大气压空气中管-板电极结构重复频率纳秒脉冲的放电特性

Characteristics of Repetitive Nanosecond-pulse Discharge in Atmospheric Air with a Tube-to-plane Gap

由于重复频率窄脉冲气体放电具有的高过电压倍数,能够稳定地激励大气压空气等离子体,近年来受到了广泛关注。为此,利用上升沿15ns、半高宽30～40ns的负极性ns脉冲激励大气压管-板电极结构空气放电,通过电压电流测量,放电图像拍摄和X射线探测研究了ns脉冲气体放电模式和X射线辐射特性。结果表明,ns脉冲放电存在电晕、弥散和丝状3种模式,各模式及其转换与气隙距离相关。放电中测得的X射线辐射能量主要集中在30～90keV。

Repetitive nanosecond-pulse is focused on because it can provide extremely high overvoltage for excitation of non-thermal plasma at atmospheric air.With an excitation of negative repetitive pulses of 15 ns rise-time and 30~40 ns duration,characteristics of repetitive nanosecond-pulse discharge in atmospheric air with a tube-to-plane gap are investigated by the measurement of their electrical discharge parameters,images,and X-ray diffraction.Results show that nanosecond-pulse discharge has 3 discharge forms,which is corona,diffuse,and filamentary discharge,respectively,and the discharge modes and their transition are affected by the air gap spacing.In addition,it is detected that the main part of X-ray energy in X-ray diffraction locates at 30 to 90 keV.