Hyperfine quenching of the metastable 4s4p 3P0 and 3P2 states of Zn-like ions1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (4) ◽  
pp. 473-482 ◽  
Author(s):  
M.H. Chen ◽  
K.T. Cheng
Keyword(s):  
Large Scale ◽  
Decay Rates ◽  
Oscillator Strengths ◽  
Energy Separation ◽  
Configuration Interaction Method ◽  
International Colloquium ◽  
Theoretical Predictions ◽  
Relativistic Configuration ◽  
Relativistic Configuration Interaction ◽  
Hyperfine Quenching

The hyperfine-induced 4s4p 3P0,2–4s2 1S0 transition rates for Zn-like ions with Z = 30–66 are calculated using a large scale relativistic configuration-interaction method. Comparisons are made between different approaches to hyperfine quenching studies, and discussions are given to the significance of various contributions. For the 3P0 state, the effect of the 1P1 state on hyperfine quenching is found to be quite substantial and cannot be ignored in spite of the large energy separation. For the 3P2 state, hyperfine quenching leads to different decay rates to the ground state for different hyperfine levels and the induced decays can dominated over the unperturbed M2 transition. The present results are compared with the other theoretical predictions, and reasons for the discrepancies are discussed.

Higher order interelectronic-interaction correctionsto the ground-state hyperfine splitting in lithiumlike ions

2000 ◽  
Vol 78 (7) ◽  
pp. 701-709 ◽  
Author(s):  
O M Zherebtsov ◽  
V M Shabaev
Keyword(s):  
Ground State ◽  
Hyperfine Splitting ◽  
Nuclear Model ◽  
Magnetization Distribution ◽  
Configuration Interaction Method ◽  
Nuclear Magnetization ◽  
Theoretical Predictions ◽  
Relativistic Configuration ◽  
Relativistic Configuration Interaction ◽  
Interelectronic Interaction

The interelectronic-interaction corrections of the second order in 1/Z to the ground-state hyperfine splitting in lithiumlike ions are evaluated. The calculations are performed by using the relativistic configuration-interaction method and perturbation theory. In addition, the nuclear magnetization distribution effect on the interelectronic-interaction correction of the first order in 1/Z is evaluated within the single-particle nuclear model. The calculations provide an improvement in the theoretical predictions for the hyperfine splitting in lithiumlike ions. PACS Nos.: 31.30Gs, 31.30Jv

Allowed and forbidden transition rates and corresponding wavelengths for Si-like Au ion (Au65+) by relativistic configuration interaction method

2018 ◽  
Vol 96 (10) ◽  
pp. 1116-1137
Author(s):  
S.M. Hamasha ◽  
A. Almashaqba
Keyword(s):  
Configuration Interaction ◽  
Energy Levels ◽  
Theoretical Data ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Transition Rates ◽  
Interaction Method ◽  
Configuration Interaction Method ◽  
Relativistic Configuration ◽  
Relativistic Configuration Interaction

Large-scale atomic calculations are carried out to produce data of atomic structure and transitions rates for Si-like Au ion (Au65+). Generated atomic data are essential for modeling of M-shell spectra of gold ions in Au plasma, and fusion research. Energy levels are calculated by applying two methods: the relativistic configuration interaction method (RCI) of the flexible atomic code (FAC) and the multi-reference many body perturbation theory method (MR-MBPT). Energy levels, oscillator strengths, and transition rates are calculated for transitions between excited and ground states from n = 3l to n′l′, where n′ = 4, 5, 6, and 7; and l and l′ are the proper angular momenta of shells n and n′, respectively. The electric dipole (E1), electric quadrupole (E2), electric octupole (E3), magnetic dipole (M1), magnetic quadrupole (M2), and magnetic octupole (M3) transitions are all considered in the calculations. Correlation effects, relativistic effects, and QED effects are also included in the calculations. The two methods yield comparable values of energy levels. Data of energy levels of low-lying states and data for inner shell transitions reported in this study demonstrate good agreement with published experimental and theoretical data.

