ISSN 0289-842X

RIKEN
Accelerator
Progress Report
vol.

17

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

RIKEN Accelerator Progress Report i1 (()) (6) Ii))
January-December U'71 (Q) ~!m 11:: ~ ~ff ~ jilT
the Inslilute of Physical and Chemical Research
Wako-shi, Saitama, 351-0 I JAPANEditors

Y. Awaya

Y. GonoM. Imamura

T.

H. Kamitsubo

M. OderaE.

Inamura

Vagi

This volume contains recent information of the accelerators at RIKEN (lPCR), 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 fromthe publisher.

CONTENTS
Page
I.

INTRODUCTIONII.

OPERATION OF ACCELERATORS

III.

1.

Cyclotron Operation ..........................................

2

2.

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

4

3.

TANDETRON -Operation ......................................

6

4.

Implanter Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

7

RESEARCH ACTIVITIES
1.

Nuclear Physics
1.

Possible Evidence for Lower Critical Angular Momentum inComplete Fusion .............................................

92.

Re-evaluation of Friction Coefficients for
Deep Inelastic Heavy-Ion Collisions .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 123.

Effects of Two Particle - Two Hole Excitations
on the Mass Distributions in the 16 0 + 40 Ca Reaction ................ 15

4.

Fusion and Evaporation Phenomena in Heavy-Ion
Reaction of Relatively Light-Mass System .......................... 17

5.

Effective Moment of Inertia of Medium-Mass
Fissioning Nuclei ............................................. 20

6.

High-Lying Proton Single-Particle States in
Heavy Nuclei ................................................ 21

7.

Chemical Effects on Internal Conversion ofOuter-Shell Electrons in 125 Te .................................. 238.

High-Spin States of Er Isotopes in theInteracting Boson Model ....................................... 25

9.

Multiple Coulomb Excitation of 161 Dy and 163 Dy . . . . . . . . . . . . . . . . . .. 26

10.

Angular Distributions of Gamma-Rays from Dy
under Transient Magnetic Field .................................. 27

Page

2.

II.

Spin Polarization of Residual Nucleus
in 6 Li-Induced Reaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28

12.

Correlation between Angular Anisotropy of
Fission Fragment and Its Mass in the Systemof 16 MeV p + 238 U ........ . ............. . ................... 29

13.

Fission in 1 4 N Induced Reactions on 2 3 8 U
at 120 MeV ......................... .. ....... . .. . ........... 31

14.

Isomeric Transitions of 211 mpo and 212 mpo .. . . . . . . . . . . . . . . . . . . . .. 33

15.

In-Beam -y-Ray Study of 212 Po . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35

16.

Delayed -y-Ray Study of 21 7 Ac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 36

Atomic and Solid-State Physics
1.

Theoretical Study of Charge Transfer fromH or He to Multicharged Projectile Ions at
Impact Energies of keV/amu - MeV/amu .......................... 37

2.

Critical Angle Scattering in High-Velocity
Three-Body Coulomb Rearrangement Collisions ............. . .. . .... 39

3.

Charge Equilibrium of Energetic Heavy Ions and Its Effecton the Stopping Power of Gaseous Media. . . . . . . . . . . . . . . . . . . . . . . . . .. 42

4.

Transitions of Molecules between High-AngularMomentum States ............................................ 44

5.

Beam-Foil Spectroscopy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 46

6.

Optical Detection of Atomic Spin Polarization
Produced by Beam-Foil Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 48

7.

K X-Rays from Ar-Ions Passing through Foils (I) . . . . . . . . . . . . . . . . . . . .. 49

8.

K X-Rays from Ar-Ions Passing through Foils (II) .................... 51

9.

Au L3 -Subshell Alignment Induced by Heavy-Ion Impact .............. 53

10.

Angular Distribution of REC for Ar4 + on C at 1 MeV/u .. . ............ 55

11.

Krypton Recoil Ions Produced by 42 MeV
Ar4 + Ion Bombardment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 58

Page
12.

Projectile Charge-State Dependence of the Fractional Yields
of Recoil Ions in Different Charge States . . . . . . . . . . . . . . . . . . . . . . . . . .. 60

13.

Measurement of Total Ionization Cross Section for
Production of Recoil Ions by Heavy Ion Impact
on Gas Target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 63

14.

Ar L-MM Auger Spectra in Ar4+ + Ar Collisions ..................... 65

15.

Krypton M-Shell Auger Spectra Produced in Collisions
with about 0.2 MeV /amu Heavy Ions. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 67

16.

Secondary Electrons Induced by N 2 + Ion Bombardment. . . . . . . . . . . . . .. 69

17.

Stopping Power of AI, Ni, Ag, Au, and Pb for
5 - 7 MeV/nucleon a Particles and Carbon Ions:
Deviation from the Bethe Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 70

Zf
18.

Reactions Induced by High Energy Ions at the
Pd-Si Interface ..... . .......... . ..... . . . . . . . . . . . . . . . . . . . . . . . .. 72

19.

Emission Mossbauer Studies of Dilute 119 Sb Ions Adsorbed
on Ferrimagnetic Cobalt Ferrite Surfaces ...... ' . . . . . . . . . . . . . . . . . . . .. 74

20.

Perturbed Angular Correlation of 'Y-Rays Emitted from111 CdC +- 111 In) in a-Fe 0.. . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .. 76
2 3

21.

Perturbed Angular Correlation of ')'-Rays Emitted from111 CdC +- 111 In) in MFe 04 (M = Fe, Mn, Co, and Mg) ............... 78
2

22.

Plasma Wall Interaction ........................................ 80

23.

Studies of a-Si:H Growth Mechanism by Rutherford
Recoil Measurement of Hand D in Films Preparedfrom SiH 4 -D 2 and SiD 4 -H 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

24.

Depth Profiling of Hydrogen in Solids by Using
Nuclear Reaction 1 He 1 B, a) aa ................................. 84

25.

Lattice Location of Hydrogen in Tantalum as Observed by
Channeling Method Using Nuclear Reaction 1 He 1 B, a) aa ............. 85

26.

Annealing of Cd-Implanted GaP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 87

27.

Defect-Impurity Interaction in Sn-Implanted Al ..................... 88

28.

Wear Properties of Nitrogen-Implanted Steels ....................... 90

Page

3.

4.

29.

Irradiation Creep Experiments under 16 MeV Proton
Bombardment in a Torsional Creep Apparatus. . . . . . . . . . . . . . . . . . . . . .. 91

30.

Effect of Injected Helium on the Mechanical
Properties of Ti-6.5 Al Alloy .................................... 93

Radiochemistry and Nuclear Chemistry1.

Radioisotope Production and Labelled Compound Synthesis. . . . . . . . . . .. 95

2.

Charged Particle Activation Analysis .............................. 96

3.

Oxygen Concentration in Antimony-Doped Silicon ................... 98

4.

Infrared Absorption and Composition of
Evaporated Silicon Oxide Films .................................. 100

5.

Rutherford Recoil Detection Method .............................. 102

6.

Characterization of Surface Hydrogen by the
Rutherford Forward Recoil Measurement .......................... 104

7.

Depth Profiling of Hydrogen and High Sensitivity Analysis
of Deuterium with 15 N-Induced Nuclear Reactions ................... 106

8.

Chemical States of Carrier-Free 119 Sb 5 + at a-Fe2 03 -Aqueous
Solution Interfaces Studied by in situ Emission Mossbauer
Spectroscopy ................................................ 109

9.

Mossbauer Emission Study of Defect 119 Sn Atoms
in p- and ~-Irradiated SnS ...................................... 111

Radiation Chemistry and Radiation Biology
1.

Measurements of Photoemission Spectra and their Decay at
Different Locations along a 50 MeV N-Ion Trajectory in
Helium Gas at 400 Torr and at 5 K ............................... 113

2.

Inactivation of Bacterial Spores by a Single Heavy Ion ................. 116

3.

Rescue of Mitomycin C Sensitive Mutants of Deinococcus
radiodurans by Irradiation with UV, 'Y-Rays, or N-Ions
Following Mitomycin C Treatment ............................... 117

4.

Effect of 3-Aminobenzamide on Sister Chromatid Exchange Frequency
in Chinese Hamster V79 Cells Irradiated with Heavy Ions .............. 119

Page
5.

6.

IV.

Instrumentation
1.

Test of MCP and PSD for Electron Spectrograph
Using Alpha-Source ........................................... 121

2.

Experimental Setup for Electron Spectroscopy ...................... 122

3.

Experimental Setup for PIXE .................... . ............... 123

4.

Nuclear Data Acquisition System with CAMAC ...................... 124

5.

Neutron Multiplicity Filter ...................................... 125

6.

He-Jet Transport System ....................................... 127

7.

A Goniometer for Internal Transient Magnetic Field Study ............. 129

8.

In-Beam Alpha- and Electron-Measurements witha Superconducting Solenoid ..................................... 131

Miscellaneous
1.

PIXE Analysis for Environmental Substances ........................ 132

2.

Application of PIXE to Medical Science (I) ......................... 134

ACCELERATOR DEVELOPMENT
1.

Present Status of the RIKEN SSC Project .......................... 136

2.

Control System of the RIKEN SSC ............................... 138

3.

On the Fundamental Constitution of the SSC
Control System .............................................. 141

4.

Extraction of Off-Centered Beam in the RIKEN SSC .................. 143

5.

Model Study of RF Resonator for the RIKEN SSC ................... 145

6.

Grid Tuning Circuit of RF Power Amplifier ofthe RIKEN SSC .............................................. 148

7.

Study of the RF Power Amplifier for the RIKEN SSC
Design of Plate Circuit ...................................... 149

8.

Study of the RF Power Amplifier for the RIKEN SSC
DC Blocking Capacitor for Plate Tuning Circuit .................. 152

Page

V.

9.

Calculation of RF Electromagnetic Field byFinite Element Method (III) ..................................... 153

10.

Vacuum System of the RIKEN SSC ............................... 156

11.

Structure Analysis of a Pneumatic Expansion Seal .................... 159

12.

Numerical Orbit Calculation for a Linac and Improvementof the Transmission Efficiency of a Beam .......................... 161

13.

Energy Tuning and Energy Resolution of RILAC .................... 164

14.

Change of Longitudinal Phase Motion in the First Tank of
RILAC against the Frequency Adjustment .......................... 167

15.

TOF Measurement of Beam Energy ............................... 169

16.

Design of a Compact Deflection Magnet ............................ 171

17.

Compact and High Efficiency Arc Pulsing Power Supply
for PIG Ion Source of the RILAC ................................ 173

18.

Design Study of the ECR2 ...................................... 175

19.

Production of Highly Charged Ions in a
Hexapole-Mirror Magnetic Field .................................. 177

20.

Circuit for Axial Extraction PIG-Source Power
Supply and Control ........................................... 178

21.

Modification of Axial Extraction PIG Ion Source .................... 180

22.

Operation of Axial Extraction PIG Ion Source ....................... 181

23.

On a Possible Medium-Beta RFQ Structure II ....................... 183

24.

A Low-Beta RFQ Structure ..................................... 185

25.

Small Computer System in Operation of the 160 em Cyclotron .......... 186

26.

Present Status of the Baby Cyclotron at the Nakano Hospital ........... 188

RADIATION MONITORING
1.

Radiation Monitoring Station .................................... 189

2.

Neutron Skyshine from the Cyclotron ............................. 190

Page

3.

Routine Monitoring of the Cyclotron .............................. 193

4.

Leakage-Radiation Measurement at the Underground
Passage of the Cyclotron Building ................................ 194

VI.

LIST OF PUBLICATIONS ........................................... 195

VII.

LIST OF OUTSIDE USERS AND THEIR THEMES ... . ................. 204

VIII.

LIST OF SEMINARS .......... . ................. . .................. 205

IX.

LIST OF PERSONNEL ............................................. 207
AUTHOR INDEX

1

I.

INTRODUCTION

Since collaborative research works using the 160 cm
cyclotron started in 1967 at the Institute of Physical andChemical Research (RUffiN), experimental studies on

The perturbed angular correlation method wasapplied to investigate the electronic states in magnetic
oxides. Emission Mossbauer spectroscopy of 119 Sn

nuclear physics, atomic and solid state physics, radiochemistry, material engineering, radiation chemistry andusing cyclotron-produced 119Sb was extended in thisperiod to in situ measurement on solid state-aqueous
solution interfaces. Depth profIling of surface hydrogenradiation biology have been extensively carried out.
The main facilities being dedicated to these researchworks are the 160 cm cyclotron, the variable frequency
linear accelerator (RILAC) and the electrostatic accelerator (TANDETRON) of I MV.

was made by measuring the recoil protons from the
Rutherford scattering with incident Ar ions and also bymeasuring high energy gamma-rays from IsN-induced

During the past one year the cyclotron was in goodcondition as before. A small computer was introduced
to aid the operation of the cyclotron. The RILAC has
been in steady operation in this period. Various kinds ofions of both gaseous and solid materials were accelerated
in the frequency range of 17 to 30 MHz. Test acceleration was succeeded at 45 MHz. Beam dynamical behavior of the ions in the RILAC was studied and acceleration efficiency was improved considerably. The
TANDETRON has been in steady operation in thisperiod.

measurement the growth mechanism of amorphous Si:H
layer was analyzed. The first determination of thelattice location of hydrogen in a bcc metal has beenreactions on hydrogen and deuterium nucei. From thesemade by the channeling method using a nuclear reaction
11 B + p. The success of this technique is believed toopen a new possibility for investigating the isotope dependence of the site occupancy of hydrogen atoms.
As to the irradiation effects on materials, the ion implantation effect, the ion mixing and the helium embrittlement of nuclear materials have been studied. In
addition, irradiation creep experiment on fusion reactor
materials was started with 16 MeV proton beam.

A majority of the research works have been carriedout with heavy ions. In the field of nuclear physics a
considerable progress has been made in development of
the instruments such as a neutron multiplicity fIlter,a helium jet transport system and a superconducting
solenoid. Experiments with these new tools as well asa Compton-suppressed spectrometer using large BGO
crystals now under construction have partly been
started this year and are expected to be more extensive
in future. In addition to these, experiment has also
started to solve a long-standing puzzle on low angularmomentum cutoff in fusion reactions.
Atomic Processes Laboratory was organized in April,
1983, to promote research works on atomic physics
theoretically and experimentally. In this year most of

In charged particle activation analysis, the detection
limits were considerably lowered by improving thechemical separation procedures after irradiation as wellas the detection system. Contamination of lightelements in GaAs, Sb-doped Si and other semiconductormaterials of industrial importance were successfully
determined. Bromoperiodol labeled with 77 Br was
prepared for the study on the dopamine receptor in thebrain. In the field of radiation chemistry, photo emission
spectra along a N-ion induced trajectory in heliumgas were studied.
Construction of the separated sector cyclotron isin progress. During the past one year the last sector
magnet was completed at the factory. Fabrication of

the experimental works were made using various kinds

the power supplies for the sector magnets as well as trimof heavy ions from the RILAC. By the measurement of
X-rays, Auger-electrons and recoil ions, multiple ionization mechanism and dynamical process of highly charged

coils is now under way. Construction of the cyclotron
vault was almost finished.

ions were investigated. In addition to these atomic collision experiments, study of beam-foil spectroscopy has
started this year and its first report is given in thisvolume. Some theoretical activities also began to workfrom this year mainly in the field of heavy particle collision, rearrangement collisions and electron-molecule
collisions.

1~'vL
H. Kamitsubo
Editor

2

II .

OPERATION OF ACCELERATORS

1.

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

During the period from Oct. 23, 1982 to Oct. 22,
1983 the cyclotron was operated on the 24 h a day

net beam time obtained from the difference of readingof time meter over the past 11 years.

basis. Statistics of machine operation time is shown in
Table 1. The total operation time of 4096.0 h is 3 %(269.3 h) shorter than that of the last year. This de-Table 2 shows the beam time allotment to various
activities in this period. The scheduled beam time wasincreased by 185 h compared with that of the last year.

crease in operation time is due to decreased ratio of net
beam time to scheduled beam time . Figure 1 shows the

For the new study of Test of track detector and Single
event upset in the LSI memory, 137 h was allotted inTable 1.

Cyclotron operation
Oscillator Ion-source

BeamReading of time meter on Oct. 23, 1982
Reading of time meter on Oct. 22, 1983
Difference

7632 5.3
81388.55063.280614.2
85751.2
5137.045692 .5
49788.5
4096.0Percentage of 365 days

57 .8 %

58.6 %

46.8%

Schedule in this period
Beam time
Overhaul and installation work
Periodical inspection and repair
Vacation and holidays

234 (days)
54
27
50

Net beam Time
Scheduled beam time

1. 0
- . - Heavy ions

~

0.7

l!

---...

E4000./.-- _.-..

.

- x-

Net beam time............
'./.

.--.-.--.

(f)~' ':::;I

E<U&) 2000

1973

Total

5 OOO~x--~x/(;)6000~~ Light particleso/.--./

x-x--X--.x_;x_x.--.--.-................-.

'83
Calendar year

Fig. 1. Net beam time and the ratio of net
beam time to scheduled beam time.

Fig. 2. The cyclotron beam time history .

3this scheduled beam time.
Table 3 shows the distribution of the scheduled beamtime among particle accelerated. Ions such as 9Be 3+ and6Li 2 + were newly accelerated and several experiments
were performed by using these ion beams. In thisperiod, the beam times for deuteron, 7Li 2 +, 0 5 + and

Figure 2 shows the beam time of heavy and light ionsover the past 9 years. Although the request for heavy ion
beam was slightly, i.e. 96 h, increased, the ratio of heavy
ion beam time to light ion beam time was almost thesame as that of the last year. The cyclotron was
operated to accelerate heavy ions for more than 70 % of
total scheduled beam time in the past 6 years.

newly accelerated ions were increased in contrast to thedecrease for N 5 +, 2oNe6+, and 1 3C 4 +.

Table 2. Scheduled beam time and subjects of activity in the period XVIII.
Heavy ionLight particle

In·beam spectroscopy
RI production

2689 (h)478
54

95 (h)
0304

2784 (h)478358

Fields others
than Nucl.
Phys.

Nuclear chemistry
Radiation biology
Radiation chemistry
Solid state physics
Atomic collision
Study of radiation damage

0
123
288
46
60
0

397
44
0
70
94
250

397
167
288
116
154
250

Outside users

Study of radiation damage
RI production
Test of track detector
Single event upset
in the LSI memory

0
0
0
118

159
67
19
0

159
67
19
118

3833

1522

5355

Subject{ Nuclear reaction
Nucl. Phys.

Total

71.6 %

Percent in total~. . . . . . .. . .. .. .. ..

..

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

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

..

..

..

.. .. ..

Total

28.4 %
100%. .. .. .. .. .. .. .. .. .. . . .. . . .. ..

Maintenance, operation and engineering
Exchange of ion sources
Machine inspection and repair

88 (h)
648
736

Total

Table 3. Distribution of beam time among particles accelerated.
Particle(h)(%)

Particle

(h)

(%)

p

9.9
2.1
3.5
12.9
2.8

N5 +

600
1102
308
134

11.2
20.6
5.8

12C4+

529
115
189
689
151
474

N4 +

767

d

3He 2 +
4He2 +
7Li 2 +

8.9
14.3a) Newly accelerated ions.

0 5+
2oNe6+
13C4+
9Be 3+ a)

108
93

2.5
2.0
1.7

6Li 2 + a)

96

1.8

Total

5355

18 0 5 +

100

4

11-2.

RILAC Operation

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

ions and 25 % for N2 + ions. 1 sN 2 + ion beam was also
supplied to the user. Its beam has been utilized to theanalysis of hydrogen contents in some materials. A ten
percent enriched 1 5 N gas was fed to the ion source to
get the 1 5 N2 + ion beam. In order to increase the energyof ion having mass larger than that of argon, it is necessary to get highly charged ions. A pulsed arc power

The Riken heavy ion linear accelerator , RILAC, hasbeen in steady operation in this period and various kindsof ion beams were transported to various targets. Table 1
gives statistics of operation in the period Sept. 1, 1982 Aug. 31,1983. The beam time of 167 days used for theexperimental works includes three days of unscheduled
shut down of RILAC. Therefore , the beam time which
has actually been available to the user was 98 .2% of thescheduled time. Figure 1 shows statistics of ions usedin this period. It is clear that most of the users preferred
the beam of Ar 4 + ions and of N2 + ions to heavier
projectiles. Percentage of the beam time for the experiment in the total machine time was 64% for Ar 4 +Table 1.

supplyl) for PIG source was installed in a 500kV highvoltage terminal of the injector in the spring of 1983 .
By use of the pulsed power supply, Kr 8 + (88.7 MeV)
and Xe 9 + (108 Me V) ions were accelerated and usedin some experiments. A charge stripper, which is installed in the beam line between cavity No . 6 andSW magnet, was frequently used at the request of users.
Carbon foil of the stripper has thickness of 10 microgram/cm2 and is 15 mm in diameter.
Beam line C of the beam transport system is in linewith the acceleration axis of the linac, so that small
amount of undesired beam with different charge states

Statistics of operation in the period
Sep. 1, 1982 - Aug. 31 , 1983.

167 days
Beam time
Overhaul and improvement work 46
Periodical inspection and repair
39
113
Scheduled shut down
365
Total

45 .8 %
12.6
9.9
31.0
100.0

will be present in the beam arriving the target in thiscourse . To avoid the mixing of undesired beams in themain beam, a compact deflection magnet 2 ) (CD) was
installed in the beam line C.

102

100

o M. T
70
(f)

>,

<U

o

50

40
30

~

0

Charge state 1

H2

He

2

2

14N

15N

DR

[jl

23

2346

5

2°Ne

Ar

63C U

n odd

8
84Kr

679

129Xe

Ion species

Fig. 1. Statistics of Ion Used in the period Sept. 1, 1982 - Aug. 31 , 1983 .

* Sumijyu examination and inspection corporation .

5Many improvements were done to get simple andstable operation of the linac. Total accelerating voltageof 16 MV was obtained easily by use of an automatic rf
voltage recovering circuit,3) which instantaneously
changes mode of excitation of the cavities to suppress
continuation of discharge, in the case when the acceleration voltage was lost by sparking during operation of thelinac. There is no need of step by step adjustment of
RF parameters by the operators to get the accelerating
voltage. The divider resistance of accelerating column ofinjector was changed from 5 X 10 9 ohm to 1.75 X 10 9
ohm. The reason for the change is to avoid the abrupt
potential change of accelerating electrodes when a straybeam hits them. The beam injected to the linac became
stable by this improvement.
The linac cavity had several troubles in this period: aquadrupole magnet in a drift tube (DT /11 -13) had insulation failure in its tape coil and the beam was accelerated

without this magnet excited in operation of the linac;
silver strips (thickness O.2mm) inserted between the
inner conductor of the coaxial section of cavity and thebase of the drift tube supporting horizontal piece meltedwith heat generated by rf current at positions of poor
contact. The melted contact strips in the cavities No.3
and No.4 were replaced by beryllium copper strips. It is
expected that the beryllium copper strips can withstandthe repeated thermal stress which is supposed to cause
the poor contact in the case of the silver sheets.

References
I) M. Hemmi and Y. Miyazawa: p. 173 in this report.
2) M. Hemrni, Y. Miyazawa, and S. Motonaga: p.171
in this report.
3) T. Kubo: RII<EN Accel. Progr. Rep., !§, 168(1982).

6

II -3.

TAN DETRON-Operation

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

In one year from the November of 1982 the machine
was operated for 76 days in total. The machine time

crystals,(2) Lattice location of H atoms in Ta and V crystals ,(3) Depth profiles of H atoms in amorphous solids ofSi,(4) Depth profiles of Au atoms in ZnSe crystals,(5) Radiation damage in Cd-implanted GaP crystals,(6) Blistering of stainless steel surfaces by He Im-

ion gun of the sputter ion source. A canal conducting Csvapour from a furnace to the ionizer, which provides
primary Ce ions for sputtering, corroded to have a hole.
A new gun prepared by us has operated without any
trouble.
A remote switching system to change the polarity ofa magnet was designed and constructed, which chooses
the ion source to be used between a duoplasmatron andthe sputter ion source. A similar system was prepared
for another magnet to select a course for the accelerated
beam. Both systems have operated well.
To install a new beam transporting system for anelectron microscope for the study of radiation damage,an ion optical apparatus are being prepared. It isscheduled to be completed at the end of fiscal year

plantation.
For studies of (1), (4), (5), and (6) 4He+ ions were used
and for those of (2) and (3), 1 1 B+ ions.
The largest trouble in this year occured in the cesium

1983.
Many works of repair and improvement of the
T ANDETRON and the surrounding instruments wascollaborated by the work shop.

showed a decrease against the previous year. It wascaused by partial reconstruction of the room which took
3 months. Except this period the machine has beenworking almost satisfactorily.
Subjects of the experimental studies were as follows :(1) Lattice location of Sn atoms implanted into AI

7

11-4.

Implanter Operation
M.lwaki

The RIKEN 200 kV Low Current Implanter is described in details in the previous report.!) This machine
has been utilized in the fields of modification of surface
layers of materials such as metals, insulators and semiconductors. Main items under practice are as follows:(1) Compositions and structure of ion-implanted
pure irons(2) Mechanical and electrochemical properties of
ion-implanted pure irons and steels(3) Compositions and structure of ion-implanted
diamonds(4) Electrical and electrochemical properties of ionimplanted diamonds(5) Compositions and structure of ion-implanted
graphites(6) Electrochemical properties of ion-implanted
graphites(7) Ion beam mixing of Ti deposited Cu and Ni(8) Ion beam mixing of GaAl As-GaAs(9) Annealing of ion-implanted GaP.
In order to perform modification of materials, manykinds of elements were used for implantation, whichwere given in a table in the previous report.!) Additional other elements implanted are shown in Table 1,
which also presents the typical beam current obtainablefrom the feeding materials charged in the furnances of
the Nielsen type ion source. Recently this machine has
been operated almost everyday and the need for
operation with some kinds of target materials andMicrowave
Ion source
supplies
cabinetimplanted species is showing the tendency to increase
still more.
Table 1. Typical beam current obtained by the RIKEN
200 kV Low Current Implanter.
Element

Current (pA)

Charged materials

F
Na
Ca
Mn
Fe
Kr

10
10

BF3
NaCl
CaC1 2
MnC1 2
FeC1 2
Elem.

5
20
20

5

In order to develope many works which require ahigh current ion beam to get a high production rate ofspecimens, a high current ion implanter is now underconstruction by the help of Special Coordination Funds
for Promoting Science and Technology. Figure 1 shows
the schematic layout of this RIKEN 200 kV High
Current Implanter, which is a modified Lintott High
Current Machine (Series III). The Lintott machine witha well-known Freeman type ion source is designed to befloating at post-acceleration potential and a target
chamber at ground potential. The 40 kV accelerator iscontained in an isolated terminal mounted on insulatorsfrom a base frame. This terminal can float at 0~160kV
to give the post-acceleration.
The modified implanter has the advantages of having

Control
panel

Processor chambers

Fig. 1. Schematic drawing of RIKEN 200 kV High Current Implanter.

8

own microwave ion source (produced by Hitachi Ltd.)and .owning two target chambers. The microwave discharge ion source has a comparatively long life time due
to lack of hot-filament , which restricts the life time of a
Freeman type ion source usually used in obtaining a highcurrent ion beam. In its operation, it is easy to discharge
feeding materials at their low flow rate. During the discharge of metal chlorides, the chloride ions and radicals
in the plasma do not consume any component of thismicrowave ion source and might prevent metal todeposit on the inner walls of the discharge chamber bybombarding and chemically cleaning the walls. Therefore, this ion source is considered to be suitable for production of metallic ions.
The ion beam extracted from the ion source at the
maximum voltage of 40 kV is a ribbon beam and the ion
trajectries are parallel in the vertical plane and divergent
in the holizontal plane . The divergent beam from theion source enters the analysing magnet, which has arotatable entrance pole. This enables the beam to befocussed into the resolving slit without the use of any
electrostatic focussing lenses. The magnet is capable ofbending ions with masses up to 130 at full extraction
voltage of 40 kV and larger masses at decreased extraction voltages.
The post-acceleration of the beam is achieved acrossa single acceleration gap set in the center of a stainlesssteel chamber. The arrangement enabled the X-rays
emitted during the post-acceleration up to 160 kV to beshielded in the close neighborhood of the origin of the
X-rays. The beam shutter after the post-acceleration gap
and before the processor gate valve is electrically isolated
and is used to measure beam current by magneticallysuppressing secondary electrons.
Processor chamber A, which is placed at the original
position of a Lintott implanter, has nine target holders
for performing ion implantation at the ambient temperature. Maximum implanted area of the sheet is
150 X 240 mm 2 for each target holder. Processor B installed at the end of the beam line has two types of target holders . One can be utilized for ion implantation ina sheet of 50 X 40 mm 2 at controlled temperature fromoliquid nitrogen temperature up to 500 e. The otherenables ion implantation in a cylinder, of which
maximum size is 100 mm in diameter and 50 mm inlength.
This high current implanter will easily perform
modification of material surface-layers.

Reference
1) M. Iwaki: RIKEN Accel. Progr. Rep.,Q, 7 (1981).

9

III.

RESEARCH ACTIVITIES

1.

Nuclear Physics

Possible Evidence for Lower Critical AngularMomentum in Complete Fusion

1.

T. Nomura, H. Kudo, S. Kohmoto, K. Sueki, and T. Kubo

NUCLEAR REACTIONS 1 2Ce 60, xnypzO''Y), E = 70 . .:. . 120 Mev,~~

natural target; 24Mg(0', xnypzO''Y), E = 30 - 50 MeV, enriched target;

measured E'Y' Iy Evaporation calculation; experimental evidence
for the existence of lower Qer in fusion.

The existence of a lower cutoff (Q<)
in angularermomentum that limits the complete fusion cross section
in a heavy-ion reaction has been predicted by the timedependent Hartree-Fock (TDHF) calculation 1) as well
as by the semiclassical coupled-channels model calculations. 2 ) However, no clear experimental evidencp. for

1 60-beam of 70 -120 MeV. There are two reasons forusing the thick target in the 'Y-ray measurement. One isto prevent residual nuclei from recoiling out of thetarget, so that the yield estimate becomes reliable.
Another is to decrease the Doppler shift (broadening) in
the prompt spectra as far as possible. Special attention

e1-25 Na) to see

Qer< has so far been found. A main difficulty in the ex-

was paid to the yield of Na isotopes

perimental search for Qer< lies in the fact that the ex-a possible effect of Q<. The nuclei 22Na and 24Na arepected magnitude of the effect influences only a small
fraction of the reaction cross section. We should there-

kown to have low spin isomers at the first excitederstates. The isomer ratio of these nuclei is also expected

fore look for observables that are sensitive to theexistence of Qer<.

102~--------------------------~

It is well known that high-spin states in a highly
excited light

16 0 (115 MeV)on 12C

nucleus preferentially decay by theevaporation of O'-particles, and that low-spin states
deexcite mainly by the emission of nucleons .3 ) When23Na

the evaporation residues resulting from the fusion reaction

areclassified

by

the

numberof O'-particles

evaporated in the decay chain of the compound nucleus,
those nuclei produced without the emission of 0'particles

originate mainly from lowest-spin states in thecompound nucleus. The yield of such residual nuclei is

I·

-010
ill
">-,

ro

ill
0:::

.- ..)

25Na(X10)/'

I·

yields of 24Na and 2 sNa produced in the 12Ce 60, 3p)•/. -·70·
I· · \

and 12Ce 60,3pn) reactions, respectively, are found to
originate from compound states with spin values lower
than 1011, while the yield of 23Na, for instance, comesmainly from states with much higher spins. The TDHF
calculations predict Qer< ::::: 31i at the bombarding energyof 80 MeV, 11 i1 at 90 MeV and 15 Ii at 100 MeV4 ).
We have measured cross sections of residual nuclei
using the technique of 'Y-ray spectroscopy in the bombardment of a thick natural carbon target with•

22Na(X 1/10)/"" ............

• •"........... ~therefore considered to have high sensitivity to test the< as shown in Fig. 1, where thepossible existence of Qer

24Na

/

•

/.

I· .

.

· / l-

I · ./ \ i
\

5

10
15
J (n)

20

25

Fig. I. Product cross sections of some Na ,isotopes inthe bombardment of 12 C with 115 Me V 16 0 beam asa function of angular momentum of the compound
nucleus. They are calculated by the code GROGI2.

10

+
i
+

Q)

Z

Prompt

(Y)

(\J

~
{\J
Z {\J

~

~~

+
.q-

~
(\J

i

u

(j)

+

b()

!2

A

Delayed (ms)

fff *

--0
Qj

' >'
Q)

>
+='
(\J

b()

~

Qj

0:::

Delayed (ns)

a

500

1000
Er (keV)Fig. 2. A part of the -y-ray spectra taken in the 11 0 MeV 16 0 bombardment of a natural thick carbon target. The assignment of
dominant -y-rays belonging to either Na isotopes or related nuclei are
given. Note that the energy scale is only correct for the prompt
spectrum and the delayed spectrum in the ms region, and that it isslightly different for the delayed spectrum in the ns region.

to be influenced seriously by the existence of Qcr<. Forshould be noted that the product cross sections in thecomparison , the yields of the same residual nuclei were

24Mg + a reaction have been multiplied by a factor ofalso measured in the 24Mg + a reaction at 30 - 50 MeV,(";:0 /~(X)2, where ~o and "A(X are the relative wavelengths
in the 1 60_ and a-induced reactions, respectively , at thewhich forms the same compound nucleus but is believed
not to have non-zero value of ' Qcr< .

same excitation energies of the compound nucleus.

Gamma rays resulting from the above reactions were
measured with a 80 cm 3 Ge(U) detector. In addition to

Therefore, the values of the product cross sections (a)prompt -y-rays, delayed spectra were taken in theoriginated from the decay of the compound nuclei

nanosecond range using the cyclotron natural beam
bursts as well as in the millisecond range using the pulsed

having the same distributions of angular momenta. The

ion source . A purpose of measuring the delayed spectra(1) The yields of -y-rays belonging to 2SMg and24Nam in the 160-induced reaction are much smallerin the ns range is to estimate the yield of the 1+ isomershould be equal to each other if the residual nuclei arefollowing points should be noted.

(tl/2 = 243 ns) in 22Na, while that of the delayed

than those of the same -y-rays in the a-induced reactions.

spectra in the ms region is to see the 1+ isomer

Since these isotopes are mainly produced from low-spin(tl/2 = 20.2 ms) in 24Na and the decay of otheractivities having rather short half-lives produced in

low angular momenta in the entrance channel do notvarious reactions. Typical examples of the measured-y-ray spectra are shown in Fig . 2.

the case of the 16 0 + 1 2C reaction . Note that 2 SMg has

A preliminary analysis of the results yields the experi-

the similar spin dependence as 2SNa because it is pro-mental excitation functions of some -y-rays in Na

duced by the same three-nucleon emission.
(2) The yields of the 5/2+ ~ 3/2+ -y-ray in 23Na as

isotopes as shown in Fig. 3. They were deduced fromthe difference of the thick target yeilds at various
energies in the case of the 1 60-induced reaction . It

states in the compound nucleus, this fact indicates that
contribute to the formation of the compound nucleus inwell as those of the 4+ ~ 3+ plus 5+ ~ 3+ -y-rays in
22Na are nearly equal to each other in both the 16 0_

11

10 3'

I

1 02~

10 F

-

·0.

Q~

~ I

I

~ ~~ ~;;;

25

I

f

I

I

23Na (5/ 2+-3 /2 +)
X 10

!

10~

10 2

I

I

I

~ IQI:>

Mg

e/2+-1/r)
3/2+-5/ 2+ -22Na(4+-3+ & 5+-3+)
I

;;;

1f--

-

-:: 5

22Na m(1 +-3+)
x 1/10-2 2i I

D

S

1b

4

I

-:::

b

D

S

11-

b
Q~ I

lOb

~Q I

21Ne (5/ 2+-3/ 2+)I

2 ;;; 2

~ 2

I
I

I

!

24Nam (1 +-4+)

0.11t;

I

I

24Na (gnd)

11-

10--

0 : a on 24Mg
• : 160 on 12C
0.1 '
40

I

I

I

50

60
(MeV)

70

ECN

0.1

40

I

I

I

50

60
(MeV)

70

ECN

Fig. 3. Excitation functions of some 'Y-rays in various isotopes measured in the 1 60 + 1 2 Creaction (dosed circles) and in the 24 Mg + a reaction (open circles). Note that the yields forthe a-induced reaction are multiplied by the factor explained in the text.

and a-induced reactions. Since these isotopes are notsensitive to Qcr< , this indicates that the upper criticalis therefore understood also by the existence of Qcr< .
A more detailed analysis is now in progress.

angular momentum for fusion is nearly the same inboth reactions.
(3) The values of a for the 1+ -+ 3+ 'Y-ray in 22Na m
and 5/2+ -+ 3/2+ 'Y-ray in 21 Ne are also smaller in the
16 0 + 1 2Csystem, although the difference is not so large
as the case of 2SMg and 24Nam. The 1+ -+ 3+ 'Y-ray in
22Na m represents the low-spin yield of 22Na, andshould be somewhat sensitive to the existence of Q<
cr .
The nucleus 21 Ne is produced by the three-nucleon
emission in addition to one a particle , and must have thesimilar spin dependence as 25 Mg. The smaller productcross section of these isotopes in the 1 60 + 1 2 C reaction

References
1) S. E. Koonin , K. T. R. Davies , V. Maruhn-Rezwani,
H. Feldmeir, S. J . Drieger, and J. W. Negele: Phys.
Rev., C15, 1359 (1977) .
2) R. A. Broglia , C. H. Dasso, G. Pollarollo, and A.
Winther: Phys. Rev. Lett., 40, 707 (1978).
3) T. Nomura, J . Delaunay, C. Tosello, and N.
Bendjaballah: Nuc!. Phys., A305, 262 (1978).
4) Y. Yamaji: Private communication.

12III -1-2.

Re-evaluation of Friction Coefficients for Deep Inelastic
Heavy-Ion Collisions
S. Yamaji and A. Iwamoto

NUCLEAR REACTIONS Microscopic calculation of friction 'J[linear response theory.

It is necessary to take into account the effect of the
lifetime of particle-hole states to treat the discrete

results for both cases give the same order of magnitude
and about half of the proximity friction, which was

spectrum in the microscopic calculation of friction

estimated in Ref. 4. It can also .be seen from this figure

coefficients for heavy-ion reactions using the formalismof linear response theory. 1)that "100 for CTA depends more strongly on T and R
than that for IPM.

Our previous works 2 )-4) have introduced one freeparameter r to take into account its effect in the independent particle model (IPM).

36Zn + 1~~Pt

In the present report , we have done a numericalcalculation of friction coefficients with new formalism,
which Jensen et al. S) have derived, approximating the

T - dependence

particle-hole Green function in the response function by
the coherent term of one-body operators. We call thisapproximation the coherent term approximation (CTA).
Since the expression for the friction coefficients, which
is given in detail in Ref. 6, differs much between these
two models (IPM and CTA) , the calculated results for
CTA are compared with the previous ones for IPM.3),4)----- IPM r =OAn wo- - eTA- - - Proximity

300

no-neck
8=0.0
1f 3
wo = 50AMeV
ro = 1. 123fm

N

I

E

n

>
~ 200
M
N

I

3.0

o.......

Three kinds of the shape parameters, the relative
distance R, deformation (j and mass number of projectile-like nucleus Al are taken. Three diagonal friction
coefficients "1 R R' "100 and "1 A 1 A 1 are calculated as afunction of these shape parameters.

100(1) Radial-radial friction coefficients 'YR R
In Fig. 1, we show friction 'YR R for the system
64 Zn + 19 6Pt as a function of the relative distance R
between two nuclei for several values of temperature
T. From this figure, one sees that "1 R R for CTA depends
more sensitively on temperature than that for IPM andthat it increases with increase of temperature. Although
the strength of "1 R R for CTA at temperature of about 2
MeV, that is, the typical temperature in deep inelastic
collisions, is still smaller than that for IPM, calculations
for CT A and IPM give "1 R R of the same order ofmagnitude and reproduce the order of magnitude of
the proximity friction (shown by the dot-dashed line)in the surface region of R = 12 '" 14 fm.

(2) Deformation-deformation

frictioncoefficients"100

Figure 2 shows "100 calculated for the system 64Zn +196pt as a function of R for several values of T. The

O L-L---~~±=~~~-L--~

10

12

14

16

18

R ( fm )Fig. 1. The radial-radial friction coefficient "1 R R for
the system 64 Zn + 196 Pt as a function of the relative
distance R between two nuclei for several values of
the temperature T.
The solid and dashed lines correspond to the calculated results by the method of coherent terms approximation (CTA)S) and by the independent
particle model (IPM) with the smearing widthr = 0.4 nw~) -4), respectively. The dot-dashed line
shows the proximity friction. The deformation (jof two nuclei is set to be zero and the neck formation
is not included. The oscillator parameter nwo istaken to be 50 A- l / 3 MeV in the same way as inRef. 4. The touching distance shown by the arrow isestimated to be 11.l fm by the relation R t = 1.l23 X(A! /3 + A~ /3) fm.

13(3) Mass asymmetry-mass asymmetry friction co-

20000~--63-40-Z-n+-1-9768-P-t-----------------'€=0.6 0'=1/0.0
nWo=4 1A- 3 MeV
ro = 1. 18f m

T - dependence----- I PM

efficients 'Y A A
1

1

We calculated 'Y A A ' for ten systems given in Ref.3.
1

r = O.4nwo
--eTA

1

We plot here the inverse of 'Y A ' A instead of 'Y A A as
1

1

1

1

a function of R as in Ref.3. This is done because

15000

1h A A is equal to mass diffusion coefficient per unit
11temperature D A /T in the transport equation, if we~neglect the coupling between mass transfer motion and>Q)other motions and assume overdamped motion for mass~transfer.

fo 10 000

Some examples of D A/T are shown as a function of.........

R in Fig.3. Since the friction 'Y A A for IPM depends
11very weakly on T, the calculated values of 'Y A A for
1

1.0

1

IPM are plotted only for the average temperature.

5 000

Although the dependence of 'Y A A
1

1

for CTA on T isstronger than that for IPM, it is still too weak to reproduce the dependence of the experimental values on
0.5

temperature for the cases of 40 Ar + 197 Au and 40 Ar +232Th reactions. The shape of two touching nuclei

8

10

12

14

16

18

when mass exchange occurs seems to be more importantRUm )to reproduce such temperature dependence of D A/T.

Fig. 2. The deformation-deformation friction coefficient 'Y88 for the system 64 Zn + 196 Pt as a functionof the relative distance R for several values of T.
The solid and dashed lines correspond to the calculated results for eTA and IPM with r = O.4flw o 'respectively. The deformation 8 is set to be zero andthe neck-parameter e defined in Ref. 3 is taken to
be 0.6. The oscillator parameter flwo is taken to be
41 A-I /3 MeV.

It can be concluded that both calculations for IPM
and CTA reproduce the experimental values of friction
coefficients within one order of magnitude, although
the friction coefficients on the basis of Ref.S(CTA)
depend more strongly on the temperature and configuration than our previous ones (IPM).3,4)

1. 0 ~----"-----r-----r-----'---"------'------'
E

I
>Q)
~

T ( MeV )2.3- {288MeV

L ab -

340MeV--- -- rPM r = OAnwo- - CTA

2. 7

2.5 " ' ,lu"-...
T ( MeV l
M~ O. 11-------+=~,.----------2. 3§----- rPM r =OAn wo- - CTAT ( MeV )1--------"o.~-+----- 2. 0

1------------+-----"'.;,,0;:--- - - -2.8

2.3

2.7

2.5

1-- - - -- + - - - ------ 2. 7

€ = 060=0.0 nwo = 41A- 1I3 MeV

TO = 1. 18fm€= 0.6 0= 0.0 nwo=41A- 1/3 MeV
To = 1.18fm

15
Fig. 3. The calculated mass diffusion coefficient per unit temperature as a function of the relative
distance R up to the distance where the neck-radius becomes zero.
The solid and dashed lines correspond to the calculated results for eTA and IMP with r = 0.4 hw o 'respectively. The experimental values are shown by horizontal lines. The numbers at the calculated solidlines and experimental values 7 ),8) show the values of temperature estimated from the two experimental
data of different incident energies. The results for IPM are calculated at the average temperature. The
vertical lines show the position of two touching spheres, which is estimated by the relation R = 1. 18 X
(A~ /3 + A~ /3) fm.

14

Refere.nces
1) H. Hofmann and P.J. Siemens: Nucl. Phys., A275,
464 (1977).
2) K. Sato, A. Iwamoto, K. Harada, S. Yamaji, andS. Yoshida: Z. Phys. A-Atoms and Nuclei, 288,383 (1978).
3) S. Yamaji, A. Iwamoto, K. Harada, and S. Yoshida:Phys. Lett., 108B, 433 (1981).
4) A. Iwamoto, K. Harada, S. Yamaji, and S. Yoshida:z. Phys. A-Atoms and Nuclei, 302,149 (1981).
5) A.S. Jensen, J. Leffers, K. Reese, H. Hofmann, and
P.J. Siemens: Phys. Lett., 117B, 5 (1982).
6) S. Yamaji and A. Iwamoto: Z. Phys . A-Atoms andNuclei, 313, 161 (1983).
7) S. Ayik, B. Schurman, and W. Norenberg: ibid.,279,145 (1976).
8)

G. Wolschin and W. Norenberg: ibid., 284, 209(1978).

15

III -1-3.

Effects of Two Particle - Two Hole Excitations on theMass Distributions in the 16 0 + 40Ca Reactions. Yamaji and M. Tohyama*
NUCLEAR REACTION DIC calculation of mass distributions.][ 16 0 + 40Ca time-dependent coupled-cluster approximation.

The time-dependent Hartree-Fock (TDHF) theory has
been extensively applied to analysis of heavy ion colli-

Then, the mean number NR of particles and thevariance a ~ of the mass distribution in the right frag-sions and has succeeded to reproduce the total kinetic
energy loss and mean values of the mass distributions

ment can be expressed in terms of the right-hand overlap
integrals of single particle wave functions and twoparticle-two hole amplitudes at the time when two
fragments are well separated in the final stage of thecollision. 3 )etc.
The variances of mass distributions calculated in the
TDHF, however, are always an order of magnitude
smaller than observed values. l ) This result suggests theimportance of two-body collisions, which are not included in the standard TDHF. One way to include theireffect is to use the time-dependent coupled-cluster approximation (TDCCA) proposed by Hoodbhoy et al. 2 )We previously applied this method to the analysis ofmass distribution in heavy ion collisions. 3 ) The calculation showed that the variances of the mass distributionsin TDCCA are very much enhanced as compared withthose in TDHF, while both approximations give similar
results to the expectation values of the mass distributions. This calculation 3 ) was, however, only limitted to
one-dimensional collisions.
In the present note, we report on the calculation extended to treat realistic collisions. Here, we give a brief
discription of our treatment. The detail is given in
Ref. 3.
The equations to be solved numerically are derived bytaking the lowest-order terms of the two particle-twohole amplitude in TDCCA:
i a~ q.>lI(t) = h(t) q.>1I(t)(1)

i d~ <,0 1 ,0 21s 21111 11 2> A = <,0 1.0 21V i llI 112> A.

(2)

The first equation determines the time-evolution of thesingle-particle basis, where h (t) is the HartreeFock(HF) Hamiltonian. We assume that the particle
states I{Jp (t) also obey the same equation as the hole
states I{J v (t). The indices v and p denote hole andparticle states, respectively. The second equation
specifies the time-evolution of the two particle-two holeamplitude <PI P2 I S2 I V 1 V2 >A·*

Institut, fUr Theoretishe Physik, Giessen University, West
Germany.

We have performed numerical TDCCA calculations
for the collision 320 MeV 16 0 + 40Ca on the basis of
the Skyrme force TDHF-code with axial symmetry.4)
The initial densities of two fragments are obtained bysumming the square of the static Hartree-Fock wave
functions over all hole states. The orbitals of the hole
states are Os and Op for 160 and Os, Op, Od and 1s for
40Ca. The initial particle states, which are restricted to
Od and 1s orbitals for 1 60 and to Of and 1p orbitals for
40Ca, are obtained from the static Hartree-Fockpotential. The time-evolution of particle states are
assumed to obey the same TDHF equation as that for
the hole states.

ooei -We use the o-function vCt,1) = V
10 as theresidual interaction. The strength V is adjusted so thatothe depth of one-body potential obtained by folding theresidual interaction with the density reproduces approximately that of the HF potential. We get
Vo = -400 MeV fm 3 , if we use the value of 0.17 fm- 3
for the density and of - 50 MeV for the depth of HF
potential, and get Vo = -530 MeV fm 3 , if we use thevalue of 0.15 fm - 3 for the density and of -60 Me V forthe depth of HF potential.
With this residual interaction of strength - 400 ,...,
530 MeV fm 3 , the increase of a~ due to the extentionof the space for neutron particle states of 16 0 to Of 1P shells is found to be less than 3 percent and the increase of a~ due to the extention of the space forneutron particle states of 40Ca to Og - Id - 2s shells isfound to be less than 6 percent.
Concerning the calculated results, inclusion of two
particle-two hole excitations gives only a few percent
change to the net mass exchange of TDHF. However, as
shown in Fig. 1, the variances are enhanced very much in16

D A '" A X 10 20 (amu)2/sec , where A is the total mass
/ '" "

320MeV 16 0 + 40Ca

6/

- --- - 2DA ,

5 (DA=56 x/
I1020(amu)2 / sec) I
:J 4

/

I

number of the composite system and T is the collision\\ Vo=
530M V ftime. The relation a ~ = 2D AT can be extrapolated tolighter systems. 6 ) The collision time T is calculated by

3

e .m

TDHF in the present work, defining it as the intervalN

during which the minimum density along the sym-E~

metry axis between the fragments exceeds 1/4 of nuclear
matter density. The rDCCA results shown by theNo::\: ) 3 W-r'~Cr'h'-"'r'''shaded area are slightly smaller than the empirical one

2

shown by the dashed line in Fig . 1. Considering Vo to
be an adjustable parameter, small increase of Vo fromthe values used here yields the empirical values.

TDHF

o

40

60

80

100

To summarize , the realistic calculation with two-bodyFig. 1. The variance a~ versus the initial angularmomentum Q for the 320 MeV 16 0 + 40 Ca reaction.

pirical values of a~ for the 320 MeV 16 0 + 40Ca reac-

20

l (n)

collisions reproduces the order of magnitude of emtion, although one-dimensional calculations could show
only that a ~ increases, if the effect of two-body collisions is included.

TDCCA. As an example, in DIC with the initial angularmomentum Q = 80ti, a~(TDCCA) is 2.0'" 3.4 (amu)2,
while a ~(TDHF) is 0.18 (amu)2. The nonvanishing two
particle-two hole amplitudes are found to oscillate withthe time period (0.05'" 0.1) X 10- 21 sec and have theReferences
1) K. T. R. Davies and S. E . Koonin: Phys. Rev. C, 23,absolute value of 0.001 '" 0.01. Although each term
which is proportional to the square of two particletwo hole amplitude in the summation of the expression

2)

P. Hoodbhoy and 1. W. Negele : ibid. , CI9., 1971
(1979).

3)

M. Tohyama and S. Yamaji:

For lack of observed values for this reaction , the cal-

4)

K. T . R. Davies : unpublished.

culated values are compared with the empirical values of

5)

W. U. Schroder and 1. R. Huizenga: An. Rev. Nucl.

6)

Sci., 27,465(1977).
S. Yamaji, A. Iwamoto, K. Harada, and S. Yoshida:Phys. Lett., 108B, 433 (1981).

2042 (1981).

a ~ is very small , it is found to contribute coherently.

Phys. Lett., 123B,

16 (1983).

a ~ estimated by the use of the relation a ~ = 2D A T )Swhich can well reproduce observed mass distributions
for heavy systems with the mass difusion coefficient17

III-1-4.

Fusion and Evaporation Phenomena in Heavy-Ion
Reaction of Relatively Light-Mass System
M. Magara,* K. Sueki, Y. Hamajima,* H. Nakahara,
H. Kudo, and I. Kohno

NUCLEAR REACTIONS 62Ni(14N ,X), Elab ::: 40 - 120 MeV,. total]~reaction cross sections, fusion cross sections, excitation functionsof residues, calculation of evaporation.

In heavy-ion reactions, formation of a compound
nucleus and its decay from high angular momentum
states are most fundamental problems to be clarified.
Many papers have been published on these problems!)
and most of them concluded that the ordinary statisticalevaporation model was applicable to explain the excitation function of compound-like residues even without
taking into account the critical angular momentum 1cr
for fusion and the angular momenta carried away byemitted particles. 2 ) The aim of this work is tounderstand the effect of those angular momenta on
excitation functions of compound-like residues.
As a reaction system, 14N + 62Ni was chosen andtwo kinds of experiments were performed; namely,observation of excitation functions of compound-like
residues by the radiochemical technique and that offusion cross sections by a 6E - E counter telescope consisting of a gas proportional counter and a surface barrier
detector. Details of the former experiment were reported in the previous progress report. 3) Some of theresults are shown in Fig. I for 73Se, 72 As, 71 As, and70 As by filled circles. The solid lines were drawn
through the data points to guide the eye. They are
cumulative cross sections including those of t3-decay
precursors. For the study of fusion cross sections, a selfsupporting enriched 62Ni target of 600 Ilg/cm2 thickness
was bombarded with 115 MeV and 96 MeV 14N beams,
and products were observed at lab angles of 3 to 26
degrees. Elastic scattering data were also taken over thesame lab angles in order to get the maximum angularmomentum, Imax' of the reaction. Results of the fusioncross section study are shown in Fig. 2 by open circles.
From the elastic scattering data, grazing angles werededuced by the quarter-point method, and 1cr 's andtotal reaction cross sections at were evaluated with theclassical approximation, the latter values being given
in Fig. 2 by filled circles. Total reaction cross section
Faculty of Science, Tokyo Metropolitan University.

data were fitted by the classical relationshipat ::: 1TR2 (l-B/E cm ) as shown by the solid line. The
dotted line shows the theoretical fusion cross sections
predicted by Bass, and the broken line is drawn throughthe data points with the assumption that the incident
energy dependence of fusion cross sections obeys theprediction of the Bass mode1. 4 ) From the solid line andthe broken line were evaluated the 1max and 1cr values
used in the evaporation calculations discussed below.
Two kinds of computer codes were used to test theeffect of angular momenta on the formation cross sections of compound-like residues. They were ALICE code
and GROGI2 code. In the two codes, transmission coefficients are calculated with the same optical parameters, and the energy dependence of level densities aretreated similarly. However, in ALICE code, variation ofangular momentum distributions emitted particles iseither completely neglected or approximately treated byassuming that a certain kind of emitted particles always
carries away a fixed amount of angular momenta. In
this code, the internal excitation energy is given by
subtraction of the rotational energy from the total excitation energy. In GROGI2 code, angular momenta aretreated rigorously by calculating angular momentum
distribution of the residual nucleus after each particle
evaporation. In Fig. 1, results of ALICE code calculation in which 1cr values are fed in as the maximum
angular momentum for fusion are shown by dotted anddot·dashed lines. The former are the results of calculations with complete neglect of angular momentum
balance and the latter are the results with assumptionthat neutrons, protons, and alpha particles always carryaway 1:h, 1:h, and 4:11 angular momenta. Agreementwith the experimental data is extremely poor and eventhe peak energies can not be reproduced. The dashedlines show the results of GROGI2 calculations in which
1cr values are fed in. Although the absolute cross sections and high energy tails of the excitation function
curves (e.g. in 73Se) are not reproduced well, the peak

18

10 3

10 3

102f-

-

b

-

10°

1011-

10°1-

H

~O

40 50

60

70 80
E lab

90 100 11 0 120

o

I

I

(MeV)

I

El ab

103

I

I

80 90 100 110 120
(MeV)

103

b

10°

1011-

10° r-

I

30 40

I

30 40 50 60 70

50 60

70

80 90 100 110 120

E lab

(MeV)

30 40

I

I

50 60

I

I

I

I

I

70 80 90 100 110
E lab

(MeV)

Fig. 1. Excitation functions of compound-like residues prodcued by the 14N on 62Ni. Filled
circles show the results of experiments and the solid lines are drawn through the data points toguide the eye. The dotted and dot-dashed lines are the results calculated by use of ALICE codewith complete neglect of the angular momentum balance and with the assumption that emitted
particles carry a way angular mo menta , n = 1TI, p = 1h, and ex = 4h, respectively . The dashed lines
are the results of GROG 12 code calculation.

energy and general trend of the experimental data aresidual nucleus after neutron , proton , and alpha particle

better reproduced. Any further adjustment of para-emission from the compound nucleus are depicted. The

meters such as pairing energies was not attempted. The

solid and dashed lines show the results of calculations

GROGI2 calculations were also performed by using

when the 1cr and 1max are used , respectively.

1max values instead of 1cr values. Use of an incorrect

As a conclusion, the excitation functions of com-

maximum angular momentum for fusion in the entrance

pound-like residues produced in heavy-ion reactions canchannel was found to affect primarily alpha particle

be understood well by the ordinary statistical evapora-

In Fig. 3, angular distributions of the re-tion model if angular momenta in the entrance and exit

emissions.

19

\

2 000

60

1 500

1-----._--- ..

::0--- ... _--- ...

in50

Im ;1x50j--.. .......

,- 40
:--.

Bass

5
b

60

t

Op~n

cir~e~l100 MeV40..-..,

+

...D

N 30

1000

305

'"+<
I:::

20

20

500
10

o

0,01
0,02
l / Ec m (MeV- I)

0,030
Fig. 3. The angular momentum distribution of
the compound nucleus (thick solid line), andthose of the daughter nuclei after a neutron,
proton, and alpha particle emission from thecompound nucleus when incident energy is
100 MeV. The thin solid and dashed lines show
how angular momentum distributions will change
if the ler and 1max are fed into the GROGI2
code as the input of the maximum angularmomentum for fusion, respectively.

Fig. 2. The filled and open circles are,respectively, total and fusion cross sections 0 btained from the measurement with the .0.E - E
counter telescope. The solid line shows the best
fit to the data of total reaction cross sections byuse of the classical relationship. The dotted line
shows fusion cross sections predicted by Bass andthe broken line is drawn through the data points
with the assumption that the incident energy
dependence of fusion cross sections obeys theBass model.

References
channelsarerigorouly

treated.

The

effectof

1)

M. Langevin, J. Barreto, and C. D6traz:

2)

Rev., C14 , 152 (1976) etc.
P. Misaelides: Radiochim. Acta, 28 , 1 (1981).

pre-equilibrium emission on cross sections was foundinconspicuous for most of the products investigated inthis work except for 73 Se. No assumption of extra-

3)

analysis unlike that postulated in heavier reaction
systems.

K. Sueki, Y. Hamajima, M. Takahashi, Y. Nagame,
H. Nakahara, and I. Kohno:
Rep., lQ, 9 (1982).

ordinary emission of alpha particles was required in the
4)

Phys.

R.Bass:RIKEN Accel. Progr.

Nucl.Phys .,A231,45 (1974).

20

III -1-5

Effective Moment of Inertia of Medium-Mass
Fissioning Nuclei
G. x. Liu*

NUCLEAR REACTIONS IlBSne4N,f) , E = 120 MeV; IlBsneONe,f),]
E = 135 MeV; measured angular distributions of fission fragments,[ fission cross sections; deduced 1eff.

Angular distributions of fission fragments have beenmeasured in 14N_ and 2 °Ne- induced reactions on 11 BSn

to deduce an effective moment of inertia at the saddle
point of relatively light fissioning nuclei. A self-supporting 11BSn target of about 400 J.1.g/cm 2 thickness wasbombarded with 120 MeV 14N and 135 MeV 20Ne ionsfrom the cyclotron. Fission fragments were detectedwith mica track detectors. The preliminary analysis of
the 14N + 11 BSn data yields the angular distribution
shown inFig. 1, from which we obtain Of = 2.0 ± 0.4mb.
An effective moment of inertia is deduced to beabout 10 /l eff = 1.6 ± 0.2, where 10 is the moment ofinertia of a rigid spherical nucleus, following the prescription of Ref. 1. The above value is close to that ofsimilar light fissioning nuclei 1 32 Xe as described inRef. 2. More detailed analysis is now in progress.

100 '-------::--L.,---,,-l.-----,-l- - - - ' - - - - ' - -- - - - '

o·

30·

60·

90·

120·

150'

180·

8(:,\1 .

Fig. 1. Angular distribution of the fission fragments from the 14N + 11 B Sn reaction at
120 MeV. The data are converted to those of thecentre-of-mass system (under the assumption ofcompound nucleus formation).

* On leave of absence from Institute of Modern Physics,
Academia Sinica, Lanzhou, China.

References
1) K. G. Kuvatov et al.: Yad. Fiz., 14,79 (1971).
2)

H. Blok and B. D. Pate:Z. Phys. , A281, 255 (1977).

21

III-1-6.

High-Lying Proton Single-Particle Statesin Heavy Nuclei
E. Takada, M. Ishihara, Y. W. Lui,* Y. Mihara,*
T. Murakami,** Y. Toba,* and R. E. Tribble*

NUCLEAR RE.ACTIONS 2oBPb(a,t)209Bi at E = 60 MeV andj
20 BPbeHe,d)2 o9Bi, measured energy spectra for () = 4° - 35°,[

studied single-particle strengths.

Proton stripping reactions were used to investigate

were consistent with the results of Perry et al. 3) within

sin'gle-particle proton states at high energy regions of
5-10 MeV excitation in 209Bi and other nuclei. Con-

experimental errors.
Typical spectra obtained for the (a, t) and eHe,d)reactions on 20 Bpb are shown in Fig . 1. The triton

trary to the studies of deep-hole states, which existed
numerously, studies of highly-lying particle states havebeen rare so far. 1 ) Of particular interest are location,
width and strength of high angular momentum statessuch as Ijs /2 ' li11 /2 in 209 Bi. Such information will
help to extend basic knowledge on shell structure of
nuclei, e.g ., on locations ofstates with large n , shellstructure at 2llw excitation , and systematics of Q-s
splitting. While high-lying particle strength is generally
distributed over a wide range of excitation energy, thespreading for- those high-spin states may be relatively
confined because of their large angular momenta . Usingnnw

stripping reactions with large Q mismatch, one can thus
hope to locate high-spin single-particle strengths atcontinuum regions. Previously we have tested 2 )spectrum in Fig. lea) shows anticipated selective enhancement for high-spin states as seen in the strong
populations of the low-lying levels of h9/2 (0.0 MeV)
and i 1 3/2 (1.6 MeV). It also shows some prominent
bumps at higher excitation energies. Preliminary DWBA
analysis on angular distributions indicates high Q dominance for these bumps. A deutron spectrum from the
20Bpb eHe ,d)209Bi shown in Fig. I(b) exhibits a contrary trend in favour of low-spin final states such as
P3// 3 . I MeV) and f7 /2(0.9 MeV) levels. The spectrum
at higher excitation has a large continuum contribution
presumably due to 3He breakup process, and thein8

populating those strengths. Here we report on experiments using (a , t) reactions. Measurements with a eHe ,6availability of a heavy-ion reaction, ( 12 C,

11 B),d) reaction were also made for comparison .

208P b (3He, d) 5°
74 MeV( b)

208Pb (a, t) 14°
59 MeV( a)

4

A 60 MeV a beam and a 75 MeV 3He beam from the
A VF cyclotron at Texas A & M University were used
to bombard self-supporting 20 Bpb foils of more than

-0

2

],!
>Cl)

99% isotopical enrichment. The outgoing tritons anddeutrons, respectively, were momentum-analysed via the
ESP-IIO magnetic spectrograph with a focal plane:5m 0detector consisting of a position sensitive propor-

6

tional gas counter and a backing E counter of plastic
scintilator. Spectra spanning Ex = 0 to 18 Me V were
measured at several angles from 4° to 35°. The angularopening typically used was 1.7° . The energy calibration
was obtained from the low-lying states of 209 Bi. Cross
sections for the low-lying states in the (a ,t) reaction*

Present address : Texas A & M University, Cyclotron Institute, College Station, Texas 77843,** Present address: University of Washington, Nuclear Physics
Laboratory, Seattle, Washington 98195.

~ 8

x 1/ 54

2o

5
Excitation energy ( Me V)

oFig. 1. Typical spectra of (a) 20B Pb (a,t) 209 Bi
reaction and (b) 20B pbeHe, d) 209 Bi reactions.
Hatched peaks are due to contamination in thetarget.

22
strengths corresponding to the bump structures observedin the (Q,t) reaction are week.
Detailed quantitative analyses on highly-lying states
are somewhat hampered by uncertainties about background estimation and contamination of carbon andoxygen in the target. Analyses in terms of DWBA are
being pursued by noting the selectivity difference
between the (Q ,t) and eHe,d) reactions. Preliminary
results indicate that about 50 to 80% fractions ofand j 15/2 single particle strengths are located in
the energy region of Ex - 4.0 to 7.6 MeV.

ill/2

References
1) S. Gales, C.P . Massole, S,Fortier, E.Gerlic,
1. Guillot, E. Hourani, 1. M. Maison, 1. P. Schapira,B. Zweiglinski, P. Martin, and V. Comparat: Phys.
2)

Rev. Lett., 48, 1593 (1982).
M. Ishihara, E. Takada, T. Murakami, E. Unglicht,
Y. W. Lui, R. Trible, Y. Toba, and Y. Mihara:

REKEN Acce1. Progr. Rep., lQ, 15 (1982).
3) R. Perry, A. Nadasen, D. L. Hendrie, P. G. Prbos,
and N. S. Chant: Phys. Rev., C 24,1471 (1981).

231II-1-7.

Chemical Effects on Internal Conversion ofOuter-Shell Electrons in 125 Te
T. Miura, Y. Hatsukawa, K. Endo, H. Nakahara,
A. Hashizume, M. Fujioka, and E. Tanaka *RADIOACTIVITY 125 I; Implanted into Cu, Zn, Sn; measured
L, M, N, 0 - CE, Mossbauer spectra; deduced 5s electron density at[
nucleus.

Chemical effects on internal conversions of outermost shell electrons were investigated by several groups
in the past. 1) In the case of nuclear magnetic dipole(Ml) transition, the internal conversion coefficient ais dominated by the matrix elements which for low andmoderate transition energies are proportional to themagnitudes of the s-orbital electron wave functions near
the nucleus ~5 hJ; n5(0) 12. Therefore, one expects thatthe internal conversion coefficient of valence s-shellelectrons is proportional to their charge density near the
nucleus and, in general, differ slightly for different
chemical states of the same element.
For experiments of this type with a high resolution(3-ray spectrometer, it is necessary that the transitionenergy is less than about 50 keY for the conversion linesof the electrons in the outer-most shell to be separated
from that due to electrons in the next-inner shells. We
have already reported the chemical effect on the internalconversion process in 119Sn.2) In the present study
we chose the 35.46 keY Ml transition of 125Te that
follows the decay of 1 25 1 (T 1/2 = 60d). In this case theJ

Mossbauer spectra were measured by keeping both
source and absorber (96% enriched Zn 125 Te) at liquid
nitrogen temperature.
The internal conversion spectra were observed withthe high-resolution iron-free (3-ray spectrometer at
RIKEN and INS with the instrumental momentum
resolution of 0.10% for the Q-shell conversion of
35.46 keY transition. A gas-flow proportional counter
having a thin Mylar window of 4 pm thick was used asa detector. The L, M, N, and 0 conversion lines of the
35.46 keY transition were measured. In Fig. 1 are shown
the conversion electron spectra in the region of Nando lines from the source of Sn substrate. The NI line ando line with energy difference of 156 eV could be clearly
resolved from each other. The relative conversion
intensity ratio O/N I was evaluated using the computercode, ACSEMp3) whose function was essentially a least-

Sn sourceenergy of conversion electron is so low that high resolution measurement of the conversion electron spectra
becomes extremely difficult, and the most essential'
problem is how to prepare a source sufficiently thin,e.g. 10 pg/cm2 .
The source sample in this work were prepared by
implanting 125 1 into metals (Cu, Zn and Sn) by meansof the electromagnetic isotope separator Tohoku.
Implantation of the radioactive 125 1 was carried out at
the terminal potential of 20 kV at room temperature.
The dose rate was 3 x 10 8 atoms/cm2 'sec at the focal
plane of A = 125. From the radioactivity of the implanted sample, the number of implanted 125 1 atom
was determined to be 3 x 10 13 atoms/cm2 (,-"100pCi/cm 2). After implantation, in order to identify thechemical state of the implanted sample, emission*

Faculty of Science, Tohoku University .

E0.
u

(f)

C:::J

o
U

1
I

I
I
I
I

I
I

I
I

2.56

2.57

2.58

Voltage (V)Fig. I. The Nand 0 conversion lines of
35.46 keY MI transition in 125 Te (Sn). The
solid curve is the result of the least-squares fit,yielding the components shown by dashed lines.

24squares analysis of the spectra using empirical profiles.

Table 1.

