Work

Generalized random walk model of cathode spot motion

Year: 2025

Type: article

Abstract: Cathode spots in a cathodic arc discharge exhibit complex dynamical motion. Traditionally, this motion has been modeled as a simple random walk with fixed-step size and time, but this approach fails to reconcile the large variations in experimental measurements of step size and time and it also fails to explain the temporal self-similarity of the cathode spot process in the burning voltage noise. We propose a generalized random walk model based on a diffusive continuous time random walk, allowing step size and time to be governed by evolving probability distributions. The proposed model resolves the inconsistencies in earlier models and successfully reproduces the fractal features seen in experiments, namely, the Brownian noise in the spectral power density of the burning voltage and in light emission.

Source: Journal of Applied Physics

DOI: 10.1063/5.0283470

Authors: Jiongyu Liang, Kyunghwan Oh, Kostadinos W. Tsoutas, André Anders, David R. McKenzie, Marcela M. M. Bilek

Institutions: The University of Sydney, Leibniz Institute of Surface Engineering

Language: English

Topic: Vacuum and Plasma Arcs

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,500

Funder: Australian Research Council