At intermediate energies, the differential cross quantity R(Ep) thus represents very nearly the ratio of sections at 8=0° for hJJE=l+ and O+ (p,n) transitions interaction strengths I Ja,/J, 1. In Fig. 1 we plot are proportional to the reduced transition probabilities B(GT) and B(F) for the analogous Gamow-Teller (GT) and Fermi (F) beta decays, respectively. This proportionality may be exploited to gain information about the isovector effective i n t e r a c t i o n s t r e n g t h s . For even-A t a r g e t s wed e f i n e the empirical quantity [R(E~)]* = [C~~~(O")/B(GT)][B(F)/C~(~~)] where B(GT) and B(F) are obtainable from measured beta-decay ft values according to1 B(F)+(~ .~5)~~(~~)=(6163.4 sec)/ft . A

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This study was i n i t i a t e d t o s e a r c h f o r i s o b a r i cmeasured e x c i t a t i o n energy f o r t h e IAS of 2 0 8~b g.s.analogues of magnetic d i p o l e r a d i a t i n g s t a t e s i n 2 0 8~b , is 15.0k0.3 MeV which i s i n good agreement w i t h t h e and t o determine t h e f e a s i b i l i t y of u s i n g t h e (p,n) v a l u e of 15.17+0.02 MeV r e p o r t e d 4 by Crawley e t a l . r e a c t i o n t o a i d i n l o c a t i n g M 1 s t r e n g t h i n medium t o heavy n u c l e i . The experimental s i t u a t i o n p e r t a i n i n g t o M1 ground-state r a d i a t i v e s t r e n g t h h a s been sum-marizedl r e c e n t l y w i t h t h e conclusion t h a t l i t t l e d e f i n i t i v e information i s a v a i l a b l e f o r n u c l e i w i t h A>40. I n 2 0 8~b i t i s known t h a t t h i r t y -f o u r resonances between 7.38-7.79 MeV c o n t a i n CB (Ml) +%2.6 vo2, with about h a l f of t h i s l o c a l i z e d 3 w i t h i n a narrow doorway s t a t e a t ~7 . 5 MeV. The analogue resonances would l i e a t a n e x c i t a t i o n energy of %22.7 MeV i n 2 0 8~i , and would have T=22. I f t h e s e do not s t r o n g l y admix w i t h background s t a t e s , they might be observed i n t h e 2 0 8~b ( p , n ) r e a c t i o n . The same experiment is a l s o expected t o y i e l d information on t h e g i a n t Gamow-Teller (GT) resonance f o r which l i t t l e information i s a v a i l a b l e f o r t a r g e t s with A>90.A zero degree spectrum taken a t E -120 MeV i s P shown i n Fig. 1. Zero degree c r o s s s e c t i o n s and e x c i t a t i o n e n e r g i e s a r e given i n Table I. Our

In a series of papers1-5) in the early 1960ts, factor of two with increasing proton energy between We have used the beam-swinger f acility13) at IUCF, protons with incident energies of 120, 160, and 200MeV, and neutron flight paths of 60-70m to study the