



This PhD project focuses on the physics of plasmas generated by ultra-high-power and high-intensity lasers. The work will be carried out at the LMJ facility, using the PETAL laser which operates at intensities exceeding 10¹8 W·cm?² and enables the production of high-energy particles.
The main objective of the thesis is to investigate the generation and acceleration of relativistic electron beams in a gas jet. The potential applications of these beams will be assessed for electron–positron pair production and for electron-beam-based radiography.
The research will combine experimental and numerical approaches. The PhD candidate will take part in experimental campaigns scheduled for 2026–2027, including the implementation of diagnostics and data analysis. In parallel, Particle-In-Cell and Monte Carlo simulations will be performed to support the interpretation of the experimental results.
In a second phase, the thesis will contribute to the qualification of upgrades to the PETAL laser, focusing in particular on secondary sources of electrons, protons, and hard X-ray radiation generated by laser–matter interactions, within the framework of the PETAL-UPGRADE project.

