Performance comparison of large-area SiPM arrays suitable for gamma ray detectors

Abstract

[EN] The use of photosensors of the type Silicon Photomultpliers (SiPM) has widely been extended in recent years for multiple applications in both research and industry. However, there is a lack of comparative studies of different SiPMs under the same conditions, making it difficult to choose the most appropriate one for a specific application. SiPM arrays are suitable for gamma rays detectors, especially when covering large active areas. They are used either in clinical or pre-clinical scenarios, constituting Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) scanners, or just gamma cameras. The current work presents, for the first time, a comparative study between SensL, Hamamatsu Photonics and KETEK arrays of 12 x 12 SiPMs, with individual active areas of 3 mm x 3 mm, thus covering a total active area of about 5 cm x 5 cm. In this study, we have first evaluated their bias and temperature dependencies, resulting in a very similar behaviour with just a slightly larger dependency of the tested Hamamatsu parts. We also report the performance of detector blocks based on these three SiPM arrays, when coupled to pixelated crystal arrays and monolithic scintillators, in terms of photon impact estimation accuracy, as well as energy resolution. In the case of the monolithic crystals, also the depth of interaction resolution was determined. Both monolithic and pixelated blocks are nowadays widely used in academia or are commercially available for molecular imaging systems. The results obtained for the three SiPM arrays when using those crystals, are comparable, without observing any significant different among them.