Signal Estimation and Measurement for the Reflectometry Diagnostic at IPR

Refiectometry measures the beat frequency between radiated electromagnetic waves with a reference signal. We derive the relation between the phase change, path length and sweep rate and estimate the frequency of the beat signal. Data acquisition parameters are calculated based on the sampling frequency required for different sweep rates of the radiated waves. Synchronisation of the very short sweep time of ultra wide bandwidth of the reflectometer with the tokamak plasma pulse and its easy configuration is then discussed. To simplify and remotely operate reflectometer system an Ethernet based Lab View application software has been developed which is controlled by a single master TTL trigger. The complete system is tested in lab and also in the tokamak hall with the complete reflectometry system and is found to be working as designed.