为研究大气压介质阻挡多脉冲辉光放电的模式转化规律及其放电机理,在6mm氦气中进行了3脉冲辉光放电试验,测量了相应的电气参数,并利用增强型电子耦合器件(intensified charge-coupled device,ICCD)拍摄了放电间隙侧面的短时曝光图像,提取放电图像的灰度值并绘制出光强在气隙间的分布曲线,按放电图像特征将放电分成不同阶段,系统研究了各个阶段的放电模式及其转化规律,并探讨了放电的机理。结果表明:放电起始阶段具有汤森放电的阳极发光结构;空间电荷的作用使得放电从开始的汤森放电转化为具有完整的正柱区、法拉第暗区和负辉区的辉光放电;放电电流脉冲之间微弱的发光特性仍具有辉光放电结构,有力证明了放电并未熄灭,而是维持着较弱的辉光放电。
In order to study the mode transition and the mechanism of multi-pulse dielectric barrier glow discharge,three-pulse glow discharge in 6mm helium was obtained.The electrical signals were measured,and short exposure time images were taken using an intensified charge-coupled device(ICCD).The gray value of the images was extracted and the corresponding light distribution was drawn to make the images more visualized.According to the features of discharge images,the optical development was analyzed by dividing the current pulses into different stages.Moreover,the discharge modes and the transition law of all stages were studied systematically,and the mechanism of discharge was investigated.The results show that,in the initial stage,the discharge has an anode luminous structure of Townsend discharge.Then the discharge transits to glow mode with a structure of positive column,Faraday dark space and negative glow space.The weak luminescence between adjacent pulses still has a glow discharge structure,which strongly suggests that the discharge does not extinguish but maintains a weak glow discharge during these stages.