Investigation Of Electrical Characteristic And Emission Spectra In Homogenous Dielectric Barrier Discharge In Nitrogen At Atmospheric Pressure

Obtaining large area of homogenous discharge at atmospheric pressure is an important subject with practical values. Homogenous discharge plasma has prosperity applications in the fields of pollution control, sterilization, film deposition and so on. In this paper, the electrical characteristic and emission spectra of homogenous dielectric barrier discharge in nitrogen at atmospheric pressure have been investigated. The main results presented in the dissertation have been summarized as follow:1. Experiment setup has been optimized via adding a matching unit between the power supply and the reactor. The matching unit can increase the absorption energy of the load from power supply and improve the discharge efficiency. With the matching unit, a large area (150×300 mm) of homogenous discharge in nitrogen at atmospheric pressure with industrial values has been presented under our experimental parameters. A simple but reliable method has been applied to separate the displacement current and the transmit current from the discharge current. The discharge power has been measured via Lissajous figure obtained during the discharge. With the matching unit, the influences of the applied peak to peak voltage and driving frequency to the transmit current, the discharge power and the homogenous discharge area have been investigated. It is shown that, When the driving frequency and the gas gap is fixed, the transmit current and the discharge power increase with the increasing applied peak to peak voltage, and the homogenous discharge area is generated near the center of the electrodes, then, expands to cover the entire electrodes with higher applied peak to peak voltage. The transmit current and the discharge power increase with increasing driving frequency When the driving frequency and the gas gap is fixed. On the mean while, the homogenous discharge area is nearly fixed. In a word, higher transmit current and discharge power can be obtained with lower driving frequency and higher applied voltage.2. The emission spectra of N₂(C³Î _u→B³Î _g) and N₂⁺(B²(?)→X²(?)) have been successfully recorded. It is found that the emission intensity of N₂(C³Î _u→B³Î _g) increases with higher applied peak to peak voltage and higher driving frequency, respectively, while the emission intensity of N₂⁺(B²(?)→X²(?)) increases linear with higher driving frequency butincreases remarkably when the applied peak voltage is higher than 26 kV in pure nitrogen.3. The main physicochemical formation mechanism of N₂⁺(B²(?)) in N₂ and He+N₂ mixtures homogenous discharge is discussed. It is shown that, the electrons with high energy collides with the ground state of nitrogen is the domain reaction to generate the N₂⁺(B²(?)) under pure nitrogen working gas, while thepenning ionization between He(2³S) and ground state of nitrogen is proved to be the domain formation mechanism.