Conceptual design of a Cs2LiLaBr6 scintillator‑based neutron total cross section spectrometer on the back‑n beam line at CSNS  

作　　者：Da‑Jun Zhao Song Feng Pin‑Jing Cheng Rong Liu Wen Luo Hao‑Qiang Wang Jie‑Ming Xue Kun Zhu Bo Zheng 

机构地区：[1]School of Nuclear Science and Technology,University of South China,Hengyang 421001,China [2]Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621900,China

出　　处：《Nuclear Science and Techniques》2023年第1期23-32,共10页核技术（英文）

基　　金：supported by the Key Laboratory of Nuclear Data Foundation(No.JCKY2022201C153);National Natural Science Foundation of China(No.11505216),Educational Commission of Hunan Province of China(No.19B488);Natural Science Foundation of Hunan Province of China(Nos.2021JJ40444 and 2020RC3054).

摘　　要：To reduce the experimental uncertainty in the 235 U resonance energy region and improve the detection efficiency for neutron total cross section measurements compared with those obtained with the neutron total cross section spectrometer(NTOX), a dedicated lithium-containing scintillation detector has been developed on the Back-n beam line at the China Spallation Neutron Source. The Fast Scintillator-based Neutron Total Cross Section(FAST) spectrometer has been designed based on a Cs2Li La Br6(CLLB) scintillator considering the γ-ray flash and neutron environment on the Back-n beam line. The response of the CLLB scintillator to neutrons and γ-rays was evaluated with different 6Li/7 Li abundance ratios using Geant4. The neutron-γdiscrimination performance of the CLLB has been simulated considering different scintillation parameters, physical designs,and light readout modes. A cubic 6Li-enriched( > 90%) CLLB scintillator, which has a thickness of 4-9 mm and side length of no less than 50 mm to cover the Φ 50 mm neutron beam at the spectrometer position, has been proposed coupling to a side readout SiPM array to construct the FAST spectrometer. The developed simulation techniques for neutron-γ discrimination performance could provide technical support for other neutron-induced reaction measurements on the Back-n beam line.

关 键 词：Neutron total cross section CLLB scintillator GEANT4 Pulse shape discrimination(PSD) 

分 类 号：O571.53[理学—粒子物理与原子核物理]