Detection system for the measurements of collective Thomson scattering spectra in fusion plasma

The detection system designed for the proof-of-principle collective Thomson scattering (CTS) experiments using a 140 GHz gyrotron as a source of probing radiation has been discussed. The system is aimed at ion temperature measurements in a moderate size fusion installations W7-AS stellarator (Garching, Germany) and FTU tokamak (Frascati, Italy) as a first step in CTS experiments using gyrotrons with the prospects of its further upgrading for alpha-particle diagnostics. It is capable of ion temperature measurements for a wide range of plasma parameters (H plasma, D plasma, density range from a few times 10/sup 13/ cm/sup -3/ to 2/spl times/10/sup 14/ cm/sup -3/, ion temperatures from few hundred eV to a few keV) in various scattering geometries with the scattering angles from 60/spl deg/ to 180/spl deg/.