Application to radiative and Quantum electrodynamics effects in extreme-intensity laser-matter interaction

In the coming years, many laser facilities like Apollon in Paris or the distributed European facility ELI will reach peak power at the 10-petawatt (PW) level, paving the way to more ambitious lasers in the 100-PW range like the Russian XCELS or French IZEST projects. They will open up a novel field of physics characterized by coupled ultra-relativistic plasma, radiative and electrodynamics (QED) effects including the nonlinear Compton emission of X and gamma photons, and their subsequent decay into electron-positron pairs. This presentation addresses the studies of different scenarii based on multi-dimensional particle-in-cell (PIC) simulations enriched with Monte Carlo QED processes. In the first part, a wire-target design will be presented optimized for the generation of collimated intense gamma-ray beams in the framework of Apollon. In a second part, we investigate the collision of a wakefield-driven GeV electron bunch with a counter-propagating high-intensity laser considered as the most promising experimental source of bright photon and antimatter sources. In the last part, we demonstrate the capability of next-generation multi-PW lasers to generate relativistic overdense pair plasma of interest for the study of electron-positron instabilities relevant for astrophysical scenarii.