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设计的CSNS工程材料衍射谱仪的闪烁体探测器结构如图1所示,探测器头部由倾斜的6LiF/ZnS(Ag)闪烁屏阵列和WLSF组成,每块闪烁屏和紧贴的两根WLSF构成探测器的像素。为提高中子探测效率,闪烁屏倾斜73°固定在定位槽内。两根WLSF均匀分布在每块闪烁屏下,将入射粒子在闪烁屏中产生的荧光光子收集并传输至后端光电转换器件(SiPM)。
目前各SiPM厂家生产的SiPM主要有1 mm × 1 mm、3 mm × 3 mm和6 mm × 6 mm三种规格,而设计的闪烁体探测器采用两根直径1 mm的WLSF作为一个像素读出(如图1所示),故为保证WLSF与SiPM的良好耦合,选取的SiPM像素应大于2 mm × 2 mm。而6 mm × 6 mm像素偏大,占用体积较大,故本次测试选择SiPM灵敏面积为3 mm × 3 mm。
为使工程探测器发挥最佳性能,需选择低暗计数率(单位时间内由SiPM材料内载流子的热激发等原因引起的计数)、高光子探测效率(单位时间内SiPM探测到的光子数与入射到SiPM表面的光子数的百分比)和高微单元密度(SiPM单位面积内的微像素个数)的SiPM。其中暗计数率会影响探测器的信噪比,光子探测效率会影响探测器输出信号幅度从而影响探测器的中子探测效率。综合考虑SiPM暗计数率、微单元密度、光子探测效率、单光电子增益(APD单元发生一次雪崩所释放的载流子数目)等参数,分别选取了Sensl MicroFJ-30035-TSV型号和Hamamatsu S13363-3050NE-16型号的3 mm × 3 mm SiPM (下文简称Sensl SiPM与Hamamatsu SiPM),厂商提供的主要性能参数如表1所列。
性能参数 SiPM型号 Sensl MicroFJ-
30035-TSVHamamatsu S13363-
3050NE-16击穿电压a/V 24.4±0.3 53±5 过偏压范围/V 1-6 3 增益a,b ~6.3×106 ~1.7×106 暗计数率a,b 150 kHz/mm2 500 kHz/Channel 温度系数/(mV/°C) 21.5 54 峰值波长/nm 420 450 光子探测效率a,b,c/% 50 40 灵敏面积 3.0 mm × 3.0 mm 3.0 mm × 3.0 mm 微像素大小/μm 35 50 微像素个数 5 676 3 584 填充因子/% 75 74 a 在特定温度条件下测试;TSensl=21 °C, THamamatsu =25 °C。 b 在特定过偏压条件下测试Vover-Sensl=6 V, Vover-Hamamatsu=3 V。 c 对峰值波长,λ Sensl=420 nm,λ Hamamatsu=450 nm。
Study on the Performance of SiPM for the Neutron Position Sensitive Detector
doi: 10.11804/NuclPhysRev.40.2022108
- Received Date: 2022-10-17
- Rev Recd Date: 2022-11-11
- Publish Date: 2023-03-20
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Key words:
- silicon photomultiplier tube /
- gain /
- avalanche breakdown voltage /
- temperature characteristics /
- neutron detection
Abstract: In order to fulfill the requirements of the engineering material diffraction spectrometer of China Spallation Neutron Source(CSNS), a new integrated and modular scintillator detector based on Silicon Photomultiplier(SiPM) readout is designed and constructed by the Neutron Detector Group of the CSNS. In this paper, the characteristics such as breakdown voltage, gain, temperature characteristics and dark count rate of Sensl MicroFJ-30035-TSV and Hamamatsu S13363-3050NE-16 model SiPM are tested. The results show that the performance of the two SiPM including the single-photon resolution, gain, dark count rate can meet the requirements of the scintillator detector. The gain of Sensl SiPM is higher than that of Hamamatsu SiPM in the same overbias and the latter is more sensitive to temperature. The temperature compensation coefficient of the Sensl and Hamamatsu SiPM are 22.0 and 53.6 mV/°C respectively, which will provide reference for the design of temperature compensation circuit of SiPM. The prototype of a scintillator detector based on the above two SiPM readout was developed and the detection efficiency of the detector has been tested on the BL09 of CSNS. The results show that the detection efficiency of detector equipped with Sensl SiPM or Hamamatsu SiPM is 76% and 68% for 2.8 Å neutrons, respectively. The results of this paper will provide reference for the selection of SiPM for the developed scintillator detector and other SiPM-based detectors.
Citation: | Chang HUANG, Bin TANG, Junjie JIANG, Xiaojie CAI, Shihui ZHOU, Xiuping YUE, Shaojia CHEN, Xiuku WANG, Qian YU, Haiyun TENG, Zhijia SUN, Zeen YAO. Study on the Performance of SiPM for the Neutron Position Sensitive Detector[J]. Nuclear Physics Review, 2023, 40(1): 66-72. doi: 10.11804/NuclPhysRev.40.2022108 |