the Institute of Physical and Chemical Research
Wako-shi, Saitama Pref., JAPANIPCR cyclotron
Progress Report 1977

Vol. 11

'PCR Cyclotron Progress ReportVol. 11The Institute of Physical and Chemical Research
HRIKAGAKU KENKYUSHO" Wako-shi, Saitama, 351 JAPAN
December, 1977

Editors
A. Hashizume

Y. Hattori

T . Inamura

H. Kamitsubo

A. Matsuyama

T. Nomura

T. Nozaki

M. Odera

N. Shiotani

This volume contains recent information of the IPCR Cyclotron , informal reports andabstracts 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

1.

INTRODUCTION

2.

MACHINE OPERATION

3.

MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS
3-1.

Improvement of the Beam Probe System of the Cyclotron

4

3- 2.

The Pulsed Ion Source

6

3-3.

Acceleration of Polarized Protons with S. F. Cyclotron at INS

8

3- 4.

Design Study of a Linac-Injected Separated Sector Cyclotron (1 )Four Sector SSC ............................................

10

Design Study of a Linac-Injected Separated Sector Cyclotron (2)Six-sector SSC

13

Beam Study on the Baby Cyclotron

IS

3- S.

3- 6.
4.

2

NUCLEAR PHYSICS
Scattering and Reactions
4 - 1.

Spin Flip in the Inelastic Scattering of Polarized Protons on 12 C

18

4 - 2.

Two-Step Process in Proton Inelastic Scattering ........................

20

4 - 3.

DWBA Analysis of Proton Inelastic Scattering from 28,29,30 Si
and Blocking Effects in the Core-Excitation of 29 Si .. ..................

22

4- 4.

Analysis of (p, t) Reaction Induced by Polarized Protons

2S

4 - S.

Analyses of the 54Fe(d, p)55 Fe Reaction Data at Ed = 24 MeV

28

4-6 .

Coupled Channel Effects on (d , p) Reactions31

4 - 7.

Quasimolecular Resonance by the 24Mg(~, 12 C)16 0 Reaction

34

4- 8.

Quasimolecular Resonances Formed by the System 12 C + 13 C36

4 - 9.

Fusion Reaction in 12 C + 14 Nand 16 0+ 1° B Systems ...................

39

4-1 O.

~-Transfer Reactions between 1p or 2s-1 d Shell Nuclei (2)40....... .............

4-11. Spin Polarization of 12B in et°B, 12B) and et 2c, 12B) Reactions
on looMo .....................................................

43

Page

5.

4-12. On the Mechanism of Two-Nucleon Transfer Reactions Induced
by Heavy Ions .................................................

45

4-13. Calculation of Friction Force in the Collision 28 Si + 20 Ne
on the Basis of the Linear Response Theory ...........................

48

4-14. Canonical Quantization from the Time-Dependent Hartree-Fock
Theory in the Lipkin Model .......................................

51

4-15. ~-Particle and Light Product Correlation in the 14N + 93Nb
Reaction ................................ .....................

54

4- 16. Light Fragment Excitation in the 14N + 93 Nb Reaction ..................

56

4-17. Angular Distribution and Energy Spectrum of "Direct" a-Particles
Emitted from the 159Tb+95MeV 14N Reaction... ..... ..... ..... ......

58

4-18. Energy Relaxation of a Composite System Deduced from
Preequilibrium ~-Particle Spectra in 209Bi + 14N Reactions. . . . . . . . . . . . . . . .

60

4-19. Preequilibrium a-Particle Emission from 209 Bi + 14N Reactions . . . . . . . . . . . .

63

NUCLEAR PHYSICS
Nuclear Spectroscopy
5-1.

Cross Section for the 4oCact60, p) 5S Co Reaction

66

5- 2.

'Y-Rays Following Fast ~-Particles Emitted in the 159Tb + 95 MeV 14N
Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67

5- 3.

High Spin States of 162 Yb

69

5-4.

High Spin States of 164Yb

72

5-5.

High Spin States of 166 Yb

74

5-6

Populations of the Particle-Hole K Isomer and the Ground State
Rotational Level ................................................

77

Half-life of 207 Bi

79

5-7.
6.

NUCLEAR INSTRUMENTATION
6-1.

A Particle Identification Program for the On-Line Use

81

6-2.

Determination of the Etching Rate Versus Restricted Energy Loss Curves
in CN Films and CT A Films by Using N-Ion Beams .....................

82

Page

7.

6-3 .

Target Chamber for Recoil- distance Lifetime Measurements .... . .... . ....

85

6- 4.

Gas 6E-E Telescope for the Particle Identification of Heavy Ions87

ATOMIC AND SOLID-STATE PHYSICS

7-1.

Energy Loss and Straggling of C and He Ions in Metal Foils

89

7- 2.

X-Rays Following Multiple Inner-Shell Ionization ( 1 )91

7- 3 .

X-Rays Following Multiple Inner-Shell Ionization (2)

93

7-4.

Gas Target System for Study of X-Rays Induced by Heavy Ions

96

7-5.

Chemical Effect in X-Ray Spectra Produced by Fast Ions

99

7-6.

Lattice Location of Ni Atoms Implanted into Al

102

7- 7.

Damage Production Rate in Ti0 2 as Measured by Channeling Method

104

7 - 8.

Perturbed Angular Correlation of 'Y-Rays Emitted from111 Cd in NiFe2 0 4.......... . .......... . ........ . ...............

106

On the Use of 48 V Source for the Study of Positron Annihilation

109

7- 9.

8.

9.

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

7 - 10. Thermal Equilibrium Measurements of Positron Annihilation Line
Shapes in KCl , KBr, and Ge ......... . ..... . .... . . ................

111

7- 11. Effects of Irradiation Temperature, Prestrain, and Helium Concentrationon the Helium Embrittlement of Type 316 Stainless Steel .............. . .

114

RADIOCHEMISTRY AND NUCLEAR CHEMISTRY

8- 1.

Charged Particle Activation Analysis for Surface Oxygen

116

8- 2.

Charge Spectra of 198 Hgn+ Ions from the 198 Au Decay

119

RADIATION CHEMISTRY AND RADIATION BIOLOGY

9- 1.

9-2.

9-3.

Emission Spectra of a KBr Single Crystal Irradiated with Heavy
Ions at 4.2 K Time-Dependent Spectra . . .. .. . . .... .. .... . ......... .

122

Yields of Trapped Electron Produced by Heavy-Ion Irradiationin Ethanol Glass at 77 K ............ . . .. . ........................

124

Further Study of High LET Effect on Template/Primer Activityof DNA in situ

126

Page

9-4.

9 - 5.

9- 6.
10.

11.

12.

Induction of Mutations in Bacteriophage ¢X 174
by ex-Particles and N-Ions

128

Inactivation of Ribonuclease A in Aqueous Solution by Cyclotron
Beams .................................................... . ...

130

The Effects of High LET Radiations on Mammalian Cells

132

PREPARATION OF RADIOISOTOPES AND LABELED COMPOUNDS

10- 1. Production of Radioisotopes and Preparation of Labelled Compounds
for Medical and Agricultural Use ................. .................

134

10- 2. Biosynthesis of Selenomethionine- 7 3Se

137

10- 3. Separation of Carrier-free Radioactive Krypton

139

RADIATION MONITORING

11-1. Routine Monitoring141

11 - 2. Leakage Radiation Measuremen t at the Underground Passage

143

HEAVY ION LINEAR ACCELERATOR PROJECT

12- 1. Status of the Constructional Work144

12- 2. The Proto-type Buncher ....... . .......................... . . _ . . . ..

145

12- 3. A Lay-out Plan of the Beam Diagnostic Elements

146

12-4. Orbit Analysis of the Beam after Charge Stripping

147

12-5. Test Facility for Heavy Ion Source ................ . ......... .. ..... .

149

13.

LIST OF PUBLICATIONS

151

14.

LIST OF PERSONNEL

159

15.

LIST OF OUTSIDE USERS AND THEIR THEMES163

AUTHOR INDEX

165.................. . ..........................

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

1. INTRODUCTION

During the year the IPCR cyclotron was operated smoothly as before. Several improvements
have been made in the machine itself and its accessory facilities which resulted in more stable andefficient operation.
In all fields of research using the machine a majority of research works have been ' carried out
with heavy ions.

Extensive studies of particle-gamma and particle-particle correlations and spinpolarization of emitted particles were performed on the nuclear reactions induced by heavy ions.
Heavy-ion induced X-rays were studied to get the information on the excitation mechanism as wellas the effects of chemical environment on the X-ray spectra.

Channeling experiments were

continued to study location of impurity atoms and radiation damage. Positron annihilation
studies were made on ionic crystals. Activation analysis by charged particles were applied to
study the surface of the semi-conductor materials. Studies of the radiation chemistry andradiation biology were continued by using heavy ions as well as a -particles.
The first resonator and the injector of the new heavy-ion linac were installed. Model studyof the separated sector cyclotron was started.

Hiromichi Kamitsubo
Editor2

2. MACHINE OPERATION

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

During the period from Oct. 23, 1976 to Oct. 22, 1977, the cyclotron was operated on 24 ha day basis.
Table 1 shows a statistics of machine operation.
5.4% compared with that of the last year.

The beam time was 4346.9 h, decreased byThis is due to the increase in the time spent foroverhaul.
Following troubles occurred in this period.

The water-cooling pipe on the moving earth-plate

was damaged as a result of rather large number of discharges between the dee and the cooling pipe,
experienced during these several years. The driving shafts for the moving earth-plate were also
damaged by discharges. Because of the operation extending over 60000 h , the motor-generator for
power supply to the main magnet (M. G) were damaged. Mainly for the repair of this M. G.
system, the overhaul time was increased.
We constructed one more heavy ion source and at present we have three heavy ion sources.
A pulsed arc power supply was also completed and pulsed operation of heavy ion source was
frequently carried out to get much intensities of 0 5 + and Ne 6 + ions.I) The automatic control
system for evacuating pumps was equipped to the cyclotron in this summer.
Table 2 shows the machine time allotted to various activities in this period. Due to therequest of research workers, beam time for heavy ions was increased in percentage compared withthat of the last year.

Table 1.

Machine operation.
Oscillator

Ion source

BeamReading of time me teron Oct. 23 , 1976

47050.3(h)50354.3(h)19474.9(h)Reading of time me teron Oct. 23 , 1977

51750.855308.8

23821.8

Difference

4700.54954.64346.9Percentage of 365 days
Schedule in this period
Beam time
Overhaul and installation work
Periodical inspection and repair
Vacation and holidays

53.7 %

56.6 %

231 (days)
65
23
46

49.6 %

3

Table 2. Scheduled beam time and subjects of activity in the period X.
Heavy ion

Ligh t particles

Total

Nuclear reaction
In-beam spectroscopy
RI production

2198(h)224
0812(h)
72
43010(h)296
4

Nuclear chemistry
Radiation chemistry
Radiation biology
Solid state physics
Inner atomic shell
excitation study
Stopping power study

13
156
99
15

133
44
99
535

146
200
198
550

234

39

273

15

44

59

0
0
0

5
192
18

5
192
18

17

0

17

2971

1997

4968

59.8 %

40.2 %

100 %Subject{

Nucl. Phys.

Fields others
than N ucl. Phys.

Outside users{

Nuclear medicin
Nuclear fuel study
RI production

Development of instruments
Total
Percen t in total
Maintenance: operation and engineering
Exchange of ion sources
Reserved for beam time adjustment
and cooling of radioactivity
Machine inspection and repair
Total

76(h)
37
552
665

Reference(1)

H. Nakajima, S. Kohara, T. Kageyama, and I. Kohno: Report I. P. C. R., (in Japanese), 53, 132( 1977).

4

3. MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS

3-1.

I mprovement of the Beam Probe System of the eye lotron

K. -Qgiw-ara and H. Takebe

Three- and four-finger beam probe(1)

In order to measure the vertical distribution of the beam in the cyclotron, a three-finger beamprobe was equipped and tested. Figure 1 shows three electrodes of the three-finger probe, lengthof which are 4 em in the radial direction of the beam orbit.
The beam intensity distributions along the radial direction measured by the three-finger probe
are shown in Fig. 2.

Three curves in the upper figure are measured by upper, medium and lower

fingers respectively.

In this figure, it is seen that the beam passed above the median plane at somepoints of radius.

The distribution of the total current measured by three fingers shows no smooth

curve, as is seen in Fig. 2 (the lower part). This kind of total current distribution is notconvenient for diagnosis of usual operation of the cyclotron. So we have made a four-finger probe
which has three differential electrodes and an integrating electrode.

Figure 3 shows the electrodesof the four-finger probe.
To sum up currents of the electrodes, the beam probe amplifier (Fig. 4, lower) has a sum
circuit with four current amplifiers which can measure from I nA to 1 rnA.
30

This amplifier is

He 2 + 22 MeV, June 15, 1976.

- - - - - - - Ifl_._lupper). - ' #2 Imedium)- - - 113 Ilower)78<---_ 40
R~~~~:--i~

80

lem)

Toto I current of 111, liZ , ond 1f3.

Be a mStem (SUS I.~

lectrodes•

Fig. 1.

rq-Almina

\

If
If

Ifl 3

r---- I

1f2

I--- --

I

. J.

6

10

(
R (em I

Three-finger beam probe.

Fig. 2.

The beam intensity distribution measured

by the three-finger beam probe (upper) and thetotal current of them (lower) along the radial
direction.

5

-Q.

No. 4

Integrot in g

0electrode

.n

6

Beam
180

No.4

Integrating electrodeFig. 3.
No.3

Four-finger beam

Coolinprobe.

No.1-3 : Differential electrodes

Fig. 4.

A view of the control panel for driving

system of the beam probe (upper) and the beamprobe amplifier (lower).
connected with a four-pen recorder.

The recorder can be switched to other operationalparameters, for instance, vacuum pressures, frequency of the RF system, current of the main
magnet and so on. It is very useful for the maintenance of the cyclotron to monitor thoseparameters for hours.
(2)

Improvement of the driving system for the beam probe

To simplify the cyclotron operation, the driving system for the beam probe was improved.
The driving motor was changed from an induction motor to a pulse motor, and an indication of
the beam probe from an analog meter to a digital meter. Figure 5 shows the schematic block
diagram of the driving system using a pulse motor. The driving speed of the beam probe is 2
mm/sec which is almost as fast as before. The control panel for the driving system, shown in
Fig. 4 (upper), assembles all of the operation keys and indicators. The beam probe is now easily
handled by only pushing a start switch after presetting a digital switch to define the distance to
move.
Beam probe ~The block diagram of theFig. 5.
driving system for the beam probe.

6

3-2.

The Pulsed Ion Source

H. Nakajima, S. Kohara, and T. Kageyama

In the cyclotron, the heavy ion source of electron bombarded hot cathode type is usuallyoperated by applying direct current for arc discharge and has an available arc power dissipation of
about 2.5 kW, which is inadequate to create highly charged light ions such as Ne 6 + and 0 6 +.
In order to produce a powerful arc discharge beyond the power dissipation limit of the source,
pulsed operation of the source was proposed. A pulsed arc power supply which allows to furnish
an ion source with an instantaneous arc power of about 10 kW was fabricated and operated
successfully. The pulsed arc power supply is composed of a power switching circuit and the DC
power supply used so far for CW operation. The power switching circuit which consists of aswitching power tube, a transistorized driver stage and a pulse generator is placed between thesource and the DC power supply, and produces periodically an arc potential at the source (Fig. 1).
AC INPUT 200V 15A
Indic at ors ARC
vol toge, cu rren t

Power sup ply

The Power Switching
Ci r cui t[on Source
Refle ctor
cat hode

fo r
dr i ve r

>
o
2
u

<[

50n.

n --- +180V----1 L

Fig. 1.

OV-200 V

Circuit of the pulsed arc power supply .

The power switching circuit as it is installed is shown in Fig. 2 and a typical wave form of arc
discharge is presented in Fig. 3. The pulsed arc power supply has realized large power
enhancements for arc discharge and a remarkable displacement of the mean charge state toward alarger value was observed in the charge state distribution of ion beams.1) Typically, the source
was operated with an arc potential drop of about 500 V and an arc current of 8 to 12 A at peak.
A duty cycle of about 30% and a pulse duration of about 1 ms were chosen.
Ne 6 + and 0 6 + ions were accelerated successfully up to 160 MeV and more than 0.1 J.lA of
those ions were extracted from the cyclotron . CS +, Ne 7 +, and 22Ne 6 + ions were also extractedwith a modest intensity . The intensities of C4 +, N4 +, N 5 +, and 0 5 + ions were increased by a factorof 5 or more , compared with those in DC operation.
Particles, energy ranges and particle yields obtained by using pulsed operation are shown in
Table 1.

A source life of about 5 h was obtained with a mean arc power of about 2 KW (7 KW7Typical wave form of arc discharge.
Fig. 3.
An arc current is shown by upper wave form.
Vertical sensitivity: 5 A/div.
Fig. 2.

at peak).

Horizontal time :The power switching

1 ms/div., Lower wave form present an arc

circuit.

potential, Vertical sensitivity: 500 V/div.

This life is very short in comparison with a life estimated from an erosion of the upper

cathode of about 20 h. The main problem remaining is to increase the source life time.
Table 1.

Energy (MeV)

Particle

c5 +*
0 6+

Particles. energy ranges and particle yields.

*

2°Ne6+*
2°Ne7+*
22Ne 6 +*

C4 +
N4 +

N5 +
0 5+

49 65 82 82 90 49 57 57 65 -

130
160
160
185
155
100
100
125
125

Extracted beam current
0.1 J..l.A
0.2 J..l.A
0 .2 J..l.A< 10 nA< 10 nA**
10J..l.A
10 J..l.A
3 J..l.A
3 J..l.A

Mean arc power: 2 kW, Pulse duration : 1.2 ms , Duty cycle: 30%.

***

Newly accelerated ions.
Natural Ne gas was fed.

Reference
1)

H. Nakajima, S. Kohara, T. Kageyama, and I. Kohno: Reports I. P. C. R., (in Japanese), 53,
132 (1977).

8

3-3.

Acceleration of Polarized Protons with S.F. Cyclotron at INS

T. Fujisawa, S. Motonaga, N. Ueda,* S. Yamada,*
T. Hasegawa,* T. Wada, Y. Toba, and H. Kamitsubo

A polarized ion source for the proton and deutron was installed on the S.F. Cyclotron at
Institute for Nuclear Study (INS) in Tanashi.1)-3) The polarized proton beams from the ion source
are vertically injected to the cyclotron at 10 keV and inflected to the median plane on the mirror
at the centre of the cyclotron. The mirror voltage is about 7 kV. The energy of the extracted
beams is 28 MeV. The size of the beam spot on a target was 2 mm X 4 mm. The intensities ofthe polarized proton beams were 5 JiA, 1.4 JiA, 50 nA, 10 nA, and 3 nA at the outlet of thesource, the mirror, the inlet of the deflector, the outlet of the deflector and the target respectively.
The carbon target for a polarimeter was a 5 mg/cm 2 self-supporting foi1. 4 ) The scattered protons
were detected by 5 cm¢ X 2 cm NaI (T£) crystals mounted on photomultipliers with defining slitsof 3 cm¢ and placed symmetrically to the beam direction at positions 45 cm from the target. Theenergy resolution is enough to separate the ground state and the first 2+ state of 12 C. The angles
where the beam polarization was measured were corrected by measuring the angular distribution of
the elastic scattering cross section of the unpolarized proton on 12 C and differences of detector
efficiencies and solid angles were corrected by measuring the asymmetries of the unpolarized andpolarized beams alternately.
Figure 1 shows the variation of the polarizati on of the proton beams against the RF field andthe static magnetic field of the RF transition. Figure 2 shows the drift of the polarization degreeof protons measured over a long time.

R-F

St at i cf ield = 0 .4 A

Po wer = 1. 35V

. ...

c
o

~ 0.5

0.5

.. . .

o

o
D-

.

0.5

0~1~____~!

St at i c f ield of R - F trans i ti on (A)Fig. I.

0.5______

1.0~!

______

Power of R-F f ield

Polarization of proton beams for static

field and R. F. power of the R. F. transition.

*

Institute for Nuclear Study, University of Tokyo.

~!~
2.0

1.5
(V)

9

80

- 75
~

.. .

..

c

o
o
N

~ 70

o

CL

65

Fig. 2.
T i me(hour)The drift of thepolarization degree of protons.

References
1)

S. Motonaga, T. Fujisawa, I. Takeshita, K. Ni shi, and H. Kamitsubo: Genshikaku-Kenkyu,(in Japanese),1..L 766 (1977) .

2)

S. Yamada, N. Ueda, Y. Sakurada , M. Sekiguchi , T. Tan abe , Y. Honma , and T. Hasegawa:ibid. , p.772.

3)

S. Motonaga, T. Fujisawa, F. G. Resmini, Y. Toba, S. Yamada, N. Ueda, T . Hasegawa, and
H. Kamitsubo : IPCR Cyclotron Progr. Rep., 10, 16 (1976).

4)

R. M. Craig, 1. C. Dore , G. W. Greenlees, 1. Lowe, and D. L. Watson: Nucl. Phys., 83,493 (1966).

10

3-4 Design Study of a Linac-Injected Separated Sector Cyclotron ( 1 )Four Sector sse
S. Motonaga, H. Kamitsubo, N. Nakanishi, K. Ogiwara,
F. Yoshida, and I. Yokoyama

A design study of a linac-injected separated sector cyclotron has been carried out in order to obtain particles
of energy over 80 MeV /n for light heavy-ions and over 12 MeV /n for very heavy-ions using as an inje.Gtor thevariable frequency he:lVy-ion linac which is under construction in IPCR!)
MeV/n for light heavy-ions to 1 MeV/n for very heavy-ions.
Table I.

Injection energy is in the range of 4

The basic parameters of this cyclotron are given in

The magnet system of the cyclotron consists of 4 sector non-spiral magnets.

product (Bp) is 3400 kG ·cm.

The effective sector angle of 50° was chosen to provide suitable axial and radial

focusing property of the ion beam.
2

appropriate soft edge field. )The maximum field-radiusFigure 1 shows the resonance diagram which is calculated by assuming an

The locus of each particle does not cross any maj or resonance line.

If the injectionenergy of light heavy-ions, such as C 6 + and Ne 9 +, are increased up to 4.8 MeV/n, these ions can be accele~ated up toenergy of 100 MeV/n.

In the case of proton acceleration to energy of about 200 MeV, the proton beam must crossthe vr - 2v z = 0 and vr = N/3 resonance lines as shown in Fig. 2.

It may not be impossible to pass through theseresonance lines without any loss or deterioration of the beam, because of large energy gain per turn and good beam
quality in this cyclotron as compared with an ordinary cyclotron. But extensive studies are needed to overcome thisdifficulty.
Table 1.

Basic design parameters of the linac-injected separate sector cyclotron.

Maximum energy
Proton H+
Carbon C6 +Uranium U40+
Number of sectors
Sector angle
Magnet fraction
Orbi tal fraction
Gap between poles
Maximum Magnetic field
Maximum field-radius product
Number of trimming coils
Injection radius
Extraction radius
Weight total
Energy gain per turn
Number of dees
Angle of dee
Orbit frequency
Accel. RF frequency
Harmonic number
Numbers in (("'200 MeV, Einj ~ 10 MeV)
80 MeV/n
15 MeV/n

4
50°
0.555
0.558
8 cm
17.3 kG
3400 kG· cm>20 set77 cm
327 cm1900 '" 2000 ton"'1 MeV222.5°
2.5 - 5.55 (8.7)MHz
17 - 45 MHz

8,6, (5)) are values in case of proton acceleration.

Ion acceleration is done by 22.5° delta-shaped two dees located at opposite valley spaces between sector
magnets.

The frequency range of the system is 17-45 MHz and its acceleration harmonics is 8 to synchronize withthe accelerating frequency of the linac.

11

0.9

0.9

0.8

0 .8

0.7

!S+,c"

0 .7
In ject io n rod ius
Maxi mu m rad ius

Ne9+ C6+

R=3.27m[= 2008, 12 14MeV

R= O 77 m

0.77m
3.27m

[ = 96, 58 MeV

0.6

0.6

-- ------ ------ - ~~ ~~--1.0

11
Part icles

C6 +Ar' 5+
Kr 24+
Xe 3O +
U4O+

Fig. 1.

12[ ini/n [ out / n B me, Wo

4.00
3.00
1.90
1. 36
0 .84

80
59
36
25
15

W rf

Part icl es [ i ni/n [ outln Bout
C6 + 4.8 100 15.2

13

Yr

13.6 5.5 44
15.3 4.8 38
15.7 3.B 30
16. 5 3.2 26
17.3 2.5 18- - 0.5 - - - - - - - - - - - - - - - - - - - - - - .

h
8
8
8
B
B

h,SOee 2rr.h/2
0

18 0
1800
18 0 0
18 0 0
180 0

Ne9 + 4.8

8n

WO

6.1

100 16.8 6.0

8IT

8n

1.0

1.1

8 IT
Brr

vr

1.2

1.3

Focusing properties calculated with soft edge approximation.

(A) Injection energy ranges between 4 MeV/ n and 1 MeV/ n , for light heavy ion(C 6 +) andvery heavy ion(U 4o+). (B) Injection energy is assumed to be 4 .8 MeV/ n for C 6+ and Ne 9+.
1.0

0.8

0.7

0.6

0.5 - - - -- - - - - - - - - - - - - - - - Porticles Elni/n Eout/n 8 mo ,-10 ~200
12.5- ~-----\~\ ~< ~t'\• 3.27• 253
0.4
1 .S0------~I.1------~1.2~----~I~.3-+--~1~.4~~--

Fig . 2 .

Fo cusing properties for various inje c tion energies

of proton bea m.

In order to specify the most favourite parameters, two 1/4-scale model magnets were constructed to obtain
detailed information on properties of sector magnets : their excitation characteristics , field distribution which
includes the interference by adjacent magnet , and field formation for accelerating the beam.
Excitation characteristics and relati ve field distribution inside and outside of the gap were measured
preliminarily using an NMR calibrated Hall plate (SBV-595) without a temperature stabilizer.

These measurementsof the magnetic field were done to get rough information on properties of the sector magnets.

The excitation

curve obtained is shown in Fig . 3 , being in good agreement with the calculated one.

It may be seen that assumed

magnetic induction at various points along the magnetic circuit is quite reasonable.

The radial distributions along

the center line of the 'sector magnet are shown in Fig. 4 at magnetic field if 1. 2, 1.5, and 1.75 Wb / m 2 .
decrease of magneti c flux near the center is supposed to be due to slight local saturation effect.
for obtaining the isochronous field can be made by triming coi Is .

TheThe correction

12

18

---

-

......e- x -

e X'"

X

e/
/

x

x~·

15
I

/e

"'0

x
l

/

e/

• measured

X ca lculated

100

Gop: 30mm I 29.935mml

xl

.~ 10

Sector Magnet

iii

W

99

/

.....
w
c::

0'

o

x

~

I

o

/

52 98

~

Ie

5

I

I

97

I

o

600

700

Pole

96
655mm
I

1

100

200

300

I

400

Coi l current

Fig. 3.

500

600

o

100

200

300

Excitation characteristics of the

500

500

700

Radial field distribution along the center line

Fig. 4.

of the model sector magnet.

model sector magnet.

400

Modele radius Imml

(A)

Relative values arenormalized to the maximum fi eld at radius of 45 cm.
Azimuthal field distributions are measured at 4 radii in two regions: one where there exists the interference by
the adjacent magnet and the other where there is no such interference.

Results are shown in Fig. 5(a) and 5(b).

Effect of interference is observed in the field distribution near the center.

Accurate and extensive measurementsof the magnetic fiel d and computations of the beam dynamics are in progress.
Mag net-I(0)0°

1.0 1---- -----.;:-..-..

(b)

0.8 R1=235mm
R2=385mm
R3=535rrun
0.6 R4=685rrm

0.4

0.2

10°

eA

50°

20°

8e

Fig. 5.

Azimuthal field profiles of the magneti c field norm alized to the maximum val ue at radius of

53.5 cm(QB) and (QA) indicate the region with and without the effect of interference by adjacentmagnets.

References

1)

M. Odera : Proc . Proton Linear Accelerator Conference ., Chalk River , p. 62 (1976).

2)

l. Miura: SPYRING CODE, private communication.

13

3-5.

Design Study of a

Linac-Injected Separated Sector Cyclotron (2)Six-sector SSC
N. Nakanishi, F. Yoshida , S. Motonaga, and H. Kamitsubo

A separated sector cyclotron (SSC) is adopted as a booster acclerator for a variable frequency
heavy ion linac.

Possibility of a 6-sector sse is investigated and a typical example is presented

herein.

It is well known that beam stability depends on the property of its betatron oscillation aroundthe equilibrium orbit.

The behavior of focusing frequencies vr and V z shows the beam stability inthe process of acceleration , in which these parameters vf' V z are respectively the radial and axial
oscillation frequencies expressed in units of the revolution frequency of the particle.

Actually , thespace of focusing frequency vr - V z is divided into several regions by resonance lines which makeoscillation amplitude large.

Thus it is required that the beam path in the vr - V z space should notcross the resonance lines , or that some measures should be t aken technically if the path intersects
the lines.
Investigations have been carried out to find out magnet configulati ons which satisfy kinematicconditions for beam focusing and isochronism.

Calculations have been made modifiing

the code developed by Gordon. 1)
The sse composed of six sectors is assumed to have straight edges and an appropriate fringing
field.

Main parame ters of the SSC are summarized in Table 1, and final energies expected forvarious particles are given in Table 2.
vr - V z space.

Figure 1 shows the behaviors of focusing frequencies in the

Since curves for proton cross the resonance lines, further investigation has to be

Table 1.

The parameters of the present separated-sector cyclotron .

Orbit

Energy constant K
Injection radius R 1
Ex traction radius Re
Burst numbers per turn
Energy ratio Ee/Ei
Betatron frequency

MagnetNumber of sectors
Sector angle
Magnet gap
Fiel d strength B
Number of trim coils
Iron weightRF

Number of dees
Dee angle
Freq uency range
Harmonic numberj260(C 6 + )'"\;340( 15 MeVp+ )'"\;445 (U40 + )0.88 m3.40 m9
14.5'"\;22.5
v r 1.0'"\; 1.5
V < 0 .9 5
z
6
29.4°
10 cm
1O"v 18 kG'"\;201500 t3
20°18'"\;45 MHz~914

Table 2.
Particle

1p+
1 p+
4He 2+
12e6+
20 Ne9+40 Ar15+84 Kr24+
132 Xe3O+
238U37+

Final energies of some particles.

Initial energy(MeV)

Final energy(MeV)

Maximum field

10
15
16
48
90
120
160
180
200

189
336
258
773
1468
1887
2452
2724
2991

12.2
16.8
13.7
13.8
16.4
15.6
16.1
17.0
19.3

(kG)

made concerning beam dynamics.
As to the number of sectors it is considered that a sse with 6 sectors is superior to one with
4 sectors because of the following reasons: (1) Resonance lines are less in the used region of thevr - V z space . (2) The total weight of the magnet is lighter. (3) There exists a possibility oflarger turn-separation owing to three dee structure.
Investigation is also in progress for the magnet with spiral edges.

Fig. 1.

Behaviors of focusing frequency in the

Vr - V z space.

Straight lines are resonance lines.

Symbols P IO and PIS represent curves corresponding
to lOMe V and 15 Me V protons, respectively.

Reference

1)

M. M. Gordon: Nucl. Instr. and Meth., 83, 267 (1970).

15

3-6.

Beam Study on the Baby eye lotron

T. Karasawa(1) Phase history of an ion

The phase, 8 1 , of an ion crossing the acceleration gap at the radius , r 1 , is given by thefollowing equation for the 2nd harmonic acceleration with two 45-degree dees in push-pushexcitation,(1)

where we is the frequency of the R. F. vol tage applied to the dees, Wo is the rotation frequency ofan ion, Bo is the magnetic field and 0 0 is the phase of an ion at the center of the magnet,
respectively.

E 1 is the energy of an ion at the radius of r 1 , mo c 2 is the relativistic expression formass and energy and Vo is half of the peak to peak R. F. voltage.
If 8 0 , Bo and B(r) are given , 8 1 can be calculated by using equation (1).

and Smith 1) have developed experimental method for the determination ofradius.

However, Garren

e as a function of
1

In Fig. 1, a calculated phase history of 9.4 Me V proton accelerated by the 2nd harmonicmode is shown together with experimental results measured by the method of Garren and Smith.
1. 04

cO

1.0

::::::
0:::

05
o

If')

1. 0 1

'<T

/
/

I
<D

-

/
/

c:

'"

/

-0.5

./
/'
/'

- 1.°0~-'lr---::2...l...00----::-3...l...
00:-----4..LOO:-----~::-----::::-:'

R2

Fig. 1.

(cm 2 )

/'

1.00

----

Displacement of the orbit centerfor three different positions of the ion
source.

10

Data points for the displacement

R

(em)

Figures attached to the points indicate theMagnetic field distribution.
Fig. 2.
Dotted line shows isochronous fiel d fornumber of revolution.

9.4 MeV proton.

correspond to ion source positions.

16

The magnetic field distribution is shown in Fig. 2.

In the case of 9.4 Me V protons, 8 0 is suitable

for the maximum energy gain per turn and isochronism js sufficient up to nearly the maximum
radius, as shown in Fig. 1.
While, in the case of 4.7 MeV deuteron accelerated by the 4th harmonic mode , wider spread of

8 0 and large phase excursion from +90 degrees to -90 degrees were observed.
(2)

Displacement of orbit center from the magnetic center at higher harmonic mode acceleration

It is well known that an orbit center of an ion is displaced by the first harmonic in themagnetic field. 2 )At the higher harmonic mode acceleration, orbit center displacement is caused byoccurrence of asymmetries of both the magnetic field and the acceleration field.

The latter isgenerated by phase di fference of the ion arriving at the acceleration gaps.3)
According to Hagedoorn and Vester,4) the displacement of orbit center from the magnetic
center is written as given by polar coordinats p and t.(J. For the 2nd harmonic acceleration withtwo 4S-degree dees in push-push excitation, variation of p and t.(J per revolution of an ion, 6p and6t.(J , can be given by following equations

6fJ=- ~Opsin (2<;0+ 8+45° ) +rr r C 1 sin (<;0- CPl)
6<;0=- ~oC!2 sin (8-45° ) -sin (2<;0+ 8-45°) J(2)r+ rr -C 1 cos (cp- ¢J + 2rr ( lJr-l )pwhere V 0, E, 8 amd r are the same meaning in the Eqn . (I) .

C 1 and '1/11 are the amplitude andphase of the first term in a Fourier expansion of the azimuthal variation in the magnetic field. vr
is the radial betatron oscillation frequency.
Figure 3 shows the results of computation of the orbit center displacement at the 2nd
harmonic mode acceleration for three different positions of the ion source.

The ion source

position works as an initial condition for the Eqn. (2).
I t is seen that a small change of the ion source position is responsible for a large displacementof the orbit center. We are now searching for an optimum accelerating condition, carring out
detailed numerical calculations and experimental study using shadow technique. S )The author would like to acknowledge the collaboration of the cyclotron group at the Muroran
Plant of Japan Steel Works in Hokkaido.

Dee

I
I
I
I
I
I

5mm

I

l

Dee

Fig. 3.

- 5mm \\\

Phase of a 9 .4 MeV proton vs.

square of radius.

17

References
1)

A. A. Garren and L. Smith: CERN 63-19 , p. 18 (1963).

2)

J. M. Nieuland : Phillips Res. Repts. Supp!., No.2. (1972) .

3)

T. Karasawa and Y. Kaneda: Reports of I.P.C.R ., (in Japanese) , 53 , 35 (1977).

4)

H. L. Hagedoorn and N. F. Verster: N. I. M. 18-19, p. 217 (1962).

5)

J. R. Richardson: Progress in Nuc!. Techniques & Instrumentation 0), p. 66 , 1965

North-Holland Pub!. Amsterdam.

18

4. NUCLEAR PHYSICS
Scattering and Reactions
4-1.

Spin FlipIn

the Inelastic Scattering of Polarized

Protons on

12C

T. Fujisawa, S. Motonaga, F. Soga, M. Yasue,*
N. Ueda,* T. Hasegawa,* M. Nakamura,**T. Wada, H. Toba, and H. Kamitsubo

The spin flip probability of polarized protons exciting the 2+ state of 12 C was measured
using the (PP''Y) method, i.e., by measuring the angular correlation between protons scatteredinelastically from the 2+ excited state and the E2(2+~O+ ground) de-excitation 'Y-rays emitted
perpendicularly to the scattering plane. 1) ,2) The polarized proton beam extracted from theatomic beam type polarized ion source which was constructed at The Institute of Physical and
Ep= 28 MeV

1.0

I

Ep =28MeV

50

o
...

Elastic
Inelastic
A-P

o

.CL

40

0.5

I
<{

I

o

§

o-!' 30

o

<{

LL
(.f)

0

20

I

I

10

o

I

o

I
0

30

60

120

90

150

- 0.5

30

60

120

150

SLob

Fig. l.
Proton spin flip probability(SF)in the reaction 12C(pp') 12 C*(4.43 MeV) at
Ep = 28 MeV.

Analyzing power of the elastic
Fig. 2.
and inelastic scattering of proton by 12 C
at 28 MeV(A). And difference between
analyzing power and polarization of theinelastic scattering (A-P). The open andclosed circles represent the analyzing
powers of the inelastic and elastic scattering,
respectively. The triangle represents A-P.

*

Institute for Nuclear Study , University of Tokyo.

**

Department of Physics, Kyoto University.

19

Chemical Research was accelerated to 28 MeV in the SF Cyclotron of Institute for Nuclear
Study.3) The beam current at the scattering chamber named SF 80 was about 1 nA and thesize of the beam spot on the target was 2 mm X 3 mm. The )'-rays were detected with a
7.6 cm X 7.6 cm NaI(TP) crystal mounted on a 56 AVP photomultiplier which was situatedabove the chamber. It had a slit made of lead 10 cm thick with an aperture of 57 mmet>. The
scattered protons were detected by ORTEC 5000 /lm surface barrier and 5000 /lm Li-drift SSDS
with defining slits of 6 mm¢ placed symmetrically to the beam direction at points 11 cm fromthe target. The detectors monitoring the beam polarization which were consisted of two 2000
/lm surface barrier units with aluminum absorbers 2 cm thick and defining slits of 6 mmet> weresituated at angles of 62.5 degrees from the beam direction symmetrically in the same scatteringchamber because the analyzing power of 1 2 C for the proton is known at the same energy. 4)
Difference in the efficiencies of two detectors and the difference of solid angles were compensatedby measuring the asymmetry of the polarized and unpolarized beams alternately. Figures 1 and 2
show the preliminary result.

References
1)
2)
3)

4)

F. H. Schmidt, R. F. Brown, JB. Gerhart, and W. A. Kolasinski: Nucl. Phys., 52, 253(1964).
T. Fujisawa: Genshikaku Kenkyu (in Japanese), 1..1. No.4, p. 849 (1976).
T. Fujisawa, S. Motonaga, N. Veda, S. Yamada, T. Hasegawa, T. Wada, H. Toba, and
H. Kamitsubo: IPCR Cyclotron Progr. Rep., ~ 8 (1977).
R. M. Craig, J. C. Dore, G. W. Greenlees, J. Lowe, and D. L. Watson: Nucl. Phys., 83,493( 1966).

20

4-2.

Two-Step Process

Proton Inelastic Scattering

In

H. Amakawa, A. Mori, * and K. Yazaki**

The reaction mechanism of single particle excitation reaction induced by protons is studied
using the three-body model. In this model, the target nucleus is assumed to consist of a neutron
and inert core nucleus. Employing the two-step approximation, the reaction amplitude T fi of thismodel is decomposed into three terms: the DWBA term, the (p, d , p') term (pickup-stripping
process via the ground state deuteron (d) propagation) and the (p, d *, p') term (pickup-stripping
process via the continuum p-n system (d *) propagation).

Thus, T fi is expressed as follows:+ ~where X's are distorted waves, k is a relative momentum between p and n, Ho and vpn are kinetic
energy operator and p-n interaction, respectively. ¢ d and ¢k (+) denote the internal wave
functions for d and d * whose energies are Eo and Ek ' respectively. Ud is an appropriate potential
(bI

(a)

17

0 ( p, p'1170 * ( 112 + , 0.871 MeV I'7 0 ( p , p'I'70*( 112+ , 0 _87 1 MeV)

Ep= 10. 5 MeV

Ep = 35MeV
10'--- ----- - -/// ----. -:: : "".- --====-=------=-- ------- .l Oa//~ -- - - . - - - . - - -- - - . - . ..------------ -------------~~ 10-'- - Total--To;a 1

DWBA- - - - - - (p , d , p' I

DWBA
( p , d , p' )( p, d* , p'l-- - ( p,d* , p'l--

DWBA + Ip , d* , p'l

DW BA+ { p,d ,p'l

0'

60°

120°

8,.m. ( deg - I

180 0

D°

60 0
8,.m. ( deg. 1

Fig. l.
Calculated cross sections for 170(p, p') 17 0*(l/2+, 0.871 MeV) reactions at
Ep = 35 MeV (Fig_ l(a)) and 10.5 MeV(Fig. l(b)). Solid curves denote the coherent sumof the DWBA , (p , d , p' ) and (p , d *, p') cross sections. Spectroscopic amplitudes are
assumed to be 1.0.
* Num azu Technical College .

**Department of Physics, University of Tokyo.

21

which depends only on the p-n center-of-mass coordinate relative to the core nucleus.

In thefollowing numerical calculations, we use the optical potentials for U d which reproduce the elastic
scatterings of deuteron.
We calculate these three terms in the case of 17 0 (p, p') 17 0* (1/2+, 0.871 Me V) reactionsat 35 and 10.5 MeV bombarding energies.

It has previously been pointed out that the finite range

effect of the pickup-stripping transition is important. 1)

Therefore, we have performed the exact

finite range calculations using the computer code TWOFNR.2)

For the p-n continuum state, only

the s-state was included. The integration over K was replaced by the summation over €k'parameters of the optical potentials were taken from Ref. 3 and 4.

