Spectroscopic and neutron detection properties of rare earth and titanium doped LiAlO₂ single crystals

In this study, LiAlO₂ crystals doped with rare-earth elements and Ti were produced by the CZ method and spectroscopic and neutron detection properties were investigated. Photoluminescence revealed no clear luminescent activation of LiAlO₂ by the rare-earth dopants though some interesting luminescence was observed from secondary phases within the crystal. Gamma-ray pulse height spectra collected using a ¹³⁷Cs source exhibited only a Compton edge for the crystals. Neutron modeling using Monte Carlo N-Particle Transport Code revealed most neutrons used in the detection setup are thermalized, and while using natural lithium in the crystal growth, which contains 7.6% ⁶Li, a 10 mm Ø by 10 mm sample of LiAlO₂ has a 70.7% intrinsic thermal neutron capture efficiency. Furthermore, the pulse height spectra collected using a ²⁴¹Am-Be neutron source demonstrated a distinct neutron peak.