Theoretical investigation on a 1-THz third harmonic gyrotron

In this paper, a 1-THz TE _15,9 mode third harmonic gyrotron is numerically designed by the selfconsistent non-linear theory. With the beam voltage of 20.8 kV, the beam current of 0.95 A, the output power is 2.3 kW and the maximum beam-wave interaction efficiency is 12%. Meanwhile, by using the time-dependent multi-mode nonlinear theory, the mode competitions of the gyrotron are investigated. The effects of electron beam voltage, beam current, pitch angle and magnetic field to the efficiency are also analyzed in detail.