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

Journal Article · Sat Nov 15 00:00:00 EST 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4891415· OSTI ID:22308626

Peebles, W. A. ^[1]; Ruskov, E. ^[2]; Deng, B. H.; Gota, H.; Gupta, D.; Tuszewski, M.; Douglass, J.; Binderbauer, M.; Tajima, T. ^[3]

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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)

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.

• OSTI ID: 22308626
• Journal Information: Review of Scientific Instruments, Vol. 85, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

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