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Title: Effect of collisional heat transfer in ICRF power modulation experiment on ASDEX Upgrade

ICRF (ion cyclotron range of frequencies) heating experiments were performed in D-H plasmas at various H concentrations on ASDEX Upgrade. The rf power was modulated to measure the electron power deposition profile from electron temperature modulation. To minimize the contribution from indirect collisional heating and the effect of radial transport, the rf power was modulated at 50 Hz. However, peaking of electron temperature modulation was still observed around the hydrogen cyclotron resonance indicating collisional heating contribution. Time dependent simulation of the hydrogen distribution function was performed for the discharges, using the full-wave code AORSA (E.F. Jaeger, et al., Phys. Plasmas, Vol. 8, page 1573 (2001)) coupled to the Fokker-Planck code CQL3D (R.W. Harvey, et al., Proc. IAEA (1992)). In the present experimental conditions, it was found that modulation of the collisional heating was comparable to that of direct wave damping. Impact of radial transport was also analyzed and found to appreciably smear out the modulation profile and reduce the phase delay.
Authors:
 [1] ;  [2] ; ; ; ; ;  [1] ;  [3] ; ;  [4] ;  [5] ;  [6] ;  [7] ;
  1. Max-Planck-Institut für Plasmaphysik, Garching (Germany)
  2. (Japan)
  3. Max-Planck-Institut für Plasmaphysik, Garching, Germany and Universiteit Gent, Gent (Belgium)
  4. JET-EFDA Culham Science Center, Abingdon (United Kingdom)
  5. (Belgium)
  6. CompX, Del Mar (United States)
  7. XCEL Engineering, Oak Ridge (United States)
Publication Date:
OSTI Identifier:
22263862
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1580; Journal Issue: 1; Conference: 20. topical conference on radiofrequency power in plasmas, Sorrento (Italy), 25-28 Jun 2013; Other Information: (c) 2014 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; ASDEX TOKAMAK; COLLISIONAL HEATING; CYCLOTRONS; DISTRIBUTION FUNCTIONS; ELECTRON TEMPERATURE; ELECTRONS; FOKKER-PLANCK EQUATION; HEAT TRANSFER; HYDROGEN; IAEA; ICR HEATING; ION CYCLOTRON-RESONANCE; IONS; MODULATION; PLASMA; SIMULATION; TIME DEPENDENCE