Endurance of the highly heat-stressed units exposed to cycling loading in 1MW/170GHz CW gyrotron for ITER

Collector of worked-out electron beam and RF cavity resonator are the most-heat-stressed units of 1MW CW gyrotron. To withstand near 1MW power of a worked-out electron beam it is swept along the collector surface exposing it to cycling loading. In the cavity, at over 40 kW dissipated power cycling loading appears only when a modulation of output power is used. Cycling aggravates work of heat-stressed electrodes.