Emission Spectroscopy and energy transfer process in atmospheric dielectric barrier discharge in oxygen

To investigate physical chemical behaviors of dielectric barrier discharge at atmospheric pressure in oxygen, the chemical active species which might exist in plasma were analyzed with the diagnosis technique of optical emission spectroscopy (OES) in oxygen discharge system. From the oxygen atom emission spectra in 500-950 nm, the electronic temperature was calculated by some atomic lines to be (1.02 +/- 0.03) eV. The oxygen atmospheric band O-2 (b(1)Sigma(+)(g)-X-3 Sigma(-)(g)) in 760 nm was analyzed, and the rotational temperature (gas temperature) was calculated by its rotational structure to be (650 +/- 20) K. The first negative system O-2(+)(b(4)Sigma(-)(g)a(4)II(u)) in 500-700 nm and the Hopfield system O-2(+)(c(4)Sigma(+)(u)-b(4)Sigma(-)(g)) in 190-240 nm were observed. The research showed that there were various reactive species in plasma of dielectric barrier discharge at atmospheric pressure in oxygen, such as a series excited oxygen atoms, excited oxygen molecules, ground and excited states of oxygen molecular ions. The formation of reactive species concerned many procedures of excitation, dissociation and ionization of oxygen, many energy transfer steps were included in every procedure. The oxygen atoms produced from oxygen molecule dissociation were ruling factor leading to generate reactive species besides electron.