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Passive neutron multiplicity device for 240Pu measurement based on FPGA

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第9期35卷 1-14页

作者： Zhang, Yan Zhang, Hao-Ran Wang, Ren-Bo Li, Ming-Yu Chen, Rui Wang, Hai-Tao Meng, Xiang-Ting Zhou, Shu-Min Tang, Bin East china Univ Technol Fundamental Sci Radioact Geol & Explorat Technol L Nanchang 330013 Peoples R China East china Univ Technol Engn Res Ctr Nucl Technol Applicat Minist Educ Nanchang 330013 Peoples R China Pan china Detect Technol Co Ltd Nanchang 330013 Peoples R China

A passive neutron multiplicity measurement device, FH-NCM/S1, based on field-programmable gate arrays (FPGAs), is developed specifically for measuring the mass of plutonium-240 (Pu-240) in mixed oxide fuel. FH-NCM/S1 adopts an integrated approach, combining the shift register analysis mode with the pulse-position timestamp mode using an FPGA. The optimal effective length of the He-3 neutron detector was determined to be 30 cm, and the thickness of the graphite reflector was ascertained to be 15 cm through MCNP simulations. After fabricating the device, calibration measurements were performed using a Cf-252 neutron source; a detection efficiency of 43.07% and detector die-away time of 55.79 mu mu s were observed. Nine samples of plutonium oxide were measured under identical conditions using the FH-NCM/S1 in shift register analysis mode and a plutonium waste multiplicity counter. The obtained double rates underwent corrections for detection efficiency (epsilon) and double gate fraction (f(d)), resulting in corrected double rates (D-c), which were used to validate the accuracy of the shift register analysis mode. Furthermore, the device exhibited fluctuations in the measurement results, and within a single 20 s measurement, these fluctuations remained below 10%. After 30 cycles, the relative error in the mass of Pu-240 was less than 5%. Finally, correlation calculations confirmed the robust consistency of both measurement modes. This study holds specific significance for the subsequent design and development of neutron multiplicity devices.

关键词： Spent fuel Non-destructive assay neutron multiplicity Pu-240 FPGA UNCERTAINTY URANIUM MODEL FLUX

Development of a Spin-Exchange Optical Pumping-Based Polarized ^(3)He System at the china Spallation neutron source (CSNS)

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Chinese Physics Letters 2021年第9期38卷 38-42页

作者： Chuyi Huang Junpei Zhang Fan Ye Zecong Qin Syed Mohd Amir Zachary Norris Buck Ahmed Salman Wolfgang Kreuzpaintner Xin Qi Tianhao Wang Xin Tong Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation neutron source Science Center Dongguan 523803China

Polarized 3He neutron spin filters(NSFs)can be used as a vital tool for neutron polarization production and *** china Spallation neutron source(CSNS),as one of the major neutron facilities in china,has committed resources to the development of a polarized ^(3)He NSF program to support its growing polarized neutron research.A spin-exchange optical pumping(SEOP)-based polarized ^(3)He system and other necessary hardware for NSF transport has been recently *** performance of the system is benchmarked using an in-house developed cell named“Trident”.neutron beam measurements yield a ^(3)He polarization of 77%with over 200 h of on-beam relaxation *** this newly developed SEOP system with the recently reported cell fabrication station,CSNS is now capable of the fully self-sustained production of ^(3)He NSFs that shall support its future neutron polarization research.

关键词： polarized system relaxation

Status of CSNS H-ion source

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Chinese Physics C 2015年第5期39卷 121-125页

作者：刘盛进黄涛欧阳华甫赵福祥肖永川吕永佳曹秀霞薛康佳张俊嵩徐韬光李芳卢艳华李刚杨雷李仪 china Spallation neutron source (CSNS) Institute of High Energy Physics (IHEP)Chinese Academy of Sciences (CAS) Dongguan Institute of neutron Science (DINS) Dongguan University of Technology

A new H^- ion source has been installed successfully and will be used to serve the china Spallation neutron source （CSNS）. In this paper, we report various components of the ion source, including the discharge chamber, temperature, cooling system, extraction electrodes, analyzing magnet, remote control system and so on. Compared to the previous experimental ion source, some improvements have been made to make the ion source more compact and convenient. In the present arrangement, the Penning field is generated by a pair of pole tip extensions on the 90° analyzing magnet instead of by a separate circuit. For the remote control system, F3RP61-2L is applied to the accelerator online control system for the first time. In the running of the ion source, a stable pulse H^- beam with a current of 50 mA at an energy of 50 keV is produced. The extraction frequency and pulse width is 25 Hz and 500 μs, respectively. Furthermore, an emittance scanner has been installed and measurements are in progress.

