Particle modeling of vacuum arc discharges

Abstract

Metal vapor vacuum arcs (VAs) are widely used in various fields of industry, such as circuit breakers, ion sources, electrical thrusters, and deposition systems. VAs usually originate from metal vapors eroding from the surface of a cathode, where they burn as tiny bright points, hence their name “cathode spots” (CS). Due to their high plasma density, short life span, and micrometer scale, the in situ and non-intrusive diagnostics of CS are a challenge. Numerical simulation is one method used to study CS with the aid of high-performance computing. The well-established particle-in-cell method provides solutions for the spatial-temporal electromagnetic field and the microscopic distribution functions of plasma species in phase space from which the macroscopic parameters of the plasma can be calculated. This Perspective reviews the progress in particle modeling of VAs with an emphasis on the non-stationary and non-local physical processes that are not reproduced by fluid models. Furthermore, a personal outlook on future challenges is provided: the physical modeling of plasma–electrode interactions, the collection and evaluation of collision cross sections, the trade-off between heavy computation cost and predictive ability, and the verification and validation of the simulation code.

Observation of prior light emission before arcing development in a low-temperature plasma with multiple snapshot analysis

“…Since arcing itself is a high-density and high-temperature plasma that causes severe damage to material surfaces [7][8][9][10][11][12] , it has received enormous attention in research fields as well as industry for over 120 years 13 . Numerous studies have revealed arcing initiation mechanisms in direct current (DC) and radio frequency (RF) voltage environments in ultra-high vacuum, like field emission 14 and thermo-field electron emission 15 induced by a high electric field, which is on the order of several tens of GV/m and realized under circumstances of several tens of kV with micro-gaps 16 . Besides ultra-high vacuum conditions, arcing has also been observed in middle vacuum with low-temperature plasmas (LTPs), and several studies have investigated its ignition mechanisms [17][18][19][20] .…”

A tutorial overview of the angular scattering models of electron–neutral, ion–neutral, neutral–neutral, and Coulomb collisions in Monte Carlo collision modeling on low-temperature plasma

“…The MC swarm calculation is also performed by an inhouse PIC-DSMC code with the implemented anisotropic ionization model, which is initially designed for simulation on vacuum arcs [122][123][124]. The electron number is not fixed during ionization [25]: the initial electron number is 10 4 , and the simulation stops if the electron number reaches 10 7 .…”

Initial kinetics of electrons, ions and electric field in planar vacuum diode with plasma cathode

“…This approximation is not suitable for describing the transport of particles under vacuum conditions. Kinetic or hybrid approaches are also used [15][16][17]. Most of them are implemented by PIC/MCC methods (Particle-in-cell/Monte-Carlo).…”