Emission spectroscopy analysis of atmospheric pressure air plasma

The UV-visible emission spectroscopy has been used to analyse an atmospheric natural air plasma type glidarc. Besides the N and O atomic lines, the most intense molecular bands belong to the NO systems and on account of the presence of water in air to the OH bands. We have derived the rotational temperature (1500 ± 100K) and the vibrational temperature (4000 ± 200K) from the comparison between theoretical and recorded spectra of (A 2 Σ → X 2 Π) γ system of NO and (A 2 Σ → X 2 Π) OH band. In spite of the NO band overlapping within the 230-260 nm spectral range, the intensity of the γ system band has been estimated. With the hypothesis that the electronic excitation temperature can be equated to the vibrational one the NO molecule number density has been measured in the plasma.