同轴电极交流电压下瞬态火花放电特性研究

近年来瞬态火花放电由于可以产生高密度、高能量电子,为等离子体化学提供更多的活性粒子受到了广泛关注;并已成功应用于环境治理和生物医学。为了进一步研究瞬态火花的放电特性,采用了交流电源和同轴电极实现放电。通过采集放电的电压和电流,研究了其在不同占空比和不同脉冲频率下的放电特性。结果表明,在外、内电极直径比为2.4时,放电呈现脉冲放电的形式,从流注放电转化为瞬态火花放电,其典型特征是电流脉冲短,放电电流大;与常规火花放电相似,放电通道之间任何地方的流注都能扩展;由于首次放电产生的空间电荷和放热引起的负载特性变化的共同影响,每个周期内后续放电的击穿电压小于首次的;随着占空比的升高和电源脉冲频率的降低,放电通道增多,周期间的放电形式呈现一定的规律变化。

Research on the characteristics of AC transient spark with coaxial electrical electrodes

Recently, high density energy electron can be generated in TS(transient spark),which may produce more reactive radicals through collision for the plasma chemistry and TS has been successfully applied for several environmental and bio-medical applications. To go a step further on the transient spark, AC power and coaxial electrodes are used in this paper. Electrical characteristics are investigated at different duty ratio and pulse frequency of the power through measuring the working current and voltage. It is founded that the streamer will be transformed to transient spark(TS) and is characterized with pulse discharge ;TS has a pulsed character with short and high current; to be similar with the conventional spark, the streamer at any place in the discharge channel can develop; the breakdown voltage is smaller thanthe first discharge due to the memory effect and load capacity; with higher duty ratio and lower AC frequency, the discharge channels gain and the .discharge pattern between circles present certain changes.