Evaporation residue cross sections for the 64Ni + 144,154Sm reaction -- Energy dissipation in hot nuclei

The fission hindrance of hot nuclei was deduced recently from an enhanced emission of GDR γ rays, neutrons and charged particles prior to scission of heavy nuclei. In the most recent experiments addressing this topic, namely new measurements of the pre-scission γ rays and evaporation residues from the 32S + 184W reaction, a rather sharp transition from negligible to full one-body dissipation occurs over the excitation energy region Eexc = 60-100 MeV. However, the cross section does not appear to level out or start to decline again at the upper end of the energy range as expected in this interpretation. It is therefore clearly desirable to extend the excitation energy range to look for such an effect in order to either corroborate or refute this interpretation