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Painted beehive panels are representative examples of folk art specific and unique to Slovenia. Although without precedence in European ethnographic art, not much attention has been given in the past to the artists’ materials involved in the creation of these paintings. This study, which included three different panels (dating from the beginning of the 19th to the second half of the 20th centuries), was focused on material characterization using Raman and Fourier‐transform infrared spectrometer (FTIR) spectroscopy (non‐, minimally invasive and invasive). The analyses showed that many of the examined paint layers were composed of historically commonly available colouring agents, although less traditional ones were also detected on individual panels. Additionally, the research suggests that lipids are the main or even the sole component of the paints’ binder. This evidence corresponds fairly well with written texts of the 20th century.

The financial support of the Swiss National Science Foundation (Grant No. 200020-146739) is acknowledged by F.?Z., J.?H., and J.-Cl.?D. M.?G. acknowledges the support of the FCT, under the Contract No. SFRH/BPD/92455/2013 and the project PTDC/FIS-AQM/31969/2017, ?Ultra-high-accuracy X-ray spectroscopy of transition metal oxides and rare earths.? This work was also partly supported by the research center grants nos. UID/FIS/04559/2013 to LIBPhys-UNL, and UID/MULTI/04046/2013 to BioISI, from the FCT/MCTES/PIDDAC. We report on measurements of the Kβ diagram, valence-to-core (VtC), and hypersatellite X-ray spectra induced in metallic Cr by photon single and double K-shell ionization. The experiment was carried out at the Stanford Synchrotron Radiation Lightsource using the seven-crystal Johann-type hard X-ray spectrometer of the beamline 6-2. For the Kβ diagram and VtC transitions, the present study confirms the line shape features observed in previous works, whereas the K h β hypersatellite transition was found to exhibit a complex spectral line shape and a characteristic low-energy shoulder. The energy shift of the hypersatellite relative to the parent diagram line was deduced from the measurements and compared with the result of extensive multiconfiguration Dirac–Fock (MCDF) calculations. A very good agreement between experiment and theory was found. The MCDF calculations were also used to compute the theoretical line shape of the hypersatellite. A satisfactory agreement was obtained between the overall shapes of the experimental and theoretical spectra, but deviations were observed on the low- and high-energy flanks of the hypersatellite line. The discrepancies were explained by chemical effects, which were not considered in the MCDF calculations performed for isolated atoms. publishersversion published

We report on the radiative decay of double $K$-shell vacancy states produced in solid Ca, V, Fe, and Cu targets by impact with about 10 MeV/amu C and Ne ions. The resulting $K$ hypersatellite x-ray emission spectra were measured by means of high-energy-resolution spectroscopy using a von Hamos bent crystal spectrometer. The experiment was carried out at the Philips variable energy cyclotron of the Paul Scherrer Institute. From the fits of the x-ray spectra the energies, line widths, and relative intensities of the hypersatellite x-ray lines could be determined. The fitted intensities were corrected to account for the energy-dependent solid angle of the spectrometer, effective source size, target self-absorption, crystal reflectivity, and detector efficiency. The single-to-double $K$-shell ionization cross-section ratios were deduced from the corrected relative intensities of the hypersatellites and compared to theoretical predictions from the semiclassical approximation model using hydrogenlike and Dirac-Hartree-Fock wave functions and from classical trajectory Monte Carlo calculations.

While traditional proton induced X-ray emission (PIXE) analytical technique is based on the energy dispersive solid state detectors used to collect the X-ray fluorescence from the sample, wavelength dispersive X-ray (WDX) spectrometers are applied in high energy resolution PIXE (HR-PIXE) analysis. The main drawback of the WDX spectroscopy is the relatively low efficiency making it less applicable for trace element PIXE analysis. However, the efficiency was enhanced significantly in modern spectrometers employing cylindrically or even spherically curved crystals combined with position sensitive X-ray detectors. The energy resolution of such a spectrometer may exceed the resolution of the energy dispersive detector by two orders of magnitude while keeping the efficiency at a high enough level to perform trace element analysis. In this paper, the recent history and the development of HR-PIXE spectroscopy at the J. Stefan Institute in Ljubljana is presented. Our current setup based on in-vacuum Johansson-type crystal spectrometer is presented in more details followed by some most recent applications.

