Computer simulation of four-layer depth of interaction detector for PET

A project for developing a next generation PET scanner named ´jPET-D4´ is going on at the National Institute of Radiological Sciences of Japan. In this project, a new four-layer depth of interaction (DOI) detector is proposed to achieve high resolution and high sensitivity. The DOI detector consists of Gd₂SiO₅:Ce (GSO) crystal array with proper optical reflectors and position sensitive photomultiplier tubes (PSPMT). Previously we have developed a Monte Carlo simulation for the DOI detector of 2×2×4 crystal elements. In this study, in order to simulate the latest version of DOI detector with more crystal elements, we developed a much faster, simplified simulator. The content of simplified simulator and some simulation results for multiple scattering in detector are presented.