A modular table-top setup for ultrafast x-ray diffraction

Area of Science:

• Materials Science
• Condensed Matter Physics
• X-ray Science

Background:

• Femtosecond time-resolved X-ray diffraction (TRXRD) is crucial for studying ultrafast material dynamics.
• Existing TRXRD setups can be complex and lack accessibility.
• Developing compact, user-friendly TRXRD systems is essential for broader research applications.

Purpose of the Study:

• To present a novel table-top setup for femtosecond time-resolved X-ray diffraction.
• To demonstrate a modular and accessible design for TRXRD experiments.
• To showcase the system's capability for high-precision measurements at a low repetition rate.

Main Methods:

• Utilized a Cu Kα (8.05 keV) laser-driven plasma X-ray source.
• Implemented a pre-pulse scheme to optimize Kα-yield.
• Employed a magnifying multilayer X-ray mirror (Montel-Helios geometry) for radiation collection.
• Used a gas ionization chamber detector for diffraction signal normalization.
• Conducted time-resolved diffraction experiments on laser-excited epitaxial Bi films.

Main Results:

• Achieved a quasi-collimated flux of >10^5 Cu Kα photons/pulse at 10 Hz repetition rate.
• Demonstrated the capability to measure relative signal changes <1%.
• Successfully performed time-resolved diffraction on epitaxial Bi films.
• Validated the setup for Debye-Scherrer measurements on polycrystalline samples.

Conclusions:

• The developed table-top setup provides an accessible and efficient platform for femtosecond time-resolved X-ray diffraction.
• The modular design enhances usability and component accessibility.
• The system is suitable for studying ultrafast dynamics in various materials, including thin films and polycrystalline samples.