A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements

Jinhao Tan; Jianrong Zhou; Lin Zhu; Xiaojuan Zhou; Lixin Zeng; Liang Xiao; Yuanguang Xia; Hong Xu; Xingfen Jiang; Wenqin Yang; Yanfeng Wang; Gui-An Yang; Yuguang Xie; Haiyun Teng; Jiajie Li; Yongxiang Qiu; Peixun Shen; Songlin Wang; Yang Liu; Jingtao Zhu; Jian Zhuang; Yubin Zhao; Zhijia Sun; Yushou Song; Yuanbo Chen

doi:10.1063/5.0155280

A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements

Rev Sci Instrum. 2023 Oct 1;94(10):103304. doi: 10.1063/5.0155280.

Authors

Jinhao Tan^{1

2

3}, Jianrong Zhou^{1

2

4}, Lin Zhu^{1

2

4}, Xiaojuan Zhou^{1

2}, Lixin Zeng^{1

2}, Liang Xiao^{1

2}, Yuanguang Xia^{1

2}, Hong Xu^{1

2}, Xingfen Jiang^{1

2}, Wenqin Yang^{1

2

4}, Yanfeng Wang^{1

2}, Gui-An Yang^{1

2}, Yuguang Xie¹, Haiyun Teng^{1

2}, Jiajie Li^{1

2}, Yongxiang Qiu^{1

2}, Peixun Shen^{1

2}, Songlin Wang^{1

2}, Yang Liu^{1

2

5}, Jingtao Zhu⁵, Jian Zhuang^{1

2

4}, Yubin Zhao^{1

2

4}, Zhijia Sun^{1

2

4}, Yushou Song³, Yuanbo Chen^{1

2

4}

Affiliations

¹ State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
² Spallation Neutron Source Science Center, Dongguan, Guangdong 523803, China.
³ Harbin Engineering University, Harbin, Heilongjiang 150000, China.
⁴ University of Chinese Academy of Sciences, Beijing 100049, China.
⁵ Key Laboratory of Advanced Micro-structured Materials, Ministry of Education, School of Physical and Engineering, Tongji University, Shanghai 200092, China.

PMID: 37791858
DOI: 10.1063/5.0155280

Abstract

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.