First Performance Results of Ce:GAGG Scintillation Crystals With Silicon Photomultipliers

A new single-crystal Cerium doped Gd₃Al₂Ga₃ O₁₂₃Al₂Ga₃ O₁₂ (GAGG) scintillation crystal with high luminosity, high density and relatively fast decay time has successfully been grown. We report on the first performance results of the new GAGG scintillation crystal read out with silicon photomultipliers (SiPM) from Hamamatsu (MPPC) and FBK. The best energy resolution (511 keV peak of Ge-68) of 7.9% was attained with GAGG coupled to MPPC and 9.0% with the FBK SiPM after correcting for non-linearity. On the other hand, the best coincidence resolving time (FWHM) of polished 3 × 3 × 5 mm³ and 3 × 3 × 20mm³crystals were 464 ±12 ps and 577 ±22 ps for GAGG crystals compared to 179 ±8 ps and 214 ±6 ps for LYSO crystals respectively with MPPCs. The rise time of GAGG was measured to be 200 ps (75%) and 6 ns (25%) while the decay time was 140 ns (92%), 500 ns (7.7%) 6000 ns (0.3%).