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Title: Bi-fluid and neoclassical effect on a Double-Tearing mode in Tore Supra

Tearing modes associated to hollow current profiles are prone to grow in moderate performance plasmas and often constrain the realization of non-inductive discharges in the Tore Supra tokamak, where long pulse duration is performed using Lower Hybrid waves for providing most of the plasma current. The prediction of MHD boundaries in such scenarios is complicated by the importance of diamagnetic effects, combined with curvature stabilization, which determine the stability of these modes. We show that diamagnetic effects, as well as neoclassical forces, are playing a key role in the linear and nonlinear regimes of Double-Tearing Modes on q = 5/3 and q = 2 in these experimental conditions. Detailed comparison with experimental measurements, combined with a scaling in plasma resistivity, give constraints about the experimental equilibrium. Resistive-Interchange Modes destabilized by diamagnetic rotation could also play a role in degrading the energy confinement in the negative magnetic shear region.
Authors:
; ; ;  [1] ; ;  [2]
  1. CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)
  2. Centre de Physique Théorique, Ecole Polytechnique, CNRS (France)
Publication Date:
OSTI Identifier:
22304194
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 6; Other Information: (c) 2014 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; CONFINEMENT; ELECTRIC CURRENTS; EQUILIBRIUM; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETOHYDRODYNAMICS; NEOCLASSICAL TRANSPORT THEORY; NONLINEAR PROBLEMS; PLASMA; PULSES; STABILITY; TEARING INSTABILITY; TORE SUPRA TOKAMAK