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Development of an enhanced online tritium monitoring system using plastic scintillation fiber array

NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-11页

作者： Cheng, Wen-Yu Deng, Ke Zeng, You-Shi Liu, Wei Zhang, Qin Chinese acad sci Shanghai Inst Appl Phys Shanghai 201800 Peoples R China Univ Chinese acad sci Beijing 100049 Peoples R China

Tritium, a radioactive nuclide discharged by nuclear power plants, poses challenges for removal. Continuous online monitoring of tritium in water is crucial for real-time radiation data, given its predominant existence in the environment as water. This paper presents the design, simulation, and development of a tritium monitoring device utilizing a plastic scintillation fiber (PSF) array. Experimental validation confirmed the device's detection efficiency and minimum detectable activity. The recorded detection efficiency of the device is 1.6x10-3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.6\times 10{-3}$$\end{document}, which exceeds the theoretically simulated value of 4x10-4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$4\times 10{-4}$$\end{document} by four times. Without shielding, the device can achieve a minimum detectable activity of 3165BqL-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$3165\,\hbox {Bq}\,\hbox {L}{-1}$$\end{document} over a 1600-second measurement duration. According to simulation and experimental results, enhancing detection efficiency is possible by increasing the number and length of PSFs and implementing rigorous shielding measures. Additionally, reducing the diameter of PSFs can also improve detection efficiency. The minimum detectable activity of the device can be further reduced using the aforementioned methods.

关键词： Tritium Plastic scintillating fiber array Detector WATER SOIL

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Design of 10 MeV electron linear accelerator for space environment simulation

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NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-14页

作者： Zhang, Shu Meng, Cai Zhou, Zu-Sheng He, Xiang Zhang, Jing-Ru Iqbal, Munawar Zhang, Zhan-Dong Bai, Bo-Wen Chi, Yun-Long Chinese acad sci Inst High Energy Phys Beijing 100049 Peoples R China Univ Chinese acad sci Beijing 100049 Peoples R China Harbin Inst Technol Inst Special Environm Phys Sci Shenzhen 518055 Peoples R China

A compact 10 MeV S-band irradiation electron linear accelerator (linac) was developed to simulate electronic radiation in outer space and perform electron irradiation effect tests on spacecraft materials and devices. According to the requirements of space environment simulation, the electron beam energy can be adjusted in the range from 3.5 to 10 MeV, and the average current can be adjusted in the range from 0.1 to 1 mA. The linac should be capable of providing beam irradiation over a large area of 1 m2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\hbox {m}2}$$\end{document} with a uniformity greater than 90% and a scanning rate of 100 Hz. A novel method was applied to achieve such a high beam scanning rate by combining a kicker and a scanning magnet. Based on this requirement, a design for the 10 MeV linac is proposed with an RF power pulse repetition rate of 500 Hz; it includes a thermal cathode electron gun, a bunching-accelerating section, and a scanning transport line. The detailed physical design and dynamic simulation results of the proposed 10 MeV electron linac are presented in this paper.

关键词： Electron linac Accelerating structure Beam scanning Beam homogenization Irradiation linac

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Research and development of a 0.5-m-long helical superconducting undulator prototype

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NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-10页

作者： Yang, Xiang-Chen Yu, Xiao-Wu Wei, Jun-Hao Zhang, Xiang-Zhen Chen, Zi-Lin Bian, Xiao-Juan Li, He-Ting Feng, Guang-Yao Li, Yu-Hui Univ sci & Technol China Natl Synchrotron Radiat Lab Hefei 230029 Peoples R China Chinese acad sci Inst High Energy Phys Beijing 100049 Peoples R China Chinese acad sci Inst High Energy Phys China Spallat Neutron Source Dongguan 523000 Peoples R China Chinese acad sci Inst Plasma Phys ASIPP Hefei 230031 Peoples R China

The helical undulator is in high demand in synchrotron radiation facilities for circular polarization generation. Owing to the higher field strength provided by the superconducting undulator compared to the conventional permanent-magnet undulator, greater research efforts should be directed toward this area. The helical superconducting undulator holds great potential in synchrotron radiation facilities, especially in low-energy storage rings that seek circularly polarized radiation with the highest possible radiation flux. Following the successful development of planar superconducting undulators, the Institute of High Energy Physics conducted research and development for the helical superconducting undulator. A 0.5-m-long Delta-type superconducting undulator prototype was developed and tested. Detailed information on the design, fabrication, and cryogenic testing of the prototype is presented and discussed.

