Total fusion-evaporation cross sections for the systems ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ + ${}_{}{}^{16,18}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Si}$ + ${}_{}{}^{16,18}{}_{}{}^{}\mathrm{O}$ have been measured in the energy range $34 \mathrm{MeV}\le E_{\mathrm{lab}}\le 81 \mathrm{MeV}$ by detecting the evaporation residues in a time-of-flight spectrometer. The fusion cross sections for all systems were found to saturate at 1150-1200 mb. Fusion barriers have been deduced with the parametrization of Glas and Mosel. The data have also been discussed in terms of the Bass model.

NUCLEAR REACTIONS ${}_{}{}^{16,18}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{16,18}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Si}$; $E_{\mathrm{lab}}=34-81\mathrm{}$ MeV; measured ${\sigma }_{\mathrm{fusion}}$; deduced fusion barriers.

• Received 22 January 1979

DOI:https://doi.org/10.1103/PhysRevC.20.1028