Atomic parameters of Hf XLVIII, Ta XLIX, Os LII, Pt LIV, and Au LV

2020 ◽  
Author(s):  
Dan Huang
Keyword(s):  
Electron Correlation ◽  
Vacuum Polarization ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Transition Rates ◽  
Self Energy ◽  
Magnetic Quadrupole ◽  
Strong Transition ◽  
Good Agreement ◽  
Atomic Parameters

Ab initio multiconfiguration Dirac-Fock calculations are performed for energy levels and lifetimes of the lowest 115 fine-structure levels generated from the 3s<sup>2</sup>3p<sup>6</sup>3d<sup>7</sup>, 3s<sup>2</sup>3p<sup>5</sup>3d<sup>8</sup>, 3s3p<sup>6</sup>3d<sup>8</sup>, 3s<sup>2</sup>3p<sup>4</sup>3d<sup>9</sup>, and 3s3p<sup>5</sup>3d<sup>9</sup> configurations of Hf XLVIII, Ta XLIX, Os LII, Pt LIV, and Au LV of fusion interest. Furthermore, radiative rates are calculated for all electric dipole, electric quadrupole, magnetic dipole, and magnetic quadrupole transitions. Electron correlation is treated through multiconfiguration expansions in the active space approximation. The Breit interaction and the leading quantum electrodynamic corrections, in the form of self-energy and vacuum polarization, are included. Another theoretical attempt, based on the Flexible Atomic Code is presented for the atomic structure to serve as an independent check of the MCDF values and the results show fairly good agreement with the MCDF ones. Comparisons are made with available results in the literature. The uncertainties of our energies and strong transition rates are found to be approximately 0.25% and 2%, respectively. The extended and consistent data presented in this study should be of notable interest in various fusion research.

Energies, wavelengths, lifetimes, E1, M1, E2, and M2 transitions rates for the sulfur isoelectronic sequence Fe XI, Nb XXVI–In XXXIV

2017 ◽  
Vol 95 (4) ◽  
pp. 393-401 ◽  
Author(s):  
K. Wang ◽  
S. Li ◽  
R. Si ◽  
C.Y. Chen ◽  
J. Yan ◽  
...  
Keyword(s):  
Quantum Electrodynamics ◽  
Energy Levels ◽  
Theoretical Data ◽  
Electric Quadrupole ◽  
Oscillator Strengths ◽  
Transition Rates ◽  
Isoelectronic Sequence ◽  
Fusion Plasma ◽  
Magnetic Quadrupole ◽  
Theoretical Results

Energies, wavelengths, lifetimes, oscillator strengths, electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transition rates among the 42 fine structure levels belonging to the 3s23p4, 3s23p33d, and 3s3p5 configurations for S-like Fe and S-like ions with 41 ≤ Z ≤ 49 are calculated using the fully relativistic multiconfiguration Dirac–Fock (MCDF) method. In the calculations, contributions from correlations within the n = 6 complex, Breit interaction, and quantum electrodynamics effects are included. Detailed comparisons are made between the present results and the available experimental and other theoretical data. We found that our calculated energy levels generally agree within ≤0.5% with the experimentally compiled results, and the transition rates agree within ≤12% with other theoretical results for a majority of the transitions. These accurate theoretical data should be beneficial in fusion plasma research and astrophysical applications.

scholarly journals Theoretical studies of energy levels and transition data for Zr III

2020 ◽  
Vol 637 ◽  
pp. A10 ◽  
Author(s):  
P. Rynkun ◽  
G. Gaigalas ◽  
P. Jönsson
Keyword(s):  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Energy Spectra ◽  
Transition Rates ◽  
Hartree Fock ◽  
Self Energy ◽  
Relativistic Configuration ◽  
Experimental Values

Aims. We seek to present accurate and extensive transition data for the Zr III ion. These data are useful in many astrophysical applications. Methods. We used the multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2018. The transverse-photon (Breit) interaction, vacuum polarization, and self-energy corrections are included in the RCI computations. Results. Energy spectra were calculated for the 88 lowest states in the Zr III ion. The root-mean-square deviation obtained in this study for computed energy spectra from the experimental data is 450 cm−1. Electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition data, line strengths, weighted oscillator strengths, and transition rates are computed between the above states together with the corresponding lifetimes. The computed transition rates are smaller than the experimental rates and the disagreement for weaker transitions is much larger than the experimental error bars. The computed lifetimes agree with available experimental values within the experimental uncertainties.

