Creation and direct laser acceleration of positrons in a single stage

TL;DR

This paper proposes a novel single-stage method to generate and accelerate positrons using intense laser propagation in plasma, enabling GeV-level energies in a compact setup for advanced physics research.

Contribution

It introduces a new approach for positron creation and acceleration in a single plasma stage, overcoming previous limitations in compact accelerator design.

Findings

Generated a 20 fC positron beam with GeV energy

Achieved positron acceleration within 0.5 mm of plasma

Demonstrated a new laser-electron collision method for positron production

Abstract

Relativistic positron beams are required for fundamental research in nonlinear strong field QED, plasma physics, and laboratory astrophysics. Positrons are difficult to create and manipulate due to their short lifetime, and their energy gain is limited by the accelerator size in conventional facilities. Alternative compact accelerator concepts in plasmas are becoming more and more mature for electrons, but positron generation and acceleration remain an outstanding challenge. Here we propose a new setup where we can generate, inject and accelerate them in a single stage during the propagation of an intense laser in a plasma channel. The positrons are created from a laser-electron collision at 90 degrees, where the injection and guiding are made possible by an 800 nC electron beam loading which reverses the sign of the background electrostatic field. We obtain a 20 fC positron beam, with GeV-level central energy within 0.5 mm of plasma.