Development of a Compact W-Band Gyrotron System With a Depressed Collector

We present the design and experiments on a 100-kW level W -band gyrotron. The gyrotron was developed as a prototype for an active denial system. We measured a peak output power of 100 kW with 50 kV, 6-A electron beam in 50- \mu \text{s} pulses at a repetition rate of 50 Hz. Driven by the long pulse power supplies with 2-A current limited by the specification, the gyrotron operates at the output power of 37 kW with the total efficiency of up to 48% at a collector depression of 18 kV. The gyrotron was also driven in long pulse up to the pulselength of 2 s at the current of 2 A.