The radiation hardness of Pr:LuAG scintillating ceramics

Scintillating ceramics have been considered to be used in upgraded HL-LHC (high luminosity large hadron collider) systems in high energy physics. However, the relationship between defects, annealing process, and radiation hardness still remains to be explored and understood. In this paper, Pr:LuAG ceramics were investigated as the promising scintillators due to the application requirements in HL-LHC, including the effects of ionizing irradiation, air annealing and sintering aids. Si4+ and Mg2+ were found to promote a concentration increase of oxygen vacancies without causing additional radiation induced color centers, while ionizing irradiation bring severe damage preventing light output. The Pr3+/Pr4+ ions act not only as luminescent center, but also as compensator of intrinsic defects which could be attributed to the distinguish irradiation differences observed between Pr:LuAG and LuAG. Annealing was found to have an opposite effect on radiation induced absorption. From this study, it is confirmed that elimination of specific impurities from raw materials is a demanding step in ceramic optimization, and proper use of sintering aids could not only contribute to the ceramic transparency but also bring less harm to radiation hardness.