arXiv subjects

Shiqing Xie

Publications and source records attributed to Shiqing Xie.

2 recordsLinked to original sources

arXiv2025

R&D of KLM Upgrade for Direct Measurement of Neutral Hadron Momentum via Time-of-Flight in Belle II

Accurate momentum determination of a neutral hadron, such as a KL meson or a neutron, remains a significant challenge in particle physics and nuclear physics experiments. The Belle II experiment presents an opportunity to address this challenge through an upgrade incorporating Time-of-Flight (TOF) capability for its large KL and Muon Detector (KLM). We investigate the feasibility of momentum determination via TOF measurement. To achieve high time resolution for the KLM upgrade, we conduct research and development of cost-effective plastic scintillators in collaboration with GaoNengKeDi Company, and technology utilizing silicon photomultipliers(SiPMs) arrays. A bulk attenuation length of 120 \pm 7 cm has been achieved with a 135 cm-long sample, along with a time resolution of 70 \pm 7 ps at its midpoint. A 50 cm-long scintillator demonstrates an exceptional time resolution of 47 \pm 2 ps. These results highlight the potential of the proposed technology for improving neutral hadron momentum measurements in an upgraded Belle II KLM detector.

physics.ins-det↗

arXiv2025

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

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.

physics.ins-det↗