Influence of partial coherence on analyzer-based imaging with asymmetric Bragg reflection

Area of Science:

• Physics
• Optics
• Materials Science

Background:

• X-ray imaging requires high resolution and phase contrast for detailed analysis.
• The Bragg Magnifier, a novel technique, offers sub-micrometer resolution and phase contrast.
• Previous theoretical models did not account for partially coherent illumination.

Purpose of the Study:

• To extend the theoretical formalism for the Bragg Magnifier to include partially coherent illumination.
• To analyze the impact of partial coherence on X-ray imaging characteristics.
• To experimentally validate the extended theoretical model.

Main Methods:

• Development of a theoretical formalism for partially coherent illumination in the Bragg Magnifier.
• Numerical simulations of X-ray imaging under polychromatic (partially coherent) synchrotron conditions.
• Experimental verification of the theoretical model, including dispersive interactions.

Main Results:

• Partial coherence, primarily from polychromatic illumination, reduces image contrast by approximately 50% compared to monochromatic illumination.
• Sub-micrometer spatial resolution is maintained even under partially coherent conditions.
• The extended theoretical formalism accurately describes crystal interactions, crucial for data evaluation.

Conclusions:

• The Bragg Magnifier technique is robust to partial coherence, retaining high resolution.
• Understanding the effects of partial coherence is vital for accurate interpretation of Bragg Magnifier X-ray images.
• The validated theoretical framework enables precise data evaluation in synchrotron-based imaging applications.