序贯试验法激光诱导击穿光谱实验条件优化

Experimental condition optimization of laser-induced breakdown spectroscopy based on sequential test

采用波长为1064nm的Nd:YAG脉冲激光作为光源聚焦于铝合金表面产生激光诱导等离子体,使用三光栅光谱仪和门宽控制的ICCD检测光谱信号。实验分析了实验参数对AlⅠ394.40nm和AlⅠ396.15nm两条特征谱线强度和信背比的影响。研究表明,ICCD探测延时、ICCD门宽和激光脉冲能量对光谱信号和信背比有较大的影响,其中ICCD门宽变化会引起光谱信号信背比起伏变化。通过优化这些实验参数,确定了最佳实验条件,在低激光脉冲能量下获得了高光谱强度和信背比的信号,为定性和定量分析铝合金成分提供了有利条件。

The Nd： YAG pulsed laser with 1064 nm wavelength was used as a light source to produce laser-induced plasma on the surface of the aluminum alloy, and the spectral signal was detected with three-grating spectrometer and width controlled ICCD. The intensity and the signal to background ratio of two characteristic lines of A1 I 394.40 nm and A1 I 396.15 nm were analyzed. It is shown that the delay of the ICCD detection, the width of the ICCD gate and the energy of laser pulse have great in- fluences on the spectral signals and the signal to background ratio, and the variation of the width of the ICCD gate leads to the fluctuation of the signal to background ratio. By optimizing the parameters, the optimum conditions were determined, and high spectral intensity and signal to background ratio were obtained under low laser energy. The experimental results lay a foundation for the qualitative and quantitative detection of the components of the aluminum alloy.