发射光谱研究多针对板正电晕放电形貌

利用光学发射光谱(OES)法检测N₂发射光谱，研究了常压下多针对板正电晕放电中辉光放电和击穿流光放电的高能电子分布，并与相同电极结构下负电晕放电进行了比较。根据N₂第二正态激发谱峰I_SPB在空间的分布，较精确地确定了辉光放电电离区形貌和击穿流光放电电通道形貌，体积分辉光放电中I_SPB获知I_SPB与放电电流I之间的关系。辉光放电中，电离区范围和I_SPB比负电晕放电小，电子雪崩沿针径向比沿轴向发展范围大；随着U升高，电离区范围只沿针轴向小幅度增大；I_SPB的积分值与I近似成二阶线性关系。击穿流光放电中，针板之间形成放电通道；针尖周围I_SPB较强的区域成“子弹状”，距离针尖较远的放电通道内高能电子密度沿针轴向分布比较均匀，沿针径向先略有增大后减小。

Morphology Determination of Multi-Needle-to-Plate Positive Corona Discharge

Using the method of OES (optical emission spectrum) for measuring N₂ emission spectrum, the distribution of the energetic electrons in multi-needle-to-plate positive corona discharge at atmospheric pressure was investigated, and compared with that in negative corona discharge. According to the distribution of N₂ second positive band’s intensity I_SPB, the outline of the ionization region in glow discharge and the streamer channel were drawn rather accurately. The relationship between I_SPB and the discharge current I in glow discharge can be obtained through the volume integral of the I_SPB. In glow discharge, both the ionization region scale and I_SPB are smaller than in negative corona discharge, the electron avalanche develops farther along the radius direction of needle than along axis direction, and only the arrange along axis direction is enhanced slightly with the rise of the applied voltage U. The integral of I_SPB is second order linear to I. In streamer discharge, the discharge channels develop from needlepoint to the plate, while the shape of the region in which I_SPB is higher looks like a bullet. The density of energetic electron in the channel farther away from the needlepoint is relatively uniform along the axis direction, but first increases then decreases along the radius direction.