In: Spectrochimica Acta Part B: Atomic Spectroscopy, 2017, vol. 136, p. 23–33
We review the high energy resolution off-resonant spectroscopy (HEROS) technique. HEROS probes the unoccupied electronic states of matter in a single-shot manner thanks to the combination of off-resonant excitation around atomic core states using wavelength dispersive X-ray detection setups. In this review we provide a general introduction to the field of X-ray spectroscopy together with the...
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In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2017, vol. 411, no. Supplement C, p. 63–67
In the present work high energy resolution off-resonant X-ray spectroscopy (HEROS) was employed at a synchrotron to study a silica supported Ta(V) bisalkyl catalyst activated in hydrogen. The Ta Lα1 HEROS spectra were measured during oxidation of the starting complex and the relative species’ concentration was successfully retrieved as a function of time using the fingerprint HEROS spectra...
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In: Physical Review Letters, 2014, vol. 112, no. 17, p. 173003
X-ray emission spectra recorded in the off-resonant regime carry information on the density of unoccupied states. It is known that by employing the Kramers-Heisenberg formalism, the high energy resolution off-resonant spectroscopy (HEROS) is equivalent to the x-ray absorption spectroscopy (XAS) technique and provides the same electronic state information. Moreover, in the present Letter we...
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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...
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Thèse de doctorat : Université de Fribourg, 2007 ; no 1568.
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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...
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In: Physical Review Letters, 2009, vol. 102, no. 14, p. 143001
By means of a high resolution resonant inelastic x-ray scattering spectroscopy, we have for the first time separated spectral features pertaining to different two-electron atomic processes in the vicinity of an inner-shell threshold. Contributions of shakeoff, shakeup, and resonant 1s3p double excitations were extracted from the Ar KM-M2,3M...
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In: Physical Review A, 2007, vol. 76, p. 032506
A series of x-ray emission spectra of xenon in the region of L₃M 5,4(Lα1,2) and L₃N5,4 (Lβ2,15) lines were recorded along the polarization direction of the incoming photons with energies ranging from 4779.4 to 4804.4 eV. A combination of monochromatic photon beam and high resolution x-ray spectrometer...
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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...
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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 ...
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