关键词： Helical Superconducting undulator Delta DESIGN

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Big Disaster from Small Watershed: Insights into the Failure and Disaster-Causing Mechanism of a Debris Flow on 25 September 2021 in Tianquan, China

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INTERNATIONAL JOURNAL OF DISASTER RISK sciENCE 2024年第4期15卷 622-639页

作者： Hou, Runing Wu, Mingyang Li, Zhi Chen, Ningsheng Chen, Xiaohu Peng, Taixin Huang, Na Chinese acad sci Key Lab Mt Hazards & Surface Proc Inst Mt Hazards & Environm Chengdu 610041 Peoples R China Univ Chinese acad sci Beijing 100049 Peoples R China Yangtze Univ Sch Geosci Wuhan 430100 Peoples R China acad Plateau sci & Sustainabil Xining 810016 Peoples R China

The occurrence of debris flow events in small-scale watersheds with dense vegetation in mountainous areas that result in significant loss of life and missing individuals challenges our understanding and expertise in investigating and preventing these disasters. This has raised concerns about the occurrence of large debris flow disasters from small watersheds. This study focused on a catastrophic debris flow that took place in Longtou Gully (0.45 km2) in Tianquan County, Ya'an City on 25 September 2021, which resulted in 14 deaths and missing individuals. Through comprehensive field investigations, high-precision remote sensing data analyses, and numerical simulations, we analyzed the triggering mechanisms and dynamic processes of this event. Our results indicate that the convergence hollow at the channel head exhibited higher hydraulic conditions during rainfall compared to gentle slopes and convex terrains, leading to the instability of colluvial soil due to the expansion of the saturated zone near the soil-bedrock interface. The entrainment of material eroded from the channel resulted in an approximately 4.7 times increase in volume, and the channel scarp with a height of about 200 m amplified the destructive power of the debris flow. We emphasize the need to take seriously the possibility of catastrophic debris flows in small-scale watersheds, with colluvial deposits in hollows at the channel head under vegetation cover that serve as precursor material sources, and the presence of channel scarps formed by changes in the incision rate of the main river, which is common in the small watershed on both sides. This study provides insights for risk assessment of debris flows in small-scale catchments with dense vegetation cover in mountainous areas, highlighting the importance of vigilance in addressing disasters in small-scale catchments, particularly in regions with increasing human-environment conflicts.

关键词： China Colluvial soil Low-frequency debris flows Risk reduction Topographic hollows HILLSLOPE EROSION SHALLOW LANDSLIDES MODEL ENTRAINMENT RATES SOIL RADIOCARBON TOPOGRAPHY DEPOSITION CATCHMENT

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Towards adaptable synchrotron image restoration pipeline

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NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-13页

作者： Li, Chun Bi, Xiao-Xue Zhang, Yu-Jun Zhang, Zhen Wang, Li-Wen Zhuang, Jian Chen, Dong-Liang Dong, Yu-Hui Zhang, Yi Chinese acad sci Inst High Energy Phys Beijing Synchrotron Radiat Facil Beijing 100049 Peoples R China Spallat Neutron Source sci Ctr Dongguan 523803 Peoples R China Univ Chinese acad sci Beijing 100049 Peoples R China Univ sci & Technol China Natl Synchrotron Radiat Lab Hefei 230029 Peoples R China

Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions. Image restoration methods are often applied to recover the reduced resolution, providing improved image details that can greatly facilitate scientific discovery. Among these methods, deconvolution techniques are straightforward, yet either require known prior information or struggle to tackle large experimental data. Deep learning (DL)-based super-resolution (SR) methods handle large data well, however data scarcity and model generalizability are problematic. In addition, current image restoration methods are mostly offline and inefficient for many beamlines where high data volumes and data complexity issues are encountered. To overcome these limitations, an online image-restoration pipeline that adaptably selects suitable algorithms and models from a method repertoire is promising. In this study, using both deconvolution and pretrained DL-based SR models, we show that different restoration efficacies can be achieved on different types of synchrotron experimental data. We describe the necessity, feasibility, and significance of constructing such an image-restoration pipeline for future synchrotron experiments.

