Leveraging extreme laser-driven magnetic fields for gamma-ray generation and pair production

TL;DR

This paper demonstrates that laser-driven magnetic fields in plasma can be used to generate dense, directed gamma-ray beams and produce electron-positron pairs, advancing high-energy photon and antimatter research.

Contribution

It introduces a novel method leveraging relativistic transparency to generate strong plasma magnetic fields that enhance gamma-ray emission and enable controlled pair production.

Findings

Dense gamma-ray beams with multi-MeV energies achieved

Over 1000 electron-positron pairs produced in simulations

Positron directionality controlled by beam collision angle

Abstract

The ability of an intense laser pulse to propagate in a classically over-critical plasma through the phenomenon of relativistic transparency is shown to facilitate the generation of strong plasma magnetic fields. Particle-in-cell simulations demonstrate that these fields significantly enhance the radiation rates of the laser-irradiated electrons, and furthermore they collimate the emission so that a directed and dense beam of multi-MeV gamma-rays is achievable. This capability can be exploited for electron-positron pair production via the linear Breit-Wheeler process by colliding two such dense beams. Presented simulations show that more than $10^3$ pairs can be produced in such a setup, and the directionality of the positrons can be controlled by the angle of incidence between the beams.