Progress of The Experiments With the European 1Mw, 170Ghz Industrial Cw Prototype Gyrotron For Iter

The first series of experiments with the EU 1 MW, 170 GHz CW industrial prototype gyrotron¹ for ITER have been completed at the KIT test facility at the end of 2016. Depressed collector operation with 180s pulses (pulse length limited by the HV power supply at KIT) at the Low Voltage Operating Point (Ib~45 A, Vacc~71 kV) resulted in 0.8 MW RF output power with 37 % total efficiency. Similar results were obtained for the High Voltage Operating Point (Ib~40 A, Vacc~80 kV) also. The experiments on the CW gyrotron with pulse duration of up to 1 hour will be continued in 2017 at SPC, Lausanne. In parallel, further experiments with the almost identical, modular short-pulse (SP) version of the gyrotron², which delivered more than 1.2 MW, are currently ongoing at KIT in order to identify ways to further improve the performance of the CW prototype.