Polycapillary x-ray lenses for single-shot, laser-driven powder diffraction.

Area of Science:

• Materials Science
• High-Energy Physics
• Condensed Matter Physics

Background:

• Characterizing phase transitions in dynamically compressed high-Z matter at Mbar pressures requires high-fidelity X-ray diffraction data.
• Existing methods using large-scale laser systems face challenges with low X-ray conversion efficiency and background noise.
• High photon energy and fluence are critical for single-shot diffraction measurements.

Purpose of the Study:

• To improve the quality and feasibility of X-ray diffraction measurements for dynamically compressed high-Z matter.
• To overcome limitations of low X-ray conversion efficiency and background noise in laser-driven X-ray sources.
• To enable high-fidelity characterization of phase transitions at extreme pressures.

Main Methods:

• Utilizing polycapillary X-ray lenses in powder X-ray diffraction experiments.
• Employing solid target X-ray emission from Z-Beamlet (long-pulse) and Z-Petawatt (ZPW) (short-pulse) laser systems.
• Comparing performance against conventional pinhole apertures for fluence and background reduction.

Main Results:

• Polycapillary lenses achieved a 100-fold increase in X-ray fluence compared to pinholes.
• Significant reduction in unwanted background radiation was observed.
• Enabled diffraction measurements up to 16 keV at the few-photon signal level.
• Facilitated diffraction experiments with the ZPW laser at full intensity.

Conclusions:

• Polycapillary X-ray lenses are effective in enhancing X-ray diffraction measurements for high-pressure materials science.
• This technique significantly improves data fidelity and enables new experimental regimes.
• The method provides a pathway for detailed studies of matter under extreme dynamic compression.