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PEstOE/FIS/UI0303/2011 PTDC/FIS/117606/2010 PTDC/FIS-AQM/31969/2017 UID/FIS/04559/2019 SFRH/BD/52332/2013 Contract No. EMMI HA-216 Hubert Curien PESSOA 38028UD PAUILF 2017-C08 Grant No. 01 3 0002 Grant No. ANR-06-BLAN-0223 Grant No. 70NANB15H051 We have measured the widths and energies of the 1s2s2p2P1/2,3/2→1s22s2S1/2 transitions in lithiumlike sulfur and argon, as well as the energies of the forbidden 1s2s2p4P5/2→1s22s2S1/2 M2 transition in both elements. All measurements were performed with a double-flat-crystal spectrometer without the use of any reference line. The transition energy measurements have accuracies ranging from 2.3 to 6.4 ppm depending on the element and line intensity. The widths and the intensity ratios of the 1s2s2p2P1/2,3/2→1s22s2S1/2 lines have also been measured. These are reference-free measurements of transitions in core-excited lithiumlike ions and have an accuracy comparable to the best relative measurements. We have also performed multiconfiguration Dirac-Fock calculations of the widths, energies, and intensity ratios. An extensive comparison between existing experimental results and theory is performed, and Bayesian techniques are employed to extract the energy of the 1s2p24P1/2→1s22p2P1/2 transition in sulfur and identify contaminant transitions. publishersversion published

Physical review / A covering atomic, molecular, and optical physics and quantum information 101(6), 062505 (2020). doi:10.1103/PhysRevA.101.062505, Published by Inst., Woodbury, NY

We have performed multi-configuration Dirac-Fock calculations of the transition energies in the transitions of 1s²2p²PJ-1s²2s²S1/2, J=1/2, 3/2, core-excited transitions of 1s2s2p²PJ-1s²2s²S1/2, J=1/2, 3/2 and 1s2s2p4PJ-1s²2s²S1/2, J=1/2, 3/2, 5/2, and Auger transition energies of 1s2s2p2PJ-1s2 1S0 and 1s2s2p4PJ- 1s2 1S0, J=1/2,3/2 in the lithium isoelectronic sequence for low- to high-Z ions (Z=10-96). Quantum-electrodynamic corrections with effective operator model and electronic correlation corrections are included in Dirac wave functions with finite nuclear size. All-order Breit and vacuum polarization corrections are also included in the calculation, with a fully optimized active set wavefunction. Extensive comparisons between existing theorical results and experiment are performed. We also evaluate nuclear parameters that minimize the weighted theory-experiment discrepancy in muonic 208Pb with two-parameter Fermi and three-parameter Gauss models. We obtain r=5.5057 fm in the Fermi model and r=5.5031 in Gauss model by polynomial-fitting. We also analyze the individual contributions of muonic 226Ra and 248Cm using the same prescription of exact QED correction for the upcoming experiments., Nous avons effectué des calculs Dirac-Fock multi-configuration des énergies de transitions de structure fine 1s²2p²PJ-1s²2s²S1/2, J=1/2, 3/2, les transitions à partir d'états excités en couche internes 1s2s2p²PJ-1s²2s²S1/2, J=1/2, 3/2 et 1s2s2p4PJ-1s²2s²S1/2, J=1/2, 3/2, 5/2, et les transitions Auger à partir de ces mêmes états 1s2s2p4PJ- 1s2 1S0, J=1/2, 3/2 dans la séquence isoélectronique du lithium, pour des ions de numéro atomique 10 ≤ Z ≤ 96. Des corrections électrodynamiques quantiques avec modèle d'opérateur efficace et des corrections de corrélation électronique sont incluses dans les fonctions d'onde de Dirac avec une taille nucléaire finie. Des corrections de polarisation de Breit et de polarisation du vide de tous les ordres sont également incluses dans le calcul, avec une fonction d'onde d'ensemble actif entièrement optimisée. Des comparaisons approfondies entre les résultats théoriques existants et l'expérience sont effectuées. Nous évaluons également les paramètres nucléaires qui minimisent l'écart pondéré entre la théorie et l'expérience dans les modèles muoniques 208Pb avec des modèles Fermi à deux paramètres et Gauss à trois paramètres. Nous avons obtenu r = 5.5057 fm dans le modèle de Fermi et r = 5.5031 dans le modèle de Gauss par ajustement polynomial. Nous analysons également les contributions individuelles de 226Ra et 248Cm muoniques en utilisant la même prescription de corrections exactes de QED pour les expériences à venir.

This research was supported in part by Projects No. PEstOE/FIS/UI0303/2011 and No. PTDC/FIS/117606/2010, and by research center Grant No. UID/FIS/04559/2013 (LIB-Phys), from FCT/MCTES/PIDDAC, Portugal. We acknowledge partial support from NIST (P.I.), from PESSOA Huber Curien Program No. 38028UD, and PAUILF Program No. 2017-C08. P.A., J.M., and M.G. acknowledge support from FCT under Contracts No. SFRH/BPD/92329/2013, No. SFRH/BD/52332/2013, and No. SFRH/BPD/92455/2013, respectively. Laboratoire Kastler Brossel (LKB) is "Unite Mixte de Recherche de Sorbonne Universite, de ENS-PSL Research University, du College de France et du CNRS No. 8552." P.I. is a member of the Allianz Program of the Helmholtz Association, Contract No. EMMI HA-216 "Extremes of Density and Temperature: Cosmic Matter in the Laboratory." The SIMPA ECRIS has been financed by grants from CNRS, MESR, and University Pierre and Marie Curie (now Sorbonne Universite). The experiment has been supported by BNM Grant No. 0130002 and ANR Grant No. ANR-06-BLAN-0223. We wish to thank Jean-Paul Desclaux for his help improving the MCDFGME code, and Dr. Martino Trassinelli (INSP) for valuable discussions and his help during early stages of the experiment. We performed a reference-free measurement of the transition energies of the 1s2p1P1→1s21S0 line in He-like argon, and of the 1s2s22p1P1→1s22s21S0 line in Be-like argon ions. The highly charged ions were produced in the plasma of an electron-cyclotron resonance ion source. Both energy measurements were performed with an accuracy better than 3 parts in 106, using a double flat-crystal spectrometer, without reference to any theoretical or experimental energy. The 1s2s22p1P1→1s22s21S0 transition measurement is the first reference-free measurement for this core-excited transition. The 1s2p1P1→1s21S0 transition measurement confirms recent measurement performed at the Heidelberg electron-beam ion trap. The width measurement in the He-like transition provides test of a purely radiative decay calculation. In the case of the Be-like argon transition, the width results from the sum of a radiative channel and three main Auger channels. We also performed multiconfiguration Dirac-Fock calculations of transition energies and rates and have done an extensive comparison with theory and other experimental data. For both measurements reported here, we find agreement with the most recent theoretical calculations within the combined theoretical and experimental uncertainties. publishersversion published