Fast-scan fourier spectrometer for diagnosis of high-temperature plasma

This paper describes a fast-scan Fourier spectrometer for spectra of electron cyclotron radiation in closed magnetic traps. Results of tests of the instrument on the L-2 stellarator are presented. The instrument operates in the frequency range of 50-150 GHz, the spectral resolution is about 3 GHz for a scanning-mirror travel of 4.6 cm, the scanning time for one interference pattern is about 1 msec, and the threshold sensitivity with an n-type InSb detector is about 20 eV.