We present the main characteristics of the experimental set-up used to perform gas-phase RIXS studies in the tender X-ray range. A complete in-vacuum curved-crystal X-ray emission spectrometer in Johansson geometry has been built for a 2–6 keV energy range with sub natural line-width energy resolution. The spectrometer operates in a dispersive geometry, employing a relatively large X-ray source placed inside the Rowland circle and a position sensitive detection of diffracted X-rays. A short review of the most recent experimental applications is given focusing on RIXS studies on isolated atoms and molecules.

We present a theoretical and experimental study of resonant inelastic x-ray scattering on a large group of chlorinated hydrocarbons: CH3Cl, CH2Cl2, CHCl3, CCl4, CH3CH2Cl, ClCH2CH2Cl, CH3CHCl2, CH3CCl3, C2H2Cl2-iso, C2H2Cl2-cis, C2H2Cl2-trans, and C6H5Cl. Differences in structural and dynamical properties of the molecules generated by diverse chemical environments are observed in the measured Cl(K(α)) spectral maps as well as in the Cl(K) total fluorescence yield spectra. The energy position, relative intensity, and the width of the Franck-Condon distribution of low-lying σ* and π* resonances are extracted by a fitting procedure taking into account the experimental broadening. The theoretical values obtained with the transition potential and Δ Kohn-Sham methods are in good agreement with the experimental parameters indicating subtle differences due to variations in the molecular structure.

We have observed ${L}_{23}^{2}\ensuremath{-}{M}^{3}$ Auger decay in argon where a double vacancy is filled by two valence electrons and a single electron is ejected from the atom. A well-resolved spectrum of these two-to-one electron transitions is compared to the result of the second-order perturbation theory and its decay branching ratio is determined.

We report on the surface-sensitive grazing emission X-ray fluorescence technique combined with synchrotron radiation excitation and high-resolution detection to realize depth-profile measurements of Al-implanted Si wafers. The principles of grazing emission measurements as well as the benefits offered by synchrotron sources and wavelength-dispersive detection setups are presented. It is shown that the depth distribution of implanted ions can be extracted from the dependence of the X-ray fluorescence intensity on the grazing emission angle with nanometer-scale precision provided that an analytical function describing the shape of the depth distribution is assumed beforehand. If no a priori assumption is made, except a bell shaped form for the dopant distribution, the profile derived from the measured angular distribution is found to reproduce quite satisfactorily the depth distribution of the implanted ions. Copyright © 2012 John Wiley & Sons, Ltd.

In this work, a Johansson-type crystal spectrometer was employed to record the high-resolution L X-ray emission spectra of pure Ag, Pd and Cd target in order to determine minimum detection limits (MDL) for trace amounts of Pd and Cd in silver. The X-ray emission was induced by a 3 MeV proton beam as well as by monochromatic synchrotron radiation with excitation energy tuned just below the Ag L3 edge. As a direct consequence of extremely high spectrometer resolution reaching below the natural line widths of the measured L X-ray lines, detection limits of a few tens of parts per million were reached in case of proton excitation. These limits were additionally lowered by an order of magnitude using energy-selective photoexcitation with synchrotron radiation as the signal from the resonant Raman scattering (RRS) was completely separated from the Pd signal. The method presented in this work can be used in general to substantially improve detection limits in case of trace elements with atomic number in the close vicinity of the atomic number of the target matrix element. Copyright © 2011 John Wiley & Sons, Ltd.

A wavelength dispersive X-ray spectroscopy was employed to measure the proton induced Lα X-ray emission spectra of Ag, Pd and Cd targets in order to lower detection limits for trace amounts of Pd and Cd in silver matrix. The measurements were performed with a Johansson-type crystal spectrometer having an energy resolution below the natural linewidths of the measured L X-ray lines. As a direct consequence of such ultrahigh experimental energy resolution, detection limits of only few tens of ppm were reached. The method presented in this work can be used in general to improve substantially PIXE detection limits compared to standard energy dispersive spectroscopy for the measurement of trace elements with atomic number in the close vicinity of the atomic number of the target matrix element.

The synchrotron radiation based high-resolution grazing emission X-ray fluorescence (GEXRF) technique was used to extract the distribution of Al ions implanted with a dose of 1016 atoms/cm2 in Si wafers with energies ranging between 1 and 100 keV. The depth distributions of the implanted ions were deduced from the measured angular profiles of the Al-Kα X-ray fluorescence line with nanometer-scale precision. The experimental results were compared to theoretical predictions of the depth distributions resulting from ion implantation. A good agreement between experiment and theory was found which proved that the presented high-resolution grazing emission X-ray fluorescence technique is well suited to perform depth profiling measurements of impurities located within the extinction depth, provided the overall shape of the distribution can be assumed a priori.

