22 research outputs found
Photoelectron and photoion spectroscopy on atomic Lu in the region of the 5p excitation
The resonances of atomic Lu have been investigated
by photoelectron and photoion spectroscopy using monochromatized synchrotron
radiation in the vacuum ultraviolet energy region.
The total photoion yield has been compared to calculations in which
the extended Fano theory (Mies formalism) and the Hartree-Fock method were applied.
The resonance structure is dominated by the spin-orbit splitting of
the 5p core hole.
In the photoion yield spectra of singly and doubly charged ions
a high fraction of Lu2+ ions has been found in the region of
the resonances.
Photoelectron spectra, recorded in this resonance region, have been
investigated with respect to deexcitation channels connected with
Lu2+ ions.
The resonances predominantly autoionize by
spin-flip into states, which decay in the second
step into Lu2+ final ionic states
The Use of Bragg Reflection on Single Crystals for the Production of Polarized Excitation Radiation in the EDXRF
Adiabatic Compressed Air Energy Storage co-located with wind energy—multifunctional storage commitment optimization for the German market using GOMES
Advanced Absorption Correction for 3D Elemental Images Applied to the Analysis of Pearl Millet Seeds Obtained with a Laboratory Confocal Micro X‑ray Fluorescence Spectrometer
We present a novel
absorption correction approach for elemental
distribution images obtained with a laboratory confocal micro X-ray
fluorescence spectrometer. The procedure is suited especially for
biological samples, as a constant dark matrix with a varying minor
or trace element distribution is assumed. The constant absorption
in the sample is extracted from depth dependent measurements. By using
the concept of an effective excitation energy, depth-dependent, and
element-specific excitation energy values are calculated. For each
voxel of a full 3D measurement, a correction is performed taking into
account the actual number of voxels in the excitation and detection
path. As proof of concept, the embryonic region of pearl millet seeds
is investigated. Data are measured from the top and bottom side, resulting
in a good agreement after the application of the absorption correction
procedure. The distribution of elemental micronutrients is compared
in seeds of two pearl millet genotypes. The corrected images illustrate
different localization patterns of the micronutrient elements in pearl
millet seed tissues
Grazing-incidence x-ray fluorescence analysis for non-destructive determination of In and Ga depth profiles in Cu(In,Ga)Se 2
Development of a non-destructive method for underglaze painted tiles – demonstrated by the analysis of Persian objects from the nineteenth century.
The paper presents an analytical method developed for the nondestructive study of nineteenth-century Persian polychrome underglaze painted tiles. As an example, 9 tiles from French and German museum collections were investigated. Before this work was undertaken little was known about the materials used in pottery at that time, although the broad range of colors and shades, together with their brilliant glazes, made these objects stand out when compared with Iranian ceramics of the preceding periods and suggested the use of new pigments, colorants, and glaze compositions. These materials are thought to be related to provenance and as such appropriate criteria for art-historical attribution. The analytical method is based on the combination of different nondestructive spectroscopic techniques using microfocused beams such as proton-induced X-ray emission/proton-induced γ-ray emission, X-ray fluorescence, 3D X-ray absorption near edge structure, and confocal Raman spectroscopy and also visible spectroscopy. It was established to address the specific difficulties these objects and the technique of underglaze painting raise. The exact definition of the colors observed on the tiles using the Natural Color System®© helped to attribute them to different colorants. It was possible to establish the presence of Cr- and U-based colorants as new materials in nineteenth-century Persian tilemaking. The difference in glaze composition (Pb, Sn, Na, and K contents) as well as the use of B and Sn were identified as a potential marker for different workshops