The

In the 35 MeV case (Fig. I (a)), the (p, d *, p') term has a magnitude comparable to other two
terms.

If one does not include the (p, d *, p') term in the reaction amplitude, the cross section(double-dotted-solid curve of Fig. 1 (a)) at forward angles is reduced by a factor of 1/4.

Thisclearly shows the importance of the (p, d *, p') term at this bombarding energy.
On the other hand, in the 10.5 Me V case (Fig. I (b)), the (p, d, p') term almost dominates
over the reaction amplitude. The DWBA and (p, d *, p') terms do not play an important role atthis bombarding energy.

ReferencesI)

P. D. Kunz and L. A. Charlton: Phys. Lett., 61B, I (1976).

2)
3)

M. Igarashi: unpublished.
M. D. Cooper, W. F. Hornyak, and P. G. Roos: Nucl. Phys., A218, 249 (1974).

4)

E. Newman, L. C. Becher, B. M. Preedom, and J. C. Hilbert: ibid., AIOO, 225 (1967).

22

4-3.

DWBA Analysis of Proton Inelastic Scattering from 28,29, 3 °Si
and Blocking Effects in the Core-Excitation of 29Si

Y. Toba, N. Nakanishi, H. Sakaguchi,* A. Goto,*
F. Ohtani,* N. Kishida, M. Yasue,** and T. Hasegawa**

In order to investigate the blocking effect in the core-excitation of 29 Si caused by the Pauliprinciple, proton inelastic scattering experiments on 28,29,3 Si were performed with a 16.2 MeV
proton beam from the IPCR cyclotron and a 51.9 MeV proton beam from the INS
synchrocyclotron. The experimental results at IPCR have already been reported. 1 ) In theexperiments at INS, a broad range magnetic spectrograph 2 ) was used for the detection of scatteredparticles. The targets which were used in the 28,3 °Si (p, p') experiment were a 1.02 mg/cm 2
thick foil of natural silicon 8 Si 92.2% abundant) and a 0.165 mg/cm 2 thick foil of enriched

°

e

30

silicon oxide ( Si 95.6% abundant) with 0.5 mg/cm 2 Mylar backing. These were prepared by acentrifugal precipitation method. 3 ) A 29 Si 0.135 mg/cm 2 self-supporting foil of enriched siliconoxide 9 Si 92.2% abundant) was prepared by vacuum evaporation.

eFigures 1, 2, and 3 show 51.9 MeV and 16.2 MeV data together with results of the DWBA
calculations, respectively. In the DWBA calculations of the inelastic scatterings to the 2+ states of
2 8~ 30Si, a macroscopic form factor was used.
In the case of the 3/2t 1.27 MeV, 5/2~ 2.03 MeV,
3/2; 2.43 MeV, and 5/2; 3.07 MeV states of 29 Si, wave functions calculated with the intermediatecoupling model by Castel et a1. 4 ) were used.

On that occasion, core-exci tations were calculated

Optical potential parameters used in
the opti cal model and DWBA calculations.

Table 1.

Ep

VO(MeV)rO(fm)aO(fm)

51.9 MeV

36.4561.18

0.7

16.2 MeV

53.575

1.186

0.65

WV(MeV) WV(MeV)rI(fm)

al(fm)VSO(MeV)

7.043

1.394

1.182

0.692

5.4

0.659

10.249

1.085

0.533

5.424

rc = 1.25 fm , and rso and aso are the same as fO and ao ' respectively, except aso = 0.6 fm fOf Ep = 16.2 MeV

Table 2. {32 -value deduced from the DWBA calculations.
Ep

Si

29

Si

51.9 MeV

0.42

0.364

16.2 MeV

0.51

0.434

Faculty of Science, Kyoto University.

**

28

Institute for Nuclear Study, University of Tokyo.

3

°Si

0.36

23

with macroscopic form factors and single particle excitations were calculated microscopically with
the Blatt-Jackson potential for the two-body interaction.

Optical potentials used in the calculations

are shown in Table 1. Collective 2+ strengths {32 deduced from the analyses are shown in Table 2.
Apart from the 16.2 MeV data which are affected remarkably by giant resonances, the 51.9 MeV
data show that the core-excitation of 29 Si is reduced by about 25% compared with 28 Si, but isalmost the same as 3 0 Si.

Si ( p , plSi

Elastic

5l~O\ AGViiot G.S

28S i

•

'tj

Ep= 519MeV

0-

\

• j'

-29Si ( p, p' ) 29Sio~,.-..,'~\

10

Ep =51.9MeV
scattering

~'-"\

29 Si

5 "

',:--

....,. (\3/2t 1. 27 MeV

1I2 t G.S

,
5

\ J
\i'

'\.
.~

30 Si

0+ G.S

05~

Inelast ic

scatte r ing
2+ 1.78 MeV

0.1
0.05

3/2 t

2.43 MeV

0.1
0.01
30

60

90

120

SCM. (deg. )

90

30

120

SCM( deg.)

Angular distributions of 51.9
Fig. 1.
MeV elastic proton scattering on 28,29, 30 Si

Angular distributions of 51.9
Fig. 2.
Me V inelastic proton scattering to theand inelastic scattering to the 2+ state of
28,30 Si. The solid curves represent the

3/2~ , 5/2~ , 3/2;, and 5/2; states of 29 Si.

optical model fits and DWBA calculations.

tions. In the case of 3/2 ~ state , thecontributions of the core-excitation(CE) and the single particle excitation(SPE) are represented by a dashed and

The solid lines represent DWBA calcula-a dash-dotted curve respectively.

24

10

Ep= 16.2 MeV

5.......

3/2 +1.27MeV105.. . .

if>

512 + 2 .03 MeV

'D

10

E

-

Ci'"

. ..... --..~.~

5

---.~
• ••••••••• •~

l::l

b
l::l

....
0.5

~

3/ 2+ 2 ,4 3 MeV

'-'~"

t

,I

0.0 1

t ttl I'---- I t .

60

•
t

•••••

~

'

~

90
SC M

Fig. 3.

t~/-t It'"

5/2 + 3.0/MeV

30

."

~.

120

150

(deg . 1

Angular distributions of 16.2 MeV

inelastic proton scattering to the 3/2; ) 5/2;,
3/2;, and 5/2! states of 29 Si and DWBA curves.

References

1)
2)

Y. Toba , N. Nakanishi, H. Sakaguchi, A. Goto, N. Kishida, and F. Ohtani: IPCR
Cyclotron Progr. Rep., ~ 21 (1976).
K. Yagi, H. Ogawa, Y. Ishizaki, T. Ishimatsu , 1. Kokame, and K. Matsuda: Nuc!. Instr.
Meth. , 52, 29 (1967).

3)

I. Sugai: ibid., 145,409 (1977).

4)

B. Castel, K. W. C. Stewart, and Harvey: Can. 1. Phys., 48, 1490 (1970).

25

4-4.

Analysis of(p, t)

Reaction

Induced by Polarized Protons

T. Kammuri

Some (p, t) and (p, 3He) reactions using a 49.5 MeV polarized proton beam were studied by
Nelson et al.l ) Only poor fits to the experimental cross 'sections and analyzing powers wereobtained by the zero-range DWBA calculation. Here we present the analysis for the 1 2 C (p, t)1 0 C
ground state reaction by the DWBA method which includes the effects of the finite-range force andthe sequential transfer. 2 ) Simultaneous transfer process is treated by the sum of interaction
method, thus making it convenient to see the competition between one- and two-step processes.
The parameters of the optical potentials used are listed in Table I.

In treating the finite-range force, we take the Yukawa interaction (Vo = 100 MeV, J1 = 1 fm) together with the Hulthentype wave functions for light ions, and the Gaussian force (Vo = 70 MeV, J1 = 1.58 fm) with theGaussian wave functions. Zero-range strengths D5 (in unit of 104 MeV 2 fm 3 ) are 8.8, 1.02, and3.37 for (p, t) (p, d) and (d, t) respectively.
Table 1.
rO

aO

W

rI

aI

Vs

132.9 1.54
131.2
35.2 1.15
109.2 1.0

0.57

19.5
19.7
4.87
22.3

1.82

0.22

1.10
1.52

1.14
0.50

0
5.0
3.42
0

V
t
t
p
d

Optical parameters for 12C(p, t) lO C calculations.

0.68
0.9

rS

1.54
0.62

as

rC

0.57
0.24

0.81 a)0.81 b)1.25 C )1.0 4 )

Imaginary part of triton and proton potentials are of volume type , while thatof deutron has surface-peaked shape.
Potentials a), b), and c) are taken from Ref. 1, referred there as HB3, SHB3, and PEe ,respectively.

Firstly we discuss results of simultaneous transfer. Oscillations in the differential crosssections cannot be obtained by the zero-range calculation while they are stronger than the data in
the finite-range case (Fig. I). Inclusion of the spin-orbit term in the triton potential affects theanalyzing power A(e) but the fit to the data becomes worse (Fig. 2). It can be seen that all onestep results cannot dissolve disagreement with experimental A(e).
Secondly we cosider the results obtained by assuming the sequential transfer. Differential
cross sections show oscillatory behavior with shapes similar for the zero- and finite-range
calculations (Fig. 3). Good agreement with experimental cross sections can be seen. Predicted
A(e) differs considerably from the one-step results and gives better fit to the data (Fig. 4).

In summing one- and two-step transition amplitudes expressed in the prior and prior-priorrepresentations respectively, the one-step amplitude is reduced considerably by the nonorthogonality term, leaving 1/4 of the original magnitude.

This is the reason why the composite

cross section resembles very much with the latter, although the one-step cross section has the26comparable magnitude with that of the two-step process. Therefore the conclusions obtained in
the two-step calculations can be applied to the composite case.

10
12 C (p,t 1 CgS

Ep = 49.5 MeV
one step

Fig. 1.

Comparison of experimental

cross sections and one-step DWBA
calculations for the 12C(p, t)1 0 Cg . S .
reaction at 49.5 MeV incident energy.
Solid and dot-dashed curves are zero-range
results with HB3 and 5HB3 potential
respectively, while dashed and dottedcurves are finite-range results wi th
Gaussian and Yukawa interactions
respectively.

12C (p,t )l °CgS

Ep=49.5 MeV

one steplO
I t (p,t ) Cgs

Ep =49.5 MeV
two step

08

t}

A

I

i

0.4

f i

0

- - ZR-04-- .- - ZR 5HB3---- - FR- 0.8

Same as Fig. 1 except for the
Fig. 2.
analyzing power.

FR

Gauss
YukawaSame as Fig. 1 except for the
Fig. 3.
two-step calculations.

27

12C(p,t )1 0 ~s

Ep =49.5 MeV

two step

0.8

A
0,4

o

~

-0.4

-OB

Fig. 4.

Same as Fig. 2 except for thetwo-step calculations.

References
1)

J. M. Nelson , N. S. Chant, and P. S. Fisher: Nucl. Phys. , A156 , 406 (1970).

2)
3)

T. Kammuri: to be bublished.
J. R. Shepard , W. R. Zimmerman , and 1. J. Kraushaar: Nucl. Phys. , A275 , 189 (1977).

4)

C. M. Perey and F. G. Perey: Phys. Rev., 132,755 (1963).

28

4-5.

A no lyses of the 54Fe (d, p) 55 Fe Reac tion Data at Ed = 24 MeV

N. Kishida, N. Nakanishi, Y. Toba, and H. Ohnuma

More detailed analyses of the 54 Fe (d, p) angular distributions for the low-lying levels in 5 5 Fe
in terms of DWBA, CCBA and the adiabatic theory for deuteron breakup (ADB) have been madesince the last report. 1)
Various distorting potentials are used in the calculations.

The deuteron potential D 1 is an

optical potential which fits the elastic angular distribution, D2 is the same as D I but without
spin-orbit potential, D3 is an adiabatic potential;) D4 is obtained from Ref. 3, and D5 from Ref. 4.
The proton potential P I is obtained from Ref. 5, P2 is a set without spin-orbit potential
searched for so as to reproduce the elastic angular distribution calculated with Pl.
The potential sets D I , D4 and D5 reproduce the elastic angular distribution well. Thus thosepotentials are used in DWBA calculations for the ground state transition (Fig. I). As the potential
sets D4-P I presented the best result , they are primarily used in the following calculations.
G. S. (3/2-). The results of DWBA and ADB calculations are shown in Fig. 2. Only the
55Fe G. S. 3/2DWBA

FRNL- - D4-Pl------ D1-P1

1.0

o

30

60

90
SCM

Fig. 1.

10- - - D5-P1

120

150

180

o

30

(deg)

Comparison of DWBA calculations
with various distorting potentials.

60

90

120

150

180

9 CM (de g)

DWBA and ADB calculations
Fig. 2.
compared with the experimental angular
distribution for ground state (3/2-).

ZRL,

FRL, and FRNL denote zero-range local,
finite-range local, and finite-range nonlocal
calculations, respectively.

Local energy

approximation has been used in FR and
NL corrections.

29

FRNL DWBA calculation can reproduce the experimental angular distribution. Especially it
should be noted that the effect of nonlocality is very large.
O. 411 MeV state 0/2-). Fig. 3 shows the results of calculations. The ADB calculation gives
a good fit. The FRNL DWBA calculation reproduces an overall shape, but it does not fall off
beyond the third maximum.
0.941 MeV state (5/2-). FRNL DWBA calculation without spin-orbit potential (D2-P2)

reproduces the angular distribution very well (Fig. 4), although its significance is not clear.

We

are inclined to think that this is related to the fact that I! -= 3 j-dependence cannot be reproducedin (p, d) and (d, p) reactions at relatively high incident energies.
55Fe 0.941 MeV 5/2- - DWBA D4-Pl FRNL
- - - DWBA D4 - Pl ZRL
A0B... ......... OWBA

03 - Pl Z R L

02-P2 FRNL
(noVso)

-2

10

o

30

60

90

120

150

180

8 CM (de g)

o

30

60

90

e cM(deg)

120

150

180

Fig. 3.
DWBA and ADB calculations for
the 0.411 MeV 0/2-) state compared with

Fig. 4.
DWBA and ADB calculations for
the 0.941 MeV (5/2-) state compared withthe experiment.

the experiment.

1.317 + 1.409 MeV states (7/2-). DWBA and ADB calculations cannot reporduce thisangular distribution (Fig. 5).

These states are not good f 7/2 single-neutron states, because 54 Fe

is an f 7/ 2 closed shell nucleus. At least one of them can rather be regarded as a phonon-particle
coupled state. Indeed a good fit is obtained by CCBA calculation as shown by solid line in Fig. 6,
if a small direct f7/2 ampritude is included. The CCBA calculation has been made without
FRNL correction whose effects are very large for other transitions. Moreover a sophisti cated form
factor is required when the configuration mixing is large and the direct ampritude is small.
Nevertheless the calculation suggests the presence of the ground state correlation in 54 Fe(j v P~/2 f772> configuration etc.).

Exact-finite-range DWBA calculations are also performed in which D-state of the deuteronground state is included. It is found that the inclusion of the deuteron D-state has very small
effects on calculated angular distributions.

30

55Fe1.317+1.409 MeV 7/2DWBA
DWBA

D4-Pl FRNL
D4-Pl Z RL

AD B

D3-Pl ZRL

55Fe 1.317+1.409 MeV 7/2CCSA ZRL

D4-P1

"3

6~

"o'T 7/ ''j:,,712'

"0

1.0

o· ~ - (2- ) ~ 31254 Fe

55 Fe

SA(1)=-014(f 7l2 )SA(2)=
SA(3)=

o

30

60

90
120
9 CM (deg)

150

180

Fig. 5.
DWBA and ADB calculations forthe 1.317 + 1.409 MeV (7/2-) statescompared with the experiment.

o

30

60

90

9 CM (deg)082(P Jt2)
081(2+®P m )

120

150

180

Fig. 6.
ZRL CCBA calculations comparedwith the experimental angular distribution
for the 1.317 + 1.409 MeV (7/2-) states.

References
1)

N. Kishida, N. Nakanishi, Y. Toba, and H. Ohnuma: IPCR Cyclotron Progr. Rep., 10, 23

2)(1976).
J. D. Harvey and R. C. Johnson: Phys. Rev., C3, 636 (1971); R. C. Johnson and P. J. R.

3)
4)
5)

Soper: ibid., Cl, 976 (1970) .
J. D. Childs, W. W. Daehnick, and M. J. Spisak: ibid., CI0, 217 (1974).
E. Newman, L. C. Becker, B. M. Preedom, and J. C. Hiebert: Nucl. Phys., AlOO, 225 (1976).
F. D. Becchetti and G. W. Greenlees: Phys. Rev., 182, 1190 (1976).

31

4-6.

Coupled Channel Effects on(d, p)

Reactions

M. Ichimura, B. Imanishi, and M. Kawai

Rearrangement collisions are studied in a frame work of coupled channel formalism (CC) in
which rearranged channels couple to each other. The purpose of this work is to investigate theeffects of multistep transfer processes and thus to get some insight on limitation of the validity of
DWBA and further to clarify the role of non-orthogonality terms which is characteristic of thecoupling between rearranged channels.
(d, p) reactions are taken as an example, because they involve fairly simple system (a proton,a neutron and the core nucleus) and they have been studied quite well by DWBA.

For simplicity,

we only consider a process in which the neutron goes back and forth between the proton and thecore. Namely, only the coupling between the initial deuteron (d) channel and the final proton (p)channel is taken into account.
Following the formalism presented before,1) the coupled equations for the wave functions,Xa (ra), of the relative motion of the channels are written as

1.0 ~-I· --+---+--=:--l ----!..,..L,-g

0.11 :-.--+- -+--+----j--t-----::I"0 (d,d)10.0 _--r:::-~__-t----t--- +Ed = 10.49MeV

IOO.O L - - t - - - - + - - ' - - l - - - - - ! - -- 1\~-

- - -17- ---'P--'- [ / - - -01 P
E p =11.54MeV
10.0 :---// .

,>'-'-" \, f/\"':'_~ I .i

"

,

/ '1

I. \:' (.

t-------1r-r+-t-----+ t ~ I

\1

0.1

-.-

Vnp only----OPT

90"

-8

-8

180"

0.10""--'-...i-.J'-'-.............--'-..L.....L9O"-'--~-I.--L-J.....J.....I...J18O"-8

Fig.!.
The cross sections calculated by CC with full kernel (full line), by CC without
non-orthogonality (dash-dot-dashed line) and by DWBA or OPT (dotted line).

32

where the coupling kernel is decomposed into the interaction kernel V~p due to neutron-protoninteraction and the so-called non-orthogonality kernel Na(3'Numerical analyses have been done for the reactions (1) 16 Oed, p) 1 70(s-state) with Q-value
Q = 1.046 MeV and the incident energy E c .m . = 10.49 MeV and (2) 4°Ca(d, p) 41 Ca (p-state)with Q = 4.19 MeV, and E c .m . = 10.48 MeV, and the (d , d) and (p , p) scattering associated withthe above (d, p) reactions through the coupling. The results obtained by CC with the full kernel(V~p + N a(3)' with only V~p kernel and by DWBA or the optical model (OPT) are compared 2) inFig. 1. This clearly shows appreciable effects of the coupling as well as the importance of the
non-orthogonality.

In order to investigate how many steps should be taken into account, we solved the coupledequations, the kernels of which are artificially multiplied by a constant X, for several values of X.
Then, the S-matrix elements for a given total angular momentum J are simulated by a polynomialwith respect to X. The power, n, of X corresponds to the number of steps if the series converges.
In particular, n = 0 corresponds to OPT and n = 1 corresponds to DWBA.
of necessary steps is shown in Table 1 for the case of oxygen .

An estimate of number(Calculation has also been done

for calcium,) Effects of the coupling are stronger for lower partial waves.

It must be noted that

number of steps depends very much on the process.
We also investigated the energy dependence of the effects of the coupling by performing
similar calculations for various incident energies (2 - 30 MeV) with the fixed distorting potentials
Comparing the S-matrix elements obtained by CC with those by DWBA (or OPT), one candistinguish, in (E c .m . - J) plane , a CC-region and a distorted wave (DW)-region where DWBA andVa'

Table I . Number of steps for the reaction 16 0 + d -.
1 70 (s) + p at Ed = 10.5 MeV.
J

(d ,d)(d,p)(p ,p)

0
1

8
0

>10
8

2

2

3

0
0
0

> 11
5
3
5

4
5

2

4
2
2

Ed
(MeV)

30

20

20
10

5

5

2

2

5

Fig. 2.

10

J

5

10

J

Decomposition into the CC-region and the DW-region.

33

OPT are valid. The analysis is summarized in Fig. 2.
Judging from the calculated cross sections, one concludes that the effects of the coupling issmaller as the incident energy increases. This is partly explained from Fig. 2. Namely, the ratioof the CC-region to the DW-region becomes smaller as the energy increases. We also recognizedthat the absolute value of the difference between the S-matrix element obtained by CC and that by
DWBA relative to the absolute value of the S-matrix element of DWBA itself becomes smaller.

References
1)

T. Ohmura, B. Imanishi, M. Ichimura, and M. Kawai: Prog. Theor. Phys.,~ 391 (1969).

2)

B. Imanishi, M. Ichimura, and M. Kawai: Phys. Letts., 52B, 267 (1974).

34

4-7.

by

Quasimolecular Resonancethe

24Mg (a, 12C) 16 0

Reaction

F. Soga, J. Shimizu, N. Takahashi, K. Takimoto,
R. Wada, T. Wada, T. Fujisawa, and H. Kamitsubo

Since the discovery of the E c .m . = 19.7 Me V resonance in the 1 2 C + 16 0 system, there is a
growing accumulation of experimental evidences to suggest that anomalies not consistent withstatistical fluctuations exist in the compound system 28 Si. However, in many cases the spin
assignments have not been firmly established.

To confirm the existence of resonances anddeterm'ine their spin-parities, we have made an experiment on a-induced reaction on 24 Mg target,
which produces the intermediate states of the same excitation energies as those reached by theheavy-ion incident reaction.
The 24Mg (a, 12 C) 16 0 reaction was studied using the a-beam accelerated by the cyclotron.
The 1 2 C ion ranging from 15 to 7 Me V was detected and identified with a .6E-E counter telescopeof 6.8 11m and 30 11m Si detectors. The carbon recoil from the elastic and inelastic a-scattering on
the small amount of C contaminant which had approximately the same energy as the true event
was dropped off by the anticoincidence with the associated a-particles scattered at the backward
angles.
The measured excitation function, the energy ranges of which were selected with considerationof the existence of anomalies, is shown in Fig. 1. Two peaks correspond to anomalies at E c .m . =10.7 and 12.7 MeV in the 12 C + 16 0 reaction. (Refs. 1 and 2). Figure 2 is the angularI

I"...0 2

bl

u

E

0

I

-

••• ••-I"'- 10 -

t +••

b

+

U

tf\

,~

\

t \\-+\

•.•.•

I

+

q
U

r+\+ ~

I

-

•

.0

\

~

I

•

0

""'- 10 r-

\

E
u
"'-

If)

8 LA B = 7°

A

I

~

24 Mg ( a,12 C ) 16 0
If)

I

EC.M.(12C +160 ) =10.7 MeV

•

~

I

Mg (a ,12 C ) 16 0
Ea = 20.41 MeV

24
1

10 r-

3

I

t

++

-

• ••

••• •

+

+ +

+

-2

10 r-

-

+

t

+
i

I

I

I

I

I

I

I

I

I

10 20 3040 50 60 70 8090 100

8 C. M.
Fig. 1.

Excitation function for

Fig. 2.
Angular distribution for24Mg(a,12C)160 reaction at E c .m .

10.7 MeV.

35

distribution at E c.m . = 10.7 MeV. This angular distri bution reflects the interference effectprobably due to the presence of the neighboring smaller peak in Fig. 1. If this anomaly can be
attributed to a resonance, the possible value of spin may be 7 or 8.
Figure 3 is the angular distribution taken at E c .m . = 12.7 MeV. The existence of theresonance at this energy has already been established in exit channels of neutron, proton, dueteronand ex-particles from the 1 2 C + 16 0 reaction. 2) Solid line shows the X2 fit curve obtained byusing linear expansion with Legendre polynomials up to 16th order. The coefficient of 14th orderis much larger than those of the other terms. Dashed line shows the square of Legendre
polynomial of 7th order and it can be said that the spin-parity of this resonance is 7 ~24 M 9 ( a ,12 C ) 16 0

Ea = 22.77 MeV
E c.M.('2C +'6 0 ) = 12.7 MeV

~

D

0.1

"-

b

u

0.01
Fig. 3.

tAngular distribution for24 Mg(a, 12 C)16 0

reaction at Ec.m. = 12.7 MeV.

Solid line shows the X2 fit curve wi th Legendre

10 20 3040 5060 70 8090 100

e C.M.

polynomial expansion.

Dashed line shows

P~ (cos ()) curve.

References
1)

M. L. Halbert, F. E. Durham, and A. Van der Woude: Phys. Rev., 162,899 (1967) .

2)

P. Taras, G. Rao , N. Schulz , J. P. Vivien , B. Haas, J. C. Merdinger, and S. Landsbercer:
Phys. Rev., C15, 834 (1977).

36

4-8.

Quasimolecular Resonances Formed by the System

12C + 13C

B. Imanishi

In the elastic scattering of 12 C + 1 3 C, non-statistical structures have been observed by several
authors 1) -4) in the excitation function in the energy region above the Coulomb barrier.

In thesystem 12C + 1 3C one of the nuclei has an additional neutron which is not so tightly bound as theother neutrons.

Of the inelastic scattering induced by 12 C and 1 3 C those going to the channels

concerned with this neutron excitation, are strongly enhanced. S )This suggests the possibility ofthe quasimolecular formation, in which the valence neutron plays an important role through theinteraction between nand 12 C.
Here, by assuming that the resonance system is formed in the system spanned by the channels,
12C1 + 13C (1/2~ gr.~ 12C1 + 13C* (1/2+, 3.. 086 MeV), 12C1 + 13C* (5/2\ 3.854 MeV) and their"core-exchange" channels 3 C--+ 12 C 2 + n), we carried out the coupled-channel calculation.

e

The potentials between nand 12 C and between two 1 2 C nUclei 6 ) are assumed as- 56.7 - 6. In (R )1 + exp j (R - 2.26 ) / 0.705 f- - 1 d1
- 28.4 (R·s )R dR l +exp~ ( R - 2.26)/0.705?

(1)

and
Ucc (x) = 100e O. lX 2

- Vo/[ I +ex p{ (x - 6.2 )/0.55 f] - \:V 'E

cm/ [ (1 + exp { (x - 5.82 ) / 0. 2U ] ,

(2)

with
Vo

l3.8MeY,

W' = 0.24 MeV

for ground channel,Vo15.3 MeV,

W' = 0.1

for other channels.

MeV

In Fig. 1 the results of preliminary calculation for the real part of the elastic scattering phaseshifts 8 J£ (J = 11/2, 13/2 and 15/2) are shown as functions of the incident energy. Resonant
behaviour is seen in each curve. Especially, in the curve for J'lT = 13/2+ (£ = 7) there appear two
prominent resonances, i. e., the one with narrow width at Ecm = 10.2 MeV and the other withbroad width at Ecm = 9.3 MeV. The broad one seems to be single-particle resonance of theelastic channel which may correspond to the one (£ = 7) derived by Crozier and Legg 3) from theresonance analysis of the elastic scattering, and the narrow one seems to be the doorway-state
resonance enhanced by the above broad resonance through the double resonance mechanism. 7)°

In our present calculation of J£ for J = 11/2 - 17/2, we could not find marked resonance atthe energy region near Ecm rv 8 MeV, where Willet et al. have observed prominent structures.
Strong coupled-channel effects are seen in the curves of 8 J£ (elastic).

The difference between

0J=£ + 1/2,£ (elastic) and 0J=£ - 1/2,£ (elastic) in Fig. 1 is due to the coupling effects between theelastic and other channels. If there are no coupling effects on the elastic channel, these phase37

shifts must agree with each other in the heavy-ion approximation.
Resonances with such strong coupled-channel effects cannot be understood only by the
distorting potentials for respective channels.

However, such resonances can be plainly explained by

8

the following potential ) (adiabatic potential) which is defined by the diagonalization:~ i(r) =L: {A~l(rnik {U(r) + €}kl Ali (r) +€i,

(3)

j{,l

where € = [€i 0ik] is a matrix consisting of the exci tation energies €i of I 3 C* .
In Fig. 2 the lowest two of the adiabatic potentials S"i (17r = 13/2+) (r) are shown.
potentials explain the nature of the resonances with the coupled-channel calculations.

These
What wewould like to pay particular attention to is that the lowest adiabatic potential ~ I (r) describing theelastic scattering is pushed down from the potential U I1 (r) by about 6 MeV at r = 5.5 fm and by
about I MeV at the barrier peak.

Decrease of the barrier height make the resonance width at

Ecm = 9.2 MeV broad.

[
IS

he V

fot y(').
0+~. d.

Fig. 1.

Real part of the elastic scattering

phase shifts <5 J p, where J(= P ± 1/2)
represents the angular momentum of thetotal system and P the partial-wave angularmomentum for the relative motion between
12 C(O+, gr.) and 13 C*(1 / 2 ~ gr.).

Fig. 2.

Distorting potentials Ui\J1T) (r)(i = I, 2) and adiabatic potentials ~i(11T)(r)(i = I, 2) for the elastic and inelastic
1 13 Ce 2C,12C)13C*(l/2+, 3.854 MeV) ~ channels

belonging to the angular momentum for

J1T = 13/2+.

38

References

2)

U. Weiss, D. Fick, K. D. Hildenbrand, and W. Weiss: Nucl. Phys., A274, 253 (1976).
D. Fick: in Proc. of the Intern. Conf. on the Resonances in Heavy Ion Reactions (Hvar,
Yugoslavia, 1977) to be published.

3)

D. J. Crozier and J. C. Legg: Phys. Rev. Lett., 33, 782 (1974).

4)

D. A. Bromley: in Proc. of the Intern. Conf. on the Resonances in Heavy Ion Reactions(Hvar, Yugoslavia, 1977) to be published; S. J. Willet, S. K. Korotky, K. A. Erb, M. M. Hindi,and D. A. Bromley: in Proc. of the Intern. Conf. on Nucl. Structure - Contributed Paper Tokyo, p.64l (1977).
L. T. Chua: in Doctor thesis of Yale University (1974).
G. Michaud and E. Vogt: Phys. Rev., C5, 350 (1'972).
W. Scheid, W. Greiner, and R. Lemmer: Phys. Rev. Lett., 25, 176 (1970).
M. Nogami: in Proc. of the INS-IPCR Symp. on Cluster Structure of Nuclei and Transfer
Reactions Induced by Heavy-Ions, Tokyo, p.40l (1975).

1)

5)
6)
7)
8)

39

4-9.

Fusion Reaction

In

12C

+

14N

and

16

0

+

lOB

Systems

T. Motobayashi, S. M. Lee, T. Shimoda,
H. Utsunomiya, M. Yanokura, and I. Kohno

In order to study the behavior of the fusion reaction at high energies, especially to investigate
its incident channel dependence, we have measured the yield of 6 Li particles emitted through12 C + 14 Nand 16 0 + 1°B reactions. The results were analyzed using the Hauser-Feshbachtheory to extract critical angular momenta for fusion (J cr) as reported previously [1, 2] . They
indicated some difference in the behavior of J cr values arising from the difference in the incident
channel (Fig. 1).

This suggests that the fusion reaction process is mainly governed by the reaction

dynamics of the two colliding nuclei and not by the property of the compound nucleus 26 AI.
To re-examine this incident channel dependence of the J cr values in a different way, wemeasured here the cross section of the evaporation residue for the same systems (14 N + 1 2 C and
16 0 + lOB).
The experiments were performed with 14 Nand 16 0 beams from the cyclotron and theenergies were 91.3 MeV and 97 .9 MeV, respectively.

These values were chosen so as to produce

the 26 Al compound nucleus with the same excitation energy (57.2 MeV) in both cases of 1 4N +°The emitted particles with Z = 6 - 12 were detected with a counter

12 C and 160 + 1 B.

telescope which consists of a gas proportional 6E counter and a Si E detector.

Since theevaporation residue are emitted in the forward direction, special attention was paid upon the0

forward angle measurement and consequently detection at 3.5 was achieved.

Targets were of2

self-supported lOB (40 J1gjcm 2 ) and 12C (70 iJ.gjcm ) foils.

To eliminate the contribution fromthe contaminant in these targets, we also measured the systems of 16 0 + 160, 16 0 + 12 C, and
14 N + 16 0, to know such contribution.

A Ti0 2 foil (60 iJ.gj cm 2 ) was used for 1 60 target.

Data analysis is now in progress.
o
~<.O

>~

~
.......

-

<.04N

'-'

xO
WLO

•
J(f1 )

20

Fig. 1.
Values of J cr extracted from the
Hauser-Feshbach calculations on the reactions
12Cct4N, 6Li) 2°Ne and lOBct 6 0,6 ·Li)20Ne.

References
1)

T. Ooi, T. Motobayashi, I. Kohno, M. Ishihara, T. Numao, T. Fukuda, and S. M. Lee: IPCR

2)

Cyclotron Progr. Rep., ~, 10 (1975).
I. Kohno, T. Motobayashi, T. Ooi, M. Ishihara, T. Numao, T. Fukuda, and S. M. Lee: ibid.,ill, 38 (1976).

40

4- 1 o.

a-Transfer Reactions between 1 p or 2s-1 d She 11

N uc 1 ei(2)T. Motobayashi, I. Kohno, T. Ooi, and S. Nakajima

In spite of recent progress in the DWBA theory for heavy-ion induced reaction, the mechanismof the a-transfer reaction has not been fully understood yet.
always been much smaller than the experimental ones.

The calculated cross sections have

To investigate this descrepancy, we

performed a series of experiments on a-transfer reaction between light nuclei

eo B, 12 C, 14 N, 160,

and 20 Ne). For these nuclei the a-cluster structure has been well studied theoretically with theshell modep),2) or the cluster model. 3),4) The experimental procedure and the experimental
results were already reported. 5)

We present here some results of the DWBA analysis.

Some results of the DWBA calculations are shown in Fig. 1 together with the experimental
data. The exact finite range code SATURN-MARS 6) was revised so as to be suitable for the
calculation of the a-transfer reactions. 7 )The bound state wave functions were obtained withWoods-Saxon potentials (a = 0.7 fm and R = 1.3' A 1/ 3 fm) by the separation-energy procedure.
The distorting potentials were that of the optical model which reproduce the angular distributionsof the elastic scatterings. The values in parenthesis in the right hand side of each curve in Fig. 1.

100 r-

100

10

(j)

"-

.D

~

C'

~

~

10

10

10f--

788MeV~t\+y+
072 1; , 0+

++

t

~I

10.8 \-t~( 022 )~"
t t/ t +"l+J--t~t~54
2.16

00 O'

=
1000-

1 ; ,0 ~~-'.

4 25 2° Ne 4 +

-

~
.~+

~

10

20

30

40

( 0 11 )

100L-l._ _ _ _L-1_ _ _~1---..L.----'
40
30
20
10

Angular distributions for some alpha transfer reactions. The solid curves
Fig. 1.
correspond to the DWBA calculations with the normalization constants written inparenthesis in the right hand side of each curve.

41

are the values of the normalization constant n, which were obtained by comparing the calculated
cross section with the experimental ones as(1)

The values of n obtained for various reactions are listed in Table 1.

If the DWBA calculations

performed here are correct in describing these reactions, n should be equal to the products of two
S-factors corresponding to two O'-core systems involved in the reactions. Hence, we can extract
the values of S-factor for each O'-core system from the analysis of the case of elastic transfer
Table 1.

The values of nand S for various reactions.
0.211)

Reactionsn2°Nee 60, 2°Ne)160 0+

160e2C,160)12C
lOB e 4 N, loB)14N

2+
4+
0+

0.80
0.22
0.11
1.0
82

S
0+
0.89
0.89
0.89

n for other reactions.

0.19 1)0.23 2)
16 0

4+

0+

0.69 2)
14N

0.25
0.12
1.0
9. 1

12Ce4N,IOB)160
16 0( 16 0, I 2C)2 oNe 0+2+(n = S2; see also in Table 1).

0.211)2°Ne
2+nn( cal)

10
0.62
0.34

9.1
0.89
0.25

Using these extracted values of S, we can calculate the values of

As is seen in Table I, these values agree fairly well with the ones

extracted directly from Eqn. (1).

This fact provides an evidence for the consistency of the

DWBA analysis for these O'-transfer reactions.
However, values of S-factor extracted here are much larger than the ones predicted by thetheory (listed in Table 1). We have now to re-examine the O'-core wave function. In Fig. 2
the microscopic wave function 8 ) for the ground state of 20 Ne is shown. This wave function
includes the effects of the anti-symmetrization between the nucleons in the O'-particles and theones in the core-nucleus. For comparison, the wave function corresponding to the Woods-Saxon
potential (which was used in the present calculations) and the same function multiplied by the squareroot of S (= 0.21 [1]) are also shown in Fig. 2.

It is clearly seen that the microscopic wave

function has damped amplitude in the interior region of the nuclei, and has amplitude as large as
the simple Woods-Saxon wave function in the nuclear surface region. Therefore, we can conclude
that the S-factor obtained from the analysis of the experimental data is not the S- factor itself
predicted by the theory, because the transfer cross sections is affected strongly by the nuclear
surface on account of the strong absorptive nature of the heavy-ion scattering, and the behavior of
the Vsu (r) is very different from that of y (r) in the nuclear surface region. Therefore, it is not42

surprizing that the S-factors obtained are much larger than ones predicted by the theory.

To

understand more precisely the mechanism of the a-transfer reactions, microscopic wave
function itself sould be used in the analysis.

0.6

u(r)

r (fml

-0.2

. /
-0.4

Fig. 2.

\..

Comparison of the various kinds of the alpha-core wave function.

The solid curve corresponds to the microscopic wave function [8], thedashed-dotted one corresponds to the simple Woods-Saxon wave function,and dashed one Woods-Saxon wave function multiplied by the square rootof the theoretical values of S (=0.21).

References
1)
2)
3)
4)
5)

M. Ichimura, A. Arima, E. C. Halbert, and T. Terasawa: Nuc!. Phys., A204, 225 (1973).
D. Kurath: Phys. Rev., C-7, 1390 (1973).
T. Matsuse, M. Kamimura, and Y. Fukushima: Progr. Theor. Phys., 53, 706 (1975).
I. Shimodaya, R. Tamagaki, and H. Tanaka: ibid., 27 , 793 (1962).
T. Motobayashi, I. Kohno, T. Ooi, and S. Nakajima: IPCR Cyclotron Progr. Rep., 10, 35(1976).

6)
7)

T. Tamura and K. S. Low: Comput. Phys. Commun., li, 349 (1974).
T. Matsuura: Private communication.

8)

K. I. Kubo, F. Nemoto, and H. Bando: Nuc!. Phys., A224, 573 (1974).

43

4-11.

Spin Polarization of 12B in

COB, 12B) and

M. Ishihara, K. Tanaka, H. Kamitsubo, N. Takahashi, Y. Miake, Y. Nojiri
T. Minamisono, * A. Mizobuchi, * and K. Sugimoto*In previous papers (1) we reported on the measurement of spin polarization of 12 B
performed to study the mechanism of energy and angular momentum transfer in the heavy ion
collisions. In that experiment the polarization P as a function of reaction Q-value wasdetermined for the reaction 10 °Moe 4 N, 1 2 B) 10 2 Ru at 90 and 125 Me V by measuring ~-rayasymmetry of the decaying 12 B products. The results obtained may be summarized as follows:(i)

In the high energy region of the energy spectrum, where the quasi-elastic humpdominates, P varies smoothly from large negative (P = - 0.3 to - 0.5 at highest energies) to~~~(P>O when P / /k f X k i )(ii) Zero crossing of P occurs around the Q-value corresponding to the peak of thequasi-elastic hump.
(iii) In the low energy region, where the deep inelastic hump becomes dominant, P isnegative but relatively small (IPI<O.l).
positive as the Q-value becomes more negative.

A remarkable aspect about these results is that they generally do not conform to thepredictions from the classical model (2) of heavy ion collisions in terms of frictional forces.
Especially the Q dependence of P in high energy region as described in (i) is opposite to theclassical prediction. On the other hand, a microscopic consideration based on the kinematicalmatching conditions (1, 3) for the particle-transfer reaction well accounted for qualitative
features of experimental results.
This indicates for the reaction studied that mass transfer is the main mechanism responsible
for the energy and angular momentum transfers rather than the process of inelastic nature (notaccompanied with mass transfer) which may be phenomenologically represented by frictional
forces.
To confirm the validity of the microscopic model employed, the measurement of P was
extended to pick-up and mass-exchange reactions, for which the model predicts different Q
dependence of P from that for the stripping reaction (14 N, 12 B). The reactions 10 Mo( 1 B,
12B)98Mo at EeoB) = 67 MeV and looMoe2C, 12B)looTc at Ee 2 C) = 90 MeV were used.

°°

Figure 1 shows P and the yield of 12 B as a function of Q-value obtained for the eo B, 12 B)
reaction. A characteristic feature of the energy spectrum is that the peak position of thequasi-elastic hump is pushed towards the small Q value close to Qgg = 0.6 MeV. This complies
with the expectation from the matching conditions that the cross section is favoured towards
positive Q values for pick-up reactions, though it is towards negative Q values for stripping
reactions; the optimum Qeff value Q eff may be expressed as12
1\2Qeff = -2 mv - hvR2
for pick-up reactions as compared to*Faculty of Science, Osaka University.

(1)

44

(2)
for stripping reactions , where v is the relative velocity of the colliding nuclei and A2 and Al are thez-component of the orbital angular momentum of the transferred cluster with respect to center ofmass of lOB and 14 N, respectively.
loo Mo(I OB, 12 B)98Mo

0 .6

E=67MeV

e = 20Z

0C'Q. 04

02
~
•
•

0

40

02

I

I

50

60

0.1
0

D- 0.1- 0 .2Q (MeV)-0 .3 -30

-20

~I--~--~
I-10

Fig. 1.

