Berlin 2005 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 38: Fallen & Kühlung I
Q 38.7: Vortrag
Dienstag, 8. März 2005, 12:45–13:00, HU 2002
Collisions in a cloud of cold metastable neon atoms — •Wouter van Drunen, Norbert Herschbach, Peter Spoden, Martin Zinner, Wolfgang Ertmer, and Gerhard Birkl — Institut für Quantenoptik, Universität Hannover, Welfengarten 1, D-30167 Hannover, Germany
We report on the experimental investigation of
elastic and inelastic collisions of 20Ne and 22Ne
in the metastable 3s[3/2]2-state, which
is of crucial importance for creating ensembles of high phase space densities.
We investigate elastic collisions
by observing the cross-dimensional relaxation of ensembles prepared in a
non-equilibrium state.
We present measured relaxation rates
and an analysis for the extraction of the scattering length.
Inelastic collision rates of spin-polarized atoms in the magnetic trap
are determined from atom loss and heating rates.
These collisions predominantly originate from Penning ionization (PI), as we could verify
by detecting the produced ions on an MCP detector.
Both neon isotopes show a suppression of PI due to spin-polarization.
This effect, however, is less pronounced than predicted theoretically.
Due to a larger ratio of elastic to inelastic collisions, 22Ne is better suited for
evaporative cooling than 20Ne.
Experiments on the evaporation of 22Ne are in progress
and an increase in phase space density
has already been observed.