INTERACTION POTENTIAL AND FUSION OF A HALO NUCLEUS

The interaction potential for the scattering of a neutron-rich nucleus is studied using the double folding procedure of the M3Y force. It is shown that the height of the potential barrier considerably decreases when the separation energy of the valence neutrons becomes small enough to develop a neutron halo similarly, to the Li-11 nucleus. A simple model calculation of the fusion cross section, which takes into account the realistic interaction potential and the coupling of the translational motion to a soft dipole mode of excitation of the halo nucleus, is then performed to show that the fusion cross section of a halo nucleus is drastically enhanced at low energies because of the lowering of the fusion barrier and the coupling of the translational motion to soft modes of excitation associated with the neutron halo.