Optical study of OH radical in a wire-plate pulsed corona discharge

Abstract

In this study, the emission spectra of OH (A 2Σ → X 2Π, 0–0) emitted from the high-voltage pulsed corona discharge (HVPCD) of N 2 and H 2O mixture gas and humid air in a wire-plate reactor were successfully recorded against a severe electromagnetic interference coming from HVPCD at one atmosphere. The relative vibrational populations and the vibrational temperature of N 2 (C, v′) were determined. The emission spectra of the Δ v = + 1 (1–0, 2–1, 3–2, 4–3) vibration transition band of N 2 (C 3Π u → B 3Π g) is simulated through gauss distribution. The emission intensity of OH (A 2Σ → X 2Π, 0–0) has been exactly gotten by subtracting the emission intensity of the Δ v = + 1 vibration transition band of N 2 (C 3Π u → B 3Π g) from the overlapping spectra. The relative population of OH (A 2Σ) has been obtained by the emission intensity of OH (A 2Σ → X 2Π, 0–0) and Einstein's transition probability. The influences of pulsed peak voltage and pulse repetition rate on the relative population of OH (A 2Σ) radicals in N 2 and H 2O mixture gas and humid air are investigated separately. It is found that the relative population of OH (A 2Σ) rises linearly with increasing the applied peak voltage and the pulse repetition rate. When the oxygen is added in N 2 and H 2O mixture gas, the relative population of OH (A 2Σ) radicals decreases exponentially with increasing the added oxygen. The main involved physicochemical processes have also been discussed.