LIBS signals statistics for gated and time-integrated acquisition

Abstract

The impact of gating conditions, self-absorption effect and plasma temperature fluctuations on laser induced breakdown spectroscopy (LIBS) signals distribution functions have been studied in detail since analysis accuracy (error of concentration determination) and sensitivity (limits of detection) are defined by the analytical signal distribution function type. It was demonstrated that both time-resolved and time-integrated atomic line plasma emission signals should be described by the Fréchet distribution function while molecular emission signal corresponded to a normal distribution. The self-absorption effect had a moderate impact on the LIBS signals statistics but did not qualitatively change the results. Plasma temperature fluctuations were normally distributed, but these couldn't explain the observed Fréchet distribution of the LIBS signals.