Ce and Eu-doped LiSrAlF6 scintillators for neutron detectors

Ce 1%, Eu 1%, and Eu 2%-doped LiSrAlF6 (LiSAF) single crystals were grown by the micro-pulling-down method for thermal neutron applications. The crystals were transparent, 2.0 mm in diameter and 20-40 mm in length. Neither visible inclusions nor cracks were observed. Their transmittance spectra were measured. The strong absorption lines were observed at 200, 240, and 300 nm for Ce:LiSAF due to Ce3+ 4f-5d transition. In Eu:LiSAF, 200 (4f-5d) and 300 (4f-4f) nm absorption lines were detected. The samples demonstrated strong emission peaks at 300 nm (Ce:LiSAF) and 370 nm (Eu:LiSAFs) when they were irradiated with 241Am α-rays simulating the α-particles from the 6Li(n, α) reaction. Thermal neutron responses were examined under 252Cf irradiation. The absolute light yield of Ce, Eu 1%, and Eu 2% crystals were 3400, 18000, and 30000 ph/n, respectively. Main components of the scintillation decay time of Ce, Eu 1%, and Eu 2%-doped LiSAFs were 63, 1293, and 1205 ns.