Fusion of a halo nucleus and synthesis of superheavy elements

We discuss two related subjects concerning heavy ion fusion reactions. First we show that the fusion cross section of a nucleus with a neutron halo is drastically enhanced at low energies because of the decrease of the fusion barrier and the coupling of the translational motion to soft vibrational modes of excitation characteristic to halo nuclei. We then discuss the advantages and the disadvantages of neutron rich beams in synthesizing superheavy elements by heavy ion collisions. (orig.)