A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements.
A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements.
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DOI：
10.1063/5.0155280
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发表时间：
2023-10
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影响因子：
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通讯作者：
Jinhao Tan;Jianrong Zhou;Lin Zhu;Xiaojuan Zhou;Lixin Zeng;Liang Xiao;Yuan-guang Xia;Hong Xu;Xin-feng Jiang;Wenqin Yang;Yanfeng Wang;Gui-an Yang;Yuguang Xie;Haiyun Teng;Jia-jie Li;Y. Qiu;Peixun Shen;Songlin Wang;Yang Liu;Jingtao Zhu;Zhuang Jian;Yubin Zhao;Zhi-jia Sun;Yushou Song;Yuan-Bai Chen
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文献类型：
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作者：
Jinhao Tan;Jianrong Zhou;Lin Zhu;Xiaojuan Zhou;Lixin Zeng;Liang Xiao;Yuan-guang Xia;Hong Xu;Xin-feng Jiang;Wenqin Yang;Yanfeng Wang;Gui-an Yang;Yuguang Xie;Haiyun Teng;Jia-jie Li;Y. Qiu;Peixun Shen;Songlin Wang;Yang Liu;Jingtao Zhu;Zhuang Jian;Yubin Zhao;Zhi-jia Sun;Yushou Song;Yuan-Bai Chen
中子散射仪在研究物质内部结构中起着重要作用。中子束监测器是中子散射仪器中常用的探测器。大多数中子束监测器的探测效率很低（10-4-10-6）。然而，在一些具有低中子通量的实验中，例如小角中子散射（SANS）和非弹性中子散射实验，需要具有更高探测效率（对于热中子为10%）的中子束监测器来减少实验的持续时间。为了满足这一要求，本研究开发了一种基于陶瓷气体电子倍增器的中子束监测器，该中子束监测器配备了1 μm 10 B4 C中子转换器。它的性能在实验和模拟中确定。实验测量了1.8-5.5 nm波长范围内的探测效率，并通过模拟结果进行了验证。提出了一种基于事件选择和位置重构的算法，将空间分辨率提高到1 mm左右。在光束线20（BL 20）中测量波长光谱，并与使用商业监视器获得的结果一致。最大计数率为1.3MHz。整个100 × 100 mm 2有效面积上的不均匀性确定为1.4%。由于该监测器的优良性能，它已被用于中国空间中子源的SANS和高能直接几何非弹性谱仪等中子仪器中。
Neutron scattering instruments play an important role in studying the inner structure of materials. A neutron beam monitor is a detector commonly used in a neutron scattering instrument. The detection efficiency for most neutron beam monitors is quite low (10-4-10-6). However, in some experiments with a low neutron flux, such as small angle neutron scattering (SANS) and inelastic neutron scattering experiments, a neutron beam monitor with a higher detection efficiency (∼1% for thermal neutrons) is required to reduce the duration of the experiment. To meet this requirement, a ceramic gas electron multiplier-based neutron beam monitor equipped with a 1 µm 10B4C neutron converter was developed in this study. Its performance was determined both experimentally and in simulations. The detection efficiency in the wavelength range of 1.8-5.5 Å was measured experimentally and was confirmed by the simulation results. An algorithm based on event selection and position reconstruction was developed to improve the spatial resolution to about 1 mm full-width-half-maximum. The wavelength spectrum was measured in beamline 20 (BL20) and agreed well with the results obtained using a commercial monitor. The maximum counting rate was 1.3 MHz. The non-uniformity over the whole 100 × 100 mm2 active area was determined to be 1.4%. Due to the excellent performance of this monitor, it has been used in several neutron instruments, such as the SANS and the High-Energy Direct-Geometry Inelastic Spectrometer instruments in the China spallation neutron source.