Experimental Research On The Optical Emission Spectra Of Pulsed Dielectric Barrier Discharge Using Needle-plate Electrode Configuration At Atmospheric Pressure

In this study, a diffuse nanosecond high-voltage pulsed discharge is generated by using needle-plate electrode configuration at atmospheric pressure. The extension on the number of the needle electrode is achieved in air at atmospheric pressure. The morphology of the discharge and the optical emission spectra is discussed in this paper. The main research is shown as follows:1. A bi-directional nanosecond pulse power supply is used to generate a diffuse dielectric barrier discharge plasma under the single needle-plate configuration in N2at atmospheric pressure. The effects of pulse peak voltage, pulse repetition rate and the electrode gap distance on the light emission intensity, diffuse performance and the emission intensities of OH (Aâ†'X,0-0), N2(Câ†'B,0-0), N2+(Bâ†'X,0-0) of the discharge are studied. It is found that the emission intensities of OH (Aâ†'X,0-0), N2(Câ†'B,0-0), N2+(Bâ†'X,0-0) increase with increasing both the pulse peak voltage and the pulse repetition rate, but decrease with an increase in the electrode gap distance. Increasing of the electrode gap distance is not benefit to improve the uniformity of the discharge. The temperature of plasma in N2is obtained to be about370K by measuring the optical emission spectra of the first negative band of N2+(Bâ†'X,0-0).2. The effect of adding different concentrations of O2and He on the optical emission spectra is studied. As the study shown, the emission intensities of OH (Aâ†'X,0-0), N2(Câ†'B,0-0), N2+(Bâ†'X,0-0) are increase with the increase of the concentration of He, but decrease with the increase of the concentration of O2. Adding He to N2is benefit to both the uniformity and the light emission intensity of the discharge, but the light emission intensity and the uniformity of the discharge get worse with increasing the concentration of O2.3. A diffuse bi-directional nanosecond pulse dielectric barrier discharge under multiple needles-plate electrode configuration is obtained in air at atmospheric pressure. The effects of the pulse peak voltage and the pulse repetition rate on the area of the plasma near the dielectric barrier plate are studied. It is found that the area of plasma will increase with the increase of the pulse peak voltage, and the area of the plasma will arrive to about700mm2 when the pulse peak voltage is30kV. The effect of the pulse repetition rate on the area of plasma is not so obviously as the effect of the pulse peak voltage.