Multi-region relaxed magnetohydrodynamics with anisotropy and flow

TL;DR

This paper extends the multi-region relaxed magnetohydrodynamics model to include pressure anisotropy and plasma flows, providing a new variational principle for anisotropic equilibria with nested flux surfaces.

Contribution

It introduces an anisotropic extension to the MRxMHD model, connecting it to anisotropic ideal MHD with flow as the number of regions increases.

Findings

Reduction to anisotropic ideal MHD with flow in the continuum limit

First variational principle for anisotropic plasma equilibria with flow

Extension of MRxMHD to include pressure anisotropy and flow

Abstract

We present an extension of the multi-region relaxed magnetohydrodynamics (MRxMHD) equilibrium model that includes pressure anisotropy and general plasma flows. This anisotropic extension to our previous isotropic model is motivated by Sun and Finn's model of relaxed anisotropic magnetohydrodynamic equilibria. We prove that as the number of plasma regions becomes infinite, our anisotropic extension of MRxMHD reduces to anisotropic ideal MHD with flow. The continuously nested flux surface limit of our MRxMHD model is the first variational principle for anisotropic plasma equilibria with general flow fields.