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Title: Generation of a magnetic island by edge turbulence in tokamak plasmas

We investigate, through extensive 3D magneto-hydro-dynamics numerical simulations, the nonlinear excitation of a large scale magnetic island and its dynamical properties due to the presence of small-scale turbulence. Turbulence is induced by a steep pressure gradient in the edge region [B. D. Scott, Plasma Phys. Controlled Fusion 49, S25 (2007)], close to the separatrix in tokamaks where there is an X-point magnetic configuration. We find that quasi-resonant localized interchange modes at the plasma edge can beat together and produce extended modes that transfer energy to the lowest order resonant surface in an inner stable zone and induce a seed magnetic island. The island width displays high frequency fluctuations that are associated with the fluctuating nature of the energy transfer process from the turbulence, while its mean size is controlled by the magnetic energy content of the turbulence.
Authors:
 [1] ;  [2] ; ; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. Aix-Marseille Université, CNRS, PIIM, UMR 7345, Marseille (France)
  2. (France)
  3. IRFM, CEA, St-Paul-Lez-Durance 13108 (France)
  4. Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
Publication Date:
OSTI Identifier:
22408173
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 3; 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; COMPUTERIZED SIMULATION; EDGE LOCALIZED MODES; ENERGY TRANSFER; EXCITATION; MAGNETIC ISLANDS; MAGNETOHYDRODYNAMICS; PLASMA; PRESSURE GRADIENTS; THREE-DIMENSIONAL CALCULATIONS; TOKAMAK DEVICES; TURBULENCE