Fast Ce,Ca:LuAG scintillation ceramics for HEP: Fabrication,characterization, and computation

High-energy physics community is looking for a hard, fast, and low-cost scintillation material, and Ce:Lu₃Al₅O₁₂ (Ce:LuAG) ceramic is one of the competitive candidates. This work presents Ce,Ca:LuAG scintillation ceramics with good optical quality, and the influence of Ce and Ca concentrations on optical and scintillation properties was fully analyzed. At relatively low level of Ce concentration, the less Ca²⁺ content is needed to achieve a significant intensity increase in fast scintillation component while maintaining a relatively high light yield (LY). The introduction of only 0.1 at% Ca²⁺ could increase the LY_{0.5 μs}/LY_{3.0 μs} from 79.9% to 96.1% in Ce,Ca:LuAG ceramics of 0.1 at% Ce. First-principles investigations are further performed to reveal the tuning mechanisms of the scintillation properties of LuAG by Ce and Ca codoping. We show that the Fermi level shifts down with Ca codoping, which increases the Ce⁴⁺ content and decreases the depth of the electron traps (V_O), resulting to a faster decay. Moreover, the formation preference of Ca-V_O complexes over Ce-V_O leads to the suppression of the non-radiative decay of Ce via V_O. In summary, our study demonstrates the realization of the performance tuning of LuAG via Ce and Ca codoping.