针-极板内氦气等离子体射流电场监测研究

Study on electric field monitoring of helium plasma jet in needle plate

小空间下强电场测量方法的研究是一个难点,借助谱线的Stark效应,选择合理的原子或离子,可在无干扰的情况下完成测量。设计了一套大气压纳秒脉冲放电实验装置,通过针-极板放电产生强电场,试验He 447.1 nm谱线在不同放电电压下产生的强电场下的分裂情况,在谱线展宽难以直接通过观察谱线的方法得到的情况下,借助非线性最小二乘法,分析谱线的允许分量、禁止分量和场无关分量,求出对应的波长偏移量,由此得出电场大小。根据Mason公式,在能量等效的基础上,实验结果符合理论预期,通过该方法可以实现对小空间内强电场的测量。经分析,理论与实验结果之间的偏差可能是由氦气在被击穿时产生等离子体形成的屏蔽导致。

The study of measurement methods for strong electric fields in small spaces is a challenge.By utilizing the Stark effect of spectral lines and selecting reasonable atoms or ions,measurements can be completed without interference.This article designs a set of atmospheric pressure nanosecond pulse discharge experimental device,which generates a strong electric field through needle electrode discharge,and tests the splitting of He 447.1nm spectral lines under strong electric fields generated at different discharge voltages.When the spectral line broadening is difficult to obtain directly by observing the spectral line,by using the non-linear least squares,the allowable component,the prohibited component and the field independent component of the spectral line are analyzed and the corresponding wavelength offset is calculated to obtain the electric field size.According to Mason’s formula,based on energy equivalence,the experimental results meet theoretical expectations,and this method can be used to measure strong electric fields in small spaces.Analysis indicates that the discrepancy between theoretical and experimental results may be attributed to the shielding effect caused by the plasma produced when helium gas undergoes breakdown.