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Atomistic study on the microscopic mechanism of grain boundary embrittlement induced by small dense helium bubbles in iron

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Nuclear Science and Techniques 2024年第3期35卷 84-95页

作者： Lei Peng Yong-Jie Sun Jing-Yi Shi Yi-Fei Liu Shang-Ming Chen Liu-Liu Li state key laboratory of particle detection and electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China Science and Technology on Reactor System Design Technology laboratory Nuclear Power Institute of ChinaChengdu 610213China

The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion *** order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics *** results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile *** atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation ***,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at *** bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation ***,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.

关键词： Helium bubble Grain boundary Embrittlement Reduced activation ferritic martensitic steel Molecular dynamics Bain path

Effect of multiple coulomb scattering on the beam tests of silicon pixel detectors

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Nuclear Science and Techniques 2024年第4期35卷 200-207页

作者： Lan-Kun Li Ming-Yi Dong Ze Gao Liang-Cheng-Long Jin Shu-Jun Zhao School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China state key laboratory of particle detection and electronics(Institute of High Energy Physics CAS)Beijing 100049China University of Chinese Academy of Science Beijing 100049China University of South China Hengyang 421001China

In the research and development of new silicon pixel detectors,a collimated monoenergetic charged-particle test beam equipped with a high-resolution pixel-beam telescope is crucial for prototype verification and performance *** the beam energy is low,the effect of multiple Coulomb scattering on the measured resolution of the Device Under Test(DUT)must be considered to accurately evaluate the performance of the pixel chips and *** study aimed to investigate the effect of multiple Coulomb scattering on the measured resolution,particularly at low beam *** were conducted using Allpix^(2) to study the effects of multiple Coulomb scattering under different beam energies,material budgets,and telescope *** simulations also provided the minimum energy at which the effect of multiple Coulomb scattering could be *** with the results of a five-layer detector system tested with an electron beam at DESY,the simulation results were consistent with the beam test results,confirming the reliability of the simulations.

关键词： Silicon Pixel Detectors Beam Telescope Multiple Coulomb Scattering Spatial Resolution

Detector performance of the Gamma-ray Transient Monitor onboard DRO-A satellite

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Science China(Physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 79-94页

作者： Pei-Yi Feng Zheng-Hua An Da-Li Zhang Chen-Wei Wang Chao Zheng Sheng Yang Shao-Lin Xiong Jia-Cong Liu Xin-Qiao Li Ke Gong Xiao-Jing Liu Min Gao Xiang-Yang Wen Ya-Qing Liu Xiao-Yun Zhao Fan Zhang Xi-Lei Sun Hong Lu key laboratory of particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences University of Chinese Academy of Sciences state key laboratory of particle detection and electronics Institute of High Energy Physics Chinese Academy of Sciences

The Gamma-ray Transient Monitor(GTM) is an all-sky monitor onboard the Distant Retrograde Orbit-A(DRO-A) satellite with the scientific objective of detecting gamma-ray transients ranging from 20 ke V to 1 MeV. The GTM was equipped with five Gamma-ray Transient Probe(GTP) detector modules utilizing a NaI(Tl) scintillator coupled with a SiPM array. To reduce the SiPM noise, GTP uses a dedicated dual-channel coincident readout design. In this work, we first studied the impact of different coincidence times on the detection efficiency and ultimately selected a 0.5 μs time coincidence window for offline data processing. To test the performance of the GTPs and validate the Monte-Carlo-simulated energy response, we conducted comprehensive ground calibration tests using the Hard X-ray Calibration Facility(HXCF) and radioactive sources, including the energy response, detection efficiency, spatial response, bias-voltage response, and temperature dependence. We extensively present the ground calibration results and validate the design and mass model of the GTP detector, thus providing the foundation for in-flight observations and scientific data analysis.

关键词： NaI(Tl) detector energy response ground calibration gamma-ray detector DRO-A satellite

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FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT

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Nuclear Science and Techniques 2024年第3期35卷 96-108页

作者： Wei Jiang Ping Cao Yi-Ming Wu Xian-Ke Liu Zhu-Jun Fang Zhi-Yong Zhang Bin Shi Jun Chen state key laboratory of particle detection and electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China National key laboratory for Metrology and Calibration Techniques China Institute of Atomic EnergyBeijing 102413China

A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas *** address the issue of long processing times in traditional offline position reconstruction methods,this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber *** method encapsulates key technical aspects:a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length,fast sorting,a coordinate-matching technique based on the mapping between signal timestamps and random access memory(RAM)addresses,and a precise start point-merging technique utilizing a circular combined *** performance test of the selfadaptive serial link shows that the bit error rate of the link is better than 10-12 at a confidence level of 99%,ensuring reliable data *** experiment utilizing the readout electronics and Micromegas detector shows a spatial resolution of approximately 1.4 mm,surpassing the current method’s resolution level of 5 *** beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beams online,thus validating the feasibility of the position reconstruction *** online position reconstruction method avoids traditional methods,such as bubble sorting and traversal searching,simplifies the design of the logic firmware,and reduces the time complexity from O(n2)to O(n).This study contributes to the advancement in measuring neutron beam flux for BNCT.

