Neutron-induced thermoluminescence of Mg²⁺- and Pr³⁺-co-doped LiTaO₃ ceramics

We developed the Mg 2+ - and Pr 3+ -co-doped LiTaO 3 ceramics using 6 Li or n Li ( n Li represents isotope content in the natural abundance ratio) as thermoluminescence materials for thermal neutron detection. Here, Mg acts as an electron trap and Pr as a luminescent center. Photoluminescence (PL) spectra indicate that sharp emission peaks at 550-650 nm originating from 4f–4f transitions of Pr 3+ . Since thermal neutron irradiation facilities generally accompany gamma rays, we first confirmed similar TL intensities in both samples after X-ray irradiation, which indicates that they have similar TL response to gamma rays. After thermal neutron irradiation, the 6 Li-enriched sample exhibited a much higher TL intensity than that of the n Li-containing one, because the 6 Li-enriched sample contains a higher fraction of 6 Li, which has a large neutron capture cross-section, than the n Li-containing sample. The difference in TL intensities within ±15 K of the peak temperature showed excellent linearity at 10 6 –10 10 neutrons/cm 2 .