References of "Lundberg, H"
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See detailOscillator strengths for lines of astrophysical interest in Rh II
Quinet, Pascal ULg; Biémont, E; Palmeri, P et al

in Astronomy and Astrophysics (2012), 537

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See detailAtomic data for VUV lines of astrophysical interest in singly ionized rhodium
Quinet, Pascal ULg; Biémont, E; Palmeri, P et al

in Journal of Electron Spectroscopy & Related Phenomena (2011), 184

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See detailRadiative parameters of Nb I excited states
Malcheva, G; Nilsson, H; Engström, L et al

in Monthly Notices of the Royal Astronomical Society (2011), 412

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See detailLifetime measurements and calculations in Y+ and Y2+ ions
Biémont, E; Blagoev, K; Engström, L et al

in Monthly Notices of the Royal Astronomical Society (2011), 414

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See detailLifetime measurements and transition probabilities in Mo II
Lundberg, H; Engström, L; Hartman, H et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2010), 43

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See detailExperimental and theoretical lifetimes and transition probabilities in Sb I
Hartman, H; Nilsson, H; Engström, L et al

in Physical Review. A (2010), 82

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See detailTransition probabilities of astrophysican interest in the niobium ions (Nb II and Nb III)
Nilsson, H.; Hartman, H.; Engström, L. et al

in Astronomy and Astrophysics (2010)

Aims. We attempt to derive accurate transition probabilities for astrophysically interesting spectral lines of Nb ii and Nb iii and determine the niobium abundance in the Sun and metal-poor stars rich in ... [more ▼]

Aims. We attempt to derive accurate transition probabilities for astrophysically interesting spectral lines of Nb ii and Nb iii and determine the niobium abundance in the Sun and metal-poor stars rich in neutron-capture elements. Methods. We used the time-resolved laser-induced fluorescence technique to measure radiative lifetimes in Nb ii. Branching fractions were measured from spectra recorded using Fourier transform spectroscopy. The radiative lifetimes and the branching fractions were combined yielding transition probabilities. In addition, we calculated lifetimes and transition probablities in Nb ii and Nb iii using a relativistic Hartree-Fock method that includes core polarization. Abundances of the sun and five metal-poor stars were derived using synthetic spectra calculated with the MOOG code, including hyperfine broadening of the lines. Results. We present laboratory measurements of 17 radiative lifetimes in Nb ii. By combining these lifetimes with branching fractions for lines depopulating the levels, we derive the transition probabilities of 107 Nb ii lines from 4d35p configuration in the wavelength region 2240−4700 Å. For the first time, we present theoretical transition probabilities of 76 Nb III transitions with wavelengths in the range 1430−3140 Å. The derived solar photospheric niobium abundance log = 1.44 ± 0.06 is in agreement with the meteoritic value. The stellar Nb/Eu abundance ratio determined for five metal-poor stars confirms that the r-process is a dominant production method for the n-capture elements in these stars. [less ▲]

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See detailRadiative decay data for highly excited Zr I levels
Malcheva, G.; Mayo, R.; Ortiz, M. et al

in Monthly Notices of the Royal Astronomical Society (2009), 395

Radiative lifetimes of 17 excited levels in Zr I, in the energy interval 29 000–40 974 cm−1, have been investigated using the time-resolved laser-induced fluorescence method. The levels belong to the ... [more ▼]

Radiative lifetimes of 17 excited levels in Zr I, in the energy interval 29 000–40 974 cm−1, have been investigated using the time-resolved laser-induced fluorescence method. The levels belong to the 4d25s5p, 4d35p and 4d5s25p electronic configurations and were excited in a single-step process from either the ground term, 4d25s2 a 3F, or from the low-lying 4d25s2 a 3P and a 5F terms. For three levels, we confirm previous measurements while for 14 of the levels the lifetimes have been measured for the first time. The experimental results are compared to theoretical calculations performed with a multiconfiguration relativistic Hartree–Fock method including core-polarization effects. Theoretical transition probabilities of astrophysical interest, scaled by the experimental lifetimes, for the depopulating channels of the investigated levels are also presented. [less ▲]

