Radiative trapping in intense laser beams

TL;DR

This paper investigates how electrons are trapped in intense laser beams due to radiation reaction effects, providing analytical insights and exploring implications for gamma-ray production and pair cascades.

Contribution

It introduces analytical expressions for electron attractors in laser fields and identifies conditions for stable trapping based on beam intensity ratios and radiation reaction parameters.

Findings

Analytical limit cycles for electron trajectories are derived.

Stable trapping depends on the ratio of laser beam intensities.

Optimal conditions for gamma-ray and pair production are identified.

Abstract

The dynamics of electrons in counter-propagating, circularly polarized laser beams are shown to exhibit attractors whose ability to trap particles depends on the ratio of the beam intensities and a single parameter describing radiation reaction. Analytical expressions are found for the underlying limit cycles and the parameter range in which they are stable. In high-intensity optical pulses, where radiation reaction strongly modifies the trajectories, the production of collimated gamma-rays and the initiation of non-linear cascades of electron-positron pairs can be optimized by a suitable choice of the intensity ratio.