Effect of Plasma Gas and the Pressure on Spatially and Temporally Resolved Images of Copper Emission Lines in Laser Induced Plasma Optical Emission Spectrometry

This paper investigated two-dimensional spatial and temporal images of a copper emission line in laser-induced breakdown spectroscopy (LIBS), order to clarify the excitation/de-excitation processes occurring plasma. The measurements were carried out under different plasma gases (argon, krypton, helium, nitrogen), pressure levels (100 – 900 Pa) delay times 1000 ns) with aim monitoring their effects on behavior emission. Depending gas type level, large differences found shape intensity evolution profile. Namely, krypton produced most compact emitting larger intensities, compared argon an increase made these plasmas shrink, which could be related principally stopping power applied gases. Through temporally resolved analysis, profiles obtained for each gas, indicating that helium disappeared more rapidly than plasmas. It was suggested variations would determined by interactions between particles highly energetic as well excited species during expansion. These insights prove useful understanding background LIBS optimization its practical applications.