the Institute of Physical and Chemical Research
Wako-shi, Saitama Pref., JAPANIPCR cyclotron
Progress Report 1976

Vol. 10

,peR

Cyclotron Progress ReportVol. 10The Institute of Physical and Chemical Research"RIKAGAKU KENKYUSHO" Wako-shi , Saitama, 351 JAPAN
December, 1976

Editors

A. Hashizume

T. Inamura

H. Kamitsubo

A. Matsuyama

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

PREFACE TO PUBLICATION OF THE 10TH PROGRESS REPORT1.

INTRODUCTION

2.

MACHINE OPERATION

3.

MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS
3-1.

2

3

The Production of Multiply Charged Lithium and Magnesium Ions
from a PIG Source .............................................

5

3-2.

An Improved Heavy Ion Source

7

3-3.

An Automatic Control of the Pumping System for the Vacuum Chamberof the Cyclotron ....................... . . . . . . . . . . . . . . . . . . . . . . .

10

3-4.

Ultra-compact Cyclotron

13

3-5.

Operation of the IPCR Polarized Ion Source for the INS Isochronous
Cyclotron ....................................................

16

Design Study of a Separate-Sectored Cyclotron for Heavy-Ions

19

3-6.
4.

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

NUCLEAR PHYSICS
Scattering and Reactions

4-1.

Blocking Effect in the Core-Excitation of 29 Si

21

4-2.

Study of the S4Fe(d, p)SS Fe Reaction at 24 MeV

23

4-3.

Particle-Particle Correlation in Heavy Ion Reaction

26

4-4.

Gamma Ray Multiplicities for Deep Inelastic and Quasi-elastic
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29Complete Fusion Cross Section Measurement by Beam Attenuation
Method31

Measurement of the Efficiency of 8 Be Detection by Position
Sensitive Detector and Study of the 12C(a, 8Be)8Be Reaction

33

4-7.

a-Transfer Reaction between 1p or 2s-1d Shell Nuclei

35

4-8.

Critical Angular Momentum in 10 Be + 16 0 Compound Reactions . . . . . . . . .

38

4-5.

4-6.

Page
4-9.

5.

Repeated Neutron Transfer in the Elastic- and Inelastic Scatteringof 16 0 on 17 0 ................................................

40

4-10. Nuclear Deformation and Finite Size Effect of Projectile inInelastic Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

434-ll. DWBA Analysis of Four-Nucleon Transfer Reaction 208 Pbe 6 0, 12 C)212 Po

46

4-12. Effects of Recoil and Sequential Transfer in 12Ce4N, 12C)14N
Reaction at 79 MeV Incident Energy ...............................

49

4-13. Collective Mass Transfer in the Collision 238 U_ 238 U ...................

51

4-14. Elastic and Inelastic Scatterings of Deuteron from Even-Mass
Isotopes of Molybdenum .........................................

54

4-15. Polarization Measurement of 12 Bg.s. Produced in 14N-Induced Reaction

.....

56

Gamma Rays from an Incomplete Fusion Reaction Induced by
95 MeV 14N ...................................................

59

NUCLEAR PHYSICS
Nuclear Spectroscopy
5-1.

6.

7.

eHe, 3n) Reaction

5-2.

Excited States in 104Cd via the

5-3.

Internal Conversion Electrons of 136 Ba . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

62
65

NUCLEAR INSTRUMENTATION
6-l.

Efficiency for Detecting 8Be Nuclei with a Position Sensitive Detector. . . . .

68

6-2.

A Modified ~E-E Counter Telescope

70

6-3.

A Gas Target System for Heavy Ion Reactions................ :-. . . . . .

72

6-4.

Computer Development. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
On-line Computer OKITAK 4500

75

6-5.

A Charged Particle Identifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

76

ATOMIC AND SOLID-STATE PHYSICS
7-l.

K X- ray Spectra of AI, Ti, Cr, Fe, and Ni Induced by Nitrogen Ions. . . . .

78

7-2.

Measurement of Radiative Electron Rearrangement in Ti

81

7-3.

The L2 - L3 X Coster-Kronig Transition Probability in Hf

83

Page
7-4.

8.

Energy Loss and Straggling of C and He Ions in Foils of Metals
and Compound .................................................

85

7-5.

Bonding Effects in X-ray Spectra Induced by Heavy Ions ...............

86

7-6.

Positron Study of Phase Transformations in Alloys. . . . . . . . . . . . . . . . . . . . .

89

7 - 7.

Positron Lifetime Measurements for Aluminum and Magnesium Using
the Internal Sources Produced by Nuclear Reactions ...................

91

7 -8.

Atomic Displacements in Metals Caused by Irradiation .................

93

7 -9.

Observation of Defect Structures of Slightly Reduced Rutile (Ti0 2 )by Channcl~g Method ...........................................

96

7 -10. Perturbed Angular Correlation of Gamma-Rays Emitted from 111 Cd in
NiFe204 ......................................................

99

7 -11. Nitrogen Ion Implantation in CdTe for Optical Waveguides andWaveguide-type Electrooptic Modulators .............................

102

7-12. Helium Embrittlement of CTR Materials Simulated by Alpha Particle
Bombardment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

104

RADIOCHEMISTRY AND NUCLEAR CHEMISTRY
8-1.

8-2.

9.

Charge and Mass Spectra of Ions Occurring along the (X-Particle
Tracks in Mica106

Mossbauer Emission Studies of Defect Atoms in Solid after Nuclear
Decays and Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

109

RADIATION CHEMISTRY AND RADIATION BIOLOGY
9-1.

Isomerization of cis-2-Butene Induced by Heavy-Ion Irradiation. . . . . . . . . ..

III

9-2.

Emission and Absorption Spectra of KBr Irradiated with Heavy Ionsat 4.2 K ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

112

Influence of Air Layer in Front of Samples on the Inactivation of
Phage <j>X174 by Cyclotron Beam. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

114

The Effects of Cyclotron Beams on Survival of Cultured Chenease
Humster Cell V-79 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

117

LET Effect on the Trapped-Electron Formation in Organic Glasses
at 77 K ...... ............. ....................... .............

119

9-3.

9-4.

9-5.

Page

10.

PREPARATION OF RADIOISOTOPES AND LABELED COMPOUNDS

10-1. Production of Radioisotopes and Preparation of Labeled Compounds
for Medical Use .................................................
11.

12.

120

RADIATION MONITORING

11-1.

Routine Monitoring

123

11-2.

Neutron and Gamma-Ray Dose Measurement around Targets Bombarded
by Deuterons ................................. ' . . . . . . . . . . . . . . ..

125

HEAVY ION LINEAR ACCELERATOR PROJECT

12-1.

Status of Constructional Work in 1976

126

12-2.

Fabrication of the Drift Tubes of the First Accelerator Tank

127

12-3.

Fabrication of Quadrant-stacked Spiral Plate Coil

129

12-4.

Cooling Characteristics of Tape Coil .............................. , 130

12-5.

Cooling Characteristics of the Quadrant-stacked Spiral Plate Coil

132

12-6.

Deviation of the Magnetic Axes of the Quadrupoles from theGeometrical Center of the Drift Tubes. . . . . . . . . . . . . . . . . . . . . . . . . . . ..

133

12-7.

Field Harmonics of the Drift Tube Quadrupole Magnets

135

12-8.

A Digital Data Acquisition and Processing System for Study ofMagnetic Field ...............................................

138

Measurement of Alignment Error of the Drift Tube Array by the
Hot Wire Method .............................................

140

12-10.

Evacuation Test of the First Resonator

143

12-11.

Radiofrequency Characteristics of the First Resonator

144

12-12.

Trial Fabrication of Tape Coil for an Ordinary Quadrupole Magnet .....

145

12-13.

Design of the Ion Source for the Linac...........................

147

13.

LIST OF PUBLICATIONS .............................................. '

148

14.

LIST OF PERSONNEL .................................................

154

15.

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

157

AUTHOR INDEX .....................................................

159

12-9.

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

PREFACE TO PUBLICATION OF THE 10TH PROGRESS REPORT

After World War II , our institute underwent prolonged financial difficulty for years andthe facilities became obsolete in that period. Gradually, however, situation began improving
thanks to the endeavour of people of the institute and helps from outside. The legislation of1958 to reorganize RIKAGAKU KENKYUSHO as a non-profit research institute and subsequent
government approval of acquiring a new site of the institute at the present location to movefrom the old crowded Komagome area warranted the renewal of RIKEN. Construction of thecyclotron was planned at that time to take the place of the Nishina's cyclotron destroyed
after the War and symbolized our determination to improve our facilities. All the basic design
was made by members of the institute and constructional work was completed in the fall of
1966.
The design was unique at that time in its capability of acceleration of heavy ions such as
12 C, 14 N

and 16 0 as well as lighter ions and in the possibility of changing particle energy

widely. Shortly after the completion of the cyclotron , acceleration of heavy ions by tandem
Vande Graaffs became popular abroad. However in Japan , there were few other cyclotrons or
tandems which can accelerate heavy ions to sufficiently high energy until few years ago.
The RIKEN cyclotron has been the only high energy heavy ion facility in this country for these
10 years. Fortunately , operation of the cyclotron was found simple and easy in spite of its use
for wide variety of particles and energy . It must be mentioned that the people working in thefield other than nuclear physics have used high energy heavy particles as new means of researchin their fields and many remarkable results have been obtained. It is needless to say thatimportant contributions to nuclear study have also been made. All those studies have beenrecorded in the Progress Reports issued for these 10 years together with the technicalachievements made by the engineering staffs. This is the 10th volume and shows still growing
activity around the cyclotron. We are proud of our achievements made in the past and also areglad to see prospect of further development of research in this institute by use of the cyclotron
and the new heavy ion linac under construction.

;Ji.r7Jv£~
Shinji FUKUIPresident

2

1. INTRODUCTION

Ten years have elapsed since the first beam was successfully accelerated in our cyclotron.
Our cyclotron is the first one in Japan that has widely been used in fields not only of nuclear
physics but also in solid state physics, chemistry and biology.
The cyclotron continued to work, as before, in good condition all through last year.
Several improvements have been made in the machine and its accessory facilities.
A number of experimental studies on nuclear reactions and level structures were continued
from previous years. Heavy-ion induced X-rays were studied using a Bragg crystal spectrometer aswell as Si(Li) detectors with good energy resolution. Channeling experiments were continued
with high energy alpha particles. Perturbed angular correlation (PAC) studies were made ontransition metal ions in magnetic oxides.

Positron annihilation studies on metals were continued.

Emission spectra of alkali halides were measured under low temperature heavy-ion irradiation to
obtain information on initial species produced. Effects of heavy ions on DNA synthesis inbacterial and cultured mammalian cells have been investigated, together with the production ofradioisotopes and labelled compounds for the medical use.
The first resonator and the injector of the heavy-ion linear accelerator were installed in a newbuilding.

Hiromichi Kamitsubo
Editor3

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

During the period from Oct. 23, 1975 to Oct. 22 , 1976 the cyclotron was operated on the
24h-per-day basis.

Statistics of machine operation is given in Table 1.

The working time

meter for the beam , which indicated 4597h, was increased by about 19 % (744h) comparedwith that of the last year.

This increase in working time is due to the decrease in holidays

and in the loss by troubles.

Table 1.

Machine operation.

Date

Oscillator

Ion source

BeamOct. 23, 1975

42088.3 (h)45174.3 (h)14878.2 (h)Oct. 22, 1976

47050.3 (h)50354.2 (h)19474.9 (h)365 days4962.0 (h)5179.9 (h)4596.7 (h)56.6 %

59.1 %

52.5 %

Percentage of 365 days
Schedule in this period
Beam time

246 (days)

Overhaul and installation work

46 (days)

Periodical inspection and repair

32 (days)

Vacation and holidays

41 (days)

Table 2 shows beam time alloted to various activities in this period.

Requests for heavy

ion beams continued to increase and the cyclotron was operated 143 days with the heavy
ion source, which was 58.4 % of the total scheduled beam time.

The beam time alloted tothe inner atomic shell excitation study was increased by about 300 h and the study of
stopping power with heavy ion beams was newly begun.
Following troubles occurred during this period.
deionized cooling water was broken.

A bearing of the circulation pump for

Vacuum leak developed at vacuum seal of a ceramic

insulator which connects copper cooling water tube to the shorting plane.
seal was found eroded by electrolysis.
These troubles brought about a loss of about 12 days.

Metal of the vacuum

4

A cooling tower to remove heat from the cyclotron facilities was set on the roof of thecyclotron vault instead of the cooling pond used until then.

Table 2.

Scheduled beam time and subjects of activity in the period XI.
Heavy ionLight
particles

2241 (h)935 (h)3176 (h)321 (h)122 (h)443 (h)RI productiono (h)153 (h)153 (h)Nuclear chemistryo (h)155 (h)155 (h)Radiation chemistry

138 (h)74 (h)

212 (h)Fields other

Radiation biology

128 (h)80 (h)

208 (h)than Nucl. Phys.

Solid state physics

12 (h)

546 (h)558 (h)Inner atomic shell
excitation study

344 (h)48 (h)

392 (h)Stopping power study

34 (h)o (h)34 (h)

o (h)
o (h)
o (h)

75 (h)

75 (h)

106 (h)106 (h)

5 (h)

5 (h)

24 (h)

12 (h)

36 (h)

Total

3242 (h)2311 (h)5553 (h)Percent in total

58.4%

41.6 %

100 %Subject[ Nuclear reaction
In-beam spectroscopy

Nucl. Phys.

[ Nuclear medicine
Outside users

Nuclear fuel study

RI production
Development of instruments

Maintenance: operation and engineering
Exchange of ion sources

80 (h)

Reserved for beam time adjustment
and cooling of radio-activity

271 (h)Machine inspection and repair

744 (h)Total1095 (h)

Total

5

3. MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS

3-1.

The Production of Multiply Charged Lithium and Magnesium
Ions from a PIG Source

A. Shimamura, T. Tonuma, and 1. Kohno

In order to develop an ion source of lithium and magnesium for the cyclotron we
have studied the production of multiply charged ions of these metals from a PIG source.
Details of the ion source is shown in Fig. 1. The anode is made of stainless steel without
cooling and a stainless steel oven is used for the production of metal vapour.
operation of the ion source the use of a supporting gas is essential.

For theIts first function is toenable an arc to be struck in the ion source, and its second function is to keep the metal
vapour to maintain a stable arc.

We used argon as the supporting gas and studied the productionof multiply charged ions of lithium and magnesium.

The ion beam extracted from the ion-11 emfFig. 1. Cross-sectional view of the ion source.

CD - filament (W), G) - hot cathode(W),0- anode box (copper), 8)- slit plate(Mo),(1)- reflector cathode (W), @- cooling tube,(j)- ceramic chimney, 0- ceramic tube for thermo couple,
0- oven (stainless steel), @- ceramic paper,@- gas feed

6

)1A
100
)1A
90

Arc voltage

340V

Arc current

2.SA

Magnet i c field

6500G

Oven temp.

600°C

Ar

Ar3 +

90

SO

70

Arc volta ge

320V

Arc current

2.6 A

Magnetic f ield

5500G

Oven temp.

600°C

SO

70

60

60

50

50

40

lj+ lj2+

~

40
Mg+

X. l M 2+
10 g

30

30

20

20

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

10

O~~~==~----~~--------------

"l\
\

" A
Ar+

A

)\
o

V

V

\

--)

Fig. 2. M/q spectrum of ion beams

Fig. 3. M/q spectrum of ion beams ofof magnesium (supporting gas:lithium (supporting gas: argon).

argon).
0source was analyzed by a 180 mass-spectrometer.
lithium measured are shown in Figs. 2 and 3.

The charge spectra of magnesium and

7

3-2.

A n

Improved Heavy Ion Source

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

Heavy ions such as C,N and 0 have been accelerated in the cyclotron since 1967.

The

variety of particles and range of energies of the cyclotron are limited by its minimum accelerating frequency and maximum dee voltage (Fig. 1).

All kinds of ions are accelerated byfundamental mode since we cannot extract the beam by any harmonic mode on account of
adoption of the R-F type deflector.
Besides, ions of charge to mass ratio Zi! A = 0.25 (such as C 3 +, 0 4 + , and Ne s +) are notaccelerated because it was difficult to hold dee voltage for accelerating such ions. Os+ isroutinely accelerated instead of 0 4 + although the extracted beam intensity is about 5 % of
the beams of N 4 + and C4 +.

Therefore , it is necessary to increase the intensity of highly

charged ions from the ion source to extend the performance of the cyclotron.
According to our experimental data and several publications by others the production rateof multiply-charged ions in the PIG ion source with indirectly heated cathode , increases inproportion to the square or cube of the arc power and to inverse of the 12 th power of thegas flow rate. 1)

We have also experienced an increase in intensity of highly charged ions by adischarge chamber having a smaller diameter than that used at present.
An improved ion source was designed based on these well recognized facts.

The mainfeatures are as follows: a precise assembly of the electrodes, no hole other than ion extraction
slit is provided to allow reduction of gas flow and the use of an arc chamber with a smaller
Energy in MeV/ nucl.

7

4 4.5 5
i

j

I

i

8
I

9

10
I

i

11 12
i

j

13 14 15 16 17 18
j

I

I

i

[

I

2 0 ,---~~~,,~~~~~-y~~-,-,

Fig. 1. The resonance condition of the
IPCR 160 cm variable energy cyclotron,radius of beam exit is 74 cm. The dotted
6

7

10

8

9

Osci l lator

frequency in MHz

11

12

12.5

lines indicate the upper limit of dee
voltage.

8Fig. 2. Cross-sectional view of the ion source.

Kl : hot cathode (W), K2 : reflector cathode(W),CM : cathode mount (copper and water-cooled),
HSH : cathode heat shield (W), SH: electron shield,
F : filament, B : anode box (copper), SP: slit plate (Mo),S : Source aperture,o : distribution plenum, A : exhaust window,
I : insulator (steatite), J : cooled joint,
L : leading tube, T : supporting tube, G: copper spacer,
Power
input
AC 200V

to Console
lore

Vo~

j -- ~ ---300 VPower
supplyfordr iver

Pulse
input
QI

2SA 739

Q2 - Q14 2SC 1172

Fig. 3. Circuit of the pulsed arc power supply.

9bore diameter (see Fig. 2).

Also a pulsed arc power supply was designed which can produce

a large instantaneous arc power.

10 kW is available at peak.

The circuit consists of a power

tube and a transistorized driver stage and will be used with the above ion source and the power
supply working at present (Fig. 3).
We hope to be able to raise the intensity of N 5+ and 0 5+ and to accelerate new ionssuch as 0 6 + and Ne 6 +.

Reference

1)

Y. Miyazawa, I. Kohno, T. Inoue, T. Tonuma, A. Shimamura, and S. Nakajima: IPCR Cyclotron
Technical Report, No. 2(1972).

10

3-3.

An Automatic Control of the Pumping System

for the Vacuum

Chamber of the Cyc lotron

K. Ikegami, T. Kageyama, T. Watanabe, and T. Noda

The pumping system of the cyclotron is composed of 32", 14" and 6" oil diffusion pumps
connected in series, and several roughing pumps as shown in Fig. 1.1) Instead of manual
operation an automatic control device of the pumping system was developed and many valves
were replaced with pneumatic ones.
In the new control system, pumps and valves are operated automatically according to theindication of Pirani-detectors to evacuate the chamber of the cyclotron up to the pressureof 0.7 '" 1.0 X 1O~ Torr, and also to protect the pumping system against vacuum failure by
accidental leakage in the chamber.

Pirani detectors used can give trip signals at arbitraryvalue of pressure chosen between atomosphere and 1 X 10- 3 Torr. Figure 2 shows the graphic
handling board of the pumping system which is installed on the control panel, and each switch
is provided with a name card showing its function briefly.

When the switch "Auto" ispushed the pumping system can be operated automatically according to the predeterminedsequence for evacuation of the chamber by pushing the running switch but in the state of"MANU" the pumping system is operated by switching each pump and valve manually.
Figure 3 shows the standard circuit for the new control system which is the same one
as the unit circuit used previously. 2) In Fig. 4 the sequence of operation of the pumping

Pneumatic i so loti on
adm ittance vaLve
Air admittance valve
Ionization gauge
Pirani gauge
Mechan ical pump1500 Umin

Fig. 1. Schematic diagram of the vacuum system for IPCR
160cm cyclotron.

11

system is shown. The sequence begins from starting up of 1500 flm rotary pump andproceeds in due order up to evacuation of the chamber by the main diffusion pumps.

o@ AC 200V AC100V DC48V

@

@

000
P03

o

P5

P34

0

P6

:0::0::0::0:

0

o

o

@

-,--;--,------------------r- +48V
Lamps
o

o
WATE
OFF

ON

00

o

OFF ON

00
@

CillJ
0

NOT

0

OFF

ON

PIO 0

Qill

cS 0
0 0 P20

LV

P~1 ~2 ~3II

61 62 PJ4 ~ 66 ~1 ~2III_ _ _ _ _ _ _ _ _ _ _ _ ..J

AVl-6 C~P DP S DP R MPP S2 RP1500 RP650 M8300

000000000

o

@

@

@

Fig. 2. A diagram of handling board of thevacuum system.

+48V

0

Fig. 3. A diagram of a circuit for control
system.

12

Closing leak valve for accelerating chamber

Po> 5Torr
10-1< Po<5Torr
and P1<5Torr

Fig. 4. A sequence diagram of automatic operation of theinstallation. Po indicates the pressure at the accelerating
chamber. Pn (n=0""'6) corresponds to the vacuum at eachplace of the vacuum system shown in Fig. I.

References

1)

T. Tonuma, Y. Miyazawa, K. Yoshida, T. Karasawa, and H. Kumagai: J. Vacuum Soc.
Japan, 12, 11 (1969).

2)

T. Inoue, I. Kohno, and S. Takeda: Reports IPCR (in Japanese), 46, 103 (1970).

13

3-4.

Ultra-compact eyc lotron

T. Karasawa and K. Sakabe*

Cyclotron-produced radionuclides have been widely used in nuclear medicine as well as otherfields. Of all the different kinds of accelerators, a cyclotron is the most useful source ofradio nuclides. Carbon, nitrogen and oxygen are physiological key elements. Radionuclides of theseelements with short half-lives of 2 to 20 minutes cannot be transported and require "in-house"
preparation.
The ultra-compact cyclotron, the so-called "desk top" cyclotron to be described, aimes
particularly at radionuclides production of 11 C, 13 N, 15 0, and 18 F. The cyclotron is a 4-sector
radial ridge fixed energy AVF cyclotron. Its performances are shown in Table 1.
Table 1.

Performances of the ultra-compact cyclotron.

Target**energyRadionuclides

Nuclearreaction2

9.3 MeV

11 C, 13 N(p, d)

54 MHz4

4.3 MeV

11C, 13N, 15 0(d, n)

12.5 MeV

38 MHz2

11.5 MeV

18 F

9.4 MeV

54 MHz4

7.7 MeV

Particle

Energyf

Proton9.4 MeV

54 MHzDeuteron
3 He++

4.7 MeV

a-particle

Harmonic
numbereHe++, p)

f: Frequency of oscillator.
**: After passing through an entry window foil of target box.
1 500 Dia
10 N source

Feeder

o
o

t[)

N

Beam robe

Fig. 1. Birdeye view of the cyclotron.

* The Japan Steel Works, Ltd.

14

8co

Fig. 2(a) Holizontal section.

Fig. 2(b) Vertical section.

Table 2. Detailed parameters of the cyclotron.
(1)

MagnetGap

WeightDiameterFieldpole tip

600mm

Fe

7.5tonhill

50mm

2.4Teslapole base

720mm

Cu

0.5tonvalley 90mm

1.6Tesia

outermost

1500mmaverage

64.3mm

1. 84Tesla

Exciting coil: water cooled hollow conductor, 4A/mm 2 , 336tums
Power supply:

440AX90V 40kW, normal 24kW

Trimming coil:

two harmonic coil pairs at extraction radius

Extraction radius:

240mm(2) Radio-frequency system(3) Vacuum system

Frequency:

54MHz and 38MHz

Turbo-molecular pumps

two 250.e/s

Dee voltage:

35kV

Roots blower pump

30m 3 /hRotary pump

100f/min.

Final vacuum

1 X 10-5 Torr.

Operating vacuum

8 X I 0- 5 Torr.

Q-value:

3000

Shunt impedance:

65k-ohm

MOP A (master oscillator power amplifier)
Capacity-coupled
Coaxial resonator
Power amplifier 3CW20000A 7 (EIMAC)

15

Figure 1 is a birdeye view when upper yoke is lifted and Fig. 2-(a) and 2-(b) are holizontal
and vertical sections of the cyclotron , respectively.

The detailed parameters of the cyclotron

are given in Table 2.
Design features of the cyclotron are self-radiation shielding l ) and push-button operation.
The circular magnet yoke surrounding the cyclotron absorbs radiations coming from inside sothat the cyclotron can be installed in a small vault with thin concrete walls. The control
system is of such an arrangement and structure that the cyclotron may be operated by pushingsix buttons and adjusting ion source power.

Thus the cyclotron can be operated in goodstability by those who have no high discipline and experience.
The project of the prototype cyclotron was started in December 1972 under a patent
licence agreement between IPCR and the Japan Steel Works.
Type Cyclotron".l)

The patent is "Self Shielding

All components necessary for the electromagnet including field mapping

equipment were assembled in spring 1974 at the Muroran plant of JSW.

We then beganmagnetic field mapping and finished it in autumn 1975. We started beam test in spring thisyear at the Muroran plant and were able to accelerate both proton and deuteron up to the
maximum radius on the

16th of July. The beam current measured by the probe vs. radius

is shown in Fig. 3.
I ooof--t-'+--_+__-+-----+--t------i--t--1 -- t - - - t - ------t------1
j~ 800 ~~-~-+-+-~-~~

Proton• Deuterono~500~~-+--+-~~--f--+---+---+-----+--t-~

~ 400

-~

:
\

I

r\J"F"~~ 200 i----1',j :",

>'

I

"\

V

o ~/I \j~\i./\·!'···r--..
- -·----±-- -T=----·-c---T::---:::-:t --·_-.--.,d ---:=-----~----i'=-'--- ~·..d·-Ik-:-::-::-----·~---·ib=----·~·---lo 20 40 50 80 100 120 140 160 180 200 220 240=-"---

Probe rod i US (mm)Fig. 3. Beam current versus radius.
During construction of the prototype, following three problems appeared but were successively
solved step by step: (1) formation of isochronous magnetic field distribution 2 ) for 9.4 MeV
proton without circular trimming coils, (2) development of dees and resonators with a moderate
Q-value at relatively high frequencies and (3) adjustment of initial motion of beam and precessionof orbit center resulting from the harmonic acceleration.

Reports on these problems will be3

described in other papers. )References
1)

Japanese Patent 818015 and USA Patent 3921019.

2)

T. Karasawa and Y. Toda: Reports of IPCR, (in Japanese) , 52, 185 (1976).

3)

T. Karasawa: ibid. , 53, 35 (1977).

16

3-5.

Operation of the IPCR Polarized Ion Source for the INS
Isochronous Cyc lotron

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

A polarized proton and deuteron source of an atomic beam type for the INS isochronous
cyclotron has been built and installed.

All of the mechanical parts and electrical power

supplies were manufactured by the workshop of IPCR.
The polarized ion source is mounted vertically on the cyclotron roof shielding as shown in
Fig. 1, its beam being injected axially into the accelerator through a bore in the upper yoke.
An axial beam injection line, whose optical elements are an einzel lens· and two electrostatic
quadrupole triplets, brings the beam 4.3 meters down to the cyclotron median plane.

A

~
I

<l>

~I

""co

.9 <.0

0'

o

0
g

(")

N

u(J>

.~

---

o

Bending "magnetoD..-

External

Hydrogen gas; 35cc l min

500

Hydrogen gas; 41 cc / min

Hyd rogen gas; 50cclmi n

500
RF powe r for di sc harge (watts)

Fig. 1. Simplified layout of the ion

Fig. 2. Intensity of polarized beam as asource and the axial injection system.

function of power in the rf discharge.

* Milan University, Italy.
** Institute for Nuclear Study, University of Tokyo.

500

17

gridded electrostatic mirror inflects the beam into the dummy dee.

More details of theinjection system and experimental results have been described in a recent paper.l)

Typical beam

current measured at the normal operation were up to 5J.LA of polarized protons at the exit of
the source, O.IJ.LA accelerated in the cyclotron , 0.03J.LA external beam with polarization of70%.

A brief account and the operating characteristics of the IPCR polarized ion source areas follows: Molecular hydrogen or deuterium is dissociated in rf-discharge, driven by a 1 kW ,25 MHz oscillator. The discharge tube and nozzle are cooled by flowing water.

The gas flowout of the tube is in the range of 50 cc/min. The atomic hydrogen emerging from the nozzle
is restricted by a skimmer, and then collimated by a diaphragm at the entrance to the sextupole
magnet at a distance of 60 mm from the skimmer. Atomic hydrogen which could not go
through the skimmer is evacuated with two oil diffusion pumps having a speed of 4000 £/s.
A trouble arose which is inherent in a system using a high pressure discharge tube. It is the
rapid polymerization of the diffusion pump oil resulting from the large atomic hydrogen gas
load. The pumps on the nozzle exhaust chamber were most seriously affected and needed to
be cleaned and oil recharged after about 150 h of operation.
DC-70S oil.

Oil used at present is Silicon

In the early stage of the operation of the polarized ion source, the operation of

the discharge tube was found to be unstable. The polarized beam current went out frequently
to zero in a periodic fashion , the period depending on the power of the discharge. A watercontainer was then installed in a gas line to give moisture to the hydrogen. Thereafter stable
operation of the dissociator with increased polarized beam intensity has been obtained.
Measurement of the polarized beam intensity with different gas flow rates into the discharge
tube as a function of the discharge power for dissociation was carried out.

Figure 2 shows

results of such measurement with wet hydrogen gas.
The separation of the hyperfine-structure components is done by a sextupole magnet
having an axial length of 35 em , an entrance aperture of 6.5 mm, and an exit aperture of
13.5 mm.

The magnet produces the maximum field of 7.2 KG at poletips.

High values of nuclear polarization can be achieved by use of RF transitions between
Table 1.

RF-transition parameters.

# 1

#2

Particl e

Transi tio n

F requency(MHz)

Stati c field(gauss)Hyd rogen

1TI -+ 3

10

6

Grad ien t
HTransition

F requ e ncy(MH z)

Static fi eld(ga uss)

Gradien t
H

Polariza ti on
P z , P zz
- I,

°2 -+ 4

1480

I SO

+I,

° 3 -+ 5

378

11 7

+~ - I°3 -+ 5378

11 7

-3' -I

Deu ter iu m

1T I -+ 4

1T1 -+ 4

10

10

Static field is perpendicular to rf fie ld
Stat ic fie ld is parallel to rf field

II

II

3'
I

18

hyperfine-structure levels. Table 1 shows the proposed operating scheme for hydrogen anddeuterium atoms and degree of nuclear polarization after the strong field ionizer. The polarization
value of the Table 1 are of ideal one and smaller values were obtained in practice.

For

the case of 28 MeV polarized proton beam, Pz =±0.7 was obtained from the measurement--+
using the C(p,p)C reaction, when the transition 1--+3 was induced. At the present test, thesign of the vector polarization is reversed by reversing the magnetic field in the ionizer but it
resulted in a loss of beam intensity of about 10 %. The reason for this phenomenon is notcompletely understood.
The atomic beam is ionized in the strong field ionizer by electron collision. A magnetic
field of about 1300 gauss is applied parallel to the beam axis. Figure 3 shows schematic
diagram (a) and a typical operation parameters of the electrical potentials along the axis (b) of
the ionizer
Positive potential
EI

IOOOV
800V
600V

r-'-\

I

,

I

,

I
\
I
,
E2
1 \'--..;;;....;;;..-----,
I
J

I
,
200V
I
,

400V
Sole noid
I-+++H-+--lonization ( E2)
co lumn(Max.20kV)Or--1k
F

11+I---H-t - - - -Gr id (E1)

- - -- --.-----

-

-

2 kV
3kV
4 kV
5 kV

Fig. 3. Schematic diagram (a)

6 kV
7 kV
Cathode ( F )~ At omic beam(a )and electrostatic potentials (b)Negative potential

in the strong field ionizer.
( b)

The solenoid coil, the filament and all of the electrodes are biased at a maximum positive
potential of 20 kV to the ground in order to inject the ion beam into the cyclotron. The
value of ionization efficiency is estimated to be 5 X 10-3 .
Typical pressure in the different sections of the polarized ion source were measured under
the normal operating condition in which the gas flow rate from the nozzle was 50 cc/min.
The results obtained are p = 1.2 X 10-4 Torr in the dissociator, p = 1.8 X 10-6 Torr in the
sextupole magnet and p = 2.2 X 10-7 Torr in the ionizer.

Reference

1)

S. Yamada, N. Ueda, U. Sakurada, M. Sekiguchi, T. Tanabe, T. Honma, and T. Hasegawa:
Genshikaku Kenkyu., 21, 772 (1976). Circular in Japanese.

19

3-6.

Design Study of a

Separate-Sectored eyc lotron for Heavy-Ions

S. Motonaga, H. Kamitsubo, and N. Nakanishi

A separate-sectored ring cyclotron was proposed as an energy booster of particles from a
low energy accelerator at this institute.
as an injector.

A variable frequency linac for heavy ions is supposed

Injection energy ranges between 4 MeV /amu and 1 MeV /amu for light andvery heavy ions, and the cyclotron post accelerator extends the maximum energy to 7 5 MeV /amu and 10 MeV/amu for light and very heavy-ions like Uranium, respectively.

Table 1 lists

the design parameters of the cyclotron. The cyclotron consists of 4 sector magnets whichhave maximum field-radius product of 3600 KG·cm, and azimuthal pole width of 50°.

The

effective sector angle of 50° was chosen to provide strong axial and radial focusing of the ion
beam without encountering resonances due to magnet periodicity and field inperfections. 1 )The machine dimensions from edge to edge are about 10 meter on the magnet yokes.

Anenergy gain of up to 1 MeV per turn is achieved with two resonators in opposite valleys.
Design study of the proposed accelerator will be made along an iterative design procedureand consists of successive measurements by model magnets (Fig. 1).

In order to obtain

detailed information on properties of a sectored magnet, a 1/4 scale model of the magnet has

Table 1. Design parameters of the post-stripper accelerator:
Separate sectored ring cyclotron.

Maximum energy, MeV/amu
Uranium 38 U42 +)e
Carbon e2C +)6Energy constant, K, (E=Kq2/ A)

10
75
320

Number of sectors

4

Sector angle, degree50°

Orbital magnet fraction

0.55

Gap between poles, (cm)12

Maximum magnetic field, (KG)

17

Injection radius, (cm)53.1

Extraction radius, (cm)212.4

Energy gain per turn, (MeV)

1

Number of dees

2

Width of dee, degrees

22

20

Fig. 1. A view of the 1/4 model
magnet.

been constructed, and the measurements of magnetic excitation characteristic, and the field
distribution inside and outside the magnet gap at various field strength are being in preparation.

The isochronism and focusing characteristics of the beam will then be calculated usingr~sultsof the measurements.

