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P
Ménesguen, Y., {M. C. } Lépy, Y. Ito, M. Yamashita, S. Fukushima, M. Polasik, K. Słabkowska, Syrocki, E. Wȩder, P. Indelicato, {J. P. } Marques, {J. M. } Sampaio, M. Guerra, F. Parente, and {J. P. } Santos. "Precise x-ray energies of gadolinium determined by a combined experimental and theoretical approach." Journal Of Quantitative Spectroscopy & Radiative Transfer 236 (2019). Abstract

We combined different experimental techniques with a theoretical approach to determine a consistent set of diagram lines energies and binding energies. We propose an original approach consisting in determining the mass attenuation coefficients in an energy range covering the L-, M- and N- absorption edges, including a detailed evaluation of the associated uncertainties, to derive precisely the binding energies. We investigated the Lα, Lβ and M spectra of Gd with an independantly calibrated high-resolution anti-parallel double-crystal x-ray spectrometer. All the lines were identified and found in excellent agreement with the binding energies previously derived. Morever, we identified for the first time M5−O2, M4−O2,3 and M4−N2,3 diagram lines.

Santos, J. P., M. C. Martins, A. M. Costa, J. P. Marques, P. Indelicato, and F. Parente. "Production and decay of chlorine ion excited species in an electron cyclotron resonance ion source plasma." Physica Scripta T144 (2011): 014005. AbstractWebsite

The most important processes for the creation of chlorine ion excited states from the ground configurations of Cl 10+ to Cl 15+ ions in an electron cyclotron resonance ion source, leading to the emission of K x-ray lines, were studied. Theoretical values for inner-shell excitation and ionization cross-sections, including double KL and triple KLL ionization, transition probabilities and energies for the de-excitation processes, were calculated in the framework of the multi-configuration Dirac–Fock method. With reasonable assumptions about the electron energy distribution, a theoretical Kα x-ray spectrum was obtained, which was then compared with recent experimental data.

Santos, J. P., M. C. Martins, A. M. Costa, J. P. Marques, P. Indelicato, and F. Parente. "Production and decay of chlorine ion excited species in an electron cyclotron resonance ion source plasma." Physica Scripta T144 (2011): 014005. AbstractWebsite

The most important processes for the creation of chlorine ion excited states from the ground configurations of Cl 10+ to Cl 15+ ions in an electron cyclotron resonance ion source, leading to the emission of K x-ray lines, were studied. Theoretical values for inner-shell excitation and ionization cross-sections, including double KL and triple KLL ionization, transition probabilities and energies for the de-excitation processes, were calculated in the framework of the multi-configuration Dirac–Fock method. With reasonable assumptions about the electron energy distribution, a theoretical Kα x-ray spectrum was obtained, which was then compared with recent experimental data.

Martins, M. C., J. P. Marques, A. M. Costa, J. P. Santos, F. Parente, S. Schlesser, Le E. - O. Bigot, and P. Indelicato. "Production and decay of sulfur excited species in an electron-cyclotron-resonance ion-source plasma." Physical Review A (Atomic, Molecular, and Optical Physics) 80 (2009): 032501. AbstractWebsite
The most important processes for the creation of S12+ to S14+ ions excited states from the ground configurations of S9+ to S14+ ions in an electron cyclotron resonance ion source, leading to the emission of K x-ray lines, are studied. Theoretical values for inner-shell excitation and ionization cross sections, including double-KL and triple-KLL ionizations, transition probabilities and energies for the de-excitation processes, are calculated in the framework of the multiconfiguration Dirac-Fock method. With reasonable assumptions about the electron energy distribution, a theoretical Kalpha x-ray spectrum is obtained, which is compared to recent experimental data.
Martins, M. C., J. P. Marques, A. M. Costa, J. P. Santos, F. Parente, S. Schlesser, E. O. Le Bigot, and P. Indelicato. "Production and decay of sulfur excited species in an electron-cyclotron-resonance ion-source plasma." Physical Review A 80 (2009): 032501. AbstractWebsite

The most important processes for the creation of S12+ to S14+ ions excited states from the ground configurations of S9+ to S14+ ions in an electron cyclotron resonance ion source, leading to the emission of K x-ray lines, are studied. Theoretical values for inner-shell excitation and ionization cross sections, including double-KL and triple-KLL ionizations, transition probabilities and energies for the de-excitation processes, are calculated in the framework of the multiconfiguration Dirac-Fock method. With reasonable assumptions about the electron energy distribution, a theoretical Kalpha x-ray spectrum is obtained, which is compared to recent experimental data.

