Transparent traveling-wave tubes with multivelocity electron beams

We present results of a theoretical and experimental investigation of the output characteristics of transparent (containing no local absorbers) traveling-wave tubes (TWTs) operating on multivelocity (turbulent) electron beams. It is established that higher gain (up to 20 dB) and higher efficiency (40–50%) can be achieved in this case in comparison to the output characteristics of transparent TWTs employing monovelocity (laminar) electron beams. This effect is explained by the formation of space-charge bunches of much higher density in multivelocity electron beams than in monovelocity beams.