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Title: Gyrokinetic turbulence cascade via predator-prey interactions between different scales

Abstract

Gyrokinetic simulations in a closed fieldline geometry are presented to explore the physics of nonlinear transfer in plasma turbulence. As spontaneously formed zonal flows and small-scale turbulence demonstrate “predator-prey” dynamics, a particular cascade spectrum emerges. The electrostatic potential and the density spectra appear to be in good agreement with the simple theoretical prediction based on Charney-Hasegawa-Mima equation | ϕ{sup ~}{sub k} |{sup 2}∼| n{sup ~}{sub k} |{sup 2}∝k{sup −3}/(1+k{sup 2}){sup 2}, with the spectra becoming anisotropic at small scales. The results indicate that the disparate scale interactions, in particular, the refraction and shearing of larger scale eddies by the self-consistent zonal flows, dominate over local interactions, and contrary to the common wisdom, the comprehensive scaling relation is created even within the energy injection region.

Authors:
;  [1]
  1. Laboratoire de Physique des Plasmas, CNRS, Paris-Sud, Ecole Polytechnique, UMR7648, F-91128 Palaiseau (France)
Publication Date:
OSTI Identifier:
22410278
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 22; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; 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; ANISOTROPY; DENSITY; ELECTRIC POTENTIAL; GEOMETRY; MICROWAVE AMPLIFIERS; NONLINEAR PROBLEMS; PLASMA; PLASMA SIMULATION; PREDATOR-PREY INTERACTIONS; REFRACTION; SCALING LAWS; SPECTRA; TURBULENCE

Citation Formats

Kobayashi, Sumire, E-mail: sumire.kobayashi@lpp.polytechnique.fr, and Gurcan, Ozgur D., E-mail: ozgur.gurcan@lpp.polytechnique.fr. Gyrokinetic turbulence cascade via predator-prey interactions between different scales. United States: N. p., 2015. Web. doi:10.1063/1.4920965.
Kobayashi, Sumire, E-mail: sumire.kobayashi@lpp.polytechnique.fr, & Gurcan, Ozgur D., E-mail: ozgur.gurcan@lpp.polytechnique.fr. Gyrokinetic turbulence cascade via predator-prey interactions between different scales. United States. doi:10.1063/1.4920965.
Kobayashi, Sumire, E-mail: sumire.kobayashi@lpp.polytechnique.fr, and Gurcan, Ozgur D., E-mail: ozgur.gurcan@lpp.polytechnique.fr. Fri . "Gyrokinetic turbulence cascade via predator-prey interactions between different scales". United States. doi:10.1063/1.4920965.
@article{osti_22410278,
title = {Gyrokinetic turbulence cascade via predator-prey interactions between different scales},
author = {Kobayashi, Sumire, E-mail: sumire.kobayashi@lpp.polytechnique.fr and Gurcan, Ozgur D., E-mail: ozgur.gurcan@lpp.polytechnique.fr},
abstractNote = {Gyrokinetic simulations in a closed fieldline geometry are presented to explore the physics of nonlinear transfer in plasma turbulence. As spontaneously formed zonal flows and small-scale turbulence demonstrate “predator-prey” dynamics, a particular cascade spectrum emerges. The electrostatic potential and the density spectra appear to be in good agreement with the simple theoretical prediction based on Charney-Hasegawa-Mima equation | ϕ{sup ~}{sub k} |{sup 2}∼| n{sup ~}{sub k} |{sup 2}∝k{sup −3}/(1+k{sup 2}){sup 2}, with the spectra becoming anisotropic at small scales. The results indicate that the disparate scale interactions, in particular, the refraction and shearing of larger scale eddies by the self-consistent zonal flows, dominate over local interactions, and contrary to the common wisdom, the comprehensive scaling relation is created even within the energy injection region.},
doi = {10.1063/1.4920965},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 22,
place = {United States},
year = {2015},
month = {5}
}