Determination of the Stark broadening coefficients of tantalum emission lines by time-independent Extended C-sigma method

In this paper we introduce a new time-independent Extended C-sigma approach for the analysis of Laser Induced Breakdown Spectroscopy (LIBS) spectra and apply it to the determination of the Stark broadening coefficient of several neutral and ionic emission lines of tantalum. The method proposed is based on the recently introduced Extended C-sigma procedure and exploits the spectral information extracted from LIBS spectra acquired at different delay times after the laser pulse for building a time-independent Extended C-sigma curve. The method intrinsically includes in the calculation the effects of self-absorption, which is one of the main sources of indetermination in LIBS applications to the determination of spectroscopic fundamental parameters, such as transition probabilities and Stark broadening coefficients.