Temperature dependence of friction from pre- and post-scission neutron emission Original Research Article

The magnitude of nuclear friction has been investigated in recent years by measuring pre- and post-scission neutron multiplicities. These data have been analysed mostly in the frame of the statistical model by introducing ad-hoc delays to go from equilibrium to saddle and then to scission. We present here a more simple approach based on remaining excitation energies at saddle. This leads to analytical formulae which reproduce almost all the published data. The temperature at which one observes transition from pre-scission to post-scission emission is the only parameter in the calculation. Its values show no significant variation with the total mass nor with bombarding energy, supporting the concept of temperature dependent friction. The mean value averaged over all published data is 1.11±0.05 MeV.