用PET薄膜覆盖金属丝网电极实现大气压空气中均匀放电

Realization of homogenous discharge at atmospheric pressure in air using wire mesh covered by PET films

将325#不锈钢丝网电极和0.1mm厚的PET薄膜紧贴在一起,平整地固定在Rogowski电极基座上,用50Hz工频电压源及并联稳压电容,在大气压下2mm空气间隙中实现了均匀放电.实验表明:将放电电流和电荷量波形作为判断放电均匀性的依据并不是完全可靠的,它只能判断放电在时间上的一致性,而不足以判断放电在空间上的均匀性.只有拍摄曝光时间不大于100ns的放电图像,才能可靠地判断放电的均匀性.在金属丝网电极覆盖PET薄膜的大气压气体放电实验中,这种放电图像被拍摄到,并说明大气压空气中的均匀放电只是汤森放电,而非辉光放电.

Homogenous discharges were produced in a 2-mm air gap at atmospheric pressure by using 325^# fine wire mesh as electrodes covered with 0.1 mm PET films and 50 Hz line power source paralleled with a discharge-stabilizing capacitor. For obtaining such a homogeneous discharge it is important to attach tightly the wire mesh together with the PET film on the surface of a Rogowski electrode. The experiments show that the commonly used method to distinguish a homogenous discharge from a non-homogeneous one by the waveforms of discharge current and transferred charge is not always reliable since the waveforms could tell only the discharge simultaneity rather than the discharge homogeneity. A fast image of discharge with an exposure time not longer than 100 ns should be used instead to judge the discharge homogeneity. It is the first time in the experiments of atmospheric pressure discharge using wire mesh electrode covered by PET film such fast images were obtained, which indicates that the homogeneous discharge is a Townsend discharge rather than a glow discharge.