中国激光, 2014, 41 (7): 0715001, 网络出版: 2014-06-13
含铅污泥中铅的激光诱导击穿光谱特性研究
Research on the Characteristics of Lead Contained in Lead Slime by Laser-Induced Breakdown Spectroscopy
光谱学 激光诱导击穿光谱 含铅污泥 铅 等离子体温度 电子密度 spectroscopy laser-induced breakdown spectroscopy lead slime lead plasma temperature electron density
摘要
利用波长为1064 nm的NdYAG脉冲激光器作为激发光源,以高分辨率、宽光谱段的中阶梯光栅光谱仪和增强型电荷耦合器件为谱线分离器件和探测器件,研究了含铅污泥中铅的激光诱导击穿光谱特性。选取铅的特征谱线PbⅠ405.78 nm为分析线,分别测量了PbⅠ405.78 nm的谱线强度与信噪比随延时和门宽的变化关系,确定了最佳延时td=2.5 μs,最佳门宽tg=3.0 μs。在局部热力学平衡近似下,选取铁在360~441 nm波长范围内的13条特征谱线,利用玻尔兹曼图,计算得出等离子体温度为6934 K;对PbⅠ405.78 nm其进行洛伦兹拟合,得到等离子体的电子密度为8.3×1016 cm-3。这些参数为进一步实现对含铅污泥的快速定量分析提供方法和技术支持。
Abstract
The laser induced breakdown spectrum characteristic of lead contained in lead slime is studied with a 1064 nm wavelength NdYAG laser as the exitation source, a echelle spectrometer of high resolution and wide spectral range for spectral seperation and a intensified charge coupled device for high sensitive detection. The characteristic spectrum line of PbⅠ405.78 nm is selected as the analytical line, the relationship of spectrum intensity and signal to noise ratio of PbⅠ405.78 nm varying with delay time and gate time are measured respectively. The optimum delay td=2.5 μs and gate tg=3.0 μs are confirmed. Under the approximation of local thermal equilibrium, 13 characteristic spectrum lines of Fe within the wavelength range of 360~441 nm are choosed, the temperature of plasma calculated by the means of Boltzmann diagram is 6934 K, and the electron density of plasma gained by using Lorentz fitting on PbⅠ405.78 nm is 8.3×1016 cm-3. These parameters provide a method and technical supports for fast quartitative analysis of lead sime.
余洋, 赵南京, 王寅, 孟德硕, 胡丽, 张大海, 马明俊, 刘建国, 刘文清. 含铅污泥中铅的激光诱导击穿光谱特性研究[J]. 中国激光, 2014, 41(7): 0715001. Yu Yang, Zhao Nanjing, Wang Yin, Meng Deshuo, Hu Li, Zhang Dahai, Ma Mingjun, Liu Jianguo, Liu Wenqing. Research on the Characteristics of Lead Contained in Lead Slime by Laser-Induced Breakdown Spectroscopy[J]. Chinese Journal of Lasers, 2014, 41(7): 0715001.