Modeling of Photonic Crystals into the GATE LUT Davis Model for Detector Simulation

Positron Emission Tomography (PET) plays a pivotal role in clinical care and biomedical research. Improving PET timing and spatial resolution contributes to enhancing image quality. A PET scanner consists of multiple radiation detectors composed of a scintillator, photodetector, and readout circuit. Radiation detectors currently are limited by scintillator size, stopping power, etc. In addition, optical photons emitted by the scintillator may be trapped inside the scintillator and not be detected by the photodetector due to total internal reflection. Losing optical photons will degrade the detector energy and timing resolutions. Longer crystals increase the number of emitted optical photons, but the timing resolution may deteriorate. Photonic Crystals (PhC) are periodic nanostructures with a size comparable to optical photons’ wavelength that increase the number of collected optical photons by breaking the critical angle limit. Scintillator detector design software such as GATE currently cannot model PhC into scintillator detector simulation because optical photons are modeled as discrete particles, obeying geometric optics rules and not wave optics principles that optical photons transported in PhC must follow. To connect PhC with GATE optical photons simulation, we build a bridge between geometric optics and wave optics, using our previously developed framework of the LUT Davis model. The transmission pattern obtained from numerical modeling of PhC has good agreement with experiment results. We develop and incorporate new PhC LUT into the LUT Davis model. This novel strategy makes scintillation detector design work more versatile.