Real-time observation of particle interactions in matter using laser-driven accelerators

This is achieved by exploiting advances in laser technologies that enable transient absorption experiments via pump-probe methodologies across numerous materials, using picosecond scale bursts of x-rays and protons generated via Bremsstrahlung and Target Normal Sheath Acceleration (TNSA) respectively, as the pump source and chirped light with an adjustable wavelength as the probe.

The role of localised and delocalised particle interactions within ordered and disordered media is examined in various forms of SiO2. By tracking the transient opacity the recovery time of excited electrons is found to be > 150 times greater in nanostructured aerogel than in bulk fused silica, a magnitude of > 15 more than expected. While the bulk response behaves as expected the introduction of disorder in matter demonstrates the significance of characteristic heterogeneity on the nanoscale in material response.