Forced Reconnection in Voigt-Regularized MHD

TL;DR

This paper studies how Voigt regularization affects forced magnetic reconnection, revealing an early linear phase and proposing a model for nonlinear island growth with implications for equilibrium states.

Contribution

It introduces a new model for nonlinear island growth in Voigt-regularized MHD, highlighting the impact of regularization on reconnection dynamics.

Findings

Voigt regularization causes an early linear reconnection phase.

A Rutherford-like model for island growth is developed.

Drag leads to precise MHS equilibria over time.

Abstract

Forced reconnection in Voigt-regularized MHD is investigated in the Hahm-Kulsrud-Taylor problem. It is shown that Voigt regularization introduces an early linear phase of reconnection that partially bypasses the ideal current sheet formation phase. A Rutherford-like model of nonlinear island growth and saturation is introduced, including time-dependent spatial variation in the island current distribution and the braking effects of regularization and viscosity. It is conjectured, with numerical justification, that the inclusion of drag in the momentum equation results in precise MHS equilibria in the long-time limit.