Hamburg 2009 – scientific programme

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MO: Fachverband Molekülphysik

MO 13: Molekülphysik Poster 1

MO 13.46: Poster

Tuesday, March 3, 2009, 16:30–19:00, VMP 8 Foyer

Collisional effects in the formation of cold guided beams of polar molecules — Michael Motsch, Christian Sommer, Laurens D. van Buuren, Martin Zeppenfeld, •Pepijn W.H. Pinkse, and Gerhard Rempe — Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany

Electric guiding and velocity filtering produces high fluxes of cold polar molecules [1]. Here, we investigate different aspects of the beam formation. Variation of gas density and, to a lesser extend, temperature in the source results in characteristic changes in the guided beam. These are observed in the velocity distribution of the guided molecules as well as in characteristic electrode voltage dependencies. The behaviour can be understood by taking into account velocity-dependent collisional losses of cold molecules in and near the nozzle. The description including collisional effects clarifies the parameter dependence of the detected signal as measured by a quadrupole mass spectrometer and provides a more detailed understanding of the velocity filtering and guiding process [2].

[1] T. Junglen et al., Eur. Phys. J. D 31, 365 (2004)

[2] M. Motsch et al., ArXiv:0812.2850