TY - RPRT TI - X-ray free-electron lasing in a flying-focus undulator AU - Ramsey, D. [University of Rochester, NY (United States)] (ORCID:0000000265565139) AU - Malaca, B. [Universidade de Lisboa, Lisbon (Portugal)] AU - Simpson, T. T. [University of Rochester, NY (United States)] AU - Formanek, M. S. [The Extreme Light Infrastructure ERIC, Dolní Břežany (Czech Republic)] (ORCID:0000000327046474) AU - Mack, L. S. [University of Rochester, NY (United States)] AU - Vieira, J. [Universidade de Lisboa, Lisbon (Portugal)] (ORCID:0000000255153624) AU - Froula, D. H. [University of Rochester, NY (United States)] (ORCID:0000000169813956) AU - Palastro, J. P. [University of Rochester, NY (United States)] (ORCID:0000000267211924) PY - 2025 DO - 10.1038/s42005-025-02028-x UR - https://www.osti.gov/biblio/2553051 ID - 2553051 ER -