Compact gamma detectors based on FBK SiPMs for a Ps Time Of Flight apparatus

Abstract

Silicon Photomultipliers (SiPMs) are single-photon detectors currently used in many applications as a valid alternative to Photomultiplier Tubes (PMTs). In fact, SiPMs present several advantages compared to PMTs, in terms of size, ruggedness, insensitivity to magnetic fields and voltage supply.In this work, we evaluated the use of SiPMs produced by FBK (Fondazione Bruno Kessler)-AdvanSid (Trento, Italy) in Positronium Time Of Flight (Ps TOF) technique. The aim of this technique is the study of the energy of Ps emitted by porous media for advanced experiments in the field of antimatter physics and, in the future, for open porosities characterization.The TOF spectrometer in operation at the positron beam of the University of Trento (Italy) is based on five gamma detectors composed of NaI(Tl) scintillators coupled to PMTs. We compared the performance of one of these standard detectors against a detector formed by two 4×4 mm 2 SiPMs coupled to a 4×4×30 mm 3 LYSO (Cerium-doped Lutetium Yttrium Orthosilicate) scintillator. The LYSO+SiPM detector was characterized for timing and energy resolution as well as for the background emission level.It is shown that SiPMs, thanks to their small size and versatility, can be coupled successfully to small scintillators, obtaining more compact detectors with respect to the NaI(Tl)+PMT detectors. The design of an array of detectors with wide angular acceptance and spatial resolution is discussed in order to improve the performances of Ps-TOF setups.

Single-shot positron annihilation lifetime spectroscopy with LYSO scintillators

“…As a result these materials have found applications in areas such as positron emission tomography (PET) [25] and high energy physics [26]. Because of its high stopping power LYSO is well suited for studies of low-energy photons [27], which is useful not only in PET scanners [28] but also other positron physics applications (e.g., [29][30][31]). As we shall discuss, these same properties also make LYSO a good material to use for SSPALS, especially when conducting experiments with Rydberg Ps atoms.…”