Micro-focused MHz pink beam for time-resolved X-ray emission spectroscopy

Area of Science:

• Chemical Physics
• Materials Science
• Spectroscopy

Background:

• Studying transient species in liquid phase reactions requires high time resolution and sensitivity.
• Traditional X-ray spectroscopy methods often lack the necessary flux or temporal resolution for dynamic processes.

Purpose of the Study:

• To develop and implement an efficient nonresonant X-ray emission spectroscopy (XES) technique for transient species in liquids.
• To achieve high flux and picosecond-to-microsecond time resolution for tracking photoexcited systems.

Main Methods:

• Microfocusing of synchrotron undulator radiation (5-12 keV) using beryllium compound refractive lenses.
• Overlapping the X-ray microbeam with a high-repetition-rate optical laser on a fast-moving liquid jet.
• Utilizing a dispersive spectrometer geometry for X-ray emission spectroscopy.

Main Results:

• Achieved usable flux above 10^15 photons/s at 8 keV on target.
• Enabled tracking of photoexcited systems in the liquid phase with time resolutions from tens of picoseconds to microseconds.
• Captured the full emission spectrum, including weak valence-to-core signals sensitive to electronic properties.

Conclusions:

• The developed microfocused XES technique is efficient for studying transient species in liquids.
• This method provides crucial insights into chemically relevant electronic properties of dynamic systems.
• The high flux and time resolution open new avenues for ultrafast chemical dynamics research.