激光脉冲重复频率对等离子体辐射特性的影响  

Effects of Laser Shot Frequency on Plasma Radiation Characteristics

作　　者：陈金忠[1] 白津宁[1] 宋广聚[1] 孙江[1] 邓泽超[1] 王英龙[1] 

机构地区：[1]河北大学物理科学与技术学院,河北保定071002

出　　处：《光谱学与光谱分析》2012年第11期2916-2919,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(10804025);河北省自然科学基金项目(A2006000951)资助

摘　　要：为了提高激光诱导击穿光谱质量,采用Nd∶YAG激光器输出的纳秒脉冲激光激发产生土壤等离子体,采用光栅光谱仪和光电检测系统记录了元素谱线AlⅠ394.401nm,BaⅠ455.403nm,FeⅠ430.791nm和TiⅠ498.173nm的辐射强度和信背比,研究了激光脉冲重复频率(5,10和15Hz)对等离子体辐射特性的影响。实验结果表明,在相同的激光输出能量条件下,当采用15Hz的激光脉冲重复频率时,元素Al,Ba,Fe和Ti的谱线强度要比5Hz时的分别提高50.94%,112.7%,107.46%和99.38%,光谱信背比分别提高15.16%,24.08%,40.26%和72.06%。通过测量等离子体参数,解释了激光脉冲重复频率对等离子体辐射特性的影响机理。To improve the quality of laser-induced breakdown spectroscopy,nanosecond pulse laser generated by Nd∶YAG laser was used to excite soil sample.The intensity and signal-to-background ratio of Al Ⅰ 394.401 nm,Ba Ⅰ 455.403 nm,Fe Ⅰ 430.791 nm and Ti Ⅰ 498.173 nm were observed using a grating spectrometer and a photoelectric detection system.The effects of laser shot frequency（5,10 and 15 Hz）on the radiation characteristics of laser-induced plasma was studied.The experimental results show that as compared with the laser shot frequency of 5 Hz,the spectral line intensity of Al,Ba,Fe and Ti increased by about 50.94%,112.7%,107.46%,and 99.38% at 15 Hz respectively under the same laser energy,while the spectral signal-to-background ratio increased byabout 15.16%,24.08%,40.26% and 72.06% respectively.The effects mechanism of the laser shot frequency on radiation characteristics of plasma is explained by measuring plasma parameters.

关 键 词：激光诱导等离子体 激光脉冲重复频率 光谱强度 信背比 

分 类 号：O433.2[机械工程—光学工程]