The Temporal Evolution of the Boltzmann Plot as a Tool for the Characterization of Plasma Generated by Laser

FAUSTO O BREDICE; MAYO VILLAGRÁN-MUNIZ; C SÁNCHEZ-AKÉ

Simposio; 9th Euro-Mediterranean Symposium on LIBS; 2017

In transient thin plasmas assumed in LTE condition such as LIP, the slope of the Boltzmann plot varies with time depending on the experimental conditions in which the plasma was generated. The variation in time of the Boltzmann plot describes a surface in the space defined by the coordinates X= Energy, Y=Time and Z= ln (Ij/gjAjl), where Ij is the integrated intensity of the spectral line, gj is the statistical weight of the level j and Ajl is the transition probability of the considered line, so if we know several points corresponding to that plane, it is possible to predict the value of another unknown point. The aim of this work is to represent the time evolution of the intensities of the spectral lines through a reduced number of constants B1, B, ... Bs and therefore the temporal evolution of the plasma temperature. From the comparison between the polynomials corresponding to different spectral lines which belong to the same ion under analysis, it is possible to determine whether they are useful for Boltzmann plots by a simpler procedure than others, and if their superior energy levels have been properly assigned.