the Institute of Physical and Chemical Research
Wako-shi, Saitama Pref., JAPANIPCR cyclotron
Progress Report 1973

Vol. 7,peR

Cyclotron Progress Report;.~;. ---------------~t_---Vol. 7

The Institute of Physical and Chemical Research
URIKAGAKlJ KENKYUSHO" Wako-shi. Saitama. 351 JAPAN
December, 1973

Editors
F. AmbeM. Imamura

M.OderaH. Sakai ri

A. Hashizume

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

CONTENTS
Page
1.

INTRODUCTION .......................................................................................................... .

2.

MACHINE OPERATION ............................................................................................. ..

3.

MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS
3-1.

Increase of Maximum Energies of Cyclotron Beams

5

3-2.

Study of Composition of Residual Gas in the
Cyclotron Chamber ...........................................................................................

7

Improvement of the Structure of Septum Holder at the
En trance of Beam Deflection Channel .............................................................

10

Improvement of Standard Voltage Source for theCurrent Stabilizer of Magnet ...........................................................................

14

Trial-Making of a Current Stabilizer for a Quadrupole Magnet ......................

15

3-3.

3-4.

3-5.
4.

2

NUCLEAR PHYSICS
Scattering and Reactions

4-l.

DWBA Calculations of Inelastic Scatterings of I2C and I4N..........................

17

4- 2.

The Finite Range DWBA Analyses of the Reactions
52Cr C4N, 13C) 53Mn and 52Cr C2C, 11 B) 53Mn ........... ..................................... .....

22

Angular Distributions of Transfer Reactions Induced by
Heavy Ions .......................................................................................................

27

A Study of Transfer Reactions Induced by
14N and 12C on 208Pb and 209Bi .......................................................................

32

Angular Distributions and Linear Momentum Transfers ofTarget Residue in the 209Bi + 12C Reaction ......... ...........................................

37

Limit of the Cross Section for the Compound Reaction
between Complex Nuclei ..................................... ............ ....... ........ ........ .........

39

4- 7.

eHe, d) Reactions on Cr Isotopes at an Energy of 29 .3 MeV.. ........ ............

42

4- 8.

The eHe,3He), eHe, 3He'), and eHe, a) Reactions on 13C...........................

46

4-9.

Two-Step Process in the 12CeHe, a) l1 C Reaction

4- 3.

4- 4.

4-5.

4-6.

4- 10. Sum Rule Approach for Isovector Nuclear Vibrations ............... ..... ........ .........

47

51

4-11. Momentum Transfer Dependence of the Effective Charge
for Electro-excitation ........................................................................................

4-12. Effects of Monopole Core Polarization...........................................................

53
55

4-13. The Splitting of the Isospin and Spin-Isospin
Dipole Resonances in 12C

5.

6.

7.

58

4-14. New Giant Resonances60

4-15. Sum Rules and Nonexchange Force62

NUCLEAR PHYSICS
Nuclear Spectroscopy

5-1.

Asymmetric Fission of 236U

65

5- 2.

Alpha-Decay of 215Fr

69

5-3.

Magnetic Moment of the 29/2+ State in 213Fr

71

5- 4.

The Blocking Effect of the M 1 Core Polarization
Studied from the g-Factor of the (1Th 9/2 )6 8+ State in 214Ra

74

5-5.

In-Beam Alpha- and Gamma-Spectroscopy of 216Ra

77

5- 6.

Measurement of Half-Life in ms Region witha Mechanical Chopper ............................ ..........................................................

79

NUCLEAR INSTRUMENTATION

6- 1.

New Data Processing System

83

6-2.

Interface between PHA Units and OKITAC 4500C Computer

86

ATOMIC AND SOLID-STATE PHYSICS

7-1.

Inner-Shell Excitation by N Ions and Alpha-Particles (1)

87

7- 2.

Inner-Shell Excitation by N Ions and Alpha-particles (2)

93

7-3.

Positron Annihilation in V and Nb .................................................................

98

7 -4.

Positron Annihilation in Paramagnetic Nickel Single Crystal ..... "...................

10 1

7-5.

Point Defects in Irradiated Copper and Cu 3 Au

103..............................................

8.

RADIOCHEMISTRY

8-1.

8-2.
9.

12.

Charge States of Ions from 18F Decay

110...........................................................

Heavy Ion Radiolysis of Liquid Ketones
Effect of Water on the Radiolysis of Acetone112

ESR Studies of Free Radicals Produced in Organic
Crystals Irradiated with Heavy Ions .................. .............................................

114

9-3.

Inactivation of Bacterial Cells by Charged Particles.......................................

117

9-4.

LET Dependence of DNA-Strand Breaks in ~.coli Bs- 1 ... ...... ........ ................

122

9- 2.

11.

105

RADIATION CHEMISTRY AND RADIATION BIOLOGY
9-1.

10.

Mossbauer Emission Spectroscopy of 119Sn after
the EC Decay of 119S~ b ...................................................................................

PREPARATION OF RADIOISOTOPES AND LABELED COMPOUNDS

10-1. Measurement of Excitation Curves for theFormation of Medical-Use Radioisotopes

126

10-2. Preparation of 18F-Labelled Compounds ..........................................................

129

10-3. Preparation of 119Sb for Mossbauer Emission
Spectroscopy of 110Sn ......................................................................................

132

RADIATION MONITORING

11-1. Routine Monitoring134

11- 2. Residual Radiation in the Cyclotron Vault after
Deuteron Acceleration ... ........ .................... ....... ............................ ..................

136

A NEW MACHINE

12-1. Specifications of Variable Frequency Linac
12-2. The Variable Frequency Linac Project
Results of Measurements on Model Cavity

140.........................................

143

12-3. The Variable Frequency Linac Project
Orbit Dynamics: Radial Acceptance147

12-4. The Variable Frequency Linac Project
Orbit Dynamics: Phase Oscillation and Energy Resolution14912-5. Two Examples of Heavy-Ion Cyclotron with
External Injection Provision ....... ............. ..... .. .......... ...... ......... ... ..... .... ...... .....

151

13.

LIST OF PUBLICATIONS

155

14.

LIST OF PERSONNEL

158

15.

LIST OF OUTSIDE USERS AND THEIR THEMES161

AUTHOR INDEX

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

1.

INTRODUCTION

In this year our cyclotron was operated smoothly as before.

Several improvements havebeen made in the machine itself and its accessory facilities which resulted in more stable andefficien t operation.

In all fields of study uSIng the machine a majority of research works have been carriedout with heavy ions.

A theoretical approach to heavy ion nuclear reactions has started andoffered a promissing prospect.

A new data processing system with on-line use of a computerhas been completed.
A preliminary work has been done in the field of atomic physics in which the inner-shellionization produced by heavy ion bombardment was investigated by X-ray measurements.
A project of construction of a new heavy ion machine is expected to be supported by theGovernment and will be realized in this and the next fiscal years.

A number of preparatory

studies on the basic problems in the construction of the new machine were almost completed
during last three years as seen in the foregoing issues of Progress Report.

The new machineis a linear accelerator and its performance was designed to yield a beam of heavy ions up touranium having energy of I to 6 Me V/nucleon.

We hope that the completion of this machine

would be beneficial to research in new fields unworked yet.

Hitosi Hagihara, Chairman
The Cyclotron Board

2

2.

MACHINE OPERA liON

Machine GroupThe cyclotron was operated without any serious machine failure in the period from
October 27, 1972, to October 23, 1973, on the 24 h -a-day basis. Statistics of machine operation
are shown in Table 1. The recorded working times of the oscillator and the ion source areslightly longer than those of the last year. Beam time for heavy ions continues to rise in spiteof necessity of more maintenance work of the ion source than for the acceleration of ordinary
light ions. Table 2 shows machine time allotments to various activities in this period. More than
95 % of the schedule was fulfilled. Declaration of loss of machine time due to machine failure
was only thrice in this period. The figure had been about 10 for the past few years.
Efforts of improvement of various parts of the cyclotron are being continued : Replacementof insulators which support the shorting device with much sturdy ones, eliminating occurrenceof failure due to insulation breakdown : Removal of an old dee-voltage pick-up arm from thecenter of the accelerating chamber and installation of a new pick-up at the side of east dee,
improving the reliability of indication of operating voltage : Renewal of diffusion oil of the32" pump to one of superior quality and detection and stopping of small vacuum leakage atTable 1.

Machine operation time indicated by working-time meter.

Date

Oscillator

Ion source

BeamOct. 27 , 1972

27555 (h)30038 (h)1698 (h)Oct. 23 , 1973

32976 (h)35693 (h)6652 (h)361 days

5421 (h)5655 (h)4954 (h)62.6 %

65.4 %

57.2 %

Percent of 361 days

Schedule in this period:
Machine time214 (days)

Overhaul and installation work

41 (days)

Periodical inspection and repair

28 (days)

Vacation, holiday , and Sunday

78 (days)3

Table 2.

Scheduled machine time and subjects ofactivity in this period YIll.

Subject

Hours

Heavy IOn reaction

531

Direct reaction with light particles

1209

In-beam spectroscopy with heavy ions883

In-beam spectroscopy with light particles

216

Radioisotope production for nuclear spectroscopy

176

Nuclear chemistry

310

Radiation chemistry

157

Radiation biology

269

Solid state physics

279

Inner atomic shell excitation study

216

Nuclear medicine in cooperation with otherorganizations

185

Nuclear fuel study

132

Radio-isotope production

50

Instrument development and beam channelalignmen t by use of beam

125

Exchange of ion source

66

Reserved for machine time adjustment
and cooling of radiation

148

Machine inspection and repair

672

Percent

Nucl. phys.
53.6 (%)

Fields otherthan nucl. phys.
21.9 (%)

Ou tside users
6.5 (%)

Total

Maintenance
operation andengineering
18.0 (%)

5624

100 (%)

4

the throat of the main pump resulting in the attainment of better ultimate pressure with lesspumping time , and the pressure in the accelerating chamber without gas loading from ion
source is 5 x 10-7 Torr normally .l )These improvements made possible to obtain ions of higher

energy than hitherto obtained, for instance, 112 MeV for C and nearly 60 MeV for Ci particle. 2 )Rectified l8V - 350A heater power supply for the oscillator tube was manufactured andinstalled in the oscillator housing in place of the AC supply hitherto used. I t is expected todecrease low-frequency ripples of the radiofrequency waveform and to improve beamcharacteristics in cooperation with increased filtering of high-voltage power supply, made lastyear.

References

1)

Y . Miyazawa, T. Kageyama , and T. Karasawa : IPCR Cyclotron Progr. Rep., 2, 7 (1973).

2)

Y. Miyazawa, K. Ogiwara, T. Tonuma, S. Fujita, M. Hemmi, K. lkegami , T. Inoue ,T. Kageyama, S. Kohara, H. Nakajima, A. Shimamura , and O. Terajima : ibid. , p . 5·

5

3. MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS

3-1.

Increase of Maximum

Energies of Cyclotron Beams

Y. Miyazawa, K. Ogiwara , T. Tonuma , S. Fujita , M. Hemmi,
K. Ikegami, T . Inoue , T. Kageyama, S. Kohara,
H. Nakajima, A. Shimamura, and O. Terajima

In an ordinary cyclotron, the maximum energy of beam is limited dependillg 011 theaccelerating voltage which can be maintained by the dee without sparking.

The limit alsochanges according to the starting phase of ion leaving the ion source.
III September, 1973, the central region geometry of the cyclotron was improved as follows:
The screen I ) that defines the first half turn orbit of beam attached on the ion source for lightparticles was removed.

The removal allowed the beam to have a large positive phase withrespect to the rf-field.

In other words. it became possible to accelerate the beam leaving theion source even after the dee voltage had attained a peak.

Besides, the width of z-slit waschanged to 80 mm from 60 mm to improve the extraction efficiency of the beam at the
deflection channel.

I t clips the height of beam at the first two or three turns within 15 mm.

To eliminate the possibility of break down, the insulators of the moving short werechanged to those of a new type and the unused pick-up arm for the dee voltage was also
removed.

With these improvements, the dee voltage above 85 kV was enabled to reach easily

in the oscillation above 8 MHz.

Table 1 shows the comparison of accelerating energies before

Table 1. Comparison of beam energies before and after improvem ent.

Particle

Before improvement
Energy (MeV)

After improvement
Energy (MeV)

p

4.5

17.5

f

4.5

17.5

f

d

9

25

Vd

9

30

Vd

3 He ++

13

48

Vd

13

50

f

4He++

16

50

Vd

16

60

Vd

The f and V d show the maximum energies of beam restricted by the upper frequency ordee voltage limits in the cyclotron, respectively.

6

and after the improvements were done in the cyclotron.
maximum energies for several kinds of ion beam.

We could get new records of the

The maximum energies of the both protonand 3 He+ + beams were only restricted by the limit of the highest frequency of the oscillation
after the improvements.

The extracted beam of alpha-particles of 60 MeV was obtained in thenominal dee voltage of 85 kV.

Though we did not try to accelerate the deuteron beam, it issure that the 30 MeV deuteron beam can be accelerated under the same operating conditions of
the 60 MeV alpha-beam.
Figure I shows the comparison of the operating dee voltages before and after the
improvements were done.

As seen in the figure , the dee voltage necessary for acceleration of

the ions to corresponding energies had decreased after the improvements by about 15 % ascompared with that before the improvements.
Heavy ions such as C4 + and N4 + will also be accelerated to extend the maximum energIes
in the near future.
100

•

•
I

•

•

~
Q)

0'>

~

0

50

>

•

Q)
Q)

•

With screenoWithout screen

0

10

20
EnergyFig. l.

4050olpha - beam

(MeV)

30
ot

60

70

Comparison of operating dee voltages before and after
improvement.

Reference

1)

Y. Miyazawa , K. Ogiwara, S. Fujita. M. Hemmi, K. Ikegami, T. Inoue, T . Kageyama,
S. Kohara , H. Nakajima, A. Shimamura, O. Terajima, and T . Tonuma : IPCR Cyclotron
Progr. Rep., 6 ,

7 (1972).

7

3-2.

Study of Composition of Residual Gas
in the Cyclotron Chamber

Y. Miyazawa, T. Kageyama, and T. Karasawa

The accelerating chamber of the cyclotron}) has a volume of 1 X 104 liter and the surface
area in vacuum of about 140 m 2 •The main oil diffusion pump is 32 in. in diam. andconnected in series with a 14 in. pump.

The pump fluid is the Lion S.

The analysis ofresidual gas in the accelerating chamber was made by using a quadrupole mass filter (M.F).
The measurements were done at times of 5, 24, 31, and 290 h after evacuation from theatmosphere.
A typical mass spectrum after the chamber was evacuated for 290 h is shown in Fig. 1.
The mass numbers 17 and 18 were assigned to OH and H 2 0, respectively.
the residual gas is mostly consisted of water vapor. 2)

It was shown that

The peaks of 28 and 32 were also

assigned, for the most part, to be N2 and O 2 , respectively.

The existence of N2 and O 2 gasesin the chamber can be regarded as due to the leakage of air in this vacuum system.

Firstly,

the leakage of the chamber is below 1 X 10-3 Torr liter/sec measured with the pressure rise
test and secondly, the leakage of about 2 x 10-3 Torr liter/sec occurred in the top flange ofthe 32 in. pump.

Many peaks of hydrocarbons (CnHm) are also seen in the spectrum.

The

groups of CH m , C2 H m , . . . . . . . , and C6 Hm are detected in the range of mass up to 85.
The yields of CHm and C2 Hm groups could not be determined accurately because those peaks
E
I

U

'"

-

7

p=6Xl 0- (Torr.) without a liq. N trap

N

I
I
I

2.5X 10- 7 Torr.

- --- p=5.3 X 10- 7 ( Torr.) with a liq. N trap

0.4 mA

Emission current

E
I

-,...

uI

E

U
I

E

J

"',...
"'",

I

E

U

o

...

E

=s

u

("")

'"
,...

10- 12

N

100

Mass

Fig. 1.

number

110

120

130

140

( M/ q)Residual gas composition in the cyclotron chamber after
evacuation for 290 h.

150

8

were masked by large yields of N+ and Nt peaks.

Besides, the peak 141 3 ) characterizing thepump fluid of Lion S was detected in the spectrum.

The peaks 2 and 3 are also detected withthe relatively large yield.

Most part of peak 3 seems to be the DR produced by the deuteriumgas (D 2 ) fed in the ion source.
The results of measurement in using a liquid nitrogen trap on the pump head is shown in
Fig. 1.

Unfortunately , a small leakage occurred at the bottom of the liquid nitrogen trap when

the liquid nitrogen was supplied into the trap.

The yields of masses 28 and 14 with theliquid nitrogen are, therefore, increased than those of the case without the liquid nitrogen. The
yields of other peaks were reduced to one third or less.
Figure 2 shows the change of the typical peaks with the evacuation time.

The yields ofthe peaks 18, 17, and 2 were almost inversely proportional to the evacuation time.

It is seenthat the peaks 28 and 32 do not decrease with time because of the air leakage in this system.
The yields of hydrocarbons had decreased slowly with time and, especially , the yields of thehydrocarbons with large mass number had hardly changed with time. The peaks measured
after 31 h became slightly larger than those after 24 h.

This is the effect due to theoutgassing in the operation of the cyclotron.
To increase the final vacuum , it is necessary to eliminate both the leakage air and water
vapor in this system.

Therefore, the use of cryogenic pumps into the chamber will be useful

to decrease the pump-down time.

Further investigation is in progress.
(Nude gauge 1

10- 9
c::

t

:::J

U

:::J

Q.
.....,
5 10- 10

10- 110- -- -- -- - ---0.'0- ___ - - - - - - - _____ D

69 ( C5 Hm1

0- -- ---------- 0- ___________ ___ "83 (C H l
6

12

10-

34 5

10

50

100

m

'500 1000

Time -of ev acuat ion (h 1

Fig. 2.

Change of the typical peaks with theevacuation time.

9

References

1)

T. Tonuma , Y. Miyazawa, K. Yoshida, K. Yada, T. Karasawa, and H. Kumagai
Soc. Japan , 11, 405 (1969).

2)

J. Blears:

J. Sci. Instr. , Suppl. No.1 , p.36 (1951).

3)

Y. Koyama and K. Maeda:

J. Vacuum Soc. Japan, .Li, 141 (1971).

J. Vacuum

10

3-3.

Improvement of the St ru cture of Septum Holder at the
Entra n ce of Beam Deflection Channel

K. Ogiwara and Y. Miyazawa

The structure of the septum holder at the entrance of beam deflection channel has been
improved with the objects of increasing the intensity of beam extractable, ensuring the stable
operation of the cyclotron, decreasing the necessity of frequent replacement of the septum
plate by lengthening the life of the plate against damage by the beam, and reduction ofradiation exposure for people doing replacement work by reducing the time they have to takeby simplifying the procedure.
The cyclotron has two dees.
east dee facing a deflector plate.

As shown in Fig. 1, the septum is attached to the side ofIons accelerated by the cyclotron are deflected by theradio-frequency field between this septum and the deflector and extracted to the outside of theaccelerating chamber.

The distance of the septum from the center of the cyclotron is 741 mm

at the entrance and 831 mm at the exit.
of angular width.

Total length is 1060 mm extending about 80 degrees

Tungsten plates 0.5 mm thick and 48 mm high are used as the septum.

Initially, the total length was subdivided into three parts; 160 mm at the entrance, 400 mm at
the middle part, and 500 mm at the exit part.

It was intended to differentiate the degree of-+-tt-- t - \ - - - + - - - - - - - : b > - + - - - - - - --East

Fig. l.

Dee

Wes t

Dee

Plan of the accelerating electrodes showing theposition of deflector-septum channel.

11~()()Iing~i

Fixing copper plate

pi pe

/

Gra phite electron/ stopper- U- sh ope sl ot

o deg.

Fig. 2.

--1

L...

Deflector
15 deg .

Copper cover

Riken Cyclotron Lob.
The Sept um (Beam splitter)
Scal e1/3

Details of the structure of septum at the entrance part.

damage of each part and to simplify the manufacture and replacement of the damaged part.
Fig. 2 shows the entrance region.

Later, it was found that a small step-like form is apt tooccur at the junction of the entrance and the middle part and is heated locally by beams
resulting in deformation and bulging of the plate.
part have been unified into one 560 mm unit.

Since then, the entrance and the middle

The septum plates are fixed tightly onto theseptum mount made of copper by screwing the fixing plates also made of copper.
electron stoppers made of graphite are provided at the entrance part.
described in detail later.

The stopper will be

Following is a brief description of the improvement.
(a) V-shape slot septump lote

Fig. 3.

,,,t,m PIQ~3(b)U-shape slot(c)

1m roved U-shape slot

The shape of septum plate at the septum
entrance portion.

Secondary12

The shape of slot cut at the beginning of the septum was changed from V-shaped to(1)

U-shaped last year.

Heating of the septum by beams was most intense at the cusp of V-slot,

bringing about bulging outward.

Therefore good extraction condition was impaired and lossof beam at this point increased.

The effect was cumulative and the life of the septum plate

was about one or two months for this V-cut.

By modifying the shape to U the life has been

improved by about two-fold, that is, four-month life has been achieved this year.

As shown

in Fig. 3 (c), several holes were further provided in this period to absorb the thermal stressaround the slot, which decreased the deformation of this part notably.
(2)

The secondary electron stopper was made of graphite.

plates were attached before the entrance part of the septum.

As seen in Fig. 2, graphite

Formerly, the septum mounts

were extended to this region so as to be able to change the position of the initial part of the
septum.

Thermal electrons generated at the septum slot are accelerated by the combined effectof main magnetic and electric fields between the septum and the deflector plates and can reachthe extended part, resulting in the multiplication of electrons by secondary emission.

Thequantity can be very large when the beam lost at the slot exceeds some threshold value, andcauses heating and melting of the extended part of the septum mount under a long time
operation.

Violent flashover between the earth plate and this heated part is often generated.

It is impossible to continue operation of the cyclotron under such condition and the power

supply of the oscillator must be switched off to cool down the heated part.
be resumed carefully enough with a limited beam intensity.

&----61000~

Melted copper drops on the earth

Radiation dose for septum ch anging in year

~
~

10~

E

4

'"
0

I

)\

~

I

E
I...

E

E

t::

<l)

c
0
+-'
0

"0
0

c::

c

<l)

\
\

E

\

:::>

\

c

-B

~

+'
\
I

0-

500~

co

I

co

~

u

\
\
\

00
"0

<l)

\

v>

a.

\

Q)

\

(/)

\
\

5r-

!

\
\
\

.§a.

\
\

<l)

\
\

(/)

\~
\
I

)------- .....

O~--~O~--~~--~~--~~--~----~--1969

1970

-

1971

1972

1973

Ye ar

The broken line shows the amoun t ofradiation exposure for persons during
the septum replacement in a year.
Fig. 4.

Operation must

Statistics of septum replacement.

13plate and the droplets thus formed easily induce a new discharge, which forces the operator
to limit the beam intensity within a low level until the dusts are removed.

The replacementof this damaged part often met difficulty because of the melting of heads of screws which fix
the part to the dee.

The work requires about one hour for two men and radiation exposureof each one amounts to as high as 100 mrem at times.

This trouble has been removed

completely by replacing the septum mount with graphite blocks.
(3)Now, the parts to be replaced are standardized and even an unskilled person can do

the job within 20 min.

The replacement work is to be done depending on the working

conditions of the cyclotron such as the kind of particles, and the energy and intensity required.
At present, three times a year seem sufficient for stable operation of cyclotron.
the statistics of replacement.

Fig. 4 shows

14

3-4.

Improvement of Standard Voltage Source
for the Current Stabilizer of Magnet

H. Nakajima

The beam handling system of the cyclotron is operating every day and the magnets in thissystem are excited by stabilized power supplies.

The stabilizers have a power control circuitcomposed of some transistors and silicon controlled rectifiers (S.C.R.) as well as a standard
voltage referring source to detect deviation of the output current.
We have hitherto used a mercury battery as the standard voltage source.

But this battery

has not a life long enough to be used without frequent care in daily operation.

Therefore, we

haVe adopted a solid state reference voltage generator instead of the mercury battery.
circuit is composed of some temperature-compensated zener diodes and transistors.

The

We have

replaced the battery with the improved voltage source except for a stabilizer for the SW-II
magnet, by which a long life for practical application and excellent performance have beenachieved.

Particulary for the reaction particle analyzer which requires high stability, we havechosen a temperature compensated zener diode IN946.

In addition, the diode current wasstabilized by a circuit to secure the superior quality of this diode.

By this means, we haverealized a stability of the output voltage with an accuracy better than 1 X 10- 5 at 5.2 V for

24 h.
... - -- -- ------ -,-- - - -- - -- ------ ------------.'

8 (OV)
0.5p 16:Vt,-----1'<""--T---~~r___------r___-__,___¢~.....--1--¥tv---+--"M "12ktrimer

100-1

6.3V~
L 5.5V
OV
i
i

t (I)

* MFC

Vz W T,I

E : - 15V

0....0=-:'--------'

pu:(620-20) :,-----"--<;>---'--'-+----+--+.--------+-K1------4 200( 8)
:

0.1 A

,

ou

' A (55 V):

L__ _______ ~~ ~ _____ _____________ ____ ___ _1

11 0V
100V r O - - - - , . . .

;J; 0.02tL 50Y

f' OVI
8",tp,t 121( 5.5V)A( 2)

AC 100V
50Hz'------; L C 0
2 -15- 25N

S. C. Inc.

Fig. 1.

C~

o

0

E f--

Schematic circuit of the standard voltage source for reaction particle analyzer.

15

3-5.

Trial- Making of a Current Stabilizer foraQuadrupole Magnet

H. Nakajima and M. Hemmi

Many quadrupole magnets are installed and in operation at the beam handling system of
the cyclotron.

These Q-magnets are classified into two groups with respect to dimensions of

their aperture.

The resistance of coil is about 6.5 n and the maximum excitation current is

20 A.
I)

We have trially made and tested a current stabilizer for the Q-magnet.
Outline of circuit design

We choose 7 n as the load resistance for the stabilizer in view of the average resistance of
the Q-magnet and 20 A as the largest output current.
140 V.

Then the maximum output voltage is

We take 0.01 % as an acceptable deviation of output current for 10 % line voltage

variation, and 0.1 % for its stability for 12 h.

We designed a feed-back loop suitable for slow

response of load, and also cared for the problems of trouble shooting and maintenance.
Integrated circuits and some hybrid circuits are adopted to decrease the quantity of parts.
The circuit is composed of two feed-back loops, one is a controller of output current andthe other is collector voltage compensator for a series transistor.

A standard voltage generator

and a power source are combined with the main circuit, and a power limiter protects thetransistor from over-dissipation. The block diagram of the current stabilizer is shown in Fig. 1.

Input

Circuitbreaker

Condit ion of 0 eration[Magnet COOling
Dissipation of series transistor
Rect if iers
Tr iacand filterPowertransformer
Pha secontrollerof triac

Seri es
tra ns istor

Stabilized
outputResistancefor
Current
detector
Driverofserre'Stransi sterFeed -backloop

Different ia \amplifierPowersupp\ ies
Potentiometer

Referring vo ltage generator

Fig. 1.

Block diagram of current stabilizer.

16

2)

ResultStability of output current was measured at several different currents each for 24 h.
Damping and rising characteristics were not measured.
is shown in Fig. 2.

An example of stability of output current

The results of running test were generally satisfactory , but modification of

the circuit and change of value of a resistor for current detection were found to decreaseripple and noise further.

Simplification of the circuit seems possible and is in progress.

663mV

"'=.;
0......
:::J

o

c

o

662 mV><l.l

Cl

Outputocur re nt

7A

15

10

5

Start
Ti me

Fig. 2.

Fig. 3.

(h)Stability of output current at 7 A.

Photograph of the stabilizer.

17

4. NUCLEAR PHYSICS
Scattering and Reactions

4-1.DWBA

Calculations of Inelastic Scatterings of 12C

and

14N

I. Kohno

Experimental results of elastic and inelastic scatterings of 12C and 14N and an opticalmodel analysis of the elastic scatterings were reported previously. 1)
The experimental differential cross sections of the inelastic scatterings were analyzed by
the DWBA method assuming collective excitation.

The collective excitation of colliding

fragments are described in terms of a non-spherical optical potential where the departure fromsphericity is contained in the radius parameter RCD.'):

V(r, n')=-V o[l +exp{(r - R(n' )) /a}] - l(1)

R (.0') =RC~) [ 1 +Y, ~l ) Y (n CI),)] + RC
; t 1 + Y, ' a (Z)y (n CZ),)]kg kq kq
kg kq kq
=R2+R(~)+oRc l+oR(2) Ro+oR(2)

Here a kq are the usual collective coordinates, D.' refer to the body-fixed axes, and suffixes ( 1)and (2) show pr~jectile and target nuclei respectively.
A Taylor expansion of the potential about R=Ro yields the series

(-l)n
n dn
V=V(r-Ro)+L:- (oR) - n V(r-Ro)(3)n> O nldr
In the case of single excitation of target or projectile 0 R = 0 R( 1 ) Or 0 R(2), if the otherfragments are supposed to be spherical, and the DWBA analysis can be treated equally as in the
inelastic scatterings of p, d, and a particles.
When the excitation is a single excitation with transition of angular momentum L between
the initial spin state J A and the final spin state J B' the differential cross section can be
represented by the INS DWBA I code*using the reduced cross section aLCO) as follows:d a _ 2JB+ 1 (2L+ 1) -1 f1LRif )2V6 () (m b )
-- X
3 X
2
VL f)
dn
2JA+ 1
5.093X10
a
Sr.

(4)

Here ~L is the deformation parameter, V 0 and a are the real part of strength anddiffusivity parameters of the optical potential, respectively, and Ro (p ) is Ro(l ) or Ro (2) following
the single excitation of projectile or target nucleus.

In the calculation of DWBA, the effectof Coulomb potential in the outer region of nucleus was considered besides the nuclear
excitation, because the Coulomb excitation was expected not to be neglected in heavy ion
scattering. The calculations were done by the code which was modified by Yamaji so as to beable to treat higher partial wave Cf. max=200) than in the INS DWBA I code.

*

T. Udagawa, H. Yoshida, K. Kubo, and G. Yamaura: INS. DWBA I code.

18
10

,

10 ' F"c+ N - Vo = 55MeV,f=84MeV --- Vo = 22 MeV
14

t--i

'-1-- I--"c +"N

Vo: deep2+ I 4.43 MeV I ---Vo : shallow

3

10

-

10

1---

,

\ /'

I

I

\ /; \ f\10,

2+ 14.43MeV)

~

10

==

-\7!

.

, '\ °\\\)

10 - - -

.".

\10

P \
\ r,'

10 I--bf--

rb

1\-.0 0\10

T 19.6 MeV)
10

°, ,

\

.

E .. 65 MeV

I

~

,

r-

\I!

I

\,

."

V.

/:ii\ .

',,,

~,

~

"

10

#

l· I ~'.

f=88MeV

I

(

10

30

20

40

50

o

60

10

20

Fig. 1.

50

40

30

9 c.m .

••

\ I

~

60

9 c.m•DWBA predictions for the excitations of

DWBA predictions for the excitation ofFig. 2.

2+ (4.43 MeV) and 3-(9.6 MeV) states

2+ (4.43 MeV) state of 12 C by 14 N

of 12 C by 14 N particles at the energy ofparticles at the energies of 65 and 88

84 MeV compared with the data. Solid

MeV compared with the data. Solidlines show DWBA predictions using thelines show DWBA predictions using theoptical experimental parameters with

optical experimental parameters witha deep real potential and dashed curvea deep real potential and dashed curve

the shallow potential.

the shallow potential.

..

c ~;~M'V~V'1\\ ( ·"c + " cInelastic
Elastic scattering

E,

10"

·V

~

Optical model fit

~

•

..

~

Q = -9.63 MeV IL=3)

V
blO

...
•

..

-o~

E

\

Q=-8.86MeV 11,=2 L,=2)

°

10

~

10'

E= 70 MeV
DWBA I

scattering

Inelastic

L =2

DWBAI

o

Fig. 3.

a)

10

20

30

40

50

60

Optical model fit to the elastic

20

Fig. 3.

b)

30

40

50

DWBA predictions for the ex-

scattering of 70 MeV 12 C form 12 C andcitation of 3-(9.6 MeV) state of 12C

DWBA prediction of 2+ (4.43 Me V)

by 12 C and for the mutual excitation

state compared with the experimentalof 12 C particles to their 4.43 Me V 2+

data. Parameters of the opticalstates compared with the experimental

potential are given in Table I in Ref. 1)

data.

19

[ma,

Rmax

120
50
38

25
15
15

,

'\
I
I
I

I

Y' ~

I
\

I'

\'

I I:
II'

I(

o

10

20

40

30

50

8c.m

Fig. 4.

Calculated angular distribution of inelastic scattering of
12C projectile to 2+ state (1.78 MeV) on 28Si varying
the values of Rmax and.e max'

103c------ -----------------------__~

10

~.
b

1

_

o
Fig. 5.

10

a)

20

30
8 c. m40

DWBA predictions for the

"~

c-

o

50

"s;

~..

10

1

3- , 688 MeV on

10

20

30

40

50

8 c.m.

Fig. 5,b)

DWBA prediction for theexcitations of 1.78 MeV 2+ state of

excitation of 6.88 MeV 3-state of 28 Si

28 Si and 4.43 MeV 2+ state of 12 C

by 12 C particles at the energy of 70

in collision between 12 C projectile and

MeV compared with the data.

28 Si target at the energy of 70 MeV
compared with the data.

20

The differential cross sections obtained for 12C + 14N and 12C + 12C are shown in Figs.
1",3 in comparison with the experimental data.

As the effect of Coulomb excitation waslarge in 28Si + 12C at 70 MeV, partial waves with large f values and large value of Rmax
which limits the region of integration must be considered.

In Fig. 4 the calculated angular

distributions of inelastic scattering to 2+ state (1.78 MeV) of 28Si are represented for various
values of Rmax and £max'

From these calculations it was found that f max value above 120

and Rmax value above 25 fm which is nearly 4 times R o , were necessary to include completely
the effect of Coulomb excitation. In 12C + 14N, £max=45 and R max =2R o were satisfactoryfor making DWBA calculation.

