Investigation of YSO–SiPM detector response for alpha spectroscopy applications

The applicability of a yttrium orthosilicate (YSO) scintillator coupled to a silicon photomultiplier (SiPM) array for alpha-particle spectrometry was investigated. Although scintillators such as ZnS(Ag) and CsI(Tl) are widely used for alpha detection, the alpha-spectrometric performance of YSO scintillators has received limited attention. In this work, alpha particles from a ²³⁸Pu source were measured in the energy range from approximately 0.4 MeV to 5.5 MeV by varying the air gap between the source and detector. A 10×10×10 mm³ YSO crystal was coupled to a Hamamatsu S13360-3050 multi-pixel photon counter (MPPC) array and read out using CAEN digitization electronics. The detector exhibited stable and approximately linear response behavior across the investigated energy interval, with an estimated deviation of about 3% from linearity. The measured energy resolution varied from approximately 10.5% at 5.5 MeV to 21% at 0.4 MeV. The experimentally measured alpha-particle flight distance in air was consistent with SRIM simulations. The obtained results demonstrate that the YSO–SiPM configuration represents a promising compact and mechanically robust solution for alpha spectrometry, radiation monitoring, safeguards, and field-deployable nuclear instrumentation.