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See detailRadiative lifetime measurements and oscillator strength determination for transitions in singly ionized praseodymium (Pr II)
Biémont, Emile ULg; Lefèbvre, P.-H.; Quinet, Pascal ULg et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2003), 27(1), 33-41

New radiative lifetimes for 20 levels of Pr II have been measured using the time-resolved laser-induced fluorescence (LIF) technique. The combination of these experimental values with theoretical ... [more ▼]

New radiative lifetimes for 20 levels of Pr II have been measured using the time-resolved laser-induced fluorescence (LIF) technique. The combination of these experimental values with theoretical branching fractions (BF) obtained with the pseudo-relativistic Hartree-Fock (HFR) approach has allowed us to determine oscillator strengths and transition probabilities for about 150 lines appearing in the spectral region between 369.9 and 741.2 nm. A detailed discussion of our new results and comparisons with previous data are also given in the present paper. [less ▲]

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See detailRadiative lifetime measurements and oscillator strengths of astrophysical interest in HoIII
Zhang, Z. G.; Somesfalean, G.; Svanberg, S. et al

in Astronomy and Astrophysics (2002), 384(1), 364-370

Radiative lifetimes of three long-lived levels belonging to the 4f(10)5d configuration of Ho III have been measured, for the first time, using the time-resolved laser-induced fluorescence technique. A ... [more ▼]

Radiative lifetimes of three long-lived levels belonging to the 4f(10)5d configuration of Ho III have been measured, for the first time, using the time-resolved laser-induced fluorescence technique. A good agreement between the experimental lifetimes and theoretical results obtained within a multiconfigurational pseudo-relativistic Hartree-Fock (HFR) approach including core-polarization (CP) effects is observed provided an adequate scaling factor is applied to the <4f|r|5d> transition matrix element. From the comparison theory-experiment, it has been possible to assess the reliability of the oscillator strengths of the 4f-5d transitions of astrophysical interest, particularly for the lines depopulating the levels considered in the present work. The present results fill in a gap concerning the f-values of doubly ionized holmium and are needed for a quantitative evaluation of the holmium abundance in some peculiar stars. [less ▲]

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See detailRadiative lifetime measurements and semi-empirical transition probability calculations in neutral rhenium
Palmeri, P.; Quinet, Pascal ULg; Biémont, Emile ULg et al

in Physica Scripta (2006), 74(3), 297-303

Radiative lifetimes of 11 odd-parity levels of neutral rhenium (Re I) were measured using time-resolved laser-induced fluorescence techniques. For ten levels, there were no previous results available. The ... [more ▼]

Radiative lifetimes of 11 odd-parity levels of neutral rhenium (Re I) were measured using time-resolved laser-induced fluorescence techniques. For ten levels, there were no previous results available. The new results have been used to assess the accuracy of calculations with a Hartree-Fock-plus-relativistic-corrections model that takes configuration interaction and core-polarization effects into account and they have allowed the deduction of reliable semi-empirical transition probabilities for 81 Re I lines. [less ▲]

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See detailRadiative lifetime measurements and transition probabilities of astrophysical interest in Er III
Biémont, Emile ULg; Garnir, Henri-Pierre ULg; Bastin, Thierry ULg et al

in Monthly Notices of the Royal Astronomical Society (2001), 321

Radiative lifetimes of seven excited states of Er III have been measured using time-resolved laser-induced fluorescence following two-photon excitation. Relativistic Hartree-Fock calculations taking core ... [more ▼]

Radiative lifetimes of seven excited states of Er III have been measured using time-resolved laser-induced fluorescence following two-photon excitation. Relativistic Hartree-Fock calculations taking core-polarization effects into account are found to be in excellent agreement with the experimental results. A large set of new calculated transition probabilities is presented for many transitions of astrophysical interest. These results will be useful for investigating the composition of chemically peculiar stars. [less ▲]

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See detailRadiative lifetime measurements and transition probability calculations in lanthanide ions
Quinet, Pascal ULg; Palmeri, P.; Biémont, Emile ULg et al

in Journal of Alloys and Compounds (2002), 344(1-2), 255-259

We have undertaken a systematic investigation of spectroscopic properties of lanthanide ions (Z=57-71). Using time-resolved laser-induced fluorescence following one- or two-photon excitations, a large ... [more ▼]

