A 100 Gc high-power backward-wave oscillator

A pulsed backward-wave oscillator designed to produce 100 kw peak power and 1000 watts of average power at 100 Gc has been constructed. The tube utilizes a disc-loaded waveguide circuit and a perveance 0.125 × 10^-6electron gun having an area convergence ratio of 900 to 1. The electron beam has a power density of 280 mega-watts/cm²and a current density of greater than 1000 amps/cm²at 200 kv. Beam transmission has been measured at 96 per cent through a .062 inch diameter beam hole at a voltage of 194 kv and a current of 10.3 amperes. Initial measurements have resulted in oscillation from 94 to 101 Gc with an input voltage of 72 to 198 kv. Peak power output of 107 kw and an average power of 324 watts have been measured.