the Institute of Physical and Chemical Research
Wako-shi, Saitama Pref., JAPANIPCR cyclotron
Progress Report 1979

Vol. 13,peR

Cyclotron Progress ReportVol. 13The Institute of Physical and Chemical Research"RIKAGAKU KENKYUSHO" Wako-shi, Saitama,
December, 1979

351 JAPAN

Editors
F. AmbeA. Hashizume

Y. Hattori

H. Kamitsubo

T. Nomura

M. Odera

M. UdaT. Wadas. Yamaji

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

4.

2

3-1.

Study of Field Correction by the Trim Coils for the SSC Magnet

4

3- 2.

Design of Injection System for Separated-Sector Cyclotron

7

3-3.

Design of RF Resonator for Proposed Separated-Sector
Cyclotron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

10

3- 4.

Computer Code for the Accelerated Orbit in a Separated-Sector
Cyclotron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12

3 - 5.

Improvement of the Heavy Ion Source ................................

15

3-6.

Metal Ion Source for the Cyclotron and Acceleration of Metal Ions . . . . . . . . . ..

17

3- 7.

Present States of the Baby Cyclotron

20

NUCLEAR PHYSICS
Scattering and Reactions

4-1.

Adiabatic Treatment of Deuteron Breakup on a Nucleus ....... . ..... . ....

21

4-2.

Fission Fragment Angular Distributions in 15 MeV Proton-Induced
Fission of 232Th ................... . ..... . ........................ 24

4 - 3.

Spin-Flip Asymmetry in the Inelastic Scattering of Protons on
12C at 24.1 , 26.2 , and 28.0 MeV .......... ! . . . . . . . . . . . . . . . . . . . . . . . . . .. 27

4 - 4.

Vector Analyzing Power and Polarization Measurement for the
116Sn(d, p) 117 Sn (g.s. 1/2+) and the Deuteron D-state Effects ............... 30

4-5.

Measurements of Particle-,), Angular Correlations for the
58Ni(p , d) 57 Ni Reaction at Ep = 30 MeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33

4 - 6.

Coulomb Nuclear Interference in the Inelastic Scattering of 18 0 ............ 36

4- 7.

Semiclassical Treatment of the Direct Reactions Induced
by Heavy Ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39

Page

4 - 8.

Mass Exchange in an Analysis of the Heavy-Ion Reaction
Based on the Linear Response Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

42

Study of the 27 Ale 4N, HI ex) Reaction ................................

45

4-10. Systematic Study of Reaction Cross Sections in the
14N + 93Nb Reaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

48

4-11. Spin Polarization of 12B in the 197 Au( 19 F, 12B) Reaction
at 186 Me V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

51

4-12. Isotopic Dependence of the Fission-Like Events in the 115 MeV
Nitrogen-Induced Reactions on Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

54

4- 13. Preequilibrium Alpha Particle Emission Following Heavy-Ion
Transfer Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

56

4-14. 'Y-Ray Multiplicity Measurement Following Preequilibrium
a-Particle Emission in 14N-Induced Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . ..

59

4-15. Relaxation of Angular Momentum Following Preequilibriuma Emission in Heavy-Ion Reactions

62

4-9.

5.

6.

NUCLEAR PHYSICS
Nuclear Spectroscopy and Instrumentation
5 -1.

Recoil-Distance Lifetime Measurement of States in 118Xe . . . . . . . . . . . . . . . . ..

65

5-2.

'Y-Ray Spectroscopy in the 144Nd + 20Ne Reaction . . . . . . . . . . . . . . . . . . . . . ..

67

5-3.

In-Beam CX-, 'Y-Spectroscopic Study on 214 Rn . . . . . . . . . . . . . . . . . . . . . . . . . . ..

70

ATOMIC AND SOLID-STATE PHYSICS

6-1.

X-Rays Following Multiple Inner-Shell Ionization (4) . . . . . . . . . . . . . . . . . . . ..

73

6-2.

Systematics in Multiple Ionization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

76

6-3.

Contribution of Electron Transfer to K-Shell Ionizations
by N 7+ -Ion Bombardment ..........................................

79

6-4.

K X-Rays of Kr Measured with a Crystal Spectrometer

82

6-5.

K X-Rays of Kr Measured with a Si(Li) Detector ........................

84

6-6.

Vacancy Rearrangement in the M Shell Prior to X-Ray Emission. . . . . . . . . . ..

86

Page

6- 7.

7.

8.

9.

Effects of Strain Rate on High Temperature Mechanical
Properties of Helium-Injected Fe-Ni-Cr Austenitic Alloys

89

6-8.

Lattice Location of Sn Atoms Implanted into Al ........................

92

6-9.

Secondary Electron Emission from Metals by High-Speed Proton
Bombardments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

94

6-10. Angular Correlation of Positron Annihilation Radiation andCompton Profiles in Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

97

6-11. Mossbauer Study. of 119Sn in Chromium and Manganese Dioxides

100

RADIOCHEMISTRY AND NUCLEAR CHEMISTRY

7-1.

Charged-Particle Activation Analyses of Oxygen in GaAs 1_X Px

102

7-2.

Yield of Low-Z Radionuclides in Charged-Particle Reactions

104

7-3.

Recoil Range of 18F Formed by Various Reactions ...................... 106

7 -4.

119 Sn-Mossbauer Emission Study on Se and SnSe Doped with
119rnTe .......................................................... 109

7 -5.

Chemical States of Defect Tin Atoms in InSb and In 2Te 3 by
Mossbauer Emission Spectroscopy . ....... ............................ 112

7-6.

Exchange Reaction of Seleno-Compound with Elemental Selenium

115

RADIATION CHEMISTRY AND RADIATION BIOLOGY

8-1.

Measurement of the Decay of the Emission from a-Excitons
Produced in a KBr Crystal by Heavy-Ion Irradiation. . . . . . . . . . . . . . . . . . . . .. 117

8-2.

New Apparatus for Cyclotron-Beam Irradiation of
Biological Samples ................................................ 118

8-3.

Inactivation of Ribonuclease A in Solution by Cyclotron
Beams .......................................................... 120

8-4.

Studies on Mutation Induction in Microorganisms by Cyclotron
Beams ...................... . ................................... 121

RADIATION MONITORING

9-1.

Routine Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 124

Page

9-2.
10.

Leakage-Radiation Measurement at the Underground Passage . . . . . . . . . . . . .. 126

HEAVY ION LINEAR ACCELERATOR PROJECT

10-1.

Status of the Constructional Work ................................... 128

10-2.

Vacuum System ................................................. 131

10- 3.

Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 134

10-4.

Installation of the Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 137

10- 5.

Insulating Pipe and Column Structure for Supply of Coolant
to the High Voltage Terminal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 140

10-6.

Plate Power Supplies for the Exciter Amplifiers of the IPCR
Heavy-Ion Linear Accelerator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 141

10-7.

Initial Operation of the Proto-Type Power Amplifier Coupled with
the First Cavity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 143

10-8.

Current Load of the Injector High-Voltage Generator without
Beam Acceleration ............................................... 145

10- 9.

Performance Test of Injector System ................................. 147

10-10. Beam Buncher Characteristics ...................................... 149
10- 11. Design of a Magnet for the Side-Extraction PIG-Type Ion Source

151

10-12. Performance of the Quadrupole Magnets of the Beam Transport
System ........................................................ 154
11.

LIST OF PUBLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 156

12.

LIST OF PERSONNEL .................................................. 16 1

13.

LIST OF OUTSIDE USERS AND THEIR THEMES ............................ 165
AUTHOR INDEX.... . ................................................. 167

1. INTRODUCTION

During the past one year the IPCR cyclotron was operated in good condition as before.
Several improvements have been made in the machine itself and its accessory facilities which
resulted in more stable and efficient operation.
In the fields of research using the cyclotron a majority of research works have been carriedout with heavy ions. Extensive studies on preequilibrium emission of light particles and energy
relaxation phenomena were performed in nuclear reactions induced by heavy ions.

Nuclearstructure studies were also continued. Multiple ionization phenomena in the collision of heavy
ions on gaseous and solid materials were extensively studied to get information on the excitation
mechanism as well as the effects of chemical state of surroundings on X-ray spectra. Positronannihilation and Mossbauer studies were made on several materials. Activation analysis by charged
particles were applied for the study of semiconductor surfaces. Studies of radiation chemistry
and radiation biology were continued using heavy ions as well as alpha particles.
The new heavy-ion linac has been completed and the first acceleration test was performed in
the pre-injector and the first resonator. Design study of the separated sector cyclotron was
continued.

Hiromichi Kamitsubo
Editor2

2. MACHINE OPERA liON

S. Kohara, T. Kageyama, K. Ikegami, K. Ogiwara,
S. Fujita, H. Takebe, and 1. Kohno

During the period from Oct. 23, 1978 to Oct. 22, 1979, the cyclotron was operated on the
24 h a day basis.
Table 1 shows the statistics of machine operation.

The total beam time of 4516.0 h isnearly equal to that of last year.
Table 2 shows the beam time allotted to various activities in this period. The beam time
allotted to nuclear physics groups was. slightly, i.e. 196 h decreased and the time to groups offields other than nuclear physics was increased hy 168 h compared with that of last year.
Table 3 shows the distribution of the beam time among particles accelerated. In this period,
deuteron was not accelerated. Most of the highly charged ions as N5+, 0 5+, and Ne 6+ ions were
produced and accelerated using pulsed operation of the heavy ion source.
The sputtering ion source for production of metal ions was tested during the time of
periodical inspection and overhaul, and Li 2+, Be 3+, and B3+ ions were successfully accelerated in
the cyclotron.
Table 1.

Reading of time meteron Oct. 23, 1978
Reading of time meteron Oct. 22, 1979
Difference
Percentage of 365 days
Schedule in this period
Beam time
Overhaul and installation work
Periodical inspection and repair
Vacation and holidays

Machine operation.
Oscillator

Ion-source

Beam56752.7 (h)60594.1 (h)28357.1 (h)61899.6

65865.6

32873.1

5146.958.8 %

5271.560.2 %

245 (day)
53
29
384516.051.6 %

3

Table 2.

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

Total

Nuclear reaction
In-beam spectroscopy
RI production

2778 (h)351
030 (h)
072

2808 (h)351
72

Fields others
than Nucl. Phys.

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

25
356
156
0
498

285
0
176
685
127

310
356
332
685
625

Track measurement
Nuclear fuel study
RI production

24oOutside users

o
o

126
31

24
126
31

4188

1532

5720

Subject{

Nucl. Phys.

[

Total
Percent in total

73.2 %

Maintenance, operation and engineering
Exchange of ion source
Machine inspection and repair
Total

Table 3.

26.8 %

97 (h)
696
793

Distribution of beam time among particles accelerated.

Particle

(h)

(%)

P
d
3He++
4He++
C4 +
N4 +
N5 +
0 5+
2ONe 6 +

725
0
161
646
497
2133
1159
117
282

12.7
0
2.8
11.3
8.7
37.3
20.3
2.0
4.9

Total

5720

100.0

100 %

4

3.

MACHINE DEVELOPMENT AND ACCELERATOR PHYSICS

3-1.

Study of Field Correction by the Trim Coils for the SSC Magnet

H. Takebe, S. Motonaga, T. Wada,J. Fujita, and K. Ogiwara

Studies on magnetic field have been made for IPeR separated-sector cyclotron using about 1/4 scale modelof a single sector magnet. Some experiments by the model on the characteristics of the trim coils were made to
get data useful for the design of feasible trim coils to produce an isochronous magnetic field for all accelerating
particles.
Proposed separated-sector cyclotron accelerates all heavy ion up to uranium. The beam energy ranges from
120 Me V/ A for fully stripped ions to 15 Me V / A for very heavy ions. Acceleration of proton is also possible up to
200 MeV. The large range in energy and particles requires that the radial profIle of magnetic field is adjustable tomatch ·the accelerated particles. An increase of the field from injection to extraction radius of about 22 % isneeded in case of proton of 200 MeV and for very heavy ions the field profIle have to rise approximately 1.5 %.
The sector magnet with angular width of 50° has been designed to operate at maximum field strength of 17.5 kG.
It is estimated that in the sector magnet 30 pairs or more of trim coils will be mounted which are of varying width
to achieve the isochronous field for all particles.
The design of the trim coils was started recollecting the calculation on the circular trim coils mounted on themagnet pole faces of the cyclotron. 1)
First experiment was done with seven pairs of coils mounted at various radial positions.
13 0 = 0 kG
No 3 coil 200AT-

Calcu lated

The measurement

No. 7 coil 200AT

80

8t
60

60

~

]

c3

<.:J

J

40

-::: 40

20

20

J

,

0

"-

R ( mm )0-

R ( mm )8 0 = 175 kG
I

80

80~

No.3 coil 200 AT

60

No . 7 cod 200AT

60

Ul

Ul
Ul

~

:::0

c3 40

<.:J

40

~~

:f:

~

20

20

0

-J

0

\

H ( mm )\\,----20

Fig. 1. Comparison between measured andcalculated values of field induced by the test
trim coil.

5

was made along the center line of the sector magnet using a Hall generator with precision of 0.05 %.
Some examples of the results for the radial field profIles are shown in Fig. 1. This figure shows comparison
between the measured and calculated values. The measured value was 10 % lower than the calculated one whenthe main field is 17.5 kG, and decrease of field at outer radius of the coil was larger by about a factor of two
than the result of the calculation. Profiles of radial distribution of the measured and calculated ones haveidentical slope. A desirable magnetic field gradient can be obtained by superposition of induced field which has
been measured on the model.
On the basis of the procedure mentioned above, a system of the trim coils was designed and fabricated forthe model magnet. A configuration of the trim coils is shown in Fig. 2. The trim coils consists of 14 pairs ofcopper bands which have an individual center of the curvature. There are two different coil widths , 30 mm and
15 mm. The coils #2 and #3 or #4 and # 5 together may act as single trim coil each in case of field correction
which require the same current in both conductors.
Then the effective width of coil in that combination is 60 mm (2 gap lengths) radially. The coils #6 - 10
have width of 30 mm (1 gap) and #11 - 14 have width of 15 mm (1/2 gap). The curved shape of every coilconforms to the equilibrium orbit shape of the hard edge calculation. Figure 3 shows the coils assembled. Allof the trim coils are made to return their cirrent around the side and outer periphery of the pole tip.

Fig. 2. Configuration of the trim coils for the model
magnet.

Fig. 3. A photograph of the trim coilsystem for 1/4 scale magnet.

Figure 4 shows an example of the radial profIles of the induced field by three trim coils at the main field of
15 kG. The increments or decrements of the induced field are proportional to exciting currents of the trim coils
and smooth change of the field strength within the width of each coil is seen in this figure.
The induced field strength is affected by the strength of the main field. 1), 2) Figure 5 shows the dependence
on the main field of the induced field corresponding to coil current of 50 A and 100 A. The field change
induced by the trim coil tends to decrease with increasing the main field. This effect is due to the change ofpermeability of the pole iron with field strength. If the permeability of the iron is known exactly, effect can be
estimated numerically.
In order to form a desired isochronous field for the model magnet, the currents for every trim coil must be
determined by iterative procedure of the superposition of those data. The measurement of the radial field
distribution was made along the center line of the sector magnet.
Results of the measurement for the fields required for acceleration of C6+ to 45 MeV/A and U 37+to 8.5
Me V/ A are shown in Fig. 6. Relative values were normalized to the magnetic field at injection radius. The

6

1.0
i shlm = 50A

0.5

/J

0.0

~

-

:;-

5- -0.5'>E +1.0

+150A
+100A
:::: +0.5+50A(9&; 0.01::--- - -t-T-t----tf-t----:=::::ft- - -/ Coil li8- , /-

=:)

o

Cl.

~ - 1.0
1.0
~

"l

400

450

500

j

Cl.

0.0

-150A

I

~2

600

700

coil
4.5
200

300

-0.5 I--

650 (mm )
10 kG
15
17.5

I/'

v Coil li 8

/'

I

800

600

/~

-1.0 400450

Model radius (mm )Fig. 4.

550

i shlm = 100A

0.5

:5 +0.5

g 0.0__---~_t_--__l\_1__--_++---50A! -0.5-lO'dA

10 kG
15" 17.5

500

-

550

600

650

Radial distance (mm )Radial field proftles induced by excitation

Fig. 5.

Dependence on the main field ofof trim coils #4 and #5 combined, #8 and #12

the induced field corresponding to coilseparately at the main field of 15 kG.

currents of 50 A and 100 A.

102.0

u37+

C6 + B ( 100 %) = 10.000 kGauss• Test2
E;nj= 4MeV/ A
o Test3o Test5

101.0

BOOO % ) = 15.506 kGauss
E;nj. =084MeV / A

xx Test 4
6 6 Test 5

0.0,6 ~.~.A" . :~ ... ;. ~~......
Isochro.

100.5

101 .0Base field
100.0= = ==== /~~ C=::2
Shim coils
numbers# 2 3 4 5 6 7 8 9 10 11 1213 14
Currents (A)Test 2 6 19 17 17 33 36 33 43 52524348 52
Test 3 17 29 27 27 51 38 50 44 52524248 52
Test 5 16 19 20 20 31 37 50 43 45 524241 52
R e XL
R;nj.
I
I, I
I
!,
300
400
500
600
700
800
200
Radius in model magnet (mm )Fig. 6.

l< . . . . . .

Cq~ ..,JC . If--.x,.."•1000 ~~--------~~
Shim coi ls#2 3 4 5 6
7 8 9 10 11121314
99.5
Shim
-30 -19 -18 0 -5 11 13 11 13 6 141327 Test 4

Currents (A) -34- 22 -18 0 -5 11 13 11 13 4 15 14 30 Test 5
R;nj.
I
I,
200
400
300
500
600
700
800
Radius in model magnet (mm )Comparison of measured field distribution with the trim coils

excited and isochronous field for acceleration of C6 + to 45 Me V / A
and U 37 + to 8.5 MeV/A.
figure shows comparison of measured field distribution with 14 trim coil pairs and calculated isochronous field(thin solid line).

The distributions of the main fields of the sector magnet were also shown in the figures.

Currents of the trim coils are indicated below each figure.
isochronous field can be made as small as 0.06 %.

It is observed that the maximum deviation from the

The radial distance between the coil #3 and #4 was found to

be too wide for correction of the main field over 15.5 kG.
The isochronous field profIles were obtainable by this configuration of the trim coils as far as radial
distributions.

Measurement of azimuthal distribution is now in progress.

References
1)

N. Nakanishi, S. Motonaga, and T. Karasawa: Japan. J. appl. Phys. , .§., 1229 (1969).

2)

D.L. Friesel and R.E. Pollock: IEEE Trans. Nucl. Sci., NS-22, 189 (1975).
E.H. Hudson, J. A. Martin, M.L. Mallory, and F.E. McDaniel: Proc. 7th Int. Conf. on Cyclotron, p. 201 (1975).

7

3-2.

Design of Injection Sys tern

for Separated-Sector eyc lotron

Y. Yano, T. Wada, s. Motonaga, and H. Kamitsubo

The injection system for the separated sector cyclotron (SSC) planned l ) at IPCR has been designed
as shown in Fig. 1. A transported beam from a variable frequency linac 2) and an A VF cyclotron,
which is injected to the central region of the sse through one of the valleys, is guided onto thefirst equilibrium orbit 'by means of three types of inflecting elements, i.e., bending magnets (BM I,
BM2, BM3), magnetic inflection channel (MIC) and electrostatic inflection channel (EIC). The
main characteristics of the injection elements are given in Table 1. A considerable effort isdevoted to the feasible design of these elements since they must be capable of bending particles
with large magnetic rigidity up to about 800 kG-cm and be located in the limited available spaceof the SSC central region.

MAIN MAGNETMAGNETIC INFLECTIONCHANNEL (MIC )MAIN MAGNET

o

Q5

1m

~!------~!------~!

Layout of injection
Fig. 1.
elements in the central regionof SSC.

The bending magnets, as illustrated in Fig. 2, are of a modified window frame design with apure iron yoke. A magnet of this type is just like a hybrid between an H-shaped magnet and awindow frame one. It can generate uniform magnetic field over a whole region of the aperture.
The magnetic field distributions have been calculated by using a computer code TRIM3) andascertained to have the homogeneity of more than 99.95 % over the beam range in the gap. The
leakage flux outside the side yokes is evaluated to be less than 2 G. To produce a magnetic flux
density of 18 kG in the air gap, current densities up to 53 A/mm 2 are required in 9 mm X 9 mmcopper hollow conductors with a 6 mm(j> cooling water duct. Cooling calculations show that the
conductor temperature can be limited to 60°C by adopting independent cooling for 6 pancakeswith 4 electric turns, with maximum water velocities up to 5.53 m/sec and a pressure drop of

8

Table l.

Characteristics of injection elements.

Bending magnets
Element

Angle of bend (deg)Radius (cm)

BMI
BM2
BM3

Maximum magnetic field (kG)

46
46
46

18
18
18

Inflection channeis
Angle of bend(deg)

Length(cm)

Radius
(cm)

MIC

65.3

40

EIC

7l.6

44

Element

Main magnetic
field (kG)

Maximum added fielddB (kG)dE (kV/cm)

16.8
+2.6
(in case of 238U4(}t, 0.81 MeV/u)
14.8+22(in case of 12C6+, 5.6 MeV/u)

INSULATOR(05mm' )COPPER HOLLOWCONDUCTOR(9mmX9mm )COOLING WATER
DUCT (6mm¢ )

/

o

i

Lf)

YOKE

50

I 20 18 / 12 1

112 18 / 20

I

70
460R

Fig. 2.
magnet.

Cross-Section of bending

4.4 kg/cm 2 for a cooling water temperature difference of 30°C between at the inlet and outlet

ends of the cooling circuits. A model of the magnet will be built at the end of 1979.
The magnetic inflection channel is composed of two coils as shown in Fig. 3. One is used toaccomplish the adequate field rise (channel coil) and the other to compensate for an undershootwhich is described below (compensation coil). The superposition of the sector field with thechannel coil field gives rise to the undershoot of the sector field outside the coil. The field
produced by the compensation coil whose current direction is opposite to that of the channel coilbrings about the overshoot and is able to cancel the undershoot in the accelerating area. This

9

II III //Uj ,1/,//1/'
I CO~ENSATION/
L" ..
/ ]
r

j'

I.

cal

I / I 1/; I /Main Magnet Pole/- 'I - ]

I

I

/ j

injected beam, 1 , ///1

HANNEl cal~/,

2nd equilibrium/ I
orbit beam'"AI/ /j /. /// L4!-/'L~

/
/

\

.

Insulator 0.5'
Copper Hollow Conductor
9mm x 9mm
Cool ing Water Duct
6mm¢

100
Maximum Current Density = 45 A/ mm2Fig. 3.

Cross-Section of magnetic inflection channel.

fact has been verified in the calculations by TRIM.
The electrostatic inflection channel is illustrated in Fig. 4. Shapes of the anode and thecathode have been designed to produce sufficiently homogenious electric field (> 99.9 %) in thevolume occupied by the beam. This was done using a trial-error method with the aid of acomputer program solving the Laplace equation (VEPO 2).4) The maximum E.V value is about
7000 k V2 / cm.

.7/ 77

Anode (A I)

I~--.:....:=,-=---////;0,,//High voltage supply

Fig. 4.

Cross-Section ofelectrostatic inflection channel.

References
1)

2)
3)
4)

H. Kamitsubo et al.: IPCR Internal Report SSC-l; Presented at the 2nd Symposium on
Accelerator Science and Technology, at INS, Tokyo, March (1978) .
M.Odera: Proc. of the 1976 Proton Linear Accelerator Conf.. ; M. Tonuma, F. Yoshida, andM. Odera: IEEE Trans. Nucl. Sci., NS-23, 1031 (1976).
J .S. Colonias and J. H. Porst: Magnet Design Applications of the Magnetostatic Program
Called TRIM, UCRL-16382 (1965).
H. N. Jungwirth: Private communication.

10

3-3.

Design of RF Resonator for Proposed Separated-Sector eyc lotron

K. Ogiwara, F. Yoshida, H. Takebe,and T. Fujisawa

Possibility of use of a quater-wave structure in stead of the half-wave one of previous
design 1) was investigated this year. The new resonator is shown in Fig. 1. This system wasdesigned to facilitate design and installation of the vacuum chamber and the magnetic inflection
system of sse. The length of this RF resonator is about 4 m. The delta shaped dee is attachedto the triangle stem. The height of the dee is 20 cm and the aperture is 6 cm. The resonant
frequency is changed by a travelling shorting plate as in the former design. The coaxial length,
the Q value and the maximum current density at shorting end vs resonant frequency are calculated
and shown in Fig. 2 (a). The distribution of RF voltage and current are calculated along the dee
22.5 °«
000......

0

I

Dee

0
0
......

L.!)

<.D

0
0

co

......

9

g'

«
«

Stem

~l

Scale

0
I

1
I

2m
I

Fig. 1.
Cross-sectional top and side view of the new resonator for
proposed SSC.

3
(a)
L

u

'--.

:::
~
~

L

~ 40

~

t

"'ii:i
>Q)

"D

~

20000

-'=

Q)

:=J

15000 ~

(ij

g? 30
c

2

OJ

~

0

U

1-

10000

20

u

E

@

10

x

~
17

20

25

30
35
Frequenc y (MHz )40

45

Fig. 2(a).
The calculated RFcharacteristics of the new resonator.

11

300

(b)

~----1740
F = 45 MHz

15

Fig. 2(b).

The calculated distributionof RF voltage and current in the newresonator along the stem.

stem from the dee top to shorting end resulting in the curve shown Fig. 2 (b).

A half-scale model

cavity for this design was constructed to investigate these RF characteristics. Measurement of the
RF characteristics of this model cavity is now in progress. Effect on the beam dynamics ofpossible asymmetry of the accelerating field with respect of the median plane of the dee of thisstructure is also being studied by calculation.

Reference
1)

H. Nakajima, K. Ogiwara, F. Yoshida, and 1. Fujita: IPCR Cyclotron Progr. Rep., 11, 16(1978).

12

3-4. Computer Code for the Accelerated Orbit ina Separated-Sector Cyc lotron

N. Nakanishi and S. Motonaga

A computer code EO for the equilibrium orbit in a separated sector cyclotron has been developed andcalculations have been done on various particles at the different initial conditions using the magnetic field of amodel magnet.I) The content of the code was described briefly elsewhere. 2) Now, a code for the accelerated
orbit has been developed extracting some subprograms from the code EO and adding new ones.
The program is composed of several parts which read input data, calculate some basic constants, set up
differential equations to be solved, and execute the integration. For the purpose of obtaining the phase-plot
information, the equilibrium orbits can also be calculated at various energies by this code.
Numerical integration is carried out on 14 equations which describe variation of positions and radial momentaof the reference beam and of the slightly radially and axially disturbed beams, giving variations of time, mass,azimuthal angle and so on. Some typical equations solved are as follows:,Prr = rQ,Pr = Q -

rB +

mrE r

m

r Eo

+ rP-r Er

X

QX + OJ P

Pr

r p2

Q

Q

x

P '= _ ( o( r B) _ mEr) x _
x
or
Q .

Pr (1-

Q

z

Pr
Q

oB
of)) Z

1

Q = ( P 2 _ P/ )2

where prime means didO. Symbols r, Pr , m, and P represent radius and radial momentum of the reference beam,mass and momentum of the particle, respectively. Variables x(z) and Px(Pz) are radial(axial) displacement andradial(axial) momentum deviation from the reference beam. Er and Ee are radial and azimuthal components of theaccelerating electric field, respectively. The axial component Ez of the field is neglected at present. In this code
cyclotron units are adopted.
Informations have to be prepared on the isochronous field, geometrical shape of dee structure, and radialand frequency- dependence of accelerating voltage in advance of use of the code. As the measured isochronous
field is not available at present, the calculated ones are employed. As described in Ref. 3, the accelerating gap isdesigned to be constant, and the edge is straight in the radial direction. Parameters which specify the geometricalshape are shown in Fig. 1. Radial- and frequency- dependence of the accelerating voltage were measured using amodel cavity.3) The radial distribution of voltage is expanded in a polynomial expression at each RF-frequency,
and then the corresponding coefficients of each term are expressed by the polynomials of frequency.

13

Fig. 1.
B= O - - - - - - " ' - ' - - - -- -- --12e6 +

590

Geometrical parameters a, b, and c

specifying the dee structure.

B

E ln =48MeV
R l n =73.l5 cm
fill = 44,50MHz
Vmax =250kV

~

Cl)

u

Cl)

c

-5

E

E

.g
Cl)

u

~

U)

(5

70
0

90

180

270

360

B ( deg,)

Fig. 2.

Equilibrium (not-accelerated) and accelerated orbits in the first two turns.

~

..
~
V

accelerating gap
10,0

~

12e6+

~

. . ~ E =48MeV
ln

Rln = 73.l5cm

f Rf = 5,56x 8MHz
Vmax =250kV

0 r-----t-t--~-=---+------f-=-=-=------rH-:::..:....:::..l-\-\,_______H_T__-___+=-:::~-B-( deg )j0...

first tumsecond tum-- 20,0Fig. 3.

Phase slip of a particle against the accelerating radio-frequency.

Positions of sector magnets and accelerating gaps are also shownin the figure.

14Some preliminary results are given below for 12 C6+ injected at the radius of 73.15 cm at the energy of
4 Me V/ A. Figure 2 shows the eqUilibrium orbit and the accelerated trajectories in the first few turns. Phase slipof a rotating particle against radio-frequency is shown for the first few turns in Fig. 3. Peak of the accelerating
voltage is set coincident at the starting angle (8 = 0) of the particle. Behavior of the particle displaced from thereference orbit in phase space is shown in Fig. 4 for the first few turns in both of the cases with and without
acceleration. The phase plot is often used to investigate the limits of radial stability of a particle . For aparticle specified by some initial conditions for energy, radius and radial momentum, its motion is described overmany revolutions by plotting the radius and radial momentum at a certain azimuthal angle. Figure 5 shows
the phase plot for the 211 MeV 12 C6+ ion.

12C 6+

E 1n = 48MeV
R in = 73.15cm
f Rf = 5.56 x 8MHz
Vmax =250kV
lIx =

x'

1071

x accelerated
0 not -accelerated

P

T -

Pre

12C6 ~

E = 211 MeV
liT = 110
B =00
re = 1504 em
Pre = 00
0

- 0.1

"

Fig. 4.

x
°__

0_

0

Behavior of a disturbed particle inphase space. Closed circles show the starting
points of each revolution.

Fig. 5.

Radial phase plot for 12C6+ at 8 = 0

and E = 211 MeV. Symbols re and Pre are theradius and radial momentum of the equilibrium
orbit , respectively at 8 = O. Two curves aredifferent in the initial conditions. The outerone represents the limit of radial stability .

References
1)
2)

M.M. Gordon, T.A. Welton, T.!. Arnette, and H.C. Owens: ORNL 59-11-2.
N. Nakanishi and S. Motonaga: IPCR Cyclotron Progr. Rep., 12, 18 (1978).

3)

H. Nakajima, K. Ogiwara, F. Yoshida, and J. Fujita: ibid., p. 16.

15

3-5.

Improvement of the Heavy Ion Source

K. Ikegami and I. Kohno

At present, the heavy ion source used for the cyclotron is of the electron bombarded hot
cathode PIG type and is operated in both DC model) and pulsed mode. 2)
It is known that performance of a heavy ion source is generally evaluated by the capacity to

produce higher charged ions, high intensity current of these ions and life time of the source
under such working conditions. In order to obtain large quantities of multiply charged ions withthis type of PIG source, following two conditions are prerequisite:
an arc power as high as possible,
a gas flow as small as possible.
The life time of the PIG source is limited by erosion of the upper cathode of the source. Erosionof the cathode is caused by the sputtering of the cathode material with bombardment by the ions.
Therefore, the life time of the source decreases when the high arc power is applied to the source.
We have tried to lengthen the life time and increase the intensity of multiply charged ions byselecting material of the cathode and changing the geometries around the cathode, i.e., its heatshield and its holder. Until now tungsten (W) has been used for the upper cathode. In thisreport, test of the cathodes made of Hf and Ta is described. In the case of Hf cathode, it melted
when the arc power of 1.5 kW was applied to the source, and this value of the arc power isinsufficient to produce large quantity of the multiply charged ions such as N 4+ , C4+ , and 0 5+. The
Ta cathode was better for production of the multiply charged ions and permitted to lengthen thelife time than the W cathode. However, in the case of Ta, arc discharge became unstablefrequently at the beginning when the arc discharge is ignited. In order to avoid such an
instability, we changed the geometries of the cathode as shown in Fig. 1. Using the improved Ta
cathode we could obtain the life time of about 35 h with the intensity of N 5+ ions sufficient
to do experiments. Such efforts to improve the heavy ion source will be continued to carry out
the experiments more effectively by the cyclotron.
I

¢ 18

I

~
( b)

I

¢22

I

~
(a)

( c)

Fig. 1.

(a): A cross sectionalview of the heavy ion source,(b) and (c): old and new upper
cathode, heat shield and cathodemount.

-------

16

References
1)
2)

Y. Miyazawa, 1. Kohno, T. Inoue, T. Tonuma, A. Shimamura, and S. Nakajima: IEEE Trans.
Nucl. Sci., NS-19, 105 (1972).
H. Nakajima, S. Kohara, T. Kageyama, and 1. Kohno: Reports IPCR (in Japanese), 53,
132 (1977).

17

3-6.

Metal Ion Source for the Cyclotron and Accelerationof Meta I Ions

K. Ikegami, T . Kageyama, and I. Kohno

A metal ion source for the cyclotron has been developed to accelerate metal ions in thecyclotron. The structure and function of this source were already described before. I) In thisreport we describe production and acceleration of several metal ions (Li 2+, Be 3+, and B 3+) in thecyclotron.

°

As the materials to charge, single crystal of LiF, single crystal of B2 3 , boron nitride andmetallic Be were used for Li, B, and Be ions, respectively. In the case of insulator such as LiF ,B2 0 3 and boron nitride a copper rod 1.2 mm in diameter was buried in the insulator which madecontact with the water-cooled supporting metal of the sputtering electrode.
The ion source is burnt with Ar gas at first.

When a negative voltage with respect to theanode is applied to the sputtering electrode, the electrode material is sputtered by bombardmentwith Ar ions in the arc plasma and the sputtered atoms are ionized in the plasma.
Figure I shows variations of the sputtering current and the current intensity of 7Li 2+ extracted
from the cyclotron versus the sputtering voltage under a constant arc power. At the same
sputtering voltage the sputtering current increases with the increase of the arc power applied to theion source. It is clearly observed that the current intensity of 7Li 2+ extracted from the cyclotron
increases linearly with the increase of the applied sputtering voltage. Figures 2 and 3 show current
intensities of 6 Li2+ and 7Li2+ , and Be 3+extracted from the cyclotron versus the arc power applied
The intensities of multiply-charged metal ions such as Li 2+ and Be 3+
increase greatly with the increase of the arc power. In the case of Li 2+ ions, sufficient current wasto the source, respectively.

extracted from the cyclotron when the source was operated at the arc power of about 1.2 kW andthe sputtering voltage of 200 V.

The life time of the source was about 12 h under suchcondition.

Frequency : 7.3MHz
Dee voltage : 64.8 kV
B : 1.68Wb / m 2
Arc voltage: 350V
Arc current : 2.0A

1.5

150

,

-

:;:
--3 1.0

100 ~
E

~
t:ID

c

~
:::J

<lJ

£

ro
x

~

)'

..,.....-X

u

iii
=§

.(ij

c

<lJ

.:s

50

0.5

0

-----

100
200
Sputtering voltage (V)

0.

(f)

Fig. 1.

The variations of sputtering

current (Is) and the current intensityof 7Li 2+ extracted from the cyclotron300

vs. the sputtering voltage under aconstant arc power.

18

2.0

1.5

E: 42MeV
Frequency: 7.3MHz
Dee voltage: 64.8kV e Li 2+)
63. 7kV (6Li 2+)
1.00

Supporting gas: Ar , 1.31 cc/ min
Sputtering voltage : 200 V
Sputtering current : 70mA

E: 54MeV
Frequency : 7.302MHz
Dee voltage: 57kV
Charge material : Be
Supporting gas : Ar, 1. 58cc/ min
Vs : Sputtering voltage ( V ):? 0.75
::t

ro

0.50

0.5
0.25

Arc power ( kW )Arc power (kW)The current intensities of 6Li 2+
Fig. 2.
2
and 7Li + extracted from the cyclotronvs. the arc power under a constant
sputtering voltage.

Table 1.

Fig. 3.

The current intensities of Be 3+

extracted from the cyclotron vs. the arc
power at the sputtering voltage of 300 V
and 700 V.

Current intensities of several ions extracted fromthe cyclotron with the metal source.

Particle

Energy (Me V)

Arc power
voltage (V)Current (A)Sputtering
voltage (V)Chargematerial

Intensity
at the gate (J.l.A)

7Li 2+

29 - 48

320

3.7

200

Lif

1.5 - 2.0

7Li 3+

29 - 75

340

5.5

50

Lif

30 - 50 nA

6Li 2+
Be 3+

25 - 48

280

4.5

200

LiF

100 - 200 nA

45

470

4.6

700

Be

0.7 - 0.8

llB 3+

66

400

4.5

0

B2 0 3

1.2 - 1.3

10B3+

60

400

4.5

0

B2 0 3250 - 300 nA

llB4+

66

400

4.5

0

B2 0 3

3 nA

0 5+

96

400

4.5

0

B2 0 36 nA

llB 3+

66

400

5.0

900

BN

100 nA

Supporting gas : Ar,gas flow:

1.31 - 1.60 cc/min

19

Table 1 shows the results obtained from the test of this ion source to produce multiply
charged metal ions and acceleration of metal ions in the cyclotron. In the case of B3+ ions it wasmore effective to use an ion source employing gaseous BC 13 2) in producing ions compared withthe sputtering method described here.

References
1)

2)

K. Ikegami and I. Kohno: IPCR Cyclotron Progr. Rep., 11, 24 (1978).
A. Shimamura and I. Kohno: ibid., .§., 4 (1974).

20

3-7.

Present States of the Baby eye lotron

T. Karasawa and T. Nozaki

1)

Prototype

A prototype of the Baby Cyclotron was installed at the National Nakano Chest Hospital. A
cyclotron building was completed in April 1979. It has a floor space of 150 m 2 in all and thecyclotron room is of a cubic shape with 4.5 m dimension. The thickness of shielding wall of thecyclotron room is I m or 0.6 m.
Since May, the cyclotron has been routinely operated and beam diagnosis has been studied
using half of the machine time to improve beam extraction efficiency and to increase bombarding
current.
A small magnetic channel was inserted between the deflecter and the beam extraction window.
It was composed of three ferrocobalt octagonal bars of 80 mm length and 10 mm diameter.
At present, internal beam current is about 50 J1A and extraction efficiency is from 10 to 30 %.
The other half of the machine time has been devoted to isotope production. The generation
kits for 11 CO 2 and 11 CO,I) which work satisfactorily, were already attached to the cyclotron at thetime of its installation. An aqueous solution of 13 NH3 was found to be obtained easily andefficiently by the microwave heating of the proton-bomberded water added with TiCl 3 and NaOH.
H 2 15 0 was produced by the usual method.1) Some 11 C-labelled organic compounds such as
glucose, fructose (by photosynthesis) and palmetic acid have been prepared. Also, 13 N-labelled
glutamic acid has been obtained.
In near future, the production systems for the following radioisotopes will be completed:
13N2 (both gas and aqueous solution), 15 O 2(in N 2 ), 18F(carrier-free aqueous solution), 79Kr(by the
79 Br(p, n) 79 Kr reaction) and radio-bromines. In the 18 F production, enriched H2 18 0 will bebombarded by protons. Also, the following labelled compounds will be synthesized: some 11 C
amino acids, 11 C-deoxyglucose, 11 C-mannose, 18 F- or radiobromine-steroids and some other
18 F-compounds.
2)
The second baby cyclotron
In 1977, the second baby cyclotron, by which 6 MeV deuteron and 10 MeV proton can be
accelerated, has been designed and manufactured. In mid course of magnetic field mapping, thedesign was modified to increase the energy of deuteron up to 7 Me V for higher yield of 18 F by
20 Ne(d, ~)18 F reaction. We improved the shape of the pole tip sector pieces which generate thehill magnetic field of 2.3 Tesla and mounted a pair of circular trimming coil on the pole surface.
Then, we have achieved the isochronous field for 7 Me V deuteron and lOMe V proton at meanmagnetic field 1.8 Tesla and 1.5 Tesla, respectively.
At the Muroran Plant of the Japan Steel Works, beam test have been continued and thecyclotron will be exported to Canada early 1980.
Reference
1)

J.C. Clark and P.D. Buckingham: Short-lived Radioactive Gases For Clinical Use, Butterworths& Co, Ltd. London and Boston (1975).