Reference

1)

M. M. Gordon: Ann. Phys., 50, 571 (1968); Nucl. Instr. Methods, 58, 245 (1968).

21

4. NUCLEAR PHYSICS
Scattering and Reactions
4-1.

Blocking Effect In the Core-Excitation ofSi

29

Y. Toba, N. Nakanishi, H. Sakaguchi, *A. Goto,*N. Kishida,** ' and F. Ohtani*

When an odd-A nucleus is core-excited by certain nuclear particles, the hindrance of thecore-excitation is expected due to the presence of an odd valence particle.

This blocking effectcaused by the Pauli exclusion principle will be seen more apparently in inelastic scatterings onan odd-A nucleus with low j-value of an odd nucleon.
Inelastic scattering experiments of 28,29 Si were performed using momentum analysed 16.2
MeV proton beam accelerated by the cyclotron.

Angular distributions of protons to thefollowing final states were measured: o1"(g.s.), 2+0.78 MeV), 4+(4.61 MeV), Oi(4.97 MeV),
3+(6.27 MeV), of 28Si, and 1/2+(g.s.), 3/21"0.273 MeV), 5/21"(2.032 MeV), 3/2i(2.427 MeV),

5/2i(3.069 MeV) of 29 Si.

Self-supporting targets were prepared by vacuum evaporation ofnatural silicon powder and silicon oxide powder of enriched isotopes
ORNL.

e Si( 2 ) obtained from
9

Scattered particles were detected with a silicon surface barrier detector.

The angular distributions obtained are shown in Fig. I and Fig. 2. Data are normalized,
for the present, to the best X2 fitted elastic scattering cross sections by optical model
calculations. 1 )The angular distributions of the 5/21" and 3/2i states are very similar to eachother and to that of the 2+ state in 28 Si, as will be the case, when the former two states are
weak-coupling states [ 28 Si(2+) ® (2Sl/ 2 )] 5/2+, 3/2+, which are to be expected. 2),3)
However, the cross sections of the two states are reduced considerably, compared with the
weak-coupling scheme.

Besides, the 3/21 state is very enhanced, although this state is considered

to be a 2d 3 / 2 single neutron state. 4 ) Therefore, the core-coupling component and the single
particle one of the wave function may have mixed with each other in the two states.

The

summed cross section of the three states, 3/21, 5/21, and 3/2i, is, however, reduced by about
30 %, compared with that of the 2+ state in 28 Si.
blocking effect.

To study this effect further, the inelastic scattering experiments from othertargets, for example, 88 Sr and 89 Yare in progress.

***

This reduction may be ascribed to the

Faculty of Science, Kyoto University.
Tokyo Institute of Technology.

22

I

I

I

I

I

29 Si ( p, p ) 29Si

29Si ( p, p) 2 8 Si
Ep= 16. 2MeV

Ep = 16. 2 MeV--

MeV 1/21 000000

xxxx
00

xx

000000000

xX

000 0

o

2 .0 32 MeV 5/2

0

ox x
0
000
2S
o ox QooCSoO

000
XX

i

2.427 MeV 3/21 1.273 MeV 3/2;

0 0
0

o

I

I

I

I

I

8 c.m.

Fig. I. Angular distributions of theFig. 2. Angular distributions of the elastic

elastic and the inelastic scatterings on

and the inelastic scatterings on 29 Si. Solid28

Si. Solid lines show coupled channelline shows optical model calculation,

calculation,S) using following

using the same parameters of the potential

parameters: V=49.7 MeV, WD=6.54

for 28 Si.

MeV, VSO =6.5 MeV, rO=1.2 fm,
rD =1.07 fm, rSO = 1.2 fm, rC = 1.25 fm,
aO =0.625 fm, aD =0.585 fm, aSO =0.625
fm, {32 =- 0.46.

References
I)

T. Wada: Reports I.P.C.R. , (in Japanese), 46 , 21 (1970).

2)

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

3)

W. R. Coker, T. Udagawa, and G. W. Hoffmann: Phy. Rev. , CIO , 1792 (1974).

4)

M. C. Mermaz, C. A. Whitten, J . W. Chomin, A. J. Howard , and D. A. Bromley:
ibid., C4, 1778 (1971).

5)

T. Wada and S. Yamaji: Sci. Papers I.P.C.R. , 68 , 65 (1974).

23

4-2.

Study of the54

Fe (d, p) 55 Fe Reaction at 24 Me V

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

Lee and Schiffer l ) observed a very pronounced J-dependence in (d, p) angular distributionsin the region of incident deuteron energies around 12 MeV.

Such effects have been

reproduced to some extent by the distorted wave Born approximation (DWBA) calculations.
Yntema and Ohnuma 2) investigated the 54 Fe(d, p)55 Fe reaction at Ed = 23 MeV.

They had touse very large nonlocality parameters in optical potentials to obtain reasonable fits to experimental
angular distributions.
We have studied the 54 Fe(d, p )55 Fe r~action with the 23.80 Me V deuteron beam from theReaction products were measured with two ~E-E Si counter telescopes and particle

cyclotron.

identification systems. The target was a 0.5 mg/cm 2 thick metallic foil of enriched (97.12 %)54 Fe, and was set with its normal making an angle of 45° to the beam.
resolution was about 100 k e V for both systems.

Overall energy

Angular distributions were observed in ther-- -j- --V~

I=- Ft =--~f----l- 1 _~~

1=- - L J

Ed= 23.80 MeV-

1--1-- -

! t~1

---T'

,

L-~

V>

.~

.-

t •

-

>.

~ ~\ I I G.S . p~/~l
..

q~

r£

!-~

~:-;

r--

L

o

.
00411 MeV

•
PV2
- I--

-

I

I

~

I--

I

-

I--r-

--

r--.,
e=1Y.
-= r----I
'\ ,

~

I

I

'
:

i :J -.:'

t --

fT\.

.

1

I

J...
T

•

~ .-

-=--t--. ~-===--rc
t

'

~~

===t -~ -\±"

-

1---

--+-

,

30

. -+-+~~~+-+

j--

I

r
t

-----l-o:\\:-t~-t----I--~TI~··~- :~-I-- ~ r --' -

I

-

I

1~

I'-..,.

