空间高效多通道反符合探测器系统设计

Design of Space Efficient Multi-Channel Anti-Coincidence Detector System

摘要: MeV伽马射线天文台(MeV Gamma Ray Observatory, MeVGRO)是目前在研预计实现对MeV能区伽马射线高分辨、高灵敏度探测的大型空间天文望远镜。反符合探测器(Anti-Coincidence Detector, ACD)作为MeVGRO的有效载荷之一，需要实现带电粒子的高效探测，从而区分空间带电粒子和伽马射线。本文基于硅光电倍增管(Silicon photomultiplier, SiPM)和ASIC (Application Specific Integrated Circuit)，设计了一款可以应用于空间的反符合探测器样机，可高效的输出带电粒子的触发信号，兼具大动态范围测量，并对其进行了基线噪声测试、动态范围测试和宇宙线测试。测试结果表明该样机工作稳定、性能良好，实现了动态范围最大到500 pC，各通道的电子学台阶一致性在1.1%以内，最小电离粒子(Minimum Ionizing Particle, MIP)的能谱信噪比优于0.2 c.u.。

Abstract: The MeV Gamma Ray Observatory (MeVGRO) is a large space telescope currently under development, aimed at achieving high-resolution and high-sensitivity detection of MeV gamma rays. The Anti-Coincidence Detector (ACD), as one of the effective payloads of MeVGRO, is required to efficiently detect charged particles in order to distinguish them from gamma rays in space. Based on Silicon photomultiplier (SiPM) and Application Specific Integrated Circuit (ASIC), this paper presents the design of a prototype of an Anti-Coincidence Detector that can be applied in space. It can efficiently output triggering signals for charged particles, and has a large dynamic range measurement. The prototype underwent baseline noise testing, dynamic range testing, and cosmic ray testing. The test results indicate that the prototype operates stably and has good performance, achieving a dynamic range of up to 500 pC, with electronic step consistency of each channel within 1.1%, and a signal-to-noise ratio for the Minimum Ionizing Particle (MIP) better than 0.2 c.u.