MIRI: a multichannel far-infrared interferometer/polarimeter for TFTR

A double path multichannel far-infrared interferometer/polarimeter employing retroreflectors for density and current profile determination has been developed for TFTR. The system containing about 400 optical components is mounted on a 70,000-lb vibration-free stand which encircles TFTR. Optically pumped cw CH/sub 3/OH (lambda = 110 ..mu..m, p similarly ordered 100 mW) twin lasers with a frequency separation of 1 MHz are employed as a source. Quasioptical Schottky diodes (NEP similarly ordered 10/sup -9/ W ..sqrt.. Hz) are used as detectors. Considerable efforts are devoted to have remote control capabilities for future D-T operation. The detailed design characteristics of this system together with preliminary results of chord averaged density information will be presented. Also the theoretical aspects of Faraday rotation for TFTR plasma will be discussed.