The calculated differential cross sections of inelastic scatteringsof 12C to 2 + state (1.78 MeV) of 28Si, 2 + state (4.43 MeV) of 12C, and 3- state (6.88 MeV)of 28Si at 28Si + 12C are shown in Fig. 5.
The differential cross sections of mutual excitation (4.4 MeV state of projectile andtarget 12C) at 12C + 12C were calculated using the Eqn. (5) following Bassel et a1. 3 ) :X:L < PIP200ILO> 2 :L1_d_BMI~
L

M

dR o

(5)

L

Here J1 is the reduced mass of the system, Ka and Kb the wave numbers of incident andoutgoing channels, and £ I and C2 multipolarities of final states of nuclei I and 2.
is a differential of Br: which is a transition amplitude of single excitation.

dBr / dR o

In this case, nuclei

1 and 2 were both 12C and fl=£2 =2, and the values of B~ were calculated by DWBA for
single excitation of 2 + state of 12C at 12C + 12C.

The results of calculation are shown in

Fig. 3 (b) and the feature of angular distribution seems to become less diffraction-likecompared with that of single excitation, and to reproduce the experimental results.
In Table I the deformation parameters {3Q and the deformation length {3f R for 2 + and3 - levels of both 12C and 28Si obtained from DWBA analyses of the inelastic scatterings are
summerized.

The calculated values of (32 for 2 + level of 12C are scattered between 0.4 and

0.9, but these values are close to ones obtained from other heavy ion inelastic scatterings
Bassel et a1. 3 ) obtained the values of 0.56 to 0.9 from DWBA analyses of 12C + 12C and
12C + 160, and Oertzen et a1. 4) obtained 0.3 ± 0.1 from DWBA analyses of 12C + 14N. The
agreement of (3f for 2 + and 3 - levels of 28Si with the values s ) obtained from the inelastic
scatterings of p, n and a particles are not necessarily good.

21

Table l.

The deformation lengths ~eR and the deformation parameters ~e obtained from
DWBA prediction.

Transition

12C + 12C

0--+ 2, 0 --+ 0

0.50

l.35

70.0

0--+ 2, 0 --+ 2

0.716

l.94

70.0

0--+ 2

0.492

l.37

88.0

0--+ 2

0.466

l.39

88.0

0--+ 2

0.405

l.13

84.0

0--+ 2

0.381

l.14

84.0

0--+ 2

0.450

l.26

65.0

0--+ 2

0.607

l.82

65.0

0--+ 0 , 0--+ 2

0.932

2.20

70.0

12C + 12Ca)

12C + 14N
12C + 14N*

12C + 14N
12C + 14N:l<

12C + 14N
12C + 14N*

28Si + 12C-~eR(fm)Reaction

-

-

-- -

28Si + 12C

-

-

~e

E(MeV)------- - --- ----- ----- -- ----- ------

0--+ 2 , 0 --+ 0b)-- ----- -- -

0.664

2.07

70.0

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

12C + 12C

0--+ 3 , 0--+ 0

0.534

1.45

70.0

12C + 14N

0--+ 3, 0--+ 0

0.35

0.97

84.0

0--+ 3 , 0--+ O .

0.39

l.17

84.0

o --+ 3, 0 --+ 0

0.705

2.20

70.0

12C + 14N*

* shallow potentiala) Mutual excitationb) Single excitation of l. 78 MeV 2+ on 28Si

References

1)

I. Kohno, S. Nakajima, T. Tonuma, and M. Odera : IPCR Cyclotron Progr.

Rep., ~ 15 (1969).
2)

R. H. Bassel, G. R. Satchler, and R. M. Drisko : Nucl. Phys., 89,419 (1966).

3)

W. V. Oertzen, M. Liu, C. Caverzasio, 1. C. lacmart, F. Pougheon, M. Riou, 1. C. Royntette, andC. Stephan: ibid., A143, 34 (197).

4)

H. Sherif and 1. S. Blair: ibid., A140, 33 (1970);
1. Kokame, K. Fukunaga, and H. Nakamura: Phys. Lett., 20, 672 (1963) ;R. H. Stelson , R. L. Robinson, H. 1. Kim, 1. Rapaport, and G. R. Satchler :Nucl. Phys., 68, 97 (1965).

22

4-2.

The Finite Range DWBA Analyses of the Reactions
52 Cr (lAN, l3C) 53 Mn and 52 Cr (12C, l1 B)53 Mn

S. Nakajima

The finite range DWBA analyses are being performed for the single-proton transfer
reactions induced by 90 and 70 MeV 14N ions and 60 MeV 12C ions on a 52Cr target.
on details of the experiments is under preparation.

A report

The calculations utilize the program

INS-DWBA-4 1 ) written by H. Yoshida and adapted by S. Yamaji to the F ACOM 230-60
computer of the IPCR.

This code treats exactly the six-dimensional integral and includes

accurately the recoil effect.
The calculated cross sections are shown in Figs. I and 2 together with experimental values
obtained in this laboratory.

The optical potential parameters used for calculation were ofWoods-Saxon type and are shown in Table 1. The same parameters were used for the exit

52Crl'2C ,"B J 53 Mn

52Cr('4N , I3C )53Mn

E,zc= 60MeV

E'4N= 70MeV'00.5

Ex = 0 MeVf.

5(17/2 slate)

Ex = 0 MeV
I f7/Z st ate)

0 .1

-

I

,

0.5

.

E
-

-I
I-

Ex = 2.4 MeV( P3/2 state)

0.5

1

.Q

J

05

E

~

E, "2 .4 M,V~ P 3/2 st ate)

'b

"b

~

Ex= 3.7MeV1( f 5/ 2 stale J

0 .5
I

1
0.5

I

I

J

0 .1

0.1

10

b

'b

!

30

20

20

40

30

40

50

8,m . 1de g.)

Fig. 1.

Angular distribu tions of
52 Cr

e4 N, 3C) 53 Mn at
1

Fig. 2.

Angular distributions of
52Cr(12C , 11B)53Mn at

Eeab = 70 MeV for transitions to

EQab = 60 MeV for transitions to

the ground (7/2-), 2.4 MeV (3/2-)

the ground, 2.4 MeV and 3.7 MeV

and 3.7 MeV (5/2-) excited states.

excited states. The solid curves are

The solid curves are those of thethose of the finite range DWBA

finite range DWBA calculations
normalized arbitrarily to fit to
the data.

calculations normalized arbitrarily
to fit to the data.

23

channel.

Bound state wave functions were solved in a Woods-Saxon potential with a = 0.67 fm
and r 0 = 1.27 fm. The calculations of Cohen and Kurath 2) were used for the spectroscopic
factor of an incident particle S(a--+b+x).
shown in Table 2.

The values of (2.e+l)W 2 (Raja£t>ib;s£)S(a--+b+x) are

The calculated angular distributions and absolute cross sections do not

Table l. Optical potential parameters for the elastic scattering of 14N on 52Cr at 70 MeV
and 12C on 52Cr at 60 MeV.

V(MeV)

W(MeV)r o(fm)

60.0

18.25

1.04

0.739

1.04

0.516

60.6

11.1

l.03

0.700

l.16

0.516

Table 2. Spectroscopic amplitude (2e + I) W2

ce aja£bjb;s£) S (a--+ b+x).

Spectroscopic

factor of an incident particle S (a--+ b+x) is taken from the calculation of Cohen
and Kurath.

That of a residual nucleus S (B--+ A+x) is not multiplied in this table.

Transition

e= 4

e= 3

£=2

p.l --+ fl2
20.00050.00070.0007f~0.00130.000560.00015--+2--+ p.l2pl--+ fl220.00080.258--+ f~
2--+ p.l20'. 0008

0.0003

0.191
0.287

0.057

e= 1

.e = 00.59

0.24

e2C --+ 11 B+P)

Transition

e= 4

€ = 3

e=2

p.l --+ fl
2
2

0.381

0.534

0.509

--+ f~
2

0.916

0.396

0.113

--+ pl
2

e= 0

0.086
0.152

(2£ + 1) W2 (£aja£bjb; sf) S

e= 1

0.59

24

necessarily agree with the data.

But, slightly changing the bound state or the optical potential

parameters in the exit channel, it may be possible to reproduce the data.
The recoil effect is investigated and the results are shown in Figs. 3 and 4.

In these figures ,the /!. = I and the .e = 3 transfers have an unnatural parity which is not allowed in a no-recoil
DWBA theory.

As the incident energy increases, the f! = I transfer becomes larger inmagnitude , that is, the recoil effect becomes more significant.

Moreover, the angular

distributions with even parity are in phase to each other, but are out of phase with opposite
parity.

When an unnatural parity transfer is comparable in magnitude with a natural parity

transfer, the sum of them will show a damping of diffraction oscillation as pointed out byDodd and Greider. 3) In our case, however, the recoil effect does not necessarily play animportant role because of the smallness of their spectroscopic amplitude (2£+ 1) W2 (eaja ebjb ; sf!)
S (a--+ b+x) S (A--+ B+x) or the calculated DWBA amplitude.

52Cr (' 4N , '3C )53 Mn
E,=2AMeV-- - 1=1-[=2

52Cr (12 C • "8 I 53Mn
E"c =60 MeV
g. s.

10 '

-

<l.>

"" '"",a~ 10 2"-'~"".. . . .- / "'"[=2',,-------',,-_::: --:::-:.:--'''-.,''-..
,

".g
-

/--.."

>><~,

10° "

---.....-.~."'"

[ =4

\
\

)0'

/

1/

70MeV

\
\

L=3

10'
50M eV) 0°'':::0 '---'----'-----------::":20: ----8 cm

Fig. 3.

------:3::'-:::0----4L-----'--------'------.l0'0(deg. )

Comparison of the magnitude and its

20

30

40

ecm . I deg . 1

Fig. 4.

Contribution of the angularenergy dependence between the £ = 2

momentum transfers £ = 2, 3

and the £ = 1 transfers in the reaction

and 4 to the cross section in the

52 Cre 4

N, 13 C) 53Mn leading to the 2.4

Me V excited state in 53 Mn.

reaction 52Cre2C, lIB) 53Mn
leading to the ground state inSpectroscopic amplitudes are neglected

53 Mn. The sum of these curvesin the calculation. These weighting

gives the final cross sections.

factors are 5 and 1 for £ = 2 and £ = I ,respectively.

25

The dependence of the angular distribution on the optical parameters is seen in Fig. 5.
Change of the optical parameter set influences the absolute magnitude and the shape of thecurve.

Several parameter-sets can reproduce the elastic scattering, but few of them is able tofit to transfer reactions.
Because of strong absorption, the distorted waves are only sensitive to the nuclear surface
and the interior of the nucleus does not contribute to the transition amplitude.

Then, it ispossible to cut off a lower radius or lower partial waves in the DWBA calculation.

Fig. 6

illustrates a radial cut-off effect in the calculation using the imaginary part of the opticalpotential W = 11 MeV.

Difference is not distinct in two curves of the ' angular distribution.
It is seen that a suitable

The effect of the cut-off of lower partial waves is illustrated in Fig. 7.

cut-off of them scarcely affects the absolute magnitude and the form of the angular distribution.
The time necessary for calculation can be reduced with such a cut-off.
Further investigation is in progress for extracting the spectroscopic factors of the residual
nucleus and the dependence of the reaction amplitude on the kinematic conditions.

52Cr(14\) , 13C) 53 fVin

52Cr('2C ,"BI"Mn

E 14N = 90 MeV

E",= 60 MeV

E, = ?.4MeV

l= 2
/=0
a

~ 10- 1/'--1
/ / - .... "

.. /1

-

( cu t off = 7fm---( cui off

[= I

10- 2

10

=3fm

V(MeVI W(MeVI (o(fml oo(f ml r1 ifm I ol(fm I

60.0 18.25---6061 1.1

20

1 04 0 .739 1.04 0.516
1.100.6371.180.5 16

30

40

10

20

Be m ( deg. 1

Fig. 5.

The dependence of the angular30

40

8 om ( deg, )Fig. 6.

The dependence of the angular

distribution on the optical parameterin the reaction 52Cr(l2C, IlB) 53 Mn

distribution

leading to the 2.4 MeV excited state

52 Cr (l4 N, 1 3 C) 53 Mn leading toin 53 Mn at E 1ab = 60 MeV.

the ground state in 53Mn at E lab

on the lower radial

cut-off in the reaction= 90 MeV.

26

52Cr( l~N • 13C )53 Mn

ElOb =90MeV
Ex = 0.0• 30 :::: L ~ 60

10

10-

1

10

x

0 :::: L ~ 60l>

0 :0:: L ~ 6 5

20

30

40

S c. rn.

Fig. 7.

The influence of cu t-off of lower
partial waves in the calculation of thereaction S 2 Cr

e N,
4

13

C) S 3 Mn leading to

the ground state in S3 Mn at Elab = 90
MeV.

References

1)

H. Yoshida : Reference Manual for INS-DWBA-4 , Institute of Nuclear Study, Universityof Tokyo (1972).

2)

S. Cohen and D. Kurath : Nucl. Phys., AlOl, 1 (1967).

3)

L. R. Dodd and K. R. Greider : Phys. Rev., 180, 1187 (1969).

27

4-3.

Angular Distributions of Transfer Reactions

Inducedby Heavy Ions

M. Yoshie, K. Katori, 1. Kohno, S. Nakajima,
T. Motobayashi, T. Mikumo, and H. Kamitsubo

Transfer reactions studied using the beams of 14N and 12C on the (fp) shelP) and heavy
nuclei 2) showed various patterns in their angular distribution. We note here qualitative featuresof these patterns and intend to interpret these angular distributions theoretically based on themodel of peripheral collisions developed by Strutinsky.3 ),4)
We present here two cases; (1) 52Cr + 14N at 90 and 70 MeV and (2) 208Pb + 14N at 90
MeV. In both cases, for single nucleon transfer reactions the yield concentrated at states near
the ground state, and for multi-nucleon stripping reactions the energy spectra showed broad
bumps, whose shapes varied with the bombarding energies and the number of transferred
nucleons.
For the stripping reactions induced by 90 MeV 14N ions on 52Cr, the angular distributionsof products integrated over whole energy spectra peak forward in the angular range from
10 4

104

10 5

52C r(1 4N,1 2C) 54Mn

52Cr( 14N, 13C ) 53Mn
70 MeV3

10 -90 MeV

90 MeV

7 0 MeV

10 3~~~
3.7 If5/2

lOS

10 4

4
10

17.3~20 . 7

18.0~21.6\~2

10 3 1"<f)

'-

.D

E

10 2 -c::.:'b

2.5 2P~~

11,\
2:2

"'-

10

3

'Pi
10 2

13.8~17.3

104

1.3

~.

"-

~

E

£

4

~ \0

-

"'b

~

'b

-

2

Q

~~
0.O Q\f7/2

10°

20°

30°
8 c.m.

Fig. 1.

3

~

2

40°

10 2

102

10°

20°

30°
8 c. m.

~
40°

4

"l",
"'",-

.~

0

o

~
~

'\

~

\
10

\0 - 3.45 ~6 .9

10 3

c

10

6.9- -9 . .
.~lOA 9-0-...¢ ¢.~'b

10 3 1-""'"\ 0.4~ \ 3.8

'b

b

~

10 4

\00

10

30°

~~_'
" u 08
¢

¢

' .,

\

, ,~\

¢

\

Energy interval of
exc itation

20°

3

'"

"" "'"" I 0.8~ 14.4

10 2

40°

8c. m

10°

'\

.\

3.6~ 7.~~· :
20°

30°

40°

8 c. m.

Angular distributions of 13 C and 12 C from 52 Cr + 14 N at 90 and 70 MeV. For 13 C,
those of some selective peaks are shown, and for 12 C, those of integrated crosssections over energy intervals of 3.5 MeV are shown. The solid curves are obtainedby calculation with the Strutinsky model fitting to the data.

28°cm=16° to 0cm=45.o Fig. I shows some angular distributions of l3C and 12C emerging from
52Cr + 14N at 90 and 70 MeV.

In the case of 13C, angular distributions of a few selective

peaks corresponding to energy levels of 53Mn are shown.

Angular distributions of 12C yields

integrated over about 3 MeV energy intervals are shown in Fig. 1.

In each case, the shapes ofangular distributions do not depend strongly on excitation energies or transferred angularmomenta.
At 70 MeV, the cross section maxima are observed at 0cm=24° for 13C, and a bumpappeared at 0cm=24°

for 12C.

For multi-nucleon stripping reactions ~~ = e - K8 holds approximately.

The slopediminishes as the mass of the observed particles becomes smaller.
In Fig. 2 are also shown the angular distributions of 13C, 12C, 12B, and lOB from 208Pb + 14N
reactions at 90 MeV. They all have maxima at 0cm=70'"'-'80'o.

, / t~

Tota l

t~ ~

50

60

70

80

:°.36

6-82.0( 14N lOB)

90

0

100

6 c•m.

Fig. 2.

Angular distributions of 13 C, 12 C, 12 B, andlOB

from 208 Pb + 14 N at 90 MeV. The upper

two data are those of specific levels, andothers are those of integrated cross sections
over energy intervals indicated on the figure.
The solid curves are obtained by calculation
with the Strutinsky model fitting to the data.

29

Stru tinsky gave (1n expression for the differential cross section as

~ ','

do

2

dO

7[f 0 sint9

exp (

'>

)

where ~ ::: (~q + ~;)1 /2 is the total angular dispersion deten:nined by the quantal dispersion
coefficient ~q ::: V2/b. e and by the dynamic quantity ~r ::: V2Kb./!.
Neglecting the second term in the parentheses which oscillates rapidly with angle,
parameters ~ and e were found by fitting the data to the formula.
rather arbitrarily.

Normalization was madeResults of the fitting are also shown in Figs. I and 2 and parameters arepresented in Figs. 3 and 4.
3 0 , - - - - - - - - - - - - - - - - - , 12C Excitation
Intervals
90 MeVI 3.6 ~ '.2 MeV
I

II

2 7. 2-1 0 8
3 10.8-14.4
4 14.4-18.0
18.0~2 1.6

5

70MeV
I
3.45 - 6.9
2 6.9-10 .4
3 lOA - 13.8

10

4 13.8- 17.3

,5 17.3 - 20.7
13C

levelsI

0 .0 If7/2

Ex

tI

0.3

I

2

1.3 2p3/2

3

2.4 2P3/z
3.7 If 5/2

4

IJ..f

0.2 -

I

Fig. 3.

2

3 4

5

~

I it

I

2 3 4

• 70 MeV
90 MeV

Strutinsky's parameters obtained from theexperimental differential cross sections of 13 C
and 12 C projectiles from the reaction 52 Cr +14

N at energies of 90 and 70 MeV (see Fig.

(a) and (b)). The numbers on the abscissa
indicate the excitation intervals of summationfor 1 2 C, and the levels of 53 Mn for 13 C as
defined in the figure.

30

90,-----------------------------------------~

I I

80

f I 1

70
0.4
W'

I!

0 .3

I
If!

f
~ ~!

0.2

0.9 / /

I

!

!

!

I f

3.1

2
\ 2C

3

7

Exci tation intervals

1
2
3
4

5

6
7

8

Fig. 4.

456

3 ~ 6 MeV
6~ 9
9 ~ 1212 ~ 1515 ~ 18
18 - 2 1
21 ~ 24
24'"'-' 27

82345678
13C

Excitation intervals

1

4 ~ 7 MeV

2
3

7 - 10
10- 1313 - 164
5
6
7

16 - 19
19 - 2222 ~ 25

Strutinsky's parameters obtained from the experimental
differential cross sections of 13 C, 12 C, 12 B, and 10 B
projectiles from the reaction 208 Pb + 14 N at 90 MeV (seeFig. 2). The numbers on the abscissa indicate the excitationintervals of summation. The parameters of two specificlevels are also given.

We obtained some characteristic features on the parameters:

First, for 52Cr + 14N(1)

B decreases and ~ remains constant as born barding energy increases(2)

B remains constant and ~ increases as excitation energy increases ;(3)

B decreases and ~ increases as stripped mass increases.

Secondly for 208Pb + 14N , ~ is slightly larger in the case of 12C than in the case of l3C.
For 13C, parameters which fit the data of specific levels and of unresolved part in the energy
spectra are given in Fig. 4.

The parameters vary continuously.
The DWBA theory can accoun t for the C4N , l3C) data for specific levels of both 52Cr + 14N

and 208Pb + 14N qualitatively.
Strutinsky's phenomenologically introduced parameters can be interpreted in connection
with the DWBA theory.

When the number of transferred nucleons increases, and when the31born barding energy increases, there is systematic deviation In the values of parameter fromthose obtained for single nucleon transfer.
This suggests the existence of a new mechanism in heavy ion reactions , which becomes
more important at high energies.

References

1)

I. Kohno, S. Nakajima, I. Yamane·, M. Yoshie, M. Odera, and H. Kamitsubo:

Cyclotron Prog. Rep., ~ 23 (1972);

S. Nakajima, 1. Kohno, 1. Yamane, M. Yoshie,

H. Kamitsubo, M. Odera, and T. Mikumo:
2)

ibid., p. 27 (1972).

T. Motobayashi, I. Kohno, S. Nakajima, M. Yoshie, K. Katori, T. Mikumo, and
H. Kamitsubo:

IPCR

ibid., 7,32 (1973).

3)

V. M. Strutinsky

JETP, 12, 1401 (1964).

4)

V. M. Strutinsky

Phys. Lett., 44B, 245 (1973).

32

4-4.

A Study of Transfer Reactions Induced by
14 Nand 12C on 208 pb and 209 Bi
T. Motobayashi, I. Kohno , S. Nakajima, M. Yoshie,
K. Katori , T. Mikumo , and H. Kamitsubo

A study of the transfer reactions induced by 14N and 12C on (fp) shell nuclei at energies 2
or 3 times higher than the Coulomb barrier has been reported previously. 1 )In these experiments,

the energy spectra of the emitted particles showed a large "bump" at multi nucleon transfer
and selective peaks which correspond to several levels of the residual nuclei only at one nucleon
transfer reaction, and the angular distributions showed forward peaks. These features are very
different from experimental results of other transfer reactions on (fp) shell nuclei at the energy
near the Coulomb barrier. 2 ), 3 )In these cases, "bumps" were very small or not found , and theangular distributions showed a simple "bell shape" which had a broad peak at the grazing angle.

In order to study what features are found in the transfer reactions on the heavy targets at the

91 MeV

209Bi +'4N10

8 l0b = 70°

\
\ 11B

\

\

"~B\

\ lOBe

\

\. 9B

\

\

e

\

\

"oB\

0. 1
I

I

I

I

0

-5

- 10

-15

I

I

-20

-25

208Pb + '4N

90 MeV< 2C~', 12C

,

10

5

\

~

\

.Q

5-

• 14 C~BlOb =70°

\

~ liB

\

"b

\,'2 B

""

\

\

\

\

,

~ lOBe

\

\

\

'~~O

\

\

,\°8
\

0.1

- 10

- 20

9

Be

\

\
- 25

Q (MeV)

Fig. 1.

Differential cross sections at tJ max (700 in this case)plotted v.s. ground state Q values of the corresponding
reactions.

33

(0 )

40

208Pb(14N ,DC )209Bi

90 MeV
65°
(J)

+-'

c:

'"

o

U

20

0

!

!

!

30

20
Ex (MeV)10(b)

208Pb( 14 N, 12C) 210Bi

40

90 MeV
70°

(J)

+-'

c:

'"0

u

20

o~------~~L-~~~--------------------------~~~-----(c I

209Si ( 12C,lOSe) 211At

78 MeV

20

70°

OL---------~~~wwL+-L----_.------~,_--------------

15

10

Ex

Fig. 2.

5
(MeV)

o

(a) and (b) 13 C and 12 C spectra due to 90 MeV 14 N reactions on
2osPb, (c) lOBe spectrum due to 78 MeV 12C reaction on 209Bi.
For 13 C spectrum, the known proton single-particle states are labeledaccording to their shell model orbits.

34

energy above the Coulomb barrier, we have done experiments of the transfer reactions inducedee

by 14N and 12C on 208Pb and 209Bi at energies of 90 MeV 4 N) and 78 MeV 2 C). Experimental
procedure has been described in a previous report. 4) The thickness of targets was about
400Jlg/ cm 2 •Experimental results(1)

The differential cross sections (da/ dU)O max for all emitted particles have the same

regularities as that reported by Dubuna group.S)

For the same atomic number of the emitted

particles, the regularity is represented by relation log(da/dU)Omax=const.

Qgg as shown in

Fig. 1, where (da/dU)Omax means the differential cross section at the angle, at which theangular distribution has a maximum value, and Qgg is the ground state Q-value for eachtransfer reaction.
(2)

In the energy spectra of multi-nucleon transfer reactions, typical bumps were foundas seen in the transfer reaction on (fp) shell nuclei at higher energies.
are shown in Fig. 2(b) and (c).

Examples of these bumps

However, the width of bumps is smaller and the peak positionof them is nearer to Ex=O compared with the bumps found in the case of the transfer reaction
on (fp) shell nuclei.
In the energy spectrum of one-proton transfer reaction on 208Pb, some selectively excitedpeaks corresponding to the single proton levels of 209Bi and a small bump at higher Ex are
observed as shown in Fig. 2(a).
In case of selective peaks it is well known that the transfer yields have strong Q- and Ldependencies, which are reproduced by the classical picture.

We have tried to understand theseQ- and L- dependencies for some selective peaks of this experiment by calculating the,09Bi -levels\ 3.64 3p'/2 V

1. 5"-Il l :L2

1.0

4. 0

2f5(2 V I.l

2. 1

\

i 2.S2--J 1.6 1
'-J

3t:y2

..J / 0 00

I ho/2I " B, ,0Be I

72 .2MeV
Q =- 7.7v 2 .2 :===J

I iq/20 .90 ~2

L\

"

L\
3 f)

("C ,"S I

78MeV
Q= -12.2

1. 5

1. 9 1 - - - - - - - '1. 1

2 .3 ==:JI
06 ~==::J ('4N,"C I

02) 1--_
0 .3

Fig. 3.

_ _ _~

90 MeVQ = -3. 7

I. S

1" O,15 N I

104 MeV

Q= - S3
1.2

os

1.9 p

2.2

2 .3

2.0

Comparison of the calculated values of J (the degreeof mismatching) and the relative intensities of six
known single-proton states of 209 Bi. The 3p~

e

2fs states in 4 N, 13 C) reaction are mixed by72
poor resolution. It is assumed that the spin oftransferred proton is not flipped.

and

35

momentum- and angt:lar momentum-mismatching classically.

When the classical trajectories are

assumed both in incident and exit channels of the transfer reactions and the transfer process
takes place at the periphelion of the orbit, the angular momentum mismatch ~L=K~D can becalculated.

Here K is the relative momentum of the bulk motion and W=Df-Di-Wrecoil

where Di and Df are the distances of closest approach in initial and final channels respectively,6)and ~ Drecoil is the change in the distance between centers of mass of two nuclei before andafter the transfer of a nucleon.

Linear momentum mismatch of transfered nucleon is given by~=k-Al/RI-A2/R2 following Brink's condition. 7) According to the semiclassical theory, ~L~ 2
and iR~k::;1T are the conditions under which the transfer probability is large,7 ) and then
~ = [(R~k/21T)2+ (K~D/2)2 P/2 -S f2~ 1.4. The calculated values of ~ are compared with therelative intensities of several peaks in the reaction 2osPbe 4 N, 13C)209Bi and other reactions
2osPbe 6 0, lSN)209Bi, 2osPbe 2C, IIB)209Bi S ) and 2osPbe1B,lOBe)209Bi 9 ) in Fig. 3. In this figure in
208P b +14N(

14

N ,"C)

E = 90 MeV

1Jc

Ex = 0.9 MeV

13C

Ex = 3 MeV

Ex = 0.9 MeV

Ex = 10 ~ 13 MeV

12

50

60

70

80

90

100

1.4

B c. mFig. 4.

Angular distributions of various reactions

Fig. 5.

1.5

1.6

8 tot al

1.7

d (fm ) = Df( A'{3 + A'~3)

The cross sections of various

induced by 90 MeV 14 N on 20 S Pb. Solidreactions induced by 90 MeV 14 N

lines r_esult from calculations byon 208 Pb plotted v.s. d=D/

Strutinsky model fitting to the data.

(A{3 +AY3 ), where D is thee4 N, 2C) and one of the e N, 13C)

distance of closest approach forreactions, the cross sections are integrated

the Rutherford trajectory. The

over the energy range indicated. The cross

cross sections are divided by thesections of 10' 12 B are totally integrated

Rutherford cross sections (dashedover the energy spectra.

lines) and by the elastic cross

For

1

4

sections of the initial channel(Solid lines).

36

general the smaller ~ value shows the more enhanced yield of the peak.
(3)

The angular distributions obtained show a typical bell shape as shown in Fig. 4.

Solidlines are the differential cross sections calculated by Strutinsky modePO) that fits to the data.
The analysis by Strutinsky model are described elsewhere 11 ) in this Cyclotron Progress Report.
Figure 5 shows the differential cross sections of transfer reactions divided by the
Rutherford cross sections (a/~) and those divided by the elastic scattering cross sections of theinitial channel (alael) as a function of the distance of closest approach D.

In cases of

e N, 13C)
4

reactions, for a larger distance aluR becomes smaller because of the smaller overlap of the wave
function of the transferred nucleons, and for a smaller distance alaR becomes smaller because of
the absorption of the incident and outgoing waves. As for alael the absorption is compensatedand the lines of log(alael) v.S. D become straight. However in case ofe N, 12B) reaction, for4

small distance the curve of alaR v.s. D becomes flat as already seen in our previous data of

52Cre4N, 12C)54Mn reaction at the energy of 90 Me V. l2 ) This suggest that the reaction mechanismof multinucleon transfer reaction which makes the "bump" in energy spectrum is different fromthe mechanism of one nucleon transfer reaction.

References
I)

I. Kohno, S. Nakajima, I. Yamane, M. Yoshie, M. Odera, and H. Kamitsubo

IPCR

Cyclotron Progr. Rep., .2., 23 (1972).
2)

F.D. Becchetti, P. R. Christensen, V.I. Manko, and R. J. Nickles

Phys. Lett.,

43B, 279 (1973).
3)

M. C. Lemaire:

4)

S. Nakajima, I. Kohno, I. Yamane, M. Yoshie, M. Odera, and H. Kamitsubo

Phys. Rep., 7C, 280 (1973).
IPCR

Cyclotron Progr. Rep., Q, 89 (1972).
5)

A. G. Artukh, V. V. Ardeichikov, J. Era, G. F. Gridnev, V. L. Mikheev, V. V. Volkov,
and J. Wilczynski:

Nucl. Phys., A160, 511 (1971).

6)

P. R. Christensen, V.I. Manko, F.D. Becchetti, and R. J. Nickles

7)

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

8)

D. G. Kovar, F. D. Becchetti, B. G. Harvey, F. Piih1hofer, J. Mahoney, D. W. Millor, and
M. S. Zisman:

9)

ibid., A207, 33 (1973).

Phys. Rev. Lett., 29, 1023 (1972).

J.L.C. Ford, Jr., K. S. Toth, D. C. Hensley, R. M. Caedke, P. J. Riley, and S. T. Thornton
Proc. of Symp. on Heavy Ion Transfer Reactions at Argonne, Argonne Physics Division
Informal Report, PHY·1973B, 495 (1973).

10)

V. M. Strutinsky : Phys. Lett., 44B, 245 (1973).

11)

M. Yoshie, K. Katori, I. Kohno, S. Nakajima, T. Motobayashi, T. Mikumo, and H. Kamitsubo
IPCR Cyclotron Progr. Rep., 7, 27 (1973).

12)

H. Kamitsubo, M. Yoshie, I. Kohno, S. Nakajima, I. Yamane, and T. Mikumo:

Proc. of

Symp. on Heavy Ion Transfer Reactions at Argonne, Argonne Physics Division Informal
Report, PHY-1973B, 549 (1973).

37

4-5.

Angular Distributions and Linear Momentum Transfers of Target
Residue in the 209 Bi+ 12C Reaction

K. Hiruta, T. Nomura, M. Yoshie,
and o. Hashimoto

Angular distributions of residual nuclei produced in the 209Bi + 12C reaction were
measured to distinguish the reaction products due toe C,axn) from those due to e C,xn).
2

2

A selfsupporting 209Bi target of about 100 J.lg/cm 2 in thickness was bombarded with 80 MeV
12C-ions supplied from the cyclotron.

In Fig. I, the reaction products recoiled from the target

were caught by an aluminum foil and alpha-decays emitted therefrom were detected with a Si
surface-barrier diode placed about 1.5 cm under the stopper to identify the reaction products.
A slit of 0.5 cm in diameter was set between the catcher foil and the Si-detector so thata-particles and reaction products from the target could not enter the detector.

The catcher

foil was made rotatable around the target on the horizontal plane including the beam axis.
The distance between the target and stopper was 12.5 cm.

Beam

Fig. 1.

Experimental set-up.

The measured angular distributions for various reaction products at 80 MeV are shown in
Fig. 2.
(1)

The following points are to be noted:
The angular distributions of 217Ac (and also its decay product 213Fr) and 218Ac, whichwere produced in theel=, 4n) and e2C , 3n) reactions, respectively, increase monotonously

as the angle decreases.
(2)

A p,ossible maximum must lie near 0°

The angular distribution of 21SFr, which was produced in thee C,a2n) reaction,2

shows a broad maximum at about 15°, being completely different from those of 217 Ac and218Ac.
(3)

The angular distribution of 214Fr has also a peak at 15°, but shows a rapid increase in

If we subtract the yield of 218Ac from that of 214Fr, the resultant canbe considered to represent the yield of 209Bi( 12 C,a3n) 214 Fr reaction. As seen in Fig. 2 thisthe neighborhood of 0°.

angular distribution is very similar to that of 21sFr.
Recoil velocities of 217 Ac and 2 1S Fr were measured by the time-of-flight method (See Fig. 1)

38

and were determined to be V=(1.866±0.032)XI08cm / sec (E r = 3.91 MeV) for 217Ac andV = (1.706 ± 0.026) X 108cm I sec (E r = 3.25 MeV) for 215Fr.

The recoil energy experimentally

determined for 217Ac agrees very well with the value Er (cal) = 4.12 MeV calculated on theassumption of full momentum transfer, indicating that 217 Ac is produced in the compoundreaction.

It is interesting to note that the experimental recoil energy for 215Fr is far from thevalue Er (cal) given above.

