Design of a Modularized Automatic Measurement and Control System for Laser-Induced Breakdown Spectrometer

In order to improve the compatibility of laser-induced breakdown spectroscopy（ LIBS） instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and control system was developed. Based on the characteristics of each LIBS component, the following development steps have been performed：（ 1） a summary of characteristic parameters of the component are established;（ 2） the integration mechanism of multiple electrical interfaces is designed;（ 3） the component control instruction library is developed. The experimental results indicate that the measurement and control system is compatible with most LIBS parts in the market.Spectrometer and laser can be compatible with at least three different types of parts. In addition,a multilayer iterative testing process is designed to improve the efficiency of optimization process of LIBS parameters. The experimental results have shown that the automatic optimization of the delay time compared to the manual testing provides significant gain in testing efficiency. The range of delay time in the experiments is 1. 28 to 10. 28 μs and the step value is 1,0. 5,0. 2 and 0. 1 μs. The gain in testing efficiency has been found to be increased by 73. 76%,75. 93%,78. 81% and 80. 42%,respectively.     

基于激光诱导击穿光谱技术的水垢成分分析

将1064nm激光聚焦到水垢上产生等离子体,通过分析水垢等离子体光谱,定性地证认元素钙和镁．通过10条钙原子谱线的Bohzmann图,计算得到水垢等离子体的电子温度是4793K．通过测量镁原子谱线285．21nm的Stark展宽,求得水垢等离子体的电子密度是6．1×1018cm-1．实验结果表明,激光诱导产生的水垢等离子体满足局部热力学平衡模型,并处于光学薄状态,等离子体的频率是2．2×1013Hz,韧制吸收系数为8．87cm-1．     

用LIBS方法测量铝合金中的合金元素

将高能激光脉冲聚焦在合金样品表面形成样品的高温等离子体,用光栅光谱仪与增强型电感耦合装置(ICCD)分析等离子体的发射谱线来测定合金中的元素种类与浓度.实验以系列标准铝合金的光谱来标定Fe,Si,Cu的定量分析标准曲线,分析了铝合金中主要元素的测量精度与探测限.研究表明,该方法在合金元素质量分数大于0.01%时,测量相对误差在5%之内;在合金元素质量分数低于0.01%时,测量绝对误差在0.001%之内,对3种合金元素的检出限可达6×10-5~10×10-5左右,且采用基体元素作为内标可进一步提高分析精度.     

AlCl3水溶液的激光诱导击穿光谱特性研究

利用自建的液相射流单脉冲激光诱导击穿光谱(LIBS)实验装置,系统地研究了激光能量、ICCD探测延时和ICCD门宽等实验参数对AlCl_3水溶液LIBS特性的影响,确定了将LIBS用于AlCl_3水溶液中Al元素定量分析时的最佳实验条件.     

LIBS谱线自动寻峰在炉渣成分在线分析中的应用

采用激光诱导击穿光谱技术对炉渣成分实时在线监测的研究过程中,谱峰的中心波长及其积分强度是定量分析的基础。为了快速自动识别海量的谱峰数据,文章基于有限状态机的句法编译了一套自动寻峰程序,并介绍了产生谱峰描述语言的文法和谱峰自动识别机。将该寻峰程序应用于自动识别激光诱导炉渣等离子体发射光谱数据和炉渣成分的在线分析,取得了较好的分析速度和精度,证明了该技术的有效性。     

环境气体的性质和压力对LIBS信号影响的实验研究

系统地研究了(Ar,He,air,)三种环境下的缓冲气体压力以及激光能量对铅黄铜样品中LIBS谱的影响,并分析了不同环境气体中LIBS的时间分辨特性,寻找合适的实验参数以提高LIBS技术用于痕量分析的灵敏度和准确度.得出最佳实验条件为:光谱测定延时约为4us,激光能量约为120mJ,对于氩气缓冲气体,气体压力约为200Torr,空气中约为100Torr,氦气中约为300Torr.