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Title: Effects of heating power on divertor in-out asymmetry and scrape-off layer flow in reversed field on Experimental Advanced Superconducting Tokamak

The dependence of divertor asymmetry and scrape-off layer (SOL) flow on heating power has been investigated in the Experimental Advanced Superconducting Tokamak (EAST). Divertor plasma exhibits an outboard-enhanced in-out asymmetry in heat flux in lower single null configuration for in reversed (ion ∇B drift direction toward the upper X-point) field directions. Upper single null exhibits an inboard-favored asymmetry in low heating power condition, while exhibits an outboard-favored asymmetry when increasing the heating power. Double null has the strongest in-out asymmetry in heat flux, favoring the outer divertor. The in-out asymmetry ratios of q{sub t,out}/q{sub t,in} and P{sub out}/P{sub total} increase with the power across the separatrix P{sub loss}, which is probably induced by the enhanced radial particle transport due to a large pressure gradient. The characteristics of the measured SOL parallel flow under various discharge conditions are consistent with the Pfirsch-Schlüter (PS) flow with the parallel Mach number M{sub ∥} decreasing with the line averaged density but increasing with P{sub loss}, in the same direction as the PS flow. The contributions of both poloidal E×B drift and parallel flow on poloidal particle transport in SOL on EAST are also assessed.
Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1] ;  [1] ;  [2] ;  [1] more »;  [3] ;  [4] ; « less
  1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)
  2. (United States)
  3. (China)
  4. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Publication Date:
OSTI Identifier:
22403359
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 12; 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; ASYMMETRY; CONFIGURATION; DIVERTORS; HEAT FLUX; HEATING; HT-7U TOKAMAK; PLASMA SCRAPE-OFF LAYER