A W-band Gyro-BWO based on helically corrugated waveguide

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 is presented. The electron beam system and the beam-wave interaction were optimized for output power and frequency bandwidth by numerical simulations. A 3dB bandwidth of ∼84–104 GHz and output power ∼10 kW were predicted using a 40 kV, 1.5 A axis-encircling electron beam with an alpha of 1.6 from the cusp gun. The W-band helically corrugated interaction region was manufactured with dispersion from 76GHz to 110GHz measured in good agreement with simulations and