最新刊期
      卷 43 ， 期 10 ， 2020

        SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS

      • “在高能同步辐射光源领域，专家通过模拟分析，建立了Nd2Fe14B磁阵列辐照剂量和退磁的关系，为解决退磁问题提供解决方案。”
        LIU Pingcheng,LIU Qiongyao,MA Zhongjian,ZHANG Huijie,YAN Mingyang,WANG Qingbin
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100101
        摘要：BackgroundIn synchrotron radiation facilities, the insertion devices are installed on the storage ring to produce high brightness, high coherence, and adjustable polarization synchrotron radiation, which are composed of periodic permanent magnet arrays. The permanent magnets are continuously exposed to beam loss electrons due to the Touschek effect. As a result, the permanent magnets can be more or less damaged and deteriorates the magnetic field of insertion devices. Radiation-induced demagnetization of permanent magnets in the insertion device is one of the critical issues for synchrotron radiation facilities.PurposeThis study aims to simulate the irradiation field and radiation damage of the Nd2Fe14B permanent magnet insertion devices during the routine operation of the high energy photon source (HEPS).MethodsFirst of all, Monte Carlo code FLUKA was utilized to calculate the relationship between the absorbed dose and demagnetization of Nd2Fe14B magnet array based on the Spring-8 experiment. Then the different electronic sampling modes were set to calculate the irradiation field in the insertion device according to the actual beam loss conditions at HEPS. Finally, the demagnetization and countermeasures were analyzed according to the spatial distribution of absorbed dose.ResultsWhen HEPS works in top-up mode, the irradiation of the magnetic pole in the upstream end of the insertion device is more severe. Most of the absorbed dose (about 99.7%) is contributed by photon, electron and positron. According to the beam loss parameters by physical calculation, the expected life of the insertion device is 2.1 to 4.6 years.ConclusionsPlacing local shielding layer and increasing the gap are the effective measures to protect the insertion devices, hence slow down radiation demagnetization of permanent magnet.  
        关键词：Demagnetization;Permanent magnet;Insertion device;HEPS;FLUKA   
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        发布时间：2024-10-25

        ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS

      • “中子共振技术在核检测领域取得显著进展，专家总结了国内外研究状况，并展望了发展趋势。”
        TUO Xianguo,LIU Fule,WANG Qibiao,DENG Chao,SHI Rui,MU Keliang,NIU Jiang
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100201
        摘要：BackgroundNeutrons play an important role in nuclear detection applications, and make up for the shortcomings of X-ray detection insensitivity to the atomic number. In a specific energy range, the cross section of neutron reaction varies drastically with the neutron energy, and resonance occurs. The resonance spectrum of nuclides is unique, and qualitative and quantitative analysis of nuclides can be carried out based on this. Among them, the resonance energy range of medium-heavy nuclei is in the eV~keV energy range, which is an important part of neutron resonance analysis.PurposeDue to the lack of conclusive articles on neutron resonance in medium-heavy nuclei, this paper summarizes the current research on neutron resonance.MethodsBy querying a large number of journal papers and books related to neutron resonance, the theory and application of neutron resonance of medium and heavy nuclear are summarized.Results & ConclusionsAt present, there have been many research results, and they have been widely used in temperature measurement, imaging, non-destructive analysis, nuclear data measurement, and other aspects. In this regard, by reviewing the literature and books on neutron resonance, the research status of neutron resonance at domestic and overseas are summarized and analyzed, and its development tendency is forecast.  
        关键词：Neutron resonance;Medium-heavy nucleus;Research status;Nondestructive testing   
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        发布时间：2024-10-25
      • “螺旋γ扫描技术新进展，THGS提高放射性废物桶测量精度，误差控制在50%以内。”
        TANG Xinhai,GU Weiguo,YANG Hui,WANG Dezhong
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100202
        摘要：BackgroundHelical gamma scanning (HGS) is one of non-destructive assay (NDA) for the measurement of radioactive waste drum. However, the accuracy of HGS in measuring the heterogeneous radioactive waste is poor.PurposeThis study aims to evaluate the performance of two-measurement position helical gamma scanning (THGS) for a 400-liter high density waste drum.MethodsOn the basis of HGS, THGS adds eccentric helical scanning measurement. The equivalent radius of the radioactive source in the waste drum was determined by the ratio of the counting rate of the two positions. Finally, the activity of the radioactive source was reconstructed. The reconstruction process of three radionuclides in 400-liter waste drum was simulated by numerical calculation method to verify the accuracy of THGS.ResultsFor a single line source in high density 400-liter waste drum, the maximum reconstruction error of HGS is more than 400%, while that of THGS is less than 50%. When two detectors are used, the measurement time of THGS is the same as that of HGS.ConclusionsTHGS is suitable for measuring 400 L-waste drum whose density is high.  
        关键词：HGS;Two-measurement position;Equivalent source;Radioactive waste drum   
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        发布时间：2024-10-25

        NUCLEAR ELECTRONICS AND INSTRUMENTATION

      • “在X射线管研究领域，专家利用蒙特卡罗方法模拟微形结构靶对出射光斑的影响，发现微锥形银靶结构可显著减小光斑尺寸，提高成像精度。”
        ZUO Zhuo,HE Xing,ZHANG Song,YAN Yucheng,QIN Jun
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100401
        摘要：BackgroundMicro target X-ray source has attracted much attention in X-ray microscopy imaging. The focus spot size of X-ray directly affects the spatial resolution of sample.PurposeThis study aims to investigate the influence of target materials and target microstructures on the emission spot of X-ray tube by simulation. The influence of different target materials on the focus size of X-ray tube is also discussed.MethodsMonte Carlo simulation code MCNP5 was employed to calculate the focus size with five different target materials, i.e., Mn, Mo, Silver, Rt, Wu and three different target microstructures, i.e., hemisphere, cone and cylinder. The full width at half maximum (FWHM) of the light intensity distribution line was used as the standard to measure the spot size.ResultsThe results show that the minimum focus size can be achieved by micro cone structure target at the incident electron energy of 100 keV. Moreover, different target materials have obvious influence on the focus size behind the target. The focus size decreases with the increase of the atomic number of the target material at the beginning, but expands to a certain extent with the further increase of the atomic number, showing a suppression trend. The influence of different target microstructures on the focus size is obviously related to the target type. The difference of focus size between cylinder and cone is up to 30 μm. Compared with the cylindrical tungsten target, the spot size decreases by 17.93% by using micro cone target structure and the silver target.ConclusionsCompared with the traditional transmission X-ray tube, the micro target X-ray tube is easy to implement because it does not need strong electron focusing equipment. The methodology and the Monte Carlo simulation results are valuable for guiding the design and optimization of micro target X-ray tube source.  
        关键词：Micro target X-ray tube;Target material;Focus size;Monte Carlo stimulation   
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        发布时间：2024-10-25
      • “在核电安全领域，专家研制了一种新型监测装置，可快速准确监测放射性惰性气体活度浓度，及时发现泄漏，确保核电站安全运行。”
        HU Changli,GAI Wenjia,REN Cai,WANG Juzhi,JIANG Hao,WAN Xinfeng,DAI Chuanbo,WANG Dongqin,SUN Guangzhi
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100402
        摘要：BackgroundAfter the Fukushima nuclear accident, China's nuclear power authorities have put forward new requirements for the safety management of nuclear facilities in operation. A variety of radioactive inert gases are produced in nuclear power plant (NPP) accidents.PurposeThe aims of this study is to develope a special inert gas monitoring device for NPP.MethodsWith the combination of flow gas differential detection component and local processing/display unit, a fixed inert gas monitoring device was developed by integrating the relevant detection device, filter device, gas sensing instrument (flowmeter, pressure gauge), sampling pipeline, valve (stop valve and regulating valve), sampling joint and various components together on this fixed equipment platform. The sensitivity of the detector was predicted by using simulation software MCNP to ensure the satisfaction of requirements.ResultsThe fixed inert gas monitoring device developed in this study not only preserves all functionalities, optimizes the measurement index, but also reduces the volume and weight. Compared with the similar equipment, the integrated layout is convenient for maintenance and management with better performance index, smaller volume and lighter weight.ConclusionsThis device canbe employed to monitor the activity concentration of radioactive inert gas in the environment more quickly and accurately, find the leakage of radioactive gas in the nuclear power plant in time, and ensure the safe operation of the nuclear power plant and the radiation safety of the field personnel.  
        关键词：Nuclear facilities;Inert gas;Flow gas differential;Integrated;Detection device   
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        发布时间：2024-10-25

        NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH

      • “在空间辐射探测领域，专家设计了基于硅微条半导体的多叠层望远镜结构探测器，可实现0.01~100 MeV·cm2·mg-1内LET谱的探测，为载人航天任务提供数据支持。”
        AN Heng,WEN Xuan,LI Detian,WANG Yi LI Cunhui,YANG Shengsheng,QIN Xiaogang WANG Jun,ZHANG Chenguang,CAO Zhou
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100501
        摘要：BackgroundAccurate detection of the linear energy transfer (LET) spectrum of space radiation particles plays an important role in long-term space missions, such as the moon landing plan and the space station operation.PurposeThis study aims to obtain effective parameters such as dose equivalent through real-time monitoring of the LET spectrum of space radiation particles, providing powerful data input for the safety of astronauts in manned space missions and the accurate prediction of space weather changes.MethodsBased on the LET spectrum of heavy ions in semiconductor materials and the simulation analysis data, detection technology and design analysis of LET spectrum of space radiation particles were carried out. A multi-stack telescope structure detector based on silicon micro strip semiconductor with multi-layer stack was designed to detect the LET spectrum in the range of 0.01~100 MeV·cm2·mg-1.Results & ConclusionsThis design of LET spectrum detector can provide technical reference for the design and development of particle detection load in the follow-up space station and moon landing mission, and can also provide necessary data input for the safety early warning of spacecraft in orbit.  
        关键词：Space LET spectrum;Detection load;Space station;Deep space exploration   
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        发布时间：2024-10-25
      • “在氢同位素分离领域，石墨烯与SPE电解法结合，显著提升分离系数，为高效分离技术提供新思路。”
        WEI Fei,TANG Fangdong,LIU Jiayu,XIN Zhiwei,ZENG Youshi,CHU Xinxin,LIU Wei
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100502
        摘要：BackgroundAs a new type of high-selective permeable membrane material, graphene is expected to improve the separation effect of solid polymer electrolyte electrolysis (SPE) on hydrogen isotopes.PurposeIn this study, graphene was combined with the proton exchange membrane in SPE electrolysis to explore the effect of its separation performance for hydrogen isotopes.MethodsBased on the B3LYP/6-31G (d) theory, quantum chemistry calculation software Gaussian 09 was used to calculate the penetration barrier of the graphene model to protons. At the same time, the effect of zero-point vibrational energy was taken into account to obtain the separation coefficient of graphene for hydrogen isotope ions.ResultsThe computation results of the separation coefficients of H+/D+ and H+/T+ are 12.4 and 37.5, respectively, at room temperature (293 K). The research resultants indicate that the optimized model structure and the presence of different types of defects reduce the penetration barrier of protons, the existence of Stone-Wales defect does improve the separation performance.ConclusionsGraphene can be used to effectively improve the separation coefficient of hydrogen isotopes in SPE electrolysis, which is expected to promote the establishment of truly efficient hydrogen isotope separation technology.  
        关键词：Graphene;Hydrogen isotope separation   
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        发布时间：2024-10-25

        NUCLEAR ENERGY SCIENCE AND ENGINEERING

      • “在熔盐空间堆发电系统领域，专家设计了翅片式熔盐通道与多孔式斯特林内部热接收器，通过数值模拟研究，发现增加翅片可显著提升换热能力，为斯特林加热器设计提供参考。”
        ZHAO Heng,ZOU Yang,DAI Ye,XU Hongjie,ZHANG Jie,HE Fan
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100601
        摘要：BackgroundStirling heater is used for heat capture in the molten salt space reactor power generating system, and its heat transfer performance has a great influence on the output power and efficiency of the space reactor energy conversion system.PurposeThis study aims to improve the heat transfer performance of the heater by numerical simulation of designed fins in molten salt channel and porous Stirling internal thermal receiver.MethodsThe computational fluid dynamics program Fluent was employed to design and optimize the structure of the heater. Thermal-hydraulic characteristics of different fins and molten salt channel types, such as flow field, pressure field and heat flux distribution were simulated and compared.ResultsAdding fins in the molten salt channel can improve the heat transfer performance of the Stirling heater, and with the increase of fin height and the decrease of fin spacing, the heat transfer performance further improves. Compared with radial inlet and tangential inlet, the double-radial inlet and outlet channels have more uniform heat flux distribution and better heat transfer performance.ConclusionsThe results of this study provide useful references for the design of the Stirling heater in molten salt space reactor.  
        关键词：Stirling heater;Structure design;Numerical simulation;Heat transfer performance   
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        发布时间：2024-10-25
      • “在核能领域，专家基于MCNP和MOBAT程序分析了熔盐堆中钍含量对钍铀转换及堆中子学特性的影响，为钍资源核能利用提供解决方案。”
        CHEN Peng,ZHOU Bo,YAN Rui,ZOU Yang
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100602
        摘要：BackgroundThorium-uranium fuel cycle has the advantages of making use of abundant thorium resources, producing less nuclear waste and low toxicity, as well as nuclear non-proliferation. Molten salt reactor is an ideal type of nuclear energy utilization of thorium resources. The amount of thorium added in the core fuel can affect the thorium-uranium conversion performance in the molten salt reactor.PurposeThis study aims to understand the effect of thorium addition on the conversion performance of thorium and uranium in molten salt reactor.MethodsBased on MCNP (Monte Carlo N Particle Transport Code) program, the core physical model was established. The neutron physical characteristics and thorium-uranium conversion characteristics of 2 MW (thermal power) liquid fuel experimental reactor under different thorium additions running at full power for 300 days were analyzed by using MOBAT (burnup code coupled with MCNP and ORIGEN2 using BATch language) burnup program. Analysis objectives included the energy spectrum changes at the beginning and the end of burnup, Xe equilibrium, as well as the consumption ratio and transfer characteristics, and the evolution of important nuclides in thorium uranium chain.ResultsThe results show that the consumption rate of thorium decreases with the increase of added amount. CR raises with the increase of Thorium addition, but the growth rate decrease gradually. The rate at which 233Th concentration reaches the maximum value is linearly related to the thorium mass, and the 233Pa has the same evolution trend as the 233Th. The higher the thorium content in the fuel, the higher the concentration of 233U, and the accumulation of 233U increases with the running time. Based on the radiochemical detection limit, 80 kg thorium can meet the minimum detection value after 4 days.ConclusionsBased on the data of thorium-uranium conversion, the amount of uranium fuel needed to maintain the back-up reactivity, the limit of radiochemical detection and other factors, the experimental reactor can carry out the utilization of thorium in the order of tens to hundreds of kilograms and the verification experiment of Thorium-Uranium cycle, with the priority of about 80 kg. In addition, the more thorium was added, the more Uranium needed to be added. The increase of 135I concentration will increase the equilibrium concentration of Xe. The more thorium is added, the harder the neutron spectrum and the higher the 233U output will be, which means that it is easier to achieve transformation or proliferation under the fast neutron spectrum.  
        关键词：Consumption rate;Thorium-uranium chain;Thorium-uranium conversion;Neutron energy spectrum;Proliferation   
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        发布时间：2024-10-25
      • “中国聚变工程试验堆诊断窗口电磁载荷研究取得进展，为装置结构稳定性提供解决方案。”
        PEI Kun,WANG Ming,LU Mingxuan,LU Kun
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100603
        摘要：BackgroundChina fusion engineering test reactor (CFETR), a fully superconducting tokamak device designed and developed in China, aims to solve the physical and engineering problems between international thermonuclear experimental reactor (ITER) and the DEMO. The diagnostic port plug is a key part of the CFETR device and its internal diagnostic system can realize the monitoring and feedback control of the device's operating parameters. As the diagnosis port plug is close to the plasma area, the huge electromagnetic (EM) load induced on this component during the plasma disruption will affect the stability of the device structure.PurposeThis study aims to analyze the EM load on equatorial diagnostic port plug (EDPP) under different EM conditions.MethodsFirst of all, the conceptual design of EDPP was completed according to the requirements of CFETR diagnostic system. Then, the EM loads of 10 MA plasma under linear and exponential conditions were evaluated using the commercial finite element analysis software ANSYS. Finally, the effects of the integrated and distributed scheme designs on the EM load distribution of the EDPP were discussed.Results & ConclusionsThe results show that the maximum stress generated on the EDPP with an integrated or distributed design are both less than 10 MPa, which meets the design requirements. In addition, the maximum EM load on the EDPP shows that the plasma linear disruption is greater than the exponential disruption.  
        关键词：CFETR;EDPP;MEC;EM load   
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      • “在核能系统领域，专家采用SCALE6.1程序研究钍基气冷快堆燃耗特性，为换料方案提供参考。”
        HAN Dong,ZOU Chunyan,CAI Xiangzhou,CHEN Jingen
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100604
        摘要：BackgroundAs one of the reactor types selected by the fourth generation nuclear energy system international forum, gas-cooled fast reactor has the advantages of high temperature gas cooled reactor and fast reactor, with high breeding rate and short fuel-doubling time.PurposeThis study aims to analyse the neutronic characteristics of different fissile nuclides in operation using the TRITON module in SCALE6.1.MethodsFirstly, the changes of breeding rate and fissionable nuclides with burnup were analyzed. The breeding performance of fissionable nuclides was weighted according to the characteristics of gas-cooled fast reactor. Then, the difference of doubling time between two different evaluation methods of breeding rate and weighted breeding gain were compared. Finally, the doubling time was optimized by using an equivalent start-up method.Results & ConclusionsThe results show that the analysis of the doubling time of different fissionable nuclides using weighted breeding gain and equivalent elimination mass difference can describe the breeding characteristics of fast reactors more accurately, providing a reference for the refueling scheme of thorium-based gas-cooled fast reactor.  
        关键词：Thorium-based gas-cooled fast reactor;Breeding ratio;Breeding gain;Doubling time   
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        发布时间：2024-10-25
      • “在核能领域，专家搭建实验装置，研究了高温含铍熔盐颗粒的粒径分布特征，为监测和去除提供解决方案。”
        LIU Lizhi,FU Haiying,LIU Zhongying,MA Jifei,DU Lin,TANG Xiaoxing,QIAN Yuan,YAO Jian,LI Yulan
        Vol. 43, Issue 10, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.100605
        摘要：BackgroundBeryllium bearing molten salt has strong chemical toxicity, hence needs to be accurately monitored and effectively removed at high temperature.PurposeThis study aims at the characteristics of particle size distribution of high temperature FLiBe molten salt.MethodsBased on the experimental device of low pressure distillation of molten salt and Dekati low pressure impact sampler (DLPI), an experimental device for measuring the particle size of high temperature molten salt particles was set up, and the particle size distribution of FLiBe molten salt under different experimental conditions was studied. The effect of gas purging and different sampling time on the particle size distribution of molten salt particles under high temperature were investigated, and scanning electron microscope (SEM) was employed to examine the experimental measurement results.Results & ConclusionsThe experimental results show that the particle size of the molten salt particles is concentrated above 2.5 μm at room temperature, while at high temperature, it is concentrated at 0.26~2.5 μm. The sampling time has no obvious influence on the particle size distribution of molten salt particles; although the final concentration of molten salt particles is changed by gas purging, it does not significantly affect the particle size distribution. The SEM results of the collected samples verify the accuracy of the particle size scale of the experimental device, and it is observed by SEM that the molten salt particles are in the shape of regular spherical rather than crystalline, which may be caused by the collision and deposition of molten salt particles.  
        关键词：TMSR;FLiBe;High temperature molten salt;Particle size distribution   
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