DISIS—Discrete Scintillation Imager Simulator

To foresee the response of a discrete scintillation imager, operating in single-photon modality, a computer simulation code has been developed and tested. The simulator, whose acronym is DISIS, may be used for designing and/or evaluating devices based on scintillation arrays coupled to a position sensitive light sensors by light guides. The simulator can be classified as a deterministic code because it is based on: (i) an analytical model describing the scintillation light distribution for charge integrals calculation, (ii) an algorithm using charge values for event centroiding and (iii) a Gaussian model for spreading the events on the image according to the inherent imager resolution. Particularly, DISIS allows one to study the influence of each setup parameter on the device spatial response. The imager optimization can be achieved by improving the pixel identification. To this aim the best trade-off has to be found between: (a) the light distribution at photocathode, (b) the light sampling capability over the photocathode area and (c) the centroiding algorithm