最新刊期
      卷 47 ， 期 4 ， 2024

        INVITED REVIEW

      • “在3d过渡金属化合物电子结构研究领域，专家基于软X射线吸收谱学，为解析其精细电子结构提供新方法。”
        FAN Yalei,ZHOU Jing,HU Zhiwei,WANG Jianqiang,ZHANG Linjuan
        Vol. 47, Issue 4, Article number: 040001(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040001
        摘要：Transition metal compounds with partially filled 3d electron shells exhibit a variety of physical and chemical properties. They are widely used in sensors, magnetic memory, photoelectronic devices, photocatalysis, and electrochemistry. Therefore, determining and understanding their electronic structure is extremely important. The quantitative analysis of soft X-ray absorption spectroscopy depends on theoretical calculation method for the full multiplet based on crystal field theory and hybridization theory. By incorporating these elements, full multiplet theory can provide an accurate model of the fine electronic structure of transition metals and their ligands. A brief introduction of the basic principles, key parameters, and software relevant to soft X-ray absorption spectroscopy is firstly provided in this review. Subsequently, the applications of theoretical calculation in analyzing the electronic structures of 3d transition metals are discussed with an emphasis on its application in the field of electrochemistry. Finally, some prospects for future development in this field are proposed.  
        关键词：sXAS;Transition metal;Configuration-interaction;Spin state;Crystal field   
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        发布时间：2024-10-25

        ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS

      • “在航空γ能谱数据处理领域，专家提出了基于CUDA的GPU并行方案，实现了数据降噪处理的高效加速，为该领域研究提供了新方向。”
        XIONG Chao,WANG Xin,WANG Xinjie,WU Hexi
        Vol. 47, Issue 4, Article number: 040201(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040201
        摘要：BackgroundThe volume of aviation gamma spectrum data is immense. If only a central processing unit (CPU) is used for data post-processing, it would be constrained by computational efficiency.PurposeThis study aims to propose a CUDA-based graphics processing unit (GPU) parallel solution that optimally accelerates the denoising of airborne gamma-ray spectral data using wavelet transformation.MethodsFirst, the impact of different block sizes on computational time was tested to determine the optimal block size for processing airborne gamma-ray spectral data. Subsequently, a GPU, instead of a CPU, was used to calculate the acceleration ratio for handling airborne gamma-ray spectral data of different volumes, and wavelet basis functions were used for those with the same data volume. Finally, by introducing white noise to the experimentally measured airborne gamma-ray spectral data, the signal-to-noise ratio of denoised data was calculated to optimize the threshold denoising method suitable for parallel acceleration of the GPU.ResultsThe optimal two-dimensional block sizes for denoising airborne gamma-ray spectral data are 64×64 and 128×128. Among the wavelet basis functions, those that achieved a total time acceleration ratio exceeding 100 compared to CPU processing account for 80%, while those that reached an acceleration ratio exceeding 90 constitute 91%. The coif5 function achieves an acceleration ratio of 353 times whilst the acceleration ratio of the threshold denoising function approaches 570.ConclusionsAll wavelet functions exhibit insufficient denoising effects at low signal-to-noise ratios and excessive denoising effects at high signal-to-noise ratios. Significant denoising can be achieved using hard thresholding of coif5, soft thresholding of coif1, and improved thresholding of bior3.7.  
