样品温度和空间约束两种方法相结合对激光诱导击穿光谱的影响  

Effects of the combination of sample temperature and spatial confinement on laser-induced breakdown spectroscopy

作　　者：于丹[1] 孙艳[1] 冯志书[2] 代玉银[3] 陈安民[4] 金明星[4] YU Dan;SUN Yan;FENG Zhi-shu;DAI Yu-yin;CHEN An-min;JIN Ming-xing(Basic Aviation College,Air Force Aviation University,Changchun 130022,China;Aviation Operations Service College,Air Force Aviation University,Changchun 130022,China;Nuclear Medicine Department,The First Hospital of Jilin University,Changchun 130021,China;Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,China)

机构地区：[1]空军航空大学航空基础学院,吉林长春130022 [2]空军航空大学作战勤务学院,吉林长春130022 [3]吉林大学第一医院核医学科,吉林长春130021 [4]吉林大学原子与分子物理研究所,吉林长春130012

出　　处：《中国光学》2021年第2期336-343,共8页Chinese Optics

基　　金：国家自然科学基金资助项目(No.11674128,No.11674124,No.11974138);吉林省教育厅“十三五”科学技术研究规划项目(No.JJKH20200937KJ)。

摘　　要：升高样品温度和采用空间约束能提高激光诱导击穿光谱的信号强度,两种技术的结合可以进一步提高激光诱导击穿光谱的光谱强度。本文在空气环境中研究了升高样品温度和空间约束效应两种方法相结合对激光诱导击穿光谱的影响,测量了激光诱导铝等离子体的时间分辨光谱。实验结果表明:升高样品温度能增加激光诱导击穿光谱的信号强度,高温样品能耦合更多的激光能量;当圆柱形腔被用于约束等离子体时,信号强度得到了进一步提高。两个实验条件的结合对于激光诱导击穿光谱信号增强的效果明显强于单独升高样品温度或者单独采用空间约束的增强效果。单一200°C高温下样品的Al(I)396.2 nm线强度增加了1.4倍;单一空间约束条件下的Al(I)396.2 nm线强度增加了1.3倍;而在200°C和空间约束的组合条件下,Al(I)396.2 nm线强度增加了2.1倍。这个结合效应增强效果产生主要由于激光照射高温样品产生更强的冲击波,从而能更有效地压缩高温下产生的更大尺寸的等离子体羽,进一步提高了激光诱导击穿光谱的强度。The signal intensity of Laser-Induced Breakdown Spectroscopy(LIBS)can be improved by increasing sample temperature and confining space confinement.The combination of the two techniques can further improve the spectral intensity of LIBS.In this paper,the effects of increasing a sample’s temperature and spatial confinement on LIBS are studied in air,and the time-resolved spectra of laser-induced aluminum plasma are measured.The experimental results show that increasing the sample’s temperature can increase the signal intensity of LIBS since a sample with a higher temperature can absorb more laser energy;when the cylindrical cavity is used to confine the plasma,the spectral emission is further improved.The effect of the combination of the two experimental conditions is that the signal intensity of LIBS is significantly stronger than that of either condition alone.The intensity of Al(I)396.2 nm increases to 1.4 times at 200°C with higher temperature conditions alone,1.3 times when spatial confinement is applied alone,and 2.1 times at 200°C with spatial confinement.The emission intensity with the combined effects is higher than the sum of that under the two individual conditions.The effect of the combination is mainly based on the fact that laser irradiation of the sample under a higher temperature generates stronger shock waves that can more effectively compress a larger-sized plasma plume,thereby further improving the spectral intensity of LIBS.

关 键 词：激光诱导击穿光谱 样品温度 空间约束 光谱增强 等离子体 

分 类 号：O657.3[理学—分析化学]