The Studies Of Electrical Characteristic And OH Radicals' Emission Spectrum In DBD Of Needle-plate Electrodes At Atmospheric Pressure

1. The electrical studies of atmospheric DBD with a needle-plate electrode in various operation conditions. The investigations involves discharges image in the "up" process and the "down" one,â… -â…¤waveforms, Lissajous figures, which refers that the "up" process meaning the voltage increasing operations and the "down" process for the voltage decreasing without any restart of the power supply. The results have indicated that: the discharge has been intensified with the discharge multi-peak during the "down" process and much steadier than that in the "up" one with the same voltage, which is also well agreed by the three-times energy transformation and the intenser emission spectra of OH (A²âˆ‘→X²Î 0-0).2. The influences on the product process of the emission spectra of OH (A²âˆ‘→X²Î 0-0). under various discharge situations. For the emission intensity of OH (A²âˆ‘→X²Î 0-0). has been exactly gotten by subtracting the emission intensity of theΔv = +1 vibration transition band of N₂ (C³Î _u→B³Î _g) from the overlapping spectra, we use the following way to get the precise emission intensity of OH (A²âˆ‘→X²Î 0-0).: firstly, to obtain the relative vibration population and the vibration temperature of N₂(C, v') by the emission intensity of theΔv= -3 andΔv= -4 vibration transition band of N₂ (C³Î _u→B³Î _g), finally, the emission intensity of OH (A²âˆ‘→X²Î 0-0). exactly obtained by subtracting the emission intensity of theΔv= +1 vibration transition band of N₂ (C³Î _u→B³Î _g) from the overlapping spectra. The results of the experiments about the effects of voltage and discharge frequency indicate that the emission intensity of OH (A²âˆ‘→X²Î 0-0). increased with the increasing discharge voltage and frequency. Besides, it is calculated that the relative population of OH radicals increases with increasing the distance from the needle electrode to the ground electrode, as well as that of N₂⁺ (B²âˆ‘u⁺). 3. The influences of the added gas Ar/O₂ on the production of the OH radicals. With the impurity gas of Ar/O₂ added in the needle-plate-atmospheric-DBD in the N₂/H₂O mixed discharge gas, the emission intensity of OH (A²âˆ‘) radicals increases with increasing Ar flows, but decreases with the addition of O₂.