介质阻挡放电中栅栏发光斑图等离子体参量研究

Investigation on The Plasma Parameters of The Fence Pattern in Dielectric Barrier Discharge

采用高速录像机和光谱仪,研究了在双水电极介质阻挡放电装置中首次得到的由长短交替的棒状放电结构组成的栅栏斑图。通过观察20μs曝光录像照片发现栅栏斑图由体放电和沿面放电组成。采用发射光谱法,利用N2第二正带系(C3Πu→B3Πg)的发射谱线和ArⅠ(2P2→1S5)谱线的展宽,分别测量和比较了不同体放电和沿面放电不同位置处的分子振动温度和电子密度。结果发现:斑图中具有较强沿面放电的体放电比具有较弱沿面放电的体放电拥有较高的分子振动温度和电子密度;在沿面放电的方向上,沿面放电的分子振动温度和电子密度均逐渐降低。理论分析证明,壁电荷在狭缝内的非等量分布是影响栅栏斑图形成的主要因素。

The fence pattern that consists of volume discharges ( VDs ) and surface discharges ( SDs) is observed by using the dielectric barrier discharge device with two water electrodes. The VDs uniformly distribute along the slit, and SDs are perpendicular to the slit and own two kinds of intensity. The short-exposed photograph is obtained by a high speed video camera. The plasma pa-rameters of fence pattern are investigated by spectrograph. The emission spectra of the N2 second positive band( C3Πu→B3Πg ) is collected, and the molecule vibrational temperature is calculated by the emission intensities. Furthermore, the width of ArⅠ696. 5 nm is used to estimate the electron density. The results show that the volume discharges with strong surface discharges have higher mol-ecule vibrational temperature and higher electron density than those with less surface discharge. Be-sides, along the surface discharge direction, surface discharge’s molecule vibrational temperature and the electron density gradually decrease. The unequivalent distribution of the wall charges con-tributes to the formation of fence pattern.