Improving the accuracy of hard photon emission by Sigmoid sampling of the QED-table in particle-in-cell-Monte-Carlo simulations

TL;DR

This paper introduces a Sigmoid sampling method to improve the accuracy of hard photon emission modeling in particle-in-cell Monte Carlo simulations within the quantum-electrodynamic regime, addressing resolution issues in existing QED tables.

Contribution

The paper presents a novel Sigmoid sampling technique that enhances the resolution and accuracy of photon energy sampling in PIC-MC simulations for strong-field QED processes.

Findings

Significantly reduces numerical errors in photon emission simulations.

Ensures accurate representation of high-energy photon spectra.

Improves reliability of laser-plasma interaction modeling in QED regime.

Abstract

Research on laser-plasma interaction in the quantum-electrodynamic (QED) regime has been greatly advanced by particle-in-cell & Monte-Carlo simulations (PIC-MC). While these simulations are widely used, we find that noticeable numerical error arises due to inappropriate implementation of the quantum process accounting for hard photon emission and pair production in the PIC-MC codes. The error stems from the low resolution of the QED table used to sample photon energy, which is generated in the logarithmic scale and cannot resolve high energy photons. We propose a new sampling method via Sigmoid function that handles both the low energy and high energy end of the photon emission spectrum. It guarantees the accuracy of PIC-MC algorithms for hard photon radiation and other related processes in the strong-field QED regime.