We have undertaken a systematic investigation of spectroscopic properties of lanthanide ions (Z=57-71). Using time-resolved laser-induced fluorescence following one- or two-photon excitations, a large number of radiative lifetimes have been measured at the Lund Laser Centre for singly, doubly and trebly ionized atoms. These new measurements have been used for testing theoretical calculations performed within the framework of a relativistic Hartree-Fock approach taking core-polarization effects into account. Using the experimental lifetimes (when available) and the theoretical branching fractions, a large number of transition probabilities, most of them of astrophysical interest, have been deduced and are stored in a new database (DREAM). Up to now, the results obtained concern the following ions: La2+, Ce2+, Ce2+, Pr2+, Ho2+, Er2+, Tm2+, Tm2+, Yb2+, Yb2+, Yb2+, Lu2+ and Lu2+. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailRadiative Lifetime Measurements in Dy II and the Solar Abundance of Dysprosium
Biémont, Emile ULg; Löwe, R. M.

in Astronomy and Astrophysics (1993), 273

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See detailRadiative lifetime measurements in ErII by time-resolved laser spectroscopy
Xu, H. L.; Jiang, Z. K.; Zhang, Z. G. et al

in Journal of Physics B-Atomic Molecular and Optical Physics (2003), 36(9), 1771-1781

Radiative lifetimes of 30 excited states of Er 11, ranging in energy from 25 592 to 36 148 cm(-1), have been measured by means of a time-resolved laser-induced fluorescence (LIF) technique. Free, singly ... [more ▼]

Radiative lifetimes of 30 excited states of Er 11, ranging in energy from 25 592 to 36 148 cm(-1), have been measured by means of a time-resolved laser-induced fluorescence (LIF) technique. Free, singly ionized erbium ions were produced in a laser-induced plasma. A tunable laser, with 1 ns duration pulse, was employed to selectively excite the Er+ ions. The lifetime values were evaluated from the transient LIF signals recorded by a fast detection system. A comparison of the new results with previously published values is given. HFR calculations, including core-polarization contributions, are found to be in reasonable agreement with experiment, but the present calculations clearly indicate that further laboratory and theoretical work is urgently needed, particularly for the low lying odd configurations of this complex ion. [less ▲]

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See detailRadiative lifetime measurements in Tm III with time-resolved laser spectroscopy and comparisons with HFR calculations
Li, Z. S.; Zhang, Z. G.; Lokhnygin, V. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2001), 34

Natural radiative lifetimes of eight levels in Tm III were measured with the time-resolved laser-induced fluorescence (LIF) technique. Free doubly ionized thulium ions were obtained in a laser-produced ... [more ▼]

Natural radiative lifetimes of eight levels in Tm III were measured with the time-resolved laser-induced fluorescence (LIF) technique. Free doubly ionized thulium ions were obtained in a laser-produced plasma. Three even-parity levels were excited from the ground state with one-photon excitation, using a laser system generating pulses of 1 ns duration. Five odd-parity levels were excited from the ground state with two-photon excitation, where a picosecond laser system was employed. In both cases, the lifetimes were evaluated from transient LIF signals detected with a fast-detection system. The experimental lifetime results were compared with Hartree–Fock calculations including relativistic corrections. Good agreement was achieved for the 4f126p levels while larger discrepancies are noted for some 4f125d levels. [less ▲]

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See detailRadiative lifetimes along even-parity J = 1, 2 Rydberg series of neutral tin
Zhang, W.; You, S.; Sun, C. et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2009), 55

Using the time-resolved laser-induced fluorescence (LIF) technique in a tin atomic beam, 40 natural radiative lifetimes have been measured for the even-parity J = 1 5pnp (n = 10–13, 15–19) and J = 2 5pnp ... [more ▼]

