Hannover 2010 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

MO: Fachverband Molekülphysik

MO 28: Poster: Cold Molecules

MO 28.1: Poster

Thursday, March 11, 2010, 16:00–18:30, Lichthof

Cold molecular anions in a multipole rf trap — •Rico Otto, Petr Hlavenka, Thorsten Best, Sebastian Trippel, Martin Stei, and Roland Wester — Physikalisches Institut, Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg

When studying interaction processes of trapped cold anions only few quantum states of the investigated systems are populated. Energies on the scale of rotational levels become dominant at temperatures of only a few Kelvin. We study slow collisions [1] and laser induced processes of cold anions in a 22pole radio frequency trap. Near threshold photodetachment serves as a tool to determine internal temperatures of molecular ions. A novel laser depletion tomography method allows us to measure absolute photodetachment cross sections of trapped ions with high accuracy [2]. For O⁻, a calibration standard system for photodetachment, we found a significant deviation from ab initio calculations. The OH⁻ photodetachment cross section showed no temperature dependence in the range between 8 - 300K [3]. Using this 2D tomography technique we are able to image the distribution of trapped ions inside the 22pole trap. This reveals unexpected information on the structure of the trapping potential [4].
R. Otto et al., Phys. Rev. Lett. 101, 063201 (2008)
S. Trippel et al., Phys. Rev. Lett. 97, 193003 (2006)
P. Hlavenka et al., J. Chem. Phys. 130, 061105 (2009)
R. Otto et al., J. Phys. B 42, 154007 (2009)