        关键词：GPU;Airborne gamma-ray spectra;Threshold denoising   
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        发布时间：2024-10-25
      • “在硼中子俘获治疗领域，新型曲面中子靶提升了出射中子前向性和散热性能。”
        WANG Junyan,KONG Haiyun,LI Deming
        Vol. 47, Issue 4, Article number: 040202(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040202
        摘要：BackgroundBoron neutron capture therapy (BNCT) is a promising tumor therapy method that irradiates 10B attached tumors with thermal or epithermal neutrons. Specifically, 7Li(p,n)7Be is one of the main methods for producing thermal or epithermal neutrons. The Li target is a critical component for BNCT device.PurposeThis study aims to design a composite material Li target with a semi-tirelike surface structure that rotates around a central axis.MethodsBased on a 2.5 MeV, 20 mA proton beam, the TOPAS Monte Carlo software was used to simulate the influence of curved lithium target with different radial axial ratios on the angular distribution, energy spectrum, and flux of neutrons. The steady-state temperature distribution of the neutron target was simulated by using ANSYS software to investigate the impact of radial axial ratios on heat dissipation.ResultsThe simulated results show that the semi-tirelike curved surface enhances the concentration of the output neutron beam. When the radial axis ratio is 1.5, the number of neutrons with an exit angle of 0°~45° is 2.59 times that of the same plane target whereas the number of neutrons with an exit angle of greater than 90° is only 0.29 times that of a planar target in the same situation. The heat dissipation performance is improved by the fold channel design and curved surface structure. The maximum temperature of the lithium layer is only 100 ℃ for a 50-kW proton beam incident, which satisfies the heat dissipation requirement.ConclusionThe innovative curved neutron target of this study significantly improves the forward performance of the outgoing neutron and heat dissipation performance when compared with the conventional plane target. These types of advancements will lead to good prospects in the field of BNCT.  
        关键词：Boron neutron capture therapy;Neutron target;Monte Carlo simulation   
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      • “在第四代反应堆中，核石墨在高温辐照条件下的缺陷演化行为和机理研究取得进展，为提高反应堆安全性提供解决方案。”
        LI Yiyan,HE Zhoutong,ZHAO Xiuliang,PENG Shancheng,MA Huilei
        Vol. 47, Issue 4, Article number: 040203(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040203
        摘要：BackgroundWithin GEN-IV reactors, nuclear graphite plays a crucial role as both a moderator and reflector in an environment characterized by high temperatures and intense fast neutron irradiation. The exposure to fast neutron irradiation induces the formation of numerous Frankel defects in the nuclear graphite. These defects undergo processes of annihilation and diffusion, ultimately giving rise to larger defect clusters. This transformation in the microstructure of nuclear graphite directly impacts its macroscopic properties, necessitating a thorough investigation.PurposeThis study aims to comprehensively explore the evolution of defects in nuclear graphite under conditions of high-temperature irradiation which is essential for advancing reactor safety.MethodsFirstly, the 30 MeV 107Ag5+ ion source was employe to irradiate IG-110 nuclear graphite at 420 ℃, simulating the defect evolution behavior during fast neutron irradiation of nuclear graphite. Then, the energy loss, defect distribution, and ion implantation profiles of 30 MeV 58Ni5+ and 107Ag5+ ion beams bombarding standard nuclear graphite ICRU-906 (density of 2.26 g∙cm-3, displacement energy of 28 eV) were calculated using the full cascade damage model in the SRIM (Stopping and Range of Ions in Matter) software. The cross-sectional structure of IG-110 nuclear graphite was characterized using micro-Raman spectroscopy. Finally, the relationship between the Raman spectroscopic features at various depths of IG-110 nuclear graphite and the irradiation damage dose was compared to investigate the evolution of IG-110 nuclear graphite microstructure with increasing irradiation damage dose (Displacements Per Atom, DPA).ResultsWith the increase in particle fluence, the characteristic parameters of the Raman spectra of nuclear graphite, including the ID/IG ratio (the ratio of the D peak height to the G peak height), the Full Width at Half Maximum of the G peak (FWHM(G)), and the shift of the G peak, all show significant increments. Compared to samples irradiated with 58Ni5+ at the same irradiation damage dose, the graphite Raman spectra irradiated with 107Ag5+ demonstrate higher ID/IG ratios and FWHM(G). At the same FWHM(G) level, the ID/IG ratio of the graphite Raman spectra irradiated with 107Ag5+ is greater than that of the samples irradiated with 58Ni5+.ConclusionsThe results of this study suggest that irradiation with heavier ions induces a higher rate of defect accumulation in nuclear graphite, leading to a more rapid reduction in graphite grain size and promoting the progression towards nanocrystallization.  
