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Title: The dynamics of long wavelength electrostatic turbulence in tokamaks

Abstract

From extensive simulation of simple local fluid models of long wavelength drift wave turbulence in tokamaks, it is found that conventional notions concerning directions of cascades, locality and isotropy of spectral transfer, frequencies of fluctuations, and stationarity of saturation do not hold for moderate to long wavelengths ([ital k][rho][sub [ital s]][le]1). In particular, at long wavelengths, where spectral transfer of energy is dominated by the [ital E][times][ital B] nonlinearity, energy is carried to short scale (even in two dimensions) in a manner that is anisotropic and highly nonlocal (energy is efficiently passed between modes separated by the entire spectrum range in a correlation time). At short wavelengths, transfer is dominated by the polarization drift nonlinearity. While the standard dual cascade applies in this subrange, it is found that finite spectrum size can produce cascades that are reverse directed (i.e., energy to high [ital k]) and are nonconservative in enstrophy and energy similarity ranges (but conservative overall). In regions where both nonlinearities are important, cross-coupling between the nonlinearities gives rise to large nonlinear frequency shifts which profoundly affect the dynamics of saturation by modifying the growth rate and nonlinear transfer rates. These modifications produce a nonstationary saturated state with large amplitude,more » long period relaxation oscillations in the energy, spectrum shape, and transport rates. Methods of observing these effects are presented.« less

Authors:
;  [1]; ;  [2]; ; ;  [3]
  1. Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
  2. Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)
  3. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Publication Date:
OSTI Identifier:
5072543
DOE Contract Number:  
FG02-89ER53291
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas; (United States)
Additional Journal Information:
Journal Volume: 1:5; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TOKAMAK DEVICES; TURBULENCE; ELECTROSTATICS; ENERGY SPECTRA; ENERGY TRANSFER; FLUCTUATIONS; PLASMA SIMULATION; CLOSED PLASMA DEVICES; SIMULATION; SPECTRA; THERMONUCLEAR DEVICES; VARIATIONS; 700340* - Plasma Waves, Oscillations, & Instabilities- (1992-)

Citation Formats

Newman, D E, Terry, P W, Diamond, P H, Liang, Y, Craddock, G G, Koniges, A E, and Crottinger, J A. The dynamics of long wavelength electrostatic turbulence in tokamaks. United States: N. p., 1994. Web. doi:10.1063/1.870935.
Newman, D E, Terry, P W, Diamond, P H, Liang, Y, Craddock, G G, Koniges, A E, & Crottinger, J A. The dynamics of long wavelength electrostatic turbulence in tokamaks. United States. https://doi.org/10.1063/1.870935
Newman, D E, Terry, P W, Diamond, P H, Liang, Y, Craddock, G G, Koniges, A E, and Crottinger, J A. Sun . "The dynamics of long wavelength electrostatic turbulence in tokamaks". United States. https://doi.org/10.1063/1.870935.
@article{osti_5072543,
title = {The dynamics of long wavelength electrostatic turbulence in tokamaks},
author = {Newman, D E and Terry, P W and Diamond, P H and Liang, Y and Craddock, G G and Koniges, A E and Crottinger, J A},
abstractNote = {From extensive simulation of simple local fluid models of long wavelength drift wave turbulence in tokamaks, it is found that conventional notions concerning directions of cascades, locality and isotropy of spectral transfer, frequencies of fluctuations, and stationarity of saturation do not hold for moderate to long wavelengths ([ital k][rho][sub [ital s]][le]1). In particular, at long wavelengths, where spectral transfer of energy is dominated by the [ital E][times][ital B] nonlinearity, energy is carried to short scale (even in two dimensions) in a manner that is anisotropic and highly nonlocal (energy is efficiently passed between modes separated by the entire spectrum range in a correlation time). At short wavelengths, transfer is dominated by the polarization drift nonlinearity. While the standard dual cascade applies in this subrange, it is found that finite spectrum size can produce cascades that are reverse directed (i.e., energy to high [ital k]) and are nonconservative in enstrophy and energy similarity ranges (but conservative overall). In regions where both nonlinearities are important, cross-coupling between the nonlinearities gives rise to large nonlinear frequency shifts which profoundly affect the dynamics of saturation by modifying the growth rate and nonlinear transfer rates. These modifications produce a nonstationary saturated state with large amplitude, long period relaxation oscillations in the energy, spectrum shape, and transport rates. Methods of observing these effects are presented.},
doi = {10.1063/1.870935},
url = {https://www.osti.gov/biblio/5072543}, journal = {Physics of Plasmas; (United States)},
issn = {1070-664X},
number = ,
volume = 1:5,
place = {United States},
year = {1994},
month = {5}
}