关键词： H^- ion source Penning surface plasma source CSNS emittance

Large area^(3)He tube array detector with modular design for multi‑physics instrument at CSNS

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Nuclear Science and Techniques 2023年第1期34卷 1-12页

作者： Lin Zhu Jian‑Rong Zhou Yuan‑Guang Xia Liang Xiao Hong Luo Xiao‑Juan Zhou Wen‑Qin Yang Bei‑Ju Guan Xing‑Fen Jiang Yan‑Feng Wang Hong Xu Hai‑Yun Teng Li‑Xin Zeng Jia‑Jie Li Lei Hu Ke Zhou Yong‑Xiang Qiu Pei‑Xun Shen Jun Xu Li‑Jiang Liao Xiao‑Zhuang Wang Gui‑An Yang Huai‑Chan Chen Ju‑Ping Xu Zhi‑Duo Li Song‑Lin Wang Jian Zhuang Yu‑Bin Zhao Jun‑Rong Zhang Wen Yin Zhi‑Jia Sun Yuan‑Bo Chen Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation neutron source Science Center Dongguan 523803China University of Chinese Academy of Sciences Beijing 100049China

The multi-physics instrument(MPI)is the first user cooperative instrument at the china Spallation neutron source(CSNS).It was designed to explore the structures of complex materials at multiple scales based on the neutron total scattering *** imposes the requirements for the detector,including a high detection efficiency to reduce the measurement time and a large solid angle coverage to cover a wide range of momentum *** satisfy these demands,a large-area array of 3He-filled linear position-sensitive detectors(LPSDs)was constructed,each with a diameter of 1 inch and pressure of 20 *** uses an orbicular layout of the detector and an eight-pack module design for the arrangement of 3He LPSDs,covering a range of scattering angles from 3°to 170°with a total detector area of approximately 7 *** detector works in air,which is separated from the vacuum environment to facilitate installation and *** characteristics of the MPI detector were investigated through Monte Carlo(MC)simulations using Geant4 and experimental *** results suggest that the detectors are highly efficient in the wavelength range of the MPI,and an efficiency over 25%is achievable for above 0.1 A neutrons.A minimal position resolution of 6.4 mm full width at half maximum(FWHM)along the tube length was achieved at a working voltage of 2200 V,and a deviation below 2 mm between the real and measured positions was attained in the beam *** detector module exhibited good consistency and an excellent counting rate capacity of up to 80 kHz,which satisfied the requirements of experiments with a high event *** of its operation over the past year have shown that the detector works steadily in sample experiments,which allows the MPI to serve the user program successfully.

关键词： neutron detector LPSD Position resolution Counting rate capacity

Development of a large nanocrystalline soft magnetic alloy core with highμ'_(p)Qf products for CSNS-Ⅱ

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Nuclear Science and Techniques 2022年第8期33卷 45-54页

作者： Bin Wu Xiao Li Zhun Li Chun-Lin Zhang Yang Liu Wei Long Xiang Li Jian Wu Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation neutron source Science Center Dongguan 523803China University of Chinese Academy of Sciences Beijing 100049China

A waterproof nanocrystalline soft magnetic alloy core with a size of O.D.850 mm×I.D.316 mm×H.25 mm for radio frequency acceleration was successfully developed by winding 18μm 1k107b MA ***μ'_(p)Qf products reached 7.5,10,and 12 GHz at 1,3,and 5 MHz,***μ'_(p)Qf products of the MA core(O.D.250 mm×I.D.100 mm×H.25 mm)manufactured using a 13μm MA ribbon further increased by 30%.Detailed improvements on the MA core manufacture process are discussed *** high-power tests on the new MA cores demonstrated its good performance of waterproofness,particularly its stability of highμ'_(p)Qf *** MA core with highμ'pQf product and large size can operate under a high average RF power,high electric field,and in deionized water,which will be used in the china Spallation neutron source PhaseⅡ(CSNS-Ⅱ).

