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Title: Validation of full-wave simulations for mode conversion of waves in the ion cyclotron range of frequencies with phase contrast imaging in Alcator C-Mod

Mode conversion of fast waves in the ion cyclotron range of frequencies (ICRF) is known to result in current drive and flow drive under optimised conditions, which may be utilized to control plasma profiles and improve fusion plasma performance. To describe these processes accurately in a realistic toroidal geometry, numerical simulations are essential. Quantitative comparison of these simulations and the actual experimental measurements is important to validate their predictions and to evaluate their limitations. The phase contrast imaging (PCI) diagnostic has been used to directly detect the ICRF waves in the Alcator C-Mod tokamak. The measurements have been compared with full-wave simulations through a synthetic diagnostic technique. Recently, the frequency response of the PCI detector array on Alcator C-Mod was recalibrated, which greatly improved the comparison between the measurements and the simulations. In this study, mode converted waves for D-{sup 3}He and D-H plasmas with various ion species compositions were re-analyzed with the new calibration. For the minority heating cases, self-consistent electric fields and a minority ion distribution function were simulated by iterating a full-wave code and a Fokker-Planck code. The simulated mode converted wave intensity was in quite reasonable agreement with the measurements close to the antenna, but discrepanciesmore » remain for comparison at larger distances.« less
Authors:
 [1] ; ; ; ; ; ; ;  [2] ;  [3] ;  [4] ;  [5]
  1. Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561 (Japan)
  2. MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)
  3. XCEL Engineering, Inc., Oak Ridge, Tennessee 37830 (United States)
  4. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
  5. CompX, Del Mar, California 92014 (United States)
Publication Date:
OSTI Identifier:
22490054
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALCATOR DEVICE; ANTENNAS; CALIBRATION; COMPUTERIZED SIMULATION; DISTRIBUTION FUNCTIONS; ECR CURRENT DRIVE; ELECTRIC FIELDS; FOKKER-PLANCK EQUATION; ION CYCLOTRON-RESONANCE; MODE CONVERSION; PLASMA RADIAL PROFILES; VALIDATION