-t -=-~T-If;j,j- T11=~- r---t- \' +-.-::f=-\-=
1==1= '\'-, .
\.
_-c~'------,- ,

o

1

L' -

i

~~~- '

'{\

~

~

l

•\

~~

L

Ed = 23 . 8 MeV,--:-1--~~-J----::cI-'----'--

II

t-- -:r--. I

I -+---

54Fe (d . pi 55Fe
[= 1

-

r-

60

90

.

-+--

!
I

120

150

180

Be,," ( deg. I

SC M(deg. I

Fig. 1. Angular distributions for the groundFig. 2. Angular distributions for the 0.931 MeV

state (3/2-) and the 0.411 MeV state (1/2- ).

state (5/2- ) and 1.361 +1.407 MeV states (7/2-)

FRNL and ZRL DWBA calculations are shown

solid lines are FRNL calculations.

by solid and dashed lines, respectively.

* Tokyo Institute of Technology.

24

range of angles between 15° and 115° in step of 5°.

The angular distribution of the elastic

scattering was also measured simultaneously , and was used to check optical model parameters for
DWBA calculations and target thickness.
Angular distributions obtained are shown In Figs. 1 and 2 together with DWBA calculations.
Optical model parameters used in the calculations are given in Table 1.

The deuteron opticalpotential parameters are those obtained with the code ELAST2 3 ) so as to reproduce the elastic
angular distribution obtained in the present work.
Ref. 4.

The proton parameters are those used in

Calculations were made with zero-range local potential (ZRL) and finite-range and non-local potential corrections (FRNL) within the framework of the local energy approximation.
Finite-range parameter of 0.658 , and nonlocality parameters of 0.54 for a deuteron and 0.85 fora proton were used in FRNL calculations.

Form factors were calculated with conventional well-depth description of the separation energy method.
DWUCK4 5)

All the DWBA calculations are made byusing the HITAC-8700 computer at Tokyo Inst. Technology.

In contrast to low energy works , there is no marked difference between the angular
distributions for the ground state (P 3/2) and for the 0.411 MeV 1st excited state (P 1/2) (Fig. 1).
On the other hand, in the case of £ = 3 transitions (Fig. 2) , the f5/2 angular distribution isshifted forward relative to one of the f7/2 state.

Present results show that DWBA calculations

can not reproduce well the experimental angular distribution.
Table 1. Optical model parameters used in the DWBA
calculations.
d

p

n

50.40

a)

Vo

(MeV)

76.97

ro

(fm)

1.292

l. 11 1

1.25

ao

(fm)

0.594

0.790

0.65

Wo

(MeV)

2.99

ro

(fm)

1.296

ao

(fm)

0.616

Wo

(MeV)

11 .85

4.35

ro

(fm)

1.040

1.397

ao

(fm)

1.016

0.545

5.67

6.73

(fm)

1.024

0.958

as o (fm)

0.558

0.709

1.3

1.12

0.54

0.85

VSo (MeV)
rso
rc

(fm)

NLOC
a)
b)

Adjusted to give binding equal to separation energy.
Spin-orbit coupling of A times the Thomas term.

25

References

1)

L. L. Lee, Jr. and J. P. Schiffer: Phys. Rev. Lett., ~ 108 (1964).

2)

J. L. Yntema and H. Ohnuma: ibid., ~ 1341 (1967).

3)

M. Igarashi: INS-PT-26 (1970).

4)

P. D. Geaves, V. Hnizdo, J. Lowe, and O. Karban: Nucl. Phys., A179, 1 (1972).

5)

P. D. Kunz: Private communication.

26

4-3.

Po rtic Ie-Po rtic Ie Corre lotion

In

Heavy Ion Reac tion

H. Kamitsubo , M. Ishihara, T. Shimoda, T. Fukuda
T. Motobayashi, T. Ooi, and I. Kohno

Heavy ion induced reactions at incident energies well above the Coulomb barrier haverevealed a vriety of new phenomena in reaction mechanism by the systematic studies. 1)
In these processes multinucleon transfer reactions accompanied by large negative Q values are
dominant and are called quasi elastic and deeply inelastic collisions.

Because of considerable

amount of energy transfer, emission of a third particle in addition to the usual binary
reaction products is often possible in deeply inelastic collisions.

In fact , a measuremene) of'Y ray multiplicities has indicated a considerable rate of a emission in such processes.

To see the reaction mechanism of deeply inelastic collisions, we measured particleparticle correlation between the light reaction products and p's or O:"s in a bonbardment ofe

8A= -35°

10

2

e_

singlesocoinc.(disk)
with ae10

3

6.=0/.
e~~

I...(/)

2;10

1

E

- - - - - -0- -- - -- -- - -- - /

0/

~, /

<l:

q
~IOo

o

"D

I

I

I

I

I

O""l

c

(/)

'"

10 1 <..:>
c

oLo

0

u

\0/ \6

10- 1

I

e

A__ t:>bI

10 2 (/)
Q)

- - -

10°

I

p

a

Reaction

Be

B

Prod uctA

Li

c

Fig. 1. Energy integrated cross sections for O:"sFig. 2. Closed circles are cross sections forcoincident with particle A's at () A = - 35~ CPA =multi-nucleon transfer reactions at ()lab = -35°.

CPa = O~ A's are p, 0:' Li, B, and C. Abscissa isOpen circles are cross sections for multi-

the laboratory angle of a's.

nucleon transfer reactions at ()lab. = _35

0accompanying secondary emission of O:"s.
Triangles are ratios of the two quantities.

27

a 93Nb foil (4.0 mg/cm 2 ) with 95 MeV 14N ions from the cyclotron.

The light reaction

products, C, B, Li, a and p were detected and identified with a 6E-E counter telescope of
30 and 2000 J.Lm Si detectors fixed at 8l ab = - 35° and -42°.

Coincident p's and a's weredetected with a similar tel escope, which was moved and located at several angles between
8l ab = +30° and - 65° and at 8l ab = 160° in the same reaction plane as the fixed telescope((jllab = 0°).

To see the (jl dependence we also measured correlation at 8lab = -15° and(jllab = 14°, 18° and 26°.

A 90 J.Lm aluminum absorber was placed in front of the lattertelescope to cut off the particles of elastic scattering. The fixed and movable telescopes
subtended solid angles of 7.9 and 4.7 msr, respectively.

Two pairs of energy and identified

particle spectra and time correlation were registered event by event in a computer system.
In Fig. I energy integrated cross sections for a's coincident with C, B, Li, a, and p on
the fixed telescope are plotted versus the lab angle of the movable telescope.

The angularcorrelations show curves of almost symmetric shape with an exponential slope.

The center

angles coincide neither with the emission angles of light products nor recoil angles of heavy
products. The data at 8 lab = 160° suggest that the yields decrease continuously for larger
angles.

The results suggest that the third particles were emitted with a considerably short

reaction time.

It is interesting to note a trend that the half width of the distribution becomeswider as the product becomes lighter from C to p.

We also observed that the center anglesof Band Li data shift about 7° to the fixed telescope when it was placed at 8l ab = - 42°.
The cross sections (a~oin) for multi-nucleon transfer reactions at -35° accompanying
secondary emission of a's can be estimated by integrating the angular correlations over anglesof 8a and (jla.

The ratios of a goin to a single' cross sections for multi-nucleon transfer

reactions at -35°, are shown in Fig. 2.

60

93
0

40
..........

>

Q)

~
t:I

w

Nb(14N, a C )Zr
8 a =_150~ec~-35O~:t~~OQ\~~

20
Fig. 3. Energy contour map of C and a. The ordinate
is laboratory energy of a, and the abscissa is that of C.

0
(J)

300

20

+-

0

100
0

single
/'

c 200

/
/

:::J
U

80

60
40
Ec(MeV)
/
./

/

/

"-

\i
\

"-

The inclined line is kinematicaly allowed one in thecase of zero reaction Q-value. At the left above,
distribution of Q-value is shown. Energy spectrum ofC emitted independently of a as well as spectrum"-"-

coincident with a is below the contour map.

28

We have also measured energy correlation in those reactions.

Figure 3 shows the result ofenergy correlation, C at - 35° and ~ at - 15° in the same reaction plane. We note that themulti-nucleon transfer reactions accompanying a emission are dominant in large energy transfer
region, namely deeply inelastic collisions from the comparison of the energy spectrum of
single events with the projection of energy contour map to the C energy axis.

References
1)V. V. Volkov: Proc. Int. Conf. on Reactions between Complex Nuclei, Nashville, 2,363 (1974).

2)

M. Ishihara, T. Numao, T. Fukuda, K. Tanaka, and T. Inamura: Proc. Symp. on
Macroscopic Features of Heavy-Ion Collisions, Argonne, II, 617 (1976).

29

4-4.

Gamma Ray Multiplicities

for Deep Inelastic andQuasi-elastic Processes

M. Ishihara, T. Numao,* T. Fukuda,
K. Tanaka, and T. Inamura

It has been shown that processes called quasi-elastic (QE) and deep inelastic (D!) collisions

exist in the reactions induced by heavy ions with energies well above the Coulomb barriers. 1 )It is interesting to know what angular momenta are brought into the fragments emitted in theseprocesses.

Multiplicities of ,),-rays from the fragments will provide information on the angularmomenta in question.

Accordingly, an experiment was carried out to measure the ,),-ray multi-

plicities for QE and DI in the bombardment of 93 Nb, 169 Tm, and 181 Ta with 90 and 120 Me V
14N.
14N
93Nb(t4N, C) Mo

20+ 93Nbf Lob :=" 120 MeV

ELob .= 120 MeV

eLOb~ 40°

• QE
o 01

15

Li

10

~

..0
L

o

5

60

40

80

100

00

2

Energy spectra of carbon

6

8

10

12

Moss of light productEc. m . (MeV)

Fig. 1.

4

Fig. 2.

The -y-multiplicity M-y versus

from the 93Nbct4N,C) Mo

the light fragments emitted in thereaction at Elab = 120 MeV.

bombardment of 93Nb with 120 MeV
14 N : The dotted line is obtained
from the model of sticking motion 3)
to be compared with the DI result.
The solid line is from the model ofgrazing collision 4) to be comparedwith the QE result.

*

University of Tokyo .

30

We measured energy and identified particle spectra in singles and in coincidence with ,),-rays
for each reaction.

The ,),-ray multiplicity M')' is determined by M')'= Ncoin(Ef)/.s1')'Nsing(Ef),where NSing and Ncoin represent singles and coincidence counting rates of the identified particles
with energy Ef, respectively; and n')' is the solid angle subtended by the ')'-counter.

Details of

this technique were described in Ref. 2.
Figure 1 shows energy spectra of carbon from the 93 Nb(l4 N, C) Mo reaction at
Elab = 120 MeV.

It is seen that the QE humps (higher energy peak) gradually diminishes, while

the DI hump (lower energy peak) becomes dominant towards backward angles.
The multiplicity M')' can be related to the initial spin I of the residual nucleus by I = fMT
At the moment, we have no accurate knowledge about angular-momentum dissipation due toparticle emission.

However, we have found that an effective f-value of 2.4 h is needed toaccount for the total spin dissipation by ,),-rays and particles.
In

We shall tentatively use this value

the analysis.
Figure 2 shows a typical plot of M'Y measured at the centres of QE and DI humps versus

mass of the light fragments.

The dotted line represents the multiplicities expected from the

sticking motion of colliding nuclei;3) this line is to be compared with the DI result.

The solidline represents the result obtained by assuming the velocity of transfered nucleons to be thesame as that of the projectile. 4 )This is compared with the QE result.

It is interesting to notethat the M')' values for DI and QE processes are described welI by these simple models.

Similarresults were obtained for the Tm and Ta targets.

References

1)

M. Lefort: Rep. Prog. Phys., 39, 129 (1976).

2)

T. Numao, M. Ishihara, T. Inamura, and T. Fukuda: IPCR Cyclotron Prog. Rep., ~ 13(1975).

3)

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

4)

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

31

4-5.

by

Complete Fusion Cross Section Measurement

Beam A ttenuation Method

T. Fukuda, M. Ishihara, T. Inamura,T. Numao,* T. Shimoda, and T. Nomura

Recently, complete fusion cross sections 0cf for heavy ion induced reactions have extensively been measured to determine the critical angular momentum fer.

However, the methods

using mica track detectors or counter telescopes are not always reliable in discrimination offusion reaction events from direct reaction ones and have some difficulty in application toheavier targets.
We have developed a new technique of 0cf measurement, which is simple and free fromabove mentioned difficulties.

As mentioned in Ref.

1 the basic principle of the method is2similar to that of the beam attenuation method ) used for the measurement of the proton total
reaction cross section.

As shown in Fig. 1, the set -up consists of two beam defining countersin front of the target, a fixed backward annular counter (C4) and a movable stopping counter(C3) positioned downstream the beam.

The stopping counter detected projectiles which passed

through the target or were elastically scattered and the whole light charged particles of reaction
products emitted in forward direction.

Heavy fragments like evaporation residues were stopped

by a thin aluminum foil in front of the stopping counter.

The solid angle of the stopping

counter was chosen to cover a forward semisphere large enough to register the whole direct
reaction events.
1.6

I

I

I

1.4

•

1.2

I

I

Cu + 14No

Nb + 14 N•

Tb + 14N

s~ 1.0beam
counter

C1
beam ~~••

ca l l i motor

I
C2
~

C4
C52

i

\

\

•

II

It

+

C3

I~

':::-.:( 0.8

!Q ~

~

t

-

Q r}

'-

1 0.6 f-

!2
!

b

0.4

I

0.2
0
0

I

I

0.4

0.2

I

1

0.6

0.8

1.0

(V IEe.m.1

Fig. 1. The schematic experimental set-up:

Fig. 2.

CI, C2, CS2, C3, and C4 are plastic

complete fusion cross section. E c .m . iscounters.

the center of mass energy and V equals

Energy dependence of theto ZlZ2e2/rc (Al113+A2113) with
fc==1.47 fm.
* University of Tokyo.

32

In principle, the difference in the number of counts between the beam defining counterand the stopping counter gives the cross section for fusion events without charged particle
evaporation.

Since the fused nucleus frequently decays via charged particle evaporations, wehave to make the correction for such evaporation processes.
In the case of the lighter target like Cu or 93 Nb, almost all of the fused nucleus decay via
charged particle evaporations at the incident energies used, so that we made the following
consideration: The cross section of fused nucleus decaying via fission should be negligibly small
in our case.

The differences in the number of counts between the beam defining counter andthe stopping counter, Nf, is proportional ton~i {I - (1 - nf)n } on,

0cf -and the coincidence events between the backward counter and the above differences, Nb, is
proportional ton~i { (1 - nf)n - (1 - nf - nb)n } on'where ° 1 denotes the cross section of fused nucleus decaying via emission of one charged
particle, neutrons and 'Y-rays, 02 denotes the cross section of fused nucleus decaying via two
charged particles, neutrons and 'Y-rays, and so on.

nf and nb denote the solid angle of C3 andC4 counter respectively.

The sets of Nf and Nb are measured as a function of nf, nb being
fixed. Then 0cf, 1, 02 etc. can be deduced as parameters from X2-fits.
We measured 0cf for the reactions of 14N ions on Cu(2.47 mg/cm 2 ), 93Nb(2.38 mg/cm 2 )°and 159Tb(3.76 mg/cm 2 ) targets at Elab = 78, 88, 99, 109, 118 MeV.

Figure 2 shows the energy

dependence of the measured complete fusion cross section.

The experimental data are in accord
with the Bass model ) with as = 17.0 MeV, d = 1.35 fm and R12 = 1.02 X (Ar3 + Ay3) fm,
3

where as is the surface energy parameter of the liquid drop model mass formula, d is the rangeof the interaction and RI2 is the cut off radius.

We did not find such a kinking effect as4

predicted by the model of Glas & Mosel ) with the Orsay type potential and the criticaldistance of approach Rcr = 1.00 X (Ar3 + Ay3) fm.
We also measured 0cf for the reaction of 16 0 ions on Cu, 93 Nb and 159 Tb targets at
Elab = 86, 97, 112 MeV.

The analysis of this experiment is now in progress.

References
I)

T. Fukuda, M. Ishihara, T. Inamura, T. Numao, and T. Nomura: IPCR Cyclotron Progr. Rep.,
9, 15 (1975).

2)

1. 1. H. Menet, E. E. Gross, 1. 1. Malanify, and A. Zucker: Phys. Rev., C4, 1114 (1971).

3)

R. Bass: Phys. Lett., 47B, 139 (1973).

4)

D. Glas and U. Mosel: Nucl. Phys., A237, 429 (1975).

33

4-6.

Measurement of the Efficiency ofsBe Detection by Position Sensitive

Detector and Study of the

12C(a, 8Be)8Be Reaction

T. Ooi, T. Motobayashi, K. Katori, and I. Kohno

A position sensitive detector (PSD) can provide large detection efficiency and good resolution of energy in detecting 8 Be nuclei. 1) ,2)
The detection efficiencies were measured by observing 7 Be and 8 Be particles emitted fromthe 12

Ce He, Be)8Be reaction induced by He + beams from the cyclotron. The Be particles
7

3

2

7

were identified and detected by a ~E-E counter telescope and 8 Be particles by a counter
telescope of PSD and ~E detector with divided rectangular collimator.

The efficiency is

obtained as the ratio of 8 Be yield to 7 Be yield, which is normalized by the incident beam
intensity and the solid angle sub tended by the detector.

%
20
>u
c

/

Q)

;;: 10

.....
w

0

10

tJ20
Energy of

30 MeVsSe

Fig. 1. Efficiency for the detection of 8Be(g.s.) nuclei vsenergy of 8Be nuclei. The solid curve is based on
calculation. The dots represent the experimental results.

Cq.-= 48 MeV

30
Q;
c:
c:
0
.r::.

u

Gate

1.5 mm20........

'"c:

+-'

::J

0

u

10

200

300
ChannelnumberFig. 2. Energy spectrum from the 12C(~ , 8Be) 8Be reaction.

34

The experimental results are compared with the calculated curve in Fig. 1, where the efficiency is plotted versus the kinetic energy of 8 Be nuclei.

The results are in good agreementwith the calculated curve.
The differential cross section for the 12 C(a, 8 Be(g.s.»8 Be(g.s.) reaction at bombarding
energy of 48 MeV was measured by the PSD system.
4 He2+

beams from the cyclotron.

The experiment was performed with

The target was a self-supporting foil of 12 C of 100 Ilg/ cm2in thickness.
Figure 2 shows typical energy spectrum for the 12 C(a, 8 Be)8 Be reaction.

The energy

resolution was about 400 keV at FWHM, which is due mainly to kinematical broadening.

The

differential cross sections are tabulated in Table 1.
Table 1. Differential cross section for the 12 C(a, 8 Be)8 Be reaction.

Ea = 48 MeV(~~ ) CM (mb/sr)\

Gate width = 1 mm

1.5 mm2 mm

27.5

0.031 ± 0.010

0.033 ± 0.011

0.028 ± 0.014

30.7

0.059 ± 0.010

0.057 ± 0.012

0.062 ± 0.023

35.6

0.042 ± 0.009

0.043 ± 0.011

0.049 ± 0.013

40.5

0.025 ± 0.009

0.027 ± 0.009

0.029 ± 0.012

45.3

0.039 ± 0.009

0.039 ± 0.011

0.038 ± 0.013

50.1

0.049 ± 0.007

0.045 ± 0.007

0.049 ± 0.009

54.9

0.070 ± 0.009

0.068 ± 0.011

0.070 ± 0.013

59.6

0.137 ± 0.011

0.114 ± 0.014

0.106 ± 0.017

64.3

0.130 ± 0.013

0.124 ± 0.014

0.130 ± 0.017

68.9

0.060 ± 0.007

0.055 ± 0.008

0.055 ± 0.010

73.4

0.043 ± 0.011

0.046 ± 0.012

0.041 ± 0.0 15

77.9

0.043 ± 0.006

0.038 ± 0.007

0.034 ± 0.008

82.4

0.042 ± 0.007

0.043 ± 0.008

0.047 ± 0.009

86.8

0.046 ± 0.007

0.043 ± 0.008

0.061 ± 0.011

References
1)

T. Ooi, T. Motobayashi, K. Katori, and I. Kohno: IPCR Cyclotron Pro gr. Rep., 10, 68(1976).
2)

G. J. Wozniak, N. A. Jelley, and Joseph Cerney: Nucl. Instr. Meth., 120, 29 (1976).

35

4-7.

a-Transfer Reactions between 1 p or 2s-1 d Shell N uc lei

T. Motobayashi, 1. Kohno, T. Ooi, and S. Nakajima

To investigate the reaction mechanism of a-transfer reactions induced by heavy ions, angular
distributions for a-transfer reactions were measured for several targets and projectiles of 1p or
2s-ld shell nuclei, namely lOB, 12C, 14N, 160, and 2°Ne.
studied theoretically. 1),2)

The structure of these nuclei are wellEspecially in the case of 20 Ne and 160, a-cluster structure has been

well investigated in a microscopic way by the cluster model. 3 )Hence it is suitable to use these

nuclei for studying the mechanism of the a-transfer reactions.
Reactions studied are listed in Table 1. The beams of 14 N4+ and 16 0 5+ from the cyclotron
were used. Gas target was employed for 16 0 and 20 Ne, and 10 B target was made by evaporation. 4 )Outgoing particles were identified with a ~E-E SSD counter telescope in which E

counter was a position sensitive detector.

A four slit collimators in front of the telescope0defined four position windows 1 apart from each other and made it possible to measure theTable 1. The list of the reactions and the optical potential parameters used in the
DWBA calculations.

In the column of J7T, right hand side corresponds to thespin and the parity of the ejectile and left hand side the residual nuclei. V
and W (in Me V) are the real and the imaginary well depth of the opticalpoten tials.
Reactions

16 oct 4 N, 10 B) 20 Ne

1OBct 4 N,IOB) 14 N

20Ne(160, 2°Ne)160

12Cct4N, IOB)16O

16 0(160, 12C)20Ne

J7T

Ex(MeV)

3+ 0+

0.0

2+

1.63

1+ 2+

2.35

3+ 4+

4.25

1+
r 3+
1+

0.0

1

1+

0.72

Ii

1+

2.16

0+ 0+

0.0

2+ 0+

1.63

4+ 0+

4.25

3+ 0+

0.0

0+

0.72

Ii 0+

2.16

0+ 0+

0.0

0+

1.63

EL(MeV)3+
76.2( 73.9)
93.6

94.8

78.8

95.2

i
(
( It
{

2+

V(MeV)

W(MeV)

75

10

60

20

65

15

)

65

20

}

65

15

)
1

36

reaction products at 4 angles simultaneously.
are discussed

elswhere 5 ),6)

Details of the gas target and the counter telescopein this progress report.

Some examples of energy spectra are shown in Fig. 1.

Energy resolutions were 400 ke V to

Me V, the main contribution to which is the energy spread of the ions in the entrance andexit windows (nickel or mylar foils) of the gas target (in the case gas target is used) or the
kinematical broadening of energy of the scattered particles (in the case foil target is used).
The spectrum shape was fitted by the skewed Gaussian form by a program SPFIT-4 7 ) on a DDP
124 computer.
Exact finite range DWBA calculations for <x-transfer reactions were performed on some caseswith a computer code SATURN-MARS-2 8 ) which was revised to be suitable for <x-transfer
reactions by Matsuura (IPCR).

Optical potentials were determined to fit the angular distribu-

tions of the elastic scatterings of incident channel for each reaction.

Only the depth of the real.

and imaginary parts were searched and the radius and the diffuseness of both real and imaginary

20Ne(160,20Ne ) 16 0

EL = 94.8MeV
BL = 7"~I OOr-:; 1000r~
16 0 ( 14N , I

Os ) 20Ne

b
~

500

EL = 76.2 MeV
BL = 8°lOr-lOS (14N, lOS) 14N

IO~O--~--~10~o~~--720~O~~~3~0~O~--4~0~O--~

EL = 73.9 MeV

8 c •m .

Fig. 2.

Angular distributions of somea-transfer reactions. The solid lines
Fig. 1.

Energy spectra of some a-transfer

correspond to the exact finite range

reactions. The solid lines correspond to

DWBA calculations with the normalization

the skewed Gaussian fit.

constants written in the figure.

37

parts were taken to be the same for all cases 9 ) (rR = 1.21 fm, rI = 1.35 fm, aR = 0.48 fm,
and aI = 0.25 fm).

The DWBA form factors were constructed phenomenologically, namely fromthe cluster wave functions which were solved in Woods-Saxon wells (r 0 = 1.3 fm and a = 0.7 fm,
the depth was determined so as to reproduce the binding energy of the a-core system).

The

DWBA cross section for stripping type reaction A(a, b)B is written as:~ = NS, S2 {:~ )SM ,where SI = 1< a I} b, a> 12 and S2 = I < B I} A, a> I 2 are the spectroscopic factors of
a-cluster in the projectile and the residual nucleus respectively, and N is a normalization
constant which is necessary to fit the calculated results to the experimental data.
Some results of DWBA calculations are shown in Fig. 2 in which N has the meaning
mentioned above when SI and S2 were taken to be the shell model values listed in Table 2,
and n denotes the overall normalization NS I S2 . The normalization constant N takes various
values depending on the combination of the projectile and target, and on the spin of the final
state.

It is very interesting to see if these tendencies are reproduced by constructing the form

factors of DWBA from the microscopic wave function.

Systemsa) Ref. 2.

Table 2. Spectroscopic factors for the

J7T
a

J7T
b

f

0+

!

0+

0

0.21 a)

14 N.

2+

0+

2

0.21

spin and the parity of the

4+

0+

4

0.19

0+

0+

0

0.23 b)nuclei, 2oNe, 160, and 14N,
and J~ corresponds to those

1+

3+

2
4

0.012b)
0.69

1+

1+1

0
2

0.004
0.13

1+

Ii

0
2

0.082
0.094

S

a-cluster in 20 Ne, 160, andJ~ corresponds to theof the core, 16O,

12C, and

10 B respectively. f is theorbital angular momentum
between the a-cluster andthe core nucleus.

b) Ref. 1.

References

1)

D. Kurath: Phys. Rev., C 7, 1390 (1973).

2)

Y. Akiyama, A. Arima, and T. Sebe: Nucl. Phys., A 138, 273 (1969).

3)

T. Suzuki and K. Ikeda: Prog. Theor. Phys., ~ 1621 (1974); T. Matsuse and
M. Kamimura: ibid., 49, 1765 (1973).

4)

Fabricated by M. Mihara (lPCR; Work Shop).

5)

T. Motobayashi: IPCR Cyclotron Progr. Rep., 10, 70 (1976).

6)

T. Motobayashi: ibid., p.72.

7)

Revised from the code SPFIT-3 (developed by T. Wada (IPCR): unpublished).

8)

T. Tamura and K. S. Low: Comput. Phys. Commun., ~ 349 (1974).

9)

I. Kohno, S. Nakajima, T. Tonuma, and M. Odera: J. Phys. Soc. Japan, 30, 910 (1971).

38

4-8.

Critical Angular Momentum

In

lOBe +

160Compound Reactions

I. Kohno, T. Motobayashi, T. Ooi, M. Ishihara,

T. Numao,* T. Fukuda, and S. M. Lee**As was reported,1) in the 12

Ce N, 6 Li)20 Ne reaction, the compound nucleus formation is4

the main process at incident energies between 20 and 90 MeV, and the critical angular momenta(lcr) in the compound formation have been derived from Hausser-Feshbach (HF) analysis ofcross sections for individual levels in the relevant outgoing channels.
In order to see the behavior of 1cr in the other incident channel, we have studied the10

Be 0, 6 Li)20 Ne reaction at energies of 84.7, 90.6, and 98.8 MeV.
6

The experiments were performed with the 16 0 5+ beams from the cyclotron. The target of10

B was a self-supporting foil of about 87 Ilg/cm2 in thickness.
Excitation functions for some 2°Ne levels measured at 8° are presented in Fig. 1.

Solidcurves indicate the HF calculation with 1cr values which were chosen to give the best fit to theexperimental data. 1cr values are listed in Table 1.

From the present analysis we obtained thelcr values of 19,20, and 21h at Elab = 84.7,90.6, and 98.8 MeV, respectively.
IOS( 160 .6 Li ) 20Ne

~(~

Ir--

These lcr values

Blob:: 8°

5.63+5.80
T , 1-+-............+
-

lOr-

~-

10 2 r-

"k

-

~

</"

.......

1.63
2+

.0

~
~

10f-

"b
~

-

7.04+ 7.17 + 7.20
40+
T

t

-,-+~
10 2 ---

10-

425+4.97
4+ , rFig. 1. Excitation functions for some 2°Ne
10

80

90

100

80

90

100

flob. (MfN)***

Faculty of Science, University of Tokyo.
University of Strasbourg.

states measured at 8° in the laboratory
system for the lOBe 6 0,6Li) 2°Ne reaction.

39

Table 1. J cr , Jgf' and Ofus values obtained from experimental data.
Ofus indicates a fusioncross section.

Incident energy (Me V)

ECM(MeV)

Jgr(h)

Jcr(h)

Ofus (mb)

84.7

32.6

20

19

1170

90.6

34.8

21

20

1200

98.8

38.1

22

21

1220

are smaller than the grazing angular momentum J gr by lh. J gr is defined as the angularmomentum for which the transmission coefficient of the incident channel is 0.5.
The transmission coefficient was extracted from the optical model parameters which wereobtained from fits to measured elastic scattering of 16 0 from 10 B. A set of parameters obtainedis as follows: the real well depth V = 65 Me V; the imaginary well depth W = 20 Me V; thediffusivity aR = 0.48 fm and aI = 0.25 fm; and the radial parameters rR = 1.21 fm andrI = 1.35 fm for the real well and the imaginary well, respectively.
It can be seen in Fig. 1 that considerably good fits to the data for all the outgoingchannels in the 10 B(16 0, 6 Li)20 Ne reaction are obtained.

This is taken to be a proof of thedominance of the compound process similar to the 12 C(14 N, 6 Li)20 Ne reaction.

Reference
1)

T. Ooi, T. Motobayashi, I. Kohno, M. Ishihara, T. Numao, T. Fukuda, and S. M. Lee:
IPCR Cyclotron Progr. Rep., ~ 10 (1975);
C. Volant, M. Conjeaud, S. Harrar, S. M. Lee, A. Lepine, and E. F. Da Silveira: Nucl.
Phys., A238, 120 (1975).

40

4-9.

Repeated Neutron Transfer In the Elastic-and Inelastic
Scattering of

16

0

on

17

0

B. Imanishi, O. Tanimura,* and H. Ohnishi**°

Coupled Channel Analysis of the elastic- and inelastic scatterings, 16 0_ 17 and170e 60 , 160 ) 17 0 * 0/2+ , 0.871 MeV) (Ecm = 11.33 , 12.36, 13.43,14.42, 15.51 , and 16.48MeV)

has been carried out by the use of the core-exchange model,1)-3 ) where the transfer processes,
17 0 (* ) ( = 16 0 + n (Od 5/2 or Is 1/2) ) + 16 0 -+ 16 0 + 17 0(*) (= 1602+n (Od 5/2 or Is 1/2)),
1
2
1
are assumed.

The multi-step processes due to the transfer- and "direct" elementary - processes(see Fig. 1) are found to give important contribution to the inelastic cross sections.
Vne

Vne

c

nc

Vij(j - 6ij)

e

Vne

Uee

ne
Vij

c

en
U!ji

c

Uee

nc
K!i1i

cn
L ij

c

nc

(VK\J\jccn(U!eiK!IJ) ij

di rect process

S t r i ppi ng
or pi ck - up

Elementary processes for the

knock - onelastic- and inelastic scattering of 16 0

t r o nsfe r process

on 17 0 by the core-exchange model.

~

disto rting poten tial

Fig. 1.

The angular distributions (for example, Ecm = 13.43 and 15 .51 Mev) calculated by the
coupled channel method and by the DWBA method are compared in Fig. 2 with the experimental data of Ref. 3. The solid lines show the results due to the full elementary processesof Fig. I , while the dotted lines the results from the transfer process only.

Similarcomparisons are made for the excitation functions at (j cm = 60° and 129° in Fig. 4.
Maher's optical potential (ro = 1.35fm, a = 0.49fm, V = 17.0 MeV, rI = 1.27fm, aI = 0.15fm
and W=(0.8+0.2 Ecm) MeV) , which was obtained from the optical model analysis of 16 0_ 16 0
scattering, has been used in this analysis for the coree6O)-core interaction. The coupledchannel analysis shown by the solid lines gives excellent fits to the data both for the angular
distributions and for the excitation functions, while the DWBA fails to fit to the data.

Itshould be noted that the coupled channel results based on the transfer process only also agreewith the data fairly well.
The results of these analyses can be summarized as follows:
1) The bump observed in the forward angular region is formed to a large part from themulti-step transfer processes, i.e., repeated transfer processes (RTP) of outer neutron between
two core-nuclei, 160'S, the RTP's occurring even times.
formed mainly by the one-step 'direct' process.
* Faculty of Science, Kyoto University.
** Colledge of General Education, Hosei University.

In DWBA prediction this bump is

However, this contribution is rather small to41give the bump observed by the experiments.
2) The dominant RTP is the neutron transfer process between the Is 1/2 orbits ofrespective 160-nuclei (see Fig. 4) .
3) The RTP's occurring odd times interfere incoherently in the backward angular region
170(160,160 )170 * ( I/,> + ,O.8 71MeV)

Moher et. ol. pot.
Ecm =15.51 MeV

DWBA

1 0~------------~----~---r--~- 14mb/sr.
II mb/s r.
- 9 mb/sr.

~--

3.0 mb/sr
2.4 mb/sr.

19.5 mb/sr.
15.5mb/sr.
13 mb/sr.

I...
V>

".D

E

170(ISO~60l170"( 1/2 +,0.871MeV.,

cc

Moher et. 01. pot.

Ecm= 15. 51 MeV

I Or-------------~----~~~--~

0.33 mb sr. r\
I

I
I
I
I

I

1
\

I

I

\
\

Em =15.5IMeV

-r
\

'.1
-

1 \

\

I

\ I
\ I
,I

I

J
90

0

170(1 60 ,1 60 )170*(112+) 180e (deg.)Fig. 3.

Angular distributions of

170ct60,160)170*(1/2+,0.871 MeV)
calculated by the transfer process
only. The solid lines are the results90°e ( deg.lof calculations with full RTP , theAngular distributions of the inelastic
scattering, 17 Oct 60,16 0)17 0*(1/2+,0.871 MeV)

full-dotted lines with the one-step

Fig. 2.

process for the transition,

are due to the full processes, the full-dotted

1601+170(= 1602+n( Od 5/2))~
170*ct601+n(1s 1/2)) + 16 0 2,
and full RTP for the transition,
16 0 + 17 0*(= 1602+n{ls 1/2))~
1
170*ct601+n(1s 1/2)) + 16 0 2,

lines due to the transfer process and theand the dotted lines with one-step

dotted line due to the direct process.

process.

at Ecm = 15.51 MeV. The curves in the upper
half of figure are obtained by DWBA
calculations and those in the lower half bycoupled channel calculations. The solid lines042with the one-step transfe r process, 170(=1 601 +n (Od5/2 )) + 16

O 2 ~ 16 0 1 + 17 0* (= 16 O 2 +n

(1s 1/2) ).
destructively in the angular4) The processes related to direct elemen tary process interfe reses (see Figs. 2 and 4).
region of 90° ~ 120° with the one- or multi step transfe r proces

0.1 t------~-----~~__l\ ~,r\j'.
DWBA"-.......

~ 10r--~~~-~------__lFig. 4.

Excita tion functio ns of theinelastic scattering,
170ct6 0,160) 170*(1 /2+,0. 871 MeV).
The curves in the upper half of the
figure are obtain ed by DWBA
calculations and those in the lower
half by coupled channe lcalculations. The solid lines are due tothe full processes and the full-do tted

- - Full int.
{ - - - TI -only

0.1 r - - - -- - - - - - > L - - - - -__llines due to the transfe r process only.
At forward angle, ecm = 60°, bothlines due to the coupled channe lcalculations agree with each other

10

20

15
[em

25

fairly well.

(MeV)

References
1)

2)
3)
4)

G. Baur and H. H. Wolter: Phys. Lett., 5IB, 205 (1974) .
.
B. Imanishi, H. Ohnishi, and O. Tanim ura: ibid., 57B, 309 (1975), Y. Horow itz, S.
D. Kolinsky, D. Melnik, U. Smilansky, N. Trautn er, B. A. Watson.
Mordechai, G. Baur, and D. Pelte: Nucl. Phys., A250, 364 (1975)
lski, H. L. Harney, andC. K. Gelbke, G. Baur, R. Bock, P. Braun-Munzinger, W. Grechu
R. Boch: ibid., A219, 253 (1974) .

43

4-10.

Nuclear Deformation and Finite Size Effect of Projectile inInelastic Scattering

T. Matsuura and T. Wada

Macroscopic treatment of inelastic scattering (generalized optical model) is a simple andpractical way in obtaining the nuclear deformation parameters of L-pole ({JL) from inelastic
scattering on the deformed target, and the extracted values of (JL are considered to be insensitive
to the reaction mechanism or the choice of projectile causing the scattering.
However, projectile dependent systematic deviation in the deformation parameters can beseen by careful analysis of the data. I)

For the lowest 2+ and 3- excitations by (p, pI), (d, d'),and (a, a') scatterings on Mo isotopes, deformation parameters determined by the macroscopic
model exhibit projectile dependent behavior, aside from the complicated isotope dependent
differences (Table 1). It can be pointed out that in general (p, pI) scattering tends to give larger
values than those of (d, d') and (ex, a') scatterings.

Different spin or isospin structure of the

projectile may be expected, in principle, to cause the above-mentioned systematic deviation.

A

preliminary calculation indicates, however, that this effect seems to be too small to explain therequired order of magnitUde. I)
Table 1. Deformation parameters ((JL) determined by generalized optical model.

J7T(E x MeV)
92Mo

94Mo
96Mo

98Mo
lOoMo

(p, pI) 12.5 MeV 3 ) (d, d') 21.5 MeVI) (a, a') 30.87 MeV4 )2+(1.150)

0.080

0.083

0.078

3-(2.850)

0.170

0.124

0.113

2+(0.871 )

0.154

0.155

0.125

3-(2.533)

0.198

0.148

0.130

2+(0.777)

0.163

0.165

0.143

3-(2.230)

0.179

0.153

0.138

2+(0.788)

0.193

0.153

0.145

3-(2.024)

0.239

0.176

0.160

2+(0.534)

0.259

0.224

0.187

3-(1.910)

0.215

0.158

0.139

In this report we propose an alternative explanation of the descrepancy by the finite size
effect of the projectile, by employing Watanabe model of elastic scattering2 ) as the theoreticalbasis and applying it to inelastic scattering.

In Watanabe model, optical potential of composite

particle is constructed from a phenomenological nucleon-nucleus optical potential by the folding
procedure.

We also assume that the inelastic scattering form factor of the composite particle

projectile is constructed from the phenomenological macroscopic form factor of proton.

Thismodel may be verified under the following conditions.
(1)Composite particle is rigid enough to neglect the break-up effect during the scattering.

This condition seems to hold well for a-particles but not for deuteron.

44

I

I

f d =21.5 MeV
/

1.0

I

+ (j

96Mo

96 Mo + d

fa = 30.S7 MeV

....

,n

1\:lTtpf\/\b1 \q ("

0.1

~

/'\

6-~

/ ~

I%<k:t~b

Q.

:::-- O. Ibb/" -.;.,

1\ \ /

I f( d

I

0.01

'.

1'-"

:Yo-

0\
\

cr
,,

P,

t

-

/

~

0.0 I

1\ r[\
/

../

a

20

40

60

SO

100

120

140

160

ISO

o

10

20

30

Fig. 1.

40
SC M

S CM (deg .)50( deg.)

60

70

SO

90

Elastic scattering cross sections for 96 Mo + d, Ed=21.5 MeV and 96 Mo + 0',

Ea =30.87 MeV. the solid lines represent the predictions from Watanabe model and thebroken lines represent the results of the best fit parameter sets of optical model analysis.
Table 2. Nucleon Optical parameters used for Watanabe model.
(1) Central depths of proton and neutron potentials

AZ) + 0.4 X Z! A
0.32 X E - 24 X (N AZ)

0.32 X E + 24 X (NVn = Vo(2)

113.

96Mo + p (12.5 MeV)
Vp = 52.504, Wv = 6.850, Vso = 7.5 (MeV)ro = rv = 1.2769, ao = av = 0.5361 , rso = 1.25, aso = 0.47 , rc = 1.25 (fm)(2) Contributions from two or more nucleon exchange between projectile and target aresmaller than that from one nucleon exchange.

This may be true for inelastic scattering becauseof reduction of the nuclear overlap function for exchange processes.

It should be noted that

one nucleon exchange effect is considered to be taken into account effectively by using thephenomenological proton optical potential.
The basic optical parameters for 96Mo-p scattering (Ep = 12.5 MeV) are shown in Table 2.
For simplicity, the same radius and diffuseness parameters are assumed for real and imaginary