We report on the investigation of the photon energy dependence of double 1s photoionization of light atoms and compare the cross sections for hollow atom and He-like ion production. Measurements of the Kα hypersatellite x-ray spectra of Mg, Al, and Si were carried out using the Fribourg high-resolution x-ray spectrometer installed at the ID21 and ID26 beam lines at the ESRF. The double-to-single photoionization cross section ratios were derived as a function of the incident photon beam energy and compared to convergent close-coupling (CCC) calculations for He-like ions. The dynamical electron-electron scattering contribution to the DPI cross-sections was found to be more important for neutral atoms than for the He isoelectronic series.

We discuss general characteristics of the resonant X-ray scattering and briefly illustrate its applications in atomic, molecular and solid state physics by a few selected examples. The Ljubljana high resolution spectrometer set-up is presented, which was recently employed at ELETTRA and ESRF synchrotron beamlines to study X-ray emission of inner-shell excited states of xenon and argon, and of simple sulfur containing molecules and solid compounds.

A four-body classical trajectory Monte Carlo (CTMC) method is applied in the study of single and double ionization cross-sections of the silicon K-shell. The calculations are based on the independent particle model. As projectiles, we consider protons with energies between 0.25 and 4.5 MeV. Our CTMC results are compared with the existing theoretical and experimental data.

We summarize recent results dealing with high resolution (resonant) X-ray spectroscopy of atomic and molecular targets in the tender X-ray energy region. We comment on advantages, new possibilities and problems related to RIXS spectroscopy with respect to the standard photoabsorption technique, where scanning the probe energy is the only option. In particular, three research areas are covered: X-ray emission mediated by energy dependent photoabsorption to multi-electron excited states, the Cl K core-hole clock studies exemplified by systematic study of chloro(fluoro)-hydrocarbon targets and the polarization dependent X-ray emission studies. Due to its spectral selectivity and simultaneous detection capability, high resolution wavelength dispersive X-ray spectroscopy has the capability to resolve structural and dynamical properties of matter within new instrumentation frontiers.

International audience; We present an experimental and theoretical study of resonant inelastic x-ray scattering (RIXS) in the carbon disulphide CS 2 molecule near the sulfur K-absorption edge. We observe a strong evolution of the RIXS spectral profile with the excitation energy tuned below the lowest unoccupied molecular orbital (LUMO) absorption resonance. The reason for this is twofold. Reducing the photon energy in the vicinity of the LUMO absorption resonance leads to a relative suppression of the LUMO contribution with respect to the emission signal from the higher unoccupied molecular orbitals, which results in the modulation of the total RIXS profile. At even larger negative photon-energy detuning from the resonance, the excitation-energy dependence of the RIXS profile is dominated by the onset of electron dynamics triggered by a coherent excitation of multiple electronic states. Furthermore, our study demonstrates that in the hard x-ray regime, localization of the S 1s core hole occurs in CS 2 during the RIXS process because of the orientational dephasing of interference between the waves scattering on the two sulfur atoms. Core-hole localization leads to violation of the symmetry selection rules for the electron transitions observed in the spectra.

High-resolution measurements of the Kα x-ray spectra of metallic Ca, Ti, Cr and Fe were performed with a von Hamos Bragg crystal spectrometer. The target x-ray emission was induced by 34, 72 and 134 MeV C ions, 28, 64 and 230 MeV O ions and 43, 160 and 380 MeV Ne ions. The energies of the resolved KαLN x-ray satellite lines were determined. The possible variation of the energy differences between neighboring KαLN lines with the projectile energy, projectile atomic number and number of target L shell spectator vacancies was probed. No significant dependence on the projectile characteristics was observed. In contrast, the absolute energies of the KαLN satellite lines were found to depend on the projectile velocity. This dependence was attributed to the additional M shell ionization of the target atoms. Copyright © 2003 John Wiley & Sons, Ltd.

For fitting PIXE spectra with a computer program the detector response function should be known with good enough precision to guarantee accurate determination of the elemental yields. The response of a semiconductor detector to monochromatic X-ray radiation does not have a simple dependence on energy. Normally, it can be described by a linear combination of several analytical functions: Gaussian or Voigt for the line itself, and additional tail contributions simulating the incomplete charge collection (ICC) – exponential tails and step functions – on the low-energy side of the line. In this work thin MicroMatter monoelemental targets were irradiated with 1–3 MeV protons and corresponding X-ray spectra were measured. It was found that the response functions can be satisfactorily reproduced for the X-ray energy range 4–10 keV. The precision of the response function determination is slightly hampered for soft X-rays (below 4 keV) due to bremsstrahlung background from the Nuclepore backing. Our procedure has been applied for the two Si(Li) detectors used for routine PIXE analysis in the laboratory.

