If you are longing for a good scientific talk - in these times - here is an opportunity. Professor Bas van de Meerakker, Radboud University is giving a seminar on Thursday Nov 19 starting at 13:15. The title is (abstract is attached): Cold and controlled collisions using tamed molecular beams The seminar is a special lecture for the class Reaction Dynamics and will contain a thorough introduction to the research field and methodologies. The duration is 2 x 45 min with a 15 min break in between. Join Zoom Meeting https://aarhusuniversity.zoom.us/j/61016970097 Topic: Bas van de Meerakker - Seminar Time: Nov 19, 2020 01:00 PM Copenhagen Join Zoom Meeting https://aarhusuniversity.zoom.us/j/61016970097 Meeting ID: 610 1697 0097 Join by SIP 61016970097@109.105.112.236<mailto:61016970097@109.105.112.236> 61016970097@109.105.112.235<mailto:61016970097@109.105.112.235> Join by H.323 109.105.112.236 109.105.112.235 Meeting ID: 610 1697 0097 Cold and controlled collisions using tamed molecular beams Sebastiaan Y.T. van de Meerakker Radboud University, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands The study of molecular collisions with the highest possible detail has been an important research theme in physical chemistry for decades. Experimentally, the level of detail obtained in these studies depends on the quality of preparation of the collision partners before the collision, and on how accurately the products are analyzed afterward. Over the last years, methods have been developed to get improved control over molecules in a molecular beam. With the Stark decelerator, a part of a molecular beam can be selected to produce bunches of molecules with a computer-controlled velocity and with longitudinal temperatures as low as a few mK [1]. The molecular packets that emerge from the decelerator have small spatial and angular spreads, and have almost perfect quantum state purity. These tamed molecular beams are excellent starting points for high-resolution crossed beam scattering experiments. I will illustrate the possibilities this new technology offers to study molecular collisions with unprecedented precision. I will discuss our most recent results on the combination of Stark deceleration and velocity map imaging. The narrow velocity spread of Stark-decelerated beams results in scattering images with an unprecedented sharpness and angular resolution. This has facilitated the observation of diffraction oscillations in the state-to-state differential cross sections for collisions of NO with rare gas atoms [2,3], the observation of scattering resonances at low-energy inelastic [4-6] collisions that reveal the influence of individual partial waves to the scattering dynamics, and product-pair correlations for bimolecular scattering processes [7]. Finally, I will present a new Zeeman decelerator, the magnetic analogue of the Stark decelerator, which we specifically developed for applications in crossed beam experiments [8]. [1] H.L. Bethlem et al., Phys. Rev. Lett.83, 1558 (1999) [2] A. von Zastrow et al., Nature Chemistry 6, 216 (2014) [3] J. Onvlee et al., Nature Chemistry9, 226 (2017) [4] S. Vogels et al., Science 350, 787 (2015) [5] S. Vogels et al., Nature Chemistry10, 435 (2018) [6] T. de Jongh et al., Science 368, 626 (2020) [7] Z. Gao et al., Nature Chemistry 10, 469 (2018) [8] T. Cremers et al., Phys. Rev. A 95, 043415 (2017) Henrik Stapelfeldt, Villum Investigator Professor, dr. scient. Department of Chemistry Aarhus University DK-8000 Aarhus C, Denmark Telephone: (45) 871 55974