Noise Reduction for Single-Shot Grating-Based Phase-Contrast Imaging at an X-ray Backlighter.

Area of Science:

• Physics
• Materials Science
• Optical Engineering

Background:

• X-ray backlighters provide short exposure times for imaging fast dynamic processes.
• Moiré imaging allows simultaneous measurement of absorption and differential phase-contrast (DPC).
• Single-shot imaging limits photon flux, leading to noisy images, and dynamic processes prevent repeated experiments.

Purpose of the Study:

• To evaluate two methods for processing multiple reference images to improve DPC and transmission image quality from single-shot acquisitions.
• To assess the impact of reference image processing on noise reduction and contrast-to-noise ratio (CNR) in X-ray imaging.

Main Methods:

• Two distinct approaches for processing multiple reference images were tested in conjunction with a single object image.
• Image quality was evaluated based on improvements in CNR for DPC images.

Main Results:

• Processing multiple reference images significantly improved image quality.
• With only five reference images, a 13% increase in CNR was observed for DPC images.
• This method mitigates noise issues caused by shot-to-shot fluctuations in X-ray spectra and source position.

Conclusions:

• Processing multiple reference images is an effective strategy to enhance image quality in single-shot X-ray imaging.
• This technique offers significant improvements for studying dynamic processes in high-energy density physics experiments.
• The findings are particularly relevant for backlighter X-ray sources like the PHELIX facility.