A new optical simulator for light collection estimation in scintillation detectors

In order to predict the behavior of a gamma camera based on scintillators, both to optimize its design and performances in the position and energy reconstructions, a new simulation toolset has been developed. It consists of a set of graphic user interfaces written in MATLAB^® language, with the purpose of simulating the expected behavior of the gamma rays interactions and optical photons distribution inside the scintillator crystal. For these latter, a new optical simulator has been designed, focusing especially on the reflection phenomena on rough interfaces. This program simulates the photons´ paths implementing a three layer model (scintillator, adhesive layer, cover) for the crystal boundaries, while the behavior at the interfaces is described through the parametric UNIFIED model. The comparison between simulated and experimental data has provided a validation to the programs and models implemented. Finally, the efficiency and speed of the program is further enhanced thanks to the use of the Parallel Computing Toolbox, which allows to employ all the computer processors for the simulation.