Journal Article

PUBDB-2026-03411

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png High-power attosecond x-ray free-electron lasers: Physics and design strategy

Xu, C.XFEL.EU*DESY* ; Yan, J. (Corresponding author)DESY* ; Chen, Y.DESY* ; Decking, W.XFEL.EU*DESY* ; Guetg, M.XFEL.EU*DESY* ; Long, T.DESY* ; Yan, B. ; Deng, H. (Corresponding author)

2026
American Physical Society College Park, MD

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Please use a persistent id in citations: doi:10.1103/hqjn-r9k9  doi:10.3204/PUBDB-2026-03411

Abstract: Attosecond pulses from x-ray free-electron lasers (XFELs) have opened new opportunities for probing ultrafast electronic dynamics on the Ångstrom-attosecond spatiotemporal scale. Most attosecond XFEL concepts rely on generating an ultrashort high-current spike through either external laser modulation or accelerator-based beam manipulation. Despite their different implementations, these approaches share the same essential physics, namely, that the XFEL amplification is confined to a short effective lasing window within the electron beam. However, existing studies are often scheme-specific and do not yet provide a unified quantitative picture of how fundamental electron-beam properties constrain high-power attosecond performance. In this work, we investigate the general physics and scheme-independent requirements for generating high-power attosecond x-ray pulses from a short current spike. From the perspective of postsaturation superradiant evolution, we show that the electron-beam length governs both the attainable peak power and the pulse duration. We further examine the distinct roles of slice energy spread, slice emittance, energy chirp, and transverse beam tilt. Our results reveal the trade-off between peak power, pulse shortening, and single-spike probability, and provide facility-independent guidelines for optimizing electron-beam phase-space manipulation toward terawatt-class attosecond XFEL operation.

Note: The numerical simulations werecarried out using the “MAXWELL” computational resour-ces operated at Deutsches Elektronen-Synchrotron DESY,Hamburg, Germany.

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Contributing Institute(s):

1. XFEL (MXL)
2. Beschleunigerphysik (MPY)
3. XFEL (XFEL)

Research Program(s):

1. 621 - Accelerator Research and Development (POF4-621) (POF4-621)
2. 6G13 - Accelerator of European XFEL (POF4-6G13) (POF4-6G13)

Experiment(s):

1. Facility (machine) XFEL

Appears in the scientific report 2026

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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