Aiming to measure the difference in arrival times of two coincident γ-photons with an accuracy in the order of 200ps, time-of-flight positron emission tomography systems commonly employ silicon photomultipliers (SiPMs) and high-resolution digitization electronics, application specific integrated circuits (ASICs). This work evaluates the performance of the TOFPET2 ASIC, released by PETsys Electronics S.A. in 2017, dependent on its configuration parameters in multi-channel coincidence measurements. SiPM arrays fabricated by different vendors (KETEK, SensL, Hamamatsu, Broadcom) were tested in combination with the ASIC. Scintillator arrays featuring different reflector designs and different configurations of the TOFPET2 ASIC software parameters were evaluated. The benchtop setup used is provided with the TOFPET2 ASIC evaluation kit by PETsys Electronics S.A. Compared to existing studies featuring the TOFPET2 ASIC, multi-channel performance results dependent on a larger set of ASIC configuration parameters were obtained that have not been reported to this extend so far. The ASIC shows promising CRTs down to 219.9 ps in combination with two Hamamatsu S14161-3050-HS-08 SiPM arrays (128 channels read out, energy resolution 13.08%) and 216.1 ps in combination with two Broadcom AFBR-S4N44P643S SiPM arrays (32 channels read out, energy resolution 9.46%). The length of the trigger delay of the dark count suppression scheme has an impact on the ASIC performance and can be configured to further improve the coincidence resolution time. The integrator gain configuration has been investigated and allows an absolute improvement of the energy resolution by up to 1% at the cost of the linearity of the energy spectrum. Measuring up to the time-of-flight performance of state-of-the-art positron emission tomography (ToF-PET) systems while providing a uniform and stable readout for multiple channels at the same time, the TOFPET2 ASIC is treated as promising candidate for the integration in future ToF-PET systems.

中文翻译：

---

在多通道重合实验中评估PETsys TOFPET2 ASIC

为了测量两个重合的γ光子到达时间的差异，精度约为200ps，飞行时间正电子发射断层扫描系统通常采用硅光电倍增管（SiPM）和高分辨率数字化电子设备，即专用集成电路（ASIC）。这项工作评估了PETsys Electronics SA在2017年发布的TOFPET2 ASIC的性能，具体取决于其在多通道一致性测量中的配置参数。由不同厂商（KETEK，SensL，Hamamatsu，Broadcom）制造的SiPM阵列已与ASIC结合进行了测试。对具有不同反射镜设计和TOFPET2 ASIC软件参数不同配置的闪烁体阵列进行了评估。PETsys Electronics SA的TOFPET2 ASIC评估套件提供了所使用的台式设置。与现有的采用TOFPET2 ASIC进行的研究相比，获得了取决于较大组ASIC配置参数的多通道性能结果，因此尚未对此进行报告。远的。ASIC与两个Hamamatsu S14161-3050-HS-08 SiPM阵列（读出128个通道，能量分辨率为13.08％）相结合，显示出低至219.9 ps的CRT，与两个Broadcom AFBR-S4N44P643S SiPM阵列（32个通道）相结合显示出216.1 ps的CRT读出来，能量分辨率为9.46％）。暗计数抑制方案的触发延迟时间长短会影响ASIC性能，并且可以配置为进一步改善重合解决时间。已经对积分器增益配置进行了研究，并以能谱线性度为代价，使能量分辨率绝对提高了1％。TOFPET2 ASIC可测量最先进的正电子发射断层扫描（ToF-PET）系统的飞行时间性能，同时可为多个通道提供一致且稳定的读数，因此被视为有前途的候选产品用于将来的ToF-PET系统的集成。