Over the barrier electron transfer from a micron sized charged dust particle to an ion in gas discharge plasmas

Abstract

A simple semiclassical model for the calculation of the electron transfer cross section from the dust particle to the ion is presented. The key ingredient of the model is the transition rate of the electron from the charged dust particle to the ion as a function of the distance between them. Particularly, over the barrier electron transfer from the micron sized spherical dust particle to the surrounding plasma ion is considered. The cross section of this process for the strong dust particle-ion coupling regime, which corresponds to the case of the room temperature gas discharge plasma, is presented. The obtained data were analyzed by comparing them with the ion absorption cross section on the surface of the dust particle. It is found that in the case of micron sized dust particles, more than 15% of ion recombinations with a charged dust particle's electron is due to over the barrier electron transfer. It has been shown that in the considered range of parameters, the cross section of over the barrier electron transfer from the negatively charged dust particle to the ion can be presented in a simple analytical form despite strong nonlinearity of the ion-dust scattering problem.