21

4. NUCLEAR PHYSICS
Scattering and Reac tions

4-1.

Adiabatic Treatment of Deuteron Breakup on a

Nuc leus

H. Amakawa and K. Yazaki*

The breakup process of the high energy deuteron is investigated within the framework of athree-body model. In the three-body model, a deuteron-nucleus scattering system is assumed toconsist of a proton, a neutron and an inert target nucleus.

We use the adiabatic approximation

which consists of neglecting the excitation energy of the p-n relative motion. This approximation
has been used to include the breakup effect in the elastic deuteron scattering.1) If the adiabatic
approximation is used, the Schrodinger equation for this scattering system is reduced to(1)R

where t andare the relative and the center of mass coordinates of the p-n pair with respect tothe target, € d is the deuteron binding energy, T R is the kinetic energy operator of the center ofmass motion and V (t,is given by the sum of the p-target and the n-target potentials. The

R)

three-body wave function 'I! (t, R) is expressed as(2)

We solve the coupled equation for XfLJ (r, R) with fixed rand J, and obtain the r-dependent
t-matrix T{L ':fL (r). The elastic cross section is given by l)-3)(3)where <Pd is the deuteron wave function and k is the wave number of the center of mass motion.
The breakup cross section is defined byanda b (1) =4k~ L L ( 2 L + 1 ) 1< 1; e, ciT ~L~: O LCr) 11; d > 12 ,eL'c

* Department of Physics, University of Tokyo.

(4)

22

where CPo<-,c is the wave function of the p-n relative motion with angular momentum C and energy c.
The integration over c can be performed to give.
0b (L)=~ L:(2L + 1) <¢dIITe~/: o L(r)121¢d > -Oee(L).

(5)

eL'

We can easily calculate the breakup cross section abo
The breakup cross sections of the deuteron scattered from a 58 Ni target are calculated at
Elab = 80 MeV. The parameters of the nucleon- 58 Ni optical potential are taken from Ref. 4 andevaluated at half the incident energy of the deuteron. The coupled equation is solved with thes-wave (C = 0) and d-wave (C = 2) breakup channels. The coupled-channel program CCSEARCH 5)
is used with a minor modification. The t-matrix T~ ' L ' :fL (r) is a rather smooth function of the
p-n relative distance r. The integrations over r in Eqns. (3) and (5) are carried out with a 0.4
fm interval up to r = 24 fm.
The various cross sections are listed in Table 1. The Watanabe potential 6) (folding
potential) which does not contain the breakup effect gives the largest elastic cross section.
Adding the breakup channels reduces the elastic cross section, bringing it towards the value
obtained by the phenomenological optical potential (serie 1 of Ref. 7). which reproduces theexperimental elastic cross section very nicely. The d-wave breakup cross section is about two
times larger than the s-wave breakup cross section. The importance of the d-wave breakup is also
seen by comparing the results with and without its effect. The breakup cross section is about
9 % of the reaction cross section.
Table 1.

Various cross sections of d_ 58 Ni scattering at Elab = 80 MeV inunits of mb. ael' ar' atot, and ab represent the elastic, reaction,
total and breakup cross sections, respectively. ab ,sand ab , dare,
respectively, the s-wave and d-wave breakup cross sections.

Watanabe
Adiabatic s
Adiabatic s+ d
Phenom. Pot. a)
a)

ael

ar

atot

1573.51510.81351.61313.81437.31515.83010.83026.6

1533.01601.72884.62915.5

93.0
45.9

97.5

93.0
143.4

serie 1 of Ref. 7 .

Figure 1 shows the various partial-wave cross sections of the deuteron- 58Ni scattering as afunction of the angular momentum L.

The reaction cross section a r (L) is a smooth function ofL, while the elastic cross section aet. (L) has some fluctuations reflecting the effect of the realpotential. The breakup cross section is small for the internal partial waves (L :S 12) but becomesappreciable in the surface region (L '" 16), giving about one third of the reaction cross section
for L '" 20. The s-wave breakup cross section ab ,s (L) has a dip at L = 12, which seems to becorrelated with the variation of aet. (L) and is therefore ascribed to the effect of the realpotential. A similar behaviour of ab s (L) appeared in the coupled-channel calculation for
deuteron-4 oCa scattering at Ecm = 22:9 MeV. 3)

23

(L)
(L)
(L)
abo. (L)ab,d ( L )--- -- ael

100

-

-

-- --

o

--

aT
ab

30
L: Angular Momentum

Fig. 1.

Partial-wave cross sections of d_ 58 Ni scattering at

E lab = 80 Me V as a function of the angular momentum L.
Conventions used are the same as in Table 1.

References
1)
2)

H. Amakawa, S. Yamaji, A. Mori, and K. Yazaki: Phys. Lett:, 82B, 13 (1979).
Yu. A. Berezhnoi and E. V. Inopin: Yad. Fiz., i, 1197 (1967)~ [English transl. Sov. J. Nucl.

3)

Phys., §, 872 (1968)].
N. Austern, C. M. Vincent, and J. P. Farrell Jf.: Ann. Phys., (N. Y.), 114,93 (1978).

4)
5)
6)
7)

F. D. Becchetti, Jr. and G. W. Greenless: Phys. Rev., 182, 1190 (1969).
T. Wada and S. Yamaji: Sci. Papers I. P. C. R., 68, 65 (1974). This program is aversioll of JUPITOR-I written by T. Tamura modified to make an automatic parameter search.
S. Watanabe: Nucl. Phys., .§., 484 (1958).
G. Duhamel, L. Marcus, H. Langevin-Joliot, J. P. Didelez, P. Narboni, and C. Stephan:Nucl. Phys., AI74, 485 (1971).

24

4-2.

Fission Fragment Angular Distributions in 15 MeV
Proton-Induced Fission of 232Th

H. Kudo,* H. Muramatsu,* H. Nakahara,* K. Miyano,**I. Kohno, and M. Yanokura

Angular distributions of fission fragments were observed as a function of fragment masses in order toclarify the role of fission configurations on the mass division in fission process.

It has been established that theangular distributions of the fission fragments produced from the fission of nuclei at the medium excitation energy
are determined by the total angular momentum J of the compound nucleus and the K quantum number at thesaddle point configuration. I) In general, a Gaussian K distribution is assumed for the fissioning compound nucleus
and the average value Ko is given by the relation, K~ = tlefph 2 , where t is the nuclear temperature and 1eff is theeffective moment of inertia for the saddle point configuration. If we know the angular distributions for various
specific fragment masses, we can deduce the values of tIeff corresponding to each mass splitting.
According to Flynn et al,2) who measured the 42 MeV alpha particle induced fission of 209Bi, the massdependence of fission fragment anisotropy could not be observed for most of the fragment masses, although theyfound that the anisotropy of 83Br was 10 % smaller than those of other masses. This was explained by the
N = 50 shell effect on the saddle point configuration and by the higher excitation energy required to form theprecursor of 83Br. Vandenbosch et al. 3) reported that in the 234U(d, pf) reaction the mass dependence of theangular anisotropy was not observed within the experimental accuracy. Recently, Vorob'eva et al. 4) reported on
the 3 MeV neutron-induced fission of 232Th, in which they concluded that the saddle point configurations were thesame for symmetric and asymmetric modes of separation. In the Flynn's system, however, the symmetric mass
division might have been predominant, whereas in the Vandenbosch and Vorob'eva systems, they observed only afew symmetric events. Cohen et al.S) reported in 1955 that the angular distributions of the 22 MeV proton
induced fission of 232Th is dependent on the fragment masses. In this system the yields of the symmetric andasymmetric mass divisions are comparable. In the so-called medium energy fission, however, there are possibilities
of multiple chance fissions, and, therefore, the analysis of the data becomes more complicated.
In this work, we chose the Cohen's system, namely, the 32 Th + p) reaction with the incident proton energyeof 7 MeV lower than that they used.

In order to better understand the degree of the contributions of multiple

chance fissions, we examined in detail the excitation functions of (p, xn) reactions and those of fission fragments.
We attempted to interprete the observed data in terms of the two-mode hypothesis, and for this purpose, we
modified the Alice code 6) to include the symmetric and asymmetric fission barriers and the sub-barrier penetration
terms.
Bross ho lder(unit=mm)

AI catcher foil

~ ~O~I_ ~2J2Th\;lo,g"(30 ':Jg/':2) :,42~ Fo,tu~....

3mm'llcollimaterFig. 1.

* Tokyo Metropolitan University.
** Niigata University.

Target assembly, schematically drawn.

25

The target assembly for the measurement of the fragment angular distribution is schematically drawn in Fig. 1.
The 232Th target was prepared by electroplating 232Th onto the nickel foil of 10 J1m thickness. The thickness of
232Th itself was about 300 J1g/cm 2 .

The bombardment was performed at the cyclotron with the proton energy of

15 Me V and the beam current of 0.5 - 1 J1A for 5 to 12 h, and after the bombardment the AI catcher foil was
taken out and sliced to strips of an appropriate width.

The solid angle of each AI slice was about I % of 41T.

Some product nuclides were directly measured with Ge (Li) detector equipped with a 2048 channel pulse height
analyser, and, for some low-yield species, the 'Y-ray spectrometry was performed after chemical separations.
From the analysis of the (p, xn) and fission excitation functions and the peak-to-trough ratios of the mass
yield curves, the not-well-established parameters involved in the calculation of the competition between the neutron
evaporation and fission were determined. When the two-mode hypothesis is assumed and those parameters areused, the average nuclear temperature of the fissioning nuclides at the saddle point configurations for the symmetricmass divisions is expected to be higher than that for the asymmetric mass divisions becuase of the different
contributions of multiple chance fissions according to the two-mode hypothesis. Therefore, if the moment ofinertias are about the same for the symmetric and asymmetric saddle configurations, the angular anisotropy forthe symmetric mass division is expected to be larger than that for the asymmetric mass division.
In Fig. 2 is shown, as an example, the observed angular distribution for the fission fragment, 143Ce. The
anisotropy of the angular distribution was evaluated by a least squares fitting of the experimental results with theform of Wee) = a + b'cos 2 8. Experiments were carried out several times to obtain these results. The angularanisotropies of some fragments thus evaluated are summarized in Fig. 3. In the figure the Cohen's data are also

14

s-en

13

o

00

o

~ 1·2

b
31.1

o

0

8

80 '6
00

10

Q)

oe

000

0

Fig. 2.

Angular distribution of 143Ce

the curve fitted by the leastsquares analysis with Wee) = a + bocos 2 e;oExperimental results.

0:8Iab(deg)'·0'·0

I

I

I

'·2

'·4

,·6

Mass ratio (AH/AL )Fig. 3.

Angular anisotropies of various fragment masses
Cohen's data (Ref. 5).

26

shown by the dashed curve. Since the data of 112 Pd is quite reliable, although that of llS Cd is still preliminary,
the anisotropy for symmetric mass division is defmitely smaller than that for asymmetric mass division, which is inagreement with the results expected from the nuclear temperature analysis. As the Cohen's data were obtained at
the proton energy of 22 MeV, the effective temperature is expected to be higher than ours, and thus, our results of
the anisotropy should be higher than the Cohen's. This expectation is also in agreement with the experimental
results.
As a conclusion, the mass dependence of the angular anisotropies seems to be qualitatively explicable by thetwo-mode hypothesis, namely, the final mass division being governed by the saddle point configuration. However ,in order to draw more definitive conclusion we have to improve the llS Cd data and also add some more data in the
mass-ratio regions of about 1.2 to 1.3 and beyond 1.6.

References
1)
2)
3)
4)
5)
6)

A. Bohr: Proc. U. N. Int. Conf. Peaceful Uses at. Energy, New York, b 151 (1956).
K. F. Flynn, C. E. Clendenin, and J. R. Huizenga: Nucl. Phys., 58,321 (1964).
R. Vandenbosch, J. P. Unik, and. J. R. Huizenga: Proc. IAEA Symp. Phys. Chern. Fission, Salzburg,
IAEA, Vienna, l, 547 (1965).
V. C. Vorob'eva, N. P. D'yachenko, V. S. Mitrosanov, B. D. Kuz 'minov, A. I. Sergachev, and D. Poenaru:
Sov. J. Nucl. Phys., 26, 508 (1977).
B. L. Cohen, B. L. Ferrell-Bryan, D. J. Coombe, and M. K. Hullings: Phys. Rev., 98, 685 (1955).
F. Plasil: ORNL Report, TM-6054 (1977).

27

4-3.

Spin - Flip Asym metry in the Inelastic Scattering ofProtons on

at 24.1, 26.2, and 28.0 MeV

12C

T. Fujisawa, T. Wada, M. Nakamura,* K. Hatanaka,*
M. Yasue,** N. Ueda,** T. Hasegawa,** M. Sekiguchi, **F. Soga,** H. Kamitsubo, T. Tanaka,*** and Y. Toba****The spin flip asymmetry (SF A) and the difference between the analyzing power and thepolarization (A-P) in the inelastic scattering of protons on 1 2 C(4.43 MeV state) were determined bymeasuring the spin flip probability of polarized protons. I) The large values of (A-P) were found at
24.1 and 26.2 MeV. Macro- and micro-scopic DWBA calculations were carried ollt for the 28 MeV
data. Such calculations however failed to account for the spin-dependent data.
A polarized proton beam was extracted from an atomic beam type polarized ion source which
was constructed at IPCR, and accelerated by the SF Cyclotron at Institute for Nuclear Study of
University of Tokyo. The beam current on the target was about I - 3 nA and the beam polarization
was 50% on the average. The details of the experimental procedure have already been reported.I)
The results obtained are shown in Figs. 1 - 4. The drastic changes of the shape and magnitudeof (A-P) with the change of energy suggest an effect of some resonance on the direct reaction. 2)
To explain these changes, the analysis is in progress by the method of coupled-channel
calculation with Breit-Wigner terms using Jupitor-1 code developed by T. Tamura .

~100L

l°L

28 MeV

~100~

10

x

x

x

0 0

o

E

li

26 ·2MeV

10.

.

~
0

28MeV.
0
50

•

~lOQ

. . ..

Ule,;'" 100

'
10.

..

90

~

150

180

00

o

Xx

x

x

0
0

X

xx)!

0

0

x,

0

x

24 . 2 MeV.

24 · 2 MeV
30

026.2MeV« 50

262MeV

x

X)(xX

120

o

~ 0

1.
60

0

0:

)(

1.

-

..

oe

28MeV

24·2MeY.

30..... ...

50

60

90

120

150

180

-40 30

60

90

120

150

x

180

aCM

Fig. 1. Differential cross sections in the elastic and inelastic scattering (4.43 Me V 2+) andthe asymmetry in the elastic scattering of protons on 12C at 24.1, 26.2, and 28.0 MeV.

* Department of Physics, Kyoto University.
** Institute for Nuclear Study , University of Tokyo.

*** Department of Engineering, Kyushu University.
**** Department of Physics, Tsukuba University.

28~E p= 28tv'eV • e
500

Ep =26·2MeY.

.

P

50
o

•A

50

••

~

c;'?

........
~

o~------~--~--~~

~
ttl

ttl

<i -30

c::

<i

50

-50

o

o~--~--~--~~~~

1:J

-50
40

~ 2~t :' ':. "'. :.

o-40 30--~60---9~0--~12-0--1~5-0~180-40 30

60

90

120

150

180

0

0

0

-40 30

0

•

60

90

9 C.M

9CM

Fig. 2.

0

120

150

180

9 CM

Analyzing power (A), Polarization (P) and A-P in the inelastic scattering of

protons on 12C(4.43 MeV 2+).

Ep = 28 MeV

50

50

I
~
<i

E p = 26 . 2 Me Y.

"

0

pI

i J

50

E p ~ 24·1 MeV .

Il!'II Ii

0

0

Ii

If

LL

if)

-30
-50

50

40

40

;? 30

30

~ 20
if)

20

10

10

o 30

60

90

120

150

180

-50

o 30

60

90

6 CM

Fig. 3.

!i

~

i

120

150

180

I

~r

o 30

.....

..
0

0

0

60

120

90

150

180

9 CM

9 CM

Spin flip asymmetry (SF A) and spin flip probability in the inelastic scatteringsof protons on 12C(4.43 MeV 2+).

10.

~

E p=28MeV.

~•

E p =26-2MeV.

!

10·

E p=24 .1 MeV.

10

!
...:
~

1.

,.

l:.

.D

o

6' ... ""

~

{).o

.8

CO

b

A",

b>

0

E

~

'"!6 &' ~'" '" Ai~0t.

.11. 0

2 Il

u

0·1

e:,
0

0 ·1

t::.

'" c. _
c_.

0·01

t::.

30

60

90

120

150

6 CM

Fig. 4.

180

0

... -

~ ~ ~ '"... t.
A

~

0·1

30

60

90
6 CM

120

0·01

150

180

30

60

90

120

150 180

0 CM

Partial differential cross sections in the inelastic scatterings of protons on

12C(4.43 MeV 2+).

0o ,.ac oa ~~e A ~ ~,,~
o

to.
{).

V

0· 01

0

Ii

~

f

Q ••

G'__

Q

1·

0

...

.A. • • • .& ...

29

References
1)

2)

T. Fujisawa, M. Nakamura, M. Yasue, N. Ueda, T. Hasegawa, H. Kamitsubo, K. Hatanaka,
T. Tanaka, M. Sekiguchi, T. Wada, Y. Toba, and F. Soga: IPCR Cyclotron Progr. Rep., ~,29 (1978); Proc. INS Intern. Symp. on Nucl. Direct. Reac. Mech., p. 71 (Fukuoka Japan1978).
T. Tamura and T. Terasawa: Phys. Lett., ~, 41 (1964); H.Y. Geramb, K. Amos, R. Sprickman,
K.T. Knopfle, M. Rogge, D. Ingham, and C. Mayer-Boricke: Phys. Rev. C, 12, 1697 (1975).

30

4-4. Vector Analyzing Power and Polarization

Measurement

the Deuteron D-state

Effects

T. Kubo, N. Kishida, H. Ohnuma, T. Hasegawa,N. Ueda, T. Fujisawa, T. Wada,
K. Iwatani, and T. Suehiro

It has been pointed out!) that the separation of proton and deuteron spin-orbit distortion canbe approximately achieved through the quantities Sp = 2(Py - Ay) and Sd = 3Ay - 2P y' Here Py
is proton polarization, and Ay vector analyzing power, in an.e n = 0 (d, p) reaction. Especially weare interested in the effects of the deuteron D-state on Sd' There is only one report 2) of theSp and Sd measurements at 8.22 MeV.
We have measured the cross section and vector analyzing power for the 116Sn(d, p) 117 Sn(g.s. 1/2+) reaction at Ed = 22 MeV. Instead of measuring polarization of outgoing protons, wehave measured the analyzing power for the 117Sn(p, d) 116 Sn(g.s. 0+) reaction at Ep = 27 MeV.
Polarized beams were provided by an atomic-beam type polarized ion source, and injected
into INS SF cyclotron. The average beam intensity was about 10 nA at the target. The beampolarization was continuously monitored by using a carbon-foil polarimeter, and was 40 % for
deuterons and 50 % for protons. Self-supporting targets of enriched isotopes were used. Particles
were detected with 6E-E counter telescopes. Experimental results are shown in Figs. 1- 4 alongwith calculations.
Exact-finite-range DWBA(EFR-DWBA) calculations have been performed using the code
TWOFNR 3) modified so as to include the deuteron D-state effects. 4) Distorting potential
parameters are given in Table 1. The deuteron parameters are those searched for by using thecode ELAST2 5) to fit the cross section and polarization data for the elastic scattering measured
simultaneously with (d, p). The proton parameters are obtained from the global fits of Becchetti
and Greenlees. 6)
do
dQ

-- s
----- S+D

Fig. 1.
Cross section for the
116Sn(d, p) 117 Sn (g.s. 1/2+) at 22 MeV.

30

60

The curves are the results of EFR-DWBA
calculations with and without the deuteronD-state contributions.

31

Ay

-- s

0.5

,
I
I
I

,

,,

-0.5

Fig. 2.
Vector analyzing power for the
116Sn( d, p ) l17 Sn (g.s. 1/2+). See caption
60

30

OCM ( deg )for Fig. 1.

OCM (deg.)

Fig. 3.
Vector analyzing power for the
117Sn(p, d) 116 Sn (g.s. 0+) at 27 MeV. See
caption for Fig. 1.

90

0.5

-0.5

30

0.5

60

90

0.5

-- S
------ S+D

Fig. 4.
Angular distributions of Sp andSd obtained from Ay and Py' See caption
for Fig. 1.

0.5

-0.5

60

30

60

30
OCM ( deg)

Particle
p
d

Vo

rO

1.17
53.0
99.64 1.10

Table 1.

Distorting potential parameters.

aO

W

WD

rw

aw

Vso

rso

aso

rc

0.75
0.887

3.17

6.87
16.3

1.32
1.33

0.61
0.72

6.20

1.01

0.75

1.25

4.16

0.81

0.113

1.3

32

Following the results of EFR-DWBA calculations, the effects of the deuteron D-state are notvery large for the cross section, vector analyzing power and proton polarization. However, very
remarkable D-state effects are found in Sp and Sd' Especially the fit to Sd is very poor without
D-state effects. Thus it is found that the D-state effects can play an important role even in thefirst-rank polarization quantities.
Measurement of Py at larger angles and further analyses are in progress.

References
1)

R. C. Johnson: Nuc!. Phys., 35, 654 (1962); A90, 289 (1967).

2)
3)
4)

R. R. Cadmus, Jr. and W. Haeberli: ibid., A327, 419 (1979).
M. Igarashi: unpublished.
N. Kishida and H. Ohnuma: J. Phys. Soc. Japan., 46, 1375 (1979).

5)
6)

M. Igarashi: INS-PT-26 (1970).
F. D. Becchetti and G. W. Greenlees: Phys. Rev., 182, 1190 (1969).

33

4-5.

Measurement of Particle-y Angular Correlations for the
58 N . (I.
p, d ) 57 N'I Reactlon
at Ep= 30 MeV

N. Kishida, 1. Kasagi, T. Kubo, Y. Kamatani,
T. Murakami, H. Ohnuma, and M. Yasue*

The mechanism of the (p, d) reaction has been mainly investigated by measuring differential
cross sections, analyzing powers, and occasionally polarizations of outgoing particles.

In general,

residual nuclei are also left polarized, and this polarization gives information independent of theabove quantities. An assembly of polarized nuclei is described by a density matrix or statisticaltensors. We measured correlation functions between ejected deuterons and de-exciting ')'-rays forthe 58 Ni(p, d)57 Ni reaction at 30 Me V in order to obtain experimental information on the statisticaltensors of residual nuclei. There have already been differential cross section and analyzing power
measurementsl) for this reaction at the same incident energy.
The experiment was done with a 30 MeV proton beam from the INS SF cyclotron. Four2" X 2" NaI(T I) detectors and four 6E-E counter telescopes were used to detect ')'-rays anddeuterons, respectively. Correlation functions were obtained by taking coincidences between,),-ray detectors and particle detectors. The target was 2.4 mg/cm 2 thick metalic foil of enriched
58 Ni.
Differential cross sections, analyzing powers, and correlation functions of the transition to the2.58 Me V (7/2-) state in 57 Ni are analyzed by DWBA and adiabatic deuteron breakup theory (ADB)
including the D state of the deuteron ground state. The method of calculations are described inRef. 2. Proton distorting potential parameters are taken from Ref. 3 and deuteron parametersfor DWBA calculations from Ref. 4. The deuteron adiabatic potential is constructed from theproton and neutron parameters of Ref. 5 following Ref. 6.
in local-energy approximation.

Non-locality corrections are included

The form factor is generated by usual separation energy method.

Results of the calculations are shown in Figs. 1- 4 together with experimental data.
normalization is used for S + D and S calculations.

The same

The DWBA calculations including the

D-state reproduced differential cross sections, analyzing powers and correlation function at (j d = 25°
well.

They also reproduce the correlation function at (j d = 45°, but the fit is worse for large (j r
10hnson and Santos stated 7) that the D-state effects gave a partial account of f = 3

l-dependence raising j = 7/2 cross sections at minima. The D-state effects in fact increase thecalculated cross sections around 45°, but the effects are barely noticeable at this energy (Fig. I).
On the other hand, the D-state effects are appreciable on the correlation functions at (j d = 45° andconsiderably improves the fit to the data. At maxima of cross sections, e.g. at (j d = 25°, theD-state effects are small even on the correlation functions.
The S + D DWBA calculations consistently reproduce the experimental data, but the fit to
the correlation function at (j d = 45° is not as excellent as the fits to cross sections and analyzing
powers. This fact shows the advantage and importance of particle-,), angular correlation data intesting reaction models.
All the calculations here are made by using the computer F ACOM 230 - 75 at IPCR.
*

Institute for Nuclear Study, University of Tokyo.

34

58Ni ( p, d)57 Ni\2. 58MeV %- Ep =30MeV

2.58 MeV ~ -DWBA S+D-S ------ADB S+D _. S

DWBA S+D-S ------ ADB S+D - - S - -- -

----

-0.5

20°

60°

40°

80°

BcM .

Fig. 1.
DWBA and ADB calculations
with (S + D) and without (S) the D-statecompared with the differential crosssections.

Fig. 2.
DWBA and ADB calculations
with (S + D) and without (S) the D-statecompared with the analyzing powers.

W (Bd = 45°, tpd = OO; B7 , tp7=1800)
2.58 MeV ~ - -.2..G.S. Yz-

DWBA S+D-S --- ---S+D - - S ----0=0
E2
W ( Bd =25°, ~ = Oo ; B7 , '1>7=180° )DWBA S+D-S ------ADB S+D - . S ----

1.5

ADB

1.5

'/'
3 1.0

(/

'/

//
'/

0.5 /

0°

0.5

30°

60°

90°

180°

B7

Fig. 3.
DWBA and ADB calculations
with (S + D) and without (S) the D-statecompared with the correlation function
at (J d = 25°.

0°

180°

By

Fig. 4.
DWBA and ADB calculations
with (S + D) and without (S) the D-statecompared with the correlation function
at (J d = 45°.

35

References
1)

2)
3)
4)
5)

T. Hasegawa, N. Veda, N. Kishida, H. Ohnuma, T. Fujisawa, T. Wada, K. Iwatani, T. Tanaka,
and Y. Wakuta: Proc. of "1978 INS Intern. Symp. on Nuclear Direct Reaction Mechanism",
unpublished.
N. Kishida and H. Ohnuma: J. Phys. Soc. Japan, 46, 1375 (1979).
G. W. Greenlees and G. J. Pyle: Phys. Rev., 149, 836 (1966).
F. T. Baker, S. Davis, C. Glashausser, and A. B. Robbins: Nucl. Phys., A233, 409 (1974).
C. M. Perey, F. G. Perey , J. K. Dickens, and R. J. Silver: Phys. Rev., 175, 1460 (1968);
F. D. Becchetti, Jr. and G. W. Greenlees: ibid., 182, 1190 (1969).

6)
7)

G. L. Wales and R. C. Johnson: Nucl. Phys., A274, 168 (1976).
R. C. Johnson and F. D. Santos: Phys. Rev. Lett., 1.2, 364 (1967).

36

4-6.
in

Coulomb Nuclear InterferencetheInelastic Scattering of18

0

M. Ichimura and A. Ichimura *It is well known that in the inelastic scattering between heavy ions with incident energy

slightly above the Coulomb barrier, the angular distribution and the excitation function show atypical interference pattern between the Coulomb excitation and the nuclear excitation. Most ofsuch phenomena are well explained by the conventional DWBA with collective form factors andfor some cases the importance of the channel coupling (CC) effects is reported.
However, it was reported 1),2) that the inelastic scattering induced by 18 which results in the
projectile excitation of the 18°°

first 2+ excited state (Ex = 1.98 Me V) shows anomalous pattern inthe angular distribution, which cannot be explained by DWBA or CC analysis with the conventional
collective form factors. In Fig. 1 the experimental angular distribution of the reaction
58Ni( 18 0, 180*)58Ni at E = 63 MeV is compared with the DWBA results where the vibrationalmb(mb)
58 Ni ( IBO . 180' ( 2+. 198MeV )) 5H Ni

/-J
-0 x

""

!.

10

DWBA
w. Microscopic t.t

CCw Microscopic f.f\ \,. ....

,I // /

-

10
.....

"

,
'x
,

,

DWBA
w. Collective f.f

Fig. 1.
Experimental and theoreticalcross sections of the inelastic scattering
58Ni 8 0, 18 0* (2+, 1.98 MeV)) 58Ni.

'~\

~\

e

\
\

X\

\
\

\

,

The dotted line denotes the result of
DWBA with the vibrational form factor,
while the broken line represents thex\\

Rutherford Ratio'"O+58Ni
1~'I' h = 63 MeV

\

\

\

0.1

30°

50°

* Institute of Physics, University of Tokyo.

70°

90°

result of DWBA with the microscopic
form factor. The full line shows theresult of the coupled channel (CC)calculation with the reorientation effects
in terms of the microscopic form factors.
The experimental data are shown by thecrosses.
The elastic scatterings are also shown
where the results of the optical potential
are denoted by the dotted line while theCC results are denoted by the full line.

37

form factor is used with the assumption that the nuclear deformation parameter is equal to the
Coulomb deformation parameter. Marked differences are seen in the height of the peak at about
e = 50° and the position of the peaks and dips.
Several attempts have hitherto been made to explain this discrepancy: (i) Assume anomalously
large nuclear deformation parameters and carry out the CC calculation where the reorientation
effect is find to be very significant.1) However, this assumption of large deformation contradicts
with recent improved measurement 3) of the quadrupole moment of the 2+ state of 18 0; (ii)
Adjust the phase of the nuclear collective form factor to reproduce the experimental data by
DWBA,2) but this procedure has no physical justification; (iii) Adjust the geometrical parameters of
the form factor as a simulation of a microscopic form factor 4) but the values of the chosenparameters have poor theoretical justification; (iv) Take into account the two step process 5)
18 0 ~ 17 0 ~ 18 0*, which somewhat improves the position of the dip at about e : : : 40° but thefit for the large angle cross section is very poor.
Here we build up microscopic form factors for the transition from the ground state to the18
first 2+ state of 0 and for the reorientation within the first 2+ state. For the calculation of58
the microscopic form factors, we folded the nUcleon-target ( Ni) optical potential by the shellmodel wave functions 6) of the ground and the first excited states of 18 O.

The single particle wave

functions of the bound state are calculated by the half-of-the-separation-energy method. In Fig. 2
we show the collective and the microscopic form factors for the transition from the ground state to
the first excited state at the tail region, considering the fact that analysis shows that thecontribution comes from the region from 8 fm to 13 fm. One sees much longer tail of the
microscopic form factors which is due to the loosely bound valence nucleon in 18 0 .
DWBA and CC calculations with the reorientation in terms of the microscopic form factors
are performed, and the results are compared with the experimental data and the DWBA results ofthe collective model in Fig. 1. As far as the magnitude of the peak at about e : : : 50° is
MeV____ !~e Coulomb excitation------------10r( fm )----- -----

11 - - - - - - - - - - 11T2 - - - - -0 ~----~----+-----~~~4_----~=--=~--==~

- 1

-2

DWBA form actors
or 5sNi ( 180 . 10 0 " 2 + , 5SN i

Comparison between theFig. 2.
microscopic transition form factor andthat of the collective model at the tail- 7

region.

38

concerned, much improvement has been obtained by using the microscopic form factors , but the
DWBA calculations with the microscopic form factor gave much too large cross sections at large
angles. If we take into account the reorientation effect in the CC calculation , the cross sectionsat large angles are considerably reduced and the fit is improved though not yet satisfactory.
We used the optical potentials as the distorting potential in the present CC calculation andhave not yet readjusted them to reproduce elastic scattering data. Therefore, the predictedelastic cross section is larger than the experimental one at large angles. By performing thisreadjustment, we may obtain more improved results.
As to the position of the dip at about 8 ~ 40°, half of the difference between theexperimental data and the result of the collective model DWBA calculation is remedied by the CC
calculation with the reorientation effect by using the microscopic form factors.
Further investigations are in progress.

References
I)

F. Videbaek, P. R. Christensen, Ole Hansen, and K. Ulbak: Nucl. Phys. , A256 , 301 (1976 ).

2)

K. E. Rehm, H. 1. Korner, M. Richter, H. P. Rother, 1. P. Schiffer, and H. Spieler: Phys.
Rev., C12, 1945 (1975) ; H. Essel, K. E. Rehm, H. Bohn , H. 1. Korner, and H. Spieler:
ibid., C19, 2224 (1979).

3)

M. P. Fewell, A. M. Baxter, D. C. Kean , R. H. Spear, and T. H. Zabel: Nucl. Phys. , A232 ,
457 (1979).

4)
5)
6)

A. 1. Baltz and S. Kahana: Phys. Rev. , C17 , 555 (1978).
K. S. Low : Proc. Intern. Conf. Nuclear Structure, Tokyo , p. 267 (1977).
T. Inoue, T. Sebe , H. Hagiwara, and A. Arima: Nucl. Phys. , 59, 1 (1964).

39

4-7.

Semiclassical Treatment of the Direct Reactions
Induced by Heavy Ions

T. Kammuri, K. Matsuoka, * and M. Sano*

Gross features of one-particle transfer reactions induced by heavy ions can be understood ina simple way by considering the conservation of the linear and angular momenta. 1) We havederived an expression for the transition probability of the one-particle transfer, which agrees withthe one originally given by Brink.!) We have extended the treatment to the inelastic scatteringand sequential transfer.
We start from the semiclassical theory of Broglia and Winther. 2) The differential crosssection is given by the product of the elastic scattering cross section and the transition probability
p = 1cif 12. The amplitude c Wof the one-step process is given by
C(.l ) = ~S OO f ( . l ) (t) dt ,If
Ih- 00 If

where f(1)

it (t) is the form factor multiplied by the energy-dependent exponential function. We

assume that the reaction is a peripheral one and that the main contributions come from the region
between two nuclei. For one-particle transfer reaction, fit (t) is given by( 1 )(

f if

t

) _

( 1)

- N ifexp{Ik)2}exp (- "2 (R6
~

TJ

2

2

t -

.

l wt

)

.

(2)

Here
w = L:" L ~R'(3)* Department of Physics, Osaka University.

40

and N

\p lumps together c.f.p. 's, Clebsch-Gordan coefficients, reduced widths etc. We follow

Ref. 1 for the definitions and notations on 6k, 6L etc.

Integration of Eqn. (2) over t gives(4)
In the macroscopic approach of the collective excitation of the target nucleus, the form
factor is proportional to the derivative of the Woods-Saxon potential.
given byc (.1) ex
If

The amplitude is then

! ex p {_ l ( 6L )2}
2

71

a2

(5)

•

Here u2 2 is given by Ria, with the surface diffuseness a, and

6 L = A2

+ QR / iiv.

(6)

For the transition to a decaying collective level with the energy Wo and width r, we have to
multiply a Lorentzian factor,3)(; ( 1 )= c ( l )

if

if

(E*)
·

( r / 27r)1/2
E* - wo + ir/ 2(7)where E* is the excitation energy of the corresponding nucleus.
The two-step amplitude is given by(8)
For the sequential transfer of two particles, it becomese\~ )oc ~1~2 {I + erf(ix) } exp [- t

1 {(R:[k')\ ( "a~ ; nJ.

(9)in which erf(z) is the error function andx71171 '2.

(10),,/ r; '2.

71 '2.

1

2

Quantities with suffices i = 1, 2 refer to the first or second step of the two-step processrespectively. In the calculation on the lOoMo (14N, 12B) 102Ru reaction at E = 90 MeV, both thesimultaneous and sequential transfer processes give practically the same energy spectra andpolarization distributions.
The energy spectrum can be approximated by
(11 )

41

For one-particle transfer, the optimum value of the effective Q and the width Ware given by(12)
In the case of sequential transfer, we haveQ m ,,--. 1
eff "-- -2

E

2

2

L: m·v·i= l

1 1

W ~ (_1 + 1) {L:
2
i

2 1/2
(tlVj
.)}
R °21

(13)

Increase of the widths with incident energy can be seen in the experilnental results4) on 52 Cr + 14 N
for the incident 14N energies between 64 MeV and 95 MeV.
the numbers of transferred nucleons up to about 4.

Experimental widths increase with

References
1)

2)
3)
4)

D. M. Brink: Phys. Lett., 40B, 37 (1972).
R. A. Broglia and A. Winther: Nucl. Phys., A182, 112 (1972).
D. Drechsel and H. Uberall: Phys. Rev., 181, 1383 (1969).
T. Mikumo, I. Kohno, K. Katori, T. Motobayashi, S. Nakajima, M. Yoshie, and H. Kamitsubo:
ibid., C14, 1458 (1976).

42

4-8.

Mass

Exchange in an Analysisof the Heavy-Ion Reaction

Based on the Linear Response Theory

S. Yamaji

In our previous works,1),2) realistic calculations of friction tensors for the 20Ne + 28Si system were performed
using the two-center shell model on the basis of the linear response theory and the coupled dynamical equationsof motion with friction were solved, taking the relative distance R and the deformation 0 of each nucleus as thecollective variables. It was found 2) that the calculated angular distribution reproduces the nearly exponentiallydecreasing feature of the experimental data of 120 Me V 20Ne with 27 Al and that the calculated total kinetic
energy loss reproduces nicely the experimentally observed most probable kinetic energy loss due to the inclusionof the deformation degree of freedom involved in the exit channel. 3),4)
However, our calculated cross section 2) had to be compared with the sum of the cross sections of thevarious reaction products in the experiment, because the effect of mass exchange S),6) was neglected.

In Ref. 5,

only the relative distance R and the mass asymmetry 'Tl = (AI - A2)/(A 1 + A2) were treated as the collective
variables within the cranking formalism, neglecting the deformation degree of freedom. Although, in Ref. 6, thedynamical coupled equations of motion derived from the linear response theory 7) were solved treating R and 'Tl
as collective variables, friction tensors 'YRR' 'Y'Tl'Tl' and 'YR'Tl were approximated with a phenomenological one,constant value and zero, respectively. The energy density potential written in a simple analytic form was taken
as the nuclear interaction potential.6 )Table 1.

Order of magnitude of friction and mass tensors for 0 = 0.0 and 0.4.

The values of tensors

relating to the mass asymmetry such as 'YR'Tl' 'Y-O'Tl' 'Y'Tl'Tl' mR'Tl' mO'Tl' and m 77'Tl are taken justinside the touching distance ~('Tl), i.e. at R = ~('Tl) - 0.5 fm for 'Tl = 0.0 ,....., 0.6. The
values of other tensors are those in the surface region with R = ~('Tl)-0.5 '" ~('Tl)+0.5 fm for'Tl = 0.0 ,....., 0.6. The nuclear temperature and the smearing width necessary for the calculationof friction tensors are taken to be 3 MeV and 0.2 hw o (hw o = 11.3 MeV), respectively.

