Modelling cathode spots in glow discharges in the cathode boundary layer geometry

TL;DR

This paper models cathode spot patterns in glow discharges within the cathode boundary layer geometry, using a computational approach that aligns well with experimental observations.

Contribution

It introduces a computational model for cathode spots in glow discharges in the boundary layer geometry, capturing multiple solution modes and matching experimental patterns.

Findings

Multiple solution modes for cathode spots are identified.

Computed patterns agree with experimental observations.

The model applies to the geometry used in most experiments.

Abstract

Self-organized patterns of cathode spots in glow discharges are computed in the cathode boundary layer geometry, which is the one employed in most of the experiments reported in the literature. The model comprises conservation and transport equations of electrons and a single ion species, written in the drift-diffusion and local-field approximations, and Poisson's equation. Multiple solutions existing for the same value of the discharge current and describing modes with different configurations of cathode spots are computed by means of a stationary solver. The computed solutions are compared to their counterparts for plane-parallel electrodes, and experiments. All of the computed spot patterns have been observed in the experiment.