Characterization of stilbene and EJ-276 scintillators coupled with a large area SiPM array for a fast neutron dose rate detector
Characterization of stilbene and EJ-276 scintillators coupled with a large area SiPM array for a fast neutron dose rate detector
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DOI：
10.1016/j.nima.2021.165566
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发表时间：
2021-09
影响因子：
1.4
通讯作者：
F. Ferrulli;N. Dinar;L. G. Manzano;M. Labalme;M. Silari
中科院分区：
文献类型：
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作者：
F. Ferrulli;N. Dinar;L. G. Manzano;M. Labalme;M. Silari
1 英寸二苯乙烯和 EJ-276（塑料）有机闪烁体的特征在于它们在便携式测量仪中的使用，用于辐射防护中的快速中子检测和剂量率测量。它们与大面积硅光电倍增管 (SiPM) 阵列结合，并在中子/γ射线 (n/γ) 辨别能力、计数率线性、计数率饱和效应、温度稳定性和中子检测效率方面进行了表征。开发并测试了堆积拒绝 (PUR) 算法，以随着剂量率的增加而提高其计数率线性。结果表明，与塑料相比，二苯乙烯在以下方面表现出更好的性能：脉冲形状辨别 (PSD)，品质因数 (FOM) 分别为 1.5 与 1.1、能量分辨率（662 keV 时为 15% 与 20%）和快中子效率（AmBe 源为 12% 与 9%）。对于这两种闪烁体，使用 137 Cs γ 射线源时，剂量率响应呈线性，高达 1 mSv/h。对于中子源，响应是线性的，并且当剂量率高达 1.5 mSv/h 时，FOM 几乎恒定。当探测器受到高达 10 mSv/h 的 γ 射线源照射时，PUR 可以将假中子事件减少一个数量级，并且当探测器受到 1.5 mSv/h 的 AmBe 源以及高达 60 μSv/h 的 137 Cs 源照射时，它可以正常工作。所提出的 PUR 算法很有前景，但需要使用更高强度的混合 n/γ 场进行测试。还在− 10° C 至+ 40° C 的温度范围内研究了两个探测器的温度稳定性。降低温度时，两个探测器的光输出增加了约 25%。相同温度范围内中子计数率的变化约为10%。这项工作提供了这些探测器性能的完整概述，以及具有相同实验设置的两种类型闪烁体之间的连贯比较。
A 1-inch stilbene and EJ-276 (plastic) organic scintillators were characterized in view of their use in a portable survey meter for fast neutron detection and dose rate measurements in radiation protection. They were coupled with a large area Silicon Photomultiplier (SiPM) array and characterized in terms of neutron/γ–ray (n/γ) discrimination capability, count rate linearity, count rate saturation effects, temperature stability and neutron detection efficiency. A Pile-Up Rejection (PUR) algorithm was developed and tested to increase their count rate linearity with increasing dose rate. Results show that the stilbene exhibits better performance compared to the plastic in terms of: Pulse Shape Discrimination (PSD) with a Figure Of Merit (FOM) of 1.5 vs. 1.1, energy resolution (15% vs 20% at 662 keV) and fast neutron efficiency (12% vs. 9% with an AmBe source). For both scintillators, the dose rate response is linear up to 1 mSv/h with a 137 Cs γ-ray source. With a neutron source, the response is linear, and the FOM is almost constant for dose rates up to 1.5 mSv/h. The PUR reduces the false neutron events by one order of magnitude when the detectors are irradiated with a γ-ray source up to 10 mSv/h, and it correctly works when irradiated with an AmBe source at 1.5 mSv/h together with a 137 Cs source up to 60 μ Sv/h. The proposed PUR algorithm is promising but needs to be tested with a higher intensity mixed n/γ field. The temperature stability of both detectors was also studied in the temperature range from− 10° C to+ 40° C. The light yield increases by around 25% for both detectors when reducing the temperature. The variation of the neutron count rate is around 10% in the same temperature range. This work provides a complete overview of the performance of these detectors and a coherent comparison between the two types of scintillators with the same experimental setup.