Magnetic island merger as a mechanism for inverse magnetic energy transfer
Author(s)
Zhou, Muni; Bhat, Pallavi; Gomes Loureiro, Nuno F; Uzdensky, Dmitri A.; Zhou, Muni
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Magnetic energy transfer from small to large scales due to successive magnetic island coalescence is
investigated. A solvable analytical model is introduced and shown to correctly capture the evolution of the main
quantities of interest, as borne out by direct numerical simulations. Magnetic reconnection is identified as the
key mechanism enabling the inverse transfer, and setting its properties: Magnetic energy decays as [˜ over t][superscript −1], where [˜ over t] is time normalized to the (appropriately defined) reconnection timescale, and the correlation length of the field grows as [˜ over t][superscript 1/2]. The magnetic energy spectrum is self-similar, and evolves as ∝[˜ over t][superscript −3/2]k[superscript −2,] where the k dependence
is imparted by the formation of thin current sheets.
Date issued
2019-08-09Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering; Massachusetts Institute of Technology. Plasma Science and Fusion CenterJournal
Physical Review Research
Publisher
American Physical Society (APS)
Citation
Muni Zhou et al. "Magnetic island merger as a mechanism for inverse magnetic energy transfer." Physical Research Review 1, 1 (August, 2019): 012004(R). © 2019 American Physical Society
Version: Final published version
ISSN
2643-1564