On the validity of drift-reduced fluid models for tokamak plasma simulation

TL;DR

This paper evaluates the validity of drift-reduced plasma fluid models in tokamak simulations, highlighting their limitations in core regions and suitability for edge regions based on linear behavior analysis.

Contribution

It provides an analysis comparing drift-reduced and full-velocity models, clarifying when drift-reduction is appropriate for tokamak plasma regions.

Findings

Drift-reduction omits important physics in the core region.

Model validity varies between core and edge regions.

Linear analysis helps determine model applicability.

Abstract

Drift-reduced plasma fluid models are commonly used in plasma physics for analytics and simulations; however, the validity of such models must be verified for the regions of parameter space in which tokamak plasmas exist. By looking at the linear behaviour of drift-reduced and full-velocity models one can determine that the physics lost through the simplification that the drift-reduction provides is important in the core region of the tokamak. It is more acceptable for the edge-region but one must determine specifically for a given simulation if such a model is appropriate.