最新刊期
      卷 43 ， 期 5 ， 2020

        SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS

      • “在同步辐射光束线调束领域，专家建立了智能优化模型，验证了差分进化算法，为解决调束效率问题提供解决方案。”
        SHI Yingzhi,GAO Mei,JIA Wenhong,YIN Guangzhi,GAO Xingyu,DU Yonghua,ZHENG Lifang
        Vol. 43, Issue 5, Article number: 050101(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050101
        摘要：BackgroundIn synchrotron radiation facilities, it is important to keep beamlines operating in optimal conditions. The debugging process is normally very time consuming due to the irregular light source beam point, and it is not easy to get global optimum.PurposeThis study aims to develop an intelligent debugging system based on Experimental Physics and Industrial Control System (EPICS) and differential evolution algorithm for synchrotron radiation beamline commissioning.MethodsFirst of all, based on the differential evolution algorithm, intelligent optimization model of beamline was established. Then the automatic optimization of beam adjusting process was implemented by using LabVIEW program and communication with the EPICS-based control system was achieved by CaLab interface module. Functions of the user interface, motion control, algorithm implementation and evolution processing were integrated in the LabVIEW program. Finally, this intelligent commissioning system was tested at the X-ray diffractive (XRD) beamline of SSRF (Shanghai Synchrotron Radiation Facility) for optimization of the beam flux at sample position by adjusting the beamline optical components.Results & ConclusionsOnline tests results show that this intelligent commissioning system converges to the optimal solution quickly, and the convergence time is about 30 min, more than one order of magnitude higher than manual optimization efficiency.  
        关键词：Differential evolution algorithm;Synchrotron radiation beamline;Intelligent optimization;EPICS   
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        发布时间：2024-10-25

        ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS

      • “在辐射防护领域，研究人员设计了无铅防护材料，有效屏蔽X射线，避免铅中毒，为放射性从业人员提供高效舒适的防护装置。”
        YAN Siqi,CHENG Peng,YU Guangyi,LIU Hanzhou,FEI Churan,OUYANG Xiaoping
        Vol. 43, Issue 5, Article number: 050201(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050201
        摘要：BackgroundThe number of radioactive practitioners has increased rapidly due to the wide application of X-ray, resulting in widespread attention to radiation protection. Lead is commonly used as a shielding material, but is extremely toxic and harmful to human health. The lead-based protective clothing on the market is too heavy and uncomfortable to wear.PurposeThis study aims to design flexible composites of lead-free for shielding X-ray of different energy ranges and evaluating its shielding effect.MethodsThe X-ray mass attenuation coefficients of high atomic number materials were calculated according to National Institute of Standards and Technology (NIST) method. Hence, the ideal functional fillers were selected as shielding materials instead of lead. The MCNP5 code was employed to evaluate protective performance of lead-free flexible composites consisting of various doped metal elements with high atomic number.ResultsSimulation results show that Bi doping is an ideal substitute for Pb doping, and Bi2O3 can be used as the first-rate functional filler in lead-free flexible composites. Shielding performance of the composite doped with Bi2O3 and Gd2O3 is obviously improved during the energy of 54~66 keV whilst the composites doped with Bi2O3 and W functional fillers achieve the best X-ray attenuation at around 70 keV of X-ray.ConclusionsA variety of bismuth-based flexible composites have been designed to replace lead-based materials. Bi2O3 is the optimal filling material for X-ray scattering energy less than 54 keV, incorporation of two functional materials, Bi2O3 and Gd2O3, can effectively improve the absorption effect of the composites for X-ray scattering energy in range of 54~66 keV. In the energy range of 66~100 keV, incorporation of two functional materials, Bi2O3 and W, is the optimal filling method whilst it is best to fill Bi2O3 alone to shield X-ray scattering energy greater than 100 keV.  
        关键词：Lead-free;Flexible material;Radiation protection;Different X-ray energy   
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        发布时间：2024-10-25

