Observations of Memory Effects and Reduced Breakdown Delay via Penning Gas Mixtures in High-Power Microwave Dielectric Window Discharges

Recent improvements in high-power micro-wave (HPM) source power and portability make protecting sensitive electronics from electronic attack critically important. The research reported in this paper examined basic phenomena associated with a distributed area, highly attenuating gas discharge for HPM attack protection. In particular, the research examined gas breakdown delay since effective protection against HPM attack requires rapid activation, significantly faster than the hundreds of nanoseconds typical of HPM pulses. These studies, conducted in mixtures of neon, argon, helium, and xenon gases from 50 to 150 torr, demonstrate how polycarbonate window precharging metastable-excited atoms and appropriate gas composition enable Penning effects to significantly reduce breakdown delay.