The fusion cross section and energy dependence of the potential radius

Focusing on the fusion reactions, the variation of the ion-ion potential with energy through its radius is studied. A new formula for the energy dependence of the potential radius at low and intermediate energy is proposed. This formula led to improved agreement between the fusion calculations and experimental data for spherical nuclei. It also accounts well for the scattering data over wide energy range. The same formula is applied successfully for the interactions including deformed nuclei as well. The anomaly of the large surface diffuseness required to the fusion cross section calculations disappeared when the energy dependence of the potential radius is considered