Ce-doped LiF–SrF2 eutectic scintillators for thermal neutron detection produced at different solidification rates

Abstract

Ce 0.1% doped LiF–SrF2 eutectic scintillators were produced by vertical Bridgman method at various solidification rates of 1, 5, 20, 80, 320, and 1280mm/hr. The LiF contained 95% of 6Li. The SEM images of the samples solidified at 1–80mm/hr demonstrated clear lamellar structures. The α-ray induced radioluminescence spectra of the scintillators had intense emission peak at 310 and 330nm due to the emission from Ce3+ 5d–4f transition of Ce:SrF2 layers. When the samples were irradiated with 252Cf neutrons, they exhibited almost the same light yields of 4500–5500 ph/n and typical decay times of 120–160ns. The optimal layer thickness of LiF–SrF2 was determined to be 0.9μm.