Elemental concentrations of Sr , Fe , Zn and Cr have been measured by in-air and microbeam PIXE to track the changes during the stalagmite growth. The objective was to find the optimal parameters for the measurements of available isotope-dated stalagmite cuts from Slovenian Karst. Significant concentration fluctuations of Fe , Sr and Cr at the scale of several millimetres have been observed by in-air PIXE. Fluctuations of trace elements observed by microbeam PIXE are contributed to the sub annual periods of growth. As demonstrated, a two-dimensional Ca , Sr , Fe and secondary electron mapping is required to avoid regions with mineral inclusions and surface irregularities during line scans over the speleothems. Optimal measuring parameters for microbeam PIXE mapping of large stalagmite cuts already mapped by isotope dating are given. These measurements would account for sub-annual growth fluctuations.

We present an experimental study of L-MM resonant Auger spectra of argon after electron impact excitation. The electron spectra were measured at ten different electron impact energies between 442.6 eV and 461.7 eV. During (e, 2e) measurement the energy of the second electron was kept fixed at 209.6 eV, corresponding to the energy of one of the strongest resonant Auger transitions from the [2p3/23d] state. Except for the monopole excitations, the recorded spectral structures are explained on the basis of photon impact data.

High-resolution K{alpha} x-ray spectra of Ca, Cr, and Fe induced by (0.7{endash}1.5)-MeV protons and of Ti induced by (0.7{endash}4)-MeV protons were measured by a flat crystal spectrometer. From the relative yields of the KL{sup 1} satellites, which are the result of multiple inner-shell ionization, the average L-shell ionization probabilities in near-central collisions were determined. The effects of the rearrangement of the inner-shell holes prior to the K x-ray emission and the changes of the fluorescence yields due to the multiple ionization were taken into account in the evaluation of the ionization probabilities. The direct Coulomb ionization probabilities in the near-central collisions were determined from the relative yields of the KL{sup 1} satellites after subtracting the shake contribution. The values obtained were compared with semiclassical approximation calculations exploiting relativistic hydrogenic and Hartree-Fock wave functions. The importance of a realistic atomic description using Hartree-Fock wave functions was demonstrated. {copyright} {ital 1997} {ital The American Physical Society}

Experimental evidence for the correlated two-electron one-photon transitions ($1{s}^{\ensuremath{-}2}\ensuremath{\rightarrow}2{s}^{\ensuremath{-}1}2{p}^{\ensuremath{-}1}$) following single-photon $K$-shell double ionization is reported. The double $K$-shell vacancy states in solid Mg, Al, and Si were produced by means of monochromatized synchrotron radiation, and the two-electron one-photon radiative transitions were observed by using a wavelength dispersive spectrometer. The two-electron one-photon transition energies and the branching ratios of the radiative one-electron to two-electron transitions were determined and compared to available perturbation theory predictions and configuration interaction calculations.

The KMM radiative Auger (RA) x-ray spectra of solid Ca were induced by monochromatic synchrotron radiation and measured with a high-resolution von Hamos bent crystal spectrometer. Two excitation energies were employed, one in the near K threshold region and the second well above the K absorption edge. The KMM RA spectral structure and relative intensity with respect to the diagram K{beta}{sub 1,3} (K-M{sub 3,2}) line are found to be independent of the excitation energy. The overall RA structure resembles the density of unoccupied s, p, and d states. Due to solid-state effects, however, spectral features resulting from the major discrete shake-up transitions could not be resolved. For the total KMM RA to K{beta}{sub 1,3} yield ratio, a value of 0.053(3) is obtained. The latter is compared to theoretical predictions and available experimental data obtained by various types of target excitation.

