An alternative simulation approach for surface flashover in a vacuum using a 1D2V continuum and kinetic model

Surface flashover across an insulator in a vacuum is a destructive plasma discharge which undermines the behaviors of a range of applications in electrical engineering, particle physics and space engineering, etc. This phenomenon is widely modeled by the particle-in-cell (PIC) simulation, here the continuum and kinetic simulation method is first proposed and implemented as an alternative solution for flashover modeling, aiming for the prevention of unfavorable particle noises in PIC models. A one dimension in space, two dimensions in velocity kinetic simulation model is constructed. Modeling setup, physical assumptions, and simulation algorithm are presented in detail, and a comparison with the well-known secondary electron (SE) emission avalanche analytical expression and existing PIC simulation are made. The obtained kinetic simulation results are consistent with the analytical prediction, and feature noise-free data of surface charge density as well as fluxes of primary and SEs. Discrepancies between the two simulation models and analytical predictions are explained. The code is convenient for updating and to include additional physical processes. The possible implementations of outgassing and plasma species for the final breakdown stage are discussed. The proposed continuum and kinetic approach are expected to inspire future modeling studies for the flashover mechanism and mitigation.

Automated summary

Surface flashover in a vacuum is a destructive plasma discharge that affects various applications in electrical engineering, particle physics, and space engineering. This paper proposes and implements a continuum and kinetic simulation method as an alternative solution for flashover modeling, aiming to prevent particle noise in PIC models. A one-dimensional spatial, two-dimensional velocity kinetic simulation model is constructed and compared with existing PIC simulation and analytical predictions. The obtained kinetic simulation results are consistent and provide noise-free data for surface charge density. The proposed approach has the potential to inspire future modeling studies for flashover mechanisms and mitigation.