'YRR
'YRo
'YR'Tl'Yo 0'YO'Tl
'Y'Tl'Tl

mRR
mRo

Unit

0=0.0

0=0.4

MeV·l0- 23 sec/fm 2
MeV·I0- 23 sec/fm
MeV·10- 23 sec/fm

55 ,....., 80- 260,....., -80

30,....., 60-140,....., -20
0,....., 120

i\leV·I0- 23 sec
MeV·10- 23 sec
MeV·l0-23 sec

1000 ,....., 2000
- 500,....., 500

pmu(proton mass unit)
pmu·fmmoo

pmu-fmpmu-fm2

mO'Tl

pmu·fm 2

m 77'Tlpmu-fm2

mR'Tl

20,....., 200

3000,.....,7000
6,....., 122000 ,....., 3000
- 200 ,....., 1500
3000 ,....., 7000
6,....., 12

0.5 ,.....,-35,.....,

1.0
0

0.5 ,.....,-40,.....,

65,.....,

85

250,....., 400-20,.....,

01000,....., 5000

-200,.....,

3001000,....., 2000

43

In the present work, friction tensors 'YI1vCJJ., v = R, 8, fI) were calculated microscopically using formulas
given in Ref. 1, the mass tensors m l1V were approximately replaced with hydrodynamical ones obtained by the useof the Werner-Wheeler method 8) and the YUkawa-plus-exponential folding potential 9 ) was taken as the nuclear
potential.
The calculation was performed over following ranges of parameters: 8 = -0.4 ~ 0.5 at intervals of 6.8 =
0.1, R = 2 ~ 20 fm at intervals of 6.R = 2 fm and fI = 0.0 ~ 0.7 at intervals of 6.fI = 0.05. The order ofmagnitude of these tensors is given in Table 1. Now the numerical calculation of mass and friction tensors andpotentials to be used in the dynamical equations of motion have been finished, it is possible to evaluate thetime evolution of the expectation value RCl(t), 8 ct'(t) and 17 c t'(t) and moments X (t) (11, v = R, 8, 17) of the
l1v
distribution using the formulas in Ref. 7.
9

8
7

.s 7
n::: 6

5
0.2

0.1

r;

r •• (MeV·1Q - 2J sec )
/=

,0_-

Na
J
>

~

0

01

~e

9

N

t

---.\

I

I

,
I

0.2

\

/

\

/

\

-5

\

/

0.5

"\
\

/

\

/

\

~

;

0.4

\

\

C

I

\ 03

~

\

/

/

/

\

'/

/

\

/

\
\

/

\/

/= 30n

_0

~

;

--- ,

~

2S 0

/

\

01

0 2-....... \03

0.4 \

-~

/

\'
\
\

- 5

I

0.5

\

/

-....,:.....

'/(hw o = 11.3 MeV) is used. The friction tensor isdrawn only within the restricted region where twonuclei overlap .

l

On
~

I

Fig. 1.
Contour map of the friction tensor'Y (R, 8, 17, T) as functions of R and 17 for 8 = 0.4
1717
and T = 3 MeV. The smearing width of 0.2 hv o

\

.~

\

.

/

I

/

I

TJ

\/

~

~ i

The potential VCR, 8, 17) as a function ofFig. 2.
17 for 8 = 0.0 and R = 9 fm. The solid curves show
the YUkawa-plus-exponential folding potential andthe dashed curves show the sum of the mutual
Coulomb energy and the shell correction energy.
The curves in the lower part include the contribution
due to the centrifugal potential which is approximately
equal to (2t?£2/AR2)fl2~ 19f12 for the angularmomentum e = 30. The dot-dashed curve
corresponds to c = - 50 MeV. The energy at
17 = 0.16 corresponding to the entrance channel (Ne)is set equal to zero.

However, it is important to perform the qualitative estimation of mass exchange, before doing such anelaborate calculation. For that , we assume that the motions of mass asymmetry and of other degrees of
freedom are statistically uncorrelated and that the acceleration term for the 17-degree can be neglected. If weuse constant values 'Y and T for the friction 'Y1717 and the temperature and assuming V = 1/2c17 2 , 17 C f (t) andX ( t) are written as
rl17

where 17 0 denotes the initial mass asymmetry and the cross section a (17, t) is proportional to44

The value of'Y can be taken as 5000 MeV· 10-23 sec from Fig. 1.

In order to obtain the constant value cin the potential V = 1/2c17 2 , the 17-dependence of the potential at 9 fm is shown in Fig. 2. The value of c forthe sum of the Yukawa-plus-exponential potential and the centrifugal potential with the angular momentum
30 h is nearly equal to zero due to the cancellation between both potentials. Using this small value of c,
we cannot reproduce the experimental results shown by the points e in Fig. 3. The fact that the cross sections
for the odd reaction products are smaller than those for the even ones implies the importance of the shelleffect in the mass transfer. Therefore, we show the sum of the mutual Coulomb energy at 9 fm and theshell correction energy obtaiped from the experimental values of mass excesses in Fig. 2. Even if we include
the contribution of the centrifugal term, we still have about - 5 MeV at 17 = 0.33 and 0.5 corresponding to 0 andC channels, respectively. F or simplicity, we restrict ourselves to the mass fragmentation induced by a-particle
transfers. Then, we can take V = -25172 shown by the dot-dashed curve as the fragmentation potential. The
temperatue is taken to be 1.5 MeV, which is half of the temperature at the final stage of the reaction. Then, inorder to reproduce the experimental values of 17 (t) = 0.36, 0.42, and 0.5 for the c.m. angles of () cm = 40°60°, and 80°, the collision time obtained are 75,90, and 108 X 10-23 sec, respectively, whose order of magnitude
is consistent with the collision time estimated in Ref. 2. The corresponding second moments x1717 (t) are evaluatedto be 0.05, 0.07 , and 0.12 which are roughly by factor 3 larger than the values reproducing experimental mass
distributions. The qualitative agreement between the calculated and experimental cross sections is seen in Fig. 3.
Cf

8cm = 40°
50
40

~

"
..0

30

E

~'.

.

~

N

F

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

Exp.

40

"..0

////

-{l "'1::l 10

E

"0

E 30

I

'?-I 20~ <i:

8cm = 80°

8cm = 60°500~>::- I E 20

~ <i:-{l "'1::l 10

50

Exp- - Cal"~ !30
Ne , /.' ' FN~ ~ ____ .. ____ - -.

Exp
- - Ca l~ 40~>::-1 E~<i:20-{l "'1::l 10

C

N~·
Na
• ___._ /__ F• ____ _ _Ne

- - CalOD Ql Q2 Q3 Q4

Q5QO Q1 Q2 03 OA Q5

TJ

TJ

03 OA 0.5

0.0 0.1 02
TJ

Fig. 3.
Differential cross sections da(17)/d8 cm at three different c.m.
angles of 40° , 60°, and 80° as a function of mass asymmetry 17.
Experimental cross sections are obtained by integrating the cross sectiond 2 a/ d8
dE in Fig. 8 of Ref. 10 over the energy. They are plotted incmunits of mb/rad. Calculated cross sections are normalized to theexperimental ones at the peaks.

References
K. Sato, A. Iwamoto, K. Harada, S. Yamaji, and S. Yoshida: Z. Physik, A288, 383 (1978).
K. Sato, S. Yamaji, K. Harada, and S. Yoshida: ibid., A290, 149 (1979).
1.P. Bondorf, 1.R. Huizenga, M.1. Sobel, and D. Sperber: Phys. Rev., C11, 1265 (1975).
H.H. Deubler and K. Dietrich: Nucl. Phys. , A277, 493 (1977).
S. Yamaji, W. Scheid, H.J. Fink, and W. Greiner: Z. Physik, A278, 69 (1976).
C. Ngo, and H. Hofmann: ibid., A282, 83 (1977).
H. Hofmann and P.J. Siemens: Nucl. Phys., A275, 464 (1977).
K.T.R. Davies, A.l. Sierk, and 1.R. Nix: Phys. Rev., C13, 2385 (1976).
H.l. Krappe, l.R. Nix, and A.J. Sierk: ibid., C20, 992 (1979).
10) 1.B. Natowitz, M.N. Namboodiri, R. Eggers, P. Gonthier, K. Geoffroy, R. Hanus, C. Towsley, and K. Das:
Nucl. Phys., A277, 477 (1977).
1)
2)
3)
4)
5)
6)
7)
8)
9)

45

4-9.

Study of the2

A IC 4 N, Hla)Reaction

T. Sugitate, T. Nomura, M. Ishihara, T. Inamura,
H. Utsunomiya, Y. Gono, and K. Ieki

In-plane angular correlations between ejected heavy ions (HI) and alpha particles(a) have been studied in the
27 AI + 14N reaction.

A self-supporting 27 AI target of 2.2 mg/cm 2 thickness was bombarded with 95 MeV

14N-beam from the cyclotron.

HI (2~~8) and a-particles were detected by counter telescopes consisting of

20-2000 pm and 30--2000 pm llE- E Si detectors, respectively. The HI counter was fixed at 8~P = -25° and-40° (the negative sign denotes angles on the HI counter side with respect to the beam axis), while coincident
a-particles were detected' at several angles in the reaction plane. An aluminium absorber (I 00 pm) was placed in
front of the a-counter in the case of forward angles (i.e. , 8~b = ±7° and -10°) in order to remove elastic particles.
Figure 1 shows energy integrated cross sections of a-particles coincident with various heavy ions. The
yields have maxima near the beam axis and fall slowly with exponential slope on the side of positive angles,
while they decrease rapidly at negative angles, where small dips are seen near the angles of the HI emission in
the case of B, C, N, and 0 channels.
a ( x~ ) ...

Bift'U = - 25Deg

a (x~ ) ...
Li t::,.

Li [;;

Be '" -

Be A

B 0
C •

B0
C •

_

N0

o•

10 1

10- 1

10 1

- 50

o

+50

Balah ( Degrees )Balab (D egrees )Fig. 1.

10 1

Energy integrated cross sections of a-particles coincident with various heavy ions in the

27 Al + 14N reaction at 95 MeV at

e~~ = -25° and -40°. The lines are drawn for the Li, B, and C

channels to guide the eye. The arrows indicate the beam axis and the HI detection angle.
Figure 2 shows contour plots of the differential cross sections of a-velocity in the case of Li, B, and C
channels, which are obtained from the following transformation I) :The three-fold differential cross sections thus obtained are invariant with respect to the Gali1ei transformation,neglecting relativistic effects.

From these figures, we obtained energy spectra of a-particles at various angles

46

27AI (I.IN , Lia ) e l~,' b = - 25Deg
d 3 (J[ b/ str 2C 3]
d.QL;d9 adVa3( a)27AI ( "N, Ba ) e ~·'b = - 25Deg
d 3(J[b/str 2C 3J
d.Q B d9 a dVa3
-16

~

1.0

Oi_;'b = - 40Deg

d 3 r;
dQ ",dS2 adVa3[ b/ str 2C 3J::~~}_6

0:
16

( b)

14

Fig. 2.

0.2
02 -

(d )

27 AI ( " N, Ca l 8l;'b = - 40 De gd 3(J[ b/ str 2C3J
dQ c dQ adVa3~; :~E',~ ~0~~2

-_

~

V

(I ';

(£;r ·

0.1
16

/

16

10
08
0.1 ,

12 4 .5 8 10121416
v"d'b [SIlOO]

7.0
./ 50
30
/'
10
, - 05_---- 0.1

, VT

d9 B ~.~adVa3

l~r:~ f~~lb "\27AI ('4N, Ba ) 8~'b = - 40Deg
2 3[b / str C J-16

22~V;F~C

80

-Km-

\

(e )

-'

:,

16

27 AI (I 'N, Lla )1/' ~}'i~'~Ii- ,\,'
2.0 ~

/

20
1.0
10

27AI ( "N, Ca l 8C'b = - 25Deg
d 3 (J[ b/ str 2C 3J
dg e d9 a dVa3;,;~f405~\-"
2.5 ~.
't. ~\ ): 025,

16

(c)

( f)

22

vl -~~5

,1.8
14
10

,

10

16
VaL'b

Contour plots of differential cross sections d 3 a/dD HI dD CY dV 3CY for a-particles coincident with Li,

B, and C ions. The vectors VB ' Vern ' V p ' and VT correspond to the velocities and directions of the incident
beam , the centre-of-mass , the ejected heavy ion, and the target-like nucleus, respectively. Cross sections andvelocities are represented in the units of [b/sr 2 c 3 ] and [c/lOO] , respectively, where c is the velocity of light.

in the c.m. system (Fig. 3(a)) and in the rest frame of the target-like nucleus (Fig. 3(b)), of which the average
direction and energy were calculated by assuming a binary reaction process.
The following points should be noted.
(1) The yields of a-particles are not symmetric with respect to the beam axis nor the HI direction (Fig. 1).
(2) The yields and average velocities of a -particles on the positive-angle side decrease smoothly withincreasing angles, and the values of most probable energy of a-particles are nearly constant in the rest frame of
the target-like nucleus (Fig. 3(b )).

On the other hand, those in the c.m. system, for instance, show a suddenchange between 60° and 80° , and thereafter result in an unnatural increase with increasing angles as seen in
Fig. 3(a). We therefore conclude that the results obtained at positive angles mainly originate from the preequilibrium decay of the target-like nucleus.
(3) The situation is very complex on the negative-angle side as well as at forward angles. The energy
spectra of ex-particles for the Be - N channels show two peaks in the laboratory system; one corresponds
roughly to the beam velocity especially for the data at e~r = - 25° This indicates that the observed correlations
originate from a fast process like projectile fragmentation. Another is situated at much lower energies. The
detailed analysis is now in progress.
The observed energy spectra of pre-equilibrium decay of the target-like nucleus always show the MaxwellBoltzmann distribution with high nuclear temperature(T). Figure 4 shows the values of T deduced from the fit
as described in Ref. 2 at various angles, which is 4-5 Me V at small angles and decreases smoothly with increasing
angles, reaching an equilibrium value at about 80°. The pre-equilibrium decay mentioned above is consistent
with that expected in the hot-spot model,; 3) when the observed projectile-like fragment (HI) comesfrom transfer reactions, the excited target-like nucleus starts to rotate due to the transferred angular momenta.
The direction of the above rotation is positive or negative according to the positive or negative deflection of
HI. The present data therefore suggest the positive deflection of HI and the negative deflection of coincident
ex-particles on the side of positive angles.

47

6

I

I

I

27

( a)

27AI (1' N. Ca l 95. MeV
b

8·E· = - 25Deg .
8i·

m

1

10

~

.D

-.3
~
'1;j

oj
'1;j

OJ

~
0

';;

(b)

I

= - 40°

2q

l~t
wt

2

~ 2 q 2

~

0°

o

~

0

~

!!

ttl

~ 3

Teq

_______________

h~0 ~~-L--~--~~1~~--~~7-~~- 60 - 40 - 20
0
20
40
60
80
100

6

27 AI (" N. Ba )o B~ = - 25Deg

5o Q 2 <2 2Q

± _~___ t

2

t

20°

J,

!

>

Q

J
w~,

~ f~

8a = -10°• B~, = - 40Deg

~
Q

1Cf

-20°

2:

AI ( 14 N .Ca ) 95 MeV

rest frame of target - like nuclus

10 2

><lJ

27

8CL• b = - 25Deg.

c.m. system

AI (I ' N. Li a )') oL = -25 Deg

2. e~ =- 40Deg

4
>

o

0

~

! 3

40°
Q

Q

2
Q

Q

o

60°

0

o

I

- 60 -40 -20

o

20

6
o

80°

0

60

80

100

2' AI ( "N. Cal

2 2o B~ = -25Deg• B~ = - 40Deg

~

4
>

100°
o

40

~ 3

0

2

10

2

It0 1 110
E~mFig. 3.

E;( MeV )

20

- 60 - 40 - 20

(MeV )

Differential cross sections of ~-particles at various

Fig. 4.

0

20

B;( Degrees )

40

60

80

100

Nuclear temperature plots atangles coincident with carbon at Ol~b = -25 in the different

O~~ = -25 (open circles) and -40

frame obtained from Fig. 2( e).
a) Energy spectra in the c.m. system.
b) Energy spectra in the rest frame of the target-like nucleus.

(solid circles) versus emission angle (O!) .

0

Angles (O!) are measured from the direction of the00Dashed lines show the equilibrium
nuclear temperature of residual nuclei ,and dashed-dot line shows the value

target-like nucleus. Solid curves show the fitted spectra

when the ejected carbon is excited at

as described in Ref. 2.

4.4 MeV.

References

1)

P. Gonthier, H. Ho, M.N. Namboodiri, J.B. Natowitz, L. Adler, O. Hartin, P. Kasiraj, A. Khodai, S. Simon,

2)
3)

and K. Hagel: Progr. in Research 1978-1979, Cyclotron Institute, Texas A & M University, p. 7.
T. Nomura, H. Utsunomiya, T. Motobayashi, T. Inamura, and M. Yanokura: Phys. Rev. Lett., 40,694 (1978).
R. Weiner and M. Westrom: Nucl. Phys., A286, 282 (1977).

48

4-10.

Systematic Study of Reaction Cross Sectionsin the14N+93Nb Reaction

M. Ishihara, H. Kamitsubo, T. Fukuda,*
M. Tanaka,** H. Ogata,*** and 1. Miura***d2 a
Since the classical workl) of Wilczynski, the behaviour of the differential cross section dEde

as a function of kinetic energy E and scattering angle e has been used to argue the deflection
function of the heavy ion reaction. So far two categories of deflection functions corresponding
to orbitingl) and focusing 2) have been recognized. It was further argued 3) that a single parameter,where v' is the relative velocity of two ions at the interaction barrier; may well serve as a criterion
to determine the type of the deflection function. Systems with r;' ::S 150-200 are supposed to
2give rise to orbiting; the ridge of d a gradually moves from positive to negative angles withdEdedecreasing E.
d2 a
In this work we measured dEde for the 14 N + 93 Nb reaction at 110, 159, and 209 Me V.
The reaction system studied has extremely small r/ of 10 - 22 in favour of orbiting. The experiment
was performed at RCNP at Osaka University.

The cross sections for various final channels were

measured with Si-detector telescopes over an angular range from 1.5° to 60°. The measurement
at very forward angles was carried out by incorporating a quadruple magnet lens and a deflection
magnet to eliminate the disturbing contributions from the incident beam and the elasticallyscattered particles.
Some examples of Wilczynski plots are shown in Fig. 1.

Contrary to the expectation, thefocusing feature of the deflection functions is eminent. Namely the ridge of df:e almost
stays at a constant angle over the wide E range, and it moves to larger angles for the lowest E.
No appreciable indication for crossover of the deflection angle from positive to negative is observed.

This feature may be more clearly illustrated in Fig. 2, where d~:e for given E bins are plottedvs. e. Similar features of Wilczynski plots were observed for the other final channels. This
was the case for all the incident energies used, though the favoured angle varied from"" 10° for
209 MeV to ",,20° for 110 MeV.

According to Strutinski, the angular distribution of the heavy ion reaction cross section may
be approximated 4) as

do

dO

*
**
***

Department of Physics, Osaka University.
Kobe Tokiwa Junior College.
Research Center for Nuclear Physics, Osaka University.

49

14 N( 209NeV) +93 Nb_ 7Li

14N (l 59MeV ) + 93 Nb
_

12

Oc.m.

Fig. 1.
The differential cross sections d~2d~ measured for the
93Nb(14N, 12C) and (14N , 7Li) reactions with incident energies of
209 and 159 MeV are shown in contour plots in the plane of theenergy E vs . the scattering angle of the outgoing particle. The
relative magnitude of the cross section is indicated by the number
labelled to the contour line.

I

10 ' -I

I

I

I"'N ( 209 MeV ) +"'Nb __ '1C

I

I

I

I

I I

--

I

I

I

N (209 MeV ) +":< Nb-- "LI

I

-

-

-

-

-

I

I

20°

I
40°

I

I
60°

d2 a
Fig. 2.
The angular distributions of dQd8 obtained for given
Q-values are shown for the 93 Nbe 4 N, 12 C) and e 4 N, 6 Li)

reactions with the 209 MeV incident energy . The angular
distribu tions are drawn in the order of (- Q) value from thebottom to the top. The Q-value bins are taken in 20 MeV step.

C

50

Then the ridge of the cross section should nearly correspond to the deflection angle l/I. However
it is to be remembered that this approximation fails at very forward angles 8 ~ I II!, where I! isthe angular momentum of the outgoing channel. The rough evaluation of f values may be madeusing the relation,e = RJ 2/1 ( E - B) ,where R is the reaction radius, B is the interaction barrier and J1 is the reduced mass.

The

critical angle thus deduced was at most 3° for the most part of the spectra, assuring thecorrespondence between l/I and the ridge angle observed.
The anomalous behaviour of deflection functions discussed above casts some doubt on thesimple classification of reactions in terms of r/. Within the framework of the classical modelwith friction forces, the observed results may indicate that two isolated bins of initial angularmomenta contribute to the reaction so that the deflection angle jumps from positive to negativesides without intersecting zero (forward) angle. To test such a hypothesis, the measurement of
gamma-ray multiplicities is in progress.

References
1)2)

1. Wilczynski: Phys. Lett., B47, 484 (1973).
1.R. Huizenga, 1.R. Birkelund, W.U. Schroder, K.L. Wolf, and V.E. Viola: Phys. Rev. Lett.,

37,885 (1976).
3)
4)J. Galin: Colloque du Journal de Physique, 37, C5-83 (1976).
V.M. Strutinski: Phys. Lett., 44B, 245 (1973).

51

4-11.

Spin Polarization of 128

in the197Au

C9 F, 12 8 )Reaction at 186 MeV

M. Ishihara, T. Shimoda, H. Kamitsubo, H. Frohlich, *K. Nagatani, T. Udagawa,** and T. Tamura **In a series of previous reports, we reported on the measurements of spin polarization P of
12 B for several heavy ion reactions. The reactions so far studied were limited to a few nucleon
transfer reactions such as (14N, 12B), (lOB, 12B), ( 12 C, 12B), and (13C, 12B). These reactions all++

exihibited a common feature of P: By defining polarization axis as parallel to ~ X kf' P is
positive for high energies E of 12 B and goes to negative as E is decreased. Obviously thisbehaviour is opposite to the prediction of the classical model in terms of friction forces. The
theoretical analysesl) ,2) which followed revealed that such a feature of P is actually a signatureof a direct reaction process in which a cluster is transferred in a single step reaction.
Provided that this conclusion is established, one may use the spin polarization as a probe to
explore the degree of influence of the direct reaction process in various reactions. In thisrespect it would be most interesting to study some exhotic reactions with large energy and masstransfers, since such reactions are usually regarded as typical deep inelastic reactions due tomultiple scatterings.
Here we report on the resu1t 3) of such an investigation performed for the 197Aue 9 F, 12 B)
reaction at 186 MeV. The measurement was made using the cyclotron at Texas A & M
University. Experimental techniques used were similar to those of the previous experiments.
However special cares were exerted to reduce background (3 rays from and outside of the target
by improving the beam optics and by employing a long duty cycle of the pulsed beam. The
latter helped to sufficiently reduce the contamination of long-life (3 rays which strongly appearedin this reaction.
The Wilczynski plot for this reaction is shown in Fig. 1. The distribution of df:e exhibitsa feature of a strongly damped reaction with cross sections concentrated in the low energy
region in the vicinity of the Coulomb barrier. Moreover the pattern of the contour plot issuggestive of negative angle deflections in accord with the expectation from the friction model.
Figure 2 shows the energy spectrum and the spin polarization measured at 25°. The featureof a damped reaction is again eminent in the energy spectrum with Q-values involved of typically(- 100) MeV. In spite of such appearance of the energy spectrum, the spin polarization shows
the characteristic feature of Q-value dependence, which should be attributed to the direct
reaction mechanism.

In fact calculated results (shown by solid lines) using the DWBA theory2)

reproduce the experimental data fairly well over a wide region of 12 B energy.

However it isalso to be remarked that the theory deviates from the data at very low energies. This indicatesthe presence of more complicated reaction processes for those most damped components.

* Physikalisches Institut, Universitat Erlangen-Niirnberg, Erlangen, West Germany.
** Department of Physics, University of Texas, Austin, Texas.

52

Au (19 F ,

19 7

200 r

12

8 ) 20 4 8 iela st i c2d adE d8

150

~

~

~

m100
N

W

Fig. 1.
The Wilczynski plotd2 aof dEd8 obtained for the
197 Au 9 F, 12 B) reaction at

e

~

50 r

186 MeV . The contour lines
da

0

~

1

o·

40·

20·

6 0·

8

80·

d

.

o f dEd8 are rawn In stepsof a factor of 2.

d2 a

~
~

197Au ( 19 F, 12 8) 204 B i

80

J~ 60

1

- 120

I

I

1

-100

-80

-60

I~

-40
Q (MeV)

-20

W

40

and Q-value. The experimental points

C;
-0

'b

20

are shown by open circles. The histogramin (a) shows the energy spectrum
obtained in a separate measurement using

N

"0

0

20

(b)

10

~
c

e

the incident energy 186 MeV are shown
as a function of the energy Eb of l2 B

.&l

-0

Fig. 2.
The cross section dndE (a) andthe spin polarization P(b) of the reaction
197 Au 9 F, 12 B) measured at 25° with

0

.9

2 -10

"§

"0

0.. - 20

-30
40

60

80

100
120
Eb (MeV)140

160

Si detectors. Solid lines represent theresults of the DWBA calculation. The
dot line in (a) corresponds to crosssections in excess of the calculation.
The dot-dash line for P was obtained byattributing the zero polarization to theextra component in excess of thecalculated cross section.

In the past years, heavy ion reactions have been customarily described 4 ) in an unified way
using the classical model in terms of the composite dinuclear system. In such descriptions thereactions are presumed to occur via multiple nucleon scatterings (or exchanges), regardless of themagnitudes of energy and mass transfers. However the present result exhibits the presence ofa regime of reactions where the above unified picture is certainly inappropriate. Combined withthe related studies5) on energy spectra, the dominant role of the simple direct reaction appears
to be general in those heavy ion reactions induced by relatively light (A ~ 20) ions.
Two of the authors (M.! and H.K) are indebted to Cyclotron Institute, Texas A & M
University, for the support during this experiment.

53

References
1)
2)
3)
4)
5)

M. Ishihara, K. Tanaka, T. Kammuri, K. Matsuoka, and M. Sana: Phys. Lett., 73B, 281(1978).
T. Udagawa and T. Tamura: Phys. Rev. Lett., 41, 1770 (1978).
M. Ishihara, T. Shimada, H. Frohlich, H. Kamitsubo, K. Nagatani, T. Udagawa, and T.
Tamura: ibid., 43, 111 (1979).
For a review see for instance: W. Schroder and 1.R. Huizenga: Ann. Rev. Nucl. Sci., 27,
465 (1977).
H. Frohlich, T. Shimada, M. Ishihara, K. Nagatani, T. Udagawa, and T. Tamura: Phys.
Rev. Lett., 42, 1518 (1979).

54

4-12.

Isotopic Dependence of the F iss ion-like Events in the 115 MeV
Nitrogen-Induced Reactions on Nickel

M. Yanokura, I. Kohno , Y. Nagame, and H. Nakahara

The aim of the present work is to investigate the isotopic dependence of the heavy ion
reactions in a relatively light system, with emphasis on the behavior of the fission-like events.
Fissionability depends on a nuclear mass in the same charge systems. Reaction systems investigatedare 14N + 58Ni and 14N + 64Ni. The neutron to proton ratios varied from 1.07 in 58Ni to 1.29
in 64Ni.
The experiment was performed with the 115 MeV 14 N for the cyclotron. Self-supporting
foils of 58Ni and 64Ni of about 600 Ilg/cm2 thickness were used. A single counter telescopeconsisting of a gas fill counter and a 300 11m thick SSD was used. Product charges from Z = 6
to 16 were well resolved. The quarter-point angles 8 1/4 were observed to be the same within
the experimental error for the two reaction systems, i.e., 23.5°. The maximum angular momentum
f max ' and the interaction radius evaluated from the 8 1/4 were 51 hand 8.83 ± 0.05 fm, respectively.

The measurement was performed from 8 lab = 12° to 45° . In the energy spectra of the reaction
products, the characteristic single bell-shaped kinetic energy peaks for the strongly damped events
could be observed for Z> 11. Shape of energy spectra was no meaningful difference between
the two reaction systems. The centroid energies of the products with Z> 11 were found to be
independent of the angles for 8 c.m.>25° , and close to the values expected from the Coulomb
repulsion energies of the two touching spheres (ro = 1.44 fm).
Figure 1 shows the energy-integrated differential cross sections for various reaction productsin the 14 N + 58 Ni system.

It is to be noted that Al which is six charges away from the projectile

10 3

\
10 2

.\ ~
\

\+\.-~-.

-0

cu

'-D

E
Cb
"'(j

b
-------

10

¢

.~
'+
AI
"""·-·-·-·-t-"'(jo ° 9o~o r ox~p.-' t • • ·-.-t-.-. x Ys
o~

CII 9

s or(
a
0 0

0

Xl/
~o

o

Be.m. ( deg )Fig. 1.

The energy integrated
differential cross sections forvarius products from 14 N + 58 Ni
reaction .

55still shows a slightly forward peaking, whereas Si, P and S show uniform distributions from 20°
to 70° (in the ·unit of do/dO). The charge distributions of the two reaction systems at 0c.m. = 40°
are shown in Fig. 2. At this angle the events are mostly those due to strongly damped events.
There is an obvious difference in cross section for Z> 12 between two reaction systems. However
they are nearly the same for Z<ll. The difference is 5 mb when the cross sections for Z = 14,
15, and 16 are summed. If the reaction products of large atomic numbers origilIlate from deeplyinelastic collisions, it is difficult to explain this difference. On the other hand, if we assume
the distributions to originate from fission events, the difference in question can be explained by
the difference in the fission barrier height of the composite nuclei. By liquid-drop model
calculation,1) the symmetric fission barrier heights for 78 Br and 72 Br were deduced to be 14 MeV
and 6.5 MeV, respectively, for .emax ' When the fission cross section is estimated by using theAlice code 2) considering the single-particle effects 3) and using the barrier heights predicted inRef. 1, it is found to be 4 mb for 14 N + 58 Ni system and 0.04 mb for 14 N + 64 Ni system.
We found the isotopic difference in the cross sections of 14N + Nickel isotope systems.
Thus, the result for the difference between the two reactions,S mb, is in good agreement withthe liquid-drop model prediction.

10 2 --

Bern = 40

0

r-

9

-0

co

~

f9

..0

E

1Oc--

<:D

~
b

"(j

-

-

? ~ ??
t
~

ft
Ifr-

tt

58 Ni 064Ni •

I

I

I

-

-

Fig. 2.
The charge distributionof 14N + 58Ni and 14N + 64Ni
I

I

I

I

I

1

S 9 10 11 12 l3 14 1516
Z

systems at 40 degrees in c.m.
system.

References
1)

2)
3)

S. Cohen, F. Plasil, and W. J. Swiatecki: Ann. Phys., 82, 557 (1974).
M. Blann: U.S. Energy Research and Development Administration Rep, Nd;
COO-3493-29(1976), unpublished; F. Plasil: ORNL/TM-6054(1977), unpublished.
W"D. Myers and W.J. Swiatecki: Ann. Phys., 55, 395 (1969).

56

4-13.

Preequilibrium Alpha Particle Emission Following
Heavy-Ion Transfer

React ions

M. Ishihara, H. Kamitsubo, T. Fukuda,*
M. Tanaka,** H. Ogata,*** and I. Miura***In an earlier experiment,1) we studied the alpha particle emission accompanying deep
inelastic (or quasi elastic) reactions by bombarding 93Nb with 90 and 110 MeV 14N ions.

At these

ener;;ies we found that the main source of the alpha particles can be attributed to the sequential
breakup of excited light fragments produced in the primary deep inelastic reactions.

In the present

report, we discuss an extended study of such alpha particle emission at a higher bombarding energy.
The same 14 N + 93 Nb system was studied using 210 Me V 14 N ions from the RCNP cyclotron at
Osaka University .

The light (projectile-llike) fragments were detected at 22° , while the coincident

alpha particles were detected at several angles in and out of the scattering plane.
The results at 210 Me V showed some distinctive differences as compared to those at lower
bombarding energies: 1) The energy integrated angular correlations (Fig. 1) show forward peaked
distributions similar to those for lower energies. However the coincident cross sections aredramatically increased by a factor of 10 - 30. The multiplicity Ma is 0.3 - 0.7 as compared to
Ma of typically 0.05 at lower energies.

2) The contribution from the light fragment breakup isminor, while several indications are in favour of sequential alpha emission from heavy fragments.
100
0Li
6

o
/Y
/ /~ !A ·Be

OB}- c X1/ 5

10

r

0 /

.A

tn

/T /t

Ll
-------

E/ 1A !1/

~
~

i

\:

2

Li

l'~

Be

I~
B

Fig. 1.

The in-plane angular correlations

between alpha particles and different light
reaction products (Li , Be, B, and C) obtainedin the 14 N + 93 Nb reaction with 210 Me V
incident energy. The energy integratedb-------~

coincidence cross sections are plotted as afunction of the alpha detection angle e2 .
The light reaction products were detected at

0.1f)l = 22

0

(j 1

~

- 40

0

+40

0

()2

Department of Physics, Osaka University.

**

Kobe Tokiwa Junior College.

***

Research Center for Nuclear Physics, Osaka University.

= 22°. The solid curves correspond to

the theoretical fits in terms of a "hot spot"
model.

57

These arguments are based on the analysis in terms of three-body kinematics and the systematic
inspection of the energy correlations.
In the past years, a variety of possible mechanisms 2),3) have been conjectured to account forthe coincident alpha particle emission. So far none of them have been able to reproduce the data
quantitatively. In the following we present a comparison of the experimental data with calculated
results essentially based on the Hhot spot" model of Ref. 2. The basic assumptions used for the
calculation are as follows. In the course of the transfer reaction, the hot spot left in the surface
region of the host nucleus rotates about the center of the nucleus by carrying the whole angularmomentum transferred. At the same time the hot spot decays by emitting alpha particles as well
as by relaxing towards the equilibratio.n of the total nucleus.

The relaxation property may be

represented by the time variations of effective temperature T and volume V of the hot spot, thelatter of which is related to the moment of inertia of the hot spot. In the calculation thethree-body Coulomb trajectory and the shadow effect were treated in a similar way as in Ref. 2.
The assumption of the isolated rotation of the hot spot from the rest of nucleus differs from theassumption of the original model 2) that the hot spot and the rest of nucleus are stuck and rotate
together. This assumption produced significant effects in the calculated results, enhancing the
focusing of the alpha particle emission towards the direction of the moving hot spot and eliminating
the influence of shadowing.

1000

C

:::J

~ 100
:.0
~

10

\

Fig. 2.

The energy spectra of alpha particles obtained at different
angles e2 in coincidence with Li and C. The absciisa E 23 represents
the relative kinetic energy of alpha particles in the rest frame of the(a + heavy fragment) system. The solid lines are due to the theoretical
calculation.

Figures I and 2, respectively, depict the comparison between experiment and calculation for
the energy integrated angular correlations and for the energy spectra of coincident alpha particels.
In the calculation the relaxation time of 2.5 X 10- 22 sec for both T and V and the initial
temperature T = 7.0 MeV were used. The overall agreement is fair, suggesting that the model
used can reasonably simulate the undergoing reaction process. The relaxation time deduced is a

58

couple of times larger than the mean free time of the nucleon in the nucleus and may comply
with the typical reaction time of the pre equilibrium process observed in the reactions inducedby light ions such as nucleons and alpha particles.

References
1)
2)
3)

T. Shimoda, M. Ishihara, H. Kamitsubo, T. Motobayashi, and T. Fukuda: IPCR Cyclotron
Report, 46, (1978).
P.A. Gottshalk and M. Westrom: Phys. Rev. Lett. , 39, 1250 (1977).
for instance, D.H.E. Gross and J. Wilczynski: Phys. Lett. , 40, 1074 (1978).

59

4-14. ,-Ray Multiplicity Measurement Following Preequilibrium
a-Particle Emission in 14N-lnduced Reactions

H. Utsunomiya, T. Nomura, M. Ishihara,
T. Sugitate, K. Ieki, and Y. Gono

We reported in our previous papersl) that energy spectra of fast a-particles emitted in
low-energy heavy-ion reactions are well understood as the preequilibrium (PE) decay occurring
before projectile- and target-nuclei fuse completely into the compound nucleus reaching thermal
equilibrium. Using the hot-spot model of PE phenomena,2) the relaxation time of energy was
deduced from the PE a-particle spectra which were strongly dependent on the emission angles.
We here report ,-ray multiplicities following the PE a-particle emission in 14 N-induced reactions inorder to study relaxation of angular momenta.
Self-supporting 93Nb, 116Sn, and 159Tb targets of 3 - 4 mg/cm 2 thickness were bombarded with
14N beam at 95 and 115 MeV from the cyclotron. a-particles were detected with Si
lill-E(50 - 2000 J,Lm) counter telescopes placed at various angles. A 7.5 cm X 7.5 cm NaI(Tl)detector usually mounted at 10 cm from the target and at 90° to the beam in the reaction plane
was used to measure ,-rays. The measurement of angular correlation between a-particles and,-rays was also made in the 93Nb + 14N reaction at Elab = 95 MeV using a 5 cm X 5 cm NaI(Tl)detector placed at 30 cm from the target. An absorber composed of 0.5 mm-Pb, 0.6 mm-Cd, and
1.0 mm-Cu was placed in front of the above two detectors. The overall efficiency il, averaged
over the observed ,-ray spectrum was 2.1 % for the former detector and 0.11 % for the latter.
93 Nb + 14N 95 MeV

Ba=15°

14

~ 12

o

10

••

Ba= 150

•

12
• .
14 0
10

•

••••

12

10

14

~ -s. 10

14

12

10

0

14

%0II 12 • • •~0

8a= 1200 0 0.
DODD
14••

o 45 90 135 180

J::0

Ba= 45°135 180

135 18045

90 135 180

·

45

90

45

90 135 180

12

·

•

•

10

10

8

0

0

14

12

8

o 45 90

0

14

. ·
•
•

10

8

90

•

12

• •

45

135 1808

045

90 135 180

045 90 135 180

~ :D
II 10
-s.

••• •

8

o 45

a..,

90 135 180

8

T

(

degrees)Fig. 1.
angular correlations measured in the 93 Nb + 14 N reaction
at E1ab = 95 MeV. e denotes the angle of a counter with respect to thebeam and ifJ is the angle of the ,-ray counter measured from thenormal direction of the reaction plane.

60

The threshold energy was 100 ke V and 80 ke V respectively.
The ,,-ray multiplicity was determined by the following relation, M"C8 a' Ea) = Ncoin C8 a' Ea)/n"NsingC8a' Ea ), where Nsing and Ncoin represent singles and coincident events, respectively, fora-particles as a function of the emission angle 8a and the kinetic energy Ea' Figure 1 shows
in-plane and out-of-plane a...;y angular correlations, where the z-axis was chosen along the beam
direction and x-axis along the normal to the scattering plane. It should be noted that the
distribution of ,,-rays is almost independent of the emission angle of a-particles and its intensity forout-of-plane Cct> = 0° and 45°) is roughly equal to that for in-plane Cct> = 90°).

Therefore, inorder to discuss relative values of M", it is enough to measure M" at one angle. Hereafter, as thevalue of M", we use the value obtained by the above mentioned 7.5 cm X 7.5 cm NaICTl)
detector. Figures 2 - 3 show the dependence of M" on the kinetic energies CEa) and theemission angles C8 a) of a-particles in various 14 N-induced reactions. It is remarkable that M'" ispractically independent of Ea when measured at the same angle, although it slightly decreases withincreasing Ea especially in the case of the 159 Tb target. On the other hand, M" rapidly decreases
with decreasing emission angles 8a of PE a-particles.
The fact that M" is almost independent of Ea disagrees apparently with the result of theprevious ')'-ray multiplicity measurement 3) in 159 Tbct 4 N, axn')') 169 -x Yb reactions, in which M')' of
a particular residual nucleus decreases remarkably with the increase of Ea' However, thisdifference can be understood in the following way. In the previous experiment we specified thefinal nuclei 169 -x Yb by measuring their discrete ,,-rays with a GeCLi) counter. Then, the values ofM')' are strongly affected by an entry line of a particular residual nucleus, which is really expected
to cause the observed Ea dependence. In fact, the strong Ea dependence on M" is appreciably
weakened if we average M')' values over three dominant reaction channels, i.e., a3n, a4n, and a5n.
Moreover, the solid angle of the a counter in the previous measurement subtended 0.52 sr,corresponding 8a = 15.2° - 28.1°.

