Düsseldorf 2007 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 20: Plasma-Wand-Wechselwirkung
P 20.5: Vortrag
Donnerstag, 22. März 2007, 15:45–16:00, 6C
Rovibrationally excited H2 production in expanding thermal plasmas — •Onno Gabriel1, Peter Vankan2, Daan Schram1, and Richard Engeln1 — 1Department of Applied Physics, Plasma & Materials Processing, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven, The Netherlands — 2present address: Philips Lighting, Central Development Lighting, P.O.Box 80020, 5600 JM Eindhoven, The Netherlands
Plasma surface interactions are recognized to play a dominant role in the chemical kinetics of plasmas. Ions and radicals from the plasma gas phase recombine at surfaces producing new molecules. For example rovibrationally excited H2 molecules (H2rv) can be formed at surfaces under circumstances, where a volume production mechanism is much less efficient. The extra energy content of these excited molecules enhances several plasma chemical processes, like the H− formation in dissociative attachment reactions, and is hence important for the understanding of processes in this kind of plasmas. We investigate an expanding thermal hydrogen plasma by means of VUV LIF spectroscopy and measure the rovibrational energy levels in the electronic ground state of H2. The exact mechanism of the production of rovibrational excited molecules is still not clarified yet. Therefore, we measure the distribution of H2rv after the collision of the plasma jet with different surface materials. We want to show that H2rv is a product of surface association processes, and that its energy distribution reveals information on the surface process itself.