Study on the Possibility of Neutron Gamma Discrimination in GAGG Crystal

Abstract

The scintillators capable of neutron detection are being the research hotspot recently. In this manuscript, we investigated the possibility of cerium-doped gadolinium aluminium gallium garnet (GAGG: Ce) crystal to achieve neutron gamma discrimination through pulse shape discrimination (PSD) method. PSD is a method based on the principle that the waveforms of scintillation light differ for different particles. The experiments show that it’s hard for single GAGG crystal to distinguish the neutron from the gamma-ray. Therefore, a composite crystal made of gamma-sensitive crystal and GAGG crystal was furtherly developed. Using the 252Cf neutron source, the composite is proven to be capable of discriminating the neutrons from the gamma-ray and the corresponding FOM is 3.33.

New Inogranic Scintillators’ Application in the Electromagnetic Calorimetry in High-Energy Physics

“…There are a few methods that provide such an opportunity. The first one is based on a pulse shape analysis of different particles, for instance, positrons and neutrons [21,22] or photons and α-particles [23]. The second way to separate gammas and neutrons considers the difference in their radiation/interaction lengths.…”

“…The second way to separate gammas and neutrons considers the difference in their radiation/interaction lengths. This can be achieved by the usage of different crystals such as PWO and GAGG [22], or two identical GAGG:Ce crystals with one of them codoped with Mg [21]. The third option is to discriminate photons by their shower shape and suppress the charged pion and antineutron background.…”

“…Gamma spectra of 22 Na and 137 Cs radioactive sources were measured in GAGG crystals of different lengths. The measurements were conducted using a PMT-143 photomultiplier with a quantum efficiency of 17.6% [19].…”