Results of the analyses of three different sources arelisted in Table 1. Each of the M6ssbauer spectra of Zn,
Cu, and Sn sources showed a single line indicating a

metal matrices.

unique implantation site. If the effect of the change in
5s electron density on the inner s-electron densities issmall, one can deduce the 5s electron density at thenucleus from the observed O/N I ratio by using theformula (01 +--+ 5s, N 1 +--+ 4s)
1¢5S(0) 1~=1¢4S(0) 1 .(O/ N r)
2

Experimentally determined conversion line
intensity ratios and electron densities for the
35.46 keY Ml transition in 12 sTe for various

SourceOIN I

11/1 5s (0) 12SnCu

0.138 ± 0.003
0.128 ± 0.004

128 ± 3119 ± 4Zn

0.119 ± 0.007

110 ± 6(1)

where 11/1 5 s (0) 12x is the 5s electron density at the nucleus
for the chemical state x and 11/1 4s(0)1 2 is the 4s electron

References

density of the Te atom. It is noted that in Eqn. (1) the1)

observed°

shell line is treated as a pure 01 line, i.e.

See, for example, J.P. Bocquet, Y.Y. Chu, O.C.
Kistner, M.L. Perlman, and G.T. Emery: Phys.
Rev. Lett., 11, 809 (I 966); B. Martin and SchuM:

the 011,111 conversion is neglected relative to the 01
conversion. We used the relativistic value of Band et al. 4 )Phys. Lett., 46B, 367 (1973).
H. Muramatsu, T. Miura, H. Nakahara, M. Fujioka,

for the theoretical 4s density 11/14/0)12 = 928 a.u. in
Eqn. (1). The 5s electron densities at the nucleus, thus

2)

evaluated are listed in Table 1. The results show thatthe zinc atoms around the tellurium atom cause thereduction of the valence s-electron density at nucleus
by about 10% when compared to the case of tin atoms
surrounding the tellurium atom.

Progr. Rep.,1&., 91 (1982); Phys. Rev. B, (in press).
3) M. Fujioka and M. Takashima: J. Phys., 40, C2-32(I 979).

E. Tanaka, and A. Hashizume: RIKEN Accel.

4)

I. M. Band and V. I. Fomichev: Atom. Data andNucl. Data Table, 23,295 (I979).

25

III-1-8.

High-Spin States of Er Isotopes in theInteracting Boson Model
N. Yosruda , A. Arima ,* and T. Otsuka**

N~CLEAR STRUCTURE interacting boson model, high-][ spm states.

The interacting boson model (IBM) which treatspairs of particles as s- (monopole) and d- (quadrupole)bosons has been successful in describing low-lying
collective states in spherical, deformed and transitional
nucleL 1 ) The particle-plus-core model is widely used
to explain the properties of high-spin states which
couples particles. in high-j intruder. orbitals to a core
which represents collective motion of particles in other
orbitals. When one uses the IBM core, one can describe
ground- and excited bands in various kind~ of nuclei
in a unified way by varying the parameters in thehamiltonian. In a previous work, we used the IBM to
describe high-spin states of the Ba and Ce isotopestransitional nuclei.2) In that case , we took into accounttwo fermions in Oh ll / 2 and obtained a fairly good
agreement of energies and B (E2) values between thecalculation and experiment.
Irt the work we here report on, we describe high-spinstates of deformed nuclei. In the model, we treat theparticles in the intruder orbital explicitly as fermions,and consider that the particles in other orbitals are
represented by IBM bosons. The hamiltonian is
H= H B+ HF + Hint
(1)

where st , d t , and a:t are s-boson , d-boson and fermionJcreation operators, respectively. s is s-boson annihilation
operator , while a and a. are tensor operators whoseJ
components are related to those of d-boson and fermion
annihilation operators, d, a. , byJ
(5)dm= ( - 1)2 - md _ m
and(6)
The first two terms on the right-hand side of Eqn. (4) givethe quadrupole-quadrupole interaction between bosons
and fermions. The third and the fourth terms change aboson into a pair of fermions and vice versa. They
represent the monopole- and quadrupole interactions
between the particles in the intruder orbital and thosein other orbitals. The boson hamiltonian and the bosonfermion interaction are phenomenologically determinedso as to reproduce the energy levels obtained by experiment. B(E2) values and quadrupole moments are calculated using an E2 operator
T (E2) =qB( d t s+ s t d + x(d t dJ (2» +qF(ataj J (2) (7)B(Ml) values and magnetic dipole moments can becalculated using
T (Ml) = mB( d td) (1)where HB is a boson hamiltonian which can be writtenas
HB= Ccl d t

0

J + 1C(dts+ s tJ+x(d t J] (2»+m' B { ( (d t sJ (2) (d tCf J (I ) J (I ) + ((dtCfJ (1)0(s tCfJ (2) J (I) } + m F (ataj ) (I)(d t s+s t J+x (d t ;jJ(2» + l lC' (( d t ci.J (1)10 ~(dt d](I»_ _ +~
4 IC"(s t s t - d t

dt )

0

(8)

0

0

(ss- d od) ,(2)
and HF is a fermion hamiltonian with one- and twobody interactions:
HF =lnF + 2~ LJ g(j)( ( a)ta )t J (]) ( aa
JU »
(3)
.
) )
.

The model is applied to the Er isotopes. In this casethe intruder orbital is Oil 3/2 for neutrons. For the
moment , we allow up to three bosons to change into
fermions. The maximum number of fermions is therefore six. Calculation is being carried out.

0

As for HInt, the interaction between bosons andfermions , we takeH nt = x( dt s + s t d)0

(ataj] (2) + y( d t dJ (2) (araj] (2)0+Z (O) { (a jt ajtJ (O)s- s t (ajajO) }+Z (2) { (a/ a/J (2)0d - dt0(aj a j J (2) },* Department of Physics , University of Tokyo.
** Japan Atomic Energy Research Institute.

References
1)
2)

(4)

A. Arima and F. Iachello: Ann. Rev . Nucl. Part.
SCi. ,ll, 75 (1981) ; and references therein.
N. Yoshida, A. Arima, and T. Otsuka: Phys. Lett.,
114B, 86 (1982).

III -1-9.

Multiple Coulomb Excitation of 1610y
and 1630y

T. Inamura, A. Hashizume, M. Ohshima,* E. Minehara,*
S. Kikuchi,* and H. Kumahora**

NUCLEAR REACTIONS 161,16 3Dy(S BNi, 5 BNi' 'Y)j
. E = 250 MeV; measured E'Y' l.yC8), 'Y'Ycoin., 'Y'YDCO,[
lifetimes; deduced levels, J, 1T.

Multiple Coulomb-Excitation Experiment on 1 61 Dy
and 16 3Dy has been carried out with a 250 Me V 5 BNi

1601 29

beam from the JAERI 20- UR tandem accelerator. We

1363.48

23 / 2- 4.3 (8)have identified members of the ground-state rotational

1137.06

21/2- 6,000

930,97

L9 /2 - 9,000

739,971 1712 - 16( 2)568,64

1 1512- 25( 5)band up to spin 25/2. We have also measured lifetimesof these states which, when taken together with 'Y-ray
branching and mixing ratios, have enabled absolute
B(MI) and B(E2) values to be determined in a modelindependent way.
As shown in the case of 167Er whose ground-stateII

415,18281. 52
I1
167,28 IT
73.471 ~0,0 +rotational band is built on the neutron orbital il 3/2 '7/2+ [633] ,1) a considerable effect of rotational
perturbation on B(MI) is likely to be observed even at
low rotational frequency. The nucleus 1 61 Dy possesses
the neutron orbital i I3 / 2 , 5/2+[642], while 163Dy

E (keV )

•

1

1

1

13/21112912 7/2

5/ 2 [523JI:)//
T

Fig. 1. The ground-state of rotational band of
163 Dy. Nuclear lifetime T are given in units ofpsec. Numbers in parentheses indicate thestatistical uncertainties in the least significant
figure.

possesses f7 /2' 5/2- [523]. These nuclei would exhibit
contrasting behavior of the rotational perturbation
effect on transition probabilities as well as on level
energies because of considerably different orbital angularmomenta.
Figure 1 shows the ground-state rotational band of
163Dy observed in the present experiment. Levels above
15/2- have newly been established. For 161 Dy, levels
up to 33/2+ are known, but lifetimes have been reported
only up to the 9/2+ state. 2 ) Detailed analyses are in
progress.

* Japan Atomic Energy Research Institute, Tokai.
** Dept. of Physics, Hiroshima University.

References
1)

M. Ohshima, E. Minehara, M. Ishii, T. Inamura, and. A. Hashizume: J. Phys. Soc. Japan, 52, 2959
(1983).
2) Nuclear Data Sheets, ll, 493 (1974).

27

III-1-10. Angular Distributions of Gamma-Rays from Dy underTransient Magnetic Field
A. Hashizume, N. Sakai, and K. AsaiNUCLEAR REACTION Dy(40 Ar, 40 Ai ')'), E = 48 MeV; measured ')'(8)J( natural targets. Transient Magnetic Field.

In the decelerating process of recoil-ions produced by
Coulomb excitation, the ions receive extremely large

2+ state, 3 ) becauses 1 64 Dy is a deformed nucleus. However, transient field which is velocity dependent must be

magnetic field when the medium is the polarized ferromagnetic materials. This magnetic field interacts with
spins of the recoil nuclei and causes Lamour precessionof de-exciting ,),-rays emitted from the recoils. The

known to deduce the g-factor. We are now studying thefield using known g-factor of dysprosium and other kindorigin of this strong magnetic field has been the subject

3.5 r---.--,.----...,----.---.--,-..,----,,--.

of targets.

of the study for these several years, and it is believedthat the mechanism proposed by Lindhard and Winthercould be one of the origins in the low velocity region of
the recoils. For higher velocity, several phenomelogicalrel~tions were proposed for the relations between thevelocity and the transient magnetic field. One of thesimplest relations is 1)
B (v, Z) = aZ (v I v 0) x,

where v0 is the Bohr velocity, X is the magnetizationof the foil and a is a parameter which must be determined by experiments. To study such transient fieldand g-factors a goniometer for the ,),-ray angular distribution was installed in the experimental area of RILAC. 2 )When a natural dysprosium target evaporated on an ironfoil of 6 ~m in thickness was bombarded with 48 Me V
Ar4+ ions, the ,),-rays emitted from 1st and 2nd excited

,

I

I

15°

30°

45°
B

I

60°

75°

90°

Fig. 1. Field up and down angular distribution
for 169 keY ')'-rays from the 4+ state in 164 Dy .

References

states in dysprosium nuclei were observed. Figure 1
shows preliminary results of the angular distribution of
169 keV ')'-ray emitted from the 4+ state in 1 64Dy when1)magnetic fields up and down with respect to the beam

2)

direction were applied. Observed b.8 depends on
Larmour frequency and life-time of the excited state.
The g-factor of the 4+ state in 164Dy is not known. It is3)

expected that the factor is slightly different from that ofIo1.1. Eberhardt, R. E. Horstman, P. C. Zalm, H. A.

Doubt, G. Van Middelkoop: Hyperfine InteL,],195 (1977).
A. Hashizume, N. Sakai, K. Asai, H. Kumagai, andY. Yamada: p. 129 in this report.
O. Hausser, H. R. Andrews, D. Ward, N. Rud, P.
Taras, R. Nicole, J. Keinonen, P. Skensved, andC. V. Stager: Nucl. Phys.,.M:..Q6., 339 (1983).

28

III -1-11.

Spin Polarizaiton of Residual Nucleus In 6 Li-Induced Reaction
K. Ieki, M. Ishihara , T. Inarnura, S. Kohrnoto ,K. Sueki, and H. Kudo

J

NUCLEAR REACTION 197 Au(6u, a),), E = 49 MeV; measured)' ray[ circular polarization ; dependence on threshold energy of scattered), rays .

Circular polarization of gamma-rays emitted fromresidual nucleus in the 197 Au(6U, a) reaction wasshown as a function of a-particle energy Ea for threevalues of E)'t h which were set in offline analysis . The
effect of E)'th on P z is rather weak in the region of :I

measured atE = 49 Me V and ela b. = 40° to determine
the polarization of the target-like fragment. A comparison is made with previous result 1) on the 159TbCU,a)E ~ 35 MeV, but it is significant at highest E a , evenchanging the sign of Pz. The observed variation withE)'th may be related to 'Y-deexcitation process. Whenreaction , where the polarization has strong dependence
triton cluster transfer picture . The experimental
method used was the same as described previously 1 )Qtr is smaller than spin cutoff parameter, statistical )'transitions at early stage tend to cascade towards fmal
states with higher spins (If > I) while 'Y transitions at

except for the choice of the threshold energy E)'th oflower excitations may exhibit usual stretched naturescattered )' rays. In the previous study of 7 Li-induced
reaction , E/ h was set at 210 keV because lower energy(If < IJ Since statistical 'Y rays have higher energies
than stretched transitions, choice of E)'th may affect)' rays gave fairly small analyzing power. However, when
the projectile is light like Li , transferred angular

relative weight between the two types of'Y rays. In thehigher Ea region , smallest Qtr is expected and this effectwill occur most drastically.

on a-particle energy that cannot be explained by naive

momentum Qtr and 'Y- ray multiplicity M)' may be so

By setting E)'th at minimum, values of P z are fairly

small that neglect of low energy 'Y rays may affect the results significantly. In the present study , E'Yt h was set tobe minimum to accept low energy )' rays as much as
possible .

constant at P z ~ - 0.4 within statistical errors. The
negative polarization corresponds to positive deflection angle as is expected for direct-type process . The

In figure 1, the results of spin polarizationP z areenergy spectra whose shape are Gaussian , peaked at the=£n =£;7\ ~£~
I

0.9
0.6
03
cr 0 0
- 0.3
- 0.6
- 0.9

o

f-

f-

fH <
I

10

20
EC.M

30

40

() t?q

0

o

o ¢

I

10

(MeV)
(a)

20

30

40

(MeV)
(b)

Ec.YI.

o

Hf

I

1

I

10

20

30

EC.M .

(MeV)

40

50

(c)

Fig. 1. Energy spectra and spin polarization for the 197 Au(6 Li,a) reaction . Threshold energyE)'t h of scattered), rays is set to be (a) 0 ke V, (b) 160 ke V, (c) 210 ke V, respectively.

energy corresponding to the velocity of beam are considered to be the effect of kinematical matching conditions.

This is indeed indicative of a direct reaction

mechanism such as breakup fusion process.

Reference
1) K. Ieki, M. Ishihara , T . Inamura , S. Kohmoto,H. Utsunomiya, K. Sueki, and H. Kudo : RIKEN
Accel. Progr. Rep. , 12., 28 (1982).

29

III-1-12.

Correlation between Angular Anisotropyof Fission Fragment and Its Massin the System of 16 MeV p+ 238 U
Y. Hamajima,* K. Sueki,
and I. Kohno

H. Nakahara,

NUCLEAR FISSION 238U (p, nxf), E = 16 MeV; measured
complementary fragment kinetic energies; deduced <EK> (m),uEK(m), Y(m) and correlation between angular anisotropy[of fission fragment and its mass.

According to Bohr's channel theory, the angular
distribution of fission fragments are mostly determinedby the properties of the nucleus at the saddle point if
the K quantum number at the saddle point is conserved
during the deformation of the nucleus from the saddle
to the scission point and if the fission fragments separate
along the nuclear symmetry axis. 1 ) Extensive studies
have been performed with respect to the angular distributions of fission fragments 2 ) and, as far as theangular distributions are concerned, Bohr's theory has
been proved correct. Therefore, if the final fate of mass
division is determined near the saddle point, somecorrelation is expected between the final fragment
mass and its angular distribution. In 1982, Kudo et al.
reported in the 15 MeV p + 232Th system that somecorrelation existed between the angular anisotropy andthe fragment mass and that the experimental data could
be well reproduced with the assumption of two kindsof saddle points, one leading to symmetric mass division
and another to asymmetric division. 3)
In the present work the correlation between the
angular anisotropy of a fission fragment and its massis further examined in the 16 MeV p+ 2 3 8U system.
The U target was prepared by vacuum evaporation of
UF 4 onto a carbon film of about 50 jlg/cm2 in thickness. The target thickness was about 0.1 mg/cm2 . The
target was bombarded with 16 MeV p beams from thecyclotron. The coincident complementary fragments
were detected with two 60 Jlm gold-silicon surface
barrier detectors. The solid angle of one detector wascollimated to be 0.56 msr and the other, with 21.8 msT.
More than 93% of events detected with the smaller
collimated detector were coincident with the otherdetector. Three parameters were stored and recorded
on a magnetic tape: t~o corresponding to the kinetic* Faculty of Science, Tokyo Metropolitan University.

1energies of the complementary fragments and anotherone to the time-of-flight difference between the two
fission fragments in order to check accidental coincidence events.
U-238 +p(16MeV ) 200 - 159.61Deg
0;; 16.00

(c)

,

0

OJ

J'Ilq,

EbD
U500°'l;f"c:P
00.

12.00

~6'~~'

,19

0

c~

#

>

~ 180.00

0°0""'~o:"oc .,s&'

8.00

'b

(b)

/

~ 16000

~a3

~

~Ol>.

1>'"

-

,

",060>

a; u~ ~140. 00

°
0"

~<>t

"'o'l:r

~o

0

0
°

0

~
0

C6

°

;§ 120.00
6.00

0

(a)
;q

o",fl>b

~ 4.00

0

v
6>
0
0

OJ

0

co

00

""

00
0
00

0

>- 2.00

0'"
00

0.00
60.00

°

Po

0

>.

OJ

0
0

L
cu

°

~I

CD'ln:,

#'

'0,

00

80.00 10000 120.00 140.00 160.00 180.00
Mass distribution

Fragment mass (AMU)

Fig. 1. Results for proton-induced fission of

238 U observed at laboratory angle of 20°. (a)The postneutron-emission mass distribution , (b)Average
total preneutron-emission kinetic
energy as a function of mass. See text for discussion in the cause of the asymmetric distribution,(c) Root-mean-square width of total kinetic
energy distribution as a function of fragment
mass. The abnormal values for masses smaller
than 80 and larger than 150 might have resulted
from poor statistics.

30

The data were analysed with an off-line computer.
The fragment pulse heights were , event-by-event, converted into fragment kinetic energies and provisional
masses through an iteration procedure using the massdependent energy calibration method of Schmitt
U- 238 + P(16 MeV ) 90.0-88.86Deg(c)~ 16. 00
L

[frFo

0

E12.000~l:R>cq"

19
0",

if

tlO

00

'<>~>

0

~

o oooooff (,ao
00

8.00

0

0

>
~ 180.00(b)>,-I' ~~~~ ~#IJY

tlO~ ~1 60.00

./~

(l)

([j u

,
""'ISO00o~~ ~140. 00
~

0 0

0

o

ro

;§ 120 00

References
A. Bohr: Proc. of First United Nations Conf. on
the Peaceful Uses of Atomic Energy,!!, 911 (1955) .
2) R. Vandenbosch and J. R. Huizenga : in Nuclear
Fission , Academic , New York (1973).
3) H. Kudo, Y. Nagame , H. Nakahara, K. Miyano, andI. Kohno: Phys. Rev. C, 25,909 (1982).
4) H. W. Schmitt , W. K. Kiker , and C. W. Williams:
Phys. Rev., 137, B837 (1965).
5) H. W. Schmitt , J. H. Neiler , and F . J. Walter: ibid.,
141,1147 (1966) .
6) V. E. Viola, Jf.: Nucl. Data Sheets, AI, 391(1966).
1)(a)~ 4.0001--~ 2.00The preliminary results observed at laboratory angleof 20° are shown respectively in Fig . 1 a), b), and c) ,on the mass distributions , average total fragment kinetic
energy distributions and root-mean-square widths oftotal fragment kinetic energy distributions. In Fig. 2a) , b), and c) are also shown those taken at 90°. The
total kinetic energy averaged over the fragment mass
distribution was several Me V lower than that from
Viola's systematics.6 ) The asymmetric total kinetic
energy distribution might have resulted from an inaccurate correction for neutron emission and/or that ofenergy loss in the target material. The preliminary
analysis yielded no correlation between the angularanisotropy and fragment mass at this bombarding
energy. More detailed analysis of the data is now inprogress .

~
0

6.00

~

0

o ~"

"<>

0

if)

<U

0

00
0

the mass and momentum conservation
relations and the 252 Cf calibration data.

et al.,4),S)

-.

0

0

fib
'"

i't"
0

0

<P
0

0

'h
0

0

---

'\,<1il ~o

0

0
O

\

V
000
60.00 8000 100.00 120.00 140. 00 160.00 180.00
Mass distribution

Fragment mass (AMU)

Fig. 2. Results for proton-induced fission oflaboratory angle of 90°. See
Fig. 1. for explanation of Figs. (a),_ (b) and (c).

238 U observed at

31111-1-13.

Fission in 14N Induced Reactions on
238U at 120 MeV
K. Sueki, M. Magara, * Y. Hamajima, *H. Kudo, ** H. Nakahara, and I. Kohno

NUCLEAR REACTIONS 2 38Ue 4N,X) fission, measured crosj
sections of total reaction and fission, angular distributions and[ angular correlations of fission fragments.

For reactions of highly fissionable target nuclei,

angular momentum, Qgr ,and the total reaction crosswhere essentially all the fusion phenomena are accom-

section, OR' were evaluated with the classical approxi-

panied by fission, it is possible to obtain the fusion

mation.

cross section by observing angular correlations of fission
fragments. 1) The fission events preceded by incomplete

the lab system is shown in Fig. l(a). The total fission

The fission-fragment angular distribution observed into the target can be separated from those of fusion-

cross section, Of' integrated over this distribution was
1515 mb. The angular distribution in the CM systemfission by angular correlation studies. The amount ofshown in Fig. 1(b) was obtained on the very crude

transfer of the linear momenta of the incident particles

the average angular momenta given to the fissioning
nuclei can also be estimated from the observation ofangular distributions of fission fragments with respect
to the directiori of incident particles.
In the present experiment we have studied thereactions resulting from the bombardment of a 238U
target with 14N ions and observed pairs of fission
fragments in coincidence by using a small 30 JIm thick
SSD (0.5 rnsr) and a position-sensitive SSD (20 deg.),both placed in the reaction plane.
Beams of 120 MeV 14N ions were provided by thecyclotron. The target consisted of 150 JIg/ cm 2 238 UF 4
material evaporated onto a 50 JIg/cm 2 carbon foil. The
angular distribution of elastic scattering events were also

10 2
0

I

I

I

I

I

30

60

90

120

150

BLab

(deg)

observed in order to get the information on the
total reaction cross section and the grazing angularmomentum.
Some of the results are summarized in Table 1. The
grazing angle was determined in the elastic scattering

10 3

-

-

(b)

-

-

from which the interaction radius, Riot' the grazing
Table 1.

(J gr

R int
gr

OR
Of

Measured characteristics of the 120
MeV _14 N + 238U reaction system.

56.2
12.46
64
1755
1515

±
±
±
±
±

0.5 deg
0.07 fm
11
38
mb
50
mb

* Faculty of Science, Tokyo Metropolitan University.
** Present address: Faculty of Science, Niigata University.

1 020~--~
3~1
0--~~1--~~1--~1~~~1--~

60

Bc.~1

90

120

150

180

(deg)

Fig. I. The angular distribution of fission
fragments at 120 MeV 14N+238U. (a) lab
system, (b) eM system.

32
assumption that all the observed fission events originatedand the excitation energy of the fissioning nucleus.

from complete·fusion·fission and that only symmetricAs a next step, we are trying to observe the excitation

fission took place. A more accurate conversion fromenergy of the fissioning nucleus by coincidence experi·

the lab system to the CM system is now in progress.

ments between the emitted light particles and fission
fragments.

The angular correlation data observed with one
detector at 1/1 1 = 90° with respect to the beam direction
are shown in Fig. 2. There are clearly two components

1o4 r----.-----.----.-----r----.----~+'

in the angular correlation data. One is due to the com·"..........,

plete·fusion·fission whose events are centered aroundthe angle 8 12 = 160° which is very close to the angle,;-/

103 1 - .

indicated by an arrow, expected from full·momentum·

f...j!.

transfer. The other is due to the fission preceded byincomplete linear momentum transfer from the projec·
tile to the target. Fragments from the latter events

102 1-

fall on large 8 1 2' When the data are analyzed into two••\

120 MeV 14N + 238 U
cjJl at 90 deg.
\.~..._.. . .........
/"

/

/

~......

., -

f...

components on the assumption that each has a Gaussian
distribution as shown by a solid and a dashed curve in
Fig. 2, the incomplete·fusion·fission amounts to about-'

1015~0~~~--1~6~0--~~--1~7~0--~'----1~80(h2

10% of the total fission events. Similar fractions were(deg )

also obtained even when 1/1 1 was varied from 20° to 90°.

Fig. 2. Fission-fragments angular correlation for

Therefore, the fusion·fission cross section, which isthe system of 120 MeV 14N + 238 U with thefixed detector at 1/1 1 = 90°. The solid line is aapproximately equivalent to the fusion cross section,

Gaussian distribution centering around the angle
corresponding to the full-momentum-transfer,and the dashed line shows the residual area. The
arrow indicates the predicted correlation angle forfull-momentum-transfer.

amounts to about 1360 mb. From the present data, thecross sections of various reaction mechanisms can bedivided into the following fraction of the total:
Incomplete linear momentum transfer;

CaR - 0.9af )/ a R ~ 0.22
Incomplete linear momentum transfer followed byfission;O.1a f /a R ~ 0.09
Complete linear momentum transfer;

0.9a f /a R ~ 0.78.
Where the incomplete·fusion·fission cross section is
located in the 0Q vs. Q plane is unknown yet. It requires
the knowledge of the Qdependence of the fission barrier

Reference
1)

T. S. Sikkeland , E. L. Haines, and V. E. Viola, Jr.:
Phys. Rev. , 125, 1350 (1962); V. E. Viola, Jr.,
B. B. Back , K. L. Wolf, T. C. Awes, C. K. Gelbke,
and H. Breuer: Phys. Rev. C, 26, 178(1982).

33

III -1-14.

Isomeric Transitions of

211mpoand212mpoH. Kudo, T. Nomura, K. Sueki,
Y. Gono, and M. Magara*

NUCLEAR REACTION 208Pb(a,n)211 mpo , Ea = 20 - 30 Mev]
209Bi(a,p)212mpo , Ea = 30 - 40 MeV, isomeric transition, He-jet[ transport, a - "{ coincidence , "{-decay branching ratios.

(1)

Isomeric transition of 2 11 mPo

211 Po is known to have a high spin isomer whose
spin and parity is assigned as J1T = 25/2+ .1 ) This isomerictions. A part of the observed a-spectra is shown in
Fig. 2, in which the 7.450 MeV peak is clearly seen .
The decay curve of this peak is also shown in the upper
part of Fig. 2. Comparing yields of known abundantstate deexcites through a-decay with a half-life of 25 .2 s(See Fig. 1). However, a possible competing "{-decay

a-particles of 211 mPo with that of the 7.450 MeVof the isomeric state has not been observed yet, theupper limit of the isomeric transition being reported toa-particles , we obtained the branching ratio of "{-decayof 211 m Po as 0.016 ± 0.004 %.

be less than 0.2 % relative to the a-decay. We have

The isomeric ')'-ray transition is considered to takemeasured the branching ratio of "{-decay of the isomericstate by use of a hellium-jet transport system which has
recently been fabricated. 2 ) We used the reaction
20 8Pb(a,n)211 m Po at Ea;::: 20 - 24 MeV for produc-

place between the 25/2+ and 17/2+ states (see Fig. 1)
with E"{ = 35 .3 keV. Taking into account the internaltion of 211 m Po. The half life (0 .516 s) of the groundstate is fairly short compared with that of the isomericstate . After decaying out of the ground state that was
produceddirectly from the nuclear reaction
208Pb(a,n)211 gpo , we measured the a-decays from theisomeric state as well as from the ground state which waspossibility repopulated after the isomeric "{-ray transi-

I
I
I
I
I
O.10 1020 30 40 50

Time (sec)

:;0)

L

LD
CX)
CX)

~
o

nr

0.

687.0

E

N

o

0. 51 6 s

5/27% 98.92%
207 Pb

Fig. 1. Partial decay scheme of 211m Po and211gpo.
* Faculty of Science , Tokyo Metropatitan University .

ChannelFig . 2. A part of a-spectra of 211 mpo and
211 gpo (lower part) and the decay curve of the
7.450 MeV peak (upper part) .

34»

conversion ratio of this transition, the above value of theQ)

branching ratio gives a partial ,),-ray half life of 8.7 X 104
y , which corresponds to 1.8 Weisskopf estimate of theE4 transition.
(2) Isomeric transition of 212m Po

Q)

~~

o

0...

A high-spin isomer of 21 2Po was firstly acertained by
Perlman et al. 3 ) Its half life is 45 sec. while its spin and~Nparity is assigned to be (16+) or (18+). The partial
decay scheme of 212pO is shown in Fig. 3. Only an
upper limit (1.5 %) of the branching ratio of ')'-decay of
212m Po is known. The ground state of 21 2 Po has a halflife of 0.3 IlS and emits an a-particle of 8.784 MeV.

IL

TAC true~,,--_~, Jl_~

Therefore, it is possible to determine the branching ratio

10
5

0+

5-

o

0.30115

Fig. 4. A part of a-spectra obtained in a - 'Y
coincidence experiment on 212m Po. The delayed
spectrum is indicated as T AC true.

3 198 2.0%
10%~

0 97% 100%

0+208 Pb

Fig. 3. Partial decay scheme of 212mpo and212gpo.

It is necessary to know a ')'-ray multiplicity of theisomeric transition to deduce the branching ratio ofinterest from the present measurement. A preliminary
result in the a - ')' coincidence measurement yields two

by comparing yields of the 11.65 MeV a-particles fromthe isomeric state with those of the 8.784 MeV exparticles from the ground state , if we measure an aspectrum after a certain cooling time. We used the reaction 209Bi (a, p) 212m pO at Ea =30-40MeV for the
production of 212 mPo. In this case , however, 221 mPo

new ,),-rays besides the known transitions below the 8+

produced from the 209Bi(a, pn) reaction emits 8.885
Me Va-particle which corresponds to the a-decay of
2 11 mPo to the ground state of 207 Pb. As this a-particle
energy is close to that from 212 gpo, we applied a - ')'coincidence measurement to eliminate the disturbing
8 .885 MeV a-decay. The results are shown in Fig. 4,
where the 8.784 MeV peak is seen in the delayed
spectrum.

state, which yields the branching ratio of the isomerictransition to be 0.081 ± 0.023 %.

References
1) B. Fant , T. Lonnroth, and V. Rahkonen: Nucl.
Phys. , A355 , 171(1981).
2)
3)

H. Kudo. T. Nomura, and J. Fujita: p. 127 inthis report.
I Perlman , F. Asaro, A. Ghiorso, A. Larsh, and R.
Latimer: Phys. Rev. , 127, 917 (1962); A. R.
Barnett and J. S. Lilley: Phys. Rev., C2., 2010
(1974).

35

III-1-15.

In-Beam y-Ray Study of212PO

Y. Gono , Y. Itoh,* M. Sugawara, and I. Fujiwara**

NUCLEAR REACTION 210Pb (a,2n), E = 29 MeV measured][ ,,-coin deduced levels.

The nucleus 212po has been studied by manygroups 1) since the observation of the 11.65 MeV adecay from the excited state at 2.91 MeV with a halflife of 45 s. Some experimental works were made bymeasuring the a- and ,-rays following the fj-decays of
21 2Bi. Others utilized in-beam spectroscopic techniques
using the 209Bi(a,p) 212pO and 208Pb CLi,t) 212pO

Ni-foil. The target thickness was about 300 J.1g/cm 2
which corresponds roughly to 5 mCi.
We have made a test experiment on 212pO by using

reactions.
Recently we prepared 21 °Pb target for the in-beamstudies of nuclei in the light actinide region. The target
was prepared by the electro-deposition on a 100 J.1g/cm 2also seen in the spectrum since 2 ° 6Pb was contained in
the target as a decay product of 210Pb. Two new,-rays with the energies of 356 and 578 keV were
found to be in cascade with the above mentioned

the 21 °Pb (a,2n) 212pO reaction (E=29MeV). Resulted
singles ,-ray spectrum is shown in Fig. 1. The ,-rayssuch as 728, 405 , _and 223 keVin 212 Po were easily
identified. Some ,-rays which belong to 20 8po were

2 413
co
r--.

LD

1835

4.0
co

.-<
(Y)

0.-< 3.0

LD

LD

(Y)

8
6

N
N

*

121

1477
1356

(Y)

-B
c

4

~

N
N

1133

0

u

2.0

LD

0

<:::t-

(Y)

r--.

.-<

728

2

(Y)
(Y)
(Y)

1.0
co

I

N

r--.

~
0.0

500

1000

1 500

2000

2 500

3000

2 12 PoCountsFig. 1. Singles ,-ray spectrum resulted from the 21 ° Pb + a reaction
at 29 MeV. Numbers in the figure are given in ke V.

,-rays and also with each other (see Fig.2). The extensive ,,-coincidence experiment was performed recently
with better statistics. The data analysis is in progress.

* Present address: Hitachi Service Engineering Co.
** Permanent address: Kyoto University .

00Fig. 2. Level
212po.

schemeofReference
1) D. Strottman: Phys. Rev ., 20, 1150 (1979), andreferences therein.

36

III-1-16.

Delayed '}I-Ray Study of 217 Ac

Y. Gono, Y. Itoh, K. HUfuno,* T. Aoki,* Y. Nagashima,*
Y. Fukuchi,* and T. Komatsubara*

NUCLEAR REACTION 209Bie 2e, 4n) E = 77 MeV, measured][ 'Yr-coin, pulsed-beam

We reported previously a level scheme of 217 AC

higher energy than 2013 ke V. A delayed coincidence(Ref. 1). However there was still ambiguity on the loca-

analysis shows that there are some low-energy r-raystion of an isomer. Since an isomer with a half-life ofsuch as 75, 122, 156, and 200 keY in addition to thet1/2 = 810 ns was known to exist, a new experiment was
performed with a pulsed-beam of 77 MeV 12C atabove mentioned 'Y-rays (as can be seen in Fig. 2) between the two isomers. The present experiment resultedTandem Laboratory of Tsukuba University. The beam

in too low statistics to get information on the coin-pulses were given every 1.5 J.l,S width. A r'Y-coincidence

cidence relations among them. It is necessary to makeexperiment was made with a 15 cm 3 LEPS and a 70 cm 3

further experiments to clarify the level structure be-Ge(U) in between the beam-burst. A 'Y-ray coincidence

tween the isomers.

spectrum which was obtained by setting gates on thepreviously known r-rays such as 660,486,382,352, and154 keY is shown in Fig. 1.

5.0

Recently a level scheme of 21 7 Ac has also been

4.0

reported by Maier et al. 2 )Our present result is con-sistent with theirs on the r-ray coincidence relations up
to the 29/2+ state at 2013 keY. However the additional

v
~

a

:; 30
if)

5

S

820

r-rays such as 327, 372, 380, and 501 keY, which were
known from our previous report 1 ) to populate an isomer~LDl1l

~

N(Y)V
NNN

1.0

above the 1682 keY state, appear also in Fig. 1. This is600

understood only if another long-lived isomer exists at

Ola-rels

Fig. 2. A delayed coincidence spectrum obtained from the same reaction as Fig. 1. Gates
were set on 660 and 486 keV r-rays. Time gate
was also set on the part of off-prompt to see the'Y-rays above an isomer.

3

References
1) Y. Gono, Y. Itoh, S. Sasagase, M. Sugawara, T.
Kubo, T. Nomura, S. Hayashibe, and K. Hiruta:
600

1 100

1600

2100

Proc.

2600

Charnels

Fig. 1. A delayed 'Y-ray spectrum obtained fromthe 209 Bi
2 C , 4n) 217 Ac reaction at E = 77

e

Int.

Symp.

on

of

NuclearCollective Motion, Mt. Fuji 1982, p. 283 (1982).
2)

K. H. Maier, D. 1. Decman, H. Kluge, N. Roy,W.

Wiegner,M.

Guttormsen,

MeV. Gates were set on 660,486,382,352, andMenningen, and 1. Recht:

154 ke V 'Y-rays.

Progr. Rep., p. 89 (1982).

* Permanent address: Tandem Laboratory, Tsukuba University.

Dynamics

H.

Hubel,

M.

Hahn-Meitner-Institute37

III -2.

Atomic and Solid-State Physics
1.

Theoretical Study of Charge Transfer from H or He toMulticharged Projectile Ions at Impact Energies ofkeV /amu - MeV /amu

T. Watanabe, N. Toshima, H. Suzuki*
Y. Kajikawa,** and H. Ryufuku***In the continuation of theoretical work on chargetransfer prcesses, we have made a series of works onelectron capture from H or He by multicharged projectile ions in the above-mentioned energy region. 1 )This energy region corresponds to the impact velocity
which is comparable to the orbital electron velocity,
i.e., from about one tenth of to about ten times thehave investigated the validity of these approximations by
the following procedure: (a) to compare the UDWA
results directly with calculations using an atomic baseclose-coupling (ABCC) method 2 ) in the cases of H++ +Hand H+ + H, (b) to compare with the calculation in
EDWA (exponential distorted wave approximation) in
the cases of He++ + H, Li 3 + + H, Be 4 + + H, B5 + + H,

orbital velocity. One of the main difficulties in theand C6 + + H, and ( c) to compare the energy levels

theoretical treatment of electron capture by multiply
charged ions from H and He lies in the fact that so many

appearing in UDWA with the exact molecular orbitalenergy levels.
EDWA 3 ) takes into account all interactions between

electronic levels are involved in these processes. Ina coupled channel calculation of Aq+ + H ~ A(q - 1)++ H+, for example, a large number of electronic states
for A (q -1)+ should be taken into account. However ,the number is necessarily limited in practical calculations. Then, the choice of channels becomes somewhat
ambiguous. On the other hand, in UDWA (unitarized
distorted wave approximation) we can take into accountall states relevant to the process, though in the approximation only two successive states are coupled. The basic
idea of UDW A lies in the fact that the electron capture
processes

at

low

and

intermediate

energies

final states and is considered to be exact except for theomissions of the chronological time ordering operation
T and of higher ( ~ the second) order terms in overlap
integrals in the atomic base treatment. We write thecross section for electron capture a nO in terms of then-O (0 being the initial state and n the n-th final state)component of the S matrix using impact parameter
scheme as
cJnO = 27Z'SISnO I 2 b db.

aredominated by the contribution from large impact parameters. At higher energies the two state coupling approximation gives reasonable results.
In UDWA three approximations have been made; (1)to drop the chronological ordering operator in the S

The S matrix can be written as
S = exp ( - iA) ,where

matrix representation, (2) to retain only first order overlap integrals between two atomic orbitals in the coupledequations, and (3) to neglect all the matrix elements
except those involving the initial state in the expansion
series of S matrix (neglect of final state interactions). We(s: overlap matrix, H(t): the total electronic Hamiltonian matrix). Suppose that A is diagonalized by aunitary matrix U as
0

Al

*

Department of Applied Physics, University of Tokyo,
Present address: Atsugi Laboratory , Fujitsu Laboratory
Ltd ..
** Department of Applied Physics, University of Tokyo,
Present address: Central Research Laboratory, Mitsubishi
Electric Corporation.
*** Visible Information Center Ltd.

U-IAU=D=A2 .

owhere Ak is an eigenvalue of A. The S matrix can be38written as

experimental results. This feature implies that, except
for the case of second order Born terms, the dominant

exp( - i AI)
exp( - i A2 )

u- l

S= U

We take into account a limited number of atomic basechannels, Le. , Is of H and Is, 2s, 2p, ..... , 5g ofA(q - 1)+ . One of the results in illustrated in Fig . !.

interaction is confined within a very small region mainly
because of the electron translation factor. Therefore,
the distortion effect is important in the atomic basetreatment. Indeed it is taken into account in UDW A.
The second Born term predominates over the first
Born term in charge transfer processes at high energies.
This is due to the importance of the contribution fromcontinuum states. We have compared experimental
results with the calculations in UDW A, EDWA and in
ABCC in the case of He++ + Hand H+ + H. We havefound that all these results agree with one another in thevelocity region where experimental data are available.
For intermediate and low velocity impact(0.1 < v < 1 a.u .) the final state interaction will not be
negligible. In order to study this point we have also
compared the experimental data with the calculations in
UDWA, EDWA and in ABCC in the case of He++ + H
and with those in EDWA in the cases of Li 3 + + H
through C6 + + H. We have found that the omission of
T leads to an error of less than 30% in the capture crosssections in the velocity region of v> 0.3 a.u. In addition we have studied the correspondence between
atomic base and molecular base treatments by comparing the diagonal matrix elements in the distorted

10- 15;:;--- 10- 16
E

S

c

o

.~ 10- 17
(/)
(/)
(/)

o

U
10- 18wave approximation with the exact molecular baseeigenenergies.

10- 19References

0.1
Impact energy (keV / amu)

Fig. 1. Electron capture cross sections as functions of impact energy per nucleon in the case of
He ++ + H -+ He + + H+. Theories: - - EDWA 3),- - - - Molecular base close-coupling by WinterLane 4 ) , - - - -UDWA 1 ) ,0 Classical Monte Carlo
by Olson S ) , 0 Atomic base close-coupling byExperiments:
FujiwaraandToshima 2 ).
6
• Nutte et aI ), .A. Bayfield et aI 7 ) , • Olson eta1 8 ) .

1)

2)
3)
4)
5)
6)

In high velocity impact (v> 1 a.u.) the cross section
for charge transfer decreases very rapidly. This is predicted by many kinds of theories (Oppenheimer-Brinkman-Kramers (OBK), Born, second Born, continuum
distorted wave (CDW) , eikonal, distorted wave Born
approximation (DWBA), etc.) and has been verified by

7)
8)

H. Ryufuku and T. Watanabe: Phys. Rev., A18,
2005 (1979) ,; ibid ., A19 , 1538 (1979), ibid., A20,
1828 (1979).
K. Fujiwara: 1. Phys. B: At. Mol. Phys. , 14,3977(1981); N. Toshima: unpublished work.
H. Suzuki , N. Toshima, T . Watanabe , and H.
Ryufuku: Phys. Rev., A29 , 429 (1984).
T. G. Winter and N. F . Lane: Phys . Rev . AU,66(1978).
R. E. Olson and A. Salop: ibid. , AU, 1312 (1976).
W. L. Nutt , R. W. McCullough, K. Brady , M. B.
Shah, and H. B. Gilbody : 1. Phys. , B 11, 1457
(1978).
M. B. Shah and H. B. Gilbody : 1. Phys . B: At. Mol.
Phys. , N7, 630 (1974) .
R. E. Olson , A. Salop, R. A. Phaneuf, and F. W.
Meyer : Phys. Rev. , A16 , 1867 (1977).

39

III-2-2

Critical Angle Scattering in High-Velocity Three-Body
Coulomb Rearrangement Collisions
J. S. Briggs

In the process of electron transfer from a positive ion

where V.. denotes the Coulomb interaction between
IJ

particles i and j and G~ is the Green function for free

to a neutral atom such as
P + (T, e) - ( P, e) + T(P: projectile ion, T: target coreor nucleus ande: electron), there exists a problem that the scattering
amplitude in the second order perturbation approximation dominates over that in the first order approximation owing to the contribution from electronic con-propagation of all three particles. Expansion of thesecond (double-scattering) term gives four contributions denoted by T(23,13), T(l2,13), T(23,12), andT(12,12).

It is easily seen that the V 1 2 interaction plays aspecial role as the only second-order term to contain thesame interaction twice. This term describes thetinuum intermediate states in the high impact velocity(repulsive) scattering of particles 1 and 2 whilst thelimit of collision. Theoretically this effect is expected tobe significant above the impact velocity of "'-' 10 q a.u.,where q is the charge of the projectile ion. Even atlower impact velocities the second order term is

captured particle 3 is a spectator. Then capture occurs
only through the recoil of target particle 2 and does notlead to critical angles due to two correlated two-body
events, as do the other three terms in the second-order

predicted to appear (and to be discriminated from theT -matrix element.
Dettmann and Leibfried have shown that in thehigh-velocity limit *V 2 >E j , Ef(where v is the initial relative velocity and Ei' Ef the binding energies of parti-

first order term) in the form of a peak, called Thomaspeak, in the measured differential cross section (angulardependence). Recently the peak has been observed
experimentally for the first time. Here we treat generally the problem of rearrangement from the system ofa projectile particle 1 (=P) and target (2,3) (=(T,e)),which consists of particles 2 and 3, into the system of
a bound complex (1,3) (=(P,e)) and a target particle 2(= T).
The occurrence of such enhanced probabilities forcles 2 and 3 and particles 1 and 3 respectively), criticalangles occur as follows:
T(23,13) ; when(2)
T(12,13) ; whenparticle capture at certain angles of scattering of the projectile particle 1 has been analysed by Dettmann andLeibfried. l ) These critical angles occur when the
kinematics of the collision is such that the incident

cos f) = I( ~~') - 1/2

2x{ 1 + ~~' - (e' / ~) (1- ~~,)2(1- ~') -2}, (3)particle 1 and the caputured particle 3 emerge withequal velocity after the collision. Since only kinematicconditions must be satisfied, these processes have aclassical counterpart. Indeed the first example of sucha critical angle capture was described classically byThomas 2 ) in the case of electron transfer between two

and T(23,12) ; when

nuclei.

where () is the centre-of-mass angle of scattering andQuantum-mechanically the occurence of a criticalangle and concomitant enhancement of the capture
amplitude are signified by a pole in the free-particle
Green function appearing in an expansion of the~ =m2f(m2 + m 3 ) and=m l f(m l + m 3 ). That thecritical angles depend only upon mass ratios emphasises
their kinematical origin.

T-matrix element for re!arrangement to second order.
This second-order approximation issuch that the modulus of the right hand sides of Eqns.
(2)-( 4) is less than or equal to unity. This is illustrated
by the consideration of three cases of same importance.
The first is the much-studied transfer of an electronfrom a target nucleus to an incident proton where

T = <<PfI V 23 + V 121<pi>+ <<Pf I (V 23 + V 12) Gt (V + V
13

12)

I<P i >,

(1)cos f) =I( ~~') -1 / 2

2

x { 1 + ~~' - (~/ ~') (1 -~~' ) 2 (1 - ~) - 2 },(4)r

The critical angles occur when the mass ratios are40~'= (1 +~)-1

Mp

where m, MT , and Mp are masses of electron, target
nucleus and projectile proton respectively. To order(m/M p ), one finds from Eqn. (2) that a critical angle

For MT > Mp no critical angle is possible. The explanation is simple. In the first collision the incident proton
scatters off the target nucleus which then recoils andoccurs for T(23,13) scattering at

scatters the electron. For MT > Mp the recoil velocity
is never high enough that the recoiling nucleus can impact sufficient velocity to the struck electron for it tomove with the velocity of the proton.
The case of proton impact is to be contrasted withthat of positron impact, leading to positronium formation. Here one hasin the laboratory frame.
This correlated scattering is depicted in Fig. lea) where,
to order m/M T , the recoil of the target nucleus isneglected. It is the classic case considered by Thomas 2 )and observed recently by Horsdal-Pedersen et al. 3 )In the case of electron capture the term T(12 ,13) also
shows a critical angle when

For T(23,13) the critical angle is obtained from Eqn.
(2) as cos () = l/fi to order m/ M T .
This mechanism is depicted in Fig. 2( a). The incident
positron scatters the electron through 45° and bothparticles then have speed v/
The electron thenscatters elastically through 90° off the massive targetn.

This angle varies from rr when Mp = MT to rr/3 in thelimit Mp/MT -+ O. This latter case, where no target recoil
occurs, is illustrated in Fig. l(b). Here the incident
proton with speed v first scatters the electron through an

nucleus. The T(12,13) matrix element also shows acritical angle at cos 6 = 1/ f2 as may be shown from
Eqn.(3). In this mechanism, depicted in Fig. 2(b),angle 60° (whereby it acquires a speed v) and then thethe positron first scatters the electron but is then itself

proton scatters elastically off the target nucleus to('merge, still with velocity v, also at an angle 60°.

scattered through 90° off the target nucleus. Clearly, inthe case of positron impact, the two T-matrix elements
T(23,13) and T(12,13) differ only in the sign of the

Finally, one sees that for electron caputre the term
T(23,12) shows a critical angle at

(a)

(a)

Mp

7e

v/./2
v

e+

v

+

:~foe-.

MT

Fig. 1. Schematic figure of critical angle
scattering in the electron transfer process.
(a) critical angle (6«1) for T(23,13)
scattering, (b) critical angle (6 = 1T/3) for
T02, 13) scattering in the limit Mp/MT -+ O.

Fig. 2. Schematic figure of critical angle
scattering in the collision of a positron witha target atom to form a positronium.
(a) critical angle for T(23 ,13) scattering,(b) critical angle for T02,13) scattering.

41

second interaction , electron-nucleus or positron-nucleus

References

respectively. This leads to the result obtained by
Shakeshaft and Wadehra 4 ) that positronium can only beformed in odd-parity states as a result of critical angle
scattering . Finally, since m« MT one sees that
T(23,12) has no critical angles corresponding to the1)

K. Dettmann and G. Leibfried: Z. Physik, 218,
1 (1969) .

2)
3)

L. H. Thomas: Proc. Roy. Soc. , A114 , 561 (1927).
E. Horsdal-Pedersen , c.L. Cocke, and M. StOckli:

physical situation that the massive nucleus hardly recoils
after being struck by the light position.

Phys. Rev. Lett., 50,1910 (1983).
4)

R. Shakeshaft and 1. M. Wadehra: Phys. , Rev.,
A22 , 968 (1980).

42

III-2-3. Charge Equilibrium of Energetic Heavy Ions and Its Effecton the Stopping Power of Gaseous MediaS. Karashima and T. Watanabe

The problem of charge state distributions!) of heavy
ions passing through solid target as well as gaseous target
is generally of great theoretical interest and of decisive
importance for many practical purposes. 2 ),3)
When energetic heavy ions traverse through dielectric
media, the amount of energy deposited by ions closely

Ignoring the multiple-charge-exchange processes, we
can obtain the following rate equations:d¢ (v·)

N:x 1

z

=

~

[¢p(v j ) O"p, q(Vj) -¢q(Vj) O"q , p(V j )] (3)p=owith P = q ± I and 0 ~ p ~ Z.

relates to their effective charges . Then the LET (Linear

If we assume that d<l>q(vi)/dx = 0 (local balance ap-

Energy Transfer) and the range of the ion beam areproximation) for all q, and introduce Pq defined by Pq =fundamental physical quantities in the mechanism ofenergy deposition.
The fractions of ions in the beam in different charge<l>q/<I>q-I' we can obtain equations
O"q - l , q---=p
O"q,q _ lstates can be obtained from the rate equations for theelectron loss and capture processes using their crosssections. In a series of works,4) we have developed aa condition of local balance (the charges are locally inequilibrium between electron loss and capture processes). The average equilibrium charges of various inciden t heavy ions in atomic hydrogen gas, their range

(4)

and
q

¢q(V j )=simple model to describe these charge-exchange processes of energetic heavy ions passing through gaseous
atomic hydrogen. The basic rate equations for the
charge-state fractions of incident ions are obtained under

q

n

(5)

j= 1

We need the information on a q , q±1 (Vi) for electron
loss and capture processes to obtain the values of <l>q(vi)'
We estimate the cross sections for the processesX(q - l)+ + H ----. X q + + e+ H(all states)

(6)

and

and the stopping powers of atomic hydrogen for them(7)

are obtained.
When an ion of charge q collides with target atoms,
the ion may lose or capture one or more electrons in the
ion-atom collisions. Let <l>q(vi) denote the charge-state
fraction of ions with charge q and velocity vi' It is normalized as L <I> = I and the average eqUilibrium chargeqq
is given byzq(Vj) = ~ q'¢q(Vj)
q=l

(1)

F or the electron loss process (6) we made an assumption that aq-I, q may be approximated by that for thecollision of a hydrogen-like ion with an atomic hydrogenaZ-1

z· For the process (6) we scaled cross sections cal-culat~d by Shirai et al. 5 ) based on the binary encounter
approximation (BEA). The cross sections for electron
capture process (7) were obtained from the scaled results 6) based on the calculation by the unitarized-distorted-wave (Born) approximation (UDWA).7) If the

We consider the case where the ion moves by a length
dx along its trajectory in a material containing N atoms
per unit volume. If we ignore the contribution of
excited states of the ion, the change in the fraction

d<l> q can be written in terms of the charge-exchange
cross sections a q,p from charge state q to p as

momentum distribution of the outermost electrons in
the incident ion is similar to that of the Is-wave functionof a hydrogen-like ion, <l>q(vi ) can be scaled in terms of
Vi'
In Fig. 1 we show the calculated <l>q(vi) for Ne ions in
H and experimental values for Ne ions in H2 .8 ) The
average eqUilibrium charges q(Vi) are displayed in Fig. 2
in the energy range 1.5 X 10 3 "'9.5 X 10 7 eV/amu, andare compared with those in Ref. 8 . We also obtained
the LET and ranges using the Bethe formula with em-+ (contributions from Auger and autoionizing
processes).

(2)

pirical effective charges based on the numerical results ofour calculations. Figure 3 shows the calculated deposi-

43

Z=lO ( Ne )1.0(I) \Ov~_

(1)0

-

----j

Ne

100

0.5

0.8

"'E
c

~
~

u

'-.....
tlD

0.6E'-.....
>Cl)

0.4

~

Qi

0.2

~
0

Q.

tlD

12 MeV/ amu

0.0 125c.0..
Energy f eV / amu )

Q.

0

U5

Fig . I . Charge-state fractions ¢ q (v.)
1 for Ne ionsin H gas, calculated as a function of projectile
energy per nucleon. Dashed curve indicates experimental values for ¢1 ' and 1>2 in H2 8 )Fig. 3. Relation between stopping power and range
for Ne ions in H gas (solid line). Open circles indicate
experimental values 9 ), plotted against the incident
energy per nucleon (connected by broken line).

90

momentum-distribution difference between hydrogen(1s)-like and Thomas-Fermi density functions. The

70

second one is the calculation of ¢q(vi) without the
local balance assumption. When projectiles enter a

Ic:rCl)

tlD

~
u

E 50-

target with a charge far from the average equilibrium
value, they will travel a considerable distance before~

charge-state equilibrium is attained. We are obtaining

..c
~

~

0-

¢.1(q) 's and q.(v)'s as functions of the distance x the ions1
have traveled in the medium.

Cl)
Cl)

tlD

~

Cl)

>

30

«

References
10
O~~~~~~L-

10 3

10 4

__~_~~~

10 5
10 6Energy (eV/ amu)

Fig . 2. Average equilibrium charges q of C,
Ne, Ar, Kr, I, and U ions passing through Hgas, calculated as a function of incident beam
velocity (upper scale) or of energy per
nucleon (lower scale). Open circles show
experimental results for N eq + + H2 8)tion profIle for the Ne ion. The calculated Bragg curve
can be compared with experimental data. 9 )As one of our research work series we are now carry-

1)
2)
3)

H. D. Betz: Rev. Mod. Phys ., 44, 465 (1972).
T . A. Mehlhorn: l . Appl. Phys., 52, 6522 (1981).
J. Meyer-ter-Vehn and N. Metzler: Target Designfor Heavy Ion Beam Fusion (Max-Planck-Institut
fUr Quantenoptik , Garching bei Miinchen, July
1981) , p.15.

4)

S. Karashima and T. Watanabe: lpn. 1. Appl.
Phys. , 22 , 895 (1983).

5)

T. Shirai , K. Iguchi, and T. Watanabe: 1. Phys.
Soc. lpn., 42, 238 (1977).

6)

Y. Kaneko et al.: Cross Sections for Charge
Transfer Collisions Involving Hydrogen Atoms(Institute of Plasma Physics, Nagoya University,
Nagoya, IPPI-AM-15 , 1980).

7)

H. Ryufuku and T. Watanabe: Phys. Rev., A18,

ing out the following two calculations. The first one isthe calculation of the loss cross sections for arbitrary q
by a BEA formula using Thomas-Fermi statistical model

8)2005 (1978); ibid ., 20,1828 (1979).
A. B. Wittkower and H. D. Betz: Atom. Data, 2,
113 (1973).

for the momentum distribution of electrons in the pro-9)

jectile. This will give information on the efffects of the

L. C. Northcliffe and R. F . Schilling: Nuclear Data
Sec. A,l, 234 (1970).

44

III -2-4.

Transitions of Molecules between
High-Angular-Momentum States

I. Shimamura and A. C. Roy

High-energy charged particles and ionizing radiation

The two cross sections da(J--+ J ± llJ)/dw plotted versus

penetrating matter normally produce secondary elec-

J approach a value C( 16J I) common to both as J--+oo,

trons of tens of electron volts and even higher in energy.

one from above and the other from below in a manner

These electrons give up their energy to the matter innearly symmetric with respect to the horizontal line thatcollisions with the constituent atoms or molecules, andaims at the limiting value. The sum

are eventually thermalized. The energy distribution ofthe' secondary electrons in matter is of crucial im-~

1' = J ± t.J

dO"(J~J') /dw= 2C( I ~J I) 11 + O(J - 2)\(2)physics andof the two cross sections is nearly independent of J

chemistry. For molecular matter the energy distribution
is determined by the cross sections for electronic, vibrational, and rotational excitations of molecules byfor high J. This 'partial-sum' rule is to be compared with
Drozdov's sum rule 2 )portance

electrons.

in

the

study

of radiation

Among these processes rotational transi-~ dO"(J~J')/dw= (constant independent of J).

(3)

all l'

tions play a decisive role in determining the low-energy

Because the rotational energy E/l) is BJ(J + 1), B

portion of the energy distribution of secondary electrons.

being the rotational constant, the transition energiesllE(J --+ J ± lll) for a fixed value of llJ are linear in J.

The cross sections for state-to-state rotational transitions, rather than the averaged cross section, are extremely difficult to measure directly, because the

Therefore, the cross sections llE(J --+ J ± 6J)da (1 --+ J± L\J)/dw for energy loss by the electron increase with J
as£'IJ. The sum

energy resolution of electron spectrometers is too low
to resolve rotational lines, which are closely spaced, inthe energy-loss spectra. Reliable theoretical calculations~~E(J~J')dl5(J~r) / dw

1' =J ± t.J= 4B (~J) 2C( I ~J I) 11 + 0 (J -2) \(4)

are too cumbersome to carry out for many differentof the two energy-loss cross sections, however, is nearly

initial and final rotational states; molecules are normallyconstant for high J. 1 ) This is to be compared with therecently proven sum rule 3 ),4)

distributed among many different rotational states.
One of the present authors, however, has noted thatmost molecules occupy high-lying rotational states J,
and has derived simple formulas for the cross seGtions
for transitions of linear and spherical-top rotators fromhigh rotational states 1 to high rotational states J ' =J ± 6J. 1) The main virtue of these formulas is that theygive the cross sections for the transitions J--+ J ± 6J
for any high 1 in terms of a single unknown parameter
independent of J. The present work is a generalizationof these formulas for transitions of symmetric-top
rotators.

~ ~E(J~J')dO"(J~J ' ) /dw
all l'= (constant independent of J)(5)

for the mean energy-loss cross section.
Equations (1) through (5) are, in fact, applicable not
only to electron scattering but also to atom scattering,ion scattering, photoabsorption, and photoionization in
the sudden approximation ..
We are generalizing these results for rigid symmetrictop rotators. They have a well-defined quantum number
K (- J~ K ~ J)

for the projection of the rotational

Main results for the transiti.ons of linear rigid rotators
are first summarized. Assume that the collision time

angular momentum onto the body-fixed symmetry axis.

is much shorter than the rotational period, which isof the order of ,...., 10- 1 2 s. This assumption is equiv-dl5(JK~JK') / dw = C( I ~J 1= 0, 1~K I ) 11 + O(J -2 )ialent to the assumption that the electron temperature
be higher than the rotational temperature. Without any
further approximations it follows for J »1 6J I that 1)
dO"(J~J ± ~J) /d w = C( I ~J I)

x 11 ± (~J!2)] - l + O(J - 2)\.

(1)

Some of the formulas we have proved are(6)
for transitions with 61 = 0,
dO"(JK~J ± ~J, K) / dw = C( I ~J I, ~K = 0)

xlI ± (~J!2)]-l + O(J - 2) \for transitions with 6K = K' - K = 0, and

(7)

45
d ITO K - J ± ~J, K + 1) / d w = C ( , ~J , , ~ K = 1)
x (l + ~J (2K + J- 1 ± C' ( I ~J I )Xl (2K + l) / ~J I J - 1 +OO - 2)J(8)t)

ing rotationally unresolved energy-loss spectra of electrons to extract state-to-state rotational transition crosssections.4 ),S )for transitions with ~K = 1.
In all of these cases the partial-sum rules

References
1) I. Shimamura: Phys. Rev., A28, 1357 (1983).
2) S. I. Drozdov: Sov. Phys. JETP, ,l, 591 (1955);~ dlT(JK- J'K') / dw

l' = J ± tiJ=

2C ( , ~J , , ~K) 11 + 0 (J - 2 ) I

(9)
3)
4)

and
lim

~

J-+ 00 l' = J ± ti J

~E(JK-J'K ' )dlT

X (JK-J'K ') / dw

= (constant)(10)

immediately follow.
Equations (1) and (6) - (8) are useful also in analyz-

5)ibid.,]', 759 (1956).
I. Shimamura: Phys. Rev., A23, 3350 (1981).
I. Shimamura: Chap. II in Electron-Molecule Collisions, (eds. I. Shimamura and K. Takayanagi),
Plenum, New Yark p.'89 (1984).
I. Shimamura: in Wave functions and Mechanisms
from Electron Scattering Processes, (ed. F. A.
Gianturco), Plenum, New York (1984) in press.

46

III-2-S.

Beam-Foil Spectroscopy

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

One of the unique features of beam-foil experiments
lies in the point that we can make directly time resolved
studies of decay processes of excited species after leaving

can be driven along the ion beam axis as long as 50 cm,
and the accuracy of setting the disk position is within± 25 J,Lm. The monochromator used is a grazing in-a foil target. The time t of a decay process of the excitedcidence type of Nikon-McPherson (model 247) whichstate directly corresponds to the distance from the foil.
We have started a beam-foil experiment by using of

has the radius of the Rowland circle of 2 m and an
incidence angle of 86 degrees. Its entrance slit special-

the linear accelerator (RILAC) in order to carry out,

ly designed can approach the ion beam as close as 5 mm

firstly, a systematic measurement of mean life time ofthe excited states of highly ionized projectiles which willplay an important role in , for example, high temperaturefusion plasmas, high density laser plasmas, astrophysics

to have enough spacial resolution of beam length in life
time measurements. Figure 1 shows, as an example, line
spectra of nitrogen ion excited by a carbon foil of
10 J,Lg/cm 2 with incident energy of 14.8 MeV.

and so forth. We have also much interest in somedynamic feature characteristic of beam-foil interactions.

The output signal for the i ~ j transition I.~ from theIJ
detection system is given by

As a first step, we have tried to determine the relativeI?·=
I IJ···SU. IJ··) 'IJ

sensitivity of our detection system including a grazing
incidence monochromator and a channel electron multiplier (Ceratron) with a secondary electron covertor.
Some preliminary results are reported in this paper.
A detail of our experim~ntal set up is described
elsewhere. 1 ) , 2) Briefly it consists of a vacuum chamberwhere I.IJ. is the intensity of the light due to the j ~ jtransition entering into the monochromator, S(A..) is
1J

the overall sensitivity of the detection system. The
Iij(A) is related to the branching ratio by
I ·· = N · Aij
IJ
1 ~ A.

and a grazing incidence monochromator . The chamber
contains a disk on which 17 carbon foils are mounted.
A broken foil can be changed to a new one withoutk< i~ A.k is the inverse of
J'ectile after foil excitation , k<i1

10 2 ~----~----~~-0--~----~----~----~----~----~
(Y)

0.90

cor---NN(Y) (Y).--< (Y)

\..0

.--<

>
0.77

Z

1983. 3. 11(Y) (Y)

N2 + 14.79 MeV"--v--'

slit width 200l1m
charge/ ch 2 x 10- 5 Cr---r--->
Z~co

S 0.64
x

N
0'>

.--<

t..O

SS

§ 0.51
cu

..c
U

(2)

Ik

where Ni is the population of the level i of the pro-breaking vacuum condition. The carbon foil disk itself

r---~

(1)

>
z

r---o

N(y)

0'i0'i00
NN"--v--'>z'--...

~ 0.38
:::J

o

u

0.26

0.13

o
Channel number

Fig. 1. Line spectra of nitrogen ion excited by a carbon
foil of 10 J,Lg/cm 2 with the energy-of 14.8 MeV.

47

the mean life time of the level i, and A..IJ is the
spontaneous transition probability for the i ~ j transition. Therefore, if we choose two lines originating from1.54 X 10 10 S-I, and 8.33 X 10 9 S-1 for the corresponding value. 4 )-6) As shown in Table 2, the SeA)

the level i, the ratio of their intensities is given by
I ·· A ..
I ik - Aik..:..!l. - ~(3)

Accordingly, we haveIi\ .

S (A·ij) _Aik
S( A'1k) -IsA··1J
ik(4)

In the present work, the intensity measurements weremade for the following transitions of N V which arelisted in Table 1.
Table 1.

3p 2po2p 2poat 713 A(4d ~ 3p) is roughly 15 %too low from theaveraged value between S(629 A) (4p ~ 3s) andS(777 A) (4s~3p). This may be attributed to aninaccuracy in the theoretical values of LA. .; notice thatIJ
the experimental LA .. value of 1.58 X 10 10 S-1 forj<iIJ
the 4d level of N V is just 15 % lower than thecorresponding theoretical values of 1.86 X 10 10 s- 1 .

Observed transitions of N V.

Transition
3p 2po2p 2pofor the 4d ~ np transitions, the calculated value ofj.ti Aij is 1.86 X 10 10 S-1 from the table of Martin and
Wiese, while different experiments give 1.58 X 10 10 s- 1 ,Wavelength (A)Table 2.

Observed relative sensitivities. _Aki *Wavelength (in A)

S(A)*

4s

2S

777.712, 778.172

2.41

162

1.05

4s

2S

190.155, 190.249

3.42

186

1.02

4d 2D

713.518, 713.860

4.30

190

1.00

186.063, 186.149

14.3

629

0.079

628.874, 628.744

1.55

713

0.068

162.564, 162.556

5.86

777

0.084

3s

2S

4d 2D
4p 2p

2s

2S

4p 2po9* Aki is given in units of 10 sec-

1

* The relative sensitivity at 190 A
is normalized to unity.

The values of Aki are calculated from the relation
Aki = 6.670 x 10152
/ A • gi/gk· fik

0(.lin A)

(5)
3

using the multiplet f-values given by Martin and Wiese. )In Table 2 we show the obtained relative sensitivitiesof the detection system including the grazing incidence

References
1) K. Ando and K. Mori:l5., 85 (1981).
2)

monochromator as well as the Celatron with a secondary

It should be noted here that the accuracy of SeA) inagreement with the measured value of 5.8 X 10 9 S-1 of
Buchet and Buchet-Poulizac. 4 ) On the other hand, as

K. Ando, T. Tonuma, S. Kohmoto, S. Tsurubuchi,
and K. Sato; Atomic ColI. Res. in Japan, 2, 94

3)(1983).
G. A. Martin and W. L. Wiese: J. Phys. Chern. Ref.

4)

Data,2, 537 (1976).
J. P. Buchet and M. C. Buchet-Poulizac: J. O. S.

5)

L. Heroux: Phys. Rev., 153, 156 (1967).

6)

J. P. Buchet, M. C. Poulizac, and M. Carre: J. O. S.
A., 62, 623 (1972).

convertor coated with cesium iodine .
Table 2 depends only on the accuracy of the values ofA . as seen from Eqn. (4). The value of L A.. for theklj<i IJ
4s ~ np transitions of N V is, as is calculated from
Table 1, equal to 5.83 X 10 9 s- 1, which shows nice

RIKEN Accel. Progr. Rep.,

A., 64,1011 (1974).

48

III-2-6.

Optical Detection of Atomic Spin Polarization Produced by
Beam-Foil Interactions. Kohmoto, M. Ishihara, T. Nomura,and Y. Gono

For an automatic measurement of polarization of¢ dependence of S/I at EN :::: 5 MeV where two methods

light in tilted foil experiment, l ),2) we have constructed

give a same S/I value as well as at higher energy region

an apparatus which permits with the aid of a step-motor

for the purpose of clarifying the generation mechanism.

drive to rotate one of the optical elements ("-/4 plate or
linear polarizer).

This apparatus is controlled by a30(ref 4)

micro-computer and the pulse counts from the photo-------+

multiplier are accumulated in the PERKIN ELMER
computer in MCS(multi-channel scaler) mode.

.......
~

Using this system, the relative Stokes parameter S/I

C/)

for the N V (494 nm) line was measured for a single
tilted foil with the tilt angle 2 ) </> = 45° as a function ofothe incident energy of the N-ions. The 14N ion beam
was produced by the Linac. By rotating the "-/4 plateevery 2 or 5 seconds, a pair of measurements of lightintensity at ~ = + 45° and - 45° 2) were performed sothat a S/I value was obtained every 4 or 10 seconds.
After the whole measurements, these values wereaveraged over to deduce a final S/I value. Thus it was

10

5

10

15

EN (MeV)Fig. 1. Relative Stokes parameter Sf I obtained by us(open circles; tilted foil method) as well as by Randolph
et al. 3 ) (full circles; tilted foil method) and by Winteret a1. 4 ) (full squares; grazing incidence method). Our
result at EN = 5 MeV was obtained with a slightly different arrangement of apparatus.

possible to minimize an additional error due to the beam
path fluctuation during the measurement.
Figure 1 shows our results as well as those obtainedby Randolph et at. 3) (tilted foil method; TFM) with

References
1) S. Kohmoto, M. Ishihara, T. Nomura, Y. Gono, and¢ = 60° and by Winter et a1. 4 ) (grazing incidence

M. Sasagase: RIKEN Accel. Progr. Rep., 12, 86

method; GIM). It seems that the S/I of this line decreases at high energy region when a constant tilt angle(1981).
S. Kohmoto, M. Ishihara, T. Nomura, Y. Gono, and
Y. Itoh: ibid., 16,94(1982).
W. L. Randolph et al.: Hyper. Int.,.1, 279 (1979).
H. Winter et al.: ibid.,~, 261(1980).
N. H. Talk et al.: Phys. Rev . Lett., 47, 487 (1981).

is used.

