Dynamic mechanism about the fluorescence emission of NO dielectric barrier discharge plasma

Abstract

The main chemical reaction of NO dielectric barrier discharge plasma has been analyzed with the method of fluorescence emission spectrum. The plasma is generated at room temperature and low sample pressure. It is found that the spectrum comes from the transition of NO(A2Σ→X2Π) and N2(C3Πu→B3Πg). Nitrogen atoms are produced by the dissociation and ionization of NO molecules, and then a large amount of N2 molecules are formed via the chemical reaction of N+NO→N2+O or the combination of two nitrogen atoms. Thus we have observed strong spectral lines of the N2 C3Πu→B3Πg transition from the optical emission spectrum. NO can be removed by the discharge process. It is also found that the emission intensity of NO and N2 molecules greatly depends on the discharge parameters. Based on the theory of electron–molecule collision, a physical model concerning the emission intensity of NO is proposed. The fitting results of the model agree well with the experiment. In fact, it is a universal description to the emission intensity of molecules induced by electron collision.