A 94 GHz continuous operation second harmonic gyroton with 1.8 T solenoid

The continuous operation of a W-band gyrotron without superconduct magnet was realized. The gyrotron operated at the second harmonic cyclotron frequency. Its operational frequency was 94.08 GHz and the operating mode was TE₀₂. The required 1.8 T magnetic field was generated by a DC solenoid cooled by water. The power consumption of the solenoid was 28 kW and the driving current was 500 A. The inner bore diameter was 66 mm. The gyrating electron beam was generated by a triode magnetic injection gun. A high efficiency internal quasi-optical mode converter was used to separate the wave from the electron beam. In the test, 5 min stable operation was realized. The output power was 12 kW with an electron beam of 45 kV, 1.7 A. The output efficiency was 15.7%. (authors)