        NUCLEAR CHEMISTRY, RADIOCHEMISTRY, RADIOPHARMACEUTICALS AND NUCLEAR MEDICINE

      • “在正电子发射断层成像领域，利用一体化PET-MRI数据，基于MRI图像分割参考区域计算SUVR，提高了准确性和一致性，消除了个体差异。”
        LI Zaisheng,SONG Shuangshuang,ZENG Tianyi,LU Jie,HU Lingzhi,CHEN Qun
        Vol. 43, Issue 5, Article number: 050301(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050301
        摘要：BackgroundIn clinical application and scientific research of positron emission tomography (PET), the standard uptake value (SUV) is commonly used for disease assessment. In order to reduce the deviations of SUV among clinical PET images, standard uptake value ratio (SUVR) based on a specific reference region is substituted for SUV. Accurate SUVR is hardly achieved directly from PET images due to the difficulty of accurately segmenting reference regions from PET images with low resolution and high noise. The integrated positron emission tomography-magnetic resonance imaging (PET-MRI) can simultaneously acquire MRI images and PET images, hence the combination of MRI image and PET image is expected to improve the accuracy of SUVR.PurposeThis paper study aims to investigate the effect of MRI segmentation and PET segmentation on SURV calculation to improve the PET-MRI brain quantitative accuracy.MethodsFirst of all, integrated PET-MRI was used to acquire MRI and PET images of 12-age-controlled healthy volunteers simultaneously. Then the MRI images and PET images were segmented into reference regions by the atlas-based method. Based on reference regions derived from MRI and PET respectively, the SUVRs of left / right cerebrum, cerebral cortex, cerebral white matter, frontal lobe, parietal lobe, temporal lobe and occipital lobe were calculated. For each group of SUVRs, the coefficient of variation (CV) of SUVRs was calculated to measure consistency level. Finally, quantitative analysis was performed to evaluate which segmentation method offered better SUVR consistency among volunteers.ResultsCV of SUVRs based on cerebellar gray matter from MRI images and PET images were 0.020/0.021, 0.023/0.026, 0.031/0.028, 0.028/0.031, 0.033/0.036, 0.022/0.024, 0.044/0.045 and 0.052/0.055, 0.054/0.055, 0.058/0.063, 0.053/0.058, 0.063/0.065, 0.048/0.050, 0.059/0.065 respectively. When the cerebellum was chosen as reference region, MRI results and PET results were 0.017/0.019, 0.021/0.025, 0.029/0.025, 0.026/0.030, 0.032/0.036, 0.020/0.022, 0.044/0.045 and 0.046/0.050,0.049/0.051, 0.052/0.057, 0.048/0.054, 0.059/0.061, 0.044/0.045, 0.056/0.062 respectively.ConclusionsCompared with SUVRs based on reference region segmented from PET images, SUVRs based on reference region segmented from MRI images have better consistency with smaller coefficient of variation.  
        关键词：SUVR;Quantification;PET-MRI;18F-FDG   
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        发布时间：2024-10-25

