QUANTITATIVE ANALYSIS METHOD FOR ANALYZING THE ELEMENTAL COMPOSITION OF MATERIALS BY MEANS OF LIBS TECHNIQUE

摘要

The quantitative analysis method for analyzing the composition of materials of the invention is based on a functional relationship (curve Cσ) between line intensity and the concentration of the element in the material. The method comprises: obtaining characteristic parameters, selecting the spectral lines of neutral atoms and ions of the elements of interest, obtaining their atomic data; calculating, for the selected lines, a line crosssection; measuring line intensities; determining the concentrations of the elements of interest by means of fitting two graphs Cσ, one for neutral atoms and another for ions with a unit charge, the fitting being performed by means of an iterative algorithm which compares the experimental graphs with the curves Cσ calculated with a plasma model; calculating, for the data of the graphs Cσ, the product of line optical depth by Lorentzian width; evaluating, for the data of the graphs Cσ, a condition on the validity limit of the model, the datum for which the mentioned product is greater being eliminated if the condition is not complied with; repeating the three preceding steps until all data comply with the mentioned condition. The invention has the advantage of not requiring prior calibrations.