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

Abstract

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 LY0.5 μs/LY3.0 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 (VO), resulting to a faster decay. Moreover, the formation preference of Ca‐VO complexes over Ce‐VO leads to the suppression of the non‐radiative decay of Ce via VO. In summary, our study demonstrates the realization of the performance tuning of LuAG via Ce and Ca codoping.

Investigation of the Mechanism of Heterovalent Codoping on the Scintillation Properties of GAGG:Ce Crystals

“…To obtain a lower CTR, many studies have focused on accelerating the scintillation decay process. A strategy to improve the scintillation performance of inorganic scintillator materials involves codoping with divalent cations, such as LuAG:Ce,Ca, LSO:Ce,Cu, and GAGG:Ce,Ca, due to the partial conversion of Ce 3+ to Ce 4+ . Ce 4+ can bypass the initial hole-trapping process of Ce 3+ emission and provide an alternative channel for fast radiative recombination.…”

Stoichiometric modulation and scintillation property characterization of Ce,Ca:LuAG ceramics

“…Co-doping of Mg 2+ and Ca 2+ proved to be an effective strategy for accelerating scintillation decay and suppressing slow components, but these two similar divalent ions produce different practical effects. [11][12][13][14][15] Mg 2+ co-doping may show an advantage in boosting light yield (LY), while Ca 2+ co-doping is indisputable in a significant increase of the fast-to-total (F/T) ratio. [16][17][18] In 2020, in the results reported by Hu et al , 5 the F/T ratio (LY 0.2 µs /LY 3 µs ) of Ce,Mg:LuAG ceramics tops out at about 80%, while that of Ce,Ca:LuAG ceramics approaches 90%.…”