不同空间约束壁数对激光诱导铜击穿光谱的影响  

Effect of Different Numbers of Spatial Confinement Walls on Laser-Induced Cu Plasma Spectra

作　　者：代玉银[1] 于丹[2] 李英华[1] 陈安民[3] 金明星[3] Dai Yuyin;Yu Dan;Li Yinghua;Chen Anmin;Jin Mingxing(Nuclear Medicine Department,the First Bethune Hospital of Jilin University,Changchun,Jilin 130021,China;Basic Aviation College,Air Force Aviation University,Changchun,Jilin 130022,China;Institute of Atomic and Molecular Physics,Jilin University,Changchun,Jilin 130012,China)

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

出　　处：《中国激光》2022年第6期138-146,共9页Chinese Journal of Lasers

基　　金：吉林省科技厅自然科学基金(20200201334JC);国家自然科学基金(11674128,11674124,11974138);吉林省教育厅资助项目(JJKH20200937KJ)

摘　　要：提高激光诱导击穿光谱(LIBS)的信号强度是提高LIBS探测灵敏度的重要途径。本文以铜靶为烧蚀样品,研究了大气环境中不同空间约束壁数(0、2、3、4)和圆柱形约束壁对激光诱导Cu等离子体光谱的影响,并通过Boltzmann图方法测量了等离子体的电子温度。实验结果表明:当使用约束壁约束Cu等离子体时,Cu原子谱线强度、信背比和电子温度均比不存在约束时明显提高;随着腔体约束壁数增加,Cu原子谱线强度、信背比和电子温度逐渐提高;当腔体约束壁为圆柱形时,Cu原子谱线强度、信背比和电子温度最高。空间约束壁为圆柱形壁时空间约束对等离子体的约束效果最好,光谱信号最优。Objective Laser-induced breakdown spectroscopy is a powerful spectroscopy technique for the analysis of various materials.As we all know,laser pulse ablates the sample and generates plasma,and the shock wave generated by the plasma propagates at supersonic speed.When the shock wave encounters the wall of confinement cavity,it will be reflected.The reflected shock wave compresses the plasma,increasing the collision rate of particles in the plasma.It will increase the number of atoms in the high-energy state and enhance the plasma’s spectral intensity.As a result,many researchers have conducted extensive research on spatial confinement.However,no research group has yet investigated the effect of the number of spatial confinement walls on the spectra of laser-induced plasmas.For this reason,it is necessary to compare and study the plasma spectral emission characteristics for the different spatial confinement walls.Methods We focused nanosecond laser on the surface of the Cu target to generate plasmas,and analysed the spectra of the generated plasmas.To avoid laser irradiation at the same position on the target surface,the Cu target was placed on a 3D translation stage and moved along with it.The focusing lens collected the plasma emission signal,which was then transmitted via optical fibre to a spectrometer equipped with an ICCD.To ensure time synchronisation between the laser and spectral signals,the output laser triggered the photodiode.The cavities with different spatial confinement walls(2,3,4,and cylindrical walls)were machined using aluminium alloy.Each spectrum was an average of 20laser shots,and the whole experiment processes were carried out in the air.Results First,the spectra for different numbers of confinement walls at a delay time of 12.5μs were compared.The results show that the number of confinement walls has a significant enhancement effect on the intensity of the three Cu(I)spectral lines at a delay time of 12.5μs.Second,the time-resolved spectral intensity of Cu(I)at 521.82nm was measured for

关 键 词：光谱学 激光诱导击穿光谱 空间约束壁数 光谱增强 电子温度 

分 类 号：O506[理学—物理]