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Title: Fast wave heating in the NSTX-Upgrade device

NSTX-Upgrade will operate with toroidal magnetic fields (B{sub T}) up to 1 T, nearly twice the value used in the experiments on NSTX, and the available NBI power will be doubled. The doubling of B{sub T} while retaining the 30 MHz RF source frequency has moved the heating regime from the high harmonic fast wave (HHFW) regime used in NSTX to the mid harmonic fast wave (MHFW) regime. By making use of the full wave code AORSA, this work shows that direct ion damping (mainly by thermal ions localized at the 5th harmonic resonance) might be significant in NSTX-Upgrade under TRANSP predicted full performance conditions and the electron and ion absorption is sensitive to the ratio of electron and ion temperature. Launching at high toroidal wave number appears to be one way to significantly reduce the ion damping. By using the extended AORSA code, which includes a detailed description of the scrape-off layer in the field solutions, we found a large electric field amplitude outside of the last closed flux surface as previously seen in NSTX from AORSA simulations (D. L. Green, et al, Phys. Rev. Lett. 107, 145001 (2011)). Preliminary results by introducing a collision damping in the scrape-offmore » layer in the AORSA code to represent a damping process are presented, showing for the first time absorbed power in the scrape-off layer.« less
Authors:
; ; ; ; ; ; ; ; ; ; ;  [1] ;  [2] ; ; ;  [3] ; ;  [4] ;  [5]
  1. Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)
  2. XCEL Engineering Inc., Oak Ridge, TN 37830 (United States)
  3. Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States)
  4. MIT Plasma Science and Fusion Center, Cambridge, MA 02139 (United States)
  5. CompX, Del Mar, CA 92014 (United States)
Publication Date:
OSTI Identifier:
22263869
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; ABSORPTION; AMPLITUDES; COLLISIONS; ELECTRIC FIELDS; ELECTRONS; HEATING; MAGNETIC FIELDS; MAGNETIC SURFACES; NSTX DEVICE; PLASMA SCRAPE-OFF LAYER; SIMULATION