Dynamical Dipole Mode in Heavy-Ion Fusion-Evaporation and Fission Reactions in the Pb-192 Mass Region

The prompt γ -ray emission related with the dynamical dipole mode decay was investigated in the 192Pb mass region by means of the 40Ca + 152Sm and 48Ca + 144Sm fusion-evaporation and fission reactions at Elab=11 and 10.1 MeV/nucleon, respectively. The two reactions populate, through entrance channel having different charge asymmetries, the 192Pb compound nucleus at an excitation energy of 236 MeV with identical spin distribution. Preliminary results of this experiment show that the dynamical dipole mode survives in collisions involving heavier mass reaction partners than those studied previously. As a fast cooling mechanism on the fusion path, the prompt dipole γ radiation could be of interest for the synthesis of super-heavy elements through "hot" fusion reactions.