Development of a novel Lanthanum Halide-based solid solution gamma radiation scintillation material

This paper will describe scintillator materials based on certain types of halide-lanthanide matrix materials. The matrix materials contain a mixture of lanthanide halides, i.e. a solid solution of at least two of the halides, such as lanthanum chloride and lanthanum bromide. The scintillator materials also include an activator for the matrix material, e.g. cerium. These materials are of a solid solution type and have been studied in the form of pressed powders. It has been demonstrated that the solid solution form of these materials has higher light output than either one of the end members of the solid solution. Additionally, the phase diagram for this solid solution has been utilized to identify the preferred material composition for single crystal growth of these unique halide-lanthanide matrix materials. Based on the excellent spectral resolution demonstrated by LaCl3:Ce and LaBr3:Ce, the solid solution, with potentially higher light output, may have better energy resolution as well. Improved light output and energy resolution will provide better isotopic identification capabilities in systems where these types of materials are used and will also offer improved signal to noise characteristics in these systems.