Is Kramers formula applicable to describing highly excited nuclear system decay

Decay of the excited nuclear systems is investigated in the framework of the fluctuation-dissipation dynamics using the Langevin equations. The escape rates over the fission barrier and over the scission point have been calculated for different values of the fission barrier height Bf to the temperature T ratio. The influence of the value of nuclear viscosity and of the initial conditions on the time evolution of the escape rates has been studied. A special attention is paid to the case Bf=0. The systematic comparison between our results and the Kramers formula has been carried out. It showed that the formula works surprisingly well even in the most of the cases when Bf<T. If Bf=0, the escape rate over the scission point is 1.5-2 times larger than the Kramers one