关键词： Synchrotron Deconvolution Deep learning Super-resolution Pipeline SUPERRESOLUTION REGULARIZATION DECONVOLUTION SOFTWARE

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Significant risk factors for intensive care unit-acquired weakness:A processing strategy based on repeated machine learning

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World Journal of Clinical Cases 2024年第7期12卷 1235-1242页

作者： Ling Wang Deng-Yan Long Intensive Care Unit People's Hospital of Qiandongnan Miao and Dong Autonomous PrefectureKaili 556000Guizhou ProvinceChina

BACKGROUND Intensive care unit-acquired weakness(ICU-AW)is a common complication that significantly impacts the patient's recovery process,even leading to adverse ***,there is a lack of effective preventive *** To identify significant risk factors for ICU-AW through iterative machine learning techniques and offer recommendations for its prevention and *** Patients were categorized into ICU-AW and non-ICU-AW groups on the 14th day post-ICU *** data from the initial 14 d of ICU stay,such as age,comorbidities,sedative dosage,vasopressor dosage,duration of mechanical ventilation,length of ICU stay,and rehabilitation therapy,were *** relationships between these variables and ICU-AW were *** iterative machine learning techniques,a multilayer perceptron neural network model was developed,and its predictive performance for ICU-AW was assessed using the receiver operating characteristic *** Within the ICU-AW group,age,duration of mechanical ventilation,lorazepam dosage,adrenaline dosage,and length of ICU stay were significantly higher than in the non-ICU-AW ***,sepsis,multiple organ dysfunction syndrome,hypoalbuminemia,acute heart failure,respiratory failure,acute kidney injury,anemia,stress-related gastrointestinal bleeding,shock,hypertension,coronary artery disease,malignant tumors,and rehabilitation therapy ratios were significantly higher in the ICU-AW group,demonstrating statistical *** most influential factors contributing to ICU-AW were identified as the length of ICU stay(100.0%)and the duration of mechanical ventilation(54.9%).The neural network model predicted ICU-AW with an area under the curve of 0.941,sensitivity of 92.2%,and specificity of 82.7%.CONCLUSION The main factors influencing ICU-AW are the length of ICU stay and the duration of mechanical ventilation.A primary preventive strategy,when feasible,involves minimizing both ICU stay and mechani

关键词： Intensive care unit-acquired weakness Risk factors Machine learning Prevention Strategies

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Development of a MWDC prototype of the CSR external-target experiment

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NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-14页

作者： He, Zhou-Bo Qin, Zhi Ma, Peng Yang, He-Run Wei, Xiang-Lun Lu, Chen-Gui Wen, Xiang-Jie Zhang, Xiu-Ling Chen, Tao Li, Zhi-Jie Yang, Yuan-Sheng Zhan, Mei-Qiang Liu, Can-Wen Li, Meng Qiu, Tian-Li Gong, Yi-Wei Huang, Xin-Jie Yin, Xiao-Hao He, Zhi-Xuan Zhang, Jun-Wei Zou, Hai-Chuan Fu, Sheng-Wei Guo, Dong Yan, Jun-Wei Cao, Zhe Deng, Zhi Kong, Jie Xiao, Zhi-Gang Hu, Rong-Jiang Duan, Li-Min Chinese acad sci Inst Modern Phys Lanzhou 730000 Peoples R China Univ Chinese acad sci Sch Nucl Sci & Technol Beijing 100049 Peoples R China Tsinghua Univ Dept Phys Beijing 100084 Peoples R China Univ sci & Technol China Hefei 230026 Peoples R China Sichuan Univ Inst Nucl Sci & Technol Key Lab Radiat Phys & Technol Minist Educ Chengdu 610064 Peoples R China Lanzhou Univ Sch Nucl Sci & Technol Lanzhou 730000 Peoples R China North China Univ Water Resources & Elect Power Zhengzhou 450000 Peoples R China

