基于SAF-LIBS理论的铝精密检测技术研究  

Precise Testing Technology of Aluminum Based on SAF⁃LIBS Theory

作　　者：尹润涛 乔一帆 王晶晶[1] 张建宏[2] 侯佳佳 赵刚[1] 崔茹悦 武红鹏[1] 董磊[1] 马维光[1] 张雷[1] 尹王保[1] Yin Runtao;Qiao Yifan;Wang Jingjing;Zhang Jianhong;Hou Jiajia;Zhao Gang;Cui Ruyue;Wu Hongpeng;Dong Lei;Ma Weiguang;Zhang Lei;Yin Wangbao(Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,Shanxi,China;School of Electric Power,Civil Engineering and Architecture,Shanxi University,Taiyuan 030006,Shanxi,China;School of Optoelectronic Engineering,Xidian University,Xi’an 710071,Shaanxi,China)

机构地区：[1]山西大学激光光谱研究所,山西太原030006 [2]山西大学电力与建筑学院,山西太原030006 [3]西安电子科技大学光电工程学院,陕西西安710071

出　　处：《中国激光》2024年第17期299-304,共6页Chinese Journal of Lasers

基　　金：长江学者和创新团队发展计划(IRT_17R70);国家自然科学基金(12374377,61975103,11434007,61905136);111计划(D18001);山西省“1331工程”重点学科建设计划(1331KSC)。

摘　　要：利用自吸收免疫激光诱导击穿光谱(SAF-LIBS)理论对铝精密检测技术进行了研究。利用铝原子光谱线Al 396.15 nm和Al 394.40 nm的原子参数计算出这两个原子光谱线强度理论比值为I_(Al 396.15 nm)/I_(Al 394.40 nm)=1.983,以此作为光学薄判据研究了Al 396.15 nm和Al 394.40 nm两个光谱线强度实验采集比值随时间的演化规律。实验结果表明:最佳光谱采集时间与样品中的元素含量有关;激光诱导击穿光谱(LIBS)技术能够测量的最大元素含量受限于最短光谱薄时间;LIBS技术能精确测量铝质量分数为0~15.9%的样品,对于质量分数大于19.5%的铝样品,采用LIBS技术不能获得自吸收影响最小的光谱,因而不能实现精确测量。Objective Photons produced through laser-induced excitation of a sample typically encounter absorption by atoms or ions of the same class along the radiation path as they propagate outward.This self-absorption phenomenon not only induces a dip at the top of the spectral line intensity but also results in an expansion of the spectral line width.Consequently,the accurate representation of the elemental composition of a sample is compromised,leading to a potential deviation in the precision of quantitative analysis.Spectra significantly affected by self-absorption can have detrimental effects on laser-induced breakdown spectroscopy(LIBS)applications.The objective of this study is to obtain laser-induced breakdown spectra free from self-absorption.We employ a novel method to achieve a precise quantitative analysis of elements within a sample with the aim of mitigating the effects of self-absorption on the accuracy of the obtained results.Methods If the upper level transition states corresponding to different transition line wavelengths of a selected component element are the same(or approximately the same)in the ionized state Z,the intensity ratio of the doublet lines is linked solely to the physical parameters of the transition associated with the two spectral lines.This ratio remains independent of the experimental device,conditions,and time evolution.Assuming similar energy-level structures and wavelengths for the two selected lines,their changes in intensity are anticipated to be similar.Experimental measurements involve determining the actual intensity ratio at different delay time.When the experimental ratio at a specific moment equals or approximates the theoretical value,that moment is considered the point at which optical thinning of the plasma occurs.Theoretically,this represents the moment in the radiation spectrum of the plasma without self-absorption,enabling the acquisition of the intensity of the plasma radiation line in the self-absorption-free state.Utilizing spectral values in this state can signifi

关 键 词：光谱 激光诱导击穿光谱 自吸收效应 铝精密检测 原子光谱 

分 类 号：O433[机械工程—光学工程]