High definition imaging in the Mega Amp Spherical Torus spherical tokamak from soft x rays to infrared (invited)

Journal Article · Fri Oct 01 00:00:00 EDT 2004 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1789583· OSTI ID:20641234

Carolan, P G; Patel, A; Conway, N J; Akers, R J; Bunting, C A; Counsell, G F; Dowling, J; Dunstan, M R; Kirk, A; Lott, F; Price, M N; Tournianski, M R; Walsh, M J ^[1]

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1. EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom)

The Mega Amp Spherical Torus (MAST) diagnostic needs are strongly influenced by physics goals that often require diagnostic integration and cross-mapping, especially in fine-scale investigations, such as transport barriers. Conversely, the unrivalled viewing access to the edge, scrape-off layer (SOL) and divertor regions, provided by the MAST open geometry, impacts on the physics program priorities. A supporting suite diagnostics, such as the high definition Thomson scattering systems, provide considerable added value in detailed data interpretation (e.g., bremsstrahlung emissivity in terms of Z{sub eff}). Thus, to exploit these advantages, an extensive set of high-resolution imaging diagnostics have been installed, encompassing soft x-rays, visible bremsstrahlung, charge exchange recognisation radiation, D{sub {alpha}} from NBI, and edge plasma neutrals, and infrared (IR) from the divertor and wall regions. Plasma light collection optics provide near parallel illumination of narrow bandpass interference filters to give monochromatic images. One adaptation provides multiwavelength images; another accommodates smooth variation of wavelength across an image (e.g., for a range of Doppler shifts beam fast neutrals). Diagnostic synergy is enhanced by combining such diagnostics to common viewing optics which allow exact-mapping. Soft x-ray tangential imaging has been achieved by using a two dimensional charge coupled device detector in a pinhole camera. Finally, a fast IR camera monitors the power deposition on the first wall and divertor plates, important in quantifying power losses (e.g., ELMs, disruptions), and complemented by visible viewing of the SOL, and linear D{sub {alpha}} cameras.

• OSTI ID: 20641234
• Journal Information: Review of Scientific Instruments, Vol. 75, Issue 10; Conference: 15. topical conference on high temperature plasma diagnostics, San Diego, CA (United States), 19-22 Apr 2004; Other Information: DOI: 10.1063/1.1789583; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); MAST Team; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BREMSSTRAHLUNG
CAMERAS
CHARGE EXCHANGE
CHARGE-COUPLED DEVICES
DOPPLER EFFECT
EDGE LOCALIZED MODES
EMISSIVITY
IMAGES
MAST TOKAMAK
MONOCHROMATIC RADIATION
PLASMA
PLASMA BEAM INJECTION
PLASMA CONFINEMENT
PLASMA DIAGNOSTICS
PLASMA HEATING
PLASMA SCRAPE-OFF LAYER
POWER LOSSES
SOFT X RADIATION
SOLS
THOMSON SCATTERING