The Role of Thermal Conduction in Tearing Mode Theory

TL;DR

This paper investigates how anisotropic thermal diffusivity influences tearing mode stability in toroidal plasmas, deriving a dispersion relation and using a modified resistive MHD code to analyze growth rates and stability parameters.

Contribution

It introduces a dispersion relation linking growth rate to the stability parameter Delta, incorporating thermal transport effects in a resistive MHD framework.

Findings

Derived a dispersion relation for tearing mode growth rates.

Used a modified MHD code to compute stability parameters with thermal effects.

Demonstrated the code's capability to calculate basis functions for Delta.

Abstract

The role of anisotropic thermal diffusivity on tearing mode stability is analysed in general toroidal geometry. A dispersion relation linking the growth rate to the tearing mode stability parameter, Delta, is derived. By using a resistive MHD code, modified to include such thermal transport, to calculate tearing mode growth rates, the dispersion relation is employed to determine Delta in situations with finite plasma pressure that are stabilised by favourable average curvature in a simple resistive MHD model. We also demonstrate that the same code can also be used to calculate the basis-functions [C J Ham, et al, Plasma Phys. Control. Fusion 54 (2012) 105014] needed to construct Delta.