skip to main content

SciTech ConnectSciTech Connect

Title: RF wave propagation and scattering in turbulent tokamak plasmas

Drift wave turbulence driven by the steep electron and ion temperature gradients in H-mode divertor tokamaks produce scattering of the RF waves used for heating and current drive. The X-ray emission spectra produced by the fast electrons require the turbulence broaden RF wave spectrum. Both the 5 GHz Lower Hybrid waves and the 170 GHz electron cyclotron [EC] RF waves experience scattering and diffraction by the electron density fluctuations. With strong LHCD there are bifurcations in the coupled turbulent transport dynamics giving improved steady-state confinement states. The stochastic scattering of the RF rays makes the prediction of the distribution of the rays and the associated particle heating a statistical problem. Thus, we introduce a Fokker-Planck equation for the probably density of the RF rays. The general frame work of the coupled system of coupled high frequency current driving rays with the low-frequency turbulent transport determines the profiles of the plasma density and temperatures.
Authors:
;  [1] ; ;  [2]
  1. Institute for Fusion Studies, The University of Texas at Austin, Austin, TX 78654 (United States)
  2. CEA, IRFM, 13108, Saint-Paul, Durance Cedex (France)
Publication Date:
OSTI Identifier:
22496220
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1689; Journal Issue: 1; Conference: 21. topical conference on radio frequency power in plasmas, Lake Arrowhead, CA (United States), 27-29 Apr 2015; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DIFFRACTION; ELECTRON CYCLOTRON-RESONANCE; ELECTRON DENSITY; ELECTRON TEMPERATURE; ELECTRONS; EMISSION SPECTRA; FOKKER-PLANCK EQUATION; GHZ RANGE; H-MODE PLASMA CONFINEMENT; ION TEMPERATURE; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; PLASMA DENSITY; STEADY-STATE CONDITIONS; STOCHASTIC PROCESSES; TEMPERATURE GRADIENTS; TOKAMAK DEVICES; TURBULENCE; WAVE PROPAGATION; X-RAY SPECTRA