Кинетическая теория пристеночного слоя при произвольных условиях в газоразрядной плазме

Abstract

For an arbitrary relation of the Debye length to the ion free path, based on the kinetic approach, it was solved the self consistent problem of the structure of the perturbed wall sheath in a DC plasma gas discharge, near a flat surface at a negative potential in relation to the plasma. The solution was obtained without an artificial separation of the perturbed wall sheath into a quasineutral "presheath" and a wall sheath where quasineutrality is substantially violated. They were taken into account the real ion distribution function in the unperturbed plasma, the dependence of the charge exchange cross section on the ion energy, and the nonzero electric field in the unperturbed plasma. It was found that, if the mean electron energy is preserved, the structure of the perturbed wall sheath weakly depends on the form of the electron distribution function. It was shown that, even under the assumption that the mean electron energy is much higher than the mean ion energy, is the mean ion energy in the unperturbed plasma the one that has a significant effect both on the structure of the quasineutral "presheath" and on the structure of a part of the wall sheath, where there is no quasineutrality. The calculations of the parameters of the ion flux and the structure of the perturbed wall sheath are in agreement with other authors’ experimental results that didn’t have previously an adequate interpretation.