Silicon Photomultipliers (SiPM) are photon sensors featuring high detection efficiency, single photon sensitivity and extended dynamic range; they represent a valuable solution for compact and lightweight hand-held instruments ideal for border control against the illicit trafficking of radioactive material or environmental measurements. This paper reports the results obtained with a standalone compact and modular system (I-spector) customized to detect fast neutrons with gamma discrimination capability. The system consists of 4 SiPM (6× 6 mm2 each) coupled to a fast neutron sensitive scintillating material (EJ-276). It includes an HV bias generator, an on-board digitizer and a microcontroller to perform real-time pulse shape analysis, ethernet and LORA connectivity. The measurements performed to define the specifications and to steer the design will be discussed, together with the results achieved by the prototype in response to a 252Cf source. The system has been shown to be linear up to 6 MeV achieving a neutron-gamma discrimination with a Figure of Merit (FoM) of 2.52 ± 0.09 in the energy window of 1–1.5 MeV together with a FoM larger than 1.27 down to 200–300 keV

中文翻译：

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基于 SiPM 的紧凑型中子探测器的鉴定

硅光电倍增管 (SiPM) 是具有高检测效率、单光子灵敏度和扩展动态范围的光子传感器；它们代表了小巧轻便的手持式仪器的宝贵解决方案，非常适合用于边境管制以防止非法贩运放射性物质或环境测量。本文报告了使用独立的紧凑型模块化系统 (I-spector) 获得的结果，该系统定制用于检测具有伽马鉴别能力的快速中子。该系统由与快中子敏感闪烁材料 (EJ-276) 耦合的 4 个 SiPM（每个 6×6 mm2）组成。它包括一个高压偏置发生器、一个板载数字化仪和一个用于执行实时脉冲形状分析、以太网和 LORA 连接的微控制器。将讨论为定义规格和指导设计而执行的测量，以及原型响应 252Cf 源所获得的结果。该系统已被证明是线性高达 6 MeV，在 1-1.5 MeV 的能量窗口中实现了 2.52 ± 0.09 的品质因数 (FoM) 以及大于 1.27 到 200- 的 FoM 的中子伽马歧视300 keV