Light Yield and response function on YAP:Ce Multi-crystal detectors

The use of PSPMT (Position Sensitive Photo Multiplier Tube) in Nuclear Medicine imaging has recently produced some major steps forward in this fields. However, a reasonable number of light photons and a narrow PSF (Point Spread Function) are needled in order to maximize PSPMT performances, this implies the use of multi-crystal scintillation detector. In this work the response function and the light yield of a number of YAP:Ce multi-crystal detectors are studied. The light output of the crystal needles shows a strong dependence on the size of the needle itself. The light output relative to NaI(Tl) ranged between 5% and 30%. The energy resolution vried between 25% and 90% at 140 keV incident photon energy. Studies were carried out coupling the scintillation crystals to a conventional PMT and to a PSPMT Hamamtsu R2486.