Using the time-resolved laser-induced fluorescence (LIF) technique in a tin atomic beam, 40 natural radiative lifetimes have been measured for the even-parity J = 1 5pnp (n = 10–13, 15–19) and J = 2 5pnp (n = 10–13, 15–19, 27, 31, 32), 5pnf (n = 4, 5, 9–19, 22, 23) levels along the Rydberg series and for all the 5p8p perturbing levels of neutral tin with energies in the range 52263.8 to 59099.9 cm−1. A two-step laser excitation scheme was used in the experiment. A multiconfigurational relativistic Hartree-Fock (HFR) calculation taking core-polarization effects into account has also been performed for the even-parity states for testing the ability of this approach to correctly predict the radiative properties of tin atom. Through an analysis of the energy levels structure by the multichannel quantum defect theory (MQDT), the channel admixture coefficients have been obtained and used to fit the theoretical lifetimes to the experimental ones in order to predict new values for the levels not measured. A generally good overall agreement between experimental and theoretical MQDT and HFR lifetimes has been achieved except for a few levels. [less ▲]

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See detailRadiative lifetimes and transition probabilities in Hf I and Hf III
Malcheva, G.; Enzonga Yoca, S.; Mayo, R. et al

in Monthly Notices of the Royal Astronomical Society (2009), 396

Radiative lifetimes of nine odd levels in Hf III (5d6p z3P0,1, z1D2, z3D1,2,3, z3F2,3,4) and of two odd levels in Hf I (5d6s26p z3D2,3) have been determined using Time-Resolved Laser-Induced Fluorescence ... [more ▼]

Radiative lifetimes of nine odd levels in Hf III (5d6p z3P0,1, z1D2, z3D1,2,3, z3F2,3,4) and of two odd levels in Hf I (5d6s26p z3D2,3) have been determined using Time-Resolved Laser-Induced Fluorescence. The investigated levels in Hf I were excited in a single-step process from the ground term (5d26s2 a3F), whereas in Hf III we started from either the ground term 5d2 a3F or the low-lying 5d6s a3D term. For all of the investigated levels, the lifetimes have been measured for the first time. A multiconfiguration relativistic Hartree–Fock method, including core-polarization effects, has been used to compute radiative lifetimes of 15 Hf III levels, including those measured in this work. Transition probabilities for 55 transitions in Hf III are also given. [less ▲]

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See detailRadiative lifetimes and transition probabilities in TaI
Fivet, V.; Palmeri, P.; Quinet, Pascal ULg et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2006), 37(1), 29-35

Radiative lifetimes of 14 odd-parity Ta I levels, belonging to the 5d(3)6s6p and 5d(4)6p configurations in the energy range from 30 664 to 45 256 cm(-1). have been measured using the time-resolved laser ... [more ▼]

Radiative lifetimes of 14 odd-parity Ta I levels, belonging to the 5d(3)6s6p and 5d(4)6p configurations in the energy range from 30 664 to 45 256 cm(-1). have been measured using the time-resolved laser-induced fluorescence technique. Extensive calculations, taking configuration interactions and corepolarisation effects into account, are able to reproduce in a satisfying way the available experimental results but suffer from the rather fragmentary knowledge of the level structure of this atom. New transition probabilities are deduced for a set of strong lines depopulating the levels investigated experimentally in the present work. [less ▲]

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See detailRadiative lifetimes and transition probabilities of astrophysical interest in ZrII
Malcheva, G.; Blagoev, K.; Mayo, R. et al

in Monthly Notices of the Royal Astronomical Society (2006), 367(2), 754-762

Radiative lifetimes of 16 odd levels belonging to the 4d(2)5p configuration of Zr II have been measured using a time-resolved laser-induced fluorescence technique with a single-step excitation process ... [more ▼]

Radiative lifetimes of 16 odd levels belonging to the 4d(2)5p configuration of Zr II have been measured using a time-resolved laser-induced fluorescence technique with a single-step excitation process either from the ground state or from metastable levels belonging to the 4d(2)5s and 4d(3) configurations. For 12 levels, there were no previous results available. The new experimental results and the lifetime values available in the literature have allowed to test a theoretical relativistic Hartree-Fock (HFR) model including core-polarization effects and to deduce transition probabilities for 242 transitions of astrophysical interest in the range 187.8-535.0 nm. [less ▲]

