Tel Aviv Intense Laser and Ultrafast Science group

Radiation damage on the picosecond timescale

With its obvious importance to the performance and lifetime of machines that operate in radiation rich environments, material damage induced by radiation has been a major research focus for decades. These extremely fast evolving phenomena represent a gap in our understanding of solid-state science, and this gap limits our advancement of practical materials science and engineering.

Molecular dynamics simulations predict that damage forms within 10s-of-nm scale volumes, involving millions of atoms whose structure evolves over picoseconds (see figure above).

A measurement of these dynamics with picosecond time resolution is essential for understanding of the damage mechanism. Until recently, however, such a measurement was impossible, and to date no data exists. The community is now racing to conduct such measurement on large XFEL facilities.

We devised a method to measure for the first time the temporal evolution of radiation damage on a picosecond time scale using a tabletop laser system.

Our concept is to conduct a time-resolved pump-probe measurement of radiation damage in a thin layer composition sample. The sample is chosen for its high variance of reflectivity with target thickness for XUV radiation. We will induce damage by bombarding the sample with photo-fission fragments generated by laser-produced high-energy electrons. The damage formation will be probed using a coherent XUV beam generated by a process known as High Harmonic Generation off Plasma Mirrors.