Modeling the anode boundary layer of high-intensity argon arcs

This paper is concerned with numerical studies of the anode region of a high-intensity argon arc. The anode region is divided into three subzones: the anode boundary layer, the presheath and the sheath. The governing equations of the dominating processes with the boundary conditions taken from the solutions of LTE plasmas are solved by applying the Runge±Kutta procedure. One parameter h, i.e., the ratio of the heavy particle temperatures at the free-fall edge to the anode surface temperatures, is introduced into this study. The results indicate that the parameter h is an important factor in ̄uencing the local plasma properties in the boundary layer, the boundary layer thickness and the sheath potential. An estimate of the value for h is made. The potential drop in the boundary layer is slightly positive. Ó 1999 Elsevier Science B.V. All rights reserved.