Berlin 2005 – wissenschaftliches Programm
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MO: Molekülphysik
MO 32: Scattering and Energy Transfer
MO 32.2: Vortrag
Montag, 7. März 2005, 11:00–11:15, HU 2097
Reactive scattering of Li from HF and (HF)2 — •Rolf Bobbenkamp and Hansjürgen Loesch — Fakultät für Physik, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld
In a crossed molecular beam study we have measured angular distributions (ADs) and time-of-flight (TOF) distributions of products formed in the collision Li+(HF)2. The surface ionization detector used to measure the product flux is not specific with respect to Li atoms or Li compounds. However, shape and position of both the ADs and the TOF distributions suggest that the observed particle flux is due to the reaction product LiFHF. Other products such as deeply inelastic scattered Li atoms or products from higher oligomers are possible but very unlikely. A preliminary analysis of the data shows that the products are strongly backward scattered in the centre-of-mass frame with nearly maximal energy release into the translational degree of freedom.
By reducing the intersection angle between the reagent beams we have lowered the collision energy of the process Li+HF→LiF+H to the unprecedented value of 42 meV [1]. We observe still significant product flux and thus found no indication yet for the existence of a reaction threshold. We will report also the results obtained at 30 meV and the differential reaction cross sections deduced from the ADs and TOF distributions of LiF.
[1] O. Höbel, M. Menéndez and H.J. Loesch, Phys. Chem. Chem. Phys. 3, 3633-3637 (2001)