Proton damage measurements of rare earth oxide scintillators

A novel measurement technique to determine the degradation in light output under exposure to 3-MeV protons has been developed in the framework of the Fluorescent Materials and Bonding program. The rare-earth oxide scintillators included Gd₂O₂S doped with Pr, Tb, and Eu; Y₂O₂S doped with Tb and Eu; Y₃Al₅O₁₂ (YAG) doped with Ce; and ZnS doped with Ag. Four scintillator samples were painted on a rotatable water-cooled turret that is used to measure the proton beam current and that has thermocouples for temperature monitoring. The data acquisition and storage system consists of an ACRO module interfaced to a Macintosh SE/30 computer running LabVIEW software. Results indicate that the YAG doped with Ce scintillator coating withstood a proton dose an order of magnitude larger than that tolerated by the other phosphor compounds. This finding has significant implications for the use of this material for experimental scintillator applications