Hamburg 2009 – scientific programme

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MO: Fachverband Molekülphysik

MO 13: Molekülphysik Poster 1

MO 13.45: Poster

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

Stark decelerated SO₂ for dissociation and collision studies — •Oleg Bucicov¹, Eberhard Tiemann¹, and Christian Lisdat² — ¹Institut für Quantenoptik, Leibniz Universität Hannover — ²Physikalish-Technische Bundesanstalt, Braunschweig

We present a Stark decelerator for low-field-seeking states with 326 stages, with which we succeeded in decelerating SO₂ molecules to the velocity of about 50 m/s [1]. With this decelerator it should be possible to bring the relatively heavy SO₂ molecules to a standstill and to trap them electrostatically.

The state specific predissociation at the threshold of decelerated SO₂ molecules, prepared in a first excitation step using a frequency-doubled pulsed dye laser, results in producing cold SO and O fregments. The detection of the molecular fragment SO by means of the (1+1) REMPI technique using a second frequency-doubled pulsed dye laser makes it possible to measure the velocity distribution of the both photofragments.

Previous Stark-effect measurements [2] in our group showed that the dissociation process can be manipulated by an external electric field by shifting the dissociation asymptote relative to the predissociating level. In this way dissociation channels can be opened or closed at will or the velocity of the fragments can be tuned. These opportunities are very attractive for the field of cold molecules and cold chemistry.

[1] O. Bucicov, Eur. Phys. J. D 46 463 (2008).

[2] S. Jung, J. Phys. B 39 S1085 (2006).