Theoretical investigation of a high efficiency and broadband subterahertz gyrotron

This study investigates the electron dynamics of gyrotron interaction in a tapered waveguide and proposes an interaction structure for a 0.2 THz TE(02) reflective gyrotron backward-wave oscillator (gyro-BWO). The design shows the advantages of high power, continuous, and broadband frequency tuning, mode converter free, and inherently possesses mode-selective ability to suppress the potentially competing TE(22) mode. Calculated results indicate that the reflective TE(02) gyro-BWO is capable of generating a peak power of 3.3 kW corresponding to 26.3% interacting efficiency with a broad 3dB tuning bandwidth of 6.9 GHz at beam current I(b)=0.5 A and beam voltage V(b)=25 kV. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3400216]