scholarly journals Theoretical investigation of energy levels and transition data for S II, Cl III, Ar IV

2019 ◽  
Vol 623 ◽  
pp. A155 ◽  
Author(s):  
P. Rynkun ◽  
G. Gaigalas ◽  
P. Jönsson
Keyword(s):  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Energy Spectra ◽  
Astrophysical Plasmas ◽  
Internal Validation ◽  
Hartree Fock ◽  
Self Energy ◽  
Relativistic Configuration ◽  
Relativistic Configuration Interaction

Aims. The aim of this work is to present accurate and extensive results of energy spectra and transition data for the S II, Cl III, and Ar IV ions. These data are useful for understanding and probing physical processes and conditions in various types of astrophysical plasmas.Methods. The multiconfiguration Dirac–Hartree–Fock (MCDHF) and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2K, are used in the present work. In the RCI calculations the transverse-photon (Breit) interaction, the vacuum polarization, and the self-energy corrections are included.Results. Energy spectra are presented comprising the 134, 87, and 103 lowest states in S II, Cl III, and Ar IV, respectively. Energy levels are in very good agreement with NIST database recommended values and associated with smaller uncertainties than energies from other theoretical computations. Electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition data are computed between the above states together with the corresponding lifetimes. Based on internal validation, transition rates for the majority of the stronger transitions are estimated to have uncertainties of less than 3%.

Accurate study on the properties of spectral lines for Na-like Cr13+

2019 ◽  
Vol 97 (4) ◽  
pp. 436-442
Author(s):  
A.K. Singh ◽  
Mayank Dimri ◽  
Dishu Dawra ◽  
Alok K.S. Jha ◽  
Man Mohan
Keyword(s):  
Configuration Interaction ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Fusion Plasma ◽  
Configuration Interaction Method ◽  
Magnetic Quadrupole ◽  
Configuration Interaction Calculations

An extended calculation of energy levels, radiative rates, and lifetimes are reported for sodium-like chromium. Extensive configuration interaction calculations have been performed using general-purpose relativistic atomic structure package (GRASP). The radiative rates, oscillator strengths, and line strengths are listed for all electric dipole (E1) transitions. However, for magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions, only radiative rates are listed. The importance of valence–valence (VV) and core–valence (CV) correlation effects in the calculation of energy levels have also been shown. To confirm the accuracy of the present results for energy levels by GRASP, independent calculations have been performed by using Flexible Atomic Code (FAC) and configuration interaction method (CIV3). The accuracy of the present levels, wavelengths, transition rates, and lifetimes are assessed by comparing them to available experimental and other theoretical results. We believe that our extensive results may be beneficial in fusion plasma research and astrophysical investigations and applications.

Theoretical photoionization study of Ti9+ ion

2020 ◽  
Author(s):  
Hongbin Wang ◽  
Gang Jiang
Keyword(s):  
Cross Sections ◽  
Energy Levels ◽  
Radiative Transition ◽  
High Energy ◽  
Low Energy ◽  
Transition Rates ◽  
Channel Coupling ◽  
R Matrix ◽  
Good Consistency ◽  
Good Agreement

Photoionization (PI) of Ti<sup>9+</sup> ion is investigated by the Dirac R-matrix method. Multi-Configuration Dirac-Fock (MCDF) calculations are performed to construct accurate target functions. Good agreement of energy levels and radiative transition rates indicate the accuracy of target functions. PI cross sections show good consistency between length and velocity forms. The results are consistent with the previous theoretical values in high-energy regions. Partial waves contribution to the total PI cross sections are discussed for the ground and metastable states. Moreover, the PI cross sections are dominated by many resonance structures and affected by the channel coupling effects in low-energy region. In addition to providing data for the Opacity Project TOPbase, the present work promotes plasma simulation and diagnosis.

scholarly journals Theoretical investigation of oscillator strengths and lifetimes in Ti II

2020 ◽  
Vol 643 ◽  
pp. A156
Author(s):  
W. Li ◽  
H. Hartman ◽  
K. Wang ◽  
P. Jönsson
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Excitation Energies ◽  
Hartree Fock ◽  
Self Energy ◽  
Theoretical Predictions

