Silicon Photomultiplier-Based Multi-Channel Gamma Ray Detector Using the Dynamic Time-Over-Threshold Method
Silicon Photomultiplier-Based Multi-Channel Gamma Ray Detector Using the Dynamic Time-Over-Threshold Method
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DOI：
10.1088/1748-0221/11/02/c02016
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发表时间：
2016-02
影响因子：
1.3
通讯作者：
Y. Nakamura;K. Shimazoe;H. Takahashi
中科院分区：
文献类型：
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作者：
Y. Nakamura;K. Shimazoe;H. Takahashi
硅光电倍增管（SiPMs）是一种新型的光子探测器，由于其体积小、增益高（可达106），在核医学和高能物理领域受到了广泛的关注。在这项工作中，一个基于SiPM的多通道伽马射线探测器与个人读出的动态时间超过阈值（dToT）的方法的基础上实现和演示的大面积伽马射线成像仪应用的基本材料。该探测器由64个通道的KETEK SiPM PM PM 6660（6 × 6 mm 2，包含10，000个60 × 60 μ m 2的微单元）耦合到8 × 8阵列的高能分辨率Gd 3（Al，Ga）5 O 12（Ce）（HR-GAGG）晶体（10 × 10 × 10 mm 3），由1 mm厚的BaSO 4反射器分割。为了产生包含线性能量信息的数字脉冲，基于dToT的读出电路由CR-RC整形放大器（2.2 μs）和带反馈元件的比较器组成。通过模拟SiPM的脉冲、光输出和CR-RC整形放大器，根据延迟时间和动态阈值移动的时间常数数值计算积分非线性（INL）。在662 keV能量下，平均INL和能量分辨率分别为5.8±1.6%和7.4±0.9%。64通道单模探测器模块成功实施，展示了其作为大面积伽马射线成像应用的基本材料的潜力。
Silicon photomultipliers (SiPMs), which are a relatively new type of photon detector, have received more attention in the fields of nuclear medicine and high-energy physics because of their compactness and high gain up to 106. In this work, a SiPM-based multi-channel gamma ray detector with individual read out based on the dynamic time-over-threshold (dToT) method is implemented and demonstrated as an elemental material for large-area gamma ray imager applications. The detector consists of 64 channels of KETEK SiPM PM6660 (6 × 6 mm2 containing 10,000 micro-cells of 60 × 60 μm2) coupled to an 8 × 8 array of high-energy resolution Gd3(Al,Ga)5O12(Ce) (HR-GAGG) crystals (10 × 10 × 10 mm3) segmented by a 1 mm thick BaSO4 reflector. To produce a digital pulse containing linear energy information, the dToT-based read-out circuit consists of a CR-RC shaping amplifier (2.2 μs) and comparator with a feedback component. By modelling the pulse of the SiPM, the light output, and the CR-RC shaping amplifier, the integral-non-linearity (INL) was numerically calculated in terms of the delay time and the time constant of dynamic threshold movement. The experimental results of the averaged INL and energy resolution were 5.8±1.6% and the full-width-at-half-maximum (FWHM) of 7.4±0.9% at 662 keV, respectively. The 64-channel single-mode detector module was successfully implemented, demonstrating potential for its use as an elemental material for large-area gamma ray imaging applications.