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Guimarães, Diana, Maria Luisa Carvalho, Vera Geraldes, Isabel Rocha, Luís Cerqueira Alves, and Jose Paulo Santos. "Lead in liver and kidney of exposed rats: Aging accumulation study." Journal of Trace Elements in Medicine and Biology 26 (2012): 285. AbstractWebsite

The concentration of lead in liver and kidneys of Wistar rats, fed with lead since fetal period in relation to their age and to a control group, was determined. A group of rats was exposed to lead acetate (n=30) in drinking water and the other group was exposed to normal water (n=20). Samples were collected from rats aging between 1 and 11 months and were analyzed by Energy Dispersive X-ray Fluorescence (EDXRF) without any chemical preparation. The EDXRF results were assessed by the PIXE (Proton Induced X-ray Emission) technique. The formaldehyde used to preserve the samples was also analyzed by ETAAS (Electro-Thermal Atomic Absorption Spectrometry) in order to verify if there was any loss of lead from the samples to the formaldehyde. We found that the loss was not significant (<2%). Concerning the mean values of the lead concentration measured in the contaminated soft tissues, in liver they range from 6 to 22μgg(-1), and in kidneys from 44 to 79μgg(-1). The control rats show, in general, values below the EDXRF detection limit (2μgg(-1)). The ratio kidney/liver ranges from 2 to 10 and is strongly positively correlated with the age of the animals. A Spearman correlation matrix to investigate the correlation between elemental concentrations and the dependence of these concentrations with age showed that there is a strong positive correlation with age for lead in the liver but not in the kidney. The correlation matrix showed also that the concentration of lead in these two soft tissues is not correlated. The lead accumulation in liver is made by different plateaus that strongly decrease with age. It was verified the existence of two levels of accumulation in kidney, not very highlighted, which might be indicative of a maximum accumulation level for lead in kidney.

Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by X-ray Fluorescence and Electrothermal Atomic Absorption Spectrometry." X-Ray Spectrometry In press (2011). Abstract
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Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by x-ray fluorescence and electrothermal atomic absorption spectrometry." X-Ray Spectrom. 41 (2012): 80. Abstract

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Guimarães, D., M. L. Carvalho, M. Becker, A. von Bohlen, V. Geraldes, I. Rocha, and J. P. Santos. "Lead concentration in feces and urine of exposed rats by x-ray fluorescence and electrothermal atomic absorption spectrometry." X-Ray Spectrometry 41 (2012): 80. AbstractWebsite

Measurements made in feces and urine of Wistar rats exposed to lead acetate (n = 20) in drinking water since the fetal period were compared with those obtained from a control group (n = 20) in order to assess the age influence on Pb excretion. The measurements were made in different collections of rats aging between 1 and 11 months. To determine the Pb content of the samples, total reflection X-ray fluorescence (TXRF) and electrothermal atomic absorption spectrometry (ETAAS) were used for the urine samples and energy dispersive X-ray fluorescence (EDXRF) was used for the feces.The results show high concentrations of Pb being eliminated from the organism by urine and feces in contaminated rats. Values vary from (600`140)mgl1 to (5 460`115)mgl1 in urine and from (4 500`300)mgg1 to (11 400`3 300)mgg1 in dry feces. The control rats show, in general, low lead concentrations or below detection limits. The fecal/urinary ratio was studied. It was shown to be about three to four orders of magnitude and positively correlated with time. It was verified in feces and urine that excretion decreases with the animal age and that this decrease is made by different levels of excretion. The excretions of Pb in urine and in feces are positively correlated.A good agreement was found between the results obtained with TXRF and ETAAS for urine samples. This work also stresses the suitability of these techniques in the study of Pb intoxication.

