G. Stutz
National University of Cordoba
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Publication
Featured researches published by G. Stutz.
Journal of Synchrotron Radiation | 2004
German Tirao; G. Stutz; C. Cusatis
A high-resolution spectrometer aimed at performing experiments of inelastic X-ray scattering by electronic excitations is described. The spectrometer has been installed at the D12A-XRD1 beamline of the National Synchrotron Light Laboratory (LNLS), in Campinas, Brazil. Synchrotron radiation is monochromated to about 6 keV and focused horizontally onto the sample by a sagittally focusing Si(111) double-crystal monochromator in non-dispersive setting. The spectrometer operates in Rowland circle geometry and is based on a focusing Si(333) analyser in near-backdiffraction geometry for energy analysis of inelastically scattered photons. The analyser works at a fixed Bragg angle, so energy transfers are obtained by varying the incident photon energy. A relative energy resolution of the whole spectrometer of approximately 1.5 x 10(-4) at 5.93 keV has been achieved. As an example of application, inelastic X-ray scattering by plasmon excitation in polycrystalline Be was measured. Test results demonstrate that inelastic X-ray scattering experiments with eV energy resolution and an acceptable counting rate are feasible at the LNLS when focused on plasmon and particle-hole excitations.
Applied Radiation and Isotopes | 2010
Fernando Rodolfo Espinoza-Quiñones; Aparecido Nivaldo Módenes; Adriana S. Câmera; G. Stutz; German Tirao; Soraya Moreno Palácio; Alexander D. Kroumov; Ana Paula de Oliveira; Vanessa Lizeria Alflen
In this work granular activated carbon has been chosen as an absorbent in order to investigate the Cr(VI) reduced by adsorption experiments. Several batch chromium-sorption experiments were carried out using 0.25 g of granular activated carbon in 50 mL aqueous solution containing approximately 70 and 140 mg L(-1) of Cr(VI) and Cr(III), respectively. Cr-Kbeta fluorescence spectra of Cr adsorbed in a carbon matrix and Cr reference materials were measured using a high-resolution Johann-type spectrometer. Based on evidence from the Cr-Kb satellite lines, the Cr(VI) reduction process has actually happened during metal adsorption by the activated carbon.
Journal of Physics: Condensed Matter | 2007
German Tirao; G. Stutz; V. M. Silkin; E. V. Chulkov; C. Cusatis
An experimental and theoretical study of collective electronic excitations in Be is presented. The plasmon energy and linewidth were measured by means of inelastic x-ray scattering spectroscopy. Measurements were performed on a polycrystalline sample and in a broad range of momentum transfers within the plasmon excitation regime. Theoretical plasmon dispersion and its linewidth in the whole Brillouin zone were derived from ab initio evaluations of the electron density response function. The calculations were performed with full inclusion of the electron band structure within the random-phase approximation. Good agreement of experimental plasmon energy and linewidth dispersions with direction-averaged theoretical results in all investigated q-range is obtained. We conclude that, in Be, the band structure effects alone can account for the observed finite plasmon lifetime at q = 0, as well as for the linewidth dispersion in the long-wavelength domain.
Journal of Applied Crystallography | 2016
Marcelo Goncalves Hönnicke; Leonardo M. Bianco; S. Ceppi; C. Cusatis; Xian-Rong Huang; Yong Q. Cai; G. Stutz
The construction and characterization of a focusing X-ray spherical analyzer based on α-quartz 4{\bar 4}04 are presented. The performance of the analyzer was demonstrated by applying it to a high-resolution X-ray spectroscopy study of the Kα1,2 emission spectrum of Ni. An analytical representation based on physical grounds was assumed to model the shape of the X-ray emission lines. Satellite structures assigned to 3d spectator hole transitions were resolved and determined as well as their relative contribution to the emission spectrum. The present results on 1s−13d−1 shake probabilities support a recently proposed calculation framework based on a multi-configuration atomic model.
Radiation Physics and Chemistry | 2003
Alejo C. Carreras; G. Stutz; G. Castellano
Abstract Transition rates were obtained from spectra for pure metallic samples of atomic number ranging from 22 to 27, measured with monochromatic incident X-ray beams from a synchrotron source. The experimental setup for this consisted of an energy dispersive spectrometer in a conventional 45–45° geometry, mounted in an evacuated chamber. Absorption, detector efficiency and multiple scattering were taken into account. The results obtained are compared with recent theoretical and experimental data as well as with the well-known theoretical predictions from Scofield.
Chemical Engineering Journal | 2010
Aparecido Nivaldo Módenes; Fernando Rodolfo Espinoza-Quiñones; Soraya Moreno Palácio; Alexander D. Kroumov; G. Stutz; German Tirao; Adriana S. Camera
Water Research | 2009
Fernando Rodolfo Espinoza-Quiñones; Neiva Martin; G. Stutz; German Tirao; Soraya Moreno Palácio; M. A. Rizzutto; Aparecido Nivaldo Módenes; Fernando G. Silva Jr.; Nayara Szymanski; Alexander D. Kroumov
Chemical Physics | 2006
M. Torres Deluigi; G. Tirao; G. Stutz; C. Cusatis; J. A. Riveros
Chemical Physics | 2010
S. Limandri; S. Ceppi; German Tirao; G. Stutz; C.G. Sánchez; J. A. Riveros
X-Ray Spectrometry | 2002
Alejo C. Carreras; Rita D. Bonetto; G. Stutz; J. Trincavelli; G. Castellano