Broadband ultra-low-voltage terahertz gyrotron

The gyrotron is capable of efficiently generating high-power millimeter-terahertz radiation. In THz waveband, the bulky volume is one of the major factors hindering the gyrotron development. It is in pressing demand for the mini-table-top gyrotrons. In order to reduce the volume of the cathode, a broadband ultra-low-voltage gyrotron is investigated in this paper. Through parameter optimization, the gyrotron exhibits excellent performance. With electron beam of voltage as low as 1 kV, current 0.5 A, and velocity spread 5%, the gyrotron can operate on 330 GHz TE12,4 mode with peak power 50 W and frequency tuning band 9 GHz. The gyrotron is promising to be applied in 500MHz dynamic nuclear polarization enhanced nuclear magnetic resonance system.