Time-resolved laser-induced fluorescence study of NO removal plasma technology in N₂/NO mixtures

The laser-induced fluorescence technique is used to study NO removal in N 2 /NO mixtures, after excitation by a homogeneous photo-triggered discharge. Time-resolved experiments are performed in the decaying post-discharge in order to measure the NO concentration 200 µs after a 75 ns duration current pulse. For the first time the NO removal is measured for a single current pulse excitation of the polluted mixture near atmospheric pressure. We discuss the influence of both the electrical energy deposited in the discharge and the initially applied reduced electric field on the NO removal efficiency. It is shown that near 100% of the initial NO molecules can be removed with a single shot, depending on experimental conditions. A detailed kinetic analysis is performed, which leads to straightforward analytical approach used to estimate the N atom density produced by the discharge as a function of the electrical parameters values. It strengthens that, with regard to known kinetic processes, the ideal case for 100% NO removal is to create the exact number of N atoms corresponding to the number of NO molecules, at the lowest energetic cost.