关键词： Position reconstruction FPGA Readout electronics Neutron flux spatial distribution

Multi-Sensor Fusion Adaptive Estimation for Nonlinear Under-observed System with Multiplicative Noise

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Chinese Journal of electronics 2024年第1期33卷 282-292页

作者： Yongpeng CUI Xiaojun SUN School of Electronic Engineering Heilongjiang University key laboratory of Information Fusion Estimation and detection

The adaptive fusion estimation problem was studied for the multi-sensor nonlinear under-observed systems with multiplicative noise. A one-step predictor with state update equations was designed for the virtual state with virtual noise first of all. An extended incremental Kalman filter(EIKF) was then proposed for the nonlinear under-observed systems. Furthermore, an adaptive filtering method was given for optimization. The fusion adaptive incremental Kalman filter weighted by scalar was finally proposed. The comparison analysis was made to verify the optimization of the state estimation using adaptive filtering method in the filtering process.

关键词： Adaptive systems Information filters Matrices Adaptive estimation Kalman filters state estimation Nonlinear systems

Effect of Defects on Magnetic Properties of O^(+) -implanted AlN Films by Positron Annihilation Spectroscopy

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原子核物理评论 2024年第1期41卷 498-503页

作者： YE Run YE Bangjiao School of Physics and Electronic Engineering Yancheng Teachers UniversityYancheng 224007JiangsuChina state key laboratory of particle detection and electronics University of Science and Technology of ChinaHefei 230026China

Room-temperature ferromagnetism is observed in the O^(+)-implanted AIN films with O+doses of 5×10^(16) cm^(-2)(AIN:Osxion)and 2×10^(17) cm^(-2)(AIN:O_(2x1on)).The observed magnetic anisotropy indicates that the ferromagnetism is attributed to the intrinsic properties of O^(+) -implanted AIN *** out-of-plane saturation magnetization(Ms)of the AIN:O5×10^(16) is about 0.68 emu/g,much higher than that of AIN:O_(2x1017),0.09 emu/g,which is due to the excessively high O^(+)dose made more O+ions occupy adjacent A1^(3+)positions in forms of antiferromagnetic *** broadening of positron annihilation radiation measurements demonstrate the existence of Al vacancies in the O^(+)-implanted AIN *** first-principles calculations suggest that the ferromagnetism originates mainly from the Al ***,the formation of divacancies or vacancy clusters by high concentrations of Al vacancies will lead to the transformation of VA-VAi coupling from ferromagnetim to antiferromagnetism,ultimately weakening the ferromagnetism of the sample.

关键词： positron annihilation spectroscopy ion implantation semiconductors ferromagnetism

Performance optimization of the neutron-sensitive image intensifier used in neutron imaging

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Chinese Physics B 2024年第8期33卷 380-387页

作者：谭金昊宋玉收周健荣杨文钦蒋兴奋刘杰张超月周晓娟夏远光刘术林闫保军刘辉王松林赵豫斌庄建孙志嘉陈元柏 Harbin Engineering University Harbin 150000China Spallation Neutron Source Science Center Dongguan 523803China state key laboratory of particle detection and electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China key laboratory of China Building Materials Industry for Special Photoelectric Materials Institute of Special Glass Fiber and Optoelectronic Functional MaterialsChina Building Materials AcademyBeijing 100024China

As a non-destructive testing technology,neutron imaging plays an important role in various fields,including material science,nuclear engineering,and fundamental *** imaging detector with a neutron-sensitive image intensifier has been developed and demonstrated to achieve good spatial resolution and timing ***,the influence of the working voltage on the performance of the neutron-sensitive imaging intensifier has not been *** optimize the performance of the neutron-sensitive image intensifier at different voltages,experiments have been performed at the China Spallation Neutron Source(CSNS)neutron *** change in the light yield and imaging quality with different voltages has been *** is shown that the image quality benefits from the high gain of the microchannel plate(MCP)and the high accelerating electric field between the MCP and the *** the accelerating electric field is more effective than increasing the gain of MCPs for the improvement of the imaging *** the total gain of the MCP stack can be realized more effectively by improving the gain of the standard MCP than that of the n *** results offer a development direction for image intensifiers in the future.

关键词： neutron detector neutron imaging microchannel plate image intensifier

Measurement of the neutron total cross section of^(9)Be at the Back-n white neutron source of CSNS

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Chinese Physics C 2024年第8期48卷 140-152页

