Compact and Effective Detector of the Fast Neutrons on a Base of Ce-doped Gd3Al2Ga3O12 Scintillation Crystal

Gadolinium aluminum gallium garnet Gd ₃ Al ₂ Ga ₃ O ₁₂ :Ce crystal is demonstrated to be an excellent scintillation material for detection of fast neutrons for the first time. This is achieved because the material, first, has high content of Gd, which absorbs neutrons with following prompt emission of $\gamma $ -quanta, and, second, detects this radiation efficiently thanks to high stopping power and high scintillation light yield. GEANT4 modeling was used to distinguish several characteristic regions in $\gamma $ -quanta pulse height spectra acquired with GAGG:Ce crystal under neutron irradiation, with energies nearly 90 and 190, and 511 keV, which have different relative intensities depending on incident neutrons kinetic energy. This was approved by measurements on Am–Be neutron source. Sensitivity of the material to neutrons from Am–Be source was compared to ⁶ Li-based glass, and found to be superior, depending on signal selectivity.