Investigations of heavy-ion tracks' energy deposition inside solid media by methods of x-ray spectroscopy

In this paper, we present experimental results on the excitation of solid-state matter by single, energetic heavy ions. The method of x-ray spectroscopy with spatial resolution along the projectile stopping path inside solids was applied to investigate the state of the medium inside the area of heavy-ion tracks. Spectral data of quartz and aluminium media excited by Ni, Ca and Mg ions from the GSI UNILAC accelerator are presented. The ions' initial energies of 11.4 and 5.9 MeV/u and the beam current on the target in the order of 1 νA were chosen. The observation was focused on relative intensities of K_α satellite lines radiated by Si and Al multicharged ions with different charges. The aerogel medium with extremely low bulk density (0.04 g cc^-1) was used to investigate the evolution of target media radiation properties during the projectile ions' stopping and, respectively, the change of the ion's energy deposition into the solids. Due to very short lifetimes of the excited levels for the observed multicharged ions, the data for heavy-ion track area were obtained on tens of femtoseconds time scale after excitation. For further analysis and obtaining quantitative description of heavy-ion track parameters, the methods of numerical simulation are suggested.