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Title: The effect of magnetic flutter on residual flow

The hypothesis that stochastic magnetic fields disrupt zonal flows associated with ion temperature gradient turbulence saturation is investigated analytically with a residual flow calculation in the presence of magnetic flutter. The calculation starts from the time-asymptotic zero-beta residual flow of Rosenbluth and Hinton [Phys. Rev. Lett. 80, 724 (1998)] with the sudden application of an externally imposed, fixed magnetic field perturbation. The short-time electron response from radial charge loss due to magnetic flutter is calculated from the appropriate gyrokinetic equation. The potential evolution has quadratic behavior, with a zero crossing at finite time. The crossing time and its parametric dependencies are compared with numerical results from a gyrokinetic simulation of residual flow in the presence of magnetic flutter. The numerical and analytical results are in good agreement and support the hypothesis that the high-beta runaway of numerical simulations is a result of the disabling of zonal flows by finite-beta charge losses associated with magnetic flutter.
Authors:
; ;  [1] ;  [2]
  1. Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
  2. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Publication Date:
OSTI Identifier:
22218422
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 11; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASYMPTOTIC SOLUTIONS; CHARGED-PARTICLE TRANSPORT; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DISTURBANCES; ELECTRONS; HIGH-BETA PLASMA; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; NUMERICAL ANALYSIS; PLASMA POTENTIAL; PLASMA SIMULATION; STOCHASTIC PROCESSES; TEMPERATURE GRADIENTS; TURBULENCE