High-energy-resolution off-resonant spectroscopy with self-seeded x-ray free-electron laser pulses

• Published in: Structural dynamics (Melville, N.Y.) Vol. 11; no. 2; p. 024304
• Main Authors: Sohn, Jang Hyeob, Kang, Gyeongbo, Choi, Tae-Kyu, Lee, Gyusang, Lee, Changhoo, Chun, Sae Hwan, Park, Jaeku, Shin, Dongbin, Cho, Byoung-Ick
• Format: Journal Article
• Language: English
• Published: United States American Institute of Physics, Inc 01.03.2024; American Crystallographic Association; AIP Publishing LLC and ACA
• Subjects: Absorption spectra; Bandwidths; Copper; Energy; Free electron lasers; High temperature; Line spectra; Metal foils; Spectrum allocation; Spectrum analysis; X ray absorption; X ray spectra
• ISSN: 2329-7778; 2329-7778
• DOI: 10.1063/4.0000243

This paper presents the implementation of high-energy-resolution off-resonant spectroscopy (HEROS) measurements using self-seeded x-ray free-electron laser (XFEL) pulses. This study systematically investigated XFEL conditions, including photon energy and accumulated shot numbers, to optimize the measurement efficiency for copper foil samples near the K-edge. The x-ray absorption spectra reconstructed using HEROS were compared with those derived from fluorescence-yield measurements. The HEROS-based spectra exhibited consistent line shapes independent of the sample thickness. The potential application of HEROS to high-temperature copper was also explored. HEROS offers distinct advantages including scan-free measurement of x-ray absorption spectra with reduced core-hole lifetime broadening and self-absorption effects. Using self-seeded XFEL pulses, HEROS facilitates single-shot-based pump–probe measurements to investigate the ultrafast dynamics in various materials and diverse conditions.