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Title: Multi-channel Doppler backscattering measurements in the C-2 field reversed configuration

A versatile heterodyne Doppler Backscattering (DBS) system is used to measure density fluctuation levels (in the wavenumber range kρ{sub s} ≤ 50), and the toroidal E × B flow velocity in the C-2 Field-Reversed Configuration (FRC). Six tunable frequencies in three waveguide bands (26 GHz ≤ f ≤ 90 GHz) are launched using monostatic beam optics, via a quasi-optical beam combiner/polarizer and an adjustable parabolic focusing mirror (inside the vacuum enclosure) achieving Gaussian beam spot sizes of 3–5.5 cm at the X/O-mode cutoff. The DBS system covers plasma densities of 0.8 × 10{sup 13} ≤ n{sub e} ≤ 1 × 10{sup 14} cm{sup −3}, and provides access to the FRC core (up to the field null) and across the FRC separatrix into the scrape-off layer plasma.
Authors:
;  [1] ;  [2] ; ; ; ; ; ; ;  [3]
  1. Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States)
  2. Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States)
  3. Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)
Publication Date:
OSTI Identifier:
22308626
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BACKSCATTERING; BEAM OPTICS; DENSITY; DOPPLER EFFECT; ELECTRIC FIELDS; FIELD-REVERSED THETA PINCH DEVICES; FLOW RATE; FLUCTUATIONS; FOCUSING; GHZ RANGE; MAGNETIC FIELDS; MIRRORS; PLASMA DENSITY; PLASMA SCRAPE-OFF LAYER; TOROIDAL CONFIGURATION; WAVEGUIDES