Studying the spectrometric characteristics of an ionizing-radiation detector based on a LaBr 3 (Ce) scintillator and a silicon photomultiplier

The intrinsic background of a LaBr 3 (Ce) scintillator with a diameter of 5 mm and a height of 10 mm has been studied in comparison with LYSO and CeBr 3 scintillators. It is shown that due to its high energy resolution the detector based on a LaBr 3 (Ce) crystal exhibits the lowest background count rate in a specified amplitude range. The measured energy resolution of the detector based on a LaBr 3 (Ce) crystal with dimensions of Ø5 mm × 10 mm in combination with a silicon photomultiplier with an active area of 3 × 3 mm 2 are presented. It is demonstrated that a detector array with the proposed configuration (a scintillator + a silicon photomultiplier enclosed in a common container) exhibits an energy resolution of 4% for 661.7-keV γ rays and a background count rate of ~0.39 cps in the energy range of (140 ± 3σ) keV.