Q
Indelicato, P., J. P. Santos, S. Boucard, and J. P. Descalux. "QED and relativistic corrections in superheavy elements." The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics 45 (2007): 155-170. AbstractWebsite
In this paper we review the different relativistic and QED contributions to energies, ionic radii, transition probabilities and Landé g-factors in super-heavy elements, with the help of the MultiConfiguration Dirac-Fock method (MCDF). The effects of taking into account the Breit interaction to all orders by including it in the self-consistent field process are demonstrated. State of the art radiative corrections are included in the calculation and discussed. We also study the non-relativistic limit of MCDF calculation and find that the non-relativistic offset can be unexpectedly large.
Indelicato, P., J. P. Santos, S. Boucard, and J. P. Descalux. "QED and relativistic corrections in superheavy elements." The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics 45 (2007): 155-170. AbstractWebsite

In this paper we review the different relativistic and QED contributions to energies, ionic radii, transition probabilities and Landé g-factors in super-heavy elements, with the help of the MultiConfiguration Dirac-Fock method (MCDF). The effects of taking into account the Breit interaction to all orders by including it in the self-consistent field process are demonstrated. State of the art radiative corrections are included in the calculation and discussed. We also study the non-relativistic limit of MCDF calculation and find that the non-relativistic offset can be unexpectedly large.Topical Issue on the Atomic Properties of the Heaviest Elements

Guimarães, D., A. A. Dias, M. Carvalho, M. L. Carvalho, J. P. Santos, F. R. Henriques, F. Curate, and S. Pessanha. "Quantitative determinations and imaging in different structures of buried human bones from the XVIII-XIXth centuries by energy dispersive X-ray fluorescence – Postmortem evaluation." Talanta 155 (2016): 107-115. AbstractWebsite

Talanta, 155 + (2016) 107-115. doi:10.1016/j.talanta.2016.04.028

Fratini, F., L. Safari, A. G. Hayrapetyan, K. Jankala, P. Amaro, and J. P. Santos. "Quantized form factor shift in the presence of free electron laser radiation." EPL (Europhysics Letters) 107 (2014): 13002. AbstractWebsite

In electron scattering, the target form factors contribute significantly to the diffraction pattern and carry information on the target electromagnetic charge distribution. Here we show that the presence of electromagnetic radiation, as intense as currently available in free electron lasers, shifts the dependence of the target form factors by a quantity that depends on the number of photons absorbed or emitted by the electron as well as on the parameters of the electromagnetic radiation. As example, we show the impact of intense ultraviolet and soft X-ray radiation on elastic electron scattering by the Ne-like argon ion and by the xenon atom. We find that the shift brought by the radiation to the form factor is of the order of some percent. Our results may open up a new avenue to explore matter with the assistance of laser.

Fratini, F., L. Safari, A. G. Hayrapetyan, K. Jankala, P. Amaro, and J. P. Santos. "Quantized form factor shift in the presence of free electron laser radiation." EPL (Europhysics Letters) 107 (2014): 13002. AbstractWebsite

In electron scattering, the target form factors contribute significantly to the diffraction pattern and carry information on the target electromagnetic charge distribution. Here we show that the presence of electromagnetic radiation, as intense as currently available in free electron lasers, shifts the dependence of the target form factors by a quantity that depends on the number of photons absorbed or emitted by the electron as well as on the parameters of the electromagnetic radiation. As example, we show the impact of intense ultraviolet and soft X-ray radiation on elastic electron scattering by the Ne-like argon ion and by the xenon atom. We find that the shift brought by the radiation to the form factor is of the order of some percent. Our results may open up a new avenue to explore matter with the assistance of laser.

