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The double K-shell ionization of Sc, Cr and Cu induced by electron impact was investigated via high energy resolution measurements of the Kα diagram transitions and the transitions resulting from the radiative decay of K-shell double vacancy states, namely the Khα hypersatellites. For Sc, the Kβ diagram lines and Khβ hypersatellites were also measured. The measurements were carried out in-house with a von Hamos curved crystal spectrometer operated in the so-called direct geometry in which the anodes of Sc, Cr and Cu X-ray tubes were used as targets. For each element, the electron kinetic energy was chosen to be about twice the threshold energy for the double 1s ionization. The double-to-single ionization cross-sections ratios PKK were deduced from the hypersatellite-to-diagram line yield ratios, corrected beforehand for the self-absorption of the X-rays in the target and the energy dependent efficiency of the spectrometer. The obtained ratios are discussed and compared to other PKK values found in the literature for electrons and photons.

The high-resolution von Hamos Bragg crystal spectrometer was constructed for the study of K X-ray emission from low- Z elements and L and M X-ray spectra of medium to high Z elements. Recently, this instrument was applied to high-resolution XES and RIXS studies using X-ray synchrotron radiation at the ID21 and BM5 beamlines at the ESRF. An outline of the spectrometer design and performance characteristics will be given. The studies deal with the energy dependent KL double photoexcitation of argon, the L 3 and M 1 atomic-level widths of elements 54≤ Z ≤77, and the evolution of the K-edge RIXS spectra of manganese oxides.