CsCl 添加剂对激光诱导土壤等离子体辐射强度的影响

为了提高激光诱导击穿光谱技术对低含量物质成分的检测能力, 实验研究了CsCl添加剂对土壤样品发射光谱的增强效应. 利用高能量钕玻璃脉冲激光烧蚀样品, 由组合式多功能光栅光谱仪和CCD光谱采集处理系统记录等离子体光谱, 并通过测量光谱线的强度和Stark 展宽分别计算了等离子体的电子温度和电子密度. 实验结果证明, 随着CsCl加入量的增加, 激光诱导等离子体的光谱强度、信背比、电子温度和电子密度均呈现出先增大而后减小的变化规律. 当CsCl 加入量为15%时, 等离子体辐射最强, 元素Mn, K,Fe 和Ti 的谱线强度分别比无添加剂时提高了383%, 348%, 303%和267%, 信背比分别提高了204%, 149%, 150%和142%; 而等离子体的温度和电子密度比无添加剂时分别提高了10%和13%.

Effect of CsCl additive on laser-induced soil plasma radiation

In order to improve the laser-induced breakdown spectroscopy for low-level elements testing capability, the enhancement effect of CsCl additive on the emission spectra of soil samples was studied. The laser spectrum analytical system is composed of a high-energy neodymium glass laser used for abating samples, a multifunctional and automatic grating spectrometer, and a CCD data acquisition system used for recording plasma spectra. The electron temperature and electron density of plasmas were calculated by measuring spectral line intensity and stark broadening, respectively. The experimental results showed that with the increase of the CsCl additive, the intensity, signal-to-background ratio, the electron temperature and the electron density all went up firstly and then down. When 15% CsCl was added, the radiation intensity of plasma reached the maximum value, the spectral lines intensity of element Mn, K, Fe and Ti increased around 383%, 348%, 303% and 267% than that without additive; spectral signal-to-background ratio increased about 204%, 149%, 150% and 142%; while the electron temperature and electron density of plasmas went up 10% and 13%, respectively.