Multi-GeV electron-positron beam generation from laser-electron scattering

TL;DR

This paper proposes a novel method to generate multi-GeV electron-positron beams using laser-electron scattering at extreme intensities, supported by analytical and simulation models, with potential for future high-energy physics experiments.

Contribution

It introduces a new experimental setup combining laser-plasma accelerators with multi-PW lasers to produce high-energy electron-positron pairs with low divergence and net energy gain.

Findings

Pairs reach multi-GeV energies independent of initial beam energy

Generated pairs are quasi-neutral and spatially separated from initial electrons

Analytical and simulation models predict energy cutoff and experimental sensitivities

Abstract

The new generation of laser facilities is expected to deliver short (10 fs - 100 fs) laser pulses with 10 - 100 PW of peak power. This opens an opportunity to study matter at extreme intensities in the laboratory and provides access to new physics. Here we propose to scatter GeV-class electron beams from laser-plasma accelerators with a multi-PW laser at normal incidence. In this configuration, one can both create and accelerate electron-positron pairs. The new particles are generated in the laser focus and gain relativistic momentum in the direction of laser propagation. Short focal length is an advantage, as it allows the particles to be ejected from the focal region with a net energy gain in vacuum. Electron-positron beams obtained in this setup have a low divergence, are quasi-neutral and spatially separated from the initial electron beam. The pairs attain multi-GeV energies which are not limited by the maximum energy of the initial electron beam. We present an analytical model for the expected energy cutoff, supported by 2D and 3D particle-in-cell simulations. The experimental implications, such as the sensitivity to temporal synchronisation and laser duration is assessed to provide guidance for the future experiments.