Yield (upper part) and polarization (lowerpart) of 12 B as a function of Q value obtained in the0__~__~I__~__~I_

40

70

lOOMoct°B , 12B)98Mo reaction at Elabct°B) = 67 MeV
and (J lab = 20° .

The low energy portion (Q ~ - 15 Me V) of the cross section may be attributed to some othercomplex reaction mechanism .
The polarization observed for the region of QE hump (Q = 0'" -10 MeV), may also be
explained by Eqn. (1), which indicates that the component of A2 = +2 is most responsible forthis region of negative Q values while those of A2= 0 and - 2 for the region of positive Q values.
Considering the fact that the ground state spin of lOB is J7T = 3+ and thus the sign of P of
12 Bg .s. should be inverse to that of A2 (£2 = 2 assumed) , we obtain P<O in agreement withexperiment. The small posi tive P values obtained for the lower energy region remain to be
explained.
For the exchange reaction (12 C, 12 B) , small positive P values less than 0.1 were obtained
over the most part of energy spectrum.

ReferencesI)

K. Sugimoto, N. Takahashi , A. Mizobuchi, Y. Nojiri, T. Minamisono, M. Ishihara, K. Tanaka,and H. Kamitsubo: Phys. Rev. Lett., 39, 323 (1977) ; K. Tanaka, M. Ishihara, H. Kamitsubo,
N. Takahashi , A. Mizobuchi, Y. Nojiri, T. Minamisono, and K. Sugimoto : Proc. of Intern.
Conf. Nucl. Struct., Tokyo , 1977, Vol. 11 (in press).

2)

J. Wilczynski: Phys. Lett., 47B, 484 (1973).

3)

D. M. Brink: ibid. , 40B, 37 (1972) ; M. Ishihara, K. Tanaka , T. Kammuri, K. Matsuoka, and
M. Sano : ibid. , (in press).

45

4-12.

On the Mechanism of Tvvo-Nucleon Transfer Reactions
Induced by Heavy Ions

T. Takemasa and H. YoshidaTwo-nucleon transfer reactions are analyzed here to clarify the reaction mechanism. For that
purpose, the one-step (simultaneous) and two-step (successive) transfer processes are taken into
account in the analyses. Denoting the reaction as A(a, b) B, the corresponding tran~ition
amplitudes for one- and two-step processes are

T~~ = ~ dradrbXbl-l* (rb) < Bbl vbl Aa > X ~+I ( ra ) ,(1)

Tb~ = j dradrbXbl-l* (rb) V b-a (rb' rJ Xa + (r a) ,

(2a)

l 1

Vb- a(rb,r a)=f j drcdr~ < Bbl vb l Cc > G c +1( r~,rc) < Ccl va l Aa > ,(2b)where x(±) (r) and G(+) (r', r) are the distorted wave and Green functions respectively.

In Eqn. (2) ,Tgi

the transition amplitude
for the two-step process is written in the prior-post form so that the
non-orthogonality term may not appear. The finite-range calculations with full recoil are
performed here both for Tg~ and T gel. The one-step amplitude Tbi~ is calculated by the usual
exact finite-range DWBA where the microscopic form factor is constructed by the generalyzed
method l ) of Bayman and Kalli02) and the single particle wave functions with half the separationenergy of the transferred two nucleons are generated from the Woods-Saxon potential with thegeometrical parameters r 0= 1.25 fm and a = 0.65 fm.

For form factors of the two-step process,the usual separation energy method is used corresponding to the one-nucleon transfer reaction ateach step. The reaction considered here are 12 C 8 0, 160) 14 C, 48 Ca 8 0, 160) 5°Ca and

e

48 Ca

e

e60, 14 C) 5° Ti. Structure wave functions for p-shell nuclei, 180, 50 Ca, and 5° Ti are taken
Table 1. Optical potential parameters used in the analyses.

12Ce80,160)14C
48 Ca( 18 0, 16 0)50 Ca
48 Cae 6 0,1 4 C)5 ° Ti

from Refs.3-6.

Ref.

V

W

rR

r

I

aR

200
97
37

10
59.7
78

1.28
1. 21
1.35

1.28
1.14
1.27

1)
0.45
0.45
0.497 0.422 7)
8)
0.42
0.28

aT

The optical potential parameters for each reaction are listed in Table 1.

They arethe parameters that fit the elastic scattering at entrance channels. In the present analyses, thecommon parameter set is used for the entrance, intermediate and exit channels in each reaction.
The results of the calculations are shown in Figs. 1-3 together with the experiments. The dashed46

line is the calculated cross section due to the one-step process.

The dot-dash line is the calculated

cross section due to the two-step process and the solid line is the coherent sum of these two processes.
The results can be summarized as follows: The two-step process competes with the one-stepprocess and the interference of two processes is important to reproduce the angular distributions aswell as the absolute magnitude of the cross sections.

The shift of the grazing peak and the large

normalization factors predicted by the usual DWBA calculations have largely been improved by the
inclusion of the two-step process. One exception is the case of the reaction 4SCa (1 6 0, 1 4 C) 5 0 Ti,
where the normalization factor N from 10 to 25 is still needed. 9 ), 10)
The use of the morerefined structure wave functions does not seem to improve the present results. Probably the otherreaction mechanisms are playing the role in this case. 1 0) As for the role of the intermediate statesin the two-step process, the ground states give generally the dominant contribution to the crosssection with the exception of the reaction 4SCa eso, 160)SOCa, where the excited 1/2+ state of°

1 7 has the dominant effect on the cross section. This is partly due to the fact that 1S1 1 2 - orbit
has large amplitude in the nuclear interior and the two-step process is generally affected by the
nuclear interior region.

= 24 MeV

[L

0.1

1.0

0 .1

,~\

0.1

"
"
: \
I

\\

/ -\

\

0 .0 1"\I\, ,':'\/\ I'....'

1.0\\

2+ ( Ex= 3.00 MeV)

\
\

,

\
,

I

\

/

, /

/

/

/
I

o

30

60

90

150

120

180

20

40

60
SC.M .

S C.M

Fig. 1.
Angular distributions of thereaction 12
8 0, I h 0)14 C.
The

Fig. 2.
Angular distributions of thereaction 48 Cae 8 0, 160)SOCa. See thedashed line is the calculated cross section

caption to Fig. 1 for details.

Ce

due to the one-step process.

The

dot-dash line is the calculated cross section
due to the two-step process and the solidline is the coherent sum of these twoprocesses.

47

48CO (16 0 ,14 C ) 50T i[ L = 56 MeV

1. 0

0.\

1.0

0.1

Vl'.,\''-C::7

30'\/ ' "'\
140

EJC ,M,

Fig. 3.
Angular distributions of the reaction
48Ca(f60, 14C)soTi. See the caption to Fig. 1
for details.

References
1)

T. Takemasa: Phys. Lett., 55B, 28 (1975).

2)

B. F. Bayman and A. Kallio: Phys. Rev., 156, 1121 (1967).

3)

A. N. Boyarkina: Bull. Acad. Sci. USSR (Sov. Phys.), 2B, 255 (1964).

4)
5)
6)

T. Inoue, T. Sebe, H. Hagiwara, and A. Arima: Nucl. Phys. , 59, 1 (1964); 85, 184 (1966).
R. A. Broglia, P. Federman, Ole Hansen , K. Hehl , and C. Riedel: ibid., A I 06, 421 (1968).
T. T. S. Kuo and G. E. Brown: ibid., A114, 241 (1968).

7)

J. F. Petersen, D. A. Lewis, D. Dehnhard, H. P. Morsch, and B. F. Bayman: Phys. Rev. Lett.,~ 307 (1976).

8)
9)W. Henning, D. G. Kovar, B. Zeidman, and J. R. Erskinl: ibid., 32, 1015 (1974).
T. Kammuri: Nucl. Phys., A259, 343 (1976).

10)

D. H. Feng., T. Udagawa, and T. Tamura: ibid., A274, 262 (1976).

48

4-13.

Calculation of Friction Force in the Collision 28Si

+ 2°Ne on theBasis of the Linear Response Theory

A. Iwamoto,* K. Harada, * K. Sato,S. Yamaji, and S. Yoshida**

Hofmann and Siemens 1) formulated deep-inelastic collisions of heavy-ions based on thelinear response theory. This theory is rather simple and is suitable for numerical calculation.
Also it provides a relation to the classical friction model used successfully to describe these
phenomena.

However, the numerical calculation of heavy-ion reaction based on this model is done

hitherto only for a very simple system. 2 )We give here some results of calculation carried out ona more realistic case.
We adopt the two-center harmonic oscillator Hamiltonian 3) in which the center separation R
and the deformations 8(8 = 8 1 = 8 2 ) of two fragments appear as parameters.

The expression of

the friction coefficient 'YJ.lV is given as(1)

where the quantity FJ.l stands for the derivative of two-center Hamiltonian HTC with respect to the
dynamical variable J.l(R or D),(2)

and Ijk is given by
Ijk = _ __l -1 + exp (ek~A)

{ 1

1

l

1 + exp (e~~A) J(3)

In the above expressions, ej stands for the single-particle energy of j-th orbit, kT, the nuclear
temperature and A, the chemical potential. We have included a smearing width r in Eqn. (I),
which is necessary when we deal with a finite system with discrete energy levels.2 ) The quantity

r is taken to be a free parameter in our numeri cal calculation.
The introduction of r in the expression for 'YJ.lV causes a difficulty in the theory.

That is, wehave a finite value of energy dissipation arising from the relative motion of two fragments evenwhen they are far apart.

In order to eliminate this difficulty, we subtracted from F R a term

which arises by the simple translation of two centers of the potential.

So the remaining terms in

F R are such as those caused by the changes of neck shape and the oscillator parameter due to thevolume conservation, etc. This procedure is correct in the asymptotic region, but is only anapproximation when R is small. The numerical calculation was done for the system 28 Si + 20 Ne.
*

Japan Atomic Energy Research Institute.

**

Tohoku University.

49

Figure 1 shows the quantity 'YRR as a function of center separation R for three different
values of r at zero temperature.

In this and the following figures, r is given in the unit of h Wo ,the oscillator constant of the compound nucleus.

We see clearly the surface-peaked feature of

In this system, the scission configulation is at R rv 8 fm.

'Y RR .

Also seen is the fact that 'YRR

decreases as r increases.

20

I

o

-;;; 10~

Fig. 1.

Radial-radial friction coefficient 'YRR

as a function of center separation R.TemperaturekT is zero and three curves correspond to r =
o

15

10

R Ilml1.0 hw o , r = 0.5 hw 0 and r = 0.2 hw 0 ,respecti vely.

28S; + 20NeI e)

r=0.2nwo
4 000

300

_ 3000

200

20

~
>
~

'0

~IO

R Ifm)

Fig. 2.

=2000

~ 100

1000

o

S

R Ifm)R IlmlFriction coefficients as a function of center separation R.

Smearing width r

is 0.2 hwo and two curves correspond to kT = 0.0 MeV and kT = 1.0 MeV.
Figs. 2(a), 2(b) and 2(c) correspond to the radial-radial coefficient 'YRR ' thedeformation-deformation coefficient 1'00 ' and the radial-deformation coefficient'YR8 ' respectively.

50

Figure 2 shows the quantities 'Y RR , 1'00 and ORo as a function of center separation R for
temperatures of zero and 1 MeV, respectively. The smearing width r of 0.2 h ·w o is used in bothcases. The effect of finite temperature is seen to reduce the magnitude of 'Y RR ' 1'88 and 'Y Ro atsurface region. This tendency is opposite to the result of Ref. 2. We also find that the crossterm 'Y RIi is rather large, that is, the relation YRo- ~ JYRR Y0-0- holds approximately at the surface
region, which means that the coupling of Rand motions is important. 4 ) - 6)
As to the absolute magnitude of 1', we compared our value with the results of two othercalculations. One is the value of Gross-Kalinowski, 7 ) which was used in the classical friction model
calculation. The other is the one calculated by Gals-MoseI 8 ) using a microscopic model. They are
given by
2
'YRR 'V 400 X 10- 3 Me V fm -2 sec,
Gross-Kalinowski'V'V 5 X 10- 2 3 Me V fm -2 sec
Glas-Mosel

°

'RR

ours

'YRR'V 20'

X 10- 23 MeV fm- 2 sec.

Thus our value is not very different from that of Glas~Mosel, but much smaller than that of GrossKalinowski. But this discrepancy between ours and that of Gross-Kalinowski does not mean
directly that the microscopic model is useless, because the coupling between Rand motions may
cause a very large effect.

°

References2)

H. Hofmann and P. J. Siemens: Nucl. Physics, A257, 165 (1976).
P. J. Johansen, P. J. Siemens, A. S. Jensen, and H. Hofmann: Preprint, to be published in3)

Nucl. Physics A.
A. Iwamoto, S. Yamaji, S. Suekane, and K. Harada: Progr. Theor. Physics, ii, 115 (1976).

4)

R. Eggers, M. N. Namboodiri, P. Gonthier, K. Geoffroy, and J. B. Natowitz: Phys. Rev.

1)

Letters, 37, 324 (1976).
5)6)H. H. Deubler and K. Dietrich: Nucl. Physics, A277, 493 (1977).
A. Iwamoto and K. Harada: Phys. Letters, 68B, 7 (1977).

7)8)

D. H. E. Gross and H. Kalinowski: ibid., 48B, 302 (1974).
D. Glas and U. Mosel: Nucl. Physics, .h264, 268 (1976).

51

4-14_ Canonical Quantization from the Time-Dependent
Hartree-Fock Theory in the Lipkin Model

T. Hoshino, K. Yazaki~ and T. Yukawa**

In recent years, many calculations on heavy-ion reactions have been done based on the time-dependent
Hartree-Fock (TDHF) method. I) Since the TDHF method is suitable to describe the large amplitude collective
motion, it has also been investigated theoretically in many aspects. 2 )-S)

Reviewing the theoretical studies of TDHF,

we consider that interesting points to be investigated are mainly the followings: (1) How to derive from TDHF an
appropriate collective coordinate and construct a classical Hamiltonian apart from the adiabatic assumption. 2)(2 )How to quantize the classical collective Hamiltonian and to what an extent the quantized Hamiltonian and its
energy eigenvalues approximate the exact ones.

In order to clarify these points, we adopt here the exactly

solvable Lipkin model 6 ) which has often been used as a testing ground of various theoretical methods of thecollective motion. 4 ),5)
The Lipkin model consists of N fermions which occupy two N-fold degenerate levels with energies~€ and

We denote the upper (lower) orbi t by a quantum number +p (- p) (p = 1 ,2, ..... N) an~ define-1 € respectively.

a ~ightly generalized Lipkin model Hamiltonian by~~

H=cK 3+
where

~

K3

V

T

~

~

2

2

/~

(K+ +K_ ) +V K3

2

(1)

,

:::: _1
t _ t
~ =
t
~ = ~
t
t
2 ~(ap a p a_ p a_ p ) ' K+-~ap a_p ' K_ -(K+) and a±p (a±pof a particle in the ±p orbit.

is a creation (annihilation) operator

For later use , we define a Hermitian operator K2 : K 2::::+(K+ - K_) . Since K3and K± obey the quasi-spin algebra, the eigenstates of Ii are characterized by the eigenval ues of
~
~
~
1 ~~
~
~
K2 (K2::::K/ + 2 (K+K_ +K_ K+ )). It is therefore convenient to adopt for basis vectors the eigenvectorsof K2 and K3: K 2 IJ ,M>=J(J+l)IJ,M> and K3IJ ,M>=MIJ, M>, where M = - J , - J + 1, ..... .1.

We define thevacuum state of the N particle system by I J ,-J> (J=N/2) , in which all the N particles occupy the lower orbits .
We restrict our concern to those collective states which contain a component of the vacuum state.
A single Slater determinant can be defined by 18¢>=exp(-i¢K 3) exp (-i8K 2 ) IJ,-J>, where 8 ,¢ are timedependent parameters .

H consists purely of K3 and K±, and 18¢> is the single Slater determinant generated byrotating I J ,-J> in the quasi-spin space.

Consequently , i8¢> satisfies all the necessary conditions to be a solutionof the TDHF variational equation 0<8¢ i ~ - H 18¢>=O . As is well known, the above variational equation isIJequivalent to the variational equation for the action integral 01=0 Ldt=O, where L is the classical Lagrangian: 3 )where X = Y(2J - 1) and X' = y/(2J - 1).

Since L contains only the time-derivative of the parameter ¢, we first

assume ¢ as a coordinate. Then the momentum canonically conjugate to ¢ is p¢=aL/a;P=-Jcos8 , andtherefore the classical collective Hamil tonian is derived as*

Department of Physics, University of Tokyo.
Nati ona l Laboratory fo r Hi gh Ene rgy Ph ys ics .

52

(3)
According to Ref. 7, for example, the quantal transformation matrix element(4 )is equal to the Feynman path integral\t'/F( q/ t ;qt)=2\.j dqdp exp f i ~ t {p·q-H (p,q ) }dt]

(5)

In Eqn. (4), /qt>H ( /q>S) is an eigenstate of a coordinate operator QI-ft) (QS) with eigenvalue q in the Heisenberg(Schrodinger) picture (S<q' Iq>S=o(q '- q)).

The integrand on the exponent of the expression (5) is a classical

Lagrangian, in which the classical Hamiltonian is defined by

H (p, q ) = H (p, q' ~<) = ~ d (q' -q" ) exp [ - ip (q' - q" ) 1 5< q' IHlq" >(6)sWhile the quantal effect is taken into account by the integration over p and q, a classical trajectory is obtained byta; ing the variation of the action integral on the exponent.

Thus we consider it as the minimum condition inquantization that the quantized Hamiltonian reproduces the classical Hamiltonian through Eqn. (6).

Therefore thepresent quantization prescription is in general

H (p,q ) =H (P,Q) =21;rr dqdpdp exp (i ~ P) Iq > ss< qlexp (i ~ P)j(7)

exp (ipp) H (p, q) ,- 1
where Q and P are quantum operators satisfying the commutation relation [P,Q] = - . .

Applying this]prescription to HTDHF , we finally obtain a collective Hamiltonian quantized from TDHF:
~
~
X
.~
2
~ 2
• ~
X ~ 2
2J
HTDHF=cP+4JLexp (± IQ ) (J -P )ex p (± IQ)+2J P +2J-I X
I

I+This Hamiltonian is diagonalized within the space of eigenstates(m = - 1 + I, - 1 + 3, ......... .1 - 1): «

-1

Im»

of

(8)

•

P(P 1m» = mlm»), where m is finite-II HTDHF 1- 1+1» = «1-11 HTDHF 11+ 1»=0 and «mIHTDHF I

m'»*O only for m-m'=±2 or O. The finiteness of m is consistent with the fact that pcp is bounded by + 1 and - 1, i.e.,
pcp = - 1 cos

e. It should be noted that the above property of HTDHF , which leads to the finiteness of m, is notproduced by the ordinary Hermitian ordering, though we do not show a proof here.
The exact collective Hamiltonian, on the other han~, is deri ved asr

Hexact= cP+ 2 (2:-1)texp (± iQ ) (J2- p 2) {(J + 1)2- P 2} -, Yl exp (± iQ).
Xl

~ 2

+2J-I Pby using the Nodvik's expression for the quasi -spin operators: 8 )
~
1 a
I
I
Y2
1
K 3=P=iaQ ' K±=exp(±2 Q) [(1+2)2 _ p2] exp(±T
A

A

A

A

(9)

0) . The comparison ofHTDHFand Hexact"

Ashows that HTDHF approximates Hexact to the 2nd order in Pwith errors in the coefficients of 0(1 /1) with respect
to the main parts.

Since the quantal effect in this model is roughly 1/J, i.e. m is bounded by -1 + 1 and J - 1

differing by 2 , the error in the coefficients comes partly from the ambiguity in the quantization procedure of theclassical HTDHF .

This error in the first interaction term makes the number of the eigenstates of HTDHF less thanthat of Hexact by 1, which is again O(1/J) with respect to the total number.

It is not only due to the ordering

53

ambiguity but also is inherent in the TDHF approximation itself.

Although there is no problem of the operator

ordering when X = 0, one still finds the error in the coefficient of the second interaction term.

In the absence ofthe two-body interactions (X = X' 7' 0), HTDHF is equal to Hexact' which can be proved in general.
Now we proceed to discuss the results of the numerical calculation .
the N = 40 system, in which X is varied while X' is fixed to zero.

Figure 1 shows the energy spectra of

As is mentioned above, the TDHF

spectrum agrees with the exact spectrum in the limit of small X.

Although the difference between thetwo spectra becomes larger as X increases, their deviation is i1ever seriously large.
In Fig. 2, we show
the spectra of the N = 20 system for various combinations of X and X' (X' ~ 0).
In spite of the factthat all the spectra are changed much from the unperturbed spectrum, in which levels are equally spaced

wi th the energy difference of 2, and moreover the measure of the error of 0(1/1) in this case is twiceas large as that in Fig. 1, the agreement of the TDHF spectra with the exact spectra is still remarkable.
We note again, however, that there occurs an inherent error in TDHF in the presence of the two-bodyinteraction, which we see in the case X = 0 and X'

N =40= 1 of this figure.

( ;( = 0 )86

N = ~ ::.

"-'

6

"'-

u:;4
4

Exact
T DHF
O L-------------------~-----

o

Exact

x
Fig. 1.

TDHF and exact energy

spectra for N = 40 .

TOHF

X= O, Y'=1Fig. 2.

lXOC iTDH F

X = I , X'= O.5[ xa ct

TDHF

X = ~ '- 1

TDHF and exact energy spec tra

for N = 20.

References1)

See for example, J . A . Maruhn, and R. Y . Cusson: Nuel. Phys., A270, 471 (1976) and references

2)

D. M. Brink, M. J. Giannoni , and M. Veneroni : Nucl. Phys ., A258, 237 (1976).

therein.
3)

A. K. Kerman and S. E . Koonin: Ann. Phys ., 100 , 332 (1976) .

4)

G. Holtzwarth: Nucl. Phys., A207, 545 (1973).

5)

S. J. Krieger: ibid., A2 76, 12 (197 7).

6)

H. J. Lipkin, N. Meshkov, and A. J. Glick: ibid. , 62 , 188 (1965).

7)

E. S. Abers and B. W. Lee: Phys . Reports , 9C , 1 (1973).

8)

J. S. Nodvik: Ann. Phys. , 11. 251 (1969).

54

4-15. a-Partie Ie and Light Product Correlationin theld N + 93Nb Reaction

T. Shimoda, M. Ishihara, H. Kamitsubo,
T. Motobayashi, and T. Fukuda*

Recent correlation experimentsl)-4) on heavy ion reactions have revealed that O'-particles are
emitted with appreciable probability in company with reaction residues of the quasi-elastic (QE)
and deep inelastic (D!) collisions.

Because of the exclusive nature of the information provided bysuch correlations, the study of the 0' accompanying process has attracted much interest as apromising probe to explore the detailed reaction mechanism of the energy dissipating collisions.
Among the different O'-emission mechanisms proposed for the coincidence events, the process
due to the fragment decay succeeding to the primary reaction appears to be most likel y.

In fact

the present experiment on the 14 N + 93 Nb system has shown that the sequential decay of the
projectile-like residues from the QE and DI collisions is the major origin of the coincident a
particles. This conclusion is in contrast to the results 2 ) on relatively light reaction systems, where
the importance of the decay of target-like residues was suggested. It dose not either conform to
the prompt O'-emission mechanism by the dissipative force suggested theoreticallyS) andexperimentally. 3 )The experimental procedures were almost the same as those in Ref. 1.

The energy andangular correlations between the O'-particle and the projectile-like fragments (from proton to 16 0)
were measured in the bombardment of a 93 Nb metalic target by 90 and 110 MeV 14 N ions. The
projectile-like fragments were detected at lab angle e1 = 35° and the coincident particles weredetected at various angles eO' in the scattering plane defined by the beam axis and the fragment
detector.
Figure I shows some of the energy-integrated angular correlations obtained at E I ab = lIS MeV .
It is seen that the correlations for different channels are essentially the same as those at E I ab =It should be noted that there is no particular enhancement in the
cross section for the lOB - 0' channel. The strong backward-forward assymmetry and the locationof the peak of the correlation indicate the dominance of sequential O'-decay from excited light

90 Me V reported previously.t)

fragments. Especially , the fact that the peak angle eO' and e1 are generally on the same side of thebeam axis (except for 13 C - 0') is contradictory to the prediction for the heavy fragment sequential
decay and of the "piston" mode1. S)
A more straightforward evidence for the light fragment sequential decay is obtained from theenergy correlations.

A typical example of such correlation is presented in Fig. 2, wherecoincidence yields for the 10 B- Q' channel are shown by contour lines in the plane of a-particle c.m.
energy versus lOB c.m . energy. Loci for given values of relative kinetic energy E l - 2 between a andlOB , and c.m . kinetic energy Eo of the primary excited nucleus 14 N* , are also indicated in theplane by dotted and dashed lines, respectively.

The excitation energy of the decaying 14 N* may

be given by the relative energy El _ 2 and 0' separation energy.

It is seen that the coincidence

yields mainly fall into two regions. Although these two regions are separated from each other,
they correspond to the kinematical zones defined by the same energy band of El _ 2 = 1.2 ± 0.5 MeV*

Dep a rtm e nt o f Physics , Osak a Univer sity.

55

6 0\

\

\

2 .5

2.0

1.5

\ .

\

\ Eo

3 .0

\

\

\

~ 40

\
\

\

30\

20

\

90 MeV

2.0\

10.... \ . .

E~. 2~ 1.0 .

\.

\.'

· o.~

\"\
\.
/ \
/'

...

..

.
'

.

\

\

-40

0

-20

0

0

0

+20

0

0

+40

0

+60

\

\

\
\

o

60 (MeV)8aFig. 1.

The energy-integrated in-planeangular correlations between ex andvarious light products at E lab = lIS MeV.
The light fragment s were detected at the
fixed laboratory angle of eI

Fig. 2.
An examp le of the contour
plot of the energy correlations is displayedin the plane of c.m. energies of ex particle
and lOB.

= 35°.

and Eo = 55 ± 5 MeV.

Essentially the same feature was observed in the other channels except for

few channels like ex- ex.

This double-fold nature of the contour map is apparently a property

ch~racteristic of the light fragment sequential decay.

References
1)

H. Kamitsubo, M. Ishihara, T. Shimoda, T. Fukuda, T . Motobayashi, T. Ooi, and I. Kohno:
IPCR Cyclotron Progr. Rep., 10,26 (1976); H. Kamitsubo: in Proc. of the ColloqueFranco-Japonais de Spectroscopie NucH:~aire et Reaction Nucleaire and INS Symposium on
Nuclear Collectivity, Dogashima and Tokyo, 1976, p. 235.

2)

J. W. Harris, T. M. Cormier, D. F. Geesman, L. L. Lee, Jr., R. L. McGrath, and J. P. Wurm:
Phys. Rev. Lett., 38, 1460 (1977).

3)

H. Ho, R. Albrecht, W. Dunnweber, G. Graw, S. G. Steadman, J. P. Wurm, D. Disdier,
V. Rauch, and F. Scheibling: Z. Physik, A283, 235 (1977); C. K. Gelbke, M. Bini, C. Olmer,
D. L. Hendrie, J. L. Laville, J. Mahoney, M. C. Mermaz, D. K. Scott , and H. H. Wieman: Phys.
Lett., 77B, 83 (1977).

4)

R. Ost, N. E. Sanderson, S. Mordechai, J. B. A. England, B. R. Fulton, J. M. Nelson, and
G. C. Morrison: Nuc!. Phys., A265, 142 (1976).

5)

D. H. E. Gross and J. Wilczynski: Phys. Lett., 678 , I (1977) .

56

4-16.

Light Fragment Excitation

In

the

14N + 93Nb

Reaction

T. Shimoda, M. Ishihara, H. Kamitsubo,
T. Motobayashi, and T. Fukuda*

We have reported 1) that the light-fragment sequential decay is the dominant mechanism forthe coincidence process between light product and a particle in the I 4 N + 93 Nb reaction.
Appreciable yields observed for the coincidence process imply that a conciderable fraction of thelight products are populated in their excited states above the Ct separation energies when they are
produced in the primary two-body reaction.

Thus the cross section of light fragment excitation isrelated to the mechanism which determines how the light and heavy products share the internalenergy supplied from dissipation of relative kinetic energy in the primary qu,lsi-elastic and deep
inelastic process.
The total cross section of light fragment excitation above the a separation energy Sa is
deduced as a function of the scattering angle eo of the primary excited light fragment byintegrating the coincidence yields

4d 0
over the energy plane obtained at a given set
dE 1 dEa dn I dna

of angles eland ea. (subscripts 1 and a refer to the light fragment and a particles, respectively.)
To accomplish this integration the coordinate system referring to center of mass of the decaying
light fragment was used as shown in Fig. 1.

This coordinate system consists of four variables, i.e.,

2Fig. 1.
The velocity diagrams of three bodysystem displayed in (a) the laboratory system and(b) the center of mass system of the decaying
light fragment.

observed. The primary product (1 + 2) decays

3

3
(a )

Particles denoted by 1 and 2 are( b)into particle 1 and 2.

energies El _ a ' Eo and corresponding angular variables n 1 _ a' no, where E1 _ a is the relative
kinetic energy between a particle ·:m d the final light product and Eo is the kinetic energy of the
primary excited light fragment.

For given values of eland ea' no may be considered to beconstant for a large range of EI and Ea·
dEodn l

*'

-

2J

.
d ex..
do e xThe cross sectIon d~o IS gIven as dna =\ \ \JJJ dE 1 _ 2d, where J is the Jacobian relevant to the transformation of thedE J dEO' dn I dna

Department of Physics , Osaka University.

57

coordinate system. In the integration over [21 _ 2 ' isotropic angular distributions of the break-up
particles are assumed.
Figure 2 shows the cross section of the light fragment excitation probability thus obtained.

eo

The anglesof the primary products are 29° '\; 31 ° for all channels. The points are labelled by
the corresponding primary light product. The abscissa represents the threshold Q-value Q
for
ggg
= Q
the three-body process, which is related to the two-body ground state Q-value Q as Q
gg
ggg
gg
+ Sa· It is clearly seen that the relative cross sections for different isotopes with a given Z are
well represented by the expression ~ri x = fez) exp (Qggg/T eff) , which is analogous to the2expression ) for the singles cross sectidh. The value of effective temperature T eff is about 3.5
MeV for all of the B, C, N, and 0 isotopes, and is comparable with the value of Teff = 2.9 '\; 3.5
Mev for singles cross section.

I
f-\6
f.1

T

\1

0 *N*
'

-

B*

: \.'7 "\\'0-\~\\ ~

"TI

'" -2

f--

6 10 I-D:::

T =3.5 MeV

140

\C
0

Elab~ gOMeV ~6 \

){-

-

II

-

=
-

I
o

I

I

- 10

-20

Qggg (MeV)

Fig. 2.

The cross section for lightfragment excitation above a separationenergy are plotted versus the threshold
Q value for the three body process ,where the excited primary products
are emitted at the laboratory angle of
29° - 31 ° .

The solid lines

represent the function f(z)exp(Qggg/
T eff) for the case of Teff= 3.5 MeV.
The normalizations of the function
are arbitrary for each isotopes.

References

1)

H. Kamitsubo, M. Ishihara, T. Shimoda , T. Fukuda , T. Motobayashi, T. Ooi , and I. Kohno:
IPCR Cyclotron Progr. Rep ., 10 , 26 (1976).

2)

T . Shimoda, M. Ishihara, H. Kamitsubo , T. Motobayashi , and T. Fukuda: ibid. , lL. 54 (1977) .
V. V. Volkov: Proc. Int. Conf. on Reactions between Compl~x Nuclei , Nashvile,b 363 (1974).

J. P. Bondorf, F. Dickmann, D. H. E. Gross , and P. 1. Siemens: 1. de Phys. , C6, 145 (1971).

58

4-17.

Angular Distribution and Energy Spectrum of "Direct"

a-Particles Emitted

fromthe 159Tb+95 MeV 14N

Reaction

T. Inamura, K. Hiruta, S. Ise, T. Shimoda,
T. Nomura, and M. Ishihara

We have measured angular distributions of Q-particles and other ejectiles from the 159 Tb + 95
Me V 14 N reaction to study how "direct" a-particles are emitted from the reaction. This was
initiated by finding that the starting population for ,),-deexcitation following forward-peaking fast
a-particle emission is different from that in the compound reaction. 1)
To detect particles a 6E-E counter telescope was used, consisting of 30 J..Lm and 2000 J..Lm
thick Si surface-barrier detectors. The 1 59 Tb target was a self-supporting metallic foil 2.1 mg/cm 2
thick.
Figure 1 shows the observed angular distribution of a-particles with Ell' ::: 30 Me V in thelaboratory system, together with the angular distributions observed for typical ejectiles heavier thana-particle. The followings are noted: for l I e the distribution shows a bell shape whose peakcoincides with the grazing angle (8 gr = 43° in lab.), being typically quasi-elastic; from lOB to

,-

,lie

10

.

/

OOTb+95MeV 14N

\

\
,-

lOR

1\

1\
1

"' 1\

9Be
1
"-

1

f--

Cl

5

"\

-

-

I

\

~

".......

1\

'~! \
:'1

~-~

1----1
I

\

1\

"'
"-,
I

o. 5 f==- :+ 95 MeV 14N'\~\, I 1\-~

I-

159T b

10

"

-

10

\

.,

1 7Li~

o. 5

.,

I \.

'"'\

!

\t

,

1/1\

fa ~ 30 MeV
1

o.1

I

,

1

~
I

I

I

20·

40·

60

e

.

l'
80

.

100

1 O-J L----L_---"-----l_--L-_..L.---L...,....=..~-.L.,,__,,_---J

20°

40°

60°

(lob)

80°

100° 120° 140° 160°e (c.m. l

The laboratory
Fig. 1.
angular distributions ofAngular distributions ofFig. 2.
Q-particles integrated over small ranges of

Q-particles with EQ ~ 30 MeV
and other typical ejectiles heavier
than Q-particle from the 159 Tb

the kinetic energy.

+ 95 MeV 14N reaction.

59

a-particle there are rising cross sections at forward angles with increasing transferred mass and small
bumps near the grazing angle; and, except for lOB, the position of the bumps moves toward larger
angle than the grazing angle with increasing transferred mass.
Figure 2 shows angular distributions of a-particles integrated over small ranges of the kinetic
energy. The rising cross section at backward angles is considered to be due to evaporation process.
The energy spectrum of "direct" a-particles observed at 20° to the beam (22° in c.m.) is shownin Fig. 3. This was obtained by subtracting the evaporation component from the total energy
spectrum recorded. The evaporation component was deduced from the data taken at 160° to thebeam (162° in c.m.) with a reduction factor sin 162°/ sin 158°. Here we assumed that the angular
distribution of evaporated a-particles is symmetric about 90° in c. m., following the 1/sin8 rule.
I t should be noted that the shape of the "direct" a spectrum is likely to be described by a Gaussian(or Maxwell-Boltzmann) distribution, showing" a sort of statistical nature. As was suggested by
Britt and Quinton,2) this might be explained by a vector coupling between the projectile velocity(group velocity) and the intrinsic a-particle velocity in the region of reaction because the latter
distribution may be approximately given by a Gaussian distribution as is the velocity distribution of
nucleons. This idea is applicable so long as the memory of the initial linear momentum is not lost.

°e

The reaction of interest looks as if the target nucleus absorbes the transferred 1 B nucleus,
while a-particles are emitted directly, i. e. , 14N + 1 59Tb = (a + lOB) + t 59Tb ---*a+ 0B + 159Tb)= a +169Yb*.

Because of this we have applied an idea of the two-body reaction mechanism 3 ),4)

to describe the optimum Q-value and the angular momentum of the residual nucleus.

By

assuming the kinematical conditions 6k = 0 and 6L = 0 (see Ref. 4), the residual angularmomentum is estimated to be A2:::: 21 h. If "direct" a-particles are emitted tangentially from thecolliding system in the reaction plane, the incoming partial wave is estimated to be £in':::::: 39 h. This
result is in accord with the conclusion about the angular momentum distri bution of the entrance
channel on the basis of "direct" a--y coincidence measurement. l)

159Tb+ 95 MeV

14N"d ire ct " 0'Fig. 3.
Energy spectru m of "direct" a-particles
emitted to 22 ° (c.m.) from the 159Tb + 95 MeV
I O-3 L---,l;;-I
O---"--2;f;:;O---'----3;:!;;-O---'----4:!;:;
O ----<~----'t;-~~~----'

f c.m. ( MeV)

14N reaction, together with the one of evaporated
a-particles.

References
1)

T. Inamura, M. Ishihara, T. Fukuda, T. Shimoda , and K. Hiruta: Phys. Lett., 6811 51 (1977).

2)
3)

H. C. Britt and A. R. Quinton: Phys . Rev., 124 , 877 (1961).
P. 1. Siemens, J. P. Bondorf, D. H. E. Gross, and F. Dickmann: Phys. Lett. d ~l1 24 (1971).

4)D. M. Brink: ibid., 40Jt, 37 (1972).

60

4-18.

Energy Relaxation of a Composite System
Deduced from

Preequilibrium

Spec tra in 209Bi

a-Particle

14N Reac tion s

T. Nomura and H. Utsunomiya

Weiner and Westrom 1) have recently attempted to describe preequilibrium phenomena in termsof diffusion of heat in nuclear matter, starting from a "hot spot" created by a reaction at a nuclear
surface. They have shown that evaporated particles from such a locally excited system are expected
to show enhancement of high-energy parts and a large asymmetry in the angular distributions. The
angular and energy distributions of a-particles emitted in the 209 Bi + 1 4 N reaction described in thepreceding paper 2 ) seem to be consistent with this interpretation , i.e., evaporation from a locallyheated system. We thus decided to analyze the experimental a-particle spectra by the following
simple statistical formula of Ericson 3 )N ( Ea )oc: EaO" d Ea) exp( - Ea/ T ).

(1)

Here , EO' is the kinetic energy of an a-particle, ac the inverse cross section, and T the nuclear
temperature of the residual nucleus, which is related to the usual level density parameter a and theaveraged excitation energy of the residual nucleus U av with T2 ~Uav/a. Uav~30 and 40 MeV incases of 85 and 95 Me V incident energies, respectively. In Eqn. (1), we assume the spin-independent
constant nuclear temperature. This may be justified because we are treating high excitation energies
and relatively low angular momenta ; the maximum spin calculated from the sharp cut-off
approximation is 39 h (85 MeV) and 52 h (95 MeV). In fact, the spin-dependent temperaturedefined by Williams and Thomas 4 ) as Tj ~ T (1 - ErotU)/ Uav) 11 2 is close to T provided therotational energy Erot U) is calculated by the rigid-body moment of inertia.

°

As for c(Ea ), we used reaction cross sections calculated by Igo,S) who showed the results
as a function of Ea/Ba, where Ba is the barrier height of the optical potential used. A spherical
nucleus is assumed in Ref. 5, in which Ba ~ 21.5 MeV. Eqn. (1) turned out to reproduce well
the spectral shape at backward angles when T is taken to be a "compound nucleus value"described later, but the calculated peak position is by 2-3 MeV higher than the experimental one.
The similar discrepancy has been pointed out by Knox et a1. 6 ) and was attributed to the nuclear
distortion resulting in a smaller Coulomb barrier. In order to take this effect into account in
the calculation of a c' we treat Ba as a parameter to be determined and assume, for simplicity, thesame dependence of °c on Ea/Ba as in the case of a spherical nucleus. It turned out that all theobserved spectra could be fitted excellently by Eqn. (1) when we assume Ba = 19.5 Me V andtreat T as another fitting parameter.

To show this, we plotted the quantity N(Ea)/Eaoc(Ea)versus EO' on a semilog scale in Fig. I, where N(Ea) were taken from experimental spectra.

If

Eqn. (I) can reproduce experiment, the resultant plot must be a straight line. This is indeed thecase at all angles as seen in Fig. I. The slope of a straight line at each angle gives the best valueof nuclear temperature. The values of T thus determined are shown in Fig. 2. The temperature

61

30

50

4

f

50

120

90

150

180

85 Me V0of

95 MeV

"

o0
o

t oO

;'

Q

0

0

0

95 MeV ----------.--- . - -- -~--(~-~-:.: - ~t-- ~ -- ------ . --- . -8 5 MeV~~ ~~~ A= 219 ~--~-----o- -- . --~ L _ _

-

200
o

0

0

\>

<1>

1

150

~ 100

~

10
0

50
I

20

25

30

EQ

I

I

25

30

0

d o
30

50

90

120

150

ec.m ( Degree I

Fig. 2.

from experimental spectra and a c
are calculated under the assumptionof Ba = 19.5 MeV.
are indi cated.

0t( MeV I

Fig. I.
versus Ea , where N(Ea) are taken. 0}

The nuclear temperature T andsize A of a hot spot versus
emission angles.

The lab. angles

decreases monotonically with increasing angles and almost reaches, at very backward angles, a"compound nucleus value", a value expected from an energetically equilibrated system, which is
calculated from T2:::::-':U av /a and a=A/9MeV- 1 with A=219.
A possible origin of the local heating may be the following. There is some experimental
evidence that the a-particle emission of interest originates from reactions occurring at nuclear
surfaces. Quite recently, Inamura et al. 7) suggested that the associated initial channel spins are
localized just above the critical angular momentum for complete fusion, being similar to deeply
inelastic reacti ons, where relaxation phenomena become important.

At such reactions, a "hotspot" is formed as soon as the two colliding nuclei touch each other due to large radial frictional
forces, and the relative angular momenta are transformed mainly to the rotation of a heavier
nucleus, i.e., 209Bi in our case, due to its large moment of inertia. The hot spot sitting on thesurface of this rotating system is an origin of the observed a-particles, which are emitted, inaverage, in the direction of the rotational velocity at the surface.

Let us assume that the hot

spot is directed to forward angles when the system starts to rotate.

