Finite-amplitude RF heating rates for magnetized electrons in neutral plasma

TL;DR

This paper develops a theoretical model to calculate RF heating rates for magnetized electrons in neutral plasma, extending existing low-amplitude theories to high-frequency regimes relevant for ultracold plasma experiments.

Contribution

It introduces a Vlasov-Poisson based model for finite-amplitude RF heating in magnetized plasma, applicable to high-frequency RF fields and strong magnetic fields.

Findings

Heating rate varies mildly across magnetization strengths.

Including collisional relaxation reduces heating rate by less than 5%.

Model aligns with low-amplitude theory in the appropriate limit.

Abstract

A theoretical model is developed and evaluated using a Vlasov-Poisson treatment to calculate radiofrequency (RF) electric field heating rates for magnetized electrons in neutral plasma when the magnetic and electric field directions are colinear and when the RF is of sufficiently high frequency. This calculation reduces to the theory for magnetized longitudinal AC conductivity introduced by Oberman and Shure [C. Oberman and F. Shure, Phys. Fluids 6, 834-838 (1963)] in the low-amplitude limit when the electron oscillation velocity is much less than the thermal velocity. For electron coupling strengths $\Gamma=0.15$--$0.015$ and RF fields accessible to ultracold neutral plasma experiments, the model predicts mild variations in heating rate of order unity across magnetization strengths spanning orders of magnitude. The predicted effect of including a BGK-type collisional relaxation term in the Vlasov equation reduces the heating rate by 5% or less across magnetizations.