Pohl, Randolf, François Nez, Luis M. P. Fernandes, Marwan Abdou Ahmed, Fernando D. Amaro, Pedro Amaro, François Biraben, João M. R. Cardoso, Daniel S. Covita, Andreas Dax, Satish Dhawan, Marc Diepold, Beatrice Franke, Sandrine Galtier, Adolf Giesen, Andrea L. Gouvea, Johannes Götzfried, Thomas Graf, Theodor W. Hänsch, Malte Hildebrandt, Paul Indelicato, Lucile Julien, Klaus Kirch, Andreas Knecht, Paul Knowles, Franz Kottmann, Julian J. Krauth, Eric-Olivier Le Bigot, Yi-Wei Liu, José A. M. Lopes, Livia Ludhova, Jorge Machado, Cristina M. B. Monteiro, Françoise Mulhauser, Tobias Nebel, Paul Rabinowitz, Joaquim M. F. dos Santos, Jose Paulo Santos, Lukas A. Schaller, Karsten Schuhmann, Catherine Schwob, Csilla I. Szabo, David Taqqu, João F. C. A. Veloso, Andreas Voss, Birgit Weichelt, and Aldo Antognini. "Laser Spectroscopy of Muonic Atoms and Ions." In Proceedings of the 12th International Conference on Low Energy Antiproton Physics (LEAP2016), 1-12. Journal of the Physical Society of Japan, 2017. Abstract
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Pohl, R., and CREMA Collaboration. "Laser Spectroscopy of Muonic Atoms and Ions." JPS Conf. Proc. (2016): 1-12. AbstractWebsite
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Ito, Y., T. Tochio, H. Ohashi, M. Yamashita, S. Fukushima, M. Polasik, K. Słabkowska, Ł. Syrocki, E. Szymańska, J. Rzadkiewicz, P. Indelicato, J. P. Marques, M. C. Martins, J. P. Santos, and F. Parente. "Kα1,2x-ray linewidths, asymmetry indices, and [KM]shake probabilities in elements Ca to Ge and comparison with theory for Ca, Ti, and Ge." Physical Review A 94 (2016): 042506-11. AbstractWebsite
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Marques, J. P., M. Guerra, F. Parente, J. P. Santos, P. Indelicato, and J. M. Sampaio. "K-shell width, fluorescence yield, and Kβ/ Kαintensity ratio calculation for Fe in the Dirac-Fock approach." Journal of Physics: Conference Series 635 (2015): 092094-2. AbstractWebsite
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Santos, J. P., A. M. Costa, M. C. Martins, P. Indelicato, and F. Parente. "K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions." Journal of Physics: Conference Series Accepted (2011).
Santos, J. P., A. M. Costa, M. C. Martins, P. Indelicato, and F. Parente. "K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions." J. Phys.: Conf. Ser. 388 (2012): 152018. AbstractWebsite

Theoretical transition energies and probabilities for He-, Li and Be-like Praseodymium ions are calcu- lated in the framework of the multi-configuration Dirac-Fock method (MCDF), including QED corrections. These calculated values are compared to recent experimental data obtained in the Livermore SuperEBIT electron beam ion trap facility [1].

Santos, J. P., A. M. Costa, M. C. Martins, P. Indelicato, and F. Parente. "K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions." Journal of Physics: Conference Series 388 (2012): 152018. AbstractWebsite

Theoretical transition energies and probabilities for He-, Li and Be-like Praseodymium ions are calcu- lated in the framework of the multi-configuration Dirac-Fock method (MCDF), including QED corrections. These calculated values are compared to recent experimental data obtained in the Livermore SuperEBIT electron beam ion trap facility [1].

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Kim, Y. K., and P. M. Stone. "Ionization of boron, aluminum, gallium, and indium by electron impact." Physical Review A 64 (2001): 052707. AbstractWebsite

Measurements of electron impact ionization of neutral Al, Ga, and In show large cross sections compared to other elements in the same rows of the periodic table. Semiempirical and classical calculations of direct ionization cross sections are all substantially smaller. Calculations by McGuire [Phys. Rev. A 26, 125 (1982)] for aluminum that include excitations to autoionizing 3s3p2 doublet levels are 2.5 times higher than experiment at the peak. We report the direct ionization cross sections based on the binary-encounter-Bethe model of Kim and Rudd [Phys. Rev. A 50, 3954 (1994)], which is an ab initio theory. We add the autoionization contribution using scaled plane-wave Born cross sections as recently developed by Kim [Phys. Rev. A 64, 032713 (2001)] for excitations to the first set of autoionizing levels. Dirac-Fock wave functions are used for the atomic structure. Our results are in excellent agreement with experimental values and support substantial contributions from excitation-autoionization to the total ionization cross sections for these elements. We also compare the total ionization cross section of boron to available theories, though no experimental data are available.

Santos, J. P., and F. Parente. "Ionisation of phosphorus, arsenic, antimony, and bismuth by electron impact." The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics 47 (2008): 339-350. AbstractWebsite
Abstract.  Total ionization cross sections of neutral phosphorus, arsenic, antimony, and bismuth atoms by electron impact are reported and compared to the only available experimental results by Freund et al. [Phys. Rev. A 41, 3575 (1990)]. These calculations take into account the possibilities that some target atoms used in the experiments were in metastable states close to the ground state, the excitation-autoionization of nsnp4 excited states may be substantial, and the ions produced in experiments may be in excited, low-lying metastable states. The cross sections for direct ionization calculations are based on the BEB model by Kim and Rudd [Phys. Rev. A 50, 3954 (1994)]. Plane-wave Born cross sections scaled by the method developed by Kim [Phys. Rev. A 64, 3954 032713 (2001)] are used to determine the contributions from excitation-autoionization. The combination of the BEB model and the scaled Born cross sections is in agreement with the experimental data by Freund et al. These theoretical data are useful to experimentalists and can be used to complete data tables needed for plasma or astrophysical studies.
Santos, J. P., and F. Parente. "Ionisation of phosphorus, arsenic, antimony, and bismuth by electron impact." The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics 47 (2008): 339-350. AbstractWebsite

