Abstract
Proposes a semi-empirical formula for the fusion cross section of heavy ions which incorporates final-state effects through the compound-nucleus mass and entrance-channel effects by means of a contact distance. This contact distance is the sum of the distances where the two nuclear mass distributions fall to 0.002 nucleons/fm3. A general prescription is introduced to obtain the nuclear density distribution as a sum of squared Woods-Saxon wave functions. The fusion excitation functions predicted by the authors' formula are shown to describe a large amount of experimental data very well. Finally, their predictions, notably those concerning the possible shell effect on the saturation fusion cross section, sigma fusmax, are seen to compare quite favourably with other theories.