Ka-band gyroklystron operating at a combination of high-order modes

Introductory experiments with a projected 30 GHz/5 MW/30 dB three-cavity gyroklystron [1] are described. The electron gun was tested in a configuration with self-excited cavity: the 50% efficiency at the 12 MW output power of the oscillator confirmed the high quality of the electron beam. At the first experiment with the gyroklystron, 3.5 MW output power at 18 % efficiency and 27 dB gain were obtained at 0.5 μs pulse duration.