2)

Talk et a1 5 ) contend that the generation

mechanism of the atomic polarization is same for thetwo methods: the GIM is the extreme case of the TFM
with ¢ :::: 90°. Thus it will be interesting to measure the

3)
4)
5)

49

III-2-7.

K X-Rays from Ar-Ions Passing through Foils ( I )Y. Awaya, T. Kambara, M. Kase, H. Kumagai, 1. Urakawa,
H. Shibata, T. Matsuo, 1. Takahashi, and M. Namiki

We have studied the dependence of multiple innershell ionization of Ar ions passing through various target
foils on the atomic number of target element and we
had previously reported preliminary results. 1 ) We report
here the results obtained thereafter.
The experimental conditions were the same as in theprevious work, l ) : the energy of incident Ar4 + ions was
33.6 MeV and K X-rays were measured by using a broad
range X-ray crystal spectrometer. 2 ) In the present work,
Ar K X-rays from the target of Nb, Cd, Nd, Ho, Tb, andW were measured in addition to the sixteen elements
ranging from C to Au reported previously. The thicknessof the foils used in the present work was between about
0.9 mg/cm 2 and 2.6 mg/cm 2 except for Nd and W
whose thicknesses were 25 11m and 50 11m, respectively.
As discussed previously, 1 ) most of Ar. K X-rays detected
can be regarded to be emitted within first 1 mg/cm 2 of
the target.
We obtained the X-ray spectrum of energy higher
than about 3.3 keY (Cf. Fig. 1 in Ref. 1) and found thatthe peaks observed between about 3.17 ke V and 3.3

level matching occurs, the electron transfer cross section
from the target to the 2p hole of Ar ions becomes large.

(a)

~

j

a,5f- 0/ \

,.\

I

+

~0.4r- /t,\'if

f·\

•

I

.: /

\

\.~

x
~J 33,6 MeV
x 21.1 MeV

x
0.3-

o

+

I

I

I

I

I

I

I

I

10

20

30

40

50

60

70

80

90

22

ke V, which we had assigned to KP satellites and Ka
hypersatellites in the previous report, should all be
attributed to Ka hypersatellites. The KP satellites
were observed at energy higher than 3.3 keY and thiswill be described elsewhere in. this volume. 3 )The values of the ionization probability of L-shellelectrons, PL' are obtained from the spectra of KQ
satellites by assuming that the cross section of simultaneous single K-shell and multiple(n) L-shell ionization is
given by a binomial distribution of Eqn. (1) in Ref. 1.
The P L values thus obtained inclding previous data areshown as functions of the atomic number of target elements, Z2 in Fig. l(a). The P L values show an oscillatory!, behaviour against Z2 as was pointed out previously.l )The charge of Ar ions are estimated to be between
10 and 12 according to the work by BaudientRobinet. 4 ) In Fig. l(b), binding energies of orbital
electrons of the target element and those of 2p electronof Ar l 0+ and Arl 2 + are plotted against Z2' Comparing(a) and (b) of Fig. 1, we find that minima of P L
correspond to the atomic number Z2 where the binding
energy of orbital electons of target atom matches to thatof 2p electron of Ar ions. This implies that when theFig. 1. (a) The plot of ionization probability ofL-shell electron PL vs. the atomic number oftarget Z2' The open and closed circles show thevalues of PL for 33.6 MeV Ar ions and theformer corresponds to the value for thinnertarget foil (Ref. 1). The crosses show those for21.1 MeV Ar ions. (b) The binding energy ofeach orbital electrons of the target element. The
binding energies of the 2p electron of ArlO + andArl 2 + are also shown.

We also obtained preliminary values of the intensity
ratio of Ka hypersatellite X-rays and satellite X-rays,
I(Kah)/I(Ka), for each target element and plotted theresults as a function of Z2 in Fig. 2. The value ofI(Kah)/I(Ka) oscillates against Z2 and the oscillation isout of phase with that of PL' When we estimate thevalues of I(Kah)/I(Ka), we should take into account thechange of detection efficiency due to the change in
X-ray energy, because the K absorption edge of argon

50gas, which is the main component of counter gas (90%
Ar and 10% CH 4 ), is 3.203 keY. As to the KG: satellites,

3d\3dO'Z

the change of the detection efficiency from peak to peak10

is so small that it does not give rise to large errors even if
we assume that the efficiency is constant for all of themwhereas the detection efficiency changes suddenly at theabsorption edge for KG: hypersatellites. We show , how-

2pJr

ls(C)

2p 2~_2p(Ar)2s~2s(Ar)is difficult to make the correction at the present stage.

3s-

/,

/,

2s(Ar)/,>.

2pJr /, 2sa

0.0

~ 50

2p
2s

Cl)

ever, the result without any correction in Fig. 2 , since it::~2p(Ar)

0.0

~
100
c

~lS(Ar)

i:l5

Is

/

Rot.
2pa

Is(Ar)Yls(ca)

IsO'

Cr

500

Is

Sr

1000
0.10

tl
~

.~

.......

---""
<:3

~0.05

.,~

10

3do ....... .. '
3d
3p

•

.<Jd Jr

3s
>.

Ar 3d
Ar 3s
2p (Ar)2s (Ar)2p (Zn)2s(Zn)

50

0.0

90

10

Zz

Fig. 2. The values of intensity ratio of KG:
hypersatellites and satellites I(KG:h)/I(KG:) vs. theatomic number of target Z2.

Q3

a3 100
0.0
C

'6
c

4f~

4d

Sn 3d
2p(Ar).... /
2s (Ar)3do :..;/
Jr 3p (Sn)./A
3s(Sn)... ••.•11

Jd

3d
3p

Rot.

3s
2p---''-..t----l S (Ar)
2s
2pO'

i:l5

500
1000 Is

p:-

2p

25

~

IsO'

Cd

We consider that the errors, especially the systematicones, may be large but the tendency of the oscillatoryls(zn)Is (Ar)~~2p(Sn)~22s(Sn)So'~ls(S n)

Is

~

Er

IsO"

Ar10++Sn

behaviour will not change much because the main partFig. 3 . The energy level correlation diagramsof the KG: hypersatellites is distributed at energy higher

between an Ar! 0+ ion and target atoms (C, Ca,Zn, and Sn).

than the K absorption dege of Ar.
This oscillation of I(KG: h )/I(KG:) will be explained bytherotaional

coupling between molecular orbitals

formed by a projectile and a target atom during collision . In Fig. 3, some of the energy level correlation diagrams for different collisional partners and Ar ions areshown in the case where the charge of Ar is assumed tobe 10+. When the Ar ions collide with C target , there is

be reduced and I(KG:h)/I(KG:) value to be increased. The
observed behaviour of P L vs. Z2 ' therefore, is considered
to originate mainly in the level matching and partly inthe rotational coupling between molecular orbitals.

no possibility to transfer the 1s electron of Ar ion to its
2p holes, whereas for the Ca target this transition

References(electron promotion via a quasi-molecule) is possible

Takahashi, 1. Urakawa, T. Matsuo, and M. Namiki:
RIKEN Accel. Progr. Rep., l§., 72 (1982).
2) A. Hitachi, H. Kumagai, and Y. Awaya: Nucl.
Instr. Meth ., 195,631 (1982).

through 2pn - 2pa coupling and the intensity of hypersatellites relative to that of satellites increases. The
same discussion can be given to the target element Zn
and Sn. For Sn target , the rotaional coupling between
3dn - 3da plays some role.
The electron promotion from 1s to 2p in Ar ions too
has effects on the P L values. This makes the P L values to1) Y. Awaya , T. Kambara , M. Kase, H. Kumagai, 1.

3) T . Kambara, Y. Awaya , M. Kase, H. Kumagai, S.
Shafrath , H. Shibata, and T. Tonuma:

p.51 in thisreport.
4) Y. Baudinet-Robinet: Phys. Rev. A, 26, 62 (1982).

51

III-2-8.

K X-,Rays from Ar-Ions Passing through Foils (II)T. Kambara, Y. Awaya, M. Kase, H. Kumagai,
S. M. Shafroth , H. Shibata, and T. Tonuma

We report on the measurements of the K(3 X-rays
from Ar-ions passing through various foil targets withenergy of 33.6 MeV. The K(3 X-rays are emitted by electronic transitions from shells outer than the L-shell to
the K-shell of Ar-ions. The equilibrium charge state of
Ar ions in target is about 10+ - 12+ and there should bematching on the L-shell ionization probability P 4 ) isLalso seen in the K(3 X-ray spectra.
The intensity ratio between K(3 satellite X-rays andKa hypersatellite X-rays depends significantly on theatomic number of the target. For example, the K(3satellite X-rays are stronger than the Ka hypersatellite

no M-shell electrons if the ions are not excited. How-

X-rays for the Al target, but this situation is inverted

ever the ions can be highly excited by collisions with thetarget atoms . The measurement of the K(3 X-rays gives
us information about the popUlation of outer shellfor the Ti target. The intensity ratio between Ka satellite
X-rays and Ka hypersatellite X-rays is reported to bealso dependent on the target species. 4 ) We are planningelectrons in the ions which have a hole in the K-shell andto make further measurement with wider energy range

multiple holes in the L-shell .

for the ratio of the Ka satellite, Ka hypersatellite and

The experimental apparatus with a broad range
crystal spectrometer was the same as that reported
elsewhere 1 ) except that the Bragg angle of the diffraction crystal Ge( 111) was changed from 75° to 67° in

K(3 satellite X-rays.
X- ray energy (keV)

3. 2

32 0

3.3

3.4
J

3.5
I

3.6
I

3.7
I

order to look at higher energy X-rays. The targets wereC, AI, Ti, V, Cr, Ni, Mo, Ta and Au. The X-ray energy256

was calibrated by the L X-rays of indium excited byphotons.

192

Some examples of the X-ray spectra are shown in
Fig. 1. The K(3 satellite X-rays are seen in the center of128

the spectra and thehigh energy part of the Ka
hypersatellite X-rays are seen at their left hand side.
These X-rays are well separated, in contrast to the caseof Ar-target bombarded by 6 MeV/amu N-ions where64

the K(3 X-rays and the Ka hypersatellite X-rays are
mixed up in the spectrum. 2 ) The K(3 X-rays are resolved
into each satellites in the cases of Al and Ti targets,
but not in the case of Ni target.
The energy of each K(3 satellite is estimated by extrapolating those of the K(3 satellites with L-hole number
smaller than 4 , which was measured by Awaya et a1. 3 )By comparing the

Kcr Hypersatellites~~\J>-.Jrl,~1

!

Q3

c

c
m
...c

768

U

'--...
Ul

§ 512
o

u

Ti

256

o '--- --'-- -192

present X-ray spectra with theseenergies, the number of L-shell holes for the maximum
X-ray yield among the K(3 satellites is estimated to be
between 4 and 6. This is larger than the number of·-,~.:-·fJ.'"~,,,..·~..t

0

AI

128
64

average L-shell holes of the Ka satellites which is between 3 and 4. 1 ) ,4) Therefore the K(3 X-rays are

512

supposed to be emitted from higher ionized ions than

Channel number

the Ka X-rays. The X-ray energy for the peak with the
maximum X-ray yield among the K(3 satellites changes
with the target atomic number in the same way as thatof the Ka satellites. Therefore the effect of the level

Fig . 1. Examples of X-ray energy spectra from
Ar-ions in solid targets. Peaks at the center
correspond to the K{3 X-rays and those at the left
to the Ka hypersatellite X-rays.

52
References
1)

3)

Y. Awaya, T. Kambara, M. Kase, H. Kumagai, J.
Takahashi, J. Urakawa, T. Matsuo, and M. Namiki:Okano, and T. Hamada: IPCR Cyclotron Progr.

RIKEN Acce1. Progr. Rep., lQ, 72 (1982).
2)

Y. Awaya, M. Akiba, T. Katou, H. Kumagai, Y.
Tendow, K. Izumo, T. Takahashi, A. Hashizume, M.

I. Kohno, and S. Ozk6k: Phys. Rev. A, 20, 989

Rep., 10, 78 (1976).
Y. Awaya, T. Kambara, M. Kase, H. Kumagai, J.
Urakawa, H. Shibata, T. Matsuo, J. Takahashi,(1980).

and M. Namiki:

T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai,4)

p. 49 in this report.

53

111-2-9.

Au L 3 -,Subshell Alignment Induced by Heavy-Ion Impact
J. Takahashi, M. Namiki, J. Urakawa, H. Shibata, T. Matsuo,
H. Kumagai, M. Kase, T. Kambara, and Y. Awaya

We have measured the angular distribution of Au LQ

FWHM at 6.4 keY. The distance between the beam

X-rays (Ml- L3 transition) produced by heavy-ion
impact to study the projectile atomic number dependence of L3 -sub shell alignment.
The projectiles N2 +, Ar4+, Kr 8 +, and Xe 9 + were ac-

spot and the Be window of the Si(Li) detector was about
20 cm and the diameter of the Si(Li) detector was
0
6 mm, so that the angular resolution was 1.8 • The
angle between the target surface and the beam was
0147.5° for forward angle measurements and 32.5 forbackward ones. Spectra of X-rays were monitored byanother Si(Li) detector placed at a fixed angle ofcelerated by the linear accelerator, and were momentum
analyzed. The energies of the N, Ar, and Kr-ions were0.87 MeV/amu and that of the Xe-ions was 0.84
MeV/amu. The dimension of the beam spot on thetarget was 1 mm in width and 3 mm in height. The
target Au was evaporated on a 4 Jim thick Mylar foil.
The thickness of the Au was about 0.2 mg/cm 2 . The
emitted X-rays were detected at angles (8) of 25°,0045°, 70°, 90°, 110 , 135 , and 155° by a Si(Li) detector, the energy resolution of which was 230 e V

0

8 = -90 •Spectra of Au L X-rays obtained at 8 = 90° are shownin Fig. 1, where the projectile K X-rays are also seen in
the case of Kr impact.
It is expected that the radiation originating from theelectronic transitions to the L3 -subshell is anisotropic.
This anisotropy reflects the alignment of the L3 subshell

Au LX - rays

100

°3~3-0-----L-----5~8~
6----~-----r~~~~~~~

Channel number

Fig. 1. Au L X-ray spectra induced by N, Ar, Kr, and Xe-ions withthe same velocity.

54
which is caused by different population of vacancies

I mj 1=3/2 and 1/2.

t ies of the LQ and La X-rays induced by Nand Kr-ion
impact are shown as a function of cos20. The intensity

The anisotropic angular distribution of the LQ lineof the LQ X-rays depends on 0, whereas that of the(MI - L3 transition) has been observed by Jitschin et

La X-rays is almost independent of it. The anisotropy

among magnetic substates withlal . )

The angular dependence of the emitted dipole

radiation 1(0) is expressed as
1((1)=0 0/ 4 71:) 11 + bP z (cos (J) I(1 )of the LQ X-rays induced by theN-ion impact is greaterthan that induced by the Kr-ion impact. From theseangular distribution data , the values of A20 are deduced
by using the formula (1). They are plotted in Fig. 3 asa function of the projectile atomic number Zl' For

when the outgoing projectiles are not detected, wherecomparison the data obtained by litschin et a1. l ) for

10 is the total intensity, P2 (cosO) the Legendre poly-various projectiles with incident energy ranging fromnomial of the second degree and b the anisotropy

0.74 MeV/amu to 1 MeV/amu are also plotted in Fig. 3.
The alignment coefficient decreases monotonically withincreasing Zl .

The parameter b is related to the L 3alignment coefficient A 20 by a formula

parameter.
subshellb = "aA 20 . The value of the coefficient a is assumed tobe 0.5 according t o Berezhko and Kabachnik2) and thatof the dealignmen t factor K to be unity. The A 20 isgiven by0.10

where u L /3/2) and u L3 (1/2) denote the ionization
cross sections corresponding to the magnetic substates of

I mj I = 3/2 and 1/2, respectively . In Fig. 2 the intensi-

087 MeV/ amu N- Au

1.00 9-

0.90
Q:)

'-<

080

lot

o

6

-OAO O

0.94 0'0

Fig. 3. The alignment coefficient vs Zl
for Au L3 -subshell vacancies. Open circles
are obtained in the present work andclosed circles are referred from Jitschin et
al.l)

CD
0.90
---..- .
......

=

080

f

100 9

¢

L.

~

1

References
1)

W. Jitschin, R. Hippler , R. Shanker , H. Kleinpoppen,2)

R. Schuch, and H. O. Lutz: 1. Phys. B: At. Mol.
Phys. , 16 , 1417 (1983) .
E. G . Berezhko and N . M. Kabachnik : ibid. , 10 ,J

0.94 '-=0-'-0::'- - - - - - = 01.::-.5-- - --7-'
1.00::--'

e

cos 2

Fig. 2. Intensities of LQ and La X-rays as afunction of cos 2 O.

2467 (1977).

55

III-2-10. Angular Distribution of REC for Ar4+ on C at 1 MeV/u
S. M. Shafroth, Y. Awaya, M. Kase, T. Kambara,
H. Kumagai, M. Nishida, H. Shibata, and H. Tawara

We have measured the angular distribution of X-rays

that K vacancy production in the projectile is reachedarising from radiative electron capture (REC) for 45.7

at thicknesses considerably smaller than 80 J1.g/cm 2

MeV and 51.9 MeV Ar4+ ions incident on thin C targets.

Finally, there are no higher energy characteristic X-rays

In the REC process which we studied, a loosely boundarising from the target which might disturb the measure-target electron is captured into the K-shell of the proj-

ment.

ectile, and a photon is emitted. Carbon was selected as

The experimental arrangement consisted of a Si(U)a target material, since the data of Awaya et a1. l ) shows

detector whose resolution was 200 eV at 6.4 keV, withthat there is almost no double vacancy production inan active area of 28 mm 2 and a 7.5 J1.m beryllium

the projectile at 33.6 MeV, whereas other target atomic

window. It could be rotated to angles of 25°, 45°, 70°,

numbers , such as 22 (Ti) give rise to much greater90°, 110°, 135° , and 155°. At these angles 50 J1.m Be

double K to single K vacancies. Furthermore target

windows viewed the target. Air path between the2

thickness studies of REC by Shafroth et al. ) showed

detector and target chamber was smaller than 10 mm

ArKa

10 4

10 3

10 2

10 1
100
Q)

c
c
ro
.s=.

u 10 0
'----

2c

:::l

8 100
10 0
10 0

10 0
10 0
0
Channel number

Fig. 1. X-ray spectra for all angles where measurements weremade at projectile energy of 51.9 MeV. The X-rays passed
through Be-windows with total thickness of 57 .5 J1.m and an Alabsorber with a thickness of 8 p.m. The absorption correction
was not applied.

56

and it little contributed to the absorption of the REC
X-rays. 811m and 15 11m Al absorbers were placed be-

charge state of the Ar q + ions exciting the foil.
A second Si(Li) detector was also used as a monitor .

tween the target chamber exit windows and the Si(Li)It was placed at 270° relative to the beam direction anddetector, in order to attenuate the Ar K-X rays relative to REC. In the first run at 45.7 MeV Ar4+ , two

had an 811m absorber between its Be window and thetarget chamber. It had the additional advantage that allabsorber thicknesses were chosen in order to see how

runs could be summed and the resulting spectrum with

important the absorption correction was. In the second

good statistics could be used to compare with calculated

run at 51.9 MeV , only an 811m absorber was used.

shapes of REC spectra using Slater wave functions as wasdone by Kambara et al. 3 ) or more sophisticated wave

A surface barrier detector was placed at 40° withrespect to the incident beam. It served as a monitor

functions , andcounter by counting the recoiled carbon atoms from

Salpeter radiative capture cross section for free electrons
on bare nuclei. 4 )the Rutherford scattering and permits absolute crosssection to be determined , without knowing the mean

the impulse approximation, Bethe-

In the second run the target was oriented at 45° and

REC I NTENSI TY

(b )

(a )

160

:;:G..J

v\

0

2;
'-t

"'--

0.7

\ 51026

0.5

!

Q;'

40

-;::;

•

0

"J

!

1.0
0.9

.~.~

120
80

~

REC CENTROID SHIFT

\

-40
-80

0.3

- 120
0.1

- 160

•
cos

50

e

Fig. 2. (a) Angular dependence of shift of the centroid energy of REC peak relative tothat at 90°. Solid line shows the prediction from the Doppler shift, (b) Intensity of the
REC X-rays relative to that at 90°. Solid curve shows sin 2 0. The projectile energy is 51.9
MeV. A linear background is assumed .

200
160
120
80

:;:~

G..J
"'1

40
0
-40

."

REC INTENSITY

(b )

(a)

REC CENTROID SH IFT

•

~

;1

1.0
0.9

/

0
22- 0.7
'-t

•

"'--

Q;'
'-t

0.5

\

I

-80
0.3

-120

sin 2 e

- 160

I

'-

-200

0.1
10
cos e

50

90

e (deg)l30

Fig. 3. Same as Fig. 2 except that an exponential background is assumed.

\

170

57
135° to the beam, and in the first run, it was located at
45° and 90° relative to the beam. The target angle had
no appreciable effect. The beam spot on the target (1mm X 3 mm) was defined by a slit , which was located
10 cm in front of the target. Figure 1 shows X-ray
spectra at all angles where measurements were made atincident energy of 51.9 MeV.
X-ray absorption corrections were applied to theentire spectrum, channel by channel, approximating theenergy dependence of X-ray absorption by a function of
the form NINo = exp( -Ae- B ) , where A = 33.46 and7.27 and B = 2.7401 and 3 .2571 for Al and Be respectively. These values were calculated using the X-ray absorption cross sections of Veigele. S ) The corrected
spectra were then fit with Gaussian functions. The
centroid energy then shifted with angle as expected
due to the Doppler effect. Figure 2(a) illustrates thisfor the case where a linear background is assumed .
Figure 2(b) shows the angular distribution of REC
X-rays normalized to 1.0 at 90°. At the forward angles
it appear to be high compared to the expected sin2 8
distribution 4 ) and at the backward angles the datalies on the expected curve , thus a (1 - (3cos 8) - 4 correction would not describe the data either.

On the other hand , if an exponential background isassumed, as was done by Betz et al. ,6) the data agreewith sin2 8 fairly well as can be seen from Fig. 3. The
choice of background makes about 25 % difference inabsolute cross section. The absolute cross sections are
not yet determined. Further analysis is in progress.

References
1)

Y. Awaya, T. Kambara , M. Kase, H. Kumagai,
1. Urakawa, H. Shibata, T. Matsuo , 1. Takahashi,
and M. Namiki: p. 49 in this report.
2) S. M. Shafroth , K. Shima, T. Ishihara , et al.: IEEE
Trans. Nucl. Sci., NS-30 , 1055 (1983).
3) T. Kambara, Y. Awaya, A. Hitachi , M. Kase , I.
Kohno, and T. Tonuma: 1. Phys. B: At. Mol.
Phys. , 12,3759 (1982).
4) H. A. Bethe and E. E. Salpeter: "Quantum
Mechanics of One- and Two-Electron Atoms",
Plenum , New York (1977).
5) Wm. 1. Veigele: Atomic Data Tables,2, 51 (1973).
6) E. Spindler, H. D. Betz, and F. Bell: Phys. Rev.
Lett., 42 , 832 (1979).

58

III -2-11.

Krypton Recoil Ions Produced by 42 MeV
Ar 4 + Ion Bombardment

S. ozkok,* T. Tonuma, J. Urakawa, H. Kumagai, M. Kase,
H. Shibata, T. Kambara, J. Takahashi, T. Matsuo,
S. H. Be, and I. Kohno

We have bombarded Kr gas target with 42 MeV Ar4+

evacuated by a 5000 l/s cryo pump (condensation

The block diagram of the electronic system to obtain
Kr charge-state spectrum is shown in Fig. 1. Recoil ionswere detected by a channeltron (Channel Electron
Multiplier). Bias voltage of minus 2.4 kV was applied tothe channeltron. The output signals were amplified andpump) and a 220 l/s turbo molecular pump. The back-accumulated by multichannel scalar through a Timing

ground pressure and operating Kr pressure were 7.4 X
10- 8 Torr and 9.2 X 10- 7 Torr, respectively. Introduc-

Filter Amplifier circuit. The channel stepped up withintegrated beam charge of 3nC on the Faraday cup.
Step-up signals came from a current integrator. The

ion beam from the heavy-ion linac for various extraction
voltages of recoil ions. The present work is a continuation of those reported previously. 1 ),2) The apparatus istion rate of Kr gas was about 0.1 cc/min.

Channeltron
Detectoron- linecomputer(PE - 3220)

Faraday cup
Digital out

Fig. 1. The block diagram of the electronic system.
PHA: Pulse Height Analyzer
ADC: Analog to Digital Converter
TF A: Timing Filter Amplifier
CFD: Constant Fraction Discriminator
MCS: Multichannel Scalar.

charge-state spectrum of Kr ions was obtained bytheir high beam intensity and long term stability. A Kr

scanning the magnetic field by a step scanning controller

charge-state spectrum for extraction voltage of 4 kV was
obtained by subtracting the background as shown in
Fig.2(c).

and the number of counts in each channel was recordedon the on-line computer (PE-3220).
Figure 2 shows the charge-state spectra of recoil Kr
ions produced by 42 MeV Ar4+ ion bombardment. The
Ar4 + ion beams have been used preferably because of* Permanent address:

University of Istanbul, Nuclear Physics
Dept., Istanbul , Turkey .

The recoil Kr ion fraction F. is obtained as the ratioJof each peak count to the sum of all the p~ak counts.
These fractions F. are plotted as a function of theJextraction voltages in Fig. 3. It can be seen that therecoil Kr ion fractions have not so much dependence on
the extraction voltage.

59

l00f-

(a l

+I

f-

_ _ _ _ - +1

ffff-

-

+4

]

-

103
Hi

--------- + 2

U

~

i

10

01O f-

2-

U=- - - - - - - - +3
10'

-----

10°
256

512
Channel number-____ ---- + 4-____ ---- + 5

6-___ - - - +6

u

a.>

cr:

10'

0.01 f-(b )_-----+8----- +9 - :-- - - +7

- - - - - - - +10
10

3

Hi

~

t5 10

-

I-

42 MeV - Ar4 ++ Kr

2

-

He'

~

~

I

I

I

23
4
Extraction voltage (kV)U

10'Fig. 3. Recoil Kr ion fraction F j
extraction voltage from 2 to 4 kV .

versusChannel number

lOS
(el

References

10'+31) T. Tonuma, A. Yagishita, M. Kase, T, Kambara , Y.
Aways, H. Kumagai, and I. Kohno:- 103

Progr. Rep ., ~ , 72 (1981)
2) T. Tonuma, M. Kase, T, Matsuo, J. Urakawa, J.

j

U

~

i

RIKEN Accel.

Takahashi, H. Kumagai, T. Kambara , I. Kohno,
S. Ozkok, and Suck Hee Be: ibid., .!§., 85 (1982).

102

U

10'

Channel number

Fig. 2. Charge-state spectra of recoil Kr ionsproduced by 42 MeV Ar4+ ion bombardment.
(a) Charge-state spectrum for extraction voltageof 4 kV, (b) Background spectrum, (c) Spectrum
obtained by subtracting the background.

60

1II-2-12. Projectile Charge-State Dependence of the Fractional Yields
of Recoil Ions in Different Charge States
T. Tonuma, M. Kase, J. Urakawa, T. Matsuo, H. Kumagai,
T. Kambara, H. Shibata, J. Takahashi, S.Ozkbk,
S.H. Be, and I. Kohno(1) M-shell ionization

We present results of measurement of charge-state

The eight M-shell electrons in the Ar target are boundspectra of recoil ions produced in single collisions of
42 MeV Arq +(q = 4, 10-14).withAr.Arq +cq:;:: 10-14)

loosely by the nucleus and are dominantly ejected inbeam was produced by passing Ar4 + beam from the

distant collisions. Olson 1) calculated the cross section

linac through a carbon foil and selected by magneticO"janalysis. A typical charge-state spectrum of recoil ionsproduced by 42 MeV Ar l2 + ion bombardment on Ar

tional yieldfor ejecting i electrons in the M shell using an in-

dependent-electron-ejection model.

target is shown in Fig.!. Charge states up to Ar l 2+ of

8

the recoil ions were observed.

We define a frac -

8

F!V1=
F·I"'::::"
I '" F-I = (5-I"'::::"
I '" (5.I
I

The fractional yield F j of the recoil ion in a charge

i= 1

(2)

i= 1

state i is plotted in Fig. 2 against i for 42 Me V projectileq
Ar + of different charges q =4, 10 - 14. The solid anddash-dot-dashed lines are drawn to guide the eye. The

of M-shell ionized recoil ions. It satisfies the normaliza-

fractions of recoil ions in charge states lower than i = 8
do not depend so much on the projectile charge state for
10 s:: q s:: 14, but those of recoil ions with i ;:::: 9 increase

fractional yields F~ are plotted in Fig. 3. The experimental values are for the 42 MeV Arl4+ projectile andwith the projectile charge state.

-I MeV/amu and charge of 14. The theoretical F~1

The fractional yields of Ar with the atomic numberof 18 satisfy the normalization condition
18

8

16

i=1

i=l

1

the theoretical ones are for the projectile with energy of18'" F.='" F+'" F·+'"
I...::::.,
I...::::.,
I...::::.,...::::.,

i= 1

8tion relation ~ F~ = 1. Experimental and theoretical

i=9

(1)

F·I = 1 'i = 17q

42 MeV Ar ·+ on Ar

where the partial sums refer to M-, L-, and K-shell ioni10- 1

zation. The contribution from the K-shell ionization is
negligible in the present experiment.
c

Q

U
<U

4+

1+

~ 10- 2o

42 MeV Ar 12 +on Ar
~

o

u

0.98

Q)

x 16

'0

0:::

~

2

1S2

q
066

10- 3
5+

(/)

2+

c

::>
0

6

4

- 10
x 11
o 12

0 13

U

0.33

A

14

H+

00

384
Channel number

Fig. 1. Charge-state spectrum of recoil Ar ionsproduced by 42 MeV Art 2 + ion bombardmentof Ar target.

Recoil ion charge-statelFig. 2. Recoil ion charge-state fractions F j for
42 MeV Ar q + in Ar. Projectile charge state q
is 4 and 10'" 14.

61

I

I~

k,-

\

[210- 1-

I

is underestimated for small i and overestimated forIlarge i. This trend is similar to that found in Ref. 2.

(2) L-shell ionization
Figure 4 shows charge-state spectra of the recoil Ar

.~

X"'"

.""x. . . . . . x. . . .Theory
.. x

U
~

.

c

Q
0

Presentuill

0:: 10- 2 -ions with i ~ 6 that are produced in collisions of 42 MeV-

Ar q + (q = 10 - 14) with Ar. The background spectra
due to residual gas were subtracted from the observed

~

e~""

spectra. The relative yields of recoil ions with i = 6, 7,''-......

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

--.

and 8 are almost independent of q. Those of the ions-with i ~ 9 increase with an increase of q. Recoil ions.

Ar 12 + were observed when q 2 12 and increase with q .
A fractional yield F~1 of L-shell ionized recoil ions is1610-3 ~~1o__~1_ _ _L-1~1__~1__- L_ _- L_ _~~

1

23
4
567
Recoil ion charge-state i

89defined by F~ = F.(L F. and is normalized to unity
16

(~

i=9

F~= 1).

1

1

1 1=9

1

Experimental fractions F~ are plotted,against q with solid points in Fig. 5.

Fig. 3. Recoil Ar ion fraction F~1 in M-shellionization versus recoil ion charge state i. The
theoretical line is for the calculation for the
projectile energy of I MeV /amu and the projectile charge of 14 carried out by Olson. Experimental line is for 42 MeV (1 .05 MeV /amu)
Ar14+ in Ar.

The multiple-ionization probabilities Pn (b) of ejection of n electrons from the L shell containing eight
electrons in a collision with an impact parameter baregiven byn = 1, 2, ...... ,8, (3)provided that all the electrons are ejected independently.

Here,(~) is a binomial coefficient and P(b) is the ionization probability for ejecting a single electron. In the3

simplest form P(b) is a constant probability ) within

6

a defined distance of collision, namely,P(b) =p

b ~ R

=0

b> R

9---

.--.

-.__

L=

~9

12

ill
C

(4)

C

10 _· _

(\l

..c
U

~.-.

•

i10

~ 11

'----

-8
c

~.

:::J

o

~.

U

[2
14

' 11 ___

o

U
ill

0::

10 2

42 MeV Ar'l+ on Ar

10°L-__~____o- L_ __ _J -_ _~~--~~

64

128

Channel number

Fig. 4. Charge-state spectra of recoil Ar ions ofcharge state higher than 6 for 42 MeV Arq + in
Ar.

9
10 11
12
13
Projectile charge -state q

14

Fig. 5. Recoil Ar ion fraction F~1 in L-shellionization versus projectile charge state q.
Solid points are the experimental values. Solidlines show the calculated values by the use of theestimated ionization probability P.

62
where R is given by R = j2a, a being the mean shellradius of the target atom. The fraction F n of recoil ionsof the n-th charge state may be expressed as
8

Fn=Pn/~ P n ·
I

( 5)

n=l

/e'

0.20
0.18
n.. 0.16

/e
/e

>,

~ 0.14 --g 0.12/e~ 0.10~harge transfar/-e----- ___ wi'

/

/

0.06
0.04
0.02

ability P increases linearly for q = 10 through 14 whichcorresponds to the projectile with 2 through 6 L-shellvacancies as shown in the figure. By interpolating theseresults and the value for q = 4, it is found that the ionization is strongly enhanced once the projectile L-shellvacancies are brought into collisions. This means thatthe direct transfer of the target L-shell electrons into theprojectile L-shell vacancies contributes significantly tothe production of highly ionized recoil ions.

N]culated using the estimated probability P are shown withsolid lines in Fig. 5. Figure 6 displays plots of the probability P versus the projectile charge state q. The prob-

0.22 , - - -- -- - - -- - ----,~ 0.08In the present case Fn denotes the fraction F~1 (i = 9,
10, ..... , 16). The fraction Fn depends only on one
parameter P, which can be estimated by a least squares
fitting to the experimental fractions. The fractions cal-Direct Ionization

References
I

I

I

I

0L-4L-5~6~~7~8~9~10~11~
12~1~3~1~4~

Projectile charge-state q
!

I

I

I

I

I

1)
2)

I

0123456
Projectile L -s~ell vacancy I

Fig. 6. Probability P of ionization of a single
L-shell electron versus projectile charge state q
and the number of projectile L-shell vacancies.

3)

R. E. Olson: J. Phys. B, ll, 1843 (1979).
A. S. Schlachter, W. Groh, A. Muller, H. F. Beyer,
R. Mann, and R. E. Olson: Phys. Rev. A, 26, 1373
(1982).
Q. C. Kessel and E. Everhart: Phys. Rev., 146, 16(1966).

63

III-2-13.

Measurement of Total Ionization Cross Section for
Production of Recoil Ions by Heavy Ion Impact
on Gas Target

S. H. Be, T. Tonuma, H. Kumagai, M. Kase, H. Shibata,T. Kambra, H. Tawara, and I. Kohno

With the purpose of obtaining an absolute ionization
cross section of recoil ions, experiments for measuring
a relative intensity of recoil ions have been carried out asa first step. Details of experimental results will be presented in another report of this volume. 1 )Following these experiments a measuring apparatusof the total ionization cross section for production ofrecoil ions was designed and constructed. The apparatus
is shown in Fig. 1. This apparatus is similar to that of
the well-known condenser plate method 2 ) but thegeometry of the parallel-plate electrode~ is different
from the conventional one. In the conventional apparatus three pairs of electrodes are employed, whereas
in our case only one pair is employed; thus it is hoped
to have more uniform electric field since the disturbance of the electric field in the space between theelectrodes is avoided.
The condenser plate system including circuits formeasuring is shown schematically in Fig. 2. The projectile ion beam enters the gas target via the beam
defining aperture A and passes symmetrically between

parallel-plate electrodes PI' P2 before entering a Faraday
cup where its current is recorded. A voltage is applied
between the parallel-plate electrodes of strength sufficient to ensure that all recoil ions and electrons
emmited in collisions are collected by collector plates Ce
and Cj , respectively. The potentials applied to PI and P2
are arranged to be symmetrical with respect to thecenter line of the system, which is at earth potential. In
general, V pI and Vp 2 are at the same potential but thecollector plate Ce can be made positive with respect tothe grid G, as the case may be. A uniform electric field
is maintained at least between high transparency grids,
and the recoil ion collector plate Cj is biased a few ten
volts positive with respect to the grid to prevent theescape of secondary electrons. Preliminary experimental
results showed that when the collector plate Cj is about
20 V positive with respect to G. secondary electron suppression is complete. The grid G of 92 % transparency
consists of 40 11m-diameter tungsten wire strung I mmapart, and perpendicular and parallel to the beam axis.
The distance between each parallel plate and each2
Pr ojecti Ie --fl--+--II-

beam

o
!

2
!

Fig. I. Drawing of the parallel-plate condenser set-up. I: Beamdefining aperture, 2: Electrode for applying the suppressing voltageof secondary electrons produced at the edge of the beam defining
aperture, 3: parallel electrode for applying the accelerating voltageof electrons or ions produced by ionization, 4: Electron collector
plate, 5: Earth potential electrode, 6: Electrode for applying the
suppressing voltage of secondary electrons produced at the Faraday
cup by the impact of the projectile ions, 7: Insulator (Teflon),
8 : Faraday cup, 9 '" 11 : Insulator (Teflon), 12 : Recoil ion collector
plate, 13: Insulator (Teflon), 14: Grid with a high transparency.

64

MCS
interface
1 sec
Advance- _.

Faraday cup

Projectile
beam

I,

ComputerA

GateFig. 2. Condenser plate system including simple circuits
for measuring.
Vn l' VpI: Applied voltages at ion and electron
collector plates, Vn 2' V p2 : Applied voltages for producing the uniform electric field between parallel-plateelectrodes PI and P 2' Vs 1 : Suppressing voltage of secondary electrons produced at the edge of the beam
defining aperture, VS2 : Voltage to prevent the escape of
secondary electrons from the Faraday cup, Ie' Ii :Electrometer for measuring electron and ion current.

where l( cm) is a definite length of the projectile beamcollector one is 2 mm in either case. The distance be-path, P(Torr) target pressure and Ib (A) the projectile ion
beam current. A schematic diagram of the electronics formeasuring Ii' P, and Ib , which are necessary for the

Fig. 3. Schematic diagram of the electronics.

collisions we have
Q + = 2,81 x 10 - 17 Ii

(I b 1 P) cm 2 ,(3)

The gas target cell is set up in the high vacuum

determination of Q+, is shown in Fig. 3.
Using constructed apparatus and the instrument de-chamber whose ultimate pressure is 7 X 10- 8 Torr andscribed above preliminary experiments were made overevacuated via two apertures of 2 mm in diameter by

two times so far. The Q+ calculated from Eqn.(3) using
the experimental results is 3.5 X 10- 15 cm 2 for 1.14

tween parallel-plate electrodes in 20 mm.

a pressure difference between the cell and the chamber,
The ultimate pressure of the cell is 3 X 10. 6 Torr, andthe working pressure for actual experiments is above anorder 10- 4 Torr much higher than 3 X 10- 6 Torr.
In studies of this type, there occur such processes as
ionization of target atom, electron capture of projectile

MeV/amu Ar 4+ projectiles and 2.4 X 10-15 cm 2 for
C5+ of the same energy, both on the same gaseous Artarget. The measured value of the latter is in good agreement with Schlacter's result 3 ) of 2.6 X 10-15 cm 2 . The
detailed experiments are in progress .

ion and stripping of projectile one, i.e" as those in thefollowing reaction
X q + +y-->X m + +yn+ + (m+n-q).

References(1)

1)

A total ionization cross section Q+ is defined by
Q+ =2 n qO,Qmn 'T. Tonurna, M. Kase, J. Urakawa, T. Matsuo, H.
Kumagai , T. Kambara, H. Shlbata, J. Takahashi,
S. Ozkok, S. H. Be, and I. Kohno:

(2)

m, n

p . 60 in thisreport.

where q 0 Q m n is the cross section for the charge state nof recoil ions. q. is charge state of projectile ion, a is2)

charge state of target atom, m is charge state of pro-3)

Hooper McDaniel Martin, and Harmer: Phys. Rev.,

11.L 1123 (1961).
A. S. Schlachter, K. H. Berkenr, W. G. Graham, R.

target particle after collision. Q+ can be determined by

V. Pyle, P. J. Schneider, K. R. Stalder, J. W. Steans,
J. A. Tanis, and R. E.Qlson: Phys. Rev. A, 23,

measuring the current Ii due to all recoil ions of all

2331 (1981).

jectile particle after collision and n is charge state ofcharge states n. At pressure low enough to ensure single

65

Ar L-MM Auger Spectra in Ar 4 + + Ar Collisions

III-2-14.

T. Matsuo, H. Shibata, 1. Urakawa, A. Yagishita, Y. Awaya,
T. Kambara, M. Kase, H. Kumagai, and 1. Takahashi

In order to investigate the ionization mechanism into low energy, out of the present measurement range,

heavy-ion atom collisons, we have measured the energy

due to the Doppler energy shift, so that the peaks which

spectra of ejected electrons in Ar4+ + Ar collisions. In

appeared in the spectrum were attributed to thethis report, we present the line-identifications for the L-electrons from the target.

MM Auger electron spectrum. The experimental ap-

In a previous paper ,2) we have reported that theparatus used in this experiment has been described inelectron spectrum consists of sharp peaks at about 101

Ref. 1. The gaseous Ar target of pressure 10- 3 Torr was

and 112 eV, and a broad-peaked structure extending

bombarded with Ar4+ beams of energy 6.6 - 45.7 MeV

from 120 to 260 eV, and interpreted them as arisingfrom the RILAC. The energies of electrons ejected at anwith respect to the incident beam direc-

from the transitions in the initial vacancy states,
Arm +(1 S2 2S2 2 p s 3s 2 3 p O) , by referring to the theoreticaltion were measured with an electrostatic analyzer. The

result by Larkins.3) Figure 1 shows the electron energy

angle of 132

0measured energy range of electrons was from 80 to 330

spectra for projectile energies of 6.6, 14.3, and 21.0

eV. The L-MM Auger lines from projectile ions shifted

MeV. The prominent peaks are labeled by integers,
1 ,2, ..... 11. The line energies calculated by Larkins are

4
41 -

5
6
I

5
I

4

I 3

I

I

also indicated above the spectra. The broken lines show
L23-M2 3 M 23 (n)continuum background, which was evaluated assuming

12 -L 23-M ] M 23 (n)the form ae- bE . Here, E is electron energy, and a and b

I-

L 23 - M] M] (n)are parameters which were obtained by extrapolationfrom the regions above and below the Auger structure,
though the spectrum of full energy range is not shown.

21.0 MeV

It is noted that thepositions and shapes of the peaks

did not change with the projectile energy. On the other
hand, relative intensities among them changed considerably depending on the projectile energy. Relative
intensities of each peak to peak 1 are shown in Fig. 2.
It is considered that peaks (1 and 2), (3 and 4), and (5,6
14.3 MeV

and 7) are produced respectively from the same initialconfiguration states, because the intensity ratio of the

-~
(f)
c

2

.~
Q)

>
+='
m
Q3

0::

Electron energy (eV)Fig. 1. Electron energy spectra by Ar4+ impact on
0Ar, measured at an angle of 132 with respect to theincident beam direction. The energy resolution is 0.6
eV FWHM. The lines above the spectra indicate theL2 3 -MM(n) transition energies calculated by Larkins,
where the number of M2 3 - shell vacancies is indicatedIn the parenthesis. The prominent peaks are numbered.
The broken line shows the estimated background.

12

3 4

5

6 7 8 9 10 11 12 13
Peak number

Fig. 2. Variation of the relative peak intensity withthe projectile energy. The intensities of the peaks arenormalized to that of peak I. Peak number indicatedis the same as in Fig. 1.

66
constituent peaks in each peak group is independent

duced by the L23 - Ml Ml Auger transitions from the
L - shell double vacancy state , Ar 8 +(2s 1 2 p s 3s2) , andof the projectile energy.
For peaks 1 and 2, we have already interpreted themas ansmg from the L23 - MI M.I (6) transistions;those on the higher energy side from the
Ar 8 +(2s 2 2p4 3s2). Thus the spectra indicate that theAr7+(2s22ps3s2)~Ar8\2s22p6) , where the number ininner-shell double vacancy states are produced ap-

the parenthesis in the L - MM expression indicates theparently by heavy-ion atom collisions in MeV energy
region.

number ofM2 3-shell vacancies . Peaks 3 and 4, at about
110 and 113 eV, are considered to be due to thetransitions;
Ar6+(2s22pS3s23p)~
L -M M (5)23I I
Ar7+(2s22p63p). The energy splitting between the final

To study the ionization mechanism, more detailed
analysis of the data is in progress.

states, Ar7+ePI/2 and 2P 3 / 2), has been reported to be
0.3 eV by spectroscopic study4) and less than the. 5r-------------------------------~

present resolution of 0 .6 eV FWHM. The peak structure
4

is , therefore, considered to reflect the energy difference
among the initial states Ar6+e D,l p ,l S,3D ,3 p, and 3S) in
the L-S coupling scheme. Unfortunately , the energy
levels of these states are not known. Peaks 5,6 , and 7 are
ascribed to the L23 - MI Ml (4) transitions; Ars +(2s2 2 p s 3s2 3p2) ~ Ar 6 +(2s 2 2p 6 3 p 2). The energy difference among final states, Ar6 +ep,IO , and IS), is

2'
'c 3
:::J

-e
~
2c:::::::J
0U

smaller than 0.3 e V. Again, the peak structure is ascribedto the energy difference in the initial states of Augertransition, but the energy levels of the Ars +(2s 2 2 p s 3S2 3p2) are not known.
A high resolution measurement (0.35 eV FWHM)
has been made for 45.7 MeV Ar4+ impact , and theO ~~1~O~O----~1~10~--~1~2=O----~13~O~~

Electron energy (eV)spectrum is shown in Fig. 3. Peaks between 110 and 115
eV, corresponding to peaks 3 and 4 in Fig. 1, are wellFig. 3. A high resolution (0.35 eV FWHM) electron
spectrum obtained by 45 .7 MeV Ar4+ impact.

resolved into several sharp peaks, which originate fromvarious combinations of the initial and final states forthe transitions. The peaks distributed from 120 to 128
eV correspond to peaks 5,6, and 7 in Fig. 1. For theReferences
1) A. Yagishita and T. Nakamura: IPCR Cyclotron

further discussion of the identifications of the measured
peaks, it is highly required to make a more rigorous
theoretical calculation for the energy levels of the2)

multiply-ionized states.
So far, we restricted ourselves to discussion of themost intense peaks . But one can find some small peaks
around the L23 - Ml Ml (6) peaks in every spectrum.
From the result by Larkins, peaks which appear on thelower energy side of peak 1 are considered to be Pro-

3)
4)

Progr. Rep. , !!, 143 (1980).
T. Matsuo , J. Urakawa , A. Yagishita, Y. Awaya ,T. Kambara, M. Kase, and H. Kumagai: J. Phys.
B, .!.§, L239 (1983).
F . P. l..arkins: ibid. ,.1, l (1971).
S. Bashkin and J. O. Storner Jr.: "Atomic EnergyLevels and Grotrian Diagrams II" , North-Holland
Publishing Co., Amsterdam (1978) .

67

1II-2-15.

Krypton M-Shell Auger Spectra Produced in Collisions
with about 0.2 MeV/amu Heavy lions
J. Urakawa, T. Matsuo, H. Shibata, Y. Awaya, T. Kambara,
M. Kase, H. Kumagai, J. Takahashi, and A. Yagishita

In order to obtain detailed information on both
energy levels of highly ionized atoms and their production processes, energy distributions of Kr M-shell Auger
electrons produced by 0.83 MeV He+, 2.9 MeV N2 +,perimental apparatus, procedure and conditions were
described previously. 1) The energy scale of the ejected
electrons was calibrated by Kr M-NN and Ar L-MM
Auger peaks induced by 1.2 keV electron impact. The

4.14 MeV Ne 3 +, and 8.3 MeV Ar4+ ion bombardment

energy values of each M-NN and L-MM Auger peak werereferred to the results by Werme et al. 2 )on krypton have been measured at an emission angle of0

132 with respect to the ion beam direction. The projectile ions were accelerated by the RILAC. The ex-

The ejected electron spectra obtained are shown in
Fig. 1. These spectra are characterized by a continuous

7.0
6.0

3·c

::J

Li

5.0

~

.z:- 4.0

. iJj

c

2

.£
(l)

>
..;:;
ro
a:;

3.0

0::

2.0
1.0
0

40

50

60

80

90

100

110

120

Electron energy (eV)0Fig. 1. Kr M-Auger spectra produced at 132 from the beam direction by
He+, N2 +, Ne 3 +, and Ar4+ impacts with equal-velocity (0.215 MeV/amu).

background and complicated Auger structure, which issuperimposed upon the continuous background resulting

have compared the spectra with the theoretical resultsby Larkins,3) who showed that the Auger lines shift tofrom the direct ionization process. The pattern of con-

lower energies as the degree of ionization increases. Thelines above spectra in Fig. 2 indicate the energies cal-tinuous background is assumed to be expressed by afunction feE) =Ae- BE , since this function reproduces
the feature of the lower and higher energy wings of theculated by Larkins using the adiabatic model. The

measured spectra well, where A and B are fitting para-

number on each line shows the number of 4p holes in
the initial state of Auger transition. The following re-meters and E the ejected electron energy. In order tocompare the Auger structures obtained for different pro-sults can be derived from Fig. 2 :1) The intensity of normal Auger lines indicatedjectiles, the continuous background estimated by thefunction feE) was subtracted from each ejected electron
spectrum. Figure 2 shows such a comparison of theby number 1 and 2 in the figure weakens as the atomic
number Z of projectile increases and become negligibly
small for Ar 4 + .
2) Auger lines from about 40 eV to 50 eV are

Auger spectra. For an investigation of the structure, we

68

o r-.~~ s - M4SN I N2 3
270

1
o M4S-NIN 23

1-----=----,
0 M1 - M2 3 N2 3

2

6.0

~
C
:=l

-e
~

0 M~ s- M4 S N2 3 N23

1

0 M4S- N23 N 23-----,,,.----l9_-LY--=--_ _--L
f---=_ _ .Lf
M2 3 - M4 SN1_ _ 4-,-, _ _ _ _3L--_...,.--------'-f _ _--.=-....Lt_ _--,-J9 M23- M4 SN23
M I - M4S N 1 6'--_50

5-'---;:-_-----J4~----,--L3_~-.L2- -, -l__M23- NINl 65

M I - M4S N23 5

4

3

2

4

M23- NI N23 5L-_-----Ji-I..q 4.0
If)

c

Q)

.~
Q)

>

'':::;
(\)

Q)

0:::

50

60

70

80

90

Electron energy (eV)0Fig. 2. Kr M-shell Auger spectra produced at 132 by 0.83 MeV He+, 2.9
MeV N2 +, 4.14 MeV Ne 3 +, and 8.3 MeV Ar4+. The continuous backgroundestimated by the function Ae - BE is subtracted. The lines shown above thespectrum indicate the calculated energies for the corresponding transitions,which are denoted on their right or left. The number on each line shows thenumber of 4p holes in the initial state of Auger transition.

nmainly ascribed to the transition M4 s - N2 3 N 23 (1) ,jectile. These facts might imply that the Auger peaks

where n is the number of 3d holes and the number infrom about 55 eV to 65 eV are ascribed to the transition M23 -M 4s N or M23 -NN with many 3d and N-shellholes in the initial states, namely , with the number ofthe parenthesis indicates the number of 4p holes,nbecause the lines due to the transition M4 S -N2 3 N2 3 (1)shift to lower energies as the number n of 3d holes in
the initial state increases, according to the theoreiticalresults of Larkins. The experimental result that the meanenergy of these Auger lines for 0.83 MeV He+ impact ishigher than that for 2.9 MeV N 2 + impact supports the

3d holes and N-shell holes of about 9 and 6, respectively .4) In order to identify the line structure fromabout 55 eV to 65 eV, the theoretical calculations involving electron excitation with many 3d holes arehighly desired.

identification mentioned above, since the probability ofmultiple ionization increases for heavier ion impact.
3) The intensity of Auger peaks from about 55 eV
to 65 e V enhances as the atomic number Z of projectile
increases. The strong Krypton M-vacancy production is

References
1)

T. Matsuo , J . Urakawa , A. Yagishita, Y. Awaya,
T. Kambara, M. Kase , and H. Kumagai: J. Phys.
B, lQ, L239 (1983) .

velocity as the orbital velocity of the M-shell bound2)

electrons. The corresponding velocity of the projectile
is about 0.2 MeV/amu for the Kr M4S - shell. Futher-

3)

more,

4)

L. O. Werme , T . Bergmark, and K. Siegbahn: Phys .
Scr.,Q, 161 (1972); ibid.,]', 146 (1973).
F. P. Larkins: 1. Phys. B,Q, 2450 (1973).
D . Schneider, B. M. Johnson , B. Hodge , and C. F.

expected to be induced by the projectile with the samethe strong electron stripping of the outer shellis expected to be produced by a sufficiently heavy pro-

Moore:

Phys. Lett., 59A, 25 (1976) .

69

Secondary Electrons Induced by N2 + Ion Bombardment

II1-2-16.

A. Koyama, Y. Sasa, and M. Uda

It is of great importance to carry out experiments

Figure 2 shows the scattering of the data to be about

with clean surfaces and to obtain the reproducibility ofdata in the study of secondary electron emission
phenomena. Therefore the aforesaid l ) ultra high vacuum± 10 % in the spectra of secondary electrons withenergies lower than 2 eV. Figure 3 shows a similar
amount of data scattering in the spectra of L- W Auger

apparatus was examined from this standpoint.
It takes about 20 minutes to obtain the spectra ofsecondary electrons by using the apparatus in the case ofelectrons. Hereafter an effort will be made to find out
the origin of the scattering of the data and to improve
the performance of the apparatus.

ion bombardment, and the surface of the target should
be kept clean enough during the measurement aftertarget preparation.
The surface of an Al target was examined by Auger
electron analysis using 1 ke V exciting electrons. The
target was in-situ vacuum deposited in the target preparation chamber. The target was transferred into thetarget chamber, and then the Auger analysis was made.
Within 20 minutes after target preparation no contamination was detected on the surface. When the target wasleft in the target chamber for 25 h , however, carbon

I

f

1
1
1
1

1
1
1
1

J
1

1
1
1
J

<:l

~

sidered to be of no significance in this study of electron
spectroscopy.
Further the reproducibility of the data was examined

1

~ 10

impurities were detected as shown in Fig. 1. The
thickness of the adsorbed carbon compound wasestimated to be 2 '"'" 3 A, from the comparison between
Al and C peaks. Then the amount of surface impurities
would be less than the equivalent of 1% of a monolayer
after a measurement taking 20 minutes, and are con-

1
1

kl

3

1

1J'::---'--'---'----I....--;':-I--'----.J.....
I -I.I---L...I::-l::1;:-L--'....I....-L.......I....
I --:-,IL:::---'----L.-...J
a
5
10
15
Energy (eV)Fig. 2. Energy spectra of secondary electrons
from a clean A 1 target. Projectiles are N2 + ionswith energy of 1.1 MeV /amu . Different marks
correspond to different measurement runs.

for spectra of secondary and Auger electrons induced byion irradiations. Projectiles were N2 + ions with energy of
1.1 MeV/amu, and the target was also a clean Al target.

8 000
7 000
§ 6 000
5000

Q)

6

~

6 000

~ 4 000

25h after deposition

:::J

5 000

Al

83000

4 000

2000 ~~~--~--~--~~~~~--~

6 3000Channel number

Q)

c:
c:

45

~

55

60

65

70

75

80

Fig. 3 . Energy spectra of L-VV Auger electrons
from a clean A 1 target. Projectiles are N2 + ions withenergy of 1.1 Me V /amu. Different marks correspondto different measurement runs.

(}J§ 2 000

u

1000

a

50

100

200

300

Channel number

Fig. 1. Auger peaks of Al and C from the Al
target which was left in the target chamber for
25 h after in-situ vacuum-deposition . Theenergy of exciting electrons is 1 keY.

Reference

1) A. Koyama , Y. Sasa, Y. Ishibe, A. Shiraishi, T. Shiga,
H. Omori, K. Nishi , M. Fuse, and M. Uda: p. 122 inthis report.

70

III-2-17.

Stopping Power of AI, Ni, Ag, Au, and Pb for 5 - 7
MeV/nucleon a Particles and Carbon Ions: Z~ Deviationfrom the Bethe Formula
T. Takahashi, Y. Awaya, T. Tonuma, H. Kumagai, K. Izumo, M. Nishida,
A. Hashizume, S. Uchiyama, K. Masuda, and T. Dokethe stopping powers of the same material for carbon ionsand a particles of the same velocity are measured. Table
1 shows the stopping powers of Ni, Ag, Au, and Pb

The stopping power of Ni, Ag, Au, and Pb for 7 MeV/
nucleon C ions and a particles have been measured byusing the cyclotron and the results are shown in Table 1.
In order to analyze our results we use a semi-empiricalexpression(without the effective-charge correction) for carbon
ions and a particles with the same velocity as well as
the values of Ll for both projectiles obtained with theuse of three different charge-correction formulas. The
stopping powers in the table are also shown in Fig. 1

4

dE 471Noe Z2 2
- dx2
Zl(Lo +Z 1L 1 +<p)
mv A2

(1)

for the stopping power of a target with atomic number
Z2 and mass number A 2 , and a projectile of velocity v
and charge Zl e. Here, No is the Avogadro number, mand e are the electronic mass and charge, respectively,
Lo is the Bethe stopping number per target electron, Ll
expresses the Zi deviation from the bethe formula, and<l> is the Bloch term which is calculated as described inRef. 1.
From Eqn. (1), Lo + Zl Ll is given by
La + ZI Ll = L=

[-~;l

2

A2

mv 4

2

<P.

14

Ziegler(2)471Noe Z2 Z 1Au..,.,.

For the cases of both a particles and carbon ions, Lo
holds a common value if the same target is used and thevelocities of the projectiles are equal, and moreover if
the carbon ions are regarded as point charges. In such acase, Ll is given by the following formula:
Ll=(Lc-La) / (Z~-Za)'

0.8

(3)

carbon ions, and Za is the nuclear charge of a particles.
Since L can be determined from the experimental
stopping power, we can obtain Ll from formula (3) if

Ni
Ag
Au
Pb
a:
b:
c:

Ziegler (Au)Ziegler (Pb)

7.2
74
Energy (MeV / amu)

7.6

Fig. 1. Stopping powers of Ni, Ag, Au, and Pb for aparticles and C ions of '" 7 Me V IN. In this figure thevalues of nine times the stopping power for a particles
and 36 times the stopping power for protons are shown.
x: the present data for C ions, e: corrected by using
Pierce and Blann's effective-charge formula, 0: thepresent data for a particles, tJ.: Ishiwari's data for aparticles, ~: Andersen's data for protons, -: calculated
from Ziegler's formula for a particles, 0: taken from
Northcliffe and Schilling's table for a particles.

particles, respectively, Zc* is the effective charge of

Stopping
material1:

7.0

where Lc and La are L values for carbon ions and a

Table 1.

Pb

• :8"

Stopping-power values for "'7 MeV/N a particles and C ions and their Zi deviation term Ll .
Stopping power

Ll values

for Cion

Stopping powerfor Q particle(MeV/N)(MeV/mg cm 2 )(MeV/mg cm 2 )

(l)a

7.039

1.347 ± 0 .016

0.1502 ± 0.0011

7.097

l.069 ± 0.0 I 00.1190 ± 0.0008

6.908

0.839 ± 0.006

7.148

0.814 ± 0.006

Energy

(4)d

(2)b

(3)c

0.02700.0427 ± 0.014

0.04640.04000.02860.0424 ± 0.012

0.04580.04500.0928 ± 0.0007

0.03390.0453 ± 0.010

0.04790.05370.0895 ± '0.0008

0.03740.0491 ±0.012

0.05190.0558

No effective-change correction,
Corrected by Pierce and Blann's effective-charge fonnula,
Corrected by Ziegler's effective-charge formula,d: Corrected by Anthony and Lanford's effective-charge fonnula.
References are cited in Ref. 1.

71

o No effective-charge correction, 7 MeV I N

I Effective- charge correction of Pierce andBlann, 7 MeV IN--- F (b I x 1/ 2 ) x 3 / 2, 7 MeV I N
6 No effective-charge correction, 5 MeV I N
I Effective-charge correction of Pierce and
I Blann, 5 MeV I N

2.0

1.0

',Ipb

A}~~:1A 'i ~

~ 0.5
~

Au 6 g0.2.....
Ag.......

6.

NI.............. -.. ........

6.

j

NI

--

0.1

-

-- --x= I.29

_ _ ......

b= l.3878

9 10 11 12 13 14 15 16 17 18

x = v 2I ( v02Z2)

Fig. 2. Experimental values of zIti
2 -1
LI as a function of (vivo) Z2 . The
broken curve was obtained by fitting
to the'" 7 MeV/nucleon data.

Table 2.

Stopping-power values for "'5 MeV/N a particles and C ions and their Z~ deviation term LI .

Stopping
material

Stopping power
for Cion(MeV/N) (MeV/mg cm 2 )Stopping powerfor Q particle(MeV/mg cm 2 )

(I)a

(2)b

(3)c

(4)d

1.970 ± 0.014
1.612 ± 0.019
1.272 ± 0.012
0.961 ± 0.007
0.982 ± 0.007

0.2198 ± 0.0015
0.1819 ± 0.0013
0.1421 ± 0.0010
0.11 00 ± 0.0008
0.1060 ± 0.0010

0.03400.02520.03430.02220.05700.0662 ± 0.015
0.0517 ± 0.017
0.0572 ± 0.013
0.0415 ± 0.009
0.0767 ± 0.011

0.07420.05800.06280.04420.08200.05330.04820.06240.05280.0884

AI
Ni
Ag
Au
Pb
a:
b:
c:

Energy

5.368
5.339
5.354
5.149
5.412

No effective·change correction,
Corrected by Pierce and Blann's effective.charge formula,
Corrected by Ziegler's effective·charge forl11ula,

Ll valuesd:Corrected by Anthony and Lanford's effective-charge

formula.
References are cited in Ref. I .

as well as the stopping power for a particles obtainedby Ishiwari et al. with their values multiplied by nine,
and those for protons by Andersen et al. with the values
multiplied by 36. The solid lines in the figure are obtained from Ziegler's stopping-power formula. Our
values for a particles are in better agreement than withas b decreases and, in addition, it depends on theeffective charge of the projectile. On the other hand,
Bloch's value of <I> is opposite in sign to LI ZI and
depends only on the effective charge. In Fig. 2 areshown experimental values of Z~ Ll as a function of(v /v0)2 Z - ; and theoretical values for the values of b

those of Ishiwari et al., rather than those obtained from
Ziegler's formula.

found with the use of Pierce and Blann's effective charge
for Zc* in Eqn. (3). Pierce and Blann's effective-charge
correction gives a reasonable value {l.38) of b for "'7
MeV/nucleon which appears in the Ritchie-Brandt
theory, if a X value of 1.29 in their theory is assumed. 1)
Stopping power of AI, Ni, Ag, Au, and Pb have been

According to Ritchie and Brandt, L1 Z~ is expressedby a function F(b/X I / 2 )/x 3 / 2 , where x = (V/vO)2/Z2 (vois the Bohr velocity) and b =1]XZl/~. Here., X is a constant describing correlations between electrons in an
atom in a way that wp(r) should be written as
4rrZ 2 e 2p(r)/m } 1/ 2 , where per) is the number densityof electrons. If each electron acts independently, X
should be unity. The contribution from distant collisionX{

to the stopping power is calculated by integration overthe impact parameter from a minimum value a w to infmity. The parameter 1] in the definition of b relates theminimum impact parameter to the radius r of the shell,associated with the plasma frequency wp(r), by
a w =1]r. Thus, the theoretical value of Ll ZI increases

measured for "'5 Me V/nucleon a particles and carbon
ions. The results are presented in Table 2 and in Fig. 2.
Analyses are now in progress.

Reference
1) T. Takahashi, Y. Awaya , T. Tomuma, H. Kumagai,
K. Izumo, M. Nishida, A. Hitachi, A. Hashizume,
S. Uchiyama , and T. Doke: Phys. Rev., A27, 1360
(1983).

72

III-2-18.

Reactions Induced by High Energy Ionsat the Pd-Si Interface

Y. Horino,* N. Matsunami,* N. Itoh,* and K. Kimura

It has been demonstrated that silicide phase is formedof the Si0 2 layer impeded thermal growth of silicides

at the Si-metal interface under irradiation with heavyions, e.g. 300 keY Xe ions. In order to investigate theand no reaction took place at .temperatures below

mechanism of the ion-induced silicide formation, we

shown in Fig. 1, for irradiation with 40-MeV Ar ions toa dose of 5 X 10 15 /cm 2 at 180°C. The Pd spectrum

200°C.

have measured the Pd-silicide formation induced by H,
He, and Ar ion bombardment with energies ranging

shows a long tail and the Si spectrum indicates an
Si-rich phase (PdSi 4 ). This result contrasts with thePd 2 Si formation by I-MeV He and 5-keV He ion irradia-

from 1 keV/amu to 1 MeV/amu, using the Rutherford
backscattering (RBS) of 1 MeV He ions. We have also
investigated the ion-induced reactions at an Si-Pd interface with intervening Si0 2 layer. The interfaces wereprepared by evaporation of Pd on a cleaned surface ofSi substrate and on native Si0 2 -Si substrate.

The ion-induced reaction was observed, astion. This Si-rich phase formation can be due to highenergy deposition rate into inelastic collisions (highdensity excitation effect).

The

The ion-induced formation of Pd 2 Si was observedfor irradiation of 1 MeV He ions at 200°C. The RBS

thickness of the Pd layer was determined as 200 - 400
A and that of the Si0 2 layer was estimated to be ""loA.

spectrum for Pd shows a long tail, indicating that Pd

The results are summarized in Table 1, which also
includes the results obtained by Mayer et al. I ) In thecase of the Pd-Si interface, uniform Pd 2 Si and/or PdSi
layers were formed at room temperature. It was foundthat the formation yields of Pd 2 Si per ion scale withpenetrates deeply into Si, in contrast to the uniform
Pd 2 Si layer. Island structure was observed at the surfaceof this sample by a scanning electron microscope. A
probable explanation for the non-uniform silicide formation is as follows: paradium passes through ion-induced

the elastic energy deposition rates of ions at the inter-damage spots which are distributed non-uniformly in the
Si0 2 layer and reacts with silicon to form columnar

face.

This result contradicts the prediction by thePd 2 Si.

current theory, i.e. the collision mixing mechanism.
In the case of the Pd-Si0 2 -Si interface, the presence

Table 1.

Thermal and ion-induced Pd-silicide formation.
Si-Pd

Thermalgrowth
5 KeV He
lon- 300 KeV Xe
inducedreaction
1 MeV He

> 700°C

Pd 2 Si

R.T.

Pd 2 Si

R.T.

Pd 2 Si

40 MeV Ar
N.R.
R.T.

* Department:s;: 700°C

Pd 2 Si
PdSi

PdSi

no reaction,
room temperatureof Crystalline Materials Science , Faculty ofEngineering, Nagoya University.

Si-Si0 2 -Pd

R.T.

N.R.

:s;: 200°C

N.R.

R.T.
200°C

N.R.

R.T.

Pd 2 Si

Columnar Pd 2 Si 200°C
Si-rich phase(PdSi 4 )

180°C

73
(x 10 4 )(X I0 4 )
I

1.51-

I

I

I

40MeV Ar 4 +A as evaporaTed
B 5.0 X 1015 ions/ cm 2
x Si

: ....

Pd

- 3.0

' '.

180°C
A'

'. j
- 2.0

LO r-

Channel number

Fig. 1. RBS spectra of 1 MeV He+ on Si-Si0 2 -Pd irradiated with 40 MeV
Ar+ to a dose of 5 x 10- 5 cm- 2 at 180 °e.

Reference
1) J. W. Mayer, B. Y. Tsaur, S.S. Lau, and L. S. Hung:
Nucl. Instr. Methods, 182/183, 1 (1983).

74

1II-2-19.

