Validation of Detect2000-Based PetDetSim by Simulated and Measured Light Output of Scintillator Crystal Pins for PET Detectors

A new Monte Carlo simulation tool, called PetDetSim and its experimental validation is presented. The simulation environment aims to model PET detectors and applies the Detect2000 code. Light output of LYSO and GSO crystal pins of different size and surface finish, covered with diffuse or specular reflectors was experimentally determined and compared with the results of the simulations. By improving the model concerning the pin and reflector geometry and the wavelength dependent reflection of the photocathode, the figure of merit could be considerably improved. The initially 34% deviation between simulation and measurements decreased below 11% for all LYSO crystal configurations.