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arXiv · 0903.0542

Formation of Plasmoid Chains in Magnetic Reconnection

R. Samtaney·N. F. Loureiro·D. A. Uzdensky·A. A. Schekochihin·S. C. Cowley
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Abstract

A detailed numerical study of magnetic reconnection in resistive MHD for very large, previously inaccessible, Lundquist numbers ($10^4\le S\le 10^8$) is reported. Large-aspect-ratio Sweet-Parker current sheets are shown to be unstable to super-Alfv\'enically fast formation of plasmoid (magnetic-island) chains. The plasmoid number scales as $S^{3/8}$ and the instability growth rate in the linear stage as $S^{1/4}$, in agreement with the theory by Loureiro et al. [Phys. Plasmas {\bf 14}, 100703 (2007)]. In the nonlinear regime, plasmoids continue to grow faster than they are ejected and completely disrupt the reconnection layer. These results suggest that high-Lundquist-number reconnection is inherently time-dependent and hence call for a substantial revision of the standard Sweet-Parker quasi-stationary picture for $S>10^4$.

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R. Samtaney, N. F. Loureiro, D. A. Uzdensky, A. A. Schekochihin, S. C. Cowley. 2009-03-03. Formation of Plasmoid Chains in Magnetic Reconnection. https://doi.org/10.1103/physrevlett.103.105004

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