Then, we may relate theemission angle somehow to the reaction time in the similar manner as suggested in deeply inelastic

62

collisions (e.g. , negative deflection angle).8)

It seems, therefore, that the nuclear temperature

deduced from the present analysis can be interpreted to have physical significance, i.e., to show
the degree of energy relaxation of the hot spot versus the time lapse measured from the initialcollision.

The size of the hot spot can be obtained from T2 ~Uav/a and a=A/9 , assuming thatthese equalities hold even in the local heating.

The results are shown in Fig. 2.

References
1)

R. Weiner and M. Westrom: Phys. Rev. Le.tt., 34, 1523 (1975); Nuc!. Phys., A286, 282 (1977).

2)

H. Utsunomiya, T. Nomura, T. Motobayashi , T. Inamura , and M. Yanokura: IPCR

3)
4)

Cyclotron Progr. Rep. , 11 , 63 (1977).
T. Ericson: Advan. Phys., ~ 425 (1960).
D. C. Williams and T. D. Thomas: Nucl. Phys. , 53 , 577 (1964).

5)
6)

G. Igo: Phys. Rev., ~ 1665 (1959).
W. J. Knox , A. R. Quinton, and C. E. Anderson: Phys. Rev., 120 , 2120 (1960).

7)

T. Inamura, M. Ishihara, T. Fukuda, T. Shimoda, and H. Hiruta: Phys. Lett., 68B, 51 (1977).

8)

J. Wilczynski: ibid. , 40B , 37 (1972).

63

4-19.

Preequilibrium a-Particle Emission from
209Bi + 14N Reactions

H. Utsunomiya, T. Nomura, T. Motobayashi,
T. Inamura, and M. Yanokura
In reactions induced by relatively light "heavy ions" (e. g., 12 C, 14 N, and 16 0) at
bombarding energies well above the Coulomb barrier, <x-particles are known to be emitted withlarge probabilities. The a-particle emission occurs predominantly in the forward direction withappreciable enhancement of the high-energy part when compared to an evaporation spectrum
observed in compound reactions. 1 ) , 2)well understood.

The reaction process involved, however, has not yet been

In order to throw more light on this phenomenon, we have studied 209 Bi + 14N

reactions at relatively low bombarding energies, i. e., at Elab . = 85 and 95 MeV, with emphasis onenergy and angular distributions of a-particles.

The Coulomb barrier of the entrance channel

estimated from the systematics generally adopted is around 65 Me V.
A self-supporting 209 Bi target of about 1 mg/cm 2 thickness was bombarded with 85 and 95
Me V 14 N ions from the cyclotron.

The foIl owing measurements were carried out: 1) Charged

particles with Z~8 detected with conventional counter telescopes were measured between 20° and
160° at 85 MeV and between 40° and 170° at 95 MeV.

2) Fission fragments were measured

between 10° and 170° at both incident energies; we identified high-energy particles stopped withina thin (30 J1 Si) 6E counter as fission fragments. 3) Cross sections for the production of heavy
residual nuclei following fusion or fusion-like reactions such as (14 N, xn) and (14 N, axn) wereTable 1.

Summary of experimental cross section .
Cross sections (mb),a-particles a)
Fissionct 4 N, xn)
4N , axn)
4N , 2axn)

e
e

a)

85 MeV

95 MeV

42 ± 6890 ± 655± 1

(63)1350 ± 100
3± 1
49 ± 83± I

31 ± 33± 1

Estimated from the smooth ex trapolation of the observed angular
distributions at very forw ard and backward angles .

In the case of

95 MeV , the given value has a large error due to lack ofstatistics at forward angles.

measured by detecting a-decays of their ground states in-beam in the same way as described inRef. 3.
The measured cross sections are summarized in Table 1.

The following points are to be noted.

1) Fission is the almost exclusive mode of the deexcitation of the compound nucleus, neutron
evaporation being negligibly small.

Since a-particle evaporation is far less probable than neutron

64

evaporation in this mass region, we expect no significant contribution from the compoundreaction to the observed a-particles. 2) The cross section for the emitted a-particles is roughly
equal to the sum of cross sections for heavy residual nuclei produced in 4 N,axn) and 4 N,ee2axn) reactions; this shows that the rest of a composite system after the a-particle emission mostly
fuses each other.
The measured angular and energy distributions of a-particles were transformed into those in
the c. m. system under the assumption of a binary reaction , i. e. , 209 Bi + 14 N -+a + 21 9 Th, which
seems reasonable from the above mentioned facts. The present angular distributions are very
similar to those reported in similar reactions by Britt and Quinton. 1) The yield decreases rapidly0with increasing angles up to around 70 , and still continues to decrease slowly at more backward
angles; in particular, there is no such rise near 180 0 as expected from the compound reaction.
A main difference between the present angular distributions and those reported in Ref. 1 is that we
observed a small bump or shoulder , at both incident energies, near grazing angles, i. e. , at around00
100 (85 MeV) and 80 (95 MeV) , in which typical transfer reactions have peaks in their angular
distributions as shown in Fig. 1. We therefore consider these bumps as originating from the mostdirect a-particle or 8 Be emission corresponding to lOB or 6 Li transfer reaction , respectively.
In fact, the difference between on- and off-peak spectra shows a broad peak at energies
corresponding to the initial velocities in both cases as shown in Fig. 2. A preliminary measurementon the 18 1Ta + 14 Nand 197 Au + 14 N reactions at 85 MeV has shown the same features.
10 2 r -- - -209Bi

+ 14N

-

-

- - --

15-----,

2030

25(85 MeV )

...

C oo

i

85 MeV
• 99°

/

-

128°

Difference

ref.

i
j
-0
OJ

X

x

X

X

>-

1

OJ

o

Be

OJ

Q::

..........
••':) CC .-.
0 0

o 0"0 8o

8 c.m.

Fig. 1.

Angular distributions of a-particles ,Be , B, and C isotopes taken in the 20 9Bi +14N reaction at 85 MeV.

0° - ••o~ ••oo95 MeV• 74°- 94°
o Differencefa ( MeV)

Fig. 2.

Difference spectra between thosetaken at a bump in the angular distribution
and at an off-peak angle. See also Fig. 3.

The measured a-particle spectra at 85 MeV are shown in Fig. 3. At backward angles, they
are peaked at around 19.5 Me V and have nearly exponential tails toward high energies; this is afamiliar feature generally known in the evaporation process from the compound reaction. The
forward spectra are very broad and apparently quite different from the evaporation spectrum;

65

however, we can still note the existence of high-energy tails which also decay almost exponentiallybut very slowly, indicating high "nuclear temperature" of the associated composite system. The
experimental spectra at 95 MeV have nearly the same tendency.

The most probable energy, i. e.,energy at the peak position and the averaged energy at each observed angle are shown in Fig. 4.
10 6

20

30

40

I

I

I

.

160° :·· ••105.. .... ..

209Bi

+ 14N

85 MeV

125°..
••......... ..
95°

. ..

'-

a

65°

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

25

.. .

24

... ..

c=>ou

10 2 1-22~•. ............ .. .

II

-

.

0

[j

---- - - -- - - - ----

21

lU

~

0

o -- ------ 85 MeV
000

o·

o

20 -

. ...

0

• -0.

:a;

20°

10 l::-

95 MeV

[p

o

45°

o

0

23

.... •••• -.e.
••--. ....••
o.

o [ov

- - -~----- - 95 MeV

000

19
0
0

I

I

20
E~m

30
(M eV)

I

40

1800

30'

60'

90'

120

150

180'

Fig. 3.
a-particle spectra at various
angles taken in the 209 Bi + 14N

averaged energies of a-particles emitted inreaction at 85 MeV.

the 209Bi + 14N reaction at 85 and 95

Fig. 4 .

Me V.

The most probable CEp) and

The energies corresponding to initial

velocities are shown by dashed lines.

References
1)

H. C. Britt and A. R. Quinton: Phys. Rev. , 124 , 877 (1961).

2)

1. Galin, B. Gatty, D. Guerreau , C. Rousset , U. C. Schlotthauer-Voos, and X. Tarrago: ibid. ,3)

C9 , 1126 (1974).
T. Nomura, K. Hiruta, T. Inamura , and M. Odera: Nucl. Phys., A217 , 253 (1973).

66

5. NUCLEAR PHYSICS
Nuclear Spectroscopy
5-1.

Cross Section for the 40Ca C6 0, p) 55CO Reaction

H. Morinaga , M. Yanokura, J. Imazato ,*T. Nomura, and M. Ishihara

Recently studies of precompound process with heavy-ion beam have revealed some new
aspects of heavy-ion reaction mechanism. 1 ),2) In the present work the cross section for one
proton emission in case of 1 60 ions was measured in order to investigate such a reaction. A
radiochemical method was employed to determine the yield of 55 Co after the bombardment of
40Ca with 160 beam of 89 MeV for 3 h.

The target was highly enriched isotope (>99.99%)

and also chemically very pure , so that we had not to worry about contaminative reaction.
thickness corresponds to the range of beam energy E lab = 89 to 63 MeY.

Its

A 55 Co source wasprepared by ion exchange for the HCI solution of the target and the recoil stopper, and completely
separated from other strong activities . The 'Y transition of 931 keY from the 55 Co decay
with a half-life of 18 h was observed in a Ge(Li) spectrum obtained by (3-"( coincidences tosuppress the background. The cross section turned out to be 1.75±0.5 Jlb for the 4 °Ca 60 ,p)55CO reaction. Other activities observed were 48Cr, 49Cr, 52Mn , 43SC, and 44S C, they areesummarised in the table.
Table 1.

°

Cross section for the activity production in 4 C a + I 60.
Cross section

NucleusSsCo

S 2 Mn(ground state)(isomer)

49Cr
48Cr
44SC
43 Sc

1.75 ± 0.5 Jlb
42 ± 8 mb
73 ± 15 mb
244 ± 40 mb
4.1 ± 1.0 mb
0.21 ± 0.4 mb
9.0 ± 0.2 mb

References
1)

M. Blann: Nucl. Phys. , A235, 211 (1974); M. Blann, A. Mignerey , and W. Scobel: Nucleonika,~ , 335 (1976) , and references therein.

2)

T. Nomura, J. Delaunay, C. Tosello, and N. Bendjaballah: preprint; T. Nomura, H. Utsunomiya
T. Motobayashi, and T. Inamura: Proc. of Intern. Conf. on Nucl. Structure, Tokyo,(Contributed Papers) p. 736 (1977); J. W. Harris, P. Braun-Munzinger, T. M. COmlier,D. F. Geesaman , L. L. Lee , Jr., R. L. Mcgrath, and J. P. WUml: ibid., p. 698.

*

Department of Physics , University of Tokyo .

67

5-2.

y-Rays Following Fast a-Particles Emitted
in the 159Tb + 95 MeV 14N Reactions

T. Inamura, K. Hiruta, S. Ise, T. Shimoda,
M. Ishihara, and T. Nomura

We have already pointed out: 1 ),2) (1) for the 159Tb + 95 MeV 14N reaction, unlike
compound nucleus formation, the fact a-particle emitting reaction involves incoming partial waves
with angular momenta restricted to values just above the critical angular momentum fcr for fusion
reaction; (2) because of this, high-spin states are populated selectively and they decay to theground-band without feeding side-band members.

We have also inferred that fast "direct"

a-particles are emitted tangentially from the colliding system in a peripheral collision between
heavy ions. This conclusi on is in accord with the observed angular distributions of "direct"
a-particles, which show features characteristic of a peripheral collision between heavy ions. 3 )Concerning the reaction mechanism of fast a-particle emission, Gross and Wilczynski haverecently suggested that fast a-particles are emitted along the direction of the radial frictional force(from the opposite side of the target nucleus) in heavy ion reactions. 4 ) In this case there shouldbe the following characteristic features: (1) the angular momentum removed by the fast a-particle
is zero; (2) the associated incoming partial waves are identified by the direction of the a-particle
emission; and (3) the angular momentum deposited on the residual nucleus is almost identical withthe angular momentum of the incoming partial wave. Accordingly one can expect that if it isobserved in coincidence with fast a-particles, the starting population for 'Y-deexcitation depends
on the position and the finite solid angle of the a-particle detector; the starting population will
move towards higher spin states for a-particles emitted to larger angles than for those to smaller
The finite solid angle will determine the width of angular momentum window of theangles.

associated entrance channel.

That is to say, one may have a 'Y-transition yield curve similar toour observation 1),2) but with a different critical point (see Fig. I) depending on the a-detector
position.

Fig. 1.
Gamma-transition yields relative tothe 4+ -+ 2+ transition in 166 Yb that is
produced via the fast a-particle emission process
in the 159Tb + 95 MeV 14N reaction: • is for'Y-rays coincident with a-particles recorded
at 24.7° to the beam, 0 is for 28.2° and!::::. is for 12.7°. The energy of recorded

0.1

a-particles is Ea ~ 33 MeV in lab. The arrow
8+

10+

12+

14+

~

~

I

+

6+

8+

Transition

10+

12+

indicates a critical point from where the yields
of successive transitions decrease considerably.

68

We have measured )'-rays from the 1 59 Tb + 95 Me V 14 N reaction in coincidence withenergetic a-particles (Ea~33 MeV in lab.) recorded at () 1 = 12.4° (the angular width 6() = 8°) and()2 = 28.2° (6() = 8°) to the beam direction (in lab.) ; in terms of Gross-Wilczynski model 4 ) the
angular momenta of incoming partial waves corresponding to these directions are estimated to be£1 = 13 hand £2 = 26 h by assuming ro = 1.25 fm.

However, nothing different has been foundbetween the observed )'-transition yield curves at two different angles as is shown in Fig. 1.
previously observed )'-transition yield curve (() = 24.7°, 6() = 16°) is also shown in Fig.!.

The
This

result contradicts the expectation mentioned above, indicating that there exists an angularmomentum window in the entrance channel which leads to the fast a-particle emission,
independently of its direction.
In conclusion the present observation of )'-rays in coincidence with fast a-particles is not inaccord with the mechanism suggested by Gross and Wilczynski,4) in whi ch the fast a-particle isemitted along the direction of the radial frictional force.

References
1)

T. Inamura, K. Hiruta, M. Ishihara, T. Fukuda , and T. Shimoda: IPCR Cyclotron Prog. Rep.,~ 59 (1976).

2)

T . Inamura , M. Ishihara, T . Fukuda, T. Shimoda , and K. Hiruta: Phys. Lett., 68B, 51 (1977).

3)

T. Inamura , K. Hiruta, S. Ise , T. Shimoda, T. Nomura, and M. Ishihara: IPCR Cyclotron

4)

Prog. Rep. , ...!..1 58 (1977).
D.H.E. Gross and J. Wilczynski: Phys. Lett., 67B, 1 (1977).

69

5-3.

High Spin States of 162Yb

A. Hashizume, T. Katou, Y. Tendow, and H. Kumagai

Levels of 162 Yb were populated by means of the compound-evaporation reaction 1 5 5 Gd
2 C, 5n'Y) 162 Vb.
De-excitation 'Y-rays were detected with Ge (Li) detectors. In this type ofreaction, the incident heavy-ion carries a large amount of angular momentum into the compoundsystem (£= 46 h) for a classical grazing collision of 95 MeV 12C on IS sGd. The evaporated
nucleons and de-exciting 'Y-rays, on the other hand, carry away relatively little angular momentum,
amounting to at most a few h per nucleon. Thus these compound-evaporation reactions are veryesuitable for the study of the high spin states.
The excited states in 162 Yb were studied previously by the 164 Er (a, 6n'Y) reaction and theground state rotational band up to the 14+ state has been established. I) This result makes some
contrast to that of 166 Yb where the ground state band up to the 20+ state has been known.
A self-supporting and isotopically enriched target 1 55 Gd was prepared by use of vacuum
evaporation technique where Gd 2 0 3 was reduced by thorium. Figure 1 (a) shows the excitation
functions obtained by measuring 'Y-rays between the transitions in the ground state band. These'Y-rays were observed at 90° to the beam direction. Examples of excitation functions of another'Y-rays assigned to the transitions in 1 62 Yb are also shown in Fig. 1(b).

v----+ 2+- O+,(Q )166 ke V.- 4+- 2+.~ . 320
8.-------~--------~--------_,

( b)

-

<lJ

>

6

<lJ

n::

-

~

U
<lJ

0

>-

<lJ

n::

>o

n::

u

I

>-..

4

<lJ

~
>0

n::

;...
2

70

80

90

100

Ec (MeV)Fig. l(a) Excitation functions of levels of
the ground state rotational band in 162 Vb.

Ec( MeV )

Fig. 1(b) Examples of excitation functionsof another 'Y-rays also, assigned to 162 Vb.

70

The angular distributions of 'Y-rays were studied from 90° to 30° at every 15°. In 'Y-'Y
coincidence experiments, a magnetic tape recorder system developed for this purpose 2) was
employed. Figure 2 shows the sum of 7 background-subtracted 'Y-"Y coincidences resulting fromgates placed on each individual ground state band transition up to 14+ -+ 12+. All the transitionsin the ground state band up to 14+ are in good agreement with the results reported by Banaschik
et al.l) Further, the 14+ -+ 12+ transition is supposed to be a doublet, because the peak still
appeared even when the gate was opened by the same energy. This fact suggests that the energyof 16+ -+ 14+ transition nearly coincides on that of 14+ -+ 12+ transition. Other 'Y-rays such as
382 , 452, 634 and probably 570 keY coincide to members of transitions in the ground state
4000 ~----------------------------------------------'

+

MN

.t

0+

N<:t
M_

I
3000

,

b

OJ
C
C

-

+

o
-<=

N

u

g 2000

+

CD

(")

t

c.D

+o

lO

-+

of>

c
::>
a

lO 0 -

U

g:i T~

°<:t

to

N

1000

CD
M

to +N

t

, =~

I

to=

2~

Fig. 2.
Sum of 'Y-'Y coincidence
spectra gated by the transitionsin the ground-state rotational
band.

lOlO

Channel Number
150 ~----------'-----------'-----------'{J6+ --- -----3879

J4+

3257

100
12 '

2634

J0+

2023

8+

J444 .7

6+

923.3

4+

486.6

2+
0+

J66.3
0

0,1'"

N+<=

50

0.05

0.15

162 Y bFig. 3.
162 Vb.

States in

Fig. 4.
Apparent moment of inertia as afunction of the square of the rotational frequency.

71band. From their intensities, these ')'-rays are presumed to originate from the transitions in side
bands. Studies of the structures of the side bands are in progress.
The level structure of the ground band in 162 Yb is shown in Fig. 3. In the well deformed
region to which 162 Yb belongs, the lower levels of the ground state band can be described bysimple rotational model. However at high spin states, the sudden increase of moment of inertia
was observed in the nuclei of deformed region. This fact is now believed to be the crossing ofdifferent bands. Figure 4 shows the curve, giving the relation between the moment of inertia
and square of angular rotational frequency of 1 62 Yb nucleus. The curve does not show theso-called backbending shape as that of 166 Yb does.

References
1) M.V. Banaschik, C. Gunther, H. Hubel, A.C. Rester, G. Nowicki, and 1.1. Pinajan: Nucl.
Phys., A222, 459 (1974).
2)

H. Kumagai and A. Hashizume: IPCR Cyclotron Progr. Rep., ~ 70 (1975).

72

5-4.

High Spin States of 164Yb

A. Hashizume, H. Kumagai, T. Katou, and Y. Tendow

This study is one of the series experiments on high spin states in Yb isotopes. The 164 Yb
was excited by means of the 1 55 Gd 2C, 3n) reaction. The target is the same as that used forthe study on 162 Yb. Excitation functions, angular distributions of 'Y-rays and 'Y~ coincidenceswere taken by the same experimental set-up as in the case of 162 Yb. The high spin states in
2
1 64Yb have been studied by Liederl) and by Stelson ) and states up to 22 + have been reported.
No side band has yet been found.

e

The 1'-1' coincidence has been studied at the incident energy of 70 MeV C-ions. By
examining each spectrum gated at the transitions in the ground state band, the spin states up to
18+ were confirmed. Figure 1 shows the sum of 9 coincidence spectra gated by the members of
the ground state band from the 18+ state except the 8+ ~ 6+ (468 ke V) transition. The peak of
the 468 keV transition coincides accidentally with that of a 'Y-ray of another origin and its
spectrum (Fig. 2) shows the coincidence with several 'Y-rays indicated by asterisks. The origin of
104~--------------------------------------------------------------,

-

+

o

a:;

t

c
c

~ 5xl0 3o+NN-......

('J

cJ)

N

-+-'
C

:::0

o

o

Fig. 1.
The sum of 9 spectra of 'Y~ coincidence gated by the cascade transitions from18+ to ground state except the 8+ ~ 6+ transition.
2000
+

.;0

J

+

N

~

<1>

c
c
0

N

..c

('J

::: 1000

c-i

N

V'J

c:

*
N

0

to
N

l

-

+

+

r--<T

.t

~+

<T

('JtO

I -

t

+

N

I

2

-+-'

0
0"

0

JJ,

§

U

to

164Yb

+

co

8+ -+ 6+

t- +.;-

++

9~

~o

tT
;r:;t ++

gt,

-*

to -

I

:!~

--

tON
"!r--cri tO('JtOtOr-<TtOtO tO'I I II

to,.....:
<T

<D

I

500
Chonne I num ber

Fig. 2.

Coincidence spectrum gated by 8+ ~ 6+ transition 'Y-ray.

1000

73

these 'Y-rays is not yet elucidated.

The peak at 633 keY reported as 20+ ~ 18+ transition 2 )coincides also with one of the above ')'-rays of unknown origin and it was difficult from thecoincidence spectrum gated by 633 ke V 'Y-ray to conclude it as 20+ ~ 18+ transition.
Furthermore, the 713 ke V 'Y-ray has not been confirmed as 22+~ 20+ transition because of

appreciable statistical errors of the data.
In addition to the 'Y-rays in the ground state band, there was reported 1) a 647.5 keY 'Y-ray
which has nearly equal intensity as that of 16+ ~ 14+ transition.

Following our coincidence

experiment, a existence of 2.40 15 MeV state is suggested which de-excites to l. 7 540 (10+) state byemitting the 647.5 keY ')'-ray. Figure 3 shows the behaviour of apparent moment of inertia asa function of angular rotational frequencies.

Further analyses of data is in progress.

200. . - - - - - - - - - - - -- - - - ,

0.10

0 .0S
( hW ) 2

0.05

Fig. 3.

Backbending curve for 164 Yb .

I MeV' )References
1)

R. M. Lieder, H. Beuscher, W. F. Davidson, P. Jahn, H. -1. Probst, C. M. Borike: Z. Phys., 257,
147 (1972).

2)

P. H. Stelson: Private communication to Nucl. Data. Sheets, Nuc!. Data Sheets, ll, 376(1974).

74

5-5.

High Spin States of 166Yb

A. Hashizume, Y. Tendow, H. Kumagai, and T. Katou

This study is one of the series of experiments on high spin states in Yb isotopes. The
experimental set-up is the same as used in the preceding reports. The 1 66 Yb was excited bymeans of the 158 Gd 2 C, 4n) reaction. A thick, self-supporting and isotopically enrichedetarget was used.
studied .

Excitation functions, angular distributions of 1'-rays and 1'-1' coi.ncidences were

Figure 1 shows the sum of 9 spectra of 1'-"( coincidences gated by the successive cascadetransitions from 20+ to the ground state. In this spectrum coincidences with the backgroundhave been subtracted by setting a window near the gating peak. The 18+ ~ 16+ transition, as
its energy being 509 keY, could not be resolved from the annihilation 1'-rays. Therefore, thespectrum gated by the 509 ke V 1'- ray was not involved in the above sum spectrum. By
investigating each spectrum gated at the transitions in the ground state band, the spin states up

10000

»

Q)

Q)

-",-'"

Q)

c
c
o
.c

~

~ 5000
c

::>

o
U

2000
Channelnumber

200

+

+

N

+

I

..r

+

:e

1
+

+

..r

I

~

<D

~

+~

OJ

<D

+1

Q

+

<D

100

Fig. 1.
The sum of 9 spectra of coincidences
gated by 1'-rays in the ground-state rotational
band.

+

I

+

..r

+ +

'2~

OJ

t£
.;~

15'00

Channe lFig. 2.
transition.

numbe r1'-"( coincidence spectrum gated by the 20+ ~ 18+

75

to 20+ were clearly confirmed. 1)
with those of ground state band.
transition ,),-ray.

Further, there is an indication that the 656 keY ,),-ray coincides
Figure 2 shows a coincidence spectrum gated by 20+ ~ 18+

We propose tentatively that the 656 keY transition goes to the 20+ state fromhigher energy level. The peak is so weak that we could not determine E2 character of thistransition. However, if it is assumed that the 22+ state de-excites to 20+ state emitting 656 keY,),-ray, the backbending curve representing change of moment of inertia as a function of the squareof rotational frequency can be extrapolated smoothly as shown by dashed line in Fig. 3. Figure
4 shows the ground state rotational band in 166Yb.
Besides the transitions in the ground state band, there were found about 20 weak ,),-rays
which could be able to attribute to transitions in 166 Vb . These ')'-rays may be emitted by thede-excitation process from the states in side bands. Further study is in progress.
In Yb isotopes of the mass numbers from 162 to 170, there is an interesting behavior
concerning the moment of inertia of high spin states. In 162Yb, the moment of inertia of highspin states change rather rapidly, but the val ues as a function of square of angular rotationalfrequency do not make the back bending shape. Whereas the curves for 164 Yb and 166 Yb show
large backbending. In contrast, the values of 2{)/h2 rest nearly constant in 168 Vb , and 170 Yb shows
again rapid change of 2 ()/h2 , though the latter doesn't show S shape. 2 ) It is a suprising fact thatthe small change of neutron number results in the large anomalies of angular momentum. These
anomalies have been studied by the theorists 3 ),4) in the framework of Hartree-Fock-Bogoliubov
cranking model or utilizing deformed BCS trial wave functions.

They could explain the anomalies

qualitatively, though it seems that some discrepancies yet exist between experimental andtheoretical results. Further study on high spin states in lighter Yb isotopes will be interesting.

5027

122:'-+---r~:7:
20

18+

3783

1 6+~

160

14+ ~·41402175.6

12+

~ 120
~

1605.910+;;:;I::'c100

10 98.2

8+
80

0.04

0.06

0.08

ole

0.12

I

014

6+

668.0

4+

3303

2+
0+

102.2
0
166Yb

Relation between the moment
Fig. 3.
of inertia and the square of rotationalfrequency.

The ground stateFig. 4.
rotational band in 166Yb.

76

References
1)

R. M. Lieder, H. Buscher, W. F. Davidson, P. Jahn, H. -J. Probst, and C. Mayer-Brorike:z. Phys., 257, 147 (1976).
2)

H. Beuscher, W. F. Davidson, R. M. Lieder, and C. Mayer-Boricke: Phys. Lett., 40B, 44(1972); A. J. Hartley, R. Chapman, G. D. Dracoulis, S. Flanagan, W. Gelletly, and J. N. Mo:
J. Phys., 6, L60 (1973).

3)

A. Faessler, F. Grummer, L. Lin, and J. Urbano: Phys. Lett., 48B, 87 (1974).

4)

A. L. Goodman and J. P. Vary: Phys. Rev. Lett., 35, 504 (1975).

77

5-6.

Populations of theParticle-Hole K Isomer and

the Ground State Rotational

Level

H. Ejiri,* T. Shibata,* S. Nakayama,* and A. Hashizume

Recently we have found that particle-hole K isomer is populated strongly by (p, xn')')reactions with large input angular momenta per projectile nucleon, and that the ground bandrotational level with K = 0 is well populated by complex projectiles with small input angularmomenta per projectile nucleon. It provides firstly an evidence that excitations of states withsame spin but different K (microscopic structure) depend on the projectile velocity. We define theK isomer ratio P K(1)/R o(1) , where PK(J) and P 0(1) are the population of the K isomer and theground band (K = 0) levels with the spin J. Here the Po (1) is corrected for the contribution fromthe isomer.
Population of isomers following (i, xn')') reactions was previously investigated by various
authors.1)··2) The K isomer ratios, PK (1)/P 0(1) , have been found to increase 1 ),2 ) as the input
angular momentum of the projectile increases for low incident energies because of the increase of
the fraction of large K levels which preferentially feed the K isomers according to the K-banddeexcitation model. 3)
Therefore measurement of the K isomer ratios for two different mass projectiles with nearly
the same input angular momentum is crucial in order to establish the projectile (velocity)dependence rather than the previously noted angular momentum dependence. In the previous
work the P8 (8)/P o(8) were measured for the J7T K =8-8 particle-hole state (1832.S keV) and the 8+8
ground band level (1278. S keV) in 1 82 Os. They were excited by the (p, 4n')') reaction with 40
MeV P, the eHe, 3n')') reactions with 24 - 26 MeV 3He, the (a , 6n'Y) reaction with 90 MeV Ci andthe 4 N, p7n) reaction with 120 Me V 14 N. The experiments were carried out by using the 3 Heebeam provided from the Osaka Univ. energy variable cyclotron, and the a and HI beams provided
from the RCNP cyclotron. From the view point mentioned above the best comparison can,however, be made for the 40 - SO MeV (P, 4n')') data and 28 - 3S MeV eHe, 3n) data. The(P, 4n) I' reactions have been studied previously. 2),4)
The latter reaction, however, has not beenestudied although He, 3n'Y) reactions below that energy have been investigated at the Osaka Univ.
Dept. Physics, cyclotron. The RCNP cyclotron gives too high energy 3 He. Thus the IPCR
cyclotron is best suited for the purpose.
In the present work the isomer ratio P K (8)/P o (8) for the 1820S was studied by-using the eHe,3n')') reaction at E = 31 MeV.

The 3 He beam was provided from the IPCR cyclotron. Singles,ooprompt and delayed I' ray spectra were measured by two Ge (Li) detectors set at 12S and 23S tothe beam. We found the ratio P s (8)/P o (8) = 0.210 ± 0.020. The present isomer ratio and theprevious data 2),4) are plotted in Fig. 1.
We found that the P s (8)/P o (8) are almost constant for the complex projectiles with various
input angular momenta, and that the isomer ratios for protons are definitely larger than those forthe complex projectiles. The present result suggests that the 40 - SO MeV (p , 4n) reactions givean effective K distribution exp (_K2 /2K6) with a large Ko = S, while other complex projectiles givethe exp (_K2 /2K 2 ) with a smaller Ko = 3.8 (see Fig. 1). The Ps (8)/P o(8) increases smoothly as theo* Department of Physics, Osaka University.

78

0.3

(p,4~n)

_

Ko-5
~

.-

Ko =3.81~ 0.2 J-t--Jt-------f----f-'(

CD

~O.l

(a,4n)(r,3n)(a,6n) (a,8n)

Fig. 1.

Isomer ratios as a function of themodified medium spin I'm defined as LIP (1)/ :LP (I).

78

9

10 ("h)1m (MODIFIED MEDIUM SPIN)

Solid lines are calculated for the exp

2(-K /2K&) with Ko = 5 for protons and Ko
3.8 for other complex projectiles.

average input angular momentum per proj ectile nucleon (J i ) increases.

One might guess that eachnucleon of the projectile hits each paired target nucleon and has to transfer large angularmomentum to get a large K p-h pair.

On the other hand complex projectiles transfer angularmomentum to many nucleons, each exciton having rather small J and K, and populate wellrotational levels with small K.
The present experiment is one of the works being carried out in collaboration with the Dept. Physics and RCNP inbeam
PEP group (Y. Nagai, H. Sakai, T. Itahashi, M. Hoshi, T. Kishimoto, and K. Maeda).

References
1)

H. Ejiri, Y. Nagai, H. Sakai, T. Itahashi, T. Shibata, M. Hoshi, S. Nakayama, T. Kishimoto,and K. Maeda: Contribution to the Tokyo Intern. Conf. Nuclear Structure, Tokyo (1977).

2)

H. Ejiri, G. B. Hagemann, and T. Hammer: Proc. Intern. Conf. on statistical properties of Nuclei,
Albany (1971).

3)

M. Ishihara, N. Yoshikawa, H. Kawakami, and M. Sakai: Nucl. Phys., A179, 769 (1972).

4)

H. Ejiri and I. Halpern: Bull. Am. Phys. Soc., 13,700 (1968); S. M. Ferguson, H. Ejiri, and
I. Halpern: Nucl. Phys., A188, 1 (1972).

79

5-7.

Half-life of 207Bi

M. Yanokura, H. Nakahara,* and K. Miyano**

The radioactive isotope 207 Bi is widely used as a 'Y-ray standard source.

However, its

reported half-life ranges from 28 to 50 years. 1) -4) In the method of determination of thehalf-life by specific activity, one has to use data such as photon intensities per disintegrati on,'Y -ray detection efficiencies which are likely to become source of large errors.

Therefore, it isadvisable to find a method which requires as few auxiliary data as possible.
We propose a method which requires no knowlege of the number of the atoms of 207 Bi ,the 'Y-ray detection efficiencies and geometry. Figure I shows the partial decay scheme of
211 At relevant to the present work. The 570 keY level in 207Pb is fed both by alpha decay of

211 At7.23h
211 Po0.535

Clu 7. 592

0... 5.981
5/T

Fig. 1.

Decay shemes of 211 At, 21 I Po, and 207Bi.

Only the levels related to the present work are shown.
The dashed level in 211 Po is the new level, but notdiscussed in this report.

2 I 1 Po and by EC decay of 207 Bi.

Since the half-life of 2 1 1 Ate 1 1 Po) is very different from thethat of 207 Bi, the photopeak area ratio of A 1 and A 2 , which due to 2 I I Po and 207 Bi,
respectively, can be determined from the analysis of the decay curve of the 570 ke V 'Y-ray.

Thisratio satisfy the following equation.

Al (211po)
A z (207 Bi )Ao No bEClXI(1)

AzNobayz

where No is the number of 2 1 1At atoms at the end of chemical separation, bEC/ba is EC/a ratioof 2 1 1 At, a 1 is the branching ratio of the 6.868 Me Va-ray emitted from 21 1 Po, 'Y2 is theintensity of the 570 ke V 'Y-ray per disintegration of 207 Bi, and A.{) and /...2 are the decay constantof 21 1 At and 207 Bi, respectively.
*

Faculty of Science, Tokyo Metropolitan University.

**

Faculty of Science, Niigata University.

80

A metallic bismuth target (99.999% purity) about 1 mm thick was bombarded with a beamof about 1 pA from the cyclotron for one hour to produce 2 1 1At through the reaction 209 Bi(a, 2n)2 1 1 At.

The alpha energy was set below 28 Me V so as not to produce 2 10 At.

The target wasdissolved in conc- HC I, and astatine was extracted into the organic phase by diisoproplether andagain back-extracted into aqueous phase by distilled water. An aliquot of the aqueous sample
solution was pipetted to a glass vial, and the decay of 'Y-ray from 21 1 Po and 207 Bi populated by
the decay of 21 1At were followed for several days by a heavily shielded Ge(Li) detector.

A

thin bism uth target, which was vacuum-evaporated onto an aluminium foil, was also bombarded,
and reaction products recoiled out the target were collected onto a catcher foil. The a-ray from21 1 At and 21 1 Po in the catcher foil were measured by a Si-detector.
The half-life of 2 1 1At was evaluated from the decay curves of the 897 ke V photopeak and7.868 and 7 .448 MeV alpha peaks. The results of the least-sq uares analysis yielded 7.23 ± 0.02 h.
The EC/a ratio of 2 1 1At was calculated to be 0.583/0.417 from the measured spectrum.
Branching ratio of the three a decay from 2 1 1 Po and a energies were determined.
obtained are shown in Table 1.

The results

The 570 keY 'Y-ray, turned out to have two components in its

decay curve, from which we estimated the ratio of Al / A 2 . The branching ratio of the 570 keY'Y-ray from 207 Bi is taken from Ref. 5, since the decay schemes of 207 Bi is well known.
The half-life of 207 Bi evaluated from Eqn. (1) was 33.4 ± 0.8 years. The quoted error
was mainly due to the counting statistics associated with the photopeak area of the 570 keY'Y-ray emitted from 207 Bi.
Table 1.

Experimental results of energies and intensities of
the 'Y-rays and a-rays.

NuclideHalf-life

E'Y (keV)

Ea(MeV), Intensity

(%)

EC/a

211 At7.23 ± 0.2 h

686.7 ± 0.48

(5.868)41.7 ± 0.01

0.581/0.417

211 Po(0.53 s)(569 .7)(897.3)6.568 ± 0.001 0.58 ± 0.01
6.891 ± 0.001 0.60 ± 0.01
(7.448)98.82 ± 0.01

The parenthsized val ues were taken from Re f. 5.

References
1)

H. M. Neumann and 1. Perlman: Phys. Rev., 81 , 958 (1951).

2)

G. i

3)

T.

4)

E. H. Appelman: Phys. Rev. , l1..L 253 (1961).

5)

Nuclear Data Sheets, Sec. , B 5, No.3 (1971).

rbottle: 1. Inorg. Nucl. Chern., 12, 6 (1959).

Sosniak and R. E. Bell: Can. 1. Phys., 37 , 1 (1959).

81

6.

NUCLEAR INSTRUMENTATION

6-1.

A

Partie Ie Identification Program for the On-Line UseT. Nomura

A simple on-line program to identify mass and atomic numbers of heavy particles has been
made for the OKITAC 4500C (32 K core memories) data processing system. The code assumes
two different experimental arrangements for the particle identification (PI): (1) .6E-E counter
telescope and (2) time-of-flight. For the first method, we used the empirical formula proposed inRef. 1, which was slightly modified and approximated by

with

PI=n 6 £ [ (£+0.496 £) / 300l n - l,(1)

n=1.84-0.0466 E/T.

(2)

Here, .6E and E are pulse heights (in unit of MeV) from .6E and E counters, respectively; T is
thickness of the .6E detector, measured in unit of mgjcm 2 in the case of a Si counter. Eqn. (1)turned out to show remarkable improvement for PI compared to a conventional electrical circuit
w~ed for PI.
The principle of the second method is the same as described in Ref. 2. The above
two PI methods can be used separately, or if desired, can be combined together.
The program can be applied to experimental data taken in the coincidence mode with up to
four parameters stored on a disk pack in a event-by-event wise. This code is usually stored inanother disk pack as one of the utility programs of the PHA system, and can be called any time
during or after the data accumulation. "Gates" can be set on a calculated PI spectrum displayed inlog or linear scale in order to represent the corresponding energy spectra (.6E, E and / or .6E+E) andother possible spectra depending on other parameters in coincidence.

Inversely, gates can be set onenergy spectra and others to obtain the corresponding PI spectrum. The parameters for PI andgates are inputed from the teletype and can be changed any time even during the data accumulation;
When they are changed, the calculation starts from the beginning of the data stored in the disk pack.

References
1)

2)

G. W. Butler, A. M. Poskanzer, and D. A. Landis: Nucl. Ins~r. Methods, ~ 189 (1970).
F. S. Goulding and B. G. Harvey: Ann. Rev. Nucl. Sci., 22, 167 (1975).

82

6-2.

Determination of the Etching Rate Versus Restricted
Energy Loss Curves in CN Films and CTA Film s
by Using N-Ion Beams

T. Doke, T. Hayashi,* T. Yanagimachi,** and I. Kohno
F or determination of the flux of heavy charged particles with Z>40 in the primary cosmic
rays at the top of atmosphere in Japan, where the energy of the incident cosmic ray particles is in
the relativistic region, we have recently tried a series of balloon experiments using plastic nuclear
track detector arrays with a large detection area. 1)-3) In these experiments, the nuclear,charge ofcosmic ray particle passed through the plastic detectors was determined by measuring the etchingrate (V t) of the particle track and by referring it to the curve of REL (restricted energy loss)4)
versus Vt obtained by using known heavy charged particles.

In the balloon experiments, threekinds of nuclear track detectors were used. One was a 190 J1.m thick cellulose nitrate (CN, Daicel)
film, the second, a 250 J.lm thick cellulose triacetate (CTA, Fuji) film, and the third, a 200 J.lm thickpolycarbonate (PC, Teijin) film. To obtain the curves (so-called calibration curves) of REL-V t forthese plastic films, the films were irradiated with N-ions of 6.43 Me VIn.

Two geometricalarrangements of the plastic films used for the N-ion irradiation are shown in Fig. l(a) and (b).

plastic film

f>.!3MeV/n N-ion(a)Au-scatterer
1300)Jg/cm2}

plastic film

Fig. 1.
Two geometrical arrangements ofplastic films and the scatterer (Au-foil of
300 J.lg/cm 2 ) for the N-ion irradiation.
For CTA and PC, films were enveloped in

6 . 1.3MeV/n N-ion(b)

16 J1.m thick AI-absorber.

The injection

angle of the scattered N-ion to the plastic
8, = 11..700

8 =21.03

8 =18 .7°
2

films is 19° - 41 ° .

81.= 21. . 5°

After N-ion irradiation , the plastic films were immersed in the solution of 6.0 - 6.7N NaOH,
which was kept at 30° or 45°C for various lengths of time. Thus, the growth curves of the etched
track length (L(t)) for 6.43 MeV/n N-ion was obtained as a function of etching time (t). From*

Science and Engineering Research Laboratory , Waseda University.

**

Faculty of Science, Rikkyo University.

83

this grwoth curve , the REL-V t relation can easily be obtained.

Calibration curves for CN and for

CT A thus obtained are shown in Figs. 2 and 3, respectively.

In these figures, the results recen tly
obtained by using Ar-ions of 400 MeV/ n from Bevalac are also shown. S)
As seen in Fig. 2 , the result by N-ions is in agreement with that by Ar-ions within theexperimental errors.
In the results by Ar-ions,S) a remarkable difference in the response curve between the front
and back surfaces, of CT A was found, while, in the results by N-ions, no difference could be foundpresumably due to large experimental errors.
surfaces are shown in Fig. 3.
with that by Ar-ions.

For N-ions, therefore, the mean values of V t in both

The curve obtained by using N-ions seems to be roughly consistent

These results were used for the determination of the charge of particles detected in theballoon experiments carried out in 1973 and in 1976.
The calibration curve for PC could not be obtained because of the short registration range ofN-ion.

