Measurement of latent tracks in amorphous SiO2 using small angle X-ray scattering

In this paper we present preliminary yet promising results on the measurement of latent ion tracks in amorphous, 2 μm thick SiO2 layers using small angle X-ray scattering (SAXS). The tracks were generated by ion irradiation with 89 MeV Au ions to fluences between 3 × 1010 and 3 × 1012 ions/cm2. Transmission SAXS measurements show distinct scattering from the irradiated SiO2 as compared to the unirradiated material. Analysis of the SAXS spectra using a cylindrical model suggests a core–shell like density distribution in the ion tracks with a lower density core and a higher density shell as compared to unirradiated material. The total track radius of ∼48 Å is in very good agreement with previous experiments and calculations based on an inelastic thermal spike model.