Positron acceleration in plasma waves driven by non-neutral fireball beams

Abstract

Plasma-based positron acceleration is still an open question, as the most efficient regimes for electron acceleration (quasi-linear and blowout) are not directly applicable to positrons. Nevertheless, positron acceleration is a stepping stone on the path toward a plasma-based lepton collider. In this work, we propose a scheme for positron acceleration based on the spatial overlap of a driver (electron or laser) beam and a positron beam, also known as a fireball beam. Under appropriate conditions, these beams can self-consistently evolve toward a hollow driver and focused positron beam on-axis, driving plasma waves suitable for positron acceleration. This evolution seems to be a manifestation of the current filamentation instability. We discuss how the self-consistent dynamics affect the beam quality and perform a preliminary tolerance study.