Emission Mossbauer Studies of Dilute 119Sb Ions Adsorbed
on Ferrimagne-ttc Cobalt Ferrite Surfaces
T. Okada, S. Ambe, F. Ambe, and H. Sekizawa

Previously, we reported
results of emlSSlOn
Mossbauer measurement of 119 Sn arising from carrier

diamagnetic nuclei of 119 Sn 4 + ansmg from the adsorbed 1 19 Sb 5 + were shown to be under the influence

free pentavalent 119Sb ions hydrolytic ally adsorbed on
surfaces of antiferromagnetic and ferrimagnetic
oxides. 1) ,2) The present work aims to clarify theof the supertransferred hyperfine fields from themagnetic ions in the ferrite . This finding indicates thatthe 119Sbs + ions predominantly from Sb s + - 0 2 - -chemical states of dilute pentavalent antimony ions hy-

Mn + bonds with the metal ions (M) of the ferrite .

drolytically adsorbed on the surfaces of cobalt ferrite,
and also the diffusion and coagulation of the 119 Sb

Some of the observed spectra are shown in Fig. 1.
These spectra were analyzed by means of HesseRtibartsch procedure to obtain the distributions of thehyperfine magnetic field shown in Fig. 2. Our experimental findings are summarized as follows:(1) In "as adsorbed" state, the distribution function
P(H) has large values in larger field range compared withother magnetic oxides.

ions by heat treatments.
Mossbauer analysis was made on the 23.8 ke V -y-rays
emitted by the first excited states of 119Sn 19Sn*,
half life: 17.8 ns) arising from 119Sb (half life : 30.8 h)eby the EC decay. Experimental procedures have alreadybeen reported in the previous reports. 1),2) Carrier-free
119 Sb ions were adsorbed on the surfaces of theferrimagnetic oxide powdersof cobalt ferrite(CoFe 2 0 4),
the Neel temperature of which was about 520°C. The
obtained emission spectra suffered apparent broadening
compared with those of non-magnetic substrates. From
analysis of the broadening of the emission spectra, the(2) After 400°C heat treatment, there appears apeak ofP(H) at around 100 kOe.
(3) After 600°C treatment, there appears a peak ataround 0 kOe , which can be attributed to clustering of
119Sb ions.
(4)

By higher temperature treatment up to 1000 °c,

119Sb-CoFez0 4 at SDK
119Sb - CoFeZ04 at SDK"As adsorbed".' . .. As adso rbed '"
c

o
"-§

2c

~~------~------~----~~~~

";::
11)

:::J

o
U

is

-10

D

+ 10

D

Velocity (mm S-1 )Fig. 1. Emission Mossbauer spectra of the
CoFe2 0 4 _ 119 Sb S + specimens taken at liquidnitrogen temperature.

Fig. 2. Distribution of the supertransferred hyperfine (STHF) magnetic fields on 119Sn4+
arising from 119 Sb S + of the CoFe 2 0 4 specimens
derived from the spectra of Fig. 1.

75
diffusion of 119 Sb ions becomes remarkable, and afairly sharp peak appears in the higher field region accompanied by a rapid decrease of distribution in lower
field region below 50 kOe.
(5) The observed isomer shift is rather large compared with other magnetic oxides.
The detailed investigation, as well as similar studies on

various other ferrites, is in progress.
References
1) T. Okada, F. Ambe, S. Ambe, and H. Sekizawa: J.
Phys. Chern., 86, 4726 (1982).
2) T. Okada, F. Ambe, S. Ambe, and H. Sekizawa:
RIKEN Accel. Progr. Rep., lQ, 101 (1982).

76

III-2-20. Perturbed Angular Correlation of y-Rays Emitted
from 111Cd(~ ·111In)in a-Fe 2 0 3
K. Asai, F. Ambe, S. Ambe, and H. Sekizawa) denotes the Wigner 3- j symbol, I the spin

Perturbed Angular Correlation (P AC) or l'-rays isa valuable tool not only in the field of nuclear physics

where (

but also in the field of solid state physics, because it pro-

111 Cd, Imi> the state assigned by its z component mi'vides useful information on the electronic states insolids through the hyperfme interactions. 111 Cd

Ini> the eigenstate of the interaction Hamiltonian 'J(
and Enl. its energy eigenvalue. In general, A 22 (t}unlQ.
.

(+-- 111 In) is one of the most popular nuclide emitting

has I X (21+1) discrete Fourier components.

suitable cascade l'-rays for this type of measurement and

The perturbation factor A2 /t) in a-Fe 203 at 400°C
was obtained by Eqn.(I). (Fig. lea)) We assume that A22(t) is composed of two parts. One part A22 ' (t), which

many investigations using this nuclide have been done.
In these previous investigations, it has been found thatwell-defined hyperfine frequencies are observed forll1Cd embedded in metals such as Fe 1), Ni 1 ),2), andIn,3),4) while hyperfine frequencies are widely distributed in insulators such as In 2°3,4) In(OH)3 4 ) and
InP0 4 .3) Such distribution has been ascribed to thequantum number of the intermediate state of theis described well by Eqn.(2) (= C1 X A2 /t)uniQ)'
has well-defined interaction frequencies. The otherpart A22 "(t) has a widely distributed frequency
spectrum so that its value is constant (= C2) in theregion where t is sufficiently large . We obtained

after-effects of the preceding electron capture (EC)decay of 111 In; in insulators, the lifetime of the elec-

the values of C 1 ' C2 and the parameters in the
Hamiltonian 'J( by least-squares fitting with the equation

tronic holes produced by the Auger process following
the EC decay is rather long and the unstable perturbed

A2 2(t) = C1 X A2 2(t)uniq. + C2 in the regin t ~ 50 ns.
It is assumed that the asymmetry of the electric fieldstate heavily contributes to the perturbation factor.

gradient (EFG) is equal to zero and that the angle

When we apply PAC measurement to studies ofmagnetic oxides, above mentioned situation is very im-

between the directions of EFG and the hyperfine
magnetic field, Hhf' is equal to 90° from consideration

portant, because their electrical conductivities are widelyof the crystal symmetry of a-Fe 2°3' The best fitted

distributed depending on their compositions and tem-values of C 1 ' C2 ' w L (the Larmor angular frequency)

peratures. From this point of view, we have beenmeasuring PAC of l'-rays emitted from 111 Cd in aand w Q (the quadrupole angular frequency) are 0.06,

typical antiferromagnetic oxide a-Fe 0 3 at various tem2

peratures. In this report, we present the data obtained-020_-------------------,
(a)

-015

at 400°C and also preliminary results of analysis.

A22 (t)The sample was prepared by firing the coprecipitatefrom Fe 3+ and 111In 3+ solution. The firing was doneat 800°C for 2 h. For a polycrystalline specimen, theperturbation factor A2 2(t) is obtained by the normalization of the time spectra NO 80° ,t) and N(90°, t) in theform
A 22 (t) =j{N(l800,t) - N(900,t)}/ {N(l80°, t) + N(900, t) }.

(1)

For a unique but randomly oriented static interaction,
A22 is expressed in the form 5 )
A

22

(t)

uniq. ='"~

Time (ns)(_1)21+m,+m 2

N,m"m 2,n"n Z

Fig. 1. (a) Perturbation factor A2 2 (t) of the 111 Cd 'Y - 'Y
correlation in a-Fe 0 3 at 400°C. The solid curve represents2
the value of C 1 x A 22 (t)uniq. + C 2 , (b)Perturbation factorA' (t). (c) Perturbation factor A2;' (t). The solid curve
22
represents the value calculated from the frequency spectrum in
Fig. 2(b).

77

0.015, 8.27 X 10 7 rad/s and 2.52 X 107 rad/s, respectively. The hyperfine magnetic field calculated from w L
is 54.7 kOe. A22 ' (t) and A2 2" (t) are shown in Fig. 2(a)and (b), respectively. The latter is obtained by subtracting A2 2/ (t) from A2 2(t). Ratio of the former to thelatter is about 0.9. Figure 2 shows the frequency spectraof A2 2/ (t) and A2 2" (t). As can be seen, the spectrum of
A2 2" (t) is very broad without any salient features.

4r

(a)

3r
§

2 r-

Li

~ 1 t~
iJ)

I

0

§ 2c

I

I

(b)

J

~~
j

4
5
2
3
Angular frequency ( x 10 8 rad Is)
Fig. 2. Frequency spectra of (a):A2 ~/ (t).

67

A2 ; ttl, and (b):

It is considered that 111 Cd ions which contribute to

A2 2/ (t) retain little effect of the preceding EC decay andthose which contribute to A2 2" (t) feel hyperfine
interactions due to the after-effect of the EC decay.
The present study shows that 111 Cd ions in a-Fe 20 3 arerather clearly classified into the above two groups at
400°C. For further discussion measurements at othertemperatures are necessary which are now in progress.

References
1) R. S. Raghavan and P. Raghavan: Nucl. Instr. &Methods, 92, 435(1971).
2) D. A. Shirley, S. S. Rosenblume, and E. Mathias:
Phys. Rev., 170,363 (I968).
3) H. Haas and D. A. Shirley: 1. Chern. Phys., 58,
3339 (1973).
4) P. P. Lehmann and 1. Miller: 1. de Phys., ll, 526(1956).
5) H. Frauenfelder and R. M. Steffen: a-, (3-, andr-Ray Spectroscopy, Vo1.l, (ed. by K. Siegbahn),
North-Holland, Amsterdam (1964).

78

III-2-21.

Perturbed Angular Correlation of r-Rays Emitted from
111Cd(~111In) in MFe204 (M==Fe, Mn, Co, and Mg)
K. Asai, T. Okada, and H. Sekizawa

It is well known that large hyperfine magnetic fields
are observed at the nuclei of diamagnetic cations in

perturbed angular correlation of "I-rays emitted from111 Cd in M2 +Fe 3 +2 0 4 with M = Fe, Mn, Co and Mg.

magnetic materials below its magnetic transition tem-Samples were prepared by diffusing 1 11 In into theperature. Since the origin of these hyperfine magnetic
fields Hh f at the nuclei is the electron-spin polarizationinduced by the surrounding magnetic cations, the in-oxides at 1250 °c for MnFe 2 0 4 and 1150 °c for others.
Specimens about 150 J,LCi in activity were submitted tovestigation of these fields supplies important information on the exchange interactions between magnetic
cations. As for ferrimagnetic oxides with the spinel
structure, Hhf at Sn 1 ) and Sb 2 ), both occupying the B

applied perpendicularly to the counter plane.

site (octahedra!), have been investigated. Similar investigation of Hh f at the nuclei of diamagnetic ions on
the A site (tetrahedral) is also desirable, because itsupplies information complementary to that ,obtained in
the previous investigations. From this point of view, wehave been investigating Hhf at l11Cd(+- 111In) in various ferrimagnetic oxides with the spinel structure. 3 ),4)
In this report, we present experimental data of

(a)

01

M=Fe

0,05

measurement with an external magnetic field of 10 kOe
Wemeasured the time spectra at () = 90° and 180°, andthen obtained the normalized anisotropy R(t) defined asfollows:

R (t) = {N (90°, t) - N (180°, t) }/{N(900,t)+N(1800,t)} ,where, N(() ,t) denotes the time spectrum, () the angle
between the two cascade "f-rays, t the time interval
between them. For a unique and static Hhf oriented
perpendicularly to the counter plane, R(t) is expressedin the form R(t) =(-3/4)A 2 2 cos(2WL t), where wL is
the Larmor frequency. 5 )Figure 1 shows R(t) for MFe 2 0 4 (M = Fe, Mn, Co,
and Mg) at room temperature and Fig. 2 shows their

(a)
2St
2.0

M= Fe

1.5

-0,05

1.0

'22'
>.

0.5
0.0

0,05

a

2
-0
c.n

0.0

0.5

'c
<U

....... 0.4'c:::::l

-0

Q)

~

ro
E

0.05

0

z

00

0,05

o,ollJJ~M~~- 0,05 II....-_--'-_------'_ _.....L.-_------L_ _-L-._ - - - - l
a
50
100
150
200
250 300
Time (ns)Fig. 1. Normalized anisotropy R(t) of the time
spectra of "I -"I cascade emitted from 111 Cd in
MFe 2 0 4 , The solid curve represents the value reproduced from the frequency spectra in Fig. 2:
M = (a)Fe, (b)Mn, (c)Co, and (d)Mg.

(b)

M=Mn

-e 0,3~ 0.2
1:;c.n 01
c
2 0.0
..s
0.4
0.3
0.2
0.1
0,0
0.2
01

Angular frequency(rad / s)Fig. 2. Frequency spectra of R(t) for MFe 2 0 4 :
M = (a)Fe, (b)Mn, (c)Co, and (d)Mg.

79

frequency spectra. For M: Fe, R(t) has a very sharp
single frequency compoent at w = 3.6 X 10 radls andthe derived value of Hhf is equal to 118 kOe. On theother hand, for M = Mn, Co, and Mg, R(t) have verybroad frequency spectra in non-zero regions and further
have large and sharp components at w = O. The latterfeature can be explained by the fact that the axes of thehyperfine interactions are not parallel to the appliedmagnetic field at some nuclei. Since the abundance of
these nuclei is estimated to be the order of a half of thetotal 111 Cd nuclei, the contribution of these nuclei toR(t) in non-zero region is not negligible. At present, it
is considered that the broad peak in the higher frequency region in each spectrum is attributed to 111 Cd
which feel Hhf parallel to the applied magnetic field,
and the very broad plateau in the lower frequency region
is attributed to that which feel some other hyperfine
interactions. The values of Hhf corresponding to thetops of the peaks are 110 kOe, 105 kOe, and 100 kOe
for M = Mn, Co, and Mg, respectively. The average ofHhf decreases and the width of its distribution increases
8in the above order of the ions M. This tendency isqualitatively explained by the magnitude of themagnetization of the ions in the B site. More detailed
consideration will be given later.

References
1) G. V. Novikov, B. A. Trukhtanov, L. Cher, S. I.
Yuschuk, and V. I. Goldanskii: Zhur. eksp. teor.
Fiz., 56, 743 (1969).
2) B. J . Evans and L. J. Swarzendruber: Phys. Rev.,
BQ, 223 (1972).
3) H. Sekizawa, K. Asai, T. Okada, N. Shiotani, E.
Vagi, and S. Ambe: IPCR Cyclotron Progr. Rep.,
lQ, 99 (1976).
4) H. Sekizawa, K. Asai, T. Okada, N. Sakai, N.
Shiotani, and E. Vagi: ibid.,ll, 106 (1977).
5) H. Frauenfelder and R. M. Steffen: 0:-, ~- and'Y - Ray Spectroscopy, Vol. 2, (ed. by K. Siegbahn),
North-Holland, Amsterdam (1964).

80

1II-2-22. Plasma Wall Interaction
Y. Sakamoto, Y. Ishibe, K. Yano, K. Okazaki,
S. Ishii, and H. Oyama

The report deals with following three works in the
study of plasma wall interaction:with standard cracking patterns of QMA. These were

1) Discharge cleaning

identified as methane, water and carbon monoxide. Theof the Tokamak first wall for the reduction of light im-others were presumed as ethylene, propylene and carbon

purities in Tokamak plasma, 2) Formation of nitride on

dioxide. The origin of these hydrocarbons is explained as

the titanium surface as one of candidate materials forfollows:

the first wall and 3) Neutral particle measurement bylong chain hydrocarbons. Being bombarded by energetic

laser induced resonance fluorescence spectroscopy forparticles from the plasma, they are cut short into frag-the observation of the behavior of impurity particles.
Those works are complementarily related each otherments and desorbed. The bonding energy of single bondof the carbon chain is 3.44 e V and the energy of in-

and will help in understanding the surface changes andcident particles is about 5 eV, which is high enough tothe processes concerned with physical and chemical

cut the bond.

reactions on the surface caused by plasma irradiation.

(1) Fundamental Study of Electron
Resonance-Discharge Cleaning (ECR-DC).

Cyclotron

Organic substances on the surface are initiallyiii) Depth profiles of light elements near the surface.
We studied wall samples to see whether there remained some effects of discharge cleaning after the

The ECR-DC method for torus devices has beensamples had once been exposed to the atmosphere bydeveloped by our group and we have also done ex-measuring the depth profiles of light elements near the

periments with the following apparatuses: JFT-2(Tokai),l) lIPP-TII (Nagoya),2) and TEXTOR (lillich,surface using the Rutherford scattering method withRILAC .

Fed. Rep. of Germany).3) The purpose of obtaining

For CuO, the depth profiles of oxygen of the wallclean surface wall and pure hydrogen tokamak plasma

samples differed from those of the reference samples. In

which has zeff=l, has been achieved.
In the cleaning discharge, however, there still remainsome unresolved problems. Among them we have

Fig. 1 examples of measured depth profiles are shown.
The difference in the profiles is due to the effect of
ECR-DC. For the stainless steel samples, there was nostudied the following problems; the reaction of oxygen

difference in the depth profiles from those of the walland carbon on the surfaces with incoming H; and H+

reference samples. In this case the effect of ECR-DC isions, the behaviors of organic substances on the surface,obscured after the samples are once exposed to at-and the depth profile of light elements near the surface.

mosphere. It is supposed that exposure to air resulted

Investigation of the reaction of carbon within reoxidization of the surface cleaned by ECR-DC toi)hydrogen molecular and atomic ions.
The carbon peak was observed by Auger electron

have the oxide layer with the same thickness as before.
(2) Preparation of TiN samples

spectroscopy before and after irradiating a stainless steel
surface with hydrogen ion beam of energy 100 e V. In
the case of H+ ion irradiation with dose 10 18 /cm 2 , them~thod.

TiNcarbon peak height was reduced drastically, but in the

prepared by .nitriding titanium plates by chemical reac-case ofi)

samples wereprepared by following

two

In one method samples of titanium nitride were

H; ion irradiation it did not change at all with
H; ions in a plasma withtion with nitrogen ions produced by arc plasma. The

the same dose. It is shown that

schematic diagram of the apparatus for the reaction is

low energy « 100 e V) have no chemical cleaning effectshown in Fig. 2. Working gases were N2 and H2 . Theiron carbon.

mixing ratio was 6 : 1, and the total pressure was 80 Pa.

ii)

Study on the behaviors of organic substances

The typical discharge voltage and current density were

The surface exposed to atmosphere is usually con-

600 volts and 1OmA-cm - 2, respectively. The sample

taminated by organic substances. We studied how thesetemperature rose up to about 800 0 C by discharge andorganic substances on the surface of lIPP-TII tokamak

this was appropriate for nitriding. XPS and Rutherford

are removed by ECR-DC, using a quadrupole mass

scattering observation show formation of a very thickanalyzer (QMA). The mass spectra of the gases desorbed

nitride layer on the sample.

by the cleaning discharge were examined by comparing

thickness is being -carried out.

Determination of the

81

10 3

B
I

(f)

10 2

C:::J
0

U

10 1

10°

0
Fig. 1. The oxygen depth profiles of CuO samples measured by the Rutherford
scattering method. Curves are obtained (A) with discharge cleaning and (B) without
discharge cleaning reference samples. The scale of pulse counts is normalized toincident ion doses.

(3) Neutral particle measurement in the gas phase
For the purpose of understanding how materials
interact with plasmas or how they react under the irradiation with accelerated heavy ion beams, the studyof the behavior of atoms in the gas phase released
from the material surfaces gives very useful information.
For this purpose, we have adopted laser induced
resonance fluorescence spectroscopy (LFS) to measureneutral atom densities and velocity distributions close to

Fig. 2. The schematic diagram of the apparatus
for making the TiN by PCVD.

the material walls.

This method has extremely highsensitivity and moreover it is not affected by ambient
plasma parameters. So far an LFS measurement systemii)

In the second method, nitrides were produced byhas been constructed which is composed of a dye laser

cluster ion bombardment. Surface treatment by theand a fluorescence detection part. In 1984 this LFS

interaction of energetic cluster ions with solid surfaces

system is to be applied to measure the iron neutral atom

recently

density near a stainless steel sample which is irradiatedarise

interest in its application to surface

coating. The mean cluster size used was about 3 x 10 4bymolecules/cluster. Nitriding conditions were as follows:

threshold. The result will be compared with the sputter-

The cluster ion current was 0.6 /lA. This means that theing yield data of monochromatic energy.

particle current was 1.1 x 10 17 molecules/sec.
accelerating voltage of ions was 27.5 kV.

aplasmawithenergyaround the

sputtering

The

The tem-perature of the titanium was about 400°C.
After 2 hr's bombardment, the surface was examined

References1)by ESC A (electron spectroscopy for chemical analysis).

It was found from this analysis that a part of the surface
was nitrided, and the ratio of N to Ti was less than 0.5.

al.:
2)

J. Nucl. Mater., 93 & 94, 333 (1980).

Y. Sakamoto,

Y.Ishibe,

S. Ishii,

H.Oyama, and K.Yano et al.:The preliminary result suggests that nitrides can beeffectively produced by bombarding with intense cluster
ion beams.

Y. Sakamoto, Y. Ishibe, K. Yano, and H. Oyama et
K. Okazaki,

ibid., 111 & 112,

485 (1980).
3)

S. Ishii, K. Okazaki, Y. Sakamoto, and K. Yano:
Jpn. J. Appl. Phys., 22, L403 (1983).

82

III-2-23.

Studies of a-Si : H Growth Mechanism by Rutherford
Recoil Measurement of Hand D in Films Preparedfrom SiH 4 -D 2 and SiD 4 -H 2

Y. Yatsurugi,* O. KUboi,* M. Hashimoto,* H. Nagai,
M. Aratani , M. Yanokura, I. Kohno, and T. Nozaki

Hydrogenated amorphous silicon (a-Si : H) preparedby glow discharge!) in a gas mixture of SiH 4 and H2 has

shapes of the recoil spectrum give information about
their depth profIles.

been studied extensively as a new semiconductormaterial. For the improvement and control of the characteristics of this substance, it is essential to elucidate
its growth mechanism. 2 )-4) We used deuterium as a

The technique of coincidence detection of recoiled
and scattered particles was employed, in order totracer to study the growth mechanism, determining H
and D contents of the product a-Si: H fIlm by
Rutherford forward recoil measurement. s )-6) Using
samples prepared from SiH 4 -D 2 mixtures and from
SiD 4 -H 2 mixtures, we clearly determined the origin of
the hydrogen in the fIlm .
The same glow discharge system as in the literature 7 )was used . The substrate for the a-Si : H deposition wasa high-purity silicon wafer, and its temperature was set
at 250°C. The Rutherford recoil was measured in ascattering chamber. The experimental arrangement is
described in detail in a preceding report 8 ) of thisvolume.
An example of Hand D spectra is shown in Fig. 1.
Standard error in the total counts taken for hydrogen in
our experiment corresponded to ± 0.1 atomic percent.
Since the energiesof detected Hand D are dependent on
the depth in the sample where they were recoiled , the10 4 ~----------------------------~

H

1~::J 10 2oUChannel number

Fig. 1. A Rutherford forward recoil spectrumfor Hand D. Reactant gas for a-Si samples:
SiH 4 (1 vol) + D2 (4 vol)* Komatsu Electronic Metal Co.

ascertain the reliability of the quantity of H obtained asabove. A-Si: H fIlms of 2250 A in thickness preparedon several thin aluminium backings were bombarded
with a 45 MeV 3He particle beam, and recoiled H
particles were detected in coincidence with the correspondingly scattered 3He particles. A polyethylene
film of 0 .90 mg/cm2 in thickness was used as the reference substance. The argon beam method and the 3He
coincidence method gave results of 14.7 atomic percent
and 14.4 atomic percent respectively , which can be regarded as a good agreement.
The relation between the RF power for glow discharge and Hand D concentrations in a-Si : H is shownin Figs. 2 and 3 for the discharge in a SiH4 (1 vol)D2 (4 vol) mixture. It is clear that more H atoms than Datoms were incorporated in the amorphous silicon in
low RF power region. With increase in the RF power,
isotopic fraction of H decreases, while the fraction of
D increases. The correlation between the isotopic composition of the reactant gas and that of the productamorphous silicon is shown in Fig. 4 for the RF power
relatively high in the present study but usual in practicala-Si : H production. The isotopic compositions of thereactants and the products in such a RF power range areshown to be almost equal regardless of both isotopic
ratio and initial chemical forms of Hand D in thereactant gas.
From these results, we can infer the following
mechanisms for the growth of a-Si : H under the RF
glow discharge in a SiH 4 - H2 mixture. In low RF
power region, the SiH 4 is not decomposed completely

into Si and H but SiHn (n = 1 "" 3) are also formed. The
SiHn arriving at the surface of the growing a-Si: H
reacts with it, and is then incorporated in the product.
This is regarded as the principal growth mechanism for
low RF power.
With the increase in the power, the decompositionof SiH 4 and H2 proceeds more completely into atoms

83

20r-----------------~

1.0 ..-_ _ _ _ _ _ _ _ _ _;;-;~;

I

;

;

o

~
c

15

;

0.8

;

:r::

;
;;

'0 0.6
§

m

.~

c

~ 10
C(l)
c

5

o

,.~""
;;

-8 0.2 0"~0,'~;;' 8 1

o

u

o

() ){

'0

u

'0 0.00

:r::

(0 )

o0

()

;

;

~ OA

o

.•f'

0.2

1

1

0.4

0.6

0.8

1.0

isotopi c fract i on of H in reactant gas ( H )Fig. 4. Isotopic fraction of hydrogen inreactant gas and product a-Si in theregion of high RF power.
0: SiD + (D ) , (): SiD + H , C): SiH
4
4
4
2
2
+ D2 , e: SiH 4 + (H 2 ) .

10 20 30 40 50 60
RF Powp.r ( watts )Fig. 2. Concentrations of Hand D
in a-Si vs RF power. Reactant gas
for a-Si samples:
SiH 4 (I vol) + D2 (4 vol)e: H + D, 0: H, 6: D

I t is seen in Fig. 2 that the concentration of totalhydrogen (H + D) in the a-Si : H was almost independent:r:: 1 . 0 r - - - - - - - - - - - - - - ,U5 0.9I~ 0.8
g-g 0.7
Q

0.6

.~
I

'0 0.5c.2 0.4

\.

\

.""'.
----............

of the RF power. This concentration seems to be determined by some other factors, for example, substratetemperature. Deuterium can be used effectively forfurther study of a-Si : H growth. No serious attention
needs to be paid to kinetic isotope effect, as is understood from Fig. 4, but marked and predictable change iscaused in the IR absorption band by H-to-D replacement.

~ 0.3 Isotopic-----------------------.;:
fraction of H in reactant gas
u'0.8 0.2o~ 0.1

9 0.00I

10 20 30 40 50 60 70 80
RF Power ( watts )Fig. 3. Isotopic fraction of H in a -Si vs
RF power. Reactant gas for a-Si samples:
SiH 4 (1 vol) + D2 (4 vol)Isotopic fraction of H in reactant gas.
.

[H][H] + (D]References
1) W. E. Spear and P. G. LeComber: Philos. Mag., 33,
935 (1976).
2) F. J. Kampas: J. Appl. Phys., 53,6408 (1982).
3) A. Matsuda, K. Nakagawa, K. Tanaka, M.
Matsumura, S. Yamasaki, H. Okushi, and S. lizima:
J. Non-Cryst. Solids, 35-36 , 183 (1983).
4) G. Turban, Y. Catherine, and B. Grolleau: Thin
Solid Films, 77 , 287 (1981).
5) J. L'Ecuyer, C. Brassard, C. Cardinal, J. Chabbal, L
Deschenes, and J. P. Labrie: J. Appl. Phys., 47,
381 (1976).
6) H. Nagai , M. Aratani, T. Nozaki, M. Yanokura, I.

and ions of Si and H. The Si is deposited and H is

Kohno, O. Kubori, and Y. Yatsurugi: RIKEN

chemisorbed on the growing a-Si : H surface, and a partof the hydrogen atoms are incorporated in the product.
In such a RF power region which gives the results ofAccel. Progr. Rep. , li, 125 (1982) .
O. Kuboi: J . Electrochem. Soc. , 130, 1749 (1983).
H. Nagai, M. Aratani, S. Hayashi, T . Nozaki, M.
Yanokura, I. Kohno, O. Kuboi, and Y. Tatsurugi:
p. 102 in this report.

Fig. 4 the decomposition is so complete that the reactive
H can behave independently of its origin.

7)
8)

84

III-2-24.

Depth Profiling of Hydr.ogen in Solids by Using Nuclear
Reaction 1H (118, a) a a

E. Yagi, T. Kobayashi, and S. Nakamura

In the present study the depth distribution of hy-

were 5 cm 3 /min and 2 cm 3 /min (Fig. 1 (a) and 1 (b)).

drogen in amorphous Si was measured by using nuclear
reaction 1 He 1 B, a)aa. Hydrogen in amorphous Si

To each group belong two specimens. One of themplays an important role in reducing the density of dangling bonds. Then the p-n control by impurity doping

flowing hydrogen gas at a flow rate of 45 - 48 cm 3 /min. Figure 1 seems to indicate that the difference inbecomes possible.

was prepared without hydrogen gas and the other by

The nuclear reaction mentioned

flow rate of SiH 4 gas has no strong effect on the hy-

above exhibits a narrow resonance at the energy 1.793
MeV of 11 B beam. The resonance width is about 66

drogen concentration, but the hydrogen gas flow rate
has rather strong effect to the resultant hydrogen con-keV, which corresponds to the thickness of about 640 A

centration, although measurement was not made on

in Si. Hydrogen can be detected by measuring emitted

many specimens.

a-particles, energy of which extends up to about 5 MeV.

progress.

The

detailed investigation is in

From the yields of emitted a-particles measured bychanging the incident energy of 11 B beam, the depth

500 ~-------------------------'

distribution of hydrogen can be deduced.

400

A specimen was mounted at an angle of 45° withrespect to the incident beam . The emitted a-particles
were measured by a solid state detector placed at anangle of 90° with respect to the incident beam. In frontof the detector a Mylar foil of 4,um in thickness was

300

U 200

placed to detect only a-particles. The amorphous Si
specimens were prepared by growing the amorphouslayer on the Si crystals in SiH 4 atmosphere by glow discharge

method. They

were

supplied by Komatsu

Electronic Metals Co., Ltd. On four specimens prepared
under different conditions the dependence of thea-particle yield on the incident energy of 11 B beam
was measured. The results are shown in Fig. 1. Although the energy scale on the abscissa is nottransformed into the depth scale, 1.793 MeV corresponds to the specimen surface. The four specimens
are devided into two groups with respect to the flowrate of SiH 4 gas in preparation of specimens, which

SiH 4 H2 ( cc / min )400

1970 A 2
930 A 2ill>= 300

0
48

200
100

o

0

I

1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4
Incident energy E (MeV )Fig. 1. a-particle yield as a function of theincident energy of 11 B beam. The conditions for
preparation of the amorphous Si layer, i.e. theflow rates of SiH 4 and H2 gases and thethickness of the layer, are indicated in the figure.

85

III-2-25.

Lattice Location of Hydrogen in Tantalum as Observedby Channeling Method Using Nuclear Reaction
1H(118, a) all'E. Vagi, T. Kobayashi, S. Nakamura,
Y. Fukai, * and K. Watanabe*

Direct determination of the lattice location of hydrogen in metals has been made for the first time. Hydrogen diffusion in solids is an important problem< 110 > axial channels, and 1100 f and 1111 f planar

because of the great theoretical and technologicalsites on the plane perpendicular to each channel are alsointerest, e.g. tritium permeation in fusion reactor
lattice location of hydrogen is closely related to its

sh . 'wn. Hydrogen in a bcc crystal is expected to beideated at a T-site or an O-site. The different angularprofiles of emitted a-particles are expected for the O-site

diffusion behavior. Therefore the detailed knowledge

occupancy and the T-site occupancy. The detailed dis-materials, hydrogen embrittlement of metals, etc. The

challnels . The results are shown in Fig. 1, where projections of octahedral (0) and tetrahedral (T) interstitialon the location is required. There have been several experiments on the location of deuterium in metals by
1.5 1.---------------~

means of neutron scattering or channeling methods,<100>

drogen because of experimental difficulties in detectinghydrogen. But, it became possible to locate hydrogen

·H

<110>

while no experiments have hitherto been made on hy-

o

Ta

""0

~ 1.0
»
""0

Q)

by using high energy heavy ion beam. In the present

N

C'\J

investigation the nuclear reaction

1 He 1 B,a)aa wasapplied to detect hydrogen. This nuclear reaction ex-

E

00.5
z

hibits a narrow resonance at the energy 1.793 MeV oflIB beam. The hydrogen can be detected by measuring
2

the emitted a-particles. In order to locate hydrogen thisincident 11 B beam. The lattice location of hydrogenpendence of the backscattering yield of 11 B beam and

""0

~ 1.0
""0

Q)

the yield of emitted a-particles.

In the present in-vestigation the lattice location of hydrogen dissolved ina tantalum crystal TaHo .o 8 was determined. ForNmdirection. The backscattered 11 B beam was measured
by a solid state detector (SSD) placed at a scattering
angle of 150°. The emitted a-particles, the energy ofwhich extends up to about 5 MeV, were measured byanother SSD placed at an angle of 90° with respect tothe incident beam. In front of the latter SSD a Mylar
foil of 4 pm in thickness was placed to stop the scattered
11 B

beam and for only the emitted a-particles to be

detected. The angular scan was made for < 100 > and*Faculty of Science and Engineering, Chuo University.

0

4

E

-V

~

~05 I-~0~channeling analysis 2.08 MeV 11 B2 + beam was used.
A TaH o .o 8 single crystal mounted on a three-axis
goniometer was set so that the specimen surface makes
an angle of about 45° with respect to the incident beam

-4 - 2

1.5,----------------,
1111f
1100 fnuclear reaction was combined with channeling effect of
can be determined from the measurement of angular de-4

Angle ( deg )

0

f7
OJ

T

~0~

I

-4 - 2

0

I mI
T
I

2

4

- 4- 2 0

24

Angle ( deg )Fig. 1. Angular scans of backscattered 11 Bandemitted a-particles across < 100> and < 11 0>
axes, and 1100\ and \111 \ planes in a TaHo .o 8
crystal. The Incident energy of 11 B beam is
2.08 Me V. The insets in the figure indicate theprojection of the octahedral (0) or tetrahedral(T) interstitial sites on the plane perpendicular
to the related axes or planes. The circles and thelines represent the projections of atomic rows,
and those of atomic planes, respectively. The
squares represent the projected positions of theinterstitials with their relative weights which areindicated by numbers in the squares.

86
cussion is given Ref. 1. An unambiguous result was
obtained for the 1111 f planar channel. All of O-sites
are shadowed by the 1111 r planes, while all of T -sites
are located at the center of the 1111 f planar channel.
Therefore a dip is expected for the O-site occupancy,
while a central peak for the T -site occupancy. The observed result clearly shows a central peak. The result isdefinitely in favor of the T-site occupancy. The resultsof angular profiles for other channels are also in favor of
the T-site occupancy.

Reference
1) E. Vagi, T. Kobayashi, S. Nakamura, Y. Fukai, andK. Watanabe: J. Phys. Soc. Japan, 52, 3441
(1983).

87

III-2-26.

Annealing of Cd-Implanted GaP
K. Aono, M. Iwaki, and S. Namba

In our previous report, radiation damage and Cddepth profIles in Cd-implanted GaP have been investigated by means of 1.0 MeV and 1.5 MeV 4He
channeling technique, using the TANDETRON.l )Substrates used were a number of < III >, < 110 >,and < 100> orientated n-type GaP. Cadmium-implantations were performed with the dose range from 1 X

are Gaussian. No difference is exhibited between the

10 13 to 1 X 10 16 cm- 2 at the energy ofl50keV. The

the case of hot implantation.

ion beam was sent in a direction deviating by a few degrees from each crystal axis in order to reduce the deep
penetration of implanted-Cd by channeling. The target
during implantation was held at room temperature (asimplanted specimens) in some cases and at about 350°C(hot-implanted specimens) in others.
The Cd depth profIles in the random spectra of asimplanted and hot-implanted specimens are similar andRadiation damages in Cd-implanted GaP were investigated from the spectra obtained from Ga in GaP.
No difference is exhibited between random yields ofrandom and the aligned spectra of the as-implanted
specimens for < 111 >, < 110 >, and < 100> substrates. However, in the scattering yield from the hotimplanted specimen, the aligned spectra of the specimens show a strong reduction. The result shows thatmost of Cd atoms occupy substitutional lattice sites in

10 16 Cd em - 2 implanted and un-implanted < 110 >substrates, as shown in Fig. 1 (a). The random yields of< 111 > and < 100 > substrates implanted with 10 16
Cd em - 2 are comparatively lower than those of unimplanted specimens near the surface layer, as shown in-------, I

Ga Surface

\

\

\

\
\

Q)

\

>=tlO-::O>=

tlO-::O

\
I

CQ)

CQ)

0;;::

\
\

:::g

""0
Qj

0;;::

N

N

Q)=
-+-'

Q)=
-+-'

co

co

1i:lE
U"-

1i:lE
u,,-

<flO
..::s::. C<flO..::s::. C

U'----"

U'----"

co

co

OJ

OJ

1.1

1.2
Energ.y (MeV)

Fig. 1(a). Random spectra of Ga atoms
in Cd-implanted < 11 0> GaP.
(a) the un-implanted specimen.
(b) the 10 16 cm- 2 Cd-implanted specimen.
Fig. 1 (b).
We can conclude that radiation damage in as-implanted specimens depends on the orientation of substrates. Analytical treatment for this is in progress.

1.1
EnergyFig. l(b). Random spectra of Ga atoms
in Cd-implanted < 111> GaP.
(a) the un-implanted specimen.
16(b) the 10
cm - 2 Cd-implanted specimen.

Reference
1) K. Aono, M. Iwaki, and S. Namba:
Progr. Rep., 16, 111 (1982).

RIKEN Accel.

88

III-2-27.

Defect-Impurity Interaction in Sn-Implanted AI
E. Yagi and S. Nakamura

The ion implantation method is a well-developed

implanted into Al crystals was investigated by means

technique for modifying the surface layer of materials.

of channeling method and the microstructures of im-

Ion implantation introduces impurities and simultane-planted region was observed by a transmission electron microscope. The implantation of Sn+ was madeously lattice defects. The implanted atoms would be as-

at 150kV with dose of 1 X 10 14 /cm 2 , 4X 10 14 /cm 2sociated with implantation-introduced defects throughthe interaction between them. The defect-impurity
interaction plays an important role in determining theor 1 X 10 15 /cm 2 at room temperature. Backscatteringchanneling angulur scan was made with respect tolattice location of implanted atoms. Therefore, from the< 100 >, < 110 >, and < 111 > axial channels withstudy on the lattice location of implanted atoms we
can obtain information on the defect-impurity interac-

1 Me V He + ion beam. The typical angular profIles forthetion in metals implanted with impurities.

plantation doeses are shown in Fig. 1. In the case of< 110> axial channel for three different im-implantation with 1 X 10 14 Sn/cm 2 , angular scan of

In the present study the lattice location of Sn atoms

(c )

(b )

(a )

• Sn
o AI

<110>

~

-0
Qj

">'

•

101

<110>

<110>

l

•

-0

Q)

N

<U

E
0 051

Z

Angl e (degrees )Fig. 1. < 11 0> angular profiles of backscattering yield from Al and Sn atoms in the Snimplanted specimens with dose of (a) 1 X 10 14 Sn/cm 2 , (b) 4 X 10 14 Sn/cm 2 and(c) 1 X 1015 Sn / cm 2.

backscattering yield from Sn atoms exhibits dips withalso observed.

S.n = 0.5 - 0.6 and with smaller
XmIn

From the analysis of angular profIles of Sn-dips, thehalf-width than the AI-dips in three axial cases. In thelattice location of Sn atoms are determined as follows:with 4X 10 14 Sn/cm 2 , XS~
mIn

in the case of 1 X 10 14 Sn/cm 2 implantation, about

increases to 0.75 - 0.87 and is different with channel. A

35 % of Sn atoms are at substitutional sites, 50 % at

< 110 > angular profIle of backscattering yield from Sn

random sites, i.e. in the form of precipitates, andremaining 15 % at interstitial positions displaced in theminimum yieldcaseof implantation

atoms shows a small central peak. For implantation with
1 X 10 1 5 Sn/ cm 2 , angular scan of backscattering yield< 112> or < 114> direction by about 0.68 A fromthe same half-width as that of the AI-dip in each of three

a lattice point. In the case of 4 X 10 14 Sn/cm 2 implantation, a certain fraction of Sn atoms are at both

axial channeling cases. Electron micrographs are showntetrahedral and octahedral interstitial sites, and thefrom Sn atoms gives a dip with XmIns? == 0.87 and with

withothers are at the interstitial positions mentioned above,pre-substitutional sites and random sites. In the case of

cipitates of diameter several tens A are observed. In the1 X 10 1 5 Sn/cm 2 implantation, 19 % of Sn atoms arelatter case the precipitates are a little larger and voids areat substitutional sites and 81 % at random sites. To

inFig. 2.

ofimplantation

In

the

case

5X10 14 Sn/cm 2

andlXl0 15 Sn/cm 2 ,

small

89

Fig. 2. Electron micrographs of Sn-implanted Al crystals. Implantation dose is 5 X 10 14 Sn/cm2
in (a) and 1 X 10 1 5 Sn/cm 2 in (b). In the latter case precipitates (A) and voids (B) are observed.

sum up, most of Sn atoms are located at random sites
and substitutional sites in any case of three differentof Sn atoms at interstitial positions are interpreted asfollows from the point of view of defect-impurity

implantation doses. In the case of high dose only suchinteraction.

two kinds of sites are occupied, while in the case of
low dose the interstitial positions displaced in the< 112> or < 114> direction are also occupied inaddition. In the case of medium dose, tetrahedral
and octahedral sites are occupied in addition to thethree kinds of sites described above. Sn atoms are known

In the case of 1 X 10 14 Sn/cm2 implantation thedisplacement of Sn atoms into interstitial positions in
the < 112 > or < 114 > direction is induced by trappinga divacancy. In the case of4 X 10 14 Sn/cm 2 implantation, a certain fraction of Sn atoms are displaced into
T - or O-sites by trapping more than two vacancies toform a trivacancy or pentavacancy configuration.

to interact strongly with vacancies. The lattice locations

90

III-2-28.

Wear Properties of Nitrogen-Implanted Steels
M.Iwaki

The principal industrial use of small accelerators at

and N2 -implanted tool steels. The normal applied load

the present time is restricted to implanting impurities

was 0.71 kgf and the sliding distance was 69 m. The

in the Si-wafers for making semiconductor devices .
However, this ion implantation technique has a highresults show that nitrogen ion implantation reduced thewear amounts for all of the specimens although theirpotentiality for introducing desired atomic species intonear-surface layers of a material without a thermal
equilibrium process. For these ten years, therefore,

reduction rates were different among specimens. These
implanted specimens indicated the decrease in thefriction coefficient during wear testing and the essential

modifications of metals by ion implantation have been
carried out in the fields of basic researches on aqueous
corrosion, oxidation, catalysis, adhesion etc. without

increase in Knoop hardness. The improvement of wear
resistance, decrease in friction coefficients and increasein hardness can be explained by formation of iron-economic benefits. Some technological areas, where sucha process can be applied with commercial justification,
have been selected and recently one of them is considered to be tribology. This report introduces the im-nitride caused by nitrogen implantations.
These results suggest the possibility of practicalapplications of ion implantation to engineering tools.

provement of the wear resistance in various steels by
nitrogen molecule ion implantation.
Steels used as substrates were SKD61 (Fe-5%Cr 15%Mo), maraging steels (Ml, M2: Fe - 18%Ni5%Mo - 8%Co) and preharden steels (PI: Fe - 3%Ni I%Al,
P2: Fe-5%Cr-l%Mo),
which
were

temperature during ion implantation gradually rose fromroom temperature and reached about a hundred degrees
of centigrade by the heating effect of the ion beamitself.
Wear tests were carried out under unlubricated conditions at atmospheric room temperature by using! Sliding105~m/sDistance-c:>

69m---------Pin - on - Disk
3.0 Configuration
test equipment

mechanically mirror-polished by a buffing wheel with

0.3 f.1m diamond paste. Ion implantation was carried out
with a dose of 1.5 X 10 17 N)cm 2 at an energy of
150 keY, whose condition corresponds to a dose of
3 X 10 17 N/cm 2 at an energy of 75 keY. The target

Applied Load = 0.71 kgf

4.0 Sliding
velocity

unimp.

<U

Q)

~ 2.0
c:

:::J

o

E

<{

10

a pin-on-disk configuration test equipment as illustrated
at the upper and left part in Fig. 1. One of two contacting materials was always an un-implanted pin, which
was made of a high carbon steel (S45C) with a half
sphere of diameter 5 mm. The test pin was kept in contact with the surface of a disk, which was rotated continuously at a constant velocity of 105 mm/s. The
amount of wear was measured by loss in weight before
and after wear tests.
Figure 1 shows the wear amounts of un-implanted

O ~~~~~~~~~~~==~~--~

Ml
SKD61

M2

Maraging
Steel

P2
Prehard en
Steel

Fig. 1. Amount of wear loss on nitrogen implanted
SKD61, maraging steels and preharden steels. Nitrogenmolecule ion implantation was carried out with a dose of
1.5 X 10 17 N2 /cm 2 at an energy of 150 keY. Wear conditions are indicated in the figure.

91

III-2-29.

Irradiation Creep Experiments under 16 MeV Proton
Bombardment in a Torsional Creep Apparatus
J. Nagakawa, H. Shiraishi, I. Uchiyama, i* H. Kamitsubo,
I. Kohno, and T. Shikata

Materials undergo a slow plastic deformation evenwith a small load when the temperature is rather high.
This phenomenon is known as "creep". Creep of amaterial is one of the essential data imperatively neededfor designing a machine to be used at high temperatureswith that material. This creep deformation is known tobe significantly enhanced when the material is irradiatedwith energetic particles. When irradiated, atoms are displaced from their lattice sites and absorbed by dislocations, resulting in an enhanced deformation if stress isapplied. This phenomenon is called "irradiation creep"and is particularly important for the structural materialsof the fusion reactors because those materials will be
under both stress and irradiation at a rather high tem-

creep testing apparatus is newly constructed and connected to the cyclotron. The mechanism of theapparatus is schematically shown in Fig. 1. Controlled
torque is applied on a thin wire sample (""'-'130 [.lm dia.)utilizing the mechanism of a movable-coil DC current
meter. Rotation of the sample is continuously
monitored by an optical transducer attached to a turntable which follows the small mirror connected to thetorque coil. An on-line computer in the instruments
room controls the coil current and also processes therotation data as well as the beam current. Temperatureof the sample is controlled by a high temperature heliumjet (""'-'100 m/s) and, if necessary, an additional directjoule heating. The general features of the torsional

perature.
Since it is impossible to evaluate the irradiation creep

irradiation creep facility are listed in Table 1.

using the present fusion devices because of their very
short operation time, a simulation study by a light-ion
bombardment is desired. For this purpose, a sensitive

20 % cold-worked 316 stainless steel which has beenused in some experimental fusion devices. The chemicalcomposition of the sample is shown in Table 2. Bom-

IRRADIATION ROOM

p+

Irradiation creep experiments were carried out for a

60m

I NSTRUMENTS ROOM

u

GD~

(f)

::::>

co

o
o

( f)

~

Isolatedtransmi tter

Fig. 1. Schematic figure of the loading and measuring components of the torsional irradiation creep facility. Other components not shown here include chamber, helium gas loop,
beam monitors and so on.

*

National Research Institute for Metals.

92
Table 1.

General features of the TICF.

barding particles were 16 MeV protons which are thebest to simulate the irradiation by 14 MeV neutrons pro-

Strain sensitivity: -- 1 X 10- 7 (1 X 10- 3 deg)
Strain rate sensitivity: --2 X 10- lOS - 1

duced by the deuterium-tritium fusion reaction. Figure 2
shows the temperature dependence of the irradiation(in 100 min)creep rate at three stress levels. The temperature de-Stress range: ± 600 MPa (± 3 g.cm torque)pendence is quite different from that in the unirradiated,

Stress cycling: 1 Hz maximum

thermal creep case. Besides, the irradiation creep rate

Temperature range: 200 -- 800°C

itself is extremely high compared with the thermal creep

30--500°C

rate. Stress dependence is plotted in Fig. 3 for three different temperatures. The slope in the log-log plot is(gas heating only)
Temperature control: ± 1 °c

about one, which means that the irradiation creep rate

On-line computer:

is approximately proportional to the applied stress. This

digital smoothing
real-time graphic display

stress dependence also differs very much from that ofstress control

the thermal creep which gives stress-exponent of aroundfive. These results on the 316 stainless steel clearly indicate that the mechanism of creep deformation isaltered by the irradiation under the present experimental

T (OC)

condition.

10- 8 500 400

300

200

r

r

I

I

\

316 SS- 20% CW
Irradiation creep
16MeV Protons
2.5 X lO- 8 dpa's - 1

I
I
I
I

I

'I

~ 200MPa

(f)

I

9

1 X 10- 9r---~---~---.---,-,

ThermalI~ 1O- r- \ (P. Jung~et
aU
g
,

1. 2

Q
Cl)

lS

0

----,-'-:~~

1O- 10L::----_'.J...\_ _. _ _.L., _-'-45=--------,:c_'
1. 5
2.0
2.5
1/ T (K - 1. 1 000 )

C

Cr

2

1 X 10- 10 '::-------,::-'=--------'------~:___-~--:::----'
10

Fig. 2. Temperature dependence of the irradiation creep rate. Dependence is much weaker
than the unirradiated, thermal case (dashed line).
The creep rate is extremely higher than thethermal creep rate in the temperature range
examined.

Table 2.

5

if)

-

~ ,'~ 135MPau90,

316 SS- 20% CW
Irradiation creep
16MeV Protons
2.5xlO- 8 dpa's - 1

20

50
100
Stress ( MPa )Fig. 3. Stress dependence of the irradiation
creep rate. The creep rate is approximately
proportional to the applied stress. The stressexponent, i.e. n, of the thermal creep is aroundfive, much higher than the one for this case.

Chemical composition of the type 316 stainless steel sample (wt. %) .

Ni

0.043 16.09 13.92

Mn

Si

Mo

1.42

0.44

2.50

200

B

o

N

0.0006 0 .0058 0.0035

P

s

Fe

0.005

0.010

Balance93

III -2-30.

Effect of Injected Helium on the Mechanical
Properties of Ti-6.S AI Alloy

Y. Higashiguchi,* E. Yagi, Y. Suzuki,* and H. Kayano*

As a fusion reactor material, titanium alloys haveseveral attractive properties such as high strength-toweight ratio, high resistance to void swelling and compatibility with coolants such as lithium, helium andand no effect on the ultimate strength au . On the other
hand, the total elongation €f considerably decreased
with increase in the helium concentration up to
18 appm, and for higher concentration the elongationwater. But, when it is used as a first wall material inslightly increased again to be about 35 % at 30 appm
He. The minimum of the elongation appeared at about
18 appm He similarly to that of the yield stress.

a fusion reactor, it faces a serious problem. The material
will be subject to high fluence of high energy neutrons(14 MeV). Gaseous products such as helium andhydrogen are introduced into the first wall itself due tothe transmutation reactions (n, a) and (n, p). Effect ofhelium produced by such reactions may lead thematerial to significant embrittlement due to the accumulation of helium atoms at grain boundaries.
Although there are a few methods to introduce helium
into specimens, the most convenient way is to use an accelerator because helium implantation is achieved ina short time, the resultant radioactivity is relatively low
etc. For the study of the effect of helium on themechanical properties, a cyclotron which has capability
to inject high energy helium ions is suitable because
tensile test usually requires specimens thicker than
0.2 mm to obtain the data reflecting the bulk properties.
In the present study helium was injected into Ti-6.5 Al
alloys of 0.3 mm in thickness as a-particles accelerated
to 36 MeV by the cyclotron.
Ti-6.5 Al alloys were prepared by arc-melting the
mixture of Ti and Al metals. Sheets of 0.3 mm inthickness were prepared through hot forging, hot andcold roll processes. Specimens for tensile test of 5 mm inwidth and with 15 mm gauge length were cut from the
sheets and annealed at 850 0 C for 3 h in vacuum below
5 X 10- sTorr. Helium injection was carried out atroom temperature in such a way that helium distribution
will. be uniform in the direction of thickness using
a wedge-shaped graphite degrader.
Tensile test was made at 600°C in vacuum below
5X 10- s Torr at a strain rate of 1.85X 10- 4 S-1 foruninjected, 5, 18, and 30 appm He-injected specimens.
The dependence of the strength and the elongation on
the helium concentration is presented in Fig. 1.
Helium had only small effect on the yield stress ay* The Oarai Branch, The Research Institute for Iron, Steel andOther Metals, Tohoku University.

_ _ _ _ _ _ _ _ ._ 300'*

200 rf
L

'-.

'"

I::l

-+-'

(j)
(j)

0

100 (5)

cu
OJ)
c

<l)

w

He Concentrati on (at ppm )Fig. I. Dependence of the yield stress a y' theultimate strength au and the total elongation€f on the helium concentration in Ti-6.5 Al
0alloys tensile-tested at 600 C and at a strain
rate of 1.85 X 10- 4 s-1

In order to investigate in more detail, fractured
surfaces were observed by a scanning electronmicroscope(SEM). It is indicated that there is apparent difference
among the micrographs of uninjected , and 18 and 30
appm He-injected specimens (Fig. 2). The microscopic fracture mode in the uninjected specimen wasthat of ductile rupture with dimple as shown in Fig.
2(a). The mode in the 18 appm He-injected specimen
was that of mixed fracture which consists of fine dimple
and integranular fracture as shown in Fig. 2(b). The
fracture mode became simple again with increase in
the helium concentration up to 30 appm. Although thefracture was of integranular type, numerous deformations observed within all the grains.
Microstructures around fractured area were observed
by a transmission electronmicroscope (TEM) and the94

Fig. 2. Electron fractographs of the fractured
surface of tensile-tested Ti-6.5 A 1 specimens
containing various amounts of helium: (a)uninjected, (b) 18 appm , and (c) 30 appm.

results for uninjected, 18 and 30 appm He-injected
specimens are shown in Fig.3(a), (b), and (c),respectively The change in the deformation mode wasFig. 3. Transmission electron micrographs of
Ti-6.5 Al alloys tensile-tested to fracture. Specimens contain various amounts of helium: (a)uninjected, (b) 18 appm , and (c) 30 appm.

observed with increase in helium concentration. The

Effect of helium concentration on the
deformation and fracture modes oftwinning deformation was found both in uninjected andTi - 6.S Al alloys.

18 appm He-injected specimens, but not in 30 appm
He-injected one, in which the homogeneous dislocation
cell structure was observed instead of twins. As a result

Table 1.

He concentrationappm

oof detailed investigation, the deformation modes were
elucidated and they are listed in Table 1 together withthe fracture modes. The small concentration of helium
up to 30 appm changed significantly the deformationand fracture modes in Ti-6.S Al alloys at 600 °e.

Deformation
mode

Slip
Twin

18

\1012! < 10Ii >11121 ! < 1126 >Transgranular

Slip
Twin

30

Fracture
mode\11211< 1126>

Mixed

Slip
No twinIntergranular

95

III-3.

Radiochemistry and Nuclear Chemistry1.

Radioisotope Production and Labelled Compound Synthesis
T. Nozaki, S. Ambe, M. Iwamoto, and Y. Minai

The study of production and use of 29 Al has been
continued, and its distribution in rat body wasmeasured. Aluminium-29 formed by the 26Mg(a,p)29 Al
reactionintargetmagnesiumwas

separatedbyacetylacetone extraction followed by sublimation. 1)
The sublimate was dissolved in dilute hydrochloric acid,and the pH of the solution was adjusted with a NaHC0 3
solution. The 29 Al solution was injected into rats (about
0.1 rn1 for each) through a millipore filter , and theorgan distribution was measured. The result is shown in
Table 1. There remains some uncertainty in this result,because the chemical form and physical state of the
29 Al were not quite clear. We intend to repeat theexperiment.
Recently, the acetylacetone extraction of 29 Al has
been found to be very slow under ice cooling but fastover 30°C. From the organic phase, the 29 Al has proved
to be extracted back into hot dilute hydrochloric acid.
Xylene is a suitable solvent for these extractions. The
separation by extraction and back-extraction is thus now
Table 1.

preferred to that by extraction and sublimation.
Radiobromines, 77 Br and 7 SBr, were produced by
the 7S As(a, 2n)77Br and 7S As(He, 3n)7SBr reactions in
GaAs target, and separated by sublimation. 1) The
radiobromines were dissolved in dimethylformamide
or water, and used for the labelling of 6-bromo-9-benzylpurine by isotopic exchange l ) or for the synthesis ofaryl bromides by the Sandmeyer reaction. The timecourse of the brain concentration of 77 Br was measured
after injection of 6-bromo-9-benzylpurine- 77 Br into
mice, and compared with that of 1 8 F and 12 SI after injection of the corresponding fluoro- and iodo-purine.
The results will be reported soon.
No-carrier-added bromobenzene- 77 Br was synthesized with a good yield by the usual process of the
Sandmeyer reaction. The product was found to behighly volatile . Its distribution in mouse body wasmeasured. High concentrations of 77 Br were observed in
the liver and kidney, together with its rapid clearance
from the blood. The brain concentration of 77Br was

Organ distribution of 29 Al in rats.

pH of 29AI Sol.

2.5 - 3.5

about 8Time after Inject.

1m

5m

15 m

5m

Blood

7.69 ± 0.75

6.38 ± 0.67

2.55 ± 0.23

1.43 ± 0.19

Liver

1.66 ± 0.32

2.41 ± 0.10

0.97 ± 0.25

9.91 ± 0.28

Kidney2.87 ± 0.43

2.52 ± 0.06

3.18 ± 1.16

0.78 ± 0.15

Spleen1.45 ± 0.06

2.65 ± 0.66

0.97 ± 0.26

4.79 ± 0.60

Lung2.26 ± 0.40

6.47 ± 0.50

1.37 ± 0.20

2.08 ± 0.45

Heart

1.10 ± 0.19

2.34 ± 0.08

0.52 ± 0.04

1.85 ± 0.08

Muscle0.36 ± 0.00

0.30 ± 0.02

0.25 ± 0.02

0.35 ± 0.08

Bone

0 .64 ± 0.06

0.33 ± 0.12

0.68 ± 0.32

0.61 ± 0.33

Brain

0.19 ± 0.06

0.20 ± 0.04

0.07 ± 0.03

0.05 ± 0.01

The concentration is shown by [Count rate for the organ (after decay correction) j. [Animal body weight] /[Organ weight]· {Total 29 Al count rate] .

found to be low. We intend to label a variety of organic
bromides including bromoperidol with the radiobromines by the Sandmeyer reaction.

Reference
1) Y. Minai, T. Nozaki, S. Ambe, and M. Iwamoto:
RIKEN Accel. Progr. Rep., lQ, 120 (1982).

96

III -3-2.

Charged Particle Activation Analysis

T. Nozaki, Y. Itoh, M. Iwamoto, H. Shinyashiki,
K. Nomura, T. Kimura,* and H. Fukushima*

The utilization of charged particle activation analysis

In 1983, the following works have been undertaken:

has been continued mainly in collaboration with semi-(1) determination of ultra-trace amounts of oxygen in

conductor industries. The need for the determination of

GaAs produced under various conditions; (2) deter-oxygen in various semiconductor materials is still in-mination of oxygen in Sb-doped silicon, to show thecreasing. Previously we developed a highly useful
method for the separation of 1 8 F formed by the 1 60

escape of oxygen as antimony oxide; (3) analysis ofCHe, p) 18 F reaction in any matrix. 1 ) We predicted atsurface oxygen under various atmospheric conditions;(4) studies on the relationship between IR absorptionthat time that the detection limit of oxygen could be

and composition of evaporated silicon oxide films; andlowered down to 1 ppb or still less by the coincidence(5) improvement in the separation method of 11 C frommeasurement of the positron annihilation radiation withsilicon and some other matrices. Work 2 and Work 4

a pair of BGO (bismuth germanium oxide) scintillators.

are reported separately in this volume. Work 3 will

We obtained recently two BGO crystals (2" x 2"), andfurther be continued;2) its details will be reported next

have succeeded in realizing reliable determination ofyear.

such low concentrations of oxygen. The positron count-

Oxygen in GaAs has been guessed to form a deeping efficiency of our counter usually is about 20 % withlevel in the forbidden band and to play an importanta background of about 1.2 cpm. Silicon speciallyprepared for use as a radiation detector was found tocontain 2.3 ± 0.8 ppb of oxygen by this analysis.

oxygen concentrations in GaAs single crystals are so low
as to be determined reliably only by charged particle

Oxygen in many matrices and carbon and nitrogen in

activation analysis. 3 ) Some difficulties are encounteredrole in the formation of semi-insulating GaAs. However,a limited number of matrices can now be determinedeven in this method, because this matrix cannot with-reliably and routinely. In order to contribute widely tovarious fields of science and technology through thesestand the heat evolution in high-flux bombardment andbecause the matrix itself is highly activated. By ourroutine analyses, we have contracted with the Japantechnique written above, we can now determine as low

Chemical Analysis Center. The Center, thus, performs

as 1 ppb of oxygen in GaAs. A decay curve of 1 8 F

the analysis on semi-commercial base by the use of the
IPCR Cyclotron and of te~hniques we developed. The

separated from GaAs is shown in Fig . 1. The sample insamples shown in Table 1 can now be analyzed ac-tion factor for 18 F (110m half-life) can be doubled

this example was bombarded for 40 min, but the satura-

cording to the demand of any organization or personnel.
Efforts will be continued to make analyzable morevariety of samples in this trust analysis system.
10

Table 1. Samples analyzable on semi-commercial base.
Element
determined

Matrix

Lower limit
of determination

c

E

~
if)

Al

C

1Semiconductor Si

N

Semiconductor Si

0

I

Al

Semiconductor Si
Semiconductor GaAs
Almost any matrix t

1%

ppb
10 ppb
1 ppm
5 ppb.5 ppb5 ppb

20t Stable in the bombardment and dissolvable.

* Japan Chemical Analysis Center.

(wt)
(wt)
(wt)

C:::J
o

U

(wt)

(wt)
(wt)
(wt)

0.1~~:--::::-~~:;;:--;-::!:-:::---:::-:!:--::::---c~---'==-:!.

o100 200 300 400 500 600 700
Time

(min)

Fig. 1. Decay Curve of 18 F Separated
from GaAs.

97

with ease. For silicon matrix, the detection limit of

Ga and As were analyzed, together with those after

oxygen is guessed to be about 300 ppt. GaAs samples
prepared by two different methods from six-nine purity

further purification. The results are shown in Table 2.
In the analysis of carbon and nitrogen in silicon by

Table 2. Oxygen content of GaAs.

Crystal growth

Seed

LEC method
LEC method< 100>< 100>

Content(wt ppb)(at/cm 3 )Si0 2 Boat

55
7.5
180
70
8.0
16

1.1 x 10 16
1.5 x 10 15
3.6 x 10 16
1.4 X 10 16
1.6 x 10 15
3.1 x 10 15(wt ppm)

HB method
Direct synthesis

OxygenCrucible

H2 0 in B2 0 3

200

Si0 2

100
1000

PBN
PBN

the 12CeHe,aY 1 C and 14N(p,a:)11 C reactions, respec-

cedure will be established soon. With slight modifica-

tively, we converted the 11 C into Li2 C0 3 precipitate bytions, the procedure will be applicable to some otherdissolution of the silicon matrix in HF -HNO 3 oKlO 4·Some fraction of the 11 C, however, was found not to beoxidized into l1C0 by this treatment, and a con2
ventional factor was applied to the final result. Thismatrices.

correction factor was obtained by the use of 11 C-con-

1)
2)

taining silicon prepared by proton bombardment ofboron-doped silicon. We looked for some other method

Referencesin order to convert the 11 C quantitatively and easily, and found that the dissolution of the2
sample in a NaOH solution and its heating close to

into

11 CO

dryness after addition of KMn04 can provide a muchbetter process for the 11 C separation . A routine pro-

3)

T. Nozaki: J. Radioanal. Chern ., 72,527 (1982).
H. Emori, M. Umehara, T . Takeya, K. Nomura,

Y. Terai, and T. Nozaki: "Gallium Arsenide andRelated Compounds 1981 ", Inst. Phys., London ,p . 47(1982).
T. Nozaki and M. Iwamoto: RIKEN Accel. Progr.
Rep., Q, 105 (1982).

981II-3-3.

Oxygen Concentration in Antimony-Doped Silicon

T. Nozaki, Y. Itoh, T. Masui,
and T. Abe

Oxygen in silicon wafers heavily doped with an electrically active impurity cannot be determined by infrared absorption, because of the strong free-carrier absorption. The precipitation of oxygen in Czochralskigrown silicon is known not to take place by heat treatment of a sample heavily doped with antimony, withoutbardment of four samples in the cyclotron vacuum.
The method of the oxygen measurement was described
previously?) Boron- and phosphorus-doped silicon
crystals were also analyzed for oxygen.
Oxygen and antimony distributions along the growth
direction in silicon crystals are shown in Fig. 1. Ox-

which the precipitation should surely take place. 1 ) It
has not been made clear as yet whether thisphenomenon is due to an effect of antimony in the
crystal or to the reduction of oxygen concentration

solid lines are the theoretical curves of the oxygen
distribution for the given distribution coefficients afterby evaporation as antimony oxide in the crystal forma-

normal freezing. As is clear from Fig. 1 and 2, (l)tion. We measured oxygen concentration in silicon
crystals with various amounts of antimony dopant
crystallized in vacuum or under atmospheric pressure,using charged particle activation analysis with the
1 60CHe, p)l 8F reaction.

ygen concentrations normalized to the concentration
at the head of the ingot are shown in Fig. 2, where thesilicon crystals heavily doped with antimony show aremarkable decrease of oxygen concentration with anapparent distribution coefficient lower for antimony but
higher for oxygen and (2) crystals of medium or low

crystal < 111 > < 100> oriented and antimonydoped n-type with resistivities of 0.007"""" 82 n·cm.

antimony content or high boron or phosphorus content
show no remarkable decrease in oxygen concentration.
It is now highly probable that (1) antimony andoxygen partly evaporate in the crystal formation of

The sample

silicon, with its rate depending on the antimony con-

The samples used were Czochralski-grown silicon

was bombarded with a

3 He

beam of18 MeV incident energy through a 30 J.Lm thickaluminium foil for the activation of oxygen. A speciallydesigned apparatus was used for the successive born0.9
0.8

~ 0.7
~

§ 0.6
'''=;

7

0.006

E
u
c:
o

/.

>,

x

o

c
o

......../..._t--· - ·-- · -.~k.:I.~·-"""·-- ...-..

E

u

~ 0.4

Q)

0.0

o 0.3
>,

0.2

c:
Q)
0.0

~

~ 0.5

"'- -

-- ..,- -- - -- - '"0.1
QO.---.--~- -.---. - - -.- - - .

0.6

70

Solid fraction (%)

Fig. 1. Oxygen and antimony distribution ina CZ silicon. Crystallization atmosphere: 6. ..
and 0 - , vacuum; o. and "V~ , 1 atm.

0.1 0.2 Q3 Q4 Q5 0.6

Q7

Sol idification ratio

Fig. 2. Normalized oxygen distribution. Solidlines show theoretical distribution curves forgiven distribution coefficients . • : high antimony
concentration in vacuum, _: low antimony concentration in vacuum, x: phosphorous concentration in 1 atm.

99
centration and ambient atmosphere and (2) the difficulty in the formation of oxygen precipitate in siliconheavily doped with antimony is due to the decrease ofoxygen concentration itself rather than to some effects
of antimony.

References
1) A. 1. R. de Kock, W. T. Stacy, and W. M. Van de
Wijert: Appl. Phys. Lett., 34,611 (1979).
2) T. Nozaki, Y. Itoh, and M. Iwamoto: RIKEN
Accel. Progr. Rep., li, 122 (1982).

100

1II-3-4.

Infrared Absorption and Composition of Evaporated
Silicon Oxide Films
T. Nozaki, Y. Itoh, Y. Mochizuki,
M. Nakamura, and K. Usami

Oxygen-containing poly crystalline silicon films, often

air is shown in Fig. 1 for a film evaporated in a highsilicon),vacuum (0.67 mPa) at a high deposition rate (6 .2 nm

have been extensively studied because of their practicalimportance as a passivation layer of silicon devices. 1 )S-I). The relation between x in SiO x and vM (Wavenumber for the maximum absorption) is shown in

SIPOS fIlms prepared by chemical vapor deposition

Fig.2, in which x increases monotonously but notcalledSIPOS(semi-insulating polycrystalline(CVD) have macroscopic chemical compositions expressed as SiO x (0 < x < 2).2) It is well known thatsilicon oxides show a characteristic infrared absorption

Wavelength (,um ) 14

7.5 8

9

10 11 1213 15

20 25

peaks in the 9 - 10 11m region with the wave number increasing with oxygen content. However, the relationshipbetween x and the peak wavenumber has scarecely beenstudied systematically. Using charged particle activation
analysis with the 1 60eHe,p)1 8F reaction for the determination of the film oxygen content, we undertook thisstudy and obtained meaningful results.
Detailed techniques of activation analysis in the present study were quite similar to those used earlier for the
analysis of oxygen in silicon nitride films. 3 ) A silicon
dioxide fIlm with 1.05 11m thickness and 2.1 0 ± 0.02 g
cm - 3 density was prepared by steam oxidation for use
as the activation standard. This fIlm can be regarded asof the stoichiometrical Si0 2 • High purity FZ siliconplates (0 content: 10 16 at.cm- 3) with thicknesses of1082

300 11m and 1 mm were used as fIlm substrates for
1 400

activation analysis and IR measurement. The weight anddeposition rate of the evaporated film were monitored insitu by a quartz microbalance calibrated with anevaporated gold fIlm.

