High-precision relativistic atomic structure calculations and the EBIT: Tests of quantum electrodynamics in highly charged ions

2008 ◽  
Vol 86 (1) ◽  
pp. 33-43 ◽  
Author(s):  
K T Cheng ◽  
M H Chen ◽  
W R Johnson ◽  
J Sapirstein
Keyword(s):  
High Precision ◽  
Atomic Structure ◽  
Quantum Electrodynamics ◽  
Ion Trap ◽  
Strong Field ◽  
Energy State ◽  
Negative Energy ◽  
Configuration Interaction Method ◽  
Atomic Structure Calculations ◽  
Structure Calculations

High-precision relativistic atomic-structure calculations based on the relativistic many-body perturbation theory and the relativistic configuration-interaction method are shown to provide stringent tests of strong-field quantum electrodynamic (QED) corrections when compared with electron beam ion trap measurements of the spectra of highly charged, many-electron ions. It is further shown that theory and experiment are accurate enough to test not just the leading screened QED corrections but also smaller contributions from higher order Breit interactions, relaxed-core QED corrections, two-loop Lamb shifts, negative-energy state corrections, nuclear polarizations, and nuclear recoils. PACS Nos. 31.30.Jv, 32.30.Rj, 31.25.–v, 31.15.Ar

Fully relativistic atomic structure calculations for W XLIV for determination of plasma diagnostic terms

2017 ◽  
Vol 95 (10) ◽  
pp. 950-957
Author(s):  
Arun Goyal ◽  
Rinku Sharma ◽  
A.K. Singh ◽  
Man Mohan
Keyword(s):  
Atomic Structure ◽  
Quantum Electrodynamics ◽  
Energy Levels ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Plasma Diagnostic ◽  
Fusion Plasma ◽  
Atomic Structure Calculations ◽  
Structure Calculations

We report accurate calculations of W XLIV through application of multi-configuration Dirac–Fock wave functions. We have calculated the energies for the lowest 100 fine structure levels, transition wavelengths, radiative rates, oscillator strengths, and line strengths for electric (E1) and magnetic dipole (M1) transitions with the extended average level multi-configurational Dirac–Fock method in the General-Purpose Relativistic Atomic Structure Package (GRASP). We have taken into account the electron correlations, quantum electrodynamics (QED) and Breit corrections in our calculations. We have also performed parallel calculations with the flexible atomic code (FAC) to assess the accuracy of our calculations. This is a fully relativistic code that provides a variety of atomic parameters, and (generally) yields results for energy levels and radiative rates comparable to GRASP. Our calculated results match well with experimentally observed results that are obtained in ASDEX upgrade Tokamak. Additionally, we have also provided the line intensity ratios and electron density for W XLIV, which is useful and important in plasma diagnostics and modeling in future International Thermonuclear Experimental Reactor (ITER) experiments. We believe that our results would be beneficial in the areas of fusion plasma research and astrophysical investigations and applications.

scholarly journals Soft-X-ray spectra of highly charged Os, Bi, Th, and U ions in an electron beam ion trap

2005 ◽  
Vol 83 (8) ◽  
pp. 829-840 ◽  
Author(s):  
E Träbert ◽  
P Beiersdorfer ◽  
K B Fournier ◽  
M H Chen
Keyword(s):  
Electron Beam ◽  
Atomic Structure ◽  
Beam Energy ◽  
Ion Trap ◽  
Electron Beam Energy ◽  
Valence Shell ◽  
X Ray ◽  
Electron Beam Ion Trap ◽  
Atomic Structure Calculations ◽  
Structure Calculations

Systematic variation of the electron-beam energy in an electron-beam ion trap has been employed to produce soft-X-ray spectra of Os, Bi, Th, and U with the highest charge states ranging up to Ni-like ions. Guided by relativistic atomic structure calculations, the strongest lines have been identified with Δn = 0 (n = 4 to n′ = 4) transitions in Rb- to Cu-like ions. The rather weak 4p–4d transitions are much less affected by QED contributions than the dominant 4s–4p transitions. Our wavelength measurements consequently provide benchmarks with and (almost) without QED. Because the radiative corrections are not very sensitive to the number of electrons in the valence shell, our data, moreover, provide benchmarks for the evaluation of electron–electron interactions. PACS Nos.: 32.30.Rj, 39.30.+w, 31.50.+w

scholarly journals Towards B-Spline Atomic Structure Calculations

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 50
Author(s):  
Charlotte Froese Fischer
Keyword(s):  
Atomic Structure ◽  
Bound States ◽  
Virial Theorem ◽  
B Spline ◽  
B Splines ◽  
Self Consistent ◽  
History Of ◽  
Consistent Method ◽  
Atomic Structure Calculations ◽  
Structure Calculations

The paper reviews the history of B-spline methods for atomic structure calculations for bound states. It highlights various aspects of the variational method, particularly with regard to the orthogonality requirements, the iterative self-consistent method, the eigenvalue problem, and the related sphf, dbsr-hf, and spmchf programs. B-splines facilitate the mapping of solutions from one grid to another. The following paper describes a two-stage approach where the goal of the first stage is to determine parameters of the problem, such as the range and approximate values of the orbitals, after which the level of accuracy is raised. Once convergence has been achieved the Virial Theorem, which is evaluated as a check for accuracy. For exact solutions, the V/T ratio for a non-relativistic calculation is −2.

Soft-X-ray spectra of highly charged Au ions in an electron-beam ion trap

2001 ◽  
Vol 79 (2-3) ◽  
pp. 153-162 ◽  
Author(s):  
E Träbert ◽  
P Beiersdorfer ◽  
K B Fournier ◽  
S B Utter ◽  
K L Wong
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Large Scale ◽  
Ion Trap ◽  
Electron Beam Energy ◽  
X Ray ◽  
Maximum Charge ◽  
Electron Beam Ion Trap ◽  
Atomic Structure Calculations ◽  
Structure Calculations

Systematic variation of the electron-beam energy in an electron-beam ion trap has been employed to produce soft-X-ray spectra (20 to 60 Å) of Au with well-defined maximum charge states ranging from Br- to Co-like ions. Guided by large-scale relativistic atomic structure calculations, the strongest Δn = 0 (n = 4 to n' = 4) transitions in Rb- to Cu-like ions (Au42+ – Au50+) have been identified. PACS Nos.: 32.30Rj, 39.30+w, 31.50+w, 32.20R

scholarly journals Atomic Structure Calculations and Study of Plasma Parameters of Al-Like Ions

Atoms ◽  
2016 ◽  
Vol 4 (3) ◽  
pp. 22 ◽  
Author(s):  
Arun Goyal ◽  
Indu Khatri ◽  
Avnindra Singh ◽  
Man Mohan ◽  
Rinku Sharma ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Plasma Parameters ◽  
Atomic Structure Calculations ◽  
Structure Calculations
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