High-Average-Power Second Harmonic W-Band Gyrotron With Room-Temperature Solenoid

Second harmonic ${W}$ -band gyrotron with room-temperature solenoid experimental results is presented. The solenoid consumes a power of ~15 kW with a cooling water flow rate of 15 L/min and an inlet water temperature of 25 °C. The gyrotron interaction mode is TE02, and with the use of Vlasov mode converter, the output mode is Gaussian-like mode. The gyrotron produces 33-kW output power in short pulses with an efficiency of 23%, and in long pulses 10 kW with an efficiency of 14% (power supply limited). The gyrotron was successfully tested for pulse duration over than 10 s.