The thickness of the silicon

1 200

1 000

800

600

400

Wavenumber ( cm- 1 )Fig. 1. Infrared absorption spectra for asdeposited and heat-treated SiO x films.

dioxide film was measured with a thickness meter aftero

2.0

partly removing the fIlm on the substrate by etching in
1 : 1 hydrofruoric acid under a suitable masking. The
density of the fIlm was calculated from the measured
weight and thickness. Then, x in SiO x was obtained

c5 1. 5from the results of the above measurements. The(J)

infrared><

spectrumwasmeasured

from

4000

to

.s

400 cm- 1 by a Hitachi spectrometer(EPI G3) withreference to the same silicon plate. Films of SiO x withvarious values of x were prepared by the following
method. Powder of SiO (Osaka Titanium Co., <200mesh) was heated under various residual gas pressures togive evaporated films with various growth rates. The
films were then heated in air at appropriate temperatures
for appropriate times.
The change in IR spectrum on the heat treatment in

1.0!
980 1 000 1 020 1 040 1 060 1 080
Peak position ( cm- 1 )Fig. 2. Relation between IR absorption
peak position and x in SiO x ' Closed circles,
as-deposited films; open circles, heattreated films.

101

~

~40

o.X'

i / .~ 8

2.0

linearly.

1.5

maximum value exists at around x = 1.5. This can be

for

the

absorption

coefficient,its

explained from the random bonding model. Oxygen

1.0

0
(])
0.5

As

c

x

§ 20

concentration in SIPOS films is controlled by thelogarithm of oxygen pressure in the reactant gas, as
is shown in Fig. 3. Detailed results will. be publishedsoon in a journal.

u

c

got ,

References

L.......7/~-------L----:-'-110::----1-L6-o--lf f----'00

1)

T. Matsushita, T. Aoki, T. Otsu, H. Yamato, H.
Hayashi, M. Okayama, and Y. Kawana: lpn.
1. Appl. Phys., Suppl., 15,35 (1975) .

2)

M. Hamasaki, T. Adachi, S. Wakayama, and M.

Compositi on of reactant gas

Fig. 3 . Composition of the reactant gas vs.
oxygen concentration in CVD films. Film preparation: CVD method from SiH 4 , N2 O. Closed
circles, IR; open circle, charged particle activation analysis.

Kikuchi: 1. Appl. Phys., 49, 3987 (1978).
3)

T. Nozaki. Y. Iwamoto, K. Usami, K. Mukai, and
A. Hiraiwa:

l. Radioanal. Chern., 52,449 (1979).

102

III-3-5.

Rutherford Recoil Detection Method

H. Nagai, M. Aratani, S. Hayashi, T. Nozaki, M. Yanokura,
1. Kohno, O. Kuboi, and Y. Yatsurugi

We have already reported the usefulness of theRutherford forward recoil detection method for the
study of hydrogen analysis in near surface regions ofsolids. 1 ) We have further improved this method andcan be detected after passing through an aluminium absorber. The other (SSD-2) was placed at 10° backward

have obtained fairly good results.
The experimental procedures were almost the same as
described previously. 1) Some modifications were madeenergy spectra of SSD-1, shown in Fig. 2, indicate

in the detection system for recoiled and scattered atoms.
Two silicon surface barrier detectors (SSD) were used as
slwwn in Fig. 1. The one at forward angle (SSD-1) wasAr

used for the detection or recoiled hydrogen ions, whichfrom the forward SSD for the monitoring of the incident
beam current by counting recoiled silicon ions. The
that recoiled silicon ions and scattered argon ions, whichcause the continuous background spectrum to hydrogenpeak, were stopped in the aluminium absorber. By theuse of the absorber of suitable thickness, a recoil
spectrum without continuous background spectrum isobtained. These modifications brought several advantages:(1) High sensitivity and precision are achieved, since
the statistical errors are reduced.
(2) Simultaneous detection of light elements (C, N,
0) and hydrogen becomes feasible. The spectra of theseelements are shown in Fig. 3. By the present counting
method, we can discriminate C, N, and 0 peaks in thesame sample of less than 200 A thickness.
(3) Deuterium can be used as tracer, sinc~ the detection of deuterium becomes easy. The spectra ofamorphous silicon (a-Si: H) samples prepared fromdeuterated mono silane are shown in Fig. 4. Application of this technique to the study on the reaction
mechanism for the formation of a-Si : H resulted in goodresults. 2 )Fig. 1. Experimental arrangement.

(4) Precise depth profiling of hydrogen and otherlight elements is possible. The depth profiles of Hand

104~----~----~----~~----~-----.-----,------,-----,

10 3
(i)

c

C
<U

U 10 2--......
if)

C::::lo010 1Channel number

Fig. 2. Energy spectra of recoiled and scattered particles from a-Si : H : D
film for 42 MeV Ar incident particle.
Lower: with 10 f.1m Al absorber, Upper: without Al absorber.

103

10 7
H

106

w
c:

Qi
C
C

co

C

~ 10
u

III

L

u

0

4

~

-----~ 10 3i5 103

IV

U

::::l

0

U

II

III

II

10°

ou---~--~~--~--

Channel number

Fig. 4. Spectra for a-Si: H : D film observed atvarious detector angles (sample thickness: 6520 A).
I: 40°, II: 37°, III: 35°, IV: 33°.

Fig. 3. Spectra of light element forward recoils seen
as continua with narrow peaks of H.
I oxygen from quartz, II: nitrogen from SiN x 'III : carbon from PIQ (polyiminoquinone):

106r------.-----,,-----,------.------.------,------~--~

10 5

104

« ««
00

0

Lf)

Qi

c
c

co

L

U

10 3

Lf)

0

r0

.q-

0

TO

(J)

(7)

2c
-----::::l

0

U

10 2

10 1

10 0
0
Channel number

Fig. 5. Depth profiles of Hand D in three-layer a-Si film deposited in the sequenceof 1350 A a-Si: D, 450A a-Si : H, and 900 A a-Si : D on Si substrate.

D are shown in Fig.4 (IV). In the spectrum, peakwidth indicates the thickness of a-Si : H, and curve
shape of the peak indicates the distribution of hydrogen

References

concentration along the depth of the a-Si : H film. The
depth profile of deuterium in a-Si film is shown in
Fig. 5. The split peak is due to two a-Si : D layers ,of

Accel. Progr. Rep., l.§., 125 (1982).
2) Y. Yatsurugi, O. Kuboi, M. Hashimoto, H. Nagai,

900 and 1350 A thickness, respectively. The valley is
due to the a-Si : H layer of 450 A thickness. From thisspectrum, the depth resolution of hydrogen was estimated to be about 500 A.

1)

H. Nagai, M. Aratani, T. Nozaki, M. Yanokura,
I. Kohno, O. Kuboi, and Y. Yatsurugi: RIKEN

M. Aratani, M. Yanokura, I. Kohno, and T. Nozaki:
p. 82 in this report.

104

1II-3-6.

Characterization of Surface Hydrogen by the Rutherford
Forward Recoil Measurement
M. Aratani, H. Nagai, S. Hayashi, M. Yanokura, O. Kuboi,
Y. Yatsurugi, 1. Kohno, and T. Nozaki

Surface hydrogen on various materials for electronic

although it is not so prominent in c-Si without plasma-

devices has been characterized by the Rutherford for-annealing. Hydrogen peak height rapidly increase withward recoil measurement using 45 MeV argon beam

the plasma-annealing time. The hydrogen plasma-anneal-from the Riken Linear Accelerator. The following

ing was performed as a pretreatment of .the surface ofsamples were examined: high-purity crystalline siliconc-Si(c-Si), c-Si plasma-annealed in hydrogen gas for various(a-Si : H) film just before its growth. The narrow widths

substrate

for hydrogenated amorphous silicontimes, c-Si treated chemically with acids and alkalies,of the hydrogen peaks observed suggest that hydrogenand c-Si ion-implanted with hydrogen beam. The
majority of them were produced by Komatsu Electronic

atoms are situated in the surface layer not deeper than

Metal Co., and the other by Toshiba Corporation andpeaks. These peak heights are estimated to correspond tohydrogen atoms of the order of 10 1 5 per cm 2 .

Hitachi Ltd.
Experimental
reportedarrangement

previously.1 )andMarked20 nm; those peaks are referred to as surface hydrogen

The spectra obtained by the use of the aluminium

procedures were
has

absorber are shown in Fig. 2. In addition to a hydrogen

been made by the use of two silicon surface-barrier

improvement

peak, an oxygen peak is clearly observed. This is an

detectors; one was shielded from scattered argon andexample of the marked improvement of the spectra

recoiled silicon ions with a 10 J1m aluminium-foil forowing to the new experimental arrangement . These
spectra exhibit another aspect of the hydrogen plasma-

the detection of hydrogen ions , and the other was used
for the detection of recoiled silicon ions for beamannealing procedure, in which, oxygen, one of themonitoring. The improved arrangement is described inordinary residual elements in the annealing chamberdetail 2 ) in a preceding report of this volume.
The Rutherford forward recoil spectra of c-Si plasma-

under the vacuum pumping, is incorporated in the c-Si
surface, accompanied with hydrogen.
The spectra for c-Si after chemical treatment withannealed in hydrogen gas measured by the detector
without the aluminium absorber are shown in Fig. 1.
In a continuum due to scattered argon and recoiled

a mixture of HF-HN0 3 or with a NaOH solution are

silicon, a hydrogen peak is observed in every spectrum,

between the two spectra. Hydrogen and oxygen peaks

shown in Fig. 3. No distinguishable features are found

2.5
2.05

- - 5min anealing

2.24

H

- - without arrealing

1.79
1.92
~

§
x
~

1. 54

~

1.28

I

x 1.60"§~ 1.02~H

1.2§ 0.96
u

8 077

0
0.64

0.51
wilhont anealll1g

0.32

0.26
512
0

512
Charrel fUTlber

Fig. 1. Rutherford forward recoil (energy-dispersed)
spectra of the hydrogen plasma-annealed c-Si by theuse of the unsheltered detector.

Charrel number

Fig. 2. Rutherford forward recoil (energy-dispersed)
spectra of the hydrogen plasma-annealed c-Si by theuse of the detector sheltered with the 10 J1m
aluminium absorber.

105

107 '

5.12.---

106

4.48

--.-----,----,------,---.----.--- . -----,

H( ion - impliflted)

384

lOS
~

:;;. 120

~

104

U

10 3

§

H

~2.56
~
8 1 92C

128
NaOH solution

HF + HN03

110

512
Chamel number

Fig. 3. Rutherford
dispersed) spectra
coSio

forward recoil (energyof the chemically treated174
Chatn!I runber

Fig. 4. Rutherford forward recoil (energy-dispersed)
spectra of the ion-implanted coSio

attributable to the surface atoms are observed forthem. Carbon peaks are also seen. Appearance of thetherefore , is not simply estimated in this case.

carbon peak, however, cannot be attributed directly to

Rutherford forward recoil measurement using heavy ionsthe initial surface carbon, because we have observed anindicates a promising approach to surface and interface

increase of carbon peak height with irradiation time inanother experiment.

elements.

In spite of some problems left to be elucidated, thestudies intimately relating to the presence of light

A change of spectra of hydrogen ion-implanted c-Si
at the same time-intervals under the measurement isshown in Fig. 4. Two hydrogen peaks are observed

Referencesin every spectrum . They are attributed to the ion-1)

implanted hydrogen and surface hydrogen . During themeasurement, the ion-implanted hydrogen peak remains
constant. The surface hydrogen peak, on the other hand,

H. Nagai, M. Aratani, T . Nozaki, M. Yanokura, I.
Kohno, O. Kuboi, and Y. Yatsurugi:
Accel. Progr. Rep., lQ, 125 (1982).

2)

RIKEN

H. Nagai, M. Aratani, S. Hayashi, T. Nozaki , M.

slightly increases with irradiation time in general, but

Yanokura, I. Kohno, O. Kuboi, and Y. Yatsurugi:

sometimes decreases. The amount of surface hydrogen,p. 102 in this report.

1061II-3-7.

Depth Profiling of Hydrogen and High Sensitivity Analysis
of Deuterium with 15N-lnduced Nuclear Reactions
S. Hayashi, H. Nagai, M. Aratani, T. Nozaki, M. Yanokura,
I. Kohno, O. Kuboi, and Y. Yatsurugi

It is desired to determine accurately hydrogen depth
profiles in solids or thin layers, especially, of metals,
semiconductors. and nuclear reactor materials.

Thequantitative information about microscopic location oflight-elements in these materials can be obtained bymeans of position sensitive analytical techniques. We
employedHetheresonance

nuclearreaction,

1
SN,ay) C (E-y = 4.44 MeV), which has been reported to be of the most accurate method for the depth
profiling of hydrogen in solids by now. 1) - 3) The

known to have slightly poorer energy resolution, buthigher detection efficiency especially at the high energy
region than NaI(Tl). Gamma-ray pulses from the two
BCO scintillators were summed up by a sum amplifier inorder to get higher detection efficiency, and the summed
pulses were collected in a pulse-height analyzer (PHA),
see Fig. 1.

12resonance energy of lSN ions is 6.385 MeV, while theresonance width is 6.4 keV in the laboratory system.
Using the characteristics of the isolated narrow resonance width, we can determine the hydrogen concentration in any material with high accuracy. For
example, the resonance width corresponds to about
50A for silicon wafers. The resonance cross section wasreported to be about 450 mb, and off-resonance one

15N2+ beamfrom RILAC

L~fOi'( lO,ug / cm 2 )was to be three orders of magnitude smaller than theresonance peak value.
The 1 5 N ions with energy higher than the resonanceenergy lose their energies in the sample materials, andinduce the 4.44 MeV gamma-ray emission at theresonance point. We adopted two ways in determining
the depth location of hydrogen in solids. One is varying
incident 1 5 N ion energy, and the other is inclining thetarget with respect to the beam axis. By comparing withthe standard materials of known hydrogen contents, absolute hydrogen concentrations in the samples were
determined.
Samples of amorphous silicon (a-Si : H) were prepared, in Komatsu Electronic Metals Co., by the glowdischarge

decompositionof monosilane

aslayersdeposited on substrate silicon wafers. Several pieces ofthe samples for targets were settled at the center of 1 m
scattering chamber on the A 11 course in the RIKEN
heavy-ion linear accelerator (RILAC). In order toestimate the beam intensity, a thin carbon foil (about
10 p.g/cm 2 ) was placed in the upper stream from thetargets in the scattering chamber, and scattered andrecoil particles were detected with a silicon surface

Fig. 1. Experimental arrangement for gammaray measurement by 15 N-induced nuclear reactions with beam-monitoring counter system.

Typical energy spectra for gamma-rays induced by
ISN ions in the a-Si: H are shown in Fig. 2. Thereappear full energy peaks of 4.44 MeV, and single anddouble escape peaks. There are few background gammaray peaks around the 4.44 MeV region. Using the intensities of these spectra, we can obtain the depth
profile of hydrogen in the a-Si : H. An example is shownin Fig. 3, in which the energies of incident IsN ions
are given; different experimental points with the same

BGO

energy correspond to different target angles. The ab-(Bi4 Ge 3 0 12 ) scintillators (2" </> X 2"), located about
2 cm from the target center. The BGO scintillator is wellsolute hydrogen concentration in the material is obtained with reference to the standard material of TiH 1 . S .

barrierdetector(SSD).

We

employed two

107

15-

SiH.+H2 (1220 A)

>a;

c!

'0

cU
vi

~
'=t
'=t

6

7

E

<=>

1258 A

...-<

X

6

o 6.5170• 6.747
6.522

10 - 9-

6

c

•

--~
Q

1094 A-• 6.691 MeV

ot;

....u

~ ~

o
X 0.64

SiH 4 + H2 (1220 A)

6

t;

•

cQ)

u

c
0

u
:r:

948A

•

5r-

•
641 A

0

500

Channel number

1000
Depth (A)1.
1500

Fig. 3. Depth profiling of hydrogen in thea-Si: H (1220A). Incident energies of lS N
ions are shown in the figure.

Fig. 2. Typical energy spectra for gamma-rays
induced by 1
5 N,a-y)12 C (E-y = 4.44 MeV)in the a-Si: H. 12 C 4.44 MeV: full energy
peak; 12C s.e.: single escape peak; 12C d.e.:
double escape peak. Each value with angstrom
unit means the depth from the surface of thea-Si: H.

He

deuterium with 1SN-induced nuclear reactions. Figure 4
shows typical spectra of gamma-rays induced by 1 5 N
ions in a deuterium-doped a-Si : H (D). As is shown in
Fig. 4, several other gamma-ray peaks are observed

Figure 3 shows that the thickness of the hydrogen layer
thus obtained agrees well with that previously measured
with a Talystep for the a-Si : H (1220A).

in addition to 4.44 MeV originating from hydrogen. All
these peaks are shown to have originated only fromdeuterium, but not from contaminants in the sample.

Beside,S the hydrogen depth profiling, we have found

The following three nuclear reactions have been considered in order to elucidate the origins of these gamma-

a method of high sensitivity quantitative analysis of~~

4.1Ort-t--.- ---,---- ---.-- (Y)
...-<

1.0
aj

ui

3.58

HDH (1310 A)

?
~

~

3.07

2->

X 2.56

§ 205

676 A

(1J

...c
U

---.....

~ 1.54
::J

o
U

193 A

1.02
0.51

94 A

o

512
Channel number

Fig. 4. Typical energy spectra for gamma-rays in deuterium-doped a-Si:
H: D induced by I H s N,a'Y)12 C, 2D s N,P'Y)16 N (~- - decay, Tl/2 =7.13 sec), 2 D s N,n'Y)16 0 , and 2 D s N,a'Y)13 C . Notations are the same as
in Fig. 2.

e

e

e

e

108

ray peaks: a) 2De S N,P'Y) 16 N(,B- - decay, Tl/2 = 7.13sec), b) 2Dct sN,n'Y) 16 0, and c) 2Dct sN,O:'Y)13 C. In
the peaks appearing in Fig. 4, 2.75, 6.13, and7.12 MeV photo-peaks originated from the excitedstates of 16 0, and 3.08 and 3.68 MeV ones from thoseof 13C. Among these peaks, 6.13 and 7.12 MeV peaks
are very useful for deuterium quantitative analysis, because there are no interference peaks in the energy

4
HDH (l31OA)

?t ~
'I

E

?

0
.----<

x

---c:
Q

+-'

J

No precise cross section has been measured for thethree nuclear reactions, but unlike 1 He sH,O:'Y) 12 C
process, these reactions are considered not to be sharp
resonance reactions. 4 )- 6) The intensities of thesehigher-energy gamma-ray peaks (6.13 and 7.12 MeV) areproportional to the total amount of deuterium within
the ranges of 15 N incident ions in the samples. Therefore, the deuterium-originating peaks can be applied notout mutual interference by scintillation counters.

t

2

+

bc:

peak. Figure 5 shows the depth profiling of hydrogen in
the a-Si : H : CD).

to the depth profiling, but to the very high sensitivity
quantitative analysis of deuterium in solids. Further, twoisotopes, Hand D, can b.e measured simultaneously with-• 6.674 MeV
o 6.517• 6.747
6. 6.522

j

3

....u

region higher than the hydrogen-originated 4.44 MeV

Q)

u

t

tt t

References
1) W. A Lanford: Nucl. Instr. & Methods, 149, 1

2)(1978).
G. L. Clark, C. W. White, D. D. Allred, B. R.
Appleton, F. B. Koch, and C. W. Magee: ibid.,3)
4)

ibid., p. 19.
N. A. Bostron, E. L. Hudspeth, and I. L. Morgan:

c:

0

u

:r: 1

p.9.

o

500

1 000

1 500

Depth (A)Fig. 5. Depth profiling of hydrogen in
deuterium-doped a-Si: H(D) (1310A), which
consists of three layers of hydrogen, deuterium,and hydrogen; HDH. Incident energies of 15 N
ions are shown in the figure.

J. F. Ziegler et al.:Phys. Rev., 105, 1545 (1957).
J. L. Weil and K. W. Jones: ibid., 112, 1975
(1958).
6) N. A. Mansour, H. K. Saad, Z. A. Saleh, E. M.
Sayed, I. I. Zaloubovsky, and V. I. Gontchar:
Nucl. Phys., 65, 433 (1965).

5)

109

1II-3-8.

Chemical States of Carrier-Free 119Sb5+ at ,a-Fe 2 0 3 -Aqueous
Solution Interfaces Studied by in situ Emission Mbssbauer
Spectroscopy

F. Ambe, S. Ambe, T. Okada, and H. Sekizawa

We reported previously that chemical states of5

cyclotron-produced 11 9Sb + ions adsorbed on magnetic
metal oxides can be studied by emission M6ssbauer
measurement of supertransferred hyperfine (STHF)
magnetic fields on I 1 9Sn 4 + produced by the EC decayof 119 Sb S+.1)

This year, in situ measurement was

carried out on 119Sbs+ at the interfaces between
a-Fe 2°

values.

3

Typical spectra obtained are shown in Fig. 2. The
119Sn arising from 119Sbs + at the a-Fe 0 - aqueous
3

2

solution interfaces gave at pH 6.5 a comparatively
narrow emission spectrum ascribable to 1 1 9 Sn 4 +(Fig.2(a)). With lowering of the pH value, the spectrum
broadened gradually and attained a FWHM of about
7.3 mm S-1 at pH 2.5 (Fig. 2(b) and (c)).

particles and aqueous solutions of various pH
Because of insensitiveness of the M6ssbauer

effect to chemical species in the solution, exclusive information on 119Sbs+ at the interfaces was obtained.
The chemical states of adsorbed

I 19 Sb

5+ ions were

found to be dependent on pH of the aqueous phase.

(a)

To a 0.25 mol dm - 3 Liel solution of carrier-free
119Sbs+, about 30 mg of a-Fe 2 0 3 powder was added.
After adjusting pH to an appropriate value, the suspen-

c:
0'

.(])

sion was shaken at room temperature for 30 min. All
the procedures were done in a Teflon vessel equippedwith 0.5 mm Teflon window at the bottom.

After

U)

...."

I "

-E

U)

c:

~

settling of the a-Fe 2 0 3 particles, the emission spectraof 119Sn(~119Sbs+) were measured at room temperature against a barium stannate absorber with the experimental setup shown in Fig. 1. The absorber was
driven with a Ranger 700 series drive-system connected
to a Tracor-Northern TN-7200 multi channel analyzer.
-12 -8In situ em ission Mossbauer spectroscopy

-4

o

4

12

8

Relative velocity vs 8aSm 0 3 (mm/ s)

Fig. 2. in situ emission Mossbauer spectra of
119Sn arising from 119 Sb S+ at a-Fe 0 - 0.1
2 3
mol dm - 3 NaCI interfaces.

Aq, solution- 119Sb 5 +Tetlon vessel_____ Absorber : BaSn03===:==:::r::=::Fb

Figure 3 shows the distribution of hyperfine magnetic
fields on 119Sn4+ calculated from the spectra by themethod of Hesse and Rtibartsch. 2 ) At pH 6.5 and 4.5,
the distribution has a marked peak at zero field, which=

Shield : Pb=

demonstrates that the majority of 119Sn4+ arising from
119Sbs+ ions at the interfaces is not or only weaklyinteracting with magnetic Fe 3 + ions of the substrate.
The hyperfme fields at pH 2.5 have broad distribution
extending from zero field almost up to the value

Fig. 1. Experimental setup of in situ emission
M6ssbauer measurement.

observed for 119Sn4+ ions in bulk a-Fe 2

°

3

,

This showsthat a large part of 1 1 9 Sb 5 + ions at the interface~. are

110interacting with Fe 3 + ions of the substrate through
119 Sb S + _0 2 - -Fe 3 + bonds at the pH.
( a ) pH6.5~

3~-------=~=--=-----i

If)

>,

~

.0

~

It can be concluded from these observations that theso-called "hydrolytic adsorption" of metal ions is not
simply adsorption of hydrolyzed species formed in thesolution onto solid surfaces. Studies on other oxides
are in progress.

( b ) pH4.5cQ

E~-----~-----~
. ~

"t)
(5

(c ) pH 2. 5

o

50

100

150

Hyperfine fields (kOe)

Fig. 3. Distributions of STHF magnetic
fields on 119 Sn calculated from thespectra of Fig. 2.

References
1) T. Okada, S. Ambe, F. Ambe, and H. Sekizawa:J. Phys. Chern., 86,4726 (1982).
2) J. Hesse and A. Rtibartsch: J. Phys. E, 1, 526(1974).

111

111-3-9.

Mbssbauer Emission Study of Defect 119Sn
Atoms in p- and a-Irradiated SnS
S. Ambe and F. Ambe

Mossbauer emiSSIOn spectroscopy of 11 9Sn using
cyclotron-produced 119mTe and 119Sb has been
applied in this period to studies on defect structures insolids and on surfaces. Trials to incorporate I 19 Sb into
living matters were also performed. Here, a study on
defect I 19 Sn atoms in p- and a:-irradiated SnS is reported. Surface studies on magnetic oxides are described in separate reports. 1),2)
Previously, we reported the Mossbauer emission
spectra of defect 119 Sn atoms produced by
120 Sn(p,2n)119 Sb~ 119 Sn and 117 Sn(a:,2n) 119 mTe~ 119Sb ; ~ 119Sn reactions in SnSe and SnTe. 3 ),4)

The chemical states of 119 Sn were found to be different
drastically in the two matrices. The study has now been
extended to defet 119Sn in SnS.
The conditions of p- and a:-irradiations were essentially the same as in the previous cases of SnSe and SnTe.
The Mossbauer emission spectra of the irradiatedsamples were measured against a BaSnO 3 absorber atliquid nitrogen temperature.
The 1 20 SnS sample irradiated with protons gave apartly resolved asymmetric doublet as shown in
Fig. 1. We attribute it to 119Sn in Sn site of thematrix on the basis of the similarity of its Mossbauer
parameters with those of normal tin in SnS obtained byabsorption measurement. As the recoil energy of theEC decay of 119Sb is smaller than the displacement
energy in solid, it can be concluded from the observationthat the energetic I 1 9Sb atoms produced by the proton
reaction were exclusively stabilized in Sn site of SnS.

The a:-irradiated 11 7SnS gave an emission spectrum
decomposable into three Lorentzians (Fig.2(a)).
Thermal annealing of the irradiated sample resulted inremarkable change in the spectrum, as shown in
Fig. 2(b) - (d). The relative intensity of the firstpeak (numbered from left to right) decreased by annealing and disappeared at 600°C. The second andthe third peaks shifted closer to each other, giving finallya doublet similar to that observed in p-irradiated120SnS. The first peak of the as-irradiated sample(Fig.2(a)) is assigned to an unstable Sn 4 + species
from its isomer shift. The second and third peaks are
considered to be a quadrupole doublet due to I 19 Sn
in Sn site of 1 1 7SnS accompanied by local distortion of
the lattice. Thermal annealing of the sample results indisappearance of the unstable Sn 4 + and also in restoration of the distortion around the Sn 2+ .
These observations demonstrate a close similarity of

100 ·.r...... 'br~,'. I'

(a )

99

100
1:'

' lfJ

c

2

99

.~
Q)

2:

~ 100 ,I"
.\

•• II

0:::

' , ' I,

(c)

98
100

100

1:'

' lfJ

__ ;.1.

c, "'., .... "

•
I

I

•

A

III,
I

,"

•

.,. II

(d )

2

.~
Q)

>
cu

97

'''=;

Q3

0:::

92

-4

a

4

8

Relative velocity

-4

a

4

8

Relati ve velocity(mm/ s vs Barium stannate)

Fig. 1. Emission M6ssbauer spectrum of pirradiated 120 SnS at liquid nitrogen temperature.

(mm/ s vs Barium stannate)

Fig. 2. Emission Mossbauer spectra of a:irradiated 117 SnS at liquid nitrogen temperature.
(a) As irradiated, (b) after 2h annealing atlOO °c,00(c) at 200 C, and (d) at 600 C.

112

the chemical effects of p- and Q-reactions in SnS to thosein SnSe reported previously. 4 )2)
3)

T. Okada, F. Ambe, S. Ambe, and H. Sekizawa:p. 74 in this report.
F. Arnbe and S. Arnbe: J. Chern. Phys., 73, 2029
(1980).

References
1) F. Ambe, S. Ambe, T. Okada, and H. Sekizawa:p. 109 in this report.

4)

F. Ambe and S. Arnbe:
Rep., !i, 98 (1980).

IPCR Cyclotron Progr.

113

111-4.

Radiation Chemistry and Radiation Biology
1.

Measurements of Photoemission Spectra and their Decay
at Different Locations along a 50 MeV N-Ion Trajectory in
Helium Gas at 400 Torr and at 5 K
K. Kimura, T. Kato,* N. Yamazaki,* S. Kubota, and M. Imamura

Electronic excitation processes induced in matter

The beam spur of 90 MeV N-ions injected in He gas at

irradiated by heavy-ions are dependent on the ion energy

400 Torr at ca. 5 K was observed as a luminous zone ofand classified into the processes such as optical approximation, a-rays, charge exchange, multiionization, andmultiexcitation. Emission .measurements of excited

ca 10 mm in length. The emission spectra were measured
at every few mm along the beam spur by sliding a condenser lens; a typical emission spectrum is shown instates formed in matter may allow us to know theFig. 2.

Most emission peaks are assignable to those

probabilities of the aforementioned processes and theirof He excimers, their hot bands, and their rotational

characteristic excitation. In a last reportl) we revealed
that N-ion irradiated He gas at several tens of mmHg

side bands by comparing with the known peak positions
reported by many workers. 2 ) New bands were observednear

at 4945, 4598, 4585, 4521, 4289, and 4262 A, allcriticaltemperature

exhibits

characteristic

dependence of emission spectra on (1) irradiation tem-of which have not been reported in the previous op-

perature and (2) irradiation pressure. No such dependence has been observed for the emission spectrum

tical studies. In view of our special experimental
conditions, i.e. high density excitation with N-ion, low

by microwave discharge and electron irradiation at room

temperature, and high density, clusters of the He

temperature or at a liquid phase.

excimers( e.g.

He * - He *)
2
2

may

be

regardedasThis report presents experimental results on (1)plausible candidates for the origin of these new bands.

stopping power dependence of the excitation and (2)dynamic properties of excited species along an N-ion(Helium forms clusters at similar temperatures anddensities according to Gspann. 3 »)trajectory traversing through cooled and high-pressure

Intensities of all emission peaks and stopping powers

He gas.

are plotted as a function of the N-ion range in Fig. 3.

Experimental arrangements are shown in Fig. 1.

The lower five curves for peak intensities are seemingly
similar to that for stopping power except for slightdifferences in peak position, rate of increase, andshape of curve; in contrast the upper three ones show
different variations with range. These results suggestthat excimers are formed through different physical andchemicalprocesses

withdecreasing N-ion

energy.

Detailed analysis of these curves will provide information on the dynamic atomic and moleculaJ processes
which are dependent on particle energy.
To elucidate the dynamics of the He excimers at
AI- foildifferent positions along the trajectory, the time decay
curves of respective emission peaks were measured along
the trajectory. Some of the excimers were found to
decay through two steps, the lifetimes of which are tens
CRYOSTATOXFORD CF200
He- GAS

4.9 - 30K
Fig. 1. Experimental layout. OMA, optical multichannel analyzer (Princeton Applied Research Co.)of nanoseconds and milliseconds. The initial rises of thefast components are plotted as a function of the range
in Fig. 4. Figure 4 indicates that the formation of
the state d 3 has a broad maximum shifting to the smaller
range compared with the curves in Fig . 3 and thatthe state f3 increases more sensitively with increasing

114

NM
600
:: 2.0 XI 0 3

x 0.4000

·c

::::l

(.)

>-

0(Y)

'"

-0

j

;,

550
x O.2000 -0
j"
~
'""0

u

j

If)

15

~ 10 X I0 3

(Y)

f(Y)

+II'!"

cj

N
f
I "I
_ 0

~~

If)

c

"';, ;,
;,

If)

0

q

-0

-'=
Q..

NM

23000
1/cm

21 00026000

Fig . 2. Emission spectrum of He gas (at 390 Torr) irradiated with 5.33 MeV/amu N ions at 5.2 K. Measured at
10 mm of N-ion range. Assignments of peaks are due to Ref. 1.

106 r-------------------------~

C/l

C

o

-0

..c:
0...

C/l

c

-B 10 4
..c:
0...

Range

Fig. 4. Initial formation of fast emission components vs. ion range. Helium gas at 420 Torr
was irradiated with 6.0 MeV/amu at 6 .0 K.

0. 5 MeV/ amu

."":

o

10
Range (mm)Fig. 3. Peak emission intensities and stopping
power as a function of N-ion range. Incident
energy of N-ions, 5.33 MeV/amu ; He gas 420
Torr and 5.2 K.
Stopping powers were
calculated from the table by Northcliffe andSchilling. 7 )range than the others, being formed rather efficiently
near the end of the trajectory where the stopping power
begins to fall off.
The slow decay component is explainable in termsof the reformation process of the upper-state excimer
through a bilinear reaction of the excimer a 3 whichis the lowest state with the longest lifetime as was proposed by Keto et al. : 4 )a 3 + a 3 - - upper state ex cimers.

(1 )If the decay of emission includes this reformation
process , theinversesquare-rootof theemission

115

intensity, 1- 1 / 2 , must be proportional to time from theinitial excitation, t, as expressed by the following
equation:
1 -1 / 2 = 10 -1/2 + mt,(2)tion. 6 ) This year, we constructed a new detector consisting of a thin carbon foil, MCP, and a magnet insteadof the system using photomultipliers, which will be used
for the measurement of the fast decay and subnanosecond time-dependent spectra.

where Io stands for the initial emission intensity. Thus,
the slower decay processes, which were measured byusing a chopped beam and gated OMA methods, S ) werechecked whether they obey Eqn. (2) or not. The resultshows that the state d 3 and an unknown triplet at 4858,
4571, and 4598 A are reproduced by Reaction 1 but thestates Dl , Jl , h 3 , and f3 are not.
F or investigation of He density effects, emission
measurements of liquid-phase He irradiated by N-ionswere undertaken by using a new cryostat. Preliminary
experiments provides spectra different from those obtained for the gas-phase He mentioned above ; detailed
results will be reported shortly.
The fast-decay measurement of the emission using
a technique of single-ion hitting and single-photon
counting was developed to study the dynamics of theelectronic excited states formed by heavy-ion irradia-

References

1) K. Kimura, Y. Toda, and M. Imamura: RIKEN
Accel. Progr. Rep. , l§, 134 (1982).
2) See references in "Constants of Diatomic
Molecules", (eds K. P. Huber and G. Herzberg),
Van Nostrand Reinthold, New York (1979).
3) J. Gspann: Surface Science, 106, 219 (1981).
4) J. W. Keto, F. J. Soley, M. K. Stockton, and W. A.
Fitzsimmons: Phys. Rev., A10, 887 (1974).
5) K. Kimura and M. Imamura: Phys. Lett., 67 A,
159 (1978).
6)
7)

K. Kimura, K. Mochizuki, T. Fujisawa, and M.
Imamura: ibid., 78A, 108 (1980).
L. C. Northcliffe and R. F. Schilling: Nuclear Data
Tables,~, 233 (1970).

116

III-4-2.

Inactivation of Bacterial Spores by a Single Heavy Ion
T. Takahashi, F. Yatagai, T. Katayama, Y.H. Kang,s. Tamada, I. Kaneko, and S. Okada

In a recent paper. 1 ) the inactivation cross sections of

B. subtilis spores by C, N, and 0 ions have been shown
to be explained fairly well by the track-structure models
proposed by Katz and by Chatterjee and Schaefer, if
parameters of the target theory are chosen so as to allow
them to have proper experimental bases. For very heavyions, however , experimental inactivation cross sections
given by Schafer et al. 2 ) are somewhat larger thanthose calculated by our model. 1 ) The discrepancy may
be ascribed to a "long range effect" of heavy ions aspreviously pointed out by Takahashi et al. 3 )To get better understanding of the mechanism ofinactivation, experiments have been carried out tocharacterize a microscopic structure of the radiation
action around a single heavy ion. This was done bymeasuring the rate of dead spores as a function of the
distance between individual spores and the center of thepath of an ion . The spores were fixed with 10 %aqueous polyvinylalcohol solution on a CR - 39 plastic
detector , which is necessary for particle detection.
We have succeeded in incubating spores on theplastic detector and observed and photographed theoutgrowth for each spore . The plastic detectors were
irradiated by Ar ions from the heavy-ion accelerator(RILAC) and immersed in 7N - NaOH solution at
70°C. Etch pits were found to be sufficiently
developed in 60 - 75 minutes with their diameters of
about 2.5 J..lm (Fig. 1). We are also examining a
possibility that UV photons are emitted when the ion
impinges upon the plastic detecor, because photons may
also induce inactivation of the spores. Since very weak
UV light seems to be emitted by a-particles, attempts
have been made to estimate quantitative light yields.

References
1) T. Takahashi, F. Yatagai, and S. Kitayama:

Adv.

Space Res., 2, No.8, 95 (1983); T. Takahashi
and F. Yatagai: RIKEN Accel. Progr. Rep., 12,2)
3)
Fig. 1. Ar-ion tracks in CR-39 chemicallyetched with 70 ° C in 7N-NaOH for 75 min .

139 (1982) .
M. Schafer, R. Fadus, K. Baltschkat, and H.
BUcker: 7th Symp. on Microdosimetry (1980).
T. Takahashi, F. Yatagai, and A. Matsuyama: Sci.
Papers I.P.C .R., 74, 51 (1980); F. Yatagai, T .
Takahashi, Y. Kitajima, and A. Matsuyama: J.
Radiat. Res.,~, 90 (1974).

117

1II-4-3.

Rescue of Mitomycin C Sensitive Mutants of Deinococcus
radiocJurans by Irradiation with UV, r-Rays, or N-Ions
Following Mitomycin C Treatments. Kitayama and F. Yatagai
Living organisms have multiple systems to protect

defective step will be substituted by other physical orthemselves against DNA lesions made spontaneously or
induced by various physical or chemical treatments .

chemical procedures such as irradiation with '}'-rays or
ultraviolet light , or treatment with chemicals which

Among the lesions , double-strand scissions and inter-

induce strand breakage in DNA. As shown in Fig . 1,

strand cross-links in duplex DNA result in serious

cells of KI696 which is a mitomycin C sensitive mutant

damage for cells, i.e . loss of genetic information, if thewere rescued from the lethal effect of mitomycin C bycomplementary DNA strands are cut off simultaneously

irradiation with ultraviolet light (254 nm), '}'-rays from
60Co , or accerelated N-ions ("'67 MeV). It was reported

at the lesion .
It is known that Deinococcus radiodurans, one of thepreviously that incision step was defective and crosslinks in DNA were not removed in this sensitive strain. 3)

extremely radio-resistant bacteria , can repair doublestrand scissions and cross-links in duplex DNA.l ) - 3)

However, this mutant is resistant to ultraviolet light or

DNA cross-links in the cells were found to be removed'}'-rays as well as the wild type strain. Therefore, it canthrough several steps including incision of nicks on one
or both strands of duplex DNA .3) Mutation was induced

be assumed that DNA strands were incised at pyrimidine
dimer , a main photoproduct of uv irradiation . The
defective incision step following mitomycin C treatmentin the wild type strain on the removal of cross-links.4)

Mutants sensitive to mitomycin C or to psoralen-plus-

in this strain could be substituted by endonuclease forthe dimer and the cells recovered their colony forming

light were isolated and some of them were unable toability. It is also plausible that irradiation with '}'-raysor N-ions induced DNA strand breakages which relieved

induce nick at or near the lesion . As can be expectedfrom its repair deficiency , one of such mutants gave nomutant progeny after the treatment which induces
DNA cross-links. 4 ) In this mutant strain which is unable

the cells from the lethal effect of cross-links induced by

to induce nick on the removal of cross-links , themore detailed experiments must be carried out.

mitomycin C. In order to substantiate these possibilities

Time of Incubation
2nd
3With mit omycin C (m in) Treatment (dose) 100

-

10

-

10
14
14

7
7

Surv iving Fraction

10- 2

10- 1

I

I

UV (l20J/ m2)

-

I

-

I

I

I

y-rays (200 krad)

N-ions (250 krad)

1

I

I

Fig. 1. Rescue of Mitomycin C Treated D. radiodurans KI696 (mtc
F) by Irradiation with UV( 254 nm), '}'-rays or N-ions. Exponentiallygrowing cells of D. radiodurans KI696 were incubated withmitomycin C(1l1g/m1) for various time at 30 0 C. The cells were
harvested , washed and resuspended with M/15 potassium phosphatebuffer (pH 7). The resuspended cells were irradiated with uv(254nm), '}'-rays, or N-ions (""67 MeV).

118

References
1)
2)

S. Kitayama and A. Matsuyama: Biochem.
Biophys. Res. Commun., 33,418 (1968).
S. Kitayama: Biochim. Biophys. Acta, 697, 381(1982).

3)

S.

4)

Bacteriol., ill, 1200 (1983) .
F. Yatagai and S. Kitayama: Biochem. Biophys.
Res. Commun., 112,458 (1983).

Kitayama, S. Asaka, and K. Totsuka: J.

119

1II-4-4.

Effect of 3-Aminobenzamide on Sister Chromatid
Exchange Frequency in Chinese Hamster V79
Cells Irradiated with Heavy Ions

I. Kaneko , K. Nakano, and G. Okada

DNA strand breakage is required for the formationinducer of SeE in cultured cells. A majority of radiation-of a sister chromatid exchange (SeE).1) Ionizing radiation is an efficient DNA strand breaking agent and an

induced DNA breaks are very short lived, and they areresealed before they can elicit an SeE response.

Fig. 1. SCE induction in Chinese hamster V79 cells by gamma and nitrogen ion irradiation in the presence and absence of 3-aminobenzamide (3-ABA), (A): Control chromosomes, (B): Chromosomes from
cells exposed to 3-ABA, (C): Chromosomes from cells exposed to gamma-rays (4.5 Gy), (D): Chromosomes from cells exposed to gamma-rays (4.5 Gy) and 3-ABA, (E): Chromosomes from cells exposed tonitrogen ions (3.0 Gy), (F): Chromosomes from cells exposed to nitrogen ions (3.0 Gy) and 3-ABA.

120

The synthesis of poly adenosine diphosphate-ribose[poly (ADP-ribose)] is stimulated by a variety of DNA-

cantly increase a baseline of the enzyme activity. 6 )damaging agents, including alkylating agents?) ultraviolet light,3) and ionizing radiations. 4 ) DNA strand

high LET radiations, helium- or nitrogen-ions accerelated
in the cyclotron, can induce SCE in mammalian cells in

breakage appear to act as a stimulant for activity of thethe presence and the absence of 3-ABA. Gamma-rays

poly (ADP-ribose) polymerase, which can modify bothalone caused a very slight increase in SCE frequency initself and other cellular proteins by ADP ribosylation. 5 )the dose-dependent manner up to the dose of 5.0 Gy.

Inhibitors of poly (ADP-ribose) polymerase, such as
3-aminobenzamide (3-ABA) and benzamide, signifi-

The presence of 3-ABA before and/or after gamma-

The purpose of the experiment is to find whether

irradiation enhanced frequency of SCE in Chinese
hamster V79 cells (Fig. 1 and Fig. 2). The presence of
3-ABA itself did rise SCE frequency. However, no70• ,-rays
60

Chinese hamster V79 cells• N-ion.. a - rays

----

•

50

3ABA ( +)~ 40w------V5 30

sensitization effect on SCE induction was observed after
helium- or nitrogen-ion irradiation. This was clearly different from a 3-ABA sensitization effect on gammairradiated cells .

References- --.· ..
.v/:.----------

1).

20Z'---..

2)o
3ABA (-)

1.5 3.0 4.5 6.0
9.0
Dose (GY)E.

Crossen:Eviron.

R. C. Benjamin and D. M. Gill: 1. BioI. Chern.,
255,10502 (1980) .

10oW. F. Morgan and P.
Mutagenesis,l, 149 (1980) .

12.0

Fig. 2. Effect of 3-aminobenzamide (5 mM) on
sister chromatid exchange frequency in Chinese
hamster V79 cells exposed to ')'-rays and heliumor nitrogen-ions accelerated in the cyclotron.

3)

B. W. Durkacz, O. Omidji, D. A Gray, and S. Shall:
Nature , 283, 593 (1980).

4)

W. F. Morgan, 1. L. Schwarz, 1. P Murane, and S.
Wolf:

5)

Radiat. Res.,..2l, 567 (1983).

N. Nduka, C. 1. Skidmore, and S. Shall:

Eur. J.

Biochem., ill, 525 (1980).
6)

D. Cressen and S. Shall: Nature, 296, 271 (1982).

121

III -5.

Instrumentation
Test of MCP and PSD for Electron Spectrograph
Using Alpha-Source

1.

1. Urakawa, H. Kumagai, Y. Awaya, T. Kambara, M. Kase,
T. Matsuo, H. Shibata, and A. Yagishita

spectrograph using

MCP and PSD. It is noted that the MCP is recommended

a tandem microchannel plate (MCP) and a position

to be operated with saturation mode of the supplyA

parallel-plateelectrostatic

sensitive detector (PSD) has been designed for the studyof Auger electrons produced in ion-atom collisions. 1 )The MCP (Hamamatsu TV Co., Ltd.) is an image
intensifier to amplify the extended image produced byan electron energy analyzer. The output electrons
produced by the MCP are accelerated and impact upon
the surface of the PSD (Hamamatsu TV Co., Ltd. Model
S1352). In order to investigate the operating conditionof this detection system, we tested the MCP and PSD
using alpha-source of 241 Am . Figure 1 shows a typical

(()

C
::J
o

U

position spectrum obtained by setting two 50 J.l.m slits
in front of the PSD. The position resolution of the PSD
is estimated to be 360 J.l.m (FWHM), where the shaping
time of main amplifiers was 1 J.l.sec. Figure 2 shows the
position spectrum obtained by the combination of the
MCP and the PSD. The position resolution is estimatedto be about 500 J.l.m (FWHM) where each MCP iso
Position (mm)operated at the voltage of 800 V and electrons from
MCP is accelerated by the potential of 500 V between

VaeeelFig. 1 Position Spectrum of PSD.

= 500 VVM CI' I =800V

VMC l'2 =800V
({)

C
::J
o

U

o
Position (mm)Fig. 2. Position Spectrum measured by the combination of Mep and PSD.

voltage of about 1000 V but in this test the MCP wasoperated with the supply voltage of 800 V in order to
optimize the total gain of the system.

Reference
1) A . Yagishita and K. Agata:Rep.,.u, 83 (1981).

RIKEN Accel. Progr.

122

III -5-2.

Experimental Setup for Electron Spectroscopy
A. Koyama, Y. Sasa, Y. Ishibe, A. Shiraishi, T. Shiga,
H. Omori, K. Nishi, M. Fuse, and M. Uda

An ultra high vacuum apparatus has been constructed

The slit box contains slits Sl and S2' and a collimator.

in order to study spectra of electrons emitted from solid

The slits Sl and S2 are equipped for differential pump-surfaces under heavy ion bombardment. Figure 1 is its

ing. They are made of copper pipes with inner diameterphotograph and Fig. 2 shows its schematic diagram. Thisof 10 mm. Sl is 150 mm long and S2 50 mm. The slit

apparatus is mainly composed of three parts: the slit
box, the target preparation chamber and the target

box is connected to the beam transfer duct through SI .
When the pressure of the duct is 1 X 10- 6 Torr, thechamber, as illustrated in Fig. 2. Each of these chamberspressure of the slit box can be reduced to 1 X 10 - 8

can be independently evacuated into ultra high vacuum.

Torr. The collimator has an aperture of 1 mm diameter

Fig. 1. Photograph of the ultra high vacuum apparatus for the
spectroscopy of electrons induced by heavy ion bombardment.
position of the aperture, incident beams are easily introduced onto the point where the optical axis of theenergy analyser intersects the target surface.
The target preparation chamber is equipped witha vacuum deposition system and an ion gun for surface
cleaning. In-situ vacuum deposition is carried out at
Target transfer rodpressure lower than 1 X 10- 8 Torr. The target preparedcan be transferred to the target chamber by sliding thetarget transport rod within a few minutes after target
preparation.
The target chamber contains a parallel plate energy
analyser with the energy resolution (lilliE) of 1 % on aturntable, a rotatable target holder and an electron gun.
The pressure inside the chamber is in the range of

Fig. 2. Schematicshown in Fig. 1.

diagram of the apparatus

10- 10 Torr under beam irradiating conditions, and themagnetic field is reduced to about 10 mG by using
a mu-metal cage. In order to improve the reproducibilityof the data, measurements are being carried out re-for beam collimation and is movable in the plane per-peatedly and each part of the apparatus is being

pendicular to the beam direction. By adjusting theexamined.

123

III -5-3.

Experimental Setup for PIXE
K. Maeda, Y. Sasa, and M. Uda

A scattering chamber for particle induced X-ray
emission (PIXE) analysis was constructed and connected
to RILAC. A photograph of the chamber is given in
Fig. 1. The chamber is evacuated with a turbo-molecularpump and a rotary pump. The pressure in the chamber
goes down to 3 X 10- 6 mmHg after one hour pumping.

necessary, X-rays in a particular energy region can be
depressed by inserting an X-ray absorber between thetarget and the window . Six X-ray absorbers are arranged
on a disk and can be exchanged by remote control. The
detected X-ray signals are amplified by a pre-amplifier
and a linear amplifier, and then processed by a multichannel analyzer (MCA). The data obtained are transported to a personal computer (IF800) and recorded ona floppy disk. Simple, on-line data analyses are done by
the personal computer. Precise treatments of data,such as peak deconvolutions and estimation of the concentrations of elements from the peak intensities, arecarried out with an off-line computer (FACOM M-380).
A Si(Li) detector designed especially for soft X-ray
analysis is under construction.

Fig. 1. Photograph of the scattering chamber
for PIXE.

The schematic diagram of the experimental setup for
PIXE is shown in Fig. 2. A target sample placed ona sample holder is irradiated with ion beams accelerated
by RILAC. To analyze many samples rapidly, the sample
holder was of a cassette type which can be loaded with
35 samples at once . The target can be changed automatically by remote control. A graphite collimator isplaced in front of the target to prevent the target frombeing irradiated by undesired ions such as scattered ions.
Ions transmitted through the target are collected on
a Faraday cup and counted with a current integrator.
Beam current absorbed by the target can also bemeasured through a terminal (T).
X-rays emitted from the target are detected by anenergy dispersive semiconductor (Si(Li)) detector
through a thin Mylar (411m in thickness) window . If

Fig. 2. Schematic diagram of the experimental
set-up.
A: X-ray absorber, C: collimator, F: Faraday
cup, H: sample holder, S: target sample, T: terminal, V: viewing port, W: window, Z: port forarbitrary use.

124

III-5-4.

Nuclear Data Acquisition System with CAMAC

T. Inamura, T. Murakami, J. Kasagi, H. Kumagai, and Y. Gono

A CAMAC system has been developed to accommo-

hard ware. To improve the data acquisition rate further,date demands for arbitrary multi-parameter data acquisi-

we will introduce a local intelligence, for instance, astand-alone microcomputer with a buffer memory at thetion.
A computer. Perkin-Elmer 3220. that controles the
CAMAC system is in the RILAC laboratory. 1) For thetime being the nuclear experimental station will be in
the 160 cm cyclotron facility. Because of this, thesite of experimental station. The data acquisition rate
will then be several tens-kilo events/sec.

RILAC

CYCLOTRONCAMAC crate is placed in the cyclotron laboratory, andis connected to the computer with optical fiber cables
about 150 m long. We have chosen a pair of LeCroy
5210 V-port Adapters. They provide an electricallyisolated byte-serial highway, being used with a type L2
Serial Crate Controller (L2SCC) and a built-in serial
driver of the computer. The circuit system allows

E

_____
if) LO0

co .----<
~I

LO

_

o

this advantage, we are thinking of adopting optical fibertransmission of data from experimental area to thecounting room in the SSC facility. The present experi-

rate will be a few kilo events/sec without changing any

LL I
I
I
I

An example of the CAMAC data acquisition system.

Fig. 1.

ment would provide a nice feasibility test for thisThe basic acquisition software supplied has been
modified to improve the data acquisition rate. Although
we have not yet tested it fully, we hope the acquisitionu~~0.. . I

transmission of greater than 4 megabytes/sec.
Needless to say, optical fiber transmission is immune
to electromagnetic interference. Taking into accountpurpose. Figure 1 shows a block diagram in the case ofneutron-charged particle-gamma coincidence experimentthat is currently underway.2)

l:gReferences
1) H. Kumagai and M. Sasagase: RIKEN Accel. Progr.
Rep., 12., 123 (1981).
2)

T. Murakami, J. Kasagi, H. Harada, and T. Inamura:p. 125 in this report.

125

III -5-5.

Neutron Multiplicity Filter

T. Murakami, J. Kasagi, H. Harada, and T. Inamura

A neutron mUltiplicity filter and its data acquisition
system were constructed to investigate the excited statesin neutron deficient
nuclei, especially aroundA = 80 - 100, produced via heavy-ion reactions. The
neutron multiplicity filter is used to identify the residual
nuclei from which -y-rays are emitted, being coupledwith or without a .6.E - E counter telescope.

system to accept many parameters of the data. The
details are described in another re port of this volume. 1 )Neutrons and -y-rays from the 1 OOMo + 16 0 reaction
at 80 MeV were

measured using this system. Gamma

spectra in coincidence with one or more neutron
detectors are shown in Fig. 2. The prominent peaks
mainly come from the 4n reaction product 112 Sn. Ratio

Figure 1 shows a photograph of the neutron multiplicity filter. Its performance is summarized in Table 1.
Neutrons are detected with an array of six NE213

Table 1. Performance of the neutron detector.

liquid scintillators. A center detector is placed at 0 deSize

center:surrounding:

105 em 2 X 7.5 em X 1(regular pentagon)
154 em 2 X 7.5 cm X 5 (pentagon)

Scintillators &NE 213

photomultiplier

R 1250 (Hamamatsu,5"¢)

Solid 'angles

0.50 sr/the center detector
0.71 sr/the surrounding detector
in a typical case . Efficiency including
solidangle is estimated to be
1.7 %/each surrounding detector: forthe center one 1.2 %.

(XI02)
3.00,....----.----...-----.--...----,..-------,---,.----,

2.63

Fig. 1. A photograph of neutron multiplicity filter .

2.25

gree to the beam and surrounded by five detectors. The
center piece is a regular pentagon with sides of 78 mm
and its thickness is 75 mm. The other five pieces arepentagons with one side of 78 mm and four sides of
98 mm; their thickness is 75 mm. They cover 40 % of
the whole solid angle in the laboratory system. Since
the detection efficiency of the neutron detector isestimated to be around 30 %, the counting rate in which
one or more detectors are fired is about 35 % of thesingle events in the reaction of neutron multiplicity 4.
The CAMAC is adopted as the data acquisition

Channel number

Fig. 2 . Gamma spectrum observed in coincidencewith the neutron detectors (No ;S 2) for the
100 Mo + 16 0

reaction at 80 MeV.

126

0.20r---- - -- - - - - - - - - - - - - ,of the yield of N n ~ 2 to the one of N n ~ 1 is plottedin Fig. 3, where N n is the number of triggered neutron
detectors . As can be seen in the figure, the obtained
values of the ratio increase as the neutron mUltiplicity

AlI OJ5f-<:

increases and agree well with the estimated ones.

>-.
~

C'\J

AlJ OJOr

<

-- -

>-.

- ------ - ---- - -- M = 3

IIReference
1) T. Inamura , T. Murakami, 1. Kasagi , H. Kumagai,
and Y. Gono:C<

005 '-

0.5

10
E y (MeV )Fig. 3. Ratio of the yield of N n ;;S 2 to the oneof Nn ~ 1. The dotted lines are estimated values
for multiplicity M.

p. 124 in this report.

127

III -5-6. He-Jet Transport System
H. Kudo, T. Nomura, and J. Fujita

A gas-jet transport system is now widely used for theinvestigation of unstable nuclei with relatively short half
lives. Typical lifetimes covered with this transportsystem ranges from a few tens of ms to a few minutes.
The gas-jet transport system can easily be combinedwith other experimental facilities such as those of a gas
phase chemistry, a rapid chemistry, and an isotope

vapor in helium, passing through the condenser whichis cooled with water, comes to condense on NaCI seeds
and grows into aerosol particles.
2)

Reaction chamber

The reaction chamber is composed of an energy degradator, a target holder, a thermalizing room, and a
Faraday cup with a water cooling jacket as shown inseparator on line.

Fig. 2 . In the thermalizing room, the pressure of helium

We have constructed a helium-jet transport system
which consists of an aerosol generator, a reaction
chamber, and a collection tape system.

is kept at 1 atm, and the vacuum of the cyclotron is
maintained by sealing the window of the reaction
chamber with a thin metal foil. Reaction products are1)

slowed down, thermalized with helium, and deposited

Aerosol generator and gas supply system

It has been reported that aerosols in the gas flow

on surfaces of the aerosols. The aerosols are transported

passing through a capillary play an important role torealize stable efficiency and good reproducibility oftransporting reaction products through the capillary andof collecting them onto a catcher. l ) Irnanishi2 ) obtained

through a 1 or 2 mm 1> X 10m long teflon capillary to
the collection chamber.

almost 100 % efficiency for fission products by using
aerosols of dioctyl phthalate (often used as a diffusionpump oil) as a carrier of recoil products. The systemthey used was stable over a few weeks of running timeand reproducible over a period of about 6 months.
Therefore, we have made the same kind of aerosol
generator and gas supply system.
The aerosol generator system consists of a nebulizer,
a nucleater, a reheater, and a condenser, which isschematically drawn in Fig. 1. The diffusion pump oil
is vaporized by the nebulizer, and mixed in the reheater

Fig. 2. Reaction chamber
1 : energy
degrader,2 : viewer, 3 :vacuum seal foil, 4: target, 5 : vacuum
sealed rotator, 6 : graphite beam stopper,
7 : insulator, 8 : water cooling.

with NaCI seeds produced from the nucleater. Then theAt3) Collection tape system
The

collection

chamberisevacuatedwithamechanical booster pump backed by a rotary pump.
The end of the teflon capillary is finely adjustable forchanging the collection position. The transported
aerosols are deposited on a magnetic tape which serves asa collector and moves to the detector position by menas

o

0.5

1m

I~~====~I~~====~I

Fig. 1. Aerosol generator and gas supply system
I : helium gas, 2: rotameter, 3: reservoir, 4:
nebulizer, 5: nucleater, 6: reheater, 7: condenser, 8: temperature-controlled heater, 9:
water cooling, 10: check valve, 11: pressuregauge, 12 : compressor.

of a micro-computer controlled stepping-motor and two
servo motors. The end of the magnetic tape ismonitored by a photo-senser. The system is shown in
Fig. 3.
In the collection chamber, a temperature controlled
heating apparatus is mounted for the purpose ofevaporating the oil which will cause a poor resolution in
an a-spectrum. For the differential pumping needed for

128

Fig. 3. Collection tape system
I : feed reel, 2: photo-senser, 3: heater, 4: Ge( Li)
detector position, 5: Si (Au) detector position, 6:
collection tape, 7 : pulse motor, 8 : take-up reel, 9 : toroots pump, 10 : to diffusion pump.

more evacuated condition, for example, in the case ofmeasurement of electrons, a skimmer can be attached

References
1) H. Jungclas, R. D. Macfarlene, and Y. Fares: Phys.
Rev. Lett., 27, 556 (1971).

between the end of the teflon capillary and the collection tape.
Some preliminary results using this system are givenin this Report.

2)

N. Imanishi, I Fujiwara, and T. Nishi: J. Nucl. Sci.
and Tech., 11, 935 (1980).

129

1II-5-7.

A Goniometer for Internal Transient Magnetic Field Study
A. Hashizume, N. Sakai, K. Asai, H. Kumagai,
and Y. Yamada

The measurement of perturbed angular distributionsof 'Y-rays from Coulomb excited states gives us informa-

insulated from earth potential and the magnet, andserves as a Faraday cup. The angle of a detector ontion on magnetic moments or internal magnetic fields iflife-times of the excited states are already known . By
use of very large transient magnetic field caused by therecoil nucleus travelling through polarized ferromag netic
substance, g-factors of excited states with life-times inpico-second region can be measured.
A goniometer combined with a C type magnet was
installed at D1 beam channell) in the RILAC experimental area (Fig . 1). The magnet was designed also
for use in the measurement of perturbed angular distributions of 'Y-rays with external magnetic field. Withpole pieces of 70 mm in diameter and of 30 mm polegap, the maximum magnetic field of 1.25 T was obtained. The instability of current was less than
4 X 10- 3 %/3 h. The 350 kg magnet can be easily
removed from the normal position to set up a SSD ina target chamber. The target and the chamber are

Fig. 1. Photograph of the goniometerfor internal transient magnetic fieldstudy .

+24V---------Ji

Fig. 2. The circuit for the control of the goniometer.

130

a rotating arm is detected by an en corder with which

References

digitized readings of the angle can be easily obtained.
The control circuit is shown in Fig. 2. The arm can be

1)

M. Hemmi, Y. Miyazawa, and M. Odera: IPCR

controlled in an operating room. An interface between

2)

A. Hashizume , N. Sakai, K. Asai: p.27

the control circuit and an on-line computer was also
designed . Angular distributions of -y-rays from natural
dysprosium evaporated on a thin Fe backing and excitedby 45 MeV 40 Ar4+ were studied in a trial run. 2 )Cyclotron Progr. Rep., 11, 126(1980).
report.

in this131

In-Beam AI pha- and Electron-Measurementswith a Superconducting Solenoid

III -5-8.

Y. Gono, Y. Itoh, M. Sugawara, and T. Kasuya

work well enough to eliminate the electron backgroundA superconducting solenoid was installed at a beamline of the cyclotron to measure the in-beam alpha-and it was still necessary to use a timing measurement

particles and electrons.
This magnet was originally constructed for the laserlresearch use by Kasuya et al. ) The magnetic fieldwith respect to the beam-bursts. A new baffle has been
prepared recently to suppress further the background.
This system could also be applied for the in-beamstrength up to 70 kOe can be obtained with the excita-

electron measurement by using a cooled Si detector.

tion current of 32 A. The diameter of the working space
is 38 mm. These values result in the transmission ofalpha-particles with 73 and 36 msr for 10 and 20 MeV,

For this purpose a 5 mm¢ baffle was placed at the centerof working space of the solenoid to avoid a tremendous
background due to delta-electrons. One example of thedelayed electron spectrum is shown in Fig. 2. This

respectively. The detection efficiency depends on thesize of the Si detector which is used for the energy
analysis. The alpha-particle spectrum taken by a
300 mm2 Si detector with the solenoid is shown inspectrum was obtained from the 208Pbct 2 C,4n) 216 Ra
reaction at E = 80 MeV. The energy resolution of thepeaks is about 8 keV at FWHM which should be easily

Fig. 1. This spectrum is taken from the 209 Bi + 1 2 C

improved by replacing the Si detector with a better one.
10·

103

103
10?
VI

§1Q2

VI

'50

<.)

U

10 1
10 1

10 0 ,
0Channels

Fig. 1. Delayed alpha-spectrum from the
209 Bie2 C, 4n)217 Ac reaction at 80 MeV takenIby a Si detector with a superconducting solenoid.
Numbers given in the figure are in MeV.
reaction at E = 80 MeV with a Bi target of about
500 p.g/cm2 thick. The energy resolution is about

50 keV at FWHM. The continuum background issubstantially suppressed in comparison with a spectrum
taken without the solenoid. A propeller shaped baffle
was used for this measurement. However this did not

500
Channels

Fig. 2. Delayed electron-spectrum from the
208 Pb (12 C, 4n)216 Ra reaction at 80 MeV
taken by a cooled Si detector with a superconducting
solenoid. Numbers given in the figure are in keV.

Reference

1) T . Kasuya et al.: lpn . l. App!. Phys., 11, 1572
(1973).

132

III -6.

Miscellaneous
1.

PIXE Analysis for Environmental Substances

K. Maeda, Y. Sasa, M. Maeda,* M. Kobayashi, and M. Uda

Particle induced X-ray emission (PIXE) sfJectroscopy

coupled plasma emission spectrometry (ICP) and thewas applied to the elementary analysis of environmental

atomic absorption spectrometry (AAS) to get thesubstances. In environmental science, a large number ofsamples collected in various situations should be analyzed in a short time. Sometimes the samples to be ana-

absolute amount of Si and to check the results of thelyzed are very small in size or quantity. Relative con-

N2 + ions accelerated by RILAC were used for excita-

centration of each component element is important inevaluating the material balance in the system of interest.
The PIXE, which is a rapid, non-destructive, multi-tion. The elements AI, Si, P, S, CI, K, Ca, Ti, Mn, and Fe
were detected. The concentrations of these elements
were evaluated from the spectra by referring to those ofelemental, trace analysis technique, is therefore mostthe standard samples. Variations in the contents ofsuitable for analysis of environmental substances. We
describe here several examples of the application of theparticulate silicon, potassium and titanium along the

PIXE.** Figure 2 shows a typical PIXE spectrum obtained from the suspended particulates. Here 15 MeV

PIXE. The details of the experimental procedures andsetups are reported elsewhere. l ),2)
(1) River pollution at an urban area. The composition of suspended particulates in water of the TamaRiver was determined by the PIXE. The sampling was

Data No. 20331
Q3

~ 104

..c::
u

made in August 1978 at nine locations in the lower'---(j)reaches extending over 25 km from the river mouth§o 103(see Fig. 1). The samples collected on membrane filters

1:'

u

.~

102

2

J;
>,
C\J

Cf
10 1
X
100"'-'--'---'--'---'---''--'---'---'--.l...-L--U.........IlA.l....JL--L--'-..IL.-.L......I

o

5

10
15
X-Ray Energy (keV)

Fig. 2. The PIXE spectrum from the suspended
particulates collected from the Tama River waterat location 4.
I

20 km I

Fig. 1. The sampling locations forthe particulate matters .

river are given in Fig. 3. The high contents of the elements at location 6 must be due to the local perturbation of the river stream. Except the values at location 6,
the particulate silicon content did not change significantly. On the other hand, the contents of particulate

served as the targets for the PIXE without any pre-treatment. A half of each sample was used for the induced* Tokyo University of Fisheries.
** The ICP and the AAS analyses were carried out by Dr.
Takllhashi at Inorganic Analysis Center.

pota~siumand titanium showed minimum values at

location 7. The distributions of the concentrations of
AI, Ca, and Fe were similar to those of K and Ti. Thesefeatures indicate that the components originated fromminerals were deposited at an early stage and thenthe pollution arising from human actions took place.
As can be seen from Fig . 3(b) and Fig. 3( c), the results

133

601-

o

(c ) Ti

Fe

10 5

•
40r •

Date NO.20236
With 60 ,um AI
X- ray absorber

Fe

-

10 4

o
-

o 0
o~==============~

1

250

@

@

~

~ 100
::t

~

1

~

(b ) K2cu 150

@

cu
...c
u
--.......

~ 10 1

@
@

::::J

o

U

O~==============~( a ) Si

2~ 2000

000

1

0

o

3 1000
c.n

o

o

01

o

o

-::::::

no~ 10 2c@50____ 6OOOf

10 3'--' 10 5
.;::-

'Vi

cQ)

Date NO.20238
Without
X- ray absorberFe:£; 10 4
>.

~

I

0..

cu
0:::

cu
Q)

X

10

234 5 6 7 8 9

Fe

Ca
i1

E
::::J

3

~

cu
Q)

0..

en

10 2

River mouth --- Stream
Sampling location

Fig. 3. Variations of the concentrationsof the particulate silicon (a), potassium(b) and titanium (c) along the TamaRiver.
• : by PIXE,

0: by Iep,

@ : by AAS.

of the ICP and the AAS are consistent with the PIXE
data.
(2) Volcanic rocks from the Kilauea. The volcanic
rocks extravasated from the Kilauea in 1969,1974, and1979 were analyzed with the PIXE and X-ray diffraction
technique. Figure 4 shows the PIXE spectra obtained
from one of the volcanic rocks excited by 5 MeV H+
ions. The X-ray diffraction patterns suggest that themain component of the rocks is feldspar.
(3) Volcanic ashes from Mt. Asama. The volcanic
ashes from Mt. Asama were collected at Shinagawa,Tokyo in April 1982. The PIXE spectrum obtained fromthe ashes excited by 5 MeV H+ ions resembles the

10 1

o

5

10

15

X- Ray Energy (keV)

Fig. 4. The PIXE spectra from one of the
volcanic locks extravasated from the Kilauea in1979.

spectra of the volcanic rocks from the Kilauea exceptthat the content of the volatile element, S, in the ashes
is much higher than that in the rocks.
Detailed analysis of the experimental results for the
volcanic rock s and the volcanic ashes is in progress.

References(1) K. Maeda and M. Uda: Reports I. P. C. R., (inJapanese), 58,96 (1982).
(2) K. Maeda , Y. Sasa, and M. Uda: p. 123 in thisreport.

134

III-6-2.

