Evaluation of Breakdown Delay in High Power Microwave Dielectric Barrier Discharges

An essential element of distributed discharge limiter development is minimizing the delay time between high power microwave (HPM) incidence and diffuse plasma creation. We present a series of pulsed plasma experiments conducted in neon and argon from 80-760 torr designed to assess methods of reducing this delay time. Evidence is presented implicating a charge buildup effect on the dielectric window with a characteristic decay time constant on the order of tens of minutes to several hours. A detailed description of the experimental setup used in this study is provided and progress towards development of a high-frequency multi-moded signal acquisition system is also presented, including the development of a circuit analog absorber designed to provide greater than 30dB attenuation with a thickness of less than 2cm.