        NUCLEAR ELECTRONICS AND INSTRUMENTATION

      • “在核电辐射场测量领域，研究人员开发了4π叠层探测器，成功实现了放射性惰性气体的β-γ信号甄别，为测量放射性惰性气体提供了有效工具。”
        ZHOU Dongdong,YOU Simei,XIN Jie,YANG Cuiping,WEN Wanxin,YANG Yue,ZHANG Baoguo,WANG Rensheng,ZHANG Ming
        Vol. 43, Issue 5, Article number: 050401(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050401
        摘要：BackgroundThe radiation field of the radioactive inert gas generated in a nuclear power station is mainly β-γ mixed field. The phoswich detector has good ability to discriminate β and γ rays.PurposeThis study aims to develop a set of 4π phoswich detector to accurately measure the energy spectrum of the mixed field and distinguish β-γ rays.MethodsThe phoswich detector mainly consisted of a hollow cylindrical plastic scintillator EJ-200 with layer thickness of 1 mm and a cesium iodide scintillator CsI (Tl) with side wall thickness of 20 mm overlay on the outer layer of EJ200. The two photomultiplier tubes (PMT) were placed at both end surfaces of the cylinder respectively, and coupled by using silicone oil. The DT5790 dual digital pulse shape analyzer of CAEN company and the digital pulse processing-pulse shape discrimination (DPP-PSD) were used to obtain the detector output signals, and results were processed by ROOT and MATLAB software. Finally the detector was calibrated by use 133Ba and 137Cs radiation sources.Results & ConclusionsThe β-γ signal discrimination is realized by mathematical methods in back end computer software, indicating that the detector is capable of measuring radioactive inert gas.  
        关键词：Radioactive noble gases;4π phoswich detector;Digital pulse processing-pulse shape discrimination;Energy calibration;β-γ discrimination   
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        发布时间：2024-10-25
      • “编码孔径相机探测器研究取得进展，采用大面积CsI(Tl)晶体阵列与光电倍增管阵列耦合，提高探测效率，满足高灵敏度成像设计要求。”
        LI Yan,WANG Qiang,HUANG Xianchao,SHUAI Lei,CAO Daquan,ZHANG Yiwen,YANG Yao,HU Xuanhou,LIANG Xiuzuo,WU Jun,ZENG Guoqiang,ZHANG Zhiming
        Vol. 43, Issue 5, Article number: 050402(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050402
        摘要：BackgroundThe traditional gamma camera cannot locate the contaminated area of nuclear accident, and cannot obtain the information of the contaminated area and degree in real time.PurposeThis study aims to develop a coded aperture gamma camera detector system with large area and high sensitivity.MethodsA detector module of large area CsI (Tl) crystal array coupled with photomultiplier tube array was proposed. It consisted of 121 CsI (Tl) crystals at the size of 15 mm×15 mm×15 mm, and 2×2 array composed of 4 detector modules was taken as γ camera detector. Multi-channel readout electronics composed of amplification, filter shaping and single-to-differential conversion circuit was independently designed for readout processing of detector signals. Finally, the performance of this detector system was evaluated by experimental tests.ResultsThe results indicate that the detector module can achieve the position resolution, and its average energy resolution is 9.4% under the excitation of 662 keV γ-ray.ConclusionsThe detector system can satisfied the design requirements of coded aperture γ camera of high sensitivity in terms of position resolution, energy resolution, uniformity of peak position and detection efficiency.  
        关键词：Position sensitive detector;CsI(Tl) crystal array;Photo multiplier tube;Coded-aperture γ camera   
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        发布时间：2024-10-25

        NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH

      • “在电子设备辐射检测领域，研究人员利用荧光粉作为热释光剂量计，成功测量了电离辐射剂量。”
        ZHAN Mingliang,CHEN Yaoyao,XU Zhuo,XIONG Zhengye
        Vol. 43, Issue 5, Article number: 050501(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050501
        摘要：BackgroundPhosphor has become an important object of study in recent years due to their applications as potential laser crystal materials and packaging light emitting diode (LEDs). Phosphors are widely used in electronic devices, their effect of ionizing radiation to some electronic equipment needs to be evaluated in some conditions. One of the effective methods to measure the dose of ionizing radiation is thermoluminescence (TL).PurposeThis study aims to investigate a kind of phosphor which can be directly used as a thermoluminescent dosimeter.MethodFirst of all, green light emitting phosphors YGaAG:Ce(Y2.96Al3.4Ga1.6O12:0.04Ce) was prepared by the solid phase reaction method, and linear heating rate TL of the phosphor was measured. Then the linear heating rate method coupled with glow curve deconvolution (GCD) was used to calculate the activation energy and the frequency factor of electron traps within phosphor YGaAG:Ce. Finally, the dose response was measured systematically.ResultsMeasured results show that there is only one remarkable and broad thermoluminescence peak in TL curve, and the temperature of this peak is about 185 °C. Four traps are identified in the phosphor, and the activation energies are 0.83 eV, 0.99 eV, 1.15 eV and 1.23 eV, respectively, and the corresponding frequency factors are 0.98×1010 Hz, 1.28×1011 Hz, 1.41×1012 Hz and 1.45×1012 Hz, respectively. The TL response of the phosphor has good linearity in a large dose range (0.1~200 Gy), and the sensitivity of TL is about 2 mGy.ConclusionsThe research findings show that phosphor YGaAG:Ce has a broad application prospect in the radiation dose detection of electronic equipment.  
        关键词：Phosphor;Thermoluminescence (TL);Trap;Dosimeter;Garnet   
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        发布时间：2024-10-25
      • “在低密度天然气水合物地层勘探领域，专家推导出基于宽束γ射线的密度测井响应模型，为精确测量提供理论及方法基础。”
        YANG Ningning,ZHANG Yuxin,YU Huawei
        Vol. 43, Issue 5, Article number: 050502(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050502
        摘要：BackgroundWith more and more attention paid to low-density gas hydrate formation, higher requirements are raised for density measurement range and accuracy of density logging.PurposeThis study aims to improve the accuracy of density logging in low-density formation by using board beam attenuation model.MethodsFirstly, the attenuation law of γ-ray narrow beam used for density logging was analyzed. Secondly, a response model based on broad-beam γ-ray density logging was derived by combining with the broad-beam γ-ray attenuation law, hence the calculation formula of formation density was obtained by scaling. Finally, the Monte Carlo N Particle Transport Code (MCNP) was used to simulate the density logging response in low-density formation, meanwhile, the application scope and accuracy of two attenuation laws in density logging were compared and analyzed.ResultsThe response relationship of gamma rays in the formation can be better described by the broad beam attenuation model in density logging, while the narrow beam response relationship is only a special case of broad beam. By using the formation density formula based on the broad beam γ attenuation model, the density measurement range is expanded to 1.00~3.00 g∙cm-3. Furthermore, for gas hydrate formation with density ranging from 1.00 g∙cm-3 to 1.60 g∙cm-3, its average measurement error of the far detector is reduced from 0.092 g∙cm-3 to 0.009 g∙cm-3, and that of the near detector is reduced from 0.251 g∙cm-3 to 0.029 g∙cm-3.ConclusionsThe board beam γ-ray attenuation model can be used to greatly improve the accuracy and measuring range of density logging, and this provides theoretical and methodological basis for accurate measurement of gamma ray density logging in low-density formation in the future.  
        关键词：Density logging;Broad beam γ attenuation;Monte Carlo simulation;Low-density formation   
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        发布时间：2024-10-25
      • “在半导体器件领域，研究人员探索了高压VDMOS的抗辐射能力快速评估方法，通过高温辐照缩短了测试周期，为高压VDMOS器件的抗电离辐射能力评估提供了解决方案。”
        CUI Shuai,WANG Yiyuan,LI Cai,LU Jian,CHEN Bin
        Vol. 43, Issue 5, Article number: 050503(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050503
        摘要：BackgroundVertical Double-diffused MOSFET (VDMOS) is widely used in space equipment, its radiation resistance needs to be evaluated due to ionizing radiation in space environment. According to the national military standard, the normal stipulated method of normal temperature irradiation with additional 50% dose and 168 h high temperature annealing has a long test period for evaluating ionizing radiation evaluation of VDMOS.PurposeThis study aims to shorten the test period by developing a fast method to evaluate the ionizing radiation effect of VDMOS.MethodsHigh temperature irradiation was adopted for high voltage VDMOS ionizing radiation experiments. Radiation resistance of typical VDMOS digital circuits in large dose range at the temperature of 100 °C was compared with the results of the National Military Standard test.ResultsExperimetial results show that the high temperature radiation test for evaluating the radiation resistance of high voltage VDMOS in a larger dose range has quivalent effect to the national military standard method but save 168 h of annealing time.ConclusionsHigh temperature irradiation can be used as rapid evaluation method for ionizing radiation resistance of high voltage VDMOS devices.  
        关键词：VDMOS;Ionizing radiation effect;Assessment methods;Elevated temperature irradiation   
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        发布时间：2024-10-25