Application of PIXE to Medical Science(I )M. Uda, K. Maeda, Y. Yokode,* and Y. Sasa

The PlXE (Particle Induced X-ray Emission) method .

elements embeded in matrices which are mainly com-is one of the advanced techniques for elemental analysis

posed of light elements, especially in organic materials.

without destruction. This method is characterized as

Chemical compositions in biologic tissues might not(1) applicable to all the elements except

be the same as normal ones if the tissues are cut out

Z = 1 "-' 3, (2) simultaneous analysis of all the elementsfrom the affected part. The PIXE method is now ex-present, (3) high and relatively constant sensitivity to all

pected to be used for diagnosis. In this report we deal

the elements, and (4) high speed analysis. Thus, thewith a few applications of this method to medical

method has wide varieties of applications, especially inscience.

follows:

trace-elemental analyses of biological and environmental

Fresh tissue samples were freeze-dried and sectioned(pollution) materials. The most effective samples forwith a microtome at 10 J1m, and then deposited on

this are those containing small amounts of heavy

Mylar film of 4 J1m in thickness. Characteristic X-rays

A (b )A (a )~10 4c~ 10 4cc

C\J....c:

U'---(J)

C:::J 10 3

Fe

Normal Data No.20371

oU

With 60 j.1m AI
X- ray absorber..q 10 2
(J)

1

c

2

';:n 10 3

Data No.20372

oU

With 60!1m AI
X- ray absorber
I

C:::J

Z'10 2

. if>
c

Ql

.~

~ 10

Tumor

C\J

....c:

U

C

·~101

1

I

C\J

I

x

x

X - ray energy ( keV )X - ray energy ( keV )B (a )
Data No.20381

NormalWithout X-ray
absorber
2j.1C

Without X-ray
absorber
2/-LC

I
,--,

X-ray energy (keV )Fig. 1. PIXE

spectraX- ray energy (keV )obtainedfrom normal (a) and tumor (b) tissues

in a thyroid gland taken from a patient of colloid adenoma.
A : with

60 ).lm* School of Medicine, Nihon University.

Al

X-ray

absorber,

B: without X-ray absorber.

135.were emitted from these samples by irradiation of

detector. Energy calibration of X-rays was performed by

5 Me V

cyclotron, anduse of Ag Ka, Ag K~ and Ag L X-rays emitted fromdetected by a Si(U) detector. Signals from the detector

a silver foil of 1 mg/ cm2 . The bovine liver from NBS

were amplified by pre- and linear- amplifier, and finally

was used as a standard sample for most of the elements

analyzed by a multichannel analyzer and a mini-com-

analyzed here.

protons accerelated by the

PIXE spectra obtained in this experiment are shownputer. Here spot size and electric current of the proton2

and 2'" 20 nA,

in Fig. 1. Chemical compositions of the tissues used

respectively. To get better statistics for the data in a highwere estimated 1) from the individual peak intensities inenergy X-ray region an aluminum foil with 60 f.lm

these figures, and are summarized in Table 1. No traces

thickness was inserted between the sample and theof iodine were present, but zinc was much enriched inbeam were regulated to be 2 X 2 mmTable 1.

PIXE Ka peak intensities and elemental concentrations in human tissues.

Ka peak intensity (counts/f.lC)
Disease

Organ
Fe

Zn

Br

{ Thyroid glandnormal tissue

19

11

3

Thyroid glandtumor tissue

18

37

Chronic
thyroidites

Thyroid gland21

Habitual
anginaTonsilNasal
papilloma

Nasal cavity
tumor tissue

ColloidadenomaElemental concentrations (f.lg/cm 3 )
Fe

Zn

Br

7

95

32

15

3

<0.5

90

110

14

38

3

<0.5

105

38

16

17

17

4

<0.2

85

49

20

22

21

4

<0.2

110

61

18

the tumor (Colloid adenoma). Lack of iodine was also

Reference

observed from the tissue cut out from the thyroid

1)

gland with the chronic thyroiditis.

K. Maeda and M. Uda:
Japanese),~, 96 (1982).

Reports I.P.C.R., (in136

N. ACCELERATOR DEVELOPMENT
1.

Present Status of the RIKEN sse Project
H. Kamitsubo

The project for construction of a k = 540 Me V

resonator system using a moving box as a frequency

separated sector cyclotron (SSC) at RIKEN has pro-changing device. Although this system has merits thatgressed satisfactorily in 1983. The sector magnets withtotal height of the system and current density at thetwenty-nine pairs of trim coils fixed on pole faces were

contact fingers of the moving short (or box) are smaller

made one by one at Niihama Factory of Sumitomo

compared with a conventional 'A/s or half wave-length

Heavy Industries, Ltd. and the last one was completed in

type resonator, it has a demerit that shunt impedance is

October, 1983. Accuracy of machining and assembling

relatively low and it needs more electric power. To im-poles, yokes, main and trim coils and base of the magnet

prove this situation the frequency range may be reduced

was inspected for each magnet, installing it at theto that from 20 to 45 MHz. Then the problem will occur

factory. Performance of piping for cooling water and of

in matching of the SSC and the RILAC in the low

wiring for coils was also inspected. Excitation charac-frequency range since the frequency range of thelatter is 17 to 45 MHz. A possible way is to change ateristics and field distributions were measured for the
first magnet. Interference effect of fields produced byharmonic number of the SSC in the low frequency

the sector magnets at the SSC and the field distribution
in the valley region between two magnets werepreliminarily studied in 1982 by using the first andrange. At present , design work of the resonator which

secondcovers the frequency range from 20 to 45 MHz is inprogress.

magnets . The measurement was performed

Design studies of a high power amplifier for the RF

after carefully installing them in such a way that two
sectors were precisely concentric and their center radii
were perpendicular to each other. The median planes ofsystem have been pursued. The maximum output power
is 300 kW and stability of the RF voltage as well as its
frequency must be very high. A tetrode, RCA 4648, is

two magnets must coincide with each other , too. Resultsa candidate for the power tube at the final stage of theof the measurement were quite satisfactory. The beam
dynamical analysis has been pursued taking these results
into account. Distribution of the field produced by each

amplifier system. Grid tuning circuit for cathode-trim coil was also measured in 1982 along the center

the interelectrode capacitance.

grounded amplifier has been studied by taking into
account neutrization of RF voltage fed back throughradius of the sector, varying strength of the base field

Final design of the vacuum system and the vacuum

and excitation current of the trim coil. Optimizationchambers is almost finished. The vacuum system is com-method of the trim coil currents to realize theisochronous field distribution has been studied. The

posed of ten cryopumps, four turbo molecular ones andfinal data of the field distributions will be taken after

four rough vacuum systems. Total evacuation speed is
4
12 X 10 Q/sec and the final vacuum lower than 10- 7

four magnets are installed in the cyclotron vault of theTorr is expected inside the chamber. Pneumatic expan-

SSC building.
Power supplies for the main and trim coils are inresonator and the vacuum chamber. Mechanical andfabrication and will be delivered in the middle of 1984.

vacuum technological tests was continued in this period

Numbers of the power supplies for the main and trim

sion seals will be used as vacuum seals between the RF

coils are two and thirty-seven, respectively, and thosefor one-third scale models. Structure analysis using thefinite element method was also performed. Modelof parameters to be adjusted are five and fifty-six,

studies of the ECR (electron cyclotron resonance) dis-

respectively. We decided to use SCR (silicon controlled
rectifier) in the power supplies of the main coils to
reduce their costs. Protection method for SCR noise

charge cleaning of the magnet chambers were finished.

propagation is under investigation.

Electric Co. It consists of a network of three minicom-

Basic design of the computer control system wasfinished and the system was ordered to Mitsubishi

Design studies of the RF system have been carried

puters, MELCOM 350-60/500, connected with eachout in this period and we finally decided to adopt aother by double optical cable lines and CAMAC systems.

137

finished' in March, 1984. The sector magnets will be

One computer is used for control of the RILAC whereas
the other two are used for the SSC control. To savenumber of CAMAC crates and standard modules, andtransferred from the factory to RIKEN and installed byalso to realize efficient control of the accelerators, newthe control room, four experimental rooms and a

CAMAC modules named CIM (Communication Interface
Module) and DIM (Device Interface Module) are being

completed in 1985. The remaining part of the building

developed. Two prototype" models were made and arewill be constructed after the first beam is obtained.

the end of June. The second phase for construction ofcounting room will start in the middle of 1984 andbeing tested: one is for control of beam diagnostic

Design of the beam transport system to the ex-

devices and the other is for control of power suppliesof the sector magnets.

perimental areas was finished and final designlQf magnets
and beam diagnostic devices is in progress. The first

Final design of the SSC building as well as the investigation of radiation safety problems for that design

operation of the SSC in combination with the RILAC
is expected in 1986. Discussions on experiments using
the beams started this year by both inside and outside

was finished last year and construction of the building
started this year. It is devided into three phases. The firstphase is to build the cyclotron vault, which will beusers and workshops on the possible experimental
facilities to be built were organized.

138

N -2.

Control System of the RIKEN SSC

T. Wada, J. Fujita, K. Shimizu, 1. Yokoyama, and T. Kambara

RIKEN separated sector cyclotron (RIKEN SSC)
consists of two injectors (linac and AVF cyclotron) anda separated sector cyclotron. 1 ) A large number ofdevices are distributed around them. There arethousands of parameters. In order to obtain a desired
beam (particle and energy) and to transport it to aproper experimental area in a short time, complicatedand fast control sequences are necessary. Because ofthis, computers are introduced?)
The characteristics of the control system are as
follows:(1) A computer network consisting of distributed
mini-computers is adopted;

Table 1. Characteristics of MELCOM 350 - 60/500.
CPU
memory

ECL LSI
64 Kbit LSI with ECC

word length

32 bitmax . memory

16 MB

max. address

4GB

cycle time

250 ns/8 byte

cache memory

160 KBcache cycle timeregister

95 ns/8 byte
24 (32 bit)instruction

450

pipeline

5 steps

MIPS
computation time

3 .7
ADD

0.095 J1S

FADD

0.3 J1S(2) CAMAC crates are linked by a serial highwaywith optical fiber cables;(3) Micro processors are used for the interface
between CAMAC and devices;(4) A simple network is adopted for the local
control;(5) As many analog signals as possible are digitizedand sent to the control room;(6) Application programs are .written in FORTRAN
77 language .
Three mini-computers are linked using optical fiber
cables.

Each computer is of the same type, and is

MELCOM 350 - 60/500 (Mitsubishi Electric Corp.).
This is a new 32-bit industrial computer. The characteristics of the computer is listed in Table 1, where SHD
is a bit-serial highway driver. An intelligent system console includes two flexible disk drives. Many of thesystem subroutines required for real-time operation havebeen converted to firmware which allows faster execution of programs. The time critical part of operation

FMULT 0.5 J1S
SIN (x) 5 J1Sinterrupt

8 levels

network

15 .36 Mbps

CAMACSHD
GP - IB

5 Mbps
250 kBps

Table 2. Configuration of each computer.
Computer 1 (SSC)
memory3 MB

fixed disk

70MB

CAMACSHD
GP - IB
Compu ter 2 (data base)memory3MB

fixed disk

70 MB x 2

magnetic tape

2 (1600/800 bpi)

line printer

1 (670lpm)

ISS terminal

4

system can be made resident on the cache memory .

plotter

1 (7 pens)

Table 2 lists the configuration of each computer. The

communication port

11graphic display

1 (7 colors)

hard copy

1

network is that of duplex system. Even in the failure of
one line or failure/power-off of anyone computer, thecomputer link can be retained . The computer 1 and 2
are installed in the control room of SSC and the computer 3 is in the control room of RILAC.
The computer 1 controlles the SSC through the
CAMAC serial loop. The console devices such as touch
panels, color displays and shaft encoders are installedin the control desk. These devices are linked to the computer 1 without a CAMAC system. The control desk
consists of three parts (center, left and right parts). The

CAMACSHD
Computer 3 (linac)
memory2 MB

fixed diskmagnetic tape

70MB

line printer

1 (670lpm)

plottergraphic display

1 (7 pens)
1 (7 colors)

1 (1600/800 bpi)

hard copy

1character display

1 (7 colors)

GP - IB2

139left and right parts are equivalent. The devices which arelinked to the computer 1 are installed in these areas. The
minimum time of data refresh on a CRT is 280 msec.
This time interval is determined by that of the digital
displays in automobiles. The center part is prepared forthe devices such as lTV's and scopes which are notlinked to the computer.
The computer 2 is used to store the data-base of thecontrol system in large disk files. Most of the data are

DATA ~--'..,.......,

initial values, logging data and device name/link tables.
The current values are stored mainly in the memoriesof the micro processors mentioned later. The source
programs are also stored in the disk file. The machinecodes of the control programs are stored in the disk
files of control computers. The control computers pickup the necessary data or ask for remote batch jobs tothis computer. This computer is also equipped with a
CAMAC SHD and can be used as a back-up computer
for the control computers. This computer is linked tothe central computer of our institute .
The computer 3 controlles the RILAC through the
GP - IB.3)
The first computer and a CAMAC system arescheduled to be delivered in summer, 1984 and used forthe field measurement of the four sector magnets. 4 )Because a GP - IB interface is not ready by this time ,we will use a personal computer as a makeshift. The
other two computers, GP - IB interfaces and an
operator console will be installed in October, 1985.
Figure 1 shows the CAMAC system. Seven CAMAC
crates are distributed in four power supply rooms. Because the distance between these rooms and the control
computer is very long (90 m max.) , these CAMAC crates
are connected by a serial CAMAC loop using opticalfiber cables.
Two types of modules which include micro processors and memory are developed for the interface beS
tween controlled devices and the CAMAC system. )One is a CAMAC module which has 16 pairs of serial
I/O ports. The other is an interface module to eachcontrolled device and is installed at a place close to
the device. The information are transferred seriallybetween these two modules.
The advantage of using these modules is in that it
is possible to decrease the number of crates and electronic components in comparison with a system using
conventional CAMAC modules. Consequently the reliability can be enhanced and the mobility of the control computer can be improved.
These modules are named as a communication interface module (CIM) and a device interface module (DIM),

Fig. 1. Configuration of CAMAC system.

respectively. The CIM resembles the ER16VM module 6 )or LOCT module. 7 ) This includes a micro processor andis linked to each DIM by a pair of plastic optical fiber
cables. The information is transmitted with the rate ofabout 170 kbps and the maximum distance is 30 m.
Figure 2 shows the schematic diagram of a CIM, where
ROM and RAM are read only memory and random
access memory, respectively. Each DIM is addressedby a subaddress (A) of CAMAC instruction. The instruction/data between CIM and DIM are defined bya 24-bit CAMAC word. The DIM consists of a microprocessors, memories, parallel and serial I/O ports. It
can include ADC , DAC and another micro processor
depending on the controlled devices. A small console
can be connected temporarily to the DIM for standalone operation. The DIM can control several devices. It
performs necessary control sequences such as start up,
monitoring and stop. For example , the sequences ofdriving pulse motors for slits and detectors, scanninganalog data from multi-wares and storing the digital data
in memory are performed for a emittance measuring
device independently on a control computer. The
monitoring is performed at predetermined time intervals
and the results are stored onto memory. In case of the
failure of devices, the control computer reads out thecontents of memory for trouble shooting. The numbersof CIM's and DIM's are about 50 and 150, respectively.

140

#0

Comm unication
Interface adapter- l

To Each device
Interface module

Communi cation
Interface adapter - 16

CAMAC Data way# 15Internal Bus lines

Fig. 2. Schematic diagram of communication interface module (elM).

The CIM and DIM are made using multilayer boards.
The construction of the prototypes of CIM and DIM

ceiving parameter values.

(CPU 8031) will be completed this November and77 language which includes real-time functions .

Afunctional tests will be done by linking to an emittance

FORTRANthemeasuring device of linac.

interactive debugging of the programs . Many software

For the local diagnosis, it is conveninet to use
8

movable consoles. ) However , we made another decision in order to lower the cost and to have more

The application programs are written in FORTRAN
77

debugger is incorporated for

packages for graphic display, network and data-base areprepared. The source program are updated by a screen
editor.

flexibility. A simple network is adopted and only theports for CRT display are prepared at necessary places.
In making diagnosis, a CRT display is carried andplugged into the nearest port. These ports are also used

References
1) H. Kamitsubo : Proc. 9th Int. Conf. on Cyclotrons

for the display of machine operations at operator rooms
or counting rooms by selecting desired part of theand their Applications, p.13 (1981).
2)

machine from a keyboard.
As many analog signals as possible are digitized andT. Wada, J. Fujita, K. Shimizu , I. Yokoyama, and
T. Kambara: Proc. Japan - China Joint Symp. on
Accel. for Nuc!. Sci. and their Applications, (to besent to the control room through the CAMAC loop . It is
often necessary to observe wave forms of the signals

3)

published) (1983) .
T. Kambara , M. Kase , and T. Kubo:

from some beam detectors such as coaxial Faraday cups
and phase probes. For these signals a sampling method isadopted and the band width is reduced . The results are

4)

Progr. Rep., 16 , 176 (1982).
H. Takebe, I. Takeshita, J. Fujita, I. Yokoyama, T .

sent by coaxial cables (100 MHz) and displayed on the5)

Wada, S. Motonaga, and T . Sato: ibid., p. 188.
K. Shimizu , I. Yokoyama, T. Wada, J . Fujita, and Y.

RIKEN Accel.

scopes on the control desk. The contents of the display

Yano: 6th Symp. on Future Project of RCNP,

memory are read into the control computer through a
GP - IB.

6)

Osaka, Jan. (1983).
R. Baumgarten : Int. Report , GANIL 81R/062/CC/

7)
8)

09 (1981).
P. Lienard: Int. Report, CERN/PS/LI/82-15 (1982).
M. Prome: IEEE Trans. Nuc!. Sci., NS - 28, No.3 ,The operating system (OS60) is a real time and multitask system. It is also possible to transfer meassages andthe contents of disk files to other computers via a computer network. Another important function is thestarting of tasks in other computers by sending or re-(1981).

141

N -3.

On the Fundamental Constitutionof the SSC Control System

K. Shimizu, J . Fujita, T . Wada, and 1. Yokoyama

Many apparatus are used in each section of the
RIKEN sse. In order to control such a large number
of apparatus quickly and precisely, it is essential to use
a computer as a control element because the hardwareof the control system can be standardized partially andthe operation flexibility can be increased. When a more
effective control system for the sse is desired, thecomputer system should satisfy the following conditions.
(1) Several computers are employed to obtain ashort turn-around time through their concurrent operation.
(2) All the computers are compatible with eachothers to allow easy back-up of the remaining ones when
one computer fails.
(3) Each computer has high performance and a large
directly addressable memory area to process rapidly the
information such as beam adjustment and graphicaldisplay.
(4) Time delay arising from the transmission of information between computers is as short as possible.
(5) With regard to software supports, the overhead in
operating system is as short as possible. Standard language such as FORTRAN and computation libraries accepted widely are utilized to promote programmer's
productivity. An interpreter , which makes the programr

COMPUTER for RI LAC

I
1

1

J

development , testing and debugging fast and easy , isincluded .
Next we turn to interfacing systems which link thecomputers and many apparatus. The systems should
satisfy the following requirements.
(6) Since the distance from the computer to thecontrolled apparatus of the sse is very long , it is desirable to decrease the number of wires between them asmuch as possible and to enhance the noise immunity ofsignal wires. It is preferable to standardize the hardwareof the interfacing system in view of expandability andpreventive maintenance . In order to realize the above
requirements , it is necessary to divide one interfacing
system into several stories and to facilitate communication between the stories. Additionally, one should consider how to reduce the load of the control computer
due to the interfacing systems. Therefore, each story
should have the following functions: communication,
data format conversion , data storage and monitoring ofapparatus status information. Here , an interlock for protection of the controlled apparatus from stress andshock is provided.
Figure 1 shows the fundamental constitution of thesse control system, where all the above mentioned
items , system reliability and trade-offs in performanceand cost are taken into consideration.

I COMPUTER tor DATA- FILE t:-)COMPUTER for SSC

L

COMPUTER LOOP

1CAMACLoo2-- -- --- -- - --CRATE STATlON # 1

II

CRATE STATION # 7

C. - --- - ---- -- C U SIM- - - - - - - - - - -

I PC
MAC

C --- ---- --- - C U S
I PCIM-- - -------- MAC------"l~-------JI-------J~---- --~ ~--- ---~ ~ --- -- -~ ~--- - -~1I
- - - --- -- - I
MAGNET
APPARATUS

1-

RADIO
FREQUENCYAPPARATUS

BEAM
TRANSPORTAPPARATU SVACUUM
APPARATUS

Fig. 1. Fundamental constitution of the sse control system.

142

The computer system is a poly-processor system of

CAMAC's standard specification and constructed with achannel-to-channel coupled type using three computers,
each one for the LINAC, the SSC and the data-file. The

serial highway driver and a U-port adapter (UPA)
mounted in the SSC computer, seven crate stations in-computer system has a duplex optical loop connecting

cluding another UPA and a serial crate controller (SSC),

three computers. All the computers are MELCOM-350500/60 (32 bits machine) with performance capabilityof 3.7 MIPS, the maximum memory capacity of 16 M
bytes as a physical space and 4 G bytes as a logical space,and a serial loop linking the first UP A and all the cratestations.
The CIM and the DIM were devised by one of theauthors (K.S.)1) to satisfy the. requirements mentioned

and transmission rate through the loop is 15 M bps. The
computer software includes the supervisory program fora poly-processor system, user's programming language
FORTRAN77, computation libraries and a real time
debugger like interpreter written by the language.
The RILAC computer is mainly used for the control

in item 6. They consist mainly of a micro-processor andof the heavy-ion linear accelerator with a magnetic tapehandler, a magnetic disk unit and display terminals. The
computer can be operated independently of other computers by its console.

a memory. A CIM of this type is mounted on each cratestation, while a DIM of this type is connected with thecontrolled apparatus. Two plastic optical cables are used
for the connection between CIM and DIMs. The CIM
can link sixteen DIMs. The DIM has sixteen input ports
and sixteen output ports, each port having parallel eightbits.
It will be understood from the above explanationthat the designed SSC control system is a distributed

The SSC computer is used for the control of all thecontrolled apparatus of the SSC. It is connected with theinterfacing systems mentioned below as well as various

computer control system with three mini-computers
and many micro-processors, which has powerful control

peripherals.

ability.

The data-file computer is used for the data base fileapplied to the sse beam adjustment and for the backup against the sse computer failure. In future when an

Details of the SSC operator console will be described
elsewhere.

capability, expandability, flexibility and maintenanc-

A VF cyclotron is built, the computer will be used forthe control of it.
The interfacing system consists of three stories:
CAMAC equipments, CIMs (Communication Interface
Module) and DIMs (Device Interface Module). The
CAMAC

equipments

are operated

mainly in the

Reference
1)

K. Shimizu, T. Wada, J. Fujita, and I. Yokoyama:
Tenth Int. Conf. on Cyclotrons and Their Applications (1984).

143

N -4.

Extraction of Off-Centered Beam in the RIKEN SSC
N. Nakanishi, A. Goto , and Y. Yano

Possibility of extraction of an off-centered beamin the RIKEN SSC has been examined by computer
simulation. It is well known that the off-centered beamshows the oscillatory pattern in the turn separation.
The oscillatory pattern is due to the rotation of theaveraged orbit center of the accelerated particles aroundthe machine center. Such an orbit of which radiusequals to zero is called a well-centered orbit. Thus thewell-centered orbit does not show the oscillation in theturn separation . Some examples of the pattern are
shown in Fig . 1 on an off-centered and a well-centeredorbits of the 9 MeV p beam. The properties of the re-

DR= O,OOOO DPR =O,OOOOOOO DA =235
' Hl+ 900 MeV, 8=90 D¢ = 0,000 BFT =0,99994287 CO=OOO

E~

A
8,0 ---- - - - ------ --- --------- -- ---------- ------- -------- --- ------ -- ,6,0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4,0 ------- - --- --- -------- --- - -- ----- ----- ---- - - - ------------ - - ---'-,~HI IHflfj»l~
j-J H- - t - - - t - - - f - - - I- 2,0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -, . - ' Hl+ 9,00 MeV, 8- 90 DR = O,OOOO DPR =0,0019730 DA =23,50
D¢ = -3 ,524 BFT=0,99994287 CO =O,OO
8,0 - - - - . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . - - - - - - - - - - - - - - - - - - - ? -. ----

E

6,0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -~ 4.0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ...
------

-

-

-

-

----

------------

-----

--

-

----

--

---

___

_

__

0

0_0 - -- r - - - t - - - r - - - t - - - t - - - t - - - t - - - t - - - t - - - t - - - t - - '\. f- - - - t - - - f- - - - t - - - I- 2,0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Fig. 1. Turn separation of an off-centered (a) and a well-centered (b)orbits on the 9 MeV p beam. The beams in case a and b are injected0
under the conditions that r ' = 0.0 mrad and "Po = 0.0 , and that0r' = 14.21 mrad and "Po = - 3.52 , respectively.

ference orbit of the off-centered beam can be describedin the phase space with respect to the reference orbit of
the well-centered beam with the central position phaseof zero.
The radial position Rn of the reference orbit of anaccelerated particle is given byfollows : (1) The beam clears obstacles like MICI and1
EIC in our case ); (2) Necessary beam separation is
obtained at the extraction point; (3) Quality of theextracted beam is not worse than that of the wellcentered beam.
The numerical calculation has been done for a 9 Me V

where Reo is the radial position at turn number n ofa well-centered orbit , and Ao and "Po are the radial amplitude of deviation and the initial angular phase inp beam in the RIKEN SSC. The radial focusing frequency vr at the injection energy is 1.07 . The azimuthal
angle at the closest point to an obstacle after injection is
315 0 , and the radial position at the point is taken to be
97.5 cm. An example of sets of parameters to satisfy
the above conditions is as follows; radial angle r' andphase space with respect to the reference orbit of thephase deviation "Po of the reference orbit at the injection

well-centered beam, respectively. The indispensableconditions required for the extraction method are as

point are 7.68 mrad and - 2.18 , respectively. The turnseparation and phase slip of the corresponding orbit are

Rn = Ren + A o • cos { QJo - 2 7! J 0 (1.1 r - 1) dn } ,

0

144

IH I+ 9,00

MeV, 8=90 DR=0,6861 DPR = 0,0010656 DA =23.50
Oct> = - 2.1 80 BFT = 0 99994392 CO = O, OO

8,0 - - - -------- - -- - -- - - - --- - - ------------ ---- - - -------- --- --- -- -- --.

E 6,0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - .
-S 4.0 - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - .. - - - -.

2, 0 - - ----- --- -- -(f)y-~VJ)YfJ('fjJrmrrJYj~TMrIm --t - - - t - - - t - - -f-I- 2,0 - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - -- - - - -- - - - - - - - -.

10 --- ---- - ---- ---- ---- ------- ---------- -- ------ ---------- - -- - ---- .
Qi)

~

5

J:::.:::::--::::--:::------::--:::-::::~~~::::::·:-:·---·-5-10r-1--+--r-1--+--r-~~~--+_~~--+__f__4~

80

120

160

200

240
R

280

320

360

400

(em)

Fig. 2. Turn separation and phase slip of the corresponding
off-centered beam. See text for injection parameters.

330

RO= 324,00
ANG= O,OOOI
V = 80,00

§ 325
if)

0
(.)

X

a:::

216 324,7
320

I

-20

I

-10

shown in, Fig. 2.

I

I

I

0
8 (deg)10

20

Fig. 3. A last few orbits in the extraction region. Two solidlines means the EDC which is the first device for extraction. 2 )A 9 MeV p beam is accelerated to the final energy of 184 Me V
under conditions of harmonic number of 5 and an accelerating
voltage of 250 kV. In this figure RO and V are the radial
position of the center of the EDC, and applied voltage,
respectively . Numerals attached to each orbit represent turnnumber and radial position at the valley center.

It has been comfirmed that thedegradation in energy resolution is negligibly small for

References1)

are shown in Fig. 3. Extensive analysis is now in progress.

A. Goto, Y . Yano, T. Wada, and N. Nakanishi:

Sci.

Papers I.P.C.R., 74 , 124 (1980).

this solution . A last few orbits in the extraction region
2)

N. Kishida, Y. Yano, and A. Goto:(1983).

ibid ., 77, 63

145

N -5.

sse

Model Study of RF Resonator for the RIKEN

K. Ogiwara, T. Fujisawa, and Y. Oikawa

2

The RF resonator for the RIKEN sse is required toresult of the 1/5 scale model test ) and the calculations

work in a frequency range of 17 to 45 MHz at the deeof transmission line approximation, the 1/4 scale model

voltage of 250 kV (Maximum). The movable box typeresonator was constructed to investigate the RF charac-lresonator ) has been investigated. On the basis of theteristics and the method of fabrication in detail. Figure 1

Fig. 1. A photograph of the 1/4 scale model
resonator.

shows a photograph of the 1/4 scale model resonator.
Resonant frequency is changed coarsely by a pair of
movable boxes and finely by a trimmer capacitor which
is opposite to the dee. The RF power is fed througha coaxial feeder of 50 ohm characteristic impedance.
The impedance of the resonator is matched with thatof the feeder by a movable capacitive coupler which is
attached to the top of the feeder and opposite to thedee. The movable boxes, the feeder with the coupler,

Q)

10000

2
(1J
>

Q)

0.4 :5I

and the trimmer capacitor are driven by each driving
mechanism.

a0

50 0 /
o

0

c

o

o

The resonant frequencies, Q-values, shunt impedances
and the radial distributions of RF electric field along the'''::;

o
o

iii

o

o
o 0

0,2 0...
odee gap were measured and the impedance matchingconditions between the resonator and the feeder line
were studied. Q-values of the actual resonator are
estimated by multiplying the measured Q-values by thescale factor ofJ4 and resonant frequencies by 1/4.

In Fig. 2, Q-values and positions of the movable box
deduced from the experimental results are shown
against the resonant frequency together with the values
calculated by the transmission line approximation.

0 15 • 20

25

30

35

40

45

Frequency (MHz)Fig. 2. Q-values and positions of the movableboxes for the actual resonator estimated by theexperimental results. Solid lines show the calculated values by transmission line approximation.

146
50 ohms. It is realized by adjusting Cf and tuning the

The resonant frequencies measured are fairly well reproduced by the calculation. However, the measured

resonator. We applied this procedure to the model res ..

Q-values are about 1/3 of the calculated one. One reason

onator and made sure that it is feasible.

of poor agreement is attributed to poor contact between

The shunt impedance is given by

the movable box and the outer wall in the model.
Another reason considered is that the resonator is too

2

R s = V dee /(2* P) ,(2)complex to be calculated in terms of one-dimensionaltransmission line.

w here Vdee is the dee voltage (peak) and P is the power
loss of the resonator . We measured the dee voltage byRelative distributions of RF electric field along thedee gap were measured by perturbation method ~ 3) Thea calibrated voltage pick-up which gave little effect on
the resonator characteristics. RF power fed into theresonator was obtained by measurement of forward
and backward power on the feeder.

results are shown in Fig. 3, where the dee voltages arenormalized at beam injection radius.

Power feeder

Resonator

50Q
fo, Q, Rs,--------------,1 'I- -- - - - - - - -------,
Cf

Rs

fJ~

~.

r

~ 10·...........::

I

0:::

. -

t:. . . . . . .=.~,

14~

Cf: Coupler

Fig. 4. Equivalent circuit for the capacitive coupler.

,

36 7 MHz ~./

12

10.

•
The shunt impedance of the model resonator is calculated from these results and that of the actual
resonator is estimated by multiplying the model'svalue by the scale factor of 14. The capacitance Cf

.,-/e

I --·
I --·
I
1.............·

IJ

27.8 ___MH z e __ e_eO
1 ~i---==~~~==.==-----~--------12 r

satisfying impedance matching is deduced by substitut-

17.8 MHz •______ a12[
1 0 -~=-----=-=---~.

ing the shunt impedance to Eqn . (1). Figure 5 shows"I " "

08 i

t

:3

Injection

5 7 9

Radia l position

l' l 12t

Extraction

Fig. 3. Relative distributions of RF
electric field along the dee gap. The
frequency shown is 1/4 times of themeasured one.

15

150

10

100~

t:::'
Cl
'-.,

0

'Jl

OJ

~

U

c

2

Impedance matching by capacitive coupler is under .
stood according to an equivalent circuit shown in Fig. 4.
The resonator is characterized by three parameters:

(IJ

Cl
(IJ

u

DD
~

5

take a real value and its magnitude is given by

u
c

\

cu

--0

OJ
Cl

50 .S;

.~.

Ci.

C

---.---.-.

::J0

Q . value, shunt impedance Rs and F o · F 0 is the resonance frequency of the resonator including the capac ..
itance Cf . At a resonance point, impedance Zl in Fig. 4

OJ

. Cf

U

U

::J
L
U)

--e-"._e_e.

0
15

35

40

45 0

Frequency (MHz)(1)

The impedance matching means that Zl is equal to realFig. 5. Shunt impedance and capacitance Cfof the actual resonator estimated by the experimental results.

147

the results. Figure 6 gives the dee voltages of the actual

300
Input power: 300kW:;- 200
6o>resonator estimated from this shunt impedance for input
powers of 100, 200, and 300 kW.
Electrical contact involved in the structure ofresonator, especially that of sliding contact, is expected
to be improved in the actual resonator than in themodel; the maximum dee voltage higher than those in
Fig. 6 will be obtained in that case.

Q)

C!S

100

References
1) T. Fujisawa: RIKEN Accel. Progr. Rep. , 12, 196
15

35
40
Frequency (MH z)

45

Fig. 6. Estimated dee voltages vs resonant frequency. The parameter is the input power.

2)
3)(1981) .
K. Ogiwara , T. Fujisawa, and Y. Oikawa: ibid., 16,
217(1982).
L. C. Maier, Jr. and J. C. Slater: J. Appl. Phys., 23,
68 (1952).

148

N -6.

Grid Tuning Circuit of RF Power Amplifilerof the RIKEN SSC

T. Fujisawa , S. Kohara , K. Ogiwara, Y. Oikawa, and Y. Kumata *A basic design of full wave length (A) type grid tuning

characteristic and input impedance of the grid circuit

circuit for the power amplifier of the RIKEN SSC has
previously been reported. l ) Subsequently it was noticed
by experience on the amplifier of RI LAC 2 ) that theobtained in a frequency

against the frequency . The intended performance isplate-grid capacitive coupling inside the tube RCA 4648

measuring the voltage transmission ratios from the plateat the final stage would cause instability of the amplifier.

to points A and B in Figs. 1 and 2 in Ref. 3. The result

range of 17 to 45 MHz. The

effect of the neutralization was studied at 40 MHz by

The grid RF voltage induced by this coupling is propor-

is shown in Fig. 2. The voltage induced at point B istional to the frequency and the equivalent shunt im-very well cancelled by the neutrarization and that at

pedance at the grid. The shunt impedance was set at 50

point A is reduced to one fifth of the voltage withoutohm

the capacitor. Study for the grid tuning circuit is now inin the original design. In this case , the induced

voltage is estimated to reach a magnitude comparable

progress.

to the normal grid driving voltage at 45 MHz.2) Therefore , in order to improve the stability of the amplifier ,we took following two measures:(1) The shunt impedance at the grid is reduced to
12 .5 ohm while the input impedance is kept at 50 ohm;

E
10- 2
co

(2) A small variable capacitor between the plate andcthe tuning capacitor is added for neutrarization.

Q

The performance of the improved circuit was studied

E

(/)

c

on a full sized model equipped with a real tube in cold~state. The model of the final stage amplifier and its

Q)

0.0

~
o

schematic diagram are shown in Figs. 1 and 2 in Ref. 3.

>

Figure 1 shows the results of measurement for tuning

10- 3

40

50

/ c apacitance

Distance between the tuning capacitor
and neutra lization electrodeLt. 1 000
.~u

.~

u

0.0

0.0

·c
-2

u

c

c

c

-2
Q)

Fig. 2. Voltage transmission ratios fromthe plate to the grid circuit at 40 MHz. The
induced voltages were measured at points A
and B in Fig. 2. in Ref. 3.

-+-'

·5

co
Cl.
co

:S

80

60
x ( mm )

'0
50 u

500

Q)

c
co

'0

-0

Q)

Q)

c

.~

u

Cl.

-~
u

co
Cl.
co
U

Refe rences
1) S . Kohara and T. Fujisawa : RIKEN Acce1. Progr.
Rep. , lQ, 173 (1982).

20

30

40

50

2)

S. Kohara ,Freq uency (M Hz)

Fig. 1. Capacitance of the tuning capacitor andinput impedance of the grid tuning circuit against
the resonant frequency.

* Sumitomo Heavy Industries, Ltd .

T. Fujisawa and Y. Chiba: ibid. , p.169 (1982);
T. Fujisawa,

andY. Chiba: ibid.

p. 171.

3)

T . Fujisawa , S. Kohara , K. Ogiwara , Y. Oikawa , Y.
Kumata, and Y. Chiba : p. 149 in this report.

149

N -7.

Study of the RF Power Amplifier for the RIKEN

sse

Design of Plate Circuit

T. Fujisawa , S. Kohara, K. Ogiwara, Y. Oikawa, and Y. Kumata *Each of two resonators of the RIKEN SSC is to beresonator through a 50 n coaxial feeder line ('" 1 .5 m

powered by a separate RF amplifier capable of delivering
300 kW in a frequency range of 17 to 45 MHz. A
schematic diagram of the final stage of the amplifier isshown in Fig. 1 .1) An RCA 4648 tetrode is used inlength) which is coupled with the resonator in good impedance matching by a variable capacitive coupler. Loadresistance matching for the tube is made by a variablegrounded cathode connection. RF power is fed into theport of the amplifier.

Neutrari zation
ca pacitor

capacitor (20 '" 200 pF) inserted in series at the output

Pl ate stub 81Q

Impedance matchingcapacitor (Cs)

Movable short

Feeder line 50Q_I

f--Itt---- To cavity

20Q, O.3 m\
Plate DC blocking
ca pacitor

74Q , O.9m

Point B

\

\

I

I

RCA 4648

Input

T 1 200 pF
I: Point C

50Q

1~reenby pass
capacitor

11 200PF

Fig. 1. Schematic drawing of the final stage amplifier of the RIKEN SSe.

74Q, O.9m
Plate stub 81Q

I

o
o

ill

Grid tuning
capacitor/=
Gride tuning

Plate DC blocking capacitor

coaxial line
Cathode bypass capacitor

74Q , O.9m----Fig. 2. Full size model of the final stage amplifier.

* Sumitomo Heavy Industries, Ltd.

150

Structure of the plate circuit and its tuning charac-( • ) (-

teristics were investigated on a full sized model. Figure50b\

2 shows a cross sectional view of the model of the final
stage amplifier. The plate circuit is tuned by a quarterwave length coaxial stub having a movable short. The( 0 ) (- - - ) :

T\\

\\q.

~ 40

\

aluminum boxes. Cooling water pipes and DC powerline for the tube anode are to pass through the inside of
the center conductor of the stub. The internal box isconvenient to accomodate joints of cooling water pipes
and other equipments. This box is also useful to shorten
the length of the stub at the lowest frequency of
17 MHz. Equivalent circuit for this structure is given in
Fig. 3(a). The load circuit is replaced by the equivalentWith Ct.

.

\\

center conductor of the plate stub is a 18 ern diam.
copper pipe and the outer conductor and the internal
box above the plate DC blocking capacitor are square) : Without CL and R ,.

~

0\

~

"' "'

cm 20 c

o

(j)
Q)

0:::

10 -

Stroke of the movable short

o

0.5
15
2.0
2.5
1.0
Length of stub and box 1. (m)Fig. 4. Measured and calculated resonant frequenciesof the plate circuit. See the text.

resistance RL and capacitance C L as shown in Fig. 3(b).
measurement is limited to about 30 MHz because ofiiilEquivalent circuitof a plate of

RCA 46( a)

I

Blocking capacitor 1600pF

Box

Stub

~--------~

the saving in length of the model stub. The length of
the stub is estimated to be about 1.7 m to cover thelowest frequency without C L and enough margin is kept
for tuning at the highest frequency even if CL is as large
as 60 pF. The dimensions of the plate circuit
determined from the present study are listed in Table 1.

0.18m

Zw=81Q~.

Zw=27Q

10
1--"-'.2-'-=- m+-'-'- I _ _ _ _ _- iZ w=27Q
Zw=8 1Q
L

The impedance matching condition between the tube
and feeder line was also investigated on the model whose
output port was terminated by an equivalent dumy loadof 50 n. In Fig. 5, the matching characteristics obtained
are shown together with calculated values based on theequivalent circuit in Fig. 3(a). The load impedance canbe varied in an sufficiently wide range by adjusting Cs '-1.5m

Zo=50Q

Fig. 3. (a) Equivalent plate circuit, (b) Load andits equivalent circuits.

The capacitance C L varies from 70 pF at 17 MHz to
26 pF at 45 MHz, if RL is matched with the optimum
load of 300 n for the tube by adjusting the capacitanceCSi 'Dependence of the resonant frequency of the platecircuit on the length of the stub was measured in orderto estimate the stroke of the movable short. In Fig. 4 the

Q)

u

c

.~
u

m

0..

m

U

results of the measurement are plotted together with calculated curves based on the equivalent circuit in Fig.
3(a). The closed and open circles show the results ofmeasurement without C L and R L , and with CL of 60
pF, respectively. The solid and dotted lines show theresults of the calculation. The lowest frequency in the0~2~0~--~3~0~--~4~0----~50

Frequency ( MH z)

Fig. 5. Measured and calculated impedance
matching conditions against the frequency. The
parameter is the load impedance.

151

Table 1. Geometrical parameters of the plate stub designed.
Outer wall of the stub
Diameter of the stem
Internal box
Stroke of the movable short

Reference

1)

S. Kohara,

T. Fujisawa,

andY. Chiba: RIKEN

630 mm(D) x 630 mm(W) x 2400 mm(H)1>180 mm
400 mm(D) x 400 mm(W) x 400 mm(H)1800 mmAccel. Progr. Rep., !.Q., 171 (1982); S. Kohara andT. Fujisawa: ibid., p. 175.

152

N -8.

Study of the RF Power Amplifier for the RIKEN sse
DC Blocking Capacitor for Plate Tuning Circuit
S. Kohara, T. Fujisawa, and Y. Chiba

The reactive power rating of the blocking capacitor

The DC blocking capacitor of plate tuning circuit ofipower amplifier ) for the RIKEN SSC must sustain DC

is required to be more than 120 KV A at 45 MHz. That

voltage of 18 kV and high RF current of 220 A(rms) atof RDF 11 OCS is specified to be 90 KV A at 1 MHz and

45 MHz. Large capacitance is desirable to reduce the RF

50°C in the catalog but there is no description at

voltage across the capacitor. Coaxial structure of the

45 MHz. We are trying to get at least the power rating ofplate circuit suggests to use a ring array of capacitors

30 KVA at 45 MHz by cooling the improved terminal ofsurrounding the cooling pipe of the vacuum tube (Seethe capacitor by water. We are further making an in-

Fig. 2 in Ref. 2). Such an array is expected to have self

vestigation to improve the blocking capacitor array toresonances which disturb normal circuit operation. We
made an array composed of four commercially available

get higher resonant frequencies and power ratings.

400 PF ceramic capacitors (Toshiba RDFII0CS) as
shown in Fig. 1. and searched for the self resonances.
The resonances were found at around 36 and 45 MHz.
Cooling pipe of the vacuum tube
Inner conducter of plate / \coaXial resonator

~

( ~)

;-"11'1
I

I

I

I I
I I
I I

I
I
I

I

I

b:=;=:=;=====i==t==i=~"_

L s=='
C _ _,¢15 1 I~~~N

- ,- -- - N
,

::2

(b)

Before the improvement(36 MH z)
After the improvement(50 MHz)LD(45 MHz)(70 MH z)

Fig. 2. Resonance modes and frequencies in thecapacitor array. Broken lines show the voltagenode.

r=---=--------~T'~ Plate of the vacuum~ tube (RCA 4648)

Capacitor RDF 110CS(400 pF X 4)

IcmJ'l lRP
l 'm_ l ~,--- -,~--f~I,r--- "¢~LD

Capacitor RDF 110CS with mod ified
terminal block (400pF X 4)

(Unit: mm)

Fig. 1. Capacitor
RDFI10CS.

array

using four Toshiba(Unit : mm)

The modes of resonances are shown in Fig. 2. These
Fig. 3. Improved capacitor array.

resonances are in the operating frequency range of
17 to 45 MHz and are not desirable for the stable operation of the amplifier. Therefore each capacitor was improved in order to raise these resonant frequencies above

References

45 MHz. The terminal block of the capacitor was made1)

shorter and its diame ter larger in order to reduce theinductance as shown in Fig. 3. The resonant frequencies
became about 50 and 70 MHz.

S. Kohara, T. Fujisawa, and Y. Chiba: RIKEN
Accel. Progr. Rep., lQ, 171 (1982).

2)

T. Fujisawa, S. Kohara, K. Ogiwara, Y. Oikawa, andY. Kumata: p.149 in this report.

153

N --g.

Calculation of RF Electromagnetic Field
by Finite Element Method (III)F. Kikuchi, M. Hara, T. Wada, and K. Nakahara

Three-dimensional analysis of electro-magnetic fieldby the finite element method is now considered to bevery important in designing the accelerators. Efforts arecontinued to develop computer codes to calculate electromagnetic fields in cavities. We have alreadydeveloped two computer codes H2DB and HAX I ) which
are used for a resonator with constant cross section andfor an axisymmetric resonator. We have also given aformulation of three dimensional calculation, in which
the electric or magnetic field is chosen as the unknown
variables in the finite element formulation?) Then theboundary conditions imposed on the unknown functions
are fairly easy to deal with. The divergence free condition is treated by a penalty method. We have made acomputer code MAX3D according to this formulation.
But this program did not necessarily give exact resonant
frequencies. We made another code to investigate thevalidity of this method and to obtain basic data for
MAX3D.
(1) Program
New code has the following characteristics. (i) Either
E or H can be selected as the unknown variable.
(ii) Two-dimensional and axisymmetric problems canbe solved. (iii) Several types of mesh elements can beused.
(i) Basic equation
Basic equations are given in Ref. 2.
(a) correspondence of Cartesian and cylindrical coordinates.
(x, y, z) ~(r, z,O)(b) shape of function
Ex, Er: Ex (x, y) . (sin (pz) or cos (pz))
Ey, Ez: Ey (x, y) . (sin (pz) or cos (pz))
Fx, EO: Ez (x, y) . (cos (pz) or sin (pz))(c) rot E and div E
rot E:
x or r component
sgn·(~~z + p*E y ) {~f:~~y or z component
sgn. (- aE z _ Ez ± p*E )ax r*xz or 0 componentsgn.

(aE y _ aEx) {sin pz
ax
ay
coSpz

{c,?spz
sm pz

div E:+~ + aEy =+= p*E ) {sinpz
( aEx
ax r*
ay
z
coSpz
where sgn, p*, and l/r* are given in Table 1.

Table 1.

Parameters.

sgn

p*

l/r*

p

o

nlr

llr

(x,y,z)(r,z,O)-1

n=O,1,2, .....

(d) In the case of p* = 0
In the Cartesian coordinate, p* = 0 gives cut-off frequencies.
In the cylindrical cooridinate, n = 0
corresponds to the axisymmetric problem. In bothcases, following two modes are separable:
TE modeEx, Ey, Hz (Ez = Hx= Hy = 0) Ez, Hx, Hy (Ex = Ey = Hz = 0 ) - TM mode
Furthermore, in each case either = or _ is chosen as
unknowns.
(ii) Element and numerical integration
As is shown, a sinusoidal function is used in the z oro direction. In the (x, y) or (z, r) region, triangular or
quadrilateral isoparametric elements can be chosen.
Stiffness and mass matrices are ca1culated using
numerical integration technique. Boundary conditions
are Et = 0 and Hn = O. Symmetry or anti symmetry conditions are used. Oblique boundary is treated using coordinate rotation. In the finite element calculation,
matrix eigenvalue problems must be solved. In this casesubspace method is adopted.
(2) Numerical example
Some basic problems are treated.
(i) Unit square region
We solved an eigenvalue problem of Ex and Ey inunit square region . In this case, we can regard that Ex
and Ey correspond to Hy and Hx. So it can be seen thatthe problem is analyzed using Hx and Hy.
(a) Effect of s parameter
Divergence-free condition comes from a penalty term

154
S-Dependence

in the functional and s-parameter is a coefficient of that

70

(2)
I

term Dividing unit square region by 4 x 4 grid and using
4 nodes quadrangular element, s-parameter dependence
is investigated. The results are shown in Fig. 1. Twokinds of mode are seen. One has little s-dependence.

(2)60(2)(2)(1)
Q)

I

50

cu

~ 40

OD

1/

o

,.
/

,.

/

,.

,. /(1)

(1)

/

/

(2)

'"
1.0

2.0

S parameter

Fig. 1. S-parameter dependence of eigenvalue. The shape of the waveguide is asquare of unit side length and NP = 5 x 5.
Solid and broken lines show physical andunphysical solutions. Figures in thebrackets are the number of degeneracy.

Fig.2.
(ii) Rectangular region with a notch
Next, as a more practical application, we calculated
the field in an area with a "notch" shown in Fig. 3.

, ,
,, ,

,. ,. "
""
II"

I

,. ,.

I

,.
,. ,.

,.

same problem letting s be 1. The results are shown in

"

/

I

I

cm- in our calculations.
(b) Comparision of the elements
We compared the accuracy of five elements for the,. , , , , , , , ,, , , ,,, " ," ,, ", , , ", , ," "I

10 I I ",I' ;

2

1/ ,

I

I

20 ~ /
I

(2)

/
/
I

I"
U
I,

30

modes are mixed. But such modes are pushed away byletting s larger. Divergence check of the numerical solution is useful in judging the modes?) If the length isgiven in units of cm, the eigenvalue is given in units of

I

/11

W

I

I

I

I I ,
I I I
II
I"

~

The other has large s-dependence. The former is thephysically allowed solution. If s is small, many false

,, ,

I

""

,. "

,. "

,.

,. "

y

,. ,

,.
,. ,.

,

Number of nodes 6, 8, 9

Number of nodes 3, 4

ELEMENTS (number of nodes )
modes
1
2
3
....4...-

5
6
7
8
..Q.

lQ.

EXACT
3

4

4:10x106

8

9

10 . 382
10.38222 .806
22.80647 . 975
47 . 975
60.72660 . 726
73.22573.22510.38710.387
20 .773
20.77348.00048.00058.38758.38758 . 387
58 . 387

9.951
9.951
19 .90 3
19 .90340.79440.79450.74550.74550.74550.7459 . 936
9.936
20 . 528
20.52840.00040.00056.676
56 .676
59.63759.6379.944
9 . 94419.95719.95740.00040.00052 . 000
52.00057.94457.9449.944
9.944
19 .888
19.88840.00040.00049.94449 . 944
57.94457.944

Fig. 2. Comparison of the elements. Underlined modes are false.

Results using Ex and E y are shown in Fig. 4 varying thenotch depth. The same mode can be calculated with Hz·
The result with Ex and Ey gives an opposite tendency tothat with Hz except the case of small noth. The results
using Hz is right. This tendency is the same even if theregion is divided more finely. The reason for the occurrence of this phenomenon is not certain, but it
originates from the singularity in the corner. In this calculation, the boundary condition at the corner is imposed such that the average tangential component of E
is zero. In the case of a smooth notch as shown in Fig.

9 . 870
9.870
19 . 793
19.79339.47839.47849.34849 . 348
49 . 348
49 .348

Fig. 3.
Mesh ofwaveguidewithnotch. Only theupper half region isanalyzed imposing asymmetry boundary
condition.

5, both results agree well as shown in Table 2.
(iii) Cylindrical region
As an axisymmetric region, the cylinder of I in radiusand 2 in height is analyzed and the results are shown in
Table 3.
(3) Conclusion
Our approach works well in problems with sufficiently smooth solutions, but may fail in some problems with non-smooth solutions. From these results, it
is found that the penalty method is useful for the areawith a smooth boundary.

155

1.7
1.6
1.5

/

p
/

p

1.3
1.2

::l

m

/

/

1.4
Q)

1.0

jJ
/

/

/

/

/

~

>

.... "-

..-

.Jf

cQ)
tl.O

W

0.9
0.8
0.7
0.6

--Hz
---- Ex ,EyT0,"----L---'--~--' -

0,5

!

!

0.1

0.2

I

I

0.3 0.4
Notch depth a- - --

Axis of symmetryI

0,5

Fig. 5. Mesh of waveguide with smoothnotch. A three noded triangular element
is used (upper half portion) .

Fig. 4. Notch depth dependence of
eigenvalue for the waveguide shown in
Fig. 3. The eigenvalue should decrease
with the notch depth according to theperturbation theory. Calculation using Hz
gives good results. Panalty method using
Ex and Ey does not give good results forlarge notch depths.

Table 3. Eigenvalue A. for cylindrical cavity.

n=O
n=1

5 x 1010 x 20

Exact

5.80165.8841

5.78825.8641

5.78405.8567

Table 2. Lowest eigenvalue A. for waveguideshown in Fig. 5.
Mesh

Hz

Ex,Ey

n :;: 78

0.71150.70980 .70830.77940.75830.7368p

np = 119
np= 189

References
1) M. Hara, T. Wada, A. Toyama, and F. Kikuchi:
2)

Sci. Papers I.P.C.R., 75, 143 (I981).
M. Hara , T. Wada, T. Fukasawa, and F. Kikuchi:
RIKEN Accel. Progr. Rep. , lQ, 227 (1982) ;M. Hara , T. Wada, T. Fukasawa, and F. Kikuchi:
Proc. of COMPUMAG Genova (I983).

156

Vacuum System of the RIKEN

N-10.

sse

K. Ikegami, S. Nakajima, S. H. Be, I. Takeshita, Y. Oikawa, and S. Motonaga

The operating pressure of 3 ,..,., 4 x 10- 6 Pa is desiredin the acceleration chamber of the SSC. The chamberconsists of eight separate sections. The flanges between
sections are sealed with elastomer O-rings which will becompressed by a "pneumatic expansion seal". Total gas
load expected is about 5 x 10- 4 Pa.m 3 /sec. Therefore,
total necessary pumping speed amounts to 12 x 10 4
Q/sec. Cryogenic-pumps and cryogenic-panels are used
as a main pumping system.
(1) Operating pressure
The operating pressure should be 3 ,..,., 4 x 10- 6 Pa in
order to keep the beam loss less than 10 % for very
heavy ions. 1 ) For light ions an operating pressure of1 x 10- 4 Pa is adequate.
(2) Vacuum chamber
The vacuum chamber is divided into eight sections,that is, four magnet chambers, two RF resonator
chambers and two valley chambers. The sealing at theirinterfaces is made by using a pneumatic expansion
seal?) The pneumatic expansion seal is made of two
thin stainless-steel plates cut into a race track shape andwelded around the inside and outside edge. The seal isinflated and compresses O-rings by pressurized air. When
it is necessary to disassemble the vacuum chamber, theseal is made to shrink back by evacuation and becomesremovable from the gaps between the flanges. Figure 1

Vallay enclosure

Movable radial probe

/

#4

#2

!

#1

I

ob!uulnu!uuJ1000

Fig. 1. Plane view of the vacuum chamber of the sse.

shows the plane view of the vacuum chamber of the SSC.
The RF resonator and valley chambers can be pulled out
from the SSC for their overhaul and repair. The RF
resonator chamber has a partition wall to shield the
cryo-panels installed at the outer side of the chamberfrom the RF electric field and the thermal radiation of
the resonator. The RF resonator is evacuated throughmany small holes cut in the partition wall. The magnet
chamber is surrounded with additional chambers which
are evacuated to about 10 Pa to prevent the thin wallsof the magnet chamber from collapsing unde~ the at-mospheric pressure. Figure 2 shows cross section of themagnet chamber of the SSe. Geometric characteristicsof the chamber are as follows:
total diameterheights: the valley chamber
the RF resonator chamber

9m
60cm
270 cmthe magnet chamber

Scm

the additional chamber

38 cm

total volume

30 m3

total volume of the additional chambers

2.4 m 3

157

PNEUMATIC EXPANSION SEAL
+

I

rI

PNEUMATICEXPANSION

SEAL

9Rf RESONATOR
VALLEY VAC CHAMBERII VACWALL
DUMMY DEE

TRIM COIL~/
MEDIAN PLANE _ ._ _ ___!

._ _ _i_ff~+-+__ _____---'-------

1- ;/

c2t=

r-16==~~~~4 ~D

CHAMBER

~E=~

r

__

~Qu

Fig. 2. Cross section of the magnet chamber of the SSC "Surface areas exposed to high vacuum are as follows:
80 m 2magnet chambers
valley chambers
30 m 2
RF resonator chambers 240 m 2

roughing systems, four high vacuum systems and ultrahigh vacuum system. The roughing system is composedof a roots pump of 2600 m 3 /h and a rotary pump of
3000 Q/min. This system is installed at each valley
chamber. The pumping down time from atmospheric

total surface area
(3) Gas load
Many parts such as beam diagnostic probes, inflection

pressure to 10 Pa is about 20 minutes. High vacuum
system is composed of a turbomolecular pump of 5000

system, extraction system and other outgassing sources

Q/sec and a rotary pump of 2000 Q/min. This system isare inserted in the chamber. The main gas loads are thoseinstalled at each RF resonator and valley chamber. The
pumping down time from 10 Pa to 3 x 10 - 4 Pa isabout 20 hs. Ultra high vacuum system consist of ten

due to the gas given off from the metal surfaces and alsothat due to the gas given off from, and that permeatedthrough the seals used to connect each chamber. The
areas of inner material's surface of the chamber exposed

cryogenic pumps of 10 4 Q/sec and four cryogenic panelsof 5000 Q/sec. Two cryogenic pumps are installed at theto high vacuum are as follows :rear panel of the RF resonator chamber, and two

stainless-steel

167 m 2

cryogenic panels in the inside of the stems of dee. Three2

cryogenic pumps are installed at the valley chamber.
Ultra high vacuum system starts to operate at a pressureless than 3 x 10- 4 Pa. High vacuum system may becopperelastomer
3m
The total outgassing rate is estimated to be about

3.4 X 10- 3 Pa.m 3 /sec after 20 h pumping. After 100 hpumping it decreases to about 1.6 x 10- 3 Pa.m 3 /sec.
We can expect that, the total outgassing rate will bedecreased to about 5 x 10 - 4 Pa.m 3 /sec, by applying
the RF power to the resonator, by ECR (electron
cyclotron resonance) discharge c1eaning 3 ) supplyinghydrogen gas to the magnet chamber, and by baking
the valley chamber at mild temperature. The pumping
speed of 12 x 10 4 Q/sec is necessary to achieve theaimed pressure.
(4) Pumping system
The pumping system of the SSC consists of two

operated in parallel to ultra high vacuum systems . The
additional vacuum system consists of two rotary pumpsof 610 Q/min and evacuates the additional chambers toa pressure less than 10 Pa. Figure 3 shows the total
pumping system of the SSC.
The pumping system is automatically controlled bya sequence controller with a graphic panel installed at
a local control room , and also it is connected to thecentral control console via. an optical fiber. Informationof the pumping systems is sent to the central control
console and is displayed on the screen of the CRT set in
the control console.

158

CRPl

CRPl

CRP 2

Dry N2 gas

CRP 2

AMVC

RVC: RF resonator vacuum chamber.

MVC: magnet vacuum chamber.

VVC: valley vacuum chamber.

AMVC: additional magnet vacuum chamber.
RP: rotary pump, RP1: 3000 £/min, RP2 and RP5: 2000 £/min, RP3: 1000 £/min and RP4: 610 £/min.
ME: roots pump of 2600 m3 /h. TMP: turbomolecular pump of 5000 £/sec.
4
CRP1: cryogenic pump of 10 £/sec. CRP2: cryogenic panel of 5000 £/sec.
SV: safty valve (mechanical).

DV: differential valve (air operated).

No marked valve: air operated.

OME: oil mist eliminator.

LV: leak valve.

Fig. 3. Pumping system of the sse.

References
1) S. Nakajima and K.Ikegami: 9th Proc. Intern.
Conf. on Cyclotron and their Applications, Caen,p. 537 (1981).

2)

K.Ikegami, S. Nakajima, Y.Oikawa, M. Hara, S.

Motonaga, and H. Kamitsubo: Sci. Papers LP.C.R.,
3)77,87 (1982).
K.lkegami, S. Nakajima,

Y.Oikawa,

Y.Ishibe,

H. Oyama, Y. Sakamoto, S. Motonaga, and H.
Kamitsubo: ibid., p. 78.

159

N -11.

Structure Analysis of a Pneumatic Expansion Seal
M. Hara, K. Ikegami, and T. Ohkuma

culation using a structure analysis code, in order tounderstand the stress distribution and to optimize thewidth and size of the seal. We used the EPIC-IV code 2 )which has the following features.

strain curve shown in Fig. 2. In the numerical analysis,
size and shape of mesh give some effect on the results.
We investigated the mesh size effect on A type seal in
Ref. 1 (W = 100 mm, t = 1.0 mm). In Fig. 3, we show
the deformation versus pressure diagram for three kindsof mesh whose element shapes are similar. In Fig. 4, theresults for the case of longer element shape are shown.
The data with finer mesh give better results. For the case(1) Two dimensional elastic -plastic analysis can bedone.
(2) Triangular element with constant stress andstrain is used.

of number 3 in Fig. 3, deformation and yielded elements
at several pressures are shown in Fig. 5. In Fig. 6, weshow the expansion versus pressure curves for various
thickness of stainless steel plate. In these calculations,

In the plastic analysis, element is yielded one bystress is concentrated on the welded region in our expansion seal.
Next, the O-ring effect is investigated. When O-ring

A pneumatic expansion vacuum seal is to be used at
the interfaces between chambers of the SSC. We havealready constructed some scale models and tested theperformance. 1 ) In the present study, we made some cal-(3)

one (rmin method).
.
(4) Material constant is given by a x = c (a + €p)nx
Following eight kinds of input cards are needed:i) Title card, ii) Control card, iii) Node data cards,

100,00iv) Load boundary cards,v) Element data cards,vi) Material data cards, vii) Intermediate load value specification cards, viii) Output information cards.

---- 80.00"'EE

60 60.00

We calculated a case of free expansion with planestrain assumption. We took a quarter cross section of
the seal using the symmetry condition, in order to treat
this problem two-dimensionally. In Fig. 1, pneumatic
expansion seal and an example of the mesh are shown.
The expansion seal is made of thin stainless steel(SUS304). The input material data used give the stressy

/V"'-

C
~ 40.00
~

/'" V

-----

__ f--- ~

-

V

./

if)

20.00
0,00
0.00 0.04 0.08 0.120.16 0.20 0.24 0.28
StrainFig. 2. Stress and strain curve for SUS 304. Stress andstrain at yield point are 30.341 kg/mm 2 and 0.00154,
respectively.

1

10.00

Seal guide[2S8H=;'H:2l!~----::7""-==------+

O-ring

E:

0 1

LD I

]

FlangetFlange of
Welding the chamber

1(21

~ (JI

I

E;;.

~ t7

4.00

4.80

8.00 EI

6,00

I

~

1

c
0

.~ 4.00
m

;z

W

2,0.0

Fig. 1. Pneumatic expansion seal and an
example of mesh. A quarter cross section of the
expansion seal is analyzed. Arrows show theinternal pressure. Deformation at x = 0 ando ~ y ~ 1 is allowed only in y-direction (welded
region) and that at y = 50 only in x-direction.

160

240
320
Pressure (ATM)5.60

Fig. 3. Expansion vs internal pressure. Free expansion
length M/2 is calculated for three different meshes ofsimilar shape. The finer mesh gives larger expansion.
The number 4 line is the experimental data in Ref. 1.

160presses the seal near the top ( center) region, the yielded
region in the center shifts and expansion length becomes

1.60
Pressure (A TM)

small. Expansion length, deformation and stress areshown in Figs. 7 and 8.

2.40

Fig. 4. Expansion vs internal pressure. The ratio ofheight and base of triangular mesh is different from thatof Fig. 3. Mesh shape does not give large effect on the
result if the mesh is fine.

Fig. 5. Deformation and yielded elements. Deformed
shapes are shown at some pressure points. The deformation is exaggerated by a factor of 5. The elements whichyielded at that pressure are also shown.

6.00 ,---:----;-----:----.-----,-------,-----,
5.00 f----

+---

4.00

c

o

' ij'i~ 3.001----,--..f.+---h----.irl----!..-/--k- '----jf-----1
w
200f-----'H--+--t+-/---7---c~--_+-_l000

0.80 1.20 1.60
Pressure (ATM)

2.00 2.40

Fig. 6. Thickness dependence of expansion.
Thickness of the stainless steel plate is varied
from 0.5 mm to 1.0 mm. Non-labeled curveshows the experimental data for the plate with
1.0 mm thickness.

OX, DY plot, fact = 5.0

Fig. 7. Deformation and yielded elements when reactionof the O-ring is taken into account.

1O.O,------,----;----,-----,------~--,----,--

8.0 I---+---:--.L--t':---:--~___r__+-l___I

References
1) K. Ikegami, S. Nakajima, Y. Oikawa, M. Hara, S.
Motonaga, and H. Kamitsubo: Sci. Papers I.P.C.R.,E
5. 60 1---+--+-+--f--,-----'---;----'--t-----l,L__I

77,87 (1982).

N--.....

~c 40 I--T---:--+-I!----+---j.<~t---+---I

o
"ij'i
~

a.

W2.0 1-----l-------l-1-+-+-----;-:;>.L----:..----1-~:-----.:.-__I

2)

Y. Yamada and Y. Yokouchi: Elastic plastic analysis programing by finite element method - Instruction manual of EPIC-IV, (in Japanese), BAIFUU-

KAN (1981).
1.60
2.40
Pressure (ATM)

Fig. 8. Expansion vs pressure when reaction of the
O-ring is taken into account. (1) Calculation with O-ring
force. (2) Experimental data using O-ring. (3) Free
expansion calculation. (4) Free expansion experimental
data.

161

Numerical Orbit Calculation for a Linac and Improvementof the Transmission Efficiency of a BeamN -12.

A. Goto, M. Kase, Y. Yano, Y. Miyazawa, and M. Odera

The transmission effici~cy of the accelerated beamin the RILAC was not high compared with the design

effort was devoted in deducing the electric field dis-goal, especially at the low energy stage. In order tostudy the causes of this low transmission efficiency, we
have developed a computer program named LINOR with

As for the distribution of the axial component of
the electric field (E z ), we have the data that were
measured using a model cavity. We also made calcula-which beam trajectories 'are traced by numerically integrating the equation of particle motion in the realistic
electro-magnetic fields. LINOR is now used to improve
the transmission efficiency and beam quality in thetions for it by a finite element method (FEM).l ) It was
found that the calculated field distribution reproduced
well the measured one. Therefore, we decided to use
in LONOR the distribution approximated by such a

RILAC.

simple function as to fit the above distributions. An

Using the program LINOR the following calculations
were made for each of the six tanks constituting the
RILAC: 1) the rf phase excursion of an on-axis particle,

example of these distributions is shown in Fig. 1.
It is quite difficult to measure the radial component2) the acceptance of each tank and 3)a beam behavoir
when injected with a certain emittance. In 3) the transmission efficiency through a tank, the energy distribution and the beam profile at the exit of the tank wereobtained with the Monte Carlo simulations.
In order to get reliable results with this kind of cal-tribution which should be used in the calculation.

of the electric field (E).
As for Er , we assumed therdistribution which has a triangular shape with its top
located at the edge of the drift tube. The half-widthof the triangle was fixed to the value of 0.78 times theaperture of the drift tube, which was obtained with thecalculations by FEM. The height of the triangle E~ax
was given byculation, it is essential to use an electro-magnetic field
distribution as close to the real one as possible. We used
the measured magnetic field distribution for thequadrupole magnet. On the other hand, as for the rf(-.laE zr )

\2 az

(1)

'

where aE z jaz is the gradient of the linear p~rt of E Z relectric field, such a distribution is difficult to measure,especially for its radial component. Therefore, an

Gap = 40mm
Aperture = 25mm
Measured- - - FEM
- - Used in LlNOR

distribution, r the radial coordinate of the particle and aa constant. The value of a was taken to be 1.15 from theresult with FEM. An example of the distribution for Er .
is also shown in Fig. 1. In order to check the appropriateness of using the above Er -distribution in LINOR,
we made comparison between the calculation and themeasurement with respect to the dependence of thetransmission efficiency of the beam through the firsttank on the rf voltage. For this purpose, a double slit
system (the size of both slits is 1 mm x 1 mm) wasused. The reason why this narrow double slit system

LinearEr
r=10mmr

was used is that the uniformity of beam intensity in theemittance defined with it is very good. With this theambiguity of the calculation with respect to the initial
distribution of the emittance can be eliminated. Figure 2
shows the measurement together with the Monte Carlosimulations in two cases: in one case the quadrupole
magnets were excited and in the other they were notexcited. The simulation was performed for three different values of a. It is seen that the calculation re-Fig. 1. Example of the distributions of Ez and
Er used in LINOR.

produces well the measurement in the case of a = 1.15.
As for the distribution of the rf voltage in each ac-

162celerating tank, the data for the model cavity were used.
It is interesting to compare the results of LINOR andthose of the calculation using the matrix method. So we
calculated with LINOR the phase excursion of an
on-axis particle and the acceptance of a tank using theacceleration parameters obtained by the matrix method .

80 ~~~-----'-------'------~

70

60

a

1.00
1. 15
1.30

30
20

10

~ 50

~

0
-0
'-.-/ -10

c

o

"~ 40

"E

<JJ

c
~ 30

1.15
1.30

0... - 30

- 40

f--

- 50

20

10

(a)

0

o OM OFF/: , OM ON

0L-~~----9~0----~1~0~0 ----~1~1 0

RF Voltage (kV )Fig. 2. Transmission efficiencies of an on-axis
beam through the first tank in two cases: in one
case the quadrupole magnets are excited and in
the other they are not. It is noted that theoutput beam consists of all the particles having
different energies.

