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Yang, Jianqing,Zhang, Quanhu,Su, Xianghua,Li, Sufen,Zhuang, Lin,Hou, Suxia,Huo, Yonggang,Zhou, Hao,Liu, Guorong Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.5
Fast-Neutron Multiplicity Counter based on Liquid Scintillator Detector can directly measure the fast neutron multiplicity emitted by UO<sub>2</sub> rod. HPGe gamma spectrometer; which has superior energy resolution; is routinely used for the gamma energy spectrum measurement. Combing Fast-Neutron Multiplicity Counter and HPGe γ-spectrometer, the n/γ joint measurement system is developed. The fast neutron multiplicity and gamma energy spectrum of UO<sub>2</sub> rod assemblies under different conditions are measured by the n/γ joint measurement system. The induced fission rate and the <sup>235</sup>U abundance, thereby the <sup>235</sup>U mass; can be obtained for UO<sub>2</sub> rod assemblies. The <sup>235</sup>U mass deviation of the measured value from the reference value is less than 5%. The results show that the n/γ joint measurement system is effective and applicable in the measurement of the <sup>235</sup>U mass in samples.
Hou, Linjun,Zhang, Quanhu,Yang, Jianqing,Cai, Xingfu,Yao, Qingxu,Huo, Yonggang,Chen, Qifan Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.7
As a relatively new radiation imaging method, the cosmic-ray muon scattering imaging technology can be used to prevent nuclear smuggling and is of considerable significance to nuclear safety. Proposed in this paper is a new reconstruction algorithm based on density clustering, aiming to improve inspection quality with better performance. Firstly, this new algorithm is introduced in detail. Then in order to eliminate the inequity of the density threshold caused by the heterogeneity of the muon flux in different positions, a new flux correction method is proposed. Finally, three groups of simulation experiments are carried out with the help of Geant4 toolkit to optimize the algorithm parameters, verify the correction method and test the inspection quality under shielded condition, and compare this algorithm with another common inspection algorithm under different conditions. The results show that this algorithm can effectively identify and locate nuclear material with low misjudging and missing rates even when there is shielding and momentum precision is low, and the threshold correcting method is universally effective for density clustering algorithms.
Yang, Jianqing,Zhou, Jianrong,Zhang, Lianjun,Tan, Jinhao,Jiang, Xingfen,Zhou, Jianjin,Zhou, Xiaojuan,Hou, Linjun,Song, Yushou,Sun, XinLi,Zhang, Quanhu,Sun, Zhijia,Chen, Yuanbo Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.7
The <sup>n</sup>MCP (Neutron sensitive microchannel plate) combined with advanced readout electronics is widely used in energy selective neutron imaging because of its good spatial and timing resolution. Neutron detection efficiency is a crucial parameter for the <sup>n</sup>MCP. In this paper, a mathematical model based on the oblique cylindrical channel and elliptical pore was established to calculate the neutron absorption probability, the escape probability of charged particles and overall detection efficiency of <sup>n</sup>MCP and analyze the effects of neutron incident position, pore diameter, wall thickness and bias angle. It was shown that when the doping concentration of the <sup>n</sup>MCP was 10 mol%, the thickness of <sup>n</sup>MCP was 0.6 mm, the detection efficiency could reach maximum value, about 24% for thermal neutrons if the pore diameter was 6 ㎛, the wall thickness was 2 ㎛ and the bias angle was 3 or 6°. The calculated results are of great significance for evaluating the detection efficiency of the <sup>n</sup>MCP. In a subsequent companion paper, the mathematical model would be extended to the case of the spatial resolution and detection efficiency optimization of the coating <sup>n</sup>MCP.
Wang Yu,Yao Qingxu,Zhang Quanhu,Zhang He,Lu Yunfeng,Fan Qimeng,Jiang Nan,Yu Wangtao 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.12
Radionuclide identification is an important part of the nuclear material identification system. The development of artificial intelligence and machine learning has made nuclide identification rapid and automatic. However, many methods directly use existing deep learning models to analyze the gammaray spectrum, which lacks interpretability for researchers. This study proposes an explainable radionuclide identification algorithm based on the convolutional neural network and class activation mapping. This method shows the area of interest of the neural network on the gamma-ray spectrum by generating a class activation map. We analyzed the class activation map of the gamma-ray spectrum of different types, different gross counts, and different signal-to-noise ratios. The results show that the convolutional neural network attempted to learn the relationship between the input gamma-ray spectrum and the nuclide type, and could identify the nuclide based on the photoelectric peak and Compton edge. Furthermore, the results explain why the neural network could identify gamma-ray spectra with low counts and low signal-to-noise ratios. Thus, the findings improve researchers’ confidence in the ability of neural networks to identify nuclides and promote the application of artificial intelligence methods in the field of nuclide identification.
Baoan Ding,Juanshan Zheng,Xiezhong Wang,Licheng Zhang,De Sun,Quanhu Xing,Andrea Pirone,Baldassare Fronte 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.10
Objective: This study investigated the effects of 1,3-1,6 beta-glucan added to the diet of Haidong chicks reared under hypoxic conditions, to ascertain the growth performances, immunity and intestinal morphology changes. Methods: A total of 750 chicks were divided into five groups and fed diets containing 0.5 g/kg, 1.0 g/kg, and 2.0 g/kg 1,3-1,6 beta-glucan from yeast (G1, G2, G3, respectively), 0.2 g/kg Taylor rhizomorph and a control feed. Results: The body weight and body weight gain were higher in chicks fed 1,3-1,6 beta-glucan and Taylor rhizomorph than in control group. Feed conversion ratio significantly differed for G2 and G3 groups in comparison to control group. The relative weight of bursa was higher in G1, G2, and G3 groups. The white blood cells and lymphocytes were significantly increased in groups fed 1,3-1,6 beta-glucan. The immunoglobulin G of serum peak appeared in the G3 group. The villous height of the duodenum was higher in 1,3-1,6 beta-glucan feed groups. In the jejunum, the villous height was higher in G2 and G3 groups and crypt depth for all the groups fed β-glucan. At ileum level the villous height and crypt depth was higher for groups G1, G2, and G3. Conclusion: The growth performance of Haidong chicks is improved when 10 and 20 g/kg 1,3-1,6 beta-glucan is included in the diet; hence, it is suggested that 1,3-1,6 beta-glucan be included in poultry diet to reduce and replace the use of antibiotics.
Hou, Linjun,Huo, Yonggang,Zuo, Wenming,Yao, Qingxu,Yang, Jianqing,Zhang, Quanhu Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.1
Cosmic-ray muon scattering tomography (MST) technology is a new radiation imaging technology with unique advantages. As the performance of its image reconstruction algorithm has a crucial influence on the imaging quality, researches on this algorithm are of great significance to the development and application of this technology. In this paper, a fast inspection algorithm based on clustering analysis for the identification of the existence of nuclear materials is studied and optimized. Firstly, the principles of MST technology and a binned clustering algorithm were introduced, and then several simulation experiments were carried out using Geant4 toolkit to test the effects of exposure time, algorithm parameter, the size and structure of object on the performance of the algorithm. Based on these, we proposed two optimization methods for the clustering algorithm: the optimization of vertical distance coefficient and the displacement of sub-volumes. Finally, several sets of experiments were designed to validate the optimization effect, and the results showed that these two optimization methods could significantly enhance the distinguishing ability of the algorithm for different materials, help to obtain more details in practical applications, and was therefore of great importance to the development and application of the MST technology.