Coherently enhanced radiation friction in laser-plasma collisions

TL;DR

This paper demonstrates that in dense relativistic particle bunches colliding with lasers, radiation friction effects are coherently enhanced, enabling their observation at lower energies than previously thought.

Contribution

It introduces a new understanding of coherent radiation friction enhancement in dense bunches and provides a simple estimate validated by 3D simulations.

Findings

Radiation friction is coherently enhanced in dense relativistic bunches.

Enhanced effects allow observation at lower laser intensities.

Derived energy loss estimates match simulation results.

Abstract

We reconsider the footprints of radiation friction in a head on collision of a bunch of relativistic charged particles with a laser pulse by demonstrating that in a dense enough bunch forward and backward radiation and radiation friction are coherently enhanced. This should make it possible to observe radiation friction effects in laser-matter interactions at much lower energies and laser intensities than accepted ever previously. A simple estimate for the energy losses of the particles in the bunch over the collision due to radiation friction in terms of laser and bunch parameters is derived and validated by comparing with the results of three dimensional particle-in-cell simulations.