A new optical model approach for heavy ion fusion

Abstract

Fusion excitation functions and compound nucleus spin distributions have been investigated within the framework of the optical model using an energy dependent imaginary potential. The decrease in the strength of the imaginary potential for fusion with decreasing bombarding energy near the Coulomb barrier has been parametrised in terms of the relative kinetic energy at the interaction barrier rather than the center of mass bombarding energy, as is usually done. This results in an l-dependent imaginary potential in the optical model. With this new parametrisation, it has been possible to reproduce the measured fusion cross sections and mean square spin values of the compound nucleus in the reaction of the ¹⁶O+²⁰⁸Pb system.