Time-resolved fine structure mixing of cesium induced by helium and argon
Document Type
Article
Publication Date
10-31-2017
Abstract
The rates for fine structure mixing and quenching of the moderately excited 82D5/2 and 82D3/2 states of cesium under collision with argon and the more impulsive helium have been measured, using two-photon pulsed excitation and time-resolved fluorescence techniques. The pressure dependence of the eigenvalues of the rate matrix yields very rapid rate coefficients of 2.6 ± 0.2 × 10-9 cm3/(atom s) for He and 5.2 ± 0.4 × 10-10 cm3/(atom s) for Ar, about two-three times faster than for the Cs 72D5/2 ⇌ 72D3/2 relaxation. The quenching rates are also rapid, 1.07 ± 0.04 × 10-10 cm3/(atom s) and 9.5 ± 0.7 × 10-11 cm3/(atom s) for He and Ar respectively. The rapid fine structure rates are explained by the highly impulsive nature of the collisions, and the large average distance of the valence electron from the nucleus. Quenching rates (intra-multiplet transfer) are likely enhanced by the closely spaced, 92P levels. The observed rates are compared with the predictions from time-dependent perturbation theory.
Source Publication
Journal of Physics B: Atomic, Molecular and Optical Physics
Recommended Citation
Davila, R. C., Perram, G. P., & Eshel, B. (2017). Time-resolved fine structure mixing of cesium induced by helium and argon. Journal of Physics B: Atomic, Molecular and Optical Physics, 50(22), 225204. https://doi.org/10.1088/1361-6455/aa8da4
Comments
© 2017 IOP Publishing Ltd
This article is available from The Institute of Physics (IOP), through subscription or purchase using the DOI link below.
Co-author Ben Eshel was also affiliated with the Oak Ridge Institute for Science and Education (ORISE) at the time of publication.