Mechanistic studies of laser-induced spectroscopy of model

摘要

We examine a number of factors which influence the use of laser-induced breakdown spectroscopy (LIBS) to detect the cation content of physical mixtures of Eu_2O_3 and K_2Cr_2O_7 with granular, crystalline SiO_2. Excitation of the powdered specimens isby focused KrF excimer laser light (248 nm, 30 ns pulse width, fluence/pulse 0.3-30 J cm~(-2), irradiance 10-1000 Mw cm~(-2)) in 1 aim air. We -discuss the resulting time resolved UV/vis .spectra of the plasma, the parameters and physical effects whichinfluence the detection of impurities and examine the consequences of the piesence of water In the samples together with variations in the sample morphology. We also present preliminary results on spectra from mixtures of these compounds with a basalticsoil.