Université de Fribourg

Double K-shell photoionization of low-Z atoms and He-like ions

Hoszowska, Joanna ; Kheifets, A. S. ; Berset, Michel ; Bray, I. ; Cao, Wei ; Dousse, Jean-Claude ; Fennane, Karima ; Kavčič, M. ; Kayser, Yves ; Szlachetko, Jakub ; Szlachetko, Monika

In: The European Physical Journal: Special Topics, 2009, vol. 169, no. 1, p. 23-27

We report on the investigation of the photon energy dependence of double 1s photoionization of light atoms and compare the cross sections for hollow atom and He-like ion production. Measurements of the Kα hypersatellite x-ray spectra of Mg, Al, and Si were carried out using the Fribourg high-resolution x-ray spectrometer installed at the ID21 and ID26 beam lines at the ESRF. The...

Université de Fribourg

Double K-shell ionization of Al induced by photon and electron impact

Fennane, Karima ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Berset, Michel ; Cao, Wei ; Maillard, Yves-Patrick ; Szlachetko, Jakub ; Szlachetko, Monika ; Kavčič, M.

In: Physical Review A, 2009, vol. 79, no. 3, p. 032708

This paper reports on the investigation of the double K-shell ionization of metallic aluminum induced by photon and electron impact. The experimental method consisted to measure the Kα hypersatellite spectra resulting from the radiative decay of double 1s vacancy states by means of high-resolution x-ray spectroscopy using a Bragg-type von Hamos crystal spectrometer....

Université de Fribourg

Physical mechanisms and scaling laws of K-shell double photoionization

Hoszowska, Joanna ; Kheifets, A. K. ; Dousse, Jean-Claude ; Berset, Michel ; Bray, I. ; Cao, Wei ; Fennane, Karima ; Kayser, Yves ; Kavčič, Matjaz ; Szlachetko, Jakub ; Szlachetko, Monika

In: Physical Review Letters, 2009, vol. 102, no. 7, p. 073006

We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron- electron interaction to the DPI. By comparing the double-to-single...

Université de Fribourg

Relative detection efficiency of back- and front-illuminated charge-coupled device cameras for x-rays between 1 keV and 18 keV

Szlachetko, Jakub ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Berset, Michel ; Cao, Wei ; Szlachetko, Monika ; Kavčič, Matjaz

In: Review of Scientific Instruments, 2007, vol. 78, no. 9, p. 093102

High-resolution x-ray measurements were performed with a von Hamos-type bent crystal spectrometer using for the detection of the diffracted photons either a back- illuminated charge-coupled device (CCD) camera or a front-illuminated one. For each CCD the main x-ray emission lines (e.g., Kα, Kβ, Lα, and Lβ) of a variety of elements were measured in order to probe...

Université de Fribourg

Vacancy rearrangement processes in multiply ionized atoms

Czarnota, M. ; Pajek, M. ; Banas, D. ; Dousse, Jean-Claude ; Maillard, Yves-Patrick ; Mauron, Olivier ; Raboud, Pierre-Alexandre ; Berset, Michel ; Hoszowska, Joanna ; Slabkowska, K. ; Polasik, M. ; Chmielewska, D. ; Rzadkiewicz, J. ; Sujkowski, Z.

In: Journal of Physics: Conference Series, 2007, vol. 58, no. 1, p. 295

We demonstrate that in order to interpret the x-ray satellite structure of Pd Lα1,2(L₃M4,5) transitions excited by fast O ions, which was measured using a high-resolution von Hamos crystal spectrometer, the vacancy rearrangement processes, taking place prior to the x-ray emission, have to be taken into account. The measured spectra were compared with the predictions...

Université de Fribourg

High-resolution study of the x-ray resonant Raman scattering process around the 1s absorption edge for aluminium, silicon, and their oxides

Szlachetko, Jakub ; Dousse, Jean-Claude ; Berset, Michel ; Fennane, Karima ; Szlachetko, Monika ; Hoszowska, Joanna ; Barrett, R. ; Pajek, M. ; Kubala-Kukus, A.

In: Physical Review A, 2007, vol. 75, no. 2, p. 022512

X-ray resonant Raman scattering (RRS) spectra of Al, Al₂O₃, Si, and SiO₂ were measured at the European Synchrotron Radiation Facility, using a high-resolution Bragg-type curved crystal spectrometer. The x-ray RRS spectra were collected at several beam energies tuned below the 1s absorption thresholds of Al and Si. Differences in the spectral features between the elemental samples and...

Université de Fribourg

High-resolution study of x-ray resonant Raman scattering at the k edge of silicon

Szlachetko, Jakub ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Pajek, M. ; Barrett, R. ; Berset, Michel ; Fennane, Karima ; Kubala-Kukus, A. ; Szlachetko, Monika

In: Physical Review Letters, 2006, vol. 97, p. 073001

We report on the first high-resolution measurements of the K x-ray resonant Raman scattering (RRS) in Si. The measured x-ray RRS spectra, interpreted using the Kramers-Heisenberg approach, revealed spectral features corresponding to electronic excitations to the conduction and valence bands in silicon. The total cross sections for the x-ray RRS at the 1s absorption edge and the ...

Université de Fribourg

Resonant X-ray Raman scattering for Al, Si and their oxides

Szlachetko, Jakub ; Berset, Michel ; Dousse, Jean-Claude ; Fennane, Karima ; Szlachetko, Monika ; Barrett, R. ; Hoszowska, Joanna ; Kubala-Kukus, A. ; Pajek, M.

In: Nuclear Instruments and Methods in Physics Research B: Beam Interactions with Materials and Atoms, 2005, vol. 238, p. 353

High-resolution measurements of the resonant X-ray Raman scattering (RRS) of Al and Si and their oxides were performed at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, using a von Hamos Bragg-type curved crystal spectrometer. To probe the influence of chemical effects on the RRS X-ray spectra, Al₂O₃ and SiO₂ samples were also investigated. The X-ray RRS spectra...

Université de Fribourg

Natural widths of hypersatellite K-X-ray lines and lifetimes of double K-hole states in mid-Z atoms

Rzadkiewicz, J. ; Chmielewska, D. ; Sujkowski, Z. ; Berset, Michel ; Dousse, Jean-Claude ; Maillard, Yves-Patrick ; Mauron, Olivier ; Raboud, Pierre-Alexandre ; Polasik, M. ; Słabkowska, K. ; Hoszowska, Joanna ; Pajek, M.

In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2005, vol. 235 (1-4), p. 110-115

K-X-ray spectra of Zr, Nb, Mo and Pd targets bombarded with 250 MeV carbon and 360 MeV oxygen ions are studied with high resolution diffraction spectrometry. Relative yields and natural widths of the Khα1,2 hypersatellite lines are determined and compared with those of the diagram lines. The widths of Khα1,2 lines are compared with the new ...