This comes from .the recoil effect of a-particle emission in the

12

C,a2n) reaction, which is considered to be either due to the a-particle evaporation from thecompound nucleus or due to the Be 8 transfer from projectile to target.! ) A further measurement(of recoil velocities is being planned to clarify this point.

209Bi+12C (80 MeV I
'0
5

5

5

5

10' 2 '-----.1....-----:-'''::0 ----'-----::::2':::0 ----'----"""""'3"'0 _---lBLob

Fig. 2.

(deg.lAngular distributions of 209 Bi + 12 C
reaction products.

Reference
1)

R. Bimbot, D. Gardes, and M. F. Rivet

Nucl. Phys., A189, 193 (1972).

39

,4-6.

limit of the Cross Section for the Compound Reaction
between Complex Nuclei

T. Nomura

In heavy-ion induced reactions the ratio of the cross section for the compound reaction,acf' to the total reaction cross section, aR' decreases as the incident energy increases.

This isusually interpreted as the effect of the increasing maximum angular momentum brought into
Let us define a critical angular momentum, lcr' of a nucleus at a given

a compound nucleus.

excitation energy as the maximum spin that the nucleus can possess.

Then partial waves whose

angular momenta exceed J cr of a compound nucleus do not contribute to the formation of thecompound nucleus.

Based on this idea the value of J cr has been experimentally deduced to bearound 40 - 50 h at E::::::IOO MeV in the case of rare earth nuclei.

Theoretically the criticalangular momentum has been calculated from the concept of yeast levels or from the stabilityof a nucleus against fissions. 1 )Recently , experiments have been done about the measurement of the compound reaction
cross section under the condition that the same compound nucleus was made at the same
excitation energy using different projectiles? ) ,3 )If we deduce the critical angular momentum

from the relation

obtained in the sharp cut-off model, the value of J cr should be nearly the same, being
independent of entrance channels.

The above experiments have shown , however, quite different

values of lcr for different combinations of projectile and target.

This cannot be explained

solely by the concept of the critical angular momentum and suggests that the compoundreaction cross section depends on the dynamical process of fusion between two interacting
nuclei.

Then a question arises: what kind of physical quantity determines the limit of acf ?

We have found a systematics which indicates that the relative velocity of the colliding
nuclei seems to play an important role for this problem.

Fig. I shows experimental values of

acd aR plotted vs. a kinetic energy per nucleon in the vicinity of the collision.

that there is a strong correlation between these values.

It is clear

This correlat,ion suggests that the limitof acf is determined not only by the critical angular momentum but also by the relative
velocity of the system.

The latter may have connection with the nuclear viscosity.

40

1.0

r

~.

0. 9

•
•

0. 8
0.7
® ®

0.6

'"

®

0.5

iii

®

®

~

0

®
(19

0

0

•
• •

® •

®

A®

x

•

®

0.4

•
• •

•

LL

U

b

15

10

5

0

-

~

0

•

00

0.3

•

-

I. 0

0.2

O. )cOo5(Ei - EIO) /)l

1. 0

5

0

10

15

10

15

( MeV / omu )

r

•

0 .9

®

0 .8

®

0.7

®

®

~

•

®

®

•

®

0
0

•

0

• •

A®

x

•

®

•

~

0.6

•
• •
0
00

•

• •• .:J

~ 0.5
'-.

~ 0.4
0.3
0 .2
-

0.1
0

0

5
(Ei - EIO )/ J1
~

11 B

•

12C

0

16

0

®

40 Ar

x

84 Kr

~

14 N.

10

15

( MeV / omu)

• 20NeFig. 1.

Upper: Experimental values of the ratio of the compoundreaction cross section to the total reaction cross section
plotted vs. the relative kinetic energy per nucleon in thevicinity of the collision, where Ei is the incident kinetic
energy in the c.m. system, E IO the interaction barrier for
S-wave and JJ. the reduced mass. Lower: Ratio of Jcr toJmax plotted vs. the same quantity mentioned above. Jmax

is the maximum angular momentum brought into thecompound nucleus. Jcr and Jmax are calculated from the
sharp cut-off model. Data are taken from the compilation
in Ref. 3).

41

References
1)

S. Cohen, F. Plasil, and W. J. Swiatecki:

Proc. 3rd Conf. on Reactions between Complex

Nuclei (Univ. Calif. Press, Berkeley 1963), p. 325 (1963).
Phys. Rev. Lett., ~ 27 (1973).

2)

A. M. Zebelman and J. M. Miller:

3)

M. Lefort, Y. Le Beyec, and J. Peter : "On the Fusion Reactions between Complex
Nuclei", IPNO-RC-73-04 (1973), presented at the XI Winter Meeting on Nuclear Physics,
Villars, Jan. (1973).

42(3 He , d) Reactions on Cr Isotopes at an Energy of 29.3 MeV

4-7.

N. Nakanishi, S. Takeda, * H. Ohnuma, S. Yamada, H. Sakaguchi,
M. Nakamura, S. Takeuchi, ** and K. Koyama

Angular distributions of differential cross section were measured on the reactions
50,52 ,54 CrCHe, d)51,53,55Mn at an incident energy of 29.29 MeV. Figs. 1 '" 3 show deuteron
spectra for these reactions.

Remarkable features may be seen in these spectra ; many unboundanalogue states, continuous spectrum in the highly excited region and a few strongly excitedlevels (Rp = 1). Some angular distributions of 54CrCHe, d)55Mn are shown in Fig. 4, as an
example.

The upper portion is on an Ex = 0.127 MeV J7r= 7/2 - level of 55Mn nucleus andthe middle and lower portions are on an Ex = 1.527 MeV J7r= 3/2- level and Ex = 12.3 MeV
level (lAS of 55Cr) , respectively.

These experimental curves indicate typical patterns

corresponding to fp = 3, fp = 1, and unbound lAS, respectively.

In the figure, solid andbroken lines are preliminary predictions of DWBA calculation (DWUCK) using the deeper andshallower real parts of optical potential of 3He particle, respectively.

These optical model

parameters which are indicated in the figure are obtained by an automatic search procedure(SEARCH) to give the best fit to the experimental result of 52CrCHe, 3He) 52 Cr at the same

15.0

300
50Cr(3He d)5 l Mn

Eh =29.29MeV
BLab = 25°

10.0

200
(l)

c:::
c:::
0
.c
U

;;
Q)

~

><
Lu

<J)

c:::
::J

0

u

5.0

100

ChannelFig. 1.

numbe rEnergy spectrum of deuteron of 50 Cr C He, d) 51 Mn reaction.

* Present address, National Laboratory for High Energy Physics.
** Kyoto University.

43

400

52Cr(3He d) 53Mn
fh

= 29.29 MeV

15.0

Ehab = 25°

300

10.0

Cl>

c:
c:

~

;:

(.)

-....
en
c:

.....

Cl>

200

~

:>

><

0

Lu

u

5.0
100

o
Channe I number

Fig. 2.

Energy spectrum of deuteron of 52 Cr

e He, d) Mn reaction.
53

54C r (3He d ) 55Mn

Eh = 29.29 MeV

300

15.0

6Lob = 25°

~

§ 200

10.0

o

o
-....

->

~

V">

c:

><

:>

o

Lu

U

5.0

100

O ~--~40~O~--~----~6*00~--~-----8~0~0~--~----~~--~----~~~~

ChannelFig. 3.

numberEnergy spectrum of deuteron of 54Cr

eHe, d)5 5 Mn reaction.

o

44

10 1
L

~

E
~

'-..

b

•

"

,,
,

••

,,
,,

••

,
................

10 0

v

10- 1

W

179 . 54 20.04
124.27 16.37

0ro
1.1 21
1.151

00

r

0.657
0.692

1. 51 1
1.588

40

20

0.914
0.856

60

80

8 C•M•

Fig. 4.

Typical angular distribution of S4 Cr

e He, d)SS

Mn reaction.

Dots are experimental points and lines are DWBA curves.

100

50

4.20

4.30

4.40

4.50

Ep (MeV)Fig. 5.

Excitation curves of S4 Cr (p, p) S4 Cr scattering.

45

energy.

It may be seen from the agreement between them that the deeper potential family

is more suitable than the shallower one.

As for the type of the imaginary part of the opticalpotential, the difference is not recognized between the volume and surface types.
Some of the unbound analogue states were established by proton elastic and inelastic
scattering on Cr isotopes.})

We also performed the same experiment with proton in a higher

energy range using the 10 MV tandem Van de Graaff accelerator at the Kyoto University.
An example of the resonance scattering of protons by 54Cr is shown in Fig. 5.

The resonancebehavior corresponds to the Ex = 12.4 MeV unbound isobaric analogue state.

Reference
1)

J. D. Moses, H. W. Newson, and E. G. Bilpuch

Nucl. Phys., A175, 556 (1971).

46

T. Fujisawa, H. Kamitsubo, T. Wada,
M. Koike~ Y. Tagishi, and T. Kanai

Differential cross sections of CHe, 3He), CHe, 3He'), and CHe,o:) reactions on 13C havebeen measured at incident energies of 29.2, 34.7, and 39.6 MeV.

The target used wasa self-supporting foil with thickness of about 700 J.lg/cm 2 whose the purity of 13C was 90 %.
The reaction products were observed with a ~E - E counter telescope consisting of two. siliconsurface barrier units.

In Fig. 1 the typical energy spectra of 3He and o:-particle are shown.

Analyses of them are being carried out.
+

N

+

~

SLob

400

0

r-..:

+
+

+

;;;

N

~

t.n
t.n

I

ro

~

~- ~

....,0>

ut.n

r-..:

N

+

= 32°

;-

<.0

e'?

+

E3He = 39.7 MeV

Y

ro~

<.0

ro

13C(3He,3He ) 13C;;,.

-=-e'?

t.n

r-..:

D

M

~

<;t-

.¢

"0

c::
=>

300

0

l-

CJ

V">

!

c::
=>

0

u

200
f"

~

0

+
~

SX

Channe l number

~

+

I

N

~

M

0>

<.D

D

400

!

"0

c::
=>

0

CJ

+

~ 300

+ +

c::
=>

-.~

0

u

-+

+
0

~

t.n

-:

- - I'-:
~
+

+

<;t-

200

N

N

I

M

<;t<.0

100

(1)

0

"0

0

c::
=>

<.0
<.0

CJ

~

r--:

560
Channe lFig. 1.

+

0>
D
..V">

numberTypical energy spectra of 3 He and o:-particle in the 13 C C He , 3 He') and13 C C He, 0:) 12 C

reactions.

47

4-9. Two-Step Process

In

the

12C (3He,a)11 C

Reaction

S. Yamaji, T. Fujisawa, S. Motonaga, F. Yoshida,
H. Sakaguchi, and K. Masui

Previously the reaction 12C eHe,a)l1C was studied at the bombarding energies of 24.0,
29.2, 34.7, and 39.6 MeV l ) and differential cross sections were analyzed in DWBA and CCBA.
The large strength of shell-model-forbidden transition to the 5/2- state can be explained by thetwo-step process. The reaction 12CeHe, a)llC 2)'"'-'4) was also extensively studied in otherlaboratories to examine the reaction mechanism.

In lower energies (below 28 MeV)2) ,3) theshell-model-forbidden transitions are said to be mainly knock-on reactions, while at a higher
energy (42 MeV)4) they are found to be two-step processes.
The coupled channel Born approximation (CCBA) calculations were carried out by

l2C+3He

11C+aTable 1.

Optical parameter.

Incident
Energy

Vo
(MeV)

rR
(fm)

aR
(fm)

Wo
(MeV)

rO
(fm)

aO
(fm)

rC
(fm)

24.0

142.3

l.1

0.718

13.43

l.314

0.823

1.4

29.2

135.0

l.1

0.700

14.34

l.097

0.907

1.4

34.7

129.3

l.l

0.751

14.72

l.205

0.834

1.4

39.6

123.0

1.1

0.823

17.00

1.416

0.657

1.4

200.0

l.3

0.7

12.5

l.3

0.7

l.3

f (Xi) = [1 +exp(X i)] -1
X· = (r-r· Z1!3 )/a.
1

10+---llC

The number in Parentheses is the spectroscopic
amplitude of Cohen and Kurath.
Fig. 1.

Spectroscopic amplitude.

1

48

He ,a)l1C %- 4.322 MeV
Di =/.3f = - 0.5- - V6Q')= 200Me/ ----"'-,,+ ----- V6~)= 250MeV
12 C(3

1ft"! '-E3He = 24. OMe V

1. 0

..

!!!!"e-..- , __ .......... --.."
10 ,---------------------~

12C ( 3He , Q' ) llC

512 - 4.322 MeV

E3He= 3 4 .7 MeV(3; =13{ =- 0 .5......

,- - CC BA------ DWBA f S/ 2
- - - DWBA kn ok - on\\-.......
L

U)

E

"-

cD
b

.D

E

1.0

- 0.1
E

cD
b

"\ \
\

\
\

\

0.001

1.0

120

Fig. 2.

The CCBA analysis of the reaction
12C

eHe, a)11

C (5/2- ,4.322 MeV).

The strength of the interaction
Vn 3 He is 100 MeV for the case ofV~a) = 200 MeV and 120 MeV for

the case of V~a) = 250 MeV , whereV ~ a) is the depth of the real opticalpotential of the a particle. The depthof the imaginary potential is reduced
by 20% in the calculation of thetwo-step process.

Fig. 3.

Contributions of one-step pick-up
process, knock-on process, andtwo-step process.

49

Ascuitto and Glendenning s ) and Tamura et a1. 6 )We made the eeBA code based on the

JUPITOR-l* and checked it by comparing our results with those calculated by the code MARS.7)
The optical parameters of 3He on 12C were searched 8) and are shown in Table I . The
experimental data of the elastic scattering of a on 12C9) were used to obtain the optical parameters of a on IIC shown in Table 1. We used the spectroscopic amplitude in Fig. 1 which
is obtained by Clegg's wave function. 4),IO)
The calculated results are shown in Fig. 2.
Gaussian type with the range of 2.52 fm.

The interaction V n 3 He is taken to be of a

The strength is adjusted to give the rightmagnitude for the ground state transition at the bombarding energy of 34.7 MeV.
calculated cross sections can reproduce the order of magnitude fairly well.

The

However, theirangular distribution depends on the depth of the optical potential of a-particle.
We also examined the possibility of knock-on process in the case of 34.7 Me V . The
spectroscopic amplitudes for the devision of IIC into 8Be and 3He and that of 12e into 8Be anda are taken from the work of Honda et a1. 11 )The ground state of I2C and the second

excited state of IIC are assumed to be [44] II SO and[43] 22D s / 2 respectively. The finite-range
DWBA calculation of the cross section of the knock-on process l2 ) was carried out by using thecode INS-DWBA-4. * *interaction V n 3He.

The interaction between 3He and a was taken to be the same as the

The cross section for the knock-on process was found to be very small as

can be seen in Fig. 3.

If the transition is considered to be caused by the pick-up of the orbit

fS/2 and the spectroscopic amplitude of Kurath's13 ) ,14) calculation 0.022 is used , the magnitudeof the calculated cross section is smaller than that of the experimental cross section by a factorof 100.

References

1)

T. Fujisawa, H. Kamitsubo, S. Motonaga, K. Matsuda, F. Yoshida , H. Sakaguchi, andK. Masui:

IPCR Cyclotron Progr. Rep., ±, 46 (1970).

2)

T. J. Gray , H. T. Fortune, W. Trost, and N. R. Fletcher

3)

H. Fuchs and H. Oeschler : ibid. , A202 , 363 (1973).

4)

R. N. Singh, N. De. Takacsy, S. I. Hayakawa, R. L. Hutson , and J. J. Kraushaar

Nucl. Phys. , A 144, 129 (1970).

ibid., A205, 97 (1973).
Phys. Rev. , l§l , 1376 (1969) .

5)

R. 1. Ascuitto and N. K. Glendnning:

6)

T. Tamura, D. R. Bes, R. A. Broglia, and S. Landowne:

Phys. Rev. Lett., 25, 1507

(1970) ; ibid. , 26 , 156 (1971).
7)

T. Tamura and T. Udagawa:Tech. Rep. Center Nucl. Stud., Univ. Texas, No. 30 (1972).

* T. Tamura: Computer Program Jupitor-l for Coupled~hannel Calculation, ORNL-4152 (1967).
** H. Yoshida: Reference Manual for INS-DWBA-4, Inst. Nucl. Stud. Univ. of Tokyo (1972).

50

8)

T. Fujisawa, S. Yamaji, K. Matsuda, S. Motonaga, F. Yoshida, H. Sakaguchi, andK. Masui:

9)J. Phys. Soc. Japan, 34, 5 (1973).

T. Mikumo, H. Yamaguchi, I. Nonaka, M. Odera, Y. Hashimoto, M. Kondo, and T. Maki
J. Phys. Soc. Japan, 12, 1158 (1960); T. Mikumo:

ibid., lQ, 1066 (1961).

10)

A. B. Clegg:

Nucl. Phys., 38, 353 (1962)

11)

T. Honda, H. Horie, Y. Kudo, and H. Vi:

12)

S. Yamaji and S. Yoshida : Progr. Theor. Phys., 44, 125 (1970).

13)

D. Kurath: in Proc. 1967 Summer Inst. in Physics, (ed. B. Margolis and C. S. Lam)

ibid., 62, 561 (1965).

Benjamin (1968).
14)

S. Cohen and D. Kurath:

Nucl. Phys., AIOl, 1 (1967).

51

4-10.

Sum Rule Approachfor Isovector Nuclear Vibrations

T. Suzuki

The purpose- of the present article is to show that the restoring force parameter and mass
parameter for isovector nuclear vibration are obtained by making use of the generalized sum
rules.
The relation between the isovector density and the average nuclear field is given by the
nuclear symmetry potential, which is usually expressed in the form:

1
N- Z
1
Pn-Pp
V sym = - VI A 'f 3= - VI
'f 3, (VI~ lOOMeV),
4
4Po
where T 3 = + 1 for neutron andT3 =-1 for proton.

(1)

The variation of the isovector density

P in isovector A -pole vibration is uniquely determined from the sum rule for isovectorpdensity operator and the classical energy weighted sum rule. If we use the Gaussian matter( /J -ndistribution, it is expressed by
(2)
A

A

~

5 VI

8n

j9,l,u=~lri Y,l,u (r), X,l= 8R 2 (2A.+l ) A< r 2 ,l-2 > .
utilizing Eqns. (1) and (2), the variation of the isovector average nuclear field under the A -polevibration is obtained as(3 )Hence, the total nuclear potential for isovector A -pole oscillation can be written in the form:~ mw 6 2 1( ). * ~
i).
j )
V --~
-2- r i + -2 X,lL?: ri Y ,l,u( ri ) T 3) (rj Y ,l,u(rj )'f 3 . ,
A

1- 1

(4 )

fJ. I,J

where harmonic oscillator potential is taken as the average nuclear field independent of isospin
variable.

Denoting the mass parameter and eigenfrequency for A -pole vibration by BA and (1) A,

respectively, the above equation may be described as(5)yielding(6)

in which n (1)0 is the eigenfrequency of the A. -pole states in the harmonic oscillator potential.
On the other hand, the mass parameter BA is determined by the relation between thezero-point energy and the classical energy weighted sum rule value, and has a value of

52

(7)

Employing Eqns.( 6) and (7), one can find the eigenfrequency of the isovector A -polevibration in the form:
w A. = (nw 0)

!

VI

5A

1 + (nwo) 2 4rn R 2)Yz'(A > 0 ) .

When we take into account the exchange effect in the nuclear interaction, the nucleon
mass m in Eqn.( 8) reads as m * ~ m/1.4.
Examples:(1)

Dipole resonance ( A = 1, n = 1)
Theor.

WI=! 1.77wo ~ 72.6/APi (MeV) for m,

2.00wo ~ 82 / A73' (Me V) for m *,

Exp.
(WI

WI~ 80/ A 73' ( MeV).

= 1.77 (vo has been also obtained by Bohr and Mottelsson in the otherapproach. 1)(2)

Quadrupole resonance (A = 2, n = 2)
Theor. W2= { 2.88wo~ 118/ APi ( MeV)
3.16wo~ 130/ A 73' (Me V)
Exp.

for rn,for m *,

W2~ 130/ A 73' ( MeV).

In the same way, as for the A(>O)-pole vibration, the eigenfrequency of the
isovector monopole oscillation is predicted to be

w=2wo ( 1 + VI·52) Yz=W2,
8mwoR

which is different from the one obtained in the other approach. 2 )References
1)

A. Bohr and B. R. Mottelson:

in Proc. of neutron capture gamma-ray spectroscopy,

Studsvik, IAEA, Vienna, P. 3 (1969).
2)

T. Suzuki:

Nucl. Phys. (1973), to be published.

(8)

53

4-11 . Momentum

Transfer Dependence of the Effective Charge
for E lec tro-exc itation

T. Suzuki

It is naturally expected that the effective charge for electro-excitation depends on thevalue of momentum transfer, since it mainly comes from the effect of the core polarization asshown schematically in Fig. 1.

Fig. lea) represents a diagram for the bare single-particle

transition, while Fig. l(b) and (c) show the transition of the particle state coupling with thevibrational states (wavy line) of the core.

The matrix elements corresponding to the last two

diagrams, which are considered as the additional charge (effective charge) for the single particle
transition (Fig. lea)), need not have the same momentum transfer dependence as the one forthe first diagram.
The purpose of the present article is to study the effective charge and its momentum
transfer dependence in electro-excitation in the framework of the particle-vibration coupling
model.

The excitation energy for the electric A. -pole vibrational state of the core is estimatedin the self-consistent field theory and sum rule approach.

It is shown that the momentum

transfer( q) dependence of the isoscalar EA. effective charge can be written in the form:(A)( )_ Z("

anA) (j21 IrAYA"jd

8 e ff q - - e L...J 2
A n n -anAA

( j 211 j X ( qr ) YA II j 1 )R

for the single particle transition from I j 1) to I j2 ).

h ( qR )'(1)

In the above expression, n comes fromn Wo which is the excitation energy of the A.-pole states, in the harmonic oscillator potential,
carrying Q n x 100 % of the classical energy weighted sum rule value.

In the limit of (q -+ Ex),Eqn.(1) leads to the effective charge for photo-reaction:

8

(A)

eff

Z
(q=Ex) = - e2:

a A

n

(2)

A n n 2- a n A .

8V

~s

MAp.

(0 )

Fig. 1.

( b)(c)

The effect of core polarization. The first diagram
represents the bare single particle transition, while theremaining diagrams show contributions of the corepolarization to the effective charge up to the first orderin perturbation theory.

54

For example, we obtain e ~i' (q=Ex) = eZ/ A for n = 2, A = 2, and U2= I, which is thewell-known value of the effective charge for E2 transition. 1 )In Fig. 2 is shown the momentum transfer dependence of the E2 effective charge given in
Eqn.( I) for various transitions, where we choose the following nuclear radius and harmonic
oscillator length parameters:
R = 3.36 (fm), b = 1.73 (fm) for (Op) and (Os, Od) shells,
R = 4.65 (fm), b = 2.02 (fm) for (lp, Of) shell.
It is predicted that in the (Of -+ Of) transition the value of the effective charge for E2

transition decreases with increasing momentum transfer and changes drastically at aboutq = 3.34/R(fm -I )[(dj2 (x)/dx)3.34 ~ 0 ].

The most recent experiments for SIV 2 ) areconsisten t with the present results.

2 .0

Of-IP

"N .'t=Q,~

i.O r-=~---_

Of -

Of

0.5

/
2.0

Od -

00 -

is

00

N ~

Q,~ I.O~--=~:::::::=--

0.5

q (f m- 1 )Fig. 2.

The calculated values of the E2 effective charge
versus momentum transfer.

References

1)

A. Bohr and B. R. Mottelson : Nucl. Structure, Benjamin, New York , 1, 334 (1969).

2)

G. A. Peterson, K. Hosoyama, M. Nagao, A. Nakada, and Y. Torizuka:
C7, 1028 (1973).

Phys. Rev.,

55

4-12.

Effects of Monopole Core Polarization

T. Suzuki

It is the purpose of this paper to study the effects of the isoscalar and isovector

monopole core polarization.

The Excitation energies for the monopole resonances of the coreare estimated by making use of the sum rules. 1 ) ,2 ) The less model dependent forms of thevariation of the matter density under nuclear vibrations and the interaction Hamiltonian
between a single particle and the core are also obtained by utilizing the sum rules. 1 ),2 )Isotope shift
When a neutron is added to the core, only the monopole mode of the core excitation(1)

affects the charge radius to the first order in the density change.

Hence, the isotope shift is

described as:(1)
where 1 (0 s j)j) represents the neu tron state, I j), coupling with the isoscalar monopole vibrationof the core, los) , with the eigen-frequency (Os = fi0 o . 3 )Interaction Hamiltonian,

the harmonic oscillator shell model, and the variation of the charge density, 0

oY , inp; , arewritten as:A(a s=L rZ-A< r 2
i= l

» ,

(2 )

(3)

By inserting Eqns.(2) and (3) into Eqn.(l ) and using the classical energy weighted sum rulevalue for a s ' one can find the isotope shift to be of the form:

a<r?= ~1 < jlr 2 Ij> ~ < r2»
1 1;: : : - -< r2 >

(4)

A 3

which is about one half of the standard unit~ )The effect of the isovector monopole corepolarization is about 20 ,. . ., 50 % of the one from the isoscalar mode.
(2) Isospin impurity
Since isospin impurity of the nuclear ground state is caused by the mixing of the
isovector monopole state through the Coulomb interaction, it can be obtained by calculation:

P ( T = 1 ) = ~ I (w v I ~ 6' p v V cd; I ) 12 ,WvP

, (5 )

56

where Wv = 2.88 CV o 2) is the eigenfrequency of the isovector monopole vibration of the coreand 0

P; is given by 2)

v
25
A
2
op =-6AR4aVp (r)(r _ < r 2 » , (av=;L:(rl- < r2 » r~).

P

P

1=1

(6)

As the Coulomb matrix element can be estimated as follows:(7)

we obtain the T = I impurity, by employing the classical energy weighted sum rule value,2

P (T= 1 )= _ 1_ 3A(Ze )2 3.00 X 10- 6 Z%,
Wv s
40mR 4(8)( R = 1.2A73 (fm)).
It is interesting to notice that in the two-fluid hydrodynamic model the T = I impurity are

predicted4 ) to be

P (T= 1 )=5.55 X 10- 7 z %.

(9 )The lowest level in the hydrodynamic model has the eigenfrequency of 4.12 00 MeV andcarries only 49 % of the classical energy weighted sum rule value.
(3) Coulomb energy correction
Isospin impurity of the core produces the symmetry potential which acts differently on

protons and neutrons.

Therefore, it gives rise to a correction to the Coulomb energy

In the particle-vibration coupling model, Coulomb

difference between the analog states.

energy correction for the system of the core plus one particle is expressed by~E= ( - ~J (i I O'V I (wvil i) I((wvi) il~ 0' p;Vc dT I j),(10)

where I(cvvj)j) stands for the last particle coupling with the isovector monopole vibration of
the core.

The Coulomb matrix element and CV v are given in Section (2), while the coupling term

'8 V , can be obtained, by using the sum rules,2 )25 VI
2oV(r)=24 AR 4aV (r - < r 2 »r s, (VI=100MeV).

(11)

Then, by calculating Eqn.O 0), one can find5

1 VI Ze 2{ (.

~E=- ---4 w~ m R 5

2')
2}
JI r IJ -< r >(12)•

The ratio of L\ E to the so-called direct term of the Coulomb energy difference is roughly givenas~E----:::::;6~9%( j 1 Vc 1 j)which is large enough to explain the Nolen-Schiffer effect.5 )

(13)

57

References

1)

T. Suzuki and C. Hinohara:

IPCR Cyclotron Rep., No. 29 (1973).

2)

T. Suzuki:

ibid., No. 32 (1973).

3)

T. Suzuki:

Nucl. Phys., (1973), to be published.

4)

A. Bohr and B. R. Mottelson:

Nuclear Structure, Benjamin, New York, l (1969).

5)

J. A. Nolen and J. P. Schiffer:Ann. Rev. Nucl. Sci., 12.z. 471 (1969).

58

4-1 3. The Splitting of the Isospin and Spin-Isospin
Dipole Resonances in 12C

T. Suzuki and C. Hinohara*

Two electric dipole modes are known in nuclear motion.

One of them is the isospin

dipole (r - ) mode that is an oscillation of all protons against all neutrons in the nucleus.

Theother is the spin-isospin dipole (ar-) mode that is an oscillation of the spin-up protons andspin-down neutrons against the spin-down protons and spin-up neutrons.
In 12C the double splitting of the isospin dipole resonance is well known in thephoto-reaction, the first main peak near the excitation energy of 23 MeV being higher than thesecond peak near 26 MeV.

Recent measurements of the cross section for electro-excitationof 12C1 ) have shown that the spin-isospin dipole resonance is also split into two peaks in thesame way as the isospin dipole resonance.
As discussed by many authors,2) in the axially symmetric deformed even nuclei the isospin
dipole states are separated into two groups according to their excitation energy; one consistingof the K1T = 1- states with excitation energy (i.)J.' and the other of the K1T = 0- states with wz .
The total strength for excitation of the isospin mode states at (1)1- is twice that for the isospinmode states at wz · Employing the SU (2) symmetry in the axially symmetric deformed potential,

Table 1.

Electric dipole states in the axially symmetric deformed potential.
r-modear-mode~~ExcitationenergyK-BandStrength

w1-

K=1

2 Sr

Wz

K=O

Sr

K-BandStrength

K=1
K=O
K=1

2 SaT

Sar

it is shown that the spin-isospin dipole states are also classified into two groups in such
nuclei.

One is composed of the K1T = I - and K1T = 0- spin-isospin mode states with (i.)-1.' whilethe· other of the K1T= 1- states with w z . The total strength of the spin-isospin dipole oscillations
with W -L is twice that of the one with W z according to the degree of freedom of the oscillation(Table 1).
* Tohoku University.

59

We have performed a detailed calculation of the excitation energies of the electric dipole
states of 12C and the cross section for their photo- and electro-excitation based on the obi at ely
deformed nuclear shell model.

The wave function of the dipole state is constructed in the

adiabatic approximation, where the intrinsic wave function is composed of Ip (N=2)-lh(N= I)
states in the Nilsson potential (77=-4 , K=0.05).

The particle- hole pair scattering is assumed tobe caused by the usual phenomenological effective interaction.

The characteristic features of

the cross section for photo- and electro- excitation are well reproduced by the present theory 3 )which could not be explained by previous studies. 4 )References
1)

G. Ricco , H.S. Caplan, R.M. Hutcheon , and R. Malvano : Nucl. Phys., A 114, 685 (1968);
A. Yamaguchi, T. Terasawa , K. Nakahara, and Y. Torizuka : Phys. Rev. , C3, 1750 (1971).

2)

M. Danos:

Bull. Am. Phys. Soc. , L 136, 246 (1956); K. Okamoto: Progr. Theor.

Phys., ll, 75 (1956); B. R. Mottelson and S. G. Nilsson: Nucl. Phys. , U, 281 (1959).
3)

T. Suzuki and C. Hinohara:

4)

N. Vihn Mau and G. E. Brown:

ibid., A204, 289 (1973).
ibid. , 29, 89 (1962); F. H. Lewis, Jr. and J. D. Walecka

Phys. Rev. , 133 , B849 (1964); M. Kamimura, K. Ikeda, and A. Arima:
A95 , 129 (1967);

Nucl. Phys. ,F. J. Kelly and H. Uberall : Phys. Rev., 175 , 1235 (1968).

60

4-14. New

Giant Resonances

T. Suzuki

Recent studies of the nuclear continuum region have demonstrated the existence of the
giant resonances due to the new modes other than electric isospin dipole one.I) ,2 )the new giant resonance at Ex ~ 60/A

1 3/

Especially,

MeV has been systematically observed in (e,e'), (p,p'),(r/) and (a ,cl) experiments 2 ) and it is suggested to be due to isoscalar monopole and/or

quadrupole oscillations.

A broad resonance at Ex ~ 130/Al/ 3 MeV is also observed in (e,e')

experiments and is interpreted to be isovector monopole and/or quadrupole resonances.

It isthe purpose of this paper to investigate the eigenfrequencies of these collective monopole andquadrupole states, whose excitation strengths exhaust the classical energy weighted sum rulevalues.

The nuclear potential for these oscillations is obtained from the harmonic oscillator

shell model, taking into account the condition as proposed by Bohr and Mottelson. 3 ) On theother hand, the mass parameters can be determined by the classical energy weighted sum rulevalues.

The obtained restoring force parameters and mass parameters are listed in Table I for

each dynamic variable of the vibration.

In Fig. I, the present results are compared with theexperimental values of the excitation energy for giant multipole resonances.

For reference, inFig. 1 are also shown the experimental and calculated values for giant dipole resonance. 3 )Table 1

The calculated mass and ,restoring force parameters of the giant resonance state.

Mode ofresonance

Massparameter

Restoring force
parameterm

mW5

4 A < r 2>

2 A < r 2>

A

27rm

4 7rmw~i=l

5A < r2 >5 A < r 2>

Dynamic variableA~ro..........
roMonopole

a~=2: (r r- < r 2»i= l

Eigenfrequency

}2:wo

u

CfJ

0
CfJ
~

Quadrupole

s _
2
(A)
a 2P
- 2: r i Y 21-'- r i
A~0

Monopole......
ua X= L (r r- < r 2»
i= l

r i
3

m

m

4 A < r 2>

4A< r 2>

}2:wo

(2
35VI)
4wo+ -~jT9wo7VI)~j1Owo

4mR2

C)

>

0

CfJ
~

Quadrupole

A

27rm

i=l

5 A < r 2>

a 2VP = 2: r r Y 21-'- (r i h· 1

wo=41.1/ AY3 (Me V),

R = 1.2AY3 (fm),

2rrm ( 4wo+
2 -2

5A< r 2>

Vl=100 (MeV )

2mR

61

180 r -_______________________________________

160

:;;;

140

2'

H

-g: 120<::{o100... . .. .

80._A_ _ .-¥.

.·-;X _

X_

OOX x
X

EV
1

X X
0
0

100

50

Fig. 1.

. -.... ...-,. .. . ...
&

'be

xX
0

0

E6 and Ei
150

200

(A)

Systematics of the excitation energies for giant multipole
resonances. The experimental data are taken from Ref. 2)
The black circles are for E 1. The crosses and open circles
are for E2 or EO, in which the former was obtained from(p, p/) reactions and the latter from electron scattering.
The straight lines represent the calculated values of theexcitation energies.