-60
( b)

Fig. 3. Phase excursions of an on-axis particle
calculated using LINOR: (a) for the first tankand (b) for the fifth tank. Acceleration parameters are those obtained by the matrix method.
A star indicates the phase at the center of eachacceleration gap for a particle with an injection
phase equal to - 25° (the synchronous phase).

measured at the entrance of the RILAC together with
The calculation was done for two tanks, the first (lowenergy stage) and fifth (high energy stage) ones. Resultsof the calculation are shown in Fig. 3. A star indicatesthe phase at the center of each acceleration gap for aparticle with an injection phase equal to -25° , whichis the designed synchronous phase of the RILAC. It isseen that the phase of -25° is indeed synchronous in
the fifth tank but there is no complete synchronous
phase in the first tank. The beam acceptances of thefirst and fifth tanks are presented in Fig . 4. As can beseen in the figure , the results of the two kinds of calculation agree quite well with each other for the fifthtank but disagree a little for the first tank . The implication of these results is that the calculation using thematrix method gives proper results in the high energy
region but becomes less reliable at the low energy stage.
Using LINOR, we studied the matching of beamemittance and acceptance for the first tank. For thisthe calculated acceptance for a beam with an injection
phase of -25°. The measured transmission efficiency
through the first tank was 20 % in this case. The Monte
Carlo simulation with LINOR , on the other hand, gave
a value of 18.7 %, which was very close to the measured
value . The injection emittance used in this Monte Carlosimulation was assumed to have a Gaussian distribution.
It is presented in Fig. 6 , together with the calculated
acceptances of the first tank for beams with several
initial phases with respect to the rf voltage. The distribution of the initial phase was taken to be uniform in thesimulation.
We have not yet obtained the completely optimal
operational parameters of the RILAC. LINOR, how-

purpose the transmission efficiency was measured when

ever, has led to an improvement in the transmission
efficiency of the beam . In order to achieve higher
transmission efficiency and get better beam quality, we
are now developing LINOR to have a function to
optimize the currents of quadrupole magnets and the RF
voltages.

injecting a beam with several shapes of emittances.
Figure 5 shows an example of the emittances thenA more detailed report on the results of the calculation obtained using LINOR is given elsewhere. 2 )

163

"

.......

RF # 120mm -20--+-+--

co1~....... :::' 20mm...........
•••••••••••.......

ut20mrad-20....... .......

.......

.......

.......

.......

.......

.......

.......

.......

0.......

.......

.......

.......

...-.= ~-..0=-../'....... .......

--+-..............

.......

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

.......

.......

t- 20
X-Acceptance

-20
-20

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

~

-20

t- 20

~rad

.......

