Modeling Vacuum Arcs

TL;DR

This paper develops a comprehensive model of vacuum arcs, integrating mechanical failure, plasma dynamics, and surface evolution to better understand arc initiation, development, and surface damage.

Contribution

It introduces a multi-scale, self-consistent modeling approach combining molecular dynamics, PIC simulations, and surface thermodynamics for vacuum arcs.

Findings

Identifies key differences from existing models.

Provides numerical results illustrating arc development.

Highlights mechanisms of surface damage and arc termination.

Abstract

We are developing a model of vacuum arcs. This model assumes that arcs develop as a result of mechanical failure of the surface due to Coulomb explosions, followed by ionization of fragments by field emission and the development of a small, dense plasma that interacts with the surface primarily through self sputtering and terminates as a unipolar arc capable of producing breakdown sites with high enhancement factors. We have attempted to produce a self consistent picture of triggering, arc evolution and surface damage. We are modeling these mechanisms using Molecular Dynamics (mechanical failure, Coulomb explosions, self sputtering), Particle-In-Cell (PIC) codes (plasma evolution), mesoscale surface thermodynamics (surface evolution), and finite element electrostatic modeling (field enhancements). We can present a variety of numerical results. We identify where our model differs from other descriptions of this phenomenon.