激光诱导击穿光谱（LIBS）用于煤化工（煤制烯烃、煤制油等）分析具有多元素同时快速分析的优势，但部分元素的检测限难以满足行业分析要求。本项目拟发展基于共心多径腔增强的多通池耦合正交双脉冲DP-LIBS微量元素分析技术，使激光能量充分作用于等离子羽，大幅提高LIBS分析灵敏度并降低检测限；同时，利用差分单色成像和空间分辨图像重构，研究初始和再激发等离子体中多电离态粒子的时空分布；利用平面矩阵光谱扫描和等离子体光谱层析，研究二次激发前后等离子体温度、电子密度和电离度的时空分布；基于多态粒子和等离子体特征参数的时空分布特性，分析激光与等离子体及粒子间的相互作用，形成预烧蚀与再加热的双脉冲LIBS共心多径腔增强机制理论。本项目方法和技术不仅为高灵敏、低检测限、高时空分辨的LIBS微量元素分析系统的实现开辟新的途径，而且为等离子体的光谱增强机制提供理论支撑。

Laser-induced breakdown spectroscopy (LIBS) can be applied to coal chemical industry (coal to olefins, coal to oil, etc.) with advantages of simultaneous and rapid multi-element analysis. However, the detection limits of some elements are difficult to meet the practical application requirements. This project is aimed to develop a multipass cell coupled orthogonal double-pulse LIBS (DP-LIBS) technology based on concentric multipass cavity enhancement to fully interact plasma plume with laser energy, so as to significantly improve the LIBS detection sensitivity and reduce the detection limits. The temporal and spatial distribution of multi-ionized particles in the initial and re-excited plasma will be studied by using the differential monochromatic imaging and the spatial-resolved image reconstruction. The temporal and spatial distribution of the temperature, electron density, and ionization degree before and after the second excitation will be studied by using the plane matrix spectra scanning and the plasma spectra chromatography. Based on the temporal and spatial distribution characteristics of multi-ionized particles and plasma parameters, we can analyze the interaction between laser, plasma and particles, and finally form the double-pulse LIBS concentric multipass cavity enhancement theory for both pre-ablation and reheating modes. The method and technology of this project not only open up a new way for the realization of microelement analysis LIBS system with high sensitivity, low detection limit, and high spatial and temporal resolution, but also provide a theoretical support for the spectra enhancement mechanism of plasma.