大气压空气中重复频率纳秒脉冲气体放电模式研究

利用上升沿100ns、脉宽150ns的单级磁压缩纳秒脉冲电源,通过电压电流测量和放电图像拍摄实验,研究了大气压空气中极不均匀电场结构重复频率纳秒脉冲气体放电的放电模式。结果表明纳秒脉冲气体放电存在三种典型的放电模式:电晕放电、弥散放电和火花放电。施加的脉冲电压幅值对放电模式影响显著,随着电压幅值的增加,放电依次经历电晕、弥散和火花放电。固定电压幅值时,放电可能同时存在两种模式。重复频率加强了放电强度,弥散放电的激发电压随重复频率的增加变化不大,但火花放电的激发电压随着重复频率的增加而降低。因此降低重复频率有利于在较大电压范围获得大气压空气弥散放电。

Discharge mode in the repetitive nanosecond-pulse discharge in atmospheric pressure air

With an excitation of one-stage magnetic pulse compressor generator of 100 ns rise time and 150 ns duration, discharge mode of nanosecond-pulse discharges in an inhomogeneous electrical field in repetitive pulsed modes. Characteristics of nanosecond-pulse discharges are experimentally investigated by measuring their electrical parameters, images and taking their discharge photos. Results show that there were three typical discharge modes, i.e. corona, diffuse and spark discharges. The discharge modes were significantly influenced by the applied voltage, as the applied voltage increased the discharges experienced corona-to-diffuse-to-spark transition. With a fixed applied voltage, two discharge modes might simultaneously exist. Furthermore, experimental results on the effect of the pulse repetition frequency (PRF) show that, the excitation voltages of the diffuse discharges were slightly influenced by the PRF, but the excitation voltages of spark discharges decreased with the increase of the PRF. Thus, small PRF was beneficial for obtaining diffuse discharges in atmospheric-pressure air in a broad range of the applied voltage.