PICSAR-QED: a Monte Carlo module to simulate Strong-Field Quantum Electrodynamics in Particle-In-Cell codes for exascale architectures

TL;DR

This paper introduces PICSAR-QED, a Monte Carlo module integrated into Particle-In-Cell codes, enabling accurate simulation of strong-field QED processes on high-performance and exascale computing architectures.

Contribution

The work presents an open-source, portable Monte Carlo module for PIC codes to simulate strong-field QED, optimized for exascale architectures and validated through extensive tests and benchmarks.

Findings

Validated physical models with detailed tests

Demonstrated scalability on CPUs and GPUs

Successfully integrated with WarpX for exascale readiness

Abstract

Physical scenarios where the electromagnetic fields are so strong that Quantum ElectroDynamics (QED) plays a substantial role are one of the frontiers of contemporary plasma physics research. Investigating those scenarios requires state-of-the-art Particle-In-Cell (PIC) codes able to run on top high-performance computing machines and, at the same time, able to simulate strong-field QED processes. This work presents the PICSAR-QED library, an open-source, portable implementation of a Monte Carlo module designed to provide modern PIC codes with the capability to simulate such processes, and optimized for high-performance computing. Detailed tests and benchmarks are carried out to validate the physical models in PICSAR-QED, to study how numerical parameters affect such models, and to demonstrate its capability to run on different architectures (CPUs and GPUs). Its integration with WarpX, a state-of-the-art PIC code designed to deliver scalable performance on upcoming exascale supercomputers, is also discussed and validated against results from the existing literature.