Optical study of radicals (OH, O, H, N) in a needle-plate bi-directional pulsed corona discharge
State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian, 116024, P.R. China
Corresponding author: a email@example.com
Revised: 16 January 2006
Published online: 21 March 2006
In this study, analysis of optical emission spectra are used for the detection of OH (A2Σ) radicals and O (3p5P), Hα (3P) and N (3p4P) active atoms produced by the high-voltage bi-directional pulsed corona discharge of N2 and H2O mixture gas in a needle-plate reactor at one atmosphere. The relative vibrational populations and the vibrational temperature of N2 (C, v') are determined. The effects of pulse peak voltage, pulse repetition rate and the added O2 flow rate on the relative populations of OH (A2Σ) radicals and O (3p5P), Hα (3P) and N (3p4P) active atoms are investigated. It is found that when pulse peak voltage and pulse repetition rate are increased, the relative populations of those excited states radicals rise correspondingly. The relative population of OH (A2Σ) radicals decreases with increasing the flow rate of oxygen. The relative populations of O (3p5P), Hα (3P) and N (3p4P) active atoms increase with the flow rate of oxygen at first and exhibit a maximum value at about 30 ml/min. When the flow rate of oxygen is increased further, the relative populations of those excited states active atoms decrease correspondingly. The main involved physicochemical processes also have been discussed.
PACS: 52.70.Kz – Optical (ultraviolet, visible, infrared) measurements / 52.80.Hc – Glow; corona / 82.33.Xj – Plasma reactions (including flowing afterglow and electric discharges) / 52.20.Hv – Atomic, molecular, ion, and heavy-particle collisions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006