Berlin 2005 – wissenschaftliches Programm
SYCM 1.4: Hauptvortrag
Samstag, 5. März 2005, 12:45–13:15, HU Audimax
Manipulation of polar molecules with electric fields — •Gerard Meijer — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, Berlin, Germany
In this presentation I will give an overview of the various experiments that we have performed during the last few years to explore the possibilities of manipulating neutral polar molecules with electric fields. Arrays of time-varying, inhomogeneous electric fields have been used to reduce in a stepwise fashion the forward velocity of molecules in a beam. With this so-called ’Stark decelerator’, the equivalent of a LINear ACcelerator (LINAC) for charged particles, one can transfer the high phase-space density that is present in the moving frame of a pulsed molecular beam to a reference frame at any desired velocity; molecular beams with a computer-controlled (calibrated) velocity and with a narrow velocity distribution, corresponding to sub-mK longitudinal temperatures, can be produced. These decelerated beams offer new possibilities for collision studies, for instance, and enable spectroscopic studies with an improved spectral resolution. These decelerated beams have been used to load ND3 molecules and OH radicals in an electrostatic trap at a density of (better than) 107 mol/cm3 and at temperatures of around 50 mK. Ground-state ND3 molecules have been trapped in a novel AC electric field trap, slow beams of ND3 molecules have been injected in an electrostatic storage ring, and, using microstructured electrode arrays, a switchable mirror for neutral molecules has been constructed and tested. The variety of schemes that we are pursuing to further increase the phase-space density of the trapped molecules will be discussed.