Relativistic all-order many-body calculations of the<i>n</i>=1 and<i>n</i>=2 states of heliumlike ions

Plante, D. R.; Johnson, W. R.; Sapirstein, J.

doi:10.1103/physreva.49.3519

Cited by 236 publications

(256 citation statements)

References 60 publications

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“…For the heliumlike transition energies the values calculated by Drake using the unified method are taken as a reference [48]. The 0 values were calculated by Plante et al [49] summing all-orders of many-body perturbation theory (MBPT). The o's represent the values obtained by Cheng et al and Chen et al [50,51] applying relativistic configuration interaction (CI) calculations combined with ab initio QED calculations.…”

Section: Discussionmentioning

confidence: 99%

High–resolution measurements of the K-shell spectral lines of hydrogenlike and heliumlike xenon

Widmann

Beiersdörfer

Brown

et al. 2000

AIP Conference Proceedings

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Abstract.With the implementation of a transmission-type curved crystal spectrometer at the Livermore high-energy electron beam ion trap (SuperEBIT) the window on sub-eV level measurements of the ground-state quantum electrodynamics and the twoelectron quantum electrodynamics of high-Z ions has been opened. High-resolution spectroscopic measurements of the Kcr spectra of hydrogenlike Xe53+ and heliumlike Xe52+ are presented. The electron-impact excitation cross sections have been determined relative to the radiative recombination cross sections. The electron-impact energy was 112 keV which is about 3.7 times the excitation threshold for the n = 2 -+ 1 transitions. Although the relative uncertainties of the measured electron-impact excitation cross sections range from about 20% to 50% , significant disagreement between the measured and calculated cross section values has been found for one of the heliumlike xenon lines. Overall, the comparison between experiment and theory shows that already for xenon (Z=54) the Breit interaction plays a significant part in the collisional excitation process. The measured cross sections for the hydrogenlike transitions are in good agreement with theoretical predictions. Additionally, the Xe53+ Ly-or transition energy has been measured utilizing the Kcr emission of neutral cesium and barium for calibration. Surprisingly, the experimental result, (31279.2 f. 1.5) eV, disagrees with the widely accepted theoretically predicted value of (31283.77 f 0.09) eV. However, this disagreement does not (yet) call for any correction in respect to the theoretical values for the transition energies of the hydrogenlike isoelectronic sequence. It rather emphasizes the need for a reevaluation of the commonly used x-ray wavelengths table for atomic inner-hell transitions, in particular, for the cesium KQ lines. r) Email: widmannl@llnl.gov. 2, Present address:

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Section: Discussionmentioning

confidence: 99%

High–resolution measurements of the K-shell spectral lines of hydrogenlike and heliumlike xenon

Widmann

Beiersdörfer

Brown

et al. 2000

AIP Conference Proceedings

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“…The systematic A&A 592, A141 (2016) theoretical studies are mostly confined to the n = 2 complex (e.g., Drake 1988;Chen et al 1993;Cheng et al 1994;Plante et al 1994;Johnson et al 1995;Cheng & Chen 2000;Artemyev et al 2005). There are also some large-scale calculations involving n > 2 singly excited levels of helium-like ions.…”

Section: Introductionmentioning

confidence: 99%

Energy levels and transition rates for helium-like ions withZ = 10–36

Guo

Wang

et al. 2016

A&A

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Aims. Helium-like ions provide an important X-ray spectral diagnostics in astrophysical and high-temperature fusion plasmas. An interpretation of the observed spectra provides information on temperature, density, and chemical compositions of the plasma. Such an analysis requires information for a wide range of atomic parameters, including energy levels and transition rates. Our aim is to provide a set of accurate energy levels and transition rates for helium-like ions with Z = 10-36. Methods. The second-order many-body perturbation theory (MBPT) was adopted in this paper. To support our MBPT results, we performed an independent calculation using the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. Results. We provide accurate energies for the lowest singly excited 70 levels among 1snl (n ≤ 6, l ≤ (n − 1)) configurations and the lowest doubly excited 250 levels arising from the K-vacancy 2ln l (n ≤ 6, l ≤ (n − 1)) configurations of helium-like ions with Z = 10−36. Wavelengths, transition rates, oscillator strengths, and line strengths are calculated for the E1, M1, E2, and M2 transitions among these levels. The radiative lifetimes are reported for all the calculated levels. Conclusions. Our MBPT results for singly excited n ≤ 2 levels show excellent agreement with other elaborate calculations, while those for singly excited n ≥ 3 and doubly excited levels show significant improvements over previous theoretical results. Our results will be very helpful for astrophysical line identification and plasma diagnostics.

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“…Recently, a significant progress took place in theory, where a new generation of relativistic many-body calculations has established improved benchmarks for the non-QED part of the electron-electron interaction [4][5][6][7]. For the groundstate the progress achieved is particularly impressive since even the specific two-electron radiative QED corrections can nowadays be calculated without any approximations and all the two-photon exchange diagrams for the electron-electron interaction are considered in a complete fashion [2,3].…”

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confidence: 99%

Electron-Electron Interaction in Strong Electromagnetic Fields: The Two-Electron Contribution to the Ground-State Energy in He-like Uranium

et al. 2004

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Radiative recombination transitions into the ground state of cooled bare and hydrogen-like uranium ions were measured at the storage ring ESR. By comparing the corresponding x-ray centroid energies, this technique allows for a direct measurement of the electron-electron contribution to the ionization potential in the heaviest He-like ions. For the two-electron contribution to the ionization potential of He-like uranium we obtain a value of 2248 ± 9 eV. This represents the most accurate determination of two-electron effects in the domain of high-Z He-like ions and the accuracy reaches already the size of the specific two-electron radiative QED corrections.

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Relativistic all-order many-body calculations of then=1 andn=2 states of heliumlike ions

Cited by 236 publications

References 60 publications

High–resolution measurements of the K-shell spectral lines of hydrogenlike and heliumlike xenon

High–resolution measurements of the K-shell spectral lines of hydrogenlike and heliumlike xenon

Energy levels and transition rates for helium-like ions withZ = 10–36

Electron-Electron Interaction in Strong Electromagnetic Fields: The Two-Electron Contribution to the Ground-State Energy in He-like Uranium

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