Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

Journal Article · Thu Oct 15 00:00:00 EDT 2015 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4933337· OSTI ID:22482563

Chrystal, C. ^[1]; Burrell, K. H.; Pace, D. C. ^[2]; Grierson, B. A. ^[3]

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1. Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831 (United States)
2. General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)
3. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451 (United States)

Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.

• OSTI ID: 22482563
• Journal Information: Review of Scientific Instruments, Vol. 86, Issue 10; Other Information: (c) 2015 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
BEAM INJECTION
BEAMS
CALIBRATION
CALIBRATION STANDARDS
CHARGE EXCHANGE
DOPPLER EFFECT
DOUBLET-3 DEVICE
EMISSION
GEOMETRY
PLASMA
RECOMBINATION