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

The K alpha X-ray emission spectra of the low-density SiO2 aerogel target bombarded by Ca-48 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 K alpha L-0 diagram and K alpha L-n (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 K alpha L-n satellites with respect to their diagram K alpha 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. (C) 2007 Published by Elsevier B.V.