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See detailRadiative Lifetimes for States in Cu I
Biémont, Emile ULg; Fryczynski, F.; Palmeri, P. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (1996), 55

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See detailRadiative Lifetimes for the 4p Excited States of Phosphorus and the Oscillator Strengths of Solar Lines
Berzinsh, U.; Svanberg, S.; Biémont, Emile ULg

in Astronomy and Astrophysics (1997), 326

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See detailRadiative lifetimes in La III and oscillator strengths in La III and Lu III
Biémont, Emile ULg; Li, Z. S.; Palmeri, P. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (1999), 32

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See detailRadiative lifetimes of 6sns S-3(1) and 6snd D-3(1) excited states of HgI
Blagoev, K.; Pentchev, V.; Biémont, Emile ULg et al

in Physical Review A (2002), 66(3),

Natural radiative lifetimes have been measured along the 6sns S-3(1) (n=7-10) and 6snd D-3(1) (n=6-11) Rydberg series of neutral mercury using time-resolved laser-induced fluorescence spectroscopy in a ... [more ▼]

Natural radiative lifetimes have been measured along the 6sns S-3(1) (n=7-10) and 6snd D-3(1) (n=6-11) Rydberg series of neutral mercury using time-resolved laser-induced fluorescence spectroscopy in a laser-produced mercury plasma. The states of Hg I investigated in the present work were populated from the ground state by a stepwise excitation process. Relativistic Hartree-Fock calculations, including intravalence interactions and core-polarization effects, have been performed and the theoretical lifetimes have been compared with the measurements. [less ▲]

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See detailRadiative lifetimes of Cd I and Cd II excited states
Xu, H.; Persson, A.; Svanberg, S. et al

Conference (2004)

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See detailRadiative lifetimes of Zn I, II excited states
Blagoev, K. B.; Malcheva, G.; Penchev, V. et al

in Physica Scripta (2004), 69(6), 433-440

Radiative lifetimes of excited states of Zn I (3d(10)4sns S-3(1), n = 6-8; 3d(10) 4snd D-3, n = 4-7) and Zn II (3d(10) 4p P-2(1/2.3/2), 4d D-2(3/2,5/2), 3d(10)5S S-2(1/2)) have been measured using a time ... [more ▼]

Radiative lifetimes of excited states of Zn I (3d(10)4sns S-3(1), n = 6-8; 3d(10) 4snd D-3, n = 4-7) and Zn II (3d(10) 4p P-2(1/2.3/2), 4d D-2(3/2,5/2), 3d(10)5S S-2(1/2)) have been measured using a time-resolved laser-induced fluorescence technique. Single- or two-step excitation of atoms and ions produced by laser ablation was employed. The experimental radiative lifetimes have been compared with theoretical results obtained within a multiconfigurational relativistic Hartree-Fock approach taking core-polarization effects into account. [less ▲]

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See detailRadiative lifetimes, branching fractions and oscillator strengths in PdI and the solar palladium abundance
Xu, H. L.; Sun, Z. W.; Dai, Z. W. et al

in Astronomy and Astrophysics (2006), 452(1), 357-362

Transition probabilities have been derived for 20 5s-5p transitions of Pd I from a combination of radiative lifetime measurements for 6 odd-parity levels with time-resolved laser-induced fluorescence ... [more ▼]

Transition probabilities have been derived for 20 5s-5p transitions of Pd I from a combination of radiative lifetime measurements for 6 odd-parity levels with time-resolved laser-induced fluorescence spectroscopy and of branching fraction determination using a hollow cathode discharge lamp. Additional oscillator strengths for 18 transitions have been determined from measured lifetimes and theoretical branching fractions obtained from configuration interaction calculations with core-polarization effects included. These new results have allowed us to refine the palladium abundance in the solar photosphere: A(Pd) = 1.66 +/- 0.04, in the usual logarithmic scale, a result in close agreement with the meteoritic value. [less ▲]

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See detailRadiative lifetimes, branching fractions and transition probabilities in Ge I. Solar implications
Biémont, Emile ULg; Lynga, C.; Li, Z. S. et al

in Monthly Notices of the Royal Astronomical Society (1999), 303

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