Theoretical study of dynamic effects on fusion cross sections for reactions S 32,34,36 + Pb 204,206,208

Abstract

The universal fusion function prescription and the empirical coupled-channel (ECC) model are used to analyze the dynamic effects on fusion cross sections for reactions S32,34,36+Pb204,206,208. An examination of the reduced fusion functions shows that the total dynamic effects on fusion cross sections in S36+Pb204,206,208 are almost the same as those in S34+Pb204,206,208. Furthermore, at sub-barrier energies of the reactions S32,34,36+Pb208, the largest enhancement of reduced fusion function is observed in the reaction S32+Pb208. Then the enhancement of fusion cross sections due to couplings to inelastic excitation channels and neutron transfer channels with positive Q values is investigated by using the ECC model. The results show that the experimental data of the reactions S34,36+Pb204,206,208 and S32+Pb208 are reproduced well by the ECC model. In addition, it can be found that the effect of coupling to positive Q-value neutron transfer channels is necessary to reproduce the sub-barrier fusion data of the reaction S32+Pb208. Furthermore, for the two reactions S32+Pb204 and S32+Pb206, the effects of coupling to positive Q-value neutron transfer channels are predicted to be significant. The fusion cross sections for these two reactions are also predicted.