Transitional dissipative mechanism in the 32S+ 59Co reaction

In a systematic study of strongly damped reaction mechanisms between medium mass nuclei we have measured the evaporation residue and the fissionlike fragments from the 32S+ 59Co reaction. The mass and angular distributions and the total kinetic energies for fissionlike fragments were measured. A strong angular dependence of the mass distribution has been observed. The cross sections for the production of fusion evaporation and fissionlike fragments have been determined and the fusion cross section deduced. The latter were compared to various fusion model predictions including those developed to describe the so-called fast fission and quasifission. The results are interpreted in terms of a process which we call dynamical fission, the basic concepts of which are consistent with those of the extra push model and those of the fast fission model in the subcritical mass transfer regime