60~--~----~----~----~--~~--~eN100

N - ion60 N 30 e (1973)e TA (1976)• Ar - ion

6.7 N 30 e (1976)

oN -ion

D

'/

D

D

•
•

6.0N 45°C. (front)
Ar-Ion(back)°
6.7 N 45 C

80

~ 60

E

::J..

Ul

~ 40
u
QJ

20

Z (E? 3 G.V/n J

80700~--~~--~---4----~~--~--~--~

oFig. 2.

3

4

4

6

10

12

3
2
R E L (. 10 Mev·c m /g)

R E L (x10 MeYcm 2/g)

Vt -REL(or Z) relations in CN.

6

90

REL

Fig. 3.

V t - REL(or Z) relations in CTA.

The

in the re1ativi stic region depends only on thesol id lines are represen ted by the relation, V t =nuclear charge (Z).

B'REL + C, where B = 2.81, C = - 6 .53 for the

The solid curve is represented

by the relation, V t = V 0[1 - expj - A (REL

front surface and B = 7.67, C = - 22.1 for the- RELc)f] , where A = 0.356 , V 0 = 87.5 (pm/h)back surface , respectively.

and RELc = 1.32 (x 1032MeV·cm /g).

References
1)

T. Doke, H. Okamoto , E. Shibamura, T. Hayashi, K. Ito, T. Yanagimachi, S. Kobayashi,

84

K. Nagata, M. Miyajima, and T. Saito: Bull. Inst. Space and Aeronautical Sci., Univ. of Tokyo,
li, 497 (1975).
2)

T. Doke, H. Okamoto, E. Shibamura, T. Hayashi, K. Ito, T. Yanagimachi, S. Kobayashi,
M. Miyajima, T. Saito, and K. Nagata: Proc. 14th Intern. Cosmic Ray Conf., Munich,
OG 6-19,4123 (1975).

3)

T. Doke, T. Hayashi, K. Ito, T. Yanagimachi, K. Hisano, K. Nagata, and M. Miyajima: Bull.
Inst. Space and Aeronautical Sci., Univ. of Tokyo, U., 875 (1977).

4)

E. V. Benton and W. D. Nix: Nucl. Instr. and Meth., f1L 343 (1969).

5)

T. Hayashi, K. Takayama, T. Yanagimachi, and S. Kobayashi: Ionizing Radiation, Japan Soc.
Appl. Phys., ±, No.3, 22 (1977).

85

6-3.

Target Chamber for Recoil-distance Lifetime Measurements

T. Katou, H. Kumagai, Y. Tendow,
Y. Awaya, and A. Hashizume

A target chamber for recoil-distance measurements of nuclear lifetime in the range from I ps
to 1 /lS was constructed. An outline of the chamber is described in this report.
A schematic diagram of the plunger apparatus and the electronics are shown in Fig. 1. The
beam from the cyclotron enters the target chamber and passes through the collimators andfocusses at the target.

The stopper foil is held firmly in position by a holder which is electricallyinsulated from a support attached to the base of the chamber.

The equipment for controlling theijnear movement of the target is also mounted on the same base of the chamber in order to reduce
the possible relative movement between the target and the stopper when the chamber is evacuatedor the room temperature changes. The linear movement of the target is provided by a sliding
stage moved by a pulse motor (240 pulses correspond to 1 /lm).
The control system has the following functions: a) setting of the direction and distance of
movement: b) detection of the touch of the target to the stopper: c) detection of the maximum
limit of the movement.
To measure the distance of movement the output pulses from a commercially available"MAGNESCALE" are counted by UP/DOWN scaler or the advance pulses to the pulse motor arecounted.
A MAGNESCALE graduated to I /lm is used to measure the distance between the stopper
and the target foil.

The zero distance determination can be done in the same way as in Ref. 1

with capacitance method .

Figure 2 shows an example of a plot of C- 1 versus the MAGNESCALE

reading. The expected linear relation is found. The target was able to approach to the stopperwithin 5 /lm. For a typical recoil velocity of 1% of the light velocity and a lifetime of 1 ps, themean path is about 3 /lm.

The capacity is also used to monitor the thermal expansion of thesystem when the beam is present.

Ad lustment"'"

Sliding
sta geColli met ars

Beam'---- ------' ~ r~oISensor

~
4

6

8

10

12

I

!

I

I

I

Scale In em.

2

o

1+ 1,

I- I

UP:

Do wn

..

u

0~--~--~----~I O~--~'5-

Magnesco leFig. 1.

Schematic view of the plunger apparatus.

Fig. 2.
distance.

.L

20

read in g Illml

A graph giving C- 1 vs the

86

The procedure adopted for pre-aligning the target parallel to the stopper surface is to adjust
the reflected laser lights from the stopper and the target using an adjuster.
The foil-stretching technique is consisted of pressing an area of foil with a frame over thecircular end of a cylindrical tube and further stretching the foil surface from the opposite direction
with a metal insert which slides inside the tube. This double stretching technique improves a flat
foil surface and eliminates nonuniformities at the edge. The frame for mounting the foil is shown
schematically in Fig. 3.
Figure 4 shows an example of interferogram of gold target foil obtained by a He-Ne light withwavelength 663 nm. The height difference between neighboring fTinges is half a wavelength, thatis, 0.3 pm.
The test experiments using HI beam are now in progress.

(a)

(b)

(c)

(d)

o
I

Pin

Pin

2

3

I

Sca le inFig. 3.

I

4
I

em.

A schematic diagram of theFig. 4.

Interferogram of a gold target foil.

mounting frame: a) locking nut; b)
stretching insert; c) mounting frame;d) pressing frame.

ReferenceI)

T. K. Alexander and A. Bell: Nucl. Instr. and Meth.,]1, 22 (1970).

87

6-4.

Gas

L::. E-E Telescope for the Partie Ie Identification of

Heavy

Ions

M. Yanokura ~ 1. Kohno, T. Motobayashi,
H. Nakahara,* and K. Yamakoshi**

One of the most common techniques for the particle identification is the 6E-E method , where
6E is specific energy loss and E is total energy. For the detection of light particles with Z<9solid-state detector telescopes are widely used, while Gas detectors are used for the dEjdX
measurement at low energy of heavier particles.

Both ionization chamber and proportional counter

have been used as the gas detectors. General advantages of the gas counters are the following: (i)by adjusting the gas pressure the thickness of 6E detector can be varied , according to therequirements of a given specific experiment; (ii) the homogeneity of the gas 6 E detector can bebetter than 1%.

On the other hand , the gas detector have some defects. First is the difficulty inhandling the gas flow system and the mechanical weakness of the window material.

Second,resolution of 6E spectrum is affected significantly by the uniformity of the electric field.
Photograph of the gas counter was shown in Fig. 1. It has three advantages: (1) Various
length of outer tube of 6E detector can be selected; (2) A thin window film can be easily
exchanged without changing the counter setting; (3) The same counter can be used as an ionizationchamber and a proportional counter, only by exchange of the anode parts. A simplified diagramof the telescope was shown in Fig. 2. The outer tube of gas counter, entrance housing and SSD
housing are machined from brass. The grid and anode are made of Au-coated tungsten wires of
10 JIm. These wires are parallel to the trajectory of the particles. The outer tube . grid and anodeare mounted on insulators. The space between outer tube and anode is 20 mm and between gridand anode is 5 mm. The entrance window is made from VYHH film , copolymerization resin of
90% Vinyl acetate and 10% Vinyl chloride , of 10-30 JIg j cm 2 thickness. Typical outer tube lengthis 70 mm. The entrance window is 1.5 X 5 mm and can safely support a gas pressure of 42 Torr.

Outer tubeoFig. 1.
Photograph of the gas 6E - E
counter. The gas pipes, magnet andshielding wall are set.
*

Tokyo Metropolitan University.

**

Cosmic Ray Laboratory, The University of Tokyo .

Fig. 2.

50nm

The gas counter. Typical lengthof the counter was 115 mm.

88

Gas flow system is shown in Fig. 3.

The gas counter was operated with a steady flow of PRgas containing of 90% argon and 10% methane.

The gas pressure was stabilized with the mass

flow controller and a reservor of large volume.

For gas pressure 7 to 30 Torr, the stability wasbetter than 1% over a time of 12 h.

The pressure was measured by an alphatron vacuum guage

and monitored throughout the experiment.
The test experiment were performed with a 82 MeV carbon beam from the cyclotron.

The

A 1 mm thick Si-detector was used as a E counter.

Fortarget was a self-supporting 54 Cr foil.

6E detector the proportional counter was used with operating gas pressure of 17 Torr, window

thickness of 20 J.1g/cm 2 and operating anode voltage of 150 V.

As is shown in a 6E spectrum

gated with a constant E (Fig. 4) , light particles are reasonably resolved by these conditions.
~ ---- --- --- - I,

I

UNIT ofFlangegas flow systemIor-tron

I Scatteoring

I

cha~r

I

!_ _ _ _ _~.=_ _ ~~ervoi~_lvacuum glJClC)eFig. 3.

Gas flow system.

~~------------------------------------------------------------Ic

N

0
Recoil

F

Ne

No

Mg

AI

Si

600

Fig. 4 .

One of the typical 6E spectrum .

800

1000

89

7. ATOMIC AND SOLID-STATE PHYSICS

7-1.

Energy loss and Straggling of C and He Ions in Metal Foils

T. Takahashi, Y. Awaya, T. Doke, T. Hamada, A. Hashizume,
K. Izumo, H. Kumagai, T. Tonuma, and S. Uchiyamal

According to Ashley, Ritchie and Brandt, ) and Jackson and McCarthy, 2) the energy loss ofa heavy particle of charge Z 1 e and velocity v = {3c can be written as

dE =Z 2 K+Z 3 J
dx

1

1

where J /K is a small positive quantity, of the order of a few hundredths for (3 = vic = 0.1.

To

test the Zf dependence , we made preliminary experiment on AI, Ni, Ag, Au, and Pb foils, using C
and He ions of 0.10</3<0.11.

Results are shown in Table 1 and Table 2, where interpolated

values from Northcliffe and Schilling's data 3) are also shown.

Our data are in accordance with

Northcliffe and Schilling's data within the experimental accuracy, except for Pb.

Because ofexperimental errors, no conclusion can be drawn about the Zf dependence, but it seems somewhat
smaller than that predicted by the theory.

Experiments at higher energies, where the zi

dependence is expected to be more clearly observed , are now in progress.
According to Sofield et al.,4) energy straggling of 5.486 Me V He ions in Al is in excellent
agreement with the Bethe-Livingstone theory. 5) Our results on the straggling of 22 Me V He ionsshow 20 - 40% larger values than those predicted by the theory.
explained yet.
Table 1.

The reason for this is 110t

Electronic stopping power of C ions in units of MeV/(mg/cm 2 ).

Material

Energy (MeV/nucleon)

Our experiments

Northcliffe and Schilling

Al
Ni
Ag
Au
Pb

5.301
5.273
5.288
5.082
5.345

1.953 ± 0.018
1.597 ± 0.021
1.260 ± 0.015
0.956 ± 0.017
0.974 ± 0.025

1.96 ± 0.02
1.60 ± 0.02
1.27 ± 0.02
0.98 ± 0.01
0.92 ± 0.01

Table 2.

Electronic stopping power of He ions in units of MeV/(mg/cm 2 ).

Material

Energy (Me V/nucleon)

Our experiment

N orthcliffe and Schilling

Al
Ni
Ag
Au

5.295
5.273
5.300
5.076

0.222 ± 0.002
0.179 ± 0.004
0.145 ± 0.004
0.107 ± 0.003

0.219 ± 0.002
0.180 ± 0.002
0.141 ± 0.002
0.108 ± 0.002

90References
1)
2)
3)

J. C. Ashley, R. H. Ritchie, and W. Brandt: Phys. Rev., B5, 2393 (1972).
J. D. Jackson and R. L. McCarthy: ibid., B6, 4131 (1972).
L. C. Northcliffe and R. F. Schilling: Nuclear Data Tables, A 7, 233 (1970).

4)

C. J. Sofie1d, N. E. B. Cowern, J. M. Freeman, and K. Parthasaradhi: Phys. Rev., A15, 2221
( 1977).
M. S. Livingston and H. A. Bethe: Rev. Mod. Phys.,~ 245 (1937).

5)

91

7-2.

X-Rays Following Multiple Inner-Shell Ionization(1)

Y. Awaya, T. Katou, H. Kumagai, T. Tonuma,
Y. Tendow, K. Izumo, T. Takahashi,
A. Hashizume, M. Okano, and T. Hamada

The dependence of the KO' X-ray spectrum pattern on the incident energy (E) of the projectile
has been studied by exciting a Ti target with N ions of 66, 71, 84, 95, and 108 Me V and C ions of61, 72, and 82 MeV.

The dependence on the atomic number of the proj ecti1e (Zl) has also beenstudied by exciting the Ti target with 6-MeV/amu 0' particles, C, N, and 0 ions.
The 0' particles, C4 + , N 4 + (N 5 + for 108 MeV) and 0 5 + ions were accelerated by the cyclotron.
The Ti target was a self-supporting metallic foil.

Its thickness was 1.35 mg/cm 2 except for thecase of 95 MeV N-ion bombardment where a foil of 1.8 mg/cm 2 was used.
at 60° with respect to the beams.

The target was placed

The estimated energy loss of the projectile in the target is lessthan 6% of the incident energy. X-rays were measured with an automatically controlled stepscanning Bragg crystal spectrometer!) ,2) employing a flat crystal of LiF (200). The detection
system of the scintillation counter (SC) was used in most of the measurements.

When the X-ray

yield was not enough to use SC, the detection system of the proporti onal counter (PC) was used.
En ergy (ke V)
xl0

3

4.8

4.7

4.6

4.5
--1

66 MeV

~

30
20

--1

~~
m-..J~

4.8

';;:

x 10

Energy (keV)
4.7
4.6

4.5

3

20

95 MeV-..J~~-....,'"

71 MeV

c
:=J

-e

<!

5

10

-

'"

'"c

c:
:=J

OJ

0

.D
L

U

<!

0

....,
if)

15

84 MeV

c:
OJ

0

u

30

10
5
0

0

80

80
28 (deg.)

Fig. 1.

Ti KO' X-ray spectra excited by N ions of theindicated incident energy.

92

The efficiency of the spectrometer utilizing PC system is ten times larger than that utilizing SC
system for Ti K X-rays whereas the resolution of the former is worse than the latter.

This

dependes on the angular divergence of the Soller slit and the absorption of the X-rays by the
Mylar window of the chamber 1 ), 2) besides the efficiency of each counter.
The spectra ofTi Ka X-rays induced by 66, 71 , 84 , 95, and 108 MeV N-ion impact and thoseinduced by 6 Me V / amu a particles, C, N, and 0 ions are shown in Figs. 1 and 2.
denotes the m K-shell and n L-shell vacancies in the initial state.

Symbol KmL n

For some cases the K,6 X-ray

spectra were also measured. They are shown in Fig. 2. The symbol a or ~ attached to eachpeak means that the peak belongs to Ka or K,6 transition.
The analysis of the spectra will be made in part (II).
E (keV)
4.4

4.6

4. 8

o
~)

o

i::r- = =:H~
: : ~'4~~
~JL~,
'O l
,- ---A---c- , ,
74

78

82
28 (deg)86, I

Fig. 2.

Ti K X-ray spectra excited by

6-MeV/amu a particles , C, N, and 0 ions.

References
1)

Y. Awaya, Y. Tendow , H. Kumagai, M. Akiba, T. Katou, and T. Hamada: IPCR Cyclotron

2)

Progr. Rep. , ~ 79 (1975).
H. Kumagai , Y. Awaya, Y. Tendow, T. Katou , and M. Akiba: Reports I.P.C.R., (in Japanese) ,53 , 153 (1977).

93

7-3.

X-Rays FolloVv'ing Multiple Inner-Shell Ionization(2)

Y. Awaya, K. Izumo, T. Hamada, M. Okano, A. Hashizume,
T. Takahashi, Y. Tendow, H. Kumagai, T. Katou, and T. Tonuma

The previously reported data l ) on the dependence of K X-ray spectrum pattern on the atomic
number of the target element (Z2) as well as the present data described in part (I) are analysed.
(1) The diagram and satellite X-rays
Relative peak intensity obtained for N-ion bombardment are shown in Fig. I and those for
C-ion bombardment in Fig. 2. In Fig. 2, data at lower energies and the result of theoretical
calculation, in solid curves, are those of Hill et al. 2 )By assuming that there is no correlation between electrons and that the probability forionizing each sub-shell electron of the L shell is the same, the ionization cross section of m K-shelland n L-shell electrons 0mK,nL is given by the following expression,3) ,4)(1)

where PI(b) is the probability of single ionization for the I shell with N electrons, b is the impact
parameter and (~) is the binomial coefficient. For the expression of single K-shell and n L-shellionization cross section ° I K,nL' a factor [I - PK(b)] is approximated to one and, in the region
where PK(b)0, PL(b) is almost constant and can be approximated by PL(O). Then,*

OlK,nL=( ~)PC (O)[ 1 - PL(O)l8-n.2~

P K(b)2nbdb =-(~)Pt(O)II-PL(O) J 8 - n·6k
Torg et el ement
FeCr

E (MeV/omu)
5

6

7

8

Ni

I

I

I

I

I

Ti + N

40 -

+
40 1-

30-

+

>-

+-'

c

t+

~ 40
<:>

t KL

+

•+

C
Q)

u
Q)

401-

<:>

b

JO -

+-'

L

;:~

"6
~

0
+-'

0

+-'

b

20-

I j

+ KL

JOI-

c

•

+

• •

KL 2

~ 20

CL

10

I

I

I

5

6

7

E / AUL

t KL2

Q)

+

10-

Fig. 1.

K

+J

CL

0

t

~ JOIc

lS

t

>-

+

~ 20

EN =84MeV

50 1-

+ K

Ti
I

I

I

t

KL 3

I

I

8

9

0

t

I

4

• KL J

t
I

I

I

5

6

7

[ / AUL

Percent of total K~ intensity in the diagram line and satellites vs.

EjXuL' Left: the Ti target was bombarded by N-ions of energy E, Right:
the Ti, Fe, Cr, and Ni targets were bombarded by 84 MeV N-ions.

(2)

94

•
• K•

/

3

>.

.......

/

KL•

xtO- 3
1.51-

0 10

I

~

• •
KL2 •

0

N_

N
.........

o Cr+ No Fe + N

tOt-

(3

C

C2

• i

N-.I

::J

x Ni + N• Ti + 0• Ti + No Ti + C• Ti+ax~..

O.5f--

I

I

I

i

I

•
I

I

O.O~--4'------5'------6'------7'------8'------9~4£1 AUL

MeV/omu

Fig. 2.
Percent of total Ka intensity inthe diagram line and satellites vs. energy ofFig. 3.

Plot of P L (0).

per amu of projectile for C-ions. The open
circles and solid curves are taken from Ref.2.
The relative intensity of KL n X-rays has been converted to the relative ionization cross section
by using the calculated fluorescence yield wKLn. The value of wKLn was calculated by a statistical.;;caling procedure by assuming no initial M-shell vacancies and by using values of radiative transition
probability calculated by Scofield 5 ) and those of Auger transition probability by Kostroum et a1. 6 )The estimated values are listed in Table l. From the relative ionization cross section for each KL nconfiguration , the parameter P L (0) has been determined by the least square fitting.

It was foundthat the curve uL2PL(0)/Zl 2 vs. E/AUL shows the same relation which can be applied universally as
is obtained for single inner-shell ionization, where uL is the binding energy of the L electron and

A. is the mass of projectile in electron mass unit.
Table 1.

Ti

Fe

Zn

Scaled K-shell fluorescence yield wKL n of Ti, Fe, and Zn forvarious combination of 2s (n 1 ) and 2p (n2) vacancies (n = nl
+ n2)' Interpolated values are used for Cr and Ni.

n 1\ n 2

0

0

0.194
0.257
0.324
0.319
0.395
0.467
0.453
0.532
0.598

{2
{

0
1
2
0

12

The result is shown in Fig. 3.

0.197
0.272
0.352
0.325
0.414
0.499
0.461
0.553
0.628

2

3

4

5

0.197
0.286
0.383
0.327
0.433
0.533
0.467
0.573
0.661

0.189
0.296
0.418
0.319
0.448
0.570
0.460
0.590
0.694

0.168
0.295
0.450
0.291
0.449
0.604
0.431
0.593
0.724

0.118
0.252
0.447
0.217
0.400
0.603
0.340
0.547
0.726

95

(2)

The hypersatellite X-rays

The relative intensity of hypersatellite to the diagram plus satellite lines, u X (K 2 )/ux(K),increases with either the increase of E or the decrease of Z2, when Zl is constant (N-ions).

It is

2

found that when the values of u X (K )/ux(K) are plotted against the reduced parameter E/AUK'
these two kinds of points, one with increasing E and the other with decreasing Z2 , are connectedsmoothly as is seen in Fig. 4, where uK is the K-electron binding energy of the target atom.

The

points marked by atomic symbols were obtained for 84-MeV N-ion impact to the corresponding
target element and those without the marks are for bombardment of the Ti target with Nand C
ions of corresponding value of E.
The plot of u X (K 2 )/ux(K) vs. Zl 2 is shown in Fig. 5.
2This result shows that the value ofSince the value of ux(K) is proportional to Z l 2, asu X (K )/u x (K) is proportional to Zl2.

long as the ionization is caused by the direct Coulomb interaction , this shows that the value ofU

X(K2) is proportional to Z14.

This fact provides another evidence of Z\4-scaling for double

ionization of K shell obtained by Kawatsura et al.7)

Cr

Fe

Ni
I

Ti
I

I

I

0.04 -

0.03-

!

!

~

~

! !'

.......
N~>.: 0.02!

A
/

~

/

~

t

~

/

/

N
~

• N- ionso C- i ons

/

/

/

+//

::::: 0.02~

Q

2

b

0.01 ~

0 .0 3~

/

/

/

/

/
/

0.01 -

/

/
/
/

j

j

j

1

I

0.4

0.5

0.6

0.7

0.8

0. 0 0 ~... I t
4
16

Total K2 L naX-ray intensity relative tototal KLnaX-ray intensity vs E!AUK'

I

t

I

36

49

64

Z2

f / AUK

Fig. 4.

t

1

Fig. 5.
of Zi.

References
1)

Y. Awaya, M. Akiba, T. Katou, H. Kumagai , Y. Tendow, K. Izumo, T. Takahashi ,A. Hashizume, M. Okano, and T. Hamada: Phys. Letters, 6IA, 111 (1977); IPCR Cyclotron
Progr. Rep., 10,78 (1976).

2)

K. W. Hill, B. L. Doyle, S. M. Shafroth, D. H. Madison, and R. D. Deslattes: Phys. Rev.,
AI3 , 1334 (1976).

3)

J. M. Hansteen and O. P. Mosebekk: Phys. Rev. Lett., 29,1361 (1973).

4)

J. H. McGuire and P. Richard: Phys. Rev., A8, 1374 (1973).

5)

J. H. Scofield: ibid., 179, 9 (1969).

6)

V. O. Kostroum, M. H. Chen, and B. Crasemann: ibid., A3, 533 (1971).

7)

K. Kawatsura , K. Ozawa, F. Fujimoto, and M. Terasawa: Proc. 10th Intern. Conf. on Physics ofElectronic and Atomic Collisions Abstracts, Paris, p. 50 (1977).

96

7-4.

Gas Target System for Study of X-Rays Induced by Heavy Ions

T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, and I. Kohno

A gas target system equipped with gas cell was made and used in the study of K x-rays

It is advantageous in our case of using the cyclotron beam to employ a closed
gas target system equipped with windows because of following reasons: 1) thickness of gas target
induced by ions.

is easily controlled and also it is easy to get high pressure that can not be attained by a differential
pumping system; 2) after passing through a window, heavy ions (C, N) accelerated by the cyclotron
are almost naked ions.

Therefore, an initial charge state of heavy ions are regarded as a fully

stripped charge state.
Figure 1 illustrates the gas cell and the gas feeding system.

Two windows through which thebeam passes are covered with 7 J.Lm thick aluminium foils and the other window facing an x-ray
detector with 50 J.Lm thick beryllium foil.

Each window has a diameter of 12 mm.

The vessel

itself is made of aluminium. The cell is able to withstand the gas pressure of about 300 Torrwhen placed in vacuum. The pressure was monitored by an a-tron gauge throughout theexperiment. The size of the beam spot was less than 3 mm in diameter at the entrance window.

Bragg crystal
spect rometer= =-'=1==.1]1

1

Si(Li)
detect r~1l':=111=~£gOW"~ngaugengas bomb

Fig. 1.

Gas target and gas feeding system.

Channe lnumber

The Kr K X-ray spectrum induced by
Fig. 2.
84 Me V N-ions measured with a Si(Li) detector.

97

The x-rays from the gas target, emitted by the beam bombardment, were detected by aSi(Li) x-ray detectorl) and by a Bragg crystal spectrometer. 2 )The first example of the x-ray energy spectrum obtained by using this gas target system isshown in Fig. 2. The Ka and Kp spectra from a Kr gas target induced by 84 MeV N-ions were
measured using the Si(Li) detector which was placed perpendicular to the beam direction. Air
space of about 7 mm existed between the window of the target and that of detector. Eachwindow was covered with 50 11m Be foil. The pressure of the Kr gas was kept at 4.0 Torr during
the measurement. In the low energy region of x-ray spectra continuous background was observed.
This may be due to the bremsstrahlung induced by recoil electrons created by the projectiles inthe target and windows. 1 )The second example of the x-ray energy spectrum is shown in Fig. 3. The Ka diagram andsatellite line spectra of Ar gas target induced by 84 Me V N-ions were measured by the Bragg
crystal spectrometer, which had a Ge(lll) crystal and a proportional counter. In the measurement,
Bragg angle(28) was increased by steps of 0.05° after counting was done for integrated current of
1.5 IlC at each step.

The beam current was about 10 nA up to 15 nA.

The pressure of Ar gas

varied from 203 Torr to 210 Torr during three and a half hours required for the measurement.
Each peak in the figure is labelled by symbol KL n which denotes the corresponding initialconfiguration having one K-shell vacancy and n L-shell vacancies.
E (k eV)oUFig. 3.

The Ar Ka X-ray spectrum

induced by 84 Me V N-ions measured762e ( deg )with a Bragg crystal spectrometer.

Using the Si(Li) detector, the yield of Ar x-rays was determined with and without a magnet
which suppressed secondary electrons emitted from an Al foil window by the beam bombardment.
From the measurement it was found that the secondary electrons created little Ar x-rays. The
yield of x-rays created by 'Y-rays emitted from an Al foil might be also negligible because the cross

98

section were very small. The determination of target thickness requires the knowledge of thetemperature as well as the pressure of the gas. However, it is difficult to know the exact
temperature of gas during the experiment because the temperature may rise locally due to heatingby the beam. Heance , the x-ray yield or the elastic scattering yield will have to be monitored byanother counter instead of measuring the temperature. 3) The ratio SIN was rather unsatisfactory
as shown in the figure. Improvement of the SIN ratio is being tried.

References
1)
2)
3)

Y. Awaya, K. Izumo, T. Hamada, M. Okano, T. Takahashi, A. Hashizume, Y. Tendow, and
T. Katou: Phys. Rev., A13, 992 (1975).
Y. Awaya, Y. Tendow, H. Kumagai, M. Akiba, T. Katou, and T. Hamada: IPCR Cyclotron
Progr. Rep.,~ 79 (1975).
T. Motobayashi: ibid., 10,72 (1976).

99

7-5.

Chemical Effect in X-Ray Spectra Produced by Fast Ions

M. Uda, K. Maeda, Y. Awaya, M. Kobayashi,
Y. Sasa, H. Kumagai, and T. Tonuma

X-ray emission spectra induced by 84 Me Y N4 + , 72 Me Y C4 + , 24 Me Y He 2 + , and 6 Me Y H+ ionsgenerated in the cyclotron were measured with an on-line Bragg spectrometer. 1)

Integrated beam

current was kept constant for each angular setting.

Target materials used here were in the form ofthin films, thickness of which was in the range of 1- 5 mg/cm 2 . Insulators were made conducting byocoating with a thin layer (200 A) of carbon.
The present study deals with chemical effects reflected in X-ray spectra emitted from F, Na, S, Fe,Ni, and Cu in different kinds of chemical environments.

Target materials used for this purpose wereas follows: (I) for transitions between inner shells such as Fe KG', S KG' and Al KG'; Fe, G'-Fe 2 03 'CU 2 S, Na 2 SO 4' Al and AIF 3' and (2) for transitions between inner shell and valence band such as (a)F KG', Na KG', Al K{3, S K{3, Fe K{3, and Ni K{3; NaF, Na 3 AIF 6 ' AIF 3' (CF 2)n' NaSCN, Na 2 S2 06' CU 2 S,°

Na 2 SO 4' AI, Fe, G'- Fe 2 3 , Ni, and NiO, and (b) Fe LG',{3, Ni LG',{3 and Cu LG',{3; Fe, FeO, G'-Fe
2
Ni, NiO, Cu, Cu 2 0, and CuO.

°

3

,

The centroid energies and intensities of X-ray lines in F KG' and Na KG' spectra were determinedby least-square fitting of the multiple Gaussian curves to the overlappi ng peaks.
S KG' and K{3 spectra obtained from CU 2 Sand Na 2 S04 are shown in Fig. 1.
spectra emitted from S atom with mK and nL vacancies at the initial state.

KmL nG' denotes KG'

Same is true for KL nG'.

Q)

>
-+-'

o

OJ

0::

Fig. 1.

S KG' and K{3 spectra fromNa2 S04 and CU2 S induced by 84
Mey4+.

2.3

2.4
Energy

2.5
(keV)

2.6

X-rays were measured withthe gas flow proportional counter
through EDDT (020).

100

The spectra in KL nQ region are , both in intensities and centroid energies , quite similar to each other.
On the other hand , somewhat different intensity distributions can be seen in K{3 region. If
components of K2 LnQ named hypersattelite could be subtracted from this region, difference in KL n{3spectra in these two compounds would readily be noticeable.

This is because the number of electronsin 2p level which are responsible for KmL nQ emission is the same but that in 3p responsible for theemission of KL n{3 is different in these compounds.
Marked difference in LQ1,2 and L{31 band spectra modified with the high energy satellites fromthe metals and the oxides can also be seen in Fig.2(a) - (c). No appreciable difference in KQ and ~spectra between Fe and Q-Fe 2
our experimental condition.

° and also between Ni and NiO could, however, be observed under
3

,

(0 )

(C)N J(b) -g..... -1

E3

..51

-1
..0
0

?I

1=1

-1

-I

-1

I

-1

jl

I

1

<::l..

>--

-+--'
(f)

c

ill
-+-'

c

ill

>

-+--'

0
ill

cr

A

.)\r

..0
0

1

-1

1=1

Fe,O,
~,~~

) A

FeO

~\1fl

CU 20

Cu

8"1 0 860 880 900

Ener gy

1000

( eV)

Fig. 2(a)-(c).
LQl'2 and L{31 band spectra of Fe, Ni, and Cu
taken from Fe , FeO, and Fe2 0 3 (a), Ni and NiO(b) , and Cu andCu 2 0(c) which were induced by 84 MeV N4 +. RAP(OOl) andthe proportional counter were here employed.

The centroid energies and the relative intensities of F KQ and Na KQ spectra are summarized inTables 1 and 2. The bonding effect is clearly reflected in F KL nQ spectra but is indistinct in Na KQ.
Study to get the relationship between the intensity distributions of the satellite lines and ioniccharacters of the compounds used is under way.

101

Table 1.

Centroid energies, full width at half maxima (FWH) and relative intensities of F Kex spectra
induced by 84 MeV N 4 +, 72 MeV C4 +, 24 MeV He 2+ and 6 MeV H+.

Target2+

H+

Energy FWHM I

Energy FWHM
(eV)
(eV)

Energy FWHM I

684.8

3.4

85

680.1

Na3AlF6

684.8

3.7

70

A1F3
teflon

684.6
683.8

aF

684.4

3.8
3.8
3.4

63
44
57

679.6
679.7

3.7
4.0

53
54

679.6
679.8

4.0

32

680.0

3.2

3
4

7

r
r
r

aF

He

Kex(l) *(eV)

Na3A1F6
AlF3
teflon

C4 +

KLex

(eV)

aF

N4 +

KL 2exNa3AIF6
A1F3
teflonr~

Na3 A IF6
A1F3
teflon

684.6
684.4
684.3
684.5
684.4
683.6

7

684.1
684.1

3
4

683.5

4

Kex(2) *Energy FWHM
(eV)
(eV)

(eV)

(eV)

2.5 149

676.3

2.3

100

673.8

3.6

17

679.9

2.8 120676.4

2.6 100

674.1

4.0

31

680.1

2.9
2.9

676.9
676.6

2.8

100
100

673.9

3.5

36

674.1

3.5

38

675.9

2.0 100

673.8

3.0

23

676.2
676.6

2.6
2.7

100
100

673.9
673.8

3.6
3.6

676.6

2.6

100

673.7

3.6

35
46
34
35
50
67

58
2.6 145
2.6

94
80
48

2.8

680 .0

2.7

10
14

679.9
680.1

2.3
2.8

6

679.5
679.9

9
II

679.8
680.1

2.4
2.4
2.4

679.6

89

60
37
33
30
48
38
27

2.2
3.0

31

2.5

676 .1

2.1

100

674.1

676.3
676.7

2.8
2.9

100
100

673.8
673.7

3.2
4 .2
4.1

676.6
675.9
676.3
676 .8
676.8

2.4

100
2.0 100
2.5 lOa
2.6 100
2.3 100

673.7

5.1

75

674.3
673.8
673.8
673.8

5.0
3.2

35
39
54
43

3.4
3.4

* Ka spectrum is splitted into two components , Ka(l) and Ka(2) , caused by formation of molecular orbitals.
Table 2. Centroid energies, full width at half maxima (FWH) and relative intensities of Na Kex spectra
induced by 84 MeV N4 +.
KL4 a\Energy FWHM I
(eV)

(eV)

KL3 a

KL 2a

KLa

Ka

Energy FWHM

Energy FWHM

Energy FWHM

Energy FWHM I

(eV)

(eV)

(eV)

(eV)

I

(eV)

(eV)

(eV)

(eV)

NaF

1076.1 6.0

61067.2 5.9

531057.5 5.6

1211049.5 4.5

1161042.0 5.2

100

Na3AIF6

1076.3 5.8

71067.0 5.9

521057.5 5.6

1111049.5 4.4

1161042.2 5.2

100

Na2S041075.9 5.8

71067.0 5.7

521057.5 5.6

1171049.5 4.6

1221042.0 4.9

100

NaSCN

1076.6 5.9

71067.0 5.9

521057.4 5.6

1281049.5 4.6

114 1042.0 5.2

100

Na2 S2 0 61076.l 5.1

111067.0 5.5

531057.7 5.6

1211049.5 4.6

130 1042.2 5.l

100

Reference(1)

Y. Awaya, T. Tendow, H. Kumagai, M. Katou, and T. Hamada: IPCR Cyclotron Progr. Rep.,~
79 (1975).

102

7-6.

Lattice Location of Ni Atoms Implanted

into AIE. Yagi, A. Koyama, H. Sakairi, and R. R. Hasiguti

The problem about interstitial sites in f.c.c. metals is fundamental one in lattice defects. In
the present work, the location of nickel atoms implanted into aluminum was investig~ted by meansof backscattering. It is expected that the implanted nickel atoms occupy the interstitial sites
because nickel has only small solubility in aluminum. If it is the case, the information on theinterstitial site will be obtained from the determination of nickel atom location.
Aluminum single crystals were electropolished and annealed in vacuum at 550°C for 7 h.
The 180 ke V Ni implantation was carried out at room temperature with a dose of 2 X 10 16
ions/cm 2 • Channeling effects were investigated with respect to <100> and <110> axes by meansof backscattering with 4.8 - 5.8 MeV protons accelerated by the cyclotron. The beam wascollimated to have divergence less than 0.019°. The irradiated area was 0.2 mm 2 , and the beam
current was about 0.5 nA. The backscattered protons were measured by a surface-barrier solidstate detector (FWHM~15 keV) placed at a scattering angle of about 150°. The scattered cone
seen by the detector was about 9°wide. The target specimen was maintained at room temperatureduring the channeling experiment.
In order to investigate the location of the implanted nickel atoms an angular scan was
performed through <100> and <110> axes. Figure 1 (a) shows. the normalized backscattering
yields X from nickel and aluminum atoms as a function of the angle () between the incident beam
direction and the <100> axial direction. Figure 1 (b) shows the results for the <110> axis.
The backscattering yield from nickel atoms shows a dip with minimum yield Xmin of about

1.5< 100 >

I

~

~ 0.5

° Al
• Ni

(0 1

o -1.0

o

o

( bl

1.0

Ang l e (degree s 1

Normalized backscattering yield from Ni and Al atoms as a
Fig. 1.
function of the angle () between the incident beam direction and the<100> axial direction (a), and the <110> axial direction (b).

103

0.62 for the <100> axis, while a double peak for the <110> axis. The <100> Ni-dip has thesame half-width at half-minimum as that of the AI-dip. The double peak results from the fl uxpeaking effect and indicates that nickel atoms are located at interstitial sites. These experimental
results suggest that the nickel atom occupies the interstitial site displaced from the normal latticesite in an aluminum crystal by the amount of about one fourth of the lattice constant in the<100> direction. In the <110> angular scan, an AI-dip has also fine structure consisting of asmall double peak at its center. As in the case of nickel, this result suggests the presence ofaluminum atoms displaced from normal lattice sites by nearly the same amount in the <100>direction. The interstitial nickel atoms displace aluminum atoms at normal lattice sites into
interstitial sites.

104

7-7.

Damage Production Rate in Ti0 2 as Measured

by Channeling Method

E. Vagi, A. Koyama , H. Sakairi, and R. R. Hasiguti

The damage production rate of interstitials in Ti0 2 was investigated by channeling method.!)
Our previous channeling experiments 2 ) indicated that in a nonstoichiometric Ti0 2 -x crystal main
defects are Ti interstitials and they are located along the [001] mid-channel axis. In the [00 I]
angular scan of backscattered protons from Ti ions :, a small peak due to Ti interstitials was observedat the center of the Ti-dip.
In the present work ) experimental details are the same as those described in the previous
paper. 2) The channeling experiment was carried out with 5.77 Me V protons. The effect ofradiation damage by incident protons was investigated. At large irradiation dose, the stoichiometriccrystal was colored slightly blue and the increase was observed in both normalized backscattering
yield XO from Ti ions and that from 0 ions when measured for incidence parallel to the [001]axis. Thus the dose dependence of such increase 6 Xo was measured by the following procedure.
After the measurements of Xo , the irradiation was carried out in the random direction with respect
to the [00 I] axis. This process was repeated successively. Figure 1 shows the increases .6Xoo0obtained for scattering from Ii ions and from 0 ions at depths between 4000A and 7000A. The
increasing rate of 6 X o is 1.8 X 10 - 19 /(partic1es/cm 2 ) for Ti-dip and 7.9 X 10 - 19 /(partic1es/cm 2 )for O·dip. These increases of Xo are attributed to the production of Frenkel pairs of Ti ions andthat of 0 ions , respecti vely.
As previously reported ~ 2) the normalized beam flux density amounts to about 4.2 at thecenter of the [00 I] channel as a result of flux -·peaking effect. Using this value, the damage
production rate of Frenkel pairs for Ti ions can be estimated to be about 4.4 X 10- 20 /(partic1es/
0.04 , - - - - - - - - - - - - - - . . . ,o
0.03~ 0.02DOS E ( cm- Z )(X 10 1S)

Dose dependence of the irradiation-induced
Fig. 1.
increase of normalized scattering yield Xo from Ti ions and0 ions measured for incidence parallel to the [001] axis.

105

cm 2 ) in atomic fraction. This is of the same order of magnitude as that obtained in eu for
irradiation with 4.9 MeV protons at liquid-helium temperature by electrical resistivity measurement
ji.e. """'I X 10-2o/(partic1es/cm 2 )f. 3 ) For 0 ions the damage rate cannot be estimated exactly
since the location of interstitial oxygen ion is unknown. But its lowest limit is estimated to be
1.9 X 10 -19 /(partic1es/cm 2 ) , because the normalized beam flux density can be considered to beless than 4.2 at any sites other than the center of a [001] axial channel.

References
1)
2)
3)

E. Yagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: Radiation Effects in Semiconductors 1976,
Inst. Phys., London, p. 485 (1977).
E. Yagi, A. Koyama , H. Sakairi, and R. R. Hasiguti: J. Phys. Soc. Japan, 42, 939 (1977).
H. Sakairi, E. Yagi , A. Koyama, T. Karasawa, and R. R. Hasiguti: ibid., 43, 999 (1977) .

106

7-8.

Perturbed Angular Correlation of Y-Rays
Emitted from lllCd in NiFe 2 0 4

H. Sekizawa, K. Asai, T. Okada,N. Sakai, N. Shiotani, and E. Vagi

It is well known that large hyperfine magnetic fields are observed at the 'nuclei of
non-magnetic ions in a magnetic material below its magnetic transition temperature. Since the originof the hyperfine magnetic fields at the nuclei is the electron-spin polarization induced by theneighboring magnetic ions, the investigation of the hyperfine magnetic fields at the nuclei of
non-magnetic ions supplies important information about the cation=cation magnetic interactions.
In a previous report we presented experimental data on the time-differential perturbed angularcorrelation (PAC) of 'Y ··rays emitted from 111 Cd in NiFe 2 0 4 at room temperature .1 ) According
to our results , the hyperfine magnetic field at 111 Cd is distributed around 93 kOe at room
temperature. In this report we present similar experimental data at 11 OK and discuss the originof the distribution of the hyperfine magnetic field.
The procedure of sample preparation and the setup of the counter and magnet system were
the same as that described in the previous report. The sample was packed in an aluminum tube.
The normalized anisotropy of the coincidence counting rates R(t) is shown in Fig. 1. Definitionof R(t) is as follows :
x
x

0 .10

<

x

T =300K

x

~\
x

80

o~

0.05
+-'

0

8

x

~

~

0::

0.00

t

t =O

-0.05
100

50

150

200

Channel
x

~x

0.05

0::

T= IIOKx

0.00

Fig. 1.

of the coincidence counting rates R(t)

t=O

-0.05

50

The normalized anisotropy

at 300K and at 11 OK. The
experimental data are shown by the100

150
Channel200

250

symbol X, and the computer fits off(H) (see the text) by O.

