Recent Results in the Development of 170 GHz/CW Gyrotrons for ITER

Production prototype of 170 GHz/1 MW ITER gyrotron was equipped with the new quasi-optical converter to reduce the level of a stray radiation. During long-pulse test at ~500-kW power level it advanced to 120-s pulse duration. Pulse elongation was restricted within limits of the power supply. In the initial experiments with the gyrotron 100-ms mock-up designed for power level up to 1.5-1.7 MW, steady-state oscillations were obtained at about 1.5 MW generated power.