直流大气压电晕放电电子密度的光谱研究

Research on Electron Density in DC Needle-Plate Corona Discharge at Atmospheric Pressure

利用自制针—板式放电装置,在大气中进行电晕放电实验。用发光区域照片光斑的大小,讨论了电晕层厚度与电源电压的关系。在相同针板间距下,电晕层厚度随着电压的升高而增大;在相同电压下,电晕层厚度随着针板间距的增大而减小。由于高能电子密度能够通过氮分子第二正带系337.1nm的光谱强度大小反映,因此对氮分子第二正带系337.1nm谱线的强度用发射光谱法进行了测量。实验结果发现在针尖附近高能电子密度最大,并且高能电子密度随电压的升高而增大;电压一定时,高能电子密度随针板间距的增大而减小。在针板间距和电源电压不变的情况下,高能电子密度随针尖曲率半径的减小而增大。

Using needle-plate discharge device, corona discharge experiment was done in the atmosphere. Through photo of spot size of light-emitting area, the relationship between the voltage and thickness of corona layer was discussed. When the distance between tip and plate is fixed, the thickness of corona layer increases with the increase in voltage; when the voltage is fixed, the thickness of corona layer decreases with the increase in the distance between tip and plate. As spectral intensity of N2 （C3//u） （337.1 rim）reflects high energy electron density, it was measured with emission spectrometry. The results show that high ener gy electron density is the biggest near the needle tip and the relationship between high energy electron density and voltage is basi- cally linear increasing. Fixing voltage, high energy electron density decreases with the increase in the distance between tip and plate. When the voltage and the distance between tip and plate are fixed, the high energy electron density increases with the de crease in the curvature radius of needle tip. These results are of great importance for the study of plasma parameters of corona discharge.