High Speed UV Imaging of a Dielectric Barrier Discharge Excilamp Pumped by Various Waveforms
Résumé
Excilamps are potentially powerful and efficient UV sources but their properties are strongly linked to their power supply mode. One of the most efficient ways to supply Dielectric Barrier Discharge (DBD) excilamps is a high voltage (some kilovolts) pulsed voltage waveform at some hundreds of kilohertz, with a pulse width around one microsecond. This can be either achieved by high voltage switching, which leads to costly and poorly efficient power converters, or by low voltage switching followed by a step-up transformer. In this latter case, the coupling between the inductive properties of the transformer and the capacitive behavior of the DBD excilamp leads unexpected ringings in the waveforms. Time resolved UV imaging of a DBD excilamp in a Xenon/Chlorine mixture are presented to analyze the mechanisms involved in the production of exciplexes for various power supply modes.