The electron-induced ${L}_{3}M$ two-step double ionization cross sections of metallic Pd were determined experimentally for incident electron beam energies ranging from the double ionization threshold up to 18 keV. The double ${L}_{3}M$ ionization cross sections were derived from the intensity ratios (${I}_{L\ensuremath{\alpha}M}$:${I}_{L\ensuremath{\alpha}}$) of the resolved $M$ satellites to the parent diagram lines. The sample was bombarded with monoenergetic electrons from an energy-tunable 20-kV electron gun. The diagram and $M$-satellite x-ray lines were measured by means of high-resolution x-ray spectroscopy, using a reflection-type von Hamos bent crystal spectrometer. The two-step partial cross sections were determined by subtracting from the measured total double ionization cross sections the contributions due to the shake process and ${L}_{1}$-${L}_{3}{M}_{4,5}$ Coster-Kronig transitions. Despite the thick target employed in the present study, the dependence of the two-step cross sections on the incoming electron energy could be derived using a target slice decomposition method. It is shown that the obtained energy dependence can be well reproduced by the semiempirical parametrization model of Pattard and Rost.

Single-photon double $K$-shell ionization of low-$Z$ neutral atoms in the range $12\ensuremath{\leqslant}Z\ensuremath{\leqslant}23$ is investigated. The experimental method was based on measurements of the high-resolution $K\ensuremath{\alpha}{}^{h}$ hypersatellite x-ray spectra following the radiative decay of the $K$-shell double-vacancy states excited by monochromatic synchrotron radiation. The photon energy dependence of the double $K$-shell ionization was measured over a wide range of photon energies from threshold up to and beyond the maximum of the double-to-single photoionization cross section ratios. From the high-resolution x-ray emission spectra the energies and linewidths of the hypersatellite transitions, as well as the $K{\ensuremath{\alpha}}_{1}^{h}$:$K{\ensuremath{\alpha}}_{2}^{h}$ intensity ratios, were determined. The relative importance of the initial-state and final-state electron-electron interactions to the $K$-shell double photoionization is addressed. Physical mechanisms and scaling laws of the $K$-shell double photoionization are examined. A semiempirical universal scaling of the double-photoionization cross sections with the effective nuclear charge for neutral atoms in the range $2\ensuremath{\leqslant}Z\ensuremath{\leqslant}47$ is established.

The photon energy dependence of the double K-shell ionization of light atoms is reported. Experimental double-to-single photoionization cross section ratios for Mg, Al, Si and Ca were obtained from measurements of high-resolution x-ray emission spectra. The double photoionization (DPI) cross-sections for K-shell hollow atom production are compared to convergent close-coupling calculations (CCC) for neutral atoms and He-like ions. The relative importance of the initial-state and final-state electron-electron interactions to the K-shell DPI in many-electron atoms and two-electron ions is addressed. Physical mechanisms and scaling laws of the K-shell double photoionization are examined. A semiempirical universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms 2≤Z≤47 is established.

The xenon $L$-subshell Coster-Kronig (CK) transition yields were revisited via high-resolution measurements of the $L{\ensuremath{\alpha}}_{1,2}$ (${L}_{3}\ensuremath{-}{M}_{4,5}$) and $L{\ensuremath{\beta}}_{1}$ (${L}_{2}\ensuremath{-}{M}_{4}$) x-ray emission lines. The $L$ x-ray spectra were measured employing a Johansson-type curved crystal spectrometer and energy-tunable synchrotron radiation. The CK yields were derived from the relative $L$ x-ray intensity jumps at the $L$ edges by fitting the fluorescence intensities as a function of the photon energy to the $L$-subshell photoionization cross sections. The latter were obtained from the measured $L$-edge photoabsorption spectrum. Values of $0.118\ifmmode\pm\else\textpm\fi{}0.029$, $0.383\ifmmode\pm\else\textpm\fi{}0.037$, and $0.096\ifmmode\pm\else\textpm\fi{}0.016$ were found for the ${f}_{23}$, ${f}_{13}$, and ${f}_{12}$ CK yields, respectively. Thanks to high resolution, the ${L}_{1}$ fluorescence yield of $0.059\ifmmode\pm\else\textpm\fi{}0.002$ was also determined from intensity ratios of the well-resolved $L{\ensuremath{\beta}}_{4}$ (${L}_{1}\ensuremath{-}{M}_{2}$) and $L{\ensuremath{\beta}}_{1}$ (${L}_{2}\ensuremath{-}{M}_{4}$) lines.

A characteristic dependence of the proton-induced 2s subshell ionization cross section generated by the nodal structure of the 2s wave function was probed via high-resolution measurements of the Lbeta{sub 3} (L{sub 1}-M{sub 3}) and Lbeta{sub 6} (L{sub 3}-N{sub 1}) x-ray lines of Ag. The intensity ratio of the measured lines depends strongly on the proton energy exhibiting a pronounced maximum around 0.4 MeV. The experimental intensities are critically compared to the theoretically predicted values. The latter were obtained using the ionization cross sections calculated within the semiclassical approximation employing hydrogenlike and Dirac-Fock electron wave functions.