Aims. Accurate atomic data for Ti II are essential for abundance analyses in astronomical objects. The aim of this work is to provide accurate and extensive results of oscillator strengths and lifetimes for Ti II. Methods. The multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction (RCI) methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2018, were used in the present work. In the final RCI calculations, the transverse-photon (Breit) interaction, the vacuum polarisation, and the self-energy corrections were included. Results. Energy levels and transition data were calculated for the 99 lowest states in Ti II. Calculated excitation energies are found to be in good agreement with experimental data from the Atomic Spectra Database of the National Institute of Standards and Technology based on the study by Huldt et al. Lifetimes and transition data, for example, line strengths, weighted oscillator strengths, and transition probabilities for radiative electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transitions, are given and extensively compared with the results from previous calculations and measurements, when available. The present theoretical results of the oscillator strengths are, overall, in better agreement with values from the experiments than the other theoretical predictions. The computed lifetimes of the odd states are in excellent agreement with the measured lifetimes. Finally, we suggest a relabelling of the 3d2(12D)4p y2 D3/2o and z2 P3/2o levels.

scholarly journals Description of the energy levels and electric quadrupole transitions of the 92Nb and 92Mo nuclei using nuclear shell model

2021 ◽  
Author(s):  
Mustafa Mohammed Jabbar ◽  
Keyword(s):  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Electric Quadrupole Transition ◽  
Modified Surface ◽  
Electric Transition ◽  
Experimental Values ◽  
Nuclear Shell ◽  
Good Agreement

In current study ,92Nb and 92Mo isotopes have been determined for calculating energy levels and electric quadrupole transition probabilities. Two interaction have been applied in this study are surface delta and modified surface delta interactions. The calculations have been achieved by using appropriate effective charges for proton and neutron as well as parameter length of harmonic potential. Computed results have been compared with the experimental values. After this comparison, energy and the transition probability values have a good agreement with the experimental values, also there are values of the total angular momentum and parity are determined and confirmed for some of the experimental energies, undetermined and unconfirmed experimentally. Theoretically, new values of quadrupole electric transition probabilities have been explored which have not been known in the experimental data.

scholarly journals Magnetic quadrupole (M2) X-ray laser transitions from neon-like arsenic As+23

2016 ◽  
Vol 94 (11) ◽  
pp. 1233-1240
Author(s):  
Mohammad Z. Mansour ◽  
Wessameldin S. Abdelaziz ◽  
Tharwat M. El Sherbini
Keyword(s):  
Energy Levels ◽  
Not Given ◽  
Energetic Electrons ◽  
X Ray ◽  
Magnetic Quadrupole ◽  
Good Agreement

Neon-like arsenic As+23 are studied theoretically where 457 energy levels are calculated. Highly energetic electrons are considered as the main pumping source for the population of the energy levels. Relativistic calculations are considered through calculations, and the possible X-ray laser transitions are determined with their gain coefficients. The soft X-ray laser transitions (λ ≈ 17–27 nm) are dominated by the magnetic quadrupole M2. The results show good agreement with the observed data and, moreover, new transitions that are not given in the literature are calculated together with their gain values.

scholarly journals Theoretical Study of Isospin Mixing States with T> 0 in sd Even-Even N=Z Nuclei Using Shell Model

2021 ◽  
Vol 12 (2) ◽  
pp. 2470-2475
Author(s):  
Anwer A. Al-Sammarraie , Et. al.
Keyword(s):  
Shell Model ◽  
Excited States ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Electric Quadrupole Transition ◽  
The Difference ◽  
Experimental Values ◽  
Mixing States ◽  
Good Agreement

Nuclear excited states with T > 0 in sd even-even N=Z  nuclei have been studied by using shell model. The calculations have employed the USDB Hamiltonian in order to predict the energy levels, the reduced electric quadrupole transition probabilities and reduced magnetic dipole transition probabilities. The study also include the average number of nucleons in each sd- active orbitals. The results compared with available experimental data.  The comparison showed a good agreement between theoretical and experimental energy sates for most of the states studied in this work. On the other hand there was a difference between theoretical and experimental values of transition probabilities, but it can be said that it remained within the acceptable range of the difference.

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