大气压氦气多脉冲辉光放电径向光学演化过程

介质阻挡放电(dielectric barrier discharge,DBD)的径向演化及其影响因素对研究低温等离子体的机制具有重要的参考价值。采用铟锡氧化物(indium tin oxide,ITO)透明电极,进行了大气压氦气介质阻挡三脉冲辉光放电试验,利用增强型电子耦合器件(intensified charge-coupled device,ICCD)拍摄放电的侧面短时曝光照片来诊断放电模式,拍摄放电的底面短时曝光照片并绘制其发光灰度值在电极表面的三维分布图来研究放电的径向演化过程。结果表明:放电首先在圆形电极的边缘区域发生,逐渐向电极中心发展,最后又转向电极边缘并逐渐减弱;随着电流脉冲次序的增加,放电在电极中心发展越来越充分;电极结构的限流作用同外施电压和介质表面电荷一样,对径向位置上不同时刻的放电演化过程起着重要作用。

Radial Optical Development of a Multipeak Glow Discharge in Atmospheric-pressure Helium

Radial development of dielectric barrier discharge(DBD) and its influencing factors are of importance in studying the mechanism of low-temperature plasmas.Three-pulse dielectric barrier glow discharge was carried out using an ITO transparent electrode.Short exposure time images from side direction of the gas gap were taken with an intensified charge-coupled device(ICCD) to diagnose discharge modes.And the radial development was discussed by taking end-view images and drawing the corresponding three-dimensional light distribution.It was found that the discharge first originates at the peripheral part of the electrode,develops to the center and then turns to the periphery again and declines gradually.And the discharge develops more strongly in the central part as the sequence of pulses increases.The current limitation of the electrode structure together with the applied voltage and the surface charges plays a key role in the different discharging time in the radial direction.