We report on the experimental determination of the palladium L-subshell Coster-Kronig (CK) transition yields via high-resolution measurements of the L{alpha}{sub 1,2} (L{sub 3}-M{sub 4,5}) and L{beta}{sub 1} (L{sub 2}-M{sub 4}) x-ray emission lines. The L x-ray spectra were recorded by means of curved crystal spectrometers employing energy-tunable synchrotron radiation for fluorescence production. The CK yields were derived from the relative L x-ray intensity jumps at the L edges by fitting the fluorescence intensities as a function of the photon energy to the photoionization cross sections. The L x-ray intensities were corrected for solid-state effects which were estimated from the comparison of the measured and theoretical Pd L-edge x-ray-absorption spectra. Thanks to high resolution, the partial CK yield f{sub 13}{sup L{sub 1}}{sup L{sub 3}}{sup M} could be extracted from the intensities of the resolved L{alpha}M satellite transitions. For f{sub 23}, f{sub 12}, and f{sub 13} CK rates, values of 0.164{+-}0.033, 0.047{+-}0.001, and 0.730{+-}0.039 were found, respectively. For the partial CK yields f{sub 13}{sup L{sub 1}}{sup L{sub 3}}{sup M} and f{sub 13}{sup L{sub 1}}{sup L{sub 3}}{sup N}, results of 0.406{+-}0.023 and 0.324{+-}0.032, respectively, were obtained.

We report on high-resolution measurements of the ${L}_{1}$- and ${L}_{3}$-subshell x-ray lines of Pd induced by 0.5\char21{}3.0 MeV proton bombardment. The experimental results for the relative intensities of the $L{\ensuremath{\beta}}_{3}$ $({L}_{1}\text{\ensuremath{-}}{M}_{3})$, $L{\ensuremath{\beta}}_{4}$ $({L}_{1}\text{\ensuremath{-}}{M}_{2})$, and $L{\ensuremath{\beta}}_{6}$ $({L}_{3}\text{\ensuremath{-}}{N}_{1})$ lines are compared to the theoretically predicted values employing $L$-subshell ionization cross sections calculated within the semiclassical approximation and the energy-loss Coulomb-repulsion perturbed-stationary-state relativistic theory. A structure of the ${L}_{1}$-subshell cross section at low proton energies generated by the nodal structure of the $2s$ wave function, analogous to the well-known Cooper minimum in the photoabsorption cross section, has been observed also for the case of charged particle ionization. In addition, the influence of the multiple ionization on the intensity ratio of the two most intense ${L}_{1}$-subshell x-ray transitions is studied by comparing the proton-induced intensities with the corresponding photoinduced value measured in an experiment employing monochromatic synchrotron radiation with an energy tuned just above the ${L}_{1}$ edge.

This paper reports on the investigation of the double $K$-shell ionization of metallic aluminum induced by photon and electron impact. The experimental method consisted to measure the $K\ensuremath{\alpha}$ hypersatellite spectra resulting from the radiative decay of double $1s$ vacancy states by means of high-resolution x-ray spectroscopy using a Bragg-type von Hamos crystal spectrometer. Measurements of the photon-induced spectra were carried out at the European Synchrotron Radiation Facility, Grenoble, France, while those of the electron-induced spectra were performed at the University of Fribourg. The double $1s$ ionization probabilities and cross sections were derived from the $K{\ensuremath{\alpha}}_{2}$ hypersatellite to diagram line intensity ratios for photon beam energies ranging between 3.1 and 5.5 keV and for different incident electron-beam energies ranging between 4 and 20 keV. The energy and linewidth of the $K{\ensuremath{\alpha}}_{2}$ hypersatellite x-ray line were also determined for which consistent results were obtained from the photon and electron-beam measurements.

We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron-electron interaction to the DPI. By comparing the double-to-single K-shell photoionization cross-section ratios for neutral atoms with convergent close-coupling calculations for He-like ions, the effect of outer shell electrons on the K-shell DPI process is assessed. Universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms is revealed.

