Plasma Switch for 11.4 GHz Active Sled-II RF Pulse Compressor. Final report

Active rf switches at X-band employing externally-triggered plasma discharge tubes were developed that are suitable for use with SLAC-designed SLED-II low-loss dual-mode delay lines. The plasma switches were incorporated into resonance structures that exhibit a reflection coefficient that can be rapidly shifted during the rf pulse from the magnicon. These structures were successfully tested at NRL. Changing both the reflection coefficient of the switch and the phase of the RF source would yield high compression ratios (>8:1) with high efficiency (>75%). Tests of the Omega-P active switches at SLAC were started. Engineering designs were completed for rf structures and associated plasma switches to allow high rf power gains at high efficiencies for compressed X-band pulses. Plasma discharge tubes of both quartz and ceramic were evaluated. Optimized plasma switches built on these designs were installed on the SLAC dual-mode X-band resonant delay lines for testing at high power, with the aim of producing 400 ns rf pulses with peak power >400 MW and efficiency >75%.