The cooling storage ring (CSR) external-target experiment (CEE) is a spectrometer used in construction to study the properties of nuclear matter in high-baryon density regions at the Heavy-Ion Research Facility in Lanzhou (HIRFL). This study presents the design, simulation, manufacturing, and testing of a half-size prototype of a multi-wire drift chamber (MWDC) for the CEE. First, the performance of the MWDC connected to homemade electronics was simulated. The results demonstrated that an energy resolution of 18.5% % for 5.9-keV X-rays and a position resolution of 194 mu m for protons can be achieved by the current design. Because the size of the largest MWDC reached 176 cm x 314 cm, a set of 98 cm x 98 cm prototypes was built using the new techniques. The positioning accuracy of the anode wires in this prototype is better than 20 mu m. After optimization, using commercially available electronics, the prototype can achieved an energy resolution of 19.7% % for a Fe-55 X-ray source. The CEE-MWDC detector and electronics were simultaneously tested. An energy resolution of 22% % was achieved for the Fe-55 source; the track residuals were approximately 330 mu m for the cosmic rays. The results demonstrate that the current design and techniques meet the requirements of the CEE-MWDC array.

关键词： CEE MWDC Garfield plus plus Fe-55 source Position resolution DRIFT CHAMBER HIRFL-CSR

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Study on the thermo-hydraulic behaviors of the new-pattern fuel assembly in lead-based fast reactors based on OpenFOAM

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NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-14页

作者： Li, Yun-Xiang Yang, Run-Sheng Li, Yue Su, Xing-Kang Huang, Zi-Nan Meng, Lu Li, Song Xi, Bin Zhang, You-Peng Zhang, Lu Jiang, Wei Fudan Univ Inst Modern Phys Shanghai 200433 Peoples R China Lanzhou Univ Sch Nucl Sci & Technol Lanzhou 730000 Peoples R China Chinese acad sci Inst Modern Phys Lanzhou 730000 Peoples R China

To improve the heat transfer efficiency of the coolant in lead-based fast reactors, this study optimized the configuration and rotational direction of the spacer wires in fuel assemblies to design a new-pattern fuel assembly. This study conducted detailed comparisons between traditional and new pattern fuel assembly rod bundles utilizing the open-source computational fluid dynamics platform, OpenFOAM. The results indicated that the new design may significantly reduce the pressure drop along the rod bundle, which is beneficial for lowering the pressure drop. Furthermore, this new design improved coolant mixing in the subchannels, which facilitated a more uniform temperature distribution and lower thermal gradients at the assembly outlet. These factors collectively reduced the thermal fatigue and creep in nearby internal components. Overall, the new-pattern fuel assembly proposed in this study may have better heat transfer performance, thereby enhancing the Integrated Thermal-Hydraulic Factor by 48.2% compared to the traditional pattern.

关键词： Spacer wires Enhanced coolant mixing OpenFOAM CFD simulations 3-DIMENSIONAL FLOW

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In-beam gamma rays of CSNS Back-n characterized by black resonance filter

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NUCLEAR sciENCE AND TECHNIQUES 2024年第10期35卷 1-12页

