Development of a 1-THz Fourth-Harmonic Gyrotron

Development of a fourth-harmonic gyrotron which uses a large-orbit gun and operates in 1000-GHz band is presented in this paper. The overall design of the gyrotron tube is introduced in detail. The large orbit gun is optimized with the concept of zero-velocity spread and achieves impressive parameters, including 80-kVvoltage, 0.7-A current, 1.5~1.8 pitch factor, ~5% velocity spread, and small guiding center spread. The facilities for the hot test of the gyrotron including the superconducting magnet system, power supply, spectrum meter, and power meter are almost ready. The proposed THz high-harmonic gyrotron is toward generation of 1-kW power around 1-THz band.