最新刊期
      卷 38 ， 期 2 ， 2015
      • YOU Haitao,SUN Chunqing,LI Quanlin,LIU Jiaqi
        Vol. 38, Issue 2, Article number: 020101(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020101
        摘要：Background: High-resolutionary lacustrine sediments from Maar Lakes are very important to construct and understand the mechanism of paleoclimatic changes. Purpose: To study the tendency of climatic changes and the global warming in the 20th century, proxy indexes for temperature and precipitation during the Late-Holocene (from AD1282?AD1988) were obtained by high-resolutionary geochemical analysis on the varved sediments of Erlongwan Maar Lake (Northeastern China). Methods: Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) was performed on the lake sediments from Erlongwan Maar Lake and six elements including As, Br, K, Mn, Rb and Ti were obtained. Factor analysis on these elemental data was used to facilitate the interpretation of the results. Results: The three main factors, F1, F2 and F3, were extracted. These three factors are related to early diagenesis, biogenesis factor and basin erosion, respectively. The F2 