A platform for x-ray absorption fine structure study of dynamically compressed materials above 1 Mbar

Area of Science:

• High-pressure physics
• Materials science
• X-ray spectroscopy

Background:

• Studying materials under extreme pressures is crucial for understanding planetary interiors and inertial confinement fusion.
• Traditional XAFS techniques face limitations at multi-Mbar pressures due to signal weakness.

Purpose of the Study:

• To develop and demonstrate a novel experimental platform for performing X-ray Absorption Fine Structure (XAFS) measurements at multi-Mbar pressures.
• To enhance the detection of weak XAFS signals from compressed materials.

Main Methods:

• Development of a multi-shock drive and implosion backlighter system for material compression.
• Detailed characterization of the experimental setup, target design, and backlighter.
• Implementation of a quintuple-crystal design for an efficient X-ray spectrometer.

Main Results:

• Successful demonstration of extended XAFS (EXAFS) measurements on various materials compressed to multi-Mbar pressures.
• The quintuple-crystal spectrometer design significantly improved the efficiency for detecting weak EXAFS signals.
• Single-shot EXAFS observations were achieved, enabling rapid material analysis.

Conclusions:

• The developed platform provides a powerful new capability for probing the electronic structure of materials under extreme compression.
• The enhanced spectrometer efficiency opens avenues for studying transient phenomena and a wider range of materials at high pressures.
• This work advances the field of high-pressure science and materials characterization.