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Laser Spectroscopy of the y7PJo states of Cr I



Eric Norrgard, Daniel Barker, Stephen Eckel, Sergey Porsev, Charles Cheung, Mikhail Kozlov, Ilya Tupitsyn, Marianna Safronova


Here we report measured and calculated values of decay rates of the 3d$^4$($^5$D)4s4p($^3$P$^\rmo}}$)\ y$^7$P$^\rmo}}_2,3,4}$ states of Cr I. The decay rates are measured using time-correlated single photon counting with roughly 1\,\% total uncertainty. In addition, the isotope shifts for these transitions are measured by laser induced fluorescence to roughly 0.5\,\% uncertainty. The decay rate calculations are carried out by a hybrid approach that combines configuration interaction and the linearized coupled cluster method (CI+all-order method). The measurements provide a much needed precision benchmark for testing the accuracy of the CI+all-order approach for such complicated systems with six valence electrons, allowing to significantly expand its applicability. These measurements also demonstrate operation of a cryogenic buffer gas beam source for future experiments with MgF molecules toward quantum blackbody thermometry.
Physical Review A


spectroscopy, laser, fluorescence, decay rate, lifetime, configuration interaction, coupled cluster, cryogenic buffer gas beam


Norrgard, E. , Barker, D. , Eckel, S. , Porsev, S. , Cheung, C. , Kozlov, M. , Tupitsyn, I. and Safronova, M. (2022), Laser Spectroscopy of the y7PJo states of Cr I, Physical Review A, [online],, (Accessed February 24, 2024)
Created March 16, 2022, Updated November 29, 2022