用于亚毫米空间分辨率单次伽马扫描系统的基于LYSO-SiPM的高粒度位置灵敏探测器的性能评估
Performance Evaluation of a High-Granularity LYSO-SiPM-Based Position-Sensitive Detector for a One-Shot Gamma-Scanning System with Sub-Millimeter Spatial Resolution
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中文总结 AI 辅助
该研究开发了基于LYSO-SiPM的高粒度位置灵敏探测器，经模拟与实验验证其中心区域空间分辨率优于1 mm，可用于核物理实验中分段γ探测器阵列的三维表征。
中文摘要 AI 辅助
为核物理实验中使用的分段伽马射线探测器系统的空间表征与校准，开发了一种基于薄型单片LYSO晶体和96通道SiPM阵列的紧凑型位置灵敏γ探测器。该探测器设计用于提供局域化辐照和快速二维响应映射。将直径7厘米、厚度3毫米的LYSO晶体与SiPM阵列进行光学耦合，通过相邻SiPM通道收集的相对闪烁光信号重建入射γ射线相互作用的位置。采用基于不对称性的电荷共享方法，从探测到的闪烁光的空间分布确定相互作用位置。开展了包含光学光子传输的详细GEANT4模拟，以研究探测器响应并估算其固有空间分辨率。模拟预测，在理想化条件下，60 keV和511 keV的γ射线的空间分辨率约为0.5 mm。开发了探测器原型，并利用德国GSI的γ扫描设施进行符合测量以对其进行实验表征。实验测量表明，探测器中心区域的空间分辨率优于1 mm，同时研究了与位置相关的响应以及探测器边界附近的分辨率退化情况。将实验结果与GEANT4预测进行比较，以确定光学光子传输、电荷共享和探测器几何结构对所测空间分辨率的贡献。所开发的探测器为核物理实验中高度分段的γ射线探测器阵列的三维表征提供了紧凑型解决方案。
英文摘要
A compact position-sensitive γ-detector based on a thin monolithic LYSO crystal and a 96-channel SiPM array is developed for the spatial characterization and calibration of segmented γ-ray detector systems used in nuclear-physics experiments. The detector is designed to provide localized irradiation and rapid two-dimensional response mapping. A 7 cm diameter and 3 mm thick LYSO crystal is optically coupled to the SiPM array, and the position of the incident γ-ray interaction is reconstructed from the relative scintillation-light signals collected by neighboring SiPM channels. An asymmetry-based charge-sharing method is employed to determine the interaction position from the spatial distribution of the detected scintillation light. Detailed GEANT4 simulations, including optical photon transport, were performed to investigate the detector response and estimate its intrinsic spatial resolution. The simulations predict a spatial resolution of approximately 0.5 mm for 60 keV and 511 keV γ-rays under idealized conditions. A prototype detector was developed and experimentally characterized using coincidence measurements with the γ-scanning facility at GSI, Germany. The experimental measurements demonstrate a spatial resolution better than 1 mm in the central detector region, while the position-dependent response and degradation near the detector boundaries are investigated. The experimental results are compared with GEANT4 predictions to identify the contributions of optical photon transport, charge sharing, and detector geometry to the measured spatial resolution. The developed detector provides a compact solution for the three-dimensional characterization of highly segmented γ-ray detector arrays in nuclear physics experiments.