Amaro, Pedro, Beatrice Franke, Julian J. Krauth, Marc Diepold, Filippo Fratini, Laleh Safari, Jorge Machado, Aldo Antognini, Franz Kottmann, Paul Indelicato, Randolf Pohl, and Jose Paulo Santos. "Quantum interference effects in laser spectroscopy of muonic hydrogen, deuterium, and helium-3." Physical Review A 92 (2015): 022514-7. AbstractWebsite
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Amaro, Pedro, Filippo Fratini, Laleh Safari, Aldo Antognini, Paul Indelicato, Randolf Pohl, and Jose Paulo Santos. "Quantum interference shifts in laser spectroscopy with elliptical polarization." Physical Review A 92 (2015): 062506-5. AbstractWebsite
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R
Santos, J. P., F. Parente, M. C. Martins, P. Indelicato, E. P. Benis, T. J. M. Zouros, and J. P. Marques. "Radiative transition rates of 1s2s(3S)3p levels for Li-like ions with 5 <= Z <= 10." Nuclear Inst. and Methods in Physics Research, B 408 (2017): 100-102. AbstractWebsite

Nuclear Inst. and Methods in Physics Research, B, 408 (2017) 100-102. doi:10.1016/j.nimb.2017.04.015

Szabo, Csilla I., Pedro Amaro, Mauro Guerra, Sophie Schlesser, Alexander Gumberidze, Jose Paulo Santos, and Paul Indelicato. "Reference free, high-precision measurements of transition energies in few electron argon ions." AIP APPLICATION OF ACCELERATORS IN RESEARCH AND INDUSTRY: Twenty-Second International Conference 1525 (2013): 68-72. AbstractWebsite

The use of a vacuum double crystal spectrometer, coupled to an electron-cyclotron resonance ion source (ECRIS), allows to measure low-energy x-ray transitions energies in highly-charged ions with accuracies of the order of a few parts per million. We have used this installation to measure the 1s2p 1 P1 - 1s2 1 S0 diagram line and the 1s2s 3 S1 - 1s2 1 S0 forbidden M1 transition energies in helium-like argon, the 1s2s2p 2 P j 1s2 2s 2 S1/2 transitions in lithium-like argon and the 1s2s2 2p 1 P1 - 1s2 2s2 1 S0 transition in beryllium-like argon. These transition measurements have accuracies between 2 and 4 ppm depending on the line intensity. Thanks to the excellent agreement between the simulations and the measurements, we were also able to measure the transition width of all the allowed transitions. The results are compared to recent QED and relativistic many-body calculations.

Szabo, Csilla I., Pedro Amaro, Mauro Guerra, Sophie Schlesser, Alexander Gumberidze, Jose Paulo Santos, and Paul Indelicato. "Reference free, high-precision measurements of transition energies in few electron argon ions." AIP Conf. Proc. 1525 (2013): 68-72. AbstractWebsite

The use of a vacuum double crystal spectrometer, coupled to an electron-cyclotron resonance ion source (ECRIS), allows to measure low-energy x-ray transitions energies in highly-charged ions with accuracies of the order of a few parts per million. We have used this installation to measure the 1s2p 1 P1 - 1s2 1 S0 diagram line and the 1s2s 3 S1 - 1s2 1 S0 forbidden M1 transition energies in helium-like argon, the 1s2s2p 2 P j 1s2 2s 2 S1/2 transitions in lithium-like argon and the 1s2s2 2p 1 P1 - 1s2 2s2 1 S0 transition in beryllium-like argon. These transition measurements have accuracies between 2 and 4 ppm depending on the line intensity. Thanks to the excellent agreement between the simulations and the measurements, we were also able to measure the transition width of all the allowed transitions. The results are compared to recent QED and relativistic many-body calculations.

Santos, J. P., J. Machado, Guojie Bian, Nancy Paul, M. Trassinelli, P. Amaro, M. Guerra, C. I. Szabo, A. Gumberidze, J. M. Isac, J. P. Santos, J. P. Desclaux, and P. Indelicato. "Reference-free measurements of the 1s2s2p2P1/2,3/2o\rightarrow1s22s2S1/2 and 1s2s2p4P5/2\rightarrow1s22s2S1/2 transition energies and widths in lithiumlike sulfur and argon ions." Physical Review A (2020). AbstractWebsite
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Santos, J. P., J. P. Marques, F. Parente, E. Lindroth, P. Indelicato, and J. P. Desclaux. "Relativistic 2s1/2 (L1) atomic subshell decay rates and fluorescence yields for Yb and Hg." Journal of Physics B: Atomic and Molecular Physics 32 (1999): 2089. AbstractWebsite
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Santos, J. P., J. P. Marques, F. Parente, P. Indelicato, and J. P. Desclaux. "Relativistic 2s1/2 (L1) atomic subshell radiationless transition probabilities for Yb and Hg." Atomic Data and Nuclear Data Tables 76 (2000): 49-69. Abstract

Radiationless transition rates to L1 vacancy states have been calculated ab initio in the Dirac-Fock approximation. The calculations include quantum-electrodynamic corrections. Results in the jj coupling scheme for all possible L1 transitions are tabulated for elements Yb and Hg.

