The volume and surface contributions to the ion-ion optical potential

A complex effective interaction calculated from the Reid soft-core potential by solving the Bethe-Goldstone equation for two colliding pieces of nuclear matter is used to calculate the volume part of the ion-ion optical potential for several pairs of nuclei. The contributions from collective surface vibrations are taken into account by eliminating them according to the Feshbach prescription. The optical potentials together with the total reaction cross sections are calculated for energies up to about 90 MeV per nucleon in the laboratory frame. The systematics of the potentials are studied by approximating the potentials with a Woods-Saxon shape. The role of surface excitations in the reaction mechanism is further studied by performing coupled-channel calculations.