The systematics of the excitation energies for the observed new giant resonances are well
explained by the simple model.

References

1)

T. Suzuki:

2)

L. W. Fagg

Nucl. Phys., A204, 289 (1973).
Proc. Intern. Conf. Photonuclear Reactions and Applications,

Asilomar, (1973);

3)

Y. Torizuka:

idem;

M. B. Lewis:

idem.

A. Bohr and B. R. Mottelson
Studsvik, IAEA, Vienna (1969).

Proc. Neutron Capture Gamma-ray Spectroscopy,

62

4-15. Sum

Rules and Nonexchange Force*

T. Suzuki and C. Hinohara**

The purpose of this short note is to show that the form of the nonexchange residualinteraction in the harmonic oscillator shell model is determined by utilizing the sum rules for
multipole operators and nuclear transition density.
The well-known classical energy weighted sum rule} ) can be written in the natural unit:

A
2A
A(2A+ l )< r - 2 > , ( A2 1) ,nm

LW n< I fJi\.*O Iwn>< w n l/3i\.O I > = 8nwhere (Vn represents the eigenfrequency of the nuclear state , I (Vn> , and
A

i\.

~

/3AfJ. = i~l r i Y ,l,u( r lOn the other hand , the sum rule for nuclear density is expressed in the form 2l :
~ --+

1
2m

LW n< Ip(r )lwn >< wn 1fJi\.01 >= - - Arni\. - 1

A

Yi\. o( r )dp 0 (r ), ( A 2 1),
dr

(2 )

denoting the isoscalar density operator and the nuclear matter distribution in the ground state~~as (J (r) and .Do(r) , respectively.

If the classical energy weighted sum rule value is carried bya single A- pole state , IWA )' the above two equations provide the model independent form of
the nuclear transition density:
~ --+
X,l
i\. - 1
dp 0 (r )< Ip(r )lw,l > = 2 < IfJi\.Olw,l > r
Y,1O dr '(3 )Since Eqn. (3) indicates that the point r in .Do(r) goes into the point:XAr - r ( l - -fJ
2 ,10 r,1 - 2

A

Y,10 (r))(4 )under the A-pole distortion, the one-body potential VCr) can be written in the form:

X,l,1 - 1~ dVo (r )Y,1o(r) dr 'V(r )=Vo (r )+2 fJ ,10 r
assuming the self-consistency between the nuclear density and the average nuclear field.

(5 )Hence,

if Vo (r) is taken to be a harmonic oscillator potential , the total nuclear potential can be
ex pressed as(6)* T. Suzuki and C. Hinohara: Phys. Rev. c., (to be published).
** Tohoku University.

63

In case of A = 0, the sum rules are described as

Lwn< I j3 0 I wn > < wn I j3 0 I > = 2A < r 2> ,
n

(7)

m

(8)

Using the above equations and assuming the self-consistency, one can find the nuclear potential
for a breathing mode in the harmonic oscillator shell model(9)

Finally, we note the following three points.

Firstly, the nuclear potential for A = 2 given in

Eqn. (6) has the same form as the one with Q-Q interaction derived on the other approach by
B. R. Mottelson in calculating the isoscalar E2-effective moment. 3 )Secondly, the interaction

Hamiltonian used in the particle-vibration coupling model is given in Eqn.(5), which has adifferent r-dependence from the one .in the particle-"surface vibration" coupling model. 3 )Thirdly, if {Jo and (J2 are considered to be dynamic variables for nuclear EO and E2 vibrations,
respectively, the eigenfrequency of these vibrations is obtained asutilizing the nuclear potentials given in Eqns.(9) and (6).4) This value is comparable withexcitation energy for newly observed giant resonance which is interpreted to be isoscalarmonopole and/or quadrupole mo.de. s )References
1)A. M. Lane : "Nuclear Theory", Benjamin, New York (1965).

2)

E. L Kao and S. Fallieros : Phys. Rev. Lett., 25, 827 (1970);
T. 1. Deal and S. Fallieros : Phys. Rev., C7, 1709 (1973);
1. V. Noble: Ann. Phys., 67, 98 (1971);

H. Ui and T. Tsukamoto: Contribution to Intr. Conf. on Nucl. Structure Studies
using Electron Scattering and Photoreaction, Sendai (1972).
3)

B. R. Mottelson : Nikko Summer School Lectures (1967), Nordita Publication, No. 288.

4)

T. Suzuki : Nucl. Phys, 217, 182 (1973).

5)

Y. Torizuka : Proc. Intern. Conf. Nucl. Structure Studies Using Electron
Scattering and Photoreaction, Sendai (1972);
E. Spamer : idem;

64

Y. Torizuka : Proc. Intern. Conf. Photonuclear Reaction and Application,
Asilomar (1973);
M. B. Lewis : idem;
Th. Walcher: Proc. Intern. Conf. Nucl. Phys., Munich (1973).

65

5. NUCLEAR PH YSICS
Nuc lear Spectroscopy
5-1. Asymmetric Fission of

236 U

A. Iwamoto,* S. Suekane, ** S. Yamaji,
and K. Harada *One of the most· characteristic features of the low energy fission of medium to heavy
actinide nuclei is the mass asymmetry of the fragments.

In addition, the development ofexperimental techniques has made it possible to determine the fission barrier heights with good
accuracy. 1 ) We have calculated the total potential energy surface for the fission of 236U andcould reproduce the features rather well.
Assuming the fission process to be adiabatic, we calculate the total intrinsic energy of thesystem according to Strutinsky's prescription. 2 )The total energy E is then expressed as(0
where ELDM is the liquid drop energy, Esc is the shell correction energy, and Epc is thepairing correction energy.

To calculate Esc' we use the two-center shell model, generalized to3asymmetric deformations. )process.

This model is especially suited for the description of whole fission

A fourth order correction term similar to that of Ref. 3) is used in the neck region

and 1?-dependent term is defined in terms of stretched coordinate.
taken from Ref. 4).

The values of" and Jl are

The averaged energy which is needed in the Strutinsky's method was

calculated using the six-order curvature corrections and the smearing width of lh w.
pairing correction Epc was calculated following the method of Bolsterli et al. 5)

The

For the liquid6

drop energy, the Groote-Hilfs mass formula ) was used, which consists of the surface andcurvature energies, and for the Coulomb energy, uniform charge distribution was assumed.
Nuclear surface shape used in the liquid drop calculation was assumed to be the equipotential
surface of the two-center Hamiltonian.
Imposing the volume conservation and other conditions, four independent shape parameters
were finally left.

These are Zo (center separation of the two potentials), 01,02 (deformation

parameters of each fragment), and a(volume ratio of the two fragments).

The parameter Zo is

approximately considered to be the distance between two fragments.
In order to investigate the mass asymmetry, we first show in Fig. I the energy surface ofthe symmetric case.

Symmetry means that a = I and 01 = 02 = O.

From Fig. I we see thefollowing:(1)

the ground state lies at about Zo= O.Ofm. and 0 = 0.2;

(2)

the second minimum (2.0 MeV relative to the ground state) lies at about Zo = 4.0fm.

* Japan Atomic Energy Research Institute.
** Osaka City University.

66(MeV) C =0.5

Fig. 1.

Potential energy surface for 236 U in
the symmetric two-center model.
Energies are in Me V and LDM energy
is normalized to zero at the sphericalstate (0 = 0.0 and Zo = 0.0).

and {) = 0.3, in contrast to the results of the usual Nilsson model calculations (zo = 0.0);(3)8

the first barrier is about 4.0 MeV in height and lies at about Zo = 2.7fm. and

0.235;(4)

8 = 0.3

the second barrier is about 9.0 MeV in height and lies at about Zo

8.5fm, and= 0.4.

These features are quite different from the liquid drop energy surface and are mainly due tothe shell correction.
To see the effects of mass asymmetry, we then vary the parameter a from 1.0 at several
points including the first barrier, the second minimum and the second barrier.
and {) 1 are assumed to be the same as those of the symmetric case.

Parameters, Zo

Calculations show thatat the first barrier and the second minimum, the energy increases monotonously as a increases.
This means that at these points the symmetric deformation is preferred.
of the second barrier is illustrated as a function of mass asymmetry.

In Fig. 2, the heightThe solid line, which

represents the total energy, decreases as the mass ratio increases, and after the passage of a

67

minimum point it begIns to increase.

The mass ratio corresponding to the minimum totalenergy is between 138/98 and 148/88.

The energy gain from the symmetry to the mostprobable asymmetry is about 3.5 MeV, which lowers the height of the second barrier from 9.0
MeV to 5.7 MeV.

The calculated barrier height is in good agreement with the experimental

value, but the mass ratio is somewhat larger than the experimental one (140/96).

The

discrepancy could be resolved if the most probable asymmetry was determined not at thesecond suddle point but at the later stage of the fission process.

However, we do not try it

here, because many difficulties remain concerning the method of shell corrections and pairingcorrection at such two-center-like deformations.
From Fig. 2, it can be seen that preference for mass asymmetry is due to shell correction.
This fact is checked from the single particle energy spectrum at these deformations.

At thesecond barrier, the level density of the spectrum near the Fermi surface decreases as the mass
ratio increases from 1.0.

This might be the consequence of the shell structure arising from

nascent fragments.

Toto I Pot. energy- - - L.O. M. energy--------- Shell Corr. energy

2'nd
4 -------- . .
....

2

,
""

barrier

Zo=8.6fm

81= 82 = 0.3

,
'"

128

138',....

148........

Fig. 2.

158 MH",-----------

Energies at the second barrier (zo =8.6fm. and 01 = 02 = 0.3) as afunction of mass asymmetry. The
abscissa is the fragment mass and 118
means the symmetric shape. The solidline represents the total potential
energy, the dot-and-dash line, the liquid
drop energy, and the dotted line , theshell correction energy. The liquid
drop energy is normalized to zero at
the spherical state ( 0 = 0.0, Zo = 0 ,and a = 1)

.. '~

68

References
1)B. B. Brack, H. C. Britt, J. D. Garrett, O. Hansen, and B. Lerouce

Third Symposiumon the Physics and Chemistry of fission, Preprint (1973).
2)

M. Brack, J. Damgard, A. S. Jensen, H. C. Pauli, V. M. Strutinsky, and C. Y. Wong
Rev. Mod. Phys., 44, 320 (1972).

3)

J. Maruhn and W. Greiner : Z. Physik, 251,431 (1972); M. G. Mustafa, U. Mosel, and
H. W. Schmidtt : Phys. Rev., C7, 1519 (1973).

4)

C. Gustafson, 1. L. Lamm, B. Nilsson, and S. G. Nilsson: Ark. Phys., 36, 613 (1967);
D. A. Arseniev, A. Sobiczewsky, and V. G. Soloviev : Nucl. Phys., A139, 269 (1969).

5)

M. Bolsterli, E. O. Fiset, J. R. Nix, and J. L. Norton: Phys. Rev., C5, 1050 (1972).

6)

H. V. Groote and E. Hilf:

Nucl. Phys., A129, 1 (1966).

69

5-2. A Ipha-Decay of

215Fr

K. Hiruta, T. Nomura, M. Yoshie, and O. Hashimoto

The a-decay of 21sFr has been studied by the pulsed-beam method reported in our recent
papers.1 ) '"'-'3 )The francium isotope 21SFr was produced in the bombardment of 209Bi with 72",81

MeV 12C-ions from the cyclotron and its lifetime was measured between the beam bursts of the

L

LL

(")

200

N

80 MeV

~5

u

;:r.
N

i1

150

l

'"LL'-

E
L

LL

<T

<T

N

N

C'0

<t:

100

a)

~

50

Q)

c
c

a

.c
<.)

0

L
Q)

a.
<f>

+-'

c

::l

73 MeV

150

0

U

1

I.

100

1

I

50

........f. ::., ..... .......

....
.... ....
...... .........
"'~

..

~

0~O~------------~10-0----------------2~O-0------------~3~00~----~----~4~OO~--------~500

ChannelFig. 1.

numberAn a -particle spectrum resulting frombombardment of 209 Bi with 80 and 73 MeV

70

cyclotron.

Fig. 1 shows a typical delayed a-spectra from the 209Bi + 12C reaction.

The groundstate of 215Fr has been found to decay with Ea = (9.355 ± 0.020) MeV and tl/2 = (0.12±0.02) MS.
The mass assignment of 215Fr was made on the basis of its excitation function, angular
distribu tion, a-decay energy, lifetime, and a-decay chain relation.
The experimental and theoretical reduced a-widths of N= 128 isotones from 212pO to 218Th
are shown in Fig. 2.

The experimental reduced width was deduced from r~= ~~ , where A isthe decay constant and P the barrier penetrability calculated for S-wave a-particles and for apure Coulomb potential with R=1.57A l / 3 fm. The theoretical values of the reduced width
were obtained from a shell-model calculation,4 ) in which we assumed 208Pb as an inert core andput valence nucleon into the lowest shell-model orbitals outside the core , i.e. , the lh9/2 orbitalfor protons and 2g9/2 for neutrons.

The reduced a-width of 215Fr fits very well to thegeneral trend of N= 128 isotones and agrees with the calculated value.

This also justifies the

In consequence, the spin andassumption that the decay of 215Fr proceeds mainly via S-wave.

parity of the ground state of 215Fr are the same as those of the ground state of 211 At, whichis (9/2)-.
4.0

84

85

86

Protonnumber

87

88

89

90

91

92

I

J

~ 3.0

"U
<I)

~ 2.0

"U
<I)

n:::

1.0

Fig. 2.

Experimental (solid circles) and theoreticaP reduced a - widths forthe ground state decay of N= 128 isotones. The theoretical values
are normalized on the experimental value of 212 Po.

References

1)

T. Nomura, K. Hiruta, T. Inamura, and M. Odera

Phys. Lett., 40B, 543 (1972).

2)

K. Hiruta, T. Nomura, T. Inamura, and M. Odera

ibid., 45B, 244 (1973).

3)

T. Nomura and K. Hiruta:

4)

H. J. Mang:

Nucl. Instr., 108, 61 (1973).

Phys. Rev., 199, 1069 (1960).

71

5-3.

Magnetic Moment of the

29/2+ Statein 213 Fr

E. Recknagel, Y. Yamazaki, O. Hashimoto,
S. Nagamiya, and K. Nakai

The level structure of the neutron-closed 213Fr nucleus (N :::: 126) was recently studied byMaier et al. 1) and the existence of the isomeric 29/2+ state (T 1/2:::: 0.5 /..ls) was discovered asshown in Fig. l.
29/2+.

The main configuration of this state was assigned to be [(1Th49 / 2 ) 8+ @ 1Ti13/2)'

Measurement of the g-factor of this state will give a good check of the above assignment.

If the assignment was found to be valid, this state would be very suitable for deduction ofeffective orbital g-factor.
A liquid metallic target of enriched 204Hg was bombarded with 94 MeV 14N beams fromthe cyclotron to populate the 29/2+ isomeric state via the 204HgC 4N, Sn) 213 Fr reaction. The
680 keY (29/2+ ~ 23/2-) gamma-ray was detected with two NaI (Tl) counters placed at ± 135

0

to the beam axis , in order to observe the n ::: 2 storoboscopic resonance. The result shown in
Fig. 2 gives g (uncorr) ::: l.04 ± 0.0 l.

If a correction 0.0 ± l.0 % is made for the Knight shift

and diamagnetism, we obtaing (corr) ::: l.04 ± 0.02.
There exists appreciable enhancement in the B (E3) value from the 29/2+ state to the 23/2 state in 213Fr as well as in the corresponding transitions in 211 At and 21OPO.

If theseenhancements are ascribed to the admixture of the core-excited 3 - state in 208Pb, we candeduce the mixing amplitudes by use of the weak coupling model, as shown in Table 1.

After

the correction due to this admixture, we obtain

1.00r------....,---------1f---,-------"j2535 - - . . - - - 29/2+ "--0.5 fLs

n= 2 Resonance1854 - - + - - - 23/21 589

2 1/ 2 -

1410
1188

17/2-

"-' 1 fLs

13/2-

o
+-'

o
L

0.95

(I)

::0
::J
o

a

0-------

Fig. 1.

Energy levels of 213 Fr proposedby Maier et al. 1 )O. 90 L----------:- 0----------",--::0.l-.0:::-------:-,~1.0
9
H (kG)
L-.

Fig. 2.

The n ::: 2 storoboscopic resonance.
Solid curve gives the best fit assuminga Lorentzian line shape.

72g([(rrh4 9/2 ) 8+@rri 13 / 2 ] 29/2+) = 1.05 ± 0.03.

In Table 2, the g-factors of the (rrh9/2 )n-1 @rri I3 / 2 states are listed , where the value for 210pO
has been calculated from the experimental g-factors by use of the additivity relation. The
agreement of these g-factors supports the configuration assignment by Maier et aLI)
The effective gQ-factor can be obtained by use of the following equation, because theg-factor in question is insensitive to the ambiguity of the effective gs-factor and the first orderconfigura tion mixing 8 J.L 1st.

Table

1.

B(E3) values of 11 - -+ 8 2+ in 210PO and 29/2+ -+ 23/2 - in 211At and 213Fr.
Bexp (E3)* in e 2fm 6

210pO

46000 ± 10000
51000 ±

211 At35000 ±

5000

0.10 ± 0.04

5000

0.10 ± 0.06

5000

0.06 ± 0.03

7000 6 )

40000 ± 10000 5 )213Fr

a 2 ***

Bs. p.(E3 ,rri I3 / 2-+rrf 7/2 ) * *9000* The experimental values for 210pO and 213Fr were measured by Fant 4 ) and byMaier et ai, I) respectively,

The difference between the values reported by

Bergstrom et a1. 6 ) and by Maier et a1. 5 ) for 211At was due to the difference inthe estimation for the branching ratio.
* * This single particle value was calculated by use of the radial matrix element<f7/2lr3Ii 13/2>=196 f m3.6 )* * * Squares of mixing amplitudes of the collective 3- state were deduced by use of
the weak coupling model.

Table 2.

The g-factors of (rrh9/2 )n-l @ rri 13 / 2 states and the deduced
anomalous orbital

Nucleus

Jrr

gexp

21OPO

11 -

1.107 ± 0.019

211At

29/2+

l.03

213Pr

29/2+

l.04

g-factors.

g ([rrh9/2rri13/2 ] 11)* g([(rrh9/2 )n- l @rri I3/2 ] 29/2+)*
l.15 ± 0.03

8gQ

l.09 ± 0.03**

0.13 ± 0.03

± 0.041.05 ± 0.05

0.10 ± 0.05

± 0.02

1.05 ± 0.03

0.10 ± 0.03*

These values are corrected for the mixing of the collective 3- state.

**Calculated by use of the additivity relation from g(rrh 9/2 ) = 0.910. 8 )73

If we use the value obtained from the blocking effect 2 ) as the first order configuration mixing

6' PI s1' we obtainogQ = 0.10 ± 0.03,

which is in good agreement with the previously reported va1ue. 3 )References
1)

K. H. Maier, J. R. Leigh, F. Piihlhofer, and R. M. Diamond: Suppl. J. de Physique,32, C6-211 (1971).

2)

Y. Yamazaki, O. Hashimoto, H. Ikezoe, S. Nagamiya, K. Nakai, and T. Yamazaki:
IPCR Cyclotron Progr. Rep., 1 74 (1973).

3)

T. Yamazaki, T. Nomura, S. Nagamiya, and T. Katou: Phys. Rev. Lett., 25, 547 (1970).

4)

B. Fant: Physica

5)

K. H. Maier, J. R. Leigh, F. Piihlhofer, and R. M. Diamond

Scripta,~,

175 (1971).
Phys. Lett. ,35B, 401(1971).
6)

I. Bergstrom, B. Fant, C. J. Herrlander, K. Wikstrom, and J. Blomqvist

Scripta , 1, 243 (1970).

Physica

74

5-4. The Blocking Effectof the Ml Core Polarization
Studied fromthe g-Factor of the(Jrh9 / 2)6 8 + State in214Ra

Y. Yamazaki, O. Hashimoto , H. Ikezoe, S. Nagamiya,

K. Nakai, and T. Yamazaki

In the past few years, a number of magnetic moments of isomeric states have beenmeasured in the lead region.

Among them, g-factors of (1Th 9/2 )n states measured so far haveagreed well within experimental errors, as expected from the additivity.

According to theconfiguration mixing theory of Arima and Horie, l) however, a correction due to the corepolarization of (1Thl~:21Th9/2 )1+ type is proportional to the number of holes in the h9/2 orbital,
so that the g-factor of the (1Th9/2)n state decreases as the number of protons in the orbital
increases.

By observing this so-called blocking effect, we can study the mechanism of the corepolarization.
Recently, Maier et al. 2) have found an isomeric 8+ state (T 1/2 = 67 Ils) in 214Ra, whose
main configuration is considered to be (1Th9/2)6 8+.
states for the study of the above problem.

This state is one of the most suitable

In addition, the measurement of the g-factor ofthis state presents another interesting problem as to whether the nuclear alignment is preserved
over a few 10 Ilsec or not.

2CGPt,( 12C ,4n )214 RQ(a)8+ state

206 P b (12C , 4 n ) 21 4Ra

at 270°C(b)

8+ stateroom tempe rature

14 ·V= 6167!OAkHz

1.3

H, = 33G\.6
Y= 640.4! O.lkHz

o
en

Z

~1l

~

z

z

'-

o

z 1.6

v= 640 .1! 0.3 k Hz

HI = 5.5G

1.5
1.4

1.2

HI = 2 .7 G

~ 611U
Y ~? ??
II

y= 64 1.1 ! O. 2 k Hz

1.3
800

900

1000

BO O

1100

9 00

H (G)

1000
H o(G )

Fig. 1.

Typical NMR patterns for the8+ state in 214 Ra.

1100

75

The measurement was carried out by use of the in-beam r-ray NMR method (NMR/PAD).
The state was populated via the 206Pb 2C, 4n)214Ra reaction with the 90 MeV 12C beam fromethe cyclotron.

The r-rays followed by the reaction was detected by two NaI(Tl) detectors

placed at 90° and 0° with respect to the beam direction.

A static external magnetic field Ho

was applied parallel to the beam direction and its strength was varied automatically.

An

rf-field with fixed frequency was applied perpendicularly to H o , and the ratio N(00)/N(900)
was observed at two different temperatures, 270°C and room temperature.

Typical NMR

patterns obtained are shown in Fig. 1, where the solid curves are those fitted by the theoretical
function by Matthias et a1. 3 )No significant difference was observed between the two temperatures.

In addition, the present NMR experiments indicate that the relaxation time is about 300 J.1.s oreven longer at room temperature, while the relaxation time due to the interaction with
conduction electrons is estimated to be 150 J.1.S from the data of 207Pb in the Pb metal.

The

above two facts suggested the small effect due to quadrupole interaction by the radiation
damage.
The g-factor obtained isg(corr) = 0.881 ± 0.006,
where the correction of 0.0 ± 0.5 % was made for the Knight shift and diamagnetism , because
they are expected to cancel out each other approximately.4 ) , 5 )The g-factors of the (7Th 9/2 )n states will decrease linearly with the particle number n as
given by the following equation:

0 .92

0.90

------..;(

r--.. -.. . .

0.88

0.86

0.84

2

Fig. 2.

3

4

5

The g-factors of the (Kh%)n
sta tes. The dotted line gives
the best fit for the experimental
da ta, and the solid line shows
the theoretical prediction by
Arima and Rorie. 1 )76

g = gSchmidt +2+ 1

2 + 1/2 8g e +9 - n
88 gcore(p) + 8gcore (n) + 8gothe f'where 8g e is the anomalous part of the orbital g-factor,6 ) 8gcore (p) and 8gcore (n) arecorrections due to proton and neutron core polarization in the n = 1 case, respectively, and8gother is the other possible corrections such as the anomalous part of the gs-factor due tomesonic exchange current or the higher order configuration mixings.

The third term of theabove equation represents the blocking of the proton core polarization of (1Thl~:2 1Th9/2 ) 1+ type.
From the data of the g-factors of the states in question summarized in Fig. 2, we can deducethe 8g core (p) to be
8gcore(p) = 0.05 ± 0.01
Possible isotone dependence of the 8got her will reduce the blocking effect. *, * * By taking thisdependence into account, we obtain
8gcore(p) = 0.07 ± 0.02
This value is about one half of the theoretical predictions. 1 ), 7 ), 8 )to be 0.13,6 ) we obtained 8gcore (n) + 8gother = 0.12 ± 0.02.

Since the value 8gQ is known

One of possible interpretationsof this fact will be given by assuming that 8gcore (p) is comparable to 8g core (n).

Thecalculation performed very recently by Arita* seems to support this assumption.
References

1)

A. Arima and H. Horie : Progr. Theor. Phys., 12, 623 (1954).

2)

K. H. Maier, J. R. Leigh, F. Piihlhofer, and R. M. Diamond: J. de Physique, 32, C6-2l1(1971).

3)

E. Matthias, B. Olsen, D. A. Shirley, J. E. Templeton, and R. M. Steffen

Phys. Rev.,A4, 1626 (1971).
4)

L. E. Drain : Met. Rev., 12, 195 (1967).

5)

F. D. Feriock and W. R. Johnson: Phys. Rev. Lett., 21, 785 (1968).

6)

T. Yamazaki, T. Nomura, S. Nagamiya, and T. Katou : ibid. , 33B, 574 (1970);
S. Nagamiya and T. Yamazaki: Phys. Rev., C4, 1961 (1971); T. Yamazaki: Suppl. J.
Phys. Soc. Japan, 34, 17 (1973).

7)

H. A. Mavromatis and L. Zamick : Nucl. Phys., Al 04, 17 (1967).

8)

J. Blomqvist, N. Freed, and H. O. Zetterstrom : Phys. Lett., 18, 47 (1965).

***

K. Arita:
K. Ogawa:

Private communication (1973)
ibid.

77

5-5. In-BeamAlpha- and Gamma-Spectroscopy of216Ra

T. Nomura, K. Hiruta, M. Yoshie, and O. Hashimoto

By means of the in-beam alpha- and gamma-spectroscopy, we have investigated the levelstructure of 216Ra, about which nothing is known at present. Delayed alpha- andgamma-transitions were measured in the 208Pbe 2C, 4n) 216 Ra reaction by the pulsed beam method
using natural beam bursts of the cyclotron.

The results obtained are listed in Table 1.

Thesealpha- and gamma-transitions were assigned to 216Ra on the basis of their excitation functions
and found to have the same lifetime of about 7 ns.

This indicates the existence of an

Table 1. Delayed a- and r-transitions in the 208Pb e 2 C,4n) 216 Ra reaction.
Relative
intensity

9349 (6)*9525 (7)o9551(14)9731(15)206(10)

1.0 X 10-2

10182(20)10374(21)849( 16)

1.6 x 10-3

10491 (1 0)10689(11 )1164 (6)2.5 x 10-3

10823(10)11027(11)1502 (6)3
5.6 X 10-11027(10)11235(11)1710 (6)

8.7 X 10-311345(24)11559(25)2034(20)4
9.6 x 10-11640(30)11860(31)2335(30)

4
3 x 10-(keY)

Relative
intensity

203.7

0.97

Q

309.3

1.06

D

314.8

1

Q

343.9

2.07

Q

475.8

1.37

Q

613.4

1.04

D

688.0

1.12

Q

Er

Multipolarity*** The ground-state decay.
** Q: quadrupole transition; D: dipole transition.

78

isomeric state in 216Ra with t 1/ 2 : : : : 7 ns.

Angular distribution measurements were carried out

for gamma-rays to assign their multipolarity.
The proposed level scheme of 216Ra is shown in Fig. l.

--~--1710.0

-

8+

203.2

---+--- 1507.8 6+
344.0---+- - 1163.8 4+
688,0
or
475.8
-

-+-- - 475 ,82+475.8 (or 688.0)
or
688.0

8+ <1680 - ------ 6+ 1540
4+ 150 1- - - 2+1274 - - - -0+0 ----

Fig. 1.

A proposed level scheme in 216 Ra.

79

5-6. Measurement of Half-Life in ms Region
with a Mechanical Chopper

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

For the study of half-life in the millisecond region, some improvements have been madein the mechanical beam chopper previously reported. 1) The time base depended on the rotational
speed of a DC motor.

But instability of the speed prevented very accurate measurement. The

block diagram of the new system is shown in Fig. 1. The time base generator consists of a
10kHz quartz-oscillator and a frequency divider which is controlled by external start-stop
pulses. The time interval of output pulses defines the time resolution of this system.
At the time of beam passage, the start pulse from a photo-transistor is applied to a timebase generator.

The output pulses of this generator advance the 4-bit binary scaler.

Paralleloutput signals of this scaler are coupled directly to the multichannel analyzer and the time baseis determined.

On the other hand, the linear gate for signals from the Ge(Li) detector is

opened by the output pulse of the binary scaler after some delay from the start pulse, which
is defined by the time base generator.

When the binary scaler was overflowed, a stop pulse

from the scaler is applied to the generator and to the linear gate, and these gates are closed
until the next cycle begins.

Thus we can obtain a two-dimensional spectrum with time andenergy base.
The half-life of 2.757 MeV (7 or 8- ) state in 132Xe excited by the 130Te(a,2n) reaction
has been determined.

The spectrum is shown in Fig. 2 and each peak was processed witha computer by fitting Gaussian distribution and decay curves obtained were analyzed by themethod of least squares fitting.
fitted curve.

A representative decay curve is shown in Fig. 3 with the

The weighted mean of half-life of 538, 600, 773, and 668 keY r-rays is

8.39 ± 0.11 ms.

Fig. 1.

Schematic diagram to study the half-life inmillisecond region.

80

14 ch

6 ch

~6'h

16ch.

102~------~---------L--------~--------~------~--------~
300
o
100
200
100
200
0
Channe I num ber

The time base of Y-coordinate is 5 ms/ channel.
Fig. 2.

Delayed r -ray spectra between 15 ms to 85 ms after bombardment.
10 5r - - - - - -_ _ _ _ _ _ _--...
132 Xe53 8 keJ a- Ray

1d '----'-_"""'"----'_........._....I...-----Io----L..--J-----J

o

10

20

30

40

50

60

70

80

T (ms)

Fig. 3.

An example of the decay
curve of de-exciting r -rays
in 132Xe.

81

5

10 ~~
I

170Er(~. 3n )171Yb

I

105r-----------~----------~
iD
)

104

I,/)

........

104~

2 Ch.~h

2Ch

C
::::l

0

u

4.......
Ch .
--...L..-.

10

4

~Ch.

6Ch. ~Ch.
o

100

200

300

0

20

40

60 0

20

40

60

Channel number

The time base is 5 ms/ channel.
Fig. 4.

Delayed r -ray spectra emitted from the 170 Er (a, 3n) 171 Yb
reaction.

The isomer in 95.2 keY (7/2+ [633]) state in I7IYb is expected because of large changeof K-quantum number to de-excite to the 75.9 keY (5/2-[521]) state. This state de-excites
to the ground state with 9.2, 66.7, and 75.9 keY r-rays.

There was only one private report 2)

I70Er enriched to 96 % was bombarded withpresenting a value 5 ms without citing any error.

38 MeV a-particles and this isomeric state was excited by the I70Er(a,3n) reaction.
spectra and a decay curve are shown in Figs. 4 and 5.
5.25 ± 0.24 ms.
ratios. 3 )The

The half-life was determined to be

The 19.4 keY isomeric transition is reported to be pure El from L-subshell

Following the selection rule of asymptotic quantum numbers for El transitions, theabove isomeric transition is expected to be highly forbidden because of I~KI = 3 and

~I\ =

- 2.

8

Comparing with the Weisskopf's estimate, the hindrance factor is 2 x 10 .
The 257 keY r-ray corresponding to the transition from 0.382 MeV state to 0.125 MeV
state in 90Nb decays with 6.19 ± 0.08 ms half-life as shown by the curve c in Fig. 6. The
half-life previously reported was 10 to 20 ms. 4 )with TI/2 = 14 ms.

The 0.232 and 0.443 MeV r-rays decay

These r-rays are not yet determined from which nucleus they emitted.

It is necessary to measure excitation functions for mass assignment.
It was observed that 366 and 380 keY r-rays decayed with half-life of 9.7 ms from thestudy of the r-ray spectra obtained from the Au target by bombarding with 90 MeV I2C ions.
In the r-ray spectra taken in the time interval from 5 to 85 ms after the bombardment , the608, 425, 515, and 683 keY r-rays were observed.
S

These energies agree with those studied

by the decay of 204At by Dairiki ) and can be attributed to the (4 or 5-) -+ 6+ -+ 4+ -+ 2+ -+82

105.-------------------r
17'Yb 76 keY a-Ray

10 5 r - - - - - - - - - - - - - - - - - ,B9 y + cx{oj 232 keY '(-roy(b) 443
10 )

(c)

258

~

Ib)

T.,.=5·7ms

\

~! I
j

1
10 0!---::''-:-0--=2'-:-0--=3'::-0--:"'-:-0---=507----::670 --=7':-0---='80iO

20

T (ms)

Fig. 5.

30

"0

50

60

70

Be

T (ms)

Decay curve of 76 ke V r -ray.

Fig. 6.

Decay curves of (a) 232
keY, (b) 443 keY, and(c) 258 keY r -rays.

0+ transition in 204PO with the order mentioned above.
r-rays also show a character of

The excitation functions of thesee C, 6n) reaction. The excitation function of the delayed2

r-rays almost agrees with that of thee C, 6n) reaction. And we propose the existence of a new2

isomer in 204At or 20SAt with a half-life of 9.7 ms.

Further experiment is in progress.

References

IPCR Cyclotron Progr. Rep., ~, 72 (1971).

1)

A. Hashizume and H. Kumagai:

2)

J. Radeloff, J. N. Buttler, K. W. Kesternich, and E. Bodenstedt:

Byrmont, Fachausschuss Kernphysik, (1967).
3)

G. Kaye:4)

H. B. Mathur and E. K. Hyde:

5)

J. M. Dairiki:

Nuc!. Phys., 86, 241 (1966).
Phys. Rev., 98, 79 (1955).

VCRL 20412 (1970).

