The 62Ni (3He, d) 63Cu reaction at 11.0 MeV

2 B.

I

Nuclear Phystcs A107 (1968) 639--644, (~) North-Holland Pubhshmg Co, Amsterdam

2 G

[

Not to be reproduced by photoprmt or microfilm w~thout written permlsston from the pubhsher

THE 62Ni (3He, d) 63Cu REACTION AT 11.0 MeV D L SMITHt,

H Y CHENandH

A ENGE

Department of Physics and Laboratory for Nuclear Sctence tt, Massachusetts Institute of Technology Cambrtdoe, Massachusetts, USA Received 25 September 1967 Abstract" A total o f 13 levels including f o u r unresolved multlplets in 83Cu below 2 8 M e V excitation energy was excited via the n2Nl(3He, d)63Cu reaction wath 11 0 M e V incident energy A n g u l a r d~strabutlons were m e a s u r e d for 12 o f the deuteron groups T e n o f these d~strabutlons were fitted with D W B A curves, a n d spectroscopic factors (C2S) were extracted E I N U C L E A R R E A C T I O N 6~NI(3He, d), E ~--11 MeV, m e a s u r e d cr(Ea, O) 63Cu deduced levels In, ~z, spectroscopic factors Enriched target I

The 6 Z N l ( 3 H e , d)63Ctl reaction has been stu&ed at 11 0 MeV incident energy A 41/~g/cm 2 ( + 9 ~ ) target of mckel, enriched to 97 8 ~ m 62Nt ' on formvar was bombarded with a 3He+ + beam from the M I T - O N R Van de Graaff accelerator at an average beam current of 40 nA The reactlon products were analysed m the M I T multiple-gap spectrograph 1) with an overall resolution of 21 keV The angular distribution of the elastically scattered 3He particles was measured, and the data were used for determmmg the optical-model parameters with the aid of the search code A B A C U S 2) The parameters that were obtained are listed in table 1 Fig 1 shows the resulting fit to the experimental data TABL~ 1 Optlcal-model p a r a m e t e r s for elastic scattering a) Real well

I m a g i n a r y well

V (MeV)

r0 (fro)

a (fm)

W (MeV)

aHe

164 7

1 070

0 727

16 86

d b)

90 7

1 172

0 822

WD (MeV) 0

0

18 34

r e' (fm)

a' (fro)

Coulomb radms rC (fm)

1 630

0 570

1 400

14

1 410

0 661

1 300

0 78

X2

a) S t a n d a r d n o t a t i o n , see, for instance, r e f 5) b) R e f 5), Set 3b for n3Cu (d elastic) at 11 8 M e V incident energy t Part o f this work h a s been carrted o u t by one o f the a u t h o r s (DLS) as one o f the r e q m r e m e n t s for the Ph D degree at M I T Present address Lieutenant, U S A r m y Missile C o m m a n d , R e d s t o n e Arsenal, H u n t s w l l e , A l a b a m a , U S A tt This work h a s been s u p p o r t e d m part t h r o u g h f u n d s provided by the U S A t o m i c Energy C o m m i s s i o n u n d e r A E C Contract AT(30-1)-2098 639

640

D L SMITHet al

F i g 2 s h o w s t h e s p e c t r u m o f d e u t e r o n s r e c o r d e d at 45 ° (lab a n g l e ) A t o t a l o f 13 levels m 6 3 C u was adentxfied b e l o w 2 8 M e V e x c i t a t i o n e n e r g y

The data were not

a n a l y s e d a b o v e this e x c i t a t i o n e n e r g y b e c a u s e o f l o w yield a n d i n a d e q u a t e r e s o l u t i o n T h e d e u t e r o n g r o u p s a t t r i b u t e d to 6 3 C u w e r e adentxfied by c o m p a r i s o n w~th t h e results o f t h e 6 3 C u ( p ' p , ) 6 3 C u e x p e r i m e n t p e r f o r m e d b y M a z a r x et al 3) U s i n g t h e l a b e l h n g

NI 62

104

He 3 Elashc Scattenng

\

E = II 0 MeV

u~

I°s

\

i0 ~

\% i

3O

90 •CM (degrees)

L50

Fig 1 The 6~Nl(aHe elastic) angular dxstnbutlon fitted wRh optical-model curve calculated using the parameters in table 1 TABLE 2 Spectroscopic factors for the 6~NI(~He, d)68Cu reaction Level

lp

(2J2+1)C2S

Assumed Jt

0

1

3 135

~

0 78

0 66

+18

1

1

1 421

½

071

070

+

2 3 4 7 8+9+10 12 14+15+16 22+23

3 3 3 1 1 3

1 760 0 573 2 059 0 111 0281 0 319

~ { ~ ½ ½ {

0 29 0 072 0 34 0 055 / 014 ) 0 053

0 33 0 057 0 45

--14 +26 --32 --12 --89

1

0 114

~

0 016

023 0 10 0 31(~ +) 0 013

a) Ref 7) employed normahzatxon factor N = 3 8

C2S

Blair *) C2S

Percentage difference

14

+23

I

I

¢

I

o3'

0.,

_o

= "ul

I

u~

~o

o 0

8

a.

