LabPET pulse simulator for crystal identification validation of multi-layer phoswich detectors

Abstract

A detector pulse simulator was recently developed to simulate digital output signals from LabPET, an APD-based small animal Positron Emission Tomography (PET) scanner developed at Universite¿ de Sherbrooke. The main goal of the simulator was to validate the digital crystal identification (CI) and timing algorithms implemented in the LabPET. The pulse simulator uses information generated by Monte Carlo simulation, such as energy, time of arrival and position of interactions in a LYSO-LGSO (80%Gd) phoswich detector to generate digital output signals in which Poisson photon statistics and electronic noise are included. We report here the validation of the Wiener filter CI results for new types of fast and high luminosity scintillation crystals that can potentially be used as new depth of interaction phoswich detectors. The fast Wiener filter-based CI method was investigated for discriminating two and three layer detectors using GSO, and new LSO: Ce,Ca and LGSO(10%Gd) crystals with decay time differences as close as 13 ns. CI error rate was 0.5%-3% for various two layer phoswich detectors and 6% for a three-layer detector for energies higher than 100 keV.