potentials.

Figure I shows the results obtained from Watanabe model for elastic scatterings of

96Mo-d (Ed = 21.5 MeV) and 96Mo-Q' (EO' = 30.8 MeV).

Satisfactory result is obtained for

a-scattering but rather poor fit for d-scattering.

Deuteron break-up effect is known to be very

important to reproduce the elastic scattering. 3 )Thus, the analysis of inelastic scattering by ourmodel is performed only for (0', a') case.

Figure 2 shows the results for 96 Mo(a, 0")96 Mo(2+,0.777 MeV and 3- , 2.230 MeV) and Table 3 shows the deformation parameters determined fromthe usual generalized optical model and the present folding model.

For 2+ case, the above-

mentioned discrepancy of {32 values between p and a-scatterings disappears in our folding model,
which indicates that the finite size effect of the projectile causes the projectile dependent45

Fig. 2.

Inelastic scattering cross section.

The calculated cross sections are plotted byadjusting the values of deformation parameters,
20

30

40
BC M

50

60

70

80

90

which are shown in the figure.

( deg .)

Table 3. Comparison of the deformation parameters determined by the extended
Watanabe model with those by the generalized optical model.

96Mo(~ , d),(p, pi)~12.5 MeV

0.163

3

0.179

_ __ _ _ __ _ _ _ _ _30.87 MeV~A~

Generalized optical model_ __ _ _ __ _ _ _Extended Watanabe model

0.143(3(~)/{3(p)0.163= 0.87(3(~)/{3(p)

= 1.0

0.158

0.138
(3(~)/{3(p)~= 0.77(3(~)/{3(p) = 0.88

deviation of (3L-values determined from the generalized optical model.

For 3- case, however,

unfortunately only half of the discrepancy is explained by our model.

To confirm theappropriateness of the idea presented here , further investigation is necessary , which includes theanalysis taking the break-up effect of deuteron into account. 5 )References
I)

T. Wada, H. Kamitsubo, T. Fujisawa, M. Koike, T. Nojiri, S. Yamaji, S. Kusuno, and T.
Matsuura: IPCR Cyclotron Progr. Rep., 10, 54 (1976).

2)

S. Watanabe: Nucl. Phys., ~ 484 (1958).

3)

S. J. Burger and G. Heymann: ibid· , A243, 461 (1975).

4)

K. Matsuda, Y. Awaya, N. Nakanishi, and S. Takeda: J. Phys. Soc. Japan, 33, 298 (1973).

5)

R. C. J ohnson and P. J. R. Soper: Phys. Rev., CI, 976 (1970).

46

4-11.

DWBA Analysis of Four-Nucleon Transfer Reaction
208

Pb ( 160, 12C) 212pO

T. Matsuura

It has been reported!) that the four-nucleon transfer reaction 208Pb(160, 12C)212PO at

Elab = 93 MeV shows typical bell-shaped angular distributions around 8 cm = 85° for both O;.s.
and 2i(0.727 MeV) transitions, the peak values being about 750 and 1750 nb/sr, respectively.
It has also been reported that the relative ratio of the spectroscopic factors extracted from anexact-finite-range DWBA analysis is S(2i)/S(0;.s) = 0.64, which shows reasonable agreementwith the ratio of a-decay reduced widths, 8 2(2i)/8 2 (O;.s) = 0.61 ± 0.24.
It is known, however, that the magnitude of a-cluster transfer DWBA cross section of(160, 12 C) reaction is too small to reproduce the experimental cross section. 2 )Here, weperformed an exact-finite-range DWBA analysis, by using various kinds of a-reduced width
amplitudes (form factors) for 212 Po = 208 Pb + a system, in order to see how the calculated cross(3L SL~o-=-O~-----------(4) SL:o=O.151xlO- 3-(5)

SL=o=O.120x 10- 2"'-_ _

.

.J

0.5

~

I .
.

\

I .
0

(fm)

I1. I
I
~.

.

\ )
~.
.

212po_ 208Pb+ ex(L= 0)- 0.5

Fig. 1.

Normalized reduced width amplitudes for
212 PO-+ 208 Pb+a(L=O).
(1)

lIS state of Woods-Saxon potential(R=1.25X208 1 / 3=7.41fm, a=0.65fm, B.E.=O.1 MeV).

(2) The same as Ref. 1 except for R=1.25 X(208 113 + 41/3) =9.39fm.
(3)

Single configuration (0 h9 /2)2 (0) (1 g9 12)2 (0).

(4) Glendenning and Harada.
(5) Tonozuka (89 orbits for protons and 83 orbits forneutrons). Spectroscopic factors (SL) are shown in the
figure.

47

section changes its magnitude by the different choice of form factors.

The same parameters as
those in Ref. 1 are used for optical potentials and the wave function of 16 0 = 12 C + a system.
Following form factors are examined for 212 Po = 208 Pb + a system.
1)

11 S(O+) and IOD(2+) states of the phenomenological Woods-Saxon potential(R = 1.25 X 208 113 fm, a = 0.65 fm).
2)

11 S(O+) and IOD(2+) states of the phenomenological Woods-Saxon potential(R = 1.25 X (208 113 + 4 113 ) fm, a = 0.65 fm).
3)

Form factors constructed from harmonic oscillator shell model wave function ofh~/2 (0)g~/2 (0) single configuration.

4)

Form factors constructed from Glendenning and Harada's wave function. 3 )5)Form factors constructed from Tonozuka's wave function of large space configuration

mixing (89 orbits for protons and 83 orbits for neutrons are promoted). 4 )In the cases of 3) -5), asymptotic part of the wave functions are replaced by thesolution of Woods-Saxon potential.

Bound state approximation is used in the case of 1) and2), by giving tentative binding energy of 0.1 MeV.
1.

Form factor dependence

Form factor dependence of the DWBA cross section is shown in Table 1.

In all cases, theangular distribution is nicely reproduced, but the magnitude changes so much by the radius ofform factor.
2.

(S(160; 12C) = 1.0 is assumed and form factors are normalized to unity).

Absolute value of the cross section

Assuming S(160; 12C) = (0.54)2 (the result of LS coupling shell model), comparison withexperimental cross section is made in the cases of 3) The remarkable enhancement of about 10

55) (Table 2, with the result for a-decay).

by the configuration mixing is seen, partly due tothe expansion of the range of form factor and partly due to the enhancement of the spectroscopic factor, Se 12 Po; 208 Pb).

It should be noted, however, that even in the case of 5) (large

configuration mixing) still multiplicative factor of X 24 (X 50) is necessary to reproduce thea-transfer (a-decay) experiment.
3.

Relative ratio of the spectroscopic factors

The relative ratio of the spectroscopic factors, S(2+)/S(0+), is rather insensitive to the
choice of form factor, namely, 0.64,0.57, and 0.52 for the cases 1),2), and 4), respectively.
Table 1. The peak values of the DWBA cross sections are shown.

All ofthe form factors are normalized to unity.
Form factor

a DW (peak) (mb/sr)

1)0.588 X 10-2 (82.5°)

2)0.122 X 10 1

3)0.128 X 10-2 (82 .5°)0.170 X 10-2 (82.5°)
0.432 X 10-1 (85°)

4)
5)

(86°)

Relative ratio

207
0.218
0.289
7.35

48

Table 2. Theoretical spectroscopic factors and the comparison of the
a-transfer cross sections and the a-decay reduced width with theexperiments.

S(160; 12 C) = (0.54)2 is assumed for the transfer case.

Form factor

Se 12 Po ; 208 Pb)

e~al/e~xp°cal/oexp

3)

6.7 X 10-6

4)

1.98 X 10-5
1.51 X 10-4

1.02 X 10 - 4

9.88 X 10 - 6
9.95 X 10-55)

1.20 X 10- 3

4.2 X 10-2

2.01 X 10 - 2

In this analysis, we have confirmed that the absolute value of the cluster-transfer DWBA
cross section is still too small to reproduce the experiment even in the case of large configuration mixing, though the angular distribution and the relative ratio of spectroscopic factors arewell explained.

208 Pb (1 60, 12C) 212 po

212 Po g.s.

L=O

E'60=93 MIN-'0(I) Woo ds Soxon- --(4) Glendenning - Harada-- -(5) Tonozuk a

Fig. 2. DWBA cross sections with different
form factors are shown. Calculated crosssections are normalized to the experimental
data. See the Table 1 and 2 for the
40·

60·

100·

120·

normalization factors.

References
1)

R. M. Devries, D. Shapira, W. G. Davies, G. C. Ball, J. S. Forster, and W. McLatchie: Phys.
Rev. Lett. , 35 , 835 (1975).

2)

K. I. Kubo: Proc. INS-IPCR Symp. on Cluster Structure of Nuclei and Transfer Reactions
Induced by Heavy-Ions, March, p.532 (1975).

3)

N. K. Glendenning and K. Harada: Nucl. Phys., 72, 481 (1965).

4)

I. Tonozuka: Plivate communication (Ph. D. Thesis, Department of Physics, Univ. of Tokyo(1975)).

49

4-12.

Effects of Recoil and Sequential Transfer in

12C(14N,12C)14N R·
eactlonat 79 M e V Inc id ent Energy

T. Kammuri, T. Motobayashi, I. Kohno, K. Katori,
M. Yoshie,* T. Ooi, and H. Kamitsubo

With inclusion of the recoil effect in the DWBA treatment of the transfer reaction,
additional angular momentum transfers are often intorduced, which can change the angular
A typical example is the one-proton transfer reaction 12

distribution drastically.

Ce N, C)13 N.
4

13

1)

While no-recoil DWBA predicts strong oscillation, the full-recoil angular distribution decreases
rather monotonously with angle.

Here we study similar effect of recoil on the two-nucleon

transfer reaction 12C(14N, 12C)14N at the incident energy of 79 MeV. 2 )We also aim to study

the competition of simultaneous and successive transfers of a neutron-proton- pair.
In the sum-of-interaction formulation of the two-nucleon transfer reaction, 3 ) one-step DWBA
amplitude is characterized by the set of transferred quantum numbers (fl' f2' f).

Taking post

form for the interaction, f I and.e 2 are related to the non-orthogonality overlap and the

12C ( 14 N, 12 C }14 N
Elab= 79 MeV• •• v +

.'

L

Vl

"E

+.. +.

1.0------ -1=0-----1=1-------- ----- -1 =2
sum

Fig. 1. Experimental and full-recoil two-step
DWBA angular distributions for the
12Cct4N,12C)14N reaction at 79 MeV incident

energy. Lower part of the figure shows thecalculated cross sections for the orbital
angular momentum transfer f = 0 (dot-dashed),.e = I (dashed), .e = 2 (dotted) and their incoherentsum (solid curve). In the upper part, the sum isnormalized and compared to the experimental
data. The multiplicative factor is 5.0.

* Institute of Physics, Tsukuba University.

50

interaction matrix element respectively, and .e is the vector sum of .e 1 and £2'

The same set(£1 , £2, £) specifies two-step amplitude, where £1 or £2 means the orbital angular momentum
transfer at each step.

For the case of 12C(l4N, 12C)14N reaction with transfer of OP1/2

nucleons, we have .e i = 0 and 1.

No-recoil DWBA calculations restrict £ i and .e to be zero, andgive rapidly oscillating angular distributions as shown in Fig. 1.

Full-recoil treatment allows.e = 1 and 2 transfers of the same order of magnitudes as .e = 0 component. The.e = 1
component oscillates out of phase with even £ parts, so that summed cross section showssmoothly decreasing behavior.
DWBA calculations were performed by using the program code FRATS,4) with opticalparameters listed as set A in Table 1. 5 )Angular shapes of one- and two-step processes are verymuch the same, so we have shown only the two-step post-post results in Fig. 1.
factor N ff is 5.0.

The normalization

If we use the set B which also gives good fit to the elastic scatteringof 14N on 12C, N ff becomes 25.

The ratios of two-step post-post and one-step post crosssections are 1.5, 2.1, and 2.4 for £ = 0, 1, and 2 respectively.

Although sequential transfer

has bigger cross section than simultaneous transfer process, the difference between two processes
is much smaller as compared with the case of transfer of idential-nuc1eon pair treated in Ref. 3.

Table l. Optical parameters for the 12C(l4N, 12C)14N reaction.

Set

V
(MeV)

rR
(fm)

aR
(fm)

W
(MeV)

(fm)

aI
(fm)

A

100

0.92

0.77

38.5

1.29

0.26

B

65

1.21

0.48

20

1.35

0.25

q

References

1)

R. M. DeVries and K. I. Kubo: Phys. Rev. Lett., 30, 325 (1973);
R. M. DeVries: Phys. Rev., C8, 951 (1973).

2)

T. Motobayashi, I. Kohno, S. Nakajima, M. Yoshie, K. Katori, T. Mikumo, and H.
Kamitsubo: Proc. Intern. Symp. on Cluster Structure of Nuclei and Transfer Reactions
Induced by Heavy Ions, Tokyo (1975); edited by H. Kamitsubo, 1. Kohno, and T. Marumori(IPCR cyclotron Progr. Report Sup pI. 4, p. 725 (1975). unpublished).

3)

T. Kammuri: Nuc1. Phys., A259, 343 (1976).

4)

T. Kammuri and S. Yamaji: DWBA code FRATS (unpublished).

5)

W. von Oertzen, M. Liu, C. Caverzasio, J. C. Jacmart, F. Pougheon, M. Rion, J. C.
Roynette, and C. Stephan: Nucl. Phys., A143, 34 (1970).

51

4-13.

Collect ive Mass Transfer

In

the Collision238

U _ 238 U

S. Yamaji, W. Scheid,* H. J. Fink ,* and W. Greiner*

In order to study the mass fragmentation in fission and heavy-ion scattering, it is useful tointroduce a collective fragmentation coordinate defined by 1)(1)

The mass distribution of fissioning nuclei has been explained by a dynamical treatment of thecollective coordinate 1] .2) The idea of quantized fragmentation dynamics can also be applied
straight-forwardly to the fragmentation in heavy ion reactions. 3),4)
Calculations of the mass fragmentation in U-U collisions 4) gave an estimate of the order ofthe fragmentation time. This paper is devoted to the question about the possibility of producing
superheavy elements in the U-U collision. The idea is to describe the collision of the two nuclei
by the relative coordinate R and the fragmentation coordinate Tl defined in Eqn. (1)The collective energy of the system is of the following from---- .-.
1
~
-=-.
1
.
H(R, 1] ,R,1]) = "2 BRR (R,1])R 2 + BR1] (R ,1] )R1] + "2 B1]1] (R,1] )1]2 + V(R,1]).

(2)

The potential and the mass parameters are consistently calculated within the renormalization
method and the cranking model on the basis of the asymmetric two center shell model. 5)
The fragmentation potential V(R,1]) for 238 U-238 U is shown in Fig. l.
The 1]-motion in Eqn. (2) is quantized according to the Pauli prescription. Then the massfragmentation is the solution of the time-dependent Schrodinger equation
H~(1],. ata ~(1] , t)t) = ih

h2

H = _

~

1

~ + __P_R_(t_)2_ _2Y B1]1] (R(t), 1]) a1] YB1]1] (R(t), 1]) a1]

+ 2B

RR

2BRR (R(t), 1])(3)(R(t), 1])R(t)2 + V(R(t), 1]), where the relative coordinate R(t) and its conjugate PR(t) are obtained by solving Hamilton'scoupled equations of Eqn. (2). In order to simplify the calculations, the coupling term in Eqn.
(2) is neglected because of IBR." I< < Y B B"
RR 1]1]*

as proven in Ref. 5.

Insti tu t fUr Theoretische Physik der Universitat Frankfurt/M. , Germany.

52

Equation (3) is solved directly by the finite difference method. 6) The fragmentation probability
at time t and fragmentation 11 is dW(11, t) = \ ~(11 ,t) \2) B1111 (R( t),11 )d?7.
The initial conditions are chosen in the following way: We assume that dynamical effects are notimportant for separations R>Rc where Rc is the distance of critical overlap. Therefore, we makean ansatz for the initial mass distribution at

Here, the coordinate ?7i of the initial mass fragmentation characterizes projectile and target, andthe width r the few nucleon transfer which can occur before the critical distance Rc is reached.
The critical distance, Rc = 14.5 fm, is assumed to be equal to the touching distance of the twonuclei. Therefore, the collective mass transfer starts for R = Rc at the time t = 0 when the two

Ecm=860MeV
L= 200nb= 2.8 fm
B=13r

T=200

R=10.1fm

Initial distr ibution

T=300

R=9.5 fm
R=9.1 tm
R=8.9 fm
R=9.1 fm

T=800

R=9.5fm

T=900

10Final distribution
T=1100170

11a3Q6+S6 Dy

Fig. 1. The fragmentation potential V(R,11)

Fig. 2.

between the relative distances 9.0 fm anddistributions for the incident energy

15.0 fm calculated by the fourth order

860 Me V is shown. The numbers at theLagrangian interpolation technique fromcurves are the time in units of 10-23 sec.

the values of Ref. 5. The numbers at the
curves show the values of the relative
distance in units of fm.

The time-evolution of the mass

53

colliding nuclei touch and continues until the two fragments separate at R = Rc again.
An example of the time evolution of the mass fragmentation is presented for the incident
energy Ecm = 860 MeV and the angular momentum L = 200 h in Fig.2. The width is chosenr = 0.0126 which corresponds to a spread in mass A of 6A = 3.
The mass distribution spreads out up to 200 X 10-23 sec., when the colliding nuclei comeclose to 10.2 fm.

As the small barrier at 1] = 0.02 in Fig. 1 disappears at 10.2 fm, themotion of fragmentation starts.

However, in the region 9 ""' 10 fm and 77 = 0.02 ""' 0.2,

the fragmentation moves very slowly due to the small driving force -av /a77. The appreciable

part of the distribution has already reached 1] = 0.25 at time T = 900 X 10

-23

sec.

Such large 1]-values correspond to superheavy nuclei with A ""' 300. In spite of the large
potential barrier at 1] = 0.2 for R :::::I Rc (see Fig. I) larger mass transfer is possible withincreasing incident energy, since smaller relative distances are reached. The present calculations
give evidence for the possibility of producing superheavy nuclei in the U-U-collision.

The estimated cross sections are of the order a( superheavy)=~:xw b (1/)dbL'1/"" 1b, whereWb (1])61] is the probability producing superheavy nuclei (A""'300) in the collision with the impact
parameter b.

References

1)

P. Lichtner, D. Drechsel, J. Maruhn, and W. Greiner: Phys. Lett., 45B, 175 (1973).

2)

J. Maruhn and W. Greiner: Phys. Rev., C13, 2404 (1976).

3)

H. J. Fink, J. Maruhn, W. Scheid, and W. Greiner: Z. Physik, 268, 321 (1974).

4)

S. Yamaji, W. Scheid, H. J. Fink, and W. Greiner: ibid., A278, 69 (1976).

5)

O. Zohni, J. Maruhn, W. Scheid, and W. Greiner: ibid., A275, 234 (1975).

6)

A. Goldberg, H. M. Schey, and J. L. Schwarz: Am. J. Phys., 35(3), 177 (1967).

54

4-14.

Elastic and Inelastic Scatterings of Deuteron

from

Even-Mass

Isotopes of Molybdenum

T. Wada, H. Kamitsubo, T. Fujisawa, M. Koike,
T. Nojiri, * S. Yamaji , S. Kusuno, * * and T. Matsuura

The experimental results have been reported. l )optical model.

The elastic scatterings were analyzed by an

In the range of real potential well depths between 50 and 180 MeV, three setsof optical parameters were found to give equivalent fits to the experimental data.

The

parameter set with V R 'V I 00 MeV was found best to fit the experimental data of the inelastic
scattering.

The inelastic scatterings were analyzed by coupled-channel calculations using an

automatic parameter search code CCSEARCH. 2 )The deduced values of the deformation

parameters were compared with those from other experiments with different projectiles.

The

inelastic scatterings from the isotopes of molybdenum have been studied with protons,3)-5)
deuterons,6) and alpha particles. 5),7),8) Although the deformation parameter is usually assumed
to be an intrinsic property of the nucleus and is independent of the means of excitation ,systematic differences in the values of the deformation parameters for the one-phonon states
were found between the results from the inelastic scatterings with different projectiles.
1 shows how different these results are one another.

FigureAlthough it is well known that insteadof the deformation parameter {3 the deformation length {3R must be used for comparison,
there is an ambiguity in determination of R in case of complex potential.
Fig. I.

Then we compared

Comparison of the ratio of {33

to {32 from different projectiles:-

2.0~

o for (p,p') at 15 MeV, Ref. 3.
6,

for (p ,p') at 14.5 MeV , Ref. 4.

o for (p,p') at 12.5 MeV, Ref. 5.
X for (a,a') at 31 MeV, Ref. 7.

• for (a,a') at 30.87 MeV, Ref. 8.
• for (a,a') at 32.2 MeV , Ref. 5.
• for (d,d') at 21.5 MeV , present work.
The solid curve presents the averagevalues of the results from (d,d') and

o

I

I

I

I

I

(a,a'), and the dashed curve the

92

94

96

98

100

average values of the results fromA
* Osaka University .
* * NAIG Nuclear Research Laboratory.

(p,p').

55

the ratio of the deformation parameters.

For all the five isotopes, the ratios of {33 to (32 fromCd, d ') agree quite well with those from (a,c/), while they are smaller by about I 0~20 per centthan those from (p, p').
In order to investigate the isotopic spin dependence of the excitation, the form factors
are calculated by a RPA theory where they are separated for pure isoscalar and isovector terms.
The isotopic spin dependence was found to be too small to explain the differences shown in
Fig. 1.
It has been shown that the deformation parameter of higher order is affected morestrongly if a finite size of a projectile is taken into account. 9 )We performed a folding model

calculation in which the optical potential and the form factor of nucleon were folded over theinternal wave function of projectile.

The inelastic scattering cross section from the first 3-

state was reduced by about 30 per cent, while that from the first 2+ state was not affected
greatly.

The (33 must then be increased by about 15 per cent.

difference shown in Fig. 1.

This amount is similar to the

For the scattering of alpha particles, the folding model gives

similar results as shown in 4-10.

References
1)

T. Wada, H. Kamitsubo, T. Fujisawa, M. Koike, and T. Inanaga: IPCR Cyclotron Progr. Rep.,~

33 (1972).

2)

T. Wad a and S. Yamaji: Sci. Papers I. P. C. R., 68, 65 (1974).

3)

H. F. Luts, D. W. Heikkinen, and W. Bartulini: Phys. Rev., C4, 934 (1971).

4)

Y. Awaya, M. Matsuda, T. Wada, N. Nakanishi, S. Takeda, and S. Yamaji: J. Phys. Soc.
Japan, 33, 881 (1972).

5)

S. J. Burger and G. Heymann: Nucl. Phys., A243, 461 (1975).

6)

Y. S. Kim and B. L. Cohen: Phys. Rev., 142, 788 (1966).

7)

E. J. Martens and A. M. Bernstein: Nucl. Phys., A117, 241 (1968).

8)

K. Matsuda, Y. Awaya, N. Nakanishi, and S. Takeda: J. Phys. Soc. Japan, 33, 298 (1972).

9)

D. L. Hendrie: Phys. Rev. Lett., llz. 478 (1973).

56

4-15.

Po Iarization Measurement
in

14

0

f 12 B g.s .

Prod uce d

N - 1n duced Reaction

K. Tanaka, M. Ishihara, H. Kamitsubo, N. Takahashi,
Y. Nojiri, T. Minamisono, * A. Mizobuchi, * and K. Sugimoto*

It is known that there exist two processes called "deep inelastic collision" and "quasi-elastic
scattering" in heavy ion induced reactions. I) A recent description 2) of such processes, in which

frictional forces play an important role, points out a possibility of a negative angle scattering
being supposedly responsible for deep inelastic processes and a positive angle scattering for
quasi -elastic processes.

According to such an interpretation, the spin polarization of thereaction products presents an important parameter.
Hence we have started the polarization measurement for 12 Bg .s . produced in the 14N_
induced reaction, by measuring up-and-down asymmetry of (3-ray yields with respect to thescattering plane. A 15.3mg/cm 2 thick natural molybdenum target and 14N-beam of E=95 MeV
were used.

A well established adiabatic fast passage NMR technique 3 ) was employed toeliminate spurious asymmetry effects caused by geometrical asymmetries.
cyclotron was chopped by a mechanical chopper. 4)

The beam from the

The procedure during one beam cycle was as follows: During on-beam period of 40 msec,~.

Collimater.

.

14NbeamLab

TargetTop view

Plastic detectors

Side view~--~ Magnet

poles

Plastic detectors

Fig. 1.

Schematic drawing of the experimental

arrangement.
* Faculty of Science, Osaka University.

57

12 B

products were implanted into a platinum catcher foil.

The initial polarization was preserved

by a static field of 1.5 kG which had been found to be sufficient.

During the following

off-beam period of 40 msec a R.F. field perpendicular to the static field was applied for a few
msec, and then {3-rays from the catcher were detected by a pair of three-fold plastic detectors
placed at the upper and lower side of the catcher.

(Fig. 1 )In the measurement two kinds of the beam cycles were alternated with each other: One
was so-called "on-resonance" cycle in which the frequency of the R.F. field was swept across aresonant point so that the polarization of 12 B was reversed, and the other was "off-resonance"
cycle in which the frequency was swept over the region beyond a resonant point with thepolarization unchanged. {3-ray events YU' Y L in upper and lower side of the catcher wereaccumulated for each kind of beam cycles.

Supposing the polarization P produced in thereaction points downwards, the yields for "off-resonance" cycles can be written as
y OFFU= Cu (l-AP),

yOFF
L

= CL

(l+AP),and those for "on-resonance" cycles asyONUCu (l+AP),

yON
L= CL (l-AP),

where Cu and CL are the geometrical factors of the upper and lower set of counters, respectively.
A is the asymmetry parameter and A=-I for 12 B decays.

Therefore, we can derive thepolariza tion from the ratio

y8FF / y£FF
R

(I + P ,:\2
~ I - p)= ----------------

Y8N / y£N

I

r

I

1.11-

1.0 1---- -- - -- - -- - --+--

- --1

I

Q::

0.9-

O.Sr-

Fig. 2.
-

Ratio R for each run. After arough correction for depolarization
effects, the polarization for 8 Lab =20°-

is derived from these values as
P = - 6.1 ± l.1 %. Only statistical errors

II

are taken into account.

58

Figure 2 shows the present result, which gives a rather small polarization:P-6.1 ± 1.1 %.

To examine these values , next experiment is now under consideration :An enriched target is used ; and the kinetic energy of the 12 B product is changed at small steps
by choosing suitable thicknesses of the catcher foil and of the absorber inserted between thetarget and the catcher.

ReferencesI)

A. G. Artukh, C. F. Gridnev, V. L. Mikheev , V. V. Volkov, and J. Wilczynski: Nucl. Phys.,A215, 91 (1973).

2)

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

3)

K. Sugimoto, K. Nakai, K. Matsuda, and T. Minamisono: J. Phys. Soc. of Japan, 25, 1258
(1968);
M. Hori, S. Ochi, T. Minamisono, A. Mizobuchi, and K. Sugimoto: ibid., 34, Supplement,
p. 161 (1973).

4)

A. Hashizume and H. Kumagai: IPCR Cyclotron Progr. Rep.,~ 72 (1971).

59

5. NUCLER PHYSICS
Nuclear Spectroscopy
5-1.

Gamma Rays froman Incomplete Fusion Reaction
Induced by 95 MeV 14N

T. Inamura, K. Hiruta, M. Ishi..l-}ara,
T. Fukuda, and T. Shimoda
It has already been pointed out that high-energy charged particles, in particular a-particles,

are emitted predominantly in the forward direction in the bombardment of various targets withheavy ions. 1),2) Projectiles should then pass the grazing trajectory, according to Kaufman andWalfgang. 3 )Because of this, by detecting those a-particles (hereafter we call them "direct" a-particles for convenience) it may be possible to select a reaction channel which leads toselective population of high spin states.

To test this idea we made "direct" a-'Y coincidence

measurement in the bombardment of 159Tb with 95 MeV 14N.
The 159 Tb target was a self-supporting metallic foil (2.1 mg/ cm 2 ). To detect a-particles
we used a Si surface-barrier annular detector at 0° to the beam.

The solid angle subtended was

0.73 sr (8=16.7°- 32.6°to the beam). The 'Y-ray detector used was a 60 cm 3 Ge(Li) counter
placed at 90° to the beam and 4 cm from the target.

To make the contribution from thecompound nucleus formation negligible, lower energy a-particles (Ea:S33 MeV in lab) were cut
off by using a 400 J.1m thick aluminum foil (annular as well) in front of the Si detector.
To see how different 'Y de-excitation after "direct" a-particle emission appears compared
to compound nucleus formation, we also measured 'Y-rays in coincidence with a-particles emitted
in the backward direction.

The same annular detector was placed at 180° to the beam,

the detection angle being 147.4°- 163 .3°. We used a 100 J.1m thick alminum foil instead of
the 400 J.1m thick one.
Figure 1 (a) shows the 'Y-ray spectrum observed in coincidence with "direct" a-particles.
Stronger 'Y-rays have been identified as those from 166 Yb.

This suggests that three neutrons
successively evapolate after "direct" a-particle emission, i.e. the 159 Tbct 4 N ,a3n) 166 Yb reaction
from incomplete fusion.
Figure I (b) shows the 'Y-ray spectrum observed in coincidence with "compound" a-particles .
Figure 2 shows intensities of cascade E2 transitions relative to the 4+ ~ 2+ transition in thede-excitation of the residual nuclei, such as 164 Yb, 166 Yb, and 168 Hf, in the bombardment of
159Tb with 95 MeV 14N. It is clearly seen that yields of the cascade transitions in 166Yb
produced via incomplete fusion are totally different from those in the compound-nucleus
reaction products. The former indicates that there was no side-feeding and that entry states withlimited spin values just above J= 10 were populated, feeding the ground band only.
The solid line in Fig. 2 was obtained from the Gaussian distribution with a half-width of
2 n and a mean value of 13 n.

Provided the average angular momentum of the observed a-

60

159Tb (14N, d TnT) 169-X Yb

500

(b)

E14 N =95MeV

( a)

X=3
6-4

500

X= 3

8-6

X=3

EO( ~33 MeV

10-8 511 keV

8 cx = 16.7- 32.6°
Q.

200=35.04,.uC

300
Gamma ray energy(keV)

Fig. 1. 'Y-ray spectra observed in coincidence with a) "direct"
ex-particles emitted in the forward direction (Eex<:33 MeV) andb) "compound" ex-particles emitted in the backward direction(Ecx<:15 MeV) in the bombardment of 159Tb with 95 MeV 14N.

T- rays follow ing

1.0\\d i rect II(j.

em ittingreaction_!_~ I I

Fig. 2.

'Y-transition intensities relative

to the:!

4+ ---+ 2+ transition in de-excitation of the
159Tb+95 MeV 14N reaction products: • indicates

~0.5
V>

'Y-rays from 166 Yb in coincidence with "direct"

C

'"
C

ex-particles; the solid curve was obtained using a

.~1.0
....,

Gaussian spin distribution (half-width=2h,

' v;
c

~

mean=13h) of states populated immediately after~ 0.5

evaporation of three neutrons. The lower part of

:.:;
~

'"

0::

the drawing shows the data on 'Y-rays following
T- rays following

the compound-nucleus formation: 0 for
4 N,ex3n'Y)I66Yb, and
4 N, 5n'Y)168Hf, 0 forcompo und - nucleus formation

e

I
4

6

8

10

12

14

16

l

I

l

I

III

2

4

6

8

10

Transition

12

14

6

for

e

e

4 N,ex5n'Y) I64 Yb; a thin line is drawn justto guide the eye.

61

particles (E Q .~33MeV) is given by £=21 11, a semi-classical value which is derived using the
average kinetic energy of 40 MeV in lab, the total angular momentum removed by particle
emission should be P=27 fl., on the average, because the total average angular momentum of
three neutrons is estimated to be 6 n.
angular momentum.

Then we have ,£=40 h as the mean value of the initial

It is interesting to note that this mean value is just above the criticalangular momentum Pcr=37 h in the 159Tb + 95 MeV 14N reaction.

Perhaps the initial angularmomentum distribution of the reaction channel in question is narrowly restricted to just above

Per

References

1)

H.C. Britt and A.R. Quinton:

Phys. Rev., 124, 877 (1961).

2)

J. Galin, B. Gatty, D. Guerrean, C. Rousset, D.C. Schlotthauer-Voos, and X. Tarrago:
C9, 1126 (1974).

3)

R. Kaufman and R. Walfgang:ibid., ll.L. 192 (1961).

ibid.,

62

5-2.

Exc ited States

In l04Cd

via

the(3 He , 3n)Reaction

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

104

Cd was excited via the 104 Pd eHe, 3n) reaction and excited states were investigated bymeasuring de-excitation 'Y-rays.
were studied.

Excitation functions, 'Y-'Y coincidences and angular distributions

Excitation functions were studied with the incident energies from 26 to 46 MeV.

eHe, 3n)

Typical example of excitation curves of 104 Pd

104

Cd taken for 658, 834, and 878

ke V 'Y-rays were shown in Fig. 1.
In the course of this experiment, efforts were made to elucidate 'Y-'Y coincident relations
which provide very effective means to correlate many observed 'Y-rays and the transitions
concerned in level scheme.
reported already.1)

The experimental set up of the coincidence measurement has been

The digitali zed coincidence data in 2048 X 2048 channels were stored

event by event in magnetic tapes.

Digital gates were opened by playing these magnetic tapes

and the coincident spectrum for each interested 'Y-rays was obtained. Total coincident events
registered in magnetic tapes amount to about 450000 counts.
coincident spectra.

Figures 2 and 3 show typicalIn these spectra the background obtained for the same gate width inneighbourhood of the total absorption peak was subtracted and smoothing procedure of thespectrum was performed twice.

From Figs. 2 and 3, it is evident that a strong coincident

relation exists between 538, 878, 835, and 658 keY 'Y-rays; these 'Y-rays can be attributed tocascade transitions (8+) -+ 6+ -+ 4+ -+ 2+ -+ 0+ in the order at which the photons are given,."..-.",,0. -'.........

"- ,

.

' '\

-"

'\
'\
\

Q)

§

,....-- ..........

,., ,'..

\

658 keV

.'--

-

" ,
\

\
\

\

864 keV'e _ _ _ e

+-'

o

Q)

0:
./

,

"of

t/

, _...... , ,

'\ t
'\

Fig. 1.

,
"

20

I

I

30

40
E 3he (MeV)

Excitation functions taken by658, 864, and 878 keY 'Y-rays. The

878keV., ...... _-,dotted curves were drawn through the50experimental points.

63

200

N
N

100

300

"

~

<..0

200

~

"'00

C""lr--

0000

0

'"

Gate

1002 ke V

Gate

890 keV

C""l

00

00

C""l

'"

100

<..0

0

LD

0

~

~

200

N

0
0

0

;;;
-

Gat e 878 keV
1 00 -

00"',

r---:=;

~

00",

I

300

0

b
~ 200

<..0-

200

-C""l
C""lC"l

0

u

~ 100

100

~

<..0

Gate 835 keV
0

'"

' ro

gr--

0000

Gate

841 keVGale

538 keV

0

200

300
C""l

LD

00

00

<..0<..0

200

r-ro

-

'"<..0100

0C"lC"lLDro""r-0000

'"

100

0

00

500
Ch an nel

Fig. 2 and 3.

num ber

'Y-'Y

1000

1500

Cho nne I number

coincident spectra obtained when 104 Pd target was bombarded

with 3 He of 35 MeV.
above.
2

made. )

These results confirm the assignment of 4+ -+ 2+ -+ 0+ cascade transitions previously
The 316, 331, 511, and 556 keV peaks in the spectrum of Fig. 2(b) are due todifferent contribution of activities at the gates of the peak and background.
The calibrations of energies and the determination of relative efficiency of Ge(Li) detectors
for different quantum energies were made by using 226 Ra source.

Partial level scheme with

- - - -- - . . - - - - - - - 3912
1002
3
261
3212
========:::J===t:==::;::===
890

841( 8+) ===::;::====t=w=====t==== 29 10
2871
538.4
6-t ===:±===t::;t==a::±=== 2435.4
2371.3
942:'? _ __ 2108 .7
878.4

4+----.....,

615.8_L..--1--_

1492 .9834 .62+ - - - - -658.3
658 .3

O+--------~~--------

oFig. 4.

Proposed level scheme of 104 Cd.

2000

64

their de-excitation transitions tentatively proposed is shown in Fig. 4.

In the figure, the relative

intensities of )'-rays are given by the width of arrows.
Since the structure df neutron deficient cadmium isotopes l04Cd, 102Cd, and lOoCd approachs
closed neutron shell, it is expected that the level structures of these nuclei are influenced by
the closed shell.

On the other hand, there have been reported that 100 Pd, 102 Pd, and 104 Pd

isotopes have collective properties.

The level scheme of 101 Pd and 103 Pd is also interpreted

from the view point of collective excitation where the model of variable moment of inertia
plays an essential role. 3) It can be argued that some cadmium isotopes show a feature oftransitional nuclei.

We are investigating the excited states of 100 Cd, 102Cd, and 104 Cd produced

via ( 12 C, 3n) and ( 12 C, 5n) reactions on 92Mo, 94Mo, and 96Mo.

Reduction and investigationof the data obtained are now in progress.

References

1)

H. Kumagai and A. Hashizume: IPCR Cyclotron Progr. Rep., ~ 70 (1975);
H. Kumagai, M. Okano, and A. Hashizume: Reports I.P.C.R., (in Japanese), ~ 102 (1975).

2)

A. Hashizume, T. Inamura, T. Katou, Y. Tendow , T. Yamazaki, and T. Nomura: IPCR
Cyclotron Progr. Rep., ~ 57 (1969).

3)

P. Simms, G. Smith, F. Rickey, J. Grau, J. Tesmer, and R. Steffen: Phys. Rev., C9, 684(1974 ).

65

5-3.

Internal Conversion Electrons of 136 Bo

M. Ohshima, * Y. Itoh, * S. Hayashibe,
M. Fujioka, T. Ishimatsu, * and A. Hashizume

The low lying level structure of 136 Ba is investigated from {3- decay of 136 Cs. Internalconversion electrons were measured with a V21T iron-free magnetic (J-ray spectrometer installed in
Institute for Nuclear Study of Tokyo University. So far, the conversion electron data of thisnucleus are scarce. Only Reising and Patel) and Fujioka et al. 2 ) have reported on this subject.
Xe gas was bombarded with a 15 MeV proton beam from the cyclotron. The outline of thetarget chamber and the method of preparing (3-ray source were presented in the previous report,3)
but some improvements in the target chamber were made recently. The inside diameter of thechamber was made larger to be 116 mm</> and in the chamber was inserted a glass tube of inside
diameter of 80 mm</> to prevent the collector foil from the contamination of organic substances.
Consequently the collection efficiency of activity amounted to more than 40 % and the source
was made thinner.
Typical conversion electron spectrum in the 120 - 160 keY region is shown in Fig. 1, withthe momentum resolution of the spectrometer set at 0.05 %. The presence of {3- continuum ofE{3max ::::: 330 keY made it difficult to measure the conversion electrons in this energy range. In
Table 1 is shown internal conversion coefficients calibrated with K electron of the 163 ke V E3transition for the lower energy region and of the 340 keY E2 transition for the higher one.
e- Spectrum

--.J
I

~
~
(Y")

<I>
C
C

(,Q
~

I

~
~

'"

.<::

U

:; 10

~

1

3

.....c

(Y")

~

::>

o

U

25000

27500
Channel

30000

numberFig. 1. Typical conversion electron spectrum in
120-160 keY region.

* Tohoku University.

66

Table. 1. Internal conversion coefficients in 136 Ba.
I a)

E')'

ak thea. (K/L)exp. (K/Lhheo. Multipolarity

Uk expo'Y

66.881 (17)

4.8

(2)

0.150

(9)b)

86.265 (30)

5.0

(2)

0.291

(5)

0.0841
8.93
0.293

(7)

0.21

(3)

0.914

(56)

153 .246 (4)5.77 (18)

0.260

(3)

163.920 (2)3.40 (12)

1. 12 c)166.576 (6)0.37 ( 4)

0.231

(27)

176.602 (4)

10.0

( 4)

0.0355(20)

187.285 (6)0.36 (4)

0.155

