Dependence of nuclear dissipation upon deformation or temperature: analysis of the data using a Langevin-Monte-Carlo approach

Experimental data on heavy-ion induced fission are analyzed in the framework of the Combined Dynamical Statistical (Langevin — Monte-Carlo) Model (CDSM). We aim to clarify the temperature and deformation dependence of the dissipation coefficient of the fission mode. Results of the calculations with three dissipation mechanisms, two with strong deformation dependencies and the third one with a strong temperature dependence, are compared with data for the observables which are supposed to be the most sensitive probes for nuclear friction. The coordinate-dependent friction parameter from a standard parameter set of the CDSM is shown to lead to better agreement with the data than the two others, although the available data are rather sensitive to the average value of nuclear friction than to the details of the coordinate and temperature dependence.