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Title: A drift-magnetohydrodynamical fluid model of helical magnetic island equilibria in the pedestals of H-mode tokamak plasmas

Abstract

A drift-magnetohydrodynamical (MHD) fluid model is developed for an isolated, steady-state, helical magnetic island chain, embedded in the pedestal of a large aspect ratio, low-beta, circular cross section, H-mode tokamak plasma, to which an externally generated, multiharmonic, static magnetic perturbation whose amplitude is sufficiently large to fully relax the pedestal toroidal ion flow is applied. The model is based on a set of single helicity, reduced, drift-MHD fluid equations which take into account neoclassical poloidal and toroidal flow damping, the perturbed bootstrap current, diamagnetic flows, anomalous cross-field diffusion, average magnetic-field line curvature, and coupling to drift-acoustic waves. These equations are solved analytically in a number of different ordering regimes by means of a systematic expansion in small quantities. For the case of a freely rotating island chain, the main aims of the calculation are to determine the chain's phase velocity, and the sign and magnitude of the ion polarization term appearing in its Rutherford radial width evolution equation. For the case of a locked island chain, the main aims of the calculation are to determine the sign and magnitude of the polarization term.

Authors:
;  [1]
  1. Department of Physics, Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
Publication Date:
OSTI Identifier:
21378032
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 17; Journal Issue: 6; Other Information: DOI: 10.1063/1.3432720; (c) 2010 American Institute of Physics; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOOTSTRAP CURRENT; HELICITY; H-MODE PLASMA CONFINEMENT; MAGNETIC ISLANDS; MAGNETOHYDRODYNAMICS; PLASMA; PLASMA DRIFT; POLARIZATION; SOUND WAVES; TOKAMAK DEVICES; CLOSED PLASMA DEVICES; CONFINEMENT; CURRENTS; ELECTRIC CURRENTS; FLUID MECHANICS; HYDRODYNAMICS; MAGNETIC CONFINEMENT; MAGNETIC FIELD CONFIGURATIONS; MECHANICS; PARTICLE PROPERTIES; PLASMA CONFINEMENT; THERMONUCLEAR DEVICES

Citation Formats

Fitzpatrick, R, and Waelbroeck, F L. A drift-magnetohydrodynamical fluid model of helical magnetic island equilibria in the pedestals of H-mode tokamak plasmas. United States: N. p., 2010. Web. doi:10.1063/1.3432720.
Fitzpatrick, R, & Waelbroeck, F L. A drift-magnetohydrodynamical fluid model of helical magnetic island equilibria in the pedestals of H-mode tokamak plasmas. United States. doi:10.1063/1.3432720.
Fitzpatrick, R, and Waelbroeck, F L. Tue . "A drift-magnetohydrodynamical fluid model of helical magnetic island equilibria in the pedestals of H-mode tokamak plasmas". United States. doi:10.1063/1.3432720.
@article{osti_21378032,
title = {A drift-magnetohydrodynamical fluid model of helical magnetic island equilibria in the pedestals of H-mode tokamak plasmas},
author = {Fitzpatrick, R and Waelbroeck, F L},
abstractNote = {A drift-magnetohydrodynamical (MHD) fluid model is developed for an isolated, steady-state, helical magnetic island chain, embedded in the pedestal of a large aspect ratio, low-beta, circular cross section, H-mode tokamak plasma, to which an externally generated, multiharmonic, static magnetic perturbation whose amplitude is sufficiently large to fully relax the pedestal toroidal ion flow is applied. The model is based on a set of single helicity, reduced, drift-MHD fluid equations which take into account neoclassical poloidal and toroidal flow damping, the perturbed bootstrap current, diamagnetic flows, anomalous cross-field diffusion, average magnetic-field line curvature, and coupling to drift-acoustic waves. These equations are solved analytically in a number of different ordering regimes by means of a systematic expansion in small quantities. For the case of a freely rotating island chain, the main aims of the calculation are to determine the chain's phase velocity, and the sign and magnitude of the ion polarization term appearing in its Rutherford radial width evolution equation. For the case of a locked island chain, the main aims of the calculation are to determine the sign and magnitude of the polarization term.},
doi = {10.1063/1.3432720},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 6,
volume = 17,
place = {United States},
year = {2010},
month = {6}
}