Development and characterization of highly efficient new cerium doped rare earth halide scintillator materials

Abstract

Inorganic scintillators for γ-ray detection are used in many fields from medical-diagnostic imaging to industrial measuring systems. Accordingly they face various demands with respect to e.g. response time, light yield, and energy resolution. The development of the new family of rare-earth halide scintillators LaCl₃ ∶ Ce³⁺, LaBr₃ ∶ Ce³⁺, and LuI₃ ∶ Ce³⁺ is reviewed and their properties are compared to those of the established materials NaI ∶ Tl⁺ and Lu₂SiO₅ ∶ Ce³⁺. Extraordinary properties such as the short lifetime of 15 ns and the narrow energy resolution of 2.6% in LaBr₃ ∶ 5% Ce³⁺, or the high light yield of 95000 photons per MeV in LuI₃ ∶ 5% Ce³⁺ improve the performance of scintillators in existing applications and open the way to novel ones. The development of these new materials was empowered by the close interdisciplinary collaboration between scientists in the fields of inorganic chemistry, optical spectroscopy, and applied physics.