107

0

R(t) =

W(90° , t) - W( 180 , t),0W(90° , t) + W( 180 , t)where W(B , t) denotes the coincident counts, B the angle between the two cascade 'Y-rays, t thetime interval between these 'Y-rays.

The physical meaning of R(t) is as follows: R(t) oscillateswith the frequency twice the Larmor frequency of the hyperfine magnetic field perpendicular tothe plane defined by the two cascade 'Y-rays.

It is shown in Fig. 1 that the amplitude of R(t)decreases as the time interval increases. The decrease of the amplitude can be ascribed to the
distribution of the hyperfine magnetic field at the 111 Cd nuclei. If we assume a Gaussian
distribution of the hyperfine magnetic field f(H) ex exp [- (H - HO)2 /( yf2D.H)2 ] , then , Ho = 96
kOe and 6H = 17 kOe are obtained from the computer fits of 11 OK spectrum. These values arenearly the same as those at room temperature except that Ho at 11 OK is a little larger than thatat room temperature. Figure 2 shows the distribution of the hyperfine magnetic field at III Cd(our results) and 115 In (Ref. 3).

Q)

.-t
til

u

CJl

;:...
.u

Fig. 2.

.~CJl
Cdiamagnetic ions on A site in NiFe2 0 4 .

Q)

.u
C
H

The hyperfine field of~~~_ _~_ _~~~~~~~

Hyp er f ine ma gn e t ic fi e ld

The data on In 3 + are the NMR data at
4.2K quoted from Ref. 2 and Ref. 3.

We are interested in the origin of the distribution of precession frequencies 6 W. In 3+ ionsoccupy preferentially tetragonal (A) sites ("'80%) according to the magnetic measurement. 3)
In 3 + ion at A site is surrounded by twelve B site ions. Each B site is considered to be occupied
at random by Fe 3 + or NiH ion . The hyperfine magnetic field of non-magnetic ion at A site iscontributed mainly by the neighboring magnetic ions at B sites. 2 ), 3) The contribution of Fe 3+
ion and that of NiH ion are considered to be different.

The fluctuation of the number of the3neighboring Fe + and NiH ions on the B sites will produce the distribution of the hyperfine field
at 111 Cd.

This is an important mechanism to account for the distribution of precesssion
frequencies. If we assume that situations are not much different between In 3 + and Cd H , simple

considerations lead to an expected apparent width 6H of 24 kOe for Cd 2+ , which is a little smaller
than the experimental value of 40 kOe.
In the above discussion we considered only the distribution of magnetic fields. It is reported
that a quadrupole splitting is observed in the Mossbauer spectra of S7 Fe nucleus at A site in
NiFe204 in the paramagnetic region. Its value is 0.37 mm/sec. If we assume that electric field
gradient of the same magnitude acts on 1 1 1 Cd nucleus, then , the quadrupole frequency will be
6 X 10 7 rad/sec.

This quadrupole effect in polycrystalline sample can give rise to an apparent

width of the hyperfine magnetic field comparable to the observed one.

108

Further studies on the effect of the electric quadrupole field to the PAC spectra are in
progress. It seems to be necessary to investigate the PAC spectra in the paramagmetic temperature
range.

References
1)

H. Sekizawa, K. Asai, T . Okada, N. Shiotani, E. Yagi, and S. Ambe: IPCR Cyclotron Progr.

Rep. , 10, 99 (1976).
2)
3)
4)

Y. Miyahara and S. !ida: J. Phys. Soc. Japan, 32 , 858 (1972).
Y. Miyahara and S. !ida: ibid. , 37 , 1248 (1974).
V. A. Gordienko , V. I. Niko1aer, and S. S. Yakimov: Sov. Phys. -JETP, 39, 551 (1974).

109

7-9.

On the Use of

48ySour cefor theStudy of Positron Annihilation

K. Hinode, S. Tanigawa, M. Doyama, * and N. Shiotani

For the positron lifetime measurement, the birth signals of positrons are required, so that
not all the (3+- decay nuclide can be used as a positron source for the lifetime measurement.
Fortunately, the disintegration scheme of 4 S Venables one to perform the lifetime measurementin addition to the ,,(-"y angular correlation and Doppler broadening measurements. As the birthsignal, one of the two "(-rays with energies of 1.31 and 0.98 MeV emitted from excited states of
48 Ti can be used. (Fig. 1.)
The 3He bombardment of 0.1 Coulomb (E 3He = 30 MeV) created 48 V of about 10 J-LCi in a Ti foilwith the thickness of 1 J-Lm through the nuclear reaction Ti He, pxn)48 V. (Fig. 2.)eThis source is superior to the usual 22 NaCI source in various points.
annihilation in the source foil is negligible, or less than a few percent.

1) The fraction of the

Positrons of higher energy(Emax = 0.696 MeV) are emitted by 48 V than by 22 Na (Emax = 0.545 MeV) and source wrapping
materials are not required because of the imbedded form of the sources in Ti foil. 2) Long
lifetime components due to the annihilation of positrons in the source itself (e.g. NaCl) and in thesource foil materials do not appear in the lifetime spectrum. This enables us to obtain morereliable data for long lifetime components. For example, Figure 3 shows Ii fetime spectra forneutron-irradiated Mo measured with a ,48 V source in Ti foil and with a 22 NaCI source ofequivalent intensity wrapped with 3.5 J1m Mylar. 3) This source can be used under manymeasuring conditions (e.g. at low temperature or high temperature,1) in a vacuum 1) or for liquid
metals, etc.)
However, almost simultaneously with the positron emission, a pair of "(-rays with energies of
1.31 and 0.98 MeV are emitted to nearly isotropic directions. 2 ) When one of these "(-rays enters
3He__-----'I n I~~---~ Pb Slit
46v 16.1 d4°---r--Ti

Foil (!}lm)

Al

SpacerVacuumr;=:=!~~~~~~±~:::;l--Al

Stopper

SPECIMEN/START
DETECTOR

46Ti

Cooling

OS1..lID
STOP
DETECTOR

Principle of lifetime measurement
Fig. 1.
using 48 V source.

*

Water

Schematic drawing of the target
Fig. 2.
for the production of 48 V in Ti foil.

Department of Metallurgy and Materials Science, Faculty of Engineering, The University of Tokyo.

110

10 5' , - - - - -- -- - - -- - - -- -------;
Neutron - irrad. Mo:.-....

: '..•

48V

Sou rce

".'

o
U

;

. .......

'.

.........

22Nu Source.......
~ ..'": . ::"• .• ••.•• . .::.! ••.

o

50

100

Ch ann el number ( lch = 24 psec I

150

Fig. 3.
Typical lifetime spectra ofneutron-irradiated Mo measured with 48V
source in 1,um Ti foil and 22NaCI source
wrapped with 3.5J.Lm Mylar.

into the start detector and the other into stop detector, a prompt component may be added tothe original lifetime spectrum. This may degrade the spectra. The separation of this prompt
component is possible in principle. Such an analysis is now in progress.

References
1)

S. Tanigawa, K. Hinode, R. Nagai, M. Doyama, and N. Shiotani: IPCR Cyclotron Progr. Rep.,lL 111 (1977).
2)

P. L. Roggenkamp, C. H. Pruett, and R. G. Wilkinson: Phys. Rev., 88, 1262 (1952).

111

7-10.

Thermal Equilibrium Measurements of Positron Annihilation
Line Shapes in KCI, KBr, and G e

S. Tanigawa, K. Hinode, R. Nagai,
M. Doyama, * and N. Shiotani

Line shape measurements of spectra of positron annihilation radiations were carried out for
KCl, KBr and Ge to study the interaction of positrons with lattice vacanicies at thermal
equilibrium. The experimental set-up was similar to the previous one.1) The energy resolutionof Ge(Li) detector used was 1.45 keY at FWHM for 512 keY '}I-ray from 106 Ru. 48 V
produced in a 1 Mm thick Ti foil by 3 He bombardment was used as the positron source. Meritsof this source are described in a preceding report. 2 )Figures 1 and 2 show the temperature dependence of parameter H, counts of the central
portion of the annihilation line normalized to the total counts, for KCl and KBr as a function oftemperature. Both KCl and KBr show similar temperature dependence. In the low temperature
region (region 1) i.e. in the region below 270°C for KCI and below 160°C for KBr, H decreased
linearly with temperature. In the intermediate region (region II) i.e. 270°C - 480°C for KCl and
160°C - 450°C for KBr, the increase of H was found. In high temperature region (region III),
H again decreased. The increase of H in region II can be thought as the result of trappingof positrons by vacancies at thermal equilibrium. The slopes of H in regions I and III
are nearly the same. If it is assumed that H in region I represents Hp (H in perfect crystal sites)and H in region III represents Hv (H in vacant sites) and that they have the same negative
temperature dependence, one obtains Figs. 3 and 4 by the subtraction of Hp from the observed
value of H. In this way, the formation energy of the Schottky pair (the pair of neutral cation
and anion vacancies) was estimated to be 2.00 ± 0.1 eV for KCl and 1.84 ± 0.1 eV for KBr,
respectively, by the use of trapping model of positrons by lattice defects. 3 ) Although theinterpretation of the negative temperature dependence of Hp and Hv has not yet been clear, it
may be plausible that the lattice expansion effect and the temperature dependence of positronium
states 4 ) are involved.
0,440

KCl ( 48 V)

0.410

0,435

0.405

H

H

°
°

0.395

0.420
200

Fig. 1.

600

800

The temperature dependence of

H for KCl.
*

400
Temperature <-C)

200

400

600

Temperature (OC )Fig. 2.

The temperature dependence of

H for KBr.

Department of Metallurgy and Materials Science, Facul ty of Engineering, The University of Tokyo.

800

112

1 00 - - -:- - - - - - - - - - - - - - - - - - - - - -0- -"/-_0--n-<>--.,..--

o

~H

---.1

o

000

00

o

o
0
o
100 - - - - - - - - - - - - - - - - - - -0- -n::-------,.~0-'0L..l.....---1
00

50

~H

o

o

50

o

0

o
o

o 10---0-----0-- - - - - - - - - - - - - - - - - - - - - - - - - ______ _
200

400

600

800

200

400

Temperature COC )Fig. 3.
The plot of .6H (= H - Hp) vs.
temperature for KCl.

V)

600

sao

Temperature(OC)Fig. 4.
The plot of .6H (= H - Hp) vs.
temperature for KBf.

Germanium

104 -( 48 V source)

>-

:z:

=

f-

:oL

1[2 f-

8

~

f-

0
LLJ
f'...J

---'

100 ~

«

...

&

~

• T

• . . • f • •

•
• • f

• •

,

••

98
I

100

200

300

400

500

TEMPERATURE

Fig. 5.

600

700

800

900

1000

( ·C )The temperature dependence of the peak counts

N(O) for Ge.

In Fig. 5, the peak counts N(O) of the annihilation spectrum in Ge is plotted as a functionof temperature. N(O) shows a linear dependence on temperature, only slightly increasing withtemperature , and no vacancy effect can be found. In Ge, the formation energy E¥ and migrationenergy E~ of a vacancy have been expected to be about 1.9 ey5) and about 0.15 eY,6)
respectively. The present results can be interpreted in either of the two alternative ways: (i) theconcentration of vacancies cv is too low to be detected by the positron technique , or (ii) positrons
are not trapped by thermally created vacancies. The mobility of vacancies is expected to bevery high because of low E~. At the melting point a vacancy can migrate over 5 X 10 3 lattice
points during the lifetime of positrons. Therefore, even if Cv is small the number of chances fora positron to meet with vacancies is much enhanced. So, the case (ii) may be more probable.
In Ga, similar results were reported by Segers et al. 7) Due to the loosely packed crystal structureof Ge and Ga, it can be thought that vacancies do not provide strong attractive field for positrons.

113

References
1)
2)

5)

R. Nagai, S. Tanigawa, and M. Doyama: Scripta Met., 10, 529 (1976).
K. Hinode, S. Tanigawa, M. Doyama, and N. Shiotani: IPCR Cyclotron Progr. Rep., S 109(1977).
K. Hinode, S. Tanigawa, and M. Doyama: J. Phys. Soc. Japan, 41, 2037 (1976).
T. Hyodo and Y. Takakusa: Abstract F 2 "The 4th Intern. Conf. Positron Annihilation",
Helsingor, Denmark (1976).
A. Hiraki: J. Phys. Soc. Japan, 21, 34 (1966).

6)

G. D. Watkins: Lattice Defects in Semiconductors (The Institute of Physics, London and

7)

Bristol), p. 1 (1975).
D. Segers, C. Dauwe, M. Dorikens, and L. Dorikens-Vanpraet: Appl. Phys., 10, 121 (1976).

3)
4)

114

7-11.

Effects of Irradiation Temperature, Prestrain, andHelium Concentration on

the Helium Embrittlementof Type 316 Stain less Stee I

H. Shinno, H. Shiraishi, R. Watanabe~ H. Kamitsubo,
I. Kohno, and T. Shikata
It is known that metals or alloys irradiated by fast neutrons show reduction of ductility at high temperature,
which is thought to be due to helium produced by nuclear reactions in the materials. This effect is called "helium
embrittlement", the study of which is urgently needed since it is one of the important restrictive factors indesigning controlled thermonuclear reactors. The aim of this study is to obtain information on the mechanism of
the helium embrittlement, and to utilize it for developing new metals and alloys which are highly resistant toneutron irradiation embrittlement.
The helium injection by the cyclotron was conducted, with the variation of the three following parameterswhich possibly affect the helium embrittlement; irradiation temperature, degree of cold-working, and helium
concentration. The material used in this experiment was Type 316 stainless steel commercially obtained. It wascold-rolled and annealed alternately until it became 0.2 mm thick. From this thin plate, tensile test specimens wereprepared by punching. Then, they were annealed for 30 min, at I050°C in vacuum (solution-treatment). After
that, some of the specimens were pre-elongated 5% using a tensile testing machine. Details of the helium injection
procedure were described elsewhere}) The concentration of helium injected into the specimens was 3 to 10 atomic
ppm, and the irradiation was conducted at low (room temperature - 300°C) and high (750-900°C) temperature.
The irradiated specimens were tensile tested by an Instron type testing machine with the strain rate of 5 X 10- 4
sec-l. Specimens were tested at room temperature in air or at 750°C in vacuum of 2 X IO-6 torr . The fractured
parts were cut from the tensile test specimens. Then, some pieces were annealed for 24 h at 1 100°C in vacuum.
These specimens were electrolytically jet polished and observed by a transmission electron microscope (abbreviatedTEM hereafter).
Table 1 shows the results of the tensile tests. Each experimental value shows the average of the two tests.
The results of the tests at room temperature show no effect of the helium injection, but those at 750°C show the
reduction of ductility due to the helium injection in the case of the solution-treated specimens. The effects ofvarying the above three parameters were summarized as follows: 1) No effect of the irradiation temperature wasfound as far as this experiment i.s concerned. 2) Effect of the cold-working was remarkable. The specimens
strained 5% before the helium injection did not show the reduction of ductility even at the test temperature
Table 1.

Solutiontreated

5% prestrained*

Tensile test results on helium injected and control
samples of Type 316 stainless steel at 750°C.

HeliumIrrad.

Yield

Ultimate

Uniform

Total

conc.

temp.

stresstensilestresse1ong.

e1ong.

(ppm)

(OC)

(kg/mm 2 ) (kg/mm 2 )

(%)

(%)

7.47
7.96
8.65
8.76
12.9
12.6
12.8
12.1

17.6
18.6
19.2
17.2

25.4
26.2
23.4
15.9

56.0
33.3
32.2
18.5

18.6
19.3
19.7
18.8

23.3
38.1
22.3
22.4

52.5
48.0
50.4
51.5

!j
!j

Lt. - 300
750-900
750-900
r.t. -300
750-900
750-900

National Research Institute for Metals.

115

of 750°C, though the solution-treated specimens showed notable helium embrittlement at the same testing
condition.
3) As the helium concentration increased, the reduction of the ductility increased
monotonically in the case of the solution-treated specimens, but the 5% prestrained specimens didn't show
helium embrittlement up to the helium concentration of 10 ppm, as shown in Fig. 1.

SUS 31670

Irrad. temp. 800°C
Test temp. 750°C
E = 5 X 10- 4 sec-1- - Solution-treated--- - 5% prestrained

c
c .9

o

:;::;

ru01

rn c
01 0

oC -QJ

E

Q;-rn ....(;

o ·c
I-

=:J

10
o ~--~--~--~---- ---~--~

0246
8
Heli um concentrat ion(atomic pp m)

10

Fig. 1.

Total and uniform elongations as functionsof helium concentration for Type 316 stainless steel.

An observation by the TEM showed that no helium bubbles appear in the tensile tested specimens
In those samples helium probably exist as small bubbles which
unless the heat treatment is carried out.

°
are smaller than the resolution limit of the TEM (50 A).
The precipitated carbides were not found inthese specimens.
Helium bubbles were found in the specimens annealed for 24 h at 1100°C, in thesolution-treated specimens as well as in the specimens 5% prestrained before the helium injection.
Prestraining of 5% was very effective to improve the resistivity of Type 316 stainless steel to thehelium embrittlement.

In other words, dislocations were effective for the prevention of the helium

The interaction between dislocations and helium bubbles is well known. 2 )embrittlement.

Dislocations

probably work as trapping sites of helium bubbles, and prevent the accumulation of helium to the grainboundaries.

T~etreated specimens.

reduction of ductility increased with the helium concentration in the case of solutionThe results are consistent with the previous data .3 )The tensile properties of thesolution-treated specimens irradiated at different temperatures were very similar, and the TEM observationshows no microstructural differences.

These results suggest that injected helium didn't escape from thespecimens during the irradiation at temperatures as high as 900°C .
The effects of irradiation temperature, prestrain, and helium concentration on the helium embrittlementof Type 316 stainless steel are concluded as follows: 1) there is no effect of irradiation temperature, 2) 5% prestrained
Type 316 stainless steel does not embrittle even in 10 ppm helium level, and 3) the ductility of solution-treated Type316 stainless steel decreased as the helium concentration increased.

References
1)
2)
3)

R. Watanabe, H. Shiraishi , H. Shinno, H. Kamitsubo, I. Kohno, and T. Shikara : IPCR Cyclotron
Progr. Rep. , ~ 104 (1976) .
W. Been~: Scripta Metallurgica, ~ 999 (1975) .
K. Matsumoto, T . Kataoka, M. Terasawa , M. Shimada, S. Nakahigashi, H. Sakairi, and E. Vagi :J. Nucl. Materials , 67 , 97 (1977) .

116

8. RADIOCHEMISTRY AND NUCLEAR CHEMISTRY

8-1.

Charged Partie Ie Activation Analysis for
Surface Oxygen

T. Nozaki and M. Iwamoto

Charged particle activation analysis has begun to be applied to the study of surface oxygenon high purity substances. The apparatus we use is shown in Fig. 1. The sample in the fonn of
two plates in intimate contact with each other is placed on the water-cooled target holder and set
in the bombardment vessel which can be evacuated by oil-free pumps. The reactions of
16
0 (p,~) 13N and 160eHe, p) 18 F have been adopted for radioactivation, and the incident particle
energy is so adjusted as to give the maximum cross section for the given reaction at the insidesurfaces of the sample plates. After the bombardment, the inside surfaces of appropriate
thickness are removed from the plates and their 13 N or 18 F content is measured.
T rget holder
SampleD~Beam
Cyclotron

Beam window foi I

Fig. 1.

Apparatus for radioactivation.

This method possesses the following advantages over other types of activation analysis andelectron or X-ray spectrometries for surface analysi.s: (1) freedom from the nuclear recoil effect;(2) relative insensitiveness to the ambient atmosphere, and (3) capability of the determination of
impurities in the surface layer of some thickness, such as an epitaxial layer.

Only superficial

oxygen in high vacuum can be measured by other methods, though infonnation under usual
atmospheric condition would often be more important. In the present method, it will be possible
to study on the relationship between surface oxygen quantity and oxygen partial pressure ofambient atmosphere.
Our study is still in its beginning stage, and we have so far analysed only high-purity silicon
after two different surface treatments. For the selection of the incident particle energy, theexcitation curve of the activation reaction should be known precisely. The excitation function
for the 160(p , ~)13N reaction was measured by the use of stacked Mylar foils. The result isshown in Fig. 2.

As for the 16

Oe He, p )18 F reaction, reliable excitation function is known.1)

High-purity silicon rod (2 - 3 cm, diameter) after zone melting in vacuum was cut into disks(200 or 500 j.Lm thickness). This kind of silicon is known to contain less than 100 ppb of bulk

117

60
..c

E

_~ 40
<..>
Q)

V>
V>

e20

0

0

4

6

8

10
Energy

12

14

16

(MeV)

Fig. 2.
Excitation function for the160(p, a)13N reaction.

oxygen. 2 )Thus, its surface layer with 5 mg/cm 2 thickness contains less than 0.5 ng of bulk

oxygen.

The wafer was treated with a hot solution of NaOH (10%) or cold mixture of HF and

HN0 3 (1 :3), washed in pure water with supersonic waves, and dried.

Two of the wafers were

set in the bombardment vessel and bombarded with charged particles (2 - 3 /lA, 10 min) after theevacuation of the vessel. The vacuum condition was monitored remotely during the bombardment;
it was usually 1- 2 X 10- 6 Torr throughout the bombardment, but sometimes degassing wasobserved at its beginning.
After the bombardment, a bar was stuck with wax on the outside surface of each wafer inorder to facilitate manual operation for the removal of the inside surface layer by mechanicalgrinding. The inside surface of about 5 mg/cm 2 thickness was then ground off on a glass platewith the aid of a small quantity of alumina powder and water. These powders were transferred
altogether into a polyethylene tube for activity measurement.

The annihilation radiation wasmeasured with a well-type scintillation crystal and a single channel analyser, and its decay
followed. The 13 N or 18 F component was always clearly identified in the decay curve. As
activation standard, a stack of three thin Mylar foils was bombarded with the incident particlesof the same energy as at the inside surface of the analytical sample and the inner foil of thethree foils was used.
The result of analysis for float-zone silicon is shown in Table 1.

It will be interesting tocompare results of the present method with those of the on-line activation analysis in which
protons from the 16 Oed, p)1 7 F reaction are measured.

We intend to analyse more variety ofsamples under different ambient atmosphere.
Table 1.
Surface treatment

Reactwn-16O(p,a)13N
160eHe, p) 18 FXaQuantity of surface oxygen (/lg/cm 2 ).

NaOH

e·

21

0.17
0.11
0.16
0.042

HF-HN03
0.18
0.15
0.098
0.13
0.14
0.030

118

References
1)

T. Nozaki, M. Iwamoto, and T. Ido: Intern. J. appl. Radiat. Isotopes, 25,393 (1974).

2)
3)

T. Nozaki, Y. Yatsurugi, and N. Akiyama: J. E1ectrochem. Soc., 117, 1566 (1970).
E. g., L. Gualia, G. Weber, D. David, J van Audenhove, and J. Pauwels: Eurisotop Rep.
ITE-90-E C/III/436/76-E (1976).

119

8-2.

Charge Spectra of 198Hgn+ Ions from the 198Au Decay

Y. Itoh, M. Aratani, and T. Nozaki

It is highly probable that charge spectra of recoil atoms from a thin surface layer of a solid
is affected sensitively by the surface state. We expected the usefulness of charge spectrometry
in surface science. We measured charge spectra of 198 Hgn+ from {3- decay of 198 Au in a thingold film evaporated on high puri ty silicon for different film thicknesses.

The effect of surface

oxide layer on the charge spectra was compared with that on ESCA spectra.
The silicon substrate was a mirror-polished wafer (13 mm X 9 mm X 350 J.Lm) with resistivity
larger than IOn cm and with <100> surface orientation. It was washed supersonically withacetone and etched in a 20% HF solution just before being installed in a vacuum evaporationchamber. Gold of 99.99% purity was evaporated onto the wafer from a connical basket heaterof tungsten under a vacuum of 1 X 10-6 Torr at a rate of about 0.2 nm sec-I. Gold films with
3.6 nm and 1.2 nm thicknesses were thus prepared. Their thicknesses were controlled by a
ULVAC DTM-200 type monitor and certified by ,),-ray spectrometry after neutron activation.
The 3.6 nm sample was irradiated under a neutron flux of 1.5 X 10 12 n cm- 2 sec- 1 for 12 h, andthe 1.2 nm sample under 3.5 X 1013 n cm- 2 sec- 1 for 11.5 h. Their 198Au activities at themass spectrometric measurements were 10 J.LCi and 83 J.LCi, respectively. The mass spectrometer
we used was described previously.1) A voltage of 5 kV was applied to the sample for accelerationof the primary ion. Vacuum during the measurement was kept at 1 X 10- 7 Torr.
Charge spectra of Hgn+ from the {3 - decay are clearly observed as are shown in Fig. 1 forthe two samples. For both samples HgS+ was the most abundant and for the 1.2 nm sample Hg+
was of higher ~ntensity than for the 3.6 nm sample. The difference of the charge spectra due tothe gold film thickness can be attributed to the presence of other atoms than gold on the film.
ESC A spectra of the two samples are shown in Fig. 2, which indicates the presence of more
o

200

;--

!!3.6nm",(1. 2 n m

~

o
o

-

E 150

r---

o

.;:

r---

E

r--_

Cl.
<J

-100
2o

-

I...

0'

c:

+J

~

o

50

-

<J

c:

.3

o

Fig. 1.

2345678
ChargeCharge spectra of Hg

2345678
Chargen+

for the two samples.

120

1.2n mret,..-IIIaI'\.,...---

.\;..

... •

:

....,.-~~-'""

3 .6 nm

let,

-

-

Bindin g energy...
: . lit.

Stand erd

.~:

.

--

\..

--J...:' .

41\......,.,.

Au4d

015

I

Cis

:

"'.,~,. Au4f~2 ~.:...,....~

~'

I

...

Au4f5k

....

Si2s
Au 4f
Si2 p

Fig. 3.

ESCA spectra of the gold
Fig. 2.
films evaporated on silicon.

Shift of binding energy for the gold film .

amount of SiO x on the 1.2 nm sample than on the 3.6 nm sample.

The Au4f peaks of the ESC A

spectra observed in detail are shown in Fig. 3 for the 1.2 nm sample .

These charge and ESCA

spectra suggest that the gold surface was covered with a SiO x film formed from surface oxygen
atoms and Si atoms having diffused through the gold film, and that metallic gold atoms are mixed
with gold atoms of higher binding energies. It is natural that the charge of Hgll+ is partly
neutralized in the SiO x film. The increase of SiO+ and decrease of Hg s+ after exposure of the
u

::t.

C"J
OJ

150

SiO+

E

e

'+-

~100

E 10

u

0..

.:::.
2

~

~ 50

CI'

c

5

.....C

c

:=l

o

:=l

U

0

U

c

.3

0

C

30

10

0

.........

04( Channel number)
(a)

(b)

Change of charge spectra of SiO'" andFig. 4.
Hg S + by air exposure.
(a) after exposure to air.
(b) after preservation under1 X 10-7 Torr.

4

5

5

( Charge)
( a)

( b)

Change of charge spectra of Hg4+
Fig. 5.
and Hgs+.
(a) after exposure to air.
(b) after preservation underI X 10.J] Torr.

121

sample to air are shown in Fig. 4 (a), and the decrease of SiO+ and increase of HgS+ after its
preservation under 1 X 10-7 Torr are shown in Fig. 4 (b). The increase of Hg4+ after air exposureis shown in Fig. 5 (a) and (b); this is attributed to the partial neutralization of Hg s+ into Hg4+ inthe oxide film. We also detected considerably high peaks which can be assigned to HgSiO~+ andHgSiO/+. 2 )These results indicate that charge spectrometry is applicable profitably to surface research incombination with other techniques, such as, ESCA, SEME, and AES.

References
1)
2)

Y. Kawana and M. Aratani: Inst. 1. Mass Spectrom. Ion Phys., 10,493 (1972).
D. G. Engle: 1. Opt. Soc. Am., ~ 599 (1925).

122

9.

RADIATION CHEMISTRY AND RADIATION BIOLOGY

9-1.

Emission Spectra of a

KBr Single Crystal Irradiatedwith Heavy Ions at 4.2 K. Time-Dependent Spectra

K. Kimura and M. Imamura

Emission and absorption spectra of a KBr single crystal irradiated with heavy ions have" beenfound to differ substantially from those irradiated with X- or ')'-rays at 4.2 K; the outlines ofthese results were reported in a previous report. 1 )One of the significant results was that an intensity ratio of the 0- to 1f-emission increases withincreasing LET: 2.1 for X-rays, 6-7 for He-ions, and 10-12 for C-ions. This year, extensive studies
were made on this problem by using pulsed heavy-ion beams and stationary beams as well.
For pulse irradiation,24 MeV He-, 85 MeV C-, and 95 MeV N-ion beams were chopped topulses of about 40 J.1S in width and the time-dependent emission spectra of a KBr single crystal
were recorded at 4.2 K by using an optical multichannel analyzer COMA); set-up of themeasurements is shown in Fig. 1.

Fig. 1.

Experimental set-up.

Figure 2 shows the time-dependent 1f-emission spectra observed for a KBr single crystal
irradiated with 85 MeV C-ions at 4.2 K. The half-life of the emission is 0.2 ms, which is a little
longer than 0.1 ms obtained by Pooley and Runciman 2) using electron pulses.
The intensity ratios of 0- to rr-emission, la/I1f' are plotted as a function of absorbed dose of
He-, C-, and N-ios in Fig. 3. Since the emission intensities decrease with increasing dose, thisresult indicates that the a-emission intensities for heavy-ion irradiated crystals are depressed to agreater extent than are the rr-emission intensities at a dose larger than 2 J.1C.
From these result, the increased values of la/l1f in heavy-ion irradiations may presumably be

123

o sec

500

550

Fig. 2.
Time-dependent spectra of n-emissionof a KBr single crystal irradiated with 85-MeV
C-ions at 4.2 K.

600

Almm

N ion

15

He :. .:.io:.:. . n_ _

5

x,r
O~

10 2

__- L_ _~~~~~~_ _~_ _~-L~~~~_ _~10 3

Dose/nC

10 4

Fig. 3.

Dose dependence of la/In.

ascribed, not to an increase in nonradiative decay of the n-exciton, but to an increase in radiative
decay of the a-exciton or to higher initial concentrati on of the a-exciton than that of the nexciton.

References
1)

2)

K. Kimura and M. Imamura: IPCR Cyclotron Progr. Rep. , !.2.z. 112 (1976).
D. Pooley and W. A. Runciman: J. Phys., C3, 1815 (1970) .

124

9-2.

Yields of Trapped Electron Produced

by Heavy-Ion

Irradiation in Ethanol G lass at 77 K

A. Kira, M. Matsui, and M. Imamura

Glassy ethanol at 77 K was subjected to heavy-ion irradiation.

Electrons which escapegeminate recombination are trapped in the glass and exhibit a characteristic absorption band in thevisible region as shown in Fig. 1.
A comparative study has been made on the yields of trapped electrons produced byirradiation of three different heavy lons, He-, C-, and N-ions whose incident energies were 18,
58, and 60 MeV, respectively. Ethanol was frozen on a Suprasil quartz plate attached to acopper plate cooled by liquid nitrogen.

Optical densities of irradiated glasses were measured ona Cary 14 RI spectrophotometer.
Figure 1 shows the absorption spectrum for ethanol glass irradiated with C-ions.

The

absorption band does not precisely coincide with that for ,),-irradiated ethanol glass at 77 K,
unless the 'Y-irradiated glass was slightly wanned before measuring spectrum, as shown Fig. 1.
This spectral shift, which was also observed for He- and N-ion irradiated glasses, may suggest
a temperature rise along heavy-ion tracks in glasses. No absorption band assignable to dielectrons
was observed; they might be expected to form in densely ionized regions.
In Fig. 2, optical densities of trapped electrons at 525 nm divided by the range of a heavyion are plotted against absorbed dose. The yields of trapped electron~ are not linear with dose.
Similar dose dependence of the yield has also been observed for the ,),-irradiated glass and regarded
as being due to electron capture by free radicals whose concentration increases with increasing
dose.
3

1. 0

E
E

"o

o
E

o

o

o
"-

g 0,5

0 L---~4700~--~5~0=0-----r,60~0~--~70~0~--~800
Wavelength / nm

Absorption spectra of trappedelectrons in ethanol glasses irradiated with

Fig. 2.
Trapped-electron yields (OD 525
dividedby the range of heavy ion) as a function

C-ion (solid curve); irradiated with ')'- raysof dose: D:., He; 0, C; D, N. The curves
represent Eqn. 1 by using the values

at 77 K (broken curve) and after
subsequent warming (dotted curve).

for G e and aG R listed in Table 1.

125

On the assumption of the electron capture by free radicals, the concentration of trappedelectrons, [et-] , at a dose of r is given by(1)

where G e and G R are G-values of trapped electrons and free radicals, respectively; a is an electroncapture constant of free radicals; NA is the Avogadro number.
In Fig. 2, curves are drawn to give best fit to the experimental values by taking the values forG e and aG R as listed in Table 1. The value of G e , which is the G-value for electrons escaping
geminate recombination and trapped in glasses, decreases with increasing LET of radiations.

If

the value of the capture constant, a , is assumed independent of radiation quality, G R increases
slightly with increasing LET.

Table 1.

The values for G e and aG R ·Radiation

Ge

N
C
He

1.1
1.1
1.7
3.6

'Y

aG

R

X 10-2 (M- 1 )

3.6
3.6
3.3
3.1

126

9-3.

Further Study of High LET Effect on Template/Primer
Activity of DNA

l!! situ

S. Kitayama, F. Yatagai, and A. Matsuyama

We are interested in the difference between radiochemical lesions in DNA caused by low andhigh LET radiations. The primer/template activity of DNA in bacterial cells can be assayed insitu by the preparation of their permeable cells which can incorporate deoxyribonucleoside
triphosphates into DNA.1) Irradiation at low LET range, e.g. ')'-ray irradiation, induces
mostly single-strand breakage in duplex DNA in vivo as well as in vitro.
- --

- --

About 30% of suchsingle-strand breaks has free 3 ' -OH terminal which are priming sites for DNA polymerase. Thisis one of the reason why ,),-ray irradiation stimulates DNA synthesis in permeable cells ofbacteria. 2 )-4) As indicated in the previous report ,S) it is very plausible that high LET irradiation
would induce lesions in both strands at or near the complementary strands of duplex DNA. Since
DNA which has damages in both strands proximate each other is a poor template/primer for DNA
polymerase, it would be expected that high LET irradiation caused a different effect on the DNA
synthesis in the permeable cells from that of low LET irradiation. However, no quantitative
difference in stimulatory effect between irradiations with ')'-rays and N-ions (2.9 MeV/amu)
was observed. S) This might be due to the irradiation by secondary electrons ejected from the trackcore whose range is '" 1 JIm in water and is comparable to the size of bacterial cells. The
instability of permeable cells held at room temperature during the irradiation with N-ions is also
one of the experimental difficulties. So, we have improved the irradiation apparatus to keep thetemperature near O°C by circulation of ice-water during irradiation. To avoid the formation of
dewdrops on the surface of the samples that cause serious change of LET, permeable cells werespread on a membrane filter and were held on a filter paper pad.

Moreover, the samples werecovered with a thin filter (polycarbonate filter, "'5 JIm in thickness) to eliminate the effect of
secondary electrons ejected from air layer in front of the samples. Dose-response curves of M.
radiodurans KD830 (Ade-, DNAase-)6) to ex-particles (4.78 MeV/amu) and 60Co ')'-rays areshown in Fig. 1. DNA synthetic activity in the permeable cells was compared after the irradiation
within shoulder doses of both high- and low-LET radiations. The relative synthetic rates of DNA
(a)

( b)

1000---0--0---.....

c:o......
u

~
'I-

Ol

c:

>
>

I....

:::>
(f)

10- 1

Fig. 1.
Dose-response curves of M. radioduransto ,),-rays from 60 CoCA) and a-particles(4.78 MeV/amu)
Cells of M. radiodurans KD830 at logarithmic
phase of growth were · washed with M/15
1O-2L--_-'---_--L-_~-=-- phosphate buffer(pH 7) and irradiated underocooling with ice-water as described in the text.
Dose (nC)127

during initial 20 min of incubation at 37°C are shown in Fig. 2. Although secondary electronsejected from the track core of ~-particles in water traverse much less than those of secondary
electrons produced by N-ions, ~-particles showed stimulatory effect on the DNA synthesis in thepenneable cells. However, the stimulation by ~-particles was less than that by 'Y-rays
especially at the low doses. This result may imply that a-particles as well as 'Y-rays induce
single-strand breaks which have free 3'-OH, a priming site for DNA polymerase, but percentage
of such terminal in whole lesions is somewhat different between two radiations. In other words,
if any characteristic biological lesions are induced by irradiation of high LET particles utilizing
track-segment method, such lesions would be accompanied by many lesions similar to thoseinduced by low LET radiations such as 60 Co 'Y-rays.
3
(b)

(0)

<t
Z

o
'+-

o

2

60
Dose

(krod)

Dose

80

100

( nC )

Fig. 2.

Irradiation effect of 'Y-rays(A) or~-particles(B) on DNA synthesis in permeable cells of
M. radiodurans.
Permeable cells of M. radiodurans 1 ) were irradiatedwith (A) 'Y-rays from 60Co or (B) ~-particles (4.78
Me V / amu) under cooling with circulating ice-water.
Vertical lines indicate relative rate of DNA synthesis
observed at initial 20 min of incubation at 37°C.

References
1)
2)
3)
4)
5)
6)

S. Kitayama and A. Matsuyama: Biochim. Biophys. Acta, 418,321 (1976).
D. Billen and G. R. HeUermann: ibid, 361, 166 (1974).
D. BiUen and G. R. Hellennann: ibid, 383, 379 (1975).
E. A. Waldstein and R. B. Setlow: ibid, 442, 154 (1976).
S. Kitayama, F. Yatagai, and A. Matsuyama: IPCR Cyclotron Progr. Rep.,~ 98 (1975).
S. Kitayama and A. Matsuyama: Mut. Res., 29, 327 (1975).

128

9-4.

Induction of Mutations

in Bacteriophage ¢X 174

by a-partic lesand N-ions

F. Yatagai, S. Kitayama, and A. Matsuyama

It has been reported that the inducible post-replication repair (sos repair) of overlapping

daughter strand gaps appears to be necessary for UV-induced mutagenesis to occur in a uvrA
strain of ~ coli. 1)

The overlapping daughter strand gaps are thought to be refractory to bothexcision and recombination repair. In fact , the fraction of mutants measured in a population of
UV-irradiated phage ¢X 174 increased with increasing UV-dose when the mutation frequency was
assayed on host cells which had been irradiated with a small dose of UV, while there was noincrease when unirradiated cells were used for assay .2) On the other hand , 'Y-irradiation of theamber mutants induced the reverse mutation to wild-type even when unirradiated host cells wereused for assay.3) Higher efficiency was obtained under irradiation in the presence of oxygen thanunder anoxic condition. 3) Our interest is to find out the relation between the damages insingle-strand DNA by charged particles and the induction of mutation.
In the present study, arn3 mutant of ¢X 174 has been irradiated with a-particles and N -ions inorder to determine the efficiency of reverse mutation to (pseudo) wild-type . The phage samples
which were spread on a thin filter and covered with another filter of the same type, were
irradiated with charged particles. After irradiation the surviving fraction was assayed on .E. coli
HF4714, which has an amber suppressor (su+) . Wild-type and pseudo wild-type revertants wereassayed on both UV -irradiated and unirradiated E.. coli eN (su-) . Further experimental details will
be given elsewhere.
Figures I and 2 show that survival curves of the amber mutant are almost exponential against
fluence for a-particles and N-ions of 4.6 MeV/amu.
I.()

For both ion beams, the efficiency of

Ir r a dj a lio!J. uf_l!:"parti cles (4 . (. MeV/a mu)o1.0

1 rradj..~ _t!Q!L__Qf

N- ion!..> ( 1, . (, r"' eV/ a mu)

o
....

0.1

to

o

o

o

0 . 010 . 01 L--_

10

10~. !IV - i rradia te d host c e lls ( 4OJ/m 2 )---'--_-----'-_----'-_~~: Unirra diCoited r.os t cells

....>

~ ~
~

' - - _- ' - - _fc, : UV - irradiated host cells ( 4OJ/m 2 ).

A ; Unir "radia:ed host cells

_

5

0
r<

~

'"
2
Fluence ( primary pa r ticles / cm )2
Fluence ( pr ima r y particles / cm )Fig. 1.
Induction of mutation in ¢X 174
am3 by a-particles (see text .):Fig. 2.

Induction of mutation in cj>X 174

am3 by N-ions (see text.).

129

induction to (pseudo) wild-type, which was assayed on both UV-irradiated and unirradiated hostcells, shows the same mode of dose-dependence as that of UV mentioned above (Figs. 1 and 2).
Almost no difference in the efficiency was found between a-particles and N-ions (Figs. 1 and 2);
the efficiency for these charged particles was rather low but of the same order as that of IN - or"Y-irradiation obtained in our separate experiments (Table 1). Since DNA strand breakage in ¢X
174 is lethal, this result suggests that irradiation with charged particles induces not only strand
breakage but also many other premutational damages in DNA, comparable with that of UV per
lethal hit.
Table I.

Comparison of efficiencies of mutation induction
caused by different types of radiation.

Type of Radiation

Revertants per 10 5 Survivors*

UV-light'Y-raysa-particles
N-ions

5.6
3.9
2.5
2.5

* Survival of am3 mu tan t of <jJX 174 was assayed on ~. coli C HF 4714 (su +)for different radiations indicated above.

