Operation of repetitively pulsed virtual cathode oscillators on the TEMPO pulser

The design and performance characteristics of two virtual cathode oscillators operated at a 1-Hz repetition rate for a 10-shot burst using the TEMPO pulser are presented. The 2.4-GHz hardware generated a 300 MW per pulse (radiated) in the TM/sub 02/ mode with a 1.3% total energy conversion efficiency and with a 10.5% frequency bandwidth. A 2:1 scale-tip of this hardware was used to achieve an 840-MHz operation, but it only radiated 70 MW per pulse in the TM/sub 01/ mode with a 7.3% bandwidth, since hardware constraints prevented the TM/sub 02/ component from being radiated. The relatively low beam current density of the TEMPO VCOs yielded a low diode gap closure rate that should make them suitable for long-pulse operation. In addition, the low beam current density minimized damage to the thin anode screen.<
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