Microchannel Structure of a Spark Discharge in a “Pin to Plane” Gap at Different Air Pressures
摘要
Abstract
Using high-speed photography and shadow photography, the structure of the glow and the microstructure of the spark discharge in a 1.5 mm long “pin(cathode)-plane” gap in air in the pressure range from 300 to 760 Torr has been studied. The presence of a micro channel structure of the discharge in the indicated pressure range was established—the discharge is a aggregation of a large number of micron-diameter channels. It is shown that with decreasing pressure, the evolution of the microstructure and glow of the discharge lags behind the onset of breakdown, however, their morphology retains similarity at different pressures.