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Theme 1 colloquium: “Toying with molecules; ammonia molecules in a fountain and synchrotron” (Lecture)

Tuesday 9 January 2018Add to my calendar
from 16:00
dr Hendrick Bethlem (VU Amsterdam)
"Toying with molecules; ammonia molecules in a fountain and synchrotron”

Hendrick Bethlem jan2018We use electric fields to cool and manipulate polar molecules and use these cold molecules to perform precision tests and collisions studies. I will present two experiments; in the first experiment we let beams of argon atoms collide with ammonia molecules that are stored in a synchrotron. Using a synchrotron has the advantage that the collision partners move in the same direction, resulting in a low collision energy. Furthermore,  by storing molecules many roundtrips the sensitivity to collisions is greatly enhanced [1]. In the second experiment beams of ammonia molecules are decelerated, trapped, cooled and subsequently launched upwards with a velocity between 1.4 and 1.9 m/s. Molecules with this speed will fly up 60-180 mm before falling back under gravity. We have demonstrated field-free interaction times up to 266 millisecond, two orders of magnitude longer than has been achieved with molecular beams [2]. Finally, I will discuss a new project, conducted in collaboration with the University of Groningen, to cool barium-fluoride molecules and use these to search for the electric dipole moment of the electron which is a sensitive probe for physics beyond the standard model.


[1] Cold Collisions in a Molecular Synchrotron, A.P.P. van der Poel, P.C. Zieger, S.Y.T. van de Meerakker, J. Loreau,  A. van der Avoird, and H.L. Bethlem, arXiv1706.10236

[2] Molecular Fountain, C. Cheng,  A.P.P. van der Poel, P. Jansen, M. Quintero-Pérez, T.E. Wall, W. Ubachs, and H.L. Bethlem, Phys. Rev. Lett. 117, 253201 (2016).