Atomistic two-temperature modelling of ion track formation in silicon dioxide

We study swift-heavy-ion track formation in α -quartz using the two-temperature molecular dynamics (2T-MD) model realised as a concurrent multiscale scheme. We compare the simulated track radii to the existing experimental ones obtained from small-angle X-ray scattering and Rutherford backscattering experiments. The 2T-MD model provides an explanation of the origin of the track radii saturation at high electronic stopping power. Furthermore, we study the track structure and show that defects formed outside the region of density fluctuations after a swift-heavy-ion impact may explain the conflicting track radii produced by the two experimental techniques.