FUSION EXCITATION-FUNCTION MEASUREMENTS FOR THE O-16-58 AND O-16+NI-62 SYSTEMS(NI)

High precision fusion excitation functions have been measured for the O-16 + Ni-58 and O-16 + Ni-62 systems from which fusion barrier distri butions have been evaluated. Coupled-reaction-channels (CRC) calculati ons, which describe elastic and quasi-elastic scattering, also satisfa ctorily reproduce the fusion cross sections and barrier distributions. The small value of Z(1)Z(2) in this case leads to barrier distributio ns with relatively little structure. However, in conjunction with the detailed elastic scattering data for these systems, this allows us to elucidate the role of previously ignored states in O-16 in pushing the entire distribution to lower energies. These shifts are consistent wi th derived magnitudes of polarization potentials for both systems. (C) 1998 Published by Elsevier Science B.V.