The Intrabeam apparatus, designed by Chandika Amarasinghe, is our newest instrument. It is an imaging machine directed to studying cold collisions in which quantum phenomena dominate. We recently obtained the first differential cross section measurements for rotationally and electronically inelastic collisions of highly vibrationally excited NO with argon down to 2 cm-1 collision energy. It is the focal point of our current ARO-MURI effort "Quantum State Contolled Molecular Collision Dynamics".
We achieve short pulse, high speed-ratio supersonic beams from a home built stack valve and a high-speed chopper. These short pulses reduce the local velocity spread due to the correlation in velocity-position space in the free propagation of supersonic beams. In the current configuration these are combined with nearly co-propagating beams and SEP-prepared NO(v=10,j) for state-to-state collision studies.
C. Amarasinghe, H. Li, C. A. Perera, M. Besemer, A. van der Avoird, G. C. Groenenboom, J. Zuo, C. Xie, H. Guo, J. Kłos and A. G. Suits1* “State-to-state scattering of highly vibrationally excited NO at broadly tunable energies,” Nature Chem. (2020) DOI: 10.1038/s41557-020-0466-8.
C. Amarasinghe, C. Perera and A. G. Suits, “A Versatile Molecular Beam Apparatus for Cold/Ultracold Collisions,” J. Chem. Phys. (2020) 152, 0007382, DOI: 10.1063/5.0007382
C. Amarasinghe and A. G. Suits, “Intrabeam Scattering for Ultracold Collisions,” J. Phys. Chem. Lett. (2017) 8, 5153-5159 DOI:10.1021/acs.jpclett.7b02378.
C. Amarasinghe, H. Li, C. A. Perera, M. Besemer, A. van der Avoird, G. C. Groenenboom, C. Xie, H. Guo, and A. G. Suits*, J. Phys. Chem. Lett. 2019, 10, 10, 2422-2427. DOI: 10.1021/acs.jpclett.9b00847