References of "Biémont, Emile"
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See detailTransition probabilities and lifetimes in gold (Au I and Au II)
Fivet, V.; Quinet, Pascal ULg; Biémont, Emile ULg et al

in Journal of Physics B-Atomic Molecular and Optical Physics (2006), 39(17), 3587-3598

Radiative lifetimes of three odd-parity levels of neutral gold (Au I) and one odd-parity level of singly ionized gold (Au II), measured using the time-resolved laser-induced fluorescence technique, have ... [more ▼]

Radiative lifetimes of three odd-parity levels of neutral gold (Au I) and one odd-parity level of singly ionized gold (Au II), measured using the time-resolved laser-induced fluorescence technique, have allowed the testing of the reliability of a relativistic Hartree-Fock model of the atomic structure taking configuration interaction and core-polarization effects into account. The importance of the inclusion of the latter effects in the calculations is emphasized. The laser-induced fluorescence lifetimes, combined with the theoretical branching fractions, have allowed us to deduce oscillator strengths for six 5d(9)6s(2)-5d(9)6s6p and 5d(10)6s-5d(9)6s6p transitions of Au I and for sixty-three 5d(9)6s-5d(9)6p, 5d(9)6p-5d(9)7s and 5d(10)-5d(9)6p UV transitions of Au II. [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 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 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 detailTransition probabilities and lifetimes in neutral and singly ionized osmium and the Solar osmium abundance
Quinet, Pascal ULg; Palmeri, P.; Biémont, Emile ULg et al

in Astronomy and Astrophysics (2006), 448(3), 1207-93

Radiative lifetime measurements have been performed, with a time-resolved laser-induced fluorescence technique, for 12 levels of Os I and for 9 levels of Os II. For 9 levels of Os I and 4 levels of Os II ... [more ▼]

Radiative lifetime measurements have been performed, with a time-resolved laser-induced fluorescence technique, for 12 levels of Os I and for 9 levels of Os II. For 9 levels of Os I and 4 levels of Os II, there were no previous experimental data available. From a comparison with new theoretical calculations, taking configuration interactions and core-polarization effects into account, it has been possible to deduce oscillator strengths for 129 transitions of Os I and 137 transitions of Os II of astrophysical interest appearing in the wavelength range 180.0-870.0 nm. These results have allowed us to revise the abundance of osmium in the solar photosphere (log epsilon(Os) = 1.25 +/- 0.11). The newly derived oscillator strengths have been applied as well to derive the osmium abundance in the carbon-rich metal-poor star HD 187861. [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 detailAstronomie en Terres d'Islam. Lumières sur la sacralisation de l'espace et du temps
Biémont, Emile ULg

Book published by Burillier, Vannes (2006)

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See detailRadiative parameters for some transitions in the spectrum of Ag-II
Campos, J.; Ortiz, M.; Mayo, R. et al

in Monthly Notices of the Royal Astronomical Society (2005), 363(3), 905-910

Radiative parameters for transitions depopulating the levels belonging to the 4d(8)5s(2), 4d(9)6s and 4d(9)5d configurations of Ag II have been obtained from a combination of theoretical lifetimes and ... [more ▼]

Radiative parameters for transitions depopulating the levels belonging to the 4d(8)5s(2), 4d(9)6s and 4d(9)5d configurations of Ag II have been obtained from a combination of theoretical lifetimes and experimental branching fractions. On the experimental side, a laser-produced plasma was used as a source of Ag+ ions. The light emitted by the plasma was analysed by a grating monochromator coupled with a time-resolved optical multichannel analyser system. Spectral response calibration of the experimental system was performed using a deuterium lamp in the wavelength range from 200 to 400 nm, and a standard tungsten lamp in the range from 350 to 600 nm. The transition probabilities were obtained from measured branching ratios and theoretical radiative lifetimes of the corresponding states calculated with a relativistic Hartree-Fock approach including core-polarization effects and configuration interaction in an extensive way. Theoretical and experimental data have been compared and the new data have also been compared with the few previous results available in the literature. [less ▲]

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See detailLifetimes along perturbed Rydberg series in neutral thallium
Biémont, Emile ULg; Palmeri, P.; Quinet, Pascal ULg et al

in Journal of Physics B-Atomic Molecular and Optical Physics (2005), 38(19), 3547-3558

