Kinetic Analysis of Weakly ionized Plasmas in presence of collecting walls

J Gonzalez,J M Donoso

doi:10.1088/1742-6596/958/1/012004

Abstract

Description of plasmas in contact with a wall able to collecting or emitting charged particles is a research topic of great importance. This situation arises in a great variety of phenomena such as the characterization of plasmas by means of electric probes, in the surface treatment of materials and in the service-life of coatings in electric thrusters. In particular, in this work we devote attention to the dynamics of an argon weakly ionized plasma in the presence of a collecting wall. It is proposed a kinetic model in a 1D1V planar phase-space geometry. The model accounts for the electric field coupled to the system by solving the associated Poisson’s equation. To solve numerically the resulting non-linear system of equations, the Propagator Integral Method is used in conjunction with a slabbing method. On each interrelating plasma slab the integral advancing scheme operates in velocity space, in such a way that the all the species dynamics dominating the system evolution are kinetically described.

Highlights

The description of plasma-wall interactions is an open problem of major importance in experiential plasma physics since the dynamics of light and heavy species close to a wall bears on probe measurement processes, service life of walls and coatings and surface treatment procedures
The description of this interaction is usually established by models that may not capture all microscopic processes involved, specially in Weakly Ionized Plasmas (WIP), for which the inclusion of a dense heavy cold neutral species hinders the development of such models [21, 23, 24]
Kinetic model and slabbing method For a plasma bounded by a wall capable of collecting or emitting charged particles, the species dynamics gives rise to a very complex system, related to the fast charge separation that governs the plasma evolution, at the same time modified by the collection of particles

Summary

Introduction

The description of plasma-wall interactions is an open problem of major importance in experiential plasma physics since the dynamics of light and heavy species close to a wall bears on probe measurement processes, service life of walls and coatings and surface treatment procedures. 2. Kinetic model and slabbing method For a plasma bounded by a wall capable of collecting or emitting charged particles, the species dynamics gives rise to a very complex system, related to the fast charge separation that governs the plasma evolution, at the same time modified by the collection of particles.

Results

Conclusion