Friihjahrstagung Bad

83

6. NUCLEAR INSTRUMENTATION

6-1. New

Data Processing System

T. Wada, T. Nomura, H. Kamitsubo,
Y. Chiba, and F. Yoshida

Since an on-line PHA system!) was installed in 1965 for the experiments with the IPCR
cyclotron, a new computer with higher speed and larger memory capacity is needed as thedetector system has been developed.

A new on-line PHA system with OKITAC 4500C

computer has been installed for this need.
functions.

It includes a hard-ware memory increment and list

With these functions and large capacity of disk storage, it can be used for high-speed

data acquisition.

A large memory capacity enables data processing during the data acquisition.

The brief specifications of OKIT AC 4500C computer are as follows;
Word length
16 bits + parity,
Memory16 kW, 0.6 j1sec. cycle time,Page
256 words, memory protection is in page unit,
Speed
Adding

1.4 I-Lsec

Floating point adding

3.5 I-Lsec

Multiplying

6.1 j1sec

Floating point multiplying

10.7 j1sec,

OKITA C

4500C

Exlerna I
cha nn el

i HM XC)

Fig. 1.

OKITAC 4500C PHA system configuration.

84

Interrupt level
16 levels.
I/O speed
1. 7 mega bytes/sec (max).

Figure 1 shows a block diagram of the whole system.

There are four ADCs connectedwith the computer and the following five coincidence modes can be selected;
(1)

PHA I

A (I/L), B (I/L), C (I/L), D (I/L)

(2)

PHA 2

A (I/L), B (I/L), C-D (I/L)

(3)

PHA 3

A-B (I/L), C-D (I/L)(4) PHA 4

A (I/L), B-C-D (L)(5)

A-B-C-D (I/L)

PHA 5

where the four ADCs are named A,B,C, and D, the hyphen (-) shows the coincidence pair andI/L shows the selection of increment/list mode.

In the list mode the external channel (HMXC)

transfers the data from ADCs into the computer memory independently the CPU program andsends interrupt signals only when a preset number of words are transfered, and then thecomputer dumps the words of the area on the disk storage.
plates of fixed and cartridge type.

The disk storage has two disk

The system programs are written in the fixed plate and theexperimental data are stored in the cartridge type plate.
There are switches and push buttons on the control panel simulating a wired PHA unit.

1.

MonitorArea( 2.5kWl
2.5kW

II.

PHA

Program(2 kW 1
4.5kW

m.

Data

Processing

Program( 3kW 1
7.5kW

lV.

Data

Area

( 8.5kWl

16kW

Fig. 2.

OKITAC 4500C memory allocation.

85

These are used to select the memory region to display on the CRT or to change verticalscale for and to start/ stop of data acquisition or data transfer, etc.
Figure 2 shows the memory allocation.

In the area III stored are the programs for data

manipulation, transfer of data, background subtraction, peak area integration and so on.
programs are called from the disk storage into this memory area.
programs has higher priority than the display program.

The execution of these

The previous DDP-124 system will be

used for off-line data analysis and for a variety of scientific computations.

Reference

1)

T. Wada, Y. Chiba, K. Matsuda, and M. Yoshimizu

L 62 (1967).

The

IPCR Cyclotron Progr. Rep.,

86

6-2. Interface between PHA

Units and OKITAC

4500C Computer

T. Wada, S. Takeda, and H. Kamitsubo

An interface between PHA units and the new OKITAC 4500C on-line computer has been
constructed.

Fig. I shows a schematic diagram of this interface.

The interface controls four

PHA units and up to ten scalers for start/stop data acquisition, and transfers the data stored inthese units to the computer.
(1)

Data acquisition

In order to be used for two independent measuring systems, four PHA units and thescalers can be divided into two groups.

Any units can be selected to belong to one of the twogroups or to be off-line, by a three-position change-over switch.

If the start/stop button on oneof these units or on the panel of this interface is pushed , all other units in the same group arestarted/stopped.

The on-line computer is also regarded as a PHA unit in this case.

computer sends and receives two pairs of signals of start/stop.

The

There are two pairs ofstart/stop buttons on the panel of this interface corresponding to two groups.
(2)

Data transfer

The following data are transfered to the computer : (i) the status of group selection
switches (one for each unit) , (ii) the status of power on/off of all units, (iii) the status of six
four-digit digital switches, (iv) contents of each scaler, and (v) contents of the core memory of
the four PHA units.
channel.

The contents of each PHA unit are read out through the parallel printerThe data flow is one-way.

There are two transfer-start push buttons on the panel for the two groups.
button is pushed, the interrupt signal is sent to the computer.

When theThe computer first reads thepanel data ( (i) - (iii) ), and analyzing the data (i) and (ii) by software, transfers the contents ofthe selected scalers and PHA units.

Acum . / Trons.
Start I Stopgroup 1 :group 2data---+--+--- - - - - -- - ---+----+--

l ine

con t r ol

li ne

Fig. l.

Schematic diagram of the interface between PHA
units and the OKIT AC 4500C computer.

87

7. A TOMle AND SOLID-STATE PHYSICS

7 -1 . Inner-She II Exe itation by N Ions and Alpha Partie les (1)Y. Awaya, T. Hamada, M. Okano, A. Hashizume,
T. Takahashi, K. Izumo, Y. Tendow, and T. Katou
Studies on the inner-shell electron excitation by heavy ion bombardment have been madeby many authors in these several years. Most of the experimental results obtained for the low
energy region of projectiles have been explained on the electron promotion mechanism whereformation of the molecular orbit between a projectile and a target atom is assumed.

If theprojectile energy becomes of the order of MeV/nucleon, the excitation mechanism is considered
to be different from that in the low energy region.

The Coulomb interaction between a

projectile and an electron seems to play an improtant role,I ),2 ) but experiments in this energy
region have been reported in a few cases.

The present experiment was intended to obtain

information about the inner-shell excitation mechanism in the high energy region.
The characteristic K and L X-rays from various elements excited by bombarding the target
atoms with 5 Me V /nucleon N4+ ions and a-particles have been measured with a high resolution
Si(Li) detector.

Target elements studied were 24Cr, 26Fe, 29CU, 38Sr, 47Ag, 56Ba, 1:~Nd, 71Lu,

82Pb, and 83Bi.

The targets of Cr, Fe, Cu, Ag, Pb, and Bi were made by evaporating these

metallic elements on the backing, while the others were made by sedimentation of theirinsoluble compounds.

Mylar film of 4 pm was used as the backing except Ag, for whicha thinner Formvar film was used.
Cr to about 350 pg/cm 2 for Bi.

Thickness of the target materials ranged from about .20 for

Only the K X-rays were measured for elements lighter than Sr.

In order to check

contributions of the nuclear Coulomb excitation to the X-ray spectrum, (-ray spectra were alsomeasured with a Ge(Li) detector.

The target was inclined at 45° with respect to both theparticle beam and the exit window of X-rays, and the X-rays emerging at 90° to the beam
were detected.

Between the target and the detector, there were two 50 pm Be foils, i.e.

a window of the target chamber and that of the detector, in addition to air of about 7 mm.
The relative efficiency of the Si(Li) detector was determined in the same source - detector
arrangement by using X-rays and r-rays from radioisotopes, 54Mn, 57CO, 65Z n , 109Cd, 137CS, and203Hg.

The effects on the efficiency of absorption of X-rays in the materials mentioned above

and of back-scattering from the backing were thus eliminated.

The relative efficiency curve

obtained is shown in Fig. 1.
The energy shift of X-rays was estimated by comparing the peak positions in the spectraof the X-rays from the particle-excited target atoms and those from the radioisotopes, 54Mn,
57CO, 65Z n , 88y, 109Cd, 137CS, 143,144 Pm, 175Hf, and 207Bi. The daughters of these isotopes emit

88

100

'">
-+-'

o

'"

0::

( keY)

Fig. 1.

Relative efficiency curve of the Si(Li)detector. Geometrical factors areincluded.

the same characteristic X-rays as those from the corresponding target elements but for Bi. The
peak position was determined by using the code of chi-square-fit assuming the pattern of a peak
to be Gaussian.

Unresolved peaks were also separated by the same code . In case of LX-rays

that consist of many components, the peak separation was made by referring to the transition
probabilities calculated by Scofield. 3 ) Typical spectra of K and L X-rays obtained by N ion
and a-particle bombardments and those from the radioisotopes are presented in Fig. 2.
The amounts of the energy shift of X-rays observed in the N ion bombardment are shownin Figs. 3 and 4.
separated.

The shifts in Kal and Ka2 lines are the same when these peaks can be

The shift of K{3l X-ray, which is dominantly affected by the number of vacancies

in L-shell, becomes maximum at Z ~ 38.

This may reflect the fact that the vacancy production

cross section for the L-shell becomes maximum when the condition E me/M u L

~

1 is

satisfied, where, E is energy of the projectile; M: mass of the projectile; me: electron mass;
and u L: binding energy of L-shell electron. This condition has been derived from the binary
encounter model4 ) in which it is assumed that the interaction leading to the inner-shell
excitation is the Coulomb interaction.

No shifts were observed in the case of a-particle

bombardment within the error of measurements.

10 1'00

10 2

10 2

Fig. 2.

U

o

:>

c

if)

:.eo 10 3

~

>-

:>

c

if)

104

105

V

~

:

Channel number

300

\i
'1\

1
\

,/"
I:

I

~ 'J~[~':~'I' I'1~ 1 1[~1 ., II,400,~.! (~ln~uJJhI / I,

~Nu~ UVi"~~~~/I!I\{lrIV

.
!r~

'\

Ij:J

~MJ. I ~'I

X-Rays1.,.........

:>

\,

\

/

I

~

I
'11](

I

i

Channel

300

I

1

~

\
I" ," 1 1
,

"

I

~I

Inl

'I

'1"1
"~

1'1/\

I

400

1.JJr

"

n

'IrI/1JlII~',tJ~

\I!I

~

1!1,,/I'11111/1J:!,il111;'1\'l"'~~1rll~~ Il.'I·'·I"'~

11'.1'! '1. ~II
,J

1,1

I I\I
I'

numbp.r

I

1\

I.
J

''-

\,

r",

!

L X - Rays

and by the decay of 1 75 Hf.

and by the decay of 65 Zn.

Spectra of L X-rays obtained by N ion

2 00

1\

, \,

I\

10 2n~\I't~JIIl//i1,,)f'fWf-.J'
I'""". ~. ,)~!tlll~/.;175Hfi ,( \I.{Lo + a''1'"...

(b)\

J!"'\ J\\ \ / (\4

Lu + N +",",,,,,,,.,,,,~,~,

10 2 1-

10'

Fig. 2.

8

c

<J)

E

~~ l

c,

-f

103f--

104f-,\

and a -particle bombardments on Lu target

Spectra of K X-rays obtained by N ion

200

r,

I 1I

/

I.

/
U

'

I

f\

f

I) (

I
I

\

'.

J

)

o,r,

r

ir/
\,IVJ

v

I

1\

!i n'I)\ !\\'K

and a -particle bombardments on Cu target

(a)

Zn

!

\

;110".,'/

65-~J IWI'r/11I'w\, AnAI/1~~r

rV~WU" ~.

• n n "J..IIJ\

f'-'~
/~J

r

+ N4 +

Cd a

Cu

J

!

(\
1

00

\0

90

300

200
150 I-.
0x

100 l-

.

·

x

~

0

100

0

x

50 e-

·

.

U3

x

Lrl

0

Lr2,3

>

Q)

o
x

50

x

.

x

·

x

100
Ka:

o

·

.
50

50

WI

I

·

LL

I

I

1

70

80

90

100

z

Z

Fig. 4.

Energy shift of Ka, K jJ 1

Fig. 3.

Lex

x

·

o
50

.

Energy shift of LX-rays.

and Kp 2 X-rays.

0.21-

0.1 fN4 t

X

I

I

I

I

I

j

70 MeV
20 MeVj

0 .3 xJ

x1

0 .21-

0.1 -

10

20

30

40

50

60

70

I

I

80

90

2

Fig. 5.

Kp/Ka

values obtained by

I

j

I

I

104~0----~5~0----~
50~--~7~0-----8~0~--~9~0~

Z

Z

Fig. 6.

Intensity ratio of K and L

N-ion and a -particle bombard-

X-rays obtained by N ion andments.

a -particle born bardmen ts.

91

The variations of intensity ratios K{J/Ka with the atomic number are shown in Fig. 5.
A similar tendency of variation is found for the N-ion and a-particle bombardment. The ratiosof K and L X-ray yields for N ions and a-particles are shown in Fig. 6.
The ratio of the K X-ray yields obtained for N-ion and a-particle bombardments is shownin Fig. 7.

As the charge of N ion changes in the target, it is difficult to estimate its effective

charge at the Faraday cup exactly.

But, when the work on the charge exchange done by

Tonuma et a1. 6 ) and the thickness of the targets are taken into account, it may be concluded
that it is not so different from the equilibrium charge state, 6.9? ) Assuming the fluorescence
yields for both cases to be the same, this intensity ratio means the ratio of K-shell vacancy
production cross sections. If the atomic Coulomb interaction causes the inner shell excitation,
the cross section will show the zp-dependence,4),S) where zp is the atomic number of the
projectile..

Then the value of z~ Iz~ becomes 12.25. The result expressed in Fig. 7 shows that,roughly speaking, the inner-shell excitation in this energy region is mainly due to the Coulombinteraction.

20r-

•

••
•
•

•

••

•

I

I

I

I

I

I

I

I

20

30

40

50

60

70

80

90

Fig. 7.

z

100

Ratio of K X-ray yields obtained by
N-ion and a -particle bombardments.

The present experimental results are the preliminary ones to which some corrections
should be made.

These corrections and the theoretical analysis of the results are now inprogress.

References
1)

M. J. Saltmarsh, A. vander Woude, and C.A. Ludemann: Phys. Rev. Lett., 29, 329 (1972).

2)

J. M. Hansteen and O. P. Mosebekk: ibid., 29, 1361 (1972).

3)

J. H. Scofield: Phys. Rev., 179, 9 (1969).

4)

J. D. Garcia: ibid., A.L. 280 (1970).

92

5)

E. Merzbacker and H. W. Lewis

Handbuch der Physik, Springer-Verlag, Berlin,

34, 166 (1958).
6)

T. Tonuma, I. Kohno, Y. Miyazawa, F. Yoshida, T. Karasawa, T. Takahashi, and S. Konno:
J. Phys. Soc. Japan, 34, 148 (1973).

7)

A. B. Wittkower and H. D. Betz: Atomic Data, Academic Press, New York and London,

2: 113 (1973).

93

7-2. Inner-Shell Excitation by N Ions and Alpha Particles (2)K. Izumo, Y. Tendow, Y. Awaya, T. Katou, M. Okano,
A. Hashizume, T. Takahashi, and T. Hamada

In the study of inner-shell excitation of atoms bombarded with high-energy ions,a continuous energy distribution of photons is always observed as a background in the low
energy region of X-ray spectra. I )Watson et a1. 2 ) ascribed this continuum mainly tobremsstrahlung arising from accelerated electrons produced by ionization of target atoms, but
no further detail has been given in his paper.
The experimental results obtained for X-rays emitted from various target materials
bombarded with alpha-particles or N-ions, some examples of which are presented in Fig.
(a)",(d), show the following features in the above-mentioned continuum:
The spectral distribution of photons falls off rather rapidly with increasing energy(1)and its end-point energy is quite low compared with the projectile energy.
(2)The end-point energy is almost independent of the atomic number of the target

material and also of the species of projectiles provided that their energies per nucleon are thesame.
These findings lead us to an anticipation that the continuum would be due to bremsstrahlung
from recoil electrons (delta-rays) created by the projectiles within the target.

To confirm this,we have made a rough estimation of the contribution from the bremsstrahlung to the X-ray
spectra, assuming the following procedures:(i)an incident ion collides with electrons in the target;(ii)

the recoil electrons radiate bremsstrahlung when they are passing through the electricfields of the target atoms;(iii)

a fraction a(k) of the radiated photons having a momentum k goes through thetarget itself, the backing material if any, the windows of the target chamber and the detector,
and the air between these two windows;(iv)

photons having a momentum k are detected by the Si(Li) detector with an efficiency€(k).

Then the momentum distribution of the photons dc(k)/dk is expressed by the following
equation:where

flux of the incident particles of energy E.t ;(isc(Ei,E e) : scattering cross section in which an incident ion of energy Ei transfers
an energy Ee to an electron;
6'B (Ee,k): radiation cross section in which a photon of momentum k is emitted by94

Target: Al

Projectile: 20 MeV-Q'(5 MeV Inucleon )!

5
Ene rgyof10
photon (keV)

15

Fig. lea)

Torget: Al

Projecti l e : 40 MeV-ex(10 MeV/nucleon)

10'Energy10of photon

15( keV )

Fig. l(b)2095Target: Ag

Projectile: 70 MeV-N( 5 MeV /nucleon)

1

5

10

Energy of photon

Fig.

( keV)l(c)TargetAg

Projectile:

40 MeV - CX'

1(10 MeV/nucleon)

.D
L-

o

--"'"

'-' I -0
2
-""'
-0
10

Energyofphoton( keV)

Fig. led)

Fig. 1 ( a) '" (d)X-ray spectra obtained for various conditions of ion bombardment as

indicated in each figure. The calculated energy distribution of bremsstrahlung
photons is represented by solid lines. An arrow mark in each figure shows
the position of end-point energy expected by OUf estimation.

96

an electron of energy E e ;number of electrons and that of target atoms per unit area of the target,
respectively.
We have neglected the binding energy of electrons on account of large momentum of theincident particles and effects of finite thickness of the target materials.

Electrons are treatedhere as non-relativistic.
In our case the Rutherford cross section 3 ) is represented by()sc ( E i , E e) =n ( zie 2)2mi

1

m e

e

E.

0_0-E2l

and the non-relativistic a B is written by the equation: 4 )where

ex : fine structure cons tan t;Zi

and m i : charge state and mass of incident particle , respectively

Z : atomic number of target atom;
Pe and p ~momentum of a recoil electron before and after photon emission,respectively;

r0: classical radius of electron.
Now we consider only a relative behavior of dc(k)/dk.

After simple calculations , we getdC( k)cx ~l~ (~) +~ ~(~) - ~~ Pn p+ p/
dk

k3

3

p

6 p2

P

4 p4

p- p/

I

a(k )E(k ),wherep= J k ll1ax / k
pI =

ell k
and

Eo

Jp
II.JX

2-

1

( in keY ) =2.2E o,: energy of incident particle in Me Y per nucleon.

The product of a(k) and c(k) has been obtained experimentally and its energy dependence
is shown in Fig. I of the preceding paper. 1 )In the lower energy region , however, it is very

difficult to find appropriate photon sources for calibration.
only above 10 keY.

So , we used the efficiency curve

In the lower energy region we assumed c(k) = 1 and estimated a(k) for

absorption by the two beryllium windows and air between the target and the detector.
OUf

results for the energy distribution of the bremsstrahlung photons are showngraphically in Fig. I (a)'" (d) as well as the experimental ones, where the theoretical curves
shown as solid lines have been adjusted up and down to fit the experimental distribution bestin the slope region, and an arrow mark in each figure shows the position of end-point energy
expected by our estimation.
Considering the simplicity of our estimation the agreement between the estimateddistribution and the experimental one is fairly good in each case.

For the end-point energy

97

and the slope of higher energy side the agreement is quite sufficient.

Remarkable discrepancy

in the extremely low energy part should be attributed to some other factors not considered
here.

Especially, in case of the Ag-target, it will be explained in terms of absorption of photons

in the target material.
References
1)

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

IPCR Cyclotron Progr. Rep., 2,87(1973).

2)

R. L. Watson, J. R. Sjurseth, and R. W. Howard

3)

E. Gerjuoy:

4)J. M. Jauch and F. Rohrlich : "The Theory of Photons and Electrons", Addison-Wesley

Nucl. Instr. Methods, 93, 69 (1971).

Phys. Rev., 148, 43 (1966).

(1954); W. Heitler : "The Quantum Theory of Radiation", 3rd ed., Oxford Press (1954).

98

7-3. Positron AnnihilationIn

V and Nb

N. Shiotani, T. Okada,
H. Sekizawa, and T. Mizoguchi

As a part of systematic studies of the electronic structure of transition metals, we havemeasured the angular distributions of two r -rays resulting from annihilation of positrons in V
and Nb.
The angular distribution curves were taken using a parallel-slit system. The geometricalangular resolution was 0.70 milliradian.

An about 300 milliCurie 58CO source was used.

The

electronic coincidence counting system used was a standard one with a resolving time of 100
nsec.

The coincidence counting rate N (8) was measured at an angle 8, and due corrections

were made on it for the decay of the source and the accidental coincidence.

The final counting

rate as a function of the angle was obtained by summing up the counting rates of several runs
with proper weights.

A vanadium single crystal of 99.999 % purity and a niobium single

crystal of 99.99 % purity were cut normal to the [100], [110], and [Ill] directions ofcrystals.

The surfaces of these crystals were chemically etched to remove distortions introduced

during mechanical cutting and then finished by electropolishing.

All measurements were doneat room temperature.
The experimental results on vanadium and niobium are shown in Figs. 1 and 2, respectively.
These curves show the annihilation rate as a function of the photon momentum perpendicular
to the r -rays, Pz'

They are not deconvoluted with the angular resolution functions of thesystem and of the thermal motion of positrons.
a constant.

The area under each curve is normalized to

The smoothed curves drawn through the experimental points were obtained bya procedure equivalent to evaluating at 8i the least-squares polynomial of degree 3 relevant to
the five successive points (N(8i+k)' 8i+k)' (k=-2, - 1, -----, 2).

The positions of the first

Brillouin zone boundaries along the [100], [110], and [111] directions are indicated by theletters H, P, and N, respectively in Figs. 1 and 2.

The anisotropy in the electronic structure

is clearly manifested in the angular distributions.

When the angular distribution curves arenormalized to the same area, there are little difference between V and Nb except for the finestructures on the [100] curve of Nb near P z = O.

At Pz = 0, the [110] curve is the highest

in counting rate, followed by the [111] curve, and the [100] curve is the lowest.

a concavity at H on the [100] curve.

There isBut no visible concavity is found at N or at P on the[ 110] and the [111] curves, respectively.

Beyond the zone boundaries there exsist some

anisotropies.
According to the energy band structures of V calculated by Wakoh and Yamashita, * thefirst conduction band is completely filled, the second band has a closed hole pocket, and the* S. Wakoh and 1. Yamashita: Private communication.

99

V

Experimental angu lor di stri buti ons
.t.

(110)

• • ••(11 1 )• • ••

(100)

Ao

....

(l)

+>
0
......

Fig. 1.

CT>

Experimental angular distributions in

c:

-+-'

P

c:

:::J

0

u

V along three principal axes of theHcrystal. N, P, and H indicate thepositions of the first Brillouin zone
boundaries along [110], [111], and[ 100] directions, respectively. The

angle () is converted to themomentum Pz = me () and

o.

0.5

1.0

1.5

Momentum inindicated on the abscissa in atomic

2.5

2.0
A.U.

unit.

Nb

Experimental

angular distributions
....

(110)

• • ••(11 1 )• • ••

(100)

1.5

2.0

Ao

..

(l)

-+-'

o

I...

Fig. 2.
Experimental angular distributions
in Nb along three principal axes of
the crystal. N, P, and H indicate thepositions of the first Brillouin zone
boundaries along [110], [Ill], and[100] directions, respectively.

o

0.5

1.0

Momentum in A.U.

2.5

100

third band has a set of hole surfaces which are in distorted ellipsoidal shape and a multiply
connected jungle-gym hole surfaces consisting of interconnecting arms along [100] directions.
Based on the above mentioned band structures of V, we have proposed a tentative
explanation for the observed anisotropies in the angular distribution curves. 2 ) The shape ofthe distribution curves are for the most part determined by the filled band.
d-bands add fine structures to the curves.

The partly filled

In particular, the presence of the jungle-gym holearms along [100] directions and hole surfaces is reflected on the shapes of the angular
distribution curves, especially the flat top and the concavity on the [100] curve.
Reference1)

N. Shiotani, T. Okada, H. Sekizawa, T. Mizoguchi, and S. Wakoh
Positron Annihilation, Otaniemi, Finland (1973).

3rd Int. Conf. on

101

7-4. Positron A nnih ilation in Paramagnetic Nickel Single Crystal

T. Okada, H. Sekizawa, T. Mizoguchi, and N. Shiotani

Recently, we investigated the angular correlation of positron annihilation in ferromagnetic
nickel at room temperature, and the results have been reported already elsewhere.} )The study has been extended to the paramagnetic state, i.e., above the ferromagnetic
Curie temperature of 358°C.

The experimental apparatus was almost the same as in theprevious report} ) except high-temperature specimen holder.

The (110) nickel single crystal discwas mounted on a heat-insulated plate with a heater and fixed in an evacuated holder having
a window of 5 Jim stainless steel foil.

The positron source was put just outside the window

facing the crystal.

Two glass-covered windows on both sides of the holder were provided forthe emitted r -rays.

A conventional combination of two long-slit scintillation counters and anelectronic circuit system for coincidence was employed for the detection of 511 ke V r-rays.
The angular correlation curve obtained at 360°C is shown in Fig. 1 along with the curvesat room temperature with the external magnetic field applied parallel or antiparallel to thepositron beam.

Deconvolution procedures to take account of the finite instrumental resolution

are not yet applied to these curves.

The decrease in resolution due to the thermal effect would

be much pronounced for the paramagnetic curve.

However, a rough estimation of the effectrevealed that it cannot account for the remarkable change in the shape of the paramagnetic
curve compared with the ferromagnetic ones.

We have tried} ) to explain the shapes of theferromagnetic curves based on the shapes of the Fermi surfaces of nickel calculated by

-20

-10

o

-5
Angle

Fig. 1.

in

1-Ni (110)at 360°C

2- Ni (110)

field paralle l at room temp.

3- Ni (110)

field ont ipara llel at room temp.

5

10

20

milliradians

The angular correlation curves of (110) nickel single crystal at 360° C and atroom temperature.

102

Connolly,2 ) but without much success.

Elaborate calculation of the matrix elements dominating

the momentum dependence of the positron annihilation processes based on the calculation ofelectron and positron wave functions would be indispensable for further discussions.
Further experiments on crystals with orientations other than (110) and detailed
theoretical considerations are in progress.
References
1)

N. Shiotani, T. Okada, H. Sekizawa, T. Mizoguchi, and T. Karasawa
35, 456 (1973).

2)

J. W. Connolly:

Phys. Rev., 159, 415 (1967).

J. Phys. Soc. Japan,

103

7-5. Point Defects

Irradiated Copper and Cu 3AuIn

H. Sakairi, E. Vagi, A. Koyama,
T. Karasawa, and R. R. Hasiguti

The purpose of this study is the identification of point defects contributing to annealingstages appearing on metals damaged by irradiation.

A series of experiments on copper andordered CU3 Au alloy were already performed.
This year, the annealing of disordered CU 3 Au alloy irradiated at liquid helium temperature
was experimented.

Initial specific resistivities of disordered CU 3 Au specimens used in two

irradiation runs were 9.995 and 9.649 /In ·cm respectively.

Each was irradiated by 17 MeV

alpha particles from the cyclotron, together with a pure copper specimen for comparison.
Results of irradiation and stage I annealing are listed in Tables 1 and 2.

The increase ofresistivity of disordered CU3 Au is about three times as large as that of Cu.

However, theamount of the stage I recovery of the alloy is smaller than that of Cu. That is, the stage
annealing of disordered CU 3 Au is suppressed compared with that of Cu.
difference between ~pl(CU3 Au) for two runs are not certain.

The origin of theIt may be ascribed to thedifference of the initial degree of disorder shown by the difference between initial specificresistivities of two specimens.
These results support the explanation of the annealing process with the conversion-twointerstitial model,l ) in which the stages I and III annealings are supposed to be caused by the
migration of crowdion type metastable interstitials and split type stable ones, respectively.
Table 1.

Resistivity increase by irradiation.
~p

Dose
(10-

1 5

ex/cm2)(Cu 3 Au)

(Cu)

~p

(10- 8 ohm·cm) (10- 8 ohm·cm)

Run

I

lAS

404

1046

Run

II

1.56

5.1

1.70

Table

2.

Resistivity decrease by stage I annealing.
~pl(CU3 Au)~pl(Cu)(10 - 8 0 hm·cm)(10- 8 0hm·cm)

Run

I

0040

0.92

Run

II

0.14

0.96

104

With this model, the suppression of the stage I annealing in disordered CU3 Au can be explainedby the conversion of metastable crowdions into stable and less mobile interstitials because of theunsymmetrical atomic configuration in disordered alloy.
Reference
1)

W. Bauer, A. Seeger, and A. Sosin

Phys. Lett., 24A, 195 (1967).

105

8. RADIOCHEMISTRY

8-1 . Mossbauer Em iss ion Spectroscopy ofafter the EC

119S nDecay of 119 sb

F. Ambe, S. Ambe, and N. Saito

We have been studying the valence state of 119Sn after the EC decay of 119Sb in a variety
of matrices by the nuclear gamma-ray resonance (Mossbauer effect) of the 23.8 keY transitionof 119Sn .1)"'-'S )In this period much amelioration has been attained in the procedures for
producing the source nuclides C19 Sb and 119mTe),6 ) in the counting system of the resonant
gamma-rays, and also in the computer program for analysis of the spectra obtained.

100

o

0

0 0

(a)

98
~
<J)

C
<Ll
+'
C

~

;:

10 0

0 0

a
<Ll

Ct:

( b)

119Sb

20

3

98

Relative(a)velocity(mm/sec

vs

B aSn0 3)

Decomposition into two singlets and adoublet with the same width.

(b)

Decomposition into a singlet and a pair ofdoublets each with the same width.

Fig. 1.

Typical results of the computer fitting of theemission spectra of 119 Sb 2 0 3 .

Under the106

improved conditions, the emission spectra of the metals , oxides, and chalcogenides of antimony
and tellurium were redetermined and analyzed, and, at the same time , the object of the study
was extended to other matrices such as halides, compounds with complex ligands and materials
containing tin as a macro-component.

Some results obtained are described briefly below.

The emission spectrum of 119Sb 20 3 was reported already without detailed analysis. 3 )Computer decomposition of the spectrum showed that the dominant doublet attributed
tentatively to the Sn(ll) state is asymmetric both in area and width.

Since the Sn(ll) ions arein the non-magnetic 1So state, asymmetry in area but not in width can be expected for aquadrupole doublet of the Sn(ll) species in an isotropic powder sample due to the anisotropyof the Debye-Waller factor.

Least-squares fitting of the observed doublet to a pair ofLorentzians with the same width discloses a line with an isomer shift of about 1.9 mm/sec
versus BaSn0 3 (Fig. I (a»).

The valence assignment of the fourth line is not straightforward on

the basis of the Mossbauer data accumulated so far on tin compounds, though the isomer shiftsuggests metallic tin , Sp3 type Sn(lV) species or an Sn(llI) state. Alternately the apparent
doublet can be decomposed into two sets of doublets, each with the same width, assuming two
different sites of 119Sn atoms in the Sb 20 3 lattice (Fig. l(b».
Reproducibility was finally attained in the emission spectra of 119Sb 2Se 3 3 ) as a result of
an improvement of the purity of the 119Sb metal used as the starting material.
spectrum obtained is shown in Fig. 2.

A typical

Thus a simple relation was established between thevalence distribution of 119Sn and the electronegativity of the ligand for the series of antimony
chalcogenides C19 Sb 2S 3 (sublimed samples),2 ) 119Sb 2Se 3 , and 119Sb 2Te 3 2) , 4 ) : the fraction of 119Snin the Sn(ll) state increases with the decrease of the electronegativity of the chalcogenide
ligands.

\ 00

i

\

>,

Ui
c
Q)

+-'
C
Q)

>

99 -

o
Q)

\

Sn ( IIlcr:

Sn (IV)98+8+4
Re lat i ve

Fig. 2.

ve lo city

( mm / secvS

B aSn0 3)

119Sn-Mossbauer emission spectrum of 119Sb 2 Se 3
at 78± 1 K against BaSn0 3 . In the abscissaa velocity of approach is taken negative.

107

The spectra of 119Sbl 3 consisted of two resonance lines assignable to the Snell) and Sn(lV)states respectively , as shown in Fig. 3.

The result presents an interesting contrast with thatof the corresponding cha1cogenide, 119Sb 2 Te 3 , for which no line was detected in the Sn(lV)region. 2 ) ,4 )

00

100

0

00
00

0",

0

0

"00
0

0

0

00J 0

0 0

CDQ

0

% °0 00 0 0

'1,0

"'0

119Sbl3

~
V>

c

Q)

......
cQ)>......
aSn{[V)

Q)

0:::

99

Relative

Fig. 3.

1J

velocity(mm/sec vs

Bo Sn0 3)

9Sn-Mossbauer emission spectrum of J J 9Sbl 3

at 78± 1 K against BaSn0 3 . In the abscissaa velocity of approach is taken negative.

0 0+4
Relative

Fig. 4.

velocity( mm / sec+8

vs So Sn03 )119Sn-Mossbauer emission spectrum of H6 119illTe0 6
at 78± 1 K against BaSn0 3 . In the abscissaa velocity of approach is taken negative.

108

Use of 119mTe, a parent nuclide of 119Sb, makes possible studying the valence state of
119Sn produced in matrices with hexavalent cations.
and a typical result is shown in Fig. 4.

Measurements were made on H6119mTe06

The spectra are composed of a broad peak centerednear the zero relative velocity versus BaSn0 3 , which may be identified as an unresolved
quadrupole doublet of Sn(lV).

We have already reported that the 119Sb atoms are distributed

between the Sb(lll) and Sb(V) states in the ratio of 5 to 95 after the EC decay of 119mTe
in H6 119mTe06 .7 )Taken together , the change of the valence following the successive EC

decays of 119mTe in telluric acid is summarized as follows:~ H 119mTe(VI)O

119Sb(V)

9S % /~ 119Sb(lll)

5 %119S n (lV) 100 % ~66

It was also reported already that the 119Sn atoms produced In Sb2119mTe3 are in adifferent chemical state from those in 119Sb 2Te 3 .2), 5 )A study of this type of defect atoms

has further been extended to matrices containing tin as a macro component. A result on
Sn l19 Sb* is shown in Fig. 5, together with the absorption spectrum of SnSb. As seen in the
figure , it can be concluded that the 119Sn atoms produced in Sn l19 Sb are in a defect state,whose electronic structure is different from that of the tin atoms in the normal lattice site.

