Modelling of Phase Contrast Imaging with X-ray Wavefront Sensor and Partial Coherence Beams

Area of Science:

• Physics
• Optics
• Materials Science

Background:

• The Hartmann wavefront sensor offers precise measurement of the real (δ) and imaginary (β) parts of the X-ray refractive index.
• Integrating the Hartmann sensor with tomographic setups enables direct material density measurements, expanding its applications in imaging.

Discussion:

• A novel 3D wave propagation model utilizing Fresnel propagation was developed to accurately simulate X-ray wavefront sensing experiments.
• This model accommodates varying degrees of source spatial coherence, crucial for experiments with tabletop sources, synchrotrons, and X-ray free-electron lasers.
• Physical description of beam divergence is incorporated, consistent with spatial coherence, for enhanced simulation fidelity.

Key Insights:

• The developed model accurately simulates experiments involving X-ray wavefront sensing across different coherence levels.
• High sensitivity of the Hartmann sensor to phase and absorption variations necessitates precise simulation tools for experimental optimization.
• The model supports accurate experimental design and parameter optimization for advanced X-ray imaging techniques.

Outlook:

• Further refinement of the 3D wave propagation model for complex sample geometries.
• Application of the model to optimize phase contrast imaging and quantitative phase tomography.
• Integration with advanced X-ray sources for novel material characterization techniques.