(19)

273.646 (8)

11.1

(4)

0.0137(7)

109.681(8)0.50 (5)0.0318 (42)340.547 (8)42.3 (13)0.0233 (12)a)507. 188 (10)0.97 (3)0.0130319.911

(7)

(El)
(M2)
(E 1) 7.24

El+(M2)
(3)

7.26

EI

0.922

2.42 (15)

2.45

E2

0.257

3.60

(10)

3.53

E2

1.12

1.25

(3)

1.26

E3

0.204 (Ml) 6.87 (91 ) 7.51
(E2)
0.243
3.79
0.0406
7.36 ( 57) 7.65

Ml+E2

(Ml) 5.65 (68)
0.148
(E2)
0.166
0.0126
8.83 (73)

Ml+E2

7.55
4.16
7.83

El

El

0.0356 (Ml)0.0303 (E2)
5.94 (11 )0.0250

5.82

E2

7.79
6.65
7.42

Ml+E2

Ml+E2

818.514 (12)100

0.00227 (10)0.0 III (Ml) 8.00 (100)0.00798 (E2)0.002427.70 (20)1048.073 (20)79.7 (26)0.00150 (10)0.00141

7.50 (26)

7.69

E2

1235.362 (23)

20.1

(7)

0.00098 (4)0.00100

7.75 (59)

7.80

E2

E2

a) ,),-ray relative intensities are obtained from our previous work. 4)b) These val ues are for ~. .
LI+Ln+Lm. K electron IS hidden among Auger electrons.
c) These values are used to normalize other electron intensities.

The proposed decay scheme is shown in Fig. 2.
For the 66 keY transition , Reising and Pate 1) measured the K and L electrons anddetermined the K/L ratio to be ~ 1.3 ± 0.8 which' disagrees with theoretical value of 7.01 for E1.
Our more precise measurement, however, has shown that the K electron coexists with the Auger
electrons and is difficult to separate from them. From the value of ~LI+LII+LIII we determined
this transition · to be almost El with small mixture of M2.
Three weak conversion electrons can be attributed to the transitions from newly assigned
2373 keY state to 1866 keY(4t), to 2053 keY(4i) and to 2207 keY(6+) state with transition

67

12.9d 5+~
I~~CS 1.0
0.1

<D

.'

~O-~<DM~N~N<D

6.9 ... 4+
8.0... 6+
71.2 6.2 .. 59.7 7.3.. 4+
4.8 7.9
0.8 8.7 7... 4+
11.9 8.0

1/"J("'l~~~g:?;8~<D_
ci<D",Q)~cnn-

2373756.
~

II I~~~~~~~2

I

I

I

I I I ~~~r--'a:M
I I I I N~~;;t

I II ~

2207.1192 J1Q.219
2053.872\2030.50 7':' 1866.587% Logf t~=-2.54 MeV

<l"
lCl

cO
2+

co

818.514

Fig. 2.

Proposed decay scheme of 136 Ba.

C* ) Because of small transition

probabilities, it was difficult to observe
internal conversion electrons. The value0+0

is obtained from our 'Y-ray work. 4)energies of 507, 319 and 166 ke V respectively. All of these transitions have M 1 C+ E2) character
We, therefore, determined this level to be 5+. This assignment is in agreement with log ft valueof 6.9. which indicates this transition to be an allowed one. The branching ratios of the threetransitions also support this assignment. More precise analysis is in progress.

References

1)

R. Reising and B. D. Pate: Nucl. Phys., 65, 609 (1965).

2)

M. Fujioka, T. Miyauchi, and H. Adachi: ibid., A95, 577 (1967).

3)

M. Ohshima, M. Hirasawa, S. Hayashibe, M. Yambe, J.Katakura, M. Fujioka, T. Ishimatsu,
and A. Hashizume: IPCR Cyclotron Progr. Rep.,2.z. 62 (1975).

4)

S. Hayashibe, M. Ohshima, M. Yambe, J. Katakura, and T. Ishimatsu: Research Report ofLaboratory of Nuclear Science, Tohoku University, ~ 312 (1974).

68

6. NUCLEAR INSTRUMENTATION

6-1.

Efficiency for Detecting 8Be Nuclei witha

Position Sens itive Detector

T. Ooi, T. Motobayashi, K. Katori, and I. Kohno

The ground state of 8Be decays promptly into two (X particles (t 1/ 2 "" 10- 16 sec) with a breakup energy of 92 keV. The break-up (X-particles from a rapidly moving 8Be nucleus will travel
within a cone of which axis is in the direction of the original 8Be. Since the spin of the 8Be
ground state is zero, (X particles are emitted isotropically in the 8Be rest system. By vectorial
addition with velocity of the center of mass, directions of (X particles are confined within anarrow forward cone in the laboratory frame of reference as stated above and illustrated in Fig.
1. Therefore, at the surface of the position sensitive detector (PSD) the density of (X-particles

from 8Be nucleus is proportional to the projection of spherical shell having a constant surface
density by a point source at the target.
When two (X -particles from 8Be, a l and a2, impinge on PSD in coincidence at point Xl andX2 respectively, output signals are proportional to El + E2 at energy contact and Xl El +X2 E2 atposition contact (Fig. I). El and E2 show energies of a l and (X2 respectively. The position
information iswhere El ~E2'
PS 0

c. m. momentaof Q' pa rticles

Fig. 1. Position on PSD for coincident a-particles and thepost to reject other particles.
This looks as if a 8Be particle came in at the point which is the average of Xl and X2 .
Strictly speaking, the point is not always on the extension of the direction of 8Be, but the shiftis small. For example, the shift for 8Be of 20 MeV is smaller than the position resolution ofPSD (=0.2Smm FWHM). In this method of detection by PSD, only 8Be particles can be detectedwith desirable solid angle and efficiency if the gate width is masked by a post and only position

69

signals corresponding to the area under the post are accepted so as to reject other unpaired
particles as shown in Fig.l. For measurement of 8Be nucleus we used a rectangular collimatorwhich is divided by the post, or a divided circular collimator (Fig.2).
Circularco l limator

30

~ 20

(Distance from the target = 70 mm)

10

60

40
E(sBe)

Rectangular

30

16mm
"i I
j7mm

O.., O
I-

80

(MeV)

collimator(Distance from the target = 90 mm)

4mm

Approx.

40

60

80

£ (SBe) (MeV)

Fig. 2.

Calculated detection efficiency.

To calculate overall detection efficiency of the divided collimator the ratio of number of
events where the break-up ex particles come in through two windows of the divided collimator tonumber of all 8Be nucleus which would come in the whole gate width must be calculated andaveraged}) We carried out both an exact and an approximate calculation of overall detection
efficiency. In the approximate calculation we assumed that subsequent paths of two break-up ex
particles make the same angle with the original direction of 8Be. Then, the calculation of detection
efficiency reduced to an integration of the ex-particles density on the detector surface limitedby the divided collimator. The results calculated are shown in Fig.2. It is known from this resultsthat in the energy of 8Be below 25 MeV the divided rectangular collimator is preferable, but thedivided circular collimator is better in the energy above 30 MeV for geometries given in the Fig.2.

Reference
1)

T. Ooi, T. Motobayashi, K. Katori, and 1. Kohno: Reports 1.P.C.R., (in Japanese), 52, 145(1976).

70

6-2.

A

Modified .6. E-E Counter Telescope

T. Motobayashi

To measure the reaction products of the heavy ion reaction more efficiently than before,
the counter telescope was modified so as to achieve detection at many (four in this case) angles
simultaneously.!) This system is especially usefull when the target is so thin (for example a gas
target) or the beam intensity is so low that the counting rate never goes up higher than thelimit restricted by the detection circuit.
The modified counter telescope 2 ) consists of position sensitive solid state E connter (500j1
thick, 7mmX25mm), 6E counter (30j1, 200mm 2 ), and four slit collimators as illustrated in Fig.
1. The slits are all 1.5mm wide and 5.5mm high and 3mm apart from each other. In order to0detect the reaction products at 1 intervals, the distance between four collimators and the target(or the front slit in the case of gas target) is taken to be 172mm. These four slit holes were
carefully finished so as to have the same area in order to get the same solid angle for all fourangles.
In Fig. 2 the block diagram of the detection circuit is shown. To get position signals andparticle identification signals (PI signals), a position sensitive detector analyzer (dividing circuit)and a particle identifier 3 ) were employed. A fast coincidence between 6E and E signals weretaken and a pile up rejector 3 ) was used to eliminate chance coincidences except the ones which
occur in one burst of the cyclotron. The position and the PI signals together with the energy
signals were fed into three pararell ADC's after eliminating the elastic scattering events. The

PA: pre-amplifier

MA: main amplifier

TEA: timing filter amplifier

PI: particle identifier

CFTD: constant fraction timing discriminater
PSD An.: position sensitive detector analyzer
Fig. 1.

Schematic viewof the modified counter
telescope.

TSCA: timing single channel analyzer
LGS: linear gate stretcher
Fig. 2. Block diagram of the detecti,o n circuit.

71

16 0 +20Ne

E( 16 0) = 94.8 MeV

2000

C
:::J

o
U

.'.
.: ....

1000

.
'

9°

'. ......

......

_......:.1."·.......
o
100

..,.'

.

".

• "r--.~_' ____-,==-=: _ _ _ _ _-----;:-*1~_ __"W

200. . . . . . . .:

300

400

--'---:::--::-:

500

Cho nne I

Fig. 3.
16

Position spectrum obtained by bombarding 20 Ne with

0 at 94.8 MeV.

signals from these ADC's were written in a magnetic disk by OKI 4500C computer, and wereanalyzed and monitored on-line, or transfered again to a magnetic tape for a later off-line
analysis. An example of the position spectrum is shown in Fig. 3, in which each peak corresponds
to different detection angle. The energy spectrum of a certain particle in a certain angle isobtained by putting an appropriate gate on PI and position spectum.

References
1)

Modifications of this type has already achieved, for example; I. Paschopoulos, P. S. Fisher,
N. A. Jelley, S. Kahana, A. A. Plit, W. D. Rae, and D. Sinclair: Nucl. Phys., A252, 173(1975).

2)Fabricated in the work shop of IPCR.

3)

Made by F. Shimokoshi (the University of Tokyo).

72

6-3.

A

Gas Target System

for Heavy Ion Reactions

T. Motobayashi

A gas target system was made to use it in the study of the heavy ion transfer reactions.
It is advantageous to employ a gas target because of following reasons: 1) rare gas material (Nefor example) can be used as a target: 2) the target with little impurity is easy to obtain: and3) target thickness is rather easy to estimate by measuring the pressure of the gas.
In Fig. 1 the gas cellt) is illustrated. The windows through which the beam passes arecovered with 1.25t.Lm thick nickel foils and the other windows with 4.u m thick mylar foils.
The energy spread of the ions after passing through the foil was measured to be about 8%of the average energy los& in the foil.

This cell is able to hold the gas of about 300 torr whenplaced in the vacuum. The typical pressure of the gas in the experiment was about 70 torr.
The beam was collimated by a collimator consisting of two slits, one of which determines thebeam spot 2mm wide and 6mm high on the entrance window and prevents the scatteredparticles of the stray beam from entering into the detection system.
The detection system consists of two slits and shielding strips as shown in Fig. 1.

Thefront slit (1 mm wide) placed just 5mm from the window of the cell is made in one body withthe shielding strips as is seen in Fig. 1 in order to detect the reaction products in forward
angles without cutting the beam coming out from the cell.
achieved was 7°.

Consequently the minimum angle

The shielding strips prevent other particles than those coming through thescattering chamber

Fig. 1. The gas target system: thegas cell and the detection slits. The
diameter of the cell is 60mm.

Fig. 2. Gas feeding system.

73

front slit from going into the detector through the rear slit.
2

rectangular holes. )The rear slit consists of four

The effective area of the target in the gas is determined by these twoslits and the beam itself; horizontally by the two slits and vertically by the beam itself. Thiseffective target area together with the solid angle of the slit system was estimated from thegeometry of the setting by numerical calculations. The errors in these estimation come fromthe misalignment of the detector slit system and the errors in estimating the size of the slits.
Alignment was performed wi th the telescope and its error was estimated to be of the order ofO.lmm. The size of the slits was measured with the microscope and the error was less thanO.OSmm.

These results suggest the total error in estimating the effective target area and thesolid angle to be less than 10%.
Figure 2 shows the gas feeding system. The pressure was measured by an a-tron vacuum
gauge 3 ) and monitored throughout the experiment.

Since target thickness depends not only

on the pressure of the gas but on the temperature, we must know the temperature correctly.
However, it is rather difficult to know the temperature during the experiment because thetemperature may go up being heated by the beam.

Hence, the elastic scattering yield wasmonitored by another counter instead of measuring the temperature.
An example of the energy spectrum obtained by using this gas target system is shown in
Fig. 3. The peak of double scattering caused by the two nickel foils of the windows areseen beside the elastic scattering peak.
shown in Fig. 4.

Angular distribution obtained for elastic scattering is

In that case without any re-normalization a good fit to the data was obtainedby an optical model calculation with a reasonable set of the parameters.

elastic

76.2 MeV

14N+16Q

10000

Vl

+'
C

::J

o

U

double scattering

5000

,

. 1\
(2+) inelastic (T)

j )

.\
(.
\

.~ ii \.
~.

...............~......

\\.

0L---5~0-0--~--~~--~5=5~0~--~~~~--~--~------

ChannelFig. 3. Energy spectrum of the elastic scattering of 14 N on 16 0
at 76.2 MeV obtained by using the gas target.

74'4N + '60
E(14 N ) = 76.2MeV

O.ip

Optical potent ial
V=75MeV (R = 121 f m
W= 10MeV (,= 1.35fm
QR=0.48fm
Q, =0.25fm

0.01

10

20

30

<;>

I
40

Fig. 4. Angular distribution of the elastic scatteringof 1 4 N on 1 60. The solid line corresponds to the50

optical model calculation (see Ref. 4).

ReferencesI)

All parts of the system were made in the work shop of IPCR.

2)

T. Motobayashi: IPCR Cyclotron Progr. Rep. , lO, 70 (1976).

3)

Alphatron type 82.0 Norton Vacuum Equip. Div. 160 Charlemont St. Newton. Mass. USA(see also IPCR Cyclotron Progr. Rep., ~ 43 (1973); M. Odera et al.).

4)

T. Motobayashi, I. Kohno, T. Ooi, and S. Nakajima: IPCR Cyclotron Progr. Rep., 10, 35(1976).

75

6-4.

Computer Development

On-line Computer OKIT AK 4500

T. Inamura, T. Wada, M. Ishihara, and H. Kamitsubo

Extensive use has been made of magnetic tapes to record multiparameter data, such as
particle-,), particle-particle coincidences and .6.E-E signals from particle identifiers, and to play themback for analyses later on. Eventually there is a great need for a much advanced magnetic tapeunit to save time. Because of this, the present magnetic tape unit is going to be replaced by amuch faster and reliable unit in a few months. The new unit is OKI 798F: the recording
density is 1600 bpi, being twice that of the present unit; the tape speed is 125 ips in reading
and writing, being faster than three times the present speed; and the transfer speed becomes
200 kbytes/sec, about eight times as fast as the present transfer speed. This will improve handlingof magnetic tapes greatly and save considerable time during experiments on the cyclotron.

76

6-5.

A Charged Partie Ie Identifier

F. Shimokoshi

A particle identification system based on the Beth~-Bloch formula for the rate of energy lossof charged particles in the stopping material has been reported by several authors. 1),2) When aconventional telescope consisting of ,0.E and E counters is used, the identifier output signal, PI,
can be given by
PI =(,0.E + Eo)(E + K,0.E + Eo )0.75 ,(1)

where Eo and K are parameters adjusted experimentally to keep the identifier output constant forchange of the particle energy and Eo is a circuit constant. This formula is known to be useful in
identification of light particles, such as p, t, d, 3He, cx, Li, Be, and B. However, it is rather
unsatisfactory in identifing heavier particles. To improve the performance, a function G(,0.E) isintroduced instead of K,0.E (term).
G(,0.E)= L : - - - - X 10=

(2)L} (,0.E) + L2 (,0.E) 2 + L3 (,0.E) 3 + .....

where L is the gain and M is the slope of the function.
Then we have

~OCfl ~93"! ~ S

PARTICLE IDENTifiERr-"~nNC Q,t.,lN - - :S········--,r·······_,xN

OCLAY=:~ D!?LA)!:O! t '" l; - OUlPU1S -,FG

Fig. 1.

!

E+6E

Particle identifier based on

the Eqn. (2).

Fig. 2.

An adapter to the particle

identifier: G(,0.E) function generator
for heavy particles.

77

(a)

20Ne + 100 MeV 16 0

o

(!)

U
N

(])

:r::
'<t
(])

z

LL

o
N

t

\

~ ..
+ 100 MeV 16 0

2°Ne

(b)

(])

:r::

u

'<t

LL
(])

m

Cfl

m (])
m
Cfl

(])

Z

o

N

t--

Fig. 3. PI spectrum: (a) is the spectrum observed with the adapter and (b) is
the spectrum observed without the adapter.

(3)

A function generator for G(6E) is constructed as an adapter to the identifier based on Eqn. (1)for user's convenience.
Figure 1 shows our particle identifier and Fig.2 shows the adapter.
This particle identification system has been tested on the 2°Ne + 100 MeV 16 0 reaction;
the 16 0 beam was obtained from the cyclotron, and a 30 /.lm Si-surface barrier detector was usedas the 6E counter.
The PI spectrum obtained is shown in Fig.3, together with the best spectrum obtained
without the adapter for comparison. It should be noted that for the former, L 1 , the coefficientof the first order of 6E in Eqn. (2) became 0.4, while K=0.8 was taken for the latter.

References

1)

R. G. Stokes, J. A. Northrop, and K. Boyer: Rev. Sci. Instr., 29, 61 (1958).

2)

A. D. Harmanci: Nucl. Instr. and Meth., 86, 109 (1970).

78

7. A TOMIC AND SOLID-STATE PHYSICSK X-ray Spectra of A I, Ti, Cr, Fe,

7-1.

and

N i Induced by Nitrogen Ions

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, and Ni induced by 84-MeV N-ions werestudied using a Bragg crystal spectrometer. 1) The Ka spectra of Ti induced by 95-MeV and 71MeV N-ions were also measured in order to study the dependence of the spectrum pattern on
the incident energy.
After the previous reportI) was accomplished, the energy resolution of the crystal spectrometer was improved to be 10 eV FWHM for the flourescent Ti Kf31,3 X-rays (4.931 keY) and
1.9 eV for the Al Ka l ,2 X-rays (1.54 keY). In the present work, the K X-rays of Al were
measured by an EDDT (200) crystal and a proportional counter and the K X-rays of elements
heavier than Ti were measured by a LiF (200) crystal and a scintillation counter. The targets,ranging in thickness from 0.8 mg/cm 2 to 1.4 mgjcm 2 , were placed with an inclination of 60°
with respect to the ion beam. The present incident energy of heavy ions per nucleon is higher
than that in any other works of this kind.
The K X-ray spectra of AI, Ti, Cr, Fe, and Ni obtained are shown in Fig. I. Each peak islabelled by symbol KID Ln which denotes the corresponding intial configuration having m Kshell vacancies and n L-shell vacancies. The symbol a or (3 attached to each peak means thatthe peak belongs either to Ka or K(3 transition.
Following experimental results are obtained.
(I)

The incident ions act more proton-like in multiple ionization process as the incident

energy increases or the value of Zl /Z2 decreases, where Zl and Z2 are the atomic number ofthe projectile and the target element respectively.
(2)

In the Al spectrum, the Ka hypersatellites are excited more strongly than K(3 satellites

in the present work, though only the K(3 satellites have proviously been observed in the case of

5-MeV N-ion impact. 2 ) This is because the projectile penetrates deeper into the target atom as
the incident energy increases.
(3)

The width of the satellite line is always larger than that of the diagram line.

This isconsidered to be caused by multiplet splitting, variation of distribution of L-shell vacancies among
the subshells, and the M-shell ionization which occurrs in addition.

79

E ( keV)
1.75

1.70

1.65

1.60

E (keV)
1.50

1. 55

76

72

6A

68

Ai
Ii

i I X40

8

3

!
: 6

en

:::J

;

o
U

2

o

u

4

Ie-

2
O ~--II~
O--~--12~
0--~---13~
0~~--~--~(k eV )

4.6
XI0

80

4

XI0
c:).
~y:

Ti

y:

(keV)

7.6

4

3

~

Ni

Q

3c:).

XIO

y:

Y: ,y:en.....,

en

:::J

:;J

2

c

c:

0

0

u

u

~
---.!
y:

~.r~

84

86

~O

(deg)

42
28

10

( deg )

5.4 (keV)

5.6

Cr

en
C

35

58

60

62

64

66

68

70

2 8 l deg )Fig. 1.

The K X-ray spectra of AI, Cr, Ti, Fe, and Ni induced by 84 MeV N-ions.

The Kabs denotes the K-absorption edge of the target element. The arrows indicate
the positions of KL nt3 (n= I '\;5) lines of Al observed by Knudson et al. 2)(4)

The values of the energy separation between the Ka 1,2 line and the KLna line (n=I""3)and those between the K2 a line and the K2 Ln a line (n= 1""3) are almost equal for each value ofn. The values of energy difference between the Ka ,2 and KLna lines, the K 2a and K2L n a lines,
1

the Kal,2 and the K2 a line, and the Kt3 and KL n t3 lines are shown in Fig. 2 as function of Z2·
The peak positions were determined by the chi-square fitting of multiple Gaussian curves to theoverlapping peaks.

80

The analysis concerning the intensity of satellite or hypersatellite lines relative to the diagram
line is in progress.

(0 )

120

(b)

K2L' a-K 2 a

KL"a-Ka l.2

/

100
80

>

~

W

60

<J

40
20

~.yo"

".~
.....

>ill

........

K2W

• •

-

•/

(c)

K2 a-Ka 12w•~L'-:~~~.~- ~~

300

200

./

/.
KY'

(d)
n

/.

KL j3-Kj3

/

/

/.

<J

100

Fig. 2.

Plot of KL nex satellite energies

relative to Kat ,2 (a), of K2 Lnex relative
to K 2ex (b), of K 2ex relative to Kat 2 (c),and of KL n~ relative to K~' Cd). The
16

20

24

28

12

16

20

24

28

curves are drawn for visual aid.

References

1)

Y. Awaya, Y. Tendow, H. Kumagai, M. Akiba, T. Katou, and T. Hamada: IPCR Cyclotron
Progr. Rep., ~ 79 (1975).

2)

A. R. Knudson, D. 1. Nagel, P. G. Burkhalter, and K. L. Dunnig: Phys. Rev. Lett., 26,1149 (1971).

81

7-2.

Measurement of Radiative Electron Rearrangement in Ti

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

Recently low-intensity X-ray peaks have been observed in the energy region just below theKat ,2 line. I) -s)

These peaks were first considered to be the result of the KLM or KLL

radiative Auger effect,l) or of the excitation of one or more volume plasmons in the target
material by the Kex l ,2 X-rays.2)

As a more probable explanation, the radiative electron

rearrangement (RER) process 4 ),S) was proposed later. This process assumes that the (1S)-1 (2p)-nvacancy configuration transfers to the (2s) -2 (2p) -n+l one.
A 4Mm thick Ti target was bombarded with 95-MeV N-ions.

A flat crystal spectrometer6 )

equipped with LiF (200) crystal and a NaI(T 1) scintillation counter was used to analyze the
X-rays.

A step angle of the spectrometer was 0.02°, and the integrated beam current was 3

Me at each angular setting.
The X-ray spectrum obtained is shown in Fig. 1. The RER peak positions 3) are indicatedby the arrows.

The symbol RERn denotes the transition from the (1S)-1 (2p)-n configuration

to the (2S)-2 (2p)-n+1 one. As the intensities of the RER lines are expected to be less than
0.2% of the Kex b2 line, the present poor counting statistics did not allow these lines to beobserved. We are planning to make further investigation of the RER process with improved
counting statistics.

10 5
ts

~

::.:::

ts::.:::

10 4
....

'"c:

oc

'"

0:::

0:::

w

0:::

0:::

w

+-'

W
0:::

'"

~

0

U

cr

W
0:::

103

Fig. 1. Ti X-ray spectrum induced by
95 MeV N-ions in the RER energy
10 2

region. The arrows indicate the RERnpeak positions (n= 1rv4). The peaks
labelled by KL nex are the Kex diagram
4.60

4.55

4.50

4.45

4.40

Energy (keV)

4.35

4,30

and satellite lines.

82

References
1)

P. Richard, C. F. Moore, and D. K. Olsen: Phys. Lett., 43A, 519 (1973).

2)

1. McWhether, 1. E. Bolger, H. H. Wolter, D. K. Olsen, and C. F. Moore: ibid., 45A, 57(1973).
3)

P. Richard, 1. Oltjen, K. A. Jamison, R. L. Kauffman, C. W. Woods, and J. M. Hall: ibid.,
54A, 169 (1975).

4)

K. A. Jamison, J. M. Hall, and P. Richard: 1. Phys. B, 8, L458 (1975).

5)

J. Oltjen, R. L. Kauffman, C. W. Woods, J. M. Hall, K. A. Jamison, and P. Richard: Phys.
Lett., 55A, 184 (1975).

6)

Y. Awaya, Y. Tendow, H. Kumagai, M. Akiba, T. Katou, and T. Hamada:
IPCR Cyclotron Progr. Rep., 9, 79 (1975).

83

7-3.

The l2 -l3 X Coster-Kronig Transition Probability

In

Hf

M. Akiba , Y. Awaya, M. Okano , and T. Hamada

Values of L2 - L3X Coster-Kronig transition probability , f23 , have been measured for someelements ranging from Z=63 to Z=96.

Most of the values obtained for elements of Z~ 90 arelarger than the theoretical values by about 30%.1)

As the f23 value for Hf (Z=72) was notexperimentally determined , it was measured using the coincidence method of K and LX-rays
from the decay of 179 Ta to 179 Hf by the electron capture process.
179Ta was produced by the 179Hf(p, n) 179 Ta reaction at the proton energy of 14 MeV,
chemically separated from the Hf target 2 ) and deposited on a 5-J.Lm Mylar film to prepare asource.
The K X-rays were detected by a 90-cm 3 Ge(Li) detector, while the L X-rays bya Si(Li) detector with 195-eV energy resolution (FWHM) for the 5.9-keV X-ray .
time of the standard fast-slow coincidence system was 90 nsec.

The resolving

These detectors were set

closely face to face to reduce the angular correlation effect of K X-rays and LX-rays.
Hf K X-ray spectra and gate positions of Ka l and Ka 2 lines are shown in Fig. 1.

Hf

K

X - rays

K/l;

10 5

QJ

c

c::

J

0

J

.c
C>

"-

~ 10 4
0

C>

KO'(

gate

KQ', gate

Fig. 1.

10 3

Hf K X-ray spectra

following the decay of 179 Ta.
The gate positions of Ka l and
1300

1400
Ch anne l

1500
numbe r

1600

1700

Ka 2 lines are indicated.

Figure 2 shows spectra of the L X-rays and the L X-rays in coincidence with Ka l and Ka2
X-rays.

Some impurity lines are observed in the L X-ray spectrum.

They correspond to the

Cr Ka, Mn Ka (+ Cr K(3) and Fe Ka (+ Mn K(3) X-rays energetically.
reduce the impurity lines but it failed to remove them thoroughly.
origins of impurity lines.

Efforts were made to

There are two possible

One is that they would be fluorescent K X-rays from Cr, Mn or Fe

which are contained in the housing of the Si(Li) detector induced by Hf K or L X-rays.

Theother is that there would be a radioactive impurity which emits the Cr, Mn or Fe X-rays.
In any way , as there is the possibility that the Fe K{3 line and the Hf Le line overlap each84-"'. "'

..J

~ N

o
-

~
~

10'

LL

r5

+

0".

-_

- M

..JQ
..J

r
1\

\

,

\

\

(a)

r,,! ;: :J..J

Fig. 2.

Spectra of the L X-rays (a) andthe L X-rays in coincidence with the\ O~O---2~O-;::O ----;::;3,!;;:
00;-----~-.LLW~
ChannelnumberKO' 1 X-rays (b) and with the K0'2
X-rays (c).

other, the value of 123 is obtained as follows without adopting the Lp line in the calculation:=

CLa (K0'2) SKO'l
CLa (KO'l ) SK0'2

where CI(l) is the number of coincidence counts of I X-rays with J X-rays and SI is thenumber of single counts of I X-rays.
A preliminary result obtained for the L2 - L3 X Coster-Kronig transition probability in Hf is123=

0.22 ± 0.04

This value is larger than the theoretical one, 0.14.

The difference between the present value

and the theoretical one shows the similar tendency to that found for other elements.

References

1)

W. Bambynek, B. Crasemann, R. W. fink, H. U. Freund, H. Mark, C. D. Swift, R. E. Price,and P. Veugopala Rao: Rev. Mod. Phys., 44, 716 (1972);
M. R. Zalutsky and E. S. Macias: Phys. Rev. A, l1. 71 (1975).

2)

F. F. Felber, Jr.: University of California Radiation Laboratory Report UCRL-3618 (1957)(unpublished).

85

7-4.

Energy loss and Straggling of C and He Ions in Foils
of Metals and Compounds

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

The mean excitation potential I in the Bethe stopping power formula may be calculated
for alloys and compounds by
In I B=( L: I\ Z2i) - 1 L: ni Z2i In Ii'
iif Bragg's additivity rule holds.

(1)iHere, IBis the mean excitation potential defined byequation (1), ni is the fractional number of atoms of the component i. ,Z2i
number of the component i and I iis the atomic

is the mean excitation potential of the component i .1)

Even for metal alloys, however, IB deviates from the experimentally determined value
Iexp'

Recently, Porter et a1. 2 ),3)

showed that Iexp of a cobalt-based alloy determinedfrom the Bethe formula is about 15 % lower than IB for 2.5 to 7.0 MeV deuterons.

When

the second Born approximation is introduced into the Bethe stopping power formula, which
has a term proportional to Zi the discrepancy between IB and Iexp becomes much smaller
for this alloy.
To test the Zi dependence more directly, we just began experiments on simple substances, e.g., AI, Ni, Au, and Pb foils, using C and He ions.

We are also planning to

examine whether Iexp values for C ions are the same as for He ions in metals andcompounds.

The values of Iexp for compounds, with and without Zf correction, will thenbe compared with IB obtained from equation (1).
As for the straggling of heavy ions, the discrepancy between the theory and experimentis pointed out. 4 )We are planning to clarify the cause of the discrepancy and to establish

a more plausible theory.

References
1)

C. Tschalar and H. Bichsel: Phys. Rev., 175, 476 (1968).

2)

L. E. Porter, L. C. McIntyre, and W. Haeberli: Nucl. Instr. Methods, 89, 237 (1970).

3)

L. E. Porter and C. L. Shepard: ibid., 117,1 (1974).

4)

V. V. Avdeichikov, E. A. Ganza, and O. V. Lozhkin: ibid., 131, 61 (1975).
* Science and Engineering Research Laboratory, Waseda University.

86

7-5.

Bonding Effects

In

X-ray Spectra Induced by Heavy Ions

M. Uda, K. Maeda, Y. Awaya, M. Kobayashi,
Y. Sasa, and H. Kumagai

X-ray emission spectra are sensitive to the chemical environment of the emitting atom
and are of great use for the study of bonding effects.

It has been recently established thatheavy ion excitation enhances X-ray satellites due to multiple ionization, which appear atenergies higher than the diagram X-ray lines.

Ion induced X-ray spectra are then expected

to show the enhanced chemical shifts of the atom since multiple ionization will reduce theelectron shielding of the nuclear charge.
The present study deals with the chemical effects on both inner-shell transitions, Fe

N~

-l

~

:>.

......

:>.

<J)

~

c:::

<J)

c:::

Q.)

Q.)

~

.......

......

c:::......

\

~
56

58

42

2e( deg )44

46

29 (deg )Ni Kf3 spectra from Ni foil of

Fe Ka spectra from Fe foil of
Smg/cm 2(6JIm), and a-Fe203 of 7mg/cm 2

Fig. 2.

(13JIm) on Al backing and coated withon Al backing and coated with thin

thin carbon film. LiF(200) and acarbon film. These spectra werescintilation counter were used.

measured with LiF(200) and a

Fig. 1.

O.9mg/cm2 (lJIm), and NiO of 1.lmg/cm 2 (l.SJIm)

scintilation counter.

87

KG' and Al Ka , and valence band spectra, F KG', Al K[3 , and Ni K[3.

For this purpose,

spectra from Fe, G'-Fe203' AI, NaF, Na3AIF6' AIF 3 , (CF 2 )n . . . . . teflon , Ni and NiO
were examined.

The target materials were in the form of thin films of a few 11m in thickness

hypersotellites + K L,~

Al>-....., t---- - - <J>

c:

'"c:

+-'

NaF
125

130

135

14 0

145

82

84
2 e ( deg)

28 ( deg J

Fig. 3.

Al KG' and K[3 spectra from Al

Fig. 4.

F Ka spectra from NaF

foil of O.9mg/cm2(3I1m), and AIF3 ofof 1.4mg/cm 2 (SJ1m) , Na3AIF6 of

1.Img/cm 2 (4J1m) on Ni backing andl.Smg/ cm 2 (SJ1m), AIF 3 ofcoated with thin carbon film. X-raysl.Omg/cm 2 (311m) and teflon ofwere measured with the gas flow

O.9mg/cm 2 (4I1m). Except the

proportional counter throughteflon which was self-supported,

EDDT(020).

all the other targets were coatedwith thin carbon film on mylarbacking. RAP(OO I) and the
proportional counter were
employed.

88This thickness was suitable to reduce the absorption and the charging effects and also thetemperature rise caused by the stopped ions in the target during measurements.
N4 + of 84 MeV was used throughout the experiments.

All the X-ray spectra were obtainedwith an on-line Bragg spectrometer described elsewhere. 1)

Each line in Figs. 1 - 4 is labeledby the electron vacancies in the initial state.
Figures I and 2 show Fe Ka and Ni K{3 spectra from corresponding metals andoxides respectively.

No appreciable change in spectra from the metals and the oxides

could be observed under these experimental conditions.

Figure. 3 gives Al Ka and K{3 spectrafrom Al and AIF3 which are modified with satellites caused by the multiple ionization in L
shells and with the hypersatellites resulting from double holes in K shell and multiple holesin L shells.

Difference between Ka spectra from Al and AIF3 is not remarkable.

However,

F Ka emission spectra from several fluorides shown in Fig. 4 reflect differences of thechemical environment.

Increasing the electro negativity or the effective charge of F atom fromteflon to NaF through AIF3 and Na3 AIF 6, relative intensities of the satellites caused by themultiple ionization of L shells were increased. This fact suggests that differences in theelectronic configul ations around atoms can be seen in an enhanced manner under appropriate
experimental conditions.

The study of the effect of energy change of the incident ions isunder way.

Reference(1)

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

Rep., 1., 79 (1975).

89

7-6.

Positron Study of phase Transformations In Alloys

S. Tanigawa,* R. Nagai,* M. Doyama,* and N. Shiotani

The line shape measurements of positron annihilation radiations were carried out tounderstand the aging behavior of quenched AI-Ag and AI-Zn alloys and to clarify the
crystallization mechanism of amorphous Pd-Si and Ni-P alloys.
The AI-12 at.% Ag alloy was homogenized at 530°C for two hours and then quenched
into ice water.
performed.
Fig. 1.

The isochronal annealing (held at each temperature for 10 min.) was

The results are shown in Fig. 2.

The definition of S-parameters is shown in

S-parameters decreased in the temperature range between 50°C and 100°C, increased

at about 180°C, had a small hump at about 200°C, and then greatly increased at about
260°C.

The stage near 75°C, the hump near 200°C, the dip near 220°C and the large

increase near 260°C are due to the annealing of quenched-in vacancies, the formation of
spherical G. P. zones, the reversion of the G. P. zones and the formation of hexagonal
structure of 'Y/ phase, respectively.

Similar measurements were performed for the

AI-IO.3 wt.% Zn alloy, which was homogenized at 300°C for two hours and quenched into

1.3

1.2

AI-12 ot % Ag
I 530°C X 2h -oOe)..........

.

",.-

10

..
..

..

9
x

~o

..

.-

..

A

..

5

u

1. 0

...

.. c ...."...........
o 450

550

500

._'\

0.9

J~'''./. - . -•

o

100

200
Tempe ra ture

Channe l

300

1°C)

numberFig. 1. The definition of S- and h-parameters.

Fig. 2. The variation of S-parameter for

S-parameter is given by A/(B+C) and h-parameterAI-12 at.% Ag alloy as a function ofis given by the A part devided by the area underisochronal annealing temperature.

the curve.
* Department of Metallurgy and Materials Science, Faculty of Engineering, The University of Tokyo.

90

ice water.

The results are shown in Fig. 3.

formation of ci phase.

The large hump at 160°C corresponds to the

These general features are in good agreement with those of the

AI-Cu system. 1 )The Pdo .8oSio.2o and Ni o.81 PO.19 amorphous alloys were prepared by the usual roller
squeezing and the electrodeposition methods, respectively. Figure 4 shows h-parameters as afunction of temperature for the Pd-Si alloy.
Fig. 1.

The definition of h-parameters is also shown in

The results for both alloys suggested that the amorphous state contains few

vacancy-type defects in accordance with the previous results 2 ),3) and that the possibility ofthe microcrystalline disorder structure should be excluded.

Al-10.3wt % Zn

\.20

(
.

1.15
01.10t-~;;; 1.05/' ,","ch.~~~°0 o'-o~o/

1.00 •

0.--0-/0

0. 95 - \.-.------

o50

Fig. 3.
150

100

Anneal ing tem pe r ature

200

250

(OC)

300

The variation of S-parameter

for AI-IO.3 wt.% Zn alloy as a function ofisochronal annealing temperature.

1.0-e-e___... e____.. .

e ___ e0.9

Fig. 4.
o He atin g ru n

0.8

• Coolingo200

amorphous alloy as a function of

ru n

600

400
T emperatur e

The h-parameter in the Pd o. 8o Si o.2otemperature.

(Oe)

References
1)

R. Nagai, S. Tanigawa, and M. Doyama: Scr. Met. , ~ 529 (1976).

2)

H. S. Cheng and S. Y. Chaung: phys. stat. solidi (a), 25, 581 (1974).

3)

M. Doyama, S. Tanigawa, K. Kuribayashi, H. Fukushima, K. Hinode, and F. Saito:
J. Phys., F, ~ L230 (1975).

91

7-7.

Positron Lifetime Measurements for Aluminum and Magnesiumby Nuclear Reactions

Using the Internal Sources Produced

K. Hinode,* S. Tanigawa, * M. Doyama, * and N. Shiotani

Positron lifetime measurements were carried out for high purity aluminum and magnesium .
As the positron source, 22 Na was produced in the aluminum and the magnesium specimens
themselves by the nuclear reactions 27 AICHe, 2a)22 Na and 24Mg(d, a)22 Na, respectively.
In the case of aluminum, the thickness of the specimen was large enough to stop all theincident 3He particles.

A schematic drawing of the specimen is given in Fig. I.

Figures 2 and 3 show the temperature dependences of positron mean lifetime, TM' foraluminum and magnesium, respectively.

For aluminum, change of 'M was well explainedby the positron trapping model.!) - 3)

The evaluated value of the vacancy formation

enthalpy in aluminum was O.7SeV.

In the case of magnesium, change of 'M shows nosimilar behavior as that observed in aluminum.
