Performances of a Martin-Puplett Interferometer for ECE Measurements
A multichannel instrument to measure oblique ECE has been recently installed at JET. The diagnostic has been designed to investigate features in the ECE spectra taken at different toroidal angles (0, ~10, ~22), related with the deviations of the electron velocity distribution from the Maxwellian behavior, both in the near-thermal and in the superthermal energy range. Instrumental accuracy was assessed from live system measurements using in- and ex- vessel thermal sources at different temperatures and also the attenuation of the transmission lines has been evaluated. Data look promising for providing an absolute calibration of this instrument for the first time.