Understanding fusion suppression and enhancement in the 18O + 58,60,64Ni systems

Realistic coupled-channel calculation results for the 18[O] + 58,60,64Ni systems in the bombarding energy range 34.5⩽ELab⩽65MeV are presented. The overall agreement with existing experimental data is quite good. Our calculations predict an unexpected fusion suppression for above-barrier energies, with an important contribution of the two neutron (18O, 16O) transfer channel couplings. The sub-barrier fusion enhancement and the above barrier suppression, predicted by the calculations, are consistent with the nuclear structure of the Ni region. Comparisons with recently reported similar effects in reactions induced by the 6He projectile are discussed.