Mass and energy dependence of the alpha-particle optical model potential in the energy range 90-172 MeV and in the atomic mass range 12-208 Amu

The energy and atomic mass dependent parameters of the local optical model potential for the elastic alpha particle scattering in the energy region of 90-172 MeV on target nuclei from 12 to 208 Amu have been proposed and calculated. The calculated cross-sections qualitatively well fit the experimental data in the considered energy and atomic mass region. In order to improve the fits, the structure corrections that depend on the number of nucleons outside of the last closed shell could be added to the optical model potential. (author)