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Title: Magnetic island evolution in hot ion plasmas

Abstract

Effects of finite ion temperature on magnetic island evolution are studied by means of numerical simulations of a reduced set of two-fluid equations which include ion as well as electron diamagnetism in slab geometry. The polarization current is found to be almost an order of magnitude larger in hot than in cold ion plasmas, due to the strong shear of ion velocity around the separatrix of the magnetic islands. As a function of the island width, the propagation speed decreases from the electron drift velocity (for islands thinner than the Larmor radius) to values close to the guiding-center velocity (for islands of order 10 times the Larmor radius). In the latter regime, the polarization current is destabilizing (i.e., it drives magnetic island growth). This is in contrast to cold ion plasmas, where the polarization current is generally found to have a healing effect on freely propagating magnetic island.

Authors:
;  [1]; ; ;  [2]
  1. National Institute for Fusion Science, Toki 509-5292 (Japan)
  2. Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
Publication Date:
OSTI Identifier:
22072555
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 19; Journal Issue: 7; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPUTERIZED SIMULATION; ELECTRON DRIFT; ELECTRONS; FLOW MODELS; HOT PLASMA; ION TEMPERATURE; IONS; LARMOR RADIUS; MAGNETIC ISLANDS; POLARIZATION; SHEAR; SLABS; VELOCITY

Citation Formats

Ishizawa, A, Nakajima, N, Waelbroeck, F L, Fitzpatrick, R, and Horton, W. Magnetic island evolution in hot ion plasmas. United States: N. p., 2012. Web. doi:10.1063/1.4739291.
Ishizawa, A, Nakajima, N, Waelbroeck, F L, Fitzpatrick, R, & Horton, W. Magnetic island evolution in hot ion plasmas. United States. https://doi.org/10.1063/1.4739291
Ishizawa, A, Nakajima, N, Waelbroeck, F L, Fitzpatrick, R, and Horton, W. 2012. "Magnetic island evolution in hot ion plasmas". United States. https://doi.org/10.1063/1.4739291.
@article{osti_22072555,
title = {Magnetic island evolution in hot ion plasmas},
author = {Ishizawa, A and Nakajima, N and Waelbroeck, F L and Fitzpatrick, R and Horton, W},
abstractNote = {Effects of finite ion temperature on magnetic island evolution are studied by means of numerical simulations of a reduced set of two-fluid equations which include ion as well as electron diamagnetism in slab geometry. The polarization current is found to be almost an order of magnitude larger in hot than in cold ion plasmas, due to the strong shear of ion velocity around the separatrix of the magnetic islands. As a function of the island width, the propagation speed decreases from the electron drift velocity (for islands thinner than the Larmor radius) to values close to the guiding-center velocity (for islands of order 10 times the Larmor radius). In the latter regime, the polarization current is destabilizing (i.e., it drives magnetic island growth). This is in contrast to cold ion plasmas, where the polarization current is generally found to have a healing effect on freely propagating magnetic island.},
doi = {10.1063/1.4739291},
url = {https://www.osti.gov/biblio/22072555}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 7,
volume = 19,
place = {United States},
year = {Sun Jul 15 00:00:00 EDT 2012},
month = {Sun Jul 15 00:00:00 EDT 2012}
}