Radiative lifetimes of 15 Tl I levels belonging to the 6s(2)ns(2)S(1/2) (n = 7-14) and 6s(2)nd(2)D(3/2) Rydberg series (n = 6-12) have been measured using a time-resolved laser-induced fluorescence ... [more ▼]

Radiative lifetimes of 15 Tl I levels belonging to the 6s(2)ns(2)S(1/2) (n = 7-14) and 6s(2)nd(2)D(3/2) Rydberg series (n = 6-12) have been measured using a time-resolved laser-induced fluorescence technique. All the measured levels have been excited from the ground state 6s(2)6p(2)P(1/2)(0) (odd parity) with a single-step excitation process. The general perturbation of the ns series by the 6s6p(2) configuration and the corresponding modification of the lifetimes are adequately reproduced by a theoretical model including core-polarization effects and combined with a least-squares fit to the observed energy levels. The general behaviour of the lifetime values for the 6s(2)np odd levels along the Rydberg series is also well reproduced. The use of the multiconfiguration quantum defect theory has allowed us to obtain lifetime values along the 6s(2)ns(2)S(1/2) series up to levels with n = 31. [less ▲]

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See detailTransition probabilities and lifetimes in singly ionized rhenium
Palmeri, P.; Quinet, Pascal ULg; Biémont, Emile ULg et al

in Monthly Notices of the Royal Astronomical Society (2005), 362(4), 1348-1352

Transition probabilities and radiative lifetimes have been obtained for 45 transitions of Re II using a combination of radiative lifetime values obtained with the laser-induced fluorescence technique ... [more ▼]

Transition probabilities and radiative lifetimes have been obtained for 45 transitions of Re II using a combination of radiative lifetime values obtained with the laser-induced fluorescence technique ( seven levels) and theoretical branching fractions. This new set of results, concerning ultraviolet and visible lines, will be useful in the future for investigating the composition of chemically peculiar stars. [less ▲]

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See detailDisentanglement of magnetic field mixing reveals the spontaneous M2 decay rate for a metastable level in Xe+
Schef, P.; Lundin, P.; Biémont, Emile ULg et al

in Physical Review A (2005), 72(2),

We have investigated the radiative decay of the metastable level 5d(4)D(7/2) in Xe+. Theoretically we find the decay to be heavily dominated by an M2 transition and not by M1/E2 transitions. Lifetime ... [more ▼]

We have investigated the radiative decay of the metastable level 5d(4)D(7/2) in Xe+. Theoretically we find the decay to be heavily dominated by an M2 transition and not by M1/E2 transitions. Lifetime measurements of 5d(4)D(7/2) in a storage ring are difficult since magnetic mixing of the metastable with a short-lived level quenches its population. Decay rates were determined at different magnetic field strengths (B) in order to allow a nonlinear extrapolation to B=0. The experimental lifetime of 2.4 +/- 0.8 s was in agreement with the calculated value, but much smaller than previously estimated. [less ▲]

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See detailRadiative lifetime and oscillator strength determinations in XeVI
Biémont, Emile ULg; Buchard, V.; Garnir, Henri-Pierre ULg et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2005), 33(2), 181-191

Transition probabilities have been calculated for Δ n = 0 and Δ n = 1 transitions connecting the 5s(2) nl [np ( n = 5- 8); nf ( n = 4- 5); nh ( n = 6- 8); nk ( n = 8)], 5s5pnl ( nl = 5d, 6s), 5p(3) and 5s ... [more ▼]

Transition probabilities have been calculated for Δ n = 0 and Δ n = 1 transitions connecting the 5s(2) nl [np ( n = 5- 8); nf ( n = 4- 5); nh ( n = 6- 8); nk ( n = 8)], 5s5pnl ( nl = 5d, 6s), 5p(3) and 5s(2) nl [(ns (n = 6- 8); nd (n = 5- 8); ng ( n = 5- 6); ni ( n = 7- 8)] and 5s5p(2) configurations of Xe VI. Core-polarization effects have been included in the framework of a Hartree-Fock approach. The accuracy of the present set of results has been assessed through comparisons with radiative lifetime measurements. Good agreement has been observed between theory and experiment. [less ▲]

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See detailTransition probabilities in Xe V
Biémont, Emile ULg; Quinet, Pascal ULg; Zeippen, C. J.

in Physica Scripta (2005), 71(2), 163-169

Transition probabilities have been calculated with the pseudorelativistic Hartree-Fock (HFR) approach in which core-polarization effects have been included for Deltan = 0 and Deltan = 1 transitions ... [more ▼]

