Beam loading in the nonlinear regime of plasma-based acceleration

TL;DR

This paper presents a theoretical framework for beam loading in nonlinear plasma wakefields, deriving analytical solutions and verifying them with simulations, demonstrating high efficiency and preserved energy spread.

Contribution

It introduces a new theory for negative charge loading in nonlinear plasma wakefields, providing analytical solutions and validation with simulations.

Findings

High beam-loading efficiency achievable

Energy spread of the bunch is conserved

Analytical solutions match Particle-In-Cell simulations

Abstract

A theory that describes how to load negative charge into a nonlinear, three-dimensional plasma wakefield is presented. In this regime, a laser or an electron beam blows out the plasma electrons and creates a nearly spherical ion channel, which is modified by the presence of the beam load. Analytical solutions for the fields and the shape of the ion channel are derived. It is shown that very high beam-loading efficiency can be achieved, while the energy spread of the bunch is conserved. The theoretical results are verified with the Particle-In-Cell code OSIRIS.