High-Power Test of Chemical Vapor Deposited Diamond Window for an ECRH System in SST-1

High-power tests on chemical vapor deposited (CVD) diamond window are carried out using 82.6-GHz Gyrotron. To test CVD diamond window with calorimetric dummy load, a matching optic unit is designed and fabricated with special profiled mirrors. The mirrors are fabricated by Gycom Russia and a mirror box assembly is fabricated at Institute for Plasma Research. The mirrors and mirror box are cooled with water. The mirror box consists of four arc detectors for the protection of window. The CVD diamond window is connected to a dummy load with this mirror box. The alignment of mirror is done during the testing of CVD window in pulsed condition. After achieving the desired Gaussian pattern at the exit of mirror box, system is connected to a dummy load for continuous wave test. The CVD window is tested maximum power up to 60 kW in pulse duration of 600 s.