Z:~

o

z Fo

x

~d

0

~

x o ~

~:

~o - ~

~ ~a_

.=

w

o

-I° ~ Q~

[-

clIN.LS w w ~ g V N

N3cl S N O N 3 ± n 3 0 .~o ~ I 3 8 N A N

642

D

L SMITH et al

I

Cu63 (G S) Q 632 keY

Cu6~ (2) Ex 961 key 0 329 ~eV

C~63( i } E~ ,568 keg Q 36 keY

3

--I

I0 '

~o~

91o

'

IN)

,~o

I

910

"

rSO

Cu6~(4)

'

;o

'

,;o

Cu~ (7) Ex 2012 keV O - 1380 keV

]

Cu6~ (3) Ex " 1327 keV Q -695 keV

--.,f

I

J

J-3

3

(#1

I0

I

~0

I

L

90

b! 1 ;/ 30

150

~50

Cu63 f13]

C.u63 ( 8"9+ I0) Ex 2063 L~O~2 2093 keY Q 143r 1450 I,=~1key --J I

Ex 2405keV Q 1773keY n$

o,i

K) 2

Cu~s(I2) Ex 2 3 3 7 keV Q 1705keV --J 3

I

1

90

i

I

'

~

'

,~o

OCM(degrees)

'

,5o

643

~2Nz~aHe, d)63Cu REACTION

Cu ¢~ ( 14 ÷15,* 16) EI¢ " 2497 2504,25~0 keV Q • -1865,1872 1878 keY

Cu6~(19 20 21) Ex 2673 2694 2716keY Q-2041 2062 2084key

Cu~ (22 23) E x 2761 2778 keY Q -2129 2146 key

,o '~-

I0 i "U

i

b --]

3 /-4

~,

~

Jo

~o

~) e C I",,I (degre

J ~

J ,~o

e s)

Fig 3 Angular distributions of deuteron groups corresponding to levels in 6aCu excited via the n2NffaHe, d)nsCu reactzon For unresolved levels, the excztatlon energzes and Q-values of all the known components of the multlplets are hsted [see ref a)]

scheme of Mazarl et al, we were able to identify the following levels in 6 3 C u in the present work g s , l, 2, 3, 4, 5 (weak), 7, 8 + 9 + l0 (unresolved), 12, 13, 14+ 15+ 16 (unresolved), 19 + 20 + 21 (unresolved) and 22 + 23 (unresolved) Angular distributions were measured for 12 of these levels Because of low yield, complete distributions were extracted for only the first three states A D W B A analysis was performed to fit the data using code J U L I E 4) The 3He parameters in table 1 were used in the calculation, together with a set of 11 8 MeV deuteron parameters obtained from Perey and PereyS) (see table 1) The results appear in fig 3 The sohd curves represent the best fits to the data Level 5 was too weak to permit the extraction of an angular dlstrlbunon Levels 13 and 19 + 20 + 21 (unresolved) show non-stripping patterns Values of the orbital angular m o m e n t u m transfer lp for the captured protons were assigned on the basis of these data, and spectroscopzc factors ( C 2 S ) were extracted using the relation (da/dY2)~xp = N (2,If -[- I )C 2 S (Oo'/d~"~)DWBA The normahzatlon factor N = 4 4 from ref 6) was used In the present analysis, and the most probable values for Jf were assumed The results of this analysis are given in table 2, where they are also compared with those obtained by Blair 7) who studied the 62Nl(aHe, d)63Cu reaction at 22 MeV incident energy The agreement zs generally qmte good The following differences should be noted Level 7 is resolved from level 8 + 9 + 10 (unresolved) m the present work The value of C 2 S obtained for level 12 in the present work is considerably smaller than that obtained by Blair No evidence for an lp = 4 assignment for level 14+ 15 + 16 (unresolved) was obtained in the present work (see fig 3)

644

D L SMITHet al

T h e a u t h o r s w o u l d hke to t h a n k M r Matt1 S a l o m a a a n d the staff o f the M I T - O N R V a n de G r a a f f accelerator for m a i n t a i n i n g the e x p e r i m e n t a l a p p a r a t u s in t o p o p e r a t i n g c o n d i t i o n d u r i n g the course o f this e x p e r i m e n t T h e n u c l e a r - t r a c k plates were expertly s c a n n e d b y Miss Sylvia D a r r o w a n d the gtrls o f the L a b o r a t o r y Scanning G r o u p T h e m a n u s c r i p t for this p a p e r has been carefully p r e p a r e d b y Mrs. M a r y E Whxte.

References 1) 2) 3) 4)

H A Enge and W W Buechner, Rev Scl Instr 34 (1963)155 E H Auerbach, Brookhaven National Laboratory Report BNL-6562 (1962) unpubhshed M Mazam, W W Buechner and R P de Flguelredo, Phys Rev 108 (1957)373 R. H Bassel, R M Drlsko and G R Satchler, Oak Ridge National Laboratory Report No ORNL-3240, tmpubhshed, G R Satchler, Nuclear Physics 55 (1964) 1 5) C M Perey and F G Perey, Phys Rev 132 (1963)755 6) R H Bassel, Phys Rev 149 (1966)791 7) A G Blair, Phys Rev 140 (1965) B648