Optics design for a millimeter-wave phase-imaging system and its application to plasma diagnostics

A ten-element imaging array which consists of an integrated antenna-detector system that incorporates trap-loaded Yagi antennas and Schottky diodes has been developed for operation in the millimeter-wave band around 70 GHz. Also, a prototype optical system that comprises a millimeter-wave phase-imaging interferometer has been designed and fabricated. They were fitted to the GAMMA 10 tandem mirror at Tsukuba University. A real-time measurement of the radial distribution of the plasma electron density was successfully demonstrated using those systems.