Energy Resolution of Ce:GAGG and Pr:LuAG Scintillators Coupled to 3 ~mm × 3 ~mm Silicon Photomultipliers

Silicon Photomultipliers (SiPM) have shown great promise as a suitable replacement for conventional vacuum based Photomultiplier Tubes (PMT). Progress in recent years has been vast with SiPM sensors pushing the boundaries in energy and timing resolution as well as photon detection efficiency and active surface area. In this study we report the energy resolution and linearity of two novel scintillator crystals, Cerium doped Gd3Al2Ga3O12(Ce:GAGG) and Praseodymium doped Lu3Al5O12(Pr:LuAG), readout by three different types of3× 3~mm²silicon photomultiplier sensors produced by SensL (MicroFM, MicroFB, MicroFC). Such a scintillator-SiPM architecture has applications in pre-clinical and clinical medical imaging modalities such as Positron Emission Tomography (PET). N-on-P (M series), P-on-N (B series) and low-noise P-on-N (C series) versions of the SiPM sensor platform have been coupled to the crystals and the response characterized over a range of gamma energies and detector bias values. A saturation-corrected energy resolution of 11.7% was achieved for a MicroFM device coupled to a3× 3× 30~mm³Ce:GAGG crystal at 20°C. An energy resolution of 16.1% was obtained for a MicroFB device optically coupled to to a3× 3× 30~mm³Pr:LuAG crystal at 20°C.