Influence of laser beam focusing on LIBS efficiency at the elemental analysis of metals

摘要

Efficiency of the Laser-Induced Breakdown Spectroscopy (LIBS) has been studied as applied to the development of a technique for elemental microanalysis of solid samples, when a rather low consumption of the sample material is demanded allowing the technique to be practically non-destructive and applicable, e.g., at art, archaeological, forensic and similar investigations of unique objects. Higher intensity of the laser-induced emission spectra at lower sample erosion result in the increased efficiency of the LIBS analysis. The efficiency depends on many factors and in particular on thermal properties of the sample material and on its excitation conditions. Here, an influence of the laser beam focusing has been studied for samples of Al and Pb alloys having different thermal properties.