Material identification in x-ray microscopy and micro CT using multi-layer, multi-color scintillation detectors.

Area of Science:

• Materials Science
• Imaging Physics
• X-ray Imaging

Background:

• Dual-layer scintillators enhance sensitivity in synchrotron imaging.
• Polychromatic illumination offers potential for material characterization.

Purpose of the Study:

• To explore the use of a dual-layer, dual-color scintillator for material quantification and classification with microscopic CT.
• To evaluate data-handling approaches for material decomposition and classification.

Main Methods:

• Developed and analyzed two data-handling approaches: data-domain material decomposition and image-domain material classification.
• Utilized Cramer-Rao lower bound for data-domain analysis and characterized angular separation in effective attenuation coefficient space for image-domain analysis.
• Implemented and validated the image-domain approach at a synchrotron facility.

Main Results:

• Data-domain analysis predicts achievable signal-to-noise ratios (SNR > 5) within seconds for various contrast levels and X-ray fluxes.
• Image-domain classification demonstrated robustness to calibration errors and ability to distinguish elemental stains.
• Experimental results at the synchrotron were consistent with simulation predictions.

Conclusions:

• The dual-layer scintillator construct is effective for material quantification and classification in microscopic CT.
• Both data-domain and image-domain approaches offer viable pathways for material analysis, with the image-domain method showing greater robustness.
• The developed tools can be applied to optimize parameters for diverse imaging applications.