作者： Wang, Jin-Cheng Ren, Jie Jiang, Wei Ruan, Xi-Chao Liu, Ying-Yi Yang, Hao-Lan Xu, Kuo-Zhi Pan, Xin-Yi Sun, Qi Bao, Jie Huang, Han-Xiong Bai, Hao-Fan Bai, Jiang-Bo Cao, Ping Chen, Qi-Ping Chen, Yong-Hao Duan, Wen-Hao Fan, An-Chuan Fan, Rui-Rui Feng, Chang-Qing Gu, Min-Hao Han, Chang-Cai Han, Zi-Jie He, Guo-Zhu He, Yong-Cheng Hong, Yang Hu, Yi-Wei Jiang, Zhi-Jie Kang, Ling Lan, Chang-Lin Li, Bo Li, Feng Li, Qiang Li, Xiao Li, Yang Liu, Jie Liu, Rong Liu, Shu-Bin Liu, Yi-Na Luan, Guang-Yuan Ning, Chang-Jun Qiu, Yi-Jia Ren, Wen-Kai Ren, Zhi-Zhou Song, Zhao-Hui Sun, Kang Tan, Zhi-Xin Tang, Jing-Yu Tang, Sheng-Da Wang, Li-Jiao Wang, Peng-Cheng Wang, Zhao-Hui Wen, Zhong-Wei Wu, Xiao-Guang Wu, Xuan Wu, Ze-Peng Xia, Cong Xie, Li-Kun Yi, Han Yu, Tao Yu, Yong-Ji Zhang, Guo-Hui Zhang, Hang-Chang Zhang, Qi-Wei Zhang, Xian-Peng Zhang, Yu-Liang Zhang, Zhi-Yong Zhao, Mao-Yuan Zhou, Zhi-Hao Zhu, Ke-Jun Zou, Chong China Inst Atom Energy Key Lab Nucl Data Beijing 102413 Peoples R China Chinese acad sci Inst High Energy Phys Beijing 100049 Peoples R China Spallat Neutron Source sci Ctr Dongguan 523803 Peoples R China Chinese acad sci Inst High Energy Phys State Key Lab Particle Detect & Elect Beijing 100049 Peoples R China Univ Chinese acad sci Beijing 100049 Peoples R China Peking Univ Sch Phys State Key Lab Nucl Phys & Technol Beijing 100871 Peoples R China Fudan Univ Inst Modern Phys Shanghai 200433 Peoples R China Univ sci & Technol China State Key Lab Particle Detect & Elect Hefei 230026 Peoples R China Univ sci & Technol China Sch Nucl Sci & Technol Hefei 230026 Peoples R China Univ sci & Technol China Dept Modern Phys Hefei 230026 Peoples R China China acad Engn Phys Inst Nucl Phys & Chem Mianyang 621900 Peoples R China Univ sci & Technol China USTC Archaeometry Lab Hefei 230026 Peoples R China Northwest Inst Nucl Technol Xian 710024 Peoples R China Lanzhou Univ Sch Nucl Sci & Technol Lanzhou 730000 Peoples R China Univ sci & Technol China Inst Adv Technol Hefei 230027 Peoples R China

The back-streaming white-neutron beamline (Back-n) of the China Spallation Neutron Source is an essential neutron- research platform built for the study of nuclear data, neutron physics, and neutron applications. Many types of cross-sectional neutron-reaction measurements have been performed at Back-n since early 2018. These measurements have shown that a significant number of gamma rays can be transmitted to the experimental stations of Back-n along with the neutron beam. These gamma rays, commonly referred to as in-beam gamma rays, can induce a non-negligible experimental background in neutron-reaction measurements. Studying the characteristics of in-beam gamma rays is important for understanding the experimental background. However, measuring in-beam gamma rays is challenging because most gamma-ray detectors are sensitive to neutrons; thus, discriminating between neutron-induced signals and those from in-beam gamma rays is difficult. In this study, we propose the use of the black resonance filter method and a CeBr3 scintillation detector to measure the characteristics of the in-beam gamma rays of Back-n. Four types of black resonance filters, Ta-181, Co-59, Ag-nat, and Cd-nat, were used in this measurement. The time-of-flight (TOF) technique was used to select the detector signals remaining in the absorption region of the TOF spectra, which were mainly induced by in-beam gamma rays. The energy distribution and flux of the in-beam gamma rays of Back-n were determined by analyzing the deposited energy spectra of the CeBr3 scintillation detector and using Monte Carlo simulations. Based on the results of this study, the background contributions from in-beam gamma rays in neutron-reaction measurements at Back-n can be reasonably evaluated, which is beneficial for enhancing both the experimental methodology and data analysis.

关键词： In-beam gamma rays Back-n Black filter resonance technique In-beam gamma rays Back-n CeBr3 scintillator Black filter resonance technique C6D6 DETECTOR SYSTEM LINE

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Residual Operator of Type-2 Triangular Norms on Convex Normal Upper Semi-Continuous Fuzzy Truth Values

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Journal of Mathematical Research with Applications 2024年第3期44卷 285-290页

作者： Xinxing WU Shuangfeng LUO Zhiyi ZHU Lidong WANG School of Mathematics and Statistics Guizhou University of Finance and Economics School of sciences Southwest Petroleum University Zhuhai College of science and Technology

Based on the residual implication of continuous triangular norms, we obtain the expression of residual operator for extended operators(type-2 triangular norms) of continuous triangular norms on convex normal upper sem... 详细信息

关键词： type-2 fuzzy set triangular norm (t-norm) residual operator

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