Pulse shape discrimination at the registration of 14.6 MeV neutrons with Gd3Al2Ga3O12:Ce/SiPM(PMT) detectors

Abstract

Gd3Al2Ga3O12:Ce (GAGG) scintillators with different readout photo-sensors, a 2 × 2 matrix of four SensL ARRAY J-60035-4P-BGA silicon photomultipliers (SiPMs), and a HAMAMATSU R5505-70 photomultiplier (PMT) have been tested for neutrons obtained from neutron generators exploiting d-d and d-t reactions. It was demonstrated that neutrons having energy 2.8 MeV produce in the detector materials the spectrum of secondary particles, which is identical to the spectrum measured under thermal neutrons of the isotope sources. The pulse height spectra detected under 14.6 MeV neutrons were found to be quite different. Pulse shape discrimination (PSD) data processing technique was applied to separate neutron and γ-ray signals. The signals of secondary particles, protons, and α-particles were confidently distinguished at the strong background of the γ-rays. The results gathered open up the prospects of using the GAGG scintillator to identify neutrons generated in d-t reactions against a strong background of γ-rays.