Transition probabilities have been calculated with the pseudorelativistic Hartree-Fock (HFR) approach in which core-polarization effects have been included for Deltan = 0 and Deltan = 1 transitions connecting the 5s(2)5p(2), 5s(2)5p6p. 5s(2)5p4f and the 5s5p(3). 5s(2)5p5d and 5s(2)5p6s configurations of Xe V. The accuracy of the present set of results is partly assessed through comparisons with the few experimental radiative lifetimes available. The reasons for the discrepancies between theory and experiment are outlined. [less ▲]

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See detailTransition probabilities for lines from 4d96s, 4d95d of Ag II spectrum and from 3d94d of Cu II lines
Biémont, Emile ULg; Blagoev, K.; Campos, J. et al

Conference (2005)

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See detailLes unités de division du temps
Biémont, Emile ULg

in Bulletin de la Société Royale des Sciences de Liège (2005), 74(4), 243-269

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See detailAstronomes célèbres et astronomes moins connus ... (6) John Flamsteed
Biémont, Emile ULg

in Galactée (2005), 46

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See detailRecent advances and difficulties in oscillator strength determination for rare-earth elements and ions
Biémont, Emile ULg

in Physica Scripta (2005), T119

Recent advances regarding radiative parameters determination for rare- earth atoms and ions are briefly discussed. In particular the difficulties associated with both the theoretical and the experimental ... [more ▼]

Recent advances regarding radiative parameters determination for rare- earth atoms and ions are briefly discussed. In particular the difficulties associated with both the theoretical and the experimental investigations of the elements or ions of this group are emphasized. The present status of the DREAM database is also briefly described. [less ▲]

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See detailRadiative parameters for some transitions in Cu(II) and Ag(II) spectrum
Biémont, Emile ULg; Blagoev, K.; Campos, J. et al

in Journal of Electron Spectroscopy & Related Phenomena (2005), 144-147

Radiative parameters for transitions depopulating the levels belonging to the 3d84s2 configuration of Cu(II) and 4d96s and 4d95d configurations of Ag(II) have been obtained both theoretically and ... [more ▼]

Radiative parameters for transitions depopulating the levels belonging to the 3d84s2 configuration of Cu(II) and 4d96s and 4d95d configurations of Ag(II) have been obtained both theoretically and experimentally. On the experimental side, a laser-produced plasma was used as a source of Cu(II) and Ag(II) spectra. The light emitted by the plasma was focused on the input slit of a grating monochromator coupled with a time-resolved optical multichannel analyzer system. Spectral response calibration of the experimental system was made using a deuterium lamp in the wavelength range extending from 200 to 400 nm, and a standard tungsten lamp in the range from 350 to 600 nm. The transition probabilities were obtained using measured branching fractions and available radiative lifetimes of the corresponding states. On the theoretical side, a relativistic Hartree-Fock (HFR) approach, including core-polarization effects, has been used for the calculations. A reasonable agreement theory–experiment has been observed. [less ▲]

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See detailA database of astrophysical interest covering the UV region
Biémont, Emile ULg; Quinet, Pascal ULg

in Journal of Electron Spectroscopy & Related Phenomena (2005), 144-147

Our knowledge of the spectra of the rare-earths is still very poor due to the fragmentary laboratory analyses, on the one hand, and to the complexity of the configurations involving unfilled 4f shells, on ... [more ▼]

Our knowledge of the spectra of the rare-earths is still very poor due to the fragmentary laboratory analyses, on the one hand, and to the complexity of the configurations involving unfilled 4f shells, on the other hand. The database DREAM (Database on Rare Earths at Mons University) contains presently radiative parameters (wavelengths, levels, transition probabilities, Land´e factors) for over 60 000 transitions and is continuously updated. The different tables, which cover not only the UV region, but also the visible and near infrared spectral ranges, which are located on the web page: http://www.umh.ac.be/∼astro/dream.shtml. Up to now, data are tabulated for the following ions : La III, Ce II, Ce III, Pr II, Pr III, Nd II, Nd III, Sm II, Sm III, Eu III, Gd III, Tb III, Dy III, Ho III, Er II, Er III, Tm II, Tm III, Yb II, Yb III, Yb IV, Lu I, Lu II and Lu III. Some information is also provided for Th III. The relevant references (about 40 papers), summarizing and discussing the new experimental and theoretical results obtained during the past few years, are given on this web site. [less ▲]

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