Second spectrum of Chromium (Cr II), Part II: Radiative lifetimes and oscillator strengths of transitions depopulating low lying 3d<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="mml138" display="inline" overflow="scroll" altimg="si1.gif"><mml:msup><mml:mrow/><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:math>4p levels

Bouazza, S.; Quinet, Pascal; Palmeri, P.

doi:10.1016/j.adt.2017.05.008

Cited by 3 publications

(5 citation statements)

References 21 publications

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“…914, 2899.195, 2945.277, 2967.410, 3013.455 and 3194.200 Å. Moreover, our OSP results are in close agreement with those obtained using our HFR+CPOL model, as described in [2], and with those reported by Kurucz [16]. Such comparisons can be found in Table 2.…”

Section: Oscillator Strength Determinationsupporting

confidence: 91%

“…After studying radiative parameters of low-lying Cr II 3d 4 4p levels [2], we have investigated those of higher excited 3d 4 5s levels with the same success. Using the oscillator strength parameterization method, we have fitted the computed gf-values to available experimental data, confirming in the whole their well founded basis.…”

Section: Resultsmentioning

confidence: 99%

“…The reader is invited to read one of our previous papers, for instance [2,14,15], in which the formulas and the approaches we have used to achieve our calculations are presented in detail. Usually before performing OSP calculations, we first have to select the strongest lines, not blended, and preferably those corresponding to transitions between levels with a limited number of leading components.…”

Section: Oscillator Strength Determinationmentioning

confidence: 99%

“…This paper is the third part of a detailed and systematic analysis of the Cr II spectrum. As a reminder, in the first part [1] we have studied the fine structure in order to obtain level eigenvector to transform into actual intermediate coupling the transition matrix beforehand obtained in pure LS coupling with help of Racah algebra while, in the second part [2], our efforts were mainly focused on radiative transitions depopulating lowlying 3d 4 4p levels. For Cr II the most recent compilation of energy levels is due to Sugar & Corliss [3], based on the analysis of Kiess [4] who succeeded in classifying 1843 lines linking 138 even-parity levels of 3d 5 , 3d 4 4s and 3d 3 4s 2 configurations to 139 3d 4 4p oddparity levels.…”

Section: Introductionmentioning

confidence: 99%

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Second spectrum of chromium (Cr II), Part III: Radiative lifetimes and transition probabilities from highly excited 3d45s levels

Bouazza

Palmeri

Quinet

2018

Atomic Data and Nuclear Data Tables

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In this study we have extended our previous investigations of Cr II spectrum to levels of the 3d 4 5s configuration. Once again an overall good agreement is observed for these levels between experimental oscillator strength values and our calculated data using two different approaches, namely the oscillator strength parameterization and the HFR+CPOL methods. Recurring to the latter model we have computed radiative lifetime values for 20 3d 4 5s levels, confirming the well founded basis of recent experimental data, given in literature. From the use of the former method and with the help of a least squares fitting procedure to available experimental gf-values we have taken advantage of extracting for the first time the transition radial integral value for 3d 4 4p−3d 4 5s, ⟨4p|r 1 |5s⟩ = 1.962±0.005, which is confirmed favorably by ab initio results, obtained by the HFR method scaled by a factor 0.92 or directly by the HFR+CPOL approach. Finally a long list of semi-empirical oscillator strength, transition probability and branching fraction values is generated for around 500 Cr II transitions depopulating the 3d 4 5s levels. Our new gf data are compared successfully with those given by Kurucz.

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Section: Oscillator Strength Determinationsupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Oscillator Strength Determinationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Second spectrum of chromium (Cr II), Part III: Radiative lifetimes and transition probabilities from highly excited 3d45s levels

Bouazza

Palmeri

Quinet

2018

Atomic Data and Nuclear Data Tables

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“…Recent theoretical calculations of transition probabilities include Raassen & Uylings (1996), Kurucz (2016), Bouazza et al (2018a, 2018b), and Tayal & Zatsarinny (2020. The calculations of Bouazza et al (2018a) focus on highly excited 3d 4 5s levels and those of Bouazza et al (2018b) on low-lying 3d 4 4p levels. Both papers focus on levels with previous experimental lifetime measurements.…”

Section: Previous Measurements Of Cr II Transition Probabilitiesmentioning

confidence: 99%

Branching Fractions and Transition Probabilities for UV Transitions in the Spectrum of Cr ii

Ward,

Li,

Schwartz

et al. 2023

ApJ

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We present transition probabilities for 268 spectral lines of singly ionized chromium (Cr ii) in the wavelength region 208–414 nm. Branching fractions were measured in archival Fourier transform spectra of chromium-argon and chromium-neon hollow cathode lamps and a Penning discharge source. The branching fractions were combined with previously published experimental lifetimes of 14 levels, and with lifetimes from semiempirical calculations for 14 levels to give transition probabilities. The estimated uncertainties of the transition probabilities range from 10% to 26%. A comparison with previously published experimental transition probabilities shows discrepancies of up to a factor of 2.5 for lines around 213 nm.

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Collision and Radiative Parameters for Cr ii Lines Observed in Stellar and Nebular Spectra

Tayal

Zatsarinny

2019

ApJ

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Electron excitation collision strengths (Ω) and transition probabilities (A-values) for the iron-peak element Cr ii lines are of high importance for the stellar and nebular abundance studies. Collision and radiative parameters are presented for all possible inelastic transitions between the Cr ii 512 fine-structure levels covering infrared to extreme ultraviolet lines. These parameters should allow a detailed modeling and analysis of the available measured stellar and nebular spectra from different astrophysical objects. Accurate target wave functions have been generated using the multiconfiguration Hartree–Fock method together with term-dependent one-electron orbitals and well-chosen configuration expansions. The wave functions are then used in the calculations of transition probabilities and collision rates. The B-spline Breit–Pauli R-matrix method has been employed for the calculation of electron excitation collision strengths. The semiempirical fine-tuning procedure has been applied to the energies of the local supercluster (LS) terms prior to transformation of the Hamiltonian matrices to intermediate coupling. The Hamiltonian matrices for the calculation of collision rates also include spin–orbit interaction. The 512 fine-structure levels of the Cr ii 3d 5, 3d 44s, , 3d 44p, and 3d 34s4p configurations have been considered in our work. The thermally averaged collision strengths have been determined using a Maxwellian distribution for a wide range of temperatures from 102 to 105 K. The accuracy of our results has been estimated by comparison with other calculated collision rates and available measured radiative rates.

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Second spectrum of Chromium (Cr II), Part II: Radiative lifetimes and oscillator strengths of transitions depopulating low lying 3d44p levels

Cited by 3 publications

References 21 publications

Second spectrum of chromium (Cr II), Part III: Radiative lifetimes and transition probabilities from highly excited 3d45s levels

Second spectrum of chromium (Cr II), Part III: Radiative lifetimes and transition probabilities from highly excited 3d45s levels

Branching Fractions and Transition Probabilities for UV Transitions in the Spectrum of Cr ii

Collision and Radiative Parameters for Cr ii Lines Observed in Stellar and Nebular Spectra

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