Abstract.&nbsp;&nbsp;Total ionization cross sections of neutral phosphorus, arsenic, antimony, and bismuth atoms by electron impact are reported and compared to the only available experimental results by Freund et&nbsp;al. [Phys. Rev. A 41, 3575 (1990)]. These calculations take into account the possibilities that some target atoms used in the experiments were in metastable states close to the ground state, the excitation-autoionization of nsnp4 excited states may be substantial, and the ions produced in experiments may be in excited, low-lying metastable states. The cross sections for direct ionization calculations are based on the BEB model by Kim and Rudd [Phys. Rev. A 50, 3954 (1994)]. Plane-wave Born cross sections scaled by the method developed by Kim [Phys. Rev. A 64, 3954 032713 (2001)] are used to determine the contributions from excitation-autoionization. The combination of the BEB model and the scaled Born cross sections is in agreement with the experimental data by Freund et&nbsp;al. These theoretical data are useful to experimentalists and can be used to complete data tables needed for plasma or astrophysical studies.

Szabo, C. I., P. Amaro, M. Guerra, J. P. Santos, A. Gumberidze, J. Attard, and P. Indelicato. "Ion temperature and x-ray line width measurements of highly charged argon ions in an ECR ion source." Physica Scripta T156 (2013): 014077. AbstractWebsite
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Szabo, C. I., P. Amaro, M. Guerra, J. P. Santos, A. Gumberidze, J. Attard, and P. Indelicato. "Ion temperature and x-ray line width measurements of highly charged argon ions in an ECR ion source." Physica Scripta T156 (2013): 014077. AbstractWebsite
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Kup Aylikci, N., J. M. Sampaio, A. Kahoul, V. Aylikci, İ. H. Karahan, M. Guerra, J. P. Santos, J. P. Marques, and E. Tirasoglu. "The investigation of K-shell fluorescence parameters of Zn-Fe alloys with different grain size and microstrain values." X-Ray Spectrometry 406 (2017): 1481-10. AbstractWebsite

It is known that zinc alloys with iron group metals have better corrosion resistance than pure zinc. Owing to the corrosion resistance of these alloys, Zn–Fe coatings are widely used in automotive industry...

Martins, M. C., A. M. Costa, J. P. Santos, P. Indelicato, and F. Parente. "Interpretation of X-ray spectra emitted by Ar ions in an ECR ion source." Journal of Physics B: Atomic and Molecular Physics 34 (2001): 533-543. AbstractWebsite

We examine the most important processes leading to the creation of excited states from the ground configurations of Ar8+ to Ar16+ ions in an electron-cyclotron resonance ion source, which lead to the emission of K x-ray lines. Theoretical values for inner-shell excitation and ionization cross sections, including double KL ionization, transition probabilities and energies for the de-excitation processes, are calculated in the framework of the multi-configuration Dirac-Fock method. With reasonable assumptions about the electron energy distribution, a theoretical K x-ray spectrum is obtained, which reproduces very closely a recent experimental result.

Diepold, Marc, Luis M. P. Fernandes, Jorge Machado, Pedro Amaro, Marwan Abdou-Ahmed, Fernando D. Amaro, Aldo Antognini, François Biraben, Tzu-Ling Chen, Daniel S. Covita, Andreas J. Dax, Beatrice Franke, Sandrine Galtier, Andrea L. Gouvea, Johannes Götzfried, Thomas Graf, Theodor W. Hänsch, Malte Hildebrandt, Paul Indelicato, Lucile Julien, Klaus Kirch, Andreas Knecht, Franz Kottmann, Julian J. Krauth, Yi-Wei Liu, Cristina M. B. Monteiro, Françoise Mulhauser, Boris Naar, Tobias Nebel, François Nez, Jose Paulo Santos, Joaquim M. F. dos Santos, Karsten Schuhmann, Csilla I. Szabo, David Taqqu, João F. C. A. Veloso, Andreas Voss, Birgit Weichelt, and Randolf Pohl. "Improved x-ray detection and particle identification with avalanche photodiodes." Review of Scientific Instruments 86 (2015): 053102-7. AbstractWebsite
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Kasthurirangan, S., J. K. Saha, A. N. Agnihotri, A. Banerjee, A. Kumar, D. Misra, J. P. Santos, A. M. Costa, P. Indelicato, T. K. Mukherjee, and L. C. Tribedi. "High-resolution x-ray spectra from highly charged Si, S and Cl ions showing evidence of fluorescence active resonant states." Journal of Physics: Conference Series 488 (2014): 132027-2. AbstractWebsite

