The effect of a large series resistance on the streamer-to-spark transition in dry air

The streamer-to-spark transition is an important sub-process of the flashover of high-voltage apparatus. In this paper an investigation of this transition in an electrode gap of the order of 1 cm in dry air with a non-uniform field distribution is presented. Parameters such as the gap distance, polarity of applied voltage and pressure were varied, but the study was concentrated upon the influence of a large series resistance (0-6 M Ohm) in the discharge circuit (inhibited discharges). Mainly, the positive discharge was studied, but some results for negative applied voltages are also included. The main finding was that the presence of a large series resistance in the discharge circuit substantially prolonged the duration of the streamer-to-spark transition. The effect of the inhibiting series resistance seems to be that the disruptive discharge is delayed, but not prevented.