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Title: Collisionless kinetic-fluid model of zonal flows in toroidal plasmas

Abstract

A novel kinetic-fluid model is presented, which describes collisionless time evolution of zonal flows in tokamaks. In the new zonal-flow closure relations, the parallel heat fluxes are written by the sum of short- and long-time-evolution parts. The former part is given in the dissipative form of the parallel heat diffusion and relates to collisionless damping processes. The latter is derived from the long-time-averaged gyrocenter distribution and plays a major role in describing low-frequency or stationary zonal flows, for which the parallel heat fluxes are expressed in terms of the parallel flow as well as the nonlinear-source and initial-condition terms. It is shown analytically and numerically that, when applied to the zonal flow driven by either ion or electron temperature gradient turbulence, the kinetic-fluid equations including the new closure relations can reproduce the same long-time zonal-flow responses to the initial condition and to the turbulence source as those obtained from the gyrokinetic model.

Authors:
; ;  [1];  [2]
  1. National Institute for Fusion Science, Graduate University for Advanced Studies, Toki 509-5292 (Japan)
  2. (United States)
Publication Date:
OSTI Identifier:
20974832
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 2; Other Information: DOI: 10.1063/1.2435329; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DAMPING; DIFFUSION; DISTRIBUTION; ELECTRON TEMPERATURE; HEAT; HEAT FLUX; ION TEMPERATURE; IONS; NONLINEAR PROBLEMS; PLASMA; PLASMA CONFINEMENT; PLASMA FLUID EQUATIONS; PLASMA SIMULATION; TEMPERATURE GRADIENTS; TOKAMAK DEVICES; TURBULENCE

Citation Formats

Sugama, H., Watanabe, T.-H., Horton, W., and Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712. Collisionless kinetic-fluid model of zonal flows in toroidal plasmas. United States: N. p., 2007. Web. doi:10.1063/1.2435329.
Sugama, H., Watanabe, T.-H., Horton, W., & Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712. Collisionless kinetic-fluid model of zonal flows in toroidal plasmas. United States. doi:10.1063/1.2435329.
Sugama, H., Watanabe, T.-H., Horton, W., and Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712. Thu . "Collisionless kinetic-fluid model of zonal flows in toroidal plasmas". United States. doi:10.1063/1.2435329.
@article{osti_20974832,
title = {Collisionless kinetic-fluid model of zonal flows in toroidal plasmas},
author = {Sugama, H. and Watanabe, T.-H. and Horton, W. and Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712},
abstractNote = {A novel kinetic-fluid model is presented, which describes collisionless time evolution of zonal flows in tokamaks. In the new zonal-flow closure relations, the parallel heat fluxes are written by the sum of short- and long-time-evolution parts. The former part is given in the dissipative form of the parallel heat diffusion and relates to collisionless damping processes. The latter is derived from the long-time-averaged gyrocenter distribution and plays a major role in describing low-frequency or stationary zonal flows, for which the parallel heat fluxes are expressed in terms of the parallel flow as well as the nonlinear-source and initial-condition terms. It is shown analytically and numerically that, when applied to the zonal flow driven by either ion or electron temperature gradient turbulence, the kinetic-fluid equations including the new closure relations can reproduce the same long-time zonal-flow responses to the initial condition and to the turbulence source as those obtained from the gyrokinetic model.},
doi = {10.1063/1.2435329},
journal = {Physics of Plasmas},
number = 2,
volume = 14,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}