REACTIONS OF NO IN A POSITIVE STREAMER CORONA PLASMA

The reaction of NO in a streamer corona plasma is studied systematical ly as a function of the composition of the gas mixture, the initial co ncentration of NO, and the discharge repetition rate. The experimental results show that the reactions of NO depend strongly on the composit ion of the gas mixture. Reduction is observed in the absence of oxidan ts such as oxygen and water, but at very high energy cost (>200 eV/NO) . In the presence of both these oxidants, more than 90% of the NO conv ersion is oxidation. The lowest energy costs, 24 eV/NO for He mixtures and 45 eV/NO for N-2 mixtures, are obtained at water and oxygen conce ntration above 3% and at low discharge repetition rates (<10 Hz). Chem ical kinetics calculations of the production of radicals in the plasma show a good agreement with the value derived from the experiments.