Speaker
Description
The Femtosecond X-ray Liquidography (FXL) endstation at PAL-XFEL is dedicated to femtosecond X-ray studies of solution-phase and condensed-phase samples. It combines femtosecond XFEL pulses with synchronized optical laser excitation and supports time-resolved X-ray scattering, X-ray absorption spectroscopy, X-ray emission spectroscopy, and time-resolved crystallography over an X-ray energy range of 2.3–20 keV. These methods provide complementary information on transient molecular structures and element-specific electronic and local structures in ultrafast chemical dynamics.
FXL was originally designed to support both time-resolved X-ray solution scattering and X-ray absorption spectroscopy. Both experimental directions have evolved through user operation and beamline developments. For scattering and diffraction experiments, FXL has been used for user studies of solution-phase photochemical reactions and TR-SAXS studies of deeply supercooled water and ice, and is being extended toward fixed-target and time-resolved crystallography approaches for organic and inorganic crystalline samples. These examples demonstrate the practical use of FXL for time-resolved scattering and diffraction experiments on liquid, condensed-phase, and microcrystalline samples.
For spectroscopic experiments, FXL has been expanded from XAS toward a broader range of fluorescence-based and high-resolution measurements. Self-seeded femtosecond X-ray absorption spectroscopy has been demonstrated for time-resolved XANES measurements, and tender X-ray absorption at edges such as the S K-edge and Ru L$_3$-edge is being explored. X-ray emission spectroscopy and high-resolution fluorescence-detected measurements based on von Hamos and Johann-type spectrometers are also being developed.
In this poster, we summarize the present status of the FXL endstation and representative user and beamline experiments performed at PAL-XFEL. The poster focuses on the current capabilities of FXL and its expansion toward a broader femtosecond X-ray scattering, spectroscopy, and diffraction platform for ultrafast chemical science.
| Scientific Topics | Chemistry |
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