The knowledge of atomic fundamental parameters such as the mass attenuation coefficients or fluorescence yields with low uncertainties, is of decisive importance in elemental quantification involving ...x-ray fluorescence analysis techniques. For example, several databases giving the mass attenuation coefficients are accessible and frequently used within a large community of users. These compilations are most often in good agreement for photon energies in the hard x-ray ranges. However, they significantly differ for low photon energies and around the absorption edges of the elements. Some review articles present compilations of measured fluorescence yields values found in the literature. However reliable measurements are not so many illustrating the inherent difficulties. Mass attenuation coefficients of bismuth were determined experimentally in the photon energy range from 100 eV to 30 keV by using monochromatized synchrotron radiation at SOLEIL (France). The fluorescence yields of the three L-subshells of bismuth were also determined using a reflection geometry setup. The application of high-accuracy experimental techniques resulted in low uncertainty mass attenuation coefficients and L-subshell fluorescence yields that are directly compared to existing databases and with updated relativistic configuration mixing Dirac-Fock calculations including QED corrections.
We measured the KL0 diagram, and KL1 and KL2 satellite lines in Mg, Al, and Si, ionized by photon excitation, using a high-resolution anti-parallel double-crystal x-ray spectrometer. Their energy ...values, FWHM, and relative intensities are obtained by the multiple fitting methods and compared with those reported by other excitation processes. It was found that the relative intensity of Mg and Si KL1, and KL2 satellite lines to the KL0 diagram lines depend on the method used to produce the K hole. The evidence of a new transition between Ka3 and Ka4 in Mg, Al, and Si KL1 satellite lines is suggested. These x-ray diagram and satellite lines were investigated theoretically and we found that Mg Ka1;2 diagram lines with hidden satellites are especially in very good agreement with the corresponding experimental ones. Moreover, from the absorption spectra of Mg and Al, the cross sections of the multi-electron transition processes were estimated and match the theoretical values. We also determined the mass attenuation coefficients in a wide energy range covering the K-absorption edge, including a detailed evaluation of the associated uncertainties.
In this work, we present K- and L- shell fluorescence yield values of the full isonuclear sequence of Fe ions, using a state-of-the-art multiconfiguration Dirac–Fock approach. These results may be of ...importance for spectral fitting and plasma modeling, both in laboratory and astrophysical studies, where Fe is an important benchmark element. The K-shell fluorescence yields were found to be very similar up to the removal of 14 electrons.
•We have performed K- and L- fluorescence yields of the isonuclear sequence of Fe from first principles using a multiconfiguration Dirac–Fock approach.•Changes of the fluorescence yield were assessed for K- and L- shells as a function of the charge state.•L1 subshell fluorescence yield is much more sensitive to the removal of outer electrons than the L2,3 subshell fluorescence yield.
We report on an experiment conducted at the ESR storage ring aiming at the study of the X-ray emission of
Xe
54
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ions colliding with Xe atoms at a beam energy of 50 MeV/u. The radiation resulting ...from the ion–atom interaction was observed using a high-resolution spectrometer based on metallic–magnetic calorimeter technology. In order to benchmark the capabilities of these detectors for high-precision atomic physics experiments, we identified several transitions from H-like and He-like xenon and determined their energies. Furthermore, the 1
s
-Lamb shift in
Xe
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was estimated using the measured line energies. The results are compared with previous experimental studies and theoretical predictions.
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Arrays of superconducting transition-edge sensor (TES) microcalorimeters are attractive for some X-ray experiments where the combination of higher collection efficiency than crystal spectrometers and ...much better energy resolution than semiconductor detectors is enabling. For hard X-ray (>2 keV) applications, a TES is often integrated with an extra absorber to extend its dynamic range, quantum efficiency and collecting area. For >100 keV applications, millimeter size absorbers have been manually attached to TES pixels after fabrication. At lower energies, the absorber size needs to be much smaller, because a large heat capacity degrades energy resolution. In that case, the absorber is directly electroplated or evaporated on the TES during the fabrication process. In this work, we present TES microcalorimeters optimized for the intermediate hard X-ray energy region (20 keV ~ 100 keV) that have thick absorbers directly deposited during the TES fabrication process. This microcalorimeter is designed to measure high-resolution muonic atom transition X-ray spectra as a method to study quantum electrodynamics (QED) effects. The absorber is comprised of evaporated gold and electroplated bismuth layers and is designed to optimize dynamic range, collecting efficiency, and energy resolution in the 20 keV to 45 keV energy range. A prototype with pure gold absorbers has been fabricated and characterized, in order to obtain a first experimental reference in the detector development process.
In this work, we present fluorescence yield and width values of Ne‐, Ar‐, and Kr‐like ion levels for selected values of Z, using a state‐of‐the‐art multiconfiguration Dirac–Fock approach. The results ...may be useful for the interpretation of spectra from plasmas, in both laboratory and astrophysics, as well as from ion collision experiments.
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