High flux sub-picosecond laser-based hard x-ray platform for advanced material analysis and imaging

Ultrashort laser platforms equipped with in situ, in-operando diagnostics are pivotal for advancing the frontiers of modern laser-based engineering. Aligned with this objective, we developed the LP3-ASUR platform, which combines moderate (∼1013 W/cm2) and high-intensity laser beamlines (∼1017-2.5 × 1019 W/cm2), enabling pump-probe arrangements with modular (optical/x-ray) time-resolved diagnostics. We demonstrate high-repetition rate (100 Hz), high-brilliance, hard Kα x-ray sources induced by laser-plasma interaction. Favorably, they can be synchronized with optical pump and probe laser pulses and are jitter-free with respect to them thanks to the multi-beamline, low- and high-peak power architecture of the laser platform. For x-ray analysis and imaging, these characteristics enable a high signal-to-noise ratio and minimize the need for long accumulation times, allowing for addressing demanding scientific cases. Building such a platform encompassed efforts of research and development involving the laser system, the x-ray conversion targetry, and the formatting of x-ray source characteristics under various operation conditions. To have robust and stable x-ray tools with pulsed, well-defined characteristics, the x-ray targetry is operated in front-face geometry with a massive laser-x-ray converter material. In such a configuration, a hard Kα x-ray source delivering peak performances of 109 photons/sr/shot at the repetition-rate of 100 Hz with a few-hundred femtosecond duration is routinely obtained and implemented in flexible pump-probe analytical experiments and x-ray imaging protocols operated in air. Finally, two descriptive measurements highlight the platform's ability to perform cutting-edge diagnostics, opening the door for innovative imaging and improved understanding of electron and lattice dynamics in solid materials exposed to external laser irradiation.