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Title: L-H transition dynamics in fluid turbulence simulations with neoclassical force balance

Spontaneous transport barrier generation at the edge of a magnetically confined plasma is reproduced in flux-driven three-dimensional fluid simulations of electrostatic turbulence. Here, the role on the radial electric field of collisional friction between trapped and passing particles is shown to be the key ingredient. Especially, accounting for the self-consistent and precise dependence of the friction term on the actual plasma temperature allows for the triggering of a transport barrier, provided that the input power exceeds some threshold. In addition, the barrier is found to experience quasi-periodic relaxation events, reminiscent of edge localised modes. These results put forward a possible key player, namely, neoclassical physics via radial force balance, for the low- to high-confinement regime transition observed in most of controlled fusion devices.
Authors:
 [1] ;  [2] ; ; ;  [1] ; ;  [3]
  1. Aix–Marseille Université, CNRS, PIIM UMR 7345, 13397 Marseille Cedex 20 (France)
  2. (France)
  3. CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)
Publication Date:
OSTI Identifier:
22299806
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 7; 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; EDGE LOCALIZED MODES; ELECTRON TEMPERATURE; FRICTION; ION TEMPERATURE; NEOCLASSICAL TRANSPORT THEORY; PLASMA CONFINEMENT; PLASMA SIMULATION; THERMONUCLEAR DEVICES; TURBULENCE