Scintillation and timing performance of a 3 at% yttrium-doped barium fluoride crystal

Abstract We report the scintillation and timing performance of a newly developed 200 mm× 20 mm× 20 mm large size barium fluoride crystal doped with 3 at% yttrium (BaF2:Y) to enhance the application for high time resolution. This doping effectively suppresses the slow scintillation component while maintaining most of the fast component, as confirmed by X-ray excited luminescence measurements. The BaF2:Y crystal demonstrated a transmittance of near 90% in the visible spectrum and a light response uniformity parameter of δ = (-2.74 ± 1.15)% when coupled with the tail end. The actual yttrium content varied from 2.1 at% near the seed end to 3.7 at% at the tail end. The assembled large BaF2:Y detector with silicon photomultipliers exhibited a time resolution of 82.2 ± 2.6 ps using constant fraction discrimination method in a cosmic ray test and 140.1 ± 3.8 ps using a low fixed threshold method in a beam test at Shanghai Synchrotron Radiation Facility with a 1.35 GeV electron beam. These results indicate the significant potential of BaF2:Y crystal for various applications, such as detectors for particle physics and nuclear physics.