Elastic Scattering ofO16byFe56,Ge70,74, andZr90

The elastic scattering of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ by ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{70}{}_{}{}^{}\mathrm{Ge}$, and ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ has been studied in the vicinity of the Coulomb barrier for the purpose of extracting optical-model parameters and barrier heights. Angular distributions were measured from 30° to 170° in the lab in 10° steps and in the bombarding energy range from 30 to 60 MeV in 2-MeV steps. No discrete ambiguities in the real potentials were found, probably due to the large imaginary potentials. Barrier heights determined with the optical-model parameters were found to be consistent with Greiner's calculated barrier heights and 10-20% lower than the ordinary Coulomb barrier $\frac{Z_1{Z}_2{e}^2}{1.35(A_1^{\frac{1}{3}}+A_2^{\frac{1}{3}})}$.