100
Sn 1l9Sb
emission

>-

+-'
cJl

c:

.ec:

82

Q)

>
+-'

100

0
Q)

Cl:

Sn Sb
absorption

72oRelative

Fig. 5.

velocity(mm /sec

vs

BaSn03)

119Sn-Mossbauer emission spectrum of Sn 119Sb and absorption
spectrum of SnSb at 78 ± 1 K.

In the abscissa a velocity of

approach is taken negative and positive respectively.

e* Tin metal depleted in 119Sn 20Sn 98.39 %, 119Sn 0.39 %) was used in the preparation of the samples to decrease
the resonant self-absoption of the Mossbauer gamma-rays in the samples.

109

References

1)

F. Arnbe , H. Shoji, S. Arnbe , M. Takeda, and N. Saito: IPCR Cyclotron Progr. Rep.,
4, 115 (1970).

2)

F. Arnbe , H. Shoji, S. Arnbe , M. Takeda, and N. Saito: ibid. , ~ 85 (1971).

3)

F. Arnbe , S. Arnbe , and N. Saito: ibid., ~ 102 (1972).

4)

F . Arnbe, H. Shoji , S. Ambe , M. Takeda, and N. Saito: Chern. Phys. Lett., 14, 522 (1972).

5)

F. Ambe and S. Ambe: Phys. Lett., 43A , 399 (1973).

6)

S. Arnbe and F. Arnbe: IPCR Cyclotron Progr. Rep ., ~132

(1973) ; F. Arnbe,

S. Ambe , and H. Shoji: Radiochem. Radioanal. Lett. , 15, 349 (1973).
7)

S. Arnbe, F. Arnbe, and N. Saito: IPCR Cyclotron Progr. Rep. , ~ 104 (1972) ; Radiochirn.
Acta, in press.

1108-2. Charge States of Ions from

18 F

Decay

M. Aratani

The charge states of ions from 18F decay were studied by means of a charge spectrometer.
It was previously reported that 8+, 7+, and 6+ peaks were "big three" in the charge spectrumof ions from the decay of 18 F trapped on metal surfaces. One of the best results recently obtainedwith a copper surface is shown in Fig. 1. As may be seen, each peak is a doublet. The doublet

at the 7+ peak, revealed by the measurement in higher resolution is shown in Fig. 2. According
to the values of coil current, the narrow and broad lines are attributed to 18 0 7 + and 16 0 6+, respectively. ,/180n+ ions are considered to have been derived from 18 F atoms just decayed, as was previously
reported. 1) 16 0 species, however, cannot be radiogenic in the present case. 16 0 atoms havepossibly been trapped on the surface of the source during the preparation 2 ) of 18 F by the nuclear
reaction, 16 0
He, p)18 F. Mechanism of formation of 160n+ ions is not yet clear. A series ofeexpetiments will be made on the effect of oxygen on the charge states of recoils from 18 F
decay.

300

t
t
-

8+

;. 200 u

I

II
t

t
Q)

2

tt

C">

r

c:
c:

:::>
0

r

t

U

100f-

t t tf

t

Ht
+H

+
+

t

+f

t

,

+ t
+

1+t, t

t

, +

15

,

20
Coil

Fig. 1.

t t t,+ ' + t+ +H,

current( mA )

Highly charged ions from 18F decay.

111

250r-----------~

200

-E
DU

2 150
o
c...
cr>

co
co

::>

o
U

100

16
Coil current

Fig. 2.

17(m A )

A doublet at the 7+ peak.

References
1)

S. Yokoi, M. Aratani, and T. Nozaki:

2)

M. Aratani:ibid., 6, 99 (1972).

IPCR Cyclotron Progr. Rep., l, 88 (1971).

112

9. RADIATION CHEMISTRY AND RADIATIONBIOLOGY

9-1. Heavy Ion Radiolysis of Liquid Ketones

Effect of Water on the Radiolysis of Acetone

M. Matsui, M. Imamura, and T. Karasawa

The object of this series of heavy-ion radiolysis is to elucidate the characteristic
interactions of energetic heavy ions with liquid organic compounds.

The heavy ions whichhave very high LET were shown to induce unique chemical reactions in the radiolysis of liquidcompounds in a previous report,l ) in which acetone was dealt with.
Similar results have also been obtained with methyl ethyl and diethyl ketones. For these
ketones the yields of H2 and CO increase with increasing LET and reach maxima in theovicinity of LET = 50 '" 70 eV / A.

These significant results were explained to be due to thedecomposition of ketone molecules inside the reaction zone of a fixed radius. The thermalspike effect in the track core of the heavy ions was also suggested from the fact that the ratiosof G(H 2 ) to G(CO) increase with increasing LET.
This year we have carried out similar radiolysis experiments with acetone containinga small amount (2 wt %) of water to confirm the above conclusion.

Water added to acetone

has been known to give rise to an increase of G(H 2 ) in the r-radiolysis owing to its reaction

3

pure acetone- - - acetone + H20 (2 wt % 1

02°1·~----~--~--~~~~~~10~----~--~--~~~~~~102

Z( eV/A)Broken lines show the variation for pure acetone which
was reported in Ref. 1).
Fig. 1.

Variations with LET of G(H 2 ) and G(CO) from acetone
containing 2 wt% H 2 0 (solid lines).

113

with radical cations produced in the radiolysis of acetone.

It is also considered that water

may form hydrogen bond with acetone molecules, resulting in the transfer of excess energy
outside from the core and therefore the disappearance of the peaks of G(H 2 ) and G(CO).
Since the results of r-radiolysis revealed that the increase in G(H 2 ) is invariant between 2
and 5 wt% H 20, the heavy-ion radiolysis was carried out with acetone containing 2 wt% H 20.
Heavy ions used were 4He, 12C, and 14N ions, which had energies of 18.9, 30.0 "-' 66.4, and18.0 '" 47.5 MeV, respectively.
The results are shown in Fig. 1, where G(H 2) and G(CO) are plotted as a function of

the energy-loss parameter defined by Z = (1 IE) ~ ~ (-- dEl dx )dE. (The varia tions for pureacetone 1) are also illustrated with broken lines.)

Both G(H 2) and G(CO) are lower than thosefor pure acetone in the high LET region below LET = 60 e V;'A and they continue to increase
up to the highest LET investigated.

The ratio G(H2 )/G(CO) also increases with increasing LET

qualitatively similarly as in pure acetone.
The present results seem to indicate that the added water plays a role in enlarging thesize of the reaction zone by transferring excitation energy, lowering G(H 2 ) and G(CO) andprobably shifting the peak LET to a much higher value.

However, the thermal-spike effect isregarded as being still important considering the increases in G(H 2), G(CO), and their ratiowith increasing LET, since, as assumed previously, excess hydrogen in the high LET region isbelieved to result from thermal decomposition of free radicals produced from acetone.
Some other liquid organic compounds are being subjected to heavy-ion irradiation toconfirm the thermal-spike effect in the radiolysis, and the results will be reported in a
succeeding paper.

Reference

1)

M. Matsui, M. Imamura, and T. Karasawa:

IPCR Cyclotron Progr. Rep., ~ 90 (1971);

M. Matsui and M. Imamura: Bull. Chern. Soc. Japan, in press.

114

9-2. ESR Studies of Free Radicals Produced in Organic Crystals
Irradiated with Heavy Ions

K. Kimura, M. Matsui, T. Karasawa, and M. Imamura

Electron-spin-resonance studies have been carried out on the heavy-ion irradiated malonicacid and sodium acetate crystals.

Along with previous results with eicosane ,l ) these results

serve to elucidate the distribution of free radicals and the characteristic interaction of heavy ionswith matter.

Irradiation was carried out with 23.3 MeV He-ions and 85 MeV C-ions as wellas with 60Co r-rays at 77°K.

( I)

ESR spectra were recorded at 77°K and higher temperatures.

ESR spectra and their power saturation for malonic acid crystal

Figure 1 shows ESR spectra observed at 77°K for the sliced single crystal of malonic acid
irradiated with C-ions (a) and r-rays (b) , the static magnetic field being perpendicular to the[ 100] plane of the crystal. The ESR spectrum for C-ion irradiation is regarded as being due to

(a )

If)

c

23.0

( b)

a

c

Q)

-~

-+--'

o

Q)

L

1.0
Log P (P, mW)

a : Carbon ions at a dose of 1.3 x 1019 eV/g;

Irradiation and ESR determinationsb : r-Rays at a dose of 7.8 x 1019 eV/g.
Fig. 1.

were carried out at 77°K.
• : Carbon ions;

ESR spectra of irradiated single
crystals of malonic acid. Irradiationand ESR determinations werecarried out at 77°K.

Fig. 2.

0 : r-Rays.

Curves of ESR power saturation ofirradiated single crystals of malonic
acid.

2.0

115

CH 2 COOH and CH(COOH)z radicals on the basis of its similarity to that for r-ray irradiation
where the formation of these two radicals has been confirmed.

The broader line widths of

the C-ion spectra may indicate the strong spin-spin interaction between radicals located closely.
This assumption is 'supported by the fact that the ESR spectrum for the C-ion irradiation
appears to saturate at a higher microwave-power than that for the r-irradiation as shown in
Fig. 2.

(2)

ESR spectra for sodium acetate crystals

In the r-radiolysis at 77°K, the methyl radical is a principal paramagnetic species incrystalline CH 3COONa' 3H 2 0 , 2 ) while, in the anhydrous powders, CH 2 COO - and other radicals are

,
""
"
"
"

""
"

,
,
,
,

,\

"

"

"
"
I I

J

:::

II

i:

/\ i

I

I

I

I,

,

I

II

I

II

I

II

"

V:,

;;
,, ,,

I

L

I

I

"

t

I

I

"

I

I

: r~/ : i:I

[I :; :
II
II
II
II

:

"

:,'
,I
,I
I'
If

It
"

"
,

I
r

':
::

t
I
I
I

"
"

"

"""
"
II

1

t

(0 )

Fig. 3.

( b)

Irradiation and ESR determinationstwere carried out at 77°K. Arrows

Irradiation and ESR determinations

indicate the peaks of CH 3 radical.

were carried out at 77°K. Arrows

a : Crystalling CH 3COONa·3H 2 0;

indicate the peaks of CH 3 radical.

b : CH 3 COONa. ..... : He ions

ESR spectra of r-irradiated sodium
acetate.

Fig. 4.

; - - : C ions

ESR spectra of irradiated CH 3 COONa.
3H 2 0 crystals.

116

produced and CH 3 radical production is reduced as shown in Fig. 3.

These results seem toindicate a significant effect of hydration on the nature of radicals produced with (-rays.
ESR spectra obtained with crystalline CH 3 COONa·3H 2 0 at 77°K by He- and C-ion
irradiations are shown in Fig. 4.

A triplet is seen together with a sharp quartet of CH 3 radicals

in either case, the relative intensity of the former being lower in the He-ion irradiation though.
The triplet absorption has an intensity ratio of 1 : 2 : 1 and a hf splitting constant of about
20 gauss, which is assignable to the absorption due to CH 2 COO - radicals.

The LET dependence of the radical production in sodium acetate crystals is an interesting
subject in relation to the hydration effect and further studies are in progress.

References
1)

K. Kimura, M. Kikuchi, M. Matsui, T. Karasawa , M. Imamura, Y. Tabata, and K. Oshima:
IPCR Cyclotron Progr. Rep. , ~ 110 (1972).

2)

M. T. Rogers and L. D. Kispert:

J. Chern. Phys., 46 , 221 (1967).

117

9-3.

Inactivation of Bacterial Cells

by Charged

Particles

A. Matsuyama, T. Takahashi, and F. Yatagai

B. subtilis spores, E. coli BS- 11 and .E. coli B/r were bombarded with a-particles and carbon,
nitrogen, and oxygen ions to study the LET dependence of these bacterial cells. The samples
spread on a membrane filter (Millipore filter type HA) were exposed to charged particles ofdifferent energies in air.!)2

previously described. )Dosimetry was performed by the nuclear electronic method as

All survival curves determined in this study were exponential.

From

the viewpoint of the target theory, this means that the inactivation of a sensitive target in thebacterial cells is a single lethal-hit process.

Effective inactivation cross section (effectivenessper particle), Seff' was calculated using these survival curves expressed by NINo = exp (-Seff"~),where N/N 0 is the surviving fraction for given fluence ¢. The 37 % dose, D 37 , is given by
D37= L¢37, where ¢37 is the corresponding fluence and L the total LET of the bombarding
particles.
(1)

B. subtilis spores

For a-particles, Seff increased with LET to reach a saturation level (S~at) of 0.145 112 asshown in Fig. 1. This value was evaluated from the mean values of Seff obtained fora-particles of the total LET higher than 18.0 eV/A. Using the s~at values, the LET dependenceof Seff for a-particles was analyzed by essentially the same method as used by Pollard et al.,3)
Barendsen4) and Oda et al. S ) A cut-off energy of 200 eV was employed for is-rays according,

to Barendsen. 4) To estimate the number of primary activations or ionizations, n, which haveto be produced within a critical length of a particle track to result in damage to thereproductive capacity of the spores, the experimental curve of Fig. 2 was compared withtheoretical curves derived from the equation:
s at

n- l

S ef f = Sa ( 1- ~ f j ),

( 1)

) = 0

where fj is the probability that an incident particle gives j ionizations within a critical length t,
and fj is the Poisson distribution given by U) -1 X (t Lcore/W~ X exp (-t Lcore/W), where L coreis the track core LET.4) Assuming an average energy (W) of 35 eV required to form an ionlopair,4) the best fit of Eqn. 1 to experimental data was obtained for n=6. ,., 7 and t=27,....,31 A
from a least-square analysis.

According to Barendsen,4) the steepest rise in effectiveness per

particle must correspond to a LET, whereby the average number of ions produced within thecritical length of the track equals the number of n ionizations requited for damage.

From

Fig. 2, this steepest rise occurs at a track-core LET of about 7 eV/A. Thus, the critical trackolengths were calculated to be 30 and 35 A for n=6 and 7, respectively.

These t values thus

obtained are consistent with those obtained by the least-square analysis.

This fact seems toassure the validity of such estimation.

The values of Seff for heavy ions were found to be

118

0.3
0.2

0.1

I

-

18eV/A"'::l-; 0.05
J)o : a - Particles
6 : C - Ions
® : N -Ions

0.02/l:, :

0 - Ions

Fig. 1.

LET in B. subtilis spores.

0.0 I
I

2

5

10
20
Total LET (eV IA)

50

100

0150

,,-

,,-

,// 0

Relation between Seff and the total

Solid and broken lines show theoresults of least-square analysis to fit0", "-,,-

Eqn. 1 for the experimental data,/_ 0.100

/

/

~

/.

when sa tura tion levels are chosen to

v

/
/

/

0.050

/

/
/

// 0

be 0.145 and 0.24112, respectively0(see text).

/

0

Fig. 2.

//I

Relation between Seff and the trackI

core LET of a-particles in B. subtilis

I

o

5

10
15
Track Core LET (eV I A)

20

spores.

o

0.06

0.05
,_ 0.04"~:: 0.03....

o:::: 0.02® 0157for 60Co y - roy

0 .01

Fig. 3.

Relation between RBE (1 jD 37 ) andO~----~r--~----~--~------L! ____L! ----

10
5
20
Total LET (eV/A)

50

100

the total LET in B. subtilis spores.

119

(b)
0..5

(a)
1.0.
C:.

07

- 0..3®

"'::l"

'S-

o

J 05

(J)

Q)

cB5D

0..2

o

el
0

rno

f)

8

o

f)aD{)

o

0

o
o

0..3
3

10.

5

30.

50.

o
0..1 L---::3-~5~---.Jla'::---------L3a--""5La-----.Jla-a--­lao.

Totol LET (eV;'A)

Totol LET (eV / A)

Relation between Seff and the total LET in E. coli Bs-I (a) and

Fig. 4.

E. coli Blr (b).
0.6

(a)

(b)

0.3
00 0 00..1a~---~___

5

L -_ _ _L -_ __

L-__

10.

20.

15

aL-_ _ _L-_ _ _L-_ _ _L-_ _ _L-__
10.
15
5
20.
Totol LET (eV/'A)

Toto l LET (eV / A)

(a)

(b)

Solid line shows the result of

Solid and broken lines show theresults of least-square analysis

least-square analysis.

assuming n = 1 and 2, respectively (see text).
Relation between Seff and the total LET of a-particles inFig. 5.

E. coli Bs- I (a) and E. coli Blr (b).
(b)
(a)

0..5

®

®
C:..

1.0

®

®
®

0

0
®®
C:..

C:..

0

0

C:.

C:..

®

®
C:.

0

-0.7

S

~

2-

03
o

""-

""-

J)0.5

cP

J)

02

Q)

o

(j)

8

o 0

0

° o

o

o
o

0.3

o

o
05

07

La

2.0

3.0

Energy (MeV / AMU)

Fig. 65.0.

a .I ' - - - - - - - - - - - ' - - - - - - - L -----L-- - - L - - -

05

1.0

2.0.

Energy (MeV / AMU)

Relation between Seff and energy in E.coli B s-l (a) andE.coli Blr (b).

3.0.

5.0

120

higher than s;at and increased in the order of carbon, nitrogen, and oxygen ions (Fig. 1).
Energy dependence of Seff for each heavy ion was scarcely observed.

Attempts have been madeto interpret the discrepancy between s;at and Seff for heavy ions in terms of the effect ofhigh energy () -rays, utilizing the theories developed by Dolphin and Hutchinson 6 )a1. 5 )and Oda etHowever, such attempts failed mainly because Seff values for heavy ions are almost

independent of energies. * Furthermore, the least-square analysis using Eqn. 1 cannot explain
the characteristic LET dependence for a-particles, if the saturation level of Seff be assumed tobe 0.24 p? in the LET region of heavy ions (broken line in Fig. 2). These facts seem tosuggest the necessity of adding another term to Eqn. 1, which should be negligible in the LET
region of a-particles and become appreciable in the LET region of heavy ions to account forthe present experiment.

As seen in Fig. 3, the maximum RBE was found at an LET ofo

12 e VI A.

The mean values of Seff for carbon, nitrogen, and oxygen ions were found to be

0.220, 0.233, and 0.256 J.12, respectively (Fig. 1).
The discrepancy between s;at and Seff for heavy ions may be due to the difference inthe repair capacity of the target between a-particle and heavy-ion bombardments.

An

alternative view is that another type of target different from DNA is involved in the inactivation
mechanism of spores on heavy-ion bombardments, as suggested by Haynes. 8 )It remains open

to a criticism that the discrepancy may be ascribed to long-range effects (e.g. thermal spike
effect) of bombarding particles of extremely high LET as suggested by Norman,9 ) Kondo,! 0 )and Platznan and Frank,ll ) though details of such theories are not yet well-examined.
(2)

E. coli Bs- 1 and K. coli Blr

Although an attempt has not yet been made to distinguish the effect of the track coreof particles and that of () -rays, the following results were obtained by using almost the same
method as in B. subtilis spores.

The values of Seff for a-particles increase with increasing

LET's, reaching the stationary level, s;at, of 0.537 and 0.261 J.12 for J;;.. coli Bs- 1 and E. coli Blr,
respectively (Fig. 4). The analysis of LET dependence revealed that the number of primaryactivations required to produce one lethal-hit within a very short length of the particle track is
1 and 1",,2 for E. coli Bs- 1 and E. coli Blr, respectively (Fig. 5).

The discrepancy betweens;at and Seff for heavy ions was also observed in these bacterial cells (Fig. 6). The Seffvalue for each heavy ion increases with increasing energy and this fact suggests the necessity
to take the effect of high-energy {)-rays into consideration.
(3)

Inactivation pattern

Based on the above data, the inactivation patterns for different bacteria are classified into
three types as indicated in Table l.

*Katz theory also seems to be difficult to apply in our present analysis since Fig. 20 of Ref. 7 shows considerable
dependence of Seff values on Z 2 1K.{f2 which varies with energies of bombarding particles .

121

Table l. Inactivation pattern of bacteria on bombardment with charged particles.
Inactivation
pattern

Strainss~at (,u2 )n~. coli Bs- 1

SefrC/1 )o -ray effect

0.537{ 0.630 (C)0.662 (N)+22~. coli Blr

I or 20.261{ 0.446 (C)0.490 (N)+3

B. subtilisspore

6 or 70.145{ 0.220 (C)0.233 (N)0.256 (0)+References

1) A. Matsuyama, T. Karasawa, S. Kitayama, and R. Takeshita:

IPCR Cyclotron Progr.

Rep., 1.: 101 (1969).
2) T. Karasawa, H. Seki, M. Imamura, A. Matsuyama, and M. Matsui:"The Uses of

Cyclotrons in Chemistry, Metallurgy and Biology", (Ed. C.B. Amphlett), Butterworths,
London, p. 76 (1970).
3) E.C. Pollard, W.R. Guild, F. Hutchinson, and R. B. Setlow:~

Progr. Biophys. Chern.,

72 (1955).

4) G.W. Barendsen:
5) N. Oda:

Int. J. Radiat. BioI., ~ 453 (1964).

"Biophysical Aspects of Radiation Quality", TRS No. 58, IAEA, Vienna,

p. 165 (1966).
6) G. W. Dolphin and F. Hutchinson:

RadiaL Res., 1..1 403 (1960).

7) R. Katz, S.C. Sharma, and M. Homayoonfar:"Topics in Radiation Dosimetry",(Ed. F.H. Attix), Academic Press, New York, London, p.317 (1972).
8) R.H. Haynes:

Radiat. Res. Suppl., 6, 1 (1966).

9) A. Norman:

ibid., L 33 (1967).

10) S. Kondo:

Butsuri,3 584 (1961).

11) R.L. Platzman and J. Frank:"Symposium on Information Theory", (Ed. N. Yockey),

Pergamon Press, New York, p.262 (1958).

122

9-4.

LET Dependence of DNA -Strand Breaks In ~. coli 8s-1

K. Igarashi, F, Yatagai, T. Takahashi, and A. Matsuyama

In order to measure the LET dependence of DNA-strand breaks in bacterial cells, log-phasecells of E. coli Bs- 1 labelled with 3H-TdR were bombarded in air at room temperature (,...., 20°C)
with a-particles and carbon- and nitrogen-ions, as described previouslyl ), 2 ) , and sedimentation
profiles of DNA were determined by the method of McGrath and Williams 3) using alkaline
sucrose gradients.

For inhibiting the DNA repair during irradiation, bacterial cells weresuspended in a O.OlM Tris buffer containing O.02M EDTA and an O.02-ml aliquot of the cell

10

(0 )

10

(b)
~

'~

,.~~

.

~\
\

(/)
~

C
::J

\~

~\

5

5

~I

0

I

(,)

a

~

0

~

0

0

'+-

0

Q.)
tJ)

a

15

~

c

Q.)
(,)
L

(c)

.~
f?~

..

~\
I'
:
~f\ $

(d)

10

1$ •
,

Q.)

D....

10
5

I:
;:

,

•

I

I:~

,

I

•,,
\

5

;,

~.

0

0

Fraction

number(a) a-particles(0.628 MeV/amu) 0 61.7 krad

• 93.1 krad

e 123 krad(b) C ions(2.39 MeV/amu) 0 97.3 krad

• 146

krad

e 195 krad(c) N ions

(1. 73

MeV/amu) 0 80.9 krad

• 121
36

krad

e 163 krad

krad

e

(d) 60CO r-rays
Fig. 1.

o 27

krad

•

54 kradSedimentation patterns of 3H-DNA from irradiated E. coli Bs-1 .

123

1000
500

ffi 200
"-

~ 100
~

w

50
20
10L-----~----~------~----~----~----

10

20

100

50

Total LET200

(eV / A)o a-particles, • C ions,e N ions(LET values in this report refer to energy absorbed
in DNA per unit length.)
Fig. 2.

LET dependence of the efficiency of
DNA single-strand breakage, Esb'

./

2000
1000
CD

(f)

"-

./

500

>

~
IX)
(J)

w

"~u
~

200
100
50

(;

<->

20
10

10

20

50

100

T rack Core LET (eV /Fig. 3.

200

A)

The relation of Esb corrected for
5-rays and track-core LET.

5
3
2

e e
e

-- "8- --- - - -...a...---------.J----.!--~-o -e

10

20
Track Core LET

Fig. 4.

50

100

200

(eV / A)The number of DNA single-strand
breaks by the track-core effect ofa single particle-traversal, Bt ·

124suspension was fed on a membrane filter (Millipore filter Type GS).

Some examples of thesedimentation profiles of E. coli Bs- l DNA are illustrated in Fig. 1.
From sedimentation profiles, the number-average molecular weight of DNA wascalculated4 ) and the efficiency for single-strand break production, Esb' was estimated.

The

value of Esb for each particle was found to increase with increasing total LET as shown in
Fig. 2.

This LET dependence of Esb reveals the possibility that an excessive energy might berequired to produce a single-strand break in such a high LET region as compared with X- or'Y-rays.

In Fig. 2, the discontinuous increase of Esb was also observed in the overlapping LET

region obtained by different kinds of charged particles.
taking the <5-ray effect into consideration.

This fact suggests the necessity of

After an appropriate correction for the <5-ray effect,

one can expect that the increase of Esb with increasing track-core LET in the high-LET
region is expressed by the same linear relationship for different particles, since the DNA-strand
breakage would always take place by the energy dissipation of a high-LET particle when it
traverses through the DNA strand. The trial of the <5 -ray effect correction for the data
indicated in Fig. 2 was made on the following assumptions:(1) The rate of single-strand

breakage. induced by <5 -rays is identical with that by 60Co r -rays (Fig. 1), Esb = 40 e V/break,which is calculated by the same method as that for charged particles; (2) a cut-off energy of

500 eV is employed to separate the o-ray effect from the track-core effect; (3) dividing the.

2
DNA volume, 2.4 X 10--".3 11 3 , 5 ) by the projected area of the cellular nuclear.. region, 1.111 ,determined from the electron micrograph, the mean particle traverse length through the DNAostrand is estimated to be 22 A.
As a result, a linear relationship between Esb corrected for <5 -rays and the track-core LET
was obtained (Fig. 3).

The number of single-strand breaks in DNA formed by the track-coreeffect of a single particle-traversal, Bt , was calculated with the above 0 -ray correction.

As canbe seen in Fig. 4, the values of Bt were found to be about 2, almost independent of the LETof bombarding particles.

This fact suggests that the DNA strand in bacterial cells may be on

the average distributed as a monolayer and that the traversal of a single particle of high LET
through the DNA strand results in a double-strand break.
To examine the contribution of DNA single-strand breakage for the inactivation of cells,
the number of DNA single-strand breaks by the absorbed dose of D 37 , denoted by B37 , wasTable 1. Model of inactivation of bacterial cells by charged particles.
particles

a-particles

C-ionsN-ionsA

A,----"------..

Total LET*(eV/A)
0

8.76

16.0

21.2

27.7

31.0

34.0

81.2

128

160

168

200

B37

7.53

5.31

5.61

4.26

3.22

3.78

3.12

2.63

2.68

3.09

2.18

3.64

4.33

4.66

4.48

4.43

4.26

17.4

16.8

17.2

27.7

18.8

2.74

2.28

2.22

2.05

2.08

2.04

1.50

1.22

1.36

1.45

1.18

B37

{

t

fj

B37

P37

* In DNA (p==1.71)

125

also calculated with tl-js [) -ray correction.

The values of B~7 and B})7 shown in Table 1 are

B37 for the effect of track core and 0 -rays, respectively, and B37 = B~7 + B~7'

The values ofB}7 decrease with increasing LET approaching a value of 2, while B~7 is not so affected by LET
but its level becomes higher for heavier ions.

This tendency of B37 may reveal the difficulty

to account for the inactivation of cells by the DNA single-strand breakage and the DNA
single-strand breakage by [) -rays seems to be very ineffective.
The average number of particles (P 37 ) passing through the DNA strand for an al?sorbed
dose of D37 was also calculated.

It was found that P37 decreases toward the unity withincreasing LET as shown in Table l.

The values of P 37 appear to be consistent with theeffective inactivation cross section (effectiveness per particle) of ~. coli Bs- l observed in our
separate experiments.

This fact suggests the possibility that lethal damage on the cells might

be explained by the number of heavy charged particles traversing through the DNA strand
rather than the number of DNA single-strand breaks.

According to Freifelder,6 ) there are two

principal types of lethal damage in X-ray irradiated double-strand DNA phage; (I) double-strand
breakage which is O 2 -independent and occurs at ca. one-half the rate of production of lethal
hits and (2) an O2 -dependent damage which is thought to be of alternation of the nucleotide
bases.

Taking account of O 2 -independent inactivation of the cells by high-LET particles,7) the

DNA double·strand breakage induced by the charged particle-traversals might be regarded as
an important event for the cell inactivation.

The LET dependence of the DNA double-strand

breakage on such charged particle bombardment will be discussed elsewhere.

References
1)

A. Matsuyama, T. Karasawa, S. Kitayama, and R. Takeshita

IPCR Cyclotron Progr.

Rept.,iz 101 (1969).
2)

T. Karasawa, H. Seki, M. Imamura, A. Matsuyama, and M. Matsui:"The Uses of

Cyclotron in Chemistry, Metallurgy and Biology", (Ed. C.B. Amphlett), Butterworths,
London, p.76 (1970).
3)

R.A. McGrath and R.W. Williams:

Nature, 212, 534 (1966).

4)

S. Kitayama and A. Matsuyama : Agr. BioI. Chern., 35, 644 (1971).

5)

S. Cooper and C. E. Helmstetter:

6)

D. Freifelder, S. T. Donta, and R. Goldstein:

7)

P. Todd:

J. Mol. BioI.,

Radiat. Res. Suppl., L 196 (1967).

11., 519 (1968).

Virology, 50, 516 (1972).

126

10. PREPARATION OF RADIQISOTOPES AND LABELED COMPOUNDS

10-1 . Measurement of Exc itation Curves for the Formationof Medical- Use Radioisotopes

T. Nozaki, T. Karasawa, M. Okano,
M. Iwamoto, and T. Hara
The excitation curves for the following reactions were measured: (I) Ne + d -+ 18p,
(2) Ne + 3He -+ 18p, and (3) 197Au (d, 2n) 19 7m Hg. . The thick target yields of 18p in various
reactions were calculated, and the reactions were compared in view of the practical productionof 18p in various useful physical and chemical states.
published elsewhere in the near future.

Details of the comparison will be

The excitation curves for the formation of 48Cr and

48V in the 3He bombardment of titanium are now under measurement.
Neon was sealed in target-gas containers which were metal cylinders of 60 mm in diameterand exactly 25 mm in height and with bases of aluminum foils 13 /.lm thick.

Prom 5 to 15 ofthese containers were lined up closely in series to make a target assembly, and several suchassemblies were bombarded with particle beams of various incident energies.

For the 197Au(d, 2n) 197m Hg reaction , the ordinary stacked foil technique was used.
The results are shown in Figs. 1 and 2, and the thick target yields of 18F for various
reactions are shown in Pigs. 3 and 4.
show that:

The excitation curves of the 3He reactions to give 18F

in energy regions over 15 MeV, neon gives a much higher 18p activity than does

oxygen ; under 10 MeV, only oxygen gives a sufficiently high 18p yield.

The following

bombardment, thus, can offer anhydrous 18p and aqueous 18p simultaneously in good yields:
3He particles of an incident energy over 20 MeV is caused first to pass through a neon target
layer of such a thickness as to reduce their energy down to about 15 MeV and then to entera water target.
Although the bombarded neon contains some activity of 7Be and 22Na, they are notincorporated in final products of synthetic processes of 18p labelling.
As is obvious from Fig. 2, carrier-free 197mHg can be obtained in good yield by deuteron
bombardment of a gold plate.

A simple chloride-volatilization method has been devised forthe separation of the 197mHg.

This nuclide has proved to be useful for lung tumor scanning.

It is much more effective than 197Hg because of suitable energy of its r-ray.
In the 3He bombardment of water for the production of an aqueous 18p solution, atitanium foil. is used as the beam extraction window.

We intend to separate 48Cr formed inthis window, whose thickness has been chosen from the consideration of the excitation curves.
The chemical separation technique of this nuclide is also under study.

1273001- - -

E
-

'"
0

100

u

0 ~--~~--~--------~~--------~
3LO-----

Ene r gyFig. 1.

I MeV]

Excitation curves for the reactions of
Ne + d -+ 18F and Ne + 3He -+ 18F.

200

100
.0

E

-

0

'"

50

0

'-'

20

1~~
1~~~1~~~1~~~1
10
15
20
25
Ed

Fig. 2.

( MeV)

Excitation curve for the reaction of 197 Au
Cd,2n) 197ffiHg.

128

X10 9
8~--------4----------+---------~~---

7

6 ---

t 0 5
I I

10

1

1

I

15
I

I

4

d 0 2

6

3 0 t
150 d

200
100

(mg / cm 2)

Range

2p

!

22

I

I

8

10

Ene rg y

(MeV)

12

I

14

Thick target yields of 18F for the

Fig. 3.

triton reaction on oxygen anddeuteron reaction on neon.

XI 0

9

1. 5 ~---------+-----------+--~------+--.....>:>
+-'

u

<[

0.5

50
0'

05 10
I II

3He 05
3He

Fig. 4.

I

15
I

I

20
I

I

Ra2~e
I

I

100

150

( mg /cm2 )

30
I

i

i

35I

40
I I
35

0

(0

15

20

0 5 10

I

I

I

I

I

20

25

30

35

Ene (g y( MeV)

I

15

25

30

Ne

Thick target yields of 18F for the 3 He
reactions on neon and oxygen and of
a-particle reaction on oxygen.

12910-2. Preparation of

18F-labelled Compounds

T. Nozaki, Y. Ohtsuka, A. Tahara, S. Ambe,T. Ido, K. Fukushi, and Y. Kasida

We previously reported the synthesis of 18F-labelled cholesteryl fluoride (Compd 1) and
its distribution in experimental animals. 1) ,2)
showing a slow clearance from blood.

This fluorosteroid, however, is highly hydrophobic,

With less hydrophobic fluorosteroids, more valuable
We synthesized 3tJ-acetoxy-6tJ-fluorocholestane-5a-ol-18 F

information will be able to be obtained.

