Energy relaxation in disordered insulators irradiated by ultrafast protons: a multiscale approach

Simulations of both a single track in BK7 glass and multiple tracks show that after 5ps the plasma remains highly inhomogeneous, with large gradients remaining in both the carrier density and carrier temperature. This indicates that plasma inhomogeneity must be taken into account for models of relaxation on the picosecond scale.<br><br>Finally, we apply the semiconductor to nanostructured silica aerogels, using a hierarchical model for the aerogel structure.

Experiments reveal that silica aerogels irradiated with protons display an unexpectedly long transient opacity that scales with the mass density of the aerogel. Simulation of the electron-hole plasma over 5ps indicates that the presence of the nanostructure serves to impede the diffusion of the electron-hole plasma, resulting in a longer timescale for relaxation.<br><br>