"-....... ,

o

~
co

20mm

Ot---~~~

E

~~~

n...

t- 20

X-Acceptance.......

20~--------~---------.

RF #5- -+-20 . . .. .: .: .: .: .: .: .:.:.:... --+20mm............
.........
.. ...... .

.......

X (mm)

Y- Acceptance( a)t20mrad.......

.......

- 20~

Y- Acceptance

-20

( b)

Fig. 4. Comparison between the beam acceptances
calculated using LINOR (dots) and those calculated by
the matrix method (solid line): (a) for the first tankand (b) for the fifth tank. Injection phase is taken to be_ 25 0________~________~
020
Y (mm)

Fig. 5. Measured injection emittances in thecase that the transmission efficiency through thefirst tank was 20 %. The calculated acceptances
0
for a beam with an injection phase of - 25 arealso presented in this figure (dashed line).

XP (mrad)

YP (mrad )2020"'<~.~~""""'"
- 20

- 20

-20
-------- - 50°-30°---- -10°

Fig. 6. Injection emittances used in the Monte Carlo simulation and the calculated acceptances of the first tank with different initial phases.

References
1) M. Hara, T . Wada, A. Toyama, and F. Kikuchi:

LINAC and Improvement of Its Transmission
Efficiency of a Beam", Proc. of Computing in

Sci. Papers I.P.C.R., 75,143 (1981).
A. Goto, M. Kase, Y. Yano, Y. Miyazawa, andM. Odera: "Numerical Orbit Calculation for a

Accelerator Design and Operation, Europhysics
Conference , Berlin (to be published).

2)

164

N -13.

Energy Tuning and Energy Resolution of RILAC
M. Kase, T. Kambara, T. Tonuma, and M. Odera

At the final acceleration stage of RILAC, two
methods are available to change the beam energy con-to acceleration tanks are listed in Table 1, where thetinuously without varying the acceleration frequency.
One is the phase control method reported previously!).

is made.

The other is the rf voltage control method in which therf voltage of the final acceleration tank is adjusted andthe injection phase is kept nearly constant.
The feasibility of energy tuning by these simple

comparison with the case of UNILAC Wideroe tanks

Table 1. Parameters of acceleration tank.
Tank
No.

Acceleration
mode

Tank
lengthNumber ofdrift tubes

Rotationangle

rr /3 rr
rr/rr

3m

16
18
14

380
0
165
0
120
90
70°
65°

methods at RILAC is due to the following fact. By thetechnological requirements of the variable frequency
scheme, the length of acceleration tank has to bechosen relatively short and the number of drift tubes

#1
#2
#3

inside one tank is limited to less than 12 for the last#4

12

three tanks. Therefore, the rotation angles of the accelerated ions on the energy-phase space diagram around

#5
#6

11
10

the synchronous point is small in each tank, being lessthan a quarter of turn for the final two tanks. Such acceleration tanks do not work sufficiently as a velocity
filter like an ordinary linac tank. The features relating

# 1*
#4*

rr/3 rr
rr/rr

5.5 m
7.3 m

0

0

36
26

* UNILAC Wideroe tanks

10 5

104
Q3
C
C
<U

10 3

N...c

.-<U

~2
C

<t:
06 10 2U

10 1

Channel number

Fig. 1. Energy spectra of beam emerging from tank #5 for four kinds ofsettings of the injection phase, ¢inj.

An example of the application of the phase control
is shown in Fig. 1, where one can see how the energy
spectra of beam emerging from tank #5 varies withchange of injection phase . Those spectra were obtainedby direct measurement with a surface-barrier-type semiconductor detector set in the beam line. The beam intensity was reduced by using the two sequential chargetransfer reactions 2 ) during the measurement. Bychanging the injection phase from -6 to -120 deg., thepeak position moves to the low energy side and the peakwidth becomes wider gradually.
We made a computer simulation for the phase motion
in RILAC. The results of calculation for five representative points in the longitudinal emittance after tank

165

#5 for each injection phase are shown in Fig. 2. In theagreement between calculation and measurement canfigure, one can see the tendency that, as the injection
phase varies from 0 to -100 deg., the beam energy

be seen. However, the minimum value of the obtainedenergy spread is two times larger than that of calculation. The reason for this difference is not clear atdecreases and, at the same time, the energy spreadpresent, but it may be due to the effect of the nonuniform distribution of rf voltage along the beam axis
in each tank, the unstability of rf parameters (voltage

becomes wider. The results are summarized in Fig. 3
together with the experimental ones. The fairly good

and/or phase), the coupling of radial and phase motionin the low velocity region, and so on.
Figure 4 shows the results of calculation of the energy variation at the exist of tank #5 against the injection

TANK # 5~~I~5phase. In the figure, the parameter is the acceleration
voltage of tank #5 (V #5) and the injection energy is
20

,

,

CPinj,'=_57,01

40
TANK # 5(deg)

6

cp.In).

\

\
X

\
\

.. _

<p,", -

0\

-75 \

\

<p,";

5

- 5

=-

100:

I

-10

-.~
-15

- 120 - 100 - 80 -60 - 40 -20¢inj.

Fig. 2. The results of calculation of longitudinalemittances at the exit of tank #5. The verticalaxis is scaled in terms of the relative energy difference from the energy value, Eo' of the synchronous condition. The normal operation was
assumed from the injector to tank #4. The rf
voltage, V#5' is fixed at the normal value.

0

20

40

(deg.)

Fig. 3. The variation of energy resolution ofbeam of tank #5 against the injection phase to
the tank. The solid line is the results of calculation in Fig. 2, and the solid circles are themeasured energy spreads with the semiconductor
detector.

20-40

Fig. 4. The calculated relations between the beam energy and the injection
phase for tank #5. Eo is the normal beam energy at the exit of the tank.
The rf voltage was changed from 50 to 150 % of the normal value (V 0) bystep of 10 %. The solid curve is for V0' the dashed curves are for the rf voltages less than V0' and the dot-dash ones for those higher than Vo·

166

fixed at the designed value. As V #s goes down from150 % to 50 % of the designed value, the maximumof V #s and goes down toward the normal energy ofthe previous tank (shown by a dot-dash line in theenergy decreases, the undulation of energy curves be-

figure) as V #s approaches to zero , and , on the other
hand, the energy spreads are almost constant against thecomes small and the phase giving the maximum energy
shifts slightly to the negative phase side. If the injection
phase to tank #5 is always set around the maximum
energy point for each V #s value, energy can be varied
without degrading the energy resolution. As shown in
Fig. 5, the energy varies linearly and slowly with change

V#s adjustment.
To tune energy in the routine operation, the methodby adjusting the tank voltage is superior to the phase
control method from the viewpoint of the constantbeam quality. But, when the energy several percent
greater than the normal energy of one tank (denoted bytank #N) for a given frequency is required, it is some-

120

(a)

I
I

I

-- ----- ~~.~
100 ---------~e-eI_e____ 80I.-- . --.-- . --- .~.-

I

~

I
I

~ 60
----.....
~

times difficult to apply this voltage control method. In
this case, however, there are, in principle, two possible
ways for applying the voltage control method. One is toraise the rf voltage of tank #N by 20 - 40 % and turnoff the later tanks, and the other is to operate the tank
#N normally and to operate the next tank, i.e. tank40#(N + 1), at the rf voltage level around 10 % of the20higher than the spark limit and V #( N + 1 ) is smaller thanthe lower limit of rf stabilization circuit. In that case,normal value. Neither of ways can be used when V #N isoone needs the combination of the voltage and phase conRelative

C
L

2

V~ 5

(b)

1:

~

.......

~----.....
~

"'J

0

02
Relative

V~5

Fig. 5. The variations of energy (a) and energy resolution (b) for tank #5 with change of rf voltage of thetank. The injection phase is adjusted in such way thatthe beam energy is maximized for each rf voltage. The
solid circles in both figures are the experimental dataobtained, with the semiconductor detector. In figure(a), the energy axis is normalized to the designed energyof tank # 5. The solid line shows the results of calculation, and the dot-dash line show the designed energy
levels for tank #4.

trol methods or the frequency adjustment.
Even when the beam is accelerated up to the designed
energy for a given frequency value, it is preferable to
make intentionally a small deviation from the normal acceleration condition by lowering the rf voltage of the
final tank to 90 % of the normal value and adjusting theinjection phase of the tank to maximize energy (aroundo degree) as shown in Fig. 4. It gives a good energy resolution, and saves the electric power consumption as
well.

References
1)
2)

M. Kase, T. Kambara, T. Tonuma , and M.Odera:
RIKEN Accel. Progr. Rep., 12., 150 (I982) .
M. Kase and T. Kambara: ibid. , p. 147.

167

N -14.

Change of Longitudinal Phase Motion in the First Tankof RILAC against the Frequency Adjustment
M. Kase, T. Kambara, T. Tonuma, and M. Odera

A question which is of great interest at RILAC, thefirst linac using the variable frequency scheme, is how tokeep a constant beam quality against the frequency
adjustment (17 - 45 MHz). In order to do that, it isnecessary to maintain the constancy of particle motionin the longitudinal phase space when the frequency ischanged, since the beam qualities such as the relative
energy spread, the phase spread and the phase acceptance are related closely to the phase motion.
There is, however, an inevitable ununiformity in theline shows the typical phase acceptance of a linac withthe so-called golf-club shape.

20.0 , - -- - , - - - - - - - - , - - - - - - - , - - - - , - - T " " H - - - - : : - ----::::~:::::::::~::~~::-;Oo " /

~
>,

tl.O

W

C

<l)
<l)

distribution of acceleration gap voltage along the beamline in a resonator tank due to the fact that the length ofresonator tanks is not sufficiently short as comparedwith the wave length of radiofrequency. The accelerating voltage drops generally at both ends of tank and thistendency is enhanced as the frequency increases. 1 ),2)

~

+-'

~

<l)

0:::

- 10.0 L_---.J_~~~~~_ ____.l._ _~- 60.00.0
40.0
Injection phase (deg.)

This fact causes an undesired frequency dependence ofthe longitudinal phase motion, since the geometry ofdrift tubes of RILAC was designed assuming the uniform
voltage distribution. As the result, the beam qualities
vary with change of frequency. Especially in the firsttank, where the 1T -31T mode is employed, these effects
are important, because a rotation angle of accelerated
particle in the energy-phase space is relatively large andthe deviations from the synchronism grows large inside
the tank.
Figure 1 shows the longitudinal acceptance of the00

Fig. 1. Result of calculation of the energy and phase
contour maps on the injection energy-phase space forthe first tank. The gap voltage distribution was assumed
to be uniform. The calculation was made using theimpulse approximation. 3 ) The solid contour lines givethe relative energy difference ranging from - 6 to 2 %and the dashed lines show the phase from - 40 to 40
deg.

first resonator tank calculated on the assumption thatthe distribution of gap voltage is uniform. In the figure,energy is expressed in terms of the relative energy dif-

Figures 2 (a) and (b) show the same kind of calculations as that in Fig. 1, but for non-uniform distributions
at the frequency of 17 and 45 MHz, respectively. The
synchronism at a phase angle of - 25 deg. cannot be

where e.1 and E.1 are theference given by (e.1 - E.)/E.,
1
1seen even for the lowest frequency (17 MHz). The higher

ion

energyandthedesignedenergy giving thesynchronism at the acceleration stage i, respectively . The
vertical axis is the relative energy difference at theentrance of the first tank. The horizontal axis is thephase of rf voltage when an ion is injected to the centerof first gap of the first tank. The solid curves in the
figure are contour lines of the relative energy differenceof the ion at the exit of the first tank, corresponding
to the values of -6, -4, -2,0, and + 2 %. The dashedcurves are contour lines of rf phase when the ion reaches
the center of the final acceleration gap of the first tank,corresponding to the values of - 40, -20, 0, 20, and40 deg. The synchronism can be seen at the phase of-25 deg. The -4 % energy lines or the 20 deg. phaseenergy lines are receding as the frequency increases, and°% energy line crosses the injection energy level atlarger anlge than in the case of the uniform distribution.
It can be expected that the longitudinal emittance at theexit of the tank is different from that for the uniform
distribution and the average energy of ions become
lower than the prescribed value. Moreover, theacceptable region (for example, the region enclosed by- 4 % energy line) moves slightly to the higher energy
side as the frequency increases, although the area andshape of the region are nearly constant. This fact causes
the reduction of phase acceptance for the higher frequency, if the injection energy is set according to thedesign value.

168

2o .o,-------~----,----~--~-~~(a )The correction factors Cn (f), which are functions of f,give a value of 1 when the gap voltage distribution is
uniform. ¢ tOJ.. is also a function of f , although it is a constant ( - 25 deg.) for the uniform voltage distribution.
When the relative energy difference corresponding toV..
is expressed by Lill ..
, an ion on the point (¢ ..
,
InJ
InJ
InJ

Lill. .) in the injection phase space will be the central
InJ

particle in the longitudinal phase space after the firsttank. The center of injected beam bunch should belocated at the point. The resultant phase ¢ ou t at the-10.0 L -_ _---.L-_ _-----.l.._ _ _L -_ _- L -_
0.0
-60.0

_

----'

400

Injection phase (deg.)

exit of the first tank has to be also considered in determing the parameter of the next-stage acceleration, if it
depends on the frequency.
Figure 3 shows one of the candidates for these correction factors which were obtained by the computer
simulation. They ensure that the pattern of longitudinalemittance at the exit of the first tank and the phase ac-----___________ 40° -ceptance of the tank is nearly constant over the fre->anquency range. The large correction is required for the

Q)
c
QJ

injection voltage rather than the rf voltage. The correc-

QJ

:::

~ 00~~~~~+---~----~?-~~-4------~
0:::

tions for the parameters of the later-stage acceleration
are also necessary but they are smaller than those forthe first tank and, in most cases, only the correction for- 10.0 L -_-60.0

the rf voltage is needed.
_---.L-_ _-----.l.._ _ _L -_00_- L -_ _- - '40.0

Inject ion phase (deg. )J:~:l (a) ~Fig. 2. Results of the same calculation as in Fig. 1 but
for the nonuniform gap-voltage distribution. The
measured distributions in Ref. 2 were used for the
calculation. (a) is for the lowest frequency of RILAC,
17 MHz and (b) for the highest one, 45 MHz. The rf
voltage was set in such way that the average value of the
distribution will be equal to the prescribed voltage value.

1.00

1'0

2'0

3'0 4'0f (MHz)S'O

s 1.1 0[ (b);- 1.05u
1. 00 L-:-l.l,:-O--==;2~O==3;r;O===r==~' 0::---~S'o( (MHz)In order to reduce these effects relating to the firsttank, the pattern of the energy and phase contour lines

20

around the injection energy level must be identical for
any frequency. However, little improvement can bemade by adjusting only the rf voltage of the first tank~

.2 -20contrary to our early expectation. One has to adjust all-40parameters determining the longitudinal phasemotion inside the first tank, i.e. the injection voltage( (MHz)0 1--------.l.
1O- -2-'-0- -3. .0---'. . 4'0--'SO

QJ
(j)

Q.

the

(c)

------¢OUI---- -- ---------- ¢s¢inj

Fig. 3. Calculations of the correction
factors for the injector voltage (a), for thetank voltage (b) and for the injection andoutput phases (c).

V.InJ. and the injection phase ¢.InJ. as well as the tankvoltage V # 1' The buncher voltage is also a parameter
relating to the phase motion in the first tank but lessimportant in this case. The corrected parameters, V inj
and V #1 ' can be written as follows:
V n = Kn (M /q) f 2 C n (f)(n = inj and # 1) )References

1)
2)

Y . Miyazawa: Private communication.
Y. Chiba: IPCR Cyclotron Progr. Rep., 10, 144(1976).

where Kn is a constant, Mlq the mass to charge ratio of
ions to be accelerated, and f the acceleration frequency.

3)

T. Tonuma, F. Yoshida , and M. Odera : Reports
I.P.C.R., (in Japanese), iL 53 (1975).

169

N -15.

TOF Measurement of Beam Energy
M. Kase, E. Ikezawa, and T. Kambara

At a multi-stage accelerator like RILAC, it is essential
to know the beam energy on each acceleration stage forsuitable for a heavy ion linac like RILAC, permitting the
precise estimation of the average energy of ions in beam

the fine tuning of acceleration parameters. The follow-

bunch.

ing three methods are available now at RILAC toestimate the beam energy: the direct measurement withan SSD, the momentum analysis with an NMR-calibrated
dipole magnet and the velocity measurement by the

The bunch probes used in the TOF are of a capacitive(i.e. beam non-destructive) type, having a ring-shaped
electrode matched nearly to 50 ohm impedance. The
electrode surface facing to the beam is in the form oftime-of-flight method (denoted later by the TOF) using
a couple of bunch probes. l ) Among these, the TOF isa cylinder 30 mm in diameter and 10 mm in length along
the beam line. Figure 1 shows the distribution of probes

Fig. 1. The distribution of capacitive bunch proves installed along the RILAC
beam line. BP denotes the bunch prove.

installed along the RILAC beam line. A couple of theseprobes are used which are located apart from each otherat the distance L. If any acceleration devices exist between the two probes, they should be turned off during
the measurement. The signals from the probes, whichhave a bipolar shape as shown in Fig. 2, are sent to thecontrol room via cables with the same time lag.
If one measures the time delay ~ t of the signal fromthe downstream prove relative to that from the upstreamprobe, the average velocity v of particles in beam bunchis given byl ) v = [L/(TN + 6 t)] , where T is the period ofacceleration voltage and N is the number of bunches
existing between the two probes, being equal to thelargest integer which does not exceed L/(vT). The
error in the energy can be reduced to less than 0.2 %, if
N is large enough. On the other hand, an error in theknowledge of N leads to a wrong energy value which isdifferent from the real value by 200 n/N % (n = 1,2, ...).
In practice, however, since one can easily estimate thebeam energy on each acceleration stage with an accuracy
within 10 % at RILAC, such an error in N rarely occurs
if N is smaller than 20. A combination of probes should

Fig. 2. The signal from the bunch prove BP 121.
The beam is 1.5 MeV N2 + with 1 J.lA in beam
current and the acceleration frequency is
18 MHz. The signal is amplified with a wideband amplifier (45 dB) and observed on 350
MHz oscilloscope.

make a two-step measurement: In the first step, N is
set smaller than 20 and larger in the second one. An

be selected so that the N value will be around twenty.

example of the relation between ~ t and E/ A is shown in
Fig. 3. For N as large as 44, f'j. t varies almost linearly

When a higher accuracy is required, it is necessary towith E/A.

170

Time of flight CAL.
20

20

Freq.=26.00 MHz(Deg.)

15

h

60

90

5

I

~ 0~~~--~~-L--L4~-+~L-~-L--,-~~

klklIkl
l
o

o

-5

-40

-10 --

-15
0.035

0.042

Fig. 3. The relation between the time delay ~t and theenergy of beam from the injector, in the case where thefrequency is 26 MHz and the probes BP121 and BP231
are used. The length L is 4602 mm and the bunch number N is 45 for the left line, 44 for the middle line and43 for the right line.

The TOF permits the calibration of accelerating
parameters as well as the parameter tuning. Fugure 4
shows the experimental data and the calculations for theenergy of beam emerging from the tank #3 when thetank voltage and the injection phase are changed. If one
knows the injection phase and the beam energy, theeffective voltage for tank #3 can be estimated from thecomparison with the calculations. Also a calibration of
the injector voltage can be easily done with a buncher if
the TOF method is used.

Fig. 4. The beam energy vs the injection phase for thetank #3. The vertical axis is the energy expressed interms of the relative energy difference (in %) from thenormal energy Eo at the exit of tank #3. The parameter is the tank voltage V #3. The three kinds ofcurves, that is, dot-dash, solid and dashed curves, arethe calculation for V #3 = 1.1 V0' 1.0 V0 and 0.9 V0'
respectively, where V0 is the normal tank voltage. The
open squares, circles and triangles are the results of the
TOF for V#3 = 1.1 Vm' 1.0 Vm and 0.9 Vm'
respectively, where Vm is a meter reading for the tankvoltage and is now to be calibrated. The comparison
between measurement and calculation permits the decision of the effective tank voltage with an accuracy of afew percents.

Reference1)

1. Glatz, 1. Klabunde, and P. Strehl: Proc. of the
1976 Linear Accelerator Conf., p. 306 (1976).

171

N-16.

Design of a Compact Deflection Magnet
M. Hemmi, Y. Miyazawa, and S. Motonaga

A small deflection magnet named CD was designed,
fabricated and set in the course labelled C. The course isin line with the acceleration axis of the linac, so thatalignment of the accelerator system such as the beam injection equipments and drift tubes can be checked easily
from the end of the course by optical means.
The course was very usefully used at the initial stageof accelerator construction and installation of the experimental apparatuses. However, unwanted neutral or
charge changed particles also arrive at the end of course
disturbing measurements. Since necessity of recheckingof the alignment has decreased, we decided to add a deflecting magnet in the course to remove the undesired

beams from the C course. A small deflection angle issufficient for that purpose.
The magnet has to be installed in the narrow space

101

100(%)
99~O.42gap 98
0.15gap
97
96
95
E
E

94

0

l.O

I

o

Fig. 1. Pole profile and beam pipe cross section.

-

I

10

I

I

I

20

30

I

I

40

I

50 (mm )Fig. 2. Comparison of measured (b) and calculated (a), (c) field distributions of the CD
magnet. Curves (a) and (b) are for profile shownin Fig. 1. (c) is for a straight pole with flat face.

Ace ItFig. 3. Layout of the CD magnet in the accelerator vault.

172

between the beam distributing magnet (SW) and thesatisfactory. Also, increase of the useful width in (b)shielding wall separating the accelerator vault from theover that in (c) is to be noted. The width for uniformity

experimental areas. Beam pipes of the neighboringof 1 % is 83 mm for (b) and is 58 mm for (c), for thecourses, Band D run close to the both sides of the pipe

pole width of 100 mm and gap height of 50 mm. Sinceof C. The magnet must be made as compact as possible

the maximum field required is only 3.5 kG, cross section

so that it can be fitted in the space. Firstly , we tried toof the yokes has been reduced to 60 % of the pole sur-get enough width for beam path with magnet poleface area to cut weight of the magnet further. No satura-

having relatively narrow width but moderate gap heighttion effect was observed in field distribution

by use of iron shim at the pole edge . The pole profile

excitation curve. The tape coil cooled by cold plateshown in Fig. 1. was determined by TRIM code calcula-technique, which has been applied extensively for theor intion. In Fig. 2 the result of field measurement (b) of themagnets of the RILAC, is also used here to reduce thecompleted magnet is compared with calculations. (a) ismagnet size and its power consumption. Figure 3 shows

for the profile shown in Fig. 1 and Fig. 2( c) is for a

the position it is installed and Table 1 its spectifications .

straight pole with flat face. Agreement of (a) with (b) is

Table 1. Specifications of CD magnet.

Pole gap

4/100 rad3.5 kG x 35 cm
100 mmW x 350 mmL
50 ± 0.1 mm

Width within 1 % uniformity of field

83 mm

Effective field boundary

0.52 of pole gap from the edge

Coil (a) typeTape-coil

Deflection angle
Maximum field x Length
Pole face(b) Total Amper turns

2 x 70 T x 100 Amp .

(c) Power consumption

8 V x 100 Amp(d) Cooling water

2 Q/min (head loss 0.5 kg/cm 2 )Weight170 kg

173

N -17.

Compact and High Efficiency Arc Pulsing Power
Supply for PIG Ion Source of the RILAC
M. Hemmi and Y. Miyaza wa

dinary thyristors.

The ion source of the RILAC injector terminal is(5) Necessary power to drive the gate is small enoughto simplify design and operation of the whole circuit.

of an indirectly heat ed hot cathode PIG type. For theseseveral years after completion of the linac it has been
operated in DC mode throughout. This year we designed
an arc pulsing power supply and installed it in the highOn the other hand , there are some drawbacks whencompared to the hard tube regulator . One is the slow
switching response and the other is possibility of receiving unrecoverable damage when an unexpectedvoltage terminal to increase yield of the high charge stateions of heavy elements . Since space, coolant supply andpower capacity available for the new equipment in theterminal are limited , the usual ion source pulser which

voltage spike was generated in the circuit by somereasons.
Table 1 shows specifications of the pulsing power

uses a large vacuum tube as a series regulator could not
be installed there . Therefore, the arc pulser must becompact and use power efficiently.
We solved the problem by use of a new solid state

supply and Fig.l its block diagram . Its characteristics

Table 1. Specification of GTO arc pulsing power supply.

switching element that recently becomes available inthe market, named GTO (Gate Turn Off thyristor). The
device has the following characteristics:(1) It can withstand voltage between anode andcathode as high as 2.5 kV in the off-state.

Voltage (peak)
Current (peak)
Polarity
Pulse width
Repetition rate(2) In the conducting state , the voltage drop within
the element is in the range of small value between 1.5
and 2 V. Power dissipation is so small that there is noneed of forced cooling of the element. Therefore, power

Duty factor
Rise and fall time
Sag
Power requirements

efficiency is good.
(3) In designing power supply, it is not necessary toin addition to that for the ion source.
(4) The conducting state can be switched off bysimply applying a control signal to its gate unlike the or-

WeightApprox. 200 kg

GTO

. c,s
C)<:<'0

(f)

>
Cl 0

~

0

C,S

0
..... LD

LL

Output15kV
lOAmp«,~0illIl<10 %200V 3 phase, 48 - 50 Hz,
550 x 700 x 800 (m/m)

Ch

Rec

6kVA

.~

100 '" 300 pps
30 % max.
10 and 200 psec respectively

Dimensions(W x H x D)

LA/

1 '" 3 msec

6 kVA max.

consider surplus voltage required for the series element

200V 50Hz 0-200V Transfomer
3Ph
l.2kV

100'" 1500 V
10 A maximum
Negative~"0:\Ci :-:.
<\0«; s:J\J'tV)

Fig. 1. Schematic diagram of the pulse power supply.

174

83. 7. 4

LLL•.~ lL LL-

83. 7. 4

1.

•

•

I--J
2msec

83. 7. 4

1.5

1.5

o

o

RL = 150Q

83. 7. 4

200j1sec

Fig. 2. Photographs of the pulse wave forms at pulse widths of 1 and 3 msec. Lower traces show
rising and falling edges of the pulse.

the pulse are 10 and 200 fJ.SeC, respectively, and are100

satisfactory for ion-source operation.
~_ _-_ (l)Power efficiency of the power supply was measured- (2 )

as the ratio of the averaged pulse power to the powerdrain of the AC line. Figure 3 gives the results. It is

,~:=-

»
cQ)

u

~./

~ 50

,.

w

1

o

50

100

Out put power ( % )Fig. 3. Measured power efficiency as the ratioof pulse to AC primary.
(1) At pulse width of 3 msec and 30 % duty
factor,(2) At pulse width ofmsec and 10% duty
factor.

50 % at 10 % duty-factor operation and 76 % at theoperation with the maximum duty-factor of 30 %.
Its control is made from the operation console in thecentral control room of the linac, via optical links usedfor DC operation of the source. Other optical links areused to transmit analog signals to watch arc discharge
condition of the source at the console. Wave forms ofvoltage or current of the ion source can be displayed on
the CRT of the control desk whenever it is necessary.
Ar 6 +, Kr 8 +, and Xe 9 + ions were obtained andaccelerated by the linac shortly after installation of thewere measured in the terminal. In the upper part ofpulser. It was found that charge states higher by 2 thanFig. 2 are the photographs of the wave forms for pulse

those by DC operation could be obtained for ions ofwidths of 1 and 3 msec. In the lower part are shown thethe heavy elements by use of the arc pulsing scheme.

leading and trailing edges of the pulse at the highWe are preparing for acceleration of Au and Al in thesweeping speed display. The rising and falling time of

beginning of 1984.

175

N-18.

Design Study of the ECR2

M. Yanokura, S. Ishii, Y. Sakamoto, and M. Odera

We have started developing an ECR ion source which
can continuously produce higher charge state ions com-microwave resonance heating. Microwave power sourceof same frequency is used for the second stage. Higher

pared with ordinary PIG ion sources. It is expected tocharge state ions are, therefore, expected to be formed.

improve performance of our heavy ion linac. Last year
we tested a single stage type ECR ion source, and got a
few nA Ar 7 + beam.

For the ECR2, we plan to use the coils, the 2.45 GHz
microwave power source and the high voltage extraction
power supply which have been used for the single stage

We plan to study possibility of using microwave of

ECR source to save cost of modification.

relatively low frequency to produce enough quantity ofhighly stripped ions by use of the principle of whistler
mode excitation. In the ECR sources developed to date ,high frequency (16 GHz) which is available by the mostadvanced microwave technology has been used. However , in the ECR principle, the higher the frequency, theIn the first stage of the ECR2, microwave is injectedalong the axis of the mirror field (whistler mode), instead of injecting it perpendicular to the axis as has beenstronger the magnetic field must be. Power consumption

electron plasma frequency wpe which is proportional

increases rapidly and the microwave source becomesvery expensive. Power available on our 500 kV ion
source terminal is , however, limited to 50 kV A. There-

to square-root of ne can become higher than the micro-

fore , if the required multiply charged ions could be
produced at relatively low frequency by the use of thewhistler mode, the ECR source would be more attractive
to us. This year, we have designed an ECR ion source of
two stage type which we call ECR2. At its first stage,high intensity low charge state ion plasma is formed bywhistler mode microwave heating of gas at relatively
high pressure, using a 2.45 GHz magnetron. The ion
plasma then diffuses into the second stage. At thesecond stage which is under high vacuum, electrons are
excited, and are stripped off from the low-charge stateions by collision with hot free electrons produced bydone in the first single stage model. We expect thisallows to get an overdense plasma in which the electron
density ne is much larger than the critical density andwave frequency whereas W pe can never be larger thanW in the perpendicular injection mode. In fact, we got
an electron density of 1.7 x 10 13 cm- 3 for 9 GHz in
preliminary experiment. 1 ) This value is ten times larger
than the critical density. It is predicted that some instabilities produced in the over-dense plasma will cause
trouble. We plan to suppress it by applying a dynamic
stabilization method in which modulated microwave 2 )is made incident on the plasma.
Outline of the ECR2 is shown in Fig. 1. Total lengthis about 1.2 m, including extraction system. Most of thevacuum components are made of stainless steel except
the second stage cavity. To realize the whistler mode
coupling, microwave power is fed through a coaxial wave

nTn~=~ -i~
~~

B

g

k

c;;.
o-""'!==-5 10 15cm

Fig. 1. Design of ECR2 ion source. Letter which shown in this figure means following.
first vavity (Whistler mode cavity),
second cavity (stripper stage),b: helical antenna,
a: coaxial wave guide,d: orifice,c: gas inlet,
g: cooling water inlet,
e: hexapole magnet,
i: Einzellense,h: extractor,
k: pumping port.
A:
B:

176
guide and is radiated in the axial direction of the cavity
by a helical antenna attached to the end of the centerwave power and higher charge state ions are formed byonly a long tube with a small orifice is provided between
the two stages to make differential pumping feasible.
Plasma is confined by magnetic mirror field in theaxial direction, and by hexapole field in the transversal
directions. In order to get hexapole magnetic field,
samarium cobalt permanent magnets are used.
Beam extraction system is almost the same as that of
the old ECR source. The maximum extraction voltage is
30 kV. The extracted beam is focused by an Einzellens,

successive stripping in the ECR zone. When a hexapole
field is added to the mirror field, the length of the ECR
zone becomes 20 cm and its maximum diameter will be

and the charge state of ions are analyzed by a bending
magnet. Finally the beam current is measured by a
Faraday cup.

conductor of the feeder. The pressure in the first cavity
is chosen around 10- 4 Torr. The reason for choosing
this pressure range is due to plasma stability. The second
stage is the stripper stage. Length of the second cavity is
30 cm and its inner diameter is 6 cm. This cavity
is made of aluminium. Electrons are heated by micro-

3 cm. High vacuum is necessary for this stage to avoid
ion loss due to electron capture of the highly stripped
ions by collision with the residual gas molecules. The
pressure in the stripper stage is designed to be below
10- 6 Torr, in the gas feed condition. As the pressureof the stripper stage differs from that in the first stage,

References

1) S. Ishii: Sci. Papers I.P.C.R., 74. 27 (1979).
2) Y. Sakamoto: lpn. l. Appl. Phys., lQ, 1015 (1977).

177

N-19.

Production of Highly Charged Ions In a
Hexapole-Mirror Magnetic Field
S. Ishii, Y. Sakamoto, and M. Yanokura

High temperature plasmas are important in studying
not only plasma physics but also production of highly
charged ions. We have developed an efficient method of
producing dense plasmas by launching microwaves as
whistler waves in a simple-mirror magnetic field. 1 ),2)
These plasmas are, however, not stable and the electron
temperature is too low to produce a sufficient amountof highly charged ions.
In order to obtain hot plasmas we are improving thealready-installed mirror device by adopting a hexapole
coil and a high-speed pumping assembly. The schematic
view of the device is shown in Fig. 1. It consists ofpt

I~F4800A~15~~ [JnMnnn
ULJ IJ ~~. . . . . . ~~Bn (T)

015

T

VC,.....,,.=.Ir-=,,,j0
005 015

E 04

-0.5

o

provides a radial field of 0.09 T at r = 60 mm in the midplane (z = 0). The vacuum chamber, 106 mm in diameter and, 1 m in length, is pumped -through ten manifolds. An effective pumping speed of 400 Q/s can beachieved.
Cold plasmas are produced by electron cyclotron
resonance (ECR) discharge of 9 GHz whistler wave at
one of the mirror points (z = 0.6 m). This frequency
corresponds to an ECR field of 0.32 T. The effective
microwave power of I kW can be stationarily delivered.
A plasma density of as large as 10 19 m - 3 has ever been
attained. 1 ) The plasmas trapped in the combined
field of mirror and hexapole are heated additionallyby ECR of 2.45 GHz microwave which is launched asa whistler ' wave. For this wave the combined field forms
a closed ECR surface on which the field intensity is
0.0875T. The size of this surface can be varied byonly changing the coil currents. The typical length anddiameter are 400 mm and 40 mm, respectively. Byexperience a plasma density of 10 18 m - 3 is expected insafe stationary operation; the plasmas flow along themagnetic lines of force with a mean ion velocity of
10 3 m/s; the average plasma diameter is about 30 mm.

0.5

z (m)

Fig. 1. Schematic view of the hot plasma device.
Abbreviations: P, pump; MAN, manifolds; MC,mirror coils; HC, hexapole coil; VC, vacuum
chamber.
Spatial variations of the mirror and hexapole
magnetic fields, Bm and Bo ' are shown together.
The hexapole coil is composed of sixfold woundcopper pipes.

From these parameters we can estimate a plasma flowrate of 3 Pa·Q/s which should balance the gas inlet rate.
The vacuum chamber would be maintained at a gas
pressure of 7 X 10- 3 Pa with the pumping speed of
400 Q/s. Charge exchange cross-section of, say, Ar 6 +in argon gas 3) is in the order of 10- 18 m2 . Then themean free path of Ar 6 + is estimated to be about 10 m.
Since this value is large enough compared with the sizeof the device, confinement of highly charged ions can be
expected.
To find optimum conditions for producing the highly
charged ions we will measure the plasma parameters,changing the microwave powers, the ECR zone, the gaspressure and so on. Extraction of ion beams will follow

a pair of solenoidal coils, a hexapole coii, and an
ultra-high vacuum chamber. The solenoidal coils areachievement of the optimum conditions.

separated 1.2 m from each other and provide alongitudinal field of 0.33 T at the mirror points(z = ± 600 mm). The mirror ratio is then about 5. The
hexapole coil, composed of straight conductors, isplaced at r = 110 mm, parallel to the magnetic axis andReferences
1) S. Ishii: Sci. Papers I.P.C.R., 74,27 (1980).
2) S. Ishii: J. Phys. Soc. Jpn., 50, 1383 (1981).
3) T.P. Grezdanov et al.: Phys. Lett., 66A, 191(1978).

178

N-20.

Circuit for Axial Extraction PIG-Source Power
Supply and Control
K. Hoshino

The circuit constructed for supply of power to theion source and its control is shown in Fig. 1. Figure 2 isthe arrangement of the ion source electrodes. In Fig. 2,
and electron repelling electrode R is added to the previously described design. 1 )Electrons are accelerated toward electrode E4 by apotential difference of 1.96 KV. The potential of theelectrodes E2 and E3 are given by the Zener diodegroup (ZD7 --+ 23) shown in Fig. 1. The electron current
emitted from the filament is controlled by an emission

Insulation rack

F

F

200
~=_~ I / 2

ZD2
4.7V

Sw 1 ~A
0--01'O-<"Y"-.C~~~

AC

1

lOOV

1

25M
5M1W

x5

VG
Pro .
RLI
ACIOOV

--.EL

20k80W

2.0kV
E3
19 kV
E2

C2

18-

4kWV

2.05kV

2/1
2M
4W

TGI

IOk2W

Oi l Bath
HT
i
1

I
I

1
L

lOkV
a
I
C I

'\

I nsulation rack
dielectric strength - DC 15 kV_ _ _ _ _ _ _ _ _ _ _ _ .J

Fig. 1. Circuit for power supply and control of axial extraction PIG ion source.

El- lOO V

179

0

lOOV

I

f-R

0 0
- -- - -- - -L-J L-J U
I I I I I'

F

E4

E3

I
2.0kV

lOOV

E2
1.9- 2.15kV

D

El

Ec

lOkV

2.0kV

Fig. 2. Potential distribution of electrode of axial extraction PIG ion source.

regulator circuit to which power is supplied by the transformers T2 and T3. VR 1 is a variable resistor to adjust
the electron current between 3 rnA and 20 rnA. VR 4
below Tr 2 in the figure is used for setting an upper limitof the filament heating current to protect the filament
from the enormous increase of the filament current
some times seen in strong magnetic field operations.
The upper part of lower half of the circuit whichdraws power from the transformer T4 is a circuit to cut
off the power to the transformer T5 for several seconds,
when an over current flows in the ion source power
supply by the discharge in the source. If a large current
flows in RL 2 which is connected to E 1, RL 3 is activated by the closing of contact r12-1 , which makes
Tr 6 and Tr 7 conducting. The contact point r13-1 isopend and cut off power supply to the transformer T5.
The electrical current flowing through the closed r12-1
passes through a resistor of 1 kQ and charges up C4.
When r12-1 is opend , C4 begins to be discharged.
Potential of base of Tr 7 goes down, and the time toreset RL 3 is determined by product of C4 and 100 kQ
and is 6 seconds.
The potential of the electrode E2 is controlled withina certain range of the potential determined by that of
the electrode E3. The lowest is below the potential of
E3 by 100 V and the highest above E3 by 150 V. Thispotential is controlled by VR 2. TG 1 in Fig. 1 is described in detail in the lower part of the figute. As theoutput voltage of TG 1 is 0'" 250 V, and the output
current is several rnA, TG 1 must be able to control
relatively large power.
When the ion source is operated under strong
magnetic field with large electron current, intense oscillation is generated. Frequency spectrum of the oscillation is very broad. It is easy to prevent the oscillation at very high frequencies, but suppression of thewhole oscillation in the ion source, which includes
many frequency components is difficult. The mosteffective way of suppression of the oscillation is insertion of resistors between the ion control circuit and theion source terminals. Without the resistors, high frequency current is fed back from the ion source to thepower supply , and destroys the semiconductors in thecontrol circuit. C7, C8, and C9 are chemical condensers(350 wV 1 J.lF) to protect the semiconductors fromsurge current produced by discharge in the ion source.
The condenser C1 and Zener diode ZD 1 shown on theupper part in Fig . 1 also protect the meter M2 fromsurge current caused by discharge. Five current reading
meters are installed in a high voltage insulation box
made of acrylic resin, and are used to measure thecurrent in each electrode separately.

Reference
1) K. Hoshino: RIKEN Accel. Progr. Rep., lQ, 149(1982).

180

N-21.

Modification of Axial Extraction PIG Ion Source
K. Hoshino

Construction of the ion source was already describedin a previous report. 1 ) Structure of its central part isshown in Fig. 1. Insulating spacers, which constitute partof cooling channels, were made of steatite. Vacuum seal
between the spacer and metal part was made by a small
D-ring. The sealing between the D-ring and metal wasgood, but between steatite and the D-ring was notsatisfactory. The vacuum sealing contact obtained bypressing the D-ring on the steatite surface was imperfect,
because of roughness of the surface of the steatite. ItoT

was tried to make good contact by coating the surface ofsteatite with silicon compound paste and drying before
construction. Though the maximum pressure of coolingwater was 10 kg/cm 2 , sealing by the D-ring separating
the vacuum side and the cooling water was found goodenough. Probably a similar good vacuum tightness may
by obtained by coating the steatite surface with special
chemical plating in place of the paste coating and subsequent polishing.
Effects of sputtering and evaporation were not con-lOkV+ lOOV

lOkV+ (1.9~215)kV
I

I

j

F

Fig. 1. Schematic diagram of the main part of the reconstructed axial extraction PIG ion source.

sidered in the initial design. Films of metal were foundformed after operation for a while by the evaporationof the filament material on the surface of the insulatorsnear the filament. Metalic films were also formed on theinsulation spacers by sputtering of metal of electrodewhich forms the extraction aperture. Insulation failureand discharge will be caused as a result of the formationof those films. Shield were, therefore , set around theabove mentioned insulators to prevent further film
deposition. The distance between the electrodes EG
and E 1 was chosen as 8 mm in the initial design. Considering the result of the experiments carried out later,
the distance was made larger and changed to 14 mm toobtain good focusing by extraction at 10 kV. The result
was that the ion beam could be well focused by the
extraction voltage of 11 kV. The diameter of the ion
extraction aperture in the electrode EG was enlarged to
5 mm and the diameter of the aperture of the electrode
El to 8 mm.
The electric field, which extracts electrons from thefilament, is lowered by space charges in the electron
beam of which density is increased by focusing effect ofthe magnetic field. In order to make its effect smaller,
the gap between the filament and the electrode E4 has

been made small.
The filament is made of tantalum wire of 1 mm indiameter. The electric resistivity of the tantalum wire islarger, and the heat conductivity is lower than those oftungsten wire, so that the filament wastes less power
than the tungsten filament to produce the same electron
current. The durability of the tantalum filament has
been found sufficient under the condition of use of theion source controlled by the circuit shown in Fig. 1
shown in another paper. 2 )In the initial design, ion source chimney formed by
El, E2, E3, and E4 was provided with many gaps forevacuation, as it was considered that the gas pressure in
the electrode E2 should not be high. The gap between
electrode E2 and E3 was made smaller to increase thegap pressure in the electrode E2.
For the reason of the modification, see the report on
operation in this volume.

References
1) K. Hoshino: RIKEN Accel. Progr. Rep., lQ, 149(1982) .
2)

K. Hoshino:p. 178 in this report.

181

N -22.

Operation of Axial Extraction PIG Ion Source
K. Hoshino

As the ion current extracted from the ion source iswithin the range of several tens of micro-amperes tohundreds of micro-amperes, the ion current can be readdirectly by meters without amplifiers. Because the ion
accelerating voltage is about 10 kV and the energies ofthe secondary electrons produced by collisions of theions are supposed not large , a simple ion collector isemployed. The structure of the ion collector is shown in
Fig. 1. Current lead to the collector is introduced into

electron current in the electrode E3 into which gas is
fed would be drawn out by the electrode E2 , when thepotential of E2 is lower than that of E3, and reach theextraction aperture at the electrode E1. If the potential
difference is reversed, the ions produced in the highpressure region within E3 would not be extracted. But
contrary to the expectation, a large quantity of the ions
was obtained by reversing the potential difference. Whenthe magnetic field is increased , the ion current became
smaller than that in the weak magnetic field.
The currents of E2 and E3 electrodes were observed<10Fig. 1. Ion collector.

the vacuum vessel by a glass seal at the position distantfrom the solenoid surrounding the ion source. The ioncollector is hung at the end of the lead wire. Thismethod has an advantage of the simple structure , as only
one wire is used for measurement of the ion current. But
it is impossible to know the effect of the magnet for
suppression of the secondary electron emission .
The axial extraction type ion source is considered as
an ideal one for its small emittance beams. But inpractice, the produced ion current is small compared tothe electron current for ionization.
An unexpected phenomenon occured in an experiment to increase the ion current. Ion current grew verylarge when the potential of the electrode E2 was increased higher by about a hundred volts than thepotential of the electrode E3 in relatively weak magnetic
field. The electrons emitted from the filament oscillated
between the filament and E1. See Fig.! shown inanother paper!) for symbols and potentials of each electrode. It was expected that the ions produced by theduring operation of the ion source. When the potentialof the electrode E2 was made higher than that of E3, thecurrent to E3 is diminished and that to E2 increased
and vice versa. Behavior of current of each electrode wasin opposite direction. If the electron current and thepotential of the electrode E2 are adjusted to optimize
ion current, the current of the electrode E3 decreased
ra pidly and finally the direction of the current reversed.
Conditions for the reversal of the current of theelectrode E3 are as follows: Firstly, the potential of theelectrode E2 should be higher than the potential of theelectrode E3 . Secondly, the ion accelerating voltage
should be higher than a certain threshold value, and as
the third condition the gas pressure inside of the source
should be higher than a certain value. Reversal of thecurrent of E3 means that the electrons are emitted fromE3, or the positive ions are captured by E3. The operation of the ion source under the condition, that thepotential of the electrode E2 is higher than the potentialof the electrode E3, is labeled for the sake of convenience "reverse potential operation" or RPO.
The phenomenon that the ions are produced
abundantly by the method of RPO might be explained
as follows: The electrons reflected by the electrode E1
impinge on the electrode E2 and E3 directly or indirectly. The electrons which impinge on the electrode E3
produce secondary electrons. The secondary electrons
are attracted by the electrode E2, move toward theelectrode E 1 and produce ions on the path. The secondary electrons produced at the electrode El by theimpinging ions are accelerated back and bombard theelectrode E3 again. The process is cumulative in the
RPO. A cylinder of discharge is formed around thecentral ion beam aixs by the repeated processes. A
part of the ions produced in the cylinder is extracted

182

between E2 and E3 was modified because , by thethrough the extraction aperture increasing ion yield.
The ion current produced by the method of RPO isseveral times as large as the ion current produced byis effective to obtain larger ion current. The quality of

the normal setting of potentials where the potential

the ion beam must be determined by the mass andof the electrode E2 is lower than that of E3. The gap

charge analysis in future.

500

~ 300

RPO Method

.2

E 200
m

~

\~

c

~ 300

V£2 - V£F 150V~:~T·E
::::l
E

x,

.-g
o

/ x--x-100

Optimum elec. current
for max. ion current

::::l

E
·x

\

.~\ \'x,

Optimum elec. current
for max. ion current'

20'. Optimum elec. current~ for max. ion current
\~

~
::::l

\

\
\

U
C

x
\

o

10~

\

c

.2

\

5 200
E

Q)

'x

Ordinary method
V E3= - 100V

VE2 -

",x

x

~ 100

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

\

c

\

U

20

x

\

~
::::l

~-

0r-------------------------4 0

x

C

Q)

<i3

............. .~Max. ion current

\~

-+-'

c

10~
u

\~

RPO MethodV£2- VEFlOOV~ 100

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

:su

\

c
.2

E 200

Max. ion current

c
~

x

::::l
U

\

\
x

.,\ Optimum . elec. current
x, for max. Ion current

-3

::::l

E
·x

20

l

;;: 400

•x

-+-'

c

500

\

<C

-3

:su

20

\

____ 400

RPO, the increase of gas pressure in the electrode E2;;;r-.-.-.

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

from

\

U

c

E

5E 200

Ar vs

The relations between the ion currents and thestrengths of the magnetic field are shown in Fig. 2 and~\Ordinary method
VE2- V E3 = -100V

·x

~ 100

Max. ion current
O ~--~~--~~~~--~~--~ Oo1000

Fig. 2. Ion current produced
magnetic field strength.
ion accel. vtg : 11 kV
gas supply rate : 3.9 cc.torr/sec

C

\

~
::::l

<i3

~Do

..... x .....

+-'

\

C

.2

::::l

......

\
-+-'

x

",

::::l
U
C

o

10 ~
x ....

Q)..... x.

--,

\-

T
Max. ion current.-e ___..

Fig. 3. Ion current produced from nitrogen vs magnetic
field strength.
ion accel. vtg: 11 k V
gas supply rate: 8.0 cc. torr/sec

magnetic field, and also the optimum electron current
for getting the maximum ion current.

Fig . 3 for the case of Ar and N , respectively. The
measurement by the method of RPO is shown in the upper part of each figure , and the measurement with thenormal condition in the lower part. The curves show the
maximum ion current at the given strength of the<i3

Reference

1) K. Hoshino:p.180 in this report.

183

N -23.

On a Possible Medium-Beta RFQ Structure II
M. Odera, M. Hemmi, T. Chiba, and E. Ikezawa

We are examining possibility of use of an RFQ linac
for medium-beta region of velocity of ions. As a candidate of such RFQ, a structure based on the TM-010
mode of a cylindrical cavity which has been extensively
u~ed for the Alvarez linacs is examined.
Satisfactory transit time factor was not obtained forthe previously reported open electrode structure.1) Inthat case, a large n = 0 Fourier component in the axial
field degraded the transit time factor badly. Therefore,
we tried to improve the situation by modifying theelectrode configuration. Figure 1 shows a sketch of theelectrode array. It is composed of the vertical (a) andhorizontal (b) members interlaced as (c). It looks likechain. Therefore, let us call it chain configuration or
simply chain. Note that direction of field alternates in(a )Beam -ea~\SIransversal
bar

the neighboring accelerating gaps and the focusing
sections, though the field in TM-010 mode of thecylindrical cavity from which the inter-electrode fields
are derived, has the same direction everywhere in thecavity, when it is not loaded by any drift tubes orelectrodes. The alternation of the field is expected todecrease the n = 0 Fourier component and to improve
the transit time factor. Figure 2 is the result of measurement of the axial field in the chain. Here, cell length
corresponding to the phase shift of 2 1T of the RF field
was chosen to be 48.9 mm. The cell was made to havethe same length with that of Ref. 1, in order to facilitatecomparison. Accelerating gap is 12.2 mm and bars
separating the focusing region from the accelerating gap
is 8 mm in thickness. Length of the focusing region between the bars is 20.7 mm. Note that ratio of dimensions
was deformed considerably to help understanding of its
configuration in Fig. 1. Local maximum in the center ofthe focusing region suggests weakening of the axial fieldby increase of the transversal focusing field. Figure 3
gives relative magnitudes of its Fourier components in
one period. Though the arrangement is not optimized
yet, the DC component is decreased considerably whencompared to the previous one, where it was larger bymore than 60 % than the amplitude of the componentof accelerating frequency.
Evaluation of the transit time factors was made by
a numerical integration of the measured fields multiplied
by a factor of the sinusoidal variation with time. Obtained transit time factors is 90 % for the accelerating
gaps and is 63 % for the radiofrequency quadrupolar
focusing region. In the normal Alvarez linacs, the region

Fig. 1. Chain-like configuration of accelerating electrodes (a) Vertical member electrodes made by connecting two cylindrical bars by two flat bars with beam holes
at their center. Distance between the cylindrical bars
has been drawn larger than the real proportion of models
for convenience of illustration; (b) Horizontal members;(c) Scheme of the chain arrangement made by interlacing (a) and (b). Period between accelerating gaps of thevertical and horizontal electrodes is 2 1T or one betalambda. Between the gaps there is the region of focusing
where radiofrequency quadrupolar field excerts transversal force to the ions. The sign of focusing and defocusing alternates in the next focusing region.

of focusing is enclosed within the drift tubes and noaccelerating field exists inside. In the present case, thefocusing region has also a 1T mode-like acceleration effectcontributing to energy gain of this structure. In addition,
the electric field integrated along the axis at the accelerating gap was found larger than the voltage drop
expected by the prescription in which the mean accelerating gradient of the TM-OIO mode is multipledwith the cell length of 2 1T. The method corresponds tothe usual procedure of estimation of the ga,p voltage in
the Alvarez linacs. Reason of the larger gap voltage thanthe ordinary linacs is probably that the distance between
the stems supporting the electrodes belonging to thesame vertical or horizontal members corresponds to 4 1T,

184

Center of accelration gap

1 400
1 300
1 200
1 100
1000
900
SOO
700
u
600
~
500
~
400
x
<C
300
200
100
0
-100
- 200
-300
-400

1 400
1 300
1 200
1 100
Region of focsusing
1000
2S.7
900
SOO
700
600
500
400
Center of region
300
of focusing
200
100
0
- 100
- 200
-300
100
110
400
SO 90

Region of focusing

2S. 7

I

Center of regionof focusing

10

0

~

20

Axial position

Fig. 2. Measured distribution of axial field by a magnetic analog model.
See text for relevant geometrical parameters. Dotted vertical lines show
positions of center of the transversal bars. Transit time factors were calculated for accelerating and focusing regions separately between the centersof the bars.

regions for this structure is 2.6 MY jm which, when100

multiplied by the transit time factors, results in the ef-*c.3

fective accelerating voltage gradient of 2 MY jm. Thatc3

4 times of that of the usual Alvarez linacs , if the ohmic

means its effective shunt impedance becomes as high as"'---(/)(l)

u-~

loss of the cavity remains constant. Of course, the power

50

loss can not be the same for the structure equipped with

Q

E
(IJ

electrodes more complicated than the simple drift tubes'0of the Alvarez. Also the field was obtained by use of theQ+-'magnetic analog model excited in DC mode and would

(IJ

n:::

0

not perfectly reproduce the radiofrequency field. Re0

1

2

3

4

5

6

7

Number of harmonics

Fig. 3. Amplitude of Fourier components of the axial field distribution
shown in Fig. 2.

measurements by a high frequency model are desirable
to confirm the obtained results. A reduced scale model
is being fabricated for that purpose.
Whether this structure can be a practical linac which
has an effective shunt impedance superior to theordinary linacs or not , must be examined carefully byinstead of 2 'IT in the Alvarez linacs.
When the large effective accelerating voltage in the

more detailed study of its electrical and mechanicalgaps is added by the additional acceleration effect of thenumerically by measuring the axial and transversal field

focusing region, there is a possibility for this structure

distributions in fine steps.

properties. Especially, beam orbits must be traced

to have an effective shunt impedance larger than thoseof the Alvarez linacs for the similar velocity region of
the accelerated particles. Taking for an example, for

Reference

field gradient of 1 MYjm for the TM-OIO mode of1)cylindrical cavity, the integrated voltage through the two

M. Odera, T. Chiba, and M. Hemmi:
Progr. Rep., l.Q, 178 (I982).

RIKEN Accel.

185

N -24.

A Low-Beta RFQ Structure
M.OderaPossibility of use of RFQ structures is being st udied
by us to increase accelerated energies or intensities ofions of heavy elements at the RILAC. One is use ofa structure which might be useful in the medium-betaregion of velocity of ions. 1 ) We are also beginning tostudy a low-beta and low frequency structure as aopen ends. The shorting point is chosen reasonably distant from the central region , to avoid disturbance in thequadrupolar field. As shown in Fig. 1, only two shorting
rings will be used to connect the vanes at the entrance
and exit ends of the vane structure. It is planned tofabricate a reduced scale model and study its properties.

RILAC injector , which allows acceleration of ions oflower charge states and larger current than those which
are being accelerated by the present DC injector. Charge

Verti cal vane

may be increased by stripping before injection into thefirst cavity of the RILAC.
Its resonant frequency must be equal to or lower thanthe highest frequency in the frequency range of the main
linac in order to make transfer of beam between the
RFQ and the main linac with minimum loss. On theother hand, frequencies integer multiple of that of the
RILAC can be used for the medium beta RFQ linac
mentioned above, which is to be used to boost energy of
the RILAC. Operation mode of the RFQs should preferably be continuous to match with that of the mainpart, though pulse mode is also acceptable if the duty
factor is not excessively small .
As such structure , we are planning to try a four -vane
type RFQ ~hich has less symmetry with respect to thebeam axis than those fabricated to date. Figure 1 showsits cross sections. The reason to choose this configuration is to get relatively low resonant frequencies and to

Verti ca l vane

Horizonta lvane
Horizontal vane

Fig. 1. Cross sections of the planned low frequency
RFQ model. The two longer sterns may be connected
near the open end by metal rings to suppress the unwanted dipole mode.

test possibility of frequency tuning. Effect of the asymmetry on separation of the unwanted TE-IIO from thewanted TE-2IO modes will also be studied. Finally,

Reference
1) M. Odera, T. Chiba, and M. Hemmi : RIKEN Acce!.

complete suppression of the TE-IIO will be tried byconnecting the two longer stems at the point near the

Progr. Rep.,lQ, 178 (1982); M. Odera, M. Hemrni,
T. Chiba, and E. Ikezawa: p. 183 in this report.

186

N -25.

Small Computer System in Operationof the 160 cm Cyclotron
H. Takebe, S. Fujita, and K. Ogiwara

In the 160 cm cyclotron, it is essential to provide
the operations staff with fast and easy setting of theoperational parameters for any ion species and energy.
A small computer was equipped, for this purpose, to thecyclotron control system in July 1983. Using this computer, if we only input the particle name, charge number
and the energy, then all the operational parameters are

displayed and printed out and all the radio frequency(RF) parameters are set automatically. This system canalso stabilize the frequency on line with higher
intelligence, monitor the beam current and aquire dataof the operation.
Figure 1 shows this small computer control systemwith the cyclotron. The NEC PC-9801 (CPU; i8086)

Computer set

Cyclotron and control deskNEC
PC 9801

Options.g r - - - - - - ,E.

~~

bE=fl~~~~~~r~TI?t~

c:

..Q

Fig. 1. Block Diagram of the small computer system with the 160 cm cyclotron.

was purchased at the end of March 1983. We have prelpared isolation amplifiers ) to detect the actual positions of the cyclotron moving devices connected to thepotentiometer circuits. And we have modified the pushbutton switch units (control units) of the control desk.
A 14 inch high resolution color graphic display(640 x 400 dots), a dual drive 8-inch floppy disk unit
and an 18 pins dot-matrix printer with a 64 kB buffer
memory are providing us with faster development ofprograms. The PC-9801 has a main memory of 128 kB
RAM (96 kB is opened for users N88 BASIC program),a' 96 kB graphic VRAM, a 32 kB Text VRAM and 32 KB
BASIC ROM booter. A frequency counter (TakedaRiken; TR-5822) measures the cyclotron RF ten times
a second and its data output is led to the computer
through a GP-IB interface unit. All the external interface boards between cyclotron devices and the CPU arecomercial ones. A parallel I/O interface unit (CONTEC

Co., Ltd; PIOI6/16) has photo isolation ICs and driving
transisters. We changed those transisters to connect
our 48 V relay control circuit. Following hardwares of
the RF system were changed in order to set the RFparameters using the computer:(1) Plate capasitor was replaced by a variable vacuum
capasitor with motor drive mechanism and its position isdetected using a potentiometer.
(2) A heliostat type potentiometer was equipped tothe driving system of the shorting plate, instead of a selfsynchro meter.
(3) Not only an interlock of the air valve powerswitch for a contact finger of the shorting plate but alsoa pressure detection switch of the contact finger were
led to an interlock condition of the shorting plate driving system.
Main programs :ue written in N88-BASIC and somesubroutines for I/O control and some graphic com-187

mands are written in assembler language. An assembled
monitor code is called from the BASIC main program.
We basically developed five programs for the cyclotron
operation as follows:i) CYCLOii) RF-SETiii) F -STABILIZEiv) BEAM-MONv) LOG.
When we start up the cyclotron, we use the program"CYCLO" and the computer shows us a number ofparameters on the CRT display and printed out on
paper. Figure 2 shows a flow chart of this program as an
example. Seven parameters for the RF system (seeFig. 2) are calculated from the given frequency (Fp) as
preset values. Next, the computer sends a signal to turnoff the air valve of shorting plate finger and sends asignal to set the above seven parameters through control
units until each measured position becomes equal to thepreset values within 1 % accuracy. All the parameter
calculations were done using first- to sixth-order polynomial equations. Before these programming, we derived
the coefficients of those polynomials from the newest
data of cyclotron operation using a least squares fitting
method.
The program "RF -SET" is used only for the RFparameter setting and has the same function as thelatter half of the "CYCLO", independently.
The program "F -STABILIZE" is used for stabilizing
the cyclotron radio frequency, more stably than thedigital comparating circuit 2 ) does, which was used
before. The frequency counter sends a frequency datum(F) to the computer 5 to 10 times per second. If thedatum is of reasonable value (6 < F < 12 MHz, I F- Fp 1< M x 50 kHz, etc.), the datum is registered ina Fn data, where n means a data number and M is determined by the particle and a mode of the ion source
operation. The averaged frequency data Fa of the past
four data is defined by the following equation;

If the Fa exceeds some limitation values, the computer
determines a pulse width of the moving command fromthis value and judges whether it has to send to command
t6 move the upper, lower or both earth plates or not to
do. Thus, unnecessary movements of the above frequency compensating devices must be decreased. These
procedures also can be done to the dee voltage.
The program "BEAM-MONITOR" is used by all night
experimental staff to monitor the beam intensity, deevoltage etc. with a buzzer.

Particle nameEnergyMagnetic field. current
Shim coil currents
Dee voltage
Frequency

M/Q
Gamma
Qu- Magnets currents
SW-Magnet current
Nearest M/Q resonanceFrequency and current

r----'--...., RF parameters; Shord plate

Plate loop
Plate capacitor
Cathode loop
Coupling capacitor
Upper earth platet--_ _ _ _ _ _L-,ower earth plate
HardwarePresetSequence

Fig. 2. Flow chart of the program "CYCLO" tocalculate the operational parameters for any
ion species and energy and automatic setting of
the RF parameters.

These programs manage to print out the frequency,
dee voltage, and beam currents data in a certain intervalof time and show a histogram plot of the above data of
past three to sixty minutes on a colour graphic display.
The program "LOG" is to record the cyclotron
parameters on a floppy disk.
The interpreter language, BASIC on the 16 bit CPU,
is not fast for processing for the on line control program,but good enough to control the mechanical driving
system in our cyclotron. Moreover, development ofprograms using the BASIC interpreter is quite faster thanother compiler languages.

References
1) Isolation Amp. (LH0036C) with variable gain andadjustable offset, made by Riken Machine Shop,(M. Fuse and K. Nishi).
2) H. Takebe, K. Ogiwara, and Y. Yamada: IPCR
Cyclotron Progr. Rep., 14,6 (l980).

188

N -26.

Present Status of the Baby Cyclotron
at the Nakano Hospital
T. Karasawa

satisfactorily for the production of radio-isotopes usedby a computer image processing. It is hoped that
11 C-I-glucose-mannose mixture can serve as a valuable

in diagnosis and in experiments of labelled compoundradiopharmaceutical for cancer diagnosis in humans.

During this year, the cyclotron has been working

synthesis. The beam currents at the target box were

15 J.1A and 10 J.1A for protons and deuterons, respectively. Change of accelerating particle from proton todeuteron has been simplified. The ion source position
with respect to puller is adjusted without change ofmagnetic field distribution near the center, while theo ~------------------------~~

magnetic field distribution was changed previously by- 0,5

narrowing the gap between center plugs at the deuteronacceleration.

- 1~5~----~
1 0~----~
1~
5 ----~
2~
0 --~
24

When V0 is half of peak-to-peak dee voltage, energyr (em)

gain per turn for deuterons and protons are 4V 0 coseand2j2Vocos8,

respectively.

Functional

Fig. 1. Phase history of deuterons.

relation

between sin8 and radius is termed phase history and we
can determine sine by beam fall off radius measured on
beamprobe. The equation for sin8 was reported in

the previous report. 1 ) The phase histories for deuterons
and protons under the present operating condition are
shown in Fig. 1 and Fig. 2, respectively.
The

1 So

labelled molecular oxygen and carbon

0.5
Ln
q
I
Q)

0

0

x

c

iii

-0,5

dioxide were easily produced by deuteron irradiation
and used for diagnosis of lung functions, routinely.

-1

5

15

20

24

r (em)All C-l -glucose and mannose mixture was synthesized in automatic apparatus from 11 C-HCN, which

10Fig. 2. Phase history of protons.

is produced by an in-target recoil method using proton
bombardment of mixtures of nitrogen and hydrogengases. After intravenous injection of the solution of
the glucose and mannose to tumor-bearing rabbits,
the tumor was specifically visualized on a gamma camera

Reference
1) T. Karasawa:

27 (I978).

IPCR Cyclotron Progr. Rep., il,

189

V.

RADIATION MONITORING
1.

Radiation Monitoring Station

M. Okano , M. Nishida , S. Fujita, and H. Kamitsubo

Measurement of Gamma-rays has been continued at
the monitoring station located at about 85 m SSE fromthe cyclotron by using a scintillation detector witha specially designed shield for energy compensation. 1 )The values include the contribution of soil radioactivity,
but the contributions from cosmic rays and detector
contamination were subtracted.
In Fig. 1 each bar represents the range of daily varia-

A monitoring system of the same kind was used as fortion of the dose rate and dots represent mean values overlinac monitoring posts .
The observed results of monitoring during the period
from Jan. 1982 to Oct. 1983 are shown in the figure

24 h. Higher dose rates observed from time to time are
due to radon daughters falling down with rain or snow.
No significant leakage radiations from the cyclotron

where the radiation level is given in the unit of J-LR/h .

were detected during this period as was always the case

j1 Rl h8. ----------------------------------------------------. 8

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

4~--~--~----~~--~~+_---+~------~+_~--+_--_,~ 4

1982
j1Rl h8, ----------------------------------------------------. 8

6~----------------------+_,_~------------~--------~6

1983

Fig. 1. Record of radiation monitoring at the station 85 m SSE from the cyclotron.

since 1975. Contribution of radioactive fallout due tonuclear explosions , which had been observed several
times since the station was set up in 1966, had disappeared.

Reference
1) T. Hamada , M. Okano, and M. Ota: IPCR
Cyclotron Progr. Rep., 1,81 (1967).

190

V -2. Neutron Skyshine from the Cyclotron
T. Nakamura ,* A. Hara,* T. Ohkubo,* T. Kosako,* s. Iwai,*
M. Okano, S. Fujita, H. Kamitsubo, I. Kohno, and T. Shikata

Neutron leakage through the cyclotron building into
the atmosphere was measured when the cyclotron was

neutron skyshine effect.
Acommercially-available

neutronrem

counter,

operating on 20 MeV deuteron beam acceleration andStudsvik 2202D , and the multi-moderator neutron

the beam was bombarding a 4 mm thick beryllium target

spectrometer developed by the Institute for Nuclear

in a large experimental room, in order to investigate theStudy (INS)!) were used for thi,s measurement. Figure 1
shows the cross-sectional view of INS multi-moderator
neutronspectrometer. The

distribution of leakage

neutrons from the cyclotron building was measured on
BF3 Counterr- - 282 -+13

. . ~~~

lQji:- .....

Polyethylene
thicknesslcm

r- - 34,91°

3~1---,-----c~,", ~~:}r-

the roof of the building. The height of the building was
7.7 m . The detector were placed 118 cm above the

Figure 2 shows the detect ion points on the roof and3cm

Table 1 gives the results of dose mapping. The former

Polyethylene
thickness
6cm

beam current of 7 f.1A and the latter under that ofmeasurement was carried out under the average deuteron';0'100,·=-~:;~~~~~~:"":'----c--'--_--:----'_---,.-_-'--:---f',-t,

~

°
'0

" Poiyethylene ',16 f.1A . In Table 1, the former results normalized to thelatter results are also shown . Two separate measurements

1---- -46.l- -------+j
Cadm ium (005) ,carried out twice on August 2 and December 28 , 1982.

Polyethylene
thickness

0'1.,

40,6

upper surface of the building roof and moved horizontally for neut ron dose mapping. The measurement wasshow very good agreement after the normalization.
Polyeth ylene
thickness~ 10cmFrom Table 1 , a strong neutron leakage can be clearlyseen at Positions N , S, K , especially at N , in Fig. 2 ,where the dose was stronger than 10 2 times the dose at~~================~

Fig. 1. Cross-sectional view of INS Multi-Moderated
Neutron Spectrometer. Dimensions are given in units
ofcm.

Position A which is just above the target. These positions
are above the air ducts which go through the concrete

® I

en

(Ex perimental room)

Fig. 2. Detection points on the roof of the cyclotron building.

*Institute for Nuclear Study , University of Tokyo.

191

Table 1. Neutron dose mapping data 118 cm above the roof of the cyclotron building
with the Rem Counter, Studsvik 2202D.
Dose (mrem/h)Positiona )

12/28

8/2
7 pA b )16 pA c)

16 pA b)

0.14
0.043
0.013
0 .0067

0.31
0.097
0.029
0 .0150.31

H0.00660.00950.0085
0.071

I

0.82

0 .015
0.022
0.019
0.16
1.89
0.46
2.17
0.11

A
B
C

D

E
F
G

J

0.20
0 .95
0.048

K
L
a)
b)

Dose (mrem/h)Positiona )8/2
7 pA b )12/28
16 pA b )16 pAc)

M
N
0
P

23.2

43.8
52 .5
49.9
33.0

53.0

Q

10.7
1.19
7.25
1.45

R
S
T
U

3.75

8.58

V
W

1.80

4.11

1.93
4.28
7.14
0.79

X

Position is indicated in Fig. 2. The dose conversion factor is 3.6 cps per mrem/h given in the instruction manual.
Deu teron beam intensity .
The column under c) stands for the numerical values normalized the dose rates measured under the beam current of 7 p.A to
those for 16 p.A .

roof. Detailed mapping was , therefore , done around theair duct as shown in Fig. 2 and Table 1. In parallel with
this, rough neutron energy spectra at various points on
the roof of the target chamber were measured using thedetector described previously.2) Dose rates and theflux densities of thermal neutrons obtained in thismeasurement are given in Fig . 3 . It can be seen that theareas around the Positions N, S, and K are the main
skyshine neutron source from the cyclotron building .

The measurements at Positions N and A and in thefield 84 m away from the target in the cyclotronbuilding were performed with INS multi-moderator
neutron spectrometer to get the information on theneutron energy spectrum in addition to dose. The
neutron spectrum was obtained with the SAND-II unfolding code 3 ) by using the response function given in
Ref. 1. The result is shown in Fig. 4. The dose obtained
from the spectrum in Fig. 4 is compared with the dose
directly obtained from the rem counter in Table 2. At
Position N, the dose by the rem counter is about 30 %1.00.5(0 } 5) (O PS)

11r---"1 (OlS)

0.9
1.2
1.0
(0 1 4) (o.} S) (0 16)

I

:

11

I

(017)

:

L__-, 111.2

( ~l S)1 (0 IS)

Roof on air duct . Point N(Target room)

. . .

1.8
2.5
2.0
(0.29) (040) (032)14

4.1( Main skyshine source)

1.S(OP) (0 ~5) (0 ~9)

Shielding door
1.2(0} 8)
1.2(0 19)

oN

5.6

3.9

(0 ~9 )

(0~2)

5.2

30

(0. ~3 ) (O ~S)

°A

2.5
0.45
(0.40) (0~7)- - Measured by INS multi - moderator spectrometer-- --. - Calculated by MMCR-2 Monte Carlo code

1.0
1.S
(0.29) (0 16 ). .

Fig. 3. Detection points on the roof of the target
chamber and the flux densities of thermal neutrons(n/cm 2 sec). Estimated dose rate is also given inparentheses (mrem/h).

Field 84m from target

5

10 2
10 1
10 4
Neutron energy (eV )10 5Fig. 4. Neutron-energy spectra
source and in the environment.

of10 - 10 _1 10°

10 1

10 6

10 7

sky shine

192

Table 2. Comparison of neutron doses measured by the rem counter andthe INS Multi-Moderator Spectrometer.
Dose (mrem/h)Position

Deuteronbeam

Rem counter

Multi-moderator

Studsvik 2202D

spectrometer

N

52.5

38.4

16 J.lAA

0.311
0.352 x 10 - 3

0.288
0.356 X 10- 3

16 J.lA

3

0.814 X 10- 3

16J.lA

84m{ 0.805 x 10-

in the field

intensity

7 J.lAhigher than the dose by the spectrometer, but at Posi-

with the measured neutron spectrum at 84 m away fromtion A and in the field both results show quite goodthe source in Fig. 2.

The agreement between ex-

agreement. In Table 2, the dose conversion factor was

perimental and calculated spectra is very good. The cal-set to be 3.6 cps per mrem/h given by the maker at Posi-

culated dose was 0.0456 J.lrem/h and the ratio to thetions A and N on the roof and 4.75 cps per mrem/h inmeasured dose of 0.814 J.lrem/h is 1/17.8. From thisthe field point. From Fig. 4, it is seen that the former

ratio, the effective radius of the skyshine neutron source

two spectra are roughly close to 1 IE spectra over theon the roof of the cyclotron building is decided to bewhole energy region and the spectrum in the field is

95 cm to get the absolute agreement between measured

about 1 IE below 1 MeV and l/E2 above 1 MeV. The

and calculated neutron spectra and doses.

number of 4.75 was selected, from the results of ourprevious paper,4) to be appropriate to the spectrum of
1 IE + 1/E2, since the sensitivity of the rem counter

References

deviates from the rem response defined in ICRP Publ.

1)2l.
The measured neutron spectrum in the field was

M. Kamata:

INS-TS-23,

InstituteforNuclearStudy, University of Tokyo, (in Japanese), Aug.

analyzed by the MMCR-2 Monte Carlo code developed
by Nakamura. S ) The source neutron spectrum was set

T. Kosako, T. Nakamura, S.lwai, S. Katsuki, and2)(1973).
T. Hamada, M.

Okano, K.

Izumo,

T. Katou,

to be the spectrum measured at Position N in Fig. 2,

H. Kumagai, andwhere the major neutron leakage from the cyclotronbuilding occurred. The source neutron flux was 9.6 x
10 2 n/( cm 2 . sec) per 16 J.lA of deuteron beam. The

Chosa Kenkyu Seika Ronbun Shorokushu, 22, 147(1979); ibid., 23, 155 (1980).
3)

cross sections for air at a density of 1.293 x 10- 3
made

from

the

DLC-2D library.6)

W. N. McElroy, S. Berg, T. Crockett, and R. G.
Hawkins:g/cm 3 consist of 26 energy group constants in a P8
approximation

M. Nishida: Kankyo Hoshano

AFWL-TR-67-41, Vols. I-IV, Air Force

Weapons Laboratory (1967).
4)

T. Kosako, T. Nakamura, T. Michikawa, K. Katoh,

The effect of the ground was treated by the albedo

M. Nakazawa, T. Tsujimoto ,Monte Carlo method, and the ordinary concrete albedo

Sekiguchi: J. At. Energy Soc. Japan, (in Japanese),

data of DLC-57 library 7 ) was used as the albedo data on
the ground. The plane mono-directional source which

5)24,139 (1982).
T. Nakamura and T. Kosako:

6)

168 (1981).
RSIC Data Library Collection, DLC-2D, Radiationemits neutrons perpendicularly upward was assumed to
be placed 7.7 m above the ground. The radius of theplane source r was first put at the size of the air duct,

Nucl. Sci. Eng., 77,

Shielding Information Center, Oak Ridge Nationalr = 22.6 cm, which is the major skyshine source asshown in Fig. 2, because the distribution of neutron

I. Kimura, and A.

Laboratory (1975).
7)

G. L. Simmons: SAI/EPRl

AlbedoInformation

source on the roof given in Table 1 is very complicated.

Library, EPRI NP-I017, Electric Power Research

The calculated neutron energy spectrum is compared

Institute (1979).

193

V -3.

Routine Monitoring of the Cyclotron

M. Koyama, K. Igarashi, I. Usuba, S. Fujita , and I. Sakamoto(2) Drainage

Results of routine radiation monitoring carried out
on the cyclotron from April 1982 to March 1983 are

The radioactivity concentration of the drain waterNo remarkable change in residual activities was ob-from the cyclotron building was found to be of theorder of 10 - 6 - 10- 7 pCi/cm 3 . The total quantity ofserved during this period. Some aspects of the leakage

activities in the aqueous effluents in this period wasradiation are described in the following report.

about 17 pCi, and the radioactive nuclides found by the'Y-ray spectrometry were mainly 147Gd, 60Co and
137 Cs.

described.

(1) Surface and air contamination
The surface contamination has been kept below 10- 5
pCi/cm2 on the floor of hot laboratory, and below 10- 6(3) Personnel monitoring

pCi/cm 2 in the cyclotron room, experimental areas,The

external

exposure

dose

topersonnel

wasunderground passage and chemical laboratories. The

measured with 'Y-ray and neutron film badges. The doseradioactive nuclides found by the 'Y-ray spectrometry
were 65Zn , 1850S and 137Cs. The contamination wasreceived during the present period by all the cyclotron
workers is shown in Table 1. The collective 'Y-ray dose

wiped off twice a year, and immediately after thisto all workers was 960 man-mrem , while the collective
dose owing to thermal and fast neutron exposures were

decontamination , the contamination on the floor of theabove places had been reduced to a value below 10- 7

too small to be detected. The collective dose to thecyclotron workers is about 92 % of the value in thepCi/cm 2 .

preceding period.

When the accelerating chamber was opened, slight

In this period the average annual dose per person was

contamination of the air in the cyclotron room was ob-

10.8 mrem , and the maximum individual annual doseserved. The value of radioactivity concentration (betagamma) was 10- 12 pCi/cm 3 .

was 140 mrem.

Table 1. Annual exposure dose received by the cyclotron
workers from April 1982 to March 1983.
Number of persons
Collective
Workers

Operators
Nuclear physicists
Accelerator physicists
Physicists in other fields

Dose

10 - 100> 100undetectable(mrem)(mrem)

2
8
15
20

6

8

1

9

9

24
23
7

Nuclear chemists
Radiation chemists
Biological chemists
Health physicists
Total

3
5

3
9
5
63

Average annual dose per person : 10.8 mrem
Maximum individual annual dose : 140 mrem

Total

dose
(man-mrem)

240
40
140
70
460

3

25

10
5
89

10
960

194

V -4.

Leakage-Radiation Measurement at the Underground
Passage of the Cyclotron Building
I. Sakamoto and S. Fujita

Leakage radiation during operation of the cyclotron

March 1983 by 'Y-ray and neutron film badges whichwere left at the underground passage, are shown in Table
1.

deuterons. The beam current was 10 "'15 J.lA.
As to the dose values at point No.1 measured every
months, the maximum total dose was observed in
December. In this case, the values of gamma dose andthermal neutron dose were 15000 mrem and 4340
mrem, respectively. The fast neutron dose could not be

In this period, the machine time allotted for deuteronacceleration was 24 h in August and 52 h in December.
Fast neutrons were generated in the beam course No.2
by bombarding a thick beryllium target with 20 MeV

measured because the gamma dose was too large.
The radiation levels outside the cyclotron building
due to neutrons from the cyclotron were measured inAugust.· )at the underground passage of the cyclotron building
was measured. Leakage dose received from April 1982 toTable 1. Leakage radiation dose (in mrem) at the underground passageof the cyclotron building from April 1982 to March 1983.
Point of observation *2-y-rays (mrem)
Thermal neutrons (mrem)
Fast neutrons (mrem)
Total (mrem)AugustDecember

Other months

Total

2170
590
0
2760

15000
4340

1270
380
10
1660

18440
5310
10
23760

un d etectab Ie

19340

120
90
0
210

* See the figure shown below.
t=:t:::t::t:::lO12345m

Experimental area (l) :Target__ , '-', !i0u rse
I
o.,?

1.-'

Undergrou nd passage ' / :I

II" Undergroundpassagex 1.----! ON

!i,

I

.. /'

0

I

,/

Hand foot cloth
monitorControlroom

Basement
Ground plan

Reference
1) T. Shikata, S. Fujita, I. Kohno, H. Kamitsubo,
M. Okano, T. Nakamura, T. Kosako, A. Hara, andS. Iwai: RIKEN AcceL Progr. Rep., lQ, 239(1982).

195

VI.

LIST OF PUBLICATIONS

1. Accelerator development and accelerator physics
1) s. Motonaga, H. Takebe, A. Goto, T. Wada, J.
Fujita, N. Nakanishi, Y. Yano, N. Kishida, I.
Yokoyama, L Takeshita, H. Kamitsubo, J. Abe,
T. Tsukumo, H. Saito, and T. Sato: "Sector
Magnets for the RIKEN SSC", Sci. Papers
I.P.C.R., 77,8 (1983).
2) A. Goto, H. Takebe, S. Motonaga, Y. Yano, N.
Nakanishi, and T. Wada: "Trim Coil Field
Measurement and Trim Coil Power Supply
Specifications for the RIKEN SSC", Sci. Papers
LP.C.R., 77,54 (1983).
3) N. Kishida, Y. Yano, and A. Goto: "Beam Extraction System for the RIKEN SSC (I)", Sci.
Papers LP.C.R., 77, 63 (1983).
4) T.Inamura, N. Kishida, Y. Hata, and H.
Kamitsubo: "The RIKEN SSC Beam Handling
System (II)", Sci. Papers I.P.C.R., 77,96 (1983).
5) M. Hemmi, Y. Miyazawa, T. Inoue, and M.
Odera: "Design, Fabrication and Performanceof the Dipole and Quadrupole Magnets for the
RIKEN Heavy-Ion Linear Accelerator", Reports
I.P .C.R., (in Japanese), 59, 79 (1983).
6) M. Odera: "Status of Operation of RIKEN
Heavy-Ion Linac, RILAC", J. At. Energy Soc.
Japan, 25, 769 (1983).
7) M. Kase, T. Kambara, A. Goto, Y. Yano, and M.
Odera: "Beam Characteristics of the RIKEN
Heavy-Ion Linac, RILAC", J. At. Energy Soc.
Accelerator Tech., (in Japanese), p. 101 (1983).
2. Nuclear physics and nuclear instrumentation
1) M. Ishihara: "Direct Reaction with Heavy Ions",
Nucl. Phys., A400, 153C (1983).
2) Y. Itoh, Y. Gono, T. Kubo, M. Sugawara, and T.
Nomura: "Excited States in 216 Ra", Nucl.
Phys., A410, 156 (1983) .
3) T. Fukuda, M. Ishihara, M. Tanaka, H. Ogata,
L Miura, M. Inoue, T. Shimoda, K. Katori, and
S. Nakayama: "Correlation between AlphaParticles and Ejectiles in the 208 MeV 14N on
93Nb Reaction at Three Different Ejectile
Angles", Phys. Rev. C, 27, 2029 (1983).
4) H. Utsunomiya, S. Kubono, M. H. Tanaka, M.
Sugitani, K. Morita, T. Nomura, and Y.
Hamajima: "Breakup-Fusion of 7Li", Phys. Rev.
C, 28,1975 (19'83).
Power-Polarization
5) T. Fujisawa: "Analyzing
Inequality in the Inelastic Scattering of Protons

on 12C for Incident Energies from 22.0 to 29.0
MeV", Sci. Papers I. P. C. R., 77,113 (1983).
6) M. Tohyama and S. Yamaji: "Effects of Two
Particle-Two Hole Excitations on the Mass Distribution in Ion-Ion Collisions", Phys. Lett.,
123B, 16 (1983).
7) S. Yamaji . and A. Iwamoto: "Friction Coefficients for Deep Inelastic Heavy-Ion Collisions", Z. Phys. A-Atoms and Nuclei, 313, 161(1983).
8) M. Ohshima, E. Minehara, M. Ishii, T.Inamura,and A. Hashizume: "Multiple Coulomb Excitation of 167Er", J. Phys. Soc. Japan, g 2959
(1983).
9) T. Inamura: "Spring in Crimea", Butsuri, (inJapanese), 38, 763 (1983).
3. Atomic and solid-state physics
1) K. Maeda, Y. Sasa, S. Nakamura, and M. Uda:
"Particle Induced X-Ray Emission (PIXE)
Analysis using RIKEN Heavy Ion Linac", Reports I.P.C.R. , (in Japanese), 58, 117 (1982).
2) J. Mizuno,
T. Ishihara,
and T. Watanabe:"Energy Exchange between Two OutgoingElectrons in the Post Collision Interaction Processes", Atomic Collision Res. in Japan-Prog.
Rep., No.9, p. 2 (1983).
3) H. Suzuki, N. Toshima, T. Watanabe: "Exponential Distorted Wave Approximation in
Charge Transfer", Atomic Collision Res. inJapan-Prog. Rep., No.9, p. 33 (1983).
4) K. Fujiwara, N. Toshima, and T. Watanabe:"Close Coupling Calculation of Electron Capture
at High Energies", Atomic Collision Res. inJapan-Prog. Rep., No.9, p. 36 (1983).
5) S. Karashima and T. Watanabe: "Stripping
Cross Section of Multi-Charged Ions by Neutral
Atoms", Atomic Collision Res. in Japan-Prog.
Rep., No.9, p. 39 (1983).
6) T. Matsuo, J. Urakawa, A. Yagishita, H. Shibata,Y. Awaya, T. Kambara, M. Kase, H. Kumagai,
and J. Takahashi: "Ar L-MM Auger Spectra in
Ar 3,4+ Ar Collisions", Atomic Collision Res. inJapan-Prog. Rep., No.9, p. 83 (1983).
7) Y. Awaya, T. Kambara, M. Kase, H. Kumagai, H.
Shibata, J. Takahashi, J. Urakawa, T. Matsuo,
and M. Namiki: "Multiple Inner-Shell Ionization of Argon Ions Impinging on Foils", Atomic
Collision Res. in Japan-Prog. Rep., No.9, p. 86

196(1983).

rium of Energetic Heavy Ions in Gaseous Media(Ideal Atomic Hydrogen Gas)", Jpn. J. Appl.
Phys. , 22, 895 (1983).

8) J. Takahashi, Y. Awaya, T. Kambra, M. Kase, H.
Kumagai, H. Shibata, J. Urakawa, and T. Matsuo:"Angular Distribution of Au L X-Rays by Heavy19) E. Yagi, T . Kobayashi, S. Nakamura, Y. Fukai,

Ion Impact", Atomic Collision Res. in JapanProg. Rep. , No.9, p. 89 (1983).
9) T. Kambara , Y. Awaya, M. Kase, A. Hitachi, T.

and K. Watanabe: "Lattice Location of Hydrogen in Tantalum as Observed by Channeling
Method Using Nuclear Reaction 1 He 1 B, 0: )Tonuma, and I. Kohno: "Collisional Quenchingof Hydrogen-Like Ne-Ions with Kinetic Energyof 5.5 MeV/amu" , Atomic Collision Res. inJapan-Prog. Rep., No.9, p. 91 (1983).

20) T. Kambara: "Radiative Electron Capture in
Heavy Ion-Atom Collisions", Butsuri, 38, 376

0:0:", J. Phys. Soc. Japan, 52, 3441 (1983).

10) J. Mizuno , T. Ishihara , and T. Watanabe:"Energy Shift of Emitted X-Rays Following
Inner Shell Photoionization near Threshold",(1983).
21) T. Kagawa, T. Kato, T. Watanabe, and S.
Karashima: "Atomic Processes in Hot Dense
Plasmas", IPPJ-AM-31 Report, Inst. of Plasma

Atomic Collision Res. in Japan-Prog. Rep.,
No.9, p. 136 (1983).
11) K. Fujima, T. Watanabe, and H. Adachi: "ThePhysics, Nagoya Univ. (1983).
22) I. Shimamura: "Electron Collisions with Atoms,
Molecules, and Ions. General Review", Basic

Analysis of Electronic Property of Extremely

Researches in Science of Atomic Processes,

Condensed Matters by the DV-Xo: Method I.
Application to Cold and High Density Neon

Published by the Special Research Project Group

Plasma", Atomic Collision Res. in Japan-Prog.
Rep., No.9, p. 152 (1983).
12) T. Takahashi,
Y. Awaya,T. Tonuma,
H.
Kumagai, K. Izumo, M. Nishida, A. Hitachi, A.
Hashizume,
S. Uchiyama,
andT. Doke:"Stopping Power of Ni, Ag, Au, and Pb for", 7Zi

MeV/nucleon 0: Particles and Carbon Ions.
Deviation from the Bethe Formula", Phys. Rev.

'Basic Researches in Science of Atomic Processes', p. 57 (1983).
23) I. Shimamura: "Sum Rules and Partial-Sum
Rules for Rotational Transitions of Molecules" ,Electron-Molecule Collisions and Photoionization
Processes, (eds. V. McKoy et al.), Verlag ChemieIntern., Deerfield Beech, Florida, p. 67 (1983).
4. Radiochemistry, radiation chemistry and radiationA, 27,1360 (1983).
13) I. Shimamura: "Partial-Sum Rules for andAsymmetry between Rotational Transitions J ±6J +- J", Phys. Rev. A, 28, 1357 (1983).

biology14) A. Hitachi, T. Takahashi, N. Funayama, K.
Masuda, J. Kikuchi, and T. Doke: "Effect of2) T. Takahashi, F. Yatagai, and S. Kitayama:

Ionization Density of Luminescence from Liquid
Argon and Xenon", Phys. Rev. B, 27 , 5279
(1983).
15) T. Watanabe, T. Ishihara, and J. Mizuno:"Com-parison of Threshold Effects in Auger Process Induced by Electron and Photon Impact Ionization", J. Phys. B: At. Mol. Phys., l.§, L107
(1983).
16) T. Matsuo, J. Urakawa, A. Yagishita, Y. Awaya,
T. Kambara , M. Kase , and H. Kumagai: "Ar
L-MM Auger Spectra in Ar 3 + + Ar Collisions",
J. Phys. B: At. Mol. Phys.,16, L239 (1983).
17) K. Nishiyama,
K. Nagamine,
T. Natsui, S.
Nakajima, K. Ishida, Y. Kuno, J.Imazato, H.

1) F. Yatagai, T. Takahashi, and S. Kitayama:"W-

Reactivation and W-Mutagenesis in Phage ¢X174", Adv . Space Res.,], No.8, 65 (1983).
"Ef-fect of Heavy Ions on Bacterial Spores", Adv.
Space Res. ,], No.8, 95 (1983).
3) Y. Nagame , M. Watanabe, H. Kudo, K. Sueki, H.
Nakahara, and I. Kohno, "Recoil Studies in theReaction Induced by 115 MeV 14N on 62Ni",
Radiochim : Acta, 33, 127 (1983).
4) K. Kimura and J. Hormes: "Roles of the
Rydberg Transitions in Fast Excitation Transfer
Studied in Cyclohexane and n-Heptane Using
Synchrotron Radiation", J. Chern. Phys., 79,2756 (1983).
5) I. Kaneko: "Current Topics in Potentially
Lethal Damage Repair Research", Tissue Culture,
2,328 (1983).
6) S. Ishii, K. Okazaki, Y. Sakamoto, and K. Yano:

Nakayama, T. Yamazaki, and E. Yagi: "Critical"ECR-Discharge Cleaning for Linear Containing

Phenomena in Nickel Studied with Pulsed /1 SR",J. Magn. and Mag. Mater., 31-34,695 (1983).
18) S. Karashima and T. Watanabe: "Charge Equilib-

Tokamaks", lpn. l. Appl. Phys., 22, L403
(1983).
7) A. Akanuma, F. Yatagai, K. Igarashi, K. Usuba,

197

and T. Irifune: "Mouse Skin Reactions to 40
Me V Helium Ion Irradiation", Radiological
Medicine (Hoshasenka),l, 243 (1983).
8) Y. Sakamoto: "ECR Discharge Cleaning of
Toroidal Machines", Proc. IX IVC - V ICSS, Invited Papers' Volume (1983, Madrid), p. 716(1983).

(Papers Presented at Meetings)
1. Accelerator development and accelerator physics
1) M. Kase, T. Kambara, T. Tonuma, and M. Odera:"Acceleration Test at the RILAC", Symp. on the
Next Project of RCNP, Osaka, Jan. (1983).
2) J. Fujita, T. Kambara, K. Shimizu, T. Wada, Y.
Yano, and I. Yokoyama: "Control System for
the RIKEN SSC (I)", 6th Symp. on Future Project of RCNP, Osaka, Jan. (1983).
3) N. Nakanishi: "Beam Dynamics in the RIKEN
SSC (1)", 6th Symp. on Future Project of RCNP,
Osaka. Jan. (1983),
4) A. Goto and Y. Yano: "Beam Dynamics in the
RIKEN SSC (III)", 6th Symp. on Future Projectof RCNP, Osaka, Jan. (1983).
5) M. Kase, T. Kambara, T. Tonuma, and M. Odera:"Energy Tuning by the Phase Control at the
RIKEN Heavy-Ion Linac" , 38th Ann. Meeting of
the Phys. Soc. Japan, Tokyo, Mar. (1983).
6) M. Kase, Y. Miyazawa, M. Hemmi, T. Inoue, and
T. Chiba: "PIG-Type Heavy-Ion Source for the
RILAC" , Symp. on Ion Source for Accelerator,
Tsukuba, Mar. (1983).
7) M. Hara, T. Wada, T. Fukasawa, and F. Kikuchi:"Three Dimensional Analysis of RF Electromagnetic Field by Finite Element Method",
Particle Accelerator Conf. on Accelerator
Engineering and Technology, Santa Fe, U.S.A.,
Mar. (1983).
8) M. Hara, T. Wada, T. Fukasawa, and F. Kikuchi:"A Three Dimensional Analysis of RF Electromagnetic Field by the Finite Element Method",
COMPUMAG Conf. on Computation of Electromagnetic Fields, Genoa, Italy, May (1983).
9) M. Kase, T. Kambara, A. Goto, Y. Yano, and M.
Odera: "Beam Characteristics of the RIKEN
Heavy-Ion Linac" , 8th Symp. on Linear Accelerator, Tokyo, July (1983).
10) F. Kikuchi, M. Hara, and T. Wada: "A Primitive
Variable Approach for Finite Element Analysis
of Electro-magnetic Waves", JSSC 17th Symp.
on Matrix Analysis, Tokyo, July (1983).

11) A. Goto, M. Kase, Y. Yano, Y. Miyazawa, and M.
Odera: "Numerical Orbit Calculation for a
Linac and Improvement of Its Transmission Efficiency of a Beam", Computing in Accelerator
Design and Operation, Europhys. Conf., Berlin,
W. Germany, Sept. (1983).
12) S. Motonaga, H. Takebe, A. Goto, Y. Yano, T.
Wada, and H. Kamitsubo: "Sector Magnet for
the RIKEN SSC", 8th Intern. Conf. on Magnet
Technology, Grenoble, France, Sept. (1983).
13) M. Odera: "Operation of RIKEN Variable Frequency Heavy-Ion Linac, RILAC", 2nd JapanChina Joint Symp. on Accel. for Nucl. Sci. andtheir Applications, Lanzhou, China, Oct. (1983).
14) T. Wada, J. Fujita, K. Shimizu, I. Yokoyama, and
T. Kambara: "Control System of the RIKEN
SSC", 2nd Japan-China Joint Symp. on Accel.
for Nucl. Sci. and their Applications, Lanzhou,
China, Oct. (1983).
15) M. Hara, T. Wada, T. Nakahara, and F. Kikuchi:"A Three Dimensional Analysis of RF Electromagnetic Field by the Finite Element Method",
2nd Japan-China Joint Symp. on Accel. for Nucl.
Sci. and their Applications, Lanzhou, China, Oct.
(1983).
16) N. Nakanishi, A. Goto, and Y. Yano: "BeamDynamics in the RIKEN SSC", 2nd Japan-China
Joint Symp. on Accel. for Nucl. Sci. and their
Applications, Lanzhou, China, Oct. (1983).
17) K. Hayashi, A. Goto, T. Hattori, Y.Oguri, Y.
Ozawa, Y. Sato, and E. Arai: "2.5 MeV/u IH
Heavy-Ion Linac at TIT - Beam Dynamics",
1983 Fall Meeting of the Phys. Soc. Japan, Kobe,
Oct. (1983).
2. Nuclear physics and nuclear instrumentation
M.Ohshima,
S. Kikuchi,T.
1) E. Minehara,
Inamura, A. Hashizume, and H. Kumahora:"Multiple Coulomb Excitation of 163Dy", 38th
Ann. Meeting of the Phys. Soc. Japan, Tokyo,
Mar. (1983).
2) Y. Itoh, Y. Gono, T. Kubo, M. Sugawara, and T.
Nomura: "Level Structure of the Ra-Isotopes",
38th Ann. Meeting of the Phys. Soc. Japan,
Tokyo, Mar. (1983).
3) S. Yamaji, A. Iwamoto, K. Harada, and S.
Yoshida: "The Effect of the Mass Fragmentation Potential on the Width of the Mass Distribution in the Deep Inelastic Heavy Ion Collision",
38th Ann. Meeting of the Phys. Soc. Japan,
Tokyo, Apr. (1983).
4) T. Inamura: "Fast-Particle Emission in Heavy-

198

Ion Reactions. Massive Transfer", Intern.
School Seminar on Heavy-Ion Physics, Alushta,

and Y. Awaya: " L-MM Auger Electrons in
Ar 3 +,4+ + Ar Collisions", 4th Symp. on Atomic

U.S.S.R. , Apr. (1983).
5) T. Inamura , A.C. Kahler, l.R. lolnowski, U.

Collisions by Using Accelerators, Wako, Feb.

Garg ; and T.T. Sugihara : "Gamma-Ray Multiplicity Distributions Associated with Massive
Transfer", Intern. Conf. on Nuclear Physics,
Florence , Italy , Aug. (1983) .
6) H. Kudo, T. Nomura, K. Sueki, Y. Gono, and M.
Magara: "The Gamma Decay of the 45 sec
Isomer in 212pO" , 1983 Fall Meeting of the
Phys. Soc. Japan , Kobe, Sept. (1983).
7) S. Yamaji and M. Tohyama: "Two-Particle-Two
Hole Effects on the Mass Distribution in the 1 6 0+ 40Ca Reaction", 1983 Fall Meeting of the
Phys. Soc. Japan , Kobe , Oct. (1983).
8) T . Murakami, H. Harada, J. Kasagi, and T.
Inamura: "Neutron Multiplicity Filter" , 1983
Fall Meeting of the Phys. Soc. Japan, Kobe, Oct.
(1983).
9) H. Taketani,
M. Adachi,
T. Kohno ,A.
Makishima, T. Suzuki, H. Yamada, S. Fukuda, Y.
Gono , and Y. Itoh:" g-Factor Measurements of
the Yrast Isomers", 1983 Fall Meeting of the
Phys. Soc. Japan , Kobe, Oct. (1983).
10) M. Sugawara, Y. Gono , Y. Itoh, and T. Kubo:"In-Beam Study of 215 Fr", 1983 Fall Meeting of
the Phys. Soc. Japan, Kobe , Oct. (1983).
11) K. Sueki, M. Magara, Y. Hamajima, H. Nakahara,
H. Kudo, and I. Kohno: "Heavy-Ion Reactionin Light-Mass System", 27th Symp. on RadioChern., Nagoya, Oct. (1983).
12) K. Sueki, M. Magara, Y. Hamajima, H. Nakahara,
H. Kudo, and I. Kohno: "Study on Fission
Phenomenon of Heavy-Ion Reaction, Part I",
27th Symp. on Radiochem. , Nagoya, Oct.
(1983).
13) T . Inamura, A. Hashizume , M. Ohshima, E.
Minehara,
M. Ishii,
S. Kikuchi,andH.
Kumahora: "M 1 and E2 Transition Probabilities
in the Ground-State Rotational Bands of OddMass Nuclei", Intern. Symp. on Electromagnetic
Properties of Atomic Nuclei, Tokyo, Nov.
(1983).
3. Atomic and solid-state physics
1) J. Takahashi: "The Angular Distribution of X
Rays Emitted from Heavy Ion Atom Collisions",
4th Symp. on Atomic Collisions by Using Accelerators, Wako, Feb. (1983).
A. Yagishita,J.
2) T. Matsuo,
J. Urakawa,
Takahashi, T. Kambara, M. Kase, H. Kumagai,(1983).
3) T . Kambara : " Projectile Characteristic X-Rays
and Radiative Electron Capture from HighEnergy Heavy Ion-Atom Collisions" , 4th Symp.
on the Atomic Collisions by Using Accelerators ,Wako , Feb. (1983).
andT. Watanabe : "Charge
4) S. Karashima
Equilibrium of Multicharged Ions", 4th Symp.
on Atomic Collisions by Using Accelerators,
Wako , Feb. (1983).
5) K. Hino: " Present Status of the Theory of REC(Radiative Electron Caputre)", 4th Symp. on
Atomic Collisions by Using Accelerators, Wako ,Feb . (1983) .
6) T. Watanabe: "Unitarized and Exponential Distorted Wave Born Approximation-Electrons in
Low l Initial State-Intermediate Velocities", USJapanese Cooperative Sicnece Seminar on Physics
of Highly Ionized Ions Produced in Heavy Ion
Collisions, Honolulu , U.S.A. , Mar. (1983).
7) T. Kambara, Y. Awaya, M. Kase , H. Kumagai,
I. Kohno , T. Tonuma, and A. Hitachi: "Projectile K X Rays in Heavy Ion Atom Collisions(I)- Target Gas Pressure Dependence of K X Rays
from 110 MeV Ne Ions" , U.S. - Japanese Cooperative Science Seminar on Physics of Highly
Ionized Ions Produced in Heavy Ion Collisions,
Honolulu, U.S.A., Mar. (1983).
8) Y. Awaya, T. Kambara , M. Kase, H. Kumagai,
J . Takahashi, J. Urakawa , T. Matsuo, and M.
Namiki: "Projectile K X Rays in Heavy Ion
Atom Collisions(II) - High Resolution Measurements of K X Rays from Ar Ions Impinging on
Foils", U.S. - Japanese Cooperative Science
Seminar on Physics of Highly Ionized Ions Produced in Heavy Ion Collisions, Honolulu , U.S.A .,Mar. (1983) .
9) M. Uda : "Chemical Effects in X-Rays Satellite
Spectra Due to Multiply Ionized States", U.S. Japanese Cooperative Science Seminar on Physics
of Highly Ionized Ions Produced in Heavy Ion
Collisions, Honolulu, U.S.A., Mar. (I 983).
10) T. Tonuma: "Production of Highly Charged
Ions by Heavy-Ion Bombardment of Rare-Gas
Targets", U.S . - Japanese Cooperative Science
Seminar on Physics of Highly Ionized Ions Produced in Heavy Ion Collisions, Honolulu , U.S.A. ,Mar. (1983).
11) A. Koyama, T. Shikata, E. Yagi, H. Sakairi, and199

M. Uda: "Deviation of Secondary Electron
Emission Coefficient from Z~ Proportionality",
U.S . - Japanese Cooperative Science Seminar on
Physics of Highly Ionized Ions Produced in
Heavy Ion Collisions, Honolulu , U.S.A. , Mar.
(1983).
12) T. Matsuo, J. Urakawa, Y. Awaya, A. Yagishita,
T. Kambara, M. Kase , J. Takahashi, and H.
Kumagai: "Spectra of Ar L-MM Augerlisions by Ions on Reactions at Pd-Si Interface" ,30th Ann. Meeting of the Japan Soc. Appl.
Phys. , Chiba, Apr. (1983).
S. Konno , andF . Yatagai:
23) T. Takahashi,"Theories on the Energy Deposition around a
Path of a Heavy Charged Particle and Their Ap-

Electrons in Ar n + + Ar Collisions" , 38th Ann.
Meeting of the Phys. Soc. Japan, Tokyo, Mar.
(1983).

of Ion Implanted GaP II", 30th Spring Meetingof the Japan Soc. Appl. Phys., Chiba, Apr.
(1983).
25) E. Yagi, T. Kobayashi, S. Nakamura, Y. Fukai,
and K. Watanabe: "Lattice Location of Hydrogen in Tantalum", 92th Ann. Meeting ofJapan Inst. Metals, Tokyo, Apr. (1983).

13) S. Karashima
andT. Watanabe: "Charge
Equilibrium of the Fast Heavy Ion in theMedium" , 38th Ann. Meeting of the Phys. Soc.
Japan, Tokyo , Mar. (1983).
14) N. Toshima and T. Watanabe: "Present Statusof the Theories for Extreamly High Energy Region, Symposium on Extreamely High Energy
Ion Collisions", 38th Ann. Meeting of the Phys.
Soc. Japan, Tokyo, Mar. (1983).
15) K. Fujima and T. Watanabe: "The Electronic
State of Higen Dense Ne II", 38th Ann. Meetingof the Phys. Soc. Japan, Tokyo, Mar. (1983).
16) E. Vagi : "Muon Location and Diffusion" , 38th
Ann. Meeting of the Phys. Soc. Japan , Tokyo,
Mar. (1983).
17) E. Yagi, A. Koyama, H. Sakairi, and R. R.
Hasiguti: " Lattice Location of Sn Atoms Implanted into Al Crystals" , 38th Ann. Meeting of
the Phys. Soc. Japan, Tokyo, Mar. (1983).
18) T. Takahashi, Y. Awaya, T. Tonuma, H.
Kumagai, K.Izumo, M. Nishida, A. Hashizume,
S. Uchiyama , and T. Doke: "The Z~ -Dependenceof Stopping Power and Effective Charge of 5-7
MeV/amu C and He Ions", 38th Ann . Meeting of
the Phys. Soc. Japan, Tokyo, Mar. (1983).
19) T. Kambara: "Experiments of Radiative Electron Capture", 38th Ann. Meeting of the Phys.
Soc. Japan , Tokyo , Mar. (1983).
20) T. Kobayashi, E. Vagi, H. Sakairi, and Y. Sasa :"LEC and Sputter Type Ion Source Used in .
Tandetron", Symp. on Ion Sources Used in Accelerators, Tsukuba , Mar. (1983).
21) S. Karashima and T. Watanabe: "Equilibrium
Charge of Heavy Ions in Solid Media" , The IPP
Symp. on Plasma- Wall Interaction Theories andParticle-Solid Collision Theories in the Initial
Processes of Inertial Nuclear Fusion, Nagoya,Mar. (I983).

26) Y. Higashiguchi, H. Kayano, M. Narui, Y. Suzuki,
and E. Yagi: "Helium Embrittlement of Nb, V
and their Alloys", 92th Ann. Meeting of Japan
Inst. Metals, Tokyo, Apr. (1983).
27) S. Karashima and T. Watanabe: "Equilibrium
Charge of Incident Heavy Ions in the Medium",Japan-China Binational Radiation ChemistrySymp. , Shanghai, China , Apr. (1983).
28) K. Nishiyama, E. Vagi, K. Ishida, T. Matsuzaki,
K. Nagamine , and T. Yamazaki: "New Approach in J1 + SR Study on Critical Phenomena in
Ni" , 3rd Int. Topical Meeting on J1 SR, Shimoda,
Apr. (1983).
29) E. Vagi: "Study of Lattice Location of Hydrogen in Metals by Channeling Method", Symp.
on Hydrogen in Metals, Tokyo, May (1983).
30) E. Vagi: "Muon Diffusion in Metals", Symp. on
Hydrogen in Metals, Tokyo, May (1983).
31) T. Watanabe: "Collision Processes of Atoms by
Energetic Multicharged Ions (Experimental
Studies in IPCR (RIKEN)", Asia Pacific Physics
Conf. , Singapore , June (1983).
32) T . Watanabe: " Electron Capture Processes ofMulticharged Ions from H and He (Theory)",
Asia Pacific Physics Conf. , Singapore , June
(1983).
33) J. Mizuno , T. Ishihara, and T. Watanabe:"Energy Exchange between Two Outgoing Electrons in the Post Collision Interaction Processes",
XIIIth Intern. Conf. on the Phys. of Electron.
and Atom. Collisions, Berlin, W. Germany, July
(1983).

K.

34) J. Takahashi, Y. Awaya, T. Kambara, M. Kase, H.
Kumagai, J. Urakawa, T. Matsuo, and H. Shibata:"Angular Distribution of Au L X-Rays by Heavy" Effects of Elastic and Nonelastic Col-Ion Impact", XIIIth Intern. Conf. on the Phys.

22) Y. Horino,
Kimura:plication", 30th Spring Meeting of the Japan
Soc. Appl. Phys., Chiba, Apr. (1983).
24) K. Aono , M.Iwaki, and S. Namba: "Annealing

N. Matsunami ,N. Itoh,and200of Electron. and Atom. Collisions, Berlin, W.
Germany, july (1983) .
35) Y. Awaya, T. Kambara, M. Kase, H. Kumagai, J.
Takahashi, J . Urakawa, T. Matsuo, and M.
Namiki: " High Resolution Measurements of K
X-Rays from Ar Ions Impinging on Foils", XlIIth
Intern. Conf. on the Phys. of Electron. and44) K. Fujiwara,

N. Toshima,andT. Watanabe:"Close Coupling Calculation of Electron Capture
at High Energies", XIIIth Intern. Conf. on the
Phys. of Electron. and Atom. Collisions, Berlin,
W. Germany, July (1983).
45) M. Uda, A. Koyama , K. Maeda, and Y. Sasa:"Chemical Effects of F KVV Auger Spectra Induced by Photon- and lon-Impacts", 1Oth Intern.

Atom. Collisions, Berlin, W. Germany, July
(1983) .

Conf. on Atomic Collisions in Solids, Bad Iburg,36) I. Shimamura: "Line-Shape Analysis of Electron
Energy-Loss Spectra", XlIIth Intern. Conf. on
the Phys. of Electron. and Atom. Collisions,W. Germany , July (1983).
46) A. Koyama, Y. Sasa, T. Shikata, E. Vagi, K.
Maeda, H. Sakairi, and M. Uda: "Deviation of

Berlin, W. Germany, July (1983).

Secondary Electron Emission Coefficient from37) T. Kambara, Y. Awaya, M. Kase, H. Kumagai, I.
Kohno, T. Tonuma, and A. Hitachi: "Target
Gas Pressure Dependence of Relative Yields of Kz~ Proportionality" , 10th Intern. Conf. on
Atomic Collision in Solids, Badlburg, W. Germany , July (1983) .

X Rays from 110 MeV Ne Ions" , XlIIth Intern.
Conf. on the Phys. of Electron. and Atom.

47) I. Shimamura: " Line-Shape Analysis of Photo-

Collisions, Berlin, W. Germany, July (1983) .
38) T. Matsuo , J. Urakawa, A. Yagishita, Y. Awaya,
T. Kambara , M. Kase , H. Kumagai, and J.
Takahashi, " Ar L-MM Auger Spectra in Ar 4 + +electron Spectra and Electron and Ion EnergyLoss Spectra" , Intern . Symp. on Wavefunctions
and Mechanisms from Electron Scattering Pro-Ar Collisions" , XIIIth Intern. Conf. on the Phys.

cesses , Roma , Italy , July (1983) .
48) H. Muramatsu , T. Miura, H. Nakahara, M. Fujoka
E. Tanaka, and A. Hashizume: "Calibration ofof Electron. and Atom. Collisions, Berlin, W.
Germany , July (1983).
39) J. Urakawa, T. Matsuo , H. Shibata, A. Yagishita,

the Isomer Shift of 119 Sn from Internal Conversion Measurements" , 6th Intern. Conf. on
Hyperfine Interactions, Groningen, The Nether-Y. Awaya, T. Kambara, M. Kase , H. Kumagai,
and J. Takahashi: "Kr M-NN Auger Spectra in
Ar4+ + Kr Collisions", XIIIth Intern . Conf. onland, July (1983).
49) T. Watanabe: "Extensive Study on the Validityof Atomic Base Treatment - Close Coupling,

the Phys. of Electron. and Atom. Collisions ,EDWA , UDWA", VIIIth Intern. Seminar on lonAtom Collision , Nijenrode Utrecht, The Netherlands , Aug. (1983) .

Berlin , W. Germany, july (1983).
40) S. Karashima
andT. Watanabe: "Stripping
Cross Sections of Multi-Charged Ions by Neutral
Atoms", XIIIth Intern. Conf. on the Phys. ofElectron. and Atom.
Germany, July (1983).

Collisions, Berlin, W.

41) S. Karashima and T. Watanabe: "Charge
Equilibrium of Fast Heavy Ions Penetrating
through Gaseous Media" , XIIIth Intern. Conf. on
the ' Phys. of Electron. and Atom. Collisions,
Berlin, W. Germany , July (1983).
42) H. Suzuki, N. Toshima , and T. Watanabe : "Exponential Distorted Wave Approximation in
Charge Transfer" , XIIIth Intern. Conf. on the
Phys. of Electron. and Atom. Collisions, Berlin,
W. Germany , July (1983).
43) J. Mizuno , T. Ishihara,
andT. Watanabe :"Energy Shift of Emitted X-Rays Following
Inner Shell Photoionization near Threshold" ,XIIIth Intern. Conf. on Phys. of Electron. andAtom. Collisions, Berlin , W. Germany, July
(1983) .

50) A. Ohsaki: "Resonant Collision in Strong
Magnetic Fields", Symp. on Present Status andFuture Development of Atomic
Theory , Susono, Sept. (1983) .
51) S. M. Shafroth:

Collision" Comment: ResonantandNon-resonant Electron Transfer and Excitationin Ion-Atom Collision", Symp. on Present Statusand Future Development of Atomic Collision
Theory, Susono , Sept. (1983).
52) A. C. Roy:

"Triple Differential Cross Section

Using Glauber Approximation", Symp. on
Present Status and Future Development ofAtomic Collision Theory, Susono , Sept. (1983).
53) I. Shimamura: "Electron-Molecule Collisions",
Symp. on Present Status and Future Development of Atomic Collision Theory, Susono, Sept.
(1983).
54) T. Watanabe:"ChargeTransfer

Processes",

Symp. on Present Status and Future Development of Atomic Collision Theory, Susono, Sept.

201(1983).
55) K. Aono, M. Iwaki, and S. Namba: "Annealingof Ion Implanted GaP III", 44th Fall Meeting of
the Japan Soc. Appl. Phys ., Sendai, Sept. (1983).
56) T. Tonuma, M. Kase, H. Kumagai, T. Kambara,
H. Shibata, J. Takahashi, I. Kohno , S. Ozk6k, S.
H. Be, J. Urakawa, and T. Matsuo: "Productionof Highly-Charged Ions Induced by Heavy-Ion
Impact", Intern. Ion Engineering Congr. - ISIAT'83 & IPAT '83 -, Kyoto, Sept. (1983).
57) S. M. Shafroth: "Resonant Transfer and Excitation in High-Energy Multi-Charged Ion-Atom
Collisions", 1983 ~all Meeting of the Phys. Soc.
Japan , Okayama, Oct. (1983).
58) Y. Awaya, T. Kambara, M. Kase, H. Kumagai, J.
Takahashi, H. Shibata, J. Urakawa, T. Matsuo,
and M. Namiki: "Multiple Inner-Shell Ionizationof Ar Ions Passing through Foils;' 1983 Fall
Meeting of the Phys. Soc. Japan, Okayama, Oct.
(1983).
59) J. Urakawa, T. Matsuo, H. Shibata, A. Yagishita,
Y. Awaya, T. Kambara, M. Kase, H. Kumagai,
and J. Takahashi: "Kr M-NN Auger Spectra Produced in Collisions with about 0.2 MeV /amu
Heavy Ions", 1983 Fall Meeting of the Phys. Soc.
Japan, Okayama, Oct. (1983).
60) E. Vagi and S. Nakamura: "Lattice Location of
Sn Atoms Implanted into Al Crystals", 1983 Fall
Meeting of the Phys. Soc. Japan, Okayama, Oct.
(1983).
61) S. Tamada, T. Akioka, A. Hashiba, K. Masuda,
A. Hitachi, J. Kikuchi, T. Doke, T. Takahashi,
M. Sekiguchi, and E. Shibamura: "LET Dependence of the Light Yield of the Liquefied
Rare Gases Induced by Charged Particles", 1983
Fall Meeting of the Phys. Soc. Japan, Okayama,
Oct. (1983).
62) K. Maeda, Y. Hayashi, and M. Uda: "An Oxygen Ka Emission Spectrum Free from MultipleVacancy Satellites", 1983 Fall Meeting of the
Phys. Soc. Japan, Okayama, Oct. (1983).
63) J. Nagakawa, H. Shiraishi, I. Uchiyama, H.
Kamitsubo, I. Kohno , and T. Shikata: "Irradiation Creep Experiments of 316 Stainless Steelunder 16 MeV Proton Bombardment in a
Torsional Creep Apparatus", 93rd Meeting of theJapan Inst. Metals, Akita, Oct. (1983).
64) H. Suzuki, N. Toshima, and T. Watanabe: "TheCalculation of Electron Transfer Cross Section toMulticharged Ion by UDWA, II" , 1983 Fall
Meeting of the Phys. Soc. Japan, Okayama, Nov.
(1983).

65) K. Hino, I. Shimamura, and T. Watanabe:"Theory of Radiative Electron Capture", 1983
Fall Meeting of the Phys. Soc. Japan, Okayama,
Nov. (1983) .
66) S. Karashima and T. Watanabe: "Electron Loss
Cross Sections for Projectile Many Electron Ionsin the Medium", 1983 Fall Meeting of the Phys.
Soc. Japan, Okayama, Nov. (1983).
67) S. M. Shafroth: "Non-Resonant Transfer andExcitation in Ion-Atom Collisions" , 5th Symp.
on Atomic Collisions by Using Accelerators,
Susono , Nov . (1983).
68) T. Matsuo: "Auger Electron Emission in Heavy
Ion Atom Collisions" , 5th Symp. on Atomic
Collisions by Using Accelerators, Susono, Nov.
(1983).
69) S. M. Shafroth: "Non-Resonant Electron Transfer and Exitation in Ion-Atom Collision" 5thSymp. on Atomic Collisions by Using Accelerators , Susono, Nov. (1983).
70) T. Watanabe: "Atomic Physics Using HighEnergy Heavy Ions", RIKEN Symp. on Nuclear
Physics Research in the Energy Range of 10100 MeV/u, Wako, Nov. (1983).
71) T. Watanabe and I. Shimamura: "Properties ofHigh Rydberg State Species", RIKEN Symp. on
the Physics of Rydberg States and Their Reaction Processes, Wako , Nov. (1983).
72) A. Ohsaki: " Atomic Collision in Magnetic
Fields", 1st Seminar on Elementary Processes in
Nuclear Fusions, Kyoto, Nov. (1983).
73) T. Watanabe: "Present Status of the Theories
on Charge Exchange Reactions", 1st Seminar on
Elementary Processes in Nuclear Fusions, Kyoto,
Nov. (1983).
74) S. Karashima, H. Kawagoshi, and T. Watanabe:"Charge Equilibrium Processes of Energetic Incident Ions and Their Range", IPP Symp. on
Particle Beam Application to Fusion Research,
Nagoya, Nov. (1983).
75) K. Maeda, Y. Sasa, Y. Yokode , M. Maeda, M.
Kobayashi, K. Fujima, and M. Uda: "Several
Applications of PIXE Analysis", 2nd Symp. on
Ion Beam Technology, Hosei University, Tokyo,
Dec. (1983).
76) M. Uda, H. Endo, K. Maeda, Y. Sasa, K. Fujima,
and K. Fuwa: "Application of Ion Induced
X-Ray Emission Spectroscopy to Chemistry",
2nd Symp. on Ion Beam Technology, Hosei University , Tokyo , Dec. (1983).
77) A. Koyama, Y. Sasa, and M. Uda: "Development of Ion Induced Electron Spectroscopy",202
2nd Symp. on Ion Beam Technology, Hosei
University, Tokyo, Dec. (1983).
4. Radiochemistry, radiation chemistry and radiation
biology1) M. Yanokura, I. Kohno, M. Aratani, and T.
Nozaki: "Rutherford Scattering Applied to the
Study of Hydrogen in Amorphous Silicon", 30th
Spring Meeting of the Japan Soc. Appl. Phys.,
Chiba, Apr. (983).
2) Y. Mochizuki, M. Nakamura, S. Koyama, K.
Usami, T. Nozaki, and Y. Itoh: "Composition of
CVD Silicon Film Doped with Oxygen", 30th
Spring Meeting of the Japan Soc. Appl. Phys.,
Chiba, Apr. (1983).
3) M. Aratani, H. Nagai, T. Nozaki, M. Yanokura, I.
Kohno, O. Kuboi, and Y. Yatsurugi: "Rutherford Forward Recoil Measurement Applied toCharacterization of Hydrogen", 47th National
Meeting of the Chern. Soc. Japan, Kyoto, Apr.
(1983).
4) F. Ambe and S. Ambe: "Mossbauer Isomer
Shifts of 119 Sn Coordinated with Ag - I
Atoms", 47th National Meeting of the Chern.
Soc. Japan, Kyoto, Apr. (1983).
5) I. Kaneko, T. Ohno, K. Eguchi, T. Inada, and K.

Sept. (1983).
10) M. Yanokura, I. Kohno, M. Aratani, and T.
Nozaki: "Rutherford Scattering Applied to the
Study of Hydrogen in Amorphous Silicon", 44th
Fall Meeting of the Japan Soc. Appl. Phys.,
Sendai, Sept. (1983).
11) K. Kimura and M. Imamura: "Emission Spectra
Measured at Different Location of 85 MeV N-Ion
Trajectory in He Gas at 5.2K", 26th Congr. of
Radiat. Chern., Osaka, Sept. (l983).
12) Y. Sakamoto: "ECR Discharge Cleaning of
Toroidal Machines", IX IVC - V ICSS, Madrid,
Spain, Sept. (1983).
13) S. Hayashi, H. Nagai, M. Aratani, T. Nozaki,
M. Yanokura, I. Kohno, O. Kuboi, and Y.
Yatsurugi: "Depth ProfIling of Hydrogen with
ISN-Induced Resonance Nuclear Reaction",
27th Symp. on Radiochem., Nagoya, Oct.
(l983).
14) H. Kudo, T. Nomura, K. Sueki, and M. Magara,"Measurement of Isomeric Transition of
212mpo", 27th Symp. on Radiochem., Nagoya,Oct. (1983).
15) H. Nagai, M. Aratani, S. Hayashi, T. Nozaki,
M. Yanokura, I. KOhnO, O. Kuboi, and Y.
Yatsurugi: "Rutherford Forward Scattering

Nakano: "Differential Recovery from Potentially Lethal Damage in Human Cultured Cells after
Irradiation with Photon and Accelerated N-Ion
Beam", GSI Workshop on Heavy Particles in
Biology and Medicine, Seeheim, W. Germany,
June (1983).

Applied to the Analysis of Hydrogen (II)", 27th
Symp. on Radiochem., Nagoya, Oct. (1983).
16) T. Miura, Y. Hatsukawa, K. Endo, H. Nakahara,
A. Hashizume, M. Fujioka, and E. Tanaka:

6) K. Eguchi, T.lnada, T.Ohno, S. Satoh, and I.

Various Metal Matrices", 27th Symp. on Radio-

Kaneko: "Recovery from Radiation Damage ofCultured Cells after Irradiation of Photon, Pro-

chern., Nagoya, Oct. (1983).
17) Y. Sakamoto, S. Ishii, K. Okazaki, K. Yano, andet al.: "ECR Discharge Cleaning for TEXTOR
Device, II", Japan Vacuum Congr., Tokyo, Oct.
(1983).
18) Y. Ishibe, S. Ishii, K. Okazaki, H. Oyama, Y.
Sakamoto, K. Yano, T. Nozaki, M. Aratani, S.
Hayashi, M. Yanokura, I. Kohno, and et al.:
"ECR Discharge Cleaning for lIPPT-II U",
Japan Vacuum Congr., Tokyo, Oct. (1983).
19) Y. Sakamoto and H. Oyama: "Interaction of
TiC with Hydrogen Plasma", Japan Vacuum

ton, and Nitrogen-Ion", 7th Intern. Congr.
Radiat. Res., Amsterdam, The Netherlands, July(l983).
7) K. Kimura, Y. Toda, and M. Imamura: "Effectsof LET, Temperature, and Pressure on the Emission Spectra of Helium Excimers Created by
Heavy-Ion Irradiation near Critical Temperature", 7th Intern. Congr. of Radiat. Res.,
Amsterdam, The Netherlands, July (1983).
8) F. Yatagai, T. Takahashi, and T. Katayama:"Effect of Heavy Ions on Bacterial Spores (II)",
2nd Spore Radiation Biology Meeting, Amsterdam, The Netherlands, July (l983).
9) Y. Itoh, T. Nozaki, T. Masui, and T. Abe: "IRCarib ration Curve for Nitrogen in Silicon by
Charged Particle Activation Analysis", 44th Fall
Meeting of the Japan Soc. Appl. Phys., Sendai,"Variation of Intensity on Internal Conversionof Outermost Shell Electrons in 125 Te forCongr., Tokyo, Oct. (1983).
20) S. M. Shafroth: "The 1 H(Li, nfBe Reaction as
an Intense MeV Neutron Source", Korean
Phys. Soc. Meeting, Jinhae, Korea, Oct. (1983) .
21) S. Kitayama, F. Yatagai, A. Shimotsukasa, and
K. Tsutsurni: "Repair of DNA Cross-Links in
Mitomycin C Sensitive Mutant of D. radio-

203

durans", 55th Ann. Meeting of the Genetics
Soc. of Japan, Sendai, Oct. (1983).
22) K. Kimura, S. Kubota, and M. Imamura: "Emission Spectra and Its Decay Measured at Different
Location of N-Ion Trajectory in He-Gas under
Low Temperature and High Pressure", 1983 Fall
Meeting of the Phys. Soc. Japan, Okayama, Oct.
(1983).
23) T. Takahashi and F. Yatagai: "Biological Effects of Heavy Ions", 5th Symp. on Atomic Collisions by Using Accelerator, Susono, Nov.
(1983).
24) T. Takahashi, F. Yatagai, T. Katayama, M. Inada,
and S. Konno: "Track Structure Theories andTheir Application for the Interpretation of
Biological Effects", 26th Ann. Meeting of theJapan Radiat. Res. Soc., Kyoto, Nov. (1983).
25) M. Aratani, H. Nagai, S. Hayashi, T. Nozaki,
M. Yanokura, I. Kohno, o. Kuboi, and Y.
Yatsurugi: "Characterization of Surface Hydrogen by the Rutherford Recoil Measurement",

19th Tokyo Conf. on Appl. Spectrosc., Tokyo,
Nov. (1983).
26) M. Yanokura, M. Aratani, H. Nagai, S. Hayashi,
I. Kohno, T. Nozaki, O. Kuboi, and Y.
Yatsurugi: "The Heavy-Ion Probe Rutherford
Forward Recoil Measurement Applied to theCharacterization of Hydrogen in Solids", 2thSymp. on Ion Beam Technology, Hosei Univ.,
Tokyo, Dec. (1983).
27) G. Okada, K. Kurita, K. Nakano, and I. Kaneko:"Enhancement of 3-Aminobenzamide on Radiation-Induced Mutation in Chinese Hamster V79
Cells", Ann. Meeting of Japan. Soc. of Radiat.
Res., Kyoto, Dec. (1983).
28) K. Nakano, H.lmanishi, G. Okada, and I.
Kaneko: "Effect of 3-Aminobenzamide on
Sister Chromatid Exchange
Frequency inChinese Hamster V79 Cells Exposed to N-Ion
Accelerated in the RIKEN Cyclotron", Ann.
Meeting of Japan. Soc. of Radiat. Res., Kyoto
Dec. (1983).

204

VIT.

LIST OF OUTSIDE USERS AND THEIR THEMES(Jan. - Dec. 1983)
1)

S. Yoshida and K. Mitsui

LSI R&D Lab.

"Study of Effect by Bombarding High

Mitsubishi Electric Co., Ltd.

Energy Proton on a GaAs Solar Cell"

2)

H. Ueyama

Sharp Co., Ltd.

"Study of Effect by Bombarding HighEnergy Proton on a Si Solar Cell"
3)

4)

H. Nakahara"Production of 121 Te"

Metropolitan Univ.

S. Orito and S. Nakamura

Faculty of Science, Univ. of Tokyo

Faculty of Science, Tokyo"Test of Sensibility of CR39 Track
Detector for High Energy Proton"
5)

T. AbeShinetsu Semiconductor Co., Ltd.

"Radiochemical Ana1ysis of 16 0 in Si Crystal"6)

E. TohjiToshiba Ceramics Co. , Ltd.

"Radiochemical Analysis of 14N and 16 0 in
Si Crystal"
7)8)

H. Shinyashiki

Central Res. Lab., Mitsubishi"Radiochemical Analysis of 16 0 in GaAs"

Metal Co., Ltd.

H. Yamamoto

R&D Div. , Asahi Glass Co., Ltd.

"Radiation Damage of Cover Glass for a
Solar Cell"9~

M. Yatsuhashi and T. Suematsu"Study of Effect by Irradiating Fast Neutron

Fujikura Cable Works, Ltd.

on a Insulator Coverning a Cable"
10)

A. Morio and M. Harada"Study of Single Event Upset in
Microprocessors by Bombarding 14N and 20Ne
Particles"

Japan Trust Center for Electronic Parts

205

VIII.

LIST OF SEMINARS(Jan. - Dec. 1983)
1) T. Ohshima, INS (Tokyo), 13 January"A Trial of the Determination of Neutrino
Mass by the Measurement of f3-Ray Spectrum of
Triton"2) H. H. Bolotin, Univ. of Melbourne (Australia), 26
January"Measurements of Gyromagnetic Ratios ofShort-Lived Excited Nuclear States Using theEnhanced Transient Hyperfine Magnetic Field"
3) Y. Torizuka, Tohoku Univ . (Sendai), 1 February"Prospect of the Study in the Nucleus Using
Electron Accelerators"
4) F. Kikuchi, Univ. of Tokyo (Tokyo), 10 February"Calculation of Electromagnetic Waves by the
Finite Element Method"5) K. Sato, INS (Tokyo), 17 February"RF Cavity in Cyclotron"
6) B.!. Deutsch, Aarhus Univ. (Denmark), 2 March"Atomic and Nuclear Polarization by Beam
Foil Interaction: Direct Determination via

12) P. Aguer, CSMSN, Orsay (France), 28 April"High-Spin States in Er Isotopes"
13) T. Udagawa, Univ. Texas at Austin (USA), 12 May"A Dynamical Theory of Preequilibrium Reactions"
14) Yu. Ts. Oganessian, JINR, Dubna (USSR), 25 May"Present Situation of HI Research at JINR"
15) A. Matveenko , JINR, Dubna (USSR), 25 May"A New Three-Body Equation"16) J. J. Griffin, Univ. Maryland (USA) , 30 May"Non-Linear Many Body Reaction Theories
from Nuclear Mean Field Approximation"17) K. W. McVoy, Univ . of Wisconsin-Madison (USA),
1 June"Practical Heavy Ion Optics in the Near/Far
Representation"18) P. Schwandt, ICUF, Indiana Univ. (USA), 3 June
"Optical Potential Phenomenology at Intermediate Energies"

13- Asymmetry"
7) K. Nagatani, INS (Tokyo), 3 March"Heavy Ion Reaction and Spectroscopy"8) N. Shikazono, JAERI (Tokai) , 14 March"Present Situation and Heavy Ion Spectrometer
at JAERI"
9) H. Morinaga, Tech. Univ. Miinchen (West Germany),
22 March"Mass Spectroscopy by Accelerator"

19) K. Kuroda, LAPP (France), 14 June
" Application of Position Sensitive Photomultiplier"20) H. Ohnuma, Tokyo Inst. Tech. (Tokyo), 24 June
"Recent Topics in 'Nuclear Physics in Intermediate- and High-Energy Regions' "21) S. Kato, Yamagata Univ. (Yamagata), 7 July
"On Magnetic Spectrograph"22) B. R. Barrett, Univ. of Arizona (USA), 19 July10) O.W.B. Schult, Inst . fUr Kernphysik, Jillich(WestGermany), 2 April"Thoughts about Nuclear Physics on the Intense Spallation Source"11) H. Ejiri, Osaka Univ. (Osaka), 18 April"Spin-Isospin Mode and Hypernuclei""The IBA Model and Its Formulation andApplication"23) A. Matsuyama, Univ. of Tokyo (Tokyo), 28 July"(1T, N) Reaction in the ~-Hole Model"
24) T . Murakami, INS (Tokyo), 29 July,d 2Ce 60,a) Reaction: Can 'Molecular
Resonance States' be Excited?"

20625) N. Takigawa, Tohoku Univ. (Sendai), 4 August"Coupling of Macroscopic Motion to Intrinsic
Oscillators in Heavy Ion Fusion"26) M. Gai, Yale Univ. (USA), 27 September"Molecular Dipole States in 18 0 and 218 Ra"
27) J. L. Wood, Georgia Inst. of Tech. (USA), 27
September"Shape Coexistence in Nuclei"28) Y. Zhu, IMP, Lanzhou (China), 7 November"Recent Situation at Institute of Modern
Physics"
29) A. Galonsky, MSU (USA), 7 November"Neutron Emission from 165 Ho + 14N Reaction at 35 MeV/nucleon"
30) J. B. McClelland, UCLA (USA), 8 November"HRS and Focal Plane Polarization at Los
Alamos"31) P. Kleinheinz, KFA, Jillich (West Germany), 16
November"Aligned Multiparticle Y rast Configurations
and Particle-Octupole Coupling Phenomena in
the Nuclei around 146Gd"

32) T. Hasegawa, INS (Tokyo), 9 December"Present Situation at SATURNE"
33) M. Tohyama, Giessen Univ. (West Germany), 16
December"Subthreshold 1T-Production"34) Y. Fujita, INS (Tokyo), 20 December"Development of PPAC and its Application"

207

IX.

LIST OF PERSONNEL
Members of the Board

m 11\

HASHIZUME Akira

M

J:. J;f 7i:. J1l

KAMITSUBO Hiromichi
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NOZAKI Tadashi
OKADA Shigefumi

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SEKIZAWA Hisashi~

KOHNO Isao

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IE (Chiarman)ODERA Masatoshi£ Jt

SAKAIRI Hideo

ow. A ~ ttt

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SHIMA Makoto~iR.

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UDA Masayuki~

IMAMURA Masashi

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iii ~~WATANABE Tsutomu

Cyclotron Operation and Maintenance Group
FUJIT A Shin~JT]l. ffi

KAGEYAMA Tadashi

1¥,3 III

KOHNO Isao

IjJ

fliT tJ'

it!!J:. -JL = ~IKEGAMI Kumio
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KOHARA Shigeo IJ, Ijj( !t
OGIWARA Kiyoshi

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fE\:; ~~ ~ Ut

T AKEBE Hideki

Linac Operation and Maintenance Group-=f ~ H Bfg

CHIBA Yoshiaki=

it!! iR ~IKEZAWA Eiji

KAMBARA Tadashi

1$ JJ¥..

KUBO Toshiyuki'A. 1* fib. ¥

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YANOKURA Minoru

HEMMI Masatake~ ~ if)( fE\:;

INOUE Toshihiko

j:j: 1::. fib.

KASE Masayuki

130 if~ ~ z

If:

MIY AZAWAY oshitoshig rR. 11 fib.

FUJISA WA TakashirR ~ ;=t-~Scientific and Engineering Personnel
Cyclotron Laboratory
BE Suck Hee

I~

FUJITA Jiro

f1ftl %
€l~]l. ffi -HARA Masahiro

1&]l.

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INAMURA Takashi

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GOTD Akira

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ISHIHARA Masayasu

n JJ¥.. IE ~KAMITSUBO Hiromichi

KARASAWA Takashi

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KISHIDA Norioif!

KOHNO Isao*

KOHMOTO Susumu

iliT

KUDO Hisaaki'A. BfgI]l.

I=j=l ~ ~~NAKAJIMA Shunji
NOMURA Toru

!ff 1'1

SAKAMOTO Ichiro

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J:. J;f 7i:. J1l

J¥ ill JlIJ 1:.

illJ lff

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MOTONAGA Shoshichi

5C 71< Bfg -t

NAKANISHI Noriyoshi

I=j=l

OIKAWAY oshifumi

7*lffi *2 %~ )l 1 ~ fm

SHIKATA Takashi

1m 1i ~I ~'*SHIMIZU Kazuo

iw;j( tD ~T AKESHIT A Isao

tt T JJ

WADA Takeshi

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YAMAJI Shuhei

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