Hannover 2010 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 2: Diagnostics

P 2.6: Vortrag

Montag, 8. März 2010, 15:25–15:40, B 305

Influence of the DC-Stark Effect on the Interpretation of Laser-Induced Breakdown Spectroscopy — •Waldemar Hübert, Peter Kohns, and Georg Ankerhold — RheinAhrCampus, University of Applied Sciences Koblenz, Südallee 2, 53424 Remagen, GERMANY

A serious drawback of laser-induced breakdown spectroscopy (LIBS) are line broadening and line shifting effects which often prevent the elemental identification of an unknown sample. By determining the temporal dependency of several plasma parameters like the plasma particle density, plasma temperature and the volume of the plasma cloud we show that the DC-Stark effect is the predominant cause for line broadening and line shifting. The DC-Stark effect strongly depends on the free charge carrier density inside the laser-generated micro-plasma which in turn decreases over the time as the plasma expands and the carriers recombine. These observations lead to suggestions for improved automatic LIBS software promising a smaller probability of wrong elemental identification and making LIBS more attractive for industrial applications.