作者： Jiangbo Bai Jingyu Tang Liqun Shi Yonghao Chen Han Yi Jie Bao Yu Bao Ping Cao Haolei Chen Zhen Chen Zengqi Cui Ruirui Fan Changqing Feng Keqing Gao Xiaolong Gao MinHao Gu Changcai Han Guozhu He Yongcheng He Yang Hong Yiwei Hu Hanxiong Huang Xiru Huang Haoyu Jiang Wei Jiang Zhijie Jiang Hantao Jing Ling Kang Bo Li Chao Li Jiawen Li Qiang Li Xiao Li Yang Li Jie Liu Shubin Liu Ze Long Guangyuan Luan Changjun Ning Mengchen Niu Binbin Qi Jie Ren Xichao Ruan Zhaohui Song Kang Sun Zhijia Sun Zhixin Tan Xinyi Tang Binbin Tian Lijiao Wang Pengcheng Wang Zhaohui Wang Xiaoguang Wu Xuan Wu Likun Xie Xiaoyun Yang Li Yu Tao Yu Yongji Yu Guohui Zhang Linhao Zhang Qiwei Zhang Xianpeng Zhang Yuliang Zhang Zhiyong Zhang Luping Zhou Zhihao Zhou Kejun Zhu Institute of Modern Physics Fudan UniversityShanghai 200433China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China Sate key laboratory of particle detection and electronics University of Science and Technology of ChinaHefei 230026China Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China key laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China state key laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China state key laboratory of particle detection and electronics Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Northwest Institute of Nuclear Technology Xi’an 710024China University of Chinese Academy of Sciences Beijing 100049China

The neutron total cross section data of^(9)Be are essential in the nuclear structure model research of light nuclei and nuclear power *** neutron total cross section of^(9)Be in the 0.3 eV−120 MeV energy region has been measured using time-of-flight and transmission methods with the Neutron Total Cross Sectional Spectrometer(NTOX)based on the multi-cell fast fission chamber at the China Spallation Neutron Source(CSNS)-Back-n white neutron source(Back-n).The fission count-neutron energy distributions of ^(235)U and ^(238)U without samples and with Be samples with three thicknesses were measured in the double-bunch operation mode for a beam power of 100 *** Bayesian method was used to eliminate the influence of the double-bunch problem on neutron measurement in the energy region above 10 *** neutron total cross section of^(9)Be results was consistent with ENDF/B-VIII.0 evaluation library data in the 0.3 eV−20 MeV energy *** the energy ranges of 0.3 eV to 10 keV and 0.01 to 20 MeV,the deviations between our results and the evaluation results of ENDF/B-VIII.0 were within 2.5%and 15%,*** the resonance energy region,the measured resonance energies in our experiment were 0.63,0.82,and 2.8 MeV,*** results showed that the total cross section uncertainties of three Be samples were within 2.2%in the energy region below 1 *** total cross section uncertainty of 30 mm Be from ^(235)U was the smallest and less than 5%in the energy region of 0.3 eV−120 *** results of this experiment can provide technical support for further data analysis and related nuclear data evaluation.

关键词： ^(9)Be neutron total cross section CSNS Back-n time-of-flight method transmission method multi-cell fast fission chamber

Nondestructive technique for identifying nuclides using neutron resonance transmission analysis at CSNS Back-n

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Nuclear Science and Techniques 2024年第1期35卷 178-187页

作者： Sheng-Da Tang Yong-Hao Chen Jing-Yu Tang Rui-Rui Fan Qiang Li Gong Li Dong Liu Zheng-Yao Jin Xing-Zhu Cui Tian-Xiang Chen Yi-Wei Yang Rong Liu Han Yi Yang Li Zhen Yang Qi An Hao-Fan Bai Jiang-Bo Bai Jie Bao Ping Cao Qi-Ping Chen Zhen Chen Zeng-Qi Cui An-Chuan Fan Chang-Qing Feng Fan-Zhen Feng Ke-Qing Gao Min-Hao Gu Chang-Cai Han Zi-Jie Han Guo-Zhu He Yong-Cheng He Yang Hong Yi-Wei Hu Han-Xiong Huang Wei-Hua Jia Hao-yu Jiang Wei Jiang Zhi-jie Jiang Ling Kang Bo Li Chao Li Jia-Wen Li Xiao Li Jie Liu Shu-Bin Liu Guang-Yuan Luan Chang-Jun Ning Bin-Bin Qi Jie Ren Zhi-Zhou Ren Xi-Chao Ruan Zhao-Hui Song Kang Sun Zhi-Xin Tan Li-Jiao Wang Peng-Cheng Wang Zhao-Hui Wang Zhong-Wei Wen Xiao-Guang Wu Xuan Wu Li-Kun Xie Yong-Ji Yu Guo-Hui Zhang Lin-Hao Zhang Mo-Han Zhang Qi-Wei Zhang Xian-Peng Zhang Yu-Liang Zhang Yue Zhang Zhi-Yong Zhang Mao-Yuan Zhao Lu-Ping Zhou Zhi-Hao Zhou Ke-Jun Zhu Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Institute of High-Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China state key laboratory of particle detection and electronics University of Science and Technology of ChinaHefei 230026China state key laboratory of particle detection and electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China USTC Archaeometry laboratory University of Science and Technology of ChinaHefei 230026China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China state key laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China key laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China Northwest Institute of Nuclear Technology Xi’an 710024China University of Chinese Academy of Sciences Beijing 100049China

Nondestructive and noninvasive neutron assays are essential applications of neutron *** resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an *** back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the China Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test *** results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at *** study reveals its potential future applications.

关键词： CSNS White neutron beam NRTA Nuclide identification Nondestructive method