Design and tests of a W-band gyro-TWA and its components

A W-band gyrotron traveling wave amplifier (gyro-TWA) with helically corrugated waveguide and cusp electron gun is presented. The beam-wave interaction, based on the cyclotron resonance maser instability, is driven by a 40 keV, 1.5 A axis-encircling electron beam generated by the cusp electron gun. Numerical simulations predict a maximum output of 5-10 kW with a 3 dB frequency bandwidth of 90-100 GHz and a saturated gain of 40 dB. Linear analysis and numerical simulation of the performance characteristics of the amplifier and its millimetre wave components will be presented as well as the latest experimental measurements.