Accurate modeling of plasma acceleration with arbitrary order pseudo-spectral particle-in-cell methods

TL;DR

This paper demonstrates that arbitrary order pseudo-spectral particle-in-cell methods can effectively model plasma acceleration with reduced numerical Cherenkov radiation, balancing accuracy and parallel computational efficiency.

Contribution

It introduces the use of arbitrary order pseudo-spectral methods in PIC simulations to mitigate NCR while enabling efficient parallelization through domain decomposition.

Findings

Low solver orders are sufficient to accurately model plasma physics.

Arbitrary order methods reduce NCR compared to traditional approaches.

Parallelization is feasible with localized pseudo-spectral solvers.

Abstract

Particle in Cell (PIC) simulations are a widely used tool for the investigation of both laser- and beam-driven plasma acceleration. It is a known issue that the beam quality can be artificially degraded by numerical Cherenkov radiation (NCR) resulting primarily from an incorrectly modeled dispersion relation. Pseudo-spectral solvers featuring infinite order stencils can strongly reduce NCR, or even suppress it, and are therefore well suited to correctly model the beam properties. For efficient parallelization of the PIC algorithm, however, localized solvers are inevitable. Arbitrary order pseudo-spectral methods provide this needed locality. Yet, these methods can again be prone to NCR. Here, we show that acceptably low solver orders are sufficient to correctly model the physics of interest, while allowing for parallel computation by domain decomposition.