Scintillation properties of Ce-doped LiAlO₂ for neutron detection

Abstract

Undoped and Ce-doped LiAlO₂ single crystals, a novel neutron scintillator, were synthesized by the floating zone method, and the photoluminescence and scintillation properties were investigated. Under X-ray irradiation, all the synthesized crystals showed luminescence due to oxygen vacancies with decay time constants of 250 ns and 2 µs, and Ce-doped LiAlO₂ crystals showed luminescence due to the 5d–4f transition of Ce³⁺ with a decay time constant of 40 ns as well. In the pulse height spectra under neutron irradiation from ²⁵²Cf, the synthesized crystals exhibited thermal neutron peak, and scintillation light yields increased by doping of Ce. Furthermore, neutron and gamma-ray pulse shape discrimination was examined, and 0.5 and 1.0 % Ce-doped ones showed a distinction of neutron and gamma-ray events.