Ultra wide band radar reflectometer for density profile measurement of high temperature plasmas

Reflectometry is considered to be one of the key diagnostics to measure density profiles or density fluctuations of fusion oriented plasmas. The electromagnetic wave launched into the plasma is reflected at the cutoff density layer of the ordinary (O) mode or the extraordinary (X) mode. The plasma density profile can be obtained by taking the phase difference between the incident wave and the reflected wave. The high resolution analysis method called signal record analysis (SRA) is utilized to calculate the phase difference. Since wide frequency band is needed for the reflectometry to measure wide density profiles, an ultrashort pulse which includes wide frequency component is utilized as a resource. Also, it is noted that the remote control system using super science information network (super-SINET) has been introduced to the present reflectometry system.