光谱学方法研究介质阻挡沿面放电辉光模式的电场分布

Determination of Electric Field Distribution in Dielectric Barrier Surface Glow Discharge by Spectroscopic Method

利用介质阻挡沿面放电装置,在低气压空气中实现了辉光放电模式。利用光电倍增管对放电发光信号进行检测,发现外加电压每半周期出现一个发光脉冲,并且正负半周期的光脉冲是不对称的。利用Photoshop软件处理放电的照片,研究发现平行于高压电极不同位置的发光强度基本相同,然而距离高压电极越远,发光强度减小。放电中总电场由外加电场和电介质积累的壁电荷电场共同决定,确定该电场具有重要意义。通过分析放电的发射光谱中N2+(B2Σu+→X2Σg+)谱线391.4 nm和N2的第二正带系(C3Πu→B3Πg)谱线337.1 nm的比值,可以定性地说明电场的分布。研究发现电场在高压电极附近较大而远离高压电极处较小。这些研究结果对沿面放电的数值模拟和工业应用具有重要的价值。

In the present paper,stable glow discharges were obtained in air at low pressure with a dielectric barrier surface discharge device.Light emission from the discharge was detected by photomultiplier tubes and the research results show that the light signal exhibited one discharge pulse per half cycle of the applied voltage.The light pulses were asymmetric between the positive half cycle and the negative one of the applied voltage.The images of the glow surface discharge were processed by Photoshop software and the results indicate that the emission intensity remained almost constant for different places with the same distance from the powered electrode,while the emission intensity decreased with the distance from the powered electrode increasing.In dielectric barrier discharge,net electric field is determined by the applied voltage and the wall charges accumulated on the dielectric layer during the discharge, and consequently,it is important to obtain information about the net electric field distribution.For this purpose,optical emission spectroscopy method was used.The distribution of the net electric field can be deduced from the intensity ratio of spectral line 39 1.4 nm emitted from the first negative system of N2^＋（B^2Σu^＋→X^2Σg^＋） to 337.1 nm emitted from the second positive system of N2（C^3Πu→B^3Πg）.The research results show that the electric field near the powered electric field is higher than at the edge of the discharge.These experimental results are very important for numerical study and industrial application of the surface discharge.