Since M')' decreases rapidly Cas noted in the present results)

Fig. 2.
Dependence of theaverage ,),-multiplicity on kinetic

Ecc:,. [ MeV]

energies of emitted a-particles invarious 14 N-induced reactions.
Solid lines show the energyintegrated average ,,-multiplicity,

61

I

95MeV 93 Nb! :! . !
,..'
!.

l3

12
11
10

}f(

9
8
>:~

.

0

a.
:.::;

l3

30

10

60

90

.i.

120 150 180 0

115 MeV 93Nb

L.f.. r t

12
11
9
8

:J

r

60

30

12
11
10

t

9
8

!· i

.!

·f.f: f • r

14
12

30

60

90

120
Bern (degrees )

I

I

f f

·r

9

6
150 180 0

t

·r

10

8

120 150 180

!:"j

11

7

0

90

115MeV 159Tb
l3

l3

I

115MeV 116Sn..

Fig. 3.
Dependence of theenergy-integrated average-y-multiplicity on the emission

H

f
30

I

I

90 120Bern (degrees)

60

I

150 180

angles of a-particles in various
14 N-induced reactions.

and Ea increases appreciably with the decrease of () a' the above large solid angle can also be
considered to yield the apparent Ea dependence on My
The present results (weak Ea but strong ()a dependence on M-y) are consistent with the
hot-spot interpretation of PE a particles. Since the small emission angle () a is considered tocorrespond to the short reaction time as mentioned in the previous papers,1) the relative angularmomenta brought in are not transferred into the internal degree of freedom of the whole nucleus
but are carried by the hot-spot. When the PE a particles are emitted from this hot spot, they
carry away large angular momenta, the values of which are roughly determined by the ratio of
moment of inertia of the hot-spot to that of a particles, which is independent of Ea but strongly
dependent on () a through the size of the hot-spot.

References
1)

T. Nomura, H. Utsunomiya, T. Motobayashi, T. Inamura, and M. Yanokura: Phys. Rev. Lett.,
40, 694 (1978); T. Nomura, H. Utsunomiya, T. Inamura, T. Motobayashi, and T. Sugitate:
J. Phys. Soc. Japan, 46, 335 (1979) ; H. Utsunomiya, T. Nomura, T. Inamura, T. Sugitate, andT. Motobayashi: Nucl. Phys. , A 334 , 127 (1980).

2)
3)

R. Weiner and M. Wesrom: ibid. , A286 , 28~ (1977).
T. Inamura, T. Kojima, T. Nomura, T. Sugitate, and H. Utsunomiya: Phys. Lett., 84B,
71 (1979).

62

4-15.

Relaxation of Angular Momentum Following Preequilibriuma

Emission in Heavy-Ion Reactions

H. Utsunomiya, T. Nomura, M. Ishihara,
T. Sugitate, K. Ieki, and Y. Gono

Two prominent features of the average 'Y-ray multiplicity (M'Y(O)) measured in coincidencewith the preequilibrium (PE) a particles at angle 0 are summarized as follows 1):i) M'Y(O) is small when 0 is small and increases rapidly with the increase of 0, almost
reaching a constant value at backward angles.

ii)

M'Y(O) is almost independent of the kinetic energy of a particles (Ea) measured at thesame angle O.
In this report we try to explain the above features of M'Y(O) from the hot-spot model for PE aemission.
Based on the diffusion model presented by Wolschin and N6renberg,2) the relaxation ofangular momentum is described by the following formula:(1)

Here, M'Y(t) is the average 'Y-multiplicity which is associated with a certain reaction time t, M'Y eq themultiplicity after compound nucleus (eN) formation and 7 e the relaxation time of angularmomentum. From Eqn. (I), we obtainM e q _ M ( ) ex: - t ;r e
'Y
'Y t
e-

J

(2)

which is very similar to the expression for the relaxation of energy discussed in our previous.
papers, 3) I.e.,
T(t)-T eq oc e

- tlr

f,

,

(3)

with equilibrium nuclear temperature Teq and the relaxation time of energy 7 E. We plotted
M'Yeq - M'Y(O) and T(O) - Teq versus 0 in Fig. 1, where T(O) is deduced from an energy spectrum ofa particles at 0 in the same way as in Ref. 3. A remarkable feature is that both M'Y eq - M'Y(O) andT(O)- Teq decay roughly exponentially with the same decay constant J.1 in each reaction.
Inamura et al. have reported that in the 14N + 159 Tb reaction at 95 Me V angular momenta inthe entrance channel leading to the PE (fast) a emission are localized just above the criticalangular momentum for complete fusion. 4) For simplicity, if we assume a definite value La forthe transferred angular momentum, La is expressed by

(4)

63
Multiplicity
Mr'q- Mr

Temperature
T - Teq101095 MeV 93Nb"."!t~i

95 MeV 93Nb

,u =40°,,u = 3r'f{~Q-...

K

·r",·

~
0

0

10

115MeV 93Nb

115 MeV 93Nb,

,u=44°" ·i·i.

"!'!'fJ

iLK.

,u=4f

0

10
'

...

~

"t

115MeV 116Sn

115MeV 1! 6Sn,u = 4r,u=44°'!f~

1
10........•.•'t~·!tj

11
1

115MeV 159Tb~MeV'''Tb ,,u = 53°

lfi~

Fig. 1.

M;q - M,),(e) andT(e) - Teq versus the emission
angle in various 14 N-induced/1 =52

~
0

0

000

0.1
0

30

120
60
90
8em (degrees )

150

0.1
1800

30

60
90
120
8em ( degrees )

150

180

reactions. The decay constantderived from the straight line
is given for each reaction.

where IRis the averaged angular momentum of residual nuclei which is usually related to themeasured M'Y by(5)with constant value of f. fex and fo are the angular momenta carried off by (X-particle and othernucleons like neutron and proton. If we ignor the dependence of fo on 8, we obtain(6)

where fex eq is the angular momentum carried off by evaporation of (X-particle after the compound
nucleus (eN) formation. The present results indicate, therefore, that fex is large at forward
angles and decreases with increasing e with the decay constant J1.
The above feature can be explained by the hot-spot model in the following way. Consider
that the hot-spot sitting in the surface region of the composite system and at distance R from its
center has angular momentum La and nuclear temperature T. Then, the angular momentum f(Xof ex-particle emitted from the hot-spot is roughly given by

where 1(8) is the moment of inertia of the hot spot emitting (X particles at e.

In the same way,

64

(8)
with mass A of CN.

On the other hand, the hot spot has the angular velocity w(O) given by(9)
Combining Eqns. (6) - (9), we can deduce w(8) from the measured values of M-y(O) on theassumption that values of M-y at backward angles are equal to M-ye q
Assuming that the reaction time t is related to w(O) by 6t = 60jw(O), T£ and T€ can be
estimated fromr'""-' r =£ '""-'€

fl1 w(i)
de
.

( 10)

0

Resultant relaxation time and parameters used in the present analysis are listed in Table l.
relaxation time estimated is (4 - 5) X 10- 22 sec.
Table 1

Relaxation time of angular momentum and parameters usedin the present analysis in various 14N-induced reactions.
LC )

Leqd)

0

0'

J1

TR

(h)

(h)

(h)

(degree)(10- 2 2sec)

6.94

34.5

36.5

3.41

40

3.7

38.4

6.94

41.0

43.0

4.02

44

4.4

100.8

44.6

7.29

42.3

44.3

3.41

47

5.2

103.9

54.0

7.83

43.5

45.5

2.63

53

5.3

m

Ecm

Va)
c

Rb)
cr

Lcr

(MeV)

(MeV)

(MeV)

(fm)

93Nb

95

80.8

38.4

93Nb

115

98.2

116Sn

115

159Tb

115

Elab

Targetz z e2

The

R = 1.55 ( A ~ / 3 + A~ / 3)

<J. )

1 2
V=
c - R-

b )

1/3
1/3
R cr = r cr ( A 1 + A 2)

c)

LO = Lcr +- 2

d )Leq = TLO

rcr = 1.0 ± 0.O7

1.Galin et al.: Phys. Rev. C, 2, 1018 (1974) .

4

sA

References
1)

H. Utsunomiya, T. Nomura, M. Ishihara, T. Sugitate, K. Ieki, and Y. Gono: A preceding2)
3)

report.
G. Wolschin and W. Norenberg: Phys. Rev. Lett., i!, 691 (1978).
T. Nomura, H. Utsunomiya, T. Motobayashi, T. Inamura, and M. Yanokura: ibid., 40,

4)694 (1978).
T. Inamura, M. Ishihara, T. Fukuda, T. Shimoda, and K. Hiruta: Phys. Lett., 68B, 51 (1977).

65

5. NUCLEAR PHYSICS
Nuclear Spectroscopy and Instrumentation

5-1.

Recoil-Distance

Lifetime Measurement of States

In

118Xe

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

Lifetimes of several levels in the ground band of 118 Xe were measured with a plunger
apparatus reported before.1)
The levels of interest were populated by means of the reaction 107 Age 4 N, 3n) 118 Xe at anincident energy of 62 MeV. The target consisted of a layer of 400 J.1g/cm 2 107 Ag metal evaporated
onto a 0.9 mg/cm 2 gold foil and the stopper for recoil nuclei was a gold foil 20 mg/cm 2 inthickness. The experimental conditions were similar to those described in Ref. 2.
Some of the ,),-ray spectra obtained at different distance (D) between the target and thestopper are given in Fig. 1. From such spectra a quantity R which was defined by R = 10 /(10 + Is) was determined, where 10 is the intensity of ,),-rays emitted after the recoil nuclei
have been stopped in the stopper and Is is the intensity emitted in flight. Values of 10 and Is
were estimated from least squares computer fits of appropriate parts of the ')'-ray spectra. Some
decay curves giving R versus D, obtained from the analysis, are shown in Fig. 2. The mean
velocity of the recoil nuclei was determined to be 0.0087c from the difference in centroid
energies of shifted and unshifted ')'-rays.

OL--l-l-'-oo,-----1 J~1'5----:0---:0 --1--,l-610::-::-0-----i:!)-l.1'-:-:90:-::"O-2 O-,LO'-'-I "JW\~~~-2l-'-O--!O"'}-------,2 -'-30--0-~
2 4--L:O-,O-- 2-:l-:50:-::"
O-----,-2 -:l-:60=O----'-

ChannelFig. 1.

Spectra for the 107Age4N, 3n)
separations.

118

Xe reaction, taken at several target-stopper

66

11

I'~

"no

2+~0+

0.5

~
8'~6'

lfn

01
0.05

Q

Q

I

~

; 11 j~~II I
lO'~8'

. t

01

I

i
I

~

01

6+~4 +

0.05 -

0.05

20

40

60

80

100

120 500 1500
1000

Fig. 2.
Measured and calculated decay curves for several transitions in 118Xe.
The solid lines are the results of the fitting procedure.
In order to extract the lifetimes from the function R(D), we have used the nearly same
method of correction and the error analysis proposed by Strum et al. 3)

Corrections for side-

feeding transitions were not included in the present analysis.
The lifetimes obtained in the present experiment are shown in Table 1. The value for 2+
state is in agreement with the value reported in Ref. 4, while that for 4+ is not.
Table 1.

Lifetimes of levels in 118 Xe.

Transition

EnergyLifetimes (ps)present expo

2+-0+
4+- 2+
6+-4+
8+ - 6+
10+ - 8+

337.3
472.8
586.4
676.7
74l.5

66.6 (3.9)
9.48(1.77)
4.77 (0.25)
4.42 (0.16)<2.3

Ref.. 469 (5)
17 (4)<5

References
1)

T. Katou, H. Kumagai, Y. Tendow, Y. Awaya, and A. Hashizume: IPCR Cyclotron Progr. Rep.,

11., 85 (1977).
2)

T. Katou, H. Kumagai, Y. Tendow, Y. Awaya, and A. Hashizume: ibid, 12,68 (1978).

3)
4)

R.J. Strum and M.W. Guidry: Nucl. Instr. Meth., 138, 345 (1976).
A.M. Bergdolt, J. Chevallier, J.C. Merdinger: Proc. Intern. Conf. on Nuclear Structure, Tokyo,
p.359 (1977).

67

5-2.

y-Ray

SpectroscopyIn

the 144Nd+ 20Ne Reaction

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

When medium weight nucleus 144Nd is bombarded with 2oNe-ions in the energy range between
100 and 150 Me V, the dominant types of reactions are complete and incomplete fusions, and many
reaction residues are produced in the mass range from 159 to 160. Though this experiment was
initially designed to study high spin states of 160Yb excited by the eONe, 4n) reaction,1) the origins
of many ')'-rays emitted from other reaction products were determined.
A 97.8 % enriched 144Nd target of self-supporting metalic foil of 26 mg/cm 2 in thickness wasbombarded by 100 to 150 MeV 20 Ne-ions.

Th~ prompt ,),-rays and those from short-liferadioactivities have been measured by Ge(Li) detectors. The ,),-ray spectra from short-life
activities were observed about 3 ms after the activation of I ms for each modulation cycle of theion source.
When 144Nd was bombarded by 100 Me V 2oNe-ions, the ')'-rays from radioactive nuclei of
16oYb, 161 Vb, 16oTm, 161Tm, 161 Er, and 160 Ho were observed. 160Er is also expected to be
produced by the eONe, 0') reaction or as decay product of 160Tm(9.2m), but there is no means todetect it by ')'-rays because no ,),-ray is emitted in electron capture decay of 160Er.
The decay scheme of 161 Yb has not yet been established. Only 599.8 and 631. 5 ke V andother three ')'-rays have been reported. 2) The observed ,),-ray energies and intensity ratio are ingood agreement with the above reported values. The half-life (4.2m) was also in agreement within
the experimental error. Figure 1 shows the yield of the above two ,),-rays as a function ofincident energy. Because of thick t.arget, the activity was saturated after it reached a maximum atabout 125 Me V of 2oNe-ions. The existence of 161 Yb activities in reaction residues confirmes thefirst observation of ( 2o Ne, 3n) reaction in this mass region, though this type of reaction has beenrecognized in 116Sn + 2oNe.3)

The excited states in 161 Yb are not well known though there has
been reported 232 keY de-exciting ,),-ray from 17/2+ state to 13/2+ state. 4) The 232 keY ,),-rayin prompt spectrum does not show the excitation feature of ( 2o Ne, 3n) reaction as expected,
indicating that this ,),-ray is probably contaminated by that from ( 2o Ne, 4n) reaction residues.

161

Yb

599.8keV!_ _ _

0.5

If/i- •

~

-0

Q)

>=

I--I--!--I-

1.0

1
,

I-

631.5keV.....Io9~0----~----~----~--~~----~--~----~160

Fig. 1.

Relative yield curves of 161 Yb takenwith 599.8 and 631.5 keY ')'-rays.

68

Figure 2 shows the yield curves of 160 Yb (4.8 m) produced by 144NdeoNe, 4n) reaction
obtained by measuring with 173.7 and 215.5 keY 'Y-rays and the dashed line shows the excitation
function taken by prompt 636.3 keY (10+ - 8+) ,),-ray in 160Yb, normalized to the same value as
If the half-life of {3- or electron capturethat for 215.5 ke V ,),-ray at 110 Me V of incident beam .

decay is short compared to the time for taking in-beam prompt 'Y-ray spectrum, the excitation
function taken with the prompt ,),-rays and the yield curve of radioactivity as a function ofincident beam energies should have the same character.

The curves in Fig. 2 show this feature.

40 ~-------------------------'

160Yb decay

173.2keV

/'---

30

-0

~

>-

I

20

L

e

--

160 Yb/ ' I ' \ 636.3keV. /i~.~~\

10

~.

-

215.5keV \Fig. 2.
160Yb.

/ i

/

i/'

the excitation function taken

Oe~__~__~__~__~~__~__~

100

110

Relative yield curve of
The dotted line shows

120

130

140

with 636.3 ke V (10+ - 8+),),-ray in 160Yb.

160

Two ')'-rays 166.1 and 177.0 keY are reported for the decay of 159Yb (1.7 m).5)

Figure 3shows the yield curves of 159Yb taken with these ')'-rays. These curves keep nearly the samecharacter as the excitation function taken by 447.4 ke V de-exciting ,),-ray in 159Yb (Fig. 4).
These results confirm the results of Gromov et a1. 5) De Boer has reported 173.9 and 215.7 keY')'-rays from 158Yb or possibly 159Yb.6)

Our results exclude the possibility that these ,),-rays are

emitted from 160Yb decay.
159Yb decay

159Yb

20

20

10

10

447.4 keV

OL-__~__~__~~__~__~~~~~

OL-__~__~~__

90

90

100

110

120
E20Ne

Fig. 3.
159Yb.

160

L -_ _~_ _~_ __ _~_ _~100( MeV )

Relative yield curve of/f---I. . . .

l30
Ezo:-leFig. 4.

(MeV )

Excitation function of 159Yb

taken with 447.4 keY prompt ')'-ray.

160

69

References
1)

2)
3)
4)

A. Hashizume, T. Katou, Y. Tendow, and H. Kumagai: IPCR Cyclotron Progr. Rep., .!1, 74(1978).
I. Adam, G. Beyer, M. Gonusek, K. Gromov, K. Zibert, U. Kalinnikov, A. Liatuszynskii,
S. Strusny, and M. Yakhim: Izv. Akad. Nauk SSSR, Ser. Fiz., 38, 1572 (1974).
I. Skokev: ibid., 42, 777 (1978).
D. Sarantites, J. Barker, M. Halbert, D. Hensley, R. Dayras, E. Eichler, N. Johnson, andS. Gronemeyer: Phys. Rev., C14, 2138 (1976).

5)

K. Gromov, M. Honusek, I. Penev, H. Siebert, J. Zuber, A. Latuszynski, A. Potempa, and6)

K. Zuber: Acta Phys. Polo., B8, 317 (1977).
F. de Boer, M. Cardoso, P. Goudsmit, P. Koldewijn, J. Konijin, and B. Meijer: CERN 70-30,
l, 937 (1970).

70

5-3.

In-Beamll'-,y- Spectroscopic Study on 214Rn

Y. Gono, K. Hiruta, T. Nomura, M. Ishihara,
H. Utsunomiya, T. Sugitate, and K. leki

The ground state a-decay has for a long time been studied to obtain informations on nuclear
masses as well as on the characteristics of the levels. The recent development of the heavy ion
accelerators has made this kind of experiments more important for the study of the nuclei which
locate far from the ~-stability line. Several years ago, Nomura et al. performed the pioneer workon the a-decay from the short lived isomer in 216 Ra appling the in-beam spectroscopic techniques. 1)
Recently Lieder et al.~)reported on the a-decay from the 8+ isomer in 212po using a 6E - E
counter telescope to identify the reaction channel 207 Bi(a, p)212 Po.
In this experiment, the latter technique was applied to the heavy ion induced reaction. The
nucleus 214Rn could be easily reached by specifing a reaction channel of 208Pb( 12 C, axn)216 -x Rn.
An enriched target 208Pb of about 1 mg/cm 2 was irradiated with 79 MeV 12C beam fromthe IPCR cyclotron. The emitted charged particles were detected by a 6E - E counter telescope
which consists of two 450 mm 2 annular Si surface barrier detectors of 50 J.Lm and 2000 J.Lm
thickness. A 100 J.Lm AI-foil was placed in front of them to stop the scattered beam. Those
were set at about 40 mm from the target. Another Si surface barrier detector of 200 mm 2 and1000 J.Lm thickness was set at 150° and 50 mm apart from the target to detect the discrete a-lines
from the product nuclei. The 'Y-rays were also measured with a 70 cm 3 Ge(Li) detector at 90°
in coincidence with the charged particles which were detected by the counter telescope.
The discrete a-lines observed in this work are listed in Table l. The a-ray energies of 10.48
and 10.66 Me V are higher than those of the ground state a-decay in this mass region. Hencethey must be the a-decay from the excited states. They are assigned to the a-decay from the(6+) and (8+) states in 214Rn to the 0+ ground state in 21Opo based on the following facts: (i)Those lines were observed in coincidence with the continuum a-particles.
Table l.

(ii) The a-particle

Energies and intensities of the discrete a-lines observedin the 12C + 208Pb reaction. (E = 79 MeV)

Reactionchannel

Product
nucleusEala(in the total projection
spectrum)

8 Be
a2n
p4n
a2n
a2f1

212 Po
214Rn
215Fr
214Rn
214Rn

8.798
9.037
9.345
10.48
10.66

46
100 (100)a)23
4.7 (2.2)a)4.6 (4.3)a)a) Intensities in the continuum energy a particle gated discrete a-particle spectrum.

71

emission channel in this reaction is dominated by the 208Pb( 12 C, a2n)214 Rn channel since thetotal continuum a-particle energy spectrum was well reproduced in shape by the spectrum
observed in coincidence with the 9.037 Me Va-line which had been known as the 0+grd e14 Rn)~ 0+grd e10 Po) transition. (iii) Furthermore those energies of the two a-lines fit well to thosetransition energies which were obtained after the construction of the level scheme of 214 Rn
using the 'Y-rays data. The level scheme of 214 Rn could be constructed taking the 'Y-rays whichappeared prominantly in the spectrum in coincidence with the continuum a-particles and is shownin Fig. 1. Level schemes of 212 Po(Ref. 2) and 216 Ra(Ref. 1) were also reffered in its construction.
The half-life of the (8+) state in 214 Rn was deduced to be 7 ns using the time spectra between
these 'Y-rays and the continuum a-particles.
Preliminary analysis was performed to obtain the reduced a-decay width 'Ya 2 for the
a-transition from the (8+) state in 214 Rn. The penetrability factor was calculated after
1 626
1423

14.2ns (8 +)1355.81132.97.0ns ( 8 +)
182
(6 +)

1 444

(6 +)

302
1 142

4+

( 4 +)
475.5

446
696

2+

(2 +)

687.9

696

o

0

0+
214Rn

~
+
21OpO
Fig. 1.

11.0610+

Lillfo+212Rn

Level schemes of N = 128 isotones 212po(Ref. 2), 214Rn, and 216Ra(Ref. 1). Levels and the a-decays from the excited states in 214Rn are
resulted from the present work. The a-decay energies are given by Qa-values .

.----

.-

•

g-g

Fig. 2.
The reduced a-decay widths 'Ya2 fora-transitions in N = 128 isotones.

72

Rasmussen's paper. 3) The present result is shown in Fig. 2 as well as those of the decays of
8+e 16 Ra), (8+)e 12 po) and the ground state a-decays of these nuclei.
The reduced widths 'Ya 2 of the 8+ ~ 0+ transitions are smaller than those of the 0+ grd ~0+ grd transitions for these nuclei.
The reduced widths 'Ya 2 of the 8+ ~ 0+ transitions decrease as the atomic number increases
for these N = 128 isotones in contrast to the increasing tendency of those of the 0+grd ~ 0+ grd
transitions in these nuclei.

References
1)

2)
3)

T. Nomura, K. Hiruta, M. Yoshie, H. Ikezoe, T. Fukuda, and O. Hashimoto: Phys. Lett.,
58B, 273 (1975).
R. M. Lieder, 1. P. Bibelez, H. Beuscher, O. R. Haenni, M. Miiller-Veggian, A. Neskakis,
and C. Mayer-Boricke: Phys. Rev. Lett., 41,742 (1978).
1. O. Rasmussen: Phys. Rev., 113, 1593 (1959).

73

6.

ATOMIC AND SOLID-STATE PHYSICS

6-1.

X-Rays Following Multiple Inner-Shell Ionization (4)Y. Awaya, T. Katou, H. Kumagai, T. Tonuma,
Y. Tendow, K. Izumo, T. Takahashi,
A. Hashizume, and T. Hamada
The spectra of Mo, Ag, and Sn L X-rays induced by N-ions and He-ions were measured byusing a Bragg crystal spectrometer.1) There are few reports on heavy-ion-excited L X-rays fromheavy target atoms. 2)-4)
A flat crystal of Ge( Ill) was used for Mo and Ag L X-rays and that of LiF(200) for Sn L
X-rays. The incident energy of projectiles ranged from 4.8 MeV/amu to 8.2 MeV/amu. The
detection of X-rays was made by using a side-window gas flow type proportional counter with a
I ~m polypropylene window operated at atmospheric pressure using a mixture of 90 '% argon and
10 % methan~ gases. The integrated beam current was kept constant at each angle and the2spectrometer was controlled automatically. The thickne.ss of target foils was about I mg/cm for
A:g and Sn and about 3 mg/cm 2 for Mo .
Some examples of L X-ray spectra are shown in Figs. I and 2. The arrows with the symbol
L m Mn a show the positions of peaks with m L-shell and n M-shell vacancy configuration in theE ( KeVl

3.6

34
I
If)

~~
Ag

15000 -

e

ccii

a

~

~

d

eNG

lo<;t (\JO

IIjI

IIII

jj j IIII j

~
---1

(\J

--'

---1

Fig. 1.

Mo L X-ray spectra excited by

N- and He-ions. The incident energies areshown in the figure.

74

E(KeV)
2.6

25

24

23
I

I

ci

Mo

a

c:~
-.J

c~

-.J

c~

15000 c-<t

I I I j I
t,
\

f\

CQ
r0
(f)

D
0

c

r0

~

---.J

0

CQ
-.J

a

)lVI'

~

.

N---.J

I

---.J

0'

~ ~ ~ ~ j j---.J10000 c-

N

~

'

i

I,

\'
Ii

(f)

C
::::J
o

U

Fig. 2.
28 (deg)

Ag L X-ray spectra excited by

N- and He-ions. The incident energies
are shown in the figure.

initial state predicted by Hartree-Fock-Slater calculation. S) Symbols a and (3 denote that the lines
are the satellites of La and L(3 lines, respectively. In the L X-ray spectra of Ag, which are shownin Fig. 2, a broad unresolved peak corresponding to double L-shell electron vacancies is observed.
This may be the first case in which the L2-lines are observed clearly. This peak was observed for
Sn also. The broadness of the peak is mainly due to the fact that there are three L sub-shells.
Besides this combination of two L-shell electron vacancies, multiple M-shell electron vacancies
contribute to this peak. The satellites of L(32, 15 are also observed for Ag. Symbols Ljabs(j = 1, 2, 3) denote the Lrabsorption edge and ArKabs denotes the K-absorption edge of Ar gas
used in the proportional counter.
The results of analysis of La satellite lines will be reported elsewhere in this volume. 6)

References
1)

2)
3)

Y. Awaya, Y. Tendow, H. Kumagai, M. Akiba, T. Katou, and T. Hamada: IPCR Cyclotron
Progr. Rep., 2, 79 (1975).
H. Kumagai, Y. Awaya, Y. Tehdow, T. Katou, and M. Akiba: Reports I.P.C.R., (in Japanese),53, 153 (1977).
D. K. Olsen, C. F. Moore, and P. Richard: Phys. Rev. A, 2, 1244 (1973).
P. G. Burkhalter, A. R. Knudson, and D. J. Nagel: ibid., p. 1936.

75

4)

Y. Awaya, K. Katou, H. Kumagai, T. Tonuma, Y. Tendow, K. Izumo, T. Takahashi,
A. Hashizume, M. Okano, T. Hamada, and S. Ozkok: IPCR Cyclotron Progr. Rep., !l, 79(1978).

5)

F. Herman and S. Skillman: Atomic Structure Calculation (Prentice-Hall. Englewood Cliffs,
N.J., 1963).

6)

Y. Awaya, K. Izumo, T. Tonuma, T. Katou, Y. Tendow, H. Kumagai, T. Takahashi,
A. Hashizume, and T. Hamada: IPCR Cyclotron Progr. Rep., 11, 76 (1979).

76

6-2.

Systematics In Mu Itiple

Ion ization

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

It has been found that the ionization probabilities of L-shell and M-shell electrons in multiple ionization canbe fitted to the theoretical universal curve by choosing an appropriate scaling factor. In this analysis, in addition to
the previously obtained results in our experiments,I)-3) newly obtained data on the Mo, Ag, and Sn L X-rays 4) andon the Kr K X-raysS) induced by N ions were included.

The experimental conditions are summarized in Table I,

where the target elements, projectiles and their energies are listed.
Table 1.
X-raysSummary of target elements, projectiles and energies.

Target element

Projectile

Al, Ti, Cr, Fe,

N

84

N
C

66 , 71, 84, 95, 108
61 , 72, 81

N

66 , 68, 70, 74, 78, 82

Energy (Me V)

Ni, Kr, YIi
KAr

83 .5, 86 , 107,110
Ti

He, C, N, 0

Y

N

84

Mo, AgN84, 95 , 115(Ag only)SnN

84, 115

Y, Mo, Ag, Sn

He

24 or 19

6 MeV/amu

L

The cross se9tion of simultaneous m K-shell and n L-shell ionization, 0mK , nU has been obtained byextending the impact parameter formulation for the single ionization both through the BEA (binary encounter
approximation) theory 6) and the SCA (semi-classical approximation) theory. 7) The expression becomes as follows
when each electron shell is considered to be independent:

where PK(b) and PL(b) are the probabilities per electron for ionization of the K-shell and L-shell electrons,
respectively, and b is the impact parameter.

In this expression, the probability for ionizing L-electrons is assumed

to be the same for all sub-shells. In the region where PK(b) is not zero, PL(b) is almost constant and can be
replaced by PL(O). Then the cross section for single K-shell and n L-shell ionization is reduced too 1 K , nL =(~l { P L ( 0 lY { 1 - P L(Or -where OK is the ionization cross section of K-electrons. Thus
binomial distribution.

n OK '°lK nL is approximately represented by the'

In the case of single L- and n M-shell ionization, the formula of the binomial distribution becomes

(2)

77

18 {
}n {
} 18 -n
GIL,nM =( n)PM(O)I- PM (0)
GL .

(3)

Hereafter, the ionization probability, PL(b) or PM(b) will be replaced by Pneb), where n denotes the principal
quantum number of electron shell under consideration. P n(b) is approximated from the calculated ionization
cross section of n-shell electrons, an ' of BEA 6) asb ~ R,(4)=0b > R,

by assuming proper range R for the impact parameter, where N is the number of electrons in the shell underconsideration.
Experimentally, the PL(=P 2) values are obtained by fitting the Ka X-ray data to the binomial distribution.
Some of them were reported already, though the scaling factor different from the present one was adopted.l),~)The PM(=P 3) values are also obtained by applying the same method to La satellites. We suppose this is the firstcase where the binomial distribution analysis has been applied to single L-shell and n M-shell ionization.
In this analysis, it was assumed that the fluorescence yield is the same for all satellite lines and that there
is no outer-shell rearJangement priQr to the decay of the K vacancy for K X-rays and that of the L vacancy
for L X-rays. We estimated the fluorescence yield for each satellite configuration of Ti, Cr, and Ni K X-raysby using the calculated values of radiative transition probability and those of Auger transition probability. 1)
When we take the fluorescence yield into account, the P L value becomes about 8% smaller for Ti and about 3%
smaller for Ni. Since the estimated error for PL or PM values is between 10 to 15%, the change of the value
by inclusion of the fluorescence yield is within the limit of error. The assumption as to the rearrangement was
confirmed by the work made by Schmiedekamp et al. 8)
The P L and PM values thus obtained are shown in Fig. 1 for various target elements and projectiles. The
points giving P L and those for PM lie in different region separated by the dash-dotted line. Vi is the velocityof the projectile and V n is the velocity of n-orbital electron. The broken line is drawn only to indicate thepoints of P L obtained by 84 MeV N-ion bombardment.
+

"b6
CD

•

N-84MeV6/ 4 - - - - - - - - - - - ..

•

0 15

0

/

/

{:,

D.--

•

/0

0

0='

/',

6

PL

/

010 / +'

/

)

,{i)

/

Kr

Ni
Fe

+N

Cr

/',

Ar

~

Ai

0

Ti + C
Ti + 0

CD

•

0

C-

I.
x //

~

y

• Ti

/
I

~
/

::E

...
x

__

-

-- - - - - -

0E!)

0

ffi

PM

.

@

8
~

~

~oAg 1

+N

Sn

005

o

2

3

4

5

6

Vi/ V n (n=Lor Ml

Fig.!. Experimental PL and PM values vs. scaled velocity_
Target elements and projectiles are shown in the figure.
We tried to find a universal law concerned with these values by use of a proper scaling factor. Thisscaling is derived from the formula given by McGuire and Richard 6) on the basis of BEA. According to them,Gn = ( N Z1

2

G

0 / un2)

G(V) ,(5)

where Z 1 is the atomic number of the projectile, a 0 = 1Te 4 , un is the binding energy of the electrons in the
n-orbit and G(V) is a universal function of scaled velocity, V = Vi/V n. We adopted the Gerguoy-Vriens-

78
By assuming that R = V2a in Eqn. (4) and (Zeff/n)2 = un/Ry, where a = n 2a /Z ff' a beingo eoBohr radius, Zeff being the effective nuclear charge for the n-orbit and Ry = 13.6 eV, we can derive the relationof Pn to G(V) as
Garcia's G(V).

(6)
The k is a C0nstant which represents a o/(2rra 2Ry).
o
The result is shown in Fig. 2. We used the averaged binding energy over sub-shell. The calculated
theoretical universal curve by BEA shown in the figure reproduces the experimental results fairly well. When
we multiply the calculated value by a factor of 0.84, fit is better to the points for P values, and a very goodL
fit is obtained for PM values by mUltiplying by a factor of 1.25.
1.0 r--- - - -- --05----------,-BEA

n=2 (U

C"N

-""

"-

oj 0 .1

.
+
x

...

c

0

005

•

6

...
o
'.D
®

o

y
Kr
Ni
Fe
Cr
Ti
Ar
Ai

+N

Ti + C
Ti + 0T i t Hen =3(M)

o
"' Mo
Y

o Ag
Ii> Sn1+ N

Fig. 2. Scaled PL and PM' and theoreticaluniversal curve vs. scaled projectile velocity.

This may explain that the value of R used in the calculation is a little too small for L-shell and a little toolarge for M-shell. By the correction of R of about 10%, that is by taking R = 1.09 X V2 a for the L-shelland R = 0.9 X v'2 a for the M-shell, we get the factors mentioned above. The difference in the correction factor
between L-shell and M-shell wUI be reduced to the difference between the pattern of P(b) plotted against b.
Since the value of n 2un is proportional to Zef? ' the present scaling can also be represented by(7)

References
1)
2)
3)
4)
5)
6)
7)
8)

Y. Awaya, K. Izumo, T. Hamada, M. Okano , A. Hashizume, T. Takahashi, Y. Tendow, H. Kumagai,
T. Katou , and T. Tonuma: IPCR Cyclotron Progr. Rep., 11, 93 (1977).
Y. Awaya, T. Katou, H. Kumagai, T. Tonuma, Y. Tendow, K. Izumo, T. Takahashi, A. Hashizume,
M. Okano, T. Hamada, and S. Ozkok: ibid, 12, 79 (1978).
T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, I. Kohno, and S. Ozkok: Phys. Rev. A, 20, 989 (1979).
Y. Awaya, T. Katou, H. Kumagai, T. Tonuma, Y. Tendow, K. Izumo, T. Takahashi, A. Hashizume, andT. Hamada: IPCR Cyclotron Progr. Rep., 13,73 (1979).
T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, I. Kohno, and M. Kase: ibid., 11,82 (1979).
J.H. McGuire and P. Richard: Phys. Rev. A,~, 1374 (1973).
J.M. Hansteen and O.P. Mosebekk: Phys. Rev. Lett., 29, 1361 (1973).
C. Schmiedekamp, B.L. Doyle, T. J. Gray, R.K. Gardner, K.A. Jamison, and P. Richard: Phys. Rev. A,
18, 1892 (1978).

79

6-3.

Contribution of Electron Transfer to K-Shell
7

Ionizations by N + -Ion Bombardment

M. Kamiya, A. Kuwako, M. Sebata, K. Ishii,
S. Morita, Y. Awaya, and T. Tonuma

Until now, the cross sections of electron-transfer from the K-shell of target atoms to theincident ions have been obtained from the difference of ionization cross sections between a fullystripped ion and a low-charge state ion.

But, in this method, a gas target 1 ) or an extremely thintarget 2) must be used, and it involves experimental difficulty.

Here we use a thin solid targetand derive the electron-transfer cross section from the ratio of ionization cross sections for N7 + ions and a-particles assuming the validity of PWBA including Coulomb deflection, increased-binding
and polarization effect 3 ) (PWBA-CBP) at high energy where increased-binding and polarization
effects cancel each other.

Since few measurements of electron transfer have been carried out by

heavy-ion bombardment at high energy, our aim is to measure the electron-transfer cross sectionsin this energy range in order to test the validity of existing theory.
5,6, and 7 MeV/amu N 4 + -ions and a-particles were accelerated by the cyclotron.

N 7 + -ions

10 - 30 Ilg/cm 2

were selected by a switching magnet after passing through 150 Ilg/cm2 Al foil.

targets of 20 Ca, 21 Sc, 22 Ti, 23 V, 24 Cr, 26 Fe, and 28 Ni were prepared by vacuum evaporation onto
about 30 Ilg/cm 2 Al backings. Before the heavy-ion-excitation, Ka and Kf3 spectra were taken byfluorescence excitation and the drift of amplifier gain was frequently checked by using a 57 Co
X-ray source.
Since the target thickness was not measured yet, absolute cross sections for a-particles were
determined from interpolation of published ionization cross sections 4 ) of Ca, Ti, Fe, Co, and Ni
for 5, 6, and 7 Me V protons.

The errors were estimated to be '"" I 0%.

In the case of N7 + -ionbombardment corrections of fluorescence yield due to multiple ionization was made according
to Larkins' method using L vacancy number determined from the energy shifts of Ka and Kj3lines.
Ionization cross sections for a particle agree well with PWBA-CBP, while those for N7 + -ionexceed the theoretical values and the energy dependence is different from the theoretical prediction
as is seen in Fig. 1.

This discrepancy can be attributed to the electron transfer.

cross section ratios for N7 + -ions and a-particles are shown.

In Fig. 2 theWe define the cross section ratio as

where aN and a ~ are ionization cross sections for N7 + -ions and a-particles, respectively, and D
and C refer to direct ionization and electron transfer processes, respectively.

O Ne= ( R ex p -RP WBA- C BP).O a.

Then we obtain80

K-shell ionization

10 5 -

Ca

l.8

2-

2-

16 -

2

~------ - ------------

::;-

Ca

14

w'

l. 2

v
10
~
0.8
"O'l

10'

~

a

X
~

16

~

l.4
12

10 5

v

_ _ __

~

/

l.0
0.8
14

Fe

12

_!---------/ ~--------Fe

10
a

0.8
5

6

Energy (MeV / amu )Fig. l.
K-shell ionization crosssections in N 7+ -ion and a particle
bombardment of Ca, V, and Fe.
The dashed lines show the
PWBA-CBP calculation and thesolid lines include , in addition,
electron transfer process.

10

3

4

5

6

789

Energy (MeV / amu)

Fig. 2.
The ratio of ionization
cross section in N 7+ -ion anda particle bombardment of Ca, V,
and Fe. The dashed lines show
the PWBA-CBP calculation and thesolid line includes, in addition,
electron transfer process.

Figure 3 shows that the electron transfer cross section decreases much faster, as the incident
energy increases, than the prediction from Brinkman-Kramers approximation including Coulomb
deflection and increased binding energy effects developed by Lapicki and Losonsky.5) Though
it is expected that two-center atomic expansion method is appropriate for the region Vi IV k ~ 1,
where Viand Vk are velocity of the incident ion and target K-electron velocity, respectively, we
cannot obtain the calculated results.
For N7 + -ions the ratio Kl3/Ka is 0.16 - 0.17 for all the elements investigated. The energy
shift of Ka is constant, while that of K{3 gradually decreases as the incident energy increases

81

K- electron transfer

Ca

10 5

~
2

10 5
.D

b

Energy shi ft of K X - rays

150 -

I

V

~2--~

'-':.:

(eV )

---

K~

100

10'

I

f
Fe

10' -

/ !

