Differential-phase reflectometry and electron Bernstein wave radiometry using phased-array antenna system in the QUEST

The differential-phase reflectometry has been developed to measure the density profile evolution, concerning electron Bernstein Wave (EBW) heating and current drive in the QUEST. The proper phase dependence was confirmed in developed single-side-band heterodyne differential-phase reflectometry at RIAM microwave/mm-wave test facilities. The phase time evolutions in the QUEST were also successfully measured, but the weak reflected-wave caused the small ratio of signal to noise in the measurements. The Phased Array Antenna (PAA) system was proposed for the reflectometry to obtain the large reflected-wave. The oblique viewing EBW emission can be measured by the precise phase-array measurements between the PAA waveguide elements. The PAA was confirmed to be effective, as a launching antenna for the reflectometry, and as a receiving antenna for the EBW radiometry. (author)