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Université de Fribourg

Diagram, valence-to-core, and hypersatellite Kβ X-ray transitions in metallic chromium

Zeeshan, Faisal ; Hoszowska, Joanna ; Dousse, Jean-Claude ; Sokaras, Dimosthenis ; Weng, Tsu-Chien ; Alonso-Mori, Roberto ; Kavčič, Matjaz ; Guerra, Mauro ; Sampaio, Jorge Miguel ; Parente, Fernando ; Indelicato, Paul ; Marques, José Pires ; Santos, José Paulo

In: X-Ray Spectrometry, 2019, vol. 48, no. 5, p. 351–359

We report on measurements of the Kβ diagram, valence‐to‐core (VtC), and hypersatellite X‐ray spectra induced in metallic Cr by photon single and double K‐shell ionization. The experiment was carried out at the Stanford Synchrotron Radiation Lightsource using the seven‐crystal Johann‐type hard X‐ray spectrometer of the beamline 6‐2. For the Kβ diagram and VtC transitions, the...

Université de Fribourg

In-house setup for laboratory-based x-ray absorption fine structure spectroscopy measurements

Zeeshan, Faisal ; Hoszowska, Joanna ; Loperetti-Tornay, L. ; Dousse, Jean-Claude

In: Review of Scientific Instruments, 2019, vol. 90, no. 7, p. 073105

We report on a laboratory-based facility for in-house x-ray absorption fine structure (XAFS) measurements. The device consists of a conventional x-ray source for the production of the incident polychromatic radiation and a von Hamos bent crystal spectrometer for the analysis of the incoming and transmitted radiation. The reliability of the laboratory-based setup was evaluated by comparing the...

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

High-resolution Laue-type DuMond curved crystal spectrometer

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

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...

Université de Fribourg

Application of the high-resolution grazing-emission x-ray fluorescence method for impurities control in semiconductor nanotechnology

Szlachetko, Jakub ; Banaś, D. ; Kubala-Kukuś, A. ; Pajek, M. ; Cao, Wei ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Kayser, Yves ; Szlachetko, Monika ; Kavčič, M. ; Salome, M. ; Susini, J.

In: Journal of Applied Physics, 2009, vol. 105, p. 086101

We report on the application of synchrotron radiation based high-resolution grazing-emission x-ray fluorescence (GEXRF) method to measure low-level impurities on silicon wafers. The presented high-resolution GEXRF technique leads to direct detection limits of about 10¹² atoms/cm². The latter can be presumably further improved down to 10⁷ atoms/cm² by combining the synchrotron...

Université de Fribourg

Real time determination of the electronic structure of unstable reaction intermediates during Au₂O₃ Reduction

Szlachetko, Jakub ; Sá, Jacinto ; Nachtegaal, Maarten ; Hartfelder, Urs ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Fernandes, Daniel Luis Abreu ; Shi, Hongqing ; Stampfl, Catherine

In: The Journal of Physical Chemistry Letters, 2014, vol. 5, no. 1, p. 80–84

Chemical reactions are always associated with electronic structure changes of the involved chemical species. Determining the electronic configuration of an atom allows probing its chemical state and gives understanding of the reaction pathways. However, often the reactions are too complex and too fast to be measured at in situ conditions due to slow and/or insensitive experimental techniques. A...

Université de Fribourg

The electronic structure of matter probed with a single femtosecond hard x-ray pulse

Szlachetko, Jakub ; Milne, a), C. J. ; Hoszowska, Joanna ; Dousse, Jean-Claude ; Błachucki, W. ; Sà, J. ; Kayser, Yves ; Messerschmidt, M. ; Abela, R. ; Boutet, S. ; David, Christian ; Williams, G. ; Pajek, M. ; Patterson, B. D. ; Smolentsev, G. ; Bokhoven, J. A. van ; Nachtegaal, M.

In: Structural Dynamics, 2014, vol. 1, no. 2, p. 021101

Physical, biological, and chemical transformations are initiated by changes in the electronic configuration of the species involved. These electronic changes occur on the timescales of attoseconds (10−18 s) to femtoseconds (10−15 s) and drive all subsequent electronic reorganization as the system moves to a new equilibrium or quasi-equilibrium state. The ability to detect the dynamics of...

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

Establishing nonlinearity thresholds with ultraintense X-ray pulses

Szlachetko, Jakub ; Hoszowska, Joanna ; Dousse, Jean-Claude ; Nachtegaal, Maarten ; Błachucki, Wojciech ; Kayser, Yves ; Sà, Jacinto ; Messerschmidt, Marc ; Boutet, Sebastien ; Williams, Garth J. ; David, Christian ; Smolentsev, Grigory ; Bokhoven, Jeroen A. van ; Patterson, Bruce D. ; Penfold, Thomas J. ; Knopp, Gregor ; Pajek, Marek ; Abela, Rafael ; Milne, Christopher J.

In: Scientific Reports, 2016, vol. 6, p. 33292

X-ray techniques have evolved over decades to become highly refined tools for a broad range of investigations. Importantly, these approaches rely on X-ray measurements that depend linearly on the number of incident X-ray photons. The advent of X-ray free electron lasers (XFELs) is opening the ability to reach extremely high photon numbers within ultrashort X-ray pulse durations and is leading...