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

Jang Hyeob Sohn; Gyeongbo Kang; Tae-Kyu Choi; Gyusang Lee; Changhoo Lee; Sae Hwan Chun; Jaeku Park; Dongbin Shin; Byoung-Ick Cho

doi:10.1063/4.0000243

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

Struct Dyn. 2024 Mar 26;11(2):024304. doi: 10.1063/4.0000243. eCollection 2024 Mar.

Authors

Jang Hyeob Sohn¹, Gyeongbo Kang², Tae-Kyu Choi², Gyusang Lee, Changhoo Lee¹, Sae Hwan Chun², Jaeku Park², Dongbin Shin, Byoung-Ick Cho

Affiliations

¹ Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, South Korea.
² XFEL Division, Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk 37673, South Korea.

Abstract

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.