Measurement of the positive streamer charge

Abstract

A measurement of the positive streamer charge has been performed at atmospheric conditions in a quasi-uniform electric field where the discharge was electrically triggered. By applying a square impulse voltage to the trigger electrode, which was close to, but electrically isolated from, the anode, a positive streamer discharge with one discharge event was produced. The voltage, current and luminosity associated with the streamer discharge were measured simultaneously. By placing a photographic film at the cathode, the number of individual streamers hitting the cathode was estimated within one discharge event. The amount of net charges in streamer discharges has been evaluated for different background electric fields. From the results, it has been deduced that each individual streamer channel contains a charge represented by an excess of 1.1-2.0×10¹¹ positive ions m^-1. The lower value corresponds to a background field of 400 kV m^-1 and the higher one to 600 kV m^-1. The streamer has also been simulated using a simplified streamer model. The results of the measurement and the calculation are compared and discussed.