Fusion hindrance forNi58+Fe54

Abstract

The fusion excitation function of {sup 58}Ni+{sup 54}Fe has been measured in a cross-section range from approx =1 mub up to around 450 mb. Coupled-channels calculations, using a standard Woods-Saxon ion-ion potential, reproduce the excitation function down to about 180 mub. At lower energies, fusion cross sections drop faster than calculations, with a steep slope. The astrophysical S factor shows a maximum at the lowest energies. These results are compared with various evidence from recent experiments on other systems with projectile and target in the mass range Aapprox =30-60.