激光诱导钢靶等离子体时间分辨光谱特性研究  

Spectral Time Evolution Behavior of Laser Induced Steel Target Plasma

作　　者：付杰[1,2,3] 郭喜庆[1,2,3,4] 赵天卓[1,3,4] 连富强[1,3,4] 樊仲维[1,2,3,4] 

机构地区：[1]中国科学院光电研究院,北京100094 [2]中国科学院大学,北京100049 [3]国家半导体泵浦激光工程技术研究中心,北京100094 [4]中科和光(天津)应用激光技术研究所有限公司,天津300304

出　　处：《中国激光》2017年第3期263-269,共7页Chinese Journal of Lasers

基　　金：国家科技重大专项(2014YQ120351)

摘　　要：为了改善激光诱导击穿光谱质量,使用具有时间分辨功能的光谱仪采集激光诱导钢靶等离子体光谱,研究了钢靶等离子体辐射光谱随延迟时间的变化特性。结果表明,光谱强度和背景强度随延时皆呈指数衰减,原子谱线强度在前4μs内衰减更快但寿命较长,离子谱线存在寿命较短;采集延时对不同谱线的信噪比影响不同,Mn I403.08nm、Cr I 428.97nm、CrⅡ458.82nm、Fe I 430.79nm和FeⅡ503.57nm谱线得到的最佳延时分别为8,2,0,2,4μs。采用双线法和Boltzmann曲线法计算等离子体温度、Saha-Boltzmann方程计算电子密度,验证了在0~10μs范围内采集到的光谱信号满足局部热平衡状态。In order to improve the quality of laser induced breakdown spectroscopy, we used a time-resolved spectrometer to collect steel target plasma emission spectra. The relationship between the intensity of spectral lines and the delay time was discussed. It demonstrates that both the spectral intensity and background intensity decay exponentially with the delay time. Spectral intensity of atoms decreases faster in the first 4 μs but the atoms＇ spectral lines exist for a longer time. However, ionsr spectral lines exist for shorter. Acquisition delay has different influence on signal to noise ratios of different spectral lines. The best delays of Mn Ⅰ 403.08 nm , Cr Ⅰ 428.97 nm, Cr Ⅱ 458.82 nm, Fe Ⅰ430.79 nm and Fe Ⅱ 503.57 nm spectra obtained are 8, 2, 0, 2, 4 μs, respectively. The double lines method and the Boltzmann plot method were used to calculate the plasma temperature, and the SahaBoltzmann equation was used to calculate the electron density. It is verified that the spectral signal meets the local thermal equilibrium state in the acquisition time range of 0-10 μs.

关 键 词：光谱学 激光诱导击穿光谱 采集延时 信噪比 等离子体温度 电子密度 

分 类 号：TN249[电子电信—物理电子学] O433.4[机械工程—光学工程]