scholarly journals Experimental and theoretical lifetimes and transition probabilities for spectral lines in Nb II

2019 ◽  
Vol 627 ◽  
pp. A102
Author(s):  
H. Nilsson ◽  
L. Engström ◽  
H. Lundberg ◽  
H. Hartman ◽  
P. Palmeri ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Branching Fractions ◽  
Spectral Lines ◽  
Fourier Transform Spectrometer ◽  
Core Polarization ◽  
Time Resolved ◽  
Excitation Scheme ◽  
Hartree Fock ◽  
Two Photon ◽  
Absolute Transition

Aims. We have measured and calculated lifetimes of high lying levels in Nb II, and derived absolute transition probabilities by combining the lifetimes with experimental branching fractions.Methods. The lifetimes were measured using time-resolved laser-induced fluorescence in a two-photon and two-step excitation scheme. The branching fractions were measured in intensity calibrated spectra from a hollow cathode discharge, recorded with a Fourier transform spectrometer. The calculations were performed with the relativistic Hartree–Fock method including core polarization.Results. We report experimental lifetimes of 13 levels in the 4d3(4F)5d and 4d3(4F)6s subconfigurations, at an energy around 70 000 cm−1. By combining the lifetimes with experimental branching fractions absolute transition probabilities of 59 lines are derived. The experimental results are compared with calculated values.

scholarly journals Experimental transition probabilities for 4p – 4d spectral lines in V II

2019 ◽  
Vol 622 ◽  
pp. A154 ◽  
Author(s):  
H. Nilsson ◽  
J. Andersson ◽  
L. Engström ◽  
H. Lundberg ◽  
H. Hartman
Keyword(s):  
Transition Probabilities ◽  
Branching Fractions ◽  
Theoretical Data ◽  
Spectral Lines ◽  
Time Resolved ◽  
Excitation Scheme ◽  
Photon Excitation ◽  
Experimental Transition ◽  
Experimental Values ◽  
Absolute Transition

Aims. We aim to measure lifetimes of levels belonging to the 3d3(4F)4d subconfiguration in V II, and derive absolute transition probabilities by combining the lifetimes with experimental branching fractions.Methods. The lifetimes were measured using time-resolved laser-induced fluorescence in a two-photon excitation scheme. The branching fractions were measured in intensity calibrated spectra from a hollow cathode discharge lamp, recorded with a Fourier transform spectrometer.Results. We report lifetimes for 13 levels at an energy around 73 000 cm−1. Absolute transition probabilities of 78 lines are derived by combining the lifetimes and branching fractions. The experimental values are compared with theoretical data from the literature.

Radiative lifetimes, branching fractions, and oscillator strengths of high-lying levels in Re I

2019 ◽  
Author(s):  
Yongfan Li ◽  
Sébastien Gamrath ◽  
Patrick Palmeri ◽  
Pascal Quinet ◽  
Qiu Li ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Branching Fractions ◽  
Laser Induced Fluorescence ◽  
Oscillator Strengths ◽  
Core Polarization ◽  
Radiative Lifetimes ◽  
Time Resolved ◽  
Hartree Fock ◽  
Semi Empirical ◽  
First Time

Abstract Radiative lifetimes of 19 levels in Re I were measured using the time-resolved laser-induced fluorescence method. As far as we know, 15 results are reported for the first time. By combining the experimental lifetimes determined from the present work with theoretical branching fractions obtained by a pseudo-relativistic Hartree–Fock model including core-polarization contributions, a new set of semi-empirical transition probabilities and oscillator strengths for 47 Re I lines from 18 newly measured levels were derived.

scholarly journals New Transition and Energy Levels of Three-Times Ionized Krypton (Kr IV)

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 48
Author(s):  
M. Raineri ◽  
M. Gallardo ◽  
J. Reyna Almandos ◽  
A. G. Trigueiros ◽  
C. J. B. Pagan
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Pulsed Discharge ◽  
Core Polarization ◽  
Polarization Effects ◽  
Hartree Fock ◽  
Theta Pinch ◽  
New Energy ◽  
First Time

A capillary pulsed-discharge and a theta-pinch were used to record Kr spectra in the region of 330–4800 Å. A set of 168 transitions of these spectra were classified for the first time. We extended the analysis to twenty-five new energy levels belonging to 3s23p24d, 3s23p25d even configurations. We calculated weighted transition probabilities (gA) for all of the experimentally observed lines and lifetimes for new energy levels using a relativistic Hartree–Fock method, including core-polarization effects.

scholarly journals Current Status and Developments of the Atomic Database on Rare-Earths at Mons University (DREAM)

Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 18 ◽  
Author(s):  
Pascal Quinet ◽  
Patrick Palmeri
Keyword(s):  
Rare Earths ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Current Status ◽  
Time Resolved ◽  
Hartree Fock ◽  
Lanthanide Atoms ◽  
Experimental Values ◽  
Theoretical Results ◽  
Good Agreement

