Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MO: Molekülphysik

MO 55: Poster: Collisions and Energy Transfer

MO 55.1: Poster

Donnerstag, 16. März 2006, 16:30–18:30, Labsaal

Crossed-beam imaging of ion-molecule reaction dynamics — •J. Mikosch^1,2, S. Trippel¹, R. Berhane¹, R. Otto¹, D. Schwalm², M. Weidemüller¹, and R. Wester¹ — ¹Physikalisches Institut, Universität Freiburg, 79104 Freiburg — ²Max-Planck-Institut für Kernphysik, 69117 Heidelberg

We present a new ion-molecule crossed-beam experiment with a velocity map imaging detector [1], which allows for kinematically complete studies of ion-molecule reactions at very low relative collision energies (<1 eV). With this system we aim at an improved understanding of the quantum dynamics of fundamental anion-molecule reactions, a model system being the nucleophilic substitution reaction Cl⁻ + CH₃I—→ I⁻ + CH₃Cl [2]. We are particularly interested in the vibrational state-to-state reaction dynamics and the relevance of spectator modes on the cross section [3]. Furthermore, experiments with laser-aligned molecules are projected, which open the possibility to study reactive scattering in strong laser fields.

To unravel the kinetic energy and angular distributions from measured images we have set up a Monte Carlo reconstruction algorithm. As an experimental benchmark we have studied the charge transfer reaction Ar⁺ + N₂ —→ Ar + N₂⁺.

[1] A. T. J. B. Eppink and D. H. Parker, Rev. Sci. Instrum. 68, 3477 (1997) [2] L. Sun, K. Song, W. Hase, Science 296, 875 (2002) [3] C. Hennig and S. Schmatz, Phys. Chem. Chem. Phys. 7, 1100 (2005)