Effects of dissipation and simultaneous break-up on fission at high excitation energies

The time a nucleus needs to populate its deformation space is ruled by dissipation, that is, the transfer of energy between intrinsic and collective degrees of freedom. The study of fission allows for gaining information on the strength of dissipation within a broad range of deformation. For small deformations, the hindrance of fission caused by dissipation starts to be remarkable only at high nuclear temperatures, when the statistical decay time is shorter than the dynamical delay. On the other hand, as shown in [1], thermal instabilities arise when nuclear temperatures larger than 5 MeV are reached. The aim of this work is to investigate the effects of dissipation and thermal instabilities on fission at high temperatures.