交直流电压下微间隙气体放电特性研究

Study on the characteristics of micro-gap gas discharge under AC/DC voltage

为深入研究不同间距的电极在交直流电压作用下的放电机理,搭建基于微间隙精密距离控制的放电试验研究平台,测量不锈钢电极在1~100μm间距下的击穿电压,绘制击穿电压曲线,并与巴申曲线进行对比,发现1~5μm时与巴申曲线并不相符;随着间距增大,5~100μm时击穿电压变化趋势与巴申曲线大致相同。通过计算可知,1~5μm间距下的击穿场强达到108 V/m。根据测量的击穿电压曲线,估算出有效电子产额,分析其对约化电场E/p与电场倒数之间的依赖关系,发现1~5μm间隙时,场致电子发射主要取决于高场强。最后研究不同间距与场致电子发射电流密度之间的关系,并通过F-N理论分析1~5μm间隙时击穿电压偏离巴申曲线的原因,证明场致电子发射对此起了决定作用。

In order to study the discharge mechanism of electrodes with different spacing under AC and DC voltage,an experimental platform based on micro-gap precise distance controller was built.The breakdown voltage of stainless steel electrodes at 1~100μm was measured,and the breakdown voltage curve was drawn and compared with the Paschen curve.It was found that the breakdown voltage curve was not consistent with the Paschen curve at 1~5μm.With the increase of spacing,the trend of breakdown voltage at 5~100μm was similar to that of Paschen curve.Through calculation,the breakdown field strength at 1~5μm was 10~8 V/m.According to the measured breakdown voltage curve,the effective electron yield was estimated.The relationship between the reduced electric field E/p and the electric field reciprocal was analyzed.The dependence of the relationship was found that the field emission in the 1~5μm was mainly determined by the high field strength.Finally,the relationship between different spacing and field emission current density was studied.The reason why the breakdown voltage deviated from the Paschen curve at 1~5μm gap was analyzed by F-N theory,and it was concluded that field emission played a decisive role.