Compact LWFA-Based Extreme Ultraviolet Free Electron Laser: design constraints

TL;DR

This paper explores the design constraints for a compact EUV FEL driven by a laser wakefield accelerator, demonstrating the potential for ultra-short, high-brilliance EUV photon pulses using existing electron beam parameters.

Contribution

It presents a detailed analysis of the requirements and feasible parameters for a LWFA-based EUV FEL, including beam transport and saturation conditions, advancing compact FEL development.

Findings

Achievable photon pulse energy saturation with a single undulator.

Generation of ultra-short EUV photon pulses with high peak brilliance.

Feasibility of using existing electron beam parameters for EUV FEL operation.

Abstract

Combination of advanced high power laser technology, new acceleration methods and achievements in undulator development opens a way to build compact, high brilliance Free Electron Laser (FEL) driven by a laser wakefield accelerator (LWFA). Here we present a study outlining main requirements on the LWFA based Extreme Ultra Violet (EUV) FEL setup with the aim to reach saturation of photon pulse energy in a single unit commercially available undulator with the deflection parameter $K_0$ in a range of (1{\div}1.5). A dedicated electron beam transport which allows to control the electron beam slice parameters, including collective effects, required by the self-amplified spontaneous emission (SASE) FEL regime is proposed. Finally, a set of coherent photon radiation parameters achievable in the undulator section utilizing best experimentally demonstrated electron beam parameters are analyzed. As a result we demonstrate that the ultra-short (few fs level) pulse of the photon radiation with the wavelength in the EUV range can be obtained with the peak brilliance of $\sim$2$\times$10$^{30}$ photons/s/mm$^2$/mrad$^2$/0.1%bw if the driver laser operates at the repetition rate of 25 Hz.