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Shot-to-shot two-dimensional photon intensity diagnostics within megahertz pulse-trains at the European XFEL.

Authors :
Guest TW
Bean R
Bielecki J
Birnsteinova S
Geloni G
Guetg M
Kammering R
Kirkwood HJ
Koch A
Paganin DM
van Riessen G
Vagovič P
de Wijn R
Mancuso AP
Abbey B
Source :
Journal of synchrotron radiation [J Synchrotron Radiat] 2022 Jul 01; Vol. 29 (Pt 4), pp. 939-946. Date of Electronic Publication: 2022 Jun 08.
Publication Year :
2022

Abstract

Characterizing the properties of X-ray free-electron laser (XFEL) sources is a critical step for optimization of performance and experiment planning. The recent availability of MHz XFELs has opened up a range of new opportunities for novel experiments but also highlighted the need for systematic measurements of the source properties. Here, MHz-enabled beam imaging diagnostics developed for the SPB/SFX instrument at the European XFEL are exploited to measure the shot-to-shot intensity statistics of X-ray pulses. The ability to record pulse-integrated two-dimensional transverse intensity measurements at multiple planes along an XFEL beamline at MHz rates yields an improved understanding of the shot-to-shot photon beam intensity variations. These variations can play a critical role, for example, in determining the outcome of single-particle imaging experiments and other experiments that are sensitive to the transverse profile of the incident beam. It is observed that shot-to-shot variations in the statistical properties of a recorded ensemble of radiant intensity distributions are sensitive to changes in electron beam current density. These changes typically occur during pulse-distribution to the instrument and are currently not accounted for by the existing suite of imaging diagnostics. Modulations of the electron beam orbit in the accelerator are observed to induce a time-dependence in the statistics of individual pulses - this is demonstrated by applying radio-frequency trajectory tilts to electron bunch-trains delivered to the instrument. We discuss how these modifications of the beam trajectory might be used to modify the statistical properties of the source and potential future applications.<br /> (open access.)

Details

Language :
English
ISSN :
1600-5775
Volume :
29
Issue :
Pt 4
Database :
MEDLINE
Journal :
Journal of synchrotron radiation
Publication Type :
Academic Journal
Accession number :
35787559
Full Text :
https://doi.org/10.1107/S1600577522005720