Novel large-scale pump–probe experimental platforms equipped with both high-power optical lasers and brilliant X-ray free-electron lasers (XFELs), such as the European XFEL HED/HiBEF instrument, LCLS-MEC, SACLA, and the upcoming SHINE beamlines, provide unprecedented opportunities to investigate high-energy-density (HED) physics and advance inertial fusion energy (IFE) research. In this talk, we will first present our latest pump–probe HED experimental results obtained using the 3 J, 30 fs, 100 TW ReLaX laser at the European XFEL-HED/HiBEF station, including ultrafast heating and ionization, hydrodynamic blast-wave formation and propagation, and cylindrical implosion dynamics in hot solid density plasmas driven by ultra-intense lasers, with the XFEL serving as an ideal X-ray backlighter. These experiments employ an array of advanced X-ray diagnostics, including nanometer-scale-sensitive small-angle X-ray scattering (SAXS), charge-state-sensitive resonant X-ray emission spectroscopy, and sub-micrometer-sensitive Talbot X-ray imaging, enabling the investigation of multiscale plasma dynamics with exceptional spatiotemporal resolution.
Building on these successful experiments, we further propose for active probing of doped inertial confinement fusion (ICF) capsule shells, enabling direct measurements of mix and burn dynamics at next-generation implosion facilities via resonant X-ray absorption imaging with an XFEL. The charge-state–sensitive imaging of embedded dopants provides spatiotemporally resolved constraints on ionization, opacity, and material mixing seeded by hydrodynamic instabilities in stagnated plasmas which is challenging to access by the conventional X-ray diagnostics. Atomic and radiation–hydrodynamic simulations of resonant imaging of K–L transitions in copper for direct-driven and L–M transitions in tungsten for indirect-driven schemes in doped shell targets further support the diagnostic concept. These findings could hold significant potential to advance high energy density researchand inertial fusion energy community using high power lasers.