The Design and Simulation of a W-band Gyro-BWO

This paper presents the design and simulation of a W-band gyrotron backward wave oscillator (Gyro-BWO) with a helically corrugated waveguide as the beam-wave interaction region and a cusp gun as the electron beam source. The electron beam system and the beam-wave interaction were optimized through numerical simulations for optimized output power and frequency bandwidth. A 3 dB bandwidth of ~ 84-104 GHz and output power ~10 kW were achieved using a 40 kV, 1.5 A, pitch alpha 1.6 axis-encircling electron beam from the cusp gun. Furthermore, the W-band helically corrugated interaction region was manufactured with dispersion from 76 GHz to 11 GHz measured in good agreement with simulations and theory.