for this fact.
positrons.

Two interpretations are considered to account

One is that thermally created vacancies in magnesium cannot trap the

The other is that the vacancies in magnesium can trap the positrons as In alumi-

num but unlike in aluminum the local electron density at the vacancies where the
40 MeV 3He./.......-.....
;.
..

240
99.9999% Al

Interna l source 22No

I.'220)Lm

I

220

'!'
I

.'. ~
I

E

I

~ 200

pm

t

mr

.,

I

:

c:
o

~
180

.'

f

He gas bubble~10fLm

I

I

/./

I

/

•. A'/_ _e_._e_e_e_e'6~~·----~----~~--~3~00~---'~----~~
Temperature

Fig. 1.

Schematic drawing of the aluminumspecimen.

Fig. 2.

( DC I

Positron mean lifetime, 'M' as

a function of temperature in aluminum.
Dashed line is a curve drawn to fit theexperimental results on the basis of thetrapping model.

* Department of Metallurgy and Materials Science, Faculty of Engineering, The University of Tokyo.

92

positrons are trapped is not appreciably different from the average electron density of theperfect lattice sites.
In the case of internal sources, the annihilation of positrons in the source is negligible,
but there is an appreciable long-lived component in all spectra in addition to the bulk
component as shown in Fig. 4.
of the total intensity .

The intensity of the long-lived component is about 5 %This component may have arisen from the annihilation of positrons

at the He bubble region (see Fig. I)

The very long lifetime of this component (about

900ps) suggests the formation of positronium (Ps) in this region.

99 .9999 % Al
Irradiatedby 3He

1st Irradiation
2nd Irradiat ion
600°C

6 0 min.

at mp 20mi n.
at mp. 40min.

250

(J)

c::
::J

o

U

10 2

/Resol ved: long li fetime: component

220oTemperature

Fig. 3.

( DC)

Positron mean lifetime, TM, asa function of temperature in magnesium.

T i meFig. 4.

( ns )

Positron lifetime spectra measured

after various treatments for aluminum.
Long-lived component can be evidently seen
in each spectrum.

ReferencesI)

W. Brandt: "Positron Annihilation", Academic Press, N.Y., p. 155 (1967).

2)

B. Bergersen and M. J. Stott: Solid State Commun., :L.. 1203 (1969).

3)

D. C. Connors and R. N. West: Phys. Let., 30A, 24 (1969).

93

7-8.

Atomic

Displacements

In

Metals CausedbyIrradiation

H. Sakairi, E. Yagi, A. Koyama, and R. R. Hasiguti*

Many problems in the study of radiation damage of solids by energetic particles are concernedwith the atomic displacement cascades. A matter of primary interest is the number of displaced
atoms created by collision cascade caused by primary knocked-on atoms with the energy E p 'which is called a damage function and denoted by v(E p ). Analytical expression giving v(Ep) was
first presented by Kinchin and Pease based on a simple model. 1) Values of v(Ep) calculated were,
however, larger than experimental ones by a factor of 4'""'5. Several mechanisms were presented
as the origin of this discrepancy, among which a focused repl acement collision sequence wasconsidered to be the most probable mechanism. 2 ) The form of the damage function derived on
the basis of focused replacement mechanism was presented in the previous report. 3) It was shownin that report and by other researchers 2 ) that the discrepancy can not be removed if only thatmechanism is taken into account.
Recently Robinson and Torrens presented a new model from the analysis of their results ofcomputer simulation. 4 ) In their model they took a distance criterion for permanent displacementof lattice atoms, instead of a threshold energy criterion which was adopted in the Kinchin-Peasemodel. In the new model, a displacement threshold energy is assumed to be very low, and the
movement of all displaced atoms are followed by a computer till their energy becomes very lowthat they can be regarded as being at rest. Then only the cascade atoms which are separated
from vacancies by a distance larger than recombination radius rv are stabilised, and the others areannihilated by recombination with vacancies. The essential defference between these two models
is that in the Kinchin-Pease model the stability of each Frenkel pairs is independent of the
distribution of other pairs, while in the Robinson-Torrens model it is dependent on it.
The numerical results of the simulation by Robinson and Torrens suggests that the damage
function v(Ep) is expressed as
Ev(E ) = - - pa+{rEHere E is a quantity called the damage energy , given by

E = E p -: Q
Q being a loss due to electron excitation in a displacement cascade, and a and {3 are parameterswhich are functions of recombination radius of Frenkel pairs, rv. With these equations and theassumption that rv = 2.Sa (a: lattice constant), they calculated the number of displaced atoms in*Faculty of Engineering, Science Univ. of Tokyo.

94

104 ~----------------~------------~

I
N

E
u
'c

0
+-'
0
l0-

f";,=1.0a

10 3

a.

2.0a

C")

I

E
u

3.0a

C:I~
-0-0

4 .0a

Fig. 1.

Comparison of the calculated results

and the experimental ones on the defectintroducing rate in copper irradiated with
Protonenergy(MeV)

protons.

copper metals irradiated with neutrons. The ratio of the calculated values to the experimental
ones was 2.1 for thermal neutrons and 2.2 for fission neutrons. 5 )We calculated the same quantity for proton irradiations in the same manner and compared
the results with the experimental ones obtained with the cyclotron, a part of which was reported
previously.6) The results of the calculation were expressed as a defect introducing rate, dn/d¢, ¢being the irradiation dose. The experimental results of the rate of resistivity increase, dp/d¢, werealso converted to dn/d¢. Both of them are shown in Fig. 1. The experimental points fell on a
calculated curve for rv = 4.0a. This value of rv is somewhat larger than the one deduced fromthe experimental results on the radiation annealing of the damage. 7) The value of rv = 2.5a, which
was assumed in the calculation by Robinso,n and Torrens, made the calculated values of dn/d¢twice as large as the experimental ones, as in the case of neutron irradiations.
As recognised by Robinson and Torrens themselves, their simulation has some weak points
such as the lack of a molecular dynamical treatment. Nevertheless, it seems to be also a promisingmechanism in removing the discrepancy between the theory and the experiment. At the present
stage, it can be said that the focused collision mechanism and the recombination one makealmost equal contribution to correct the damage function.

References
1)

G. H. Kinchin and R. S. Pease: Rep. Prog. Phys., 18, I (1955).

2)

M. W. Thompson: "Defects and Radiation Damage in Metals", Cambridge Univ. Press,
London, Chap. 5 (1969).

95

3)

H. Sakairi, E. Yagi, A. Koyama, and R. R. Hasiguti: IPCR Cyclotron Progr. Rep.,~

101 (1974).

4)

M. T. Robinson and I. M. Torrens: Phys. Rev., B9, 5008 (1974).

5)

M. T. Robinson: Proc. Intern. Conf. "Fundamental Aspects of Radiation Damage in Metals"(Gatlinburg, 1975), USERDA: CONF-751006-P1, 1 (1975).

6)

H. Sakairi, E. Yagi, A. Koyama, T. Karasawa, and R. R. Hasiguti: IPCR Cyclotron Progr.
Rep., ~ 101 (1971).

7)

W. Schilling, F. Burger, K. Isebeck, and H. Wenzl: "Vacancies and Interstitials in Metals"(Ed. by A. Seeger et al.), North-Holland, Amsterdam, p. 284 (1970).

96

7-9.

Observation of Defect Structures of Slightly Reduced
Rutile(Ti0 2 )by Channeling Method

E. Vagi, A. Koyama, H. Sakairi, and R. R. Hasiguti*

Stoichiometric rutile, Ti0 2 , is an insulator.

Upon slight reduction it becomes an
It is welloxygendeficient non-stoichiometric rutile, Ti0 2 - x , which is an n-type semiconductor.

established that some kinds of defects introduced into rutile crystals by slight reduction giverise to the n-type semiconductivity.

But the problem of whether the dominant defects

introduced by slight reduction are oxygen vacancies or titanium interstitials has been incontroversy, although the evidences are somewhat in favor of titanium interstitials. 1)
If titanium interstitials are dominant defects, it is to be expected that channelingexperiments would give decisive information about that problem as described below.

FigureIt has an open channel along the [001] axis.

I (a) shows a crystal structure of rutile.

It is illustrated by dotted square in the end view of atomic arrangement for the [001] axial
direction (Fig. 1 (b)).
0, 1/2) type site.
[001] channel.

It has been proposed that a titanium interstitial is at the 0/2,

If this is the case, the titanium interstitial lies at the center of the

Therefore the channeling method is directly sensitive to such interstitials.

1
u

1

a,,1

f-Fig. 1.

a----Y' 0

0

(a)

•

Ti

(b)

(a) A unit cell of a rutile crystal. Lattice

constants a=4.594A and C=2.959A. (b) The end view of
atomic arrangement for the [001] axial direction. An
open channel is indicated by a dotted square.
The stoichiometric single crystal specimen was reduced at 1100°C in vacuum of
10-6 mmHg for 240 h, and submitted to channeling experiments.

Oxygen deficiency wasestimated to be about 2 X 10 2D /cm 3 , which corresponds to x::::0.0062 in Ti0 2 - x ·After the experiments were over, the specimen was oxidized at 1100°C in air for 240 hand
was submitted again to channeling experiments as the stoichiometric specimen.
Channeling effects were investigated with respect to a [001] axis by means of backscattering using 5.77MeV protons accelerated by the cyclotron.
*

Faculty of Engineering, Science University of Tokyo.

The beam was collimated to97less than 0.025°.
1 nA.

The irradiated zone was 0.8mm 2 and the beam currents were about

The backscattered protons were measured by a surface-barrier solid state detector(FWHM:::: 15keV) placed at a scattering angle of about 150°.

Irradiation for backscattering

measurements was performed at room temperature.
In order to investigate the effect of non-stoichiometric defects, an angular scan was
performed through the [001] axis.

Figures 2(a) and 2(b) indicate the normalized° depth as a function of the angle ()backscattering yields from titanium ions at 4000A
between the incident beam direction and the [001] axis (Ti-dip) in case of Ti0 2 andTi0 2 - x , respectively.

The angular dependence of the scattering yields from oxygen ions(O-dip) was also obtained.

As to the O-dip, the normalized minimum yield Xmin and theangular half-width at half-minimum l/J 1/2 have the same values 0.065 and 0.22° respectively
in both cases of Ti0 2 and Ti0 2 -x.
value 0.29° in both cases.

As to the Ti-dip, the half-angle 1/1 1/ 2 has the same

The striking feature is that the very sharp peak with thehalf-angle 1/I p of 0.05° and with the maximum yield of 0.027 is observed at the center of
the Ti-dip in case of Ti0 2 - x and not in Ti0 2 •
Ti0 2

[001]
1·0

I-~-

I-

I

\-~n

In the latter case the value of Xmin is 0.014.
Ti~ _x

[001]

j

r
•

I

•

f--

-

•

-

I-

VT;
0·01
-10

~~]?ifJt

(0)

i

o

\I

10 -1·0

Ti

a

(b)

10

ANGLE (degrees)Fig. 2.

Backscattering yield from titanium ions in Ti0 2 (a),and in Ti0 2 - x (b) as a function of the angle () between theincident beam direction and the [00 I] axial direction.
It is known that for incidence parallel to a major axis the probability density ofchanneled beam flux attains higher values than that of random beam flux (flux-peaking
effect).2) As

a result the backscattering yield of channeled particles from interstitials in thecenter of a channel can be several times greater than that of random particles.

Therefore,

they are expected to give rise to a peak with the higher scattering yield than the random
yield in an angular scan of the backscattering yield.

The result shown in Fig. 2(b) can beinterpreted as superposition of a dip obtained with respect to titanium ions at normal
lattice sites and a peak obtained with respect to titanium interstitials.

The observed small

98

peak was explained well quantitatively on the assumption that all of excess titanium ions in
Ti0 2 -x become interstitials.
By the analysis of this peak it was confirmed that main defects in a slightly reducedorutile are titanium interstitial ions and they are located within O.4A of the [001] mid-channel
axis.

This result supports the interpretation of electron paramagnetic resonance (EPR)

experiments that a so-called C-center is a titanium interstitial ion. I)

The effect of radiation

damage by protons was also investigated on a stoichiometric specimen.

The damage

production rate of Frenkel pairs for titanium ions at room temperature was estimated to beabout 4.4 X 10-20 /(p/cm 2 ) in atomic fraction.

References
1)

R. R. Hasiguti: Ann. Rev. Mater. Sci., ~ 69 (1972).

2)

J. U. Andersen, 0. Andreasen, J. A. Davies, and E. Uggerh</>j: Rad. Effects, ~ 25 (1971).

99

7-10.

Perturbed Angular Correlation of Gamma-Rays Emitted

H. Sekizawa, K. Asai, T. Okada,N. Shiotani, E. Vagi, and S. Ambe

It is well known that to account for the magnetic properties of materials containing transition
metal ions one must know the cation-cation interactions. In contrast to transition metal ions,nominally diamagnetic cations have no unpaired electrons by themselves, so that the hyperfine
magnetic fields in them reflect directly the interactions with neighboring magnetic ions.
In this report we present experimental data on the time differential perturbed angularcorrelation (PAC) of ')'-rays emitted from III Cd in NiFe204 and then discuss the hyperfine
magnetic field on III Cd nuclei in NiFe204 at room temperature.
The sample was prepared by nitric acid method. We dissolved pure Ni and Fe metal powderin nitric acid and added III In chloride to the solution. The solution was dried, and then theresidue was ground and fired for 2 h in air. The sample was packed in an acrylate tube 4mm
in diameter and 8mm long. The spectra were taken with a conventional fast-slow two detector
set up. Two NaI(Tl) scintillation counters were used as the detectors. An external magnetic field
was applied perpendicular to the plane of the two counters. The magnitude of the magnetic field
was 3800 oe, which was sufficient to saturate the magnetization of NiFe204.
The general expression for the time differential angular correlation function perturbed by aperpendicular magnetic field H isw(a, t) ex exp (-t/7) [1 + ~(1)

Akk Pk {cos (o-w m t)}]k evenwhere 8 denotes the angle between the two ,),-rays, t is the time interval between the two cascade'Y-rays, 7 is the life time of the intermediate Cd(5/2+) state and wm is the Larmor frequency.
Since factor Akk for k~4 is much smaller than A22 , the coincidence counts are modulated with
0

opposite phase for 8=90° and 180 . We define the normalized difference in the coincidence
counting rates as follows.
R(t) -

W(90, t) - W(180, t)
W(90, t) + W(180, t)-(3/4)A 22 + (5/16)A 44
1 + (1/4)A 22 + (9/6)A 44

cos 2 wm t..... .

(2)

Figure 1 shows the coincidence counts for 8=90° and 180° after substracting accindental coincidence counts which are calculated from the ')'-ray intensity.
R(t) showed an oscillation whose amplitude decreased as the time increased. The decrease of
the amplitude can be ascribed to a distribution of the hyperfine magnetic field of 111 Cd. If weassume a gaussian distribution of the field f(H) ex exp [-(H-H o )2 /(V2LH)2 ], the normalized

100

J

(J)N

0

(/)z

I-CI:
Z(J)
:::J;:)

00

UJ:
I-

UJ
Uz

Zw

i!51U
Z

0
U

en

co
r(D

50 nseclJ)

0Fig. 1.

I

I

I

I

I

200

I

I

10 0

300

400

500

600

700

CHANNEL NUMBER

i

i

800

Coincidence counts of 'Y-rays from III Cd in NiFe204 withan external polarizing field of 3.8kOe applied perpendicular to theaxis of the two detectors. The data at 0= 1800 is shifted verticallyfor the sake of clarity.

difference in coincidence counting rate R(t) becomes as follows:
R(t) ex exp[(V2~w ot)2] cos2wo t(3)............. .

where ~w='Y~H, Wo ='YHo, and 'Y is the gyromagnetic ratio of 5/2+ state of III Cd nucleus. We
tried a computer fitting of the experimental data, based on the above assumption. The fitted
curve is shown in Fig. 2. The value of Ho was found to be 93kOe and ~H to be 17kOe at room

Ret)
It
It

00

XX
X

I

X

d/tig;x
X

0

OX

0.0
0.0

x

8

:(

8

txo
o

tt=O l80.)}:' 10 nsec
Ix 8

rx~~1

50
Fig. 2.

I

100

I

150

200 CHANNEL

The normalized difference in the coincidence

counting rates R(t). The experimental data are shown by
the symbol X, and the computer fits of Eqn. (3) by o.

101

r-"\

111Cd

Q)

M

In

3+

cd

Fig. 3.

u

The hyperfine field of diamagnetic

C)')

ions at A site in NiFe204. The data on In 3 +..0$-<

are the NMR data at 4.2K quoted fromcd

Ref. 1. For Cd ion the solid line is the>--~

spectrum at room temperature, and the dotted

·M
C)')

~

line is shifted based on the assumption that

Q)~....,cthe hyperfine magnetic field of Cd ion is
proportional to the saturation moment of

160 kOe12080
Hyperfine magnetic fieldNiFe204·

temperature. If we assume that the hyperfine magnetic field of Cd ion is proportional to thesaturation magnetization of NiFe204, Ho will be 108kOe at OK. Figure 2 shows the normalized
difference in the coincidence counting rates R(t). To know the direction of the hyperfine
0magnetic field, we took the spectra at 8= 135 • This result indicates that the hyperfine magnetic
field is parallel to the net magnetization.
In 3 + seems to occupy preferentially the tetragonal (A) site (80%) according to the magnetization data. 1} Therefore, the daughter nucleus 111 Cd is in the tetrahedral site. Figure 3 shows thehyperfine magnetic field of Cd ion (our data) and that of In 3 +.1} Thus, the direction of the fieldof Cd ion is the same as that of In 3 +, but the magnitude of the field of Cd ion is a little smaller
than that of In 3+.
It would be necessary for a full discussion to consider the effect of the preceeding decayof 111 In carefully, and also to investigate the spectra at lower temperature.

Reference
1)

Y. Miyahara and S. !ida: J. Phys. Soc. Japan, 37, 1248 (1974).

102

7-11. Nitrogen Ion Implantation in CdTe for Optical Waveguides
and Waveguide-type Electrooptic Modulators

T. Nishimura, H. Aritome, K. Masuda,
S. Namba, and I. Kohno

CdTe has a higher electro optic coefficient and a lower attenuation coefficient in the infrared
region than GaAs, and is the only material among II-VI compound semiconductors from which
p-n junction can be obtained. From these points CdTe is one of the most interesting materials
for optical integrated circuits in the infrared region.
H+ ion implantation into low-resistive CdTe can produce a thin compensated layer of free
carriers in the substrate. The ion implanted region, which has a much smaller free carrier concentration than the substrate, has a higher refractive index than that of the substrate. Opticalwaveguides and waveguide type electrooptic modulators using CdTe could be fabricated in thismanner, and were reported recently. 1),2) Further improvement in the optical absorption loss andthe efficiency of electrooptic modulation however, is important for practical use. If the carrier
compensation in the thin layer can be done by chemical doping and the lattice damage inducedby ion implantation can be removed, low absorption loss and high efficiency of the electrooptic
modulation will be expected. The layer thickness can be easily controlled by the ion energy.
From these points, nitrogen ion was chosen because it has the possibility of being the p-type
dopant having the maximum penetration depth in CdTe. The cyclotron was used to accelerate
nitrogen ion to have penetration depth enough for optical waveguiding in CdTe.
As a preliminary study chemically polished <001> oriented n-type CdTe wafers with carrier
concentration of 9.8 X 10 17 /cm 3 were ion implanted at 80 MeV with a dose of 1 X 10 15
ni trogens/ cm 2 .
In order to measure the electrooptic coefficient, a gold electrode was deposited on an ion
implanted layer and an indium electrode was deposited on the other side of the substrate. The
sample was placed between crossed polarizers and the transmittance was measured as a functionof applied voltage. But the voltage enough for measuring the change of the optical output could
not be applied because considerable current flowed through the ion implanted layer of the sample.
The reason is not understood at present why the carrier compensation is not enough for
production of the high resistive layer.

It is not so far successful to measure the electro opticalproperties in the sample implanted by nitrogen ion.
in progress to understand these results.

The study of the annealing behavior is now

103

References

1)

D. L. Spears, A. J. Strauss, S. R. Chinn , I. Melngailis, and P. Vohl: Digest of the Topical
Meeting on Integrated Optics (Optical Society of America, Salt Lake City , 1976), TuD 3.

2)

T. Nishimura, H. Aritome , K. Masuda, and S. Namba: Japan. J. app!. Phys., 15,2283 (1976).

104

7-12. Helium Embrittlement of eTR Materials Simulated
by A Ipha Partie Ie Bombardment

R. Watanabe,* H. Shiraishi, H. Shinno,
H. Kamitsubo, I. Kohno, and T. Shikata

Investigation of the mechanical properties of metall ic structural materials irradiated by fastneutrons is urgently needed for the design of the controlled thermonuclear reactor. Fast neutron
causes embrittlement of metals. The embrittlement is thought to be due to cascades of displaced
atoms caused by various kinds of collisions and due to helium atoms created by (n, a) reactions.
But the details of the mechanism of the embrittlement has not yet been clarified.
The aim of this study is to develope new structural metals and alloys which are highly resistantto neutron irradiation embrittlement. Neutron irradiation experiments is extremely expensive andtime consuming. In contrast, a-particle injection study by the cyclotron for the simulation of fastneutron irradiation damage is much easier and also considered to be applicable for estimating oneof the aspects of the degradation phenomena of materials caused by neutron irradiation. With regard
to helium embrittlement, such phenomena as helium diffusion, change of the helium distribution
profile in the specimen, and helium release from the specimen will be studied.
We constructed a new target chamber as shown. in Fig. 1. This apparatus is characterized by
the following specifications.
The sample is heated and held at a certain constant temperature which can be as high1)

as 1000 e during the a-particle bombardment. The vacuum is maintained at 2 X 10- 6 Torr at
0Fig. 1. Schematic illustration of the target chamber for helium injection by the cyclotron.
*

National Research Institute for Metals.

105

1000°C.
2)

A cylindrical frame structure on the side of which six wedge type aluminum plates arestuck along half of the circumference is driven to rotate in front of the target. The injected
helium atoms are uniformly distributed in the direction of the sample thickness. The maximum
rotation speed of the absorber drum is 1000 rpm. The time required to oscillate the beam fromsurface to bottom of the specimen can be reduced to 10- 2 sec. This value is shorter by two to
three orders of magnitude than that obtained in the usual wedge and piston movement typeabsorber system. The rotating axis of the beam absorber is coupled to the outer drive motor
through the oil seal device.
3)

Following beam current measuring system is employed to avoid the disturbance by thethermal electron ejection. The total a-particle beam is transmitted through a thin gold foil 10 J1m
thick and the scattered beam is continuously monitored by a solid state detector. At the sametime, the transmitted beam is measured by the Faraday cup and the ratio of the scattered to thetransmitted beam is determined. This ratio is used for the determination of the helium injection
dose of the sample.
The preliminary operation test of various components is now under way. The a-particle
bombardment of samples will be started at the beginning of 1977.

106

8. RADIOCHEMISTRY AND NUCLER CHEMISTRY

8-1.

Charge and Mass Spectra of Ions Occurring
along the a -Particle Tracks

in MicaM. Aratani

Ions sputtered from aluminosilicate mica have been investigated under bombardment witha-particles from an 241 Am source (500 IlCi, 1 cm X 1 cm) in a charge spectrometer I) and with
10 KeV He+ ions in an ion probe mass spectrometer. 2 ) In the a-bombardment the source wasplaced in close contact behind mica foils of various thicknesses in order to study ions originatingfrom various points on the a-tracks. The 10 KeV He+ ion was expected to give information quite
similar with that a-particle gave at its stopping point.
Also, the change in sputtered ion intensity with time in the ion probe mass spectrometer
was measured for the same matrix which had been bombarded with the 241 Am source for one
month.
Intensity ratios of silicon ions with various charge states are given in Table 1 and those ofvarious ions in Table 2, where Ra is the range of 241 Am a-particle. In the case of 0.36Ra andTable 1. The intensity ratios of Sin + ions from various points along thea-particle tracks in mica.
Ions
Thickness of mica

0*0. 36R a **

1.0

0.3

0.4 8R a **

1.0

0.3

-",-,R a ***1. 2R a1.0

1.8 X 10-

0

0

0.1
0.1
3

* Data could not be obtained because of the presence of recoil ions from 241 Am.
* * See text.

* ** The values are those of 28 Sin + ions only.

1.4 X 10- 40107

0.48R , where 6 /lm and 8'/lm mIca foils were used respectively, a-particles with lower energiesathan the maximum energy at the surface of the mica foil and were responsible for the sputteringof ions in the present experimental condition. The values in Table 2 have already been correctedby considering the atomic percentage of each element in the mica foils. The values, therefore,
give removability of matrix atoms as free ions.
As is shown in Table 1, multicharged ions are less abundant at all points observed , especiallyin the neighborhood of the stopping point. Table 2 shows that potassium ion has predominantremovability from the matrix, which can be attributed to its site in mica. Complicated behaviorsof aluminium ion and aluminium oxide ion may be related to the two kinds of aluminium sites,
tetrahedral and octahedral, in mica.
The results obtained on post effect of the one month a-bombardment are illustrated in Fig.
1. The abscissa represents time of peeling, accordingly the peeled depth, by a 2 Ke V Ar+ ion
beam impinging on the surface of the damaged mica. The ordinate

indicates the sputtered ion

intensity relative to that from the surface of mica without damage. Energy and current densityof ion beam were kept constant and as low as possible in order to be free from giving any disturbance to the sample. The change in the sputtered ion intensity with time suggests that there
should exist some differences in the matrix state with the depth. The gradual decreases seen in
Fig. 1 lead us to the conclusion that there are matrix portions near the surface giving highintensities of sputtered ions, but those portions gradually disappear with the depth . The highintensity of sputtered ion can be attributed to the existence of latent tracks , consequently thedamaged parts. Further analysis of the sputtered ion intensity curve may offer more interesting
information about the post effect in the particle tracks.

Table 2. The intensity ratios of ions from various points along thea-particle tracks in mica.

Ions

Thickness of mica

0*0. 36R a **

0

1.2

13

1.0

0.8

0.05

0.4 8R a **

0

1.2

12

1.0

0.8

0.03

-"""R a ***1. 2R a

0.005

0.002

8.1

1.0

3.4

0.09

0

0

0

0

0

0

* See Table 1.
* * See Table 1.
*** The values are those of 44 (SiOt, 43 (AIOt, 39 K+, 28 Si +, and 160+, respectively.

108

Peele d depth

0

500

IA)
1000

1500

I

Fig. 1. The change in sputtered ion

2.5intensities* with peeling time from the~surface of the damaged mica by the~ 2.0

preceding Q-bombardment.

"0'"---<r- K

0-

~ SI

(f)

--fr--* The values are relative to those of

At

1.5
0

sputtered ion intensities from the surface of
10
Peeling time20
( min)

30

mica without damage.

References

1)

Y. Kawana and M. Aratani: Int. J. Mass Spectrom. Ion Phys. , 10, 493 (1973); M. Aratani,
K. Nakamura, and N. Saito: Mass Spectroscopy, 23, 315 (1975).

2)

K. Nakamura, S. Aoki , Y. Nakajima, H. Doi, and H. Tamura: ibid., 20 , 1 (1972).

109

8-2.

Mossbauer Emission Studies of Defect Atoms in Solid
after N uc lear Decays and Reactions

F. Ambe and S. Ambe

The behavior of 119 Sb and 119 m Te contained as dilute impurity atoms on recrystallizationof p- or ~-irradiated SnTe and SnSb was studied and the results were compared with those forthe recoil atoms formed by p- and ~-reactions. 1)-4)
The 120 SnTe samples irradiated with 15 MeV protons were melted and recrystallized underargon, and their 119 Sn Mossbauer emission spectra were measured against a BaSn03 absorber at
78K.
As can be seen in Fig. 1, the emission spectra showed a marked dependence on the composition of the sample. On the basis of a systematics of the isomer shift for defect and normal
119 Snatoms in Sn-Sb-Te system 1),4) the peaks with an isomer shift of about 2.3 mmls were

attributed to 119 Sn in the Te site of 120 Sn Te and the other peaks with an isomer shift of

100
>-

4--'

";:;;

(b)

c

.....,'"c'"> 94
~

'"
a::

100
( c)

94

-4

0
Relative

Fig. 1.

velocity

4(mm / s vs

119 Sn-M6ssbauer

Ba Sn03

at 78 K )emission spectra of(a) 120 SnTeO.97, (b ) 12 °SnT e, and (c) 120 SnTe 1.03
which had been irradiated with protons, melted,
and recrystallized.

110

approximately 3.4 mmls to those in the Sn site. Since no displacement of the atom is expectedin the EC decay of 119Sb to 119Sn,3),4) it can be concluded from the present observation thatthe impurity 119 Sb atoms are distributed between the Sn and Te sites in the stoichiometric 120 SnTe
samples, and that in non-stoichiometric samples the 119 Sb atoms are distributed preferentially inthe site of deficient element. These results are reasonably interpreted in terms of the fact that
Sb has an electro negativity lying between Sn and Te.
By comparing the present results with those for recoil 119 Sb atoms after p-reaction, it canalso be concluded that no melting of the SnTe matrix occurred along the track of the recoil
119 Sb, because the distribution of 119Sb after melting is much different from that of recoil 119Sb
atoms.
Similar measurements on 119m Te was also carried out using a-irradiated 117 SnSb. An emission
spectrum of 119 Sn arising from the successive EC decays, 119m Te ~ 119 Sb ~ 119 Sn, in arecrystallized 117 SnSb sample is shown in Fig. 2. The emission line is attributed to 119 Sn atomslin the Sb site from its isomer shift, which shows that the 119Sb atoms arising from 119mTe in
the recrystallized samples are exclusively stabilized in the Sb site of the matrix. This finding isagain interpreted in terms of the electronegativity sequence of Sn, Sb and Te.

'l>

100

ro" co0°0°0000

>-

+-'
<f>

c:

Q)

+-'

co

Q)

:>

+-'
0

Q)

cr::: 92

Relotive

Fig. 2.

velocity (mm/s vs BoSn03 ot

78K)

119 Sn-Mossbauer emission spectra of

117 SnSb irradiated with a-particles, melted, andre crystallized.

References
1)

F. Ambe and S. Ambe: IPCR Cyclotron Progr. Rep., 8, 108 (1974).

2)

F. Ambe and S. Ambe: ibid., 9, 89 (1975).

3)

F. Ambe and S. Ambe: Chern. Phys. Lett., 39, 294 (1976).

4)

F. Ambe and S. Ambe: 1. Physique, in press.

III

9.

RADIATION CHEMISTRY AND RADIATION BIOLOGY

9-1 .

Isomerization of c is-2-Butene Induced by Heavy-Ion
Irradiation

Y. Harata, M. Matsui, and M. Imamura

Isomerization of cis-2-butene to trans-form by C- and N-ion irradiation was studied in benzene
solution at room temperature. Photochemical and radiation chemical studies on the cis-transisomerization of olefinic compounds induding 2-butene have been the subject of numerous papers.
Most of the results have been interpreted as indicating the pathways in which electronically excitedstates participate. In radiolysis, ionic mechanisms have occasionally been proposed for isomerization of stilbene and 2-butene.
The investigation here reported was motivated by the desire to determin whether excitedstates might play an important role in the heavy-ion radiolysis more than in "I radiolysis. In fact,
the yields of trans-2-butene, G(t), were found to be as low (2 - 3) as that observed for "1irradiation ('" 2) under relatively high dose (> 10 18 eV) conditions. Heavy-ion-induced isomerization
may, therefore, be considered to proceed via excited-state pathways as in the case of "I-irradiation
under these conditions.
We have found, however, that G(t) increases steeply with decreasing heavy-ion dose andreaches a value of the order of 10 3 . The high G(t) value, somewhat higher than that for heavyion irradiation, was also observed for "I-irradiation under similar conditions.
Unexpectedly and abnormally high yields of trans-2-butene at low radiation doses may beinterpreted in terms of chain reaction in which cationic species participate; the important roleof cation radicals of cis- and trans-2-butene was admittedly proved from a series of scavenging
experiments.
The present study gives important insight not only into the primary processes in heavy-ion
radiolysis but also into the kinetic behavior of positive holes produced primarily in liquid benzene.
Extensive studies on both "I and heavy-ion radiolyses are in progress and the details will be
published.

112

9-2.

Emission and Absorption Spectra of KBr Irradiatedwith Heavy Ions at 4.2 K

K. Kimura and M. Imamura

Emission and absorption spectra were measured at 4.2 K with a single crystal of KBr
irradiated with He-, C-, and N-ions. Set-up of the measurements is shown in Fig. I. These results
were compared with those obtained by X-irradiation.
Emission bands observed with X-irradiated KBr are a a-emission at 280 nm and 7r-emission
at 510 nm, which are attributed to relaxed excitons, 1 ~u and 3 ~u' respectively. The F and H
centers are formed directly from hot excitons.

Fig. 1.

Set-up for the measurements ofemission and absorption spectra at 4.2 K.
Energ y/e V

2.0

4.0

V>

co

.....'"co
co
o

.~

E

w

Wavelength / nm

Fig. 2.

Emission spectrum of KBr at 4.2 K underirradiation of 85 MeV, l-nA C-ions. Intensity scaleof the right-hand spectrum is expanded by 5 times.

113

Energy/eV

Wavelength/nm

Fig. 3.

Absorption spectrum of KBr at 4.2 K recorded

immediately after irradiation of 85 MeV, l-nA C-ions.

Figure 2 shows an emission spectrum observed on heavy-ion irradiation at relatively low doseand dose rate. Significant features revealed by comparing these results with that of X-irradiation
are: (1) An intensity ratio of the a- to 1T- emission increases with increasing LET: 2.1 for X-rays,
6 - 7 for He-ions, and 10 - 12 for C-ions; (2) A half width of the 1T-emission band broadenswith increasing LET: 0.41 for X-rays, 0.44 for He-ions, and 0.51 for C-ions; (3) A Peakwavelength of the 1T-emission band shifts to shorter wavelengths with increasing LET and radiation
dose.
Figure 3 shows the absorption spectra recorded at 4.2 K immediately after C-ion irradiation.
Absorption bands centered at 600 and 380 nm are attributable to the F and H centers, respectively.
A 285 nm band is characteristic to heavy-ion irradiation, attributable to the H' center, thedimeric H center. A 530 nm band, which also appears in X-irradiation, has not been assigned.
Intensities of these absorptions increase linearly with increasing dose except for the H center
whose intensity tends to saturate.
These results may be interpreted as due to the high density of the intermediates producedwith high-LET heavy-ion beams. We have assumed the reactions of the longer-lived 3 L u excitonwith each other and/or with the F, H, and H' centers, which result in the decrease in theemission intensity and the band-width broadening. The H' center formation and the saturation of
the H center with increasing dose may be accounted for by the reaction, H + H ~ H', and bydecomposition of the H center with 3 ~ u exciton.
Technical assistance of Mr. H. Endo is acknowledged.

114

9-3.

Influence of Air Layer

In

Front of Samples on the Inactivationof Phage

1> Xl 74 by eyc lotron BeamF. Yatagai, S. Kitayama, T. Takahashi, and A. Matsuyama

Various effects of high-LET radiations on biological materials have been investigated by many
workers. Such biological effects include at least two different events; one is the event occurred
within the track core and the other is that induced by a-rays at points far from the track core.
When there is an air layer in front of the sample, some fraction of a-rays scattered by the airlayer also reaches the target. Contribution of such a-rays will make obscure the observations ofcharacteristic biological effects due to the irradiation by the high-LET particles.
In order to study this problem, inactivation of phage ¢X174 which is of single-hit kinetics has
been studied. The high-LET radiations used were a-particles and N-ions of 1.2 and 4.6 MeV /amu.
The experiment was carried out using two different irradiation methods as shown in Fig. 1.
Figure l(a) shows the method in which the sample on a poly carbonate film (5 JIm in thickness)is covered with the same type of film in order to eliminate the influence of air layer in frontof the sample ( method CF). Figure l(b) shows the method in which the sample on the polycarbonate film is exposed to air (method EA).
