Studies of the Kα X-ray spectra of low-density SiO2 aerogel induced by Ca projectiles for different penetration depths

The Kα X-ray emission spectra of the low-density SiO2 aerogel target bombarded by 48Ca ions with initial energy of 11.4 MeV/u were measured with a high spectral and spatial resolution along 80% of the ion beam stopping path. The Si KαL0 diagram and KαLn (up to n = 5) X-ray satellite lines corresponding to the radiative decays of atomic states with one hole in the K-shell and n-holes in the L-shell were measured. Energy shifts of the KαLn satellites with respect to their diagram Kα lines were determined and compared with the results of multiconfiguration Dirac–Fock (MCDF) calculations. The experimental energy shifts are smaller than values obtained from free-ion MCDF theory assuming an empty M-shell. The influence of the valence M-shell configuration on the satellite X-ray spectra is discussed.