4 research outputs found
Cold Collisions in a Molecular Synchrotron
Ubachs, W.M.G. [Promotor]Bethlem, H.L. [Copromotor
Molecular Fountain
The resolution of any spectroscopic or interferometric experiment is
ultimately limited by the total time a particle is interrogated. We here
demonstrate the first molecular fountain, a development which permits hitherto
unattainably long interrogation times with molecules. In our experiments,
ammonia molecules are decelerated and cooled using electric fields, launched
upwards with a velocity between 1.4 and 1.9\,m/s and observed as they fall back
under gravity. A combination of quadrupole lenses and bunching elements is used
to shape the beam such that it has a large position spread and a small velocity
spread (corresponding to a transverse temperature of 10\,K and a
longitudinal temperature of 1\,K) when the molecules are in free fall,
while being strongly focused at the detection region. The molecules are in free
fall for up to 266\,milliseconds, making it possible to perform sub-Hz
measurements in molecular systems and paving the way for stringent tests of
fundamental physics theories
Investigating cooling and deceleration of SrF molecules
De begeleider en/of auteur heeft geen toestemming gegeven tot het openbaar maken van de scriptie.
The supervisor and/or the author did not authorize public publication of the thesis.
Femtosecond laser detection of Stark-decelerated and trapped methylfluoride molecules
We demonstrate deceleration and trapping of methylfluoride (CH3F) molecules in the low-field-seeking component of the J=1,K=1 state using a combination of a conventional Stark decelerator and a traveling wave decelerator. The methylfluoride molecules are detected by nonresonant multiphoton ionization using a femtosecond laser. Subsequent mass and velocity selection of the produced ions enables us to eliminate most background signal resulting from thermal gas in our vacuum chamber. This detection method can be applied to virtually any molecule, thereby enhancing the scope of molecules that can be Stark decelerated. Methylfluoride is so far the heaviest and most complex molecule that has been decelerated to rest. Typically we trap 2×104 CH3F molecules at a peak density of 4.5×107 cm-3 and a temperature of 40 mK