为了减小激光等离子体发射光谱的自吸效应, 提高激光诱导击穿光谱技术对物质成分的检测能力, 设计了一种平面反射镜装置对等离子体进行空间约束, 研究了不同实验条件下的光谱线线型, 定量分析了钢样品中的元素Mn和Ni.实验结果表明, 利用平面反射镜装置约束激光等离子体以后, 光谱线的自吸效应比常态条件下有明显减小;通过定量分析样品元素Mn和Ni的结果看出, 无平面反射镜装置时的相对标准偏差分别为3.70%和6.23%, 而实验中加入面反射镜装置以后分别降至1.86%和2.16%, 显著提高了分析结果的测量精度.

To reduce the influence of self-absorption of laser plasma emission spectra and improve the detection capability of laser-induced breakdown spectroscopy to material component,a plane mirror device was used to constraint the laser plasma.The spectral line profile of Mn and Ni in steel samples under different experimental condition were studied and analyzed quantitatively.The experimental results demonstrate that the self-absorption of spectral line decreases obviously when a plane mirror device is used.Through quantitatively analyzing Mn and Ni,once inserting a plane mirror device,the value of relative standard deviation of Mn decreases from 3.70% to 1.86%,and that of Ni decreases from 6.23% to 2.16%,which indicates that the measurements precision is improved obviously.It is thus clear that the plane mirror device could reduce the adverse effect of self-absorption on analyzing results obviously.