Singlet oxygen production in a microcathode sustained discharge

The authors report experimental results showing that high yields of singlet oxygen O2(aΔg1) can be generated 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 8mm. Experiments were performed in pure oxygen and in mixtures of oxygen with rare gases (He or Ar) at pressures up to 130Torr. O2(aΔg1) relative yields of 7.6% were measured 23cm downstream in the afterglow of the MCSD discharge.