(Compd 2) by the reaction of B18F3 with 3tJ-acetoxy-5a, 6a-epoxycholestane (Compd 3),3) andinjected it into rats to measure its distribution in their body.
By modifying the synthetic method reported by Henbest and his coworkers,4) we attempted
to prepare Compd 2 in a higher yield and shorter time.

In our cold experiment under asmall scale, the 18F yield was increased to 61 % with an organic yield of 51 % under the
optimum condition (BF 3-etherate, 0.28 eq. mol; operation time, 100 min).

However, different

conditions, such as shown in Table 1, had to be used in the actual labelling experiment,
because a part of the BF3 -etherate was decomposed by moisture in the preparation of B18 F 3etherate.
CSH17

Ca H17

F~

Aco4
HOF

Compd 1

Compd 2

~H17
AcO

0

-:c

0
II

C- NHCHzCO z H¢F

Compd 4Compd 3

F

HO

¢C>

CaH17

I

CHz --<Q>(CoF(NH 3 l s)++Compd 6

Compd 5

Table 1.

HO#
18F

Compd

O~
lsF
Compd 8

7

Yield of 18F-Iabelled fluorosteroid (Compd 2).
Org. yield(%)

Inorg. yield(%)

Radiochem.
yield (%)*

Operation
time (min)

3.313

38.5

3.9

4.3

145

2

1.125

48.0

14.2

9.8

126

3",5

1.75

25.0

4.77

5.7

91

Exp. No.

BF 3-etherateused(eq. mole)(dps of the product) x 100*(dps of the B18F 3-etherate)

130

The epoxysteroid, Compd 3, (l00 mg) was added to a benzene solution of B18 F 3 -etherate
prepared by isotopic exchange between BF 3 -etherate (50 ,...., 60 mg) in benzene (20 mf) and
18F adsorbed on the inside wall of a bombardment box in which neon or oxygen had been
bombarded.

The mixture was stirred for 10 ""' 15 min at room temperature.

After the additionof water (several drops) and alumina containing gypsum (lOg) , the mixture was filtered.

The

filtrate was evaporated and the crystalline residue subjected to preparative thin layer
chromatography on alumina, the developing solvent being benzene-chloroform (3 : 1). The
objective band was extracted and the solvent evaporated to give the crystalline 18F-labelled
fluorosteroid, Compd 2, (26 ,...., 50 mg).

The entire synthesis was carried out within a relatively

short time (90 ,...., 100 min).
The product, Compd 2, was injected with the aid of an emulsifier into rats and the
distribution of the 18F-activity in them was measured with its time change. The results areshown in Fig. 1.

Also, the change of 18F-concentration in bile secreted from rats injected withCompd 1 or Compd 2 was followed.

The results are shown in Fig. 2.

,

"~""
10

"

'~"

--'---____

Adrenal---~-------------~------

Spleen------:~­

Lf----~-~--- L ung- - Liverx------------ ~-__

B lood-------------x------. •........................................~........ K~~~~r...............

c:

o

'"

Ell

-_-...--------:a---ffi----i---- -----------.... _-----Bone

Me an va lu e------------- ------ -------------------------- - ------------------oMusc le0 .1_ _ _ - ~-

181

.-/

---181---- -----~.--.....

----

Tes tis--...----- ~--------- ....
. in~---v::::9---'::-=:=----~·-----'-"-;:B:;-:r-:a60
120
Time ofter intravenous in ject ion

Fig. l.

180(min 1

Distribution of 3fj-acetoxy-6fjfluorocholestane-5a-ol in rats and itschange with time.

131

0.02

n

3
Time after i ntr.avenous in jection(h)

I : Cholesteryl fluoride , normal rats.
II3(3-Acetoxy-6(3-fluorocholestane- 5a- 01, normal rats.

III3(3-Acetoxy-6(3-fluorocholestane- 5a-ol, polychlorobiphenyltreated rats (per os, 0.5 pg/g body).

Fig. 2.

Secretion velocity of fluorosteroids into bile.

p-Fluorohippuric acid (Compd 4) was synthesized by the Schiemann reaction with a
18F-yield of about 10 % and injected into rats.

This compound showed a very rapid clearance

into urine.

18F-Iabelled 6-fluoro-9-benzylpurine (Compd 5) has been synthesized by halogen
interchange from 6-chloro-9-benzylpurine and Ag 18 F. The behavior in vivo of this compound is
now going to be studied.
Fluoropentamminecobalt (Ill) complex ion (Compd 6) was found to be labelled with 18F
by isotopic exchange in an aqueous solution.
from rats into their urine.

The compound also showed a rapid clearance

Detailed study of this isotopic exchange is now under way.

Efforts are being made for the elevation of specific activity of the products in general.
We intend to prepare, in the near future, 18F-Iabelled 6-fluorocholesterol (Compd 7) andfluorotestosterone (Compd 8).

References
I)

T. Nozaki, A. Shimamura, and T. Karasawa : IPCR Cyclotron Progr. Rep., ~, 156 (1968).

2)

T. Nozaki, T. Karasawa, M. Okano, A. Shimamura, M. Iwamoto, T. Ido, and Y. Makide :
ibid, 6, 127 (1972).

3)

P. A. Plattner, Th. Petrzilka, and W. Lung: Relv. Chim. Acta, 27 , 513 (1944).

4)

R. B. Henbest and T. I. Wrigly : J. Chern. Soc., 1957,

4765.

132

10-3. Preparation of

119Sb for Mossbauer Em iss ion Spectroscopy of 119S n

S. Ambe and F. Ambe

A series of Mossbauer emission studies have been under way in our laboratory on 119Sn
after the EC decay of 119Sb.l)"'3 )This report describes the procedure developed for producing

119Sb by proton irradiation of tin followed by radiochemical separation and purification.
The 119Sb was produced by the 119S n (p ,n) 119 Sb and 120Sn(p, 2n) 119Sb reactions.

Thetargets were water-cooled metallic tin plates of natural isotopic abundance. The thickness ofthe tin plates was I mm and an effective area of ca. 20 cm 2 of them was exposed to a dispersed
15 MeV proton beam accelerated in the Cyclotron.

A sketch of the target assembly employedis given in Fig. 1. The beam current was usually about 15 IlA.

An irradiation with 200

mCoulomb of 15 MeV protons makes it possible to accumulate about 4 x 106 counts of the
23.8 keV r -rays in each of the 400 channels of the Mossbauer spectrometer, if an overall
yield of more than 60 % is assumed in the separation of 119Sb and the preparation of source
materials.
In a one-liter beaker cooled by water and covered with a watch glass, the irradiated target->-

He ga s inl etand out I etu<!

He gas chamber

E
o

Q)

CD

Vacu um

185 1>

Fig. 1.

The target assembly employed for theirradiation of tin targets.

133(abou t 14 g) is dissolved in 75 mt of conc. HC 1 with the aid of 25 mt of conc. HN0 3 added
slowly in small portions.

Unless carrier-free 119Sb is required, addition of a few mg of Sb 2 0 3

as a carrier at this stage is recommended.

When the greater part of the tin plate has been

dissolved, all the contents of the beaker are transferred to a porcelain evaporating-dish, and thesolution is evaporated almost to dryness at about 100°C.
makes redissolution of the residue extremely difficult.)(Complete drying-up of the solution

After cooling, the residue is dissolvedin 200 mt of 9 M HCI, and a few me of 9 M HCI saturated with chlorine are added to thesolution to ascertain the oxidation of 119Sb to Sb(V).

The 119Sb(V) in the solution is

extracted twice with 100 me each of a 3 : 1 mixture of isopropylether and benzene. The
organic phases are collected together and washed four times with 100 mt each of 9 M HCl towhich a few me of 9 M HCI saturated with chlorine are added.

The 119Sb is back-extracted

from the organic phase three times with 5 me each of 3 M LiOH.

The aqueous phases arecollected together and an equal volume of 6 M HCI is added to the solution to yield a 1.5 M
HCI - 1.5 M LiCI solution of 119Sb(V).

After a few mt of 1.5 M HCI- 1.5 M LiCI solution

saturated with chlorine are added, the solution is passed through a column of a strongly basic
anion exchanger, Diaion SA # 100 (6mE), pretreated with 1.5 M HCI- 1.5 M LiCl.

The

119Sb(V) left on the resin phase is washed out with 30 mP of 1.5 M HCI- 1.5M LiCl.

All theeluants are collected together and heated almost to boiling and the 119Sb(V) in the solution
is reduced to Sb (III) with 1 g of Na2S03.

After cooling, the solution is passed througha column of Diaion SA# 100 (3 mg) pretreated with 1.5 M HCl- 1.5 M LiCI.

The resin iswashed successively with 15 me each of 1.5 M HCI-1.5 M LiCI, 1.5 M HCI and 0.5 M HCI.
Finally, the 119Sb(lII) adsorbed on the resin bed is stripped with 15 mC of 0.5 M LiOH.
Whole the chemical procedure can be completed within 12 h.

The yield of 119Sb amounts

to about 90 % and the decontamination factor of tin is more than 5 x 106 •References
1)

F. Ambe, H. Shoji, S. Ambe, M. Takeda, and N. Saito:~>

IPCR Cyclotron Progr. Rep.,

115 (1970); ·ibid., ~, 85 (1971); F. Ambe, S. Ambe, and N. Saito:

ibid.,~,

102( 1972).
2)

F. Ambe, H. Shoji, S. Ambe, M. Takeda, and N. Saito:

3)

F. Ambe and S. Ambe:

Phys. Lett., 43A, 399 (1973).

Chern. Phys. Lett., 14, 522 (1972).

134

11. RADIATIONMONITORING

11 -1 . Routine Monitoring

K. Koda, I. Sakamoto, and I. Usuba

Results of the routine monitoring and related measurements on the IPCR cyclotron
obtained from January to December 1972 are described.
As a result of several improvements made on the machine and the accessory facilities, themachine time in this year reached as much as 270 days.

In spite of such a hard schedule ofthe machine operation, the accumulated dose to the workers decreased as described below.

(1)

Residual radioactivities on the machine

The radiation level measured around the machine 12 days after machine's shutdown was
as follows:
Dose rate (mRjh)

Locationca. 10 cm apart from septum covered with 2mm Pb

300

deflector

40

at ion source flange

12

at beam exit

200

at slit box

40

Several short-lived radioactive nuclides which account for the majority of residual
activities and have a dominant contribution to exposure of the workers during the short period
after deuteron acceleration have been identified.
lIC (half life, 20 min), 24Na (15 h),They are:
56Mn (2.58 h) , 64CU (12.8 h),

and 187W (24 h) .
There would still remain some other radionuclides left unidentified.
(2)

Surface contamination

The surface contamination of the floor of the cyclotron room, the underground passage,
and the experimental area was kept below 10-6 ", 10- 7 MCi/ cm 2 in terms of beta and gamma
activities.
(3)

The contamination was wiped off twice a year.
Personnel monitoring

The rule of work in the cyclotron vault has been revised this year in order to reduce
exposure of the operators and engineers to radiations.

The revised points are :135(a) S,e tting-up of the heavy-ion source to the machine must be begun at least 24 hafter the shutdown of deuteron acceleration.
(b) When deuterons have been accelerated over 6 henough interval for "cooling"should be taken before entering the cyclotron room .
Exposure of the personnel anticipated for various operations under the normal condition of
the cyclotron was :Working time(min)

Dose rate atwork place(mR/h)

Max. exposure
expected(mrem)

Replacement of filament of
p,d,Ck-ion source

20

less than 15

5

Replacement of ion source
itself60

7

7

Replacement of cone ofp,d,Ck-ion source

30

10

5

Inspection of oscillator

20

30

10

(c)

Workers to whom a dose over 300 mrem has been accumulated during any 6 months

period should be warned and exempted from operations involving a high exposure.
Application of the revised rule has resulted in a remarkable decrease of exposure of theworkers during this year.

Details will be described in the next report.

Exposure of workers during the replacement of septum was measured simultaneously attheir right-hand finger and breast.

The result is as follows

WorkerG

H

I

Breast20

25

20

Finger

100

80

40

(in mrem)

Similar measurements were made for operation of treating an irradiated zirconium target
for 90Nb production.

The exposure was found to be 40 mrem at breast and 600 mrem atright-hand finger.
Internal contamination of the workers with 65Zn , an induced radionuclide in theacceleration chamber, had been detected already in 1968. The body burden was measured
again this year using a body counter.

The result expressed in nCi is as follows :~---------------------------------------

~
~

K

L

1968

8

32

1972

14

11

M

3

136

11-2.

Residual RadiationIn

the Cyclotron

after Deuteron

Vault

Acceleration

I. Sakamoto , S. Fujita , and T. Karasawa(1)

Hal f-life ,nuclide, and neutron reaction

It is well known that the residual radiation level m the cyclotron vault is higher after

deuteron acceleration than after proton, Q, and helium-3 acceleration.

This high radiationlevel in the case of deuteron acceleration is due to the residual activities induced by fastneutron reactions or by neutron capture.
During this year, we have investigated the residual radiation level and mam radioactive
nuclides.
At the point A in Fig. I, where the area monitor was installed , the decay curve of theresidual radiation level was found to consist of three half-life components of 10 '"'-' 20 min or
less, 2 '"'-' 3 h, and 13 '"'-' 15 h, regardless of the energy of accelerated deuterons.
decay curve is presented in Fig. 2.

A typical

The nuclides and the types of reactions can be estimatedas listed in Table 1 from the viewpoints that (1) their half-lives are close to those observed ,(2) the target materials are contained in the cyclotron components and/or in the shielding

I

Experimental

area 151

ater tank

Cyclotronroom

Date: 29 Jan. 1973, Ed 24 MeV, Int. 63f..LA,
Defl. 29f..L A.
Fig. 1.

Acceleration time: 72 h.

Layout of the measuring locations.

137

concrete, and (3) their cross sections of reaction are substantially large.

Short-lived activitiesof less than 30 min are not discussed here.
In fact , the production of these radioactive nuclides was confirmed from the r-ray spectra
obtained with a Ge(Li) detector, which was set up in a small experimental room at the point
E in Fig. 1 and was able to detect the r -ray radiation from the cyclotron vault through thecollimater.
Other nuclear reactions which produce the radioactive nuclides in Table 1 are also
possible. For example, 56Mn is produced by the 59Co(n, a) 56 Mn reaction. But the quantity of
59CO in the cyclotron components is far less than 56Fe, only 0.3 % in stainless steel.

Theelectromagnet and the accelerating chamber are made of steel and stainless steel, respectively.
Which of the nuclear reactions, 56Fe(n, p) 56 Mn or 55Mn(n, r) 56 Mn , is more contributory for the
production of 56Mn?

Although the Mn content in the steel is usually about 0.5 % and much

Table 1.

Major radioactive nuclides and estimated nuclear reactions.

Radioactive
nuclideHalf-life

Estimated reaction~------~~~--------~

2.6 h
2.9 h
12.8 h24Na

h15

Table 2.

The cooling time in the case of 197mHg production.
Beam intensity

Date

Ed
(MeV)

27 , Dec.

20

25, Jan.

22

1, Feb.

22
24

23, Feb.

1,

Ta

Int.

Defl.

(pA)

(pA)

(h)

23

1.5

50

Radiat.A level(mR/h)

25

Norm. Tc

T(h)
(h)

3.3

2.2

3.9

I

2.6

20

1.5

2.5

0.5

2.5

9

1

2.1

0.5

l.7

20

Int.

Internal beam.

Ta

Acceleration time.

T

The time when radiation at the point A is measured after shutdown.

Norm. T c : Normalized cooling time.

Defl.: Deflected beam.

It is calculated so that the residual radiationlevel at the point C decays to 10 mR/h after shutdown of operation at theirradiation intensity of 30 pA.

138

10

I
I
I

L

.......
L

1\

E

I

,

\

I
I
\

\

I
I
I

I
\
I
I ~

100

13
1- ·

I='
I

0.1 L--l:O---lLf-\----'-----'_..l....-~-----'---------'--.L..-.--'---____='""::_---'--'----'----'-~
T i meFig. 2.

(h 1

Decay curve.

smaller than that of Fe, the cross section of the neutron capture is much larger than that of
the Cn, p) reaction.

At present, we can not solve this problem.

In the earlier stage of this study , two types of reactions,e3Na(n , r) 24 Na and 27AI(n, a) 24 Na) ,were supposed to contribute to the production of 24Na. Aluminium and sodium are contained
about 5 % and 2 % respectively in concrete of the shielding wall around the cyclotron vault.
For the determination of major reactions to produce 24Na, samples of pure aluminium andsodium chloride were exposed to deuteron-induced neutrons in the cyclotron vault and thenthe induced activity of 24Na was measured . Considering the activity induced in the samples
and the contents in the concrete, it is concluded that 24Na is produced mainly by the
23Na Cn, r)24Na reaction.
Copper is used for both the resonator (dee and' liner) in the accelerating chamber and theexciting coil of the electromagnet.

For quantitative comparison of the activities induced,

64CU and 24Na, we used a portable NaI scintillation counter with a special collimator.

This

set-up was sensitive only for forward direction and positioned between the cyclotron and theshielding wall at the point D in Fig. 1.

The r-rays from 24Na were found to emit predominantly

from the shielding wall and the 0.511 MeV r-rays of positron annihilation from 64CU
originated from the cyclotron.

Considering the energy of r-rays emitted by 24Na was higher

than that by 64CU, the exposure dose at that point seemed to consist of nearly equal parts due
to 24Na and 64CU.

(2)

Cooling period for safety

The distribution of the residual radiation level near the cyclotron was measured as a

139function of the time after shutdown of acceleration.

The radiation level of each point isaffected by several factors : energy of deuteron, intensity of beam, period of acceleration time,
efficiency of beam ex traction, and position of bombarded target.
If these factors are kept constant, we could determine the cooling period, after which

persons are allowed to enter the cyclotron vault.
cooling time are shown in Table 2.

Measured radiation levels and normalized

In this case, the target position was at the No.2 beamcourse and the factors affecting the residual radiation were kept nearly constant except beam
intensity.

The normalized cooling periods were calculated so that the residual radiation levelat the point C in Fig. 1 decays to 10 mR/h after the operation has been stopped after
continued irradiation at 30 pA beam intensity.
period should be increased.

If the beam intensity is higher, the cooling

140

12. A

NEW

MACHINE

12-1. Specifications of Variable Frequency Linac

M. Odera

Main specifications of the linac are briefly shown in Table 1, in which energy gain per
charge, power consumption, number of drift tubes, and required field gradient of drift tube
quadrupole magnets at each stage are given.
The injector is composed of a high-voltage generator rated at 500 kV and stabilized to

10-

3

,

a metallic cage on high-voltage insulators housing a heavy ion source, a charge sna lyzing

magnet , telemetering and control equipments, various power supplies, and a motor generator
driven by an insulating rod from the ground, an accelerating column, beam focusing elements,
slit systems, switching and steering magnets , and devices for beam diagnosis such as emittanceand phase measuring probes.
The Wideroe cavities are of a quarter wave coaxial resonator type and change of resonant
frequency is possible.

High-voltage end of center conductor is loaded with drift tubes.

Quadrupole magnets are provided in drift tubes at ground potential.

Table 1.

Injector

BuncherTubes at ground andSpecifications of the Linac.
Main cavity

# 2

# 3

# 4

# 5

# 6

3.2

4.0

3.8

3.1

3.3

2.8

Rf power
(kW)

60

80

100

120

130

140

Number ofdrift tubes

21

19

15

11

1I

9

7

3

1.5

1.2

1.0

0.8

# 1

[J==[Fi H H R r ]Energy gain
per charge(MeV)

Maximum
gradient of
quadrupoles(kG/cm)0.5

141radiofrequency high vGltage are arranged alternately with axes in line and the voltage developed
between the tubes accelerates ions.
a half period 1T of rf.
31T

Tube length is determined so that ions travel in it for

However, for the first several drift tubes of cavity # 1, tube length ofhas to be adopted to make field gradients of quadrupoles within technically possible limit.

Use of this length results in the relatively small effective shunt impedance of the # I cavity.
The impedance is defined by(Effective voltage gain/ unit length)2
power loss/ unit lengthand represents efficiency of the accelerating system . If it is possible to use length of 1T for all
the tubes the voltage gain of cavity # I would be larger than 4 MY.
A vacuum system comprising of cryopumps and turbo-molecular pumps will maintain thepressure in the cavities below 10- 6 Torr.

The reason for choosing the above system is tosecure a clean oil-free vacuum as well as a low pressure.

The contemporary progress ofcryotechnology seems to allow fulfilment of this aim with relatively low cost.
The most important technique critical to this project is that of the high-power radiofrequency
exciter sysrem.

The power indicated in Table I must be supplied to each cavity for frequencies

between 20 and 50 MHz.
controlled .

The amplitude should be regulated and the relative phase be

Detectors necessary to those instrumentation must have wide-band applicability.
Standard trequency gener at or(Sy nthes ize r)

Electron ic
attenuator

Ref

Elect ron ic
attenuator

RefCont ro l
room

Accele rotor
room
Phase
detector

Buncherco vit y

Fig. 1.

Phase
de tector

Cav ity#1# 2

Block diagram of the radiofrequency system.

142

Drift of resonant frequency will be detected by comparing the phase of cavity voltage and theexciter current.

Figure I is a block diagram of the radiofrequency system.

Tuning of the whole accelerator system will be made by observing beam characteristics as
emittance or phase bunching.

Suitable detecting probes may be installed at various places.

When the parameters are determined by the initial testing run the prescription of operation will
be prepared.

For a while, a small computer will memorize this prescription together with aninterpolation formula and give a table of parameters according to operator's request.
to be able to expand gradually the role of computer in future.
to be designed to allow this expansion.

We hope

The control equipments have143
12-2. The Variable Frequency L inac Project

Results of Measurements on Model Cavity 1

M. Odera , T. Tonuma, M. Hemmi, and Y. Chiba

As our variable frequency linac has no predecessor, several developmental works must be
made by ourselves.

Here the results of measurements on Model 1 of accelerating structure

which was reported previouslyl ) are described.
The resonant frequency spectra, field distribution of several modes , and its change
according to the cavity shape were investigated.
linac.

The results substantiate the design aim of the

The frequency spectra are simple and discrimination of wanted modes from unwanted

ones seems easy as was anticipated.

Fig. 1 is an example of resonant frequency spectrum.

Separation of the first higher mode fl and the lowest frequency fo is more than 10 MHz.
Compare this value with that of the Alvarez type where separation less than 100 kHz is seen
at times.

In that case , an abrupt change of beam load or a small change of dimensions ofsome part is apt to excite unwanted modes.