关键词： Large size magnetic alloy core High insulation and low stress coating Waterproof structure Transverse magnetic field annealing High power MA-loaded cavity

Facile preparation of a SiC@SiO_(2)nanowire-toughened ZrB_(2)-SiC/SiC bilayer coating with good interfacial bonding,high toughness,and excellent cyclic ablation resistance on C/CA composites

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Journal of Advanced Ceramics 2024年第4期13卷 486-495页

作者： Meng Yan Chenglong Hu Jian Li Shengyang Pang Bohui Sun Rida Zhao Bin Liang Rui Luo Sufang Tang Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Preparing antioxidant coatings to address the inherent oxidation sensitivity of carbon fiber-reinforced carbon aerogel(C/CA)composites is a feasible way to promote their application in oxidizing environments as thermal insulation ***,preparing the coatings with excellent oxidation and ablation resistance while avoiding evident damage to the C/CA substrate still remains a ***,a SiC@SiO_(2)nanowire-toughened ZrB2–SiC/SiC bilayer coating with a large thickness of 500μm was prepared on C/CA using a one-step low-temperature reaction sintering method,which simultaneously formed a sintered outer layer with even-distributed nanowires and a siliconized gradient inner *** courtesy of the synergic thermal response of the layers and the crack deflection induced by the nanowires,the resulting coating has moderate residual compressive stress of 0.08–1.22 GPa in the interface,high interfacial bonding strength of 6.02 MPa,and good fracture toughness of 4.36 MPa·m^(1/2).Benefited from the optimum components and improved structure,the coating shows excellent cyclic ablation resistance with linear ablation rates of 0.1μm/s at 1650℃for 1500 s(300 s×5 cycles)and 0.4μm/s at 1850℃for 900 s(300 s×3 cycles).The one-step preparation strategy contributes to little damage to the substrate,thus showing the well-preserved mechanical and thermal insulation properties.

关键词： coating carbon fiber reinforced carbon aerogel(C/CA)composites toughness interface residual stress

Spiking-free HGO-based DSC for flexible joint manipulator

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Chinese Journal of Aeronautics 2022年第3期35卷 419-431页

作者： Dezhi KONG Wendong WANG Yang WANG Junbo ZHANG Yikai SHI Lingyun KONG School of Mechanical Engineering Northwestern Polytechnical University Xi'an 710072China Shaanxi Engineering Research Center of Controllable neutron source School of ScienceXijing UniversityXi'an 710123China

The tracking control problem for Flexible Joint Manipulator Control System(FJMCS)with unmeasurable states is addressed in this ***,a High-Gain Observer(HGO)is constructed to estimate the unmeasurable states and the ***,a Dynamic Surface Control(DSC)scheme is developed by using the estimation of *** newly proposed controller has two advantages over the existing methods:(A)a novel Spike Suppression Function(SSF)is developed to avoid the estimation spike problem in the existing HGO-based controllers.(B)Unlike the existing observer-based partial feedback control scheme that can only estimate the unmeasurable states,the proposed HGO can estimate both the unmeasurable states and *** closed-loop system stability is proved by the Lyapunov *** results demonstrate the effectiveness of the proposed controller.

关键词： Dynamic surface control Flexible joint manipulator High-gain observer Mismatched uncertainties Partial states feedback Spike suppression

Study on the optimal incident proton energy of ^(7)Li(p,n)^(7)Be neutron source for boron neutron capture therapy

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Nuclear Science and Techniques 2024年第3期35卷 170-180页

作者： Yi-Nan Zhu Zuo-Kang Lin Hai-Yan Yu Ye Dai Zhi-Min Dai Xiao-Han Yu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Science Beijing 100049China

Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear *** various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT ***^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional *** study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head *** study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 ***,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.

关键词： Boron neutron capture therapy ^(7)Li(p,n)7Be neutron source Incident proton energy Monte Carlo simulation

Evaluation of neutron beam characteristics for D-BNCT01 facility

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Nuclear Science and Techniques 2022年第1期33卷 131-139页

作者： Jun-Yang Chen Jian-Fei Tong Zhi-Liang Hu Xue-Fen Han Bin Tang Qian Yu Rui-Qiang Zhang Chong-Guang Zhao Jun Xu Shi-Nian Fu Bin Zhou Tian-Jiao Liang Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China University of Chinese Academy of Sciences(UCAS) Beijing 100049China Spallation neutron source Science Center Dongguan 523803China Guangdong-Hong Kong-Macao Joint Laboratory for neutron Scattering Science and Technology Dongguan 523803China

An accelerator-based Boron neutron Capture Therapy(AB-BNCT)experimental facility called D-BNCT01 has been recently completed and is currently able to generate a high-intensity neutron beam for BNCTrelated *** this study,we perform several experiments involving water phantoms to validate the Monte Carlo simulation results and analyze the neutron beam *** to our measurements,D-BNCT01 can generate a neutron flux about 1.2×10^(8)n/cm^(2)/s at the beam port using a 5 kW proton *** results also show that the thermal neutron flux depth distribution inside the water phantom is in good agreement with *** conclude that D-BNCT01 may be effectively employed for BNCT research.

关键词： neutron beam Boron neutron capture therapy Water phantom