High-resolution x-ray measurements were performed with a von Hamos-type bent crystal spectrometer using for the detection of the diffracted photons either a back-illuminated charge-coupled device (CCD) camera or a front-illuminated one. For each CCD the main x-ray emission lines (e.g., Kalpha, Kbeta, Lalpha, and Lbeta) of a variety of elements were measured in order to probe the performances of the two detectors between 1 and 18 keV. From the observed x-ray lines the linearity of the energy response, the noise level, the energy resolution, and the quantum efficiency ratio of the two CCDs were determined.

A series of x-ray emission spectra of xenon in the region of ${L}_{3}{M}_{5,4}(L{\ensuremath{\alpha}}_{1,2})$ and ${L}_{3}{N}_{5,4}(L{\ensuremath{\beta}}_{2,15})$ lines were recorded along the polarization direction of the incoming photons with energies ranging from 4779.4 to $4804.4\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. A combination of monochromatic photon beam and high resolution x-ray spectrometer resulted in the experimental broadening of $1\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ allowing the observation of resonantly enhanced and narrowed emission lines from the decay of $[2{p}_{3∕2}]nd,ns$ states. The measured spectra are decomposed into the continuum and resonant contributions to determine their relative emission strengths and the energies of the lowest resonant excitations converging to the ${L}_{3}$ edge. The calculated differential cross section for inelastically scattered photons is compared to the measured data. Each of the resonant states is described by a single relativistic configuration in the frame of the Dirac-Fock model, and the continuum contribution to the scattered light is evaluated within the Caldwell-Zare approach, which neglects anisotropic interaction of the ejected electron with the ion.

The satellite and hypersatellite $K$ x-ray emission of a thin Mg foil and thick polycrystalline Si target bombarded by $34\text{\penalty1000-\hskip0pt}\mathrm{MeV}$ C and $50\text{\penalty1000-\hskip0pt}\mathrm{MeV}$ Ne ions was measured using high-resolution crystal diffractometry. The corresponding projectile reduced velocities $v∕{v}_{K}$ were 1.09 and 0.92 for C ions and 1.02, 0.86 for Ne ions in case of Mg and Si targets, respectively. An energy resolution of approximately $0.5\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ enabled separation of contributions corresponding to states with different numbers of $K$- and $L$-shell vacancies. The relative intensities of satellite and hypersatellite lines were determined by fitting the measured spectra with line shapes calculated using the GRASP92 computer code. To determine the production yields of initial states from the measured x-ray yields, the total decay schemes of initial states were considered. The decay schemes were also used to determine the relative intensities of components contributing to the observed $K\ensuremath{\alpha}$ satellites and hypersatellites and $K\ensuremath{\beta}$ satellite intensities. Including theoretical predictions in the fitted model is crucial to analyze properly the $K\ensuremath{\alpha}$ hypersatellite region which overlaps the $K\ensuremath{\beta}$ satellites. The initial-state production yields were then used to determine the $L$-shell ionization probabilities and the double- to single-$K$-shell ionization ratio corresponding to the four investigated collisions. The experimental values were compared to the theoretical predictions obtained within the independent electron model using single-electron ionization probabilities calculated by the three-body classical trajectory Monte Carlo (CTMC) method. Since the targets used were thick enough, the equilibrium projectile charge-state distributions in the solid media were assumed. While for the double- to single-$K$-shell ionization ratios a satisfactory agreement was observed between the CTMC predictions and our experimental results, the $L$-shell ionization probabilities were found to be overestimated by the CTMC calculations by a factor of about 2.

High‐resolution measurements of the K x‐ray spectra of metallic Ca, Ti, Cr, and Fe were performed with a von Hamos Bragg crystal spectrometer. The target x‐ray emission was induced by by 2–19 MeV/amu C, O and Ne ions. The energies of the well resolved KαLN X‐ray satellite lines were determined. Based on the measured values the empirical formula for the KαLN satellite energy shift of the 3d transition elements is given. For the Ca and Ti target bombarded with C ions also the KαhLN hypersatellite lines the KβLN satellite lines and even the KβhLN hypersatellite lines have been measured and their energies determined. The possible variation of the energy differences between neighboring satellite and hypersatellite lines with the projectile energy and atomic number was probed. No significant dependence on the projectile characteristics was observed. In contrast to that the absolute energies of the satellite and hypersatellite lines lines were found to depend on the projectile velocity. This dependence was attri...

