Flux growth and evaluation of optical properties of Ce doped Li₂CaSiO₄ as a candidate for noble neutron scintillator

Abstract

This study focuses on the growth of transparent single crystals of Li₂CaSiO₄ (LCS) doped with Ce as neutron scintillator candidates. LCS is a light material with a high melting point and chemical stability; thus, LCS is applicable for use in high-flux neutron environments. However, the growth of transparent single crystals from the melt has been difficult owing to the phase transitions. In this study, the LiF/LiCl eutectic was used as a flux with a lower melting point and less decomposition than LiCl, and Ce was selected as the luminescent center. The phase diagram of the LiF/LiCl-LCS system was determined, and the conditions for crystal growth were optimized, consequently, transparent non-doped LCS and Ce:LCS crystals were successfully obtained. The alpha-ray-excited scintillation spectrum and scintillation decay time of Ce:LCS were measured in a feasibility study for neutron detection. The results showed that Ce:LCS has potential as a neutron scintillator, with a significantly fast decay time of 28.46 ns.