The thesis contains three different projects belonging to the domain of X-ray spectroscopy.
The first one concerns the development of a laboratory-based setup for in-house X-ray absorption spectroscopy (XAS) measurements. The setup is based on the von Hamos crystal spectrometer of Fribourg using X-ray tubes as radiation sources. The new setup was characterized by measuring the XAS spectra around the K and L edges of several 3d, 4d and 5d transition metals. The edges energies, spectral shapes and absorption coefficients were determined from the data analysis and compared to existing experimental and theoretical data.
In the second project the double K-shell ionization of Sc, Cr and Cu induced by electron impact was investigated. The project was also carried out in-house with the von Hamos crystal spectrometer operated in the direct geometry, using the anodes of Sc, Cr and Cu X-ray tubes as targets. The energies and natural line widths of the hypersatellites were determined. The ratios PKK of the double-to-single K-shell ionization cross sections were deduced from the measured relative intensities of the hypersatellites and the results were compared to the PKK values obtained by other groups with electrons, photons and via the nuclear electron capture process.
In the third project, the influence of the chemical environment on the KℎB1,3 hypersatellite transitions was investigated for the first time. The measurements were performed at SSRL using metallic Cr and three Cr compounds corresponding to different oxidation states. For comparison, the diagram KB1,3 and valence-to-core (VtC) KB2,5 and KB ’’ transitions were also measured. Relevant dependencies of the energies, energy shifts, relative spectral intensities and line widths on the oxidation state, metal-ligand bond length or spin state could be demonstrated. The observed trends were compared to the ones of the diagram and VtC transitions.