Journal Article

PUBDB-2024-04691

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Two-bunch seeding of soft X-ray free electron lasers

Schneidmiller, E. A. (Corresponding author)XFEL.EU*DESY* ; Zagorodnov, I.DESY*

2024
American Physical Society College Park, MD

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Please use a persistent id in citations: doi:10.1103/PhysRevAccelBeams.27.110703  doi:10.3204/PUBDB-2024-04691

Report No.: DESY-24-091; arXiv:2406.19984

Abstract: Seeded Free Electron Lasers (FELs) demonstrate a good performance and are successfully used in different user experiments in extreme ultraviolet and soft X-ray regimes. In this paper a simple modification of the seeding scenario is proposed relying on generation of two closely spaced bunches with very different properties: a low-current seeding bunch, and a high-current bunch that amplifies coherent radiation, produced by the seeding bunch. This approach eliminates different limitations and mitigates some harmful effects in the standard scenario. In particular, one can generate very high harmonic numbers with a moderate laser power in a simple high-gain harmonic generation (HGHG) scheme. Alternatively, in case of moderate harmonic numbers, one can strongly reduce the required laser power thus simplifying design of high repetition rate seeded FELs. An influence of beam dynamics effects (like nonlinearities of the longitudinal phase space of electron beams, coherent synchrotron radiation, longitudinal space charge, geometrical wakefields, microbunching instabilities etc.) on properties of output radiation (spectrum broadening, pedestals, stability) can be to a large extent reduced in the proposed scheme. In this paper we illustrate the operation of the two-bunch seeding scheme in HGHG configuration with realistic start-to-end simulations for the soft x-ray user facility FLASH. We show that nearly Fourier-limited multi-gigawatt pulses can be generated at 4 nm using the present compact design of the undulator system. With several thousand pulses per second this can be a unique source for photon science.

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Contributing Institute(s):

1. Beschleunigerphysik (MPY)

Research Program(s):

1. 621 - Accelerator Research and Development (POF4-621) (POF4-621)
2. 6G2 - FLASH (DESY) (POF4-6G2) (POF4-6G2)

Experiment(s):

1. FLASH 2020+ Project

Appears in the scientific report 2024

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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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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Preprint Schneidmiller, E. A. (Corresponding author)XFEL.EU*DESY* ; Zagorodnov, I.DESY*
Two-bunch seeding of soft x-ray free electron lasers
[10.3204/PUBDB-2025-00146]     Files  Fulltext by arXiv.org BibTeX | EndNote: XML, Text | RIS

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