Modeling of a chain of three plasma accelerator stages with the WarpX electromagnetic PIC code on GPUs
Jean-Luc Vay, A. Huebl, Ann Almgren, L. D. Amorim, John B. Bell, Luca Fedeli, Lixin Ge, Kevin Gott, D.P. Grote, Mark Hogan, Revathi Jambunathan, Remi Lehé, Andrew Myers, C. Ng, Michael Rowan, Olga V. Shapoval, Maxence Thévenet, Henri Vincenti, Eloise Yang, N. Zaïm, Weiqun Zhang, Yinjian Zhao, Edoardo Zoni
Abstract
The fully electromagnetic particle-in-cell code WarpX is being developed by a team of the U.S. DOE Exascale Computing Project (with additional non-U.S. collaborators on part of the code) to enable the modeling of chains of tens to hundreds of plasma accelerator stages on exascale supercomputers, for future collider designs. The code is combining the latest algorithmic advances (e.g., Lorentz boosted frame and pseudo-spectral Maxwell solvers) with mesh refinement and runs on the latest computer processing unit and graphical processing unit (GPU) architectures. In this paper, we summarize the strategy that was adopted to port WarpX to GPUs, report on the weak parallel scaling of the pseudo-spectral electromagnetic solver, and then present solutions for decreasing the time spent in data exchanges from guard regions between subdomains. In Sec. IV, we demonstrate the simulations of a chain of three consecutive multi-GeV laser-driven plasma accelerator stages.