The main purpose of the Database on Rare Earths At Mons University (DREAM) is to provide the scientific community with updated spectroscopic parameters related to lanthanide atoms (Z = 57–71) in their lowest ionization stages. The radiative parameters (oscillator strengths and transitions probabilities) listed in the database have been obtained over the past 20 years by the Atomic Physics and Astrophysics group of Mons University, Belgium, thanks to a systematic and extensive use of the pseudo-relativistic Hartree-Fock (HFR) method modified for taking core-polarization and core-penetration effects into account. Most of these theoretical results have been validated by the good agreement obtained when comparing computed radiative lifetimes and accurate experimental values measured by the time-resolved laser-induced fluorescence technique. In the present paper, we report on the current status and developments of the database that gathers radiative parameters for more than 72,000 spectral lines in neutral, singly-, doubly-, and triply-ionized lanthanides.

scholarly journals Absolute transition probabilities of Al I and Al II spectral lines and intensity ratios within multiplets

2002 ◽  
Vol 388 (2) ◽  
pp. 704-711 ◽  
Author(s):  
V. Vujnović ◽  
K. Blagoev ◽  
C. Fürböck ◽  
T. Neger ◽  
H. Jäger
Keyword(s):  
Transition Probabilities ◽  
Spectral Lines ◽  
Intensity Ratios ◽  
Absolute Transition

scholarly journals X-ray Emission Spectra of Some Carbon-containing Molecules

1986 ◽  
Vol 39 (5) ◽  
pp. 717 ◽  
Author(s):  
RA Phillips ◽  
FP Larkins
Keyword(s):  
Transition Probabilities ◽  
Emission Spectra ◽  
Fluorescence Yield ◽  
Total Carbon ◽  
Molecular Orbital Calculations ◽  
Electronic Relaxation ◽  
X Ray ◽  
Hartree Fock ◽  
Relaxation Effects ◽  
Absolute Transition

Ab initio molecular orbital calculations for the energy and intensity of X-ray transitions associated with the carbon monoxide, hydrogen cyanide and carbon dioxide molecules have been calculated at the Hartree-Fock level. It is demonstrated that in general the absolute transition probabilities are sensitive to the inclusion of electronic relaxation effects and interatomic transition moment contributions. It is concluded that calculations for molecular X-r!ly emission henomena should be undertaken at least at the multicentre relaxed Hartree-Fock level to achieve a realistic basis for comparison with experiment. Total carbon-K X-ray rates do not show a strong variation with changes in the molecular environment. The total rates are of a similar magnitude to those reported for the atom. The calculated carbon-K fluorescence yield is also similar in both the carbon atom and the CO2 molecule.

Energy levels and spectral lines for Ge-like Zr, Nb and Tc ions

2020 ◽  
Author(s):  
Miao Wu ◽  
Zhen-Cen He
Keyword(s):  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Hartree Fock ◽  
Experimental Values ◽  
Theoretical Results ◽  
Line Strengths

The energy levels, transition probabilities, oscillator strengths, line strengths and wavelengths of Ge-like Zr, Nb and Tc ions have been calculated using the multiconfiguration Dirac-Hartree-Fock method. The Breit interactions and quantum electrodynamics correction were taken into account. The calculated values of energy levels and wavelengths have been compared with other theoretical calculations and available experimental values, good agreements are achieved for most of the energy levels and wavelengths calculated. The number of energy levels and wavelengths considered is larger than that of any other theoretical calculations. And the transition probabilities, line strengths are also given where no other theoretical results and experimental values are available.

Quantitative atomic spectroscopy, a review of progress in the optical-UV region and future opportunities

2019 ◽  
Vol 15 (S350) ◽  
pp. 301-305
Author(s):  
James E. Lawler ◽  
Christopher Sneden ◽  
Elizabeth A. Den Hartog ◽  
John J. Cowan
Keyword(s):  
Transition Probabilities ◽  
Branching Fractions ◽  
Decay Rates ◽  
Atomic Spectroscopy ◽  
Atomic Transition ◽  
Laboratory Astrophysics ◽  
Time Resolved ◽  
University Of Wisconsin ◽  
Cool Stars ◽  
The University

AbstractThe development of tunable dye lasers and a simple atomic and ionic beam source for all elements were critical in establishing a reliable absolute scale for atomic transition probabilities in the optical to near UV regions. The laboratory astrophysics program at the University of Wisconsin - Madison (UW) concentrates on neutral and singly-ionized species transitions that are observable in astronomical spectra of cool stars, emphasizing the rare earth n(eutron)-capture elements and the Fe-group elements that are important inputs to early Galactic nucleosynthesis studies. The UW program is one of several productive efforts on atomic transition probabilities. These programs generally use time-resolved laser-induced-fluorescence (TR-LIF) to accurately measure total decay rates and data from high resolution Fourier transform spectrometers (FTSs) to determine emission branching fractions (BFs). The UW laboratory results almost always are directly linked to astronomical chemical composition efforts. There are good opportunities to extend similar research to other wavelength regions.

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