Indelicato, P., G. C. Rodrigues, E. Lindroth, M. A. Ourdane, F. Parente, J. P. Santos, P. Patté, and J. Bieron. "Relativistic and many-body effects on total binding energies of Cesium and other highly-charged ion." Physica Scripta T92 (2001): 327. Abstract

The determination of atomic masses from highly ionized atoms using Penning Traps requires precise values for electronic binding energies. In the present work, binding energies of several ions (from several elements) are calculated in the framework of two relativistic many-body methods: Relativistic Many-Body Perturbation Theory (RMBPT) and Multi-Configuration Dirac– Fock (MCDF). The ions studied in this work are: Cl (He and Li-like), Se (F and Ne-like), Cs (He, Be, Ne, Al, Cl, Ar, K, Kr, Xe-like and neutral Cs), Hg, Pb and U (Br and Kr-like). Some of them are presented in this paper. Cesium has been treated in more details, allowing for a systematic comparison between MCDF and RMBPT methods. The Cs ions binding energies allow for the determination of atomic Cs mass, which can be used in a QED-independent fine structure constant determination.

Costa, A. M., M. C. Martins, J. P. Santos, P. Indelicato, and F. Parente. "Relativistic calculation of Kα hypersatellite line energies and transition probabilities for selected atoms with 12<=Z<=80." Journal of Physics B: Atomic, Molecular and Optical Physics 40 (2007): 57. AbstractWebsite
The transition probabilities of Kα hypersatellite lines and energy shifts with respect to the corresponding diagram lines are computed using the Dirac–Fock model for several values of atomic number Z throughout the periodic table. The influence of the Breit interaction on the Kα1h/Kα2h line intensity ratio, Kα1h and Kα2h line energy shifts and Kα1h to Kα2h line energy splitting is evaluated. Double-K shell hole threshold values for selected elements with 23 ⩽Z⩽ 30, calculated within the same approach, are compared with available experimental results.
Costa, A. M., M. C. Martins, J. P. Santos, P. Indelicato, and F. Parente. "Relativistic calculation of K&alpha; hypersatellite line energies and transition probabilities for selected atoms with 12 ≤ Z ≤ 80." Journal of Physics B: Atomic, Molecular and Optical Physics 40 (2007): 57. AbstractWebsite

The transition probabilities of K&alpha; hypersatellite lines and energy shifts with respect to the corresponding diagram lines are computed using the Dirac&ndash;Fock model for several values of atomic number <I>Z</I> throughout the periodic table. The influence of the Breit interaction on the K&alpha;<SUB>1</SUB><SUP>h</SUP>/K&alpha;<SUB>2</SUB><SUP>h</SUP> line intensity ratio, K&alpha;<SUB>1</SUB><SUP>h</SUP> and K&alpha;<SUB>2</SUB><SUP>h</SUP> line energy shifts and K&alpha;<SUB>1</SUB><SUP>h</SUP> to K&alpha;<SUB>2</SUB><SUP>h</SUP> line energy splitting is evaluated. Double-K shell hole threshold values for selected elements with 23 &les;<I>Z</I>&les; 30, calculated within the same approach, are compared with available experimental results.

Madeira, T. I., J. M. Sampaio, M. Guerra, F. Parente, P. Indelicato, J. P. Santos, and J. P. Marques. "Relativistic calculation of K-, L- and M-shell x-ray fluorescence yields for Ba." Physica Scripta 90 (2015): 1-3. AbstractWebsite

Physica Scripta, 90(2015) 054009. doi:10.1088/0031-8949/90/5/054009

Costa, A. M., M. C. Martins, J. P. Santos, P. Indelicato, and F. Parente. "Relativistic calculation of Kβ hypersatellite energies and transition probabilities for selected atoms with 13 ≤ Z ≤ 80." Journal of Physics B: Atomic and Molecular Physics 39 (2006): 2355-2366. AbstractWebsite

Energies and transition probabilities of Kβ hypersatellite lines are computed using the Dirac–Fock model for several values of Z throughout the periodic table. The influence of the Breit interaction on the energy shifts from the corresponding diagram lines and on the Kβh1/Kβh3 intensity ratio is evaluated. The widths of the double-K hole levels are calculated for Al and Sc. The results are compared to experiment and to other theoretical calculations.Al_Sc_Mg_Ti