Characterization of breakdown delay and memory effects in high power microwave dielectric window discharges

Summary form only given. Development of high power microwave (HPM) distributed discharge limiters relies critically on minimizing the delay time between HPM incidence and diffuse plasma creation. We present a series of pulsed plasma experiments conducted in neon, argon, and a 9∶1 mixture of the two gases from 50–760 torr. Breakdown is achieved by illuminating a gas cell with a train of ∼25kW, ∼2 kV/cm, 800ns-long pulses at 41Hz repetition rate. The results suggest that surface charge accumulation on the gas cell´s polycarbonate window from many low density precursor discharges eventually results in rapid (<30ns), high density, discharge formation. The number of precursor pulses required to form these high density discharges is significantly reduced following a previous high-density discharge.