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See detailBranching fractions and A values in singly ionized tantalum (Ta II)
Quinet, Pascal ULg; Fivet, V.; Palmeri, P. et al

in Astronomy and Astrophysics (2009), 493

Aims. We report on the theoretical and experimental lifetimes of Ta II, and calculated branching fractions for selected transitions. Methods. The theoretical data are obtained by means of a relativistic ... [more ▼]

Aims. We report on the theoretical and experimental lifetimes of Ta II, and calculated branching fractions for selected transitions. Methods. The theoretical data are obtained by means of a relativistic Hartree-Fock method with detailed attention to correlation effects. The experimental lifetimes are measured with the time-resolved, laser-induced, fluorescence technique. Results. The calculated results are in good agreement with both previously known and new experimental lifetimes. New transition probabilities have been deduced for a set of Ta II transitions of astrophysical interest. [less ▲]

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See detailExperimental and theoretical radiative decay rates for highly excited ruthenium atomic levels and the solar abundance of ruthenium
Fivet, V.; Quinet, Pascal ULg; Palmeri, P. et al

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

The solar photospheric abundance of ruthenium is revised on the basis of a new set of oscillator strengths derived for Ru I transitions with wavelengths in the spectral range 2250–4710 Å. The new ... [more ▼]

The solar photospheric abundance of ruthenium is revised on the basis of a new set of oscillator strengths derived for Ru I transitions with wavelengths in the spectral range 2250–4710 Å. The new abundance value (in the usual logarithmic scale where the solar hydrogen abundance is equal to 12.00), ARu = 1.72 ± 0.10, is in agreement with the most recent meteoritic result, ARu = 1.76 ± 0.03. The accuracy of the transition probabilities, obtained using a relativistic Hartree–Fock model including core-polarization effects, has been assessed by comparing the theoretical lifetimes with previous experimental results. A comparison is also made with new measurements performed in this work by the time-resolved laser-induced fluorescence spectroscopy for 10 highly excited odd-parity levels of Ru I [less ▲]

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See detailLifetime measurements in Ru II and calculated oscillator strengths in Ru II and Ru III
Palmeri, P.; Quinet, Pascal ULg; Fivet, V. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2009), 42

A new set of theoretical f -values is reported for 178 Ru II transitions of astrophysical interest, involving energy levels below 58 000 cm−1. The theoretical model, including core-polarization effects ... [more ▼]

A new set of theoretical f -values is reported for 178 Ru II transitions of astrophysical interest, involving energy levels below 58 000 cm−1. The theoretical model, including core-polarization effects, has been tested by comparing theoretical lifetimes with new measurements performed by time-resolved laser-induced fluorescence spectroscopy for 23 4d6(5D)5p odd levels of Ru II and by comparing theoretical and experimental Land´e g-factors. The first set of transition probabilities is proposed for 25 strong lines depopulating the 4d55p 5,7P◦ terms of Ru III. The new results will allow quantitative investigations of stellar spectra and allow the astrophysicists to refine the ruthenium abundance in stars. [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 data in the Zr I spectrum obtained by Laser Induced Fluorescence
Malcheva, G.; Mayo, R.; Ortiz, M. et al

Conference (2008)

Radiative lifetimes of 17 excited states in Zr I, in the energy interval 29000 – 40974 cm-1, have been investigated using the Time-Resolved Laser-Induced Fluorescence (TR-LIF) method. The levels belong to ... [more ▼]

Radiative lifetimes of 17 excited states in Zr I, in the energy interval 29000 – 40974 cm-1, have been investigated using the Time-Resolved Laser-Induced Fluorescence (TR-LIF) method. The levels belong to the 4d25s5p, 4d35p and 4d5s25p electronic configurations were excited in a single - step process from levels belonging to the ground 4p25s2 a 3F or to low-lying 4p25s2 a 3P, a 5F terms. For 14 levels, the lifetimes have been measured for the first time. Experimental results are compared with theoretical calculations performed with a multiconfigurational relativistic Hartree–Fock method including core polarization effects. [less ▲]

