Modified optical potential for elasticαscattering: Folding potentials and energy dependence

The surface peaked modification to the conventional six-parameter representation of an $\alpha$ particle-nucleus interaction potential has been studied further. In particular we have used a nucleon-nucleus optical potential folded over the $\alpha$ particle to derive the central well depth, and it is found that constant geometry parameters can be used to fit the $A$ dependence and energy dependence of the optical model for ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ from 40-140 MeV. It is further found that good quality fits to elastic scattering can be obtained for the entire energy range for ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ with constant geometry for the Woods-Saxon imaginary well depth, resulting in a five search parameter potential and the geometrical parameters of the modification.