Laser-driven vacuum breakdown waves

TL;DR

This paper demonstrates through 3D QED-PIC simulations that vacuum breakdown waves can propagate in an intense plane electromagnetic wave, challenging previous assumptions and revealing new dynamics in laser-foil interactions.

Contribution

It provides the first simulation-based evidence of QED cascade fronts propagating in plane waves and models their electrodynamics, advancing understanding of laser-induced vacuum breakdown.

Findings

QED cascade fronts can propagate in plane electromagnetic waves.

A growing electron-positron plasma cushion forms during laser-foil interaction.

The models predict cascade front propagation consistent with simulations.

Abstract

It is demonstrated by three-dimensional quantum electrodynamics --- particle-in-cell (QED-PIC) simulations that vacuum breakdown wave in the form of QED cascade front can propagate in an extremely intense plane electromagnetic wave. The result disproves the statement that the self-sustained cascading is not possible in a plane wave configuration. In the simulations the cascade initiates during laser-foil interaction in the light sail regime. As a result, a constantly growing electron-positron plasma cushion is formed between the foil and laser radiation. The cushion plasma efficiently absorbs the laser energy and decouples the radiation from the moving foil thereby interrupting the ion acceleration. The models describing propagation of the cascade front and electrodynamics of the cushion plasma are presented and their predictions are in a qualitative agreement with the results of numerical simulations.