Nonthermal tails of the electron distribution functions with nonlocal transport

Abstract

Quasi-self-similar solutions to the stationary electron Fokker-Planck equation in diffusive approximation have been found in inhomogeneous plasma. These solutions describe reduction in the number of bulk electrons and formation of the suprathermal tail. The characteristics of the stationary electron distributions have been treated in terms of the collisionality parameter, the ratio of the electron stoping rage to the plasma gradient scale length. The dependencies of the electron distribution functions on density profile has been studied. Fokker-Plank simulations performed demonstrate good agreement with a theory.