Scintillation and Timing Performance of a 3at% Yttrium-Doped Barium Fluoride Crystal

TL;DR

This study evaluates a yttrium-doped barium fluoride crystal's scintillation and timing capabilities, showing improved fast component suppression and promising timing resolution for high-energy physics applications.

Contribution

First demonstration of large BaF2:Y crystal with enhanced fast scintillation component and detailed timing performance in cosmic ray and beam tests.

Findings

Time resolution of 82.2 ps in cosmic ray test

Time resolution of 140.1 ps in beam test

Suppressed slow scintillation component with maintained fast response

Abstract

We report the scintillation and timing performance of a new developed 200 * 20 mm * 20 mm large size barium fluoride crystal doped with 3at% 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 delta = (-2.74 +- 1.15)% when coupled with the tail end. The actual yttrium content varied from 2.1at% near the seed end to 3.7at% 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 an 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.