QED Effects at Grazing Incidence on Solid-State-Targets

TL;DR

This paper investigates how ultra-intense laser interactions with solid targets at grazing incidence can trigger quantum electrodynamic effects, leading to cascades and increased secondary particle production, using advanced particle-in-cell simulations.

Contribution

It demonstrates that grazing incidence laser-target interactions can induce QED cascades at lower intensities than previously possible, with detailed simulation analysis.

Findings

QED cascades occur at lower laser intensities with grazing incidence.

Grazing angle enhances secondary particle production significantly.

Comparison shows target setup outperforms seeded vacuum in cascade development.

Abstract

New laser facilities will reach intensities of $10^{23} \textrm{W cm}^{-2}$. This advance enables novel experimental setups in the study of laser-plasma interaction. In these setups with extreme fields quantum electrodynamic (QED) effects like photon emission via non-linear Compton scattering and Breit-Wheeler pair production become important. We study high-intensity lasers grazing the surface of a solid-state target by two-dimensional particle-in-cell simulations with QED effects included. The two laser beams collide at the target surface at a grazing angle. Due to the fields near the target surface electrons are extracted and accelerated. Finally, the extracted electrons collide with the counter-propagating laser, which triggers many QED effects and leads to a QED cascade under a sufficient laser intensity. Here, the processes are studied for various laser intensities and angles of incidence and finally compared to a seeded vacuum cascade. Our results show that the proposed target can yield many order of magnitude more secondary particles and develop a QED cascade at lower laser intensities than the seeded vacuum alone.