Tungsten measurement on Alcator C-Mod and EBIT for future fusion reactors1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (5) ◽  
pp. 591-597 ◽  
Author(s):  
Y.A. Podpaly ◽  
J.E. Rice ◽  
P. Beiersdorfer ◽  
M.L. Reinke ◽  
J. Clementson ◽  
...  
Keyword(s):  
Ion Trap ◽  
Oscillator Strengths ◽  
Continuum Emission ◽  
Tokamak Plasmas ◽  
Ion Temperature ◽  
International Colloquium ◽  
Plasma Facing Components ◽  
Laboratory Plasmas ◽  
Electron Beam Ion Trap ◽  
Theoretical Predictions

Tungsten will be an important element in nearly all future fusion reactors because of its presence in plasma facing components. This makes tungsten a good candidate for a diagnostic element for ion temperature and toroidal velocity measurement, and it makes understanding tungsten emissions important for tokamak power balance. The effect of tungsten on tokamak plasmas is investigated at the Alcator C-Mod tokamak using VUV, bolometry, and soft X-ray spectroscopy. Tungsten was present in Alcator C-Mod as a plasma facing component and through laser blow-off impurity injection. Quasi-continuum emission previously seen at other tokamaks has been identified. Theoretical predictions are presented of tungsten emission that could be expected in future Alcator C-Mod measurements. Furthermore, spectra of highly charged tungsten ions have been studied at the SuperEBIT electron beam ion trap. This emission could prove useful for spectroscopic diagnostics of future high-temperature fusion reactor plasmas.

Large-scale CIV3 calculations of fine-structure energy levels and radiative rates in Al-like copper

2009 ◽  
Vol 87 (8) ◽  
pp. 895-907 ◽  
Author(s):  
G. P. Gupta ◽  
A. Z. Msezane
Keyword(s):  
Fine Structure ◽  
Configuration Interaction ◽  
Large Scale ◽  
Radiative Decay ◽  
Energy Levels ◽  
Decay Rates ◽  
Experimental Results ◽  
Oscillator Strengths ◽  
Correct Identification ◽  
Excitation Energies

We have performed large-scale CIV3 calculations of excitation energies from the ground state for 97 fine-structure levels as well as of oscillator strengths and radiative decay rates for all electric-dipole-allowed and intercombination transitions among the fine-structure levels of the terms belonging to the (1s22s22p6)3s23p, 3s3p2, 3s23d, 3p3, 3s3p3d, 3p23d, 3s3d2, 3s24s, 3s24p, 3s24d, 3s24f, and 3s3p4s configurations of Cu XVII. These states are represented by very extensive configuration-interaction (CI) wave functions obtained with the CIV3 (Configuration-Interaction Version 3) computer code of Hibbert. The important relativistic effects in intermediate coupling are incorporated by means of the Breit–Pauli Hamiltonian, which consists of the nonrelativistic term plus the one-body mass correction, Darwin term, and spin–orbit, spin–other-orbit, and spin–spin operators. To keep our calculated energy splittings as close as possible to the experimental values (wherever available), we have made small adjustments to the diagonal elements of the Hamiltonian matrices. Our calculated excitation energies, including their ordering, are in excellent agreement with the available experimental results. From our radiative decay rates we have also calculated radiative lifetimes of some fine-structure levels. The mixing among several fine-structure levels is found to be so strong that the correct identification of these levels becomes very difficult. We believe that our extensive calculations will be useful to experimentalists in identifying the fine-structure levels in their future work. In this calculation we also predict new data for several fine-structure levels where no other theoretical and (or) experimental results are available.

scholarly journals Coulomb (Velocity) Gauge Recommended in Multiconfiguration Calculations of Transition Data Involving Rydberg Series

Atoms ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 106 ◽  
Author(s):  
Asimina Papoulia ◽  
Jörgen Ekman ◽  
Gediminas Gaigalas ◽  
Michel Godefroid ◽  
Stefan Gustafsson ◽  
...  
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Wavelength Region ◽  
Theoretical Data ◽  
Rydberg Series ◽  
Atomic Systems ◽  
Hartree Fock ◽  
Relativistic Configuration ◽  
Atomic States ◽  
Relativistic Configuration Interaction

Astronomical spectroscopy has recently expanded into the near-infrared (nIR) wavelength region, raising the demands on atomic transition data. The interpretation of the observed spectra largely relies on theoretical results, and progress towards the production of accurate theoretical data must continuously be made. Spectrum calculations that target multiple atomic states at the same time are by no means trivial. Further, numerous atomic systems involve Rydberg series, which are associated with additional difficulties. In this work, we demonstrate how the challenges in the computations of Rydberg series can be handled in large-scale multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) calculations. By paying special attention to the construction of the radial orbital basis that builds the atomic state functions, transition data that are weakly sensitive to the choice of gauge can be obtained. Additionally, we show that the Babushkin gauge should not always be considered as the preferred gauge, and that, in the computations of transition data involving Rydberg series, the Coulomb gauge could be more appropriate for the analysis of astrophysical spectra. To illustrate the above, results from computations of transitions involving Rydberg series in the astrophysically important C IV and C III ions are presented and analyzed.

Sign in / Sign up

Export Citation Format

Share Document