Correlative multielectron processes in K-shell photoionization of Ca, Ti and V in the energy range of 8–35 keV

The Kα satellite spectra arising from the correlative multielectron processes accompanying K-shell photoionization of Ca, Ti and V were measured using a broad range crystal spectrometer. Multiconfiguration Dirac–Fock calculations were performed to interpret the observed x-ray energies and the spectral line shape. The calculations agree fairly well with the experimental results. The variation of the Kα L¹ satellite and the Kα_1,2^h hypersatellite intensities was measured as a function of excitation energy in the range of 8–35 keV. The Kα L¹/Kα_1,2 intensity ratio for each element is already saturated in our energy range, and the asymptotic values of 1.58 ± 0.08, 1.26 ± 0.06 and 0.97 ± 0.05 % for Ca, Ti and V were determined. By combining the present results and the previously measured values for various elements, we have found a Z^−3.5 scaling law for the Kα L¹/Kα_1,2 intensity ratio. The measured Kα_1,2^h/Kα_1,2 intensity ratio, for each element, is found to increase smoothly from its onset and shows a long saturation range extending up to at least 25 keV above the threshold for Ti. The evolution of the Kα_1,2^h/Kα_1,2 intensity ratio is compared with the analytic Thomas model and with the theoretical calculation based on the screened hydrogenic model.