Gyrokinetic ion and drift kinetic electron model for electromagnetic simulation in the toroidal geometry

TL;DR

This paper introduces a new electromagnetic simulation model for drift kinetic electrons in tokamak plasmas, enabling efficient and accurate analysis of various plasma instabilities without numerical constraints on grid size.

Contribution

A novel conservative split weight scheme for gyrokinetic simulations with drift kinetic electrons that improves computational efficiency and physics fidelity in toroidal geometries.

Findings

Successfully verified kinetic Alfven wave and collisionless tearing mode simulations.

Implemented the model into the gyrokinetic toroidal code (GTC).

The model allows larger grid sizes without losing physical accuracy.

Abstract

The kinetic effects of electrons are important to long wavelength magnetohydrodynamic(MHD)instabilities and short wavelength drift-Alfvenic instabilities responsible for turbulence transport in magnetized plasmas, since the non-adiabatic electron can interact with, modify and drive the low frequency instabilities. A novel conservative split weight scheme is proposed for the electromagnetic simulation with drift kinetic electrons in tokamak plasmas, which shows great computational advantages that there is no numerical constrain of electron skin depth on the perpendicular grid size without sacrificing any physics. Both kinetic Alfven wave and collision-less tearing mode are verified by using this model, which has already been implemented into the gyrokinetic toroidal code(GTC). This model will be used for the micro tearing mode and neoclassical tearing mode simulation based on the first principle in the future.