Progress on Experiments towards LWFA-driven Transverse Gradient Undulator-Based FELs

TL;DR

This paper reviews recent experimental progress in developing LWFA-driven transverse gradient undulator-based FELs, addressing challenges in beam quality and matching for effective FEL operation.

Contribution

It presents recent experimental achievements in implementing transverse gradient undulators for LWFA-based FELs, advancing the understanding of beam matching techniques.

Findings

Successful demonstration of transverse gradient undulator concept

Improved beam matching techniques for LWFA-driven FELs

Progress towards practical LWFA-based FEL applications

Abstract

Free Electron Lasers (FEL) are commonly regarded as the potential key application of laser wakefield accelerators (LWFA). It has been found that electron bunches exiting from state-of-the-art LWFAs exhibit a normalized 6-dimensional beam brightness comparable to those in conventional linear accelerators. Effectively exploiting this beneficial beam property for LWFA-based FELs is challenging due to the extreme initial conditions particularly in terms of beam divergence and energy spread. Several different approaches for capturing, reshaping and matching LWFA beams to suited undulators, such as bunch decompression or transverse-gradient undulator schemes, are currently being explored. In this article the transverse gradient undulator concept will be discussed with a focus on recent experimental achievements.