50

1 1

1

1

Ka

o 20
Energy (MeV/ amu )Fig. 3.
Cross sections for electrontransfer in N 7+ -ion bombardmentof Ca, V, and Fe. Solid lines show
the theoretical values.

21

22

23

24

25

26

27

28

Atomic number

Fig. 4.
Averaged energy shifts of
KQ and K{3 lines in N7+ -ionbombardment.

according to the decrease in L-shell ionization probability for Vi /VL > 1, where VL is the Lshell electron velocity averaged over subshells. KQ and K{3 energy shifts for N7 + -ions averaged
over incident energy is shown in Fig. 4.

References
1)

F. Hopkins, R. Brenn, A.R. Whittemore, N. Cue, V. Dutkiewicz, and R.P. Chaturvedi: Phys.
Rev., AI3, 74 (1976).

2)
3)
4)

H. Tawara, P. Richard, T.1. Gray, J. Newcomb, K.A. Jamison, C. Schmiedekamp, and 1.M.
Hall: ibid., A18, 1373 (1978).
G. Basbas, W. Brandt, and R. Laubert: ibid., A17, 1655 (1978).
G.A. Bissinger, J.M. Joyce, E.1. Ludwig, W.S. McEver, and S.M. Shafroth: ibid., AI, 841

5)(1970); R.B. Liebert, T. Zabel, D. Miljanic, H. Larson, V. Valkovic, and G.C. Phillips: ibid.,~~, 2336 (1973); R. Akselsson and T.B. Johansson: Z. Physik., 266, 245 (1974); F.
Hopkins, R. Brenn, A.R. Whittemore, J. Karp, and S.K. Bhattacherjee: Phys. Rev., All,
916 (1975).
G. Lapicki and W. Losonsky: Phys. Rev., A15, 896 (1977).

82

6-4.

K X-Rays of Kr Measured with a Crystal Spectrometer

T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai,
M. Kase, and I. Kohno

The spectra of Kr K X -rays produced by ion collisions were measured with a crystal
spectrometer equipped with a LiF(200) crystal and a scintillation counter.I)
He- and N-ionswi th energies of 6 Me V/ am u were used to born bard Kr gas contained in a gas cell.
Figure 1 shows the Ka and KI3 spectra obtained by measuring the second order reflectionin the Bragg condition when the Kr gas pressure was 270 Torr. The Ka spectrum obtainedby N-ion bombardment had an insufficient energy resolution but it was found that the spectrum
had some satellites in contrast to that obtained by He-ion bombardment. The Ka spectrum
obtained by N-ion bombardment was resolved by the least square fitting of the multiple
Gaussian curves and the probability of single ionization for L-shell electrons PL(O) was found to
be about 0.08 for Kr.
E ( keV )" ":::s::::::.::::IIE ( keV )14 8 144 140
~

6000

;

::::.::::::::.::::

I j_I:ttot:r:t

6000

NIO~

10000 -He - Ion

if)

C

~

0

u

:::S::::::.::::

4000

5000

9000

Fig. 1.

4 000-.l-.l

if)

C

~

J

I

I

0

u
2000

7000

1

49 50 51 52
28 ( deg )He- ion6000
28 ( deg )Energy spectra of Kr K X-rays produced by 6

MeV/amu He- and N-ions.

°

In the KI3 spectrum obtained with N-ion bombardment, KL 13 and KL 113 peaks wereobserved.
The energy of KLol3 line is about 38 eV higher than that of K13 1 line induced by
He-ion bombardment. The energy difference between KLol3 and KL 1 13 is about 90 eV, which
agrees with the value obtained by extrapolating X -ray energy difference data of the solid targets
under the 6 MeV/amu N-ion bombardment with respect to the target atomic number.I)

83

The KLn l3(n ~ 2) satellites were not observed because the energies of those satellites are above
the absorption edge which is shown by the arrow denoted as Kabs in Fig. 1.

Reference
1)

Y. Awaya, M. Akiba, T. Katou, H. Kumagai, Y. Tendow, K. Izumo, T. Takahashi, A.
Hashizume, M. Okano, and T. Hamada: Phys. Letters, 61A, 111 (1977).

84
6-5.

K X-Rays of Kr Measured with a Si(Li) Detector

T. Tonuma, Y. Awaya, T. Kambara,
H. Kumagai, M. Kase, and I. Kohno

K X-rays of Kr produced by 6 MeV/amu He-, N- , and Ne-ion bombardment were measured
with a Si(Li) detector as a function of Kr gas pressure. 1) Figure 1 shows KO' and K{3 spectra of
Kr obtained by He- and N-ion bombardment when the Kr gas pressure was 155 and 150 Torr,
respectively.
Figure 2 shows the ratio of K{3 to Ka X-ray yields IK{3/IKO' of Kr as a function of Kr gas
The measured intensity ratio IK{3/IKa induced by He-ion bombardment is almostpressure.

independent of gas pressure.

On the other hand, the ratios for N- and Ne-ion bombardment

decrease with increasing gas pressure and the decreasing rate of the ratio for Ne-ion is larger thanthat for N-ion bombardment.

The gas pressure dependency of IK{3/IKO' can be explained by thenfact that K{3 X-ray spectra induced by heavy-ion bombardment have satellites KL {3 and thenenergies of some KL (3(n ~ 2) satellites are above the K-shell absorption edge.

The self-absorption

in the target gas makes K{3 X-ray yields decrease as described in the preceding paper. 2)
KLn (3 X-rays are emitted by the transition of a M-shell electron to K shell when single K-shelland n L-shell electrons are ionized simultaneously by heavy ion-atom collisions.
1o5 , . - - - --

-

-

-

The decrease of-------,

Ka

10'

022 ,.-- --- - - - - ----- -- --.,

(f)

C

:::J

o

U

N- ion2

10
He - ionj

10 ~-L
10,.-------J..12-------14------I
16
1

Energy ( keV )Fig. 1.

KO' and K{3 spectra of Kr

induced by 6 MeV /amu He- and N-ions .

012 0l:------~10!:-::-0-----2~0::::-0----~300
P (To rr )Fig. 2.
IK~/IKa ratios of Kr X-rays inducedby 6 MeV/amu He-, N-, and Ne-ions as afunction of Kr gas pressure. Solid lines are
drawn to guide the eye.

85
the ratio IKI3/IKa with increasing gas pressure enables an estimation of the transition ratio of
KL n l3(n.?2) to total KI3 linesl) and, furthermore, a relative transition yield for each KL n 13 line on
the assumption that fluorescence yield for each KLn 13 is constant and the vacancy distribution in
the L shellis the binomial one.

Figure 3 shows a relative transition yield of multiple ionizationof Kr by He-, N-, and Ne-ion bombardment estimated by the present data.

The values ofparameter PL(O) are 0, 0.15, and 0.24 for He-, N-, and Ne-ion bombardment, respectively.

PLeO)

value for N-ion bombardment agrees with that obtained by a binomial fitting of KI3 spectrum whichis measured with the crystal spectrometer as shown in Ref. 2.

But this is about two times larger thanthat by the Ka: spectrum and this difference will be a further problem to be studied.
0.4
Ne ion

03
0.2
~

a
c
0

01
0

"-e

Bl 0.4

(f)
(f)

0

0.3

c

0.2

t;

0

N ion

~ 01
c
Q

g; 00
.~

a:;
0::

1.0
He ionFig. 3.

Relative transition yield of Kr KL n {3 line

produced by 6 MeV/amu He-, N- , and Ne-ion
bombardment.
The ratio of I K{3/I Ka , in particular, for a solid target has been measured with a Si(Li)detector and the ratio difference between light-and heavy-ion bombardment has been studied. 3)
The ratios of I K{3/I Ka for Kr obtained by He-, N-, and Ne-ion bombardment were 0.177±0.001,
0.205±0.002 and 0.207±0.002, respectively, by an extrapolation to zero gas pressure without the
self-absorption. The ratios did not need to be corrected by the detection efficiency which was
almost constant in the Kr Ka: and K{3 energy region. The cause of the ratio difference between
He-ion and N- and Ne-ion bombardment is attributed to the multiple ionization. 4)

It is found that the intensity ratio of Ka and K{3 X-ray yields without a self-absorption can beobtained by a change of a target thickness and by an extrapolation to zero thickness.

References
1)

T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, and I. Kohno: IPCR Cyclotron Progr.
Rep., 11, 84 (1978).

2)

T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, M. Kase, and I. Kohno:

3)( 1979).
Y. Awaya, K. Izumo, T. Hamada, M. Okano, T. Takahashi, A. Hashizume, Y. Tendow, and
T. Katou:

4)

Phys. Rev., A13, 992 (1976); T. K. Li and R. L. Watson:

ibid.,!l, 82

ibid., A9, 1574

(1974).
1. Tricomi, 1. L. Duggan, F. D. McDaniel, P. D. Miller, R. P. Chaturvedi, R. M. Wheeler,

1. Lin, K. A. Kuenhold, L. A. Rayburn, and S. J. Cipolla: ibid., A15, 2269 (1977).

86

6-6.

Vacancy Rearrangement

In

the M

Shell Prior to X-Ray Emission

M. Uda, K. Maeda, H. Endo,
Y. Sasa, and M. Kobayashi

Prior to a characteristic X-ray emission, the rearrangement of electron vacancies in thevalence band may occur. Such a change is revealed in the X-ray satellite structure resulted
from a multiply ionized state.
A quantitative analysis of the satellite intensity distributions
has been performed on F Ka spectra of several fluorides induced by p , a, 0+ and N4+

N4+
J.,

( bl

(a)

N

~
==

(el

~--J

Cu

JI
I

ri m

• 0

~

N,
M5

If')

If')

U')

U1

U')

M4

I"""'iM3

1// I' I

I"""'i ..I ("")..I t.rl..3"f'.;t 0'\('T')

C"I"'):a:m r-I:EMI"""'i:?':: r-I:E
~

M2

~

~

~

j

:E
"""; (T)~111111 t I I I

CuF
~

+oJ

M,

lJ1

""M N""L ! ) N'"
riN:;:: . :>::

:E

C
<lJ

....c

rimri m M m
~
~
~

1/ /
La,

L02 Lf31

IIII1I""";

E....-i Nr l (T')
~

<1J

>
-+oJ

f"""4

d
Qj
0::

~
r l ty)
~

1/

III

L3
L2

Cu
920

950
ENERGY

980
(eV)

920

960

Energy (eV)Fig. l.
Relationship between energy diagram and LX-ray
emission (a) , and calculated (b) and observed (c) LX-ray
spectra of Cu. RAP (00 I) and the proportional counter
were employed.

1000

87

(6 MeV/amu).1)-3)

The present study deals with L X-ray emission spectra emitted from Fe, Co,

Ni, Cu, Zn and Ge, and their chemical compounds.
Target materials used here were in the form of thin films, thickness of which was in therange of I - 5 mg/ cm 2 . 84 Me V N4+ beam was generated by the cyclotron. Energy
levels for multiply ionized states of the atoms under study were calculated by use of the
Hartree-Fock-Slater method whose computer program was written by Herman-Skillman. 4)
Figure I (a) and I (b) show the schematic energy levels and calculated L emission energies for
Cu. L I Mn denotes La emission from Cu atom with one Land n M vacancies at theinitial state. In Fig. l(c) the observed L spectra from several Cu compounds are shown.
Structures of high energy satellites of La are quite different from one compound to theother. This is caused by the vacancy rearrangement of the M shell which is one of thecomponent of the valence band. Prior to the X-ray emission, primary vacancies in the valenceband are partially filled by the valence electrons of the surrounding atoms. The rate of thevacancy refilling is proportional to the covalency or the degree of overlapping of the electron
wave functions of the compounds. Then the intensity of L I Mn is high in the most ioniccompound CuF 2 and low in the least ionic or the most covalent solid Cu.
Similar spectra were obtained from the other metals and their compounds used. Some
representatives are shown in Figs. 2(a) and 2(b) for Zn and Ge, respectively.

N4+
~

~

N4+

i

(a)

--=
~.....J.....J

3--I

~

Ge

I I

Zn

N.

..A

="

Ji

"

( b)

.....J

I---.....J

51

.D

I

d

~
o+J

~

ZnF2

o+J

en

en

.J

I

c:
Cb

c:

o+J

c:
......

<U
o+J

C......

<U

>

<U

>

ZnD

o+J

CO
<U

o+J

CO
<U

0::

0::

1280

Fig. 2.

L X-ray spectra of Zn (a) and Ge (b).

88

References
1)
2)
3)
4)

M. Uda, H. Endo, K. Maeda, Y. Awaya, M. Kobayashi, Y. Sasa, H. Kumagai, and T.
Tonuma: Phys. Rev. Lett., 42, 1257 (1979).
M. Uda, H. Endo, K. Maeda, M. Kobayashi, and Y. Sasa: IPCR Cyclotron Progr. Rep.,
11, 88 (1978).
H. Endo, M. Uda, K. Maeda, M. Kobayashi, and Y. Sasa: ibid., p. 90.
F. Herman and S. Skillman: "Atomic Structure Calculations", Prentice Hall Inc.,
Englewood Cliffs, New Jersey (1963).

89

6-7.

Effects of Strain Rate on High Temperature Mechanical Properties
of Helium -Injected Fe-N i-Cr Austenitic Alloys

H. Shiraishi, H. Shinno, R. Watanabe,
H. Kamitsubo, I. Kohno, and T. Shikata

Fe-Ni-Cr austenitic alloy is one of the candidates for first wall and blanket structural
materials of a future fusion reactor. The ductility of this material decreases at high temperature
due to the presence of helium produced by (n, ~) reactions. We previously reported the effects ofvarious metallurgical conditions on the helium embrittlement of 316 stainless steel and Fe-Ni-Cr
alloys. 1) A knowledge of the mechanical properties under impact loading is important in the core
design. In the present work, the effects of strain rate ranging from 5 X 10- 4 /sec to 5 X 10- 2 /secon the mechanical properties at the test temperature of 923 K were investigated.
Table I shows the chemical composition of materials used and metallurgical treatments
before helium injection. Sample 7506 is a solid-solution-strengthened alloy and sample 7510 isan alloy hardened by the precipitation of the intermetallic compound Ni3 (Ti, AI). Sample
7510B is aged so as to get maximum strength. Treatment conditions prior to the injection wereTable I.

Sample
No.
7506A
7506B
7510A
7510B

Chemical composition of materials usedand helium pre-injection treatments.

C

Ni

Cr

Mn

Si

Mo

0.057

35.1

14.7

1.41

0.45

1.59

/I

"

0.063
/I

35.6
/I

/I

/I

14.9
/I

ST: solution-treated, 1323K, 30 min, PS:
AG: aged for 1000 h at 923 K

/I

"

0.94

0.51

1.71

"

/I

pre-strained, CR:

/I

Ti

1.79
/I

Al

0.24

"

Pre-inj ection
treatments
ST
ST + 5 % PS
20 % CR + AG
AG + 20 % CR

cold rolled,

determined taking the following facts into account. The pre-straining of 5 % was very effective
to suppress the helium em brittlement in 316 stainless steel. 1) Also, 20 % cold work was applied
to minimize the void swelling of 316 stainless steel. Specimens for tensile test were of aplate-like form. The dimension of their gauge section was 12 mm long, 4 mm wide, and 0.2 mm
thick. Helium was injected into the specimens using the cyclotron. The tensile test was carriedout in the vacuum of 10- 4 Pa using Instron type machine. The details of experimental
procedures were reported elsewhere. 2)
Figures 1 and 2 show the effect of strain rate on the ultimate strength of both alloys.
The ultimate strength of the precipitation-hardened alloy was much higher than that of thesolid-solution-strengthened alloy. Also, the ultimate strength increase caused by the increase

90

600
7506
923 K test

5001m

Q.

L

4001-

:S
tID
C

~

3001-

(f)

1000

-

~

-:3 -

800

m

Q.

L
-

.r::.

600

tiD
c

~

2m

~

100

0

1

-

400

2m
E

::E

~

0

1

5 X 10- 3

hollow: no helium
sol id : helium injected

200

-

1

5 X 10 4

~

Ul

(a )
0 5 % Pre-strained ( b )hollow: no helium
sol id : helinm injectedo Solution - treatedE::e 2001-

7510
923K test
o 20%Cold rolled+923K, 1000h ( a)o 923K, 1000h+20% Cold ro lled (b )5 X 10- 2

5 X 10- 4

5 X 10- 2

Strain rate (s - I )Strain rate (s - I )Fig. 1.

5 x 10- 3

Effect of strain rate on ultimate

strength of helium injected 7506 alloy.

Fig. 2.

Effect of strain rate on ultimate

strength of helium injected 7510 alloy.

50.-~----------~~----------~~

40

70
7506

o Solution - treated ( a)60

o 5 % Pre - strained ( b ):.;::;

m
tID

50

0

7510
923 K test
o 20%Cold ro lled +923K, 1000h ( a)o 923K, 1000h+20%Cold rolled ( b)cohollow: no helium
solid : helium injected

Ui

*
~
tID

c

o

9 23 K test

c

* 30
~ 20

40

t--

C

0

Ui

30

m

-0

t--

10

20
holl ow: no hel ium
solid : helium injected

10

OL-~

__________

5X 10- 4~L-__________

5 X 10- 3-L~

5 X 10- 2

Strain rate (s - I )Effect of strain rate on total
Fig. 3.
elongation of helium injected 7506 alloy.

O~~~--------~-----------L~
4
2
3

5x 10-

5x 10-

5 x 10-Strain rate ( s - I )Fig. 4.
Effect of strain rate on total
elongation of helium injected 7510 alloy .

91

of strain rate was higher for the former than for the latter. Helium injection reduced thestrength of both alloys.
Figures 3 and 4 show the effect of strain rate on the total elongation. With the increaseof the strain rate of the order of two, the total elongation of the materials without helium
injection decreased by factor of two. On the contrary, the total elongation of the solid
solution type alloy bombarded with helium increased with the increase of the strain rate. The
effect of helium disappeared at the strain rate between 5 X 10- 3 / sec and 5 X 10- 2 /sec.
The
3
similar observation was reported in the helium injected 316 stainless steel ) and in the neutron
irradiated Incoloy 800 and Hasteloy X.4)
In the case of the precipitation-hardened alloy, therecovery of the total elongation was not observed, but, from Table 2, we can see that theeffect of helium is reduced with the increase of the strain rate.
Table 2.

Helium em brittlement sensitivity defined as a ratioof the total elongation of the helium-injected material
to that of the corresponding material without helium
injection.
Strain rate (sec- 1 )Sample5 X 10- 4

5 X 10- 3

7510A

0.29

0.33

0.55

7510B

0.17

0.17

0.68

References
1)
2)

H. Shinno, H. Shiraishi, R. Watanabe, H. Kamitsubo, I. Kohno, and T. Shikata:
Cyclotron Progr. Rep., 11, 114 (1977); ibid., 11, 96 (1978).
R. Watanabe, H. Shiraishi, H. Shinno, H. Kamitsubo, I. Kohno, and T. Shikata:10, 104 (1976).

IPCR
ibid.,

3)

K. Matsumoto, T. Kataoka, M. Terasawa, M. Shimada, S. Nakahigashi, H. Sakairi, andE. Vagi: J. Nucl. Mater., 67, 97 (1977).

4)

H. Bahm and K-D. Closs: Radiation Effects in Breeder Reactor Structural Materials, June
(1977), Scottsdale, Arizona, U. S. A., p. 347.

92

6- 8.

Lattice Location of Sn A tom s Implanted

in to A I

A. Koyama and H. Sakairi

By a channeling experiment on dilute aluminum alloyes which were irradiated at 40 - 70 K,
Swanson et al. showed that mixed sprit interstitials are formed by the combination of substitutional
impurities, Ag, Mn, and Zn, with Al self interstitials produced by the irradiation.1) We wereinterested in Ni atoms implanted into Al, because Ni has very small solubility in AI. The resultof the experiment, which was reported in the last issue, was that Ni atoms also produce mixed split
interstitials, which are stable at room temperature in contrast to those of the above three elements
studied by Swanson et ai. 2)This year we investigated implanted Sn atoms in Al instead of the dilutely alloyed Sn atoms
which were studied by Swanson et al. In the experiment Swanson et al. showed a strange featureof Sn interstitials such that they are not produced directly by the irradiation at 40 - 70 K but
appear only after an annealing at 220 - 240 K. This feature is strongly in contrast with thatobserved for interstitials of Ag, Mn, and Zn which annihilate by the annealing. Swanson et ai.
did not identified the configuration of the Sn interstitials, but only showed that they are not the<100> mixed split interstitials.
The channeling effect of 4.8 Me V protons accelerated by the cyclotron was investigated withthe angular scan through <100> and <110> axes of Al single crystals. The beam was collimatedto have a divergence less than 0.025°. The backscattered protons were detected by asurface-barrier solid state detector placed at a scattering angle of 150° with an acceptance angleof about 9°. Aluminum single crystals were chemically polished and annealed in vacuum at
550°C for 7 h. The implantation of 150 KeV Sn atoms was carried out at room temperature witha dose of 1 X 10 16 ions/cm 2 . The target was maintained at room temperature during theexperiment.
Figure 1 (a) shows the normalized backscattering yields from Sn and Al atoms as a function ofangle e between the incident beam direction and the <110> axis direction.

Figure 1 (b) shows

the results for the <100> axis. It can be seen that there are a quadruple peak and a triple peakin the <110> and the <100> spectra for Sn atoms, respectively.
These peaks may not be explained by only one type of the interstitial configuration. Theinterstitial configurations conceivable in fcc metals are as follows, one is a mixed interstitialwhich is split along <100> direction, and the others are those in which the impurity atoms arelocated at tetrahedral and octahedral interstitial sites. None of them can explain the occurence ofside peaks of the <100> spectrum. The mixed split interstitial along <110> direction, which is
not yet found in fcc metals, can, however, lead to their occurence. It is therefore expected thatthese spectra are explained by considering the coexistence of some of the configurations
mentioned above.
A quantitative analysis of the structure of the backscattering yields from Sn atoms and theinvestigation of the fine structure of AI-dips are now in progress.

93< 11 0)<' 100 >

1.5

-1.0

Angle

1.0
( degree)

- 1.0

1.0

Fig. 1.
Normalized backscattering yield from Sn
and Al atoms as a function of the angle () between
the incident beam direction and the <110> axial
direction (a), and the <100> axial direction (b).

References
1)

2)

M. L. Swanson and F. Maury: Canad. 1. Phys., 53,1117 (1975).
E. Vagi, A. Koyama, H. Sakairi, and R. R. Hasiguti: IPCR Cyclotron Progr. Rep., 12, 99(1978).

94

6-9.

Secondary Electron Emission from Metals
by High-Speed Proton Bombardments

A. Koyama, T. Shikata, and H. Sakairi

In the last issue we described the experimental apparatus to measure the secondary electron
emission coefficient (SEEC) of the vacuum evaporated clean surfaces. 1) This year, SEECs of AI,
Cu, Ag, and Au were measured under high speed proton bombardment.
The target materials of 99.99 % purity were vacuum evaporated on the mechanically polishediron substrates at a pressure of about 3 X 10- 7 Torr, and in-situ measurements were made at
1 '" 2 X 10- 8 Torr.

As the time necessary for one data run was less than 10 minutes, the exposureof the fresh surface to the residual gas was less than 2 X 10- 7 Torr· minutes. For such a slight
exposure to oxygen or water vapor, the decrease of the work function of Al is known to be
negligibly small. 2) The incident energy of protons from the cyclotron was 4 to 16 MeV. The
intensity of the beam current was about 1 nA/mm2.
Figure 1 shows the incident energy dependence of SEECs for the four materials. The
emission coefficient, 'Y, increases with the effective electron density, to be excited with the proton,of the target. The dotted line is taken from the experimental result for AI by Aarset et al. In
their experiment the target surface was not prepared inside the vacuum system. 3) By extraporating
the curve for Al obtained in the present experiment to the lower energy region near 2 MeV, it canbe seen that the value of 'Y obtained by them is twice as large as that obtained by us.
Figure 2 shows the relation between 'Y/S e and Ep' Se is the electronic stopping power for

O-OAl
v-VCu
4-AAg
a-cAu

C

0.14

0.12

0

'0 1.0
~ 0.8

c
g 0.6

....

.... ....

....

.... ....

....

u

II)

~

",

~.-----.-----AAg

c ____

Au-D------oc-----c----~c~ ~-; 0.4Al~o----~o-----~o~--~o~-----o............

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

0.2

~

Cu

0.08

--.v-----·-----.-----~----................,

0.06

0

0. 1
1

2

4

6 8 10 15

4

Incident Energy (MeV)

6

8

10

Incident Energy (MeV)

Energy dependence of theFig. 1.
the secondary electron emission

Energy dependence of the ratio
Fig. 2.
of the secondary electron emission

coefficien t.

coefficient to the electronic stopping
power.

1295

oprotons (eV/A) and Ep is the proton incident energy (MeV).
4

The values of Se were taken fromIt can be seen that the proportionality between

the table given by Northcliffe and Schilling. )'Y and Se holds good within the limits of the experimental error (±4 %).

The same proportionality

as this was also found in the much lower energy region from 10 to 50 keV, by Baragiola et al.
who produced clean surfaces by in-situ vacuum evaporation in ultra high vacuum. 5)
The values of 'Y/S e were listed in Table 1.

The values presented by Baragiola et al.

arealmost equal to those obtained in the present experiment for all the four materials. However,the values of 'Y/S e of AI obtained from the data by Aarset et al. is twice as large as the data fromthe other two experiments, although that of Au is almost equal to those from the other two

It will be due to the fact that the Al target used by Aarset et al. was not free fromsurface contamination.
experiments.

Table 1.

Ratio of the secondary electron emission coefficientto the eloctronic stopping power, 'Y/S e .

'Y/S e0(P,/(eV/A) )EnergyAuthors

AI

{

0.13
0.22
0.11

4 '" 10 MeV
0.7 '" 2 MeV
2 '" 50 keV

present
Aarset et al.
Baragiola et al.

eu{ 0.0820.08{ 0.126
0.13

4 '" 10 MeV
2 '" 50 keV

present
Baragiola et al.

4 '" 10 MeV
2 '" 50 keV

present
Baragiola et al.

0.10
0.085
0.12

4 '" 10 MeV
0.7 '" 2 MeV
2 '" 50 keV

present
Aarse t e t al.
Baragiola et al.

TargetAg

Au{

Figure 3 shows the value of 'Y for AI calculated as 0.13 X (Se(L) + Se (cond.)), following theobserved relation that 'Y = 0.13S e .

The values Se(L) and Se(cond.) are the energy losses per unit

length due to the ionization of L-shell electrons and the excitation of conduction electrons which
are given rise to by incident protons, respectively.

The value of Se(L) was calculated by using

the L-shell ionization cross section given by Manson. 6)

On the other hand, that of Se(cond.)

was evaluated from the equation given by Neufeld and Ritchie.1)
amounts to 84 % of the experimental one.

The calculated value of 'Y

We can conclude from this figure that in the case of

AI the ionized electrons from L-shell constitute a major part of the primarily excited secondary
electrons (PESE), and also that those excited from the conduction band constitute a minor one.
A more detailed calculation was done by considering the transport and the emission processof the inner secondary electrons.

In order to describe the transport process we took account of

the excitation of L-shell electrons and the plasmon, and the individual excitation in the conduction
band, by inner secondaries with enough energy.

With respect to the emission process it was

assumed that the inner secondary electrons must have normal velocities larger thanto overcome the surface barrier.

j£ (EF + cp)

Here, m, E F , and ¢> are the electron mass, the Fermi energy and

96

0.6
0.4

~ Ex p e r i .
0. 2

'2
.8c::

'2
o
"0....

~

~.

o

E£IS

0.1

c::
g O. 08gt.)§ 0 .0 6
~

•

0. 2

t.)
Q)

§

0. 0 4

0.1
O. 08

' .'.

~

0 . 060.04
Calc ul atio n ~ 0 . 06S CL)e0.02

o. 0 10 . 02

L....-_~L----L---'---I.--'-...l-L...L..L-'-_

1

4

6

8 10 1 2

Incident energy (MeV)

Comparison of the semi-theoreticalFig. 3.
value of the secondary electron emission coefficientfor Al with the experimental one . See the text
for the definitions of Se(L) Se(cond.).

2

4

6

8 1 0 12

Incident energy (MeV)

Fig. 4.
Comparison of thecalculated value of the secondary
electron emission coefficient for
AI with the experimetal one.
The semi-theoretical curve
expressing 0.13S e(L) given in Fig. 3
is also included. See the text forthe definition of Se(L).

the work function of AI, respectively. Figure 4 shows the result of the calculation of SEEC due
to PESE from only L-shell. The calculated value is nearly equal to 0.06 X Se(L) and is only one
half of 0.13 X Se(L) which is expected from the experiment.

A further theoretical investigation

is being continued.

References
1)
2)
3)
4)
5)

A. Koyama, T. Shikata, and H. Sakairi: IPCR Cyclotron Progr. Rep., !1, 94 (1978).
E. E. Huber, Jr. and C. T. Kirk, Jr. : Surface Science, 1, 447 (1966).
B. Aarset, R. W. Cloud, and J. G. Trump: J. Appl. Phys. , 25, 1359 (1954).
L. C. Northcliffe and R. F . Schilling: Nuclear Data Tables, A 7, 233 (1970).
R. A. Baragiola, E. V. Alouse, and A. O. Florio: Phys. Rev. , B19, 121 (1979).

6)

S. T. Manson: ibid., A6, 1013 (1972).

7)

J. Neufeld and R. H. Ritchie: ibid., 98, 1632 (1955).

97

6 - 10.

Angular Correlation of Positron Annihilation Radiation
and Compton Profiles in Magnesium

N. Shiotani, T. Okada, N. Sakai, H. Sekizawa, and S. Wakoh

The electron momentum distribution in magnesium was studied by the angular correlation
measurements and the 'Y-ray Compton profile measurements. At the same time the theoreticalelectron momentum distribution was calculated by the APW method.
l) Angular correlation of annihilation radiation
Angular correlation of annihilation radiations in magnesium single crystals was measured
along three crystallographic directions, namely r A, rK, and rM, using a parallel slit system. The
angular resolution of the system was measured to be 0.80 mrad. The crystals were kept at room
temperature in vacuum. The observed angular correlation along r A direction is shown in Fig. 1
together with the theoretical one convoluted with the experimental angular resolution. Bothcurves are normalized to the same area. There is a noticeable disagreement between the theory
and the experiment. This disagreement is similar to those found in aluminum, l ) vanadiumgroup,2) chromium group3) and in other metals. The observed crystalline anisotropy of theangular correlations is illustrated in Fig. 2 together with the corresponding theoretical one.

The

3
- - APW cony.
r~----~~------~rA•••••• EXP.
Pz II rA-

Cigar

ANISOTROPY

2

+0.1

APWconv.

+ exporA - rKp-2

z(a .u)-0.1

r f--------++-----~ rK

P,

Fig. 1.
The experimental andtheoretical angular correlations in Mg
along the r A direction.

Fig. 2.
The anisotropy of the angularcorrelations. The schematic diagrams
illustrate the side views of the large zone
and the Fermi surface with thebutterflies.

98

origin of this anisotropy is that, due to the band gap across the (lOT 1) zone face, the "butterflies",
one of the Fermi surfaces in the third zone and centered at L as shown in the inset of Fig. 1, aresmaller than those of the free electron model. This observation is consistent with the results ofother Fermi surface measurements such as the magnetoacoustic effect reported by Ketterson andStark.4 )2) Compton profile
The 'Y-ray Compton profiles were measured using 59.54 ke V 41 Am) 'Y -rays. The magnesium
crystals of 2mm thickness were the same ones as used for the angular correlation measurements.
During the measurements the specimens were kept at room temperature in vacuum. The r A
Compton profile , corrected for the background, the sample absorption, the detector efficiency,
the Compton cross section and the "long tail", is shown in Fig. 3, together with tbe theoreticalprofiles: one not convoluted and one convoluted with the experimental resolution of 0.66 a.u.

eCompton Profile of Mg I' A
oooooEXP- - - - - - APW--

APW conv

Fig. 3.
The 'Y-ray Compton
profile of Mg.

O L-----L-----~----~-----4~a-u~P,

difference
.. 3

•

•
..--... .. 2·().

....- .. 1L--.

~..--...

•• ••o·.••.- .."~-1••....• • •
""'-2
~

.

•

...........

•

•

•
..'

•••

.-..

•

. •.' ...

2

Pz (a.u.)-3

Fig. 4.
The anisotropy of the Compton
profile of Mg.

99

The agreement between the experiment and the theory is very good. However a slight disagreement
is found in the higher momentum region. The multiple scattering effect may cause this discrepancy.
Weiss 5 ) reported a large crystalline anisotropy of the Compton profile in magnesium. Our
experimental and theoretical results do not agree with Weiss's results. In Fig. 4 the experimental
and the theoretical anisotropies are shown. The theoretical anisotropy, convoluted with theexperimental resolution, is undetectably small. This is consistent with the experimental result.

References
1)

T. Okada, H. Sekizawa, and N. Shiotani: J. Phys. Soc. Japan, 41,836 (1976).

2)
3)

N. Shiotani, T. Okada, T. Mizoguchi, and H. Sekizawa: ibid., 38, 423 (1975);
S. Wakoh, Y. Kubo, and J. Yamashita: ibid., p.416.
N. Shiotani, T. Okada, H. Sekizawa, S. Wakoh, and Y. Kubo: ibid., 43, 1229 (1977).

4)5)J. B. Ketterson and P. W. Stark: Phys. Rev., 156,748 (1967).
R. J. Weiss: Phil. Mag., 24, 1477 (1971).

100

6-11.

Mossbauer Study of

in Chromium and Manganese Dioxides

119 SnT. Okada and H. Sekizawa

119 Sn Mossbauer studies of the supertransferred hyperfine magnetic field Hhf in magnetic°°

oxides such as MnFe 2 4 ' CaMn0 3 , NiFe 2 4 and V0 2 have been made to investigate themechanisms of the spin transfer in weakly covalent materials. We report new results on Hhf at
119 Sn in the system Cr I-x Mnx 02 (O~x~l) with the rutile structure.
Since Cr0 2 is known to be ferromagnetic with the simplest spin structure , Mossbauer
measurements of Hhf in Sn-doped Cr0 2 give us a valuable clue to the origins of Hhf The
magnetic properties of the system Cr I-x Mnx 02 have been measured by several authors. The
present samples were prepared by thermal reaction of the powdered mixture of Cr0 3 ' Mn02 andSnCl 2 (S5 % enriched with 119 Sn) at 420 - 550°C under an oxygen pressure of 150 kg/cm 2 .
Each sample contains 0.1 - 0.5 at % of Sn ions.
The Mossbauer spectrum of 119 Sn in Cr0 2 at SOK is shown in Fig. 1. The spectrum
consists of well resolved six lines due to 119 Sn in Cr0 2 (as drawn with the solid lines) and others.
The latter are assigned to 119 Sn in Sn0 2 and Cr 2 3 , The sign of Hhf is determined by applying
an external longitudinal magnetic field of 35 kOe. The obtained values of Hhf , the isomer shift
IS relative to CaSn0 3 , the magnetic moment 00 and the Curie temperature T c are listed in°Table 1. As can be seen , the value of IS in Cr I-x Mnx 02 decreases with the Mn content x; in
Cr0 2 the IS is +O.lS mm/sec and nearly zero in Mn0 2 . This result shows that the Sn ions are in
tetravalent state , and somewhat more covalent in Cr0 2 compared with very ionic ones in Mn0 2 .
The observed electric quadrupole splitting is negligibly small.
The observed value of Hhf at 119 Sn in Cr0 2 (+3S0 kOe) is positive and very large comparedwith the values in other magnetically ordered oxides, for instance , 250 kOe in NiFe 2 4 , In
general, the mechanisms giving rise to Hhf in various magnetic oxides have much similarity to°~~.. t1\~ffr,~~~~~
81 Elo~
l6
°
w1i
00

I)

~

"6

'f!

o
c

~

(ff'ticP°

~

0

13

g

'b

~8

CD

6'

q,

~ a

0

e

°

o

-g

0 0

o
(f)

.D

«

er02 at 80K

o

-40

+40

Velocity ( mm / sec )Fig. 1.

Mossbauer spectrum of 119 Sn in Cr0 2 containing

0.1 at % of Sn at SOK.

101

Table 1. Hyperfine field (H hf) and isomer shift (IS) at 5K at 119 Sn in
Cr 1 _x Mn x 0 2 , the magnetic moment 0oJ-LB at OK and the Curie
temperature T cx

Hhf kOe

IS mm/sec°oJ-LB

Tc

0
0.25
0.50
1.0

+380
250
120
50

+0.18
+0.14
+0.07
0.0

1.83
1.32
0.60

392
384
380
T N=90those for the superexchange interaction between the magnetic ions. In Cr0 2 , the superexchange
between the unit cell corner and the body-center Cr4 + ions via oxygen ion is thought to be thedOlninant interaction for the ferromagnetism. Therefore, we examined various paths of spintransfer from the chromium ion at the body-center to the Sn ion at the corner via the oxygenion. However, we found that these paths could give negative Hhf only.
We can understand the mechanism qualitatively as follows. The spin transfer to the Sn ion
at the corner comes directly from the Cr ions at the neighbouring corners of the unit cell. We
take the coordinate system for the nearly octahedral site for Cr ion at the corner as shown in
Fig. 2. The nearly degenerate three dE states would split into two states, the lower d yz ' dzx
states and the slightly higher d xy state, and the former states are occupied by the two d-electronsof Cr4 + with parallel spins. Fairly strong mixing is expected between the empty d xy and the5s of Sn 4 + because of the relatively short distance between the cations and the loose packing of
the oxygen ions. The mixing of the empty LCAO d xy+A5s of the relatively low energy excitedstate with the occupied d yz and d zx of the ground state results in the spin transfer giving rise to
the observed large positive Hhf at 119 Sn in Cr0 2 .
x'

Fig. 2.
The empty orbitals of the Cr ionsand the Sn ion in the rutile structure.

An alternative band model mechanism is also able to account for the Hhf correctly. The
dE orbitals of Cr ions make up a narrow band which is split by the ferromagnetic exchangeinteraction.

In this model, the d xy orbital is partly occupied by ferromagnetic electrons which

can easily be transferred to the Sn 5s orbital giving rise to the observed large positive Hhf at
the 119 Sn nucleus.

102

7. RADIOCHEMISTRY AND NUCLEAR CHEMISTRY

7-1.

Charged-Particle Activation Analyses of Oxygen

In

GaAs1_xP x

T. Nozaki, Y. Terai, F. Yajima,
M. Toyoda, and T. Tsukazaki

Oxygen in GaAs 1_x Px layers on GaP plates was analyzed by charged particle activation
analysis. The sample was prepared by Mitsubishi Monsanto Chemical Industry Ltd. for use as
light-emitting diode, and their oxygen content is suspected to have some important effect on its
luminescence character. The oxygen was activated to 18 F by the 160C He, p )18 F reaction, andthe 18 F was separated and its activity was measured.

