Kα transition probabilities of C-like to F-like Al ions

2015 ◽  
Vol 93 (3) ◽  
pp. 267-270
Author(s):  
Cuicui Sang ◽  
Feng Chen ◽  
Chao Chen ◽  
Bingcong Gou
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Emission Spectra ◽  
Radiative Transition ◽  
Transition Rates ◽  
Atomic Structures ◽  
Radiative Transitions ◽  
Electron Correlation Effects ◽  
Reasonable Description ◽  
Spectral Intensities

Kα radiative transitions of C-like to F-like Al ions are studied using the multiconfiguration Dirac–Fock (MCDF) method. The fully relativistic MCDF approach was specifically designed to calculate atomic structures and radiative transition rates, and hence it ensures a reasonable description of the emission effects and spectral intensities. The energies and wavefunctions, corresponding mixing coefficients, the influence of electron correlation effects on energy levels, and radiative transition rates for C-like to F-like Al ions are investigated in detail. Good agreement is found between the calculated Kα emission spectra in this work and the spectra from experimental measurements.

scholarly journals Radiative transitions for three lowest configurations of tungsten ions W38+–W43+

2017 ◽  
Vol 57 (3) ◽  
Author(s):  
Rasa Karpuškienė ◽  
Pavel Bogdanovich ◽  
Romualdas Kisielius
Keyword(s):  
Transition Probabilities ◽  
Relativistic Effects ◽  
Electric Quadrupole ◽  
Radiative Transition ◽  
Configuration Interaction Method ◽  
Hartree Fock ◽  
Radiative Transitions ◽  
Emission Transition ◽  
Magnetic Quadrupole ◽  
Electron Correlation Effects

The ab initio quasirelativistic approximation was used to derive transition data for the multicharged tungsten ions W38+–W43+ with an open 4p shell. The configuration interaction method with transformed radial orbitals was applied to include electron correlation effects. The relativistic effects were taken into account in the Breit–Pauli approximation for the quasirelativistic Hartree–Fock radial orbitals. The level energies E, radiative lifetimes τ, and Landé g-factors were calculated for the 4s24pN, 4s24pN–14d, and 4s4pN+1 configurations of six tungsten ions. The radiative transition wavelengths λ, spontaneous emission transition probabilities A and their uncertainties for the electric dipole, electric quadrupole, electric octupole, magnetic dipole and magnetic quadrupole transitions among the levels of these configurations are presented.

scholarly journals The Temperature Dependence of Fundamental Photophysical Properties of [Eu(MeOH-d4)9]3+ Solvates and [Eu.DOTA(MeOH-d4)]- Complexes

2021 ◽  
Author(s):  
Nicolaj Kofod ◽  
Lea Gundorff Nielsen ◽  
Thomas Just Sørensen
Keyword(s):  
Transition Probabilities ◽  
Photophysical Properties ◽  
Transition Probability ◽  
Energy Levels ◽  
Emission Spectra ◽  
Lanthanide Ions ◽  
Quantum Yields ◽  
Luminescence Spectra ◽  
Absorption Cross ◽  
Apparent Lack

The trivalent lanthanide ions show optical transitions between energy levels within the 4f shell. All these transitions are formally forbidden according to the quantum mechanical selection rules used in molecular photophysics. Nevertheless, highly luminescent complexes can be achieved, and terbium(iii) and europium(iii) ions are particularly efficient emitters. This report started when an apparent lack of data in the literature led us to revisit the fundamental photophysics of europium(iii). The photophysical properties of two complexes – [Eu.DOTA(MeOH-d4)]- and [Eu(MeOH-d4)9]3+ – were investigated in deuterated methanol at five different temperatures. Absorption spectra showed decreased absorption cross sections as the temperature was increased. Luminescence spectra and time-resolved emission decay profiles showed a decrease in intensity and lifetime as a temperature was increased. Having corrected the emission spectra for the actual number of absorbed photons and differences in non-radiative pathways, the relative emission probability was revealed. These were found to increase with increasing temperature. The transition probability for luminescence was shown to increase with temperature, while the transition probability for light absorption decreased. The changes in transition probabilities were correlated to a change in the symmetry of the absorber or emitter, with an average increase in symmetry lowering absorption cross section and access to more asymmetric structures increasing the emission rate constant. Determining luminescence quantum yields and the Einstein coefficient for spontaneous emission allowed us to conclude that lowering symmetry increases both. Further, it was found that collisional self-quenching is an issue for lanthanide luminescence, when high concentrations are used. Finally, detailed analysis revealed results that show the so-called ‘Werts’ method’ for calculating radiative lifetimes and intrinsic quantum yields are based on assumption that does not hold for the two systems investigated here. We conclude that we are lacking a good theoretical description of the intraconfigurational f-f transition, and that there are still aspects of fundamental lanthanide photophysics to be explored.<br>

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 Benchmarking Current Capabilities for the Generation of Excitation and Photoionisation Atomic Data

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 90 ◽  
Author(s):  
Catherine Ramsbottom ◽  
Connor Ballance ◽  
Ryan Smyth ◽  
Andrew Conroy ◽  
Luis Fernández-Menchero ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Cross Sections ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Atomic Data ◽  
High Quality ◽  
Astronomical Instruments ◽  
First Time ◽  
Line Strengths

The spectra currently emerging from modern ground- and space-based astronomical instruments are of exceptionally high quality and resolution. To meaningfully analyse these spectra, researchers utilise complex modelling codes to replicate the observations. The main inputs to these codes are atomic data such as excitation and photoionisation cross sections, as well as radiative transition probabilities, energy levels, and line strengths. In this publication, the current capabilities of the numerical methods and computer packages used in the generation of these data are discussed. Particular emphasis is given to Fe-peak species and the heavy systems of tungsten and molybdenum. Some of the results presented to highlight certain issues and/or advances have already been published in the literature, while other sections present new recently evaluated atomic data for the first time.

