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Title: Gyrokinetic studies of core turbulence features in ASDEX Upgrade H-mode plasmas

Gyrokinetic validation studies are crucial for developing confidence in the model incorporated in numerical simulations and thus improving their predictive capabilities. As one step in this direction, we simulate an ASDEX Upgrade discharge with the GENE code, and analyze various fluctuating quantities and compare them to experimental measurements. The approach taken is the following. First, linear simulations are performed in order to determine the turbulence regime. Second, the heat fluxes in nonlinear simulations are matched to experimental fluxes by varying the logarithmic ion temperature gradient within the expected experimental error bars. Finally, the dependence of various quantities with respect to the ion temperature gradient is analyzed in detail. It is found that density and temperature fluctuations can vary significantly with small changes in this parameter, thus making comparisons with experiments very sensitive to uncertainties in the experimental profiles. However, cross-phases are more robust, indicating that they are better observables for comparisons between gyrokinetic simulations and experimental measurements.
Authors:
;  [1] ;  [2] ; ; ; ; ;  [1] ;  [1] ;  [2] ;  [2]
  1. Max-Planck-Institut für Plasmaphysik, Boltzmannstrase 2, 85748 Garching (Germany)
  2. (United States)
Publication Date:
OSTI Identifier:
22408321
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 4; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASDEX TOKAMAK; COMPUTERIZED SIMULATION; FLUCTUATIONS; HEAT FLUX; H-MODE PLASMA CONFINEMENT; ION TEMPERATURE; KINETICS; NONLINEAR PROBLEMS; TEMPERATURE GRADIENTS; TURBULENCE