1,721,207 research outputs found
Applications of low-temperature detectors to synchrotron radiation
No full textIn this paper we review some synchrotron-radiation-based techniques that can take a great advantage from the exploitation of low-temperature detectors because of their energy resolution that can be pushed down to the eV range. X-ray Absorption Spectroscopy and X-ray Fluorescence analysis appear to be at the moment the best candidates. Other techniques like High-Resolution X-ray Emission, Resonant Inelastic X-ray Scattering and Raman scattering still demand technical improvement to these promising devices
LISA: The Italian CRG beamline for x-ray Absorption Spectroscopy at ESRF
Full text linkLISA is the acronym of Linea Italiana per la Spettroscopia di Assorbimento di raggi X (Italian beamline for X-ray Absorption Spectroscopy) and is the upgrade of the former GILDA beamline installed on the BM08 bending magnet port of European Synchrotron Radiation Facility (ESRF). Within this contribution a full description of the project is provided
LISA: the Italian CRG beamline for x-ray Absorption Spectroscopy at ESRF
No full textLISA is the acronym of Linea Italiana per la Spettroscopia di Assorbimento di raggi X (Italian beamline for X-ray Absorption Spectroscopy) and is the upgrade of the former GILDA beamline installed on the BM08 bending magnet port of European Synchrotron Radiation Facility (ESRF). Within this contribution a full description of the project is provided
Comments on treatment of EXAFS data taken in the fluorescence mode in non-linear conditions by G. Ciatto et al. (2004). J. Synchrotron Rad. 11, 278-283
No full textThe author of the comment rightly suggests the improvement of
our data-correction method II by taking into account the dead time of
the fast channel of the digital electronics. In our paper, we preferred
to neglect the dead time of the fast channel since we did not have a
reliable measurement of it, but could only estimate it from the
trapezoidal filter length. If we compare the nominal value of the slow
channel dead time reported in the XIA manual (about 8.2 ms) and the
one we have measured from the data (9.1 ms) we find an evident
disagreement; thus, we were not completely confident in using the
estimated value of 0.8 ms for the fast channel dead time...
The new beamline LISA at ESRF: Performances and perspectives for earth and environmental sciences
No full textLISA (Linea Italiana per la Spettroscopia di Assorbimento di raggi X) is the new Italian Collaborating Research Group (CRG) beamline at the European Synchrotron Radiation Facility (ESRF) dedicated to X-ray absorption spectroscopy (XAS). The beamline covers a wide energy range, 4 < E < 90 keV, which offers the possibility for probe the K and L edges of elements that are heavier than Ca. A liquid He/N2 cryostat and a compact furnace are available for measurements in a wide temperature range (10–1000 K), allowing for in situ chemical treatments and measurements under a controlled atmosphere. The sub-millimetric beam size, the high photon flux provided, and the X-ray fluorescence detectors available (HP-Ge, SDD) allow for the study of liquid and highly diluted samples. Trace elements in geological or environmental samples can be analyzed, even for very small sample areas, gaining information on oxidation states and host phases
The atomic site of as implanted in Si at ultra-low energies
No full textThe fabrication of ultrashallow junctions needs the realization of surface layers with a noticeably high (approximate to10(21) atoms/cm(2)) dopant density. In the case of As doped Si, thermal treatments lead to changes in the atomic environment of the dopant and, thus, to its electrical activity. In this contribution the local order around As dopants in low energy (1 keV) implanted crystalline Si was studied by extended X-ray absorption fine structure. Data were collected in total reflection condition in order to enhance the signal from the surface. The quantitative analysis revealed a site for As that is different from the pure substitutional one and suggests the presence of clusters of As atoms coupled to vacancies
Implanted dielectrics: Synchrotron radiation studies by absorption and diffraction techniques
No full textLocal environment of metal ions in phthalocyanines: K-edge X-ray absorption spectra
No full textWe report a detailed study of the K-edge X-ray absorption spectra of four transition metal phthalocyanines (MPc, M = Fe, Co, Cu and Zn). We identify the important single and multiple scattering contributions to the spectra in the extended energy range and provide a robust treatment of thermal damping; thus, a generally applicable model for the interpretation of X-ray absorption fine structure spectra is proposed. Consistent variations of bond lengths and Debye Waller factors are found as a function of atomic number of the metal ion, indicating a variation of the metal-ligand bond strength which correlates with the spatial arrangement and occupation of molecular orbitals. We also provide an interpretation of the near edge spectral features in the framework of a full potential real space multiple scattering approach and provide a connection to the local electronic structure
The refiEXAFS station at the GILDA beamline (BM08) of ESRF
No full textThe experimental station for measuring X-ray absorption spectra in total reflection geometry operative at the GILDA CRG beamline of ESRF is described. The main features of the station are shown, namely: the possibility of detecting very small signals from thin (a few ML) samples, of depositing thin films under controlled conditions and thermal treating the samples in order to study dynamical processes. Case studies are reported in order to show the performances of the apparatus
Multiple-order reflections from monochromating crystals for the collection of X-ray absorption spectra at extremely high energies
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