Patent ID: 8942927
Filing Date: 2015-01-27
Classification: G01J,G01N

Abstract:
1. A method for quantitative analysis of the elemental composition of a material from a sample having a plurality of elements able to generate plasma and emit radiation, each element containing several constituents, the method comprising: heating the material from the sample to generate the plasma configured to emit the radiation; measuring the emitted radiation to obtain a spectrum; identifying, from the obtained spectrum, spectral lines of interest among spectral lines emitted by the constituents of each element of the heated sample; measuring intensities of the spectral lines of interest; estimating a temperature of the plasma; estimating an electron density of the plasma; estimating a dimension of the plasma along the direction of observation; calculating a chemical composition of the plasma from the temperature and the electron density values and values relating to the elemental concentrations of each element of the sample; calculating an absorption coefficient of the plasma at the spectral lines of interest; calculating a spectral radiance of the plasma; calculating a spectrum from the calculated chemical composition, the calculated absorption coefficient, and the calculated spectral radiance of the plasma; comparing the intensity and the shape of the calculated spectrum thus calculated with the intensity and the shape of the measured spectrum; iteratively repeating the calculation of the chemical composition, the calculation of the absorption coefficient, the calculation of spectral radiance, the calculation of the spectrum, and the comparison wherein the values of the temperature of the plasma, the electron density of the plasma, the dimension of the plasma, and the elemental concentrations being adjusted at each iteration until a difference is obtained between the intensity and the shape of the calculated spectrum and the intensity and the shape of the measured spectrum that is less than or equal, by absolute value, to a predetermined threshold value; and dividing the plasma into an increasing number of zones, when a minimum of the difference between the intensity and the shape of the calculated spectrum and the intensity and the shape of the measured spectrum is obtained, the minimum being greater, by absolute value, than the predetermined threshold value.