The quenching effect of hydrogen on the nitrogen in metastable state in atmospheric-pressure N2-H2 microwave plasma torch

The atmospheric-pressure microwave N2-H2 plasma torch is generated and diagnosed by optical emission spectroscopy. It is found that a large amount of N atoms and NH radicals are generated in the plasma torch and the emission intensity of N2+ first negative band is the strongest over the spectra. The mixture of hydrogen in nitrogen plasma torch causes the morphology of the plasma discharge to change with appearance that the afterglow shrinks greatly and the emission intensity of N2+ first negative band decreases with more hydrogen mixed into nitrogen plasma. In atmospheric-pressure microwave-induced plasma torch, the hydrogen imposes a great influence on the characteristics of nitrogen plasma through the quenching effect of the hydrogen on the metastable state of N2.