Intercrystal Optical Crosstalk in Radiation Detectors: Monte Carlo Modeling and Experimental Validation.

Area of Science:

• Medical Physics
• Detector Technology
• Computational Science

Background:

• High-performance radiation detectors utilize crystal arrays.
• Intercrystal crosstalk, or light leakage between crystals, degrades detector performance.
• Accurate simulation of optical crosstalk is crucial for detector design and optimization.

Purpose of the Study:

• To develop and validate a novel optical photon transmission model for simulating intercrystal crosstalk.
• To integrate this model into the Geant4 Application for Tomographic Emission (GATE) simulation toolkit.
• To address the lack of validated transmission models in existing Monte Carlo simulation tools.

Main Methods:

• Developed a new simulation model for optical photon refraction at crystal interfaces.
• Integrated the model into the Davis Model lookup table within GATE.
• Validated the model through experimental measurements of intercrystal optical crosstalk in Lutetium-yttrium oxyorthosilicate crystals.
• Tested the model with varying crystal thicknesses and interface materials (air, glue, Teflon, ESR).

Main Results:

• The simulation model accurately predicted intercrystal optical crosstalk.
• Simulated and experimental crosstalk measurements agreed within one Full Width at Half Maximum (FWHM) across all tested configurations.
• Demonstrated the model's capability to predict optical photon transmission in multi-crystal detector geometries.

Conclusions:

• The validated model enables accurate prediction of optical crosstalk in radiation detector designs.
• This tool is valuable for optimizing detector geometry and ensuring optical isolation between photodetector responses.
• The model is available for GATE users to enhance the design of complex detector systems.