Université de Fribourg

Novel reference-free methods for the determination of the instrumental response of Laue-type bent crystal spectrometers

Szlachetko, Monika ; Hoszowska, Joanna ; Szlachetko, Jakub ; Dousse, Jean-Claude

In: Journal of Analytical Atomic Spectrometry, 2019, vol. 34, no. 11, p. 2325–2332

We report on novel reference-free methods to determine the instrumental resolution of transmission-type bent crystal spectrometers. The novel methods are based on the measurements of a selected X-ray line in several orders of diffraction. It is shown that the angular broadening of the spectrometer and the natural linewidth of the selected transition can be obtained directly from the novel...

Université de Fribourg

A DuMond-type crystal spectrometer for synchrotron-based X-ray emission studies in the energy range of 15–26 keV

Jagodziński, Paweł ; Szlachetko, Jakub ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Szlachetko, Monika ; Vogelsang, U. ; Banaś, Dariusz ; Pakendorf, T. ; Meents, A. ; Bokhoven, Jeroen A. van ; Kubala-Kukuś, Aldona ; Pajek, Marek ; Nachtegaal, Maarten

In: Review of Scientific Instruments, 2019, vol. 90, no. 6, p. 063106

The design and performance of a high-resolution transmission-type X-ray spectrometer for use in the 15–26 keV energy range at synchrotron light sources is reported. Monte Carlo X-ray-tracing simulations were performed to optimize the performance of the transmission-type spectrometer, based on the DuMond geometry, for use at the Super X-ray absorption beamline of the Swiss Light Source at...

Université de Fribourg

Double K-shell photoionization and hypersatellite x-ray transitions of 12⩽Z⩽23 atoms

Hoszowska, Joanna ; Dousse, Jean-Claude ; Cao, Wei ; Fennane, Karima ; Kayser, Yves ; Szlachetko, Monika ; Szlachetko, Jakub ; Kavčič, Matjaz

In: Physical Review A, 2010, vol. 82, no. 6, p. 063408

Single-photon double K-shell ionization of low-Z neutral atoms in the range 12⩽Z⩽23 is investigated. The experimental method was based on measurements of the high- resolution Kαh hypersatellite x-ray spectra following the radiative decay of the K-shell double-vacancy states excited by monochromatic synchrotron radiation. The photon energy dependence of the double K-shell ionization was...

Université de Fribourg

High-resolution Laue-type DuMond curved crystal spectrometer

Szlachetko, Monika ; Berset, Michel ; Dousse, Jean-Claude ; Hoszowska, J. ; Szlachetko, Jakoub

In: Review of Scientific Instruments, 2013, vol. 84, no. 9, p. 093104

We report on a high-resolution transmission-type curved crystal spectrometer based on the modified DuMond slit geometry. The spectrometer was developed at the University of Fribourg for the study of photoinduced X-ray spectra. K and L X-ray transitions with energies above about 10 keV can be measured with an instrumental resolution comparable to their natural linewidths. Construction details and...

Université de Fribourg

A von Hamos x-ray spectrometer based on a segmented-type diffraction crystal for single-shot x-ray emission spectroscopy and time-resolved resonant inelastic x-ray scattering studies

Szlachetko, Jakoub ; Nachtegaal, M. ; Boni, E. de ; Willimann, M. ; Safonova, O. ; Sa, J. ; Smolentsev, G. ; Szlachetko, Monika ; Bokhoven, J. A. van ; Dousse, Jean-Claude ; Hoszowska, J. ; Kayser, Yves ; Jagodziński, P. ; Bergamaschi, A. ; Schmitt, Bernd ; David, Christian ; Lücke, A.

In: Review of Scientific Instruments, 2012, vol. 83, no. 10, p. 103105

We report on the design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry. The spectrometer is equipped with a segmented-type crystal for x-ray diffraction and provides an energy resolution in the order of 0.25 eV and 1 eV over an energy range of 8000 eV–9600 eV. The use of a segmented crystal results in a simple and straightforward crystal preparation...

Université de Fribourg

Single-photon double K-shell ionization of low-Z atoms

Hoszowska, Joanna ; Kheifets, A. S. ; Dousse, Jean-Claude ; Bray, Igor ; Cao, Wei ; Fennane, Karima ; Kayser, Yves ; Kavčič, Matjaz ; Szlachetko, Jakub ; Szlachetko, Monika

In: Journal of Physics: Conference Series, 2010, vol. 212, no. 1, p. 012006

The photon energy dependence of the double K-shell ionization of light atoms is reported. Experimental double-to-single photoionization cross section ratios for Mg, Al, Si and Ca were obtained from measurements of high-resolution x-ray emission spectra. The double photoionization (DPI) cross-sections for K-shell hollow atom production are compared to convergent close-coupling calculations (CCC)...

Université de Fribourg

Observation of ultralow-level Al impurities on a silicon surface by high-resolution grazing emission x-ray fluorescence excited by synchrotron radiation

Kubala-Kukus, A. ; Banas, D. ; Cao, Wei ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Kayser, Yves ; Pajek, M. ; Salomé, M. ; Susini, J. ; Szlachetko, Jakoub ; Szlachetko, Monika

In: Physical Review B, 2009, vol. 11, p. 113305

We demonstrate that ultralow-level Al impurities on a silicon surface can be measured by using the high-resolution grazing emission x-ray fluorescence (GEXRF) technique combined with synchrotron-radiation excitation. An Al-impurity level of about 10¹² atoms/cm² was reached by observing the Al Kα x-ray fluorescence in the resonant Raman-scattering background-“free” regime by...

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, Jakoub ; 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 double-to-single...

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, Jakoub ; 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....