Numerical model of a hollow cathode arc discharge formation in vacuum

Abstract

Industrial application of hollow cathode arc (HCA) discharge necessitates understanding the processes of interaction between the plasma and the cathode and the anode, as well as related processes. The first step is to study the formation process of HCA discharge in vacuum with the micro-flow of plasma-forming gas through the hollow cathode. In this work presents a two-dimensional model describing the related processes of transfer of charged particles and the movement of plasma-forming gas flows. Electron density and mean electron energy are calculated by solving the drift-diffusion equations. The mass transfer equation for a multicomponent mixture is used to describe the mass transfer of heavy plasma particles. To calculate the electric field strength the Poisson equation is used. The emission of secondary electrons from the inner surface of the cathode is taken into account. The boundary conditions take into account the loss of charge as a result of chaotic motion and its occurrence due to thermal emission effects. The gas flow is determined by collisions and diffuse re-reflection from all surfaces assumed in accordance with Knudsen’s law. Calculations of plasma formation and the movement of plasma-forming gas flows were performed using the simulation package COMSOL Multiphysics.