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Title: Gyrokinetic modelling of stationary electron and impurity profiles in tokamaks

Particle transport due to Ion Temperature Gradient (ITG)/Trapped Electron Mode (TEM) turbulence is investigated using the gyrokinetic code GENE. Both a reduced quasilinear treatment and nonlinear simulations are performed for typical tokamak parameters corresponding to ITG dominated turbulence. The gyrokinetic results are compared and contrasted with results from a computationally efficient fluid model. A selfconsistent treatment is used, where the stationary local profiles are calculated corresponding to zero particle flux simultaneously for electrons and trace impurities. The scaling of the stationary profiles with magnetic shear, safety factor, electron-to-ion temperature ratio, collisionality, toroidal sheared rotation, plasma β, triangularity, and elongation is investigated. In addition, the effect of different main ion mass on the zero flux condition is discussed. The electron density gradient can significantly affect the stationary impurity profile scaling. It is therefore expected that a selfconsistent treatment will yield results more comparable to experimental results for parameter scans where the stationary background density profile is sensitive. This is shown to be the case in scans over magnetic shear, collisionality, elongation, and temperature ratio, for which the simultaneous zero flux electron and impurity profiles are calculated. A slight asymmetry between hydrogen, deuterium, and tritium with respect to profile peaking is obtained,more » in particular, for scans in collisionality and temperature ratio.« less
Authors:
; ; ;  [1]
  1. Euratom–VR Association, Department of Earth and Space Sciences, Chalmers University of Technology, SE-412 96 Göteborg (Sweden)
Publication Date:
OSTI Identifier:
22303629
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 9; Other Information: (c) 2014 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPARATIVE EVALUATIONS; DEUTERIUM; ELONGATION; HYDROGEN; NONLINEAR PROBLEMS; PLASMA; PLASMA IMPURITIES; SHEAR; SIMULATION; TEMPERATURE GRADIENTS; TOKAMAK DEVICES; TRANSMISSION ELECTRON MICROSCOPY; TRAPPED ELECTRONS; TRITIUM