A photoinduced non-self-sustained discharge in a point-plane gap at near-atmospheric pressures in nitrogen and nitrogen-oxygen mixture was studied. Molybdenum and platinum points were coated with thin layers of MgO and TiO_(2) of different thicknesses. Static current-voltage characteristics were recorded at different intensities of triggering light, layer thickness and gas pressure. The common regularities of current-voltage characteristics were independent of the electrode/coating combinations used. The studies showed that the field-assisted two-step model of emission describes the experimental findings. The electron emission is controlled by Schottky and Fowler-Nordheim mechanisms at the metal-dielectric interface and by a recombination of positive ions with 'hot' and free electrons near the dielectric-gas interface.
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