and show that one has to modify this simplified description at low temperature to correctly describe the experimental data.

Another quantity entering the Langevin equation and whose temperature dependence requires special attention is the potential $V(\vec q\,)$ namely because of the vanishing of quantal effects at high excitation energy. In our approach valid up to now for symmetric fission, it consisted of a temperature dependent Liquid Drop Model (LDM) term only. At lower energy we have to add to this macroscopic contribution the shell corrections which are evaluated at each deformation using the Strutinsky’s approach [@S67] and the pairing correlations which we calculate in the framework of the BCS model [@BCS57] with a constant pairing strength ([*seniority scheme*]{}) [@NTS69].

The generalized coordinates $q_i$ which enter the Langevin equation are either chosen as the deformation parameters generating the nuclear shape (e.g. coefficients $\alpha_{\ell}$) or as more physically relevant quantities (elongation, mass asymmetry, etc) which are determined through these parameters [@BMR96].

Up to now [@PBR96; @PNS00] we have investigated the case of highly excited compound nuclei giving rise to symmetric fission. Such a process can be described approximately by a single collective coordinate characterizing the nuclear elongation as explained in ref. [@BMR96]. 