Line emission tomography for CDX-U using filtered diodes

Journal Article · Wed Jan 01 00:00:00 EST 1997 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1147787· OSTI ID:451953

Stutman, D; Menard, J; Hwang, Y S; Choe, W; Ono, M ^[1]; Finkenthal, M; Soukhanovskii, V; May, M J; Regan, S P; Moos, H W ^[2]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2. Johns Hopkins University, Baltimore, Maryland 21218 (United States)

Electron density and temperature in the CDX-U low aspect ratio tokamak are too low to allow observation of fast magnetohydrodynamic activity using soft x-ray continuum emission. However, spectroscopic measurements show that extreme ultraviolet (XUV) line emission of intrinsic impurities is bright enough to observe such activity. In addition, a fast monitoring system for local temperature changes in the plasma core is required for planned auxiliary heating experiments. We present a spectrally resolved tomographic system for fast imaging of OVI 2s{endash}np, 2p{endash}nd (n{ge}3), CV 1s{sup 2}{endash}1s2p and CVI 1s{endash}2p XUV transitions. Using this emission, we can study both core and edge MHD activity, while the CVI to CV intensity ratio can indicate local changes in electron temperature. To achieve maximal throughput together with the needed spectral resolution, we use arrays of surface barrier diodes filtered with bandpass elemental filters. Using M edge filters (Zr, Pd, and Ag), we achieve both good discrimination between the above charge states and large transmission at the wavelengths of interest. Preliminary results obtained from CDX-U are presented. {copyright} {ital 1997 American Institute of Physics.}

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• DOE Contract Number: AC02-76CH03073; FG02-86ER53214
• OSTI ID: 451953
• Report Number(s): CONF-960543-; ISSN 0034-6748; TRN: 97:006310
• Journal Information: Review of Scientific Instruments, Vol. 68, Issue 1; Conference: 11. annual high-temperature plasma diagnostics conference, Monterey, CA (United States), 12-16 May 1996; Other Information: PBD: Jan 1997
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION
PLASMA DIAGNOSTICS
EXTREME ULTRAVIOLET SPECTRA
TOMOGRAPHY
TOKAMAK DEVICES
PHOTODIODES
IMPURITIES
EMISSION SPECTRA
ELECTRON SPECTRA
ELECTRON TEMPERATURE
ZIRCONIUM
PALLADIUM
SILVER
CARBON IONS
MAGNETOHYDRODYNAMICS
X RADIATION
plasma toroidal confinement
plasma magnetohydrodynamics
optical tomography
ultraviolet detectors
band-pass filters
plasma boundary layers
image reconstruction