A reproducible rep-rate high-power magnetron microwave tube

Observations are reported of the reproducible operation of an intense relativistic electron-beam-driven high-pulsed-power magnetron microwave tube at rep-rates of 1 Hz. These are the first observations of a reproducible rep-rate high-power magnetron, and microwave tubes in general, under several specific conditions: ultra-high vacuum; with a compact tunable modulator; and using extraction into the TE/sub 10/ mode which radiates a polarized pencil beam. The experiments were performed in the 2 pi mode. Power levels approaching 300 MW were achieved in short pulses (less than 100 ns).>