FUSION CROSS-SECTION FOR THE WEAKLY-BOUND NEUTRON SYSTEM BE-11-10 AT ENERGIES BELOW AND NEAR THE COULOMB BARRIER(BE)

The sub-barrier fusion cross section for the weakly bound neutron syst em Be-11+Be-10 is discussed in the framework of the coupled-reaction-c hannel (CRC) approach for the valence neutron in Be-11 and in connecti on with the molecular orbital formation. In the calculation we observe a big enhancement of the fusion process as well as the formation of a covalent molecule (Be-10+n+Be-10) due to very strong multistep proces ses in the inelastic and transfer transitions of the active neutron. A s a consequence of the strong CRC effects sharp resonances are observe d as fine structure of the fusion cross section, in the case that the absorption effects of the internuclear potential are weak.