High energy resolution inorganic scintillators read by SiPM arrays

Abstract

The high energy resolution inorganic scintillators as LaBr 3 (Ce) have a great importance in the field of nuclear physics and medical applications since they offer great resolution in energy and time. On the other hand, SiPMs are gaining relevance in the fields mentioned above due to its advantages as compact size, invulnerability to magnetic fields, less voltage needed, etc. The goal of this work is to be able to use relatively large scintillators crystals (25,4x25,4 mm cylindrical), for that reason we can’t use a single SiPM, because its size is much smaller than the size of the crystal, we use an array of 8x8 SiPMs of 3x3 mm2 in size from Ketek (model PA3325-WB-0808). With respect to the energy results we obtained the best value using the LaBr 3 (Ce) (25,4x25,4 mm cylindrical) coupled to the array, providing a resolution of 3,9% (FWHM) for the 661 keV photopeak.For the timing results, we acquired measurements using Co-60 and Na-22 sources and the same LaBr 3 (Ce) as scintillator crystal. Obtaining coincidence resolving times (FWHM) of 385 ps for Na-22 and 337 ps for Co-60.