Nonaxisymmetric, multi-region relaxed magnetohydrodynamic equilibrium solutions

TL;DR

This paper introduces a new MHD equilibrium model combining ideal constraints with Taylor relaxation, allowing for complex magnetic field structures and pressure profiles, solved numerically with the SPEC code.

Contribution

It presents a novel MHD equilibrium framework that incorporates topological constraints and partial chaos, with numerical solutions and benchmarks using the SPEC code.

Findings

Successfully computed equilibrium solutions with complex magnetic topologies.

Demonstrated convergence and benchmarking of the numerical method.

Extended the understanding of nonaxisymmetric MHD equilibria.

Abstract

We describe a magnetohydrodynamic (MHD) constrained energy functional for equilibrium calculations that combines the topological constraints of ideal MHD with elements of Taylor relaxation. Extremizing states allow for partially chaotic magnetic fields and non-trivial pressure profiles supported by a discrete set of ideal interfaces with irrational rotational transforms. Numerical solutions are computed using the Stepped Pressure Equilibrium Code, SPEC, and benchmarks and convergence calculations are presented.