Transition Energies of the D-lines in Na-like Ions
John D. Gillaspy, Dmitry D. Osin, Yuri Ralchenko, Joseph Reader, S A. Blundell
The NIST electron beam ion trap (EBIT) was used to measure the D1 (3s-3p1/2) and D2 (3s-3p3/2) transitions in Na-like ions of xenon, barium, samarium, gadolinium, dysprosium, erbium, tungsten, platinum, and bismuth. New relativistic many-body perturbation theory calculations were carried out for the D1 and D2 lines for every element in the isoelectronic sequence from argon (Z=18) to uranium (Z=92), taking into account some higher order terms in the QED expansion. Uncertainties in the calculated values were carefully assessed by considering the uncertainties in the various contributions to the total calculated transition energies. We conclude that at the current level of accuracy, the calculated values can be taken to reliably represent the isoelectronic sequence from Z=18 to 92. The agreement of theory and experiment for the D1 line of bismuth (Z=83) provides a test of quantum electrodynamics (QED) at the level of 0.4%. This is the most sensitive test that we are aware of for QED in highly charged Na-like ions. It is also sensitive to retardation effects due to the finite speed of light and to variations in the assumed nuclear size.
, Osin, D.
, Ralchenko, Y.
, Reader, J.
and Blundell, S.
Transition Energies of the D-lines in Na-like Ions, Physical Review A, [online], https://doi.org/10.1103/PhysRevA.87.062503
(Accessed May 7, 2021)