Monte Carlo simulation for depth encoding multicrystal detector for PET

At the EEEE MIC 1999, we presented a Monte Carlo simulator made for designing a depth encoding multicrystal detector and reported some simulation results. While the basic performance of the simulator was validated from the comparison between the simulator outputs and experimental results using a prototype detector, many factors to be implemented were still remaining for simulating real phenomena inside the detector. This time, we improved the simulator by including Compton scattering, more accurate migration of optical photons at every interface of materials, and so on. Using this simulator, discrimination characteristics were investigated with respect to thickness of scintillator block, refractive index of inter-stage material, reflectance of optical reflector and surface roughness of scintillator. From these investigations, useful information for detector design was obtained