项目名称： 基于激光诱导光学薄等离子体煤质精密分析研究

项目编号： No.61475093

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 尹王保

作者单位： 山西大学

项目金额： 85万元

中文摘要： 利用激光诱导击穿光谱对物质成分进行定量分析是光谱分析领域一种崭新的分析手段和热点。但在用该技术分析微量元素(如煤中次主要元素)的实践中，通过利用等离子体局部热平衡态理论及优化分析算法等传统的方法和措施，其分析精密度仍达不到要求，这成为制约该技术推广应用的关键问题。本项目拟在局部热平衡态条件下，基于等离子体光学薄的物理本质，通过研究激光诱导等离子体动力学过程，确定同一（或接近）上能级的原子（离子）在往不同的下能级跃迁时各自的辐射谱线参数比值与相对应的等离子体参数比值之间的关系。此关系中不包含无法确定的物理参数和设备采集参数，因而便于作为光学薄的实验判据，由此确定一个最佳延迟时间进行光谱数据采集，在获得最佳光谱数据的基础上计算各能态原子数总和，据此反演元素含量，这从物理本质上解决了影响LIBS定量分析精密度的瓶颈问题。该成果同样可应用在地矿、环保、医药、材料、考古、食品安全、生化及冶金等领域。

中文关键词： 光谱学；激光诱导击穿光谱；光学薄等离子体；元素分析；高精密度

英文摘要： The quantitative analysis for the material composition employing laser-induced breakdown spectroscopy is a new analysis method and hot spots in spectral analysis field.However, with the technical analysis of trace elements ( such as minor elements in coal ) in practice, through the use of local thermal equilibrium plasma theory and optimization analysis algorithm and other traditional methods and measures , the analysis accuracy is still below standard, which become a key issue of restricting the promotion and application of technology.The project will consider two emission lines having the same upper level(or as close as possible), the temperature effect of the Boltzmann factor on the reproducibility of the line intensity ratio is minimized and at the same time the consideration of the effciency factor of the collecting system is avoided. Neglecting the exponential factor in that condition, we can find out the theoretical value of the intensity ratio of the two lines by using the atomic parameters of the transitions. By matching this ratio with the measured values at different delay times, we find out the time window where the plasma is optically thin. The concentrations of the elements are determined by matching theoretically obtained values of electron density and relative number densities of the neutral and ionization energy states of specie element with the experimentally determined using the spectral line intensities in a time window where the LIBS plasma is optically thin and in LTE.It solves the bottleneck problems that affect the precision of the LIBS quantitative analysis from the physical nature.We hope that the results can be applied in mining,environmental protection, medicine,materials,archeology,food safety,biochemical and metallurgy and other fields.

英文关键词： Spectroscopy;Laser-induced breakdown spectroscopy;Optically thin plasma;Elemental analysis;High Precision