Stabilization of a field pattern of the Alvarez

cavity needs several devices as well as machining of high precision.
fo

f~

f1

f4

f3

f5

f6

fa

f7

~~~llLl,- -1,- - - - -,~
!

o

20

40

60

80

100

120

f

Fig. 1.

11\0

IGO

180

200

(M Hz)

220

240

1973 . 3 .

Resonant frequency spectrum of Model cavity 1.

Perturbation Measurement

Frequency shift is converted by a digital toanalogue converter to a
voltage signal and fed

Counter

to a recorder.

DAC

Fig. 2.
RecorderMethod of measurementof field distribution by
perturbation.

144

Figure 2 is an illustration of the method of measurement of field distribution by a
A small brass sphere is drawn through the axis of drift tube holeperturbation technique.
with a Nylon cord.

The sphere perturbs the electric field between drift tubes and causesa small change of resonant frequency Af.

Slater's relation allows one to know the strength offield E from this shift. It can be written as Af ex E2 AV, where AV is the volume of the sphere,
which must be small enough to make the perturbation approximation good.
of the order of I kHz for resonant frequency of around 50 MHz.

Maximum Af is

To obtain detailed

distribution between gaps the oscillator must be stable at 10- 7 at least for 5 min which is thetime the sphere travels 10 cm.

The stability was attained by a phase-tuned oscillator scheme

using a tuned-amplifier and exclusion of external vibration caused by heavy vehicles on thestreet about 50 m distant.

Figure 3 is a distribution for fo, Fig. 4 for f1' and Fig. 5 for f 2 •There are distinct differences in the figures.
modes can be easily suppressed.
variation by a shorting plane.

By choosing a suitable feeding point unwanted

These distributions are essentially constant against frequency

Small change of the relative distribution was seen by use of

capacity compensators near drift tubes.

Improvement of this structure is in progress.

Table 1 shows transit time factors To calculated from the measured field distribution.
Voltage gain in each gap is given by V 0 To cos¢s' where V 0 is the potential difference between
neighboring drift tubes and 1>s is the phase of synchronous particles.

40. 2 15MHz

ClJ
U

C

0
C

0
if)

ClJ
L

E

.....2
c
~
0
:>

~I

~1

OJ

U

>u
c
ClJ

::>

g
'--

LL

Position ofalong theFig. 3.

per tu r bing sph ere
axis at linac

Field distribution of the lowest mode.
Really, this is the distribution of frequency
shift and the abscissa is proportional tosquare of field strength. Representations
are the same as in Fig. 4 and Fig. 5.

145

N

65.9 MH,

I8
N

1I

Q)

u

>c

u

Q)

:0

f

LL

Pos ition of

pertu r bi ng spher e along the ax is of Iinae

J

Field distrib ution of the first higher mode

Fig. 4.

fl .

95.6 MHz

§
'tC

0

a
>
Q)
u
>-

u
c

<1>
:0

0'

)

Q)

L

LL

Posi t ion ofFig. 5.

perturb ing sphe r e along the axis of Iin ae

Field distrib ution of. the second higher
mode f 2 .

146

Table l. Transit time factors To at accelerating gaps determined from measured
field distribution.
Gap
number

2

3

4

5

6

7

8

To

0.800

0.830

0.865

0.880

0.895

0.910

0.920

0.930

Gap
number

9

10

11

12

13

14

15

16

To

0.935

0.940

0.945

0.950

0.955

0.960

0.963

0.966

Reference
1)

M. Odera

IPCR Cyclotron Progr. Rep. , ,2, 16 (1972).

147

12-3.

The Variable Frequency Linac Project

Orbit Dynamics:

Radial AcceptanceT. Tonuma, F. Yoshida, and M. Odera

A suitable value of injector voltage was discussed previously and 500 kV was chosen as
a compromise between requirements of orbit dynamics and economy. 1 )Figure 1 showsmagnetic field gradients of quadrupole magnets, which are provided in drift tubes, necessary
for focusing ions when an ion beam enters the linac after having been accelerated by a voltage
of 500 kV.

The fie ld gradients from 1st to 7th tubes have been estimated under the conditions

that each drift tube at high voltage potential as well as earth potential has a quadrupole magnet
and the tube length is determined so that ions travel in it for one and a half period, 31T, of rf

7.0

6.0
E
u

.......

~ 5.0

'"c
Q)

~ 4.0
0'

~
Q)

~ 3.0
~

Q)

c
0'

~ 2.0

1.0

0~-L~L5~~-L~1-0~-L~L15~~-L~2~0~

Drift tube number

EV number used is 1.5 x 10 4 kV 2 /cm,
the gaps between drift tubes are 3 cm,
and 'l's = - 25° for synchronous
particles. Upper limit is for mle = 22,
f = 18.5 MHz and lower limit for

mle = 3, f = 50 MHz.
Fig. 1.

Magnetic field gradients necessary forfocusing of beams at injector voltage
of 500kV.

148

field to make field gradients of quadrupoles within a technically possible limit.
is effective to have a large radial phase acceptance.

The condition

In the previous report , the field gradientswere calculated assuming quadrupoles being installed only in the drift tubes at earth potential. 1 )The radial acceptance in that case was much smaller than in the present configuration.

Thefield gradients after the 8th drift tube have been calculated assuming that only drift tube atearth potential are provided with quadrupole magnets and the tube length is chosen to be a half
period 1r of rf.
Figure 2 shows radial acceptance of the first cavity in the x- and y-directions by use ofmagnetic field gradients shown in Fig . 1.

The aperture of a drift tube is 20 mm.

The

different shape of the acceptance between x- and y-directions comes from the fact that the first
quadrupole magnet is divergent in the x-directions and convergent in the y-direction.

Bothradial phase acceptances are , however, about 70 '" 80 mm-mrad .
X/( mrod)

15
10

-10

-15

-15

Fig. 2.

Radial acceptance.

Reference

1)

F. Yoshida, T. Tonuma, and M. Odera:

to be submitted to the Reports of IPCR (inJapanese) a part of which was given in IPCR Cyclotron Progr. Rep. , 6 , 18 (1972) .

149

12-4. The Variable Frequency L inac Project

Orbit Dynamics: Phase Oscillation and Energy Resolution

F. Yoshida, T. Tonuma, and M. Odera

One can follow the phase oscillation of an ion which is injected at an initial phase '111
different from synchronous phase 'l!s and then passes through each drift tube.

When the phaseof 'l!s ion becomes 'l!s + 1T by passing through one section, that of 'I! 1 ion will be \}rl + 1T + ~\}rl
as shown in Fig. 1.

The phase shift Llw l in the first section is expressed by LlWl/1T = (L 2- L 2')/L 2 ,where L2 is the distance which the synchronous particle travels in a half period and L 2' is thatof 'I! 1 ion.

These distances can be written in terms of an injection energy Eo, a voltage V 0

Fig. 1.

Diagram used in iterative calculations.

between adjacent drift tusbes, a transit time factor To, and a constant K as follows:
L2 = K.J Eo + VOl T 01 cos\}r S

L 2' = K .J Eo + VOl T 01 cos'l!}Use of these relations -gives
Eo + VOl Tot cos\}rs )Eo + VOl T 01 COS\}r1

x 1T (in 31T mode, x 3) .

By renaming 'I! 1 + ~ 'l!l as \}r2, the phase shift caused by a transit of the ion to the next
section is ~'I!2'

Then,t."'2 = ( 1 L3

¥')

X "

(in 3" mode, x 3)

= K .J Eo + VOl T 01 cos\}r s + V 02 T 02 cos'l! s

L 3' = K .J Eo + VOl T 01 COS'l!1 + V 02 T 02 COS'l!2and by iteration

150~'I'n- l = ( 1 - ~:'))( " (in 3" mode, x 3)

Ln = K -J Eo + Vo 1 To l coS'l!3 + ......... + Von- lTon_ lcos'l!sThe relation of 'l!n with (En- Es)/Es is shown in Fig. 2.

Es is the energy of synchronous

particle and En is that of an arbitrary ion , and the figures show examples of the result of
step-by-step calculation starting from two extreme initial conditions.

Parameters used in theIt can be seen from Fig. 2 that the phase oscillations

calculations are tabulated in. Table 1.

are strongly damped as acceleration proceeds and the energy resolution at the exit of the linac
is about ± 0.2 %. However, the calculation does not include factors such as alignment errors,
voltage fluctuation or phase excursion of the radiofrequency system , and Fig. 2 should be taken
as gIvmg a lower limit of the quantities concerned.
Table 1.

Linac parameters used in calculations.

Cavity

# 1

# 2

# 3

# 4

# 5

# 6

Gap (em)

3.0

5.0

7.0

9.0

10.0

1l.0

Vo (kV)

200

210

320

360

380

400

Number of
section

21

19

15

11

11

9

Transi t time
factor T o

0.90

0.92

0.94

0.95

0.95

0 .95

Total L(m )

3.47

3.63

3.73

3.19

3.55

3.16

(b)

~ - fs (%)fs(a)>/1- \ _ - -,,"" - /I

fn-Es (%)
fs

-

2 -

"

2

, .....
"-

I

/

I

""
"

/

/

I

\

I

\

I
I

\

\

\

I

,*,~ .... - -

I

(

I

\

I

"" ""

/

\

-3 15

---~~

~"

0

\

\- 15 0

0

\

\

\

I
I

\
\

I

\

I

\

I

\

\
\

-2

I

,

/

" "-

-2

', ......

......

---/"" ~)"/"-3

Fig. 2.

The relation of 'l!n with (En-Es)/Es' Calculations of (a) and (b) werecarried out with'l!l = -15° and -35° respectively for a synchronous
phase 'l!s = - 25°.

151

12-5_ Two Examples of Heavy-Ion eyc lotron
withExternal Injection Provision

M. Odera and H. Kamitsubo

It was pointed out by K. Matsuda l ) that an externally inje cted cyclotron using stripping
phenomenon has several desirable characteristics.

Table 1 shows the most probable charge

states of several ions charge-stripped through media of suitable thickness. The magnetic rigidityof the ions before and after their charge is stripped is compared assuming the initial charge tobe that produced by a conventional ion source.

A large reduction of rigidity can be seen.

Figure 1 taken from Ref. 1) shows a characteristically slow increase of rigidity against largechange of energy of heavy ions.

These tahle and figure indicate a possibility of accelerationof heavy ions of large mass to moderate energies by a cyclotron of modest size.

Here two

examples of design along this scheme are presented.
Most probable charge states of after stripping at I MeV/ nucleon.

Table 1.

0- 16

Ar-40

Kr-84

Xe-13 2

Charge before stripping

4

6

8

9

Magnetic rigidity (kG·cm)

576

960

1510

2110

Stripper

gas

gas

gas

solid

gas

solid

8

12

15

20

17

26

288

480

806

605

1100

730

Ion specie

Charge after stripping
Magnetic rigidity (kG-cm)

1.5-E......

.D

<:

:;
I
-0 1.0~1 (g o 5)-- - --- - -------)Br ( go s\_ -. Ar (gas )_ _ _ --;= - ----.:-:~--.:------, Br (ga s)---- --- : : =----- ~ J ( foil)
Br (f oil)
U (foi l )u.......
ClJ
C
0'

~ 0.5

o

50

150

100

200

250

(Me V)

Fig. 1.

Magnetic rigidity of ions stripped of charge atthe energies indicated.

152

(1)

A linac-injected sector-focused cyclotron

The proposed variable-frequency linac 2 ) has the characteristics suitable for a heavy ion
injector.

Energy per nucleon of ions accelerated is larger than 1 MeV and a large increase of

the number of charges can be expected by the stripping process.
is moderate.

Also, the intensity of beam

External injection of heavy ions into a sector-focused cyclotron by a linac was

first realized in 1971 by the ALICE system in the research institute of University of Paris atOrsay.3 ) Particles are injected along the valley of magnet pole and the injection orbit isconverted into acceleration orbit by use of an abrupt change of the orbit radius by charge
stripping.

The scheme is shown in Fig. 2.

Table 2 shows an example of parameters of a

Max imum or bit
mea n rad ius 1016

Hil l
Voll ey

Injection orbit
by stripping at
Valiey- Hillbounda r y.
chorge rotio

Fig. 2.

=3

Conversion of an injection
orbit to an acceleration orbit

Injection orbit
by st r ipping ot
Hil l-Va lleyboundo r y.
chorge rotlO =3

by stripping of charge at certain
radius of a sector-focused
cyclotron.

Table 2.

An example of parameters of a linac-sector focused cyclotron
combination.

Ion species

Ar-40

Kr-84

Xe-132

Injection energy (Me V)

120

160

180

Linac frequency(MHz)

33.5

26.7

22.6

Charge before stripping

6

8

9

Charge after foil stripper

18

24

27

Ratio of charge

3.0

3.0

3.0

Magnetic rigidity (kG'cm) at injection

555

696

820

Initial orbit radius( em)

45.4

45.4

45.4

Mean field(kG)

12.2

15.4

18.0

Circulating frequency (MHz) of ion

8.38

6.68

5.65

4

4

4

10l.6

10l.6

10l.6

600

800

900

Harmonic number
Maximum orbit radius(cm)Final energy (Me V)

153

possible linac-injected s.f. cyclotron system.

Conversion of the present cyclotron into thesector-focused type of this size is feasible.

(2)

A linac-injected separate-sector cyclotron

The separate-sector cyclotron was originally invented to make external injection andextraction of beam easy.4 ) This type is very suitable for an externally injected heavy ion cyclotron.
The simplest four-sector type is shown schematically in Fig. 3. Accelerating electrodes can beinstalled in free sectors where no obstacle is present. Structure of cavity effective to generate alarge accelerating voltage can be adopted. Orbit at injection is simple and charge-changing between
narrow magnetic gap is not required. While the foil strippers must be used in the above-mentioned
s.f. cyclotron scheme between magnetic gap, the well-known fragility of foil under intense heavy
ion bombardment presents a problem which is not easy to be solved. There is no such a difficultyin case of the separate-sector cyclotron, where a gas stripper can be used before injection into theaccelerating chamber. However, the most probable charge state is considerably smaller for gas
strippers than for foils. Larger magnetic rigidity is required in price of simpler structure and easier
operation.
Table 3 shows some parameters of this scheme. Turn-separations at the initial and exist orbit
in the region free of magnet are large enough to allow good injection and extraction efficiency.
This, together with the use of stripper at a suitable place outside of the main accelerator system
greatly simplifies operation and guarantees moderate beam intensity. When the energies same withthose of Table 2 are required, the weight of magnet can be reduced to 600 ton as shown inparen thesis.
4 0 9_4 _ _Fig. 3.

A four-magnet separate-sector
cyclotron and an injection scheme.

154

Table 3. Parameters of a 1inac-injected separate four-sector cyclotron.

Ion species

Ar-40

Kr-84

Xe-132

He-3

Injection energy (Me V)

120

160

180

20

Linac frequency (MHz)

33.5

26.7

22.6

50

Charge after stripping

16

20

24

2

Magnetic rigidity at injection (kG·cm)

623

834

924

558

Width of magnet (degree)47

Gap of magnet(cm)6

Initjal orbit radius (cm)50

Initial mean radius(cm)

91
16.7

18.5

11.2

3.34

2.83

6.25

1440
(800)

1620
(900)

180
(100)

12.5

Magnetic field (kG)

1400 (600)Weight of magnet (ton)Circulating frequency of ion (MHz)

4.19

Harmonic number

8

Number of accelerating electrodes

2

Width of electrodes (degree)

22.5

Voltage gain per turn (MV)
Orbit separation at injection (cm)3

Orbit separation at extraction (cm)

1.2 ( 1.6)

Maximum orbit radius (cm)

150(112)

Maximum mean radius(cm)273(204)

Maximum energy (Me V)

1080
(600)

Numbers in () are values when the maximum energies same with those of Table 2 are required.

References
1)

K. Matsuda:Sci. Papers I.P.C.R., 66 , 33 (1972).

2)

M. Odera and T. Tonuma:

AlP Proc. No.9, Cyclotrons - 1972, (Eds. 1. 1.

Burgerjon and A. Strathdee), Vancouver, Canada, p. 283, (1972) ; M. Odera : IPCR
Cyclotron Progr. Rep., ~ , 24 (1970) ; M. Odera and H. Kamitsubo : ibid. , 6, 15 (1972).
3)

A. Cabrespine and M. Lefort:

4)M. M. Gordon:

Nucl. Instr. Methods, 97, 29 (1971).

Ann. Phys., 50, 571 (1968) ; Nuc!. Instr. Methods, 58, 245 (1968).

155

13.

LIST OF PUBLICATIONS

1) F. Akiha, T. Aburai, T. Nozaki, and Y. Murakami:

3He and Q on Chromium", Radiochim.
2) F. Ambe and S. Ambe:~

108 (1972).

"Chemical Effects of Neutron-Induced Nuclear Reactions in
The (n. r ) and (n,2n) Reactions in Chlorates",

Halates and Related Compounds IV.
Radiochim.

Acta,"Yield of 52Fe for the Reactions ofActa, in press.
"The Oxidation States of 119Sb after the EC Decay3) S. Ambe, F. Ambe, and N. Saito

of 119mTe in Te0 2 and H 6 Te0 6 ", Radiochim. Acta, in press.
4) F. Ambe and S. Ambe:"Mossbauer Spectroscopic Verification of Two Different Statesof Impurity 119S n Atoms in Sb 2Te 3 ", Phys. Lett., 43A, 399 (1973).
5) K. Hiruta, T. Nomura, T. Inamura, and M. Odera"Alpha Decay of 2I8Th, a New

Isotope", Phys. Lett., 45B, 244 (1973).
6) Y. Yamazaki, S. Nagamiya, T. Nomura, K. Nakai, and T. Yamazaki:"Magnetic Momentof a Core-Excited Isomeric State in 210pO", Phys. Lett., 44B, 440 (1973).
7) T. Suzuki and C. Hinohara:"The Splitting of the Isospin and Spin-Isospin Dipole

Resonances in 12C" , Nuc!. Phys., A204, 289 (1973).
8) C. L. Lin, S. Yamaji, and H. Yoshida:"Finite-Range Calculation of Two-Nucleon

Transfer Reaction", Nuc!. Phys., A209, 135 (1973).
9) T. Suzuki"New Giant Resonances", Nuc!. Phys., to be published.

10) T. Suzuki"Sum Rule Approach for Nuclear Vibrations and Effects of the Core

Polarization", Nucl. Phys., to be published.
11) S. Nagamiya, Y. Yamazaki, O. Hashimoto, T. Nomura, K. Nakai, and T. Yamazaki:"Magnetic Moments of the [1Th 9 72 J 8+ States in Po Isotopes and of the [(1Th 9 f2) 8+(8)1)
PI/2] 17/2- State in 209PO", Nuc!. Phys., A211, 381 (1973).
12) T. Nomura, K. Hiruta, T. Inamura, and M. Odera:"Ground State Alpha Decays of

N= 128 Isotones; 2I6Ra, 217 Ac and 2I8Th", Nucl. Phys., in press.
13) F. Ambe, S. Ambe, and H. Shoji:
II9Sn", Radiochem.

Radioanal.

"Preparation of 1I9Sb for Mossbauer Spectroscopy of

Lett., ~ 349 (1973).

14) N. Akiyama, Y. Yatsurugi, Y. Endo, Z. Imayoshi, and T. Nozaki:"Lowering of

Breakdown Voltage of Semiconductor Silicon Due to the Precipitation of Impurity Carbon"
Appl. Phys. Lett., 22, 630 (1973).
15) Y. Yatsurugi, N. Akiyama, Y. Endo, and T. Nozaki"Concentration, Solubility, andEquilibrium Distribution Coefficient of Nitrogen and Oxygen in Semiconductor Silicon",
1. Electrochem. Soc, 120,975 (1973).

16) T. Nomura and K. Hiruta:"A Method of Measuring Alpha Decays in the Nanosecond

Range", Nuc!. Instr., 108, 61 (1973).
17) T. Suzuki and C. Hinohara:
be published.

"Sum Rules and the Nonexchange Force", Phys. Rev., to15618) T. Suzuki:"Momentum Transfer Dependence of the Effective Charge for Electro-

excitation", Phys. Rev C, to be published.
19) T. Nomura, K. Hiruta, M. Yoshie, and O. Hashimoto"Alpha Decay of 215Fr", Phys.

Rev., to be published.
20) T. Fujisawa, S. Yamaji, K. Matsuda, S. Motonaga, F. Yoshida, H. Sakaguchi, andK. Masui:"The Elastic and Inelastic Scattering of 3He from 12C at 24.0, 29.2, 3~.7 and39.6 MeV", J. Phys. Soc. Japan, 34, 5 (1973).
21) T. Tonuma, I. Kohno, Y. Miyazawa, F. Yoshida, T. Karasawa, T. Takahashi, and S. Konno:"Charge Changing of Energetic Heavy Ions in Gases", J. Phys. Soc. Japan, 34, 148 (1973).
22) S. Yamaji:"The Coupled-Channel Born-Approximation Calculation of the Reaction

looMo (t, p) I02Mo", J. Phys. Soc. Japan, 34, 298 (1973).
23) C. Gil, K. Nishiyama, T. Nomura, T. Yamazaki, and K. Miyano"A New Short-Lived

Isomer in 114Sb", J. Phys. Soc. Japan, 34, 874 (1973).
24) S. Takeda, S. Yamaji, K. Matsuda, 1. Kohno, N. Nakanishi, Y. Awaya, and S. Kusuno"

IOO

Mo(t,p) 102Mb Reaction at 15.8 MeV", J. Phys. Soc. Japan, 34, 1115 (1973).

25) O. Hashimoto, T. Nomura, T. Yamazaki, K. Miyano, and M. Ishihara: "Magnetic Momentof the 8+ [( vg9/2r 2] State in 86Sr", J. Phys. Soc. Japan, 34, Suppl. 259 (1973).
26) O. Hashimoto, A. Sumi, T. Nomura, S. Nagamiya, K. Nakai, and T. Yamazaki:"Theg Factor of the 7+ Isomeric State in 202Tl", J. Phys. Soc. Japan, 34, Suppl. 269 (1973).
27) S. Nagamiya, Y. Yamazaki, O. Hashimoto, T. Nomura, K. Nakai, and T. Yamazaki:"Magnetic Moments of High-Spin Isomeric States in Po Isotopes", J. Phys. Soc. Japan,
34, Suppl. 283 (1973).
28) Y. Yamazaki, S. Nagamiya, T. Nomura, K. Nakai, and T. Yamazaki:"Magnetic Momentof a Core-Excited Isomeric State in 210pO", J. Phys. Soc. Japan, 34, Suppl. 286 (1973).
29) T. Nomura:On the Violation of the Additivity of the If7/2 Neutron Moments", 1. Phys.

Soc. Japan, 34, Suppl. 331 (1973).
30) T. Nomura:"Magnetic Moments of the If7/2 Nuclei", J. Phys. Soc. Japan, 34, Suppl.

619 (1973).
31) O. Hashimoto, T. Nomura, T. Yamazaki, K. Miyano, and M. Ishihara"The g-Factor of

the 8+ State in 86Sr" J. Phys. Soc. Japan, 35, 337 (1973).
32) N. Shiotani, T. Okada, H. Sekizawa, T. Mizoguchi, and T. Karasawa:"Positron

Annihilation in Ferromagnetic Nickel", J. Phys. Soc. Japan, 35 , 456 (1973).
33) M. Odera, Y. Chiba, T. Fujisawa, Y. Miyazawa, and O. Terajima:"The Radiofrequency

System of the IPCR (RIKEN) Variable Energy Multi-Particle Cyclotron", Sci. Papers
I.P.C.R., 67, 90 (1973).

157(Papers presented at international meetings)
1)

M. Imamura:"Some Aspects of Heavy-Ion Radiolysis", Joint U.S.-Japan Conf.

Processes and Intermediates in the Radiat.

Chern. of Condensed Phase, Catalina lsI.,

California, Feb. (1973).
2)

H. Kamitsubo, M. Yoshie, I. Kohno, S. Nakajima, I. Yamane, and T. Mikumo :"Reaction Mechanism and Level Density Informations in Multi-Nucleon Transfer
Reactions", Intern. Symp. Transfer Reactions Induced by Heavy-Ion, Argonne, March(1973).

3)

I. Kohno, H. Kamitsubo, S. Nakajima, I. Yamane, M. Yoshie, and T. Mikumo :"Single and Multi-Nucleon Transfer Reactions on N=28 Nuclei Induced by 14N and 12C",Intern. Symp. Transfer Reactions Induced by Heavy-Ion, Argonne, March (1973).
4)

T. Nozaki:"Examination of the 18F -Yield for Various Reactions and Synthesis ofSome 18F Compounds", U.S.-Japan Cooperative Sci. Semi. on Recent Advances inRadiochem. Tech. and Applications, Oiso, Nov. (1973).
5)

F. Ambe:"Mossbauer Emission Spectra of 119Sn after the EC Decay of 119Sb",

U.S.-Japan Cooperative Sci. Semi. on Recent Advances in Radiochem. Tech. andApplications, Oiso, Nov. (1973).
6)

H. Sekizawa, T. Okada, T. Mizoguchi, T. Karasawa, and N. Shiotani:"Positron

Annihilation in Ferromagnetic Nickel", Third Intern. Conf. on Positron Annihilation,
Helsinki, Aug. (1973).
7)

N. Shiotani, T. Okada, H. Sekizawa, and T. Mizoguchi:"Positron Annihilation in

Vanadium and Niobium", Third Intern. Conf. on Positron Annihilation, Helsinki, Aug.
(1973).
8)

S. Takeda, H. Ohnuma, N. Nakanishi, S. Yamada, and M. Sekiguchi:"P-n Interaction

Effect Observed by (dt) Reaction on the Isotone", Proc. Intern. Conf. Nucl. Phys.,
Munich, 1973, 1, 79 (1973).
9)

I. Kohno, H. Kamitsubo, S. Nakajima, M. Yoshie, T. Motobayashi, and T. Mikumo"Transfer Reactions Induced by 14N and 12C at High Energies", Proc. Intern. Conf.
Nucl. Phys., Munich, 1973, 1, 498 (1973).
10)

T. Nomura, K. Hiruta, M. Yoshie, and O. Hashimoto"Angular Distribution andLinear Momenta of Heavy Reaction Products in the 209Bi + 12C Reaction", Proc. Intern.
Conf. Nucl. Phys., Munich, 1973, l, 545 (1973).
11)

S. Yamaji, S. Suekane, and K. Harada:"Total Energy Surface for 236U in the Two-

Center Shell Model", Proc. Intern. Conf. Nucl. Phys., Munich, 1973, L 596 (1973).
12)

T. Nomura, K. Hiruta, M. Yoshie, and O. Hashimoto:"In-Beam Alpha Spectroscopy

ofN=128 Isotones, 215Fr, 216Ra, 217Ac, and 218Th", Proc. Intern. Conf. Nucl. Phys.,
Munich, 1973, 1, 687 (1973).

158

14.

LIST OF PERSONNEL

Members of the Board
HAGIHARA Hitosi;Il
KAMITSUBO Hiromichi
NOZAKI Tadashi ~ Uffil'* 1- (Chairman)
1-. H 7i:. ill

iE

HAMADA Tatsuji
NAKANE Ryohei
ODERA Masatoshit~ EB :i!

='* tN N Sf

+ 9= IE 1~

Users Committee=

HAMADA Tatsuji i% EB :it(Chairman)
KAMITSUBO Hiromichi L:If 7.i:. J1i
MA TSUY AMA Akira fl W~
ODERA Masatoshi IJ\ ~ iE 18t
SEKIZA WA Hisashi M iR
I6J

E3IMAMURA Masashi A, Ra
KARASAWA Takashi @= iR
NOZAKI Tadashi fl ~IE
SAKAIRI Hideo ~ A. !Ii:. tl

Managers of Users Group
HAMADA Tatsuji
ODERA Masatoshi~ EB ;@-=NOZAKI Tadashi!Y Wl\jiE

IJ\ ~ iE 1~

Opera ting Personnel
Machine GroupHEMMI Masatake ~ ~ i& TIt
MIYAZAWA Yoshitoshi '§ iR fi: ~TONUMA Tadao p lB iE bt

INOUE Toshihiko tt L ~ B
SHIMAMURA Akira JJ!b R~

Operation
FUJITA Shin iii EB
tfT
KAGEY AMA Tadashi ~ W
iE
NAKAJIMA Hisao cp UI,~ I6J bt
T AKEBE Hideki JEt $ ~ tlit

IKEGAMI Kumio ;ifu L1L=~
KOHARA Shigeo IJ\ mi £ 'R.
OGIWARA Kiyoshi ~ mi
TERAJIMA Osamu ~ JJ!b~m

Scien tific and Engineering Personnel
Cyclotron Laboratory
CHIBA Yoshiaki T ~ iff Rfl
FUJITA lira iii EB
E!I5
INAMURA Takashi ffiHi .Efl
KAMITSUBO Hiromichi J: t:if 7i:. i@:
KOHNO Isao fiiJ fl
J)J
MOTONAGA Shoshichi JL 7k fIB -t
NAKANISHI Noriyoshi cp ~ ~ .§ODERA Masatoshi IJ' ~ IE 1~
TAKEDA Shigeru 1fT EB~
TONUMA Tadao F p,.j IE it
Y AMAJI Shuhei IlJ ~ f~ f
WADA Takeshi fa 83
iii-=

FUJI SA WA Takashi Ii if( ,Wi :t;
HEMMI Masatake :& Je, i!& Ji\
INOUE Toshihiko ):\: J::. ~ ~KARASAWA Takashi ~ if(~
MIY AZA WA Y oshitoshi g J'( tk fijx
NAKAJIMA Shunji cp JJ!b §J
NOMURA TOfU ~ R
7SHIMAMURA Akira ~ tt
TAKIGAWA Noboru it II I
TOY AMA Manabu 7i- IU~
YOSHIDA Fusako '5 83 m r

-=

159

(Visitors)
EJIRI Hiroyasu IT OC 7R ~(Univ. of Osaka)
FUJI NO Takeoiii ~ ITt ~(Inst. Nuc!. Study , Univ. of Tokyo)
HANAZONO Sakae 1t ~~(Inst. Nuc!. Study , Univ. of Tokyo)
IMANISHI Bunryu
4' jt§ X. ~ (Nihon Univ.)
KATORI Kenji
JJ{ IlX Mft _(Tokyo Univ. of Educ.)
KOIKE Masahiro
IJ\ illi iE 7R(Inst. Nucl. Study , Univ. of Tokyo)
KOYAMA Katsuji IJ\ LU ~~ (Inst. Nucl. Study , Univ. of Tokyo)
MIKUMO Takashi =. ~~(Tokyo Univ. of Educ.)
MIY ANO Kazurnasa '§ Jf fDiFj(Dept. Phys. , Niigata Univ.)
NAGAMIYA Shoji
71<. 'g iE tt(Dept. Phys. , Univ. of Tokyo)
NAKAI Koji r:p it ii5(Dept. Phys., Univ. of Tokyo)
NAKAMURA Masanobu r:p ;fj- JI {?;(Dept. Phys., Kyoto Univ.)
OHNUMA Hajirne*- IB m (Inst. Nucl. Study , Univ. of Tokyo)
SAKAGUCHI Harutaka :Vj D tt ~(Dept. Phys. , Kyoto Univ.)
SEKIGUCHI Masayuki M D ~ IT
(Inst. Nucl. Study , Univ. of Tokyo)
SHIBATA Tokushi ~ H::l f,~( ;G(Dept. Phys. , Univ. of Osaka)
Sprouse, Gene (State Univ. of New York at Stony Brook)
TAGISHI Yoshihiro EE J¥ ~~~ 1i(Dept. Phys., Tokyo Univ. of Educ.)
YAMADA Satoru w EEl~:G(Tokyo Inst. Tech.)
YAMANE Isao w tN
JJJ(Res. Center Nucl. Sci. and Tech. Univ. of Tokyo)
YAMAZAKI Toshirnitsu
w Uffij ~ Jt
(Dept. Phys. , Univ. of Tokyo)
YAZAKI Koichi*- ~ mt (Dept. Phys. , Univ. of Tokyo)
YOSHIDA Hiroshi "5 tEl
iJL(Univ. of Osaka)=.

(Students)'*

HASHIMOTO Osarnu 11
tt(Univ. of Tokyo)
HIRUT A Kotaro~ EEl =¥ *~~(Tokyo Inst. Tech.)
IKEZOE Hiroshi~{Q i~-r.¥(Univ. of Tokyo)
KANAI Tatsuaki ~ jf ji 1:1)1(Tokyo Univ. of Educ.)
MOTOBA YASHI Tohru
f* ~(Univ. of Tokyo)
YAMAZAKI Yoshishige w ~ ~ pJ<.
(Univ. of Tokyo)
YOSHIE Morio i5 IT ~ 515(Tokyo Univ. of Educ.)*

Radiation Laboratory
AWAY A Yohko ~ ~ ?G .:r
HASHIZUME Akira 11 J1\Wi
KATOU Takeo tID iii ITt tt
KUMAGAI Hidekazu !i~ ~ ~ fa
TAKAHASHI Tan ~ 11£!.
(Visitors)
DOKE Tadayoshi i@: ~ I~' ~(Waseda Univ.)
no Masahiro ~ ~ 1E
(Tokyo Metropol. leriatric Hosp.)
NAGAHARA Teruaki:7k ®: Jffi tyj(Rikkyo Univ.)
SUZUKI Kazuaki~
sJI(Japan Anal. Chern. Res. Inst.)

*

*-

=-

HAMADA Tatsuji &- EEl il
IZUMO Koichi
ttl ~ Jt KONNO Satoshi ~ ~~OKANO Masaharu Rftl ~ Jt m
TENDOW Yoshihiko T. i@: 7J ~

160

Nuclear Analytical Chemistry Laboratory
AMBE Fumitoshi ~ $ )( ~ARAT ANI Michi m ~ §I€ ~MAKIDE Yoshihiro ~ ill ~ tf;tSAITO No bufusa ~ Hi 1~ m

AMBE Shizuko 'Ji. 1m ~ -T
IWAMOTO Masako :!5::$: IE -T
NOZAKI Tadashi ff ~if(Visitors)
AKIY AMA Nobuyuki tic w f§" ;;t(Komatsu Electronic Metals Co., Ltd.)FUKUSHI Kiyoshi :m ±(Nat. Inst. of Radiological Sciences)
HARA Toshihiko !*/ij&: lJ;(Nat. Nakano Chest Hosp.)
100 Tatsuo :# pi ~ 1$
(Nat. Inst. of Radiological Sciences)
KASIDA Yosihiko ~ EE ~"ffi (Nat. Inst. of Radiological Sciences)
Y ATSURUGI Yoshifumi J\ ~Ij Ei)( (Komatsu Electronic Metals Co., Ltd.)m

Synthetic Organic Chemistry Laboratory
OHTSUKA Yasuo*- ±j( ~ :!R:T AHARA Akira

EE mi

Bjg

Radiobiology Laboratory
IGARASHI Kazui

Ii+ ii-EX:MA TSUY AMA Akira

tl w

~

(Student)
Y AT AGAI Fumio

1t B3 ~)(:j((Graduate Course of Sci. Engg., Waseda Univ.)

Radiation Chemistry Laboratory
IMAMURA Masashi A,;ft
MATSUI Masao tl # if. :j(S

KIMURA Kazuie

E3

Metal Physics Laboratory
HASIGUTI R. Ryukiti 4i 0
SAKAIRI Hideo #j l\ ~ fit
Y AGI Eiichi J\

~ Ei

**-

KOY AMA Akio IJ\ w BE fit
SHI OTANI No buhiro :Ii: ~ g 5L

(Visitors)
ISHINO Shiori n ~~(Univ. of Tokyo)
MISHIMA Y oshitsugu ::::. ~ ~ *l(Univ. of Tokyo)
SHIRAISHI Haruki B 13 # tM
(Nat. Res. Inst. for Metals)
Magnetic Materials Laboratory
OKADA Takuya~

B3 !? -tQ

SEKIZA WA Hisashi

M ~

MJ

#j:.$: -~~(Vistor)MIZOGUCHI Tadashi

~ 0

if.

(Gakushuin Univ.)

Radiation Monitoring and Safety Office
KODA Kugao Efl 83 ~ :!13
USUBA Isao ff. ~~SAKAMOTO Ichiro

161

15.

LIST OF OUTSIDE USERS AND THEIR THEMES

Description is in the order of theme, energy of particle used, and names of person andinstitution responsible for the theme.

Numbers in parentheses are total beam times andfrequency of irradiation in the interval between Nov. 1972 and Oct. 1973.

Paperspublished based on the utilization of the cyclotron by the outside users are tabulated at theend of this chapter.
1)"Study of Effect of Helium Bubbles on the Mechanical behavior of Stainless SteelSUS 32 and 316"
ex -32, 34, 36 MeV
T. Katou, S. Kawasaki, and T. Furuta
Japan Atomic Energy Research Inst.

2)(88 h, 7)"Study of Method for Measurement of Helium in an Activated Stainless SteelSUS 316 "ex -34, 36 MeV

Y. Wad a and K. Tsutsumi
Power Reactor and Nuclear Fuel Development Corporation, Tokai Works. (24 h, 2)
3)"Production of 18F for Bone Tumor Search"
3He -18",28 MeV
H. Kakehi, Chiba Univ. Hospital
A. Tsuya, National Cancer Center Res. Inst.
H. Murayama, Tokyo Medical Univ.

4)(43 h, 16)"Production of 43K for Heart Diagnosis"
ex - 26, 29, 30 MeV
M. Nakamura, and Y. NoseMed. Dept., Kyushu Univ.

5)(35 h, 5)"Production of 18F for Bone Tumor Search"
3He - 19 MeV
T. Hara and M. Iio
Nakano National Hospital6)(15 h, 5)"Production of 47SC for Cancer Diagnosis"p-

16 MeVT. Hara and M. Iio
Nakano National Hospital(3 h, 1)

162

7)

"Production of 197Hg for Diagnosis of Lung Tumor"
d-22 MeV
T. Hara and M. lio

8)Nakano National Hospital"Production of 123 1 and 61CU"(39 h, 13)

3He-40, 42 MeV, a-40, 42, 45
Y. Homma and Y. Murakami
Chern. Dept., Tokyo Metropolitan Univ.
9)(36 h, 12)"Extraction of 146Eu from 146Gd"

a-30 MeV
K. TomuraInst. for Atomic Energy, Rikkyo Univ.
10)(3 h, I)

"Measurement of Excitation Function for 66Z n (a, n) 69Ge reaction"

a-20 MeV
M. Furukawa

Chern. Dept., Nagoya Univ.
11)(3 h, 1)

"Measurement of Excitation Function for 69Ga (p , n) 69 Ge Reaction"

p-8, 16 MeV
M. Furukawa
Chern. Dept., Nagoya Univ.
12)(6 h, 2)

"Production of 53Mn"
d-15, 20 MeV
S. Shibata and S. Umemoto
Chern. Dept., Kyushu Univ.

13)(10 h, 2)"Study of Decay and Level Structure of 210pO"

a-40 MeV
Y. Yamazaki
Phys. Dept., Univ. of Tokyo14)(21 h, 5)"Measurement of Nuclear Magnetic Moment of 210PO, 6+ State"a- l0",40 MeV
T. Yamazaki
Phys. Dept., Univ. of Tokyo15)(5 h, 1)

"Preparation of 52Fe for Diagnostic Use"
3He-40T. AburaiRadio-isotope School, Japan Atomic Res. Inst.

16)(4 h, 1)

"Measurement of Excitation Function for 56Fe (a, n) 59Ni reaction"

a-25 MeV
S. Tanaka
Inst. for Nucl. Study, Univ. of Tokyo(5 h, I)

163

17)

"Simulation of Swelling of Stainless Steel with Cyclotron Irradiation"
a-31
M. Terasawa
Toshiba Res. and Development Center(12 h, 1)

Publications
1.

T. Furuta, Y. Ogawa, and R. Nagasaki: "The Effect of Creep Test Temperature on
Creep Rupture Properties. of a-ray Irradiated AISI 316 Stainless Steel", Iron & Steel,~

2.

1117 (1972). (in Japanese)

T. Furuta and S. Kawasaki:"Influence of Recrystallization on the High Temperature

Embrittlement of Austenitic Stainless Steel Induced by a-Irradiation", J. Nuc!. Mat.,
47 , 102 (1973).
3.

T. Furuta, S. Kawasaki, and R. Nagasaki : "The Effect of Cold Working on Creep
Rupture Properties for Helium-Injected Austenitic Stainless Steel", J. Nuc!. Mat.,47, 65 (1973).

165

AUTHOR INDEX'!i. $ )( ~AMBE Fumitoshi'!i. $ f¥ T

AMBE Shizuko

105, 132

105, 129, 132:E:<$: lE -+IWAMOTO Masako

tiJ ~ :JIt -IZUMO Koichi

ARATANI Michim ~ ~ ~ 110

KAGEY AMA Tadashi

AWAYA Yohko~ ~ ~ T

87,93

KAMITSUBO Hiromichi

CHIBA Y oshiaki-+ if H fJJj

83, 143KANAI TatsuakilIi iR. ~ ;-0

FUJISAWA Takashi

B EEl

FUJITA Shin

46,47

~

5,136

±

iff

FUKUSHI Kiyoshi~

HAMADA Tatsuji

1Ji:; EEl i! -=-HARA Toshihiko'*fJt 1J;

1:. :Pf 7E. J1i 27,32,46,
83,86,151
46
7, 103, 112,
114,126,136~ ~R

KARASAWA Takashi*

t! EEl •

129

87,93

KA TOU Takeo

130 B Ilt fit

79,87,93

KIMURA Kazuie*;ft -

126

65

HASHIZUME Akira

11 JJ\

AA 79, 87, 93

74,77

p

114

Efl 83 ~ ~ 134

KODA Kugao

KOHARA Shigeo
KOHNO Isao~

IJ\ @ :m ~

(oJ!f

Jj]

5

17,27,32m 0 ~ 5" 103

KOIKE Masahiro

IJ\ M if 7E.

~ ~ i& Ilt 5,15, 143

KOY AMA Akio

IJ\ UJ a?:3 fit 103

HASIGUTI R. Ryukiti

B Jf miHINOHARA Chikara!If 83 $ *f!~1J

58, 62

37,69, 77

if F :Xl it 129+ ~ -8(. 122

KOYAMA Katsuji

Ij'

IKEZOE Hiroshi

al! ~~MIKUMO Takashi

INOUE Toshihiko#- 1:. ~ ft

IWAMOTO Akira

E"*

112, 114

8~#- n SJj

79

tl: #- if ~ 112, 114

MATSUY AMA Akira§§

fO

MATSUI Masao

M 1:.1L:::'~ 5A,;ft

1i~ ~ 3§~

IKEGAMI Kumio

IMAMURA Masashi

42

MASUI Kuniaki

Ii

74

46

LlJ ~~ -=-KUMAGAI Hidekazu

IGARASHI Kazui

tf

5, 7

27,32

m 37,69,71,

IDO Tatsuo

iE

m IfX ~ -=-m*

HIRUT A Kotaro

UJ

KA TORI Kenji

HASHIMOTO Osamu

HEMMI Masatake~

129@ 83 5" zM

HARADA Kichinosuke

87,93~ -tf jj fJjj

KASIDA Y osihiko

126

47

tl: W
--= ~
=

MIY AZA WA Y oshitoshi

5

MIZOGUCHI Tadashi

65

MOTOBA Y ASHI Tohru~~

117,12227,32-g iR. tE ~
~ 0

"* t*

if

5,7, 1098, 101
~

27,32

166

JC 71<. Bf3 t

MOTONAGA Shoshichi:7k '§ 1E m 71, 74

NAGAMIY A Shoji
NAKAI Koji

cp #- ~

cp ~,~ f6] t4E

NAKAJIMA Shunji

cp ~ ~

5, 14, 15-= 22, 27, 32

NOZAKI Tadashi'f IM'f~

OHNUMA Haj ime*- iB

OHTSUKA Yasuo*

OKADA Takuya

Ft ~

*

T AHARA Akira

'*

8~

129

m

TAKEUCHI Suehiro

t'J P'J

if. 126, 129

TENDOW Y oshihiko

7(

TERAJIMA Osamu-$j: ~TONUMA Tadao

p tB if. tit

139,143,147 ,
149,151

m 5,10ffi

USUBA Isaoif !§: ~129

WADA Takeshi

1m ill !j[ iE.

98, 101

m1 'f ~ m 87,93,126

RECKNAGEL, EKKEHARD

71

ti Hi 1"§ m 105

YAGI Eiiehi

;w. ~

.§.

87,93,117,122~

42, 86*rJ;

42

m 15' It 79,87,93
~

In

fa EB

46

5

5,143,147,149

134

tit

46, 83, 86* * - 103;\

YAMADA SatomUJ EB

YAMAJI Shuhei

LL ~ 1~ sv- 47,65

11$ 42YAMAZAKI Toshimitsu

UJ dffij ~ J't

74

m ~ 42,47

YAMAZAKI Y oshishige

UJ IM'f .B! fiX

71, 74

A !Jf t4E

103

YATAGAI Fumio

B- ill ~Jt~

117,1225" ill m T

47,83,147,149~ D

SAKAGUCHI Harutaka~

ffi:if 37,39, 69,77,83

42

42

OKANO Masaharu

SAITO Nobufusa

ffi

rr EB

'*

OGIWARA Kiyoshi

TAGISHI Yoshihiro

TAKEDA Shigeru

IJ\ -$j: if. {5t

ODERA Masatoshi

51,53,55,58,60,62

cp e.§ tc % 42

NAKANISHI Noriyoshi!f f1/ij& ~

*- 65

@ l§

~

c:p H JI lB"

98, 101*SUZUKI Toshio i% *TAKAHASHI Tan

NAKAMURA Masanobu

NOMURA Toru

19 B- l[ ~SHIOT ANI N obuhiro
SUEKANE Shota-= 71, 74

NAKAJIMA Hisao

SAKAIRI Hideo

47

SAKAMOTO Iehiro

~

*-

~~

134, 136

YOSHIDA Fusako

SEKIZAWA Hisashi

~

R

In]

98,101YOSHIE Morio

SHIMAMURA Akira

lffi f1~

55" IT ~ ~27,32,37,69, 77

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理化学研究所
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和光市

広沢