(0) Covered with polyco rbonote 1-il m ( CF)~/

Vuccum window~-

Samplesbea mPolycorbonote fil m(t hick ness, 5jlm)(b) Exposure to air laye r bef ore samples (EA)

Fig. 1.

Irradiation method ; samples arecovered with a poly carbonate film (a),and they are exposed to air (b), seetext.
In method EA , another polycarbonate film is placed at about 2 mm before the sample sothat the beam energy at the sample may be equal to that in method CF. Method CF can beconsidered a good approximation to the case of irradiation of biological samples in water since
the highest energy of secondary electrons in our experiment is about 10 keV and the range ofthe electron is about 2.4 JIm in water. Other procedures of cyclotron-beam irradiation anddosimetry were already described. 1 )Survivals after irradiation were measured by the plaque-forming ability of ¢XI74.
Survival curves somewhat concave upward were obtained after irradiation by a-particles andN-ions as shown in Fig. 2. The simple target theory is inapplicapable to these cases, but thetarget concept in broad sense may still be relevant. Therefore, effective inactivation cross section ,115

Seff was calculated from DIO value in order to express the effectiveness per particle. As can beseen in Table 1, values of Seff for EA samples were found to be higher than those for CF
samples even in low energy a-particles and N-ions.
The result obtained shows that the lethal effect on </>X174 is enhanced by secondary electronsejected from the track core of a-particles and N-ions passing through the air layer in front of thesample.
( b)(a)a- particles

irr ad iation

1.0

a-pa rtic les

irradiation

1.23 MeV/omu

4.62 MeV/amu

109 keV/}-Lm

34.0 keV/jim

Phoge ¢X-174¢X -1 74

Phage

c

c

o

-~

+-'

CF ; 0
EA; 6

o

U

+-'

.t 0.1

U

0

0.1

L

'+0'
C

-:;

o

>
=>

(f)

o

0 .01

0 .0 1

o

1.0

2.0

3.0

4.0

Dose

(Mrad )

5.0

6.0

o

7.0

2.0

1.0
Dose

(c)

( Mrad )Nitrogen - ion

irradiation
4.65 MeV/ amu
400 keV /ji m

1.3 MeV/amu
870 keV/}Lm

1.0\

Phage ¢X-174

Phage ¢X-174\

CF ; 0
EA;6

\

\
\

\

\

c

0

c
-~

\

:3

\

~ 0 .1

4.0(d)Nitrogen - ion irradiation

\

3.0

\

u

CF ; 0
EA ; 60\6~ 0 .1

o

\

\
6

0
\

o

\
\

\

,

',~

o

""
6

"

0.01

',......

a0.0 1................. ~.............................................

..... ~

o

5

15

10
Dose

Fig. 2.

(Mrad)

20

25

30

o

2

3

4

Dose

( Mrad )5

6

7

Survival curves of phage </> X 174 for 1.23 MeV /amu a-particles (a),4.62 MeV/amu a-particles (b), 1.3 MeV/amu N-ions (c), and 4.65 MeV/amu N-ions (d).

Reference
1)

F. Yatagai, T. Takahashi, Y. Kitajima, and A. Matsuyama: 1. Radiat. Res., G 90 (1974).

116

Table 1. Radiosensitivity of phage ¢ X 1974.

a-particles

Particles

Seft<l1m2 )[Seff/SO]

[ CF

EA

N-ions

4.62 MeV/amu

1.23 MeV /amu

4.65 MeV/amu

1.3 MeV /amu

34 keV/~m

109 keV/l1m

400 keV/~m

870 keV/~m8.36 X 10-4

1.36 X 10-3

4.37 X 10-3

4.94 X 10-3

[ 1.70][2.77][8.90][ 10.1 ]1.25 X 10-3

1.59 X 10-3

6.10X 10-3

6.54 X 10-3

[2.55][3.24 ]

[12.4 ]

[13.3]

117

9-4.

The Effects of Cyclotron Beams on Survival of
Cultured Chenease Humster Cell V-79

Y. Yamawaki,* F . Yatagai, 1. Kaneko,
K. Sakamoto , S. Okada, and A. Matsuyama

In view of the current interest in high-LET radiations in radiation therapy, some fundamental
cellular studies were initiated by use of the cyclotron beams. Heavy-ion beams have been reported
to show several biological and physical features , i.e. , comparatively high relative biologicaleffectiveness (RBE) value com paired with that for X- or ,),-rays, the dose depth characteristics,
no oxygen effect and no recovery of the Elkind-type in the tissues. It seems likely that because
these characteristics, heavy ion irradiation is more feasible in therapy for inactivation of tumour
tissues as compared with X- or ')'-rays.
Our program in the first year was to sol ve several technical problems which do not arisein X- or ')'-ray experiments. When we irradiate the cultured Chinease hamster cells by thecyclotron beams, it is necessary to give them a very small dose of 100 -1000 rad. Therefore ,in the dosimetry system, two sets of the detector of sillicon surface barrier type were used forcounting very small number of particles elastically scattered by a thin metallic foil (Fig. l .(a) and(b)). Moreover, using a mechanical chopper, number of particles passing through the vacuum was
Ta king off
the medi um

Incubationfor 24 hours

Looding

~
~

~
o

8

Cop
6)1 alum inium foil for protecting
dryness of cells
Poly carbonate film
Petri dish for culturing cells(radius 20 mm )~~§ Target plate

T ripsiniza ti on

Dilution

Mitotic dela yCounting*

Incu bation

Fixationsurvived cells

Fig. I(a) Schematic representation ofFig. l(b) Photograph of exposure apparatus.

cell-handling procedures.

Petri dishes are in place.

Faculty of Medicin, University of Tokyo.

118

Vacuum feed throu h connector

Sil icon surface barrier detector(TB- 018-025- 0700)
Vacuum window

Absorber & slit

Fig. 2 (a) Sketch of overall arrangement for

Fig. 2(b) Photograph of overall

dosimetry and exposure of mammalian cells toarrangement for dosimetry andcyclotron beams.

exposure of mammalian cultured
cells to cyclotron beams .

.decreased. Physical iimitation was overcome by extensive adaptation of the cell culture procedures(Fig. 2. (a) and (b)). About 7 X I 0 4 cells were seeded in each petri dish and allowed to grow for
approximately 24 h at 37° C. For determination of colony-forming ability, cells were trypsinized off
the vessel as soon as possible after the exposure to cyclotron beams, and the resulting suspensions
were diluted appropriately for single plating.
The survival curve of cultured Chenease humster cell V-79 exposed to nitrogen ions was ofthe exponential type with Do -value of 190 rad. This survival curve without a shoulder suggeststhat irradiation with nitrogen ions does not cause sublethal damages in the cells which allow the
Elkind-type recovery. The cells irradiated with alpha-particles showed a survival curve having ashoulder and the extrapolation number was 2. The RBE for nitrogen obtained at Do was 1.9 andthe value for alpha-particle obtained at exponential part of the survival curve was 1.55.
These preliminary results should be confirmed by further investigations. Studies on recovery
from the cell damages caused by the cyclotron beams and comparative studies on strand breakage
of DNA in the mammalian cells due to heavy ions as well as other types of radiations are alsoscheduled in our programs.

119

9-5.

LET Effect on the Trapped-Electron Formation

In

Organic Glasses at 77 K

A. Kira, M. Matsui, and M. Imamura

Ionizing radiation produces mobile electrons in condensed matter.

In glassy liquids at low

temperature, a part of the electrons disappears by geminate recombination and the remainder
is trapped in the media.

The yield of the trapped electron is expected to reflect thecompetition between recombination and trapping; the ratio of these processes is considereddependent on LET.

The measurement of the trapped-electron yield under varied LET conditions,

therefore, will furnish valuable information on kinetics of the geminate recombination which isone of the basic problems in radiation chemistry.
During this period, we have been preparing to determine the G-values of trapped electrons
for alcohols, ethers, and alkanes at 77 K by measuring their optical absorption bands
characteristic to the glasses.

Since the target area subjected to the optical measurement is

to be irradiated homogeneously, our efforts were devoted to design the suitable apparatus forheavy-ion irradiation.

A series of performance tests were carried out satisfactorily for 19.9-MeV

4He-ion irradiation of ethanol glass.

120

10. PREPARATION OF RADIOISOTOPES AND LABELED COMPOUNDS

10-1 .

Production of Radioisotopes and Preparation of Labeled
Compounds for Medical Use

T. Nozaki, S. Ambe, Y. Ito, M. Iwamoto,T. Karasawa, M. Okano, K. Fukushi, T. Irie,
T. Hara, and K. Taki

Our works in the present period can be summarized as follows: (I) a rapid biosynthesis ofselenomethionine-73 Se was made possible, (2) some radio-halogen derivatives of cholesterol weresynthesized and their behaviors in animal body measured, (3) aluminum arsenide (AlAs) was
proved to be a suitable target substance for the production of 77 Br and 73 Se by the reactions of
75 As(a, 2n)77 Br and 75 As(p, 3n)73 Se, respectively, and (4) efforts have been continued for the
improvement in the distribution measurement of positron emitters in human body by the use of
18 F.

The production of 18 F, 43 K, and 123 I has also been continued to supply them to medical

users.
The Gee He, xn)73 Se reaction was used in our preparation of selenomethionine- 73 Se, though
the 75 As(p, 3n)73 Se is clearly preferable when protons of higher energy are available.

The

excitation curve for the former reaction was measured as shown in Fig. 1. The bombarded
germanium was dissolved in HN0 3-HF containing selenium carrier (0.1 mg), and the selenium
was reduced with hydrazine into precipitate of red selenium, which was then converted into
HP Se03'

A strain very effective to the present synthesis was screened and used.
120

100

~
E

80

c
o

:.:: ro
~ 0
U'l
U'l

o

o 40
20

%L-----~~----~~----~------~4~0------~50

Energy (MeV 1

Fig. 1.

Excitation curve for the reaction of

Gee He,xn)73 Se.

After a con-

121

0.3 r - - - - - - - - - - - - - - - - - - - - ,

u

E

10

~ 0.2
5

/

,.0 .......

x#(F,Br,l )o......

.....

o

/

0::

I

F

I

sr--

0 h

/

0.5

/
/
/

d
o

10

20

0.1 L--..L.--...L2-~3----I-----:~-I t--...I...----::~--:--dCultivation time after addi tion of 73Se (hiFig. 2.

Uptake of 73 Se by the pre cultivatedstrain. Figures on the curves are precultivation

Time after injection

Fig. 3.

Adrenal-to-blood concentration

ratio for cholesteryl halides.

times. Ordinate value is for the addition of
1.00 mCi of 73 Se.
venient time of precultivation of the strain in a medium for the synthesis of methionine, the

HP Se0 3 was added to the medium and the cultivation continued.

The precultivation time andcultivation time were so selected from our experimental results shown in Fig. 2 as to give theoptimum incorporated activity of 73 Se, nuclide of 7.1 h half-life.

The strain containing 73 Se

was then treated with hydrochloric acid to give its hydrolysis products, from which
selenomethionine- 73 Se was separated by starch column chromatography. It took about four
half-lives of 73 Se for the entire process, and about 50 /lCi of the final product was obtained
from 1 mCi of 73 Se in the germanium target.
Following radio-halogen derivatives of cholesterol were prepared and their organ distribution
intercompared: cholesteryl fluoride, bromide and iodide; 6-fluoro-3-acetoxy-5-hydroxy-cholestan,
5-fluoro and 5-bromo-3-acetoxy-6-hydroxy-cholestan; 19-iodocholesterol, 6-bromomethyl- and6-iodomethyl-19-nor-cholest-5 [ 10] -en-3~-ol; and excitation-labeled 123 I-and 77 Br-cholesterol.

Thelabeled cholesteryl halides were prepared by isotopic exchange and halogen interchange reactions.
They showed slow clearances from blood, reflecting their hydrophobic character.

Time

122

dependences of their adrenal-to-blood concentration ratios are shown in Fig. 3. The flurohydrins,
which were synthesized by the reaction of BI8 F 3 with epoxide, demonstrated high adrenal conconcentrations shortly after intravenous injection. In general, the fluorine-carbon bonds in thesteroids showed much higher stabilities than the other halogen-carbon bonds.

For adrenal

imaging, 6-iodomethyl-19-nor-cholest-5 [ 10] -en-3J3-ol was found to be superior to the bromomethyl
compound.

The 123 I excitation labeling gave an organic yield of about 50 %, with its one third

being of fairly stable iodosteroid.
in vivo behavior.

This iodosteroid, however, showed no particularly interesting

Similar labeling with 77 Br gave poorer and less reproducible organic yield.

Aluminum arsenide, which is stable up to about 2000 K, was found to be a very nicearsenic target.

It is commercially available as grey powder soluble in condensed polyphosphoricacid containing H2 O 2 .

The 77 Br in the target was separated carrier-free by this dissolution andsubsequent distillation.

Carrer-free separation of the 73 Se from the target is now under study

by the use of solvent extraction of elementary selenium.

123

11. RADIATION MONITORING

11-1 .

Routine Monitoring

K. Igarashi, 1. Sakamoto, and 1. Usuba

Results of routine radiation monitoring on the cyclotron from April 1975 to March 1976
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- 5 MCi/cm 2 on the floor of cyclotronroom and the underground passage, and below 10-7 MCi/cm 2 in the experimental areas, hotlaboratory and chemical laboratories.

The contamination was wiped off twice a year, and after

each decontamination, the higher level contamination could be reduced below 10- 7 MCi/cm 2 •When the accelerating chamber was opened, slight contamination of the air in the cyclotronroom was observed.

The value of radioactivity concentration (beta-gamma) was 10- 12 MCi/cm 3 •Tritium still remained in the accelerating chamber since the last triton acceleration in
December 1970.

10-5 MCi/cm

3.

The tritium concentration of the air in the chamber was of the order ofAs the air in the chamber is purged completely before overhauling, aircontamination was not found in the cyclotron room.
(2)

Drainage

The radioactive concentration of the drain water from the cyclotron building was found to
be of the order of 10 - 6 -10-7 MCi/cm 3 .

The total quantity of activities in the aqueous release in this period was about 55 MCi, andthe radioactive nuclides found by the gamma-ray spectrometry were mainly 58 Co and 60 Co.
(3) Personnel monitoring
The external exposure dose received during the present period, by all cyclotron workers towhom the gamma- and, to some of them also, the neutron film badge are provided, are shownin Table 1.

The collective gamma-ray dose to the workers was 2040 man-mrem, while thethermal and fast neutron exposure were too small to be detected.

124

Table 1. Annual exposure dose distribution of the cyclotron workers
from April 1975 to March 1976.

Workers

Dose distribution (mrem),

Unde tectableA.

.

10-100>100

Operators

1

4

2

Nuclear Physicists

12

12

1

Physicists of other fields

4Radiochemists

0

Radiation chemists

3

Biological chemists

3

Health Physicists
Average annual dose per person:

38.5 mrem

Maximum individual annual dose: 320 mrem

7

125

11-2.

Neutron and Gamma-Ray Dose Measurement
around Targets Bombarded by Deuterons

I. Sakamoto

In the course of an experiment on fast neutron irradiation of biological samples, theneutron and gamma-ray dose distribution has been measured at various distances from a thickberyllium target and a thin deuterium target* bombarded by 15 MeV deuterons at a current of
750 nA.
The fast neutron flux was measured by activation method employing the reaction of
32 S (n, p) 32 P

whose threshold energy is about 2 MeV.

The value of flux obtained was converted

into the dose equivalent rate using the conversion factor given in ICRP Publication 21.
The minimum detectable level of neutron flux in this measurement was about 5 X lOs n cm -2 S-1 .
A "rem meter"** was also used to measure the dose equivalent rate for fast and slow
neutrons at a point 270 cm apart from the target.
The gamma-ray dose was measured with the BeO thermo luminescent dosimeter, the range ofmeasurement of which is 20 mR to 2000 R.
The result of the measurement is shown in Fig. 1.

In all cases, the dose rates decrease

with the distance a little more slowly than those expected from the inverse square law.

Theratios of neutron dose to gamma dose are about 45 for the Be target and about 30 for the Dtarget.

o Be- n• Be - r
D - n... D - Y

6.

o

o

E
E
o

0'

Fig. 1.
10Distance from target

*
**

10
(cm)

Neutron and gamma-ray dose rate

distribution around targets bombarded bydeuterons.

Code No . DBT 53, produced by The Radiochemical Centre, Amersham, England.
Neutron Dose Rate Meter 2202, manufactured by AB Atomenergi, Sweden.

126

12. HEAVY ION LINEAR ACCELERATOR PROJECT

12-1.

Status of Constructional Work In 1976

M. Odera

During the Period between the fall 1975 and July 1976, effort was made in cooperation
with Sumitomo Heavy Industries Co. to fabricate a proto-type drift tube which contains acompact quadrupole magnet capable to deliver high field gradients without excessive heating of
its exciting coil.

It proved successful and details of factory production prescription were fixed.

Measured maximum field gradients and characteristics of field harmonics of the quadrupole
magnets were satisfactory.

Distortion of the tube shell by electron beam welding was small,which made possible to align the acceleration axis by use of the optical targets inserted in thecenter of the shell.

The alignment was cross-checked by a hot wire magnetic method and theresult was found consistent with each other.
The first tank was completed and its vacuum and radio frequency characteristics were
measured when the tank was still in the factory.
within a week.

Several vacuum leaks were located and stopped

After that, a pressure of 2 X 10-6 Torr was reached in a day.

A range ofresonant frequency expected in the initial design was obtained and power loss was found to bewithin the value estimated by models.
The accelerator vault was completed in October and installation of the first tank and theinjector high voltage terminal will be completed until the end of November 1976.

A proto-typefinal stage amplifier and its power supply are under construction and will be installed in Spring
1977.
A proto-type hot cathode PIG ion source was constructed.
source of the cyclotron was modified to accept the new source.

The test stand for the ion
Its poles were replaced withthose which have cross section designed to give proper focusing force to extracted ions.

It isexpected that the similar cross section will be used for the linac source unless any trouble wasfound by the test stand operation.

Study of generation and beam formation of the multiply

charged heavy ions in the ion source assembly will be made throughout 1977.

127

12-2.

Fabrication of the Drift Tubes of the First Accelerator Tank

Y. Miyazawa and M. Odera

Figure 1 shows cross sections of the drift tubes which contain quadrupole magnets.
end plates, and bore tube are made of OFHC copper and are welded by electron beam.
made of ordinary copper and welded to the shell under the inert gas atmosphere.

Shell,
Stem isThe outer

diameter of the drift tube is 160 mm and the diameter of the magnet yoke is 150 mm leaving
10 mm for the shell.

Thickness of the yoke is 15 mm and density of magnetic flux in theyoke is well below saturation for the highest excitation of coil.

Figure 2 shows excitation

characteristics of the field gradient.

Fig. 1. An example of drift tube structure and its cross sections.
10

Coi I 26 turns
Aperture

28mm

~

E

~

~

.....,
c:

'"

-0

e 5
C1'

-0
Q)

lL.

Fig. 2.
Coi I current

ler (Al

gradient.

Excitation characteristics of the field128

Two kinds of coils, the tape coil and the quadrant stacked coil were made.

Both types

have achieved packing factor above 90 % and enable to realize necessary field gradients forcontinued excitation.

Direct cooling of the coil and the tube shell is made by Freon-l 13 flowing

around the coil and in the grooves cut in the surface of the magnet yoke.
supplied through copper tubes which also serve as current leads.

The liquid is

A thermo-switch is sealed in

the stem and detects unusual temperature rise of the coolant and cuts off power supply of themagnet to avoid vaporization of the Freon and sudden pressure rise in the drift tube.
Figure 3 shows drift tubes attached on the center conductor of the accelerator resonator.
Since those tubes have no magnets, smaller diameter can be used than that for the tubes
containing magnets.
milling machine.

They are fabricated by welding copper blocks in inert gas, and shaped by a

Cooling is made by water.

"9-

o

o

Fig. 3.

Drift tube structure attached on

the inner conductor of the resonator.

129

12-3.

Fabrication of Quadrant-stacked Spiral Plate CoilI. Takeshita and M. Odera

Improvement of the plate coil previously reported 1 ) was made by use of thin (1 mm) plates
instead of thick (3 mm) plates.

Figure 1 shows structure of the coil.

slots are cut in the square plates.
solder to make a square spiral.

Two holes are drilled andPortion of slots of neighboring plates are butt joined by hardThis part of the procedure requires most handwork.

Perhaps

vacuum or hydrogen furnace hard soldering will be more suitable for large number fabrication.
After heat treatment to soften copper, the square spiral is shaped into quadrant by pressing in acylindrical die.

Then insulation papers impregnated with epoxy resin are inserted and heattreatedto make stacked coil layers into a solid monolithic structure.

Bore to accept pole pieceis drilled and surfaces are finished by a milling machine. Short circuiting of layers across insulator
caused by the cutting process are removed by chemical etching.

Procedure after insertionof insulation paper is entirely the same with that of the tape-coil.

However, for a fixed numberof effective turns, the number of layers for the quadrant stacked coil is the half of that of thetape-coil and so copper sheets twice as thick can be used for a given space. Since the numberof insulators is also half, better packing factor can be achieved if insulator of the same thickness
is used.

Figure 2 is a photograph of the coil made in this way.
Hard solderingof layers on
this line

Fig. 1.

Fig. 2.

Structure of a quadrant coil.

Photograph of the coil fabricated.

130

12-4.

Cooling Characteristics of Tape CoilY. Miyazawa, T. Inoue, M. Hemmi, Y. Chiba,
F. Yoshida, and M. Odera

Figure 1 shows the principle of the function of tape coil. 1 )Currents flowing in the twolayers of copper tape are made to form a closed single turn around a pole by cutting alternate
slots in the tape as shown in the figure.

Directions of turns for neighboring poles automaticallychange alternately and symmetry of turn number for each pole is assured.

Thus, coils for aquadrupole magnet can be formed simply by winding copper tape with suitable slots as describedabove.

This ingenious tape coil proposed by Main 1) has also excellent packing factor and iscapable of giving a large ampere-turns for limited volume.

However, cooling must be made on

the surface of the coil and heat generated in the innermost region must be brought to thesurface by conduction.

Since no current flows at the part where slot is cut, effective packing

factor in that region is half the apparent conductor density.

Though current density and heatgenerated per volume of conductor are largest there, the region is directly in contact with colling
liquid and so temperature rise will not be excessive.

Because permissible working temperature of

insulator is limited to a temperature below 120°C, any part of the coil structure must not beheated above this limit.

Besides, since boiling temperature of Freon-I 13 is 47 .SoC, surface
Tape-cod tes t-- 26 turns. 52 layers
T emperature rise of each layer at thermal equllbrium
Coil Curren! 150Amp.

60

~X--X

.~aICUla!l On 150Amp. ~

X

50

for

(

125Amp.
~X--X---..........
--.. -- _ _ _ ~ ~

.L..

X

/"

1/ /

j/

X

----~~
100Amp.

______X-x~
/

20

X

Freon- I 13.

l 2Q ! 1lls
10 L----l_ _- " - - _ - : L - _ - - - ' - _ - - - - . J ' - - _-'--_ - - ' -60
Tape layer

Fig. 2.

Distribution of temperature risein layers of the coil at thermal
equilibrium. Dotted line shows thecalculated mean temperature rise ofeach layer assuming radial heat flow
Fig. 1.

Illustration of structure

across insulator layers and uniform

and function of the tape-coiltemperature distribution on the surface

taken from Ref. 1.

of the coil in contact with coolant.

131

temperature of the coil is not desirable to exceed this value.

Therefore, cooling characteristicsof the tape-coil were measured to confirm calculated results under the probable condition of use.
Coolant enters through 12 mm diameter copper tubing into groove cut on the yoke surface.
Then it enters through axial groove into narrow space between coil end and end plate of thedrift tube, flows radially inward on the end surface of coil to the center, goes axially throughthe space between center tube and inner surface of the coil up to the other end, then radiallyoutward on the end surface, and returns via axial and circumferential grooves into anothercopper tubing.

(See Fig. 1 of 12-2 of this progress report for structure of the drift tube.)

Temperature rise of each layer of coil was measured by soldering thin wires to the sides ofcopper sheets and observing variation of resistance of each layer.
distribution of temperature rise.

Figure 2 shows an example ofSince current density in the copper sheets decreases roughly as

inverse of radius, heat generated should change as inverse of square of radius.

However, innersurface of the coil block is well cooled and heat generated in the inner several layers will be
removed through radial inward conduction across thin insulator layers.
maximum temperature shifts outwards.
that of numerical calculation.

Therefore, region ofThis result of qualitative explanation was compared with

A qualitative agreement was obtained, but for better reproduction,

the boundary condition of uniform temperature on the surface of coil block in contact withliquid needs to be modified.

There seems to exist abrupt change of temperature in the surface

film layer between liquid and coil.

At some parts of the surface boundary, the film seems toconsist of mixed vapor and liquid phase, since, as can be seen in Fig. 2, temperature of coil
exceeds boiling temperature of liquid at some layers.

Temperature drop across this region

cannot be the same as at the region where coolant remains in liquid state.

We found it possible

to reduce temperature rise of coil by making liquid temperature as low as 3°C. Whether thisfact supports or not the above statement of the existence of vapor phase in the surface film at
higher liquid temperature is not clear.

These cooling tests were performed in a transparent

vessel simulating drift tube shell and generation of bubbles was expected to be clearly seen when
it is present.

However, no distinct change of surface appearance nor bubble formation bychange of liquid temperature from 3°C to 20°C could be observed.

Reference

1)

R. M. Main and R. Yourd: Proc. Fourth Intern. Conf. on Magnet Tech., p. 349 (1972).
R. M. Main, J. M. Haughian, and R. B. Meuser: VCRL 17156 (1966).

132

12-5 .

Cooling Characteristics of the Quadrant-stacked
Spiral Plate CoilI. Takeshita and M. Odera

Though the tape coil has good cooling characteristics, its margin of safety is sometimes still
not sufficient for use with some drift tubes. Main limitations come from the end region where
the packing factor is half the expected conductor ratio of 90 %. Also temperature rise in the
innermost region is proportional to square of the distance from the end surface of the coil andfor a long coil the temperature limit of insulator may easily be exceeded.

In the quadrant

stacked coil, distance of heat conduction is very small and the packing factor of the conductor
always coincides with the apparent value.

Figure 1 is result of measurements of the coil in thesame configuration and dimension as the tape coil.

As expected , temperature rise is very small

and roughly one third of that of the tape coil. Nowhere of the surface of the coil the temperature
exceeds the boiling point of the coolant.

Since the number of layers is the half of thetape coil, the number of insulator is also half and packing factor is better, hence power
dissipation is smaller than the tape coil.
60~ T at12 Q/ m ; F reoll -l13

<l)

~ 40
~

'"
co
~

gO)

: 20
co
<l)

L

Fig. 1.
o ~~--~--~--~--~--~--~---

4000

6000

A mpere tu r n

A. T.

Mean temperature rise of coils.

x .......... X Quadrant stacked coil
• - - - • Tape coil

Thus, cooling characteristics of the quadrant stacked coil is definitely superior to the tapecoil.

However, fabrication requires more handwork unless hard soldering process in vacuum orhydrogen furnace is adopted.

Therefore it was decided to use this type of coil only in the drift

tubes where use of the tape coil is not supposed to be quite safe for continued operation.

133

12-6.

Deviation of the Magnetic

Axes of the Quadrupoles fromthe

Geometrical Center of the Drift Tubes

I. Takeshita, I. Yokoyama, and M. Odera

As reported previously the magnetic axes of the quadrupoles to be contained in the drift
tubes was found well coincident with the geometrical center of the magnet. 1 )However, themagnet has to be sealed vacuum tight in a copper shell by electron beam welding to form adrift tube.

Deformation of the tube shell may be expected by thermal stress induced by thewelding process.

In that case, the field center will not necessarily coincide with the geometricalcenter of the drift tube shell.

Since alignment of the tubes in the manufacturer's factory is to

be made by using optical targets set in the geometrical center of the tubes, extent of deviationof the field center from the geometrical one must be known.

The device developed todetermine center of the quadrupole field by a rotatable Hall probel) is also suitable to investigate
this problem.

(See the reference for its structure.) In its use, geometrical center was first

fitted to the device center by use of a dial gauge attached to the rotatable holder of the Hall
probe.

Next, the dial gauge was replaced by the Hall plate and position of the field center wasdetermined relative to the device center.

Another apparatus was used which consists of a brassrod the diameter of which was carefully machined to fit snugly into the center bore of the drift
tube and of a Hall prove imbedded in the rod.

However, bore of some drift tubes was found

not perfectly circular at its entrance and exit ends and did not accept the rod easily.

Thisshowed the existence of deformation by welding in spite of small heat generation involved in theelectron beam processing.

After the determination of the field center those bores were reshaped

so as to permit insertion of the optical targets.
Figure 1 shows results of the measurement.

Axial positions where tube cross sections are

perfectly circular were chosen to avoid interference of welding deformation with determinationof geometrical center.

A and B correspond to the two end surfaces of a drift tube.

seen in the Figure, distinct deviation of the field center exists in some tubes.

As can be

For the tubes forwhich deviation larger than 50 j.1m was observed, correction of the bore was applied with a jig
borer machine.

Thus, displacement of the field center from the geometrical center is believed tobe reduced within 50 j.1m.

The drift tubes were bolted on a long supporting base of theaccelerator and aligned by a telescope.

Precision of the alignment was checked by anothermethod described in a separate report and the above expectation was confirmed. 2 )

134

1-3

1-1

X---+--(2,-18)(17,20)Depth from face A 102mm

Depth fran face B 60mm

(17,-3)(-28,5)Depth from face A 36mm

Depth from face B 36mm
-

- 7

I- 5

----- --

2
( -8,13)_--=--_ _ D_e~pt_h from face B 53mm

(0,-9 )
Depth from face A 49 mm

- -

-

-

- --

I - 11I - 9

2(-4,0)(0,0)
Depth from ~ace A 63mm Depth _from face B 63m~~(O 0)
Depth fran fa:e(-24,-30)
Depth from face B 56 mm

A 56mm1-13

1-15(0,29)(-27, 25)

Depth from face A 68mm

Depth from face B 68 mm(0,0)
Depth from fac e A 80 mm(43 ,0)Depth from face B 80 mm

Fig. 1. Deviation of the center of the magnetic field. Tube number, forinstance, 1-5 means fifth drift tube of the first resonator. Coordinates areshown below each figure together with the axial depth of measurementsfrom the entrance of bore. The coordinates are in J.Lm and the depth in mm.

ReferencesI)

1. Takeshita and I. Yokoyama: Reports I.P.C.R., (in Japanese), 52, 166 (1976).

2)

I. Takeshita, 1. Yokoyama, T. Kambara, and M. Odera: IPCR Cyclotron Progr. Rep., 10,
140 (1976).

135

12-7.

Field Harmonics of the Drift Tube Quadrupole Magnets

1. Yokoyama, 1. Takeshita, and M. Odera

In order to achieve as small aberration as possible, the field configuration of the quadrupole
magnets has to satisfy certain requirements for relative values of its Fourier components as
described below.

In a cylindrical coordinate system where center axis of the field is chosen as

coordinate axis, the field can be derived from the following complex scalar potential develop~dTable l. Fourier expansion coefficients ofazimuthal field distributions as functions of axial
positions of measurement. L=O corresponds to thecenter of the axial length. rH is the distance fromthe axis the Hall probe was placed. Only values
larger than 0.1 % of n=2 component were given.

Table 2. Fourier coefficients for the pole (b) ofPole dimensions were those of (a) of the Figures

the Figures 1 and 2. The tape coil was used. The

1 and 2. The quadrant stacked plate coil was used.

magnet was made by the machine shop of the

The magnet was made by the machine shop of theinstitute.

institute.
Y:_~=I /f.b

III nl136

Fig. 1. Dimensions of the quadrupole(al~ _ _---'-1.0-=--0-=----_ _--1

magnets measured. (a) Type 1 made by
the IPeR machine work shop , (b) Type 2
made also by the work shop , axial length
equals 90 mm, (c) Magnet fabricated by- ------- r - ------ -/---

the Sumitomo factory for the No. 9 drift--+--- - -tube of the first resonator, axial lengthr--------r--------

160 mm, (d) Magnet also fabricated by
the Sumitomo factory for the No. 11 driftitube, axial length 210 mm.
19(d)in a series
F(Z) = n~! cn zn 'z = re ie ,where rand e are usual cylindrical coordinates; and n = I component is called dipole, n = 2
quadrupole, n = 3 sextupole and so on.
no aberration.

Ideally, only n = 2 component ought to be present forThis fact means that the equipotential lines, specifically, pole profiles, are to be

exactly hyperbolic.

This condition can not be realized in practice, and terms other than n = 2

always exist in the real quadrupole magnets.
expansion shown above.

There are two kinds of such terms in the seriesFirst, the term caused by any kinds of asymmetry of constructing

material or by manufacturing defects in some poles.

Secondly, kinds of components remain

even if symmetry of the field pattern around the coordinate center is secured.
by n = 2 (2 m + 1) belong to the latter kind.

Terms specified

Here, m is positive integer beginning from O.

Therefore, the extent of symmetry achieved for a quadrupole magnet can be judged from thecoefficients of terms of the former kind and the effect of non-hyperbolic pole profile can be
known from the n = 2 (2 m + I) terms.
Tables 1- 2 show results of measurements on some quadrupoles.

In Fig. I dimensions of

the magnets measured are indicated, and Fig. 2 shows change of each term in the equation as afunction of axial position of measurements.

Generally, the coefficients are complex or when

trigonometric expansion is used, relative phase of each term appears.

However, only absolutevalues normalized by the n = 2 coefficient are given in the tables and the figures for simplicity
of presentation.

The results show sufficiently small values for the higher harmonics. Symmetry

137

achieved in fabrication seems satisfactory.

The term n = 6 is relatively large, showing the effectof deviation from hyperbolic pole profile.

But the value seems not too large to give harmful

effect in the beam dynamics.

Abrupt change of each term at the exit of magnet comes frombreak down of the two dimensional presentation of field and possibly from a slight misalignmentof pole edge.
(b)

12

(al

7
6
~

-

4

5

t:i 4

r;;=12.6mm

"0

L,J

~

3

:x ____ E"IE,

/

2

'1

x_

\

x . . . x\ ·OJ

E6 /E 2....-0 E IE
1e - - - - o - - ·102x - - - x- -x- x- x...... 0x- x_Xx _ x~.

or'H=9.1m m:! =2~~~::::i:~ot~~60~Es I E20

EIO/E 2OXi==II:::O

L (mm)L (mm)

(d)

(e 1

7

7
6

6
'H= 10mm

5

~
4
t:i
"-0

L,J 3

5

E,IE,
___- - . - . _ . _ . ___ e - -

jO

~

2

t

x- - - x-

t
1

E"IE,

x-

x-

x_

x"-x,

\

El0/£2~x~'H=625mm

~E2

X~~~~

X

o

x-

10

20

30

±E10IE2~~. _ . _ ........... - ........ /___ X===X===X_X-X-X I

40

50

60

70

80

90

i - - - x - - - x - - x - - _ x - x ' x / x .... x-x ....xj21'H= 7.5mm

~

~

El0

E6/£ 2 0x~ I -~~~I--:o ~-ILO~2-L0--3.L0-40

L (mm)

50

Z=-==
60

L

E2

I
0....-0....-0,.

70

~

80

;.:x~X~x~x~x~

90

100

(mm)

Fig. 2. Change of Fourier amplitudes with axial position. Numbers represent n of
the series expansion. (a)-(d) correspond to those of Fig. 1.

110

120

138

12-8.

A

Digital Data Acquisition and Processing SystemforStudy of Magnetic Field

I. Yokoyama

In the developmental work of a magnet, usually numerous data have to be recorded andanalysed.

Some methods of automatic recording and processing of the observed data are desirable

to make study efficiently. A simple system was constructed and used in conjunction withthe work to develope

the drift tube magnets.

It can be used for more general and complex