High resolution Kα X-ray spectra of Ca, Cr and Fe induced by 0.7–1.5 MeV protons and of Ti induced by 0.7 − 4 MeV protons were measured by a flat crystal spectrometer. The experiment was mainly performed at the J. Stefan Institute. Ti spectra induced by 2, 3 and 4 MeV protons were measured at the Ruder Boskovic Institute in Zagreb. From the relative yields of the KL1 satellites, which are the result of multiple inner-shell ionization, the average L-shell ionization probabilities in near-central collisions were determined. The effects of the rearrangement of the inner-shell holes prior to the K X-ray emission and the changes of the fluorescence yields due to the multiple ionization were taken into account in the evaluation of the ionization probabilities. It was shown that the rearrangement of the L-shell holes significantly changes the initial inner-shell holes distribution. The change of the K-shell fluorescence yield due to additional L shell hole was estimated to be negligible. The inner shell ionizati...

The dissociation process following the Cl K-shell excitation to σ* resonances is studied by high resolution spectroscopy of resonant elastic and inelastic x-ray scattering on CH3Cl, CH2Cl2, CHCl3, and CCl4 molecules. Calculations employing the transition potential and Delta-Kohn-Sham DFT approach are in good agreement with the measured total fluorescence yield and show the presence of a second quasidegenerate group of states with σ* character above the lowest σ* unoccupied molecular orbital for molecules with more than one Cl atom. A bandwidth narrowing and a nonlinear dispersion behavior is extracted from the Kα spectral maps for both σ* resonances. The fitted data indicate that the widths of the Franck-Condon distributions for the first and second σ* resonances are comparable for all the molecules under study. In addition, an asymmetric broadening of the emission peaks is observed for resonant elastic x-ray scattering with zero detuning on both σ* resonances. This is attributed to the fast dissociation, transferring about 0.15 of the scattering probability into higher vibrational modes.

The electrical resistivity of amorphous Fe(100-x)Zr(x) metal alloy films and multilayers has been investigated in a wide temperature and composition range. The overall behavior of the resistivity is consistent with bulk measurements, exhibiting prominent semiconductor-like changes at low temperatures. The transition from positive (metallic) to negative temperature coefficient of resistivity behavior is accompanied by minute changes in magnetoresistance and we can therefore rule out magnetic phase changes as being the cause for the observed changes in the resistivity. Using x-ray absorption and emission spectroscopies we are able to probe the unoccupied and occupied electronic densities of states. The corresponding spectra are found to significantly overlap, as expected for a metallic-like electronic structure and the absence of a band gap. Besides a broadening of the x-ray emission lines expected from an amorphous material, remarkably small differences are observed in the electronic structures when changing the amount of Zr. The resistivity data were modeled and agreement with the Mott variable range hopping model was found, indicating localized electronic states due the disordered structure of the Fe(100-x)Zr(x) alloys.

A short overwiev of recent results on x-ray emission obtained by JSI high resolution spectrometer is given. The report is about photoexcitation of atomic and molecular targets and deals with topics such as isolation of multiple excitation channels, the resonant Raman effect in radiative Auger decay, the interference of absorption-emission paths, and the sensitivity of resonant emission spectra to molecular relaxation.

We present measurements of the resonant inelastic x-ray scattering (RIXS) spectra of the CH(3)I molecule in the hard-x-ray region near the iodine L(2) and L(3) absorption edges. We show that dispersive RIXS spectral features that were recognized as a fingerprint of dissociative molecular states can be interpreted in terms of ultrashort natural lifetime of ∼200 attoseconds in the case of the iodine L-shell core-hole. Our results demonstrate the capacity of the RIXS technique to reveal subtle dynamical effects in molecules with sensitivity to nuclear rearrangement on a subfemtosecond time scale.

The photon energy dependence of the double K-shell ionization cross sections for light atoms and He-like ions is reported. The K-shell double photoionization DPI cross-sections for hollow atom production are compared to those of the corresponding He-like counterparts. The relative contribution of the initial-state correlations and final-state electron-electron interactions to the K-shell DPI is addressed. A semiempirical universal scaling of the double photoionization cross sections with the effective nuclear charge for neutral atoms in the range 2 ≤ Z ≤ 47 is established.

In 205 – 214 eV energy range we have measured a series of (e,2e) spectra emitted in course of an inelastic electron scattering on argon. At 457.3 eV projectile energy a lack of coincidence electron yield was observed in the spectral plane at energies of about 210 eV. This is interpreted as a state-to-state interference effect which occurs due to indistinguishability of the scattered electron – Auger electron pair emitted by the neighbouring [2p3/2]3d and [2p3/2]4d resonances.