Nonlinear electromagnetic formulation for particle simulation of lower hybrid waves in toroidal geometry

TL;DR

This paper develops and verifies a nonlinear electromagnetic particle simulation model for lower hybrid waves in toroidal fusion plasmas, improving numerical stability and capturing key wave phenomena.

Contribution

It introduces a comprehensive electromagnetic particle simulation framework for LH waves in toroidal geometry, incorporating electron and ion dynamics with improved numerical methods.

Findings

Model accurately reproduces dispersion relations.

Successfully simulates nonlinear particle trapping.

Enhanced numerical stability with new techniques.

Abstract

Electromagnetic particle simulation model has been formulated and verified for nonlinear processes of lower hybrid (LH) waves in fusion plasmas. Electron dynamics is described by the drift kinetic equation using either kinetic momentum or canonical momentum. Ion dynamics is treated as the fluid system or by the Vlasov equation. Compressible magnetic perturbation is retained to simulate both the fast and slow LH waves. Numerical properties are greatly improved by using electron continuity equation to enforce consistency between electrostatic potential and vector potential, and by using the importance sampling technique. The simulation model has been implemented in the gyrokinetic toroidal code (GTC), and verified for the dispersion relation and nonlinear particle trapping of the electromagnetic LH waves.