        关键词：Heavy ion irradiation;IG-110 nuclear graphite;Micro-Raman spectroscopy;Defect evolution laws;High-temperature irradiation;Cross-sectional Raman imaging   
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        发布时间：2024-10-25

        NUCLEAR CHEMISTRY, RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE

      • “在核医学科建设领域，专家建立了放射性废水排放管理的RJ方程组，为医院废水排放管理提供指导。”
        ZHANG Qi,GE Yunwen
        Vol. 47, Issue 4, Article number: 040301(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040301
        摘要：BackgroundIn the process of accelerated development of nuclear medicine department in recent years, the construction of decay tanks and the storage time of radioactive wastewater containing 131I have become issues of great concern for environmental regulatory agencies and hospitals. Regulations and standards, such as "Basic Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources" (GB 18871-2002), "Radiation Protection and Safety Requirements for Nuclear Medicine" (HJ 1188-2021), and "Reply to Consultation on Several Clauses of the Nuclear Medicine Standard", have stipulated the compliant discharge methods for radioactive wastewater containing 131I from hospitals.PurposeThis study aims to demonstrate the methods for calculating the optimal volume of the decay tank and the minimum storage time so as to minimize the unnecessary construction costs and land use while ensuring compliance with regulations.MethodsFirstly, according to theoretical induction, a formula for the upper bound of total activity of 131I was presented for a full decay tank in a hospital. Then, the RJ (Radioactivity Judgement) equation group was put forward to address the calculation of minimum decay time and volume of the decay tank. Finally, the actual monitoring data from four hospitals were applied to verification the recommendation of this study.ResultsVerification results demonstrate that when the temporary storage period for radioactive wastewater containing 131I reaches the minimum time calculated by the RJ equations, the total discharge activity of 131I complies with the national environmental protection standards. Among the three compliant discharge methods for radioactive wastewater containing 131I in the decay tank, the method specified in GB 18871-2002 is advantageous for the operation of the nuclear medicine department in the hospital.ConclusionsWith the methodologies detailed in this paper, it is possible to significantly reduce the required volume of the decay tank and the minimum storage time. These findings provide clear and specific guidance for the construction of decay tanks in nuclear medicine departments and for the supervision and inspection conducted by regulatory authorities.  
        关键词：Hospital;Decay tank;Radioactive Wastewater;131I   
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        NUCLEAR ELECTRONICS AND INSTRUMENTATION

      • “在X射线管研究领域，专家建立了透射式X射线管物理模型，分析了背散射电子对出射光束质量的影响，为微型X射线管数值仿真提供参考。”
        DONG Lang,WANG Ming,SUN Tiantian,DAI Wei,ZHANG Lei,LI Guodong,ZHANG Qingxian,GU Yi,ZENG Guoqiang
        Vol. 47, Issue 4, Article number: 040401(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040401
        摘要：BackgroundWhen an X-ray tube operates, a large number of backscattered electrons are generated inside the tube. Under the influence of the electric field inside the X-ray tube, these backscattered electrons are pulled back to the anode target by the electric field, generating additional X-rays, which ultimately have a negative impact on the quality of the emitted beam.PurposeThis study aims at the distribution rules of backscattered electrons in transmission X-ray tubes, and the changes in backscattered electrons caused by target materials and tube voltages as well as their impact on the outgoing beam quality.MethodsFirstly, Geant4 was used to establish the physical model of the transmission X-ray tube, and the theoretical calculations were compared with experimental data to verify the accuracy of the calculation program. Then, C, Si, Cu, Ag, and W were selected as anode target materials, and the influences of different electric field strengths and these target materials on the distribution of backscattered electrons in the X-ray tube were analyzed in details. Finally, the influence of the backscattered electrons on the outgoing beam quality under the effect of tube voltage was investigated.ResultsThe full width at half maximum, photon yield, and characteristic peak yield of the outgoing beam of the X-ray tube increase when considering the electric field, indicating that the backscattered electrons have effect on the outgoing spectrum quality. Simultanously, the backscattered electrons pulled back by the electric field in the first and second generations predominantly affect the outgoing beam quality. A change in the tube voltage alters the extent of influence of the backscattered electrons on the outgoing beam quality, and a larger tube voltage leads to a more obvious influence of the backscattered electrons on the outgoing beam quality of the X-ray tube.ConclusionsThe distribution of inside backscattered electron is closely related to the characteristics of the X-ray tube, including the tube voltage and target material. The results of this study may provide a reference for numerical simulation calculations of miniature transmission X-ray tubes.  
