COMPARISON OF THE SI-28(O-16,C-12)S-32 AND SI-28(O-18,C-14)S-32 REACTIONS AT 60 MEV INCIDENT ENERGY

Cross-section angular distributions of the Si28(O16, C12)S32 and the Si28(O18, C14)S32 reactions leading to lowlying states in S32 and the O18+Si28 elastic scattering have been measured at 60 MeV incident energy. Optical model parameters were obtained by the analysis of the measured O18+Si28 elastic scattering and the analysis of existing O16+Si28 elastic scattering data. The exact finite-range distorted-wave Born approximation analysis of the (O16, C12) reaction data showed that the transfer data could only be reproduced using a surface-transparent set of optical model parameters. On the contrary no optical model parameters could be found which provide simultaneously good fits of the O18+Si28 elastic scattering and the (O18, C14) transfer data. The transfer data could be reproduced however, using optical model parameters which do not describe elastic scattering data. Relative spectroscopic factors were extracted for both transfer reactions and are compared with previous results of (O16, O12) and (Li6,d) reaction studies. In addition we determined spectroscopic factors of the Si28(C12, Be8) S32 reaction by reanalyzing existing data. The comparision suggests the conclusion that the (O16, C12) and (O18, C14) reactions proceed through different reaction mechanisms. NUCLEAR REACTIONS Si28(O18, C14)S32; Si28(O16, C12)Si32; Si28(O18, O18); Elab=60 MeV; measured (); lab=4°-20°for (O18, C14), (O16, C12), and lab=4°-47°for (O18, O18), lab=1°, enriched target; deduced OM parameters; EFR-DWBA analysis, deduced relative spectroscopic factors. © 1979 The American Physical Society.