CdTe Based Energy Resolving, X-ray Photon Counting Detector Performance Assessment: The Effects of Charge Sharing...

Area of Science:

• Photon counting detectors
• Semiconductor detector physics
• Image processing

Background:

• Modern energy-resolving photon counting detectors utilize small pixels for enhanced spatial resolution.
• Small pixels are susceptible to charge sharing effects (CSEs), which negatively impact spectral analysis and imaging quality.
• Existing charge sharing correction algorithms (CSCAs) are often evaluated in isolation, limiting comparative performance analysis.

Purpose of the Study:

• To comprehensively compare the performance of six different CSCAs against a no-correction baseline.
• To evaluate CSCA performance across a range of pixel pitches (100-600 µm) and photon fluxes (10^6-10^8 photons mm^-2 s^-1).
• To provide novel mechanistic insights into the differing efficacies of various CSCAs.

Main Methods:

• Utilized a combination of Monte Carlo simulations and finite element methods for analysis.
• Assessed performance based on four key metrics: absolute detection efficiency, photopeak detection efficiency, relative coincidence counts, and binned spectral efficiency.
• Systematically varied detector pixel pitch and incident photon flux to simulate diverse operational conditions.

Main Results:

• Demonstrated significant performance variations among the six evaluated CSCAs.
• Quantified the impact of CSEs and the effectiveness of CSCAs across different pixel sizes and flux levels.
• Identified specific mechanistic reasons for the observed performance differences between CSCAs.

Conclusions:

• No single CSCA universally outperforms others across all tested conditions.
• The choice of CSCA significantly influences detector performance metrics, necessitating careful selection based on application requirements.
• This research provides a foundational comparison for optimizing CSCA implementation in photon counting detectors.