Hannover 2016 – wissenschaftliches Programm
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K: Fachverband Kurzzeitphysik
K 3: Laser Applications and Laser Matter Interactions I
K 3.1: Hauptvortrag
Dienstag, 1. März 2016, 14:30–15:10, f428
Vibrational-rotational and electronic temperatures in laser induced plasma of polyethylene determined by optical emission spectroscopy — •Johannes Heitz1, Juraj Jasik3, Johannes D. Pedarnig1, and Pavel Veis2 — 1Institute of Applied Physics, Johannes Kepler University Linz, Austria — 2Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia — 3Department of Organic Chemistry, Charles University in Prague, Czech Republic
Laser-induced breakdown spectroscopy (LIBS) of polyethylene (PE) is investigated employing vacuum ultraviolet (VUV) laser ablation in argon or nitrogen gas background and optical detection from VUV to visible (VIS) spectral range. In the VUV range (wavelength 115 to 200 nm), strong atomic emission lines of carbon are detected by using a homemade VUV spectrometer equipped with gated photon counter. In the VIS range, intense molecular emissions, C2 Swan and CN violet bands, are measured with an Echelle spectrometer equipped with an intensified CCD camera. Measured molecular emission spectra (C2 Swan and CN violet bands) are fitted by vibrational-rotational transitions and good agreement of measured and fitted spectra is achieved. The vibrational-rotational temperatures are determined from fits. From the atomic line intensities and molecular band intensities, we conclude that there are systematic differences of the various temperatures. These differences can be related to different locations of the atomic and molecular species in the expanding plasma plume.