| 摘要 |
A system and method for measuring elemental concentrations of a material from a sample containing several elements by LIBS analysis. The material is heated to generate plasma and its chemical composition is determined from spectral analysis of its radiation. The spectral lines of interest are identified among those emitted by the constituents of each element composing sample. The intensities of the spectral lined identified are measured. From an estimate of temperature, electron density and relative concentration values, the chemical composition of the plasma is calculated. The absorption coefficient according to wavelength is calculated for the spectral zones of the lines of interest. From an estimate of the plasma width, the spectral radiance of the plasma is calculated for the same spectral zones and then a comparison of the intensity and shape of the spectrum thus calculated with those of the spectrum measured is performed. These calculations and this comparison are repeated iteratively in order to adjust the temperature, electron density, relative values of the elemental concentrations and width of the plasma. |
