Probing strong-field QED in beam-plasma collisions

TL;DR

This paper proposes a novel method to investigate strong-field quantum electrodynamics (SFQED) effects using a high-charge electron beam interacting with a solid target, enabling laserless, controllable experiments in the nonperturbative regime.

Contribution

It introduces a new single-beam setup that mimics beam-beam collision conditions for SFQED studies, simplifying experimental requirements and enhancing controllability.

Findings

The setup can reach Schwinger field conditions in the beam frame.

Simulations show effective triggering of SFQED phenomena like pair creation.

The method offers a practical approach for laserless SFQED experiments.

Abstract

Ongoing progress in laser and accelerator technology opens new possibilities in high-field science, notably to investigate the largely unexplored strong-field quantum electrodynamics (SFQED) regime where electron-positron pairs can be created directly from light-matter or even light-vacuum interactions. Laserless strategies such as beam-beam collisions have also been proposed to access the nonperturbative limit of SFQED. Here we report on a concept to probe SFQED by harnessing the interaction between a high-charge, ultrarelativistic electron beam and a solid conducting target. When impinging onto the target surface, the beam self fields are reflected, partly or fully, depending on the beam shape; in the rest frame of the beam electrons, these fields can exceed the Schwinger field, thus triggering SFQED effects such as quantum nonlinear inverse Compton scattering and nonlinear Breit-Wheeler electron-positron pair creation. Through reduced modeling and kinetic numerical simulations, we show that this single-beam setup can achieve interaction conditions similar to those envisioned in beam-beam collisions, but in a simpler and more controllable way owing to the automatic overlap of the beam and driving fields. This scheme thus eases the way to precision studies of SFQED and is also a promising milestone towards laserless studies of nonperturbative SFQED.