2020/12/30 by Lisa Randolph, Mohammadreza Banjafar, Randolph, Lisa +58
Engineering · Physics and Astronomy · #FOS: Physical sciences #Laser Material Processing Techniques #Laser-Matter Interactions and Applications #Laser-induced spectroscopy and plasma #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.2012.15076
openalex publication_date 2020/12/30 · openalex created_date 2021/01/05 · openalex updated_date 2026/07/28
Observing ultrafast laser-induced structural changes in nanoscale systems is essential for understanding the dynamics of intense light-matter interactions. For laser intensities on the order of 1014 \rm W/cm2, highly-collisional plasmas are generated at and below the surface. Subsequent transport processes such as heat conduction, electron-ion thermalization, surface ablation and resolidification occur at picosecond and nanosecond time scales. Imaging methods, e.g. using x-ray free-electron lasers (XFEL), were hitherto unable to measure the depth-resolved subsurface dynamics of laser-solid interactions with appropriate temporal and spatial resolution. Here we demonstrate picosecond grazing-incidence small-angle x-ray scattering (GISAXS) from laser-produced plasmas using XFEL pulses. Using multi-layer (ML) samples, both the surface ablation and subsurface density dynamics are measured with nanometer depth resolution. Our experimental data challenges the state-of-the-art modeling of matter under extreme conditions and opens new perspectives for laser material processing and high-energy-density science.