Diffraction enhanced imaging utilizing a laser produced x-ray source

Area of Science:

• * Physics and Materials Science
• * X-ray Optics and Imaging

Background:

• * Fresnel diffraction imaging uses absorption and phase-contrast to determine electron density profiles.
• * Low coherence requirements enable laser-produced x-ray sources for this technique.
• * Ideal for studying material interfaces under extreme conditions generated at large facilities.

Purpose of the Study:

• * To demonstrate a proof-of-principle for an effective micrometer-scale laser-generated x-ray source.
• * To enable high-resolution imaging of material interfaces at extreme conditions.

Main Methods:

• * Utilized a laser-produced x-ray source (vanadium He-like, 5.2 keV) at the OMEGA Laser Facility.
• * Employed 1 × 30 μm² and 2 × 40 μm² slits milled into 30 μm tantalum plates.
• * Developed a 1D imaging system with micrometer-scale resolution, addressing slit taper challenges.

Main Results:

• * Achieved an effective laser-generated x-ray source size of approximately 2 μm.
• * Demonstrated micrometer-scale resolution by imaging a tungsten wire (2 ± 0.2 μm radius).
• * Identified slit tilt and taper as key factors influencing source size and alignment tolerance.

Conclusions:

• * Successfully demonstrated a viable micrometer-scale laser-generated x-ray source for Fresnel diffraction imaging.
• * The developed system shows promise for probing material interfaces at extreme conditions with high resolution.
• * Further optimization of slit geometry is crucial for achieving sub-micrometer source sizes.