M'I ni computer

Fig. 1. Diagram of the system.
-

N M.;t<f) <f) <f) <f)

u uuu

8

100.0.
10kfl

EH D
RD31 23 R

12V

5V-r--;::-;::;-n-t---1-~ - 9V
- 5V

Fig. 2. Controller of the system.

139

T.T.Y.

13 0 k.o.
>-+--.IV\!'---+--i)oC)--- - - - -

RX 0

24V

ft

HMN+~+-------------R C

lS 199 1

Fig. 3. Interface between teletype and thecontroller.
magnetic field study.

In this system, the strength of the field was digitized by use of a five digit

digital volt-meter and a Hall probe.

Resolution of the volt-meter was 1 /lV.

was transferred to a teletype printer and punched out on a paper tape.
off-line by a minicomputer Honeywell DDP-124.

Its BCD output

The tape was processed

Figure 1 is a block diagram of the system.

Figures 2 and 3 show the control and interface circuits constructed and used.

140

12-9.

Measurement of Alignment Error of the Drift Tube Arrayby the Hot Wire Method

I. Takeshita, I. Yokoyama, T. Kambara, and M. Odera

To secure a good beam transmission in the linac, magnetic field center of each quadrupole
magnet set in the drift tube is required to be aligned within 100 pm. 1 )In order to examine

this alignment, the position of the magnetic field centers were measured with a resolution of
10 pm using a hot wire method. 2 )Figure 1 is a schematic diagram of the hot wire measurement system employed.

If z-axis ischosen coincident with the field center axis and x- and y- axes are chosen in the convergent anddivergent direction of the field respectively, the force applied to the wire which is strung parallelto the z- axis and displaced by x and y from the field center is
Fx = -GILx - k (x - xo),Fy = GILy - k (y - Yo),

where G is the magnitude of the magnetic flux density gradient, I is the current flowing in thewire, L is the longitudinal length of the magnet, k is the transverse elasticity constant of thewire, and (xo, Yo) is the displacement of the wire without the field.

When the tension of thewire is W, its length is 2£, and the distance between the center of the Q-magnet and the centerof the wire is d, k is equal to 2W£I(£2 - d 2).

If k is greater than

IGIL I, an equilibrium point

exists in both x- and y- directions, which is given byx = kxo I(k + GIL),y = kyo I(k - GIL).

Fig. 1.

Schematic diagram of themeasuring system.
w

In the measurement, a dc current is sent through the wire and one Q-magnet is excited ata time until G approaches to kilL.

The direction of movement of the wire is observed by acondenser sensor with split electrodes and by an oscilloscope, adding a pulse signal to the dc
current.

The movement along the x- and y- directions are observed independently by altering

the direction of the current in the Q-magnet or through the wire, since a better resolution is
obtainable in the divergent mode.

Each wire holder at both ends has a pair of micrometerswhich define the x- and y-coordinate of the wire and the holders are moved in parallel until the141movement of the wire is not observed.

At that point, the readings of the micrometers arerecorded as the x-y coordinate of the magnetic center of the drift tube.
The measurement was done in September 1976 at the Niihama factory of the Sumitomo Heavy
Industries Co., Ltd. A tungsten wire with diameter of 0.2 mm and length of 3970 mm was used as the
hot wire.

The tension applied to the wire was varied as 720, 1000, and 1230 grw.

The effectof the vertical sag of the catenary curve was corrected using the parabola approximation.
maximum correction was about 0.6 mm.

The

Figure 2 is a photograph of the drift tubes withsensors.

Fig. 2.

The drift tubes and the sensors.

The left sensor is for the measurementin the vertical direction and the right ,for the horizontal direction.
The data obtained were fitted to a straight line with the chi-square minimization method,
and the deviations from the line are plotted.

The results are shown in Fig. 3 (solid lines), alongwith those of the geometrical centers measured by the Sumitomo factory inspector using atelescope (dashed lines).

Both results have almost the same shape and the difference is less than

40 Mm, so it is concluded that the geometrical center of the drift tube and the magnetic field
center of the Q-magnet coincide well.

In the horizontal direction, the alignment is fairly good

and the deviation is less than 60 Mm.

In the vertical direction, two drift tubes No. 3 andDrift tubes

Drift tubes[] ~ W W [JJJ [IT] [m
Cu.m)

60
0
+-'
40
0
>
20
""0
0
0-20
c

(j)

~-40
o

.':::-60
L~-80

Fig. 3.

Cum}
100
80
60
g 40
~
20
~

[]J

rn rn w ITO [ill [ill-.

O~----~~~------~--~L---­

-20
o -40
~ -60
L
-80
-100

""0

>

I

I

Deviations of the positions of the drift tube centers from the best

fit straight lines. The solid lines are the result of the hot wire method with
W= I 230grw , and the dashed lines, the geometrical measurement using atelescope. The deviations in the right and upper directions perpendicular tothe beam direction are taken as positive in the graphs.

142

No. 15 give deviations of about 100 }lm, values higher than the other tubes.

According toanother measurements by the factory staff of the flatness of the base of the drift tubes by adial gauge, some deformation is found to be present in the base, of the same tendency as thatobserved in the positions of the drift tube centers.

So the deviation seems to be mainly due tothe unevenness of the base.
We concluded that no correction is needed for the installation of the drift tube, because
observed deviation is within the planned value.

References
1)

T. Tonuma, F. Yoshida, and M. Odera: Reports I.P.C.R., (in Japanese), 2..h 53 (1975).

2)

R. M. Main: Proc. Fourth Intern. Conf. on Magnet Tech., p. 735 (1972).

143

12-10.

Evacuation Test of the First Resonator

Y. Miyazawa and M. Hemmi

Evacuation test of the first tank was made at the Niihama factory of the Sumitomo Heavy
Industries Co., Ltd. Molecular and cryogenic pumps were supplied by the laboratory to avoid
use of an oil diffusion pump.
residual gas analyser.

The vacuum leaks were located by a helium detector and a

The latter was found useful under the large outgassing condition of the

newly built vessel of large volume and surface.
surface area is about 9 X 10

5

2

cm .

Torr was obtained within a day.

The volume of the vessel is 11000 P and theAfter stopping a couple of leakages, a pressure of 10-6This result is satisfactory considering the condition of thesurface of the vessel which is not very clean and also the short period of time used for the test.
The resonator was disassembled and cleaned before shipment to the laboratory.
that a pressure of 10-

7

It is expected

Torr will be obtained after a long term evacuation in the laboratory.

144

12-11.

Radiofrequency Characteristics of the First Resonator

Y. Chiba

The radio frequency characteristics of the first resonator were measured at the Niihama
factory of the Sumitomo Heavy Industries Co., Ltd.

Figure 1 shows the quality factor andposition of shorting plane as functions of the resonant frequency.

Range of frequency expected in

the design was obtained . Quality factor was somewhat better than those measured on themodels.

Figure 2 is the voltage distributions along the acceleration axis.

The distribution ismore uniform than those measured on the models.
Gap number

1 2 3 4 5 6 7 8 9 10 11 1213141516
iii

1.0 [

._.-e

I

I
<=e

I

I

w=w

I

I

I

I

I

I

I

I

I

*_.'.-.-.,._.4"""". . . . . .

16. 19MHz

0.9

1. 0,-----.--=.=-,.-:;-=.,..-------Qual ity

5000

10000

15000

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

./

factor

0.9

20000

,

2 9 . 04 MHz

0.8

60

1.0
0.9

55

./

.-

Q)

e_ •

....... -.-.-.-.-.

\.
34.01 MHz

0.8
50

•

l ,O.--.---=-,....,..r.:-=.-- .-__-_-.----...... _.-.-.-.-.\.

.3 0.9 /

~

I

~

- 45

;;

37.53 MHz

0.8

Q).: 1. 0 r - - - - - = ; ; 0 4 " - ' = = = - - - - - - - - o/-~ 0.9 ; .

-. ........ -.-.

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

0.8

46.31 MHz

0.7

30 f-

1. 0 r - - - - - - - ,.......~~._-.-----./.......

~:; ~25'.-.-.-.-.~~.

20

15 =--------'10-=0c-::--------::-":i=0------'
2 OO
00
Position of shorting plane (mm)Fig. 1.

Quality factor andposition of shorting plane.

0.6
0.5

Fig. 2.

60.69 MHzDistribution of voltage

amplitudes at the accelerating gaps.

145

12-12 .

Trial Fabrication of Tape Coil for an Ordinary
Quadrupole Magnet

M. Hemmi and F . Yoshida

In view of success in fabrication of tape-coils for the drift tube magnets we tried to use
this type of coil also for an ordinary quadrupole magnet having a much larger aperture.

Since

the method of cooling by Freon-l 13 applied to the drift tubes, however, is neither convenient
nor economical in a large and open air working magnet, other means had to be developed.
Heat transfer through electrically insulating but thermally conducting material to a metal panel
cooled by water was tried.

Figure 1 is a disassembled view of the coil giving name andthickness of material used for thermal contact. The cooling panel is made of a thick aluminium
plate with engraved water passage and another aluminium plate welded on it .

Figure 2 shows

measured mean temperature rise of the coil in comparison with calculation.

Explanation of themeasured temperature distribution requires radial heat flow across thin epoxy impregnated insulation
paper between copper layers as was also the case in the drift tube magnets.

Importance ofthe thickness of the thermal grease layer on the overall temperature rise of the coil should be
noted.

For efficient cooling , a good surface machining and chemical etching as light as possible

to prevent short circuiting between layers are essential.
layer recede deep between insulator valley.
shown in Fig. 3.

Too much etching makes conductor

In the fabricated coil, degree of etching was as

The cooling characteristics were satisfactory and extensive use of the compact

quadrupole magnets with this type of coil seems promissing.

Figure 4 is a photograph of thecoil.

Therm o conduct ive compo und ICa sta ll - 800

200-500 m )The rm o conduct ive epoxy re sin coat i ng for elect r ical insulati on
I Castali - 3 4 3 100 m)
Anodized surface

Fig. 1.

Method of cooling the coil used for the

open air quadrupole magnets.

146

Coi I

100

Cooling ponel

Thermo couple

50

1 9.~:c.._-----

/e/

/!,T

e/e

10

5
/

Icopper taRe
O.8mm

/e/

I

1nsulator

H

O.2mm

/

!'T= (io-I) X240 (OC)

o

50

100

150

200

(Amp)

Fig. 2.

Mean temperature rise of

the coil v.s. excitation current.

Fig. 4.

Fig. 3. Etched profile of the coil andinsulator cross section.

Photograph of the coil.

147

12-13.

Design of

the Ion Source for the Linac

Y. Ikegami and I. Takeshita

A heavy ion source for the new accelerator Linac was constructed in the Work Shop.
was designed on the basis of the PIG type ion source used in the cyclotron.

It

The following

improvements were made: (1) Cleaning and replacement of anode, cathodes and insulators are
made easier.

(2) The cathode holders are made more sturdy.

Fig. 1. A heavy ion source for the new accelerator of the linac.
SH:Electron shield (Molybdenum),

SL:

Slit (Molybdenum),F:

Filament (Tungsten),C:

Anode block (Copper and water-

CH:

Cathode holder (Ceramics),

Kl:

Hot cathode (Tungsten),cooled),AH:

Anode chimney holder (Stainless

HSH: Cathode heat shield (Molybdenum),steel,CM:A:

Cathode mount (Copper and

K2:

Reflector cathode (Molybdenum),

water-cooled),

CP:

Cooling pipe (Copper),Anode chimney (Stainless steel),

S:

Source aperture.

148

13. LIST OF PUBLICATIONS

1) T. Matsuura and H. Amakawa: "On the Spin-Orbit Terms of 3 He- and 3 H-Optical Potentials",
Genshikaku Kenkyu, 21, 886 (1976).
2) T. Motobayashi: "Anomalous Angular Distributions in Heavy Ion L=l Transfer Reactions",
Genshikaku Kenkyu,~ 687 (1976).
3) T. Fukuda, M. Ishihara, T. Inamura, T. Numao, T. Shimoda, K. Tanaka, and T. Nomura:"Complete Fusion Cross Section Measurement by Beam Attenuation Method", Genshikaku
Kenkyu, (in press).
4) Y. Awaya, K. Izumo, T. Hamada, M. Okano, T. Takahashi, A. Hashizume, Y. Tendow,
and T. Katou: "K and L X Rays Induced by 5-MeV/amu a-Particle and Nitrogen-ion
Bombardment of Ten Target Elements Ranging from Cr to Bi", Phys. Rev., A, 13,992 (1976).
5) T. Mikumo, 1. Kohno, K. Katori, T. Motobayashi, S. Nakajima, M. Yoshie, and
H. Kamitsubo: "Systematics of Optimum Q Values in Multinucleon Transfer Reactions
Induced by Heavy Ions", Phys. Rev., C14, 1458 (1976).
6) T. Ooi, T. Motobayashi, K. Katori, and I. Kohno: "Detection and Identification of 8 Be
Nuclei with a Position Sensitive Detector and Counter Telescope", Reports I.P.C.R., (inJapanese), 52, 145 (1976).
7) I. Takeshita and I. Yokoyama: "A New Method for Precise Determination of Quadrupolemagnetic field of the Drift Tubes of a Heavy Ion Linear Accelerator", Reports 1.P.C.R.,(in Japanese), 52, 166 (1976).
8) T. Karasawa and Y. Toda: "An Ultracompact AVF Cyclotron (1), Electromagnet",
Reports 1.P.C.R., (in Japanese), 52, 185 (1976).
9) B. Imanishi and K. I. Kubo: "Multi-Step Core-Exchange Analysis of 16 0 + 18 0 Scatteringwith the Full-Recoil Calculation", Phys. Rev. Lett., 36, 132 (1976).
10) N. Bendjaballah, J. Delaunay, T. Nomura, and H. J. Kim: "Possible Shape Transition in
the Yrast Band of 56 Fe", Phys. Rev. Lett., 36, 1536 (1976).
11) H. Tawara, Y. Awaya, Y. Tendow, T. Katou, M. Akiba, and T. Tonuma: "Ar-K-Shell
Ionization by High E'nergy Carbon Ion Impact", Phys. Lett., 59A, 14 (1976).
12) F. Ambe and S. Ambe: "A 119 Sn Mossbauer Emission Study of Recoil 119 Sb Atoms afterProton Reactions in SnTe", Chern. Phys. Lett., 39, 294 (1976).
13) T. Tonuma, F. Yoshida, and M. Odera: IEEE NS-23, No.2, 1031 (1976).
14) Y. Awaya and K. Izumo: "X-rays Induced by Swift Heavy Ion Bombardment", Oyo Butsuri,
45, 905 (1976) (in Japanese).
15) T. Inam ura, F. Kearns, G. Varley, and J. C. Lisle: "Ground State Rotational Band in
i 'Sl Ta",

Nucl. Phys., A270, 255 (1976).

16) N. Bendjaballah, B. Delaunay, J. Delaunay, and T. Nomura: "High Spin States in 57 Co",

149

Nucl. Phys. (in press).
17) N. Bendjaballah, J. Delaunay, A. Jaffrin, T. Nomura, and K. Ogawa: "The Level Structureof S6 Fe", Nucl. Phys. (in press).
18) T. Kammuri: "On the Importance of the Sequential Transfer Process in the Two-Nucleon
Transfer between Heavy Ions", Nucl. Phys., A259, 343 (1976).
19) M. Uda: "Application of Ion Induced X-ray Spectroscopy to Solid State Chemistry and
Its Possibility", Report on Application of Heavy Ions to Atoms and Molecules I.C.P.R.,
p.53 (1976).
20) F. Ambe and S. Ambe: "Defect 119 Sn Atoms after Nuclear Decays and Reaction in SnSb
and SnTe", J. Physique (in press).
21) T. Nozaki, Y. Yatsurugi, and Y. Endo: "Charged Particle Activation Analysis - Studies on
Carbon, Nitrogen and Oxygen Mainly in Semiconductor Silicon", J. Radioanal. Chern., 32,
43 (1976).
22) A. Koyama, E. Vagi, and H. Sakairi: "Secondary Electron Emission from Ni and Al by
High-Energy Proton and QI-Particle Bombardment", Japan. J. appl. Phys.,~ 1811 (1976).
23) A. Iwamoto, S. Yamaji, S. Suekane, and K. Harada: "Potential Energy Surfaces for the
Fission of the Actinide Nuclei", Prog.

Theor. Phys., 55, 115 (1976).

24) H. Shiraishi, H. Sakairi, E. Vagi, T. Karasawa, R. R. Hasiguti, and R. Watanabe: "Growth
Process of Helium Bubbles in Aluminum", Trans. Japan Inst. Metals, 17, 749 (1976).
25) S. Yamaji, W. Scheid, H. J. Fink, and W. Greiner: "Dynamical Calculation of the Mass
Fragmentation in the Collision 238U - 238U", Z. Physik, A278, 69 (1976).
26) E. Vagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: "Defect Structures of Slightly
Reduced Semiconductive Rutile as Observed by Channeling Method", Proc. Intern. Conf.
Radiation Effects in Semiconductors, Dubrovnik, (1976), Inst. Phys., London (in press).
27) H. Sakairi, E. Vagi, A. Koyama, T. Karasawa, and R. R. Hasiguti: "Cyclotron Irradiationof CU3 Au Alloys at Low Temperatures", Proc. Intern. Conf. Fundamental Aspects ofRadiation Damage in Metals, Gatlinburg, 1975, USERDA, p. 643 (1976).

150(Papers presented at meetings)
1) T. Motobayashi: "Experiment of a-Transfer Reactions", Symposium on Scattering ofComplex Nuclei and Heavy Ion Reactions, Osaka, Jan. (1976).
2) T. Matsuura, A. Arima, T. Tomoda, and K. Yazaki: "DWBA Analysis of Four-Nucleon
Transfer Reaction 208 Pbct 6 0,12 C)212 Po", Symposium on Scattering of Complex Nuclei
and Heavy Ion Reactions, Osaka, Feb. (1976).
3) T. Suzuki, T. Matsuura, and K. I. Kubo: "Finite-Range Two-Step DWBA Code",
Symposium on Scattering of Complex Nuclei and Heavy Ion Reactions, Osaka,Feb. (1976).
4) A. Arima, T. Matsuura, T. Tomoda, and K. Yazaki: "A Method of Generating a-Transfer
Form Factors", Symposium on Scattering of Complex Nuclei and Heavy Ion Reactions,
Osaka, Feb. (1976).
5) H. Sakairi: "Radiation Damage of Solids by Particle Beams", IPCR Symp. on Study ofAtoms, Molecules and Solids with Heavy Ion Accelerator, Wako, Feb. (1976).
6) Y. Awaya: "Multiple Inner-shell Ionization Induced by Heavy Ion Impact", The IPCR Symp.
on Ion-Atom Collision, Wako, Feb. (1976).
7) H. Sakairi: "Radiation Damage of Metals by Heavy Charged Particles", Ann. Meeting ofJapan Soc. Appl. Phys., Tokyo, March (1976).
8) A. Koyama, E. Yagi, and H. Sakairi: "Secondary Electron Emission from Al by HighEnergy Proton Bombardment - Calculation", Ann. Meeting of Japan Soc. Appl. Phys.,
Tokyo, March (1976).
9) E. Yagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: "Lattice Defects of Ti0 2 -x", Ann.
Meeting of Phys. Soc. of Japan, Nagoya, Apr. (1976).
10) T. Fukuda, M. Ishihara, T. Inamura, and T. Numao: "Complete Fusion Cross Section
Measurements by Beam Attenuation Method(1)", Ann. Meeting of Phys. Soc. of Japan,
Nagoya, Apr. (1976).
11) A. Hashizume, Y. Tendow , T. Katou, and H. Kumagai: "In-Beam Spectroscopy on
94
92,
Mo+C Reaction", Ann. Meeting of Phys. Soc. of Japan, Nagoya, Apr. (1976).
12) T. Ooi, T. Motobayashi, K. Katori, and I. Kohno: "Detection of 8 Be Nuclei with a
Position Sensitive Detector", Ann. Meeting of Phys. Soc. of Japan, Nagoya, Apr. (1976).
13) H. Kumagai, Y. Awaya, Y. Tendow, M. Akiba, T. Katou, and T. Hamada: "An on-line
Bragg Spectrometer", Ann. Meeting of Phys. Soc. of Japan, Nagoya, Apr. (1976).
14) Y. Awaya, M. Akiba, T. Hamada, M. Okano, A. Hashizume, T. Takahashi, Y. Tendow,
T. Katou, H. Kumagai, and K. Izumo: "The Ka and K{3 Diagram and Satellite Lines andthe Ka Hypersatellite Lines of AI, Ti, Fe, and Ni Induced by 84-MeV N-ions", Ann. Meetingof Phys. Soc. Japan, Nagoya, Apr. (1976).
15) T. Inamura: "Angular Distributions of 'Y-rays from Coulomb Excitation of 181 Ta", Ann.
Meeting of Phys. Soc. of Japan, Nagoya, Apr. (1976).

15 116) K. Hinode, S. Tanigawa, N. Shiotani, and M. Doyama, "Positron Lifetime Measurements
for Aluminium Using An Internal Source" 78th Meeting of Japan Inst. of Metals (JIM),
Tokyo, Apr. (1976).
17) T. Nozaki, T. Karasawa, and N. Nonaka: "Manualization of Oxygen Analysis by the
160CHe,p)18F Activation", 34th Japan Chern. Soc. Meeting, Hiratsuka, Apr. (1976).
18) H. Kamitsubo: "Systematics in the Reactions Induced by C and N Ions in the 100 MeV
Region", Proc. of Symp. on Macroscopic Features of Heavy Ion Collisions, Argonne,
Apr. (1976).
19) T. Ishihara, T. Numao, T. Fukuda, K. Tanaka, and T. Inamura: "Angular Momentum
Transfer of the Quasi-elastic and Deeply Inelastic Processes in the 14 N+ 93 Nb Reaction at
E=120 MeV", Proc. of Symp. on Macroscopic Features of Heavy Ion Collisions, Argonne,
Apr. (1976).
20) T. Nomura, J. Delaunay, and N. Bendjaballah: "Unusually Large Difference between
Side-Feedings into the 6+ Doublet in 56 Fe", Intern. Conf. on Tandem Phys., Trieste,
Apr. (1976).
21) N. Bendjaballah, J. Delaunay, T. Nomura, and H. J. Kim: "Shape Transition in the Yrast
Band of 56 Fe", Intern. Conf. on Tandem Phys., Trieste, Apr. (1976).
22) M. Aratani and N. Saito: "Charge Spectra of the Si o+ Ions Sputtered from Mica under the
Helium Bombardment", 13th Ann. Meeting on Radioisotopes in the Physical Sciences andIndustry, Tokyo, June-July (1976).
23) M. Aratani and N. Saito: "Ionization of Aluminosilicate by the Presence of Alpha-Emitting
Nuclides and Its Simplified Model", 24th Ann. Meeting of the Mass Spectroscopy Societyof Japan, Tokyo, July (1976).
24) F. Ambe and S. Ambe: "Mossbauer Emission Studies of Recoil 119 Sn Atoms in Sb 2 Te3,
SnSb, and SnTe", 16th Mossbauer Spectroscopy Discussion Group Meeting, the Chemical
Society, Liverpool, July (1976).
25) Y. Awaya: "X-rays Induced by Heavy Ions", 2nd Hakone Symp. on the Electronic
Structure and Collision Process of Heavy Ions, Hakone, July (1976).
26) H. Sekizawa, T. Okada, and N. Shiotani: "Angular Distributions in Cr and Mo", 4thIntern. Conf. on Positron Annihilation, Helsingor, Aug. (1976).
27) N. Shiotani, T. Okada, and H. Sekizawa: "Angular Distribution of Positron Annihilation
Radiation in Aluminum", 4th Intern. Conf. on Positron Annihilation, Helsingor,
Aug. (1976).
28) 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 Zr 43 Alloy", 2nd Intern. Symp.
on Amorphous Magnetism, Troy, Aug. (1976).
29) K. Fukushi, T. Irie, T. Uchikawa, Y. Kashida, and T. Nozaki: "Preparation of 18 F Amino
Acids and Purine Bases and Their Distribution in Mice and Rats", 8th Intern. Symp. on
Fluorine Chemistry, Kyoto, Aug. (1976).

15230) T. Fukuda, M. Ishihara, T. Inamura, T. Numao, and T. Nomura: "A New Method ofComplete Fusion Cross Section Measurement", European Conf. on Nucl. Phys. with Heavy
Ions, Caen, Sept. (1976).
31) R. Ballini, N. Bendjaballah, S. Cavallaro, B. Delaunay, J. Delaunay, T. Nomura, andC. Tosello: "Study of High Spin States for 58 Fe and 58 Co", European Conf. on Nucl. Phys.
with Heavy Ions, Caen, Sept. (1976).
32) T. Nomura, C. Tosello, J. Delaunay, and N. Bendjaballah: "The Distribution of Residual
Nuclei from the 52 Cr + 12 C and 48 Ti + 16 0 Compound Reactions under the Condition of
the Same Excitation Energies and Grazing Angular Momenta", European Conf. on Nucl.
Phys. with Heavy Ions, Caen, Sept. (1976).
33) T. Nomura: "A Systematics on the Kinetic Energy Dependence of Heavy-Ion Fusion Cross

Sections", European Conf. on Nucl. Phys. with Heavy Ions, Caen, Sept. (1976).
34) M. Ishihara: "Coincidence Measurements for p and ~ with Various Light Products in the

14 N + 93 Nb Reaction", European Conf. on Nucl. Phys. with Heavy Ions, Caen, Sept.
(1976).
35) T. Fukuda, M. Ishihara, T. Inamura, T. Numao, T. Shimoda, and T. Nomura: "Complete

Fusion Cross Section Measurements by Beam Attenuation Method", Colloque FrancoJaponais de Spectroscopie Nucleaire et Reaction Nucleaire, Dogashima, Japan, Sept.
(1976).
36) H. Kamitsubo: "Particle-Particle and Particle-Gamma Correlation in Heavy Ion Reaction",

Colloque Franco-J aponais de Spectroscopie Nucleaire et Reaction Nucleaire, Dogashima,
Japan, Sept. (1976).
37) T. Nozaki, K. Fukushi, and T. Irie: "On Some Radiohalogen Derivatives of Cholesterol",
1st Intern. Symp. on Radiopharmaceutical Chern., BNL, Upton, USA, Sept. (1976).
38) K. Ogawa, K. Taki, and T. Nozaki: "Synthesis and Application of 73 Se-Selenomethionine",
1st Intern. Symp. on Radiopharmaceutical Chern., BNL, Upton, USA, Sept. (1976).
39) A. Hashizume, T. Katou, and Y. Tendow: "The Excited States in 104Cd following
104 PdeHe, 3 N) Reaction", INS Intern. Symp. on Collectivity of Medium and Heavy Nuclei

and Colloque Franco-Japonais, Tokyo-Dogashima, Sept. (1976).
40) T. Inamura, K. Hiruta, M. Ishihara, T. Fukuda, and T. Shimoda: "Gamma Ray Spectroscopy

with Direct (HI,~) Reactions", INS Intern. Symp. on Collectivity of Medium and Heavy
Nuclei and Colloque Franco-Japonais, Tokyo-Dogashima, Sept. (1976).
41) T. Numao, M. Ishihara, T. Inamura, T. Fukuda, and K. Tanaka: "Measurement of Gamma

Ray Multiplicities for Deeply Inelastic and Quasi-Elastic Processes", INS Intern.
Symp. on Collectivity of Medium and Heavy Nuclei and Colloque Franco-Japonais,
Tokyo-Dogashima, Sept. (1976).
42) F. Ambe and S. Ambe: "Defect 119 Sn Atoms after Nuclear Decays and Reaction in SnSb

and SnTe", Intern. Conf. on the Appl. the Mossbauer Effect, Corfu (Greece), Sept. (1976).
43) E. Yagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: "Defect Structures of Slightly Reduced

153

Semiconductive Rutile as Observed by Channeling Method", Intern. Conf. on Radiation
Effects in Semiconductors, Dubrovnik, Sept. (1976).
44) M. Odera: "RILAC, A Variable Frequency Heavy Ion Linac", 1976 Proton Linear
Accelerator Conf., Chalk Kiver Canada, Sept. (1976).
45) Kazuie Kimura, Hideaki Endo, and Masashi Imamura: "Color Center Formation in Alkali
Halides by Heavy-Ion Irradiation. III", 19th Conf. Radiation Chern., Kyoto, Oct. (1976).
46) R. Nagai, S. Tanigawa, M. Doyama, and N. Shiotani, "The Influence of Precipitation on
Positron Annihilation", The 79th Meeting of Japan Institute of Metals, Sendai, Oct.
(1976).
47) H. Sekizawa, K. Asai, T. Okada, N. Shiotani, and S. Ambe: "Perturbed Angular
Correlation of Gamma-Rays Emitted from 11ICd in NiFe2 0 4 ", Divisional Meeting of Phys.
Soc. of Japan, Yamagata, Oct. (1976).
48) Y. Yamawaki, K. Sakamoto, S. Okada, S. Suzuki, F. Yatagai, I. Kaneko, and A. Matsuyama:"The Effect of High LET Radiation on Cultured Mammalian Cells", 19th Ann. Meetingof Japan Rad. Research Soc., Hiroshima, Oct. (1976).
49) F. Yatagai, S. Kitayama, K. Yoshizaki, K. Kosaka, T. Takahashi, and A. Matsuyama:
The Influence of Air Layer before Samples on the Inactivation of Phage Xl 74 byCyclotron Beam", 19th Ann. Meeting of Japan Rad. Research Soc. Hiroshima, Oct. (1976).
50) T. Shimoda, H. Kamitsubo, M. Ishihara, T. Fukuda, T. Motobayashi, T. Ooi, andI. Kohno: "Measurement of Particle-Particle Correlation in Heavy Ion Reaction", Autumn

Divisional Meeting of Phys. Soc. of Japan, Fukui, Oct. (1976).
51) T. Fukuda, M. Ishihara, T. Inamura, and T. Shimoda: "Complete Fusion Cross Section
Measurements by Beam Attenuation Method(2)", Autumn Divisional Meeting of Phys. Soc.
of Japan, Fukui, Oct. (1976).
52) A. Hashizume, Y. Tendow, T. Katou, and H. Kumagai: "Excited States in 104Cd Revealed
by 'Y-'Y Coincidence Experiment Following 104 Pd + 3 He and 96 Mo + 12 C Reactions", Autumn
Divisional Meeting of Phys. Soc. of Japan, Fukui, Oct. (1976).
53) T. Motobayashi, T. Ooi, S. Nakajima, and I. Kohno: "a-Transfer Reactions between Light
Nuclei", Autumn Divisional Meeting of Phys. Soc. of Japan, Fukui, Oct. (1976).
54) S. Motonaga and T. Fujisawa: "Axial Injection into INS Cyclotron", Autumn Divisional
Meeting of Phys. Soc. of Japan, Fukui, Oct. (1976).
55) K. Hiruta, T. Inamura, M. Ishihara, T. Fukuda, and T. Shimoda: "Gamma Ray Spectoscopy
with Direct (HI, 0') Reactions [1]", Autumn Divisional Meeting of Phys. Soc. of Japan,
Fukui, Oct. (1976).

154

14. LIST OF PERSONNEL

Members of the Board
DOTE Toshihiko± =f fib. fl; (Chairman)
KAMITSUBO Hiromichi
1: Jf '-1i. ~NOZAKI Tadashi!Iff ~IE
KOHNO Isao
M !Iff:;I]
Users Committee=

HAMADA Tatsuji~ 83 ~(Chairman)
KAMITSUBO Hiromichi
1: Jf '-1i. ~MATSUYAMA AkiTa
m lU :5't
ODERA Masatoshi
SEKIZAW A Hisashi

HAMADA Tatsuji
NAKANE Ryohei
ODERA Masatoshi~

83 ~ $.& :lJZm'J" ~ IE ~B
IMAMURA Masashi
4- t1
E3
KOHNO Isao
f6J!Iff:9J
NOZAKI Tadashi!Iff U%lE
SAKAIRI Hideo:IN A "ff!:. ffi

Operation and Machine Maintenance Groupff
FUJIT A Shin
§ 83
KAGEY AMA TadashilU
KOHNO IsaoiOJ !Iff:9J
OGIWARA Kiyoshi~JJRm
11r r ~ ~TAKESHITA Isao

'3

IKEGAMI Kumio
i't!!1:1L = ~KOHARA Shigeo'J" JJR m ~$ ~~ ~ ffi
NAKAJIMA Hisao
T AKEBE Hideki
j\ g:j)+11~ lU - ~B
YOKOY AMA Ichiro*

Scien tific and Engineering Personnel
Cyclotron Laboratory§lR~;=t
FUJISA WA Takashi
fffi H!ji
INAMURA Takashi
KAMITSUBO Hiromichi
1: Jf '-1i. ~KOHNO Isao
f6J!Iff:9J
MOTONAGA Shoshichi
5C 7k I3B -I:::
NAKANISHI Noriyoshi$ g§~
SUZUKI Toshio~
fib. ~Y AMAJI Shuhei
JlJ 8?a ~ f

*c

*

=

FUJITA liro
§ 83~~
ISHIHARA Masayasu
KARASA WA Takashi
MATSUURA Toshihikom 00 ~ fl;
NAKAJIMA Shunji$ 9h ~NOMURA Toru
fJ t1~*
WADA Takeshi
fj] 83ffi(Visitors)
HIRUTA Kotaro!R!83$*~~(Tokyo Gakugei Univ.)
ICHIMURA Munetake ffi t1
lEt(Univ. of Tokyo)
IMANISHI Bunryu
4- g§ X il!
(Univ. of Tokyo)
KAMMURI Tetsuo
AL!f ~(Osaka Univ.)
KATORI Kenji
HE 1'& ~(Tsukuba Univ.)
KAWAI Mitsuji
lDJ -€I -:it 8?a(Kyushu Univ.)
KOIKE Masahiro'J" i't!! lE '-1i.
(Univ. of Tokyo)
MIKUMO Takashi:= ~ Jb(Tsukuba Univ.)
NOJIRI Yoichi!Iff JJL j$ (Osaka Univ.)
OHNUMA Hajime
tt1
ffi(Univ. of Tokyo)
SHIMOKOSHI Fumio ~ ~ )'( ~(Univ. of Tokyo)

*

=

"*

* On leave of absence to : DPHNBE, CEN Saclay, B.P. 2,91190 Gif/Yvette, France.

=

155

(Nat'l Res. Inst. for Metals)
SHINNO Hitoshi(Nat'l Res. Inst. for Metals)
SHIRAISHI Haruki
8:0 1I- fM(Osaka Univ.)
TAKAHASHI N oriaki ~ m ~ ~(Saga Univ.)
T AKEMASA Tadashi J1\ i& Jt ±(Tokyo Inst. Tech.)
YOSHIDA Hiroshi
E EB
iJL(Students)
FUKUDA Tomokazu m EB ~ ~(Univ. of Tokyo)
MOTOBA YASHI Tohru
JY£(Univ. of Tokyo)
001 Takao
it %: 1$
(Tsukuba Univ.)r EB lE(Kyoto Univ.)
SHIMODA Tadashi
EB m-~~(Univ. of Tokyo)
TANAKA Koichiro
7t- ;r:J E ¥(Kyoto Univ.)
TOBA Yoshiyuki

* **

*

'*'

Linac Laboratory
CHIBA Yoshiaki
f- ~ fH ~INOUE Toshihiko
fr J: flt{ W:
MIY AZAWAY oshitoshirg lR 1* flt{
SHIMAMURA Akira~;fJ£
YOSHIDA Fusako
E EB m T
Radiation Laboratory*

AWAYA Yohko~ ?G THASHIZUME Akira
m m 1mKATOU Takeo
1Jo Hi J1\ 1$
KUMAGAI Hidekazu~~ ~~TAKAHASHI Tan
~ m
Jl

*

HEMMI Masatake~ J! i& JEt
KAMBARA Tadashi
1f!:! JJf:lE
Ij, ~ lE {~ODERA Masatoshipi ¥B lE 1$
TONUMA Tadao=

HAMADA Tatsuji~ EB ~IZUMO Koichi
ill ~ ~ KONNO Satoshio KAN 0 Masaharu IllJ ff Jl! m
TENDOW Y oshihiko
x :@ 7f W:(Visitors)
AKIBA Mitsunori
fJc ~ ]t 1,1[f(Tokyo Inst. Tech.)
DOKE Tadayoshi:@,r:g, ~
(Waseda Univ.)
FUJIOKA Manabu
Hi IllJ$(Tohoku Univ.)
HAYASHIBE ShogofiB IlB(Tohoku Univ.)
no Masahiro· ~ ~ lE '1i. (Tokyo Metropol. 1eriatric Hosp.)(Rikkyo Univ.)
NAGAHARA Teruaki 7k JJf: ~ ~SUZUKI Kazuaki~~(1 apan Anal. Chern. Res. Inst.)
w t~ ~ (Kyushu Univ.)
T A WARA Hiroyuki

*

*

**

*-

Nuclear Analytical Chemistry Laboratory
AMBE Fumitoshi'ii:. fiB Y:. ~ARA T ANI Michim tl ~ ~IWAMOTO Masako£lE T
if Jli Fa m
SAITO Nobufusa*

AMBE Shizuko'ii:. fill Mt T
W 7f TITO Y oshiko
NOZAKI Tadashi
ff dffi]lE*(Visitors)
FUKUSHI Kiyoshi
HARA Toshihiko
IRIE Toshiaki(Nat. Inst. of Radiological Sciences)(Nat. Nakano Chest Hosp.)(Nat. Inst. of Radiological Sciences)

156

~

KASIDA Yoshihiko~
TAKI Ko

EE R 'ft; (Nat. Inst. of Radiological Sciences)¥(Kitazato Univ.)

Radiobiology Laboratory
KANEKO Ichiro
i: T - !'!~
MA TSUY AMA Akira
~ IlJ

~

KIT A Y AMA Shigeru~t IlJinYATAGAI Fumio
1:i- EE Ft X 7(

(Visitors)
IffiJ EE m X(Univ. of Tokyo)
OKADA Shigefumi~ /.$: ti fJ;(Univ. of Tokyo)
SAKAMOTO Kiyohiko

Radiation Chemistry Laboratory
13

IMAMURA Masashi
KIRA Akira

S

KIMURA Kazuie
MATSUI Masao(Student)
HARA T A Yasuo
Metal Physics Laboratory
KOY AMA Akio
'J' IlJ lIB til
SHIOT ANI Nobuhiro~ 1:i- If 5L.

SAKAIRI Hideo
YAGI Eiichi(Visitor)
TANIGAWA Shoichiro 1:i-)IIJ±-~~(Univ. of Tokyo)

Magnetic Materials Laboratory
ASAI Kichizo
Ii
SEKIZAWA Hisashi*

OKADA Takuyai§= 1$.
~ if{

~

M p

IE.

(Visitor)
MIZOGUCHI Tadashi(Gakushuin Univ.)

157

15. LIST OF OUTSIDE USERS AND THEIR THEMES(Jan. - Dec. 1976)
1) H. Nakahara and M. Yanokura,

Faculty of Science, Tokyo Metropolitan Univ.

"Isomeric Cross Section for the 121 Sb(ex,exn)
120m

Sb and 121 SbeHe,3He n)120m Sb

Reactions"
2) Y. Murakami, Y. Honma, E. Shirai, andFaculty of Science, Tokyo Metropolitan Univ.

M. Unno"Production of 61 Cu and 68 Ge"
3) T. Furuta, T. Katou, and S. Kawasaki,

Japan Atomic Energy Research Inst.

"Study of Effect of Helium Bubbles on the
Mechanical Behavior of Stainless Steel"4) M. Nakamura,

Faculty of Medicine, Kyushu Univ.

"Production of 43 Kr"
5) K. Shiraishi and A. Hishinuma,

Japan Atomic Energy Research Inst.

"Radiation Damage of Stainless Steel by
Alpha Irradiation"
6) A. !ida,

Faculty of Engineering, Tokyo Univ.

"X-ray Diffraction Study of the Effect ofAlpha-Bombardment of Si-Crystal"7) A. Furusawa and S. Tamaki,

Faculty of Science, Niigata Univ.

"Production of 124 Sb for Perturbed
Angular Correlation Measurement"8) Y. Murakami and M. Yanokura,

Faculty of Science, Tokyo Metropolitan Univ.

"Production of 57 Co, 62,63 Zn, 68 Ga ,67

Ge, and 123 I"

9) A. Hishinuma, K. Fukai, T. Aruga,

Japan Atomic Energy Research Inst.

T. Katou, T. Furuta, and T. Otomo ,"Simulation Test on Neutron Irradiation
Damage of Stainless Steel for Fast Breeder
Reactors by Alpha-Bombardment"10) M. Shimada, K. Une, and M. Terasawa,

Toshiba R. & D. Center"Cyclotron Irradiation for Study of
FBR Material Embrittlment"II) A. Furusawa and K. Mori,"Production of 152,154 Eu for Perturbed
Angular Correlation Measurement"

Faculty of Science, Niigata Univ.

15812) A. Hishinuma, K. Shirai, and K. Fukai,

Japan Atomic Energy Research Inst.

"Helium Effect on the Formation of Voidin SUS316 by Electron Bombardment"13) Y. Murakami and H. Nakahara,"Study of Nuclear Reaction Products for
the Purpose of Medical Use"

Faculty of Science, Tokyo Metropolitan Univ.

159

AUTHOR INDEXtx ~AKIBA Mitsunori*'

W, 78,81,83

AMBE Fumitoshi
AMBE Shizuko

HEMMI Masatake~ J!

i&:lEt130, 143, 145

HINODE Kenji'§;. ffl) M T

99, 109, 120m :fr ~ tv

ARA T ANI Michi

106

IGARASHI Kazui

1L--t-m - ~

123

102

IKEGAMI Kumio~J:.JL = ~3,10~ 1fB 9.i. ~ARITOME Hiroaki

HIRUTA Kotaro

IKEGAMI Yuji

ASAI Kichizo~~~T

AWAYA Yohko

78,81, 83,85, 86~J:.;JitPJ

IMAMURA Masashi

147
s

4f1

CHIBA Y oshiaki'f~tff-~

130, 144

IMANISHI Bunryu

DOKE Tadayoshi~*}~\~

85

INAMURA Takashi

fffl f1

DOY AMA Masao¥:1lIt'§~89,91

INOUE Toshihikoft J:. W!L 'ffi

FINK Hans J.

IRIE Toshiaki

51
§f1Oj

FUJIOKA Manabu

~

40

iii

IT ~ ~

ISHIHARA Masayasu

65

29,31,5975
130

120

--r::

IR

X

1-1

l/J'-

l.C

26,29,31,3856,
59, 75*-*ISHIMA TSU Toshiyuki

FUJITA Shin
FUJISAWA Takashi

~ ~

§

it

16,54

1M B3 ~ fIJ 26,29, 31,

FUKUDA Tomokazu

38,59

1M ±

FUKUSHI Kiyoshim

ITO Yoshiko

fjI"

51

HAMADA Tatsuji~

HARA Toshihiko

'*

B3 ~

=

fj 'ffi

120* :IE -r

:E
ttl ~

*' -

78,81,83,85

KAMBARA Tadashi

120

KAMITSUBO Hiromichi

tI\l

'*

120

78, 85III~

KAGEY AMA Tadashi

:IE
:IE

3,7,10140

1: PJZ 9.i. ~ 16,19,26,49,
54,56,75,104

KAMMURI Tetsuo

HARAT A Yasuo
HASEGAWA Takeo

ffi::fr)II:lEt~

HASHIZUME Akira

m Jl\

HASIGUTI R. Ryukiti

T

ITOH Yoshinori

IZUMO Koichi

GREINER Walter* 7i

IW AMOTO Masako

120

GOTO Akira

HA YASHIBE Shogo

4~3t~

A

111, 112, 119

13

KANEKO Ichiro

16

AA 62,65,78,81,85 KARASA WA Takashi

m IJ ~ i5'

93,96

m= ~

KA TO RI Kenji

II[ 1& ~KATOU Takeo

DO §

=

j\ ttl-1f.

13,12033,49,68
62, 78, 81

160

KIMURA Kazuie

If;:

E ~

KIRA Akira

tt - '=F~

NAKANISHI Noriyoshi

112

NAMBA Susumu

119* EB fllj 1:. 21,23

KISHIDA Norio~t

KIT A Y AMA Shigeru

itt

W

NISHIMURA Tadashi

KOBA Y ASHI Masayoshi

NOJIRI Tamaki

KOHARA Shigeo

NOJIRI Yoichi;9

KOHNO Isao

3,5,26,33,35,38,
49,68,102,104

NOZAKI Tadashi

KOYAMA Akio

NUMAO Toshio
62,78,81,
85,86

OGIW ARA Kiyoshi

LEE. S. M.

OHNUMA Hajime

MAEDA Kuniko

1W EB ~ -f-

MASUDA Kohzoh

7t EB ~ =:.
~ if IE ~MATSUI Masao

MATSUURA Toshihiko
MA TSUY AMA Akira~!I!T Pr.i'J' ~ IE ~-)( 1B

126,127,129,130,
132, 133, 135, 140

m-

23

21

111,119

OKADA Shigefumi

Wi.!

EB m Y:.

11 7

rm ~ =fa.

w~

43,46,54

114,11715 iR it fiB:

56
127,130,143

OKADA Takuyafli7] !I!T

OKANO Masaharu*- g§

ONISHI Hiroshi
001 Takao

MOTOBA Y ASHI Tohru*

MOTONAGA Shoshichi

5t 7k aB --t 16,19~

89

26,33,35,
38,49,68,
70,72'*' ~ ~ = 35

78,81,83,120
40

26,33,35,38,49,68
16

SAKABE Kiyozo
SAKAGUCHI Harutaka
SAKAIRI Hideo~ A!Ii:. ~~*-SAKAMOTO Ichiro

NAKAJIMA Hisao

• frJ
5L

jc it ~ ~RESMINI Francesco G.

MIZOBUCHI Akira

3't

120

-)( it- Y:. =fa.

~

;fit

IE

o HT ANI Fumihiko

MIY AZA WAY oshitoshi

NAKAJIMA Shunji

56

102

M Ii! ,rtf, JVJ

7k if!I!T JJL 1'$ -102

OHSHIMA Masumi

86

MINAMISONO Tadanori

NAGAI Ryo10

ODERA Masatoshi

KUSUNO Sadao
38

IE

NOMURA Toru

KOIKE Masahiro

KUMAGAI Hidekazu

tt~!I!T EBNODA Takashi

114

g§

SAKAMOTO Kiyohiko

93,96
~~

123, 125

161

SASA Y oshihiko
SCHEID Weaner::R ~ 7f ffi

TENDOW Y oshihiko62, 78,81

TO BA Y oshiyuki

ji.~E¥

16,21,23

SEKIZAWA Hisashi

TONUMA Tadao

pi rB IE

5,85

SHIKATA Takashi

UCHIYAMA Sadayuki

51

SHIMAMURA Akira

~

t1

~

SHIMODA Tadashi

~ ffi

IE

5

26,31,59

SHIMOKOSHI Fumio
SHINNO Hitoshi

UDA Masayuki~ffiK;;Z86

UEDA Nozomu

J:. ffi~

16

USUBA Isao
t

feT!f

~ ~ ~ i]1,

SHIOT ANI Nobuhiro

B ~SHIRAISHI Haruki

*.w

f.i~

WADA Takeshi

104

til

~

123

til

fUffi

89,91 , 99

WATANABE Ryoji

vtJl1 ~ frl

104

104

WATANABE Tokuji

vtJl1~frl

10/\ * * -SUGIMOTO Kenzo

YAGI Eiichi

T AKEBE Hideki

YAMADA Satoru

W ffi

TAKAHASHI N oriaki

Y AMAJI Shuhei

W ~ ~:ljZm

TAKAHASHI Tan~

TAKESHITA Isao¥r ~ ~ ~ 129, 132,133,

TAKI Ko¥

78,81,85,114

135, 140, 147

TANAKA Koichiro
TAN lGAWA Shoichiro
TANIMURA Osamu.§.

'*' m- ft~~ JI\ J± - ft~

29,56
89,91

93,96,99

Ire

16
51,54

YAMAWAKI Yuriko
Y AT AGAI Fumio
YOKOYAMA Ichiro

120

EE

43,54,75

YOSHIDA Fusako
YOSHIE Morio~ ffi~X~~W-

E ffi JJ!f T

114,117ft~

133, 135, 138, 140

130,145

IPeR Cyclotron Progress Report!11t~iff~PJT-ij-171J ~ IJ /~~fB* f;10~ ( 1976 )~p.!iiIJ~

ff Bl1;f052i:j:. (1 977 ) 3 1'1 30 8

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811;f052 i:j:. (1 977 ) 3 1'1 25 8

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1$(0484 ) 62 - 1 1 1 1£!lH t.*~}f9f.PJT-tT l' /' D ~ D /' f IJm13~ ffil it
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=;=101 **Wf-(-tEBlR#EB#1*=IIITl T § 42*!il?
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理化学研究所
埼玉県

和光市

広沢