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Proceedings Paper

A broadband quasi-optical collection system for the JET heterodyne radiometer
Author(s): L. Porte
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Paper Abstract

A multi-channel, fixed frequency heterodyne radiometer, operating inthe radiation frequency range73GHz to 127GHz, is used for electroncyclotron emission measurements on the JET tokamak (1). In atokamak,the spatial variation of the magnetic field in the plasma provides the means by whichspatially resolved measurements of theeission can be made (2). To obtain well localised measurements, itisnecessary to minimise the volume over which the measured emission is averaged. The spatialresolution along the line of sight is determined by the spectral resolution of the radiometer which, in thecase of the JET radiometer, is 500 MHz. This corresponds to a spatial resolution of =20.mm. The spatialresolution transverse to the line of sight is determined by the antenna pattern of the collection system. Atpresent a waveguide system is used and this has a spot size of -20 mm at the plasma centre. A quasi- optical system which will be used to improve this is under construction and is described in this paper.

Paper Details

Date Published: 30 August 1993
PDF: 2 pages
Proc. SPIE 2104, 18th International Conference on Infrared and Millimeter Waves, 21043L (30 August 1993); doi: 10.1117/12.2298561
Show Author Affiliations
L. Porte, JET Joint Undertaking (United Kingdom)


Published in SPIE Proceedings Vol. 2104:
18th International Conference on Infrared and Millimeter Waves
James R. Birch; Terence J. Parker, Editor(s)

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