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Title: On the nonlinear stability of a quasi-two-dimensional drift kinetic model for ion temperature gradient turbulence

We study a quasi-two-dimensional electrostatic drift kinetic system as a model for near-marginal ion temperature gradient driven turbulence. A proof is given for the nonlinear stability of this system under conditions of linear stability. This proof is achieved using a transformation that diagonalizes the linear dynamics and also commutes with nonlinear E × B advection. For the case when linear instability is present, a corollary is found that forbids nonlinear energy transfer between appropriately defined sets of stable and unstable modes. It is speculated that this may explain the preservation of linear eigenmodes in nonlinear gyrokinetic simulations. Based on this property, a dimensionally reduced (∞×∞→1) system is derived that may be useful for understanding dynamics around the critical gradient of Dimits.
Authors:
 [1]
  1. Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany)
Publication Date:
OSTI Identifier:
22408306
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 4; Other Information: (c) 2015 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; ADVECTION; EIGENVALUES; ELECTRIC FIELDS; ENERGY TRANSFER; INSTABILITY; ION TEMPERATURE; KINETIC EQUATIONS; MAGNETIC FIELDS; NONLINEAR PROBLEMS; SIMULATION; STABILITY; TEMPERATURE GRADIENTS; TURBULENCE; TWO-DIMENSIONAL SYSTEMS