Energy levels and radiative transition rates for Ba XLVIII

2016 ◽  
Vol 107 ◽  
pp. 367-405 ◽  
Author(s):  
Indu Khatri ◽  
Arun Goyal ◽  
Sunny Aggarwal ◽  
A.K. Singh ◽  
Man Mohan
Keyword(s):  
Energy Levels ◽  
Radiative Transition ◽  
Transition Rates

scholarly journals X-Ray Satellite Lines

1984 ◽  
Vol 86 ◽  
pp. 36-36
Author(s):  
J. Dubau
Keyword(s):  
Transition Probabilities ◽  
Relativistic Effects ◽  
Radiative Transition ◽  
Electron System ◽  
Great Accuracy ◽  
Atomic Data ◽  
X Ray ◽  
Spectroscopic Diagnostics ◽  
Radiative Transitions ◽  
Shell Vacancy

Satellite lines are typical features of X-ray spectra. They correspond to radiative transitions involving an inner-shell vacancy. The most studied satellite lines are of the - type, i.e., (ls–2p) transition.With the advent of Space Astronomy, X-ray spectra emitted by very hot solar plasma have been obtained. By a simple comparison of different spectra, it appears that, for highly ionized atoms, some satellite lines have intensities as large as resonance lines intensities and, more particularly, this is the case for the ls2n. – ls 2pn satellite lines of the 1s2 – ls2p resonance lines.The analysis of the different population mechanisms responsible for the satellite lines and resonance lines emission has shown that different spectroscopic diagnostics could be derived from line ratios only if atomic data of great accuracy were available. There exists nowadays different atomic data programs adapted to X-ray satellite lines. They have in common to give a great amount of data simultaneously: wavelengths, autoionization and radiative transition probabilities. They take into account correlation and relativistic effects.After tackling the simple 3-electron system, the programs give now appropriate data for more complex systems but this required large computers because the lines become blended. It is therefore impossible to limit the calculation to the most intense lines.

scholarly journals The CHIANTI Database

2005 ◽  
Vol 13 ◽  
pp. 653-656 ◽  
Author(s):  
E. Landi ◽  
K.P. Dere ◽  
P.R. Young ◽  
M. Landini ◽  
H.E. Mason ◽  
...  
Keyword(s):  
Plasma Diagnostics ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Atomic Energy ◽  
Astrophysical Interest ◽  
Future Developments ◽  
Synthetic Spectra ◽  
Atomic Energy Levels

AbstractThe CHIANTI database contains assessed atomic energy levels, wavelengths, radiative transition probabilities and excitation rates necessary to calculate line emissivities and synthetic spectra of a large number of ions of astrophysical interest. CHIANTI also includes a suite of programs to carry out plasma diagnostics. In the present paper we describe the contents of the CHIANTI database, its main applications and its future developments.

Energy levels and radiative transitions of the K-shell excited sextet states in boron-like sulfur ion

2016 ◽  
Vol 94 (10) ◽  
pp. 1054-1060 ◽  
Author(s):  
Yan Sun ◽  
CuiCui Sang ◽  
KaiKai Li ◽  
XinYu Qian ◽  
Feng Hu ◽  
...  
Keyword(s):  
Fine Structure ◽  
Relativistic Effect ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Variation Method ◽  
First Order ◽  
Radiative Transitions ◽  
First Order Perturbation

Theoretical calculations are reported for energy levels and transition probabilities of the K-shell excited sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) for the astrophysically important element sulfur. Energy levels, fine structure splittings, and transition parameters of the high-lying sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) in boron-like sulfur ion are calculated with the multi-configuration Rayleigh–Ritz variation method. To obtain the accurate energy level, the relativistic corrections and mass polarization effect are included by using the first-order perturbation theory. Configuration structures of these sextet series are assigned according to the energies, percentage contributions of basis states to the eigenvector, relativistic effect corrections, and verification of fine structure splittings. The oscillator strengths, transition probabilities, and wavelengths of electric-dipole transitions between 6So,e(m) and 6Pe,o(m) (m = 1–7) states are also systematically calculated and discussed.

scholarly journals Interpretation of the spectrum of Pb(II). Theoretical transition probabilities and lifetimes

2001 ◽  
Vol 79 (7) ◽  
pp. 999-1009 ◽  
Author(s):  
C Colón ◽  
A Alonso-Medina
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Least Square ◽  
Large Contribution ◽  
Hartree Fock ◽  
Forbidden Transition ◽  
Method Of Least Square ◽  
Experimental Values ◽  
Good Agreement

Radiative transition probabilities for 190 lines arising from the ns 2S1/2, np 2P1/2,3/2, nd 2D3/2,5/2, nf 2F5/2,7/2, and 6p2 (4P1/2,3/2,5/2, 2D3/2,5/2, 2P1/2,3/2, and 2S1/2) levels of Pb(II) have been calculated. Lifetimes of the above mentioned levels have been determined from the present transition probabilities. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. For the IC calculations, we use the standard method of least-square fitting of experimental energy levels by means of computer codes from Cowan. The results of calculations for radiative transition probabilities and excited states lifetimes are presented and compared with the experimental results present in the literature and with other theoretical values. There is generally good agreement between our values and the experimental data available. Analysis of the interaction shows that the level 4P5/2 of the 6s6p2 configuration presents a large contribution to the 2D5/2 level of the 6s26d configuration. This result explains the good agreement between our result and the experimental values obtained to the observed as the 6s6p2 4P5/2 – 6s 25f2F7/2 dipole-forbidden transition. PACS Nos.: 32.70^*, 32.70Fw, 32.70Cs

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