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See detailLifetime measurements and calculated transition probabilities in WIII
Palmeri, P.; Quinet, Pascal ULg; Fivet, V. et al

in Physica Scripta (2008), 78

New experimental lifetimes for two levels in doubly ionized tungsten, W III, have been obtained using the time-resolved laser-induced-fluorescence technique. Theoretical oscillator strengths obtained from ... [more ▼]

New experimental lifetimes for two levels in doubly ionized tungsten, W III, have been obtained using the time-resolved laser-induced-fluorescence technique. Theoretical oscillator strengths obtained from a HFR calculation including the effects of core-polarization are reported for all transitions from levels below E < 70 000 cm−1 and with log g f > −2, thus greatly extending our knowledge of the radiative data in W III. Good agreement is found between the calculated lifetimes and the experimental values from this and previous works. These new results fill a gap in the available data for this ion which is expected to play an important role in fusion reactors. [less ▲]

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See detailLifetime measurements and transition probability calculations in singly ionized tungsten (WII)
Nilsson, H.; Engström, L.; Lundberg, H. et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2008), 49

New measurements of radiative lifetimes for 9 levels in singly ionized tungsten (Wii) have been performed with the time-resolved laser-induced-fluorescence technique. Transition probabilities have been ... [more ▼]

New measurements of radiative lifetimes for 9 levels in singly ionized tungsten (Wii) have been performed with the time-resolved laser-induced-fluorescence technique. Transition probabilities have been obtained from a combination of experimental lifetimes and theoretical branching fractions. The reliability of the present results is assessed through the good agreement observed between the calculated lifetimes and the experimental values from this work and from previous publications. These new results fill in a gap in the available data for this atomic species particularly important for fusion reactors. [less ▲]

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See detailRadiative lifetime measurements and calculations in doubly ionized tantalum (Ta III)
Fivet, V.; Biémont, Emile ULg; Engström, L. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2008), 41

Radiative lifetimes of six odd-parity levels belonging to the 5d26p configuration of doubly ionized tantalum (Ta III) have been measured using the time-resolved-laser-inducedfluorescence technique ... [more ▼]

Radiative lifetimes of six odd-parity levels belonging to the 5d26p configuration of doubly ionized tantalum (Ta III) have been measured using the time-resolved-laser-inducedfluorescence technique. Supporting theoretical calculations, including core-polarization effects, have been performed to model configuration interaction and to estimate branching fractions. The excellent agreement between the theoretical and experimental lifetimes allows us to assess the reliability of the 206 calculated transition probabilities. It is expected that this new set of results will be useful to astrophysicists for the investigation of the chemical composition of stars. [less ▲]

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See detailLaser-induced-fluorescence lifetime measurements and relativistic Hartree-Fock oscillator strength calculations in singly ionized platinum
Quinet, Pascal ULg; Palmeri, P.; Fivet, V. et al

in Physical Review. A (2008), 77

Radiative lifetimes of eight odd-parity states of Pt II, in the energy range from 51 408 to 64 388 cm−1, have been measured by means of the time-resolved laser-induced-fluorescence technique. Free, singly ... [more ▼]

Radiative lifetimes of eight odd-parity states of Pt II, in the energy range from 51 408 to 64 388 cm−1, have been measured by means of the time-resolved laser-induced-fluorescence technique. Free, singly ionized platinum ions were obtained in a laser-produced plasma and a tunable laser with 1.5 ns duration pulse was used to selectively excite the Pt+ ions. The comparison of the experimental results with relativistic Hartree-Fock calculations emphasizes the importance of valence-valence correlation and of core-polarization effects in this complex ion. A new and extensive set of calculated oscillator strengths and transition probabilities is reported in the present paper. [less ▲]

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