Comparison of fusion cross sections for 12C + 12C → 24Mg and 14N + 10B → 24Mg

The total fusion cross sections have been measured and compared for two light systems, 12C + 12C and 14N + 10B, leading to the same compound nucleus at the same excitation energies. E*(24Mg) = 40, 50, 55 and 60 MeV. The critical angular momenta extracted for the formation of 24Mg via 12C + 12C and 14N + 10B are different enough to clearly indicate the presence of an entrance channel effect (limitation). The Z-distributions of the evaporation residues are compared to each other and to Hauser-Feshbach calculations. The data are also fitted with and compared to theoretical models which predict total fusion cross sections. (orig.)