Particle dynamics governed by radiation losses in extreme-field current sheets

TL;DR

This paper analyzes particle trajectories in extreme-field current sheets considering radiation losses, deriving analytical solutions in classical and quantum regimes, and validating them with numerical simulations to understand phenomena relevant to future laser experiments.

Contribution

It provides the first analytical solutions for particle motion in relativistic current sheets including radiation reaction effects, bridging classical and quantum regimes.

Findings

Analytical trajectories agree well with numerical simulations.

Quantum effects significantly alter particle dynamics in extreme fields.

Insights applicable to upcoming high-intensity laser experiments.

Abstract

Particles moving in current sheets under extreme conditions, such as those in the vicinity of pulsars or those predicted on upcoming multipetawatt laser facilities, may be subject to significant radiation losses. We present an analysis of particle motion in fields of a relativistic neutral electron-positron current sheet in the case when radiative effects must be accounted for. In the Landau-Lifshitz radiation reaction force model, when quantum effects are negligible, an analytical solution for particle trajectories is derived. Based on this solution, for the case when quantum effects are significant an averaged quantum solution in the semiclassical approach is obtained. The applicability region of the solutions is determined and analytical trajectories are found to be in good agreement with those of numerical simulations with account for radiative effects. Based on these results we gain new insights into current sheet phenomena expected on upcoming laser facilities.