O 2 ( a Δ 1 g ) production at atmospheric pressure by microdischarge

We report experimental results showing that singlet oxygen O2(aΔ1g) can be efficiently produced at atmospheric pressure in a three-electrode microcathode sustained discharge (MCSD) configuration. This configuration consists of a microhollow cathode discharge (MHCD) acting as a plasma cathode to sustain a stable glow discharge between the MHCD and a third planar electrode placed at a distance of 8 mm. Experiments were performed in He/O2/NO mixtures. O2(aΔ1g) number densities higher than 1016 cm−3 were measured in the MCSD afterglow at total flow rates up to 30 ln/mn, resulting in O2(aΔ1g) fluxes above 10 millimole per hour (mmol/h).