We have measured the x-ray spectra from highly charged Si, S and Cl ions in collisions with thin foils using a high-resolution x-ray spectrometer. The observed lines have been assigned to various transitions in H-, He- and Li-like ions. For proper identification of line positions, the theoretical calculations have been carried out using a state-of-the-art MCDF code including QED effects, with which the experimental data is in excellent agreement. We have also observed, for the first time, x-rays arising out of the decay of long-lived resonant states in the He-like ions of each species. Details will be presented.

Santos, J. P. "HCI 2018." X-Ray Spectrometry (2020). AbstractWebsite
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Marques, J. P., P. Indelicato, F. Parente, J. M. Sampaio, and J. P. Santos. "Ground-state Landé g factors for selected ions along the boron isoelectronic sequence." Physical Review A 94 (2016): 042504. AbstractWebsite

Land\'e $g$ factors for the fine-structure $1{s}^{2}2{s}^{2}2p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2}$ and $^{2}P_{3/2}$ levels in the boron isoelectronic sequence for selected $Z$ values have been calculated using the multiconfiguration Dirac-Fock method with both quantum-electrodynamic and electronic correlation corrections included. All-order Breit and vacuum polarization corrections were included in the calculation, with a fully optimized active set wave function. The results are compared with the available theoretical data, showing a very good agreement.

Marques, J. P., P. Indelicato, F. Parente, J. M. Sampaio, and J. P. Santos. "Ground-state Landé <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>g</mi></math></span> factors for selected ions along the boron isoelectronic sequence." Physical Review A 94 (2016): 042504. AbstractWebsite

Land\'e $g$ factors for the fine-structure $1{s}^{2}2{s}^{2}2p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2}$ and $^{2}P_{3/2}$ levels in the boron isoelectronic sequence for selected $Z$ values have been calculated using the multiconfiguration Dirac-Fock method with both quantum-electrodynamic and electronic correlation corrections included. All-order Breit and vacuum polarization corrections were included in the calculation, with a fully optimized active set wave function. The results are compared with the available theoretical data, showing a very good agreement.

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Santos, J. P., Mauro Guerra, Jorge M. Sampaio, Gonçalo R. Vília, César A. Godinho, Daniel Pinheiro, Pedro Amaro, José P. Marques, Jorge Machado, Paul Indelicato, Fernando Parente, and José Paulo Santos. "Fundamental Parameters Related to Selenium K\alpha and K\beta Emission X-ray Spectra." Atoms (2021). AbstractWebsite
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Kim, Y. K., J. P. Santos, and F. Parente. "Extension of the binary-encounter-dipole model to relativistic incident electrons." Physical Review A 62 (2000): 052710. AbstractWebsite

Formulas for the total ionization cross section by electron impact based on the binary-encounter-dipole (BED) model and its simpler version, the binary-encounter-Bethe (BEB) model are extended to relativistic incident electron energies. Total ionization cross sections for the hydrogen and helium atoms from the new relativistic formulas are compared to experimental data. Relativistic effects double the total ionization cross section of H and He at incident electron energy 300 keV and dominate the cross section thereafter. A simple modification of the original BED-BEB formulas is proposed for applications to ion targets and inner-shell electrons of neutral atoms and molecules. The relativistic and nonrelativistic BEB cross sections are compared to the K-shell ionization cross sections by electron impact for the carbon, argon, nickel, niobium, and silver atoms. For carbon and argon, the relativistic effects are small, and both forms of the BEB cross sections agree well with available experimental data. For the nickel and heavier atoms, the relativistic increase of cross sections becomes noticeable from about 100 keV and higher in the incident electron energy. The empirical formula by Casnati et al. [J. Phys. B 15, 155 (1982)] after correcting for relativistic effects as shown by Quarles [Phys. Rev. A 13, 1278 (1976)] agrees well with the BEB cross sections for light atoms. However, the peak values of the Casnati cross sections become higher than the relativistic BEB peak cross sections as the atomic number increases. The BEB model is also applied to the total ionization cross section of the xenon atom, and the theory agrees well with experiments at low incident electron energies, but disagrees with experiment at relativistic incident energies.