https://hal-cea.archives-ouvertes.fr/cea-01894332Vincenti, HenriHenriVincentiLIDyl - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) - CEA - Commissariat à l'énergie atomique et aux énergies alternatives - Université Paris-Saclay - CNRS - Centre National de la Recherche ScientifiqueLBNL - Lawrence Berkeley National Laboratory [Berkeley]PHI - Physique à Haute Intensité - IRAMIS - Institut Rayonnement Matière de Saclay - CEA - Commissariat à l'énergie atomique et aux énergies alternatives - Université Paris-Saclay - LIDyl - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) - CEA - Commissariat à l'énergie atomique et aux énergies alternatives - Université Paris-Saclay - CNRS - Centre National de la Recherche ScientifiqueVay, Jean-LucJean-LucVayLBNL - Lawrence Berkeley National Laboratory [Berkeley]Ultrahigh-order Maxwell solver with extreme scalability for electromagnetic PIC simulations of plasmasHAL CCSD2018Electromagnetic Particle-In-Cell methodMassively parallel pseudo-spectral solversRelativistic plasma mirrorsPseudo-spectral analytical time domain solverFinite-difference time-domain solver[PHYS.MECA.MEMA] Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph]Lebe, Caroline2018-10-12 12:31:502022-01-04 04:47:442018-10-12 12:31:50enJournal articles10.1016/j.cpc.2018.03.0181The advent of massively parallel supercomputers, with their distributed-memory technology using many processing units, has favored the development of highly-scalable local low-order solvers at the expense of harder-to-scale global very high-order spectral methods. Indeed, FFT-based methods, which were very popular on shared memory computers, have been largely replaced by finite-difference (FD) methods for the solution of many problems, including plasmas simulations with electromagnetic Particle-In-Cell methods. For some problems, such as the modeling of so-called “plasma mirrors” for the generation of high-energy particles and ultra-short radiations, we have shown that the inaccuracies of standard FD-based PIC methods prevent the modeling on present supercomputers at sufficient accuracy. We demonstrate here that a new method, based on the use of local FFTs, enables ultrahigh-order accuracy with unprecedented scalability, and thus for the first time the accurate modeling of plasma mirrors in 3D.