Brilliant X-Ray Free Electron Laser Driven by Resonant Multi-Pulse Ionization Injection Accelerator

P. Tomassini, L. Giannessi, A. Giribono, F. Nguyen, L. Gizzi

40th International Free Electron Laser Conference, Journals of Accelerator Conferences Website

Abstract

Laser Wakefield Accelerators are now sufficiently mature to provide GeV scale/high-brightness electron beams capable of driving Free Electron Laser (FEL) sources. Here,
we show start-to-end simulations carried out in the framework of the EuPRAXIA project of a Free Electron Laser driven by an LWFA accelerator with the Resonant MultiPulse Ionisation Injection (ReMPI) setup. Simulations with this model using a 1 PW Ti:Sa laser system and a 20 cm long capillary, show the injection and acceleration of an electron beam up to 4.5 GeV, with a slice energy spread and a normalized emittance below 4 × 10^(−4) and 80 nm, respectively.
The transport of the beams from the capillary exit to the undulator is provided by a matched beam focusing with a marginal beam-quality degradation. Finally, 3D simulations
of the FEL radiation generated inside an undulator show that ≈ 10^(10) photons with central wavelength of 0.15 nm and peak power of ≃ 0.3 GW can be produced for each bunch. Our
start-to-end simulations indicate that a single-stage ReMPI accelerator can drive a high-brightness electron beam having quality large enough to be efficiently transported to a
FEL undulator, thus generating X-ray photons of brilliance exceeding 10^(31) 𝑝ℎ/𝑠/𝑚𝑚2/𝑚𝑟𝑎𝑑2/0.1% bw.