Evaluations of scintillation properties of LiSrAlF<inf>6</inf> scintillator for thermal neutron detection

Abstract

Ce 1%, Eu 1%, and Eu 2%-doped LiSrAlF 6 (LiSAF) single crystals were grown by the micro-pulling-down (μ-PD) 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 appeared. When they were irradiated by 241Am α-ray simulating neutron excitation, strong emission peak appeared at 300 nm in Ce:LiSAF and 370 nm in Eu:LiSAFs, respectively. Thermal neutron responses were investigated under 252Cf irradiation. The absolute light yield of Ce, Eu 1%, and Eu 2% samples 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.