介质阻挡放电蜂窝斑图形成过程的光谱研究

Study on Formation Process of Honeycomb Pattern in Dielectric Barrier Discharge by Optical Emission Spectrum

采用光谱法,研究了氩气/空气混合气体介质阻挡放电中蜂窝斑图形成过程中等离子体参量的变化。实验发现,随着电压的增加,放电经历六边形点阵斑图及疏密点同心圆环斑图后,形成了蜂窝斑图。利用氮分子第二正带系(C^3Π_u→B^3Π_g)的发射谱线、氩原子763.26 nm(2P_6→1S_5)与772.13 nm(2P_2→1S_3)两条谱线强度比法和氩原子696.57 nm(2P_2→1 S_5)谱线的展宽,分别研究了上述三种斑图的分子振动温度、电子激发温度和电子密度。结果发现:蜂窝斑图的分子振动温度和电子激发温度均高于六边形点阵斑图相应的温度,但其电子密度却比后者的电子密度低。实验还通过电容法,测量了放电斑图的放电功率,发现蜂窝斑图的放电功率远远高于六边形点阵斑图的放电功率。工作结果对于研究介质阻挡放电自组织斑图的形成机制具有重要意义。

The authors report on the first investigation of the variations in the plasma parameters in the formation process of the honeycomb pattern in a dielectric barrier discharge by optical emission spectrum in argon and air mixture .The discharge under-goes hexagonal lattice ,concentric spot-ring pattern and honeycomb pattern with the applied voltage increasing .The molecular vi-bration temperature ,electron excitation temperature and electronic density of the three kinds of patterns were investigated by the emission spectra of nitrogen band of second positive system （C3Πu → B3Πg ） ,the relative intensity ratio method of spectral lines ofArⅠ763.51nm（2P6 →1S5）andArⅠ772.42nm（2P2 →1S3）andthebroadeningofspectralline696.5nmrespectively.It was found that the molecular vibration temperature and electron excitation temperature of the honeycomb pattern are higher than those of the hexagonal lattice ,but the electron density of the former is lower than that of the latter .The discharge powers of the patterns were also measured with the capacitance method .The discharge power of the honeycomb pattern is much higher than that of the hexagonal lattice .These results are of great importance to the formation mechanism of the patterns in dielectric barri-er discharge .