Application of far-infrared, integrated detector arrays to chord-averaged plasma measurements (invited)

Journal Article · Wed May 01 00:00:00 EDT 1985 · Rev. Sci. Instrum.; (United States)

DOI:https://doi.org/10.1063/1.1138516· OSTI ID:5539514

Young, P E

The recent development of linear, monolithic microbolometer detector arrays for the far infrared has led to the construction of active imaging diagnostics for tokamak plasmas. Detector arrays have an advantage over discrete detectors in that the cost per detector is significantly reduced since many detectors are fabricated simultaneously. Also, the plasma can be probed with a higher spatial resolution than conventional discrete-beam systems because of the higher channel density. Another advantage is provided by the increased channel number which is important to chord-averaged measurements since it allows an increase in the accuracy of the calculation of Abel inversions of the measured line density profile which are used to reconstruct the actual electron density distribution. The usefulness of this technique has been demonstrated on the UCLA Microtor tokamak (a = 11 cm, B/sub T/ = 20 kG, I = 70 kA, n/sub e/ = 5 x 10/sup 13/ cm/sup -3/) in which a 20-channel heterodyned interferometer at wavelengths of 800 and 1000 ..mu..m has been used to study the behavior of the plasma profile. Line density profiles during the startup phase of the tokamak discharge have been obtained, as well as sawtooth fluctuation profiles. The imaging technique can also be applied to Faraday rotation measurements of the poloidal magnetic field in the tokamak. A 20-channel polarimeter has been developed that operates simultaneously with the multichannel interferometer.

• Research Organization: University of California, Los Angeles, California 90024
• DOE Contract Number: AT03-76ET53019
• OSTI ID: 5539514
• Journal Information: Rev. Sci. Instrum.; (United States), Vol. 56:5
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PLASMA DIAGNOSTICS
MACH-ZEHNDER INTERFEROMETER
PHOTODETECTORS
POLARIMETERS
DESIGN
OPERATION
TOKAMAK DEVICES
BOLOMETERS
ELECTRON DENSITY
FABRICATION
FARADAY EFFECT
IMAGES
MAGNETIC FIELDS
SPATIAL RESOLUTION
CLOSED PLASMA DEVICES
INTERFEROMETERS
MEASURING INSTRUMENTS
RESOLUTION
THERMONUCLEAR DEVICES
700102* - Fusion Energy- Plasma Research- Diagnostics