Since the 3 He bombardment of the matrix

gives various radio-nuclides of arsenic, bromine, etc., a chemical process should first be established
for the separation of 18 F completely free from them. A combination of the scavenging with
Zn(OH)2' the distillation of H2 SiF 6 and the precipitation of LiF proved to give a suitable
separation.
The sample with about 1.5 cm X 1.5 cm dimension and about 100 J.lm GaAs 1_x Px layer
thickness was covered with a thin aluminium foil and set on a water-cooled target holder. It
was bombarded with a 3 He beam of 11 Me V energy at the layer surface and about IJ.lA flux
for 20 to 40 min. This energy was selected from excitation function for the 160C He, p)18 F
reaction, the sample layer thickness and the range-energy curve for 3 He particles. The sample
surface with 5 mg/cm 2 thickness was then etched off in aqua regia with the aid of ultra-sonicwaves. The sample after the surface contamination removal was put into a polyethylene bottle
containing aqua regia (30 mf) and carrier HF (2 mol/f, 2 mf). After most part of air in thebottle was rapidly squeezed out, the bottle was stoppered and placed on an ultra-sonic wave
generator. Within 15 min the GaAs 1_x Px layer was dissolved together with some part of the
GaP plate.
The solution was diluted with water (150 mE), and Zn(N0 3 )2 (20% soln, 5 mf) was added
to it. It was then neutralized with NaOH, and the precipitate thus formed was removed bycentrifugation. Fluorine in the solution was then precipitated as CaF 2 together with CaC0 3
by the usual method, and the coprecipitate was filtered on a glass filter paper and washed with
hot water. The precipitate together with the filter paper was added to HCI0 4 (60%, 150 mf),
and the fluorine was steam-distilled at 140 to 150°C as H2 SiF 6. The distillate (200 to 300 mE)
was received in a LiOH solution and treated with LiCI (2 mol/f soln, 100 mE) and ethanol(200 mR) to give LiF precipitate, which was collected by filtration and washed with 50% ethanol
containing LiCl.
Annihilation radiation from the LiF was measured with a NaI(T 1) scintillation detector
connected to a single channel analyzer, and the decay was followed. The decay curve agreed
well with that of 18 F. Also, the absence of any 'Y-ray other than annihilation radiation was
ascertained by a Ge(Li) detector. For the measurement of carrier recovery, the LiF was dissolved

103

in dil. Hel and fluorine quantity in an aliquot volume of the solution was determined by thelanthanum titration in the presence of a fluoride-sensitive electrode. As for the activation
standard, a silica plate covered with an aluminium foil thicker by 5 mg/cm 2 than the foil used in
the sample bombardment was bombarded with a lower flux and for a shorter time.
Down to about 20 ppb of oxygen in GaAs 1 _x Px was proved to be determined by thistechnique. Various oxygen concentrations were found on the present samples, ranging from 60
ppb to about 100 ppm. Some correlations can be observed of the oxygen concentration withthe production condition of the sample as well as with its luminescence characteristics. This
study is still under way to make the correlations clearer.

104

7-2.

Yield of Low-Z Radionuclides
in Charged - Partie Ie Reactions

T. Nozaki and M. Iwamoto

Several low-Z elements are abundant in nature and play roles vitally important especially inthe biosphere. Various low-Z radioisotopes are shown to , be very useful in fundamental andapplied life sciences including nuclear medicine. The excitation function, however, cannot be
predicted with confidence from any theory for reactions of low-Z nuclides. It is, therefore,
regarded as worth while collecting reliably measured excitation functions for low-Z reactions
and arrange them systematically into a chart which gives the yield of individual radio-nuclide in
relatively simple reactions of the compound nucleus mechanism.
In order to make such a chart, the branching ratio should be obtained for p-, n-, anda-emission from a compound nucleus. We have assumed that relative branching ratio for agiven compound nucleus can be approximated by (1) the mean cross section over energy range
between Eth + 2 Me V and Eth + 8 Me V when the compound nucleus is of Z5:. 9 or (2) the
maximum cross section in the excitation function when it is of Z>9. For example, the meancross sections for the following reactions are obtained to be about 7 mb and 110mb for theformation of 14 0 and 11C, respectively, from the measured excitation functions: 1)n
14N + P

15 0*/-........

P~a.. 14 0.. 14N• 11C

With further approximation that the cross section of compound nucleus formation is 60
A 2/3 mb, the mean formation cross section of 14 N in the above reaction is given to be about
230 mb. Hence, the branching ratios for n-, p-, and a-emission from 15 0 are obtained to be
2 %, 67 %, and 31 %, respectively.
Since no enough variety of excitation functions has yet been measured reliably, we set up
the following formulas to complement the insufficiency:

where Wj is the relative branching ratio for the emission of particle j, Sj is its separation energy in
MeV, 0 is the even-odd term, and B is for the Coulomb barrier correction. For even-even, odd-A
and odd-odd product nuclei 0 is taken to be -1, 0, and +1, respectively, with the exception of
16 0 where 0 = - 2 was adopted.
For proton emission, B is taken to be 0 for a compound nucleus
with Z<14 and I for 145:.Z5:.16; for a-particle emission, B = 0, 1, and 2 were adopted for

105

Z<9, 9~Z~14, and l4~Z~16, respectively. These formulas give fairly correct values for theformation of 18 F and 30 P by various reactions but a value smaller by about 35 % for 11 C.
Branching ratios which seem to be the most probable at present have been assembled to makea chart for compound nuclei with Z :;:: 6 (carbon) to Z :;:: 16 (sulphur). The chart is shown
below. This chart inevitably involves many small errors and incorrectness, which should becorrected in future. The branching ratio is thought to vary with the excitation energy of thecompound nucleus, and this also provides a future problem.

D : Stableo : T>lmin
D: T<lmin

Reference
1)

T. Nozaki, T. Karasawa, M. Iwamoto, Y. Terai, and M. Okano: IPCR Cyclotron Progr. Rep.,
12, 106 (1978).

106

7-3.

Recoil Range of

18 F

Formedby Various Reactions

T. Nozaki, M. Iwamoto, K. Usami,
K. Mukai, and A. Hiraiwa

The distribution of forward recoil range of 18 F was measured for the following formation
reactions: (1) 160eHe, p) 18 F , (2) 160(a, pn) 18 F, and (3) 2oNeeHe, ap) 18 F. The excitation
functions for these reactions are already known. 1) The incident energies for Reactions 1, 2, and 3
were selected to be 8,35, and 20 MeV, respectively, which are the energies to give the maximum
cross sections. For Reaction 1, the measurement was also undertaken for 14 MeV incident
energy.
Th~ technique of thin stacked foil recoil catcher cannot be adopted in the present study,

because oxygen on the foil surface interferes seriously.

We used a semiconductor silicon wafer ofa known surface area as the recoil catcher, because of the following reasons: (1) its surface can bemade mirror-flat, (2) its surface oxygen quantity is known,2) (3) a NaOH solution is known to besuitable as its etching solution, and the silicon concentration in the solution can be determined
conveniently by colorimetry, (4) its high purity can be guaranteed, and (5) silicon gives no notable
activity other than 30p (2.5 min half-life) in the present bombardments. The target-catcher
systems used are shown in Fig.!. A Si0 2 film with 50 or 100 nm thickness was prepared on asilicon wafer as the oxygen target. A set of a special design was prepared for the neontarget-catcher system, in which neon from a cylinder was slowly streamed between two siliconwafers of 0.3 mm aperture.

The initial energy of 3He- or a-particles was so adjusted as to be

degraded to the value given above at the layer of Si0 2 or neon.
The target-catcher system was bombarded with about 1 IlA beam for 10 to 15 min.

The

catcher wafer was then etched with 15 mt of 5 % NaOH solution heated to about 50°C in asmall polyethylene bottle. The etching duration was changed from 1 to 8 min according to thethickness to be removed. The etching was repeated 10 to 15 times in a new bottle for each time .
The annihilation radiation from the bottle was then measured with a scintillation detector
Oxygen Target):;~l~:~d:::g~::~m( 50 or 100 nm Thickness)

Si Wafer(Reco i l Catcher)

Si Wafer( 2 cm x 2 cm Area)
400 or 200 pm Thickness[ncident Beam

~...

..

¢=:l
Neon Flow

Lead Foi I(0.3 mm Thick ness)

Fig. 1.

Target assembly.

107

connected to a single channel analyzer, and the decay was followed. After more than 2 hfrom the bombardment, the decay curve showed good agreement with that of 18F. Silicon
content of the solution in each bottle was determined by the silico-12-molybdate colorimetry.
The distribution of the recoil range was thus obtained as a histogramme.
The reproducibility of the result is exemplified by Fig. 2, in which two results in six
measurements for Reaction 2 are given. Other two results lie between them, and the rest two are
outside of them. The etching uniformity was checked by electron microscopes. No etching pits
but some pyramids were found in the bombarded domain after the etching, but their heights did
not exceed 1 Mm. Thus, this etching was proved to be satisfactory. Mechanical grinding was also
tried, but gave poorer results.
The distribution curves thus obtained for the forward recoil range of 18 F is shown in Figs. 3
and 4. The maximum and minimum recoil energy of 18 F can be calculated for each reaction
together with its most probable recoil energy, provided that the reaction proceeds via the

c
o
::J
.0

Vi
o

o

2

3

Fig. 2.

Ca tcher Thic kness (mg /crrf)

Reproducibility of the result.

O+3 He..........

j

j

d

a

c

c
o

:J

::J
.0

0

......

.0

14 MeV

.~

Vi

Vi

o

0

o

1

2

Catcher Thickness (mg/cm2)

Fig. 3.
Distribution of forward
recoil range.

o2Catcher Thickness (mg I cm 2 )Fig. 4.
range.

Distribution of forward recoil

3

108

compound nucleus.

These values of recoil energy are shown in Table 1 together with the

It is clearly demonstrated in Fig, 4 that the direct process
is the predominant mechanism for the 20 Nee He, O'p ) 18 F reaction. These results offer

experimental results of recoil range.

information important in the charged particle activation analysis of oxygen as well as in thedesign of gas targets for 18F production. Similar measurements are under way for the180(p, n)18F , 2oNe(d, O')18F, and 19Fe He, O') 18 F reactions.
Table 1.

Formation
reaction

160eHe, p)18F
16 0(0', pn)18 F

Forward recoil energy and forward recoil range (in Si) of 18F.

Incident

Forward recoil range(mg/ cm 2 in Si)
Highest80 % Stop
distribn.

energy
(MeV)

Max.

Min.

Highestdistribn.

8

3.15

0.17

1.20

0.3

0.45

14

5.29

0.35

2.09

0.4

0.65

10.59

3.12

6.30

1.1

1.5

12.89

2.04

8.91

-0.02

2.04

~0.2

0.8

35

160JO', d)18 F
2oNeeHe, O'p)18 F

Forward recoil energy
(MeV)

20

"

References

1)

T. Nozaki, M. Iwamoto, and T. Ido: Intern. J. appl. Radiat. Isotopes, 25, 393 (1974).

2)

T. Nozaki, M. Iwamoto, K. Usami, K. Mukai, and A. Hiraiwa: IPCR Cyclotron Progr. Rep.,
11, 111 (1978).

109

7 -4. 119Sn-Mossbauer Em iss ion Study on Se and
SnSe Doped with 119 m Te

S. Ambe and F. Ambe

Mossbauer emission spectroscopy is useful in determining the chemical state of defect atoms
produced by nuclear decays and reactions. We have studied the chemical state of 119 Sn arisingfrom the EC decay series of 119m Te -+ 119Sb -+ 119 Sn in compounds of Sb and Te. This year a
new series of experiments has been started. In this, matrices which contain neither Sb nor Te asa macro component are to be studied by doping technique. Here the emission spectra of metallic
Se and SnSe doped with carrier-free 119m Te are reported. The results are discussed in comparison
with those reported previously for Te metal and SnTe labelled with 119mTe.1) ,2)
Metallic Se doped with 119mTe was prepared by the following radiochemical procedure. A
tin plate containing 119mTe formed by irradiation with 40 Me V Q'-particles from the cyclotron was
dissolved in a mixture of HC 1 and HN0 3 . After evaporation, the residue was dissolved in dil.
HCI containing Se(IV). Carrier-free 119mTe was coprecipitated with Se metal by reduction withNa 2 S03 and N2 H4 ·2HCl. The Se(l19mTe) was purified by sublimation and was fused at 260°C
under an Ar stream. The Se metal obtained was in the hexagonal form which is isomorphouswith Te metal. 120 SnSe doped with 119mTe was prepared by fusion of a stoichiometric mixtureof 120 Sn and Se(119mTe) metals at 920°C under Ar.

Mossbauer emission spectra of the samples

were measured against a BaSn0 3 absorber at 78 K, after a radioactive equilibrium had been
attained between 119m Te and 119 Sb.
In Se metal containing a small amount of Te, the Te atoms are reported to replace Se atoms
in the lattice. 3) Therefore, carrier-free 11 9mTe occupies evidently the lattice position of Se in theSe( 119mTe) sample.

The observed emission spectrum of Se(l19mTe) is shown in Fig. I with that ofTe(119mTe) for comparison.

Least squares fitting of the experimental points with Lorentzians

assltming a singlet and a doublet resulted in lines with the isomer shifts of 1.8 and 3.2 mm/sec.

The

former line is ascribed to 119Sn(IV) and the latter to 119Sn(II) coordinated with selenium on thebasis of the Mossbauer parameters obtained in absorption experiments. 4)-6) On the other hand, no
119Sn in the tetravalent state .was found in the less electronegative Te matrix. 1)
In 120SnSe, 119mTe atoms are considered to be in the Se site. The emission spectrum of
120SnSe(119mTe) [Fig. 2(a)] was decomposed into two components with isomer shifts of 1.3 and 3.09
mm/sec, which are also assigned to 119 Sn(IV) and 119Sn(II) surrounded by selenium ions. The result
obtained suggests that most 119 Sn atoms and accordingly most 119 Sb atoms have been stabilized in
the Sn site. (The position of 119Sn determined from the isomer shifts represents at the same time
the position of 119 Sb in the lattice, since the recoil energy accompanying the EC decay of 119Sb ismuch smaller than the displacement energy.1), 2») The result on 120SnSe(119mTe) presents astriking contrast to the case of 120SnTe(119mTe) [Fig. 2(b)], in which 119Sb atoms were distributed
both in Sn and Te sites. 2) Since the electro negativity of Sb lies almost in the Iniddle of Sn and
Te , 119 Sb can be stabilized both in the Sn and Te sites of SnTe as cationic and anionic defects
respectively.

The 119Sb atoms, however, are considered to have been preferentially stabilized in

110

(a)

o

100

~ 99.5
Q)

(b)

>

'"

a;

a:

o

100

0

00

0

0

99

a

-4

Relative velocity ( mm Is vs BaSn (), at 78 K )119 Sn-Mossbauer emission spectrum of (a)Fig. 1.

Se(119m Te) and (b) Te(119m Te).

o

(a )

o

o

o
o 0

°0 0
00

100

o \oo~°(j)
0

0

«>0
"

o

i

0

8

o

99

Q)

~

&!

98

- 4

o
Relative velocity ( mm / s vs BaSnO, at 78K )Fig. 2.

119 Sn-Mossbauer emission spectrum of (a)120 SnSe(119m Te) and (b) 120 SnTe(1l9m Te).

111

Sn site of SnSe as cationic defects, because the electronegativity of Sb lies much closer to that of
Sn than to that of Se.
It is also interesting to note that defect 119Sn atoms were found both in divalent andtetravalent states after the EC decays of 119m Te in Se and SnSe. This indicates that selenium
anions can stabilize defect 119Sn in the tetravalent state, though less electronegative tellurium cannot.

References
1)
2)
3)
4)
5)
6)

F. Ambe, S. Ambe, H. Shoji, and N. Saito: J. Chern. Phys., 60, 3773 (1974).
F. Ambe and S. Ambe: J. Physique, 37, C6-923 (1976).
C. H. W. Jones and M. Mauguin: J. Chern. Phys., 67, 1587 (1977).
V. Fano and I. Ortalli: ibid., 61,5017 (1974).
L. N. Vasil'ev: Izv. Akad. Nauk. SSSR. Neorg. Mater., !1, 1752 (1977).
P. P. Seregin, M. A. Sagatov, F. S. Nasredinov, and L. N. Vasil'ev: Fiz. Tverd. Tela, ~,1928 (1973) [SOY. Phys. Solid State, U, 1291 (1973)].

112

7-5. Chemical States of Defect Tin Atoms in InSb and In2Te3 by
Mossbauer Emission Spectroscopy

F. Ambe and S. Ambe

The chemical state of dilute impurity atoms in compound semiconductors is not fully explored
yet in spite of their importance in determining electrical properties of the matrices. Althoughmeasurements of macroscopic parameters such as conductivity , Hall coefficient etc. giveinformation on such impurities,1) direct determination of their lattice position and electronic
state requires spectroscopic methods with high sensitivity. The 119Sn Mossbauer emission
spectroscopy developed in our laboratory2)-4) is expected to give useful information on thechemical state of impurity tin atoms in compound semiconductors.

In this period 119 Sn atoms in

InSb and In2 Te 3 were studied.
119Sb and 119mTe were produced by bombarding a tin plate with 14 MeV protons or 40 MeV
a-particles from the cyclotron. The radiochemical procedures to prepare Sb and Te metals
labelled or doped with the source nuclides have been reported elsewhere. 2), 5) The sources wereprepared by fusing stoichiometric mixtures of indium and the labelled or doped metals under Ar.
119Sn Mossbauer emission spectra of the sources were measured against a BaSn0 3 absorber at
78K as described previously.3) , 4)
Indium antimonide labelled with 119 Sb (ln 119 Sb) gave a single emission line with the isomer
shift of 1.94 ± 0.03 mm/sec relative to BaSn0 3 as shown in Fig. 1.

The line is attributed to

119Sn occupying the Sb site in the zinc blende-type cubic lattice of InSb , since the EC decay of
119 Sb to 119 Sn causes no atomic displacement. 2)

The isomer shift shows that the 119 Sn atoms
IVcoordinated by four In atoms are in a covalent Sn state and the s-electron density at their
nuclei is only slightly smaller than that of 119Sn in the diamond-type a-tin .
In the InSb source doped with carrier-free 119mTe (lnSb (l19mTe)) the 119mTe atoms are
considered to be in the Sb site of the matrix, since the electronegativity of Te is larger than that of
Sb. The emission spectrum of the source was decomposed into two Lorentzian lines with the

100

'*

~

>,

U)

c

B

.~

~

~ 92
(l)

0:::

Fig. 1.

o4Relative velocity (mm / s )8

119 Sn-Mossbauer
emission spectrum of In 119 Sbagainst BaSn0 3 at 78 K.

113

100

*
>. (i,

c

~
(l)

>

98

~

(l)

0:::

Fig. 2.

119 Sn-Mossbauer

emission spectrum of
InSb(119m Te) against BaSn0 3
Relative velocity (mm Is )isomer shifts of 1.88 ± 0.05 and 2.3 ± 0.1 mm/sec (Fig. 2).

at 78 K.
The former line is attributed to 119Sn

remaining in the Sb site from its similarity in isomer shift with the emission line of In 119 Sb
described above. The latter line with an isomer shift typical of 119Sn (II) surrounded by Sbatoms4) is ascribed to 119Sn arising from 119Sb which had been transferred to the In site as a resultof the EC decay of 119mTe.
In2 Te 3 has a zinc blende-type structure, in which 1/3 of the In site is vacant. As shown in
Fig. 3, the In2 119m Te 3 gave an emission spectrum composed of a doublet (isomer shift 1.6 ± 0.3mm/sec, quadrupole splitting 1.5 ± 0.3 mm/sec) and a broad singlet (isomer shift 3.21 ± 0.05 mm/sec).
The doublet is considered to be due to 119 Sn in the Te site on the basis of both the isomer shift
and the quadrupole splitting:

The low isomer shift suggests electropositive ligands rather thantellurium atoms, and a quadrupole splitting is in fact expected for 119Sn in the Te site because of
the vacancies in the In site. The singlet is attributed to 119Sn (II) in the In site, since the isomer
shift lies in the region for 119Sn coordinated by Te atoms. 4)

100

*

~

>-

i

~

~

Q)

0:::

Fig. 3.

99-4aRelative velocity ( mm / s )119 Sn-Mossbauer

emission spectrum of
In2 119m Te 3 against BaSn0 3
at 78 K.

The 119 Sn Mossbauer emission spectroscopy using 119 Sb and 119m Te as the source nuclides has
thus been shown to enable determination of the electronic state of defect 119Sn in definite
lattice sites of InSb and In2 Te 3 • The results can be further utilized to determine the lattice
position of 119Sn atoms incorporated into the matrices by diffusion or by ion implantation fromtheir Mossbauer absorption spectra.

114

Similar investigations on other semiconductors are in progress.
References

2)

C. Hi1sum and A. C. Rose-Innes: Semiconducting III-V Compounds, (Pergamon Press 1961)
p.68.
F. Ambe, S. Ambe, H. Shoji, and N. Saito: J. Chern. Phys., 60, 3773 (1974).

3)
4)
5)

F. Ambe and S. Ambe: Chern. Phys. Lett., 39 , 294 (1976).
F. Ambe and S. Ambe: J. Physique, 37, C6-923 (1976).
The preceding report of this volume.

1)

115

7-6.

Exchange Reaction of Seleno-Compound with
Elemental Selenium

K. Ogawa, * K. Taki, and T. Nozaki

As reported previously,l) 75 Se- or 73 Se-2-selenouracil is obtained by the exchange reaction of
the selenium atom of 2-selenouracil with elemental selenium-75 or selenium-73. In order todecide the optimum condition for the exchange reaction, several experiments were performed using
elemental selenium-75. The elemental selenium-75 was prepared by the reduction of 75 Se-H 2 Se0 3
to red selenium with hydrazine and extracted into carbon disulfide.

The exchange reaction iscaused by heating the above selenium solution with 2-selenouracil in a sealed tube. The solution
should be well degassed to prevent the oxidation of elemental selenium and 2-selenouracil.
75Se-2-Selenouracil produced in the reaction mixture was separated by the previous method l )and its radioactivity was determined by paper chromatography using a mixture of n-butanol,
acetic acid and water (2: I: I).
2-Selenouracil is soluble in pyridine but insoluble in carbon disulfide, while elemental selenium
is soluble in pyridine and much more soluble in carbon disulfide. Therefore, the exchange
reaction was affected by the composition of the reaction mixture and also by the reaction
temperature. The activity yield of 75 Se-2-selenouracil as a function of the mixture ratio of thetwo solvents is shown in Fig. I, and the yield of 75 Se-2-selenouracil against the reaction
temperature is shown in Fig. 2. From the above results, the practical exchange reaction is100~------------------------~

100
~

.~

g
OJ

~
N

<i>

r 50f-

~

.

•

.~
0

:~

c

OJ

a;

(/)

N
cU

r 50 -

I

'0
u

a;

:;,

I

>,

of>;

/.

«
I

5

Pyridine

CS 2· Pyridine

.J

0

•

50

100

150

Temperature ('C)

Fig. 1.
Activity yield of
75 Se-2-selenouracil as a function of
mixing ratio of CS 2 and pyridine.

Activity yield ofFig. 2.
75 Se-2-selenouracil as a function of

2-Selenouracil, I mg; Elemental
selenium-75 , 4 .9 /lg (I /lCi); Solvent(various ratio) , 2 ml; Reaction time,
10 h; Reaction temp., 110°C.

I mg; Elemental selenium-75, 4.9 /lg(1 mCi); Solvent , CS 2 : Pyridine (1: 1)* Faculty of Hygienic Science, Kitasato University .

reaction temperature. 2-Selenouracil,

2 ml; Reaction time, 3 h.

116

recommended to be carried out in the mixture of pyridine and carbon disulfide (1 : 1) at 130°C.
Figure 3 shows both the specific activity and total activity of 75 Se-2-selenouracil for thevarious amount of 2-selenouracil. It seems that the exchange reaction of a small amount ofelemental selenium with a much larger amount of 2-selenouracil is of first order with respect to theconcentration of the latter. Hence , the use of a large amount of 2-selenouracil gives a fasterexchange but with lowering of the specific activity of product selenouracil.

It is necessary to2

add 2-selenouracil 2 X 10 times as much as elemental selenium in order to introduce about 70 %selenium activity under the given experimental condition.
The solid line in Fig. 4 shows the activity yield in the exchange reaction of 1 mg
2-selenouracil and 4.9 pg elemental selenium-75 in 2 me of the mixture of pyridine and carbon
disulfide (I: 1) at 130°C. When 73Se is used instead of 75 Se, the activity yield of
73 Se-2-selenouraci1 can be given by the dotted line in Fig. 4. Because of 7.1 h half life of 73 Se ,the activity yield can give the maximum value at a reaction time of about 1-2 h.
Actually , 1.3 mCi of 73 Se-2-selenouracil was prepared by the above method in 1 h from
5 mCi of elemental selenium-73 produced by the nuclear reaction 75 As(p , 3n) 73 Se.
In general, the exchange reaction is applicable to other selenium compounds having
selenocarbonyl group . 75 Se-2-Selenothymine and 75Se-6-selenopurine were also obtained from
2-selenothymine and 6-selenopurine.
100r - --

11
(5

E
.~

g
(l)

- - - ----

- -------, 10

(l)

(5

~
\

E

\

'-(5

\(-.

\

.~

~

ai

<Jl

NO.5
a.,
<JJ

\
\
\

\

>.~

u

«

E

o

.~

~

c
ai

c
(l)
ai

<Jl

N

~
(l)

js 50

~

o

c
(l)
ai

<Jl

<Jl

5 N
Q.,

~

\

..t.

'0

(5

u

(l)

0

~

~

\
\

[f

0.5 '0

\

\

'0

>-

.:;

K,

·f

~

+='
U

«

u

"'"

.~

- - - _ _ _ __ _ _ _ ..t.

0.

<JJ

5
Amount of 2·selenouracil ( m mol )Activity ( - • - ) and
Fig. 3.
specific activity (- - - ... - - -) of
75 Se-2-selenouracil as a function of theamount of 2-selenouracil. Elemental
selenium-75 , 4.9 }lg(6.2 X 10-5 m mol) ,1 }lCi; Solvent , CS 2 : Pyridine (1: 1) 2 ml;
Reaction time, 10h; Reaction temp. ,110°C.

0 ~--~5~--~1~0---~
15~0

Temperature ( hr )Activity yield ofFig. 4.
75 Se-2-selenouracil ( - • - ) andactivity of 73 Se-2-selenouracil (- - - ... - - -)as a function of reaction time.
2-Selenouracil , I mg; Elemental
selenium-75 , 4.9 }lg(1 }lCi); Solvent,CS 2 : Pyridine (I: I) 2 ml ; Reaction
temp. , 130°C.

ReferenceI)

K. Ogawa, K. Taki, and T. Nozaki: IPCR Cyclotron Progr. Rep., 12, 116 (1978).

117

8.

RADIATION CHEMISTRY AND RADIATION BIOLOGY

8-1.

Measurement of the Decay of the Em ission

fromO"-Excitons Produced

in a

KBr Crystal by

Heavy-Ion I rrad iation

K. Kimura and M. Imamura

We have continued measurement of the fast decay of the emission from a-excitons in a KBr
single crystal produced by heavy ion-irradiation, using the apparatus reported in the preceding
report. 1) The apparatus is capable of recording time-dependent spectra in the nanosecond range.
One of the striking features found from heavy-ion irradiation experiments is the enhancementof the a-emission intensity, i.e., a large ratio of a-emission to 7l'-emission intensity compared to thatobserved in electron irradiation. 2)
Extensive studies have been focused on the mechanism giving such a large la/l7l' radio in
heavy-ion irradiation. The results led to the conclusion that the a- and 7l'-excitons are produced ina ratio different from that in electron irradiation. Free excitons, which are regarded as precursorsof the a- and 7l'-excitons, are created in the heavy-ion tracks so densely that they will inevitably
experience collisions with each other. On the other hand, almost all free excitons created by
low-LET radiations undergo intersystem crossing without collision to form 0- and 7l'-exciton. No
experimental evidence has been obtained for the preferential formation of o-excitons by collision,
however. Further studies will be made on this essential point.

References
1)
2)

K. Kimura and M. Imamura: IPCR Cyclotron Progr. Rep., 11, 118 (1978).
K. Kimura and M. Imamura: Phys. Lett., 67A, 159 (1978).

118

8-2.

New Apparatus for Cyclotron-Beam

Irradiationof Biological Samples

F. Yatagai and A. Matsuyama

Beams of helium-, carbon-, nitrogen-, and oxygen-ions accelerated by the cyclotron have been
employed for biological experiments. The biological irradiation system, which has been used sofar, is summarized as follows. The ion beam passed through collimators, slits, and a scattering
foil for dosimetry, and emerged horizontally into air from an aluminum vacuum window. After
traversing an air gap, most of the beam reached the filter on which the samples to be irradiatedwere spread in a thin layer. As the size of the beam spot (2 mm square) is smaller than the areaof the filter (8 or 24 mm in diameter), the filter was moved in the plane perpendicular to the beamaxis to be uniformly irradiated. I) Solid state detectors and a Faraday cup were used for thedetermination of particle fluence according to the method of Kochanny et al. 2)
Various effects of high-LET radiations on biological materials, such as bacterial cells andphages, have been investigated by using this irradiation system. For radiosensitive materials suchas mammalian cells for which a low-dose irradiation is required, a mechanical chopper was attachedto this irradiation system to decrease the beam intensity.3) However, in such a case , an accurate
dosimetry and a uniform irradiation could not be obtained easily. A new apparatus was,therefore, constructed to irradiate various biological materials using the beam elastically scattered(1) (2)

(3)

Beam

(7)

Fig. 1.
Scheme of new apparatus for biological irradiations.
(1) Slit (2) Scattering foil (3) Vacuum gauge (4) Gatevalve (5) End of vacuum chamber (6) Faraday cup(7) Vacuum windows for low-dose irradiations (8) Vacuum
windows for high-dose irradiations (9) Arm to suspend asolid state detector (10) Sample holders.

119

at some angle by the scattering foil.

As shown in Fig. 1, the end of vacuum chamber, which is at

a distance of 800 mm from the scattering foil, has two sets of vacuum windows on different
circles. The radii of two circles are 38 and 83 mm corresponding to the scattering angle of 2° 45'
and 6°00', respectively. The radius of each of the windows located on the 2°45 ' circle is 10 mm
and that located on the 6°00' circle is 25 mm. The former is made smaller because the relative
intensity decreases rapidly at small angles with the increase of the scattering angle. There are twokinds of sample holders for the two sizes of the windows, and the sample mounted on the holder
faces the window and is made to rotate to ensure uniform irradiation. The radiosensitive samples
mentioned above can be irradiated at lower dose-rate by the ion beam passing through the larger
windows ({) = 6°00 '). Such positions and sizes of windows were determined from both thepreliminary results on dose distributions obtained with photographic paper and theoretical
calculations based on the Rutherford scattering law.
Although this new apparatus has many advantages over the previous one, further improvements
to get better dosimetry and uniform-irradiation are in progress.

References
1)

F. Yatagai, T. Takahashi, Y. Kitajima, and A. Matsuyama: J. Radiat. Res., !2, 90 (1974).

2)

G. L. Kochanny, Jr., A. Timnick, C. J. Hochanade1, and C. D. Goodman: Radiat. Res.,19, 462 (1963).

3)

Y. Yamawaki, F. Yatagai, I. Kaneko, K. Sakamoto, S. Okada, and A. Matsuyama: IPCR
Cyclotron Progr. Rep., 10, 117 (1976).

120

8-3.

Inactivation of Ribonuclease A

in Solution by Cyclotron Beams

Y. Hattori, F. Yatagai, and A. Matsuyama

In connection with the development of a new biological irradiation device, the vessel for theirradiation of enzyme solution has been improved in this period. As the range in water of heavy
ion beams accelerated by the cyclotron is about 200J,Lm, we are forced to irradiate sample solution
in a vessel with a window of thin foil or film through which the ion beams are shot into thesolution. In the previous experiments l ), 2) we used a glass vessel with a flange to which aluminum
foil of 20J,Lm thickness was fixed with a screw cap, and the sample solution therein was agitated by amagnetic stirrer during the irradiation. Recently we have been aware that fluctuations in theexperimental results were largely attributable to the vessel which was apt to form bubbles in thesample solution by the agitation because of its shape and consequently to lead to error in thedose estimation. In order to improve this fault a new type vessel was tested. It is a cuvette forspectrophotometer modified by making a window of Myler film of 10,um thickness by pasting thefilm with adhesive agent to a hole (10 mm X 10 mm) made on one side of the cuvette. The
sample solution is irradiated with ion beams through the film under agitation by a magnetic
stirrer. This irradiation vessel has proved to give more reproducible results than before.
Using the new type vessel, dilute solution of ribonuclease (RNase) A was irradiated by N-ionsfocusing attention to the stability of remaining enzymic activity after irradiation. The result
obtained up to date suggests that the RNase solution irradiated with N-ion beam would be moreunstable when kept in the refrigerator than unirradiated control. The experiment is to becontinued.

References
1)

Y. Hattori, F. Yatagai, and A. Matsuyama: IPCR Cyclotron Progr. Rep., 11, 130 (1977).

2)

F. Yatagai, S. Kitayama, Y. Hattori, and A. Matsuyama: ibid., 12, 123 (1978).

121

8-4.

Studies on Mutation

Induction In Microorganisms by
eyc lotron Beam s

A. Matsuyama, F. Yatagai, A. A. Baradjanegara,*
K. Sone, * * and H. Matsuura * *1.

Irradiation of E. coli

Mutation induction in E. coli by ~-particles, C- and N-ions accelerated in the cyclotron wasstudied with its two strains, WP2 (try-) and Sd-4 (TC).

The reverse mutation from tryptophan

requirement in WP2 (try-) and from streptomycin dependence in Sd4 (TC) was induced by theseheavy charged particles with different behaviours in the two strains.

With strain WP2, the reverse
mutation frequency increased exponentially with increasing radiation doses l ) (Table 1). At doses
giving the same lethal effect, the mutational effect of both ~-particles and heavy ions was greaterthan that of 60Co ')'-rays.

On the other hand, in the case of strain Sd-4, the effect of N-ions onmutation induction was smaller than that of 60Co ,),-rays, although the effect of a-particles was
somewhat greater than the ,),-ray effect (Table 2).

Table 1. Mutation induction in -E. coli
WP2.
-

Type ofradiation

Beam

Total

energyLET(MeV/amu)(keV/J.Lm)("'0.4)60Co ')'-rays~-particles

C-ionsN-ions{(A)

Mutation
induction b)
(B)

Ratio
(B/A)

0.088

0.079

0.90

0.112

0.089

0.80

5.5

29.1

0.110

0.115

1.05

2.9

49.2

0.179

0.235

1.31

4.8

290

0.055

0.053

0.97

{ 2.4

330
468

0.019

0.022

1.18

0.038

0.053

1.41

4.8

392

0.042

0.050

1.20

4.1

a) Decrease in surviving fraction in log/krad.
b) Increase in revertants/I0 8 survivors in log/krad.

* Bandung Reactor Center, National Atomic Energy Agency, Indonesia.
** Kaken Chemical Co., Ltd.

Lethalitya)

122

Table 2. Mutation induction in E. coli
Sd-4.
-

Type ofradiation

Beam

Total

energyLET(MeV/amu)(keV/J.Lm)

Por D30CP''EA

Por DlO'EA
CP'(""'0.4 )

300

590

4.8

33.3

315

640

4.7

33.7

430

4.9

375

101

4.8

390

155

4.8

390

4.8

390

190

170

298

215

4.8

390

110

110

198

170

60 Co "1- rays{

a-particles

N-ions

Revertants/ 1~ 0 8 survivors

350
192
150

228

118

182
240

1.04.96 MeV / amu
L,,= 380keV / ,urn~

30

Unirradiated

'*;.,

10- 1
20

'-'
c

~1O

C

0-

w

~ O ~--~~~~~~~~~~~---Relat i ve potency
~
~

30

20

~

+-'

U

~
tlD

C

.;;:
.;;:

:s

5.2x 10Bparticles / cm2(f)( 11=117)

10- 2

Relative potency
~

30

'*-

(% )

14 X 109 particles / cm2(11 = 62 1

20
;.,

'-'
c

gs 10

0W

~

O ~------~~~~~~~~~---Relative potency

1O- 3

1......-__-----,!_ _ _----L_ _ _---,J--_

Primary particle fluence ( particles / cm2 )( %)Pig. 2.

Effects of N-ions (4.96 MeV/amu) on

Survival curve of Streptomyces
Pig. 1.
griseochromogenes spores for N-ionsthe frequency distribution pattern of blasticidin(4.96 MeV/amu).

S production by ~ griseochromogenes.

123

2.
Irradiation of Streptomyces spores
In the previous experiments on mutation induction by heavy ions using ¢JX 174 phage
infected into host cells of ~. coli, mutation induction in phage was observed only with
UV-preirradiated host cells. 2) Following this finding, mutagenic effects of cyclotron beams on
the frequency pattern of blasticidin-S production by Streptomyces griseochromogenes were
determined. Spores of this strain suspended in sterile distilled water were irradiated by a-particles
and N-ions without any pre- and post-treatments (Fig. 1) and subjected to the determination of thefrequency distribution pattern of relative potency with survivors at different doses. Tentative
results indicate that the potency distribution pattern in spreading out toward both higher and lower
sides after irradiation (Fig. 2). This trend was most remarkable at doses giving 1 - 10 % survival
and the variance in the relative potency distribution appeared to become smaller at doses exceeding
this level.

References
1)

A. A. Baradjanegara, F. Yatagai, F. Kaneko, and A. Matsuyama: J. Radiat. Res., 20,

2)

60 (1979).
F. Yatagai, S. Kitayama, Y. Hattori, and A. Matsuyama: IPCR Cyclotron Progr. Rep.,
12, 123 (1978).

124

9. RADIA TION MONITORING

9-1.

Routine Mon itoring

K. Igarashi, I. Usuba, S. Fujita, and I. Sakamoto

Results of routine radiation monitoring carried out on the cyclotron from April 1978 to
March 1979 are described.
No remarkable change in leakage radiation and residual activities was observed during thisperiod.

Some aspects of the leakage radiation are described in the following report.

Surface and air contamination
The surface contamination has been kept below 10- 6 J.lCi/cm 2 on the floor of cyclotron roomand the underground passage, and below 10- 7 J.lCi/cm 2 in the experimental areas, hot laboratory
and chemical laboratories. The contamination was wiped off twice a year, and immediately after
this decontamination, the contamination on the floor of cyclotron room and the undergroundpassage had been reduced to a value below 10- 7 J.lCi/ cm 2 .
When the accelerating chamber was opened, slight contamination of the air in the cyclotronroom was observed. The value of radioactivity concentration (beta-gamma) was 10- 12 J.lCi/cm 3.
(I)(2) Drainage
The radioactive concentration of the drain water from the cyclotron building was found to beof the order of 10- 6 - 10- 7 J.lCi/cm 3 . The total quantity of activities in the aqueous effluents inTable 1.

Annual exposure dose received by the cyclotron
workers from April 1978 to March 1979.
Collective

Number of persons"

Workers

Dose

10-100101-300

>300

dose

undetectable(mrem)(mrem)(mrem)(man-mrem)

3
3
2
4
8

2

Operators
Nuclear physicists
Accelerator physicists
Physicists in other fields
Nuclear chemists
Radiation chemists
Biological chemists
Health physicists

13
6
12
4
4
8
1

890
500
20
130
990

3

Total
Average annual dose per person:

33.0 mrem

Maximum individual annual dose : 420 mrem

10
2540

125

this period was about 53.5 J1Ci, and the radioactive nuclides found by the gamma-ray spectrometry
were mainly 65 Zn, 57 Co, 58Co, and, 60Co.
' (3) Personnel monitoring
The external exposure dose to personnel was measured with gamma-ray and neutron film
badges. The dose received during the present period by all the cyclotron workers is shown in
Table 1.

The collective gamma-ray dose to all workers was 2540 man-mrem, while those owing

to thermal and fast neutron exposures were too small to be detected.
The collective dose to the cyclotron workers is about five-sevenths of the value in thepreceding period. In this period the dose to the cyclotron operators was 890 man-mrem, whichwas 35.0 % of the dose of cyclotron workers, and the maximum individual annual dose was 420
mrem.

126

9-2.

leakage-Radiation Measurement at the Underground Passage

I. Sakamoto

Leakage radiation during operation of the cyclotron at the underground passage of thecyclotron building was measured. Leakage dose received from April 1978 to March 1979 by
gamma-ray and neutron film badges which were left at the underground passage, is shown in
Table 1. No machine time was allotted for deuteron acceleration in this period.
Among dose values at the point No. 1 measured every month, the maximum dose of 360
mrem was observed in November. In this case, the values of gamma dose and thermal neutron
dose were 290 mrem and 70 mrem, respectively.
Table 1. Leakage radiation dose (in mrem) at the undergroundpassage from April 1978 to March 1979.

!

:

!

!

!

