We are building a high sensitivity preclinical PET/MRI insert using a highly multiplexed light sharing PET module. Each module incorporates four 19 × 19 arrays of 1 × 1 × 20 mm 3 LYSO crystals with dual-ended DOI encoding readout, requiring 32 readout channels for positioning and eight channels for timing. These constraints necessitate compact, robust electronics for digitization. We have characterized four linearized time-over-threshold circuits based on these detector requirements. The four circuits allow for high channel density and can digitize signals from highly multiplexed light sharing detectors. Each circuit digitizes one channel of a multiplexed SiPM array, yielding a binary output that interfaces directly with an FPGA. Using the optimal circuit, we have characterized the performance of a pair of PET modules. The four circuits were characterized based on linearity of the 22 Na photopeak positions and energy resolution at 511 keV, as well as separati...

中文翻译：

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MR兼容的临床前PET检测器的四个读出电路的特性

我们正在使用高度复用的光共享PET模块构建高灵敏度的临床前PET / MRI插入物。每个模块包含四个19×19的1×1×20 mm 3 LYSO晶体阵列，具有双端DOI编码读取，需要32个读取通道进行定位，并需要8个通道进行定时。这些限制要求紧凑，坚固的电子设备进行数字化。根据这些检测器的要求，我们对四个线性化的阈值时间电路进行了表征。四个电路可实现高通道密度，并可将来自高度复用的光共享检测器的信号数字化。每个电路将一个数字化的SiPM阵列的一个通道数字化，产生一个直接与FPGA接口的二进制输出。使用最佳电路，我们表征了一对PET模块的性能。