ASTROPHYSICAL S-FACTOR OF THE BE-7(P,GAMMA)B-8 REACTION FROM COULOMB DISSOCIATION OF B-8

The Coulomb dissociation method to obtain the astrophysical S-factor, S-17(0), for the Be-7(p,gamma)B-8 reaction at solar energies is invest igated by analysing the recently measured data on the breakup reaction Pb-208(B-8,Be-7 P)Pb-208 at 46.5 MeV/A beam energy. Breakup cross sec tions corresponding to E1, E2 and M1 transitions are calculated with a theory of Coulomb excitation that includes the effects of the Coulomb recoil as well as relativistic retardation, The interplay of nuclear and Coulomb contributions to the breakup process is studied by perform ing a full quantum mechanical calculation within the framework of the distorted-wave Born approximation. In the kinematical regime of the pr esent experiment, both nuclear as well as Coulomb-nuclear interference processes affect the pure Coulomb breakup cross sections very margina lly. The E2 cross sections are strongly dependent on the model used to describe the structure of B-8. The value of S-17(0) is deduced with a nd without E2 and M1 contributions added to the E1 cross sections and the results are discussed.