SiPM based photon counting detector for scanning digital radiography

Abstract

In the present report, we summarize the results of our efforts to create a x-ray counting detector for digital scanning radiography based on the silicon photomultipliers (SiPM) at Budker Institute of Nuclear Physics for the last year. We have performed a comparative study of the possible candidates for scintillator—YAP, LFS-3, LGSO, LYSO and two types of SiPMs—HAMAMATSU MPPC with 25 μ m pixel (S10362-33-025C) and KETEK SiPM with 15 μ m pixel (MP15V9 type) ø 2.5 mm. To measure real detector parameters we have built a detector prototype based on a 32-channel Omega EASIROC front-end chip. The results obtained in this study demonstrate that such detector could reach quantum efficiency >95%, counting rate —5 MHz, energy resolution ∼ 34% (at 59.5 keV) and spatial resolution that is determined by scintillator and SiPM size.