Application of a PWFA to an X-ray FEL

TL;DR

This paper investigates using plasma wakefield acceleration to boost electron beam energy in X-ray FELs, aiming to enhance power and photon flux without lengthening the accelerator, demonstrated through 2D simulations with SwissFEL parameters.

Contribution

It presents a novel application of PWFA to increase electron energy in existing FELs, potentially improving X-ray output efficiency.

Findings

Achieved ~2 GeV energy gain in simulations

Maintained ~1% relative energy spread

Demonstrated feasibility with SwissFEL parameters

Abstract

There is a growing demand for X-ray Free-electron lasers (FELs) in various science fields, in particular for those with short pulses, larger photon fluxes and shorter wavelengths. The level of X-ray power and the pulse energy depend on the amount of electron bunch energy. Increasing the latter will increase the power of the radiating X-rays. Using numerical simulations we explore the possibility of using a plasma wakefield accelerator (PWFA) scheme to increase the electron beam energy of an existing FEL facility without significantly increasing the accelerator length. In this paper we use parameters of the SwissFEL beam. The simulations are carried out in 2D cylindrical symmetry using the code OSIRIS. Initial results show an energy gain of ~2 GeV after propagation of 0.5 m in the plasma with a relative energy spread of ~1%.