!

o 1 2 345m

Experimental area ( L)I_

:I 2 "..L..-~.............--,
I~"'r----I:.~~--'

I
I

Underground passage/ :
I
I

: 1 ;

i t
I
I

WT

Control room

127

The fast neutron dose of 180 mrem was observed at the point No.2 in February 1979, but it
was not observed in other months in this period. As a result of the investigation, it was
concluded that the fast neutron dose was due to the 22 Me Vex-particle bombardment on a brassslit at about 100 nA in case of irradiation experiment in the beam course No.4. The slit will
be replaced by the one made of material which yields much less neutrons by alpha bombardment.

128

10. HEAVY ION LINEAR ACCELERATOR PROJECT

10-1.

Status of the Constructional Work

M.OderaThe constructional work of the linac which was started in 1975 by a contract with a factory tobuild the first resonator and has been pursued with many debates, troubles, contracts followed bycontracts with a number of firms is nearing completion.
The six resonators, the main vacuum system and the environmental radiation monitoring systemwere installed last year. They have been operated for a year and some defects such as vacuum leaks
or circuit failures which developed under various conditions were repaired and improved.
Meanwhile, high power test of the proto-type amplifier, coupled with the first resonator was
successfully carried out in January 1979. The multipactoring phenomenon in the cavity was
overcome within two hours after starting excitation of the cavity. A few days later, an
accelerating voltage of 80 % of design value was obtained across the drift tube gaps. Incorporating
the expelience obtained in that test operation, the final details of the amplifier design were fixed,
and an order was given to a factory to construct the remaining amplifiers. Installation of those
amplifiers began in March and was completed at the end of August 1979.

Figure 1 shows themain parts of the accelerator system in the vault.
Beam acceleration test was started in JUly. Firstly, alignment of the inj ector beam line and•then those of the drift tubes was examined using DC beam having a small emittance value. Ions
used were singly or doubly-charged nitrogen, neon and argon.

Acceleration simulation by the

first cavity was made in the variable frequency mode. Frequency change was found not
cumbersome at least in the range below 30 MHz used in the test operation. Drift of resonant
frequency of the cavity was not excessive and could be easily compensated manually. Fast
response of the feed back loops for the phase and amplitude stabilization seems not required.
Since, wiring and conditioning of the control system is still underway in the accelerator vault,
the acceleration test can not be very complete. However, performance of the power amplifier
has been found improving day by day and the maximum accelerating voltage has exceeded thedesign value in a week after the test has begun.

Stability of the amplifier against vacuum

sparking also improved by time, showing the effect of the surface condition of the vacuum
vessel on the operation of the amplifiers coupled with cavities.
Installation of the cooling system was finished in June. Though most of the system wasinstalled already in March, the Freon circulation system for cooling of the drift tubes was notcompleted until that month.
The polyethylen insulators used for measurements of the proto-type buncher characteristics
were replaced with the ceramic insulators so that insulation can withstand power test undervacuum. The length of the coaxial stem was shortened in order that the range of the resonant
frequencies desired can be covered in spite of increase of the dielectric constant of the insulators.
The low power characteristics were remeasured and were found in good agreement with those
expected.

129

Fig. 1.

The resonators and amplifiers in the accelerator vault , July 1979.

The beam bunch signal pick-up probes and beam profile monitors are being tested in the beamline together with the slits system. Those beam diagnostic elements use solely welded-bellows for
introduction of mechanical motion into vacuum .
Installation and wiring of the control system are somewhat behind the schedule and will befinished in the fall 1979. The delay is partly caused by the delay to fix detailed specifications ofcontrol sequences, which in turn are tightly related with the operation scheme of the ratio-frequency
amplifiers. Since the parallel operation of the six power amplifiers is still in the testing stage, thefinal operation scheme will not be fixed for a while. Therefore, acceleration test will be madetentatively by the local manual control. In view of the improvement observed in the amplifier
performance, the local operation mode does not seem difficult to carry out.
Figure 2 shows the plan view of the linac facility. The control and counting areas are united
in a single room in order to keep close contact between experimenters and accelerator operators.
Quick access to the irradiation rooms and the accelerator vault from this room is possible because
the rooms are on the same floor level except the biological experimental room which is situated
3.7 m under ground. Beams will be bent downward vertically into that room.

130

Target stations area
Inj ector room
Accelerator vault•

c==:::J •Control & countingo5!

Power supplies

Fig. 2.

Plan drawing of the linac facility.

10m
~

131

10-2.

Vacuum System

Y. Miyazawa

The vacuum system of the accelerator can be divided into three blocks: that for the injector,
six cavities and the beam lines in the experimental area. This report is confined to the descriptionof the vacuum equipment for the six cavities.
Each tank of the cavities has a volume of 11000 P and a surface area exposed to vacuum of
approximately 120 m 2 • Forty two percent of the exposed surface is made of stainless steel andthe rest is mostly of copper. Organic seals occupy 0.3 % of the exposed surface. Each tank isconnected to the next tank by a beam line of approximately 1.6 m which contains various
magnetic and diagnostic elements. This part of the vacuum system presents relatively large surface
area compared to volume. Figure 1 shows how the turbo-molecular pumps are connected to thetank. Conductance through the rf-compensator is 13000 .e/sec for air. Each tank is provided with
two turbo-molecular pumps having pumping speed of 5000 and 2400 -l/sec. Total pumping speed
through the rf-compensators is 4000 P/sec for air when the two pumps are used in parallel.

2400[ / 5oI-

( mm )

5000[ / 5500

Fig. 1.
Cross section of a cavity
and positions of the large capacity
turbo-molecular pumps.
A: Beam axis. B: rf compensatorsand pumping holes. C: Shorting
device.

Figure 2 shows a schematic diagram of the vacuum system. A roots pump (300 M3 / h) anda rotary pump (342 .e/min) are used as backing pumps for the two turbo-molecular pumps. The
European vacuum ISO type NW 63 pipes are used to provide the beam path between the tanks.
Roughing of the tanks from atmospheric pressure down to 0.5 Torr is accomplished by a 2500 M3 / hroots pump and a 6500 P/min rotary pump located on the lower floor of the accelerator vault. A
typical time for the tanks to reach 0.5 Torr is 7 min. When the pressure in tank reaches 0.5 Torr,a pressure switch (Pirani gauge) closes a valve (VR-) leading to the tank to prevent backstreamingof oil vapour from the mechanical pump. If the tank is dry and vacuum tight, it will reach the

132~ --------- MB~ S -------~
I
I

I
I

I
I

I
1
1

vs

I

PiG

17 500L/ M

1

IIL _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ __ I

I

I
I

I
1
L ____________________ J

Fig. 2.
Schematic diagram of the vacuum system .
TMP: Turbo molecular pump. MB: Roots pump.
RP: Rotary pump. G : Gate value.
VF-, V-, VR-: Butterfly value. PiG: Pirami gauge.
pressure of 1 X 10- 6 Torr in about 24 h. Figure 3 shows a typical pumping downcharacteristics of a tank. The calculated curve above 1 X 10- 6 Torr agrees well with the measured
value.
Table 1 shows the rate of outgassing from the surface of the tank exposed to vacuum.
Initial evacuation of the six tanks were made during the early period of 1978. First rf bake-in
tests of No.1 tank were made in January 1979. Any special treatment of the vacuum surfaces
was not done which will ease rf-excitation. When the rf power was turned on, intense glow
discharges were observed in the tank.
Full gradient of accelerating field was achieved in No. 1 cavity after one day of baking. Typicaloperating pressure in No. I tank when the beam is being accelerated is 9 X 10- 7 Torr. The
vacuum system has been in operation for 3000 h before the end of September. With exception ofa few minor problems the vacuum system for the cavities is working well.

133

I

No.2 Cavity

791001o Calculated

10- 5 --

10- 6 -

-

.B

~
~

0.
~

c

r'"

10 -7 '-----'-- - - ' - - -3'--41...-.1..5-'---'---'-'-1......
~--2.L..O - 3':-..
0 - 4':-..
0 --'50-'-''---'--"-'100
Time (h)Table 1.

Fig. 3.
Typical pumping downcharacteristics of a tank.

Outgassing rate as a function of pumping down time.
hour

Torr. .ejsec· cm 2

2

5

10

20

50

qcu

4 X 10- 5

2.2 X 10- 5

8.8 X 10- 6

4 X 10- 6

2 X 10- 6 5.5 X 10- 7

qg

7 X 10- 3

4.5 X 10- 3

2.5 X 10- 3

1.5 X 10- 3

7 X 10- 4 1.3 X 10- 4

qcu:

rate of outgassing of copper.

qg:

rate of outgassing of organic seals.

134

10-3.

Control System

T. Kambara, M. Odera, and S. Takeda

The Installation of the control system is now in progress with some delay from schedule.
In the linac vault, four data stations have been installed and the wiring between them andmagnet power supplies has been almost completed. Figure I is the photograph of one of thedata stations (right) and the power supplies for the drift tube quadrupole magnets of the cavities
I to 3. The data station has an intelligent interface HP2240A/2241A (two boxes at the bottom)
and signal conditioner modules (contained in five boxes above the interface). The intelligent
interface has a microcomputer which talks with a control computer via a GPIB and a serial link,
and provides input/output functions to control and monitor linac devices. The signal conditioner
modules are used for signal conversion and electrical isolation between the interface and linac
devices. Five types of signal conditioners are used: I) Analog input with amplification andisolation, 2) analog output (10 bit resolution) with isolation, 3) analog output (14 bit resolution)with isolation, 4) digital input from floating contact with optical isolation and 5) digital output
by contact with optical isolation. The signal conditioner modules have been manufactured, tested
and installed by the contractor.
In the control room, monitoring panels for cooling and vacuum systems, a graphic panel toshow the status of the whole linac system, and a control console have been set. The wiring for themonitoring panels and the graphic panel have been completed.

Fig. I.
A data station in the
linac vault (right) and magnet
power supplies.

Control console (right) and
Fig. 2.
monitoring panels and graphic panel on them(left) .

135

Figure 2 is a photograph of the monitoring panels, the graphic panel and the control console.
Two CRT's (HP2645A and HP2648A) which are connected to the control computer are installed in
the console to be used for the control of the linac.
The control computer system (HP system 1000) has been changed a little from that reported
previously. I) The operating system was upgraded from RTE-III to RTE-IV, and a CRT terminal(HP2621P) was added for exclusive use as the system console. An I/O extender was also added toallow future extension of the system. The graphic panel mentioned above is controlled by amicro-computer which talks with the computer with a high speed interface. In future we will
have another micro-computer for a control panel in the control console, interfaced to the computer,
where we can control the linac with more familiar devices (knobs, pushbuttons, switches etc.)
rather than alphanumeric keyboards of the CRT's. A block diagram of the resultant system isshown in Fig. 3.
Figure 4 is the layout of devices in the control room and in the computer room which is
air-conditioned separately.
The main part of the computer system has been installed and the software development isunderway in cooperation with the contractor.

.------Control

console -------.1

iCo~~I :II...._I
pane_l _ ..JII

r ,u:- ~--,:Computer I- - - I--...J
I

I

CPU
HP - 2 113B
Memory 96kw.
SystemconsoleQ
Disk

MagnetictapeCommunicationinterface
GPIB
Three otherstations

Fig. 3.

' - - - - - - Data station - - - - 'Block diagram of the computer system.

136

Control console

D

CPU Mag Tape
Disc and I/O

Power
supply(5kVA )

DO

§

bbfd

Monitoring panels.
for Cooling and
Vacuum systems
Graphic panel
is above them.

CRT

1, 1 1110 Radiation and door
1'"

OpticalCommunication
Terminalo2,moni toring panels

3m

t:::1=:::::±=::=:::JI~==::::J1

Linac
Vault

Fig. 4.

Layout of devices in the control room and the computer room.

Reference
1)

T. Kambara, M. Odera, and S. Takeda: IPCR Cyclotron Progr. Rep., 12, 131 (1978).

137

10-4.

Installation of the Cooling System

T. Inoue

Figure 1 is the diagram of the cooling system. The system consists of the part for the
injector and drift tube, and the main part. The former block was installed last year on theunderground floor of the accelerator vault and has been in operation since. It supplies highresistevity deionized water to cool the instrument on the high voltage terminal of the injector.
Table 1.

Symbols
CT-I
CT-2
CR-I
P-l
P-2
P-3
P-4
P-5

Specifications of the cooling system.

Apparatus

Power
(kW)

Weight(kg)

50 freezing-ton
500 freezing-ton
127000 kcal/h
500 £/min 5 kg/cm 2
100 £/min 9.5 kg/cm 230 £/min 5 kg/cm 2
10 £/min 2 kg/cm 21500 £/min 9 kg/cm 2

1.5
11
37
15
11
3.7
1.5
45

515
6300
1150
170
283
144
85
450

150 £/min 2 kg/cm 23500 £/min 6.5 kg/cm 2

1.5
55

90
610

150 £/min 4 kg/cm 2

3.7

105

600 £/min 2 kg/cm 2430 £/min 2.7 kg/cm 26400 £/min 3 kg/cm 21000 £ Stainless400£ Stainless2500 £ Stainless
500 e Steel. Anticorrosion
coatedlOOP Steel. Anticorrosion
coated78000 kcal/h
49000 kcal/h
75000 kcal/h
11500 kcal/h
10 P/min 5 X 10 6 ,Q-cm
18 P/min X 8 unit
5 X I0 6 n-cm

3.7
3.7
55

86
53
905
2850
700
3300
800

Specifications

P-6
P-7
P-8a
P-8b
P-9
P-I0
P-Il
T-l
T-2
T-3
T-4

Cooling tower
Cooling tower
Chilling unit
Freon pump
Injection deionizer water pump
Auxilary pump
Deionizer pump
Power amplifier deionizer
water pump
Deionizer pumpResonator cooling pump
Vacuum system
Cooling pump
Cooling tower pump
Chilled water pump
Cooling tower pumpFreon reservoir
Deionizer water reservoir
Deionizer water reservoir
Ordinary water reservoir

T-5

Expansion tank

HEX-l
HEX-2
HEX-3
HEX-4
FW-l
FW-2

Heat Exchanger
Heat Exchanger
Heat Exchanger
Heat Exchanger
Deionizer
Deionizer

}

220
970
690
2350
2670
70 X 8

It

138

CT-l

Automa tic
temperature
con trolInjector
Deionized water circuit

P-9
High insul ation
cooling pi pe
Liquid f;:reon circuitxw:r:

Dei oni zed water ci rcui t

CT-2

('()

xw

:r:

Ordinary water
circuit<:Tt--7----'--------1IP-l l

X

W

:r:

T- 5

Fig. 1.

Cooling system diagram. For meanings of symbols, see Table 1.

also contains a circulation system of liquid Freon and a chilling unit. It was built in advance ofthe main part of the whole system to provide coolant for test operation of the proto-type power
amplifiers and the injector. Installation of the main part was began from the fall last year when
the building for the experimental area was completed. A room was provided in this area for themain system. Therefore, the pumps and the heat exchangers of the injector and drift tube blockand the main part are located at the different parts of the accelerator building.

139

The main part has two circuits of ordinary water for cooling the resonators and the vacuum
pumps, and one deionized water circuit for the power tubes. Table 1 shows the specificationsof the whole system.

140

10-5.

Insulating Pipe and Column Structure for Supply of Coolant to
the High Voltage Term inal

T. Inoue

The maximum power dissipation of the instruments such as the ion sources or magnets on thehigh voltage terminal can be as high as 50 kW. In order to remove such a quantity of heatgenerated at the terminal, cooling by liquid coolant is preferable to forced air cooling. Coolant
other than water, for instance Freon 113, was a candidate because of its superior insulation
capability. However, when heat capacity, viscosity and density were taken into account, water
was considered to be the best medium as coolant.
Therefore, we decided to use long tubes made of Nylon to supply high resistivity deionizedwater.

Figure 1 shows a photograph of the structure designed to support the tubes.

It is madeof polyvinyl chloride and two identical units were fabricated. Each contain two 50 m tubes having
25.4 mm inner diameter. When the specific resistivity of water is 2 Megohm·cm, total leakage
current shall be less than 1 rnA at the terminal voltage of 500 kV. The supporting structure wasconstructed using adhesives and use of metals such as pipe connection fittings were madecarefully to minimize local high field.

No trouble has occurred for more than six months ofusage and leakage current is less than I rnA at 500 kV as expected.

Fig. 1.

Nylon tube supporting structure.

141

10-6.

Plate

Povver Supplies for

the Exciter Amplifiers of the /peR
Heavy-Ion Linear A c c e I era tor

Y. Chiba

The IPCR heavy ion linear accelerator consists of six resonators of variable frequency type,
having a tuning range from 17 to 45 MHz.1) Each resonator is excited through a respective highpower r.f. amplifier using a tetrode, RCA 4648, as the final stage.
Three sets of plate power supply are provided for the final stages. Each feeds two amplifiersin parallel and is capable of supplying the maximum r.f. output (at 45 MHz) with plate efficiencyof 60 % and power margin of ""7 %.

Their output powers and voltages are listed in Table 1

together with the maximum r.f. voltage at accelerating gaps of each resonator.
block diagram of no. 3 power supply. Two others have similar constitution.

Figure 1 shows the

The output voltage is adjustable by a step of ""2 kV in off power state by a remotely
controlled tap changer on the primary windings of transformer.

For initial curing of a new tube,

the tap changer also provides lower output voltages by delta-star conversion in the primaryconnection.
The rectifier is an oil convection cooled silicon diode stack; its series elements are equalized byparallel resistors and capacitors.
Table 1.

r.f. voltages and dissipations of linac resonators andoutput powers of plate power supplies.

Resonator No.

#1

#2

#3

#4

#5

#6

Max. peak r.f. voltage(kV)at accelerating gaps

180

200

230

250

280

300

Required r.f. power(kW)at 45 MHz for the max. gap
voltage

108

133

176

208

261

300

Plate power supply no.

#1

#2

#3

Rated output power(kW)

440

690

1000

Max. output voltage(kV)

14

14

16

The ripple voltage at the rated full load is ""3 % peak to peak.
load to the rated full load is ,...., 12 %.

The voltage drop from non

For protection of the 4648, an ignitron crowbar circuit is employed.

A rush current causedby sparking in a vacuum tube is detected by a small shunt resistor and triggers a SCR pulser; thenthe ignitron is fired by the pulser and shorts the output of power supply about 2 J,lS after the142Power distribution andswitching cubicle

Air corereactorITo no-l and 2 ----l. power
Isupplies
PF VC .
A. C
6 Ek V3¢{$'

OSo--+.- H --<::["'V:>-O:'0:

Transformer andTap changer

RectifierFilter. crowbar and control
cub icle

0.1 25 H,u--l-+~t-+-i>--7-+-<:r-o--Tl"o--+-+----,

I

I
I

-WIJ.

Motor

NO.6

Overcurrent ,I COlphase unbalance - -1
and ground curroI~-~~--.

VC co 0"011 " ood
D.C.overcurrent relay---.JamplifierIi

L ______ ~Fig. 1.

Block diagram of plate power supply No.3.

DS: disconnecting switch
PF: power fuse
VC: vacuum contactor

PT: potential transformer
CT: current transformer
ZCT: zero phase CT

outbreak of the rush current. Following the crowbar operation, a vacuum contactor takes 40 ms
to open the primary 6.6 kV lines. Surge currents on those lines during this period are limited to"'7 times as large as the rated full load current by leakage inductances of the transformer andexternal series air-core reactors.
The system is protected by overcurrent relays in both a.c. and d.c. sides, a phase unbalance
relay, ground current relay and power fuses in a.c. side.
The whole system is accomodated in 12 X 13 m 2 area in the power supply building
neighbouring the accelerator building.
These power supply systems were manufactured by Nihon-Koshuha Co. , Ltd. according to
the basic plan of IPCR.
The installation was finished at July 1979.

Reference
1)

M.Odera: IPCR Cyclotron Progr. Rep., 1, 140 (1973).

143

10-7.

Initial Operation of the Proto-Type Power Amplifier
Coupled with the First Cavity

Y. Chiba

The radio-frequency system for generation of the accelerating voltages specified by beam
dynamics,1) is composed of six high power amplifier chains coupled to each cavity separately. The
maximum power consumption in each cavity is indicated in Table 1 of the report on the plate
power supply.2) Except for the difference in the output power specifications, the components andstructure of the amplifiers are perfectly the same. A proto-type amplifier was built and its
characteristics were investigated to set final design of the amplifiers. Figure 1 shows schematicallythe diagram of the proto-type amplifier. A frequency synthesizer supplies low level signals ofaround 10mW to the six amplifier chains.

Each chain has an amplitude and phase controller as

the first stage and a solid state wide band amplifier having 100 W capacity as the second stage.
Then a vacuum tube amplifier amplifies the signal to 2 kW and excites the last stage power tube.
Both stages are grounded cathode tuned amplifiers using tetrodes.
Ampl. phase detecto r
Dri ft tube

Five
other
units

4CX3000 A
Amp\. & 10
phase
mW
compa rator

Wide
band
Amp.
100W

I

I
I

I
I

:~

13
1

.

lar
I~

5:

E

o

,...-i

IQ)

Ampl. &
phasereference

I. s:

ILL

Automa ti ctuningsystem,....--------'-------,Fre q.
Synthesizer' - - -------'

No.1 Cavity

17-45MHz

Fig. 1.

I

I

I

Plate power
supply195kW
Vmax = 14kV

* Tuning stu bs

Radio-frequency power amplifier diagram .

Test of the amplifier with a water-cooled resistance as a dummy load was done in autumn
1978. Then it was coupled with the first cavity via a power feeder. The mode of coupling is
capacitive. Impedance matching between the cavity and the feeder is made by changing theinsertion depth of the capacitance disk into the cavity; it forms the front end of center conductorof the feeder. The impedance seen from the plate of the output power tube is adjustable by avariable capacitor placed at the entrance to the feeder.
Excitation test of the cavity was started on Jan. 12 , 1979.

The multipactoring phenomenon

characterised by glow discharge and very small power drain to the cavity from the amplifier144

persisted for two hours. In the meantime, the vacuum pressure in the cavity improved gradually
except occasional sudden increases of pressure caused by sparking. In order to get through themultipactoring region we applied sharply rising signal to the control grid of the power tube so thata sufficiently large voltage develops across drift tube gaps before the phenomenon grows. Once alarge voltage is generated, condition for the secondary electron multiplying phenomenon disappears.
However, if the gap voltage is allowed to grow further it soon will become larger than the voltage
holding limit of the gap and sparking will begin. We found it possible to overcome this difficulty
by use of a frequency slightly detuned from resonance. Of course the method would not havebeen necessary if the voltage stabilization scheme by feed back of the cavity signal to the firststage of the amplifier was available.

However, the feed back loop was not completed at that time.

Frequency used for the first operation was 20 MHz. Later, excitations of the cavity upto
30 MHz were realized without difficulty. Accelerating voltage, 80 % of the design value at 20
MHz was obtained within a few days after the test operation was started. Voltage holding test atother frequencies was postponed because of lack of time. The temporary wiring and plumbing
made for the test run around the amplifier system had to be rebuilt into the final ones and thework started from Jan. 20th.
Operation above 30 MHz was found a little unstable probably because of insufficientperformance of the screen grid by-pass condensers at high frequencies. Their improvements areunder investigation. Other modification of the amplifier structure or components was found almost
unnecessary. However, for the sake of operational simplicity, the output power capacity of thewide band amplifier was increased to 250 Wand the tetrode 4CX3000A was replaced with agrounded grid triode 3CX3000A 7, so that no tuning is necessary up to this stage. Thisconfiguration was planned at first but it took years for the factory to manufacture a solid state
wide band amplifier of 250 W capacity and we had to use tentatively the circuit shown in Fig. l.
Incorporating those modifications final design of the amplifiers and the power feeders wasdetermined and orders were given to the factories to fabricate remaining parts. Those werecarried in, assembled and coupled with the cavities before November 1979. Tuning of each RF
system is in progress.

References
1)

T. Tonuma, F. Yoshida, and M. Odera: Reports I.P.C.R., (in Japanese), iI, 53 (1975).

2)

Y. Chiba: IPCR Cyclotron Progr. Rep., 13, 141 (1979).

145

10-8.

Current Load of the Injector High-Voltage Generator
without Beam

Acceleration

M. Hemmi

Current load of the injector high voltage generator was measured before carrying out the beam
acceleration test.

Figure 1 is the schematic diagram of the injector system.

Table 1 gives

various parameters at the time of measurement. Current drain from the high voltage generator as
a function of voltage is shown in Fig. 2. Total load is 1.2 rnA at 500 kV. After subtracting
known contributions from the resistances attached between the terminal and the ground, 0.7 rnA
remained. It is the current drain, of which origin we are most interested in. Since resistance ofwater in the coolant supply structurel) is roughly 1000 Mil , 0.5 rnA flows through deionized
Fig. l.

Schematic diagram of the injector
showing parts which contribute to current
load.
1) Pipes to supply cooling water to the%1-1r---+-+--+-+I'l:::!: Ion source· i terminalIntermediatestage

terminal, 2) Divider chain of acceleratingcolumn, 5000 MD.. 3) Divider chain for lightsignal guiding cable cover, 4400 MD..
4) Divider chain to give half of the terminal
potential to the intermediate stage, 3340 MD.,
5) Precision resistance for feed backstabilization of the high voltage, 3000 MD..

Table 1.

Values of parameters at the time of the load current measurement.

Ambient temperature:
Relative humidity:
Pressure in the accelerating column:
Specific resistivity of cooling water:
Resistances of various voltage dividers:Accelerating column:
Fiber optic cable container:
Divider to supply voltage to theintermediate stage of the highvoltage terminal and the motor
generator:
Precision resistance network
for stabilization of thehigh voltage:

23° C
50 %
5.2 X 10- 7 Torr
4MD.-cm
5000 MD.
4400 MD.

3340 Mn

3000 MD.

146

1.0mA

OSmA

Fig. 2.
Current drain as a function of
the terminal voltage. Some deviation

o

lOOK

200K

300K

400K

500 kVR z = 943MQ

from linear relation is seen. Calculated
contributions of various resistances arealso indicated.

water. The remaining 0.2 rnA may be the leakage current over the surface of the insulators or thecurrent lost by Corona discharge. The deviation from linearity seen in the high voltage region
might be attributed to the occurrence of discharge.

Reference
1)

T. Inoue: IPCR Cyclotron Progr. Rep., 11, 137 (1979).

147

10-9.

Pe rformance Test of In jector System

M. Kase, M. Hemmi, and S. Nakajima

Figure I shows schematically the system of the injector and low energy extension. The
qualities of nitrogen-ion beam from the injector were examined for the test of performance of theinjector system.
For producing the nitrogen ions the axially extracting PIG ion source!) was used because of
its comparatively good beam emittance and easy handling. The ion-extracting voltage, Vext' of
the ion source was fixed to 10kV in the test.
The beam profiles were observed at position A shown in Fig. I using a wire probe. Variationsof the beam width with the injector voltage, Vinj , are shown in Fig. 2. As seen from the figure,
Injector
A
)

~0/

/

DQ 1

~
BMI

~

0-500kV
Acceleration

l

BS 1

Ion source-=tfIt----'j'-7-0~_L:-_1:~

p rHl ~BD-~ 1~-----m ~v JF0-----tube

BS 2D ~SL 2 Emittancemonitor

.

v..

In).

v.

e% t

Q:] '--"'" /First cavity

7~

BS5

~

i

L5

o

TQ

DOD

BS4 ~
M2
~ ~ L4- - -0-~ BS

r-----;

Beam stopperBM

Bending magnet

DQ

Doublet quadrupole magnet

T Q ... Triplet quadrupole magnet

1m

Fig. 1.

~ S L ... Slit

D

Schematic view of the system of injector and low energy extension.

5

4
/

E

/

~3

/
I

Fig. 2.

..c

-D

'3i

E
ro

Variations of beam widthwith Vinj without magnetic fields in
DQ 1. 0 is for the case when theelectric fields of the acceleration
tube is constant; 6. is when the

2

Q)

co

electric field of the first two
O ~--~10~O~--2~OO~--3~O-O---4~O-O--~500
Injector voltage( kV )

sections of the acceleration tube ishalf that of the other 23 sections.

148

the tendency of beam broadening with Vinj can be reduced by lowering the electric field of thefirst two sections of the acceleration tube. The beam emittances were also measured at the same
position with emittance monitor 2) and the results for Vinj = 300 kV and 500 kV are shown in
Fig. 3 (a) and (b) , respectively. The beam currents after being analysed through the first bending
magnet BM I were measured by the beam stopper BS3. The results were 0.9 J1A for N/ beamand 5 J1A for N/ beam with the best adjustment of magnetic fields of the doublet quadrupole
magnet DQ 1 and BM 1. The component of the molecular ion beam is large mainly because thearc power of the ion source is small. We comfirmed that these beams could be transported to
BS5 at the entrance to the first cavity without appreciable beam losses.
( m rad )

( al

10
_ .-

X component-- -\ . component

10

20

30

( mm )- 10
10 r m rad )- - .\ component- - - \. component

-30

10

20
( mm )

30- 5

Fig. 3.
Beam emittances, (a) for VillJ..
= 200 kV and (b) for 500 kV. These- 10

data were obtained without magnetic
fields in DQ 1.

References
1)
2)

S. Nakajima: IPCR Cyclotron Progr. Rep. , !1, 141 (1978).
J. Schimizu and M. Odera: ibid., p. 133 .

149

10-10.

Beam Buncher Characteristics

M. Yanokura and M. Odera

The proto-type buncher reported previouslyl) was modified for practical use and its
characteristics were examined. The vacuum sealing insulators made of polyethylene at the drift
tube gaps were replaced with high frequency ceramic insulators made of alumina. The lengthof the coaxial stem was shortened to get desired resonant frequency, in spite of the increase of
capacity by change of the dielectric constant of the insulators at the gaps. Position of theradio-frequency power coupler was determined taking into account the decrease of Q-values. In
order to simplify operation, the usual scheme of changing coupling strength according to frequency
was not adopted. Instead, a wide band power amplifier is provided which can supply necessary
power irrespective of change of input impedance at the coupling point.

The amplifier canfunction under occurence of some power reflection from the buncher cavity. Since the shunt
impedance of the cavity at low frequency is lower than that at high frequency, coupling point near
the shorting end of the coaxial stem was chosen to give smaller SWR at lower frequency than at
higher frequency. A water cooling circuit for the center conductor and a blower for forced air
cooling of the insulators and the variable vacuum condenser were added for power testing. Figure I
shows the input impedance. Closed circles show measured values and open circles calculated
ones. The agreement is excellent. A wide band amplifier having I kW capacity is used as an
exciter. Test under vacuum showed the occurence of multipactoring phenomenon, but it could be
easily overcome. The reason is probably the use of the insulators which limits the exposure ofresonator surface in the vacuum to only a small portion of the drift tube where voltage develops
rapidly. Fast rise of voltage across the electrode gaps is known to be effective to suppress themultipactoring process. Figure 2 is the buncher in the injection line, at 3 m upstream of the firstcavity.
Impedance ( Q )

50

100

150

20

I

:E

:: 30
u

cQ)

:::J

cr
~

u..

40

o

Vacuum condenser position ( relative )Fig. 1.
Change of the input
impedance at the coupling point
and vacuum condenser position
with frequency. Closed circles
show measured values; open
circles show calculated ones.

150

Fig. 2.

A photograph of the buncher in the injection

beam line, 3 m upstream of the first cavity.

Reference
1)

M. Odera, 1. Takeshita, and F. Yoshida: IPCR Cyclotron Progr. Rep., !l, 145 (1977).

151

10-' 1.

Design of a Magnet for the Side-Extraction PIG- Type Ion Source

Y. Miyazawa, M. Yanokura, M. Hemmi, F. Yoshida,
M. Kase, and M. Odera

The axial extraction PIG ion source reported previouslyl) is being used for initial acceleration
test of the linac system. 2) With its small emittance of the extracted beam and simplicity ofoperation, it is a convenient tool for testing purposes. However, it can not yield multiply charged
ions. In order to produce ion of a large charge to mass ratio for heavy elements, we have planned touse a side-extraction indirectly heated cathode PIG source with which we have some experiences. 3)
A new magnet for the ion source was designed, fabricated and installed in July 1979.
For proper operation of the source to produce enough quantity of the multiply charged ionsof heavy elements, the height of the anode chimney in which the arc plasma is formed bydischarge must be long enough than a certain length. The pole gap of the magnet ought to belarge in order to be able to accept such an ion source. We chose 15 cm for the gap length. The
large gap makes the fringing field extend far out of the edge of the magnet, and also requires alarge excitation current to get the necessary field. Since the power available on the high voltage
terminal on which the magnet is to be installed is limited, some compromise must be made among
the maximum field strength, mass to charge ratio, trajectory curvature and extractor voltage.
Figure 1 shows region of parameter values chosen. Then by using a hard edge approximation, arough survey of the orbit properties such as horizontal and vertical focusing length was made bychanging rotation angles of the beam up to the effective field boundary and angles of exit.
Nearly parallel beam in both the horizontal and vertical directions is desirable to get a good focus
at the entrance of the accelerating column by use of an einzel lens. Figure 2 shows two examples
of such surveys. A number of configurations were chosen from such parameter search, and the
trajectories were calculated for each case taking into account the extended fringing field. The
field distributions were calculated using a program "MAGNET".4) A combination of therotation angle of 120 degree and exit angle of 30 degree was judged to give trajectories nearlyparallel horizontally and vertically. Since field patterns given by "MAGNET" code is for poles
rf:t- Uper limit of voltage~~~\:) I \D.
~\ - - ~ . v~ -?

8,-----.---------r--7

1-----+-~7'_+_-__r___+-? ~_ ~_~__~~\J---- Uper limit

1/

(j)

~ 6

of magnetic fieldC)~ 5000 ~--~~~74-----r-~--~~Acq___ ___ _ 1 _ _ _ _ __ __ Lower limit~ 4
of magnetic field
1

..g 3
Q)

c

~
L

2

Po= 12$ (mm )Fig. 1.

o

10

20

30

Ion extraction voltage Vex (kV )40

Diagram showing range ofparameters intended for theside-extraction PIG source.

152

( b)

( a)

,

n=0.05

40

40

o

'

........

,

tn'
(Y) ,

40

/I ~

&..',
•

40

1

<::).. 1.......... 1:::1....:)1<::)..

"----

20

1
1

Convergent
Convergent

- 20

-20

Exit angle f3

Fig. 2.

20

Exit angle f3

Two examples from parameter searches under the hard edge approximationfor orbit calculation: a) field is uniform within boundary, b) outward falling gradientwith field index of 0.05 along the trajectory . 4p , rotation angle ; {3, exit angle; Lh and Lv
are horizontal and vertical focusing length measured from the effective boundary .
p is the radius of curvature of beam in the field.

infinitely long perpendicular to the plane in which the distribution is calculated, the trajectories
obtained for such field are not necessarily coincident with the real ones. For the pole face shapechosen, the effect of finiteness of the magnet is a slight outward fall of the field for substantial
portion of the orbit. As seen in Fig. 2 the existence of such field gradient makes beam lessconvergent horizontally and less divergent vertically.
Therefore, the field of real magnet was measured. The relative distribution was foundconstant with the change of exciting currents. Then, the numerical calculation of the orbit using
measured distributions was carried out to accurately determine correct position and configurationof the ion source in the high voltage terminal. The magnet was installed in the terminal using theresults of the calculation. Table I shows specifications of the magnet and Fig. 3 is the plandrawing of the magnet and the vacuum chamber. Figure 4 shows the horizontal trajectory
calculated.
Table 1.
Pole gap
Pole area
Maximum field
Maximum current
Total Amp. turns
Total weight

Specifications of Magnet.
150 mm
200X280 mm 27200 gauss
150 A
1.2XI0 s AT
3000 kg

153

CiJ

c

1180
(1300 )

'E

.& 70

380

<l.l

CD

2

o>

Extraction electrode

..c

CD

I

Fig. 3.

Plan drawing of the magnet and the vacuum chamber.

/P;e - -,~J--------I ex Ar

2+

Bo = 7 156.8 gauss
Vex = 19 3kV

IIi;~Sf~~~m~

I

\

V /'

Fig. 4.

Calculated beam trajectory in the measured fieldof the magnet manufactured.

The results of this calculation show that beam extracted with spreading angle of ±10° becomesa nearly parallel beam at the exit of einzellens and well focused beam can be injected into thecenter of the acceleration tube.

References
1)

2)
3)
4)

S. Nakajima: IPCR Cyclotron Progr. Rep., 12, 141 (1978).
M. Kase, M. Hemmi, and S. Nakajima: ibid., 11, 147 (1979).
I. Kohno: ibid.,!, 13 (1967).
Ch. Iselin: CERN Computer Program Library T 600.

154

10-12.

Performance of the Quadrupole Magnets of the BeamTransport

SystemM. Hemmi and F. Yoshida

Characteristics of one of the quadrupole magnets fabricated using the tape-coil technology ascomponents of the beam transport systeml) was measured.

Table 1 shows its specifications.

Main difference from the quadrupole magnets of the drift tubes 2) is its coil cooling method whichuses metal disks having coolant channels ernbedded within and pressed tight to get close contact
with the end surfaces of the coils.
coil.

There are thin insulating layers between the disks and the

The insulation consists of thermo-conductive epoxy resin layers painted and polymerized on

the disks and layers of thermoconductive grease which usually is used for heat sink of high powertransistors. Since heat transfer across insulator layers is not efficient when compared with thedirect flood cooling technique applied to the drift tube magnets, care was taken to keep the
thickness of the layers as thin as possible. Temperature difference across the layers was calculated
for the best (epoxy 100 ,urn, grease 200 ,urn) and the worst (epoxy 100 ,urn, grease 500 ,urn) cases
as was made previously. 2)
Table 1.

Design specifications of the quadrupole magnet.

Maximum lens strength in normal operation
Distance between poles
Axial length (mechanical)
Type of coil
Number of turns
Cooling method

Power consumption

60 kG
63.5 mm ~360 mmTape coil wound from 0.8 mm copper
sheets65
Conduction cooling by the watercooled plates attached at each end of
the coil
950 W max. for each coilg.lFigure 1 is the excitation curve for the field gradient. Upper limit of the current determinedby the temperature rise of the insulator is above the design value and a sufficient margin of safety
has been realized for normal operation. Change of temperature on the surface of the innermost
turn of the coil at the center along the axial length was measured by a resistance thermometer andis shown in Fig. 2. The result is satisfactorily nearer to the curve calculated for the best casethan to that of the worst case. The theoretical curves were calculated assuming radial heat flow
across the interlaced layers of the copper and insulator as well as axial flow within copper sheets. 3)
Effective axial length deduced from the fringing field is 38.5 cm. The field gradient of 1.56
kG/cm at normal operation multiplied with this effective length gives the design lens strength of
60 kG mentioned in Table 1. Position of the field boundary which is apart from the pole edge
by about 20 % of the aperture does not move for change of the field strength shown in Fig. 1.

155( kG/em)

2.0

[ ,."
calculation~ ~,. "" L' 't f
~~,.
Iml 0
Limit of excitation set~~
excitati.on
in the design based on
the temperature riseestimated.

/. ~1.:1.:

determinedby the. temperature nse
measured.

100
80

1.5

60
Measured

40
~

5J

1.0

30

tlO

cv

'0

h

20

"'l

I 360mm I

15-s.

--- ' -J~
I
I ~

0.5

10
8
6

o

100

4

I

50

100

150 A

Coil Cur rent

Field gradient as a function ofFig. 1.
coil current. Number of turns per poleis 65.

Fig. 2.

Temperature rise of the coil at thecenter of the innermost turn as a function ofcurrent. Cal. 1 is that calculated for the casewhere the thickness of the insulation filler
between end surface of the tape coil and thecooling plate is maximum and Cal. 2 is that
calculated for the most favorable case. See,
Ref. 3.

Deviations from the quadrupole symmetry of the field were measured by a Hall probe. The
sextupole (n = 3) component at the radial distance of 80 % of the aperture was 5 % of the main
field. Other significant higher harmonics was that of n = 5 and was around I %. Those
percentages also remained constant against change of field gradient shown in Fig. 1.

