Towards a unified description of light ion fusion cross section excitation functions

Abstract

A description of light heavy-ion fusion, taking into account both entrance-channel characteristics and compound-nucleus properties, is derived within a unified theory of nuclear reactions. The dependence of the imaginary fusion potential on the level density of the compound nucleus is revealed. The12C +12C,12C +14N,10B +16O and16O +16O fusion cross sections are calculated forE cm≤120 MeV and compared with experimental data. The excitation energy dependence of the level-density parameter of24Mg,26Al and32S is inferred below 5 MeV/A. A realistic nuclear level-density model, describing the experimental level-density parameters of highly excited nuclei, is shown to be consistent with both the global features and details of the fusion cross section.12C +12C and16O +12O fusion cross section oscillations are predicted at large excitation energies, reflecting the structure of the level density of the highly excited light compound nuclei. Differences of the12C +14N and10B +16O fusion reaction mechanisms are discussed in terms of specific entrance-channel characteristics.