Measurement of the positive streamer charge

A measurement of the positive streamer charge has been performed at atmosph eric conditions in a quasi-uniform electric field where the discharge was e lectrically 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 vol tage, current and luminosity associated with the streamer discharge were me asured simultaneously. By placing a photographic film at the cathode, the n umber 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 ha s been deduced that each individual streamer channel contains a charge repr esented by an excess of 1.1-2.0 x 10(11) positive ions m(-1). The lower val ue 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 strea mer model. The results of the measurement and the calculation are compared and discussed.