基于GAGG:Ce晶体耦合SiPM的位置灵敏探测器的设计与评估

为满足当前γ相机对高分辨率、低成本、小型化探测器的需求，提出了采用硅光电倍增管（SiPM）耦合GAGG:Ce晶体阵列的方式代替传统的位置灵敏型光电倍增管（PSPMT）耦合晶体阵列的方式以构成新型γ相机探测器，并设计了均匀电荷分配电路（SCDC）和阻抗电桥电路作为探测器的读出电路，同时设计了前沿定时电路作为数据采集触发电路。实验结果表明：当温度为25 ℃、探测器供电电压为28.5 V时，该探测器在511 keV射线的激发下，散点图的峰谷比高达3.84，对511 keV和662 keV射线的平均能量分辨率分别为10.63%和9.71%，具有较好的分辨性能。

Design and Evaluation of Position Sensitive Detector Based on GAGG:Ce Crystal Coupled with SiPM

In order to fulfill the need of high-resolution, low-cost and miniaturized detector for current gamma camera, a silicon photomultiplier tube (SiPM) coupled with GAGG: Ce crystal array was adopted to form a new type of gamma camera detector instead of the conventional position-sensitive photomultiplier tube (PSPMT) coupled with crystal array. A symmetric charge division circuit (SCDC) and impedance bridge circuit were designed as a detector readout circuit, and the leading edge timing circuit was designed as a data acquisition trigger circuit. The experimental results show that the peak-to-valley ratio of the flood histogram reaches 3.84 under 511 keV ray excitation, and the mean energy resolutions are 10.63% and 9.71% respectively under 511 keV and 662 keV ray excitation when the detector voltage is 28.5 V at 25 ℃. It indicates that the detector has better resolution performance.