大气压氦气介质阻挡放电中的周期一不对称放电实验研究

大气压介质阻挡放电不仅具有对称周期一的放电形式, 还会在一定参数下呈现不对称周期一(AP1)放电. 本文采用具有平行电极结构的介质阻挡放电装置, 分别在气隙宽度1 mm, 3 mm, 7 mm和10 mm下的大气压氦气中进行了一系列放电实验, 研究了气隙宽度和外施电压频率对周期一放电对称性的影响. 实验结果表明: 在较宽的气隙宽度和外施电压频率参数区间内可以观察到显著的AP1放电; 气隙宽度越大越容易产生AP1放电, 同一气隙宽度下外施电压频率较高时则相对更容易观察到AP1放电; 随着气隙宽度增加, 首次击穿即呈现AP1 放电的外施电压频率临界值逐渐减小. 本文的研究初步验证了之前关于气隙宽度对AP1放电影响的数值仿真结果, 由此可以推测AP1放电并不只是由系统参数的不对称引起的, 也很可能是一种在一定的气隙宽度和外施电压频率下系统固有的、内在的高频不稳定放电行为. 关键词： 介质阻挡放电 不对称放电

Experimental study on asymmetrical period-one discharge in dielectric barrier discharge in helium at atmospheric pressure

Dielectric barrier discharge at atmospheric pressure not only behaves as a symmetrical period-one (SP1) discharge, but can also manifest itself as an asymmetrical period-one (AP1) discharge in certain ranges of parameters. In our study, a parallel electrode configuration is adopted and a series of discharge experiments are carried out in atmospheric helium at gap widths of 1, 4, 7 and 10 mm, respectively. The effects of gap width and driving voltage frequency on the symmetry of period-one discharge are investigated. Experimental results show that: AP1 discharge can be readily observed in a large range of parameters for the gap width and driving voltage frequency. AP1 discharge is prone to occur for a larger gap width; the critical value of the driving voltage frequency, beyond which the initial discharge is AP1 discharge, decreases as the gap width is increased. Results presented in this paper preliminarily verify the numerical simulations and the analysis which were previously reported in those papers studying the effect of gap width on AP1 discharge. Thus it can be conjectured that the AP1 discharge is not caused only by parameter asymmetry of discharge configuration, it can be also an intrinsic instability in terms of high frequency under certain parameters combination of gap width and driving voltage frequency.
Keywords： dielectric barrier discharge asymmetrical discharge