The effect of strong oscillating magnetic fields on electron transport properties in high-frequency discharges

Abstract

Strong electromagnetic resonance in cavity resonators can lead to many configurations of resonant field enhancement. Some resonant modes lead to strongly enhanced electric fields, but there also exist modes in which the magnetic field enhancement dominates. The typical fluid model of gas breakdown and electromagnetic interaction does not account for magnetic fields, which can lead to significant differences between observed and numerically computed breakdown thresholds, as well as differences in post-breakdown plasma evolution. Starting from an expansion of the Boltzmann equation for charged particles, we develop an analytical model that captures how a strong oscillating magnetic field can affect plasma transport properties. Certain parameter regimes are shown to have resonance-like behavior of diffusion, drift, and energy deposition to electrons. We develop a model that incorporates the effects of both static and oscillating magnetic fields in terms of a local effective electric field model. The fluid model parameters are compared to electron swarm behavior in a particle computation with Monte–Carlo collisions.