Fusion cross section limitation of the Li-7+B-11 reaction

The Li-7 + B-11 reaction has been studied in the energy range from 3.1 to 1 1.5 MeV in the c.m. system by measuring the cross section of the gamma-ray transitions in the residual nuclei produced. Statistical compound nucleus c alculations have been performed in order to extract cross sections of the i ndividual exit channels and eventually the fusion cross section. The hindra nce of the fusion cross section at energies above the interaction barrier h as been investigated in terms of macroscopic models.