La doped Lu2O3 scintillator

Lu₂O₃ has emerged as a highly attractive host material for gamma-ray detection, primarily due to its high density (9.4 g/cm³) and effective atomic number (68). Various dopants have been explored to enhance its scintillation properties, with notable examples including Eu³⁺ and Yb³⁺. While Eu³⁺ doping results in high luminosity, it suffers from a prolonged decay time in the millisecond range. On the other hand, Yb³⁺ produces a fast scintillation response in the nanosecond range, but at the cost of a significantly lower light yield. Both dopants present limitations for gamma-ray spectroscopy.

Recently, we developed a novel variant of Lu₂O₃ doped with La³⁺. Given the high melting point of the host material (2490 °C), ceramic consolidation techniques were employed during synthesis, leveraging the optically isotropic cubic structure of the material. This composition offers a balanced set of properties, exhibiting a light yield as high as 20,000 photons/MeV and two dominant decay time components at 530 ns and 1230 ns. Additionally, the energy resolution at 662 keV was measured to be 5.3 %, which can be attributed to the material's highly proportional response.

Optimization of La³⁺ concentration revealed that the best results were achieved at a doping level of around 5 %. The material demonstrated excellent timing properties, with a fast rise time, <600 ps, and a single-channel timing resolution measured at 511 keV is 307ps. This composition is highly suited for radiation detection applications where intrinsic background noise is not a concern, such as in radiography. Furthermore, its superior timing characteristics and high stopping power make it attractive for Positron Emission Tomography (PET).