Malka’s Lab

High-power laser systems have opened new frontiers in scientific research and have revolutionized various scientific fields, offering unprecedented capabilities for understanding fundamental physics and allowing unique applications. This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure-Nuclear Physics (ELI-NP) facility in Romania, using both of the available laser arms. The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism. Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters. Furthermore, the paper discusses the critical role of the laser temporal profile in optimizing proton acceleration, supported by hydrodynamic simulations that are correlated with experimental outcomes. The findings underscore the potential of the ELI-NP facility to advance research in laser-plasma physics and contribute significantly to high-energy physics applications. The results of this commissioning establish a strong foundation for experiments by future users.

Laser-plasma acceleration is considered to be a promising candidate for compactly delivering high-energy high-quality electron beams. One of the most common methods for injecting plasma electrons into the wakefield structure is the shock front injection. Here we present the first direct visualization of the nonlinear laser wakefield dynamics resulting from a tilted shock front using the femtosecond relativistic electron microscopy technique. Our observations reveal the occurrence of a split in the wakefield, with the formation of an on-axis laser-driven wakefield and an off-axis beam-driven wakefield just after the passage through the hydrodynamic shock. Using experimental and three-dimensional numerical evidence, we identify the mechanism of this newly observed phenomenon as an off-axis electron injection from the tilted shock, which amplified the betatron oscillations of the bunch until its breakup. These results propel our comprehension of the intricate and nonlinear laser-plasma dynamics within the widely employed shock-front injection scheme, providing crucial information for high-quality beam generation in real-time operations.

This Technical Design Report presents a detailed description of all aspects of the LUXE (Laser Und XFEL Experiment), an experiment that will combine the high-quality and high-energy electron beam of the European XFEL with a high-intensity laser, to explore the uncharted terrain of strong-field quantum electrodynamics characterised by both high energy and high intensity, reaching the Schwinger field and beyond. The further implications for the search of physics beyond the Standard Model are also discussed.