Luminescence properties and thermal neutron response of 6Li-loaded fluoride eutectics

Luminescence and scintillation properties of Eu-doped 75(6)LiF-12.5AlF(3)-12.5CaF(2) eutectics suitable for thermal neutron detection are reported. The 0.5 and 1.0% Eu-doped eutectics were grown by micropulling down (mu-PD) technique. These materials demonstrated two emission bands with maximums at 375 and 430 nm wavelengths under excitation with 250-400 nm wavelength radiation. The emission band at 375 nm was associated with 4f(6)5d-4f(7)(S-8(7/2)) transition of Eu2+ in the CaF2 phase, and the 430 nm band could be result of incorporation of Eu2+ into Li3AIF6 and other phases. When alpha-ray excited the eutectics, both Eu2+ 4f(6)5d-4f(7)(S-8(7/2)) and Eu3+ 4f(6)-4f(6) (D-5(0)-F-7(1, 2)).emission band were detected at 430 nm and 590 nm. The scintillation decay time of the eutectics were determined to be about 540 ns for Eu 0.5% and 380 ns for Eu 1.0%, respectively. According to pulse height spectra registered under Cf-252 irradiation, the relative scintillation light yield of the eutectics was observed to be 6000 ph/n (Eu 0.5%) and 2000 ph/n (Eu 1.0%) when compared to Li-6-loaded glass commercial scintillator. (C) 2014 Elsevier Ltd. All rights reserved.