References
1)
2)
3)

M. Hemmi, Y. Miyazawa, M. Odera, and F. Yoshida: IPCR Cyclotron Progr. Rep., 11
138 (1978).
Y. Miyazawa, T. Inoue, M. Hemmi, Y. Chiba, F. Yoshida, and M. Odera: ibid., 10, 130(1976); Y. Miyazawa, T. Inoue, and M. Odera: ibid., 2, 113 (1975).
M. Hemmi and F. Yoshida: ibid., 10, 145 (1976).

156

11. LIST OF PUBLICATIONS

1.

Machine development and accelerator physics

2.

Nuclear physics and nuclear instrumentation
1) A. Neskakis, R. M. Lieder, H. Beuscher, Y. Gono, D. R. Haenni, M. Muller-Veggian, andC. Mayer-Boricke: "Observation of Rotation-Aligned Band in the Odd-Odd Nuclei
190, 192, 194Au", Phys. Lett., 80B, 194 (1979).
2) H. Amakawa, S. Yamaji, A. Mori, and K. Yazaki: "Adiabatic Treatment of Elastic
Deuteron-Nucleus Scattering", Phys. Lett., 82B, 13 (1979).
3) H. Amakawa and K. Yazaki: "Adiabatic Treatment of Deuteron Breakup on a Nucleus",
Phys. Lett., 87B, 159 (1979).
4) T. Nomura, H. Utsunomiya, T. Inamura, T. Motobayashi, and T. Sugitate: "Energy
Relaxation during the Fusion Process Probed by Pre equilibrium a Emission in Heavy-Ion
Reactions", J. Phys. Soc. Japan, 46, 335 (1979).
5) N. Kishida and H. Ohnuma: "Exact Finite-Range DWBA and Adiabatic-Deuteron-Breakup
Calculations Including the Deuteron D-state for the 58Ni(p, d) 57 Ni Reaction at 52 MeV",
J. Phys. Soc. Japan, 46,1375 (1979).
6) M. Muller-Veggian, H. Beuscher, R. M. Lieder, Y. Gono, D. R. Haenni, A. Neskakis, andC. Mayer-Boricke: "10+ Isomers Observed in Even-E~en 78 Neutron Nuclei", Z. Physik,
A290, 43 (1979).
7) K. Sato, S. Yamaji, K. Harada, and S. Yoshida: "A Numerical Analysis of the Heavy-Ion
Reaction Based on the Linear Response Theory", Z. Physik, A290, 149 (1979).
8) Y. Gono, R. M. Lieder, M. MuUer-Veggian, A. Neskakis, and C. Mayer-Boricke:"In-Beam 'Y-Ray Study of 189,191,193 Au", Nucl. Phys., A327, 269 (1979).
9) H. Amakawa and K. -I. Kubo: "Analyzing Power of Two-Step (P, t) Reaction Leading
to the Unnatural-Parity State", Phys. Rev., C19, 2403 (1979).
10) T. Tamura, T. Udagawa, K. E. Wood, and H. Amakawa: "Exact Finite Range DWBA
Form Factor for Heavy-Ion Induced Nuclear Reactions", Comput. Phys. Commun., ~,163 (1979).
11) S. Yamaji: "Analysis of Heavy-Ion Reactions Based on the Linear Response Theory",
Sci. Papers I.P.C.R., 73, 19 (1979).
12) J. Fujita and M. Ichimura: "Mesonic Effects in Photonuclear Sum Rules", Meson in
Nuclei, (eds. M. Rho and D.H. Wilkinson), North-Holland Pub. Co., Amsterdam,

1:, 627 (1979).
3.

Atomic and solid-state physics
1) N. Shiotani, T. Okada, H. Sekizawa, A. Nakamoto, H. Murakami, and K. Mori: "A Two
Dimensional Position Sensitive 'Y Ray Detector for Angular Correlation Measurements",
Proc. 5th Intern. Conf. Positron Annihilation, The Japan Institute of Metals, Sendai,
p.267 (1979).
2) N. Shiotani, T. Okada, N. Sakai, H. Sekizawa, and S. Wakoh: "Angular Correlationof Positron Annihilation Radiation and Compton Profiles in Magnesium", Proc. 5th

157Intern. Conf. Positron Annihilation, The Japan Institute of Metals, Sendai, p.669 (1979).
3) K. Hinode, S. Tanigawa, M. Doyama, K. Shiraishi, and N. Shiotani: "Positron Lifetime
Study of Gas Bubbles", Proc. 5th Intern. Conf. Positron Annihilation, The Japan Instituteof Metals, Sendai, p.733 (1979).
4) N. Owada, H. Kumakura, K. Hinode, S. Tanigawa, M. Doyama, S. Okuda, and N. Shiotani:"The Annealing Study of 3He and Neutron Irradiated Platinum by means of Positron
Annihilation", Proc. 5th Intern. Conf. Positron Annihilation, The Japan Institute of
Metals, Sendai, p.775 (1979).
5) S. Tanigawa, K. Hinode, R. Nagai, M. Doyama, and N. Shiotani: "Effect of Doping
and Thermal Vacancies on Positron Annihilation in Semiconductors", J. Appl. Phys.,
18, 81 (1979).
6) M. Uda, H. Endo, K. Maeda, Y. Awaya, M. Kobayashi, Y. Sasa, H. Kumagai, andT. Tonuma: "Bonding Effect on F K~ Satellite Structure Produced by 84 MeV N4+ ",Phys. Rev. Lett., 42, 1257 (1979).
..

7) T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, 1. Kohno, and S. Ozkok: "Argon Ka
X-ray Satellites Produced by Impact of Nitrogen Ions in the 4.7 - 7.8 Me V /amu
Energy Range", Phys. Rev., A20, 989 (1979).
8) T. Takahashi, Y. Awaya, T. Tonuma, H. Kumagai, K. Izumo, A. Hashizume, S. Uchiyama,
and A. Hitachi: "Energy Straggling of C and He Ions in Metal Foils", Nucl. Instr. Meth.,
166, 587 (1979).
9) Y. Awaya, K. Izumo, T. Katou, H. Kumagai, T. Tonuma, Y. Tendow, T. Takahashi,
A. Hashizume, and T. Hamada: "The L X-rays Following Multiple Inner-Shell Ionization",
Atomic Collision Research in Japan Progress Report,~, 81 (1979).
4.

Radiochemistry, radiation chemistry and radiation biologyI) F. Yatagai, S. Kitayama, and A. Matsuyama: "Inactivation of Phage ¢X 174 by
Accelerated Ions. Enhanced 8-ray Effect by Air Layer in Front of the Samples ",Radiat. Res., 77, 250 (1979).
2) T. Nozaki, M. Iwamoto, and Y. Itoh: "Production of 77Br by Various Nuclear
Reactions", Int. J. appl. Radiat. Isotopes, 30, 79 (1979).
3) T. Nozaki, Y. Itoh, and K. Ogawa: ~'Yie1d of 73 Se for Various Reactions and Its
Chemical Processing", lnt. J. appl. Radiat. Isotopes, 30, 595 (1979).
4) T. Nozaki, M. Iwamoto, K. Usami, K. Mukai, and A. Hiraiwa: "Helium-3 Activation
Analysis of Oxygen in Silicon Nitride Films on Silicon Wafers", J. Radioanaly. Chern.,
52, 449 (1979).

(Papers presented at meetings)
1.

Machine development and accelerator physics
1) N. Nakanishi, N. Hda, S. Motonaga, T. Wada, and F. Yoshida: "Orbit Calculation I in
IPCR SSC", Ann. Meeting of Phys. Soc. of Japan, Osaka, Apr. (1979).
2) M. Odera, Y. Chiba, M. Hemmi, Y. Miyazawa, T. Tonuma, T. Kambara, T. Inoue,
M. Kase, M. Yanokura, E. Ikezawa, and F. Yoshida: "Status of the Riken Linear

158

Accelerator", Autumn Meeting of Phys. Soc. of Japan, Kochi, Oct. (1979).
3) N. Nakanishi, N. !ida, F. Yoshida, and H. Kamitsubo: "Orbit Calculation II in IPCR
SSC", Autumn Divisional Meeting of Phys. Soc. of Japan, Kochi, Oct. (1979).
4) Y. Yano, T. Wada, F. Yoshida, and H. Kamitsubo: "Design of Injection System for
RIKEN SSC 3", Ann. Meeting of Phys. Soc. of Japan, Kochi, Oct. (1979).
5) T. Wada, Y. Yano, F. Yoshida, H. Takebe, H. Kamitsubo, S. Motonaga, and K. Ogiwara:"Design of Injection System for RIKEN SSC 2", Ann. Meeting of Phys. Soc. of Japan,
Kochi, Oct. (1979).

2.

Nuclear physics and nuclear instrumentation
1) A. Ichimura and M. Ichimura: "Coulomb-Nuclear Interference Phenomena and the
Quadrupole Moment of 18 0", Ann. Meeting of Phys. Soc. of Japan, Osaka, Apr. (1979).
2) H. Amakawa, S. Yamaji, A. Mori, and K. Yazaki: "Adiabatic Treatment of Elastic

Deuteron-Nucleus Scattering", Ann. Meeting of Phys. Soc. of Japan, Osaka, Apr. (1979).
3) H. Amakawa and K. Yazaki: "Adiabatic Treatment of Deuteron Breakup on Nucleus",
Ann. Meeting of Phys. Soc. of Japan, Osaka, Apr. (1979).
4) A. Hashizume, T. Katou, Y. Tendow, and H. Kumagai: "High Spin Status Excited with
144Nd + 20Ne Reaction", Spring Divisional Meeting of Phys. Soc. of Japan, Osaka, Apr.

( 1979).
5) H. Amakawa, S. Yamaji, A. Mori, and K. Yazaki: "Validity of the Adiabatic Treatmentof Deuteron-Nucleus Scattering", Ann. Meeting of Phys. Soc. of Japan, Kochi, Oct.
6)

7)
8)

9)

10)

( 1979).
T. Sugitate, T. Nomura, M. Ishihara, and H. Utsunomiya: "Correlations between Heavy
Ions and Alpha Particles in the 27 Al + 14N Reaction at 95 MeV", Ann. Meeting of Phys.
Soc. of Japan, Kochi, Oct. (1979).
M. Yanokura, I. Kohno, Y. Nagame, and H. Nakahara: "Fission-like Events of 14N + 58Ni
System", Ann. Meeting of Phys. Soc. of Japan, Kochi, Oct. (1979).
H. Utsunomiya, T. Nomura, M. Ishihara, T. Sugitate, K. Ieki, and Y. Gono: "Relaxation
Phenomenon of Angular Momentum in Heavy-ion Reactions", Ann. Meeting of Phys.
Soc. of Japan, Kochi, Oct. (1979).
T. Kubo, N. Kishida, H. Ohnuma, T. Hasegawa, N. Ueda, T. Fujisawa, T. Wada, K. Iwatani,
and T. Suehiro: "(d, p) and (p, d) Reaction of en = 0 and the Spin-orbit Terms ofDistorting Potentials", Autumn Divisional Meeting of Phys. Soc. of Japan, Kochi, Oct.
(1979).
N. Kishida, J. Kasagi, T. Kubo, T. Murakami, Y. Kamatani, H. Ohnuma, and M. Yasue:"Measurement of Particle-,), Angular Correlations for the 58Ni(p, d)57 Ni Reaction at
Ep = 30 MeV", Autumn Divisional Meeting of Phys. Soc. of Japan, Kochi, Oct. (1979).

11) A. Ichimura and M. Ichimura: "Coulomb-Nuclear Interference Phenomena in
Inelastic Scatterings of 18 0", Autumn Divisional Meeting of Phys. Soc. of Japan,
Kochi, Oct. (1979).
12) Y. Gono, K. Hiruta, T. Nomura, M. Ishihara, H. Utsunomiya, T. Sugitate, and K. Ieki:"In-Beam CX-, ,),-Spectroscopy on Heavy Nuclei", Ann. Meeting of Phys. Soc. of Japan,
Kochi, Oct. (1979).

15913) M. Yanokura, 1. Kohno, Y. Nagame, and H. Nakahara: "Isotopic Dependence of 115 MeV
Nitrogen Induced Reaction", Discussion Meeting of Radiochem., Osaka, Oct. (1979).
3.

Atomic and solid-state physics
1) Y. Awaya, T. Hamada, T. Takahashi, K. Izumo, Y. Tendow, T. Katou, T. Tonuma, and
T. Doke: "Deviation from Z2 - Dependence of Heavy-lon-Induced Inner-Shell
Ionization Cross Section", Symp. on Atoms and Molecules, as a Part of the Special
Project Research 'Heavy Ion Science', Tokyo, Feb. (1979).
2) Y. Awaya and T. Tonuma: "Measurements of X-rays Following the Inner-Shell
Ionization", Symp. on the Production of Excited Atoms and the Interaction, Tokyo,
Feb. (1979).
3) H. Shiraishi, H. Shinno, R. Watanabe, H. Kamitsubo, 1. Kohno, and T. Shikata, "Helium
Embrittlement of High Ni Austenitic Alloys", Ann. Meeting of Atomic Energy Soc. ofJapan, Osaka, March (1979).
4) M. Uda, H. Endo, K. Maeda, M. Kobayashi, and Y. Sasa; "Bonding Effect of F Ka
Spectra on their Intensity Distributions", Ann. Meeting of Phys. Soc. of Japan, Osaka,
March (1979).
5) H. Endo, M. Uda, K. Maeda, M. Kobayashi, and Y. Sasa: "Z2 Dependence of L Shell
Vacancy Rearrangement Process", Ann. Meeting of Phys. Soc. of Japan, Osaka, March( 1979).
6) M. Uda, Y. Terasaka, H. Endo, and Y. Sasa: "Bonding Effect on X-rays Induced by Low
Energy Ions", Ann. Meeting of Phys. Soc. of Japan, Matsuyama, Sept. (1979).
7) M. Uda, K. Maeda, Y. Sasa, M. Kobayashi, Y. Terasaka, and K. Fuwa: "Chemical Effecton Ion Induced L X-ray Spectra", Ann. Meeting of Phys. Soc. of Japan, Matsuyama,
Sept. (1979).
8) T. Tonuma, Y. Awaya, T. Kambara, H. Kumagai, 1. Kohno, and S. Ozkok: "Argon Ka
X-ray Satellites by Impact of Nitrogen Ion in the 4.7 - 7.8 MeV/amu Energy Range",
XIth Intern. Conf. on the Physics of Electronic and Atomic Collisions, Kyoto, Aug.
(1979).
9) Y. Awaya: "Systematics of Multiple Ionization in Heavy Ion Collision" (Invited talk),
XIth Intern. Conf. on the Physics of Electronic and Atomic Collisions, Kyoto, Aug.
( 1979).
10) M. Uda, H. Endo, K. Maeda, Y. Sasa, and M. Kobayashi: "Chemical Effects throughElectron Rearrangement Prior to X-ray Emission", XIth Intern. Conf. on the Physics ofElectronic and Atomic Collisions, Kyoto, Aug. (1979).
11) H. Endo, M. Uda, Y. Sasa, Y. Terasaka, K. Maeda, and M. Kobayashi: "Search for
Bonding Effects on REC and MO X-rays", XIth Intern. Conf. on the Physics ofElectronic and Atomic Collisions, Kyoto, Aug. (1979).
12) M. Kamiya, A. Kuwako, M. Sebata, K. Ishii, S. Morita, Y. Awaya, and T. Tonuma:"Contribution of Electron Transfer to K-Shell Ionization by N7 + - Ion Bombardment",
VIth Intern. Seminar on Ion-Atom Collisions, Tokai, Sept. (1979).
13) M. Kamiya, A. Kuwako, M. Sebata, K. Ishii, S. Morita, Y. Awaya, and T. Tonuma:"Contribution of Electron Transfer to K-Shell Ionizations by N 7 + - Ion Bombardment",
VIth Intern. Seminar on Ion-Atom Collisions, Tokai, Sept. (1979).

16014) A. Koyama, T. Shikata, and H. Sakairi: "Measurements of Secondary Electron Emission
Coefficients from Metals under Fast Proton Bombardments", The 40th Science Lecture
Meeting of Japan Society of Applied Physics, Sapporo, Oct. (1979).
4.

Radiochemistry, radiation chemistry and radiation biology
1) K. Ogawa, K. Taki, and T. Nozaki: "Labeling of 2-Selenouracil by Exchange Reaction
with Elementary 73Se", ACS/CSJ Chemical Cong., Honolulu, Hawaii, Apr. (1979).
2) F. Yatagai, S. Kitayama, and A. Matsuyama: "Induced Mutagenesis in Phage cpX 174
Irradiated by Various Types of Radiation", 6th Intern. Congo of Radiation Research,
Tokyo, May (1979).
3) T. Takahashi, F. Yatagai, and A. Matsuyama: "Possible Long-Range Effect in theInactivation of Bacterial Cells by Heavy Ions", 6th Intern. Congo of Radiation Research,
Tokyo, May (1979).
4) K. Kimura, T. Fujisawa, and M. Imamura: "Measurement of Fast Emission Decay of
Heavy Ion-Irradiated Single Crystals: Nanosecond Time-Resolved a-Emission Spectra of
KBr", 6th Intern. Congo of Radiation Research, Tokyo, May (1979).
5) F. Yatagai, T. Takahashi, and A. Matsuyama: "Effect of Heavy Ions on Bacterial
Spores", Spore Radiobiology Meeting, Tokyo, May (1979).
6) T. Nozaki and M. Iwamoto: "Comparison of Yields of Light Nucleus by Charged
Particle Reactions", Discussion Meeting on Radiochem., Osaka, Oct. (1979).
7) T. Nozaki, M. Iwamoto, K. Usami, K. Mukai, and A. Hiraiwa: "Recoil Range of
18F Formed by Various Reactions", Discussion Meeting on Radiochem., Osaka, Oct.
(1979).
8) S. Ambe and F. Ambe: "A 119Sn-Mossbauer Emission Study on Se and SnSe Dopedwith 119mTe and 119Sb", Discussion Meeting on Radiochem., Osaka, Oct. (1979).
9) F. Ambe and S. Ambe: ,, 119 Sn-Mossbauer Emission Spectra of III-V and II-VI
Semiconductors and Related Compounds", Discussion Meeting on Radiochem., Osaka,
Oct. (1979).
10) F. Yatagai, S. Kitayama, T. Takahashi, and A. Matsuyama: "W-Reactivation and
W=Mutation in Phage ¢X 174", 22th Ann. Meeting of Japan Radiation Research Soc.,
Osaka, Nov. (1979).
11) F. Yatagai and A. Matsuyama: "A New Apparatus for Cyclotron-Beam Irradiation of
Biological Samples", 22th Ann. Meeting of Japan Radiation Research Soc., Osaka,Nov. (1979).

5.

Heavy ion linear accelerator
1) T. Kambara and M. Odera: "Control System for the IPCR Linac", Ann. Meeting of Phys.
Soc. of Japan, Osaka, Apr. (1979).
2) M. Odera, Y. Chiba, and T. Kambara: "Status of the Variable Frequency Heavy Ion
Linac, RILAC", 1979 Linear Accelerator Conf., Montauk, Sept. (1979).

161

12. LIST OF PERSONNEL

Mem bers of the Board
DOTE Toshihiko± ~ ~ tit (Chairman)
1: tf~
KAMITSUBO Hiromichi
NAKANE Ryohei
r:p t~ .& f
ODERA Masatoshi'*

Users Committee='*

HAMADA Tatsuji~ B3 :Ii(Chairman)
1: H~
KAMITS UBO Hiromichi
MATSUY AMA Akira
t~ w
Jt
NOZAKI Tadashi
SAKAIRI Hideo

!ff ~
:tp:

IT.

=

HAMADA Tatsuji~ B3 :Ii
KOHNO Isao
fpJ!ffJ3J
NOZAKI Tadashi
!ff ~
1£

IMAMURA Masashi
fpJ!ff
KOHNO Isao
MORI Kazuo~
ODERA Masatoshi
SEKIZAWA Hisashi

A ~ itOperation and Machine Maintenance Group
jf
FUJITA Shin
Jk B3
KAGEYAMA Tadashi~w
KOHNO Isao
fpJ!ffJ3J
TAKEBE Hideki~ ~5 ~ ;ftt

1£

IKEGAMI Kumio
KOHARA Shigeo
OGIWARA Kiyoshi

ttl! 1::f1=~+)]{!t=f(~)]{

m

Scientific and Engineering Personnel
Cyclotron Laboratory
AM AKAWA Hirotaka
7( ) II t:f I5i:
FUJITA Jiro
Jk B3
e5
ISHIHARA Masayasu~ )]{ 1E
KARASAWA Takashi~ YR
1f.
KOHNO Isao
fpJ!ffJ3J
MOTONAGA Shoshichi
5C 7)( at3 -t
NAKANISHI NoriyoshiIL§ ~ %SHIKAT A Takashi[1:Q 15 I5i: 3:
YAMAJI Shuhei
W ~ f~ f=**

FUJISA WA Takashi
Jk y,R ~ iG
INAMURA Takashi~ tt¥
KAMITSUBO Hiromichi
1: tf
KOHMOTO Susumu
fpJ ;$:J1!
KUMAGAI Noritaka~~ ~ 45: -'if
NAKAJIMA Shunji
r:p ~ ~NOMURA TOfU
!ff f1~
WAD A Takeshi;.fO B3
jt
YAN 0 Y asushige~!ff 17: :m

'* ~

=

(Visitors)
HATTORI Toshiaki~R ~5 1~ ~ (Inst. Nucl. Study, Univ. of Tokyo)
HAYAKAWA Shunichiro.Ef. )l1 1~ - e5 (Dept. Phys., Waseda Univ.)
HIRUTA Kotaro~ B3"*"* e5 (Dept. Phys., Tokyo Gakugei Univ.)~(Inst. Phys., College General Education, Univ.
ICHIMURA Munetake rIJ tt
of Tokyo)
KAMMURI Tetsuo
JEt
~ =f(
(Dept. Phys., Osaka Univ.)(Dept. Phys., Tokyo Metropolitan Univ.)
KUBO Kenichi
A ~ ~ 7)( ~ m =f((Texas A and M Univ.)
NAGATANI Kunior:p)]{ ~L ~ (Dept. Chern., Tokyo Metropolitan Univ.)
NAKAHARA Hiromichi(Texas A and M Univ.)
NATOWITZ J .B.
!ff B3~(Inst. Nucl. Study, Univ. of Tokyo)
NODA Akira
OHNUMA Hajime
m Wi (Dept. Phys., Tokyo Inst. Technol.)

*

*

162

~!ff
t (Nat. Res. Inst. for Metals)
SHINNO Hitoshi
S D w. ttt(Nat. Res. Inst. for Metals)
SHIRAISHI Haruki
m: i& j3- ± (Dept. Phys., Saga Univ.)
T AKEMASA Tadashi(Students)
IEKI Kazuo~ ~ %0 *(Dept. Phys., Kyoto Univ.)~ EE &iJ::E(Dept. Phys., Tokyo Inst. Technol.)
KISHIDA Norio
KOJIMA Toshiyuki+ l¥h fijJ fj (Dept. Phys. , Rikkyo Univ.)
NAGAME Yuichiro
71< § ~- l!!B
(Dept. Chern. , Tokyo Metropolitan Univ.)~ tt H: -T(Dept. Phys. , Chuo Univ.)
NAKAMURA Kyoko
NORO Tetsuo
ft g rg *- (Dept. Phys. , Kyoto Univ.)
OBANA Yoshiki+ 1:£ 7f ttt (Dept. Phys., Chuo Univ.)
1ft Ji ]! (Dept. Phys., Tohoku Univ.)
SATO Kenichi
SHIMODA Tadashi
TEElE (Dept. Phys., Kyoto Univ.)
SUGIT ATE Toru
~ 5L
11&
(Dept. Phys. , Tokyo Inst. Techno!.)TOBA Yoshiyuki)i )j)J E ~(Dept. Phys. , Kyoto Univ.)
UTSUNOMIYA Hiroaki*~~'§~liif(Dept. Phys., Kyoto Univ .)Linac Laboratory
CHIBA Toshiya
T ~ Jflj ~IKEZAWA Eiji
M ?,R !fi:.
KAMBARA Tadashil' mlEMIYAZAWA Yoshitoshi
g i,R tt ~SCHIMIZU J un
m 7k *'~TONUMA Tadao
F m IE
YOKOY AMA Ichiro
f'lfi LlJ - l!!B

CHIBA Y oshiaki-T*B~
HEMMI Masatake
Ji~i&m:INOUE Toshihiko#J:.~ ~KASE Masayuki
JJO ~ ~ ~ODERA Masatoshi+ ~ IE 1~
SHIMAMURA Akira~ ti
Y ANOKURA Minoru*- ft;§YOSHIDA Fusako
E EE m -T='*(Visitors)
DOKE Tadayoshi~ ~ IE, ~ (Sci. and Eng. Res. Laboratory, Waseda Univ.)
EJIRI Hiroyasu
IT ffL 7.i(Dept. Phys., Osaka Univ.)
FUKUZAWA Fumio?~ 1R X. it (Dept. Nuc!. Eng. , Kyoto Univ.)
HARADA Kichinosuke[~EE E ~ WJ
(Japan Atomic Energy Res. Inst.)
HISATAKE Kazuo!A m: %0 *- (Tokyo Inst. Technol.)
ISHII Keishi,fi # ~ L
(Dept. Nucl. Eng., Kyoto Univ.)
ITO Noriaki{j3- Ji 'if BB(Dept. Crystalline Materials, Nagoya Univ.)
for i;- -t,1$ (Osaka Univ.)
KAWAI Nanao
MASUDA Kozo
7t rn ~
(Tsukuba Univ.)it)} #- IE 7::. (Nagaoka Sci. and Tech. Univ.)
MATSUI Masao~ EE
75 (Dept. Phys. , Tohoku Univ.)
MORITA Susumu
OHNO Shinichi
7c!ff ~ (Japan Atomic Energy Res. Inst.)
OZAWA Kunio+ ?,R ~ *- (Japan Atomic Energy Res. Inst.)
SAKISAKA MasakatsurP:J:J:ffi: JE 1m (Dept. Nuc!. Eng., Kyoto Univ.)
1ft Ji{$ (Tokyo Inst. Techno!.)
SATO Shin
TAKEDA Shigeru
IrIr EE(Nat. Lab. High Energy Phys.)
TAWARA Hiroyuki
1*
tt z (Dept. Nuc!. Eng., Kyushu Univ.)
TSURUBUCHI Seiji~ mFl wt
(Dept. Phys., Osaka Univ.)
WATANABE Ryoji
iJt 321 *- ifJ (National Res. Inst. for Metals)
YOSHIZAWA Yasukazu
E IR%0 (Dept. Phys. , Hiroshima Univ.)

*

=-

'*

=

'*

163

Radiation Laboratory*

AWAYA Yohko
HASHIZUME Akira
KATOU Takeo
KUMAGAI Hidekazu
TAKAHASHI Tan

-r

~ ~

tt Jf\~

1l~

it ~ *0tt

Q

HAMADA Tatsuji
YAEElJi=
tti~7'tIZUMO Koichi
KONNO Satoshi~ ff~
OKANO Masaharu
IW ff ~ ff:J
TEND OW Y oshihiko
7C i@: 75- ~(Visitors)
DOKE Tadayoshi
i@: ~ J~' ~(Sci. and Eng. Res. Lab., Waseda Univ.)
FUJIOKA Manabu
Ji IW~(Dept. Phys., Tohoku Univ.)
HAY ASHIBE Shogo
iff ~~ aB ~ (Dept. Phys., Tohoku Univ.)
ISHII Keizo
D :# J.I:@ (Cyclotron, Tohoku Univ.)
MORITA Susumu~ 83
15(Dept. Phys., Tohoku Univ.)
NAGAHARA Teruaki
7]( )Jj{ Jffi ~ (lnst. Atomic Energy, Rikkyo Univ.)
TAWARA Hiroyuki
1*
tt Z (Dept. Nucl. Eng., Kyushu Univ.)(Students)
KAMIY A Masami{:E¥ it IE c (Dept. Phys., Tohoku Univ.)
KINEBUCHI Yoshiaki¥f mR ~ aB (Dept. Phys., Tohoku Univ.)~ -r~(Dept. Phys., Tohoku Univ.)
KUW AKO Akira
Metal Physics Laboratory
FUKUSHIMA Hiroshi*~ ~SAKAIRI Hideo:IN A 1A 1$
YAGI Eiichi

tt

KOYAMA Akio;]-- LlJ BB itSHIOTANI Nobuhirotl[ it g~L.

)\** -

Magnetic Materials Laboratory
ASAI Kichizo~ # tf it
SAKAI Nobuhiko:IN :# m- ~OKADA Takuya
IW EEl --'¥- -ill
SEKIZA WA Hisashi
00 I~
f6]

(Visitor)
MIZOGUCHI Tadashi

IE(Dept. Phys., Gakushuin Univ.)

Solid State Chemistry Laboratory
ENDO Hiroshi
MAEDA Kuniko
UD A Masayuki

J! Ji

j[

m -r
-+ 83 JZ z
M B3

KOBA Y ASH I Masayoshi
SA SA Y oshihiko
1ft: k;]--** 7ft ~~ ~Radiochemistry Laboratory
AMBE Fumitoshi$:: ~~ X ~ARAT ANI MichiJ¥Lit~~IW AMOTO Masako:!5:<$:IE-r
TERAI Yoshiro~ :}:I: ~ fIB

AMBE Shizuko$:: ~~ ~ -r
ITO Y oshiko{'Jl"75- -rNOZAKI Tadashi
ff ~
lE

*

(Visitors)
HIRAIW A Atsushi
MUKAI Kiichiro

Sf :!5~(Central Res. Lab., Hitachi Electric Co.)
rPJ%- fI5 (Central Res. Lab., Hitachi Electric Co.)

164

TAKI Ko~$ (Dept. of Hygen., Kitazato Univ.)
TOYODA Minoru~ ffi~ (Central Res. Lab., Mitsubishi Chemical Ind.)TSUKAZAKI Toshimasa~ ~ ~ IE (Central Res. Lab., Mitsubishi Chemical Ind.)
USAMI Katsuhisa{£ ~ .Im.?\(Central Res. Lab., Hitachi Electric Co.)YAJIMA Fumikazu j( ~ X.;fD (Central Res. Lab., Mitsubishi Chemical Ind.)"*

Radiation Chemistry Laboratory
KIMURA Kazuie

IMAMURA Masashi
Radiobiology Laboratory
HATTORI Yukihiko
KIT AYAMA Shigeru
YAT AGAI Fumio~R 1f~

IT ~

it W

11i

~ T - flB
KANEKO Ichiro
MAT SUYAMA Akira
tl W

Jt,

~ffiJ§..)(xSafety Control Affairs Office=

HAMADA Tatsuji'?fr ffi ~KOY AMA Masashi
Ij" W iI5: 9:
USUBA Isaort ~~IGARASHI Kazui
SAKAMOTO Ichiro

1i + ii. ~ ::$: -

J:X
fl5

165

13.

LIST OF OUTSIDE USERS AND THEIR THEMES(J an. - Dec. 1979)

1) M. Shimada and M. Iimura

Toshiba R&D Center"Cyclotron Irradiation for Study ofFast Breeder Reactor Material Embrittlement"
2) A. Hishinuma, T. Furuta, K. Fukai, andJapan Atomic Energy Research Inst.

T.Otomo"Helium Implantation Effect on Creep
Rupture Properties of Modified 316 StainlessSteel for Fast Reacter Material"
3) K. Suganuma and S. Yajima*

Research Inst. for Iron, Steel and Other"Development of Ferritic Stainless Steel for

Metals, Tohoku Univ.

Atomic Reactor"*Irradiation Research Lab., in JMTR

4) R. Nagura, H. Ono, Y. Narimatsu, and

T. Hishiyama

Space Development Div., Nippon ElectricCo., Ltd.

"Calibration of Space Environment Monitor
Carried on GMS-2 with Protons"
5) H. Nakahara, Y. Nakamura, H. Kudo,

K. Muramatsu, and Y. Murakami"Production of 57 ,58 Co , 113, 119mSn " 111In
196 Au , 207 Bi , and 210po"
6) Y. Homma

Faculty of Science, Tokyo Metropolitan
Univ.

Kyoritsu College of Pharmacy"Production of 61Cu and 77Br"
7) F. Yajima

Mitsubishi Chemical Industries Ltd.

"Production of 18F"8) K. Yuita"Production of 43K"

National Inst. of Agricultural Sciences

166

167

AUTHOR INDEXAMAKAWA Hirotakatt

7( )Ii$!: ~~ X ~AMBE Fumitoshi

21

IGARASHI Kazui

1i +,Iit - FX:

124

109 , 112

IKEGAMI Kumio

i'ili1:fL=-~2, 15 , 17

[5i

AMBE Shizuko

109 , 112

IMAMURA Masashi

117

AWAYA Yohko

73 , 76 , 79 , 82
84

INAMURA Takashi

45

BARADJANEGARA A. A.
CHIBA Y oshiaki

141,143 , 149

ENDO Hiroshi
FROHLICH H.

j£iR i%;t;10 , 27 , 30

FUJITA Jiro
FUJITA ShinFUKUDA Tomokazu

104 , 106tb ~ it -

73,76

if

KAGEY AMA Tadashit~

EEl ~ ~D

48,56

HAMADA Tatsuji

73 , 76

2, 17

KAMATANI Yukio
KAMBARA Tadashi

if

82,84 , 134
7, 27,48,
51,56 , 89

KAMITSUBO Hiromichi-&t:t- ) [1 iitx

27 , 30
65 , 67 , 73 ,76

HASHIZUME Akira
HAT AN AKA Kichiji

fE¥

KAMIY A Masami:e: 1E E

79
39

KAMMURI Tetsuo
KARASA WA Takashi
KASAGI Jirhota

33

145,147 , 15 1,
154

KASE Masayuki

82 , 84 , 147 , 149,151

106

KATOU Takeo

HATTO RI Yukihiko

120

HEMMI Masatake
HIRAIWA Atsushi~

KIMURA Kazuie

HIRUTA Kotaro
ICHIMURA Atsushi

IEKI Kazuo

if -=r2, 124

jf

GONO Yasuyuki

ICHIMURA Munetake~ ;$:IW AT ANI Kazuo
IZUMO Koichi

45 , 59 , 62,
65 , 70

HASEGAWA Takeo

45,48 , 51,56 ,
59,62 , 70

ISHIHARA Masayasu

IWAMOTO Masako§

137, 140ISHII Keizo

86

51

FUJISAWA Takashi*I: 1: ~ g

INOUE Toshihiko

121

y¥

m tt

* iit

45 , 59 , 62,
70

KISHIDA Norio3636;1]0 §

iit tt* tt - -*~ EEl ~Ij ~65 , 67 , 73 , 76

117
30,33

KOBAYASHI Masayoshi
KOHARA Shigeo

2

168

KOHNO Isao

+w aBlt

KOYAMA Akio

92 , 94

A~fi&¥KUBO Toshiyuki
KUDO Hisaaki

2, 15 , 17 ,24 , 54 ,
82 , 84 , 89J}J

fiiJ1ff

IfiABB24
65 , 67 , 73 ,
76 , 82 , 84

1m ~ Jfj 5fD

KUMAGAI Hidekazu+-~

ODERA Masatoshi

30 ,3 3lE

20 ,1 02 , 104 , 106 ,
115

JE 1~

128,134,149,
151

fff~

NOZAKI TadashiJ[

48 , 56

OGATA Hiroshi+17

OGAWA Koji+- JII ¥ ?X

115

~1*

m

OGIWARA Kiyoshi

*m

ifi

2, 4,1030 , 33KUWAKO Akira

~~

~

79

OHNUMA Hajime

MAEDA Kuniko

M EB

m-=r

86

OKADA Takuya

fiUjEB~ -th

97,100:tR #- f~ $97

MATSUOKA Kazuot~fiUj 5fD 7:.

39

SAKAI Nobuhiko

MATSUURA Hideot~

1ffi Jfj it

121

SAKAIRI Hideo

118 , 120 , 121

SAKAMOTO Ichiro

MATSUYAMA Akira

M W

MIURA Iwao

;'5

:5't

tRA~tl:tR;$:- e5124, 126

SANO Mitsuo

48 , 56

MIY ANO Kazumasa

SA SA Y oshihiko

MIY AZAWAY oshitoshirg lR ft ~MORITA Susumuti

MOTONAGA Shoshichi]I:

131 , 151

7'k BB -t

B J: ~ e5

MURAKAMI Tatsurho
MURAMATSU Hisakazu

4 , 7, 1233

B t~ A 5f[]

SEBATA Masao
SEKIGUCHI Masayuki

79

MUKAI Kiichiro

24~

SEKIZAWA Hisashi
SHIKAT A Takashi[Q15 I)i 3::

SHIMODA Tadashi

T

EB

t

89

~

t\tJt~

27

NAGATANI Kunio

SHIRAISHI Haruki

NAKAHARA Hiromichi
NAKAJIMA Shunji~

1* ~J" :@~ ~§l =

24 , 54SOGA Fuminori
SONE Kohei

147

lE

fi

SHIOTANI Nobuhiro~ t~ ~ 5jZ-

~BJE 1~27

SUEHIRO Teruo*$;tIl~NAKANISHI Noriyoshi

~[B~%

12

SUGITATE Toru~}[

45 , 59 , 62 , 70

TAKAHASHI Tan

:if

~1it

51

121

NAKAMURA Masanobu

fiB

97,10089 , 94~

SHINNO Hitoshi

NAGAME Yuichiro

NOMURA Toru

92 , 9430~

45,59 , 62 , 70

1l

73, 76

169

TAKEBE Hideki

JEt :g~ ~ tit

2, 4 , 10

USAMI Katsuhisa

TAKEDA Shigeru

n 83

134

USUBA Isao

TAKI Ko~

TAMURA Taro

B3tt j( f!~

TANAKA Teruaki

51

B3~lE~

B3

TEND OW Yoshihiko

~

MIA

~

124

ri~

UTSUNOMIYA Hiroaki

115$

TANAKA Masayoshi

TERAI Yoshiro

~

*1tC~

lffi ~

48 , 56
27~~7J-~=!f :# :g. f!~

65 , 67 , 73,
76

106*ti~B' ~£ ~WADA Takeshi*0 B3

WAKOH Shiny a*0 7't f~ -tQ

tit

45,59 ,
62 , 70

4 , 7,2 7, 30

97

WATANABE Ryoji

iJl J21 3f It

YAJIMA Fumikazu

*- ~

)Z

89

*0 102

102

YAMAJI Shuhei

LlJ ~ 1~ f

42*-lff$:1t

7

*ft~

~

TOBA Yoshiyuki

n:fJtf$27

YANO Yasushige

TONUMA Tadao

FlBlEtit

73 , 76 , 79 , 82 ,
84 , 149

YANOKURA Minoru

TOYODA Minoru

:1:83

102

YASUE Masaharu$: rr lE It

27 , 33

YATAGAI Fumio~B3~)Z7(

118,120, 121

tf B3 m T

10 , 151 , 154

TSUKAZAKI Toshimasa~~~~ lE* B3 rr; L* B3 )11 &UDAGAWA Takeshi
UDA Masayuki

UEDA Nozomu

YAZAKI Koichi

86

1: B3

'1I

102

24 , 54, 149,
149 , 15 1

51

27 , 30YOSHIDA Fusako

IPeR Cyclotron Progress Report!11t~ffl~pJT-fj"17 [J ~ [J /~*~'* f;13~ ( 1979 )lOD ,\j;lj

Bl5fD 55if- (1980 ) 3 ,F! 25 B

1'T

af5fD 55 if- (1980) 3 ,F! 30 B

9€

~1ti3

:Jl!. 11::

'* JE
1iJf

tt1Z1§-

m

pJT

*

1[~

1$

(0484 ) 62 - 1 1 1 1,f,W~i3:Jl!.1I::,*~jftE PJT1JDJE~fljffl~~ ~ ~lOn,\j;lj fifj

A .£ £D

~IJ

~

A

~

11

T130 JIO?,t1~ ~ EBlKiU~ l TEl 3 il 3 Ji}

5E 100 3, 000 fIl

理化学研究所
埼玉県

和光市

広沢