To determine the values ofrevertants/1 OS survivors for 10% survival, the irradiated phages were
infected to uv irradiated ~ coli C (su-).

References
1)
2)
3)

S. G. Sedgwick: Mutat. Res., 41,185 (1976).
J. F. B1eichrodt and W. S. D. Verheij: Molec. gen. Genet., 135, 19 (1974).
J. F. B1eichrodt and W. S. D. Verheij: Int. J. Radiat. BioI., 25,505 (1974).

130

9-5.

Inactivation of Ribonuc lease A

In

Aqueous Solution

by eyc lotron Beams

Y. Hattori, F. Yatagai, and A. Matsuyama

In the framework aiming to reveal specific features of the damage on biological substances
caused by heavy-ion radiations, experiments have been started on the inactivation of bovinepancreatic ribonuclease A (EC 2.7.7.16) by cyclotron beams.
Ribonuclease (RNase) A, of which purified commercial preparation is easily available, hasbeen used as an object of radiation biochemistry by many investigators. Recently Lynn 1)reported that RNase A was protected against 'Y-radiolytic destruction when the enzyme wasassociated with deoxyribonucleic acid (DNA) under conditions such that the nucleic acid was not
acting as a scavenger. Using the same model systems the effect of N-ion radiation on RNase A
activity is studied. The present experiment is done, with its attention particularly focused on themodification of radiosensitivity of RNase by the associated DNA.
Sample solutions to be irradiated were prepared according to Lynn 1) : (1) 5 X 10- 6 M aqueous
solution of RNase A (crystalline preparation of Sigma Chemical Co.); (2) 5 X 10-6 M RNase A
plus salmon sperm DNA (10 J.Lg/ml) -- RNase-DNA complex; (3) 5 X 10-6M RNase A in 0.1 M
NaCI0 4 plus DNA (10 JIg/ml) -- dissociated complex.

The irradiation of the solutions was donein Pyrex glass cells with a window of aluminum foil (20 JI) under agitation in the presence of
atmospheric oxygen at room temperature. The ion beam was shot into the solution through thecell window. Energies of N-ions and a-particles entering solutions were 4.5 and 4.6 MeV /amu,
respectively. Irradiated RNase solutions were subjected to the assay of residual activity according
to the method of Anfinsen et a1. 2) with modification.
Experimental results obtained so far are as follows: (a) RNase A, when associated with DNA,was not protected against the inactivation by N-ions, but showed higher sensitivity than without
DNA; (b) the enzyme activity was protected when DNA and NaCI0 4 were added in the solution.
These relationships are shown in Fig. i. 3 ) Thus the effect of DNA added to RNase solution in

Inactivation of RNase A in aqueous solution
Fig. 1.
by N-ion irradiation at room temperature under thelO'---_~

2. 3

__

~_~

4.6
Dose (Mrad )

6.9

__

~_

9.2

presence of air.
o 5 X 10-{)M RNase A;. 5 X 10-uM RNase A + DNA(10J.Lg/ml); ~ 5 X 10-6M RNase in O.IM NaCI0 4 + DNA(IOpg/ml). Energy of N-ions entering solution was
4.5 MeV/amu.

131case of N-ion irradiation was found to be different from that in 'Y-irradiation.l) Data on theeffect of a-particles are not yet sufficiently accumulated. Further experiments are in progress.

References
1)
2)

K. R. Lynn: Radiat. Res., 66, 644 (1976).
C. B. Anfinsen, R. R. Redfield, W. L. Choate, J. Page, and W. R. Carroll: J. BioI. Chern., 207,
201 (1954).

3)

Y. Hattori, F. Yatagai, and A. Matsuyama: 20th Annual Meeting of Japan Radiat. Res.
Soc., Sendai, Oct. (1977).

132

9-6.

The Effects of High LET Radiations on Mammalian Cells

S. Sawada, M. Sasaki, S. Okada, F. Yatagai,
1. Kaneko, and A. Matsuyama

For clinical radiation therapy, fundamental studies on cellular level are requested to getinfonnation on the radiobiological effects of ionizing radiations to be used. The advantages ofhigh LET radiations, such as a -particles and heavy ions, over x-rays and ')'-rays because of theirhigh RBE values in inducing cell death are well known.
Studies with cultured Cheniese humster cell V-79 were carried out last year to solve thetechnical problems which do not arise in x- or ,),-ray experiments. The following programs are
now in progress on the basis of the last year's results.
(1) Molecular autoradiography of high LET radiation-induced doble-strand cuts of DNA andtheir rej oining in mouse leukemic L5 178 cells.
DNA was labeled by incubating the exponentially-growing cells for 60 minutes with 3 Hthymine. The labeled cells suspended in a cold medium were placed on a Sartorius membranefilter and most of the medium was thus removed. Immediately before irradiation, the cells on
the filter were covered with a polycarbonate filter to exclude the effects of secondary electrons
which emerged into the air layer above the cells.

The cells were irradiated at room temperature

with a-particles and N-ions accelerated in the cyclotron (4.6 MeV/amu at sample).
Immediately after irradiation, the polycarbonate filter was removed and the Sartorius filter
with cells was placed in a stainless steel holder. The holder was capped and the cells were thenremoved by flushing through the filter from a syringe attached to the cap. Nearly 50% of thecells on each filter were thus collected.
To examine the rejoining of broken DNA strands, cells, together with the Sartorius filter,
were placed in a plastic culter dish and incubatecf\ n a CO 2 -incubator at 37°C. At various timesof post-irradiation incubation, the cells were removed from the filter by the method describedabove.
For DNA fiber autoradiography, an aliquot of cell suspension, containing approximately
3000 cells, was placed on a glass slide, which was coated with a mixture of gelatin and chromium
sulfate, and mixed with sodium laulyl sulfate. The slides were left at room temperature to lyse
the cells.

The lysate was then spread over the surface of the slide.

Sakura NR-M2 liquid emulsion.

The slides were dipped into

After drying, the slides were kept in a light-proof box with silica

gel and allowed to expose at 4°C for at least 5 months in the dark-room (The slides are stillallowed to expose at the present time).
(2)

Production of chromosome aberrations by a-rays in human lymphocytes.

Peripheral blood lymphocytes obtained from normal person were layered between
poly carbonate films and exposed to a-rays (4.6 MeV/aum)acceralated in the cyclotron.

The

irradiated cells were collected and incubated with the phytohemagglutinin-containing medium for
50 h so that chromosomes were analysed in the first post-irradiation mitosis. The a-irradiation
efficiently produced chromosome aberrations such as dicentrics, rings, and acentric fragments.

133

Although the experiments are now at the preliminary stage, the a-rays are about 1.6 and 4.8 times
more efficient in producing dicentrics and rings than 2 MeV and 14 MeV fast neutrons, respectively .
Detailed analysis regarding the distribution of dose in lymphocyte nuclei and dose-yield kinetics ofchromosome aberrations are now in progress.
(3) Setting up of the equipments and appratuses for preservation of cultured mammaliancells.
As a constant supply system of cells for the further investigation to confirm the preliminary
results obtained last year on the dose effectiveness curves of Chinese humster cell V-79 for thestudies on recovery from the cell damages caused by high LET radiations, and for comparative
studies on strand breakage of DNA in the mammalian cells due to heavy ions as well as othertypes of radiations, a sterilizing room, a CO 2 -incubator, and a liquid nitrogen vessel were set up
and the preservation of the cultured mammalian cells was started.

134

10. PREPARATION OF RADIOISOTOPES AND LABELED COMPOUNDS

10-1.

Production of Rad ioisotopes and Preparation of labelled
Compounds for Medical and Agricultural Use

T. Nozaki, Y. Itoh, M. Iwamoto, T. Karasawa,
K. Fukushi, T. Irie, and T. Hara*

Studies have been continued on the production of 77 Br and 73 Se and the preparation ofradiohalogen derivatives of cholesterol and phenylalanine. The excitation curves for the formationof 77 Br or 73 Se by the following reactions have been measured up to proton energy of about 50
Me V and 3He and a-particle energy of about 40 Me V, together with those for simultaneous
formation of 76Br or 72S e : (1) Se + p ~ 77Br, (2) Br + p ~ 77Kr ~ 77Br, (3) 75 As (a, 2n) 77Br,(4) 75As (p , 3n)73S e , (5) Ge + 3He ~ 73S e , and (6) Ge + a ~ 73S e .

The targets used for themeasurement were BaSe03, NaBr, Mg 2 AS2 0 7 and metallic germanium in the form of plate madeby pressing or of film made by sedimentation or evaporation onto aluminum foil. They werestacked and bombarded. The cyclotron was used for all the reactions. In the proton reactions,
the FM cyclotron of the Institute for Nuclear Study, University of Tokyo, was also used for theextension of the measurement energy range from 16 MeV up to 52 MeV.
The excitation curves are shown in Figs. 1 to 5 for the targets of natural isotopic composition.
Since the proton energy of this cyclotron was always 52 MeV, notable spreading of proton energy
JOO

200

E
800

0

-E 600

"'

c

u

0

100

u
Cl.>
U">
U">

400

<f)

e
u
200

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

Energy (MeV)

Excitation curves for the
Fig. 1.
reactions of Se + p ~ 77 Br, 76Br, 82 Br,
and Br + p ~ 77 Kr ~ 77 Br.
* National Nakano Chest Hospital.

Energy(M eV)

Fig. 2.
Excitation curves for the reactions of
75 As(a, 2nyT1Br and 7SAs(a, 3n)16'Br.

135

120
400
0
0

300

Ll

E 80

E
c

0

c
0

u
OJ
<f)

U

OJ
V>

200

V>

0

U

of>

00

0

U
40
100

20
Energy (MeV)

Fig. 3.
Excitation curves for thereactions of 7SAs(p, 3n) 73S e and
75 As(p, 4n)72 Se.

30

40Energy (MeV)

Fig. 4.
Excitation curves for thereactions, of Ge + 3He ~ 73 Se, 72 Se.

200

-

E
c

o

V>
V>

e

u

o1 0~--------~2~0--------~3~0---------4-0
Energy (MeV )Fig. 5.
Excitation curves for thereactions of Ge + a ~ 73S e , 72Se.

took place inevitably when it degraded down to 30 Me V or less in the stack. Hence, theexcitation curves for Reactions 1 and 4 involve some uncertainty in the energy region between 16
MeV and about 30 MeV. We intend to examine the curves in this energy region by the use ofanother machine.
Target substances of arseni c and selenium convenient for isotopic production were looked
for, together with methods of chemical separation of the product nuclides. As the arsenic target ,AlAs and fused cake of NaAs0 2 .. Na2 B4 0 7 have been found useful in addition to AS 20 3 . For
selenium, fused cakes of Se02 - NaOH and Se02 - NaOH - Na2 B4 0 7 have been regarded asconvenient.

136

Procedures have been set up for the chemical separati on of 77 Br and 73 Se from AlAs target.
Chemical purity of carrier-free 77Br distilled from a sulphuric acid solution of arsenic targets
was examined by neutron activation analysis.

Successive treatment of the distillate with ironpowder and BaC0 3 has proved to be effective for the removal of trace arsenic.
77

The productBr in carrier-free and salt-free state is utilized for the tracer study of bromine in rain water aswell as for organic labelling.
Solvent extraction of red selenium has been found suitable for the separation of 73 Se, when
the addition of a small amount (e.g. , 60 Jlg) of carrier is permissible. The product 73 Se has beenused for the biosynthesis of selenomethionine- 73 Se. Carrier-free separation of 73 Se from arsenic
targets is now under study.

Coprecipitation of 73 Se with elementary tellurium will offer a good

procedure , the 73S e and tellurium being separated by ion exchange.
Chemical behaviour of carbon-halogen bonds of radio-halogen derivatives of cholesterol andphenylalanine in animal body has been studied in collaboration with the National Institute ofRadiological Sciences. Doubly labelled compounds have profitably been made use of. Althoughinteresting phenomena have been observed, some further time will be needed before we can present
our results with confidence.

137

10-2.

Biosynthesis of Selenomethionine- 73 Se

K. Ogawa:~ K. Taki, T. Nozaki, and M. Okano

Selenomethionine- 75 Se is widely used in nuclear medicine for diagnostic visualization of
pancreas by scintigraphy,l) though the biological half-life of 75 Se is so long as to give noticeableinternal radiation exposure to the patient. The replacement of selenomethionine- 75 Se by
selenomethionine- 73 Se is thus desired , 73Se being a positron emitter of 7.1 h half-life. This
nuclide will become more useful with progressive development of the positron emitter localization
technique. Hence, a convenient method should be sought for rapid synthesis of selenomethionine~
73 Se in a state suitable for intravenous injection. We reported previously the preparati on ofthis compound starting from the 3He bombardment of germanium. 2)
We have continued the study of the biosynthesis of selenomethionine- 73Se using the proton
bombardment of arsenic. The yield of 73Se for the 75 As (p, 3n) 73Se reaction is described
separately in the present volume of this report.
Aluminium arsenide (AlAs) and arsenous oxide (As 2 0 3 ) were used as the target (1.4 g/cm 2
thickness). They were bombarded by protons from the synchro-cyclotron of the Institute for
Nuclear Study, University of Tokyo, through aluminium plates for the degradation of the protonenergy from its initial value of 52 MeV to 43 MeV.
The bombarded AlAs target (about 4 g) was transferred into a 500 ml flask containing
H2 Se0 3 (0.1 mg) as carrier and water (10 ml). The flask was equipped with a reflux condenser
and warmed. Then HCI-HN0 3 (1 :3, 10 ml) was added in small portions to the flask, and thewarming continued until the beginning of N0 2 evol ution. After the solution was left to cool,
insoluble particles suspending in it was removed by centrifugation and millipore filtration. As
for the As 2 0 3 target, it was simply dissolved in dil. HCl. Selenium-73 in the solution was thenprecipitated as red selenium by reduction with H2 NNH2 . HCI (20% solution, 3 ml) under heatingfor 5 to 10 min. After cooling to room temperature, the selenium was extracted into CS 2 andthe extract washed with water. By evaporation of the solvent, the 73 Se was obtained as red
selenium in satisfying radiochemical puri ty. The separation time was about 2.5 h, and the yield
about 70%.
The red selenium was dissolved in HN0 3 , and the excess acid removed by evaporation under·reduced pressure. The residue .was dissolved in water, and the pH of the resultant solution
adjusted to 7 with NaOH. This solution, as described in our previous report,2) was added to thefermented liquor on which TO-l strain had been grown for 10 h, and the strain further cultivatedfor 6 h. The strain was then harvested by centrifugation, and its protein fraction hydrolyzed
by being kept with 6 N HCI in a seald tube at 120°C for 5 h. About 80% of the 73Se was foundin the hydrolysate.
Radio-selenium compounds in the hydrolysate was then separated by starch column
chromatography with the solvent of I: 2: I mixture of n-butanol, n-propanol and 0.1 N HCl.

The

effluent was collected (0.1 ml/min elution rate) in 0.5 ml portions by an automatic fraction
collector. The selenomethionine fraction was identified by activity measurement and by paper* pepertment of Hygene, Kitazato University.

138

chromatography on Toyo Filter Paper No. 51 with the solvent of 3: 1: 1 mixture of n-butanol,
acetic acid and water. Authentic selenomethionine prepared by chemical synthesis 3) was used
for the paper-chromatographica1 identification of the se1enomethionine- 73 Se (Rf = 0.55).
The time required for the preparation was about 20 h after the end of the bombardment, and32.3 J.LCi of selenomethionine- 73 Se was obtained from 2.3 mCi of 73 Se separated from the arsenic
target.

References
1)
2)
3)

M. Brau: Biochem. Biophys. Acta, 49,389 (1961).
T. Nozaki, S. Ambe, Y. Itoh, M. Iwamoto, T. Karasawa, M. Okano, K. Fukushi, T. Irie,
T. Hara, and K. Taki: IPCR Cyclotron Progr. Rep., 10,120 (1976).
D. L. Klayman and T. S. Griffin: 1. Amer. Chern. Soc., 95, 197 (1973); G. Z. Dansky: Arkiv
Kemi,~ 550 (1962).

139

10-3.

Separation of Carrier-free Radioactive Krypton

M. Aratani and T. Nozaki

We have undertaken -some experiments to find out a simple and efficient way of separating
carrier-free radioactive krypton in a form convenient for practical use and fundamental study. Fortrapping the krypton with this intention, glass beads were thought to be preferable to any otherstrong adsorbents. The radionuclides, 77Kr* and 79Kr, were produced by the reactions, 79Br
(p, 3n) 77Kr and 79Br (p, n) 79Kr, respectively, the target being NaBr powder and pellet.
Separation system 1:
A cylindrical brass vessel with 50 Jlm stainless steel foil window in the central part was madeand used in all the following steps: i) charged particle bombardment of the powder target underwater cooling of the vessel bottom; ii) dissolution of the bombarded powder by the addition ofwater; iii) removal of the radioactive krypton from the solution by helium bubbling. The
radioactive krypton was carried by the helium, passed through NaOH-Na2 S03 to be made freefrom radiobromines, byproducts of the reactions, and then trapped on glass beads at liq. N2
temperature.
Separation system 2:
The same vessel was also used for the pellet target. The bombarded pellet was put in thevessel, and treated similarly as above.
Separation system 3:
A box-type vessel with demountable stainless steel windows on both sides was made for thebombardment to optimal amount of target material. Radioactive krypton evolving from thetarget in the course of bombardment was transferred from the vessel with a helium gas stream
and was trapped on the glass beads at liq. N2 temperature. After the bombardment a small
amount of water was introduced into the vessel. The resultant solution was then transferred intoa gas-washing vessel wi th a sintered glass inlet, by being pushed with helium gas. The krypton
in the solution was expelled with helium bubbles of small diameters formed at the sintered glass,and was trapped similarly.
The three systems above were of open types.

Though they had the advantage of simplicity,some of disadvantages were observed. For example, the radioactivity of the trapped krypton
gradually decreased after its maximum, indicating inherent difficulty in getting krypton
quantitatively. A separation system of closed type was also developed.
Separation system 4:
The separation system of closed type is illustrated in Fig. 1. The following three parts wereconnected with stopcocks, abbreviated as SC, (1, 2, 3 and 4 in Fig. 1) between them: (A) an
empty gas-washing vessel with sintered glass inlet at room temperature, (B) an evacuated NaOHNa2 S03 trap kept at dry ice temperature, and (C) an evacuated glass-beads trap kept at liq. N2
temperature.
*

A bombarded pellet was put in (A), which was evacuated by an aspirator pumpThis was produced by using F. M. Cyclotron of Institute for Nuclear Study. The University of Tokyo.

140

A . Samp le solution
Room temp .
8 ; Mixed sa lts trap
Dry ice temp.

e : Gloss bead trap
Li q. N2 temp.

Fig. 1.

The closed type system forseparation of carrier-free radioactive
krypton.
through SC 1.

Then, it was shut off.

Thus, the entire system was made closed.

With aninjector, a minimal amount of water was introduced up to the level slightly higher than thesintered glass inlet of (A).

After the pellet was dissolved, SC 2 was opened.

Due to thedifferences of pressure and temperature between the vessel and the trap, the radioactive krypton
in the solution was carried away with small bubbles formed automatically at the sintered glass,and was trapped on the NaOH-Na2 S03 cooled to the dry ice temperature.
off, SC 3 was opened.

After SC 2 was shutThus, the radioactive krypton was moved to and trapped on the glass

beads.
Distribution of the radioactive krypton in three vessels after the separation is shown in Table
1.

Collection efficiency in case of the closed system is seen to amount to nearly 100%.

In thepractical separation, care should be taken to maintain the contents of the traps at the desired
temperatures, especially in the closed system.

It is concluded that simple and efficient separationof radioactive krypton can be carried out by a glass-beads trap at liq. N2 temperature in open or
closed type.
Table 1.

He bubble
diameter

4 mm
8 mm
30-20 11m
30-20 jJ.m

Type

0*

o
o
o
C**

* open,*** 77Kr,* * closed**** 79Kr

The distribution of the radioactive krypton
after separation.
NaBr
soln.

NaOHNa2 S03

Glass
beads

(%)

(%)

(%)

42.6
64.3
5.9
15.0
1.5

7.9
10.4
14.7
2.1

57.4***
27.8
>83.7
70.3
96.4****

141

11. RADIATION MONITORING

11-1.

Routine Monitoring

K. Igarashi, 1. Sakamoto, and 1. Usuba

Results of routine radiation monitoring carried out on the cyclotron from April 1976 to
March 1977 are described.
No remarkable change in leakage radiation and residual activities was observed during thisperiod.
(1) Surface and air contamination
The surface contamination has been kept below 10-6 j.1Ci/cm 2 on the floor of cyclotronroom and the underground passage, and below 10-7 }lCi/cm 2 in the experimental areas, hotlaboratory and chemical laboratories. The contamination was wiped off twice a year, and after
each decon tamina tion, the higher level con tamina tion could be reduced below 10-7 }lCi/ cm 2 .
When the accelerating chamber was opened, slight contamination of the air in the cyclotronroom was observed. The value of radioactivity concentration ({3 - 'Y) was 10- 13 IlCi/cm 3 .
Tritium still remained in the accelerating chamber since the last triton acceleration in
December 1970.
4

5

The tritium concentration of the air in the chamber was still of the order of
3 1. )10- -10- }lCi/cm
As the air in the chamber is purged completely before overhauling, aircontamination was not found in the cyclotron room.
Table 1.

Annual exposure dose received by the cyclotron
workers from April 1976 to March 1977.

Workers

Operators
Nuclear physicists
Accelerator physicists
Physicists in other fields
Nuclear chemists
Radiation chemists
Biological chemists
Heal th physicist

Number of persons'b ose undetectable
10-100(mrem)

15
2
6

3
7

5
4
2

> 100 '\

Collective dose(man-mrem)(mrem)
4

2

1030
380
140
130
500

Total

2180

3

4

Average annual dose per person: 36.9 mrem.
Maximum individual annual dose: 270 mrem.

142

(2)

Drainage

The radioactive concentration of the drain water from the cyclotron building was found to
be of the order of 10-7 /lCi/cm 3 . The total quantity of activities in the aqueous release in thisperiod was about 3 /lei, which decreased by about one-eighteenth compared with that of the lastyear.
(3) Personnel monitoring
The external exposure dose received during the present period, by all cyclotron workers towhom the ,),-ray and , to some of them also, the neutron film badge are provided, is shownin Table 1. The collective ,),-ray dose to all workers was 2180 man-mrem, while those dueto thermal and fast neutron exposures were too small to be detected.
The dose to the cyclotron workers increased by about 7% compared with that of the lastyear. In this period the dose to the cyclotron operators was 1030 man-mrem, which was 47.2%of the dose of cyclotron workers.

Reference
1)

S. Fujita and 1. Sakamo~o: IPCR Cyclotron Progr. Rep., ~ 108 (1975).

143

11-2.

Leakage Radiation Measurement at the Underground Passage

I. Sakamoto

Leakage radiation during operation of the cyclotron at the underground passage of thecyclotron building was measured. Leakage dose received during the present period by the'Y-neutron film badges which are left at the underground passage, is shown in Table. 1. The ratio of'Y dose to thermal neutron dose was 3.0.
Among the dose at the point No. 1 measured every month, the maximum dose of 1690 mrem
was observed in September, which was 44.6% of the total dose in this period. In this month, themachine time allotted for deuteron acceleration was 91 h, which was 34.0% of total scheduled beamtime in this period.
Fast neutron dose was measured with another film badge at the point No. 1 in July 1977.
In this case, the values of fast neutron dose, 'Y dose and thermal neutron dose were 20 mrem, 770
mrem and 290 mrem, respectively.

It is shown that fast neutron dose was small compared with

'Y-ray and thermal neutron dose at the underground passage.

Table 1.

Leakage radiation dose (in mrem) at the undergroundpassage from April 1976 to March 1977

2

y - ray (mrem)
Thermal neutron (mrem)
Total (mrem)*

See the figure shown below.

Cross section

Ground plan

2840

180

950
3790

60

240

144

12. HEAVY ION LINEAR ACCELERATOR PROJECT

1 2-1.

Status of the Construe tiona I Work

M.OderaInstallation of the high voltage ion source terminal and the first resonator was completed in
December 1976. Vacuum pressure of 3 X 10-7 Torr was obtained for the resonator in January
1977. The 500 kV unit was tested to its full voltage in March. However, humidity from theconcrete wall of the injector room was still high and the leakage current as high as 300 I1A wasobserved at times. Electric dehumidifiers were installed and the state is improving.
The first high power amplifier and its power supply were installed in April. Several minor
modifications were found necessary during the low power tests and took a couple of months.

A

power feeder to the resonator was fabricated and installed in September.
The contract for construction of cooling system was made. The part for cooling of the ion
source on the high voltage terminal was completed at the end of October and will be usedtentatively for cooling of the first resonator and the radiofrequency amplifier for a year until thewhole system is installed.
Fabrication of the remaining five resonators are progressing in the factory of the contractor.
Acceptance test of No.2 cavity was also completed at the end of October. All the cavities will
be set in the accelerator vault by the end of March, 1978.

145

12-2.

The Proto-type Buncher

M. Odera, I. Takeshita, and F. Yoshida

A single frequency bunching system was investigated and a proto-type resonator was fabricatedand tested. In the variable frequency linac scheme of our machine, the accelerating frequency isadjusted according to the charge to mass ratio of ions so that the flight length of the ions in one
period of the radiofreq uency remains the same regardless of the ions under acceleration. This
makes calculation of the buncher parameters simple by normalizing time in unit of the period ofradio frequency and length in unit of the length of the drift tube cell of the buncher.
The resonant frequency of the buncher must be adjustable easily for the full range of
frequency required, by a method as simple as possible , otherwise, the buncher system adds
complication to the operation of the accelerator. As such a method we chose that of capacity
tuning.

Figure I shows cross section of the proto-type cavity.

A vacuum variable capacitor

connected to the center electrode of the buncher can adjust frequency in the required wide range.
The method of tuning has been found simple and it permits fine adjustment. The capacitor which
has the maximum capaci ty of 250 pF and the maximum voltage rating of 30 kV is selected forthe present design.
Position of the buncher is chosen 3m upstream from the first gap of the first accelerating
resonator.

Relatively low voltage less than 3 kV is expected to be sufficient for the centerelectrode of the buncher in that configuration. Therefore , there is ample margin for the vacuum
capacitor rating. Power consumption was also found small and was less then 200 W at most.
Dr ift tube center elect rode -,Vacuu m vonable capacitor=oo"------ - - - ;f---_ _- C4

Fig. 1.

Cross section of the proto-type buncher.

7

146

12-3.

A

Lay-out plan of the Beam Diagnostic Elements

M. Odera

Figure 1 shows schematically a lay-out of the beam diagnostic elements. Abbreviations are
explained at the lower part of the figure. Ions extracted from the ion source IS are focused byan electrostatic lens ESL. A slit Sl. 1 selects certain charge states and defines source profile ofthe beam. The beam intensity can be measured by a beam stopper BS. 1 which can be plunged
into the beam path by a pneumatic device. After passing through the accelerating column,
direction and centering of the beam with respect to the acceleration axis are adjusted by a pairof the steering magnets St. 1 and St. 2. The probe container box pc. 1 can house several types ofdiagnostic probes according to kind of measurement desired. Then a quadrupole doublet DQ.
focuses beam onto Sl. 2 and the state of dispersion of the beam is investigated by a profile
monitor PM. 1 in front of Sl. 3. A mass analysing magnet D. 1 can single-out any isotope-if
desired. D. 2 inflects the beam into the buncher. Performance of the buncher can be measured
by plunging into the beam path a bunch pick-up probe in PC. 2 in front of the valve V. 3. Baffles
Baf. 1- 4 define the cross section of the beam allowed to enter each cavity. Emittance variation
along the beam line can be checked by inserting emittance probes EM 1"'8 into a suitable probe
container among PC. 1"-'8. Roles of any other diagnostic elements in the Fig. 1 may beunderstood in the same way.

-[on source

V Pneumatic valve

I: D_

IQ Triplet quod rupole mognet

TVL Manua~:St:Steenng ~et_ __~C DiagnostiC probe container

Arrangement of the beam diagnostic and handling elements
Fig. 1.
along the beam transport line.

147

12-4.

Orbit Analysis of the Beam after Charge Stripping

M. Odera and F. Yoshida

Though the linac has been designed so as to be able to function without charge stripping it isinteresting to investigate effects of the charge change on the beam dynamics through the linac. If
it is possible to increase charge of the ions by that process without causing much complication tothe operation , it is very desirable in view of saving of power consumption of the linac system.
The radio frequency power loss is inversely proportional to the square of charge of the ion , whenthe energy to be gained is fixed.
The most probable charge states of Xe-8+ and Ne-·5+ when stripped between the fourth andthe fifth resonators are 24 and 9 respectively. Figure 1 shows variations of emittance of beam
after passing through the next cavity and acceptance of the later part of the linac according to thecharge states when the parameters of the machine are chosen to give best result for the ionshaving the most probable charge states. A large portion of the xenon beam is found to be able topass through all the later sections in spite of a large difference existing in charge states_ For thex ',y'

I

Acceptance : Xe

Acceptance : Ne(y , Y')--<Il-!l>-IO

q

-

x,Y

-

24

9

-+-.- 25

- +--+-

8-x-x- 26

- X- x-

7

-0-0-

6

-0-0-

29

-.-.-

-.-*- 34

Fig. 1.

5(a) and (b): variations of acceptanceof the beam of #5 cavity according to charge
states.

Stripping is made at the entrace of thecavity .

Number of charge q is as follows:

Xe: -q = 24, +--+ q = 25 , x-x q = 26,oD q = 29 , ::t-;t q = 34 ;

Ne: -

o

q = 9 , +-+ q = 8 , X-

X q = 7,

D q = 6, ~-;( q = 5 , fE-----ffi

q = 10

148

X;Y'

X',Y'

Em ittance : Xe

Emi ttance : Ne

(X , X')./ .

/-/'.7'

/%/

/:;7

. ··V
\, ~~----- x,Y------"/~"'. \ -. - -+---A/

.t.f/

/?
(/I
'f
/f

\

~.

----~~g.r---_+---~~~,__---- X,Y//'Fig. 1.
(c) and (d): variations of emittance ofthe stripped beam after the #5 cavity. Other
parameters are the same with those of (a) and(b).

neon beams, transmission is somewhat worse. However, substantial portion of particles of various
charge states seems to go through later sections in this case too. So discrimination of the charge
states by difference in emittance and acceptance seems difficult. It will cause some difficulties
in the beam diagnosis.

149

12-5.

Test Fae ility for Heavy Ion Sou ree

1. Kohno, A. Shimamura, and T. Tonuma

The linac is designed to be able to accelerate ions whose mass to charge ratios are between
4 and 24. For the production of these ions we adopted a hot cathode PIG type ion source
similar to the heavy ion source 1 ) of the cyclotron. A test facility was equipped to study the
production of multiply-charged ions of all elements and the formation of ion beam extracted
from the ion source.
Figure 1 shows the experimental arrangement. Ions of different charges were extracted
radially and separated by a magnetic field which at the same time maintains the arc plasma of
the ion source. The selected ions were deflected by about 120 degrees in the field of the source
magnet and they passed through a magnetic shield into an emittance measurement apparatus.

Emittance measurement
assembly

Faraday cup

Fig. 1.

Test facility for PIG source.

The radius of beam trajectory in the source magnet was decided to be 13 cm to extract allions with mass to charge ratios between 4 and 24.
Therefore, the required maximum fieldstrength of the source magnet was 7 kG and the electric voltage of up to 35 kV was needed forion extraction. As the hot cathode PIG ion source, which was already described,2) was 14 cm
high, the gap width of the magnet was decided to be 15 cm and the beam extraction system is
supplied with a negative high potential.

150

Furthennore, the magnetic shield was installed to reduce the magnetic fringing field resulting
from the rather large gap width of the magnet. Figure 2 shows the magnetic field distribution
with and without the magnetic shield. It is found that the magnetic fringing field is reduced by
the use of the magnetic shield.
At present we are studying the characteristics of the PIG type ion source with this test
facility.

with Field clamp

o

ill

~ 0.5

CD

Fig. 2.

Effect of the magnetic shield (fieldclamp) on the magnetic field.

6.0

18.0

Field clamp

42

References
1)

Y. Miyazawa, I. Kohno, T. Tonuma, and A. Shimamura: IEEE Trans. Nucl. Sci., NS-19, No.2,

2)

105 (1972).
K. Ikegami and I. Takeshita: IPCR Cyclotron Progr. Rep., ~ 147 (1976).

151

13.

LIST OF PUBLICATIONS

1)

M. Ichimura, M. Igarashi, S. Landwne, C. H. Dasso, B. S. Wilsson, R. A. Broglis, and
A. Winther: "On Solving Coupled Equations for Scattering Problems under the Many Channel
and Short Wave Length Conditions of Heavy Ion Collisions", Phys. Lett., 67B, 129 (1977).

2)

T. Inamura, M. Ishihara, T. Fukuda, T. Shimoda, and K. Hiruta: "Gamma-Rays from an
Incomplete Fusion Reaction Induced by 95 MeV 14N", Phys. Lett., 68B, 51 (1977).
K. Sugimoto, N. Takahashi, A. Mizobuchi, Y. Nojiri, T. Minamisono, M. Ishihara, K. Tanaka,and H. Kamitsubo: "Spin Polarization of 12B in the Heavy-Ion Reaction lOOMoct4N, 12B)102Ru",Phys. Rev. Lett., 39, 323 (1977).
F. G. Resmini, F. Soga, and H. Kamitsubo: "Possibility of Quasimolecular Bands in 28Si", Phys.
Rev., CIS, 2241 (1977).

3)

4)
5)
6)
7)

F. Kearns, G. Varley, G. D. Dracoulis, T. Inamura, J. C. Lisle, and J. C. Willmott: "Lifetimesof High Spin Rotational States", Nuc!. Phys., A278, 109 (1977).
N. Bendjaballah, B. Delaunay, J. Delaunay, and T. Nomura: "High-Spin States in 57 Co", Nucl.
Phys., A280, 228 (1977).
N. Bendjaballah, J. Delaunay, A. Jaffrin, T. Nomura, and K. Ogawa: "The Level Structure of
56Fe", Nuc!. Phys., A284, 513 (1977).

8)

S. Cavallaro, J. Delaunay, R. Ballini, T. Nomura, N. Bendjaballah, and C. Tosello: "High-Spin
States in 58 Fe-Ground-State and Quasi 'Y Bands-" , Nuc!. Phys., A293, 125 (1977).

9)

I. Kohno, K. Katori, T. Mikumo, T. Motobayashi, S. Nakajima, M. Yoshie, and H. Kamitsubo:"Single-and Multi-Nucleon Transfer Reactions Induced by 14 Nand 12 C on fb-Shell Nuclei",
J. Phys. Soc. Japan, 42, 1 (1977).
10) K. Koyama, N. Nakanishi, S. Takeda, S. Yamada, H. Sakaguchi, M. Nakamura, S. Takeuchi,
and H. Ohnuma: ,,(3He, d) Stripping to Bound and Unbound States in 29p", J. Phys. Soc.
Japan, 43,755 (1977).
11) S. Yamaji, K. H. Ziegenhain, H. J. Fi.l'1.k, W. Greiner, and W. Scheid: "The Mass Transfer in
the Collision 238U - 238U", J. Phys.,~ 1283 (1977).
12) T. Nomura, N. Bendjaballah, and J. Delaunay: "Unusually Strong Difference in theSide-Feeding to the 6+ Doublets of 56 Fe Populated in Heavy-Ion Compound Reactions",
Nuc!. Instr. Methods, 146, 310 (1977).
13) Y. Horikawa, T. Hoshino, and A. Arima: "Core Polarization Effects on the Coulomb Form
Factor", Nuc!. Phys., A278, 297 (1977).
14) T. Hoshino: "Attempts to Extend the Thomas-Fermi Approximation", Genshikaku Kenkyu,
22, 64 (1977).
15) S. Motonaga, T. Fujisawa, H. Kamitsubo, and F. G. Resmini: "Polarized Ion Source for
SF-Cyclotron", Genshikaku Kenkyu, (in Japanese), 22 , 93 (1977).
16) H. Nakajima, S. Kohara, T. Kageyama, and I. Kohno: "Production of C, N, 0, and Ne Ions byPulsed Ion Source and Acceleration of These Ions in the Cyclotron", Reports I. P. C. R.,(in Japanese), 53, 132 (1977).
17) Y. Awaya, M. Akiba, T. Katou, H. Kumagai, Y. Tendow, K. Izumo, T. Takahashi,
A. Hashizume, M. Okano, and T. Hamada: "The Ka and K{3 X-Ray Spectra of AI, Ti, Cr, Fe, andNi Induced by 84 MeV Nitrogen Ions", Phys. Lett., 6lA, 111 (1977).

15218) T. Hayashi, K. Takayama, T. Yanagimachi, and S. Kobayashi: " Variation of Response
between the Top and Bottom Surface of Plastic Films", Ionizing Radiation, Japan Soc. Appl.
Phys., (in Japanese), ~ No.3, 22 (1977).
19) T. Doke, T. Hayashi, K. Ito, T. Yanagimachi, K. Hisano, K. Nagata, and M. Miyajima:"Observation of the Tracks of Heavy Primary Cosmic Rays by Plastic and X-Ray Films", Bull.
Inst. Space and Aeronautical Sci., Univ. of Tokyo, ~ 875 (1977).
20) H. Tawara, Y. Awaya, Y. Tendow, T. Katou, M. Akiba, and T. Tonuma: "The Innershell
Ionization of Ar K-shell Electrons by High Energy Carbon Ions", Studies of Atomic
Collisions and Related Topics in Japan (Progr. Report), No.3, p. 56 (1977).
21) Y. Awaya, T. Hamada, M. Okano, A. Hashizume, T. Takahashi, K. Izumo, Y. Tendow,
H. Kumagai, T. Katou, and M. Akiba: "K X-Rays of AI, Ti, Cr, Fe, and Ni Induced by
Nitrogen Ions", Studies of Atomic Collisions and Related Topics in Japan (Progr. Report),
22)

23)
24)

25)

26)

27)

28)

No.3, p. 57 (1977).
H. Kumagai, Y. Awaya, Y. Tendow, T. Katou, and M. Akiba: "A Step Scan Controll
and a Data Accumulating System of an On-line Bragg Crystal Spectrometer", Reports I. P. C. R.,(in Japanese), 53, 153 (1977).
T. Watanabe, H. Tawara, and Y. Awaya: "By Using Heavy Ions as Projectile", Butsuri,(in Japanese), 32, 306 (1977).
T. Takahashi: "Spatial Distribution of Ionization Energy Deposited about the Path of a Heavy
Ion - Application to Target Theory", Tech. Rep. Res. React. Inst., Kyoto Univ.,(in Japanese).
E. Vagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: "Defect Structures of Slightly Reduced
Semiconducting Rutile as Observed by the Channelling Method", Rad. Effec. in Semiconduc.
1976, The Inst. of Phys., London, p.485 (1977).
E. Vagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: "Investigation of Ti Interstitials in
Slightly Reduced Rutile (Ti0 2 ) by Means of Channeling Method", J. Phys. Soc. Japan, 42,939 (1977).
H. Sakairi, E. Vagi, A. Koyama, T. Karasawa, and R. R. Hasiguti: "Atomic Displacement in
Copper Irradiated with Protons, a-Particles and Carbon Ions from a Cyclotron", J. Phys. Soc.
Japan, 43, 999 (1977).
K. Matsumoto, T. Kataoka, M. Terasawa, M. Shimada, S. Nakahigashi, H. Sakairi, and E. Vagi:"Embrittlement of Austenitic Stainless Steel Irradiated with a-Particles", J. Nucl. Materials,
67,97 (1977).

29) A. Koyama: "Contribution of Directly Excited Electrons to the Secondary Electron Emission
from Al by High Energy Proton or a-Particle Bombardment", Japan. J. appl. Phys., 16,431(1977).
30) N. Shiotani, T. Okada, H. Sekizawa, S. Wakoh, and Y. Kubo: "Angular Correlation of Positron
Annihilation Radiation in Chrominum and Molybdenum", J. Phys. Soc. Japan, 43, 1229 (1977).
31) T. Mizoguchi, S. von Molnar, G. S. Cargill III, T. Kudo, N. Shiotani, and H. Sekizawa:"Structure and Physical Properties of an Amorphous Cus 7 Zr43 Alloy, Amorphous Magnetism
II", Ed. by R. A. Levy and R. Hasegawa, p.5l3, Plenum Press (1977).
32) T. Nozaki, K. Fukushi, and T. Irie: "Some Radiohalogen Derivatives of Cholesterol",J. Labelled Comp., 13,226 (1977).

15333) Y. Harata, M. Matsui, and M. Imamura: "Radiation-Induced Chain Isomerization ofcis-2-Butene in Benzene Solution", Chern. Lett., 1977, 199.
34) S. Kitayama and A. Matsuyama: "Separation of DNA-Dependent DNA Polymerase Activities in
Micrococcus radiodurans", Biochim. Biophys. Acta, 4~ 23 (1977).
35) S. Kitayama, K. Shiratori, F. Yatagai, and A. Matsuyama: "Enhanced Lethal Effect of Various
Agents on M. radiodurans by Postincubation at Nonpermissive Temperature", Agr. BioI. Chern.,
41, 2297 (1977).

36) F. Yatagai and A. Matsuyama: "LET-Dependent Radiosensitivity of Escherichia coli K-12 rec
and uvr Mutants", Radiat. Res., 71, 259 (1977).

