Development of Gamma-Ray Detector Arrays Consisting of Diced Eu-Doped SrI₂Scintillator Arrays and TSV-MPPC Arrays

This article presents the development of diced SrI2:Eu arrays and their scintillation properties when coupled with a multipixel photon counter (MPPC) array. Using a dicing technique specific to halide scintillators, a high-energy resolution scintillator array is developed that is cost-effective and widely applicable. The developed SrI2:Eu arrays are of 3 × 3 × 3 mm3/pixel 4 × 4 matrix (TYPE1) and 1 × 1 × 1 mm3/pixel 9 × 9 matrix (TYPE2) structures. We fabricated test gamma-ray detector modules consisting of the TYPE1 and TYPE2 arrays coupled with an MPPC array. The mean peak to valleys ratio is 85.3 ± 14.9 for the TYPE1 array and 38.5 ± 16.6 for the TYPE2 array detector. The average energy resolutions obtained for the TYPE1 and TYPE2 gamma-ray detectors were 5.4 ± 0.4% full-width at half-maximum (FWHM) and 5.2 ± 0.6% FWHM, respectively, for 662-keV gamma-rays. The variation in the signal pulse height of the TYPE1 and TYPE2 detectors was only 10.6% and 10.4% in FWHM, respectively. These results demonstrated that the dicing technique proposed in this article could be applied to hygroscopic halide scintillators.