极不均匀电场下重复频率纳秒脉冲气体击穿实验研究

 实验研究了尖-板电极中，不同重复频率（10,100,500,1 000 Hz）、不同间隙(0.5,1 cm),不同气压（0.1～0.4 MPa）等条件下空气的绝缘特性。得到了击穿时延、重复频率耐受时间、施加脉冲个数等与施加电压、重复频率的关系。研究发现：在该实验条件下击穿时延随着场强与气压的比值减小而增加，但重频耐受时间和脉冲击穿个数并没有明显变化；随着重复频率的提高，击穿时延和重频耐受时间会减小，但脉冲击穿个数可能会增加；且重复频率条件下击穿的极性效应不明显；重复施加的脉冲产生大量的亚稳态粒子和残余电荷影响放电的发展过程；负离子的脱负或正离子碰撞阴极的过程，及亚稳态粒子的去激励作用给击穿提供了有效初始电子。

Experimental research of repetitively nanosecond-pulse breakdown in air under non-uniform electric field

Breakdown experiments of point-plane gas gaps were investigated with repetitive burst conditions under variant repetition rates(10,100,500 and 1 000 Hz),diverse gap distances(0.5 cm and 1.0 cm) and different gas pressures(0.1~0.4 MPa) respectively.Relations among breakdown delay time,repetitively stressing time,number of applied pulses,and repetition rates were presented.The results indicate that breakdown time lag increases with the decrease of the division between applied electric-field and gas pressure,but repetitively stressing time and applied pulse number change hardly with the division between applied electric-field and gas pressure in the experimental condition.Breakdown time lag and repetitively stressing time decrease with the increase of repetition rate,but applied pulse number increases.The experimental results also show that the polarity dependence is not distinct.Excited particles and residual charges formed during the consecutive nanosecond-pulses will present a memory effect and affect the development of gas breakdown.Detachment of negative ions,cathode collision of positive ions,or de-excitation of metastable species can provide the source of primary electrons.