Enhanced residue cross sections in the 58Ni + 112Sn system

Evaporation processes from the extremely neutron deficient 58Ni + 112Sn reaction have been studied at beam energies from 282 to 634 MeV. Residues (ER) and Light-Charged-Particle (LCP)-ER coincidences were measured. Preliminary results indicate that the ER cross section at 282 MeV is consistent with previous measurements. Cross sections at the higher energies are several times larger than those near the coulomb barrier. This is in disagreement with standard statistical model predictions. These results also demonstrate that the deexcitation of the 170Pt compound nucleus via evaporation persists in this upper energy range, contrary to an expected onset of fragmentation. THe LCP spectra imply apparent temperatures which increase linearly with incident energy. In the context of the Fermi Gas model, this can be interpreted in terms of an energy-dependent level density parameter