        关键词：Transmission X-ray tube;Backscattered electron;Tube voltage;Target material;GEANT4   
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      • “在瞬时电离辐射效应研究领域，专家采用激光装置和脉冲γ射线辐射源，对SOI器件和集成电路进行了辐照试验，揭示了其与体硅器件的差异，为相关研究提供了新思路。”
        DU Chuanhua,DUAN Binghuang,XIONG Cen,ZENG Chao
        Vol. 47, Issue 4, Article number: 040402(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040402
        摘要：BackgroundLaser simulation technology is widely used in the research of transient ionizing radiation effects in semiconductor devices. Fully dielectrically isolated silicon-on-insulator (SOI) devices exhibit different responses to dose-rate gamma irradiation compared to bulk-Si devices.PurposeThis study aims to examine the photocurrents of both Si-based and SOI NMOS transistors, and investigate the performance of a SOI MCU with varying dose rates.MethodAn irradiation experiment was conducted on three types of transistors by using a 1 064 nm/12 ns laser device, and the photocurrent was tested under various laser energies. A pulsed γ-ray source was employed to perform the transient γ dose rate radiation test on an SOI-integrated circuit. The function, electrical parameters, and flipflop chain status of the SOI-integrated circuit under different dose rates were measured. Based on theoretical model for the generation of photocurrent in SOI transistor, the dose-rate threshold for logic flipping and corresponding critical charge were estimated based on theoretical model for the generation of photocurrent in SOI transistor.ResultsThe results indicate that the peak photocurrent of the SOI transistor is approximately 20 times lower than that of the bulk silicon transistor with the same feature size under identical irradiation conditions. This reduction is attributed to the decreased charge collection sensitive area of the SOI transistor. Within a dose rate range from 1.0×109 rad(Si)·s-1 to 4.2×1011 rad(Si)·s-1, the SOI-integrated circuit exhibites no latch-up effect. However, irradiation-induced upsets are observed in the SOI-integrated circuit.ConclusionsThese upsets caused by transient radiation effects manifest as transient functional interruptions, variations in operating current and voltage, and erroneous flip-flop statuses. These irradiation-induced upsets in the SOI-integrated circuit are likely attributable to, among other factors, transistor upsets and circuit-level voltage fluctuations on printed circuit board.  
        关键词：SOI transistor;Microprocessor;Transient ionizing radiation effect;Photocurrent   
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        发布时间：2024-10-25
      • “在中子探测领域，研究者提出了一种结合KPCA、MPA和ELM的机器学习鉴别方法，显著提升了n/γ甄别效率。实验结果显示，该方法的平均甄别准确率高达99.07%，为中子探测提供了高效解决方案。”
        HU Wanping,ZHANG Guiyu,ZHANG Yunlong,TUO Xianguo,LI Hulin
        Vol. 47, Issue 4, Article number: 040403(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040403
        摘要：BackgroundNeutrons/Gamma (n/γ) discrimination is critical for neutron detection in the presence of γ radiation and traditional pulse shape discrimination methods suffer from unstable discrimination accuracy.PurposeThis study aims to implement a machine-learning method that combines the kernel principal component analysis (KPCA), marine predator algorithm (MPA), and extreme learning machine (ELM) is proposed to improve the n/γ discrimination efficiency and accuracy against the traditional pulse shape discrimination methods.MethodsThe KPCA was used to reduce the dimensionality of the pulse signal characteristics of neutrons and gamma rays. Owing to the randomness in the ELM input layer weight and hidden layer bias, the MPA was employed to optimize the foregoing factors to improve the n/γ discrimination accuracy of the ELM. Finally, experimental data of Pu-C neutron source using BC-501A liquid scintillator detector were applied to effectiveness comparison of training and test with and without KPCA dimensionality reduction.ResultsComparison results reveal that the average discrimination accuracy of the KPCA-MPA-ELM is as high as 99.07%, which is 12.19%, 2.52%, and 1.56% higher than those of the ELM, MPA-ELM, and KPCA-ELM models, respectively. Compared with the charge comparison method and pulse gradient analysis method, the accuracy is improved by 1.80% and 5.91%, respectively.ConclusionsThe proposed model has a simple structure, exhibits good stability, hence be applied to handling high-dimensional data with good discrimination and generalization ability.  
