X-ray backlighter requirements for refraction-based electron density diagnostics through Talbot-Lau deflectometry

Area of Science:

• Plasma Physics
• X-ray Optics
• Materials Science

Background:

• Talbot-Lau interferometers are crucial for mapping electron density gradients in High Energy Density (HED) samples.
• The deflectometer configuration offers comprehensive diagnostics including refraction, attenuation, elemental composition, and scatter from a single X-ray image.
• Effective X-ray backlighters are essential for accurate HED experiment diagnostics, requiring specific source size and spectral characteristics.

Purpose of the Study:

• To assess the suitability of 8 keV X-ray sources generated in high-power laser and pulsed power environments as backlighters for Talbot-Lau X-ray deflectometry.
• To evaluate the performance of different X-ray detectors with these sources for HED applications.

Main Methods:

• Investigated K-shell emission from copper targets (foils, wires, spheres) irradiated by high-power laser pulses (30 J, 8-30 ps; 60 J, 10 ps).
• Utilized single and double copper x-pinches driven by pulsed power (∼1 kA/ns) as alternative X-ray sources.
• Demonstrated Moiré fringe formation and evaluated detector performance (X-ray films, CCDs, imaging plates) based on spatial resolution, X-ray emission, and fringe contrast.

Main Results:

• Moiré fringe formation was successfully achieved with all evaluated X-ray sources.
• The study provided insights into detector performance characteristics relevant to HED diagnostics.
• The evaluated 8 keV sources show promise for Talbot-Lau X-ray deflectometry in HED research.

Conclusions:

• 8 keV X-ray sources from both laser and pulsed power facilities are viable for Talbot-Lau X-ray deflectometry.
• The findings support the development of advanced diagnostic techniques for High Energy Density physics.
• Further optimization of source parameters and detector selection can enhance diagnostic capabilities.