GEANT4 simulation for modelling the optics of LaBr scintillation imagers

The excellent scintillation properties of the LaBr3:Ce crystals makes their use very attractive in a system of gamma imaging for Single Photon Emission Tomography (SPET) applications. In this work we use GEANT4 simulations, in order to better understand the intrinsic properties of a gamma camera based on LaBr3:Ce crystals, coupled to a Hamamatsu H8500 Multi Anodes Photomultiplier (MA-PMT). All electromagnetic process are simulated, together with the detection of the scintillation light distribution on the anodic plane of a MAPMT. The position linearity response, the spatial and energy resolutions are investigated. The values obtained by Monte Carlo show a good agreement with the experimental results.