Plasma wakes driven by Compton scattering: Non-linear regime and particle acceleration

TL;DR

This paper explores plasma wakefield generation through Compton scattering in a non-linear regime, revealing relativistic electron acceleration, unique transverse fields, and potential applications in astrophysical and laboratory contexts.

Contribution

It extends linear theory to the nonlinear regime of Compton-driven plasma wakes, demonstrating relativistic effects and unique field structures not seen in laser wakefields.

Findings

Plasma waves can reach the wave-breaking limit.

Perfectly collimated drivers produce wakes at the speed of light.

Two-dimensional simulations show unique transverse fields and magnetic focusing.

Abstract

We investigate plasma wake generation via Compton scattering from photon bursts, a non-ponderomotive process relevant when the photon wavelength is smaller than the interparticle distance but larger than the Compton wavelength. In this regime, electrons can reach relativistic velocities. We extend linear theory to the nonlinear regime, showing that plasma waves can reach the wave-breaking limit. Perfectly collimated drivers produce wakes propagating at the speed of light, allowing electron phase-locking (limited by driver depletion). Non-collimated drivers induce subluminal phase velocities, limiting acceleration via dephasing. Two-dimensional simulations reveal unique transverse fields compared to laser wakefields, with a DC magnetic field leading to consistent focusing. The work considers observational prospects in laboratory and astrophysical scenarios such as around highly luminous compact objects (e.g., pulsars, gamma-ray bursts) interacting with tenuous interstellar or intergalactic plasmas, where conditions favor Comptondominated wakefield acceleration.