The ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{12}$C and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{13}$C fusion cross sections have been measured in the energy range ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=13.6 to 20 MeV. The comparison of both sets of measurements provides information on the influence of the inelastic and transfer channels on fusion. Our results indicate that both systems exhibit similar behavior in spite of the large positive Q value for the one-neutron-transfer channel in the ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{13}$C case compared to the less favorable ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{12}$C case. A small enhancement of the fusion cross sections relative to the predictions of an uncoupled barrier penetration model could be easily accounted for by including the effect of coupling to low-lying excited states of the participant nuclei.

• Received 7 December 1989

DOI:https://doi.org/10.1103/PhysRevC.41.2654