
43,47

WHELAN Colm T. 49
YAGI Eiichi I\,
6,101,103,107,109,116
YAMADAYA Tokio ili EE ;&Mj;k. 93,98
YAMAGISHI Yoshinori LU J¥ ~ ~ 230
YAMAGUCHI Hiromi LU IJ fa- ~ 19
YAMAGUCHI Hiroshi ili D
Pi 125YAMAGUCHI Hiroyuki LU tJ "5l Z 101
YAMAJI Shuhei LU ~ {~:ljZ 31
YAMAMOTO Shigeru LU;;$: ~ 252
YAMAZAKI Yasunori ili lI$t ~67,69
YANAGIMACHI Tomoki :W~ IIIJ M W 19,152

* *-

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YANO Katsuki fk.!I!f Mf ~ 114
YANO Yasushige fk.!I!f 9!.:m 2, 210
YANOKURA Minoru fk.!I!f~ ~ 3,19,114,125,126,
163,256YASUE Masaharu !i. IT iE fr::s 164
YATAGAI Fumio ;&IE~)(~ 143
YOKOUCHI Shigeru tIi Pi a; ~~f' 241, 243, 245,
YOKOYAMA Ichiro tl ili - R~ 201
YOSHIDA Hiroshi ~ IE ~ 'irJ 164
YOSHIDA Katsuhisa E IE % A 223,233
YOSHIDA Kenichiro ~ 133 ~- R~ 127
YOSHIDA Kenzo ~ EE @ -=. 141
YOSHIDA Koichi ~ 133 J't - 7,8
YOSHIDA Shiro ~ 133 }~t R~ 25
YOSHIDA Tatsuya ~ EE :it -tl1 137
YOSHII Masahito ~ it iE A 155
YOSHIYUKI Takeshi ~ IT {@ 235,237
YU Byong Gon ij« m jlj:I 126
ZHANG Xixiang ~ ~ rf 39,47

lIKEN Accelerator Progress ReportlIft~m~Wi.:bnaH$~.~.21.

(1987)

m ,\'jil] pgfl] 63 if. (1988) 10.li 25 8~

rr pgfl] 63 if. (1988) .10 .Ii 30 8~rr~

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理化学研究所
埼玉県

和光市

広沢