154(Papers presented at meetings)

1)

2)
3)
4)
5)

T. Inamura: "A Comment on Calculations of Multiple Coulomb Excitations with theWinther-De Boer Code" , The IPCR Symp. on Coul. Excit. of Atom. Nucl. and the Related
Problems, Wako, Jan. (1977).
T. Inamura: "Coulomb Excitation with Proj ectile Energies Exceeding the Coulomb Barrier",
The IPCR Symp. on Coul. Excit. of Atom. Nucl. and the Related Problems, Wako, Jan. (1977).
A. Hashizume: "Coulomb Excitation of High Spin States of Deformed Nuclei", The IPCR
Symp. on Coul. Excit. of Atom. Nucl. and the Related Problems, Wako, Jan. (1977).
T. Motobayashi: "Alpha-Transfer Reactions between Light Nuclei", Symp. on Light and Heavy
Ion Reactions, Osaka, Jan. (1977).
T. Takahashi: "Ionization Efficiency in Condensed Phases", Symp. on the Heavy Ion Irrad.
Effect on Biological Material, Oiso, Jan. (1977).

6)

A. Hashizume: -"High Spin States in Even Cadmium Isotopes", The IPCR Symp. on High
Spin States, Wako, Feb. (1977).

7)

E. Yagi, A. Koyama, H. Sakairi, M. Iwaki, and R. R. Hasiguti: "Ni-Ion Irradiation of AI",

Heavy Ion Symp. , Toyonaka, Feb. (1977).
8) I. Kohno: "Multiply-Charged Heavy Ion Source", Symp. on Ion Sources and Application
Technol., Tokyo, Feb. (1977).
9) I. Kohno, A. Shimamura, and T. Tonuma: "A Penning Multiply-Charged Ion Source for The
IPCR Cyclotron and Linac" , Symp. on Ion Sources and Application Technol. Tokyo, Feb.
(1977).
10) T. Doke, T. Hayashi, K. Ito, T. Yanagimachi, S. Kobayashi, K . .Hisano , K. Nagata, and
M. Miyajima: "Observation of Relativistic Primary Cosmic Ray Particles with Z>26", Primary
Cosmic Ray Symp. , Tanashi, Tokyo, Mar. (1977).
11) T. Fujisawa, S. Motonaga, and H. Kamitsubo: "Acceleration of Polarized Proton on the
INS-Cyclotron" , Spring Divisional Meeting of Phys. Soc. of Japan, Saga, Apr. (1977).
12) K. Hiruta: "Gamma-rays from Incomplete Fusion Reactions Induced by Heavy Ions", Spring
Divisional Meeting of Phys. Soc. of Japan, Saga, Apr. (1977).
13) Y. Toba, H. Sakaguchi, N. Nakanishi, A. Goto, F. Ohtani, and N. Kishida: "Blocking Effects
in the Core-Excitation of 29 Si and 89 Y" , Spring Divisional Meeting of Phys. Soc. of Japan,
Saga, Apr. (1977).
14) T. Shimoda, M. Ishihara, H. Kamitsubo, T. Motobayashi, and T. Fukuda: "Measurement ofParticle-Particle Correlation in Heavy Ion Reaction (II)", Spring Divisional Meeting of Phys.
Soc. of Japan, Saga, Apr. (1977).
15) H. Amakawa and K. I. Kubo: "Incident Energy Dependence of the (p, t) Reactions", Spring
Divisional Meeting of Phys. Soc. of Japan, Saga, Apr. (1977).
16) T. Hoshino: "Attempts to Extend the Thomas-Fermi Approximation", Spring Divisional
Meeting of Phys. Soc. of Japan, Saga, Apr. (1977).
17) M. Odera: "Fabrication of the Drift Tubes of the RILAC", Spring Divisional Meeting ofPhys. Soc. of Japan, Saga, Apr. (1977).
18) T. Doke, T. Hayashi, K. Ito, T. Yanagimachi, S. Kobayashi, K. Hisano, K. Nagata, and
M. Miyajima: "Observation of the Flux of Relativistic Primary Cosmic Ray Particles with
Z>26" , Spring Divisional Meeting of Phys. Soc. of Japan, Saga, Apr. (1977).

15519) T. Takahashi, Y. Awaya, K. Izumo, T. Tonuma, A. Hashizume, S. Uchiyama, and T. Doke:"Electronic Stopping Power of Several MeV /amu C- and He-ions", Spring Divisional Meetingof Phys. Soc. of Japan, Yamaguchi, Apr. (1977).
20) H. Sekizawa, K. Asai, T. Okada, and N. Shiotani: "Perturbed Angular Correlation ofGamma-Rays Emitted from Cd in NiFe2 0 4 ", Spring Divisional Meeting of Phys. Soc. of Japan,
Yamaguchi, Apr. (1977).
21) Y. Awaya, K. Katou, H. Kumagai, T. Tonuma, Y. Tendow, K. Izumo, T. Takahashi,
A. Hashizume, M. Okano, and T. Hamada: "Ti K X-Rays Induced by Heavy Ion Bombardment",
Spring Divisional Meeting of Phys. Soc. of Japan, Yamaguchi, Apr. (1977).
22) M. Uda, K. Maeda, Y. Awaya, M. Kobayashi, Y. Sasa, H. Kumagai, and T. Tonuma: " Bonding
Effect in Characteristic X-Rays Induced by Heavy Ions", Spring Divisional Meeting of Phys.
Soc. of Japan, Yamaguchi, Apr. (1977).
23) S. Kitayama and A. Matsuyama: "DNA Polymerase of M. radiodurans. I. Purification andProperties", Ann. Meet. of the Agr. Chern. Soc. of Japan, Yokohama, Apr. (1977).
24) T. Inamura: "Gamma-Rays from an Incomplete Fusion Reaction Induced by 95 MeV 14N",
Symp. on Highly Excited States, Osaka, Apr. (1977).
25) Y. Harata, M. Matsui, and M. Imamura: "Radiation-Induced Chain Isomerization of cis-2-Butene
in Benzene Solution", 36th Ann. Meet. of the Chern. Soc. of Japan, Osaka, Apr. (1977).
26) B. Imanishi: "Coupled Channel Analysis of the 12 C + 13 C Resonances with the Core-Exchange
Model", Intern. Conf. on the Resonances in Heavy Ion Reactions, Hvar, Yugoslavia,
May-June (1977).
27) O. Tanimura and B. Imanishi: "Folding Model Study of Fusion Cross Section and Resonancein 12 C + 12 C Scattering", Intern. Conf. on the Resonances in Heavy Ion Reactions, Hvar,
Yugoslavia, May-June (1977).
28) T. Motobayashi, T. Ooi, S. Nakajima, and I. Kohno: "ex-Transfer Reactions Induced by Heavy
Ions to Excite the Ground State Band of 20 Ne", Intern. Conf. on Phys. of Light and Medium
Nucl., Florence, June (1977).
29) J. Delaunay and T. Nomura: "A Possible Low Lying {) Band in 58Ni", Intern. Conf. on
Phys. of Light and Medium Nucl., Florence, June (1977).
30) Y. Awaya, T. Katou, H. Kumagai, T. Tonuma, Y. Tendow, K. Izumo, T. Takahashi,
A. Hashizume, M. Okano, and T. Hamada: "The Dependence of Multiple Inner-Shell
Ionization on the Projectile Energies and on Target Elements by Nitrogen-Ion Bombardment
at the Energy above 4 MeV/amu", 10th Intern. Conf. on the Phys. of Elec. and Atomic
Collisions, Paris, July (1977).
31) M. Uda, K. Maeda, Y. Awaya, M. Kobayashi, Y. Sasa, H. Kumagai, and T. Tonuma: "Bonding
Effect in X-Ray Spectra Induced by 84 MeV N4+ Ions", 10th Intern. Conf. on the Phys. of
Elec. and Atomic Collisions, Paris, July (1977).
32) T. Hoshino, K. Yazaki, and T. Yukawa: "Canonical Quantization from the Time-Dependent
Hartree-Fock Theory in the Lipkin Model", Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977)[Contributed Papers, p. 122].
33) J. Delaunay and T. Nomura: "Systematics of High-Spin States in Even Fe Isotopes", Intern.
Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 264] .
34) A. Hashizume, T. Katou, Y. Tendow, and H. Kumagai: "Excited States in 104Cd via theeHe, 3n) Reaction", Intern. Conf. on Nuc1. Struct., Tokyo, Sept. (1977), [ibid., p. 335].

15635) A. Hashizume, T. Katou, Y. Tendow , and H. Kumagai: "High Spin States in 16 2Yb, 164Yb
and 166 Yb" , Intern. Conf. on Nucl . Struct., Tokyo , Sept. (1977), [ibid. , p. 406] .

36) Y. Toba, H. Sakaguchi, N. Nakanishi , A. Goto, F. Ohtani, and N. Kishida: "Blocking Effects
in the Core-Excitation of 29 Si" , Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid.,
p. 494].
37) M. Igarashi and M. Ichimura: "A New Method for Solving Coupled Equations for Scattering
Problems" , Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid. , p. 503] .
38) Y. Suzuki, T. Ando, and B. Imanishi: " Coupled Channels Analysis of a + 12C Scattering with
Orthogonality Constraint", Intern. Conf. on Nucl. Struct. , Tokyo Sept. (1977), [ibid., p. 515].
39) M. Kawai , B. Imanishi, and M. Ichimura: "Energy Dependence of Channel Coupling Effects in(d , p) Reactions" , Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p . 526].

40) T. Hasegawa, T. Fujisawa, S. Motonaga, N. Veda, T. Wada, Y. Toba, and N. Kishida:"Measurement of Analyzing Power for 12C(p, d)l1C Reaction at 27.4 MeV", Intern. Conf. on
Nucl. Struct. , Tokyo, Sept . (1977) , [ibid., p. 539].

41) K. Koyama, N. Nakanishi, and H. Ohnuma: "eHe, d) Stripping to Vnbound States in Light
Nuclei", Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 546].

42) N. Matsuoka, A. Shimizu, K. Hosono , T. Saito, M. Kondo, N.. Nakanishi, Y. Toba, A. Goto,and F. Ohtani: "eHe, 3He o ) and eHe, d) Reactions on 54Fe and 58, 60 Ni of 90 MeV", Intern.
Conf. on Nucl. Struct. , Tokyo , Sept. (1977), [ibid., p. 549].
43) N. Matsuoka, A. Shimizu, K . Hosono, T. Saito , M. Kondo, N. Nakanishi, Y. Toba, A. Goto,and F. Ohtani: " Continuous Proton and Deuteron Spectra Emitted in 3He Induced Reactions",
Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 574].

44) B. Imanishi, O. Tanimura, and H. Ohnishi: Repeated Neutron Transfer in the Elastic andInelastic Scattering of 16 0 on 17 0", Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977),[ibid. , p. 588].

45)

T. Motobayashi: "A Modified Brink's Semi-classical Theory for Heavy-Ion Induced Transfer
Reactions" , Intern. Conf. on Nucl. Struct., Tokyo , Sept. (1977), [ibid., p. 615].

46) T. Motobayashi, I. Kohno , T. Ooi, and S. Nakajima: "a-Transfer Reactions between Light
Nuclei", Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 628].

47) F. Soga, J . Schimizu, N. Takahashi, K. Takimoto, R. Wada, T. Fujisawa, T. Wada, and
H. Kamitsubo: "Study of the Quasimolecular Resonance by the 24Mg(a, 1,2C) 16 0 Reaction",Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 650] .

48) T. Motobayashi, S. M. Lee , T. Ooi, T. Numao, T. Fukuda, T. Shimoda, H. Vtsunomiya,
M. Yanokura, M. Ishihara, and I. Kohno: "Fusion Reaction in 12C + 14N and 16 0 + lOB
Systems", Intern. Conf. on Nucl. Struct. , Tokyo , Sept. (1977), [ibid., p. 662] .

49) T. Nomura, J. Delaunay, C. Tosello, and N. Bendjaballah: "Test of the Evaporation Model in
Heavy-Ion Fusion Reactions" , Intern. Conf. on Nucl. Struct. , Tokyo , Sept. (1977), [ibid., p. 666].

50) T. Fukuda , M. Ishihara, T. Inamura, T. Numao, T. Shimoda, and T. Nomura: "Complete
Fusion Cross Section Measurement by Beam Attenuation Method", Intern. Conf. on Nucl.
Struct., Tokyo , Sept. (1977), [ibid., p. 667] .

51) S. Yamaji, K. H. Ziegenhain, H. J. Fink, W. Greiner, and W. Scheid: "The Mass Transfer in the
Collision 238 V - 238 V", Intern Conf. on Nucl. Struct. , Tokyo , Sept. (1977), [ibid ., p. 670].

52) A. Iwamoto, K. Harada, K. Sato, S. Yamaji, and S. Yoshida: "Description of Heavy-Ion
Reaction and Fission with Linear Response Theory", Intern. Conf. on Nucl. Struct. , Tokyo,
Sept. (1977), [ibid. , p. 680].

15753) T. Shimoda, M. Ishihara, H. Kamitsubo, T. Motobayashi, and T. Fukuda: "Three Body
Process Associated with ~ Particle Emission in the Reaction of 14N + 93Nb", Intern. Conf. on
Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 703].
54) T. Inamura, K. Hiruta, T. Fukuda, T. Shimoda, and M. Ishihara: "Emission of Fast a-Particles
and a Peripheral Heavy-Ion Reaction", Intern. Conf. on Nuc!. Struct., Tokyo, Sept. (1977),[ibid., p. 735].
55) T. Nomura, H. Utsunomiya, T. Motobayashi, and T. Inamura: "Preequilibrium a-Particle
Emission from 209 Bi+l 4 N Reactions", Intern. Conf. on Nuc!. Struct., Tokyo , Sept. (1977) ,[ibid., p. 736] .
56) M. Ichimura: "Exchange Magnetic Moment Associated with a Two-body Spin-orbit Interaction",Intern. Conf. on Nucl. Struct., Tokyo, Sept. (1977), [ibid., p. 819] .
57) A. Koyama: "Theory of the Secondary Electron Emission from Al by High Energy Proton ora-Particle Bombardment", 7th Intern. Conf. on Atomic Collisions in Solids, Moscow, Sept. (1977).
58) K. Hiruta: "Measurement of Fast ~-Particles in Coincidence with 'Y-Rays Detected by Ge(Li)and the Angular Momentum Window for the Reaction", Intern. Symp. on Macroscopic
Features of Heavy Ion Collisions and the Pre-Equilibrium Process, Hakone, Sept. (1977).
59) T. Shimoda: "a-Light Product Correlation in the 14 N + 93 Nb Reaction and the Excitation ofLight Fragments", Intern. Symp. on Macroscopic Features of Heavy Ion Collisions and the
Pre-Equilibrium Process, Hakone, Sept. (1977).
60) T. Nomura: "Preequilibrium ~-Particle Emission from 209 Bi + 14 N Reactions Statistical
Analysis of Energy Spectra and Nuclear Temperature of a Composite System" , Intern. Symp. on
Macroscopic Features of Heavy Ion Collision and the Pre-Equilibrium Process, Hakone, Sept.
(1977).
61) T. Shimoda, M. Ishihara, H. Kamitsubo, T. Motobayashi, and T. Fukuda: "Measurement ofParticle-Particle Correlation in Heavy Ion Reaction (III)", Ann. Meeting of Phys. Soc. of Japan,
Tokyo, Oct. (1977).
62) S. Motonaga, N. Nakanishi, K. Ogiwara, and H. Kamitsubo: "Design Study of Separate Sector
Cyclotron for Heavy Ion", Ann. Meeting of Phys. Soc. of Japan, Tokyo, Oct. (1977).
63) K. Hiruta, T. Inamura, S. Ise, M. Ishihara, T. Shimoda, and T. Nomura: "Fast ~-Particle
Emission Process in Heavy Ion Reactions", Ann. Meeting of Phys. Soc. of Japan, Tokyo, Oct.
(1977).
64) N. Kishida, N. Nakanishi, Y. Toba, and H. Ohnuma: "The (d, p) Reaction at Ed = 24 MeV 1:
54Fe(d, p)55 Fe", Ann. Meeting of Phys. Soc. of Japan, Tokyo, Oct. (1977).
65) Y. Tendow, T. Katou, H. Kumagai, and A. Hashizume: "High Spin States in 166Yb", Ann.
Meeting of Phys. Soc. of Japan, Tokyo, Oct. (1977).
66) A. Hashizume, T. Tendow, T. Katou, and H. Kumagai: "High Spin States in 162Yb", Ann.
Meeting of Phys. Soc. of Japan, Tokyo, Oct. (1976).
67) T. Nomura, H. Utsunomiya, T. Motobayashi, T. Inamura, and M. Yanokura: "Pre-Equilibrium
a-Particle Emission from 209Bi + 14N Reactions", Ann. Meeting of Phys. Soc. of Japan,
Tokyo, Oct. (1977).
68) S. Uchiyama, T. Takahashi, Y. Awaya, K. Izumo, T. Tonuma, A. Hashizume, and T. Doke:"Electronic Stopping Power of 5 MeV/amu C- and He-ions", Ann. Meeting of Phys. Soc. ofJapan, Tokyo, Oct. (1977).
69) I. Kohno, A. Shimamura, T. Tonuma, and I. Takeshita: "Heavy Ion Source for the Linac (1)",Ann. Meeting of Phys. Soc. of Japan, Tokyo Oct. (1977).

15870) M. Odera: "Status of the RILAC" , Ann. Meeting of Phys. Soc. of Japan, Tokyo, Oct. (1977).
71) T. Doke, T. Hayashi, T. Yanagimachi, and S. Kobayashi: "Calibration for the Identification ofRelativistic Heavy Charged Particles in Plastic Films", Ann. Meeting of Phys. Soc. of Japan,
72)
73)

74)
75)

76)

Tokyo, Oct. (1977).
K. Kimura and M. Imamura: "Excitons in Alkali-Halide Single Crystals Studied by Pulsed
Heavy-Ion Beams", 20th Conf. Rad. Chern., Sapporo, Oct. (1977).
S. Kitayama and A. Matsuyama: "DNA Polymerase of M. radiodurans. III. DNA Po1ymerases
in Postincubated Cells or Radiosensitive Mutants", 20th Ann. Meet. of the Jap. Rad. Res. Soc.,
Sendai, Oct. (1977).
Y. Hattori, F. Yatagai, and A. Matsuyama: "Inactivation of Ribonuclease A by Cyclotron
Beams", 20th Ann. Mee!:.. of Jap. Rad. Res. Soc., Sendai, Oct. (1977).
F. Yatagai, S. Kitayama, Y. Kimura, K. Nozawa, and A. Matsuyama: "Induction of Mutations
in Bacteriophage <j>X 174 by Radiations", 20th Ann. Meeting of the Jap. Rad. Res. Soc., Sendai,
Oct. (1977).
M. Yanokura, H. Nakahara, and K. Miyano: "Decay of 211 At, 211 Po, and 207 Bi", 22th Meetingof Radiochem., Kanazawa, Oct. (1977).
77) T. Nozaki, M. Iwamoto, and Y. Itoh: "Comparison of Various Methods for the Production of
77 Br", 21th Discussion Meet. of Radiochem., Tatsunokuchi, Oct. (1977).
78) T. Nozaki, Y. Itoh, and K. Ogawa: "Comparison of Various Methods for the Production of
73 Se" , 21 th Discussion Meet. of Radiochem., Tatsunokuchi, Oct. (1977).
79) T. Nozaki and M. Iwamoto: "Activation Analysis of Oxygen on High-purity Silicon Surface",
80)
81)

82)
83)
84)

85)
86)

21th Discussion Meet. of Radiochem., Tatsunokuchi, Oct. (1977).
Y. Itoh, M. Aratani, and T. Nozaki: "Charge Spectra of 198 Hgn+ Produced from the B- Decayof 198 Au", 21 th Discussion Meet. of Radiochem., Tatsunokuchi, Oct. (1977).
H. Shinno, H. Shiraishi, R. Watanabe, H. Kamitsubo, I. Kohno, and T. Shikata: "Effects ofIrradiation Temperature and Prestrain on the Helium Embrittlement of SUS 316 Stainlesssteel", 81th Meeting of Japan Inst. of Metals, Hiroshima, Oct. (1977).
S. Kitayama, S. Miyai, and A. Matsuyama: "Exonuclease Activity Associated with DNA
Polymerase of M. radiodurans", 50th Ann. Meet. of Jap. Biochem. Soc., Tokyo, Oct. (1977).
Y. Awaya: "Studies of Heavy-Ion Excited X Rays in I. P. C. R. ", 3rd Hakone Symp. on the
Elec. Struct. and Collision Process of Heavy Ions, Hakone, Nov. (1977).
T. Doke, T. Hayashi, K. Ito~ T. Yanagimachi, S. Kobayashi, K. Nagata, and M. Miyajima:"On the Observation of Heavy Primary Cosmic Rays", Primary Cosmic Ray W. G. Symposium,
Tanashi, Tokyo, Nov. (1977).
Y. Awaya: " X Rays In'duced by Heavy Ions", Symp. on the Solid State Phys. by Using Heavy
Ions, Tokai, Dec. (1977).
S. Motonaga: "Design Study of Linac-Injected Separate Sector Cyclotron", Meeting on the
Next Project of Accelerator, Osaka, Dec. (1977).

159

14. LIST OF PERSONNEL

Members of the Board
DOTE Toshihiko± ~ fii{ Tffi (Chairman)
KAMITSUBO Hiromichi
1: j;f ti. ~NAKANE Ryohei~& f
ODERA Masatoshi'J' ~ lE ~m

Users Committee=

HAMADA Tatsuji~ EE ~(Chairman)
KAMITSUBO Hiromichi
1: j;f ti. ~MATSUYAMA Akira~ LlJ~
ODERA Masatoshi'j' ~ lE ~SEKIZA WA Hisashi I*l ~r#J=

HAMADA Tatsuji~ EE ~
KOHNO Isao
?OJ!I!.J:;JJ
NOZAKI Tadashi!I!.J 0IiijlE

IMAMURA Masashi
A, M
KOHNO Isao
?OJ!I!.J:;JJ
NOZAKI Tadashi!I!.J 0IiijlE
SAKAIRI Hideo
jj£ A ~ $Operation and Machine Maintenance GroupFU JIT A Shin
!1i EE
KAGEY AMA Tadashi?OJ!f
KOHNO Isao
OGIWARA Kiyoshi

tn

IKEGAMI Kumio
KOHARA Shigeo
NAKAJIMA Hisao
T AKEBE Hideki

ifu1:JL-=~'j''* m: ~

~ ~~r#J Ulj\$~~

Scientific and Engineering Personnel
Cyclotron Laboratory
AMAKAWA Hirotaka
7( )11 tf I>i
FUJIT A Jiro
!1i EE~~ISHIHARA Masayasu
KARASAW A Takashi
MOTOBA Y ASHI Tohru
NAKAJIMA Shunji~ !iih ~NOMURA Toru
!f M
::if
WADA Takeshi
~ EE
Ul

=

=

FUJISAWA Takashi!1i ~ ~ it
INAMURA Takashi
f1B M
-&!
KAMITS UBO Hiromichi
1: j;f ti. ~KOHNO Isao
?OJ!Iff:;JJ
MOTONAGA Shoshichi
5C 7J< lIB {::NAKANISHI Noriyoshi~ g§ *,c §SHIKA T A Takashi
1m 11 ~ ~Y AMAJI Shuhei
LlJ ift ~ f(Visitors)
HIRUTA Kotaro@ EE =¥=*t!~
ICHIMURA Munetake m M(Dept. Phys. , Tokyo Gakugei Univ.)j\(lnst. Phys., College General Education, Univ. ofTokyo)
IGARASHI Masamichi
E. + i.t lE~(Tokyo Medical College)
A, ~ )( ~(lnst. Nuc!. Study, Univ. of Tokyo)
IMANISHI Bunryu
KAMMURI Tetsuo~'fg ~(Dept. Phys., Osaka Univ.)
KATORI Kenji
HE ~ ~(lnst. Phys., Tsukuba Univ.)
KAWAI Mitsuji?OJ 1!J -:it ift(Dept. Phys., Kyushu Univ.)*=

KOIKE Masahiro 'j' ifu lE ti. (lnst. Nuc!. Study, Univ. of Tokyo)
LEE S. M.
ffi a(Centrum de Recherche Nucl. Strasbourg)-= ~?rJ(lnst. Phys., Tsukuba Univ.)
MIKUMO Takashi~ 7k ~ ~(Dept. Phys., Miinchen Tech. Univ.)
MORINAGA Haruhiko

*

160

NOJIRI Yoichi
ff fJL f$ (Lab. Nucl. Study, Osaka Univ.)
OHNUMA HajirnerB-m (Dept. Phys., Tokyo Inst. Technol.)m;7}( l-l!! (lnst. Nucl. Study, Univ. of Tokyo)
SHIMIZU lun
SHINNO HitoshifT fft(Nat. Res. for Metals)
SHIRAISHI Haruki
B -;0 ~ t§j(Nat. Res. for Metals)
SOGA Furninori
1f 1X: -X ~ (lnst. Nucl. Study, Univ. of Tokyo)
TAKAHASHI Noriaki~ m ~ Wj
(Lab. Nucl. Study, Osaka Univ.)
TAKAHASHI Noriyuki~% ¥(Dept. Phys., Univ. of Tokyo)
TAKEMASA Tadashi:lE\ i& jt ± (Dept. Phys., Saga Univ.)
T AKIMOTO Kiyohikoitm 1ffi (Dept. Phys., Kyoto Univ.)
UDAGAWA Takeshi+ B3 )11 ~ (Dept. Phys., Texas Univ.)
f1J B3 ~ (Dept. Phys., Kyoto Univ.)
WADA Ryoichi
YOSHIDA Hiroshi
E B3
5L (Dept. Phys. Tokyo Inst. Techno!.)

*

m

*

(Students)
HASHIMOTO Naoki@: tlij(Dept. Phys., Tokyo Inst. Techno!.)ISE Sugao
fjf~ ~ j;l $I(Dept. Phys., Tokyo Gakugei Univ.)
KISHIDA Norio
W: B3 J{IJ 1:. (Dept. Phys., Tokyo Inst. Technol.)MIAKE Yasuo=: ~ ~~ (Lab. Nuc!. Study, Osaka Univ.)
NORO Tetsuo
ff 8 :gr ~ (Dept. Phys., Kyoto Univ.)
001 Takao# ~ $(lnst. Phys., Tsukuba Univ.)
SATO Kenichifir. .iIi 'l!l- (Dept. Phys., Tohoku Univ.)
SHIMODA Tadashi
T B3
lE (Dept. Phys., Kyoto Univ.)
TANAKA Koichiro
B3 r:pM-~~(Dept. Phys., Univ. of Tokyo)
TOBA Yoshiyuki
7i- ;y:] 5' $(Dept. Phys., Kyoto Univ.)
UTSUNOMIY A Hiroaki+$'85L1it(Dept. Phys., Kyoto Univ.)
Y ANOKURA Minoru:RffE- ~ (Dept. Chern., Tokyo Metropolitan Univ.)

m*

'*

*

Linac Laboratory~~QTWjCHIBA Yoshiaki£. ff~
HOSHINO Tohru
KAMBARA Tadashi
fIIll*IE
ODERA Masatoshi'J' ::!f IE ~TAKESHITA Isao
1fTT~~
Lll - ~~YOKOY AMA I chirom

HEMMI Masatakej! ~ i& :lEt
INOUE Toshihiko# 1:: fli;: tf;
MIY AZAWA Yoshitoshi'8 ~ 1* fi&
SHIMAMURA Akira~ M~
TONUMA Tadao
YOSHIDA Fusako
5' B3 m T

(Visitor)
TAKEDA Shigeru

1fT B3~(Nat. Lab. High Energy Phys.)

Radiation Laboratory
AWAYA Yohko~ Jlfl ® T
HASHI ZUME Akira
M
KA TOU Takeo
IJIl.iIi:lE\ !it
KUMAGAI Hidekazu~~ ~;fO
TAKAHASHI Tan
~
1=l

mm
m

*

HAMADA Tatsuji~B3:il=IZUMO Koichi
1±l ~J'tKONNO Satoshi~!Iff~
OKANO Masaharu
1tiTJ!Iff J{ mTENDOW Yoshihiko7(:@ 7f tf;(Visitors)
DOKE Tadayoshi
FUJIOKA Manabu(Sci. and Eng. Res. Lab., Waseda Univ.)(Dept. Phys., Tohoku Univ.)

161

**

HA Y ASHIBE Shogo-§=B IlR Wr(Dept. Phys., Tohoku Univ.)
no Masahiro ~ ~ IE
(Tokyo Metropol. leriatric Hosp.)
NAGAHARA Teruaki 7k~ IYj(lnst. Atomic Energy, Rikkyo Univ.)n
IYj(J apan Anal. Chern. Res. Inst.)
SUZUKI Kazuaki
TAWARA Hiroyuki
tf ~(Dept. Nucl. Eng. , Kyushu Univ.)

'*

'*

*-

*

(Student)
f*J LlJ fo ¥(Sci. and Eng. Res. Lab., Waseda Univ.)

KOY AMA Akio
Ij\ LlJ IlR fit
SHIOT ANI Nobuhiro
jtg it g iJL

SAKAIRI Hideo
ttY: A ~ fit
YAGI Eiichi/\%: ~UCHIY AMA Sadayuki
Metal Physics Laboratory*(Visitors)
f! IJ ~ 1:f(Faculty of Eng., Univ. of Tokyo)~(Dept. Metallurgy and Materials Sci. Faculty Eng., Univ.
of Tokyo)
TANIGAWA Shoichiro:fr JII J± - ~~(Dept. Metallurgy and Materials Sci. Faculty Eng. ,Univ. of Tokyo)

HASIGUTI R. Rukiti
NAGAI Ryo
7k*

(Student)
B If t±l ~.HI NODE Kenjim(Dept . Metallurgy and Materials Sci. Faculty Eng., Univ .
of Tokyo)

Magnetic Materials Laboratory
ASAI Kichizom * =g a

SAKAI Nobuhiko

:!&

* ®"

OKADA Takuya

fIITJ-9'i iQ~ ~SEKIZAWA Hisashi

fi;

EEl

(Visitor)
MIZOGUCHI Tadashi

m IJ

IE

(Dept. Phys., Gakushuin Univ.)

Ceramics Laboratory** m~

KOBAYASHI Masayoshi
IJ\
SASA Y oshihikot!r. ~ £ fi;

MAEDA Kuniko
UDA Masayuki

M EEl j:!) T

f

EEl

rc; ~

Nuclear Analytical Chemistry Laboratory
AMBE Fumitoshi~$ xf$:
ARA T ANI Michim :fr~ ~IWAMOTO Masako~ *IE TTERAI Yoshiro~~ ~~AMBE Shizuko'!i. $ M T
ITO Y oshikoW
7r T
NOZAKI Tadashi
If ~
IE

*

(Visitors)
FUKUSHI Kiyoshi
m ± iff (Nat. Inst. of Radiological Sci.)
HARA Toshihiko
f$: fI;(Nat. Nakano Chest Hosp.)
IRIE Toshiaki
A IT. ~ ~(Nat. Inst. of Radiological Sci.)KASIDA Yoshihiko~ EEl ~ fi;(Nat. Inst. of Radiological Sci.)
TAKI Ko
7t@:¥ (Dept. of Hygen. , Kitazato Univ.)

'*

*

tb1

162

Radiation Chemistry Laboratory
IMAMURA Masashi
KIRA Akira
E ~KIMURA Kazuie(Visitor)
MATSUI Masao~ it lE ~(Dept. of Pharmacy, Hokuriku Univ.)(Student)
HARATA Yasuo

1* EB

'* $

Radiobiology Laboratory
HATTORI Yukihiko
KIT A Y AMA Shigeru
Y A T AGAI Fumio~Ii tm Dfffi~t LlJin

KANEKO Ichiro~ T - .e~
MATSUY AMA Akira
~ LlJ

~.

~EB~ )(~(Visitors)(Faculty of Medicine, Univ. of Tokyo)
OKADA Shigefumi /b1.I EB m: )((Dept. Cytogenetic, Medical Res. Inst. , Tokyo Medical
SASAKI Masao
fir. k *lE~
and Dental Univ.)
SAWADA Shozo ~ EB ~ .=:(Res. Inst. Nucl. Medicine and Biology, Hiroshima Univ.)
Safety Control Affairs Office
HAMADA Tatsuji
SAKAMOTO Ichiro.li -t- il-~
IGARASHI Kazui
USUBA Isao
~ ~
~

163

15. LIST OF OUTSIDE USERS AND THEIR THEMES(Jan. - Dec. 1977)
I)

T. Furuta, K. Fukai, T. Otomo, andJapan Atomic Energy Research Inst.

H. Kamizuka"Study of Effect of Helium Babbles on
the Mechanical Behavior of Stainless Steel"2)

M. Shimada, K. Une, M. Terasawa, andToshiba R. and D. Center

K. Kohashi"Cyclotron Irradiation for Study of FBR
Ma terial Em bri ttlemen t"
3)

A. Hishinuma, K. Fukai, and T. Furuta

Japan Atomic Energy Research Inst.

"Simulation Test on Neutron
Irradiation Damage of Stainless Steelfor Fast Breeder Reactors by Ct
Born bardmen t"
4)

H. Nakahara, K. Miyano~ M. Yanokura,

Faculty of Science , Tokyo Metropolitan Univ.

M. Watanabe, and Y. Nakamura"Study of the 55 Mn + Ct Reaction"
5)

H. Nakahara, M. Watanabe,*Faculty of Science, Niigata Univ.

Faculty of Science , Tokyo Metropolitan Univ.

H. Muramatsu , M. Yanokura,
Y. Nakamura, and Y. Nagame"Study of the 55 Mn + 3 He Reaction"
6)

N. N agashima

Semiconductor Department, Hitachi , Ltd.

"Determination of C in Si by
Activation Analysis"
7)

K. Komura and N. Yanase

Faculty of Science, Kanazawa Univ.

"Measurement of Excitation Function
for the U + 3He Reaction"
8)

Y. Honma and K. Kurata"Production of 48y , 48 Cr , 51 Cr , 81 Rb ,and 82 m Rb"

Kyoritsu College of Pharmacy

164

9)

K. Hata

Japan Atomic Energy Research Inst.

"Production of 237 Pu"
10) K. Yuita

National Inst. of Agricultural Sciences"Production of 43 K"
11) H. Nakahara, N. Watanabe, and
Y. Nakamura

Faculty of Science, Tokyo Metropolitan
Univ.

"Production of 57 Cr by the 55 Mn(a, xn)
Reaction"12) K. Usami and K. Mukai

Hitachi R. and D. Center"Surface Analysis by Charged Particle
Activa ti on"13) H. Nakahara, K. Muramatsu,
M. Watanabe, and Y. Nakamura"Study of the Natural Cd + 3 He
Reaction"

Faculty of Science, Tokyo Metropolitan
Univ.

165

AUTHOR INDEX
20

IGARASHI Kazui

1i + ,lit-EX

mi:i ~ ~ 119, 139

IKEGAMI Kumio

i1jLl:::1L-=~

1M AMURA Masashi

A,M

IMANISHI Bunryu

A,@xlmAMAKAWA Hirotaka
ARATANI Michi

7()11 tW ~~#BffiJ.

ASAI Kichi zo

106
85,89,91,93
96, 99AWAYA Yohko*~~-T

DOKE Tadayoshi~

DOY AMA Masao:¥W~~* ,*, ~IT!JL~~

EJIRI Hiroyasu

FUJITA Shin

-9'!

A IT ~ ~134

INAMURA Takashi

8, 18,34

ISE Sugao

31, 36

fffi *1

109, 111

Hi iR ~;:it

FUJISAWA Takashi

122, 124

1=1

El

66

IMAZATO Jun

IRIE Toshiakj

2

M!

A,m

82,89

77

141

W~~~Mt58, 63, 67

58,67
43 , 54, 56,
58, 66, 67

ISHIHARA Masayasu

HiEEm EE ~ ~FUKUDA Tomokazum±

FUKUSHI Kiyoshi

m

54,56

ITOH Yoshiko* 7f -TW

IWAMOTO Akira

134

HAMADA Tatsuji~

HARA Toshihiko

1*

EE Ji

=

fiiJ. '§;

lli ~ ~ -IZUMO Koichi

134

KAGEY AMA Tadashi~

KAMBARA Tadashi

fIll f~48

48, 134:!fi::<$;: IE -T

89,91,93

1* EE B L WJ

HARADA Kichinosuke

at1:!fi::<$;:IWAMOTO Masako

GOTO Akira

119 , 134

116

89 , 91 , 93

Ll1

IE

2, 6

IE

96

HASEGAWA Takeo* i:i )11 ft\~

8, 18,22

KAMITS UBO Hiromichi

1: P¥ ~ J1!

HASHIZUME Akira

fi m

69, 72, 74
77 , 85, 89 ,91, 93

KAMMURI Tetsuo

lGL

1Y ~

KANEKO Ichiro

4: -T -

f!~

132

~ iR

~

HASIGUTI R. RyukitiM

fi 0 Ili B

102 , 1048, 10, 13, 18
34.43,54, 56 ,114

25

HA TTO RI Yukihiko

KARASA WA Takashi

HA Y ASHI Takayoshi

KATOU Takeo

1Jo § :IE\: 1ii

69, 72,74 , 85 , 91 , 93

KA WAI Mitsuji

iDJ ~ -Yt It'1t

31

HINODE Kenji

B !J lli;@ tEl

109 , 111

HIRUTA Kotaro~ EE *::t:~~

HOSHINO Tohru£!J

ICHIMURA Munetake

='f

58,67

KIMURA Kazuie

51

KIRA Akiram M *:lEt

31

KISHIDA Norio

5

;1(
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H - '¥~

122

124

W: EE JtIJ ~22, 2815, 134

166

~t

IlJ

itt

IJ\

** 1ft ~'* m ~2, 6

KIT A Y AMA Shigeru
KOBAYASHI Masayoshi
KOHARA Shigeo

IJ\

99

2, 39,40, 82, 87, 96
114, 149

KOHNO Isao
IJ\ IlJ fIB.$

KOY AMA Akio

102, 104* ma

69, 72, 74 , 85
89, 91, 93 , 96,
99

*~

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KUMAGAI Hidekazu
LEE S. M.

126, 12839

r:p IlJ {8 :t:~~

NAKA Y AMA Shintaro
NOJIRI Yoichi!Iff JJL i$ -NOMURA Toru

!Iff M43:Jj!

NOZAKI Tadashi

58, 60 , 63, 66 , 67, 81
116, 119 , 134, 137 ,139

if

ODERA Masatoshi

IJ\ $j= IE ~OGAWA Koji*

IJ\ )1177

144, 145, 146, 147

137

{jz

OGIW ARA Kiyoshi

V<l*

m

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m

2, 4, 10

MAEDA Kuniko

MB3*Br99

OHNUMA Hajime

MA TSUI Masao

~*IE~

124

OHT ANI Fumihiko

:*~X$

22

mllJ

:Yt

OKADA Shigefumi/U1JB3]tX

132:::: J:IJl ~ ~~43

MA TSUY AMA Akira
MIAKE Yasuo

126 , 128, 130 ,132

WI ~ I~' J{1j

MINAMISONO Tadanori

43* ;q:. 1fi

MIY ANO Kazumasa'8 ff ~ i&79

001 Takao

MIZOBUCHI Akira

~ mM

[!lj

43

SAKAGUCHI Harutaka

fIB $

20

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MORI Akihiko~ 7Jc ~ $MORINAGA Haruhiko~

MOTOBA Y ASHI Tohru
MOTONAGA Shoshiehi
NAGAI Ryo

7Jc

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91, 93,137

40:W I=l til ~*SAKAI Nobuhiko

:!&

66

SAKAI RI Hideo!& A

39,40 , 54
56, 63, 87

SAKAMOTO lehiro

8, 10 , 13
18

SASA Y oshihiko

111

106

!liTJ!Iff J{ til

OKANO Masaharu:*m~ B3 l?-OKADA Takuya

28

:!&

1§ $

106

*- 1fi*102, 104~ ~~fir:k~~

SASAKI Masao

fir:k*1E~

132

SATO Keniehi

fir:~J1l-

48

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NAKAJIMA Hisao

r:p ~~ tb1 1fi

2, 6

SA WADA Shozo

NAKAJIMA Shunji

r:p 9h ~40

SEKIZA WA Hisashi~tR

SHIBAT A Tokushi~EE~;:t

NAKAMURA Masanobu
NAKANISHI Noriyoshi

r:p

r:p

=

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1810, 13, 22,28141, 143

99'*

NAKAHARA Hiromi ehi

SHIKATA Takashi

22

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132

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77

114

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SHIMAMURA Akira
SHIMIZU lun

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SHIMODA Tadashi
SHINNO Hitoshi~ff

SHIOTANI Nobuhiro

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TAKESHITA Isao

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T AKIMOTO Kiyohiko

?It

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TENDOW Yoshihiko

7(

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145

* m '$UCHIYAMA Sadayuki

J::EB

8, 18

USUBA Isao

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WADA Takeshi

fD EB

8, 18, 34/\

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YAMADA Satoru

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89,91,93,96,99,
149

YUKA WA Tetsuyuki

18 , 22

126,128,130,132

20, 51
f!~

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10,13 , 145, 147

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SL.

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82
39, 63,66,

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8, 18, 22, 28

89

141

toEBE!:~YOKOY AMA Ichiro

43

P'l LiJ Ji ¥~WADA Ryoichi~ 7i '$ ~~ : ~~' 74, 85, YOSHIDA Hiroshi

7i- ::fI E ¥TONUMA Tadao

UEDA Nozomi

Y ANAGIMACHI Tomoki

2, 41t )11 J± - f!~

TANIGAWA Shoichiro

34

89,91,93

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TANAKA Koichiro

TO BA Y oshiyuki

43

Jit i& jT ±

fr r

99

YAGI Eiichi

43

EL

fEB M3z

WATANABE Ryoji

18, 34iWb ~ ~ ¥iWb ~T AKEMASA Tadashi

TAKIKo114

iWb ~ lM, ~TAKAHASHI N oriyuki

UDA Masayuki

UTSUNOMIY A Hiroaki
106, 109, 111* 1m ==f~

TAKAHASHI Noriaki

T AKEBE Hideki

114:IX )( 1r

SUGIMOTO Kenzo

TAKAHASHI Tan

39, 54, 56 , 58 ,67

i.i![~][SL.

SHIRAISHI Haruki
SOGA Fuminori

149

~

48

)11 'fg Z

51

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広沢