Organic and inorganic materials analysis by Laser-Induced Breakdown Spectroscopy

摘要

The present study deals with calibration-free analysis of materials by Laser-Induced Breakdown Spectroscopy (LIBS). A numerical code computes the spectral radiance emitted from a plasma in local thermal equilibrium. The numerical code includes the calculation of the plasma composition by solving the system of Saha-equations, mass conservation and neutrality equation. The chemical reactions within the plasma plume are considered, especially in case of organic materials ablation. The line intensities are then computed. In the present study, the lines are considered to be optically thin. The modeling of the chemical composition of an organic material and a steel sample is presented. Comparing the experimental spectra to the computed ones, it was possible to measure the elemental concentrations of the steel with good accuracy without any requirement of preliminary calibration.