Flashover across a dielectric surface at atmospheric pressure
Abstract
The applicability of high voltage is limited by breakdown along insulating structures. In order to characterize the breakdown phenomenology, a setup has been devised to simulate and closely monitor breakdown for a variety of conditions, for various gap distances, insulator geometries, gases, and humidities. Current, voltage, luminosity, optical emission spectra, as well as spatially and temporally resolved light emission are recorded with nanosecond to sub-nanosecond resolution. Light emission is first detected at the cathode, as result of electron emission at the cathode. Subsequently, an electron avalanche develops which strikes the anode after about 100 ns, leading to significantly higher luminosity at the anode. Gap closure is indicated by a cathode directed streamer, which reaches the cathode again 50 ns later and causes a still higher amplitude light emission. Characteristic differences in the discharge development are observed between air and nitrogen or argon, which are due to different surface charging mechanisms, which in turn are influenced by UV production in the gas. Beyond these aspects involving basic discharge physics, some technical aspects, such as the influence of humidity, will be discussed.
- Publication:
-
APS Texas Sections Fall Meeting Abstracts
- Pub Date:
- October 2003
- Bibcode:
- 2003APS..TSF.B1001N