  Gadolinium-aluminum-gallium garnet
Gd${}_{3}$Al${}_{2}$Ga${}_{3}$O${}_{12}$:Ce scintillator is demonstrated to be
an excellent scintillation material for detector of fast neutrons for the first
time. Moreover, its application allows to obtain different responses to
neutrons depending on their energy spectrum. This is achieved because the
material, firstly, has high content of Gd, which absorbs neutrons with
following emission of $\gamma$-quanta, and, secondly, detects this radiation
efficiently thanks to high stopping power, fast scintillation kinetics, high
scintillation light yield and good energy resolution. It was shown by
simulation that several characteristic regions could be distinguished in
$\gamma$-quanta pulse height spectra acquired with GAGG:Ce crystal under
neutron irradiation, with energies nearly 90 and 190, and 511 keV; all these
lines have different relative intensities depending on incident neutrons
kinetic energy. This was confirmed by followed measurements with Am-Be neutron
source. Scintillator shows coincidence time resolution better than 200ps
for$\gamma$-quanta of 511 keV energy, what makes it the material of choice to
separate neutrons by time-of-flight technique. Combining of detecting
properties creates prospects to construct compact and fast neutron detector,
capable of detection of each particle individually and registration of its
specific response. This possibility could bring benefits to neutron-based
examination techniques, e.g. utilizing time of flight methods and new
capabilities of accelerator based bright neutron sources.
