Characterization of LaGPS:Ce scintillation crystals obtained under a reducing atmosphere

Abstract

Ce-doped lanthanum gadolinium pyrosilicates are among the most efficient oxide scintillation crystals with a light yield of ca. 40 000 ph MeV⁻¹ and a high energy resolution. Moreover, the process of obtaining these crystals, as well as other rare-earth silicates, involves the use of iridium equipment in a weakly oxidizing gas atmosphere. The work is devoted to the optimization of (La,Gd)₂Si₂O₇:Ce (LaGPS:Ce) crystal growth process by the Czochralski method from tungsten crucibles in a reducing atmosphere and characterization of this material. Transparent ingots with a length of up to 40 mm were obtained. Post-growth high-temperature annealing in an oxidizing atmosphere significantly improves the scintillation characteristics of LaGPS:Ce, which are not inferior to those in crystals obtained by a conventional technology from iridium crucibles.