Effect of external force on the kinetics of diffusion-controlled escaping from a one-dimensional potential well

The kinetics of diffusion-controlled escaping (DCE) from the one-dimensiona l potential well in the presence of external force (both static and time de pendent) is analyzed in detail. It is shown that for static force the simpl e exponential kinetics (with the rate corresponding to the quasistatic diff usion over the barrier) is observed only in the limit of a strong force. Fo r weak forces the nonexponential contribution to the DCE kinetics becomes s ignificant. The general expression for the DCE kinetics in the presence of oscillating or fluctuating force is derived. With the use of this expressio n simple analytical formulas for the kinetics are obtained in the limits of slowly and fast oscillating or fluctuating force.