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arXiv · 1509.08163

Formation of current singularity in a topologically constrained plasma

Yao Zhou·Yi-Min Huang·Hong Qin·A. Bhattacharjee
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Abstract

Recently a variational integrator for ideal magnetohydrodynamics in Lagrangian labeling has been developed. Its built-in frozen-in equation makes it optimal for studying current sheet formation. We use this scheme to study the Hahm-Kulsrud-Taylor problem, which considers the response of a 2D plasma magnetized by a sheared field under sinusoidal boundary forcing. We obtain an equilibrium solution that preserves the magnetic topology of the initial field exactly, with a fluid mapping that is non-differentiable. Unlike previous studies that examine the current density output, we identify a singular current sheet from the fluid mapping. These results are benchmarked with a constrained Grad-Shafranov solver. The same signature of current singularity can be found in other cases with more complex magnetic topologies.

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Yao Zhou, Yi-Min Huang, Hong Qin, A. Bhattacharjee. 2016-02-19. Formation of current singularity in a topologically constrained plasma. https://doi.org/10.1103/physreve.93.023205

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