火花放电预电离对空气中介质阻挡放电的影响

实现大气压下空气中辉光放电的办法之一是降低空气的击穿场强,避免放电以流注的形式发生.为此,利用脉冲电路产生的火花放电为介质阻挡放电提供初始电子,以验证预电离对介质阻挡放电的作用.实验证明:1. 火花放电预电离确有"点燃"放电,降低空气击穿场强的作用,在正常大气压下,采用预电离手段可使击穿场强降低25%左右;2. 预电离的有效率随气压升高而逐渐减小;3. 在有气体流动的条件下,预电离的作用显著增强;4. 预电离并不是实现大气压下空气中的辉光放电的唯一条件.本文中的方法可以用于在较低场强下提供初始电子以建立均匀介质阻挡放电,但在目前的实验条件下,这种作用还远未达到获得大气压下辉光放电的程度.

Effect of spark discharge preionization on dielectric barrier discharge in air

One of the approaches to obtain atmosphere glow discharges in air is to decrease the electric field when discharging and prevent the air breaking down in a streamer mode. In this paper, spark discharges produced by an impulse circuit are used to provide initial electrons for a dielectric barrier discharge. The effect of preionization on the dielectric barrier discharge was investigated. The experimental results show that:1. the spark discharge preionization can ignite the discharge effectively and decrease the electric field when discharging. Under the condition of normal atmosphere, electric fields employed in the reactor decrease by about 25 percent when the preionization method is adopted;2. higher is the gas pressure, lower is the probability of effectual ignition;3. under the condition of gas flow, the effect of preionization is more prominent;4. the preionization is not the only one condition necessary for obtaining atmosphere glow discharge in air. The preionization method metioned in the paper can be used to supply initial electrons for establishing uniform dielectric barrier discharge at low electric field, however, under existing experimental conditions, the decrease is still too little to getting the one atmospheric pressure glow discharge in air.