Speaker
Description
Laser-driven ion accelerators offer multi-MeV beams with high-peak currents, enabling applications in radiotherapy, neutron generation, and fast ignition in inertial confinement fusion. However, transitioning from complex experiments to reliable particle sources requires advances in beam quality, robustness, and high-repetition-rate scalability.
Recent studies have identified the Relativistically Induced Transparency (RIT) regime as a promising pathway for enhanced ion acceleration, achieved by precisely synchronizing the laser pulse arrival with the onset of target transparency. Using the DRACO-PW and J-KAREN-P laser systems, we systematically investigated laser and target parameters to optimize acceleration performance in this regime. Our results show record proton energies of up to 150 MeV at only 22 J of laser energy. The generated proton beam featured a high-energy, low-divergence component that was both spectrally and spatially distinct. Target transparency proved to be a simple yet powerful control parameter, highly sensitive to subtle laser–target variations.
Start-to-end simulations validate these findings, revealing the influence of preceding laser light in pre-expanding the target and detailing the acceleration dynamics during the main pulse interaction. These results offer critical insights into the role of ultrashort pulse duration and laser contrast, marking a substantial step toward controlled and efficient ion acceleration in the RIT regime.
