Instrumentation Division Seminar

Silicon Photomultipliers (SiPMs) are gradually replacing Photomultipler Tupbes (PMTs) in a large number of applications, offering, among other features, more sensitivity, outstanding timing performance, lower operating voltage, insensitivity to magnetic fields, lower cost and high gain uniformity. Fondazione Bruno Kessler (FBK) has been involved in SiPM development for several years and has achieved state-of-the art SiPM performance in their most typical application, which is Time-of-Flight Positron Emission Tomography (ToF-PET). While the ToF-PET application is gradually becoming an industrial product, it is interesting to consider also other emerging applications in the fields of Nuclear Medicine and High Energy Physics. These applications are made possible by the constantly improving characteristics of the SiPMs. I will describe the latest SiPM technologies developed at FBK and discuss their performance in selected applications. The most recent SiPM technologies developed at FBK are the NUV-HD and the UHD SiPMs. NUV-HD SiPMs feature a cell size between 30 um and 40 um, with peak photon detection efficiency (PDE) of 65% at 410 nm (40 um cell). Ultra-high-density (UHD) SiPMs are characterized by a cell pitch ranging between 5 um and 12.5 um. The 5 um UHD SiPM has the remarkable cell density of 46k cells/mm2 and a PDE of almost 10% at 545 nm. We have also developed a new type of position-sensitive SiPM, called linearly-graded SiPM (LG-SiPM). These applications of these detectors include: time of flight PET with LYSO:Ce and LSO:Ce with calcium co-doping, timing of Cherenkov photons from BGO, small-animal, ultra-high-resolution PET, cryogenic applications for the readout of liquid, noble-gases scintillators, applications that require high-dynamic range or radiation hardness, such as the CMS calorimeters upgrade and prompt-gamma imaging in proton therapy.