        关键词：n/γ discrimination;Machine learning;Kernel principal component analysis;Marine predator algorithm;Extreme learning machine   
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      • “在低活度氚水浓集测量领域，采用氘内标法对固体聚合物电解水装置进行标定，避免了高活度氚水污染，提高了标定准确性和精密度。”
        WANG Chenxu,XUE Xiaochong,LIU Jiayu,ZENG Youshi,DENG Ke,ZHANG Qin,ZHU Lixiao,LIU Wei,GE Lixin
        Vol. 47, Issue 4, Article number: 040404(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040404
        摘要：BackgroundSolid-polymer electrolyte (SPE) water electrolysis has been widely used to concentrate low-level environmental tritium for measurements. It has the advantages of electrolyte elimination, infinite reduction ratio, high current, safety, and environmental friendliness. However, the use of high-activity tritium samples for the calibration of its tritium enrichment factor Et causes a tritium memory effect in the system.PurposeThis study aims to reduce the tritium contamination caused by high-activity tritium samples during calibration.MethodsFirst, the deuterium method (DM) was used to calibrate the prepared SPE-based tritium enrichment system. The strong correlation between the tritium-to-protium (β) and deuterium-to-protium separation factors (α) during the electrolysis was determined to obtain the electrolytic cell constant, k = αβ-1/βα-1. Then, based on the deuterium enrichment factor Ed, the tritium enrichment factor (Ed)k of the SPE-based tritium enrichment system was determined. Finally, the influence factors of the k-value were analyzed, and the tritium enrichment factors derived via low-level tritium measurements using the DM and spike-proxy method (SPM) were compared.ResultsThe value of k is approximately 1.088 9, with a slight variation of 0.89% among cells. The k-value depends on the electrode material, but it is almost independent of the initial volume of water.ConclusionsThe k-value can be used as a constant for calibration of the tritium enrichment factor for the same types of electrolyzer with high accuracy and precision.  
        关键词：Solid-polymer electrolyte water electrolysis;Separation factor;Tritium;Deuterium;Tritium enrichment factor;Tritium recovery factor   
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        发布时间：2024-10-25

        NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH

      • “在储层岩石物理评价领域，通过蒙特卡罗模拟方法，对比了C/H与C/O测井方法的响应效果，为低矿化度储层含油饱和度计算提供解决方案。”
        LI Xun,WU Wensheng,DONG Duo
        Vol. 47, Issue 4, Article number: 040501(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040501
        摘要：BackgroundThe accurate determination of oil saturation is an essential part of reservoir petrophysical evaluation. Both C/H and C/O logging methods are primarily used to determine oil saturation in low-salinity reservoirs.PurposeThe study aims to compare the logging response effects of the C/H and C/O methods.MethodsFirstly, a spherical model and the model set by the C/O logging instrument RPM (Halliburton Company) were applied to Monte Carlo simulations, and the window counts of the atoms formed under different geological parameters and pore structures were calculated by MCNP5. Then, the relationship between C/O and C/H with saturation and the sensitivity to saturation were analyzed, and the response effects of C/O and C/H were compared. Finally, the mechanisms underlying the different response effects of C/H under different models were clarified.Results & ConclusionThe analysis results show that C/H and C/O exhibit the same relationship with porosity and saturation in casing wells, and both can be used to calculate saturation. However, compared to C/O, C/H is more affected by the borehole environment and is less sensitive to saturation; therefore, it is not suitable for saturation calculations in complex boreholes.  
        关键词：C/O logging;C/H logging;Log responses;Numerical simulation   
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      • “在X射线自由电子激光装置领域，专家开发了自动化辐照模拟程序AISL，显著提高了材料辐照损伤模拟计算效率。”
        ZHOU Yue,HAI Xue,REN Cuilan,YIN Yaru,SHANG Kunlin,LEI Lei,HUAI Ping
        Vol. 47, Issue 4, Article number: 040502(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040502
        摘要：BackgroundExposure to high-intensity X-ray irradiation induces numerous defects in the thin films of optical components applied to X-ray free-electron laser (XFEL) facilities. These defects result in structural damage to the material and degradation of macroscopic properties, thereby affecting its service life and significantly compromising the reliability and stability of XFEL facilities.PurposeThis paper aims to design and implement an automated irradiation simulation software based on Python called automatic irradiation simulation based on LAMMPS (AISL) to support the simulation research of XFEL radiation damage to materials using molecular dynamics methods.MethodsAISL was designed to facilitate high-throughput automated studies on XFEL radiation damage by exploring the process of radiation-induced defects and promoting the accumulation of data for radiation-resistant materials. This software package established an automated workflow pipeline for simulation tasks, encompassing aspects such as batch submission management, scheduling of simulation tasks, reliable storage of computational data, and post-processing of thermodynamic information. Additionally, the metadata was automatically recorded in a radiation damage simulation database based on MongoDB, so were the workflow information, and calculation result files of the simulation. Finally, the utilization of AISL in simulating radiation damage in metal thin films of XFEL optical components was demonstrated to verify the validation of AISL.Results & ConclusionsThe demonstration results indicate that AISL is an effective, user-friendly software for conducting high-throughput automated irradiation simulation studies. It significantly enhances the efficiency of material irradiation damage simulation calculations using LAMMPS.  
        关键词：XFEL;Radiation damage;LAMMPS;Workflow;Database   
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      • “在核辐射探测领域，无铅双钙钛矿Cs2AgBiBr6材料备受关注。研究发现，Cu+掺杂能显著提高其稳定性和光电转换率。专家基于第一性原理，采用密度泛函，模拟研究了Cu+掺杂对Cs2AgBiBr6结构和电学性能的影响。结果表明，掺杂后材料稳定性提高，能带间隙缩短，具有更优的电学性能，可作为半导体辐射探测器的候选材料。”
        PAN Yangxuan,LIU Yibao,WEI Qianglin,ZHANG Zixiong,LI Kaixuan
        Vol. 47, Issue 4, Article number: 040503(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040503
        摘要：BackgroundLead-free double perovskite Cs2AgBiBr6 has garnered significant attention in the field of nuclear radiation detection as an environmentally friendly material. Experimental observations have revealed that doping Cs2AgBiBr6 with Cu+ significantly enhances the material's stability and photoelectric conversion efficiency.PurposeThis study aims to investigate the impact of Cu+ doping on the crystal structure and electrical properties of Cs2AgBiBr6.MethodsBased on density functional theory, first-principles calculations were applied to exploring the effects of Cu+ doping on the structure and electrical properties of Cs2AgBiBr6. Structural properties, such as the stability, doping formation energy, lattice parameters, elastic constants, of Cu+ doping on the lead-free double perovskite Cs2AgBiBr6 were investigated by simulation whilst the band analysis and density of states analysis were employed to study the impact of electrical performance.ResultsThe results indicate that Cu+ doping enhances the stability of Cs2AgBiBr6. The Cs2Ag1-xCuxBiBr6 compounds formed by doping, as well as the original Cs2AgBiBr6 material, exhibit indirect bandgap semiconductor behavior. The bandgap significantly narrows with an increase in the Cu+ doping ratio. Based on an analysis of the density of states (DOS), the bandgap narrowing can be attributed to the downward shift of the conduction band minimum dominated by Bi6p orbitals due to Cu+ doping.ConclusionsCs2Ag1-xCuxBiBr6 exhibits greater stability and superior electrical properties compared to Cs2AgBiBr6, making it a promising candidate material for semiconductor radiation detectors.  
        关键词：First-principles calculations;Cs2Ag1-xCuxBiBr6;Nuclear radiation detection;Electronic structure;Cu+ doping   
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      • “在磁场控制领域，研究者通过建模分析，验证了多TSR线圈协同控制偶极场线圈姿态的可行性，为磁场控制研究开辟了新方向。”
        WANG Zhao,LIU Teng,DU Junjie,LIU Yunhui,ZHANG Guoshu
        Vol. 47, Issue 4, Article number: 040504(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040504
        摘要：BackgroundWhen the suspended dipole field coils experience significant disturbances during the operation of the suspended dipole field device, the Tilt-Slide-Rotate (TSR) coils are used to control the attitude of the dipole field coils, thereby preventing them from losing control.PurposeThis study aims at attitude control of dipole fields by coil forces of the TSR coils with relatively complex geometric structures.MethodsBased on the line segment approximation method, the modeling and analysis were conducted for scenarios where the dipole field coils return to their balanced position under conditions of dipole field tilt and offset by controlling the magnetic forces generated by the TSR coils on both opposite and same sides. The coupling magnetic field between the TSR coils and the dipole field coils was calculated, and the magnetic field line structure was analyzed. The excitation magnetic field of the TSR coils, in the form of sinusoidal currents, was simulated to induce azimuthal magnetic disturbances. Analysis was performed on the magnetic field line structure and phase of the perturbation magnetic field on the Poincaré section at the equatorial plane. [Results and Conclusions] If only one group of TSR coils on the same or opposite sides is used to control the dipole field coils to restore equilibrium, exhibited mechanical instability needs necessitating coordinated control by multiple sets of TSR coils. Applying pseudo-sinusoidal currents to all TSR coils induces compression and stretching effects on the background dipole magnetic field. By controlling the current of the TSR coils to control the phase of the compression position, the feasibility of controlling the attitude of the dipole field coils with multiple TSR coils has been validated. However, this process may also cause drift in the background magnetic field and the formation of open magnetic field lines, which could drive plasma instabilities and lead to particle loss.  
        关键词：Line segment approximation method;Arbitrary curve loop current;Equilibrium analysis;China Astro-Torus No.1   
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        NUCLEAR ENERGY SCIENCE AND ENGINEERING

      • “在小型模块化熔盐堆热量传输领域，专家采用数值模拟方法，建立了印刷电路板式换热器流动传热特性的预测模型，为换热器设计提供理论基础。”
        DING Mengting,CHEN Yushuang,FU Yuan
        Vol. 47, Issue 4, Article number: 040601(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040601
        摘要：BackgroundThe printed circuit heat exchanger (PCHE) has high heat transfer efficiency and compact structure, which can be used as the key equipment for heat transfer of small modular molten salt reactor, It is of great significance to the study of its flow heat transfer characteristics.PurposeThis study aims to explore the heat transfer characteristics of printed circuit heat exchanger and compare numerical simulation result with experimental data.MethodsThe flow heat transfer characteristics of molten salt (FNaBe) -helium heat exchangers with different flow channel structures, fin types and pitch were obtained by CFD numerical simulation, and the results were compared with those of traditional straight channel structures for comprehensive evaluation. The main thermal performance parameters of the heat exchanger with various airfoil fin structures were verified by experiment to find the best structure.ResultsThe results show that the numerical simulation results are in good agreement with the experimental results. Compared with the traditional straight channel structure, the fins can strengthen the heat transfer characteristics of the heat exchanger and reduce the flow resistance. NACA0025-8 mm airfoil fin structure has the best flow heat transfer characteristics.ConclusionsThe numerical simulation method established in this study can be used to predict the flow heat transfer characteristics of printed circuit heat exchanger. The empirical correlation formula of NACA0025-8 mm airfoil fin structure is fitted, which provides a theoretical basis for the design of subsequent heat exchangers.  
        关键词：Printed circuit heat exchanger;Molten salt;Thermal-hydraulic performance;Numerical simulation   
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      • “在铅冷快堆非能动余热排出系统设计领域，专家采用MBSE方法，通过需求分析、功能分析和设计综合，提高了设计效率，降低了风险。”
        TANG Mao,ZHAO Pengcheng,LI Wenjie,WANG Kai
        Vol. 47, Issue 4, Article number: 040602(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040602
        摘要：BackgroundTraditional text-based system engineering in the design and application of passive residual heat removal systems (PRHRS) for lead-cooled fast reactors has several requirement problems, such as low development efficiency, a long iteration cycle, and model ambiguity.PurposeThis study aims to effectively address the aforementioned problems encountered in the PRHRS of lead-cooled fast reactors by adopting a model-based system engineering method.MethodsThe model-based system engineering (MBSE) method was preliminarily applied to the design requirement analysis of a PRHRS for lead-cooled fast reactors. During the design requirements study, the design process was combined with the preliminary design of the system architecture, comprising three parts: requirements analysis, functional analysis, and design synthesis.ResultsThe generated requirement and use case diagrams describe the system requirements and determine the top-level use cases of the system in the requirement analysis stage. The time sequence, activity, and state machine diagrams form the system function model and provide early confirmation and verification in the functional analysis stage. Finally, the white box model realizes the analysis and design of the system architecture in the design synthesis stage.ConclusionsThe system architecture designed by this method ensures the consistency of the design requirements. In the future, it will further reduce the design risk, improve the design efficiency, and provide an application reference for the design and optimization of digital lead-cooled fast reactors' passive residual heat removal systems.  
        关键词：MBSE;Lead-cooled fast Reactor;Passive residual heat removal system;Design requirement;Architecture design   
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      • “在核电站严重事故研究领域，专家利用MAAP程序建模，分析了不同源项释放模型对放射性污染的影响，为控制源项释放提供解决方案。”
        YUAN Xianbao,PENG Jueqin,ZHANG Binhang,MAO Zhangliang,TANG Haibo,WEI Jingyu,ZHOU Jianjun
        Vol. 47, Issue 4, Article number: 040603(2024) DOI: 10.11889/j.0253-3219.2024.hjs.47.040603
        摘要：BackgroundDuring severe reactor accidents, melten core causes the radioactive source term material to be no longer retained in the fuel but is released into the environment, causing serious radioactive contamination in the surrounding areas.PurposeThis study aims to investigate the release of fission products, both inside and outside the pressure vessel, using different models in order to analyze the effectiveness of the spray system in controlling the source term release and the decay heat generated.MethodsBased on a typical mega kilowatt pressurized water reactor (PWR) nuclear power plant model, the integrated security analysis program MAAP was applied to modeling reactor rupture accident. Then, the accident sequence and consequences of the reactor primary circuit heat pipe breakage superimposed high and low voltage safety injection failure were calculated and analyzed under CORSOR-M, CORSOR-O and ORNL-BOOTH source term release models.ResultsThe findings indicate that the fission product source term is mainly released in the pressure vessel, and the release amount is significantly higher than that released outside the pressure vessel. Under the CORSOR-O model, the pressure vessel fails the last whereas the containment fails the first; although the pressure vessel fails first in the ORNL-BOOTH model, the containment vessel fails much later than that in the other two models. The difference in source term release leads to different decay heat phenomena in different models, and the main heat source is the volatile fission product. Turning on the spray can not only keeps the suspended iodide in the containment vessel but also effectively removes the decay heat generated by the source items and reduces the pressure of containment.ConclusionsThe ORNL-BOOTH model results in lesser release of source term in the pressure vessel, the greatest variety of source term released, and the maximum time to containment failure. In addition, the opening of the spraying system effectively ensures the integrity of the containment.  
        关键词：Breaching accident;Fission product source term;Failed containment;Spray system;Decay heat   
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