        NUCLEAR ENERGY SCIENCE AND ENGINEERING

      • “在先进堆型研究领域，专家采用集总参数法建立池式快堆一回路模型，基于MATLAB编写核热耦合程序，对无保护失流事故工况进行安全分析，计算结果与实验值及其他机构计算结果对比，验证了程序的可靠性。”
        FANG Peng,YANG Yongwei,ZHAO Zelong
        Vol. 43, Issue 5, Article number: 050601(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050601
        摘要：BackgroundFast reactor is an ideal advanced reactor with high fuel efficiency and transmutable nuclear waste. The pool loop layout is widely adopted for the fast reactor, therefore, the safety analysis of pool-type fast reactor has important practical significance.PurposeThis study aims to analyze the safety of the pool-type fast reactor in unprotected flow loss condition by using lumped parameter method.MethodsFirst fo all, the lumped parameter model of the primary path of pool-type sodium cooled fast reactor was established. Then, based on MATLAB platform, the nuclear thermal coupling program was written to analyse the safety of unprotected flow loss conditions. Finally, the calculated results were compared with the experimental results and the calculation results of other institutions.ResultsThe results of the program are in good agreement with other compared results, which verifies the reliability of the program.ConclusionsThe method can provide a preliminary estimate of the core behavior and inherent safety of pool-type sodium cooled fast reactor in an unprotected flow loss accident.  
        关键词：Lumped parameter method;Pool-type sodium cooled fast reactor;Analysis of unprotected flow loss condition   
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        发布时间：2024-10-25
      • “在核能综合利用领域，专家分析了可燃毒物碳化硼颗粒对SM-FHR剩余反应性的影响，为提高堆芯安全性提供方案。”
        LIU Sijia,ZHU Guifeng,YAN Rui,ZOU Yang,XU Hongjie
        Vol. 43, Issue 5, Article number: 050602(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050602
        摘要：BackgroundSmall modular fluoride-cooled high temperature reactor (SM-FHR), with inherent safety and high temperature output ability, will accelerate the diversified development of world energy and meet the demand of comprehensive utilization of energy.PurposeThis study aims to simplify the reactivity control of SM-FHR, one of the key design goals, by using burnable poisons of boron carbide to lower the excess reactivity of SM-FHR.MethodsBased on the SM-FHR design model, burnup code MOBAT was used to analyze the excess reactivity curves under different loads, different particle sizes and different space distribution of burnable poisons in fuel compacts.ResultsCalculation results show that an optimal scheme exists when volume ratio of fuel to burnable poison (F/P) is 52, and particle size is 200 μm with lower loading in some outer assembles. Its excess reactivity is reduced from 38 000 ×10-5 to 2 500 ×10-5, and the power peak factor after layout of burnable poisons is only 1.26. The burnup time is decreased, but it still meets refueling cycle expectation for more than 2 full power years.ConclusionsThe layout scheme of burnable poisons proposed in this paper makes the core burnup depth and power distribution flattened, hence improving the core safety.  
        关键词：Small modular;TRISO;Molten salt reactor;Burnable poison;Burnup   
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        发布时间：2024-10-25
      • “火星探测成研究热点，核反应堆为火星基地提供能源，火星熔盐堆设计方案出炉，满足8年运行需求。”
        YU Shihe,SUN Qiang,ZHAO Heng,YAN Rui,ZOU Yang,LAN Bing
        Vol. 43, Issue 5, Article number: 050603(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050603
        摘要：BackgroundMars exploration has recently become a mainstream trend in space research. The establishment of a Mars base is an inevitable choice for human to study and develop Mars. Compared with the solar energy storage system, the nuclear reactor as a Mars base energy system has significant advantages in terms of system mass, operational flexibility, and environmental robustness.PurposeThis study aims to propose core design scheme of Mars molten salt reactor (M2SR-1) and calculation model in aspects of reactor physics, critical safety and thermal.MethodsThe Monte Carlo N Particle Transport Code (MCNP) and Oak Ridge Isotope Generation and Depletion Code (ORIGEN) were employed to establish core physical calculation model. Calculation and analysis were performed in aspects of physical, safety, thermal and so on.ResultsComputational results reveal that the scheme of M2SR-1 meets the requirement of 8-year-life under full power operation. Under different hypothesis falling environments, the effective multiplication factor of nuclear reactor is less than 0.98, satisfying the criticality safety requirements.ConclusionThis study provides basic theoretical reference for the design of planet surface molten salt reactor.  
        关键词：Molten salt reactor;Thorium molten salt reactor nuclear energy system;Mars surface;Criticality safety   
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      • “在熔盐快堆领域，专家基于双流体方案，优化了钍铀燃料循环，得到增殖比BR约为1.2。”
        LI Dongguo LIU Guimin
        Vol. 43, Issue 5, Article number: 050604(2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050604
        摘要：BackgroundBecause of its superior performance, molten salt reactor has been selected as one of the candidates for the fourth-generation reactors, and has become the focus of international attention.PurposeIn the molten salt fast neutron reactor, we try to find the most suitable molten salt fuel scheme to achieve the purpose of high proliferation of fissile nuclides.MethodsBased on the two-fluid cooling cycle scheme, independent cooling cycles of fission molten salt fuel and breeding molten salt, a comprehensive simulation program SCALE (Standardized Computer Analyses for Licensing Evaluation) was employed to achieve high breeding ratio (BR) in the molten salt fast reactor by utilizing the high solubility characteristics of thorium and uranium heavy metal salts in fluorinated or chlorinated molten salts at high temperatures. Three feasible molten salt fuel schemes (LiF+ThF4+UF4, NaF+ThF4+UF4, and NaCl+ThCl3+UCl3) were compared by calculating the neutron energy spectrum and the reactivity temperature coefficient. Influence factors of BR, such as the sizes of fission zone, breeding zone and ZrC reflective layer, the isotopic abundance of 6Li and 35Cl in the molten salt, molten salt density error on the calculation accuracy, and the evolution of fissile nuclides with reactor operating time, were computationally analyzed.ResultsThe breeding ratio (BR) of reactor reaches about 1.2 in all three molten salt fuel schemes when the diameter and height of the fission zone are both 260 cm.ConclusionsWith optimization of the reactor geometry, and the composition and isotopic abundance of the molten salt fuel, a high breeding ratio of the reactor is achievable for the thorium-uranium fuel cycle of molten salt fast reactor.  
        关键词：Molten salt reactor;Fast neutron reactor;Breeder;Neutron physics;Thorium-uranium cycle;Breeding ratio   
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      • “在核反应堆控制领域，专家提出了一种基于重叠网格的控制棒落棒行为仿真方法，为控制棒运动分析提供新方案。”
        MO Jintao
        Vol. 43, Issue 5, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050605
        摘要：BackgroundThe time of dropping rod is one of the most important parameters in the design of reactor control rod structure.PurposeThis study aims to offer a new method for the study of rod dropping behavior.MethodsA dynamic multi-field coupling simulation method based on overset mesh was proposed by using computational fluid dynamics (CFD) approach. Two-dimensional axisymmetric models of control rod and driving rod are established respectively. The flow field component and background mesh of the control rod and driving rod were changed adaptively according to the rod dropping behavior. The calculated fluid resistance was exchanged between the two flow fields at each time step, and the motion of control rod and driving rod were updated according to the velocity obtained by solving the motion equation, thus establishing the multi-field coupling.ResultsThe simulation results show that the method is reliable to cover the typical rod dropping behavior with good generality.ConclusionsThis method achieves a good compromise between calculation time and solution accuracy, hence can be easily extended to 3D model when the computational conditions allow.  
        关键词：Multi-field;Coupling;Overset mesh;Rod dropping behavior   
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        发布时间：2024-10-25
      • “在材料科学领域，研究人员采用2 MeV的Ne离子对Ni、Ni-Cr和Ni-Mo合金进行辐照，研究固溶元素对二元镍基合金辐照性能的影响。研究发现，离子辐照导致合金硬化，Ni-Mo合金抗辐照能力优于Ni-Cr合金，而Ni合金随辐照量增加继续硬化。”
        CAO Mingpeng,FU Chonglong,CAO Jianqing,DENG Qi,LEI Qiantao,YAN Long
        Vol. 43, Issue 5, (2020) DOI: 10.11889/j.0253-3219.2020.hjs.43.050606
        摘要：BackgroundIn recent years, nickel based alloys have been used as candidate structural materials for the advanced fission reactor. Radiation effects on nickel based alloys have been widely studied whilst little attention has been paid to the effects of solid solution elements on irradiation of nickel based alloys.PurposeThis study aims to understand the effects of Mo and Cr on the radiation resistance of binary nickel-based alloys.MethodsFirst of all, Ni, Ni-Cr and Ni-Mo alloy samples were irradiated by 2 MeV Ne ions at room temperature. The irradiation fluxes were set 1.6×1015 ions·cm-2, 3.2×1015 ions·cm-2 and 9.6×1015 ions·cm-2, respectively. Then the grazing incidence X-ray diffraction (GIXRD) was employed to investigate the microstructure changes of the samples, and the nano-indentation technique was used to measure the hardness of irradiated samples.ResultsGIXRD results show that the crystal lattices of Ni, Ni-Cr and Ni-Mo alloys have no obvious distortion, and no precipitated phase is formed. Nano indentation results show that ion irradiation causes hardening of Ni, Ni-Cr and Ni-Mo alloys. When the irradiation damage reaches 0.5~3.0 dpa (displacement per atom), the hardening of Ni-Cr and Ni-Mo alloys approaches saturation while the hardening of Ni is unsaturated. Finally, the mechanism of irradiation hardening was analyzed by using Orowan model and Makin-Minter equation.ConclusionsThe radiation resistance of Ni-Mo alloy is better than that of Ni-Cr alloy. Ni has the tendency of continuous hardening with the increase of radiation.  
        关键词：Binary nickel based alloys;Ion irradiation;Makin-Minter equation   
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        发布时间：2024-10-25
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