EFFECTS OF SCINTILLATION LIGHT COLLECTION FOR ANNIHILATION QUANTA ON THE TIME RESOLUTION OF A TIME-OF-FLIGHT DETECTOR

Using Monte Carlo methods the production and collection of scintillation light in a BaF2 crystal was simulated. The calculated results were compared to measured values for detectors with different heights. Based on this simulation a TOF detector consisting of two conical BaF2 crystals (base radius 18 mm, top radius 15 mm, height 25 mm) was assembled. The total time resolution of this system was (21025) ps FWHM for 511 keV annihilation quanta and was found to be independent of the source position between the detectors.