Frequency and spatially chirped free-electron laser pulses

Abstract

We have produced hard x-ray free-electron laser (FEL) pulses, which are chirped both in photon energy and in spatial position. The experiments have been carried out at the hard x-ray beamline Aramis at SwissFEL, located at the Paul Scherrer Institute in Switzerland. The FEL beamline was operated without any external focusing and with a tilted, energy-chirped electron bunch, whose properties are then transferred to the photon beam. The resulting FEL pulses were used for a single-shot absorption x-ray spectroscopy experiment at the Alvra endstation. But, as will be outlined, applications of this type of tailored FEL pulse go beyond such experiments, allowing for x-ray pulse compression and control of the transverse coherence within the pulse.Received 13 May 2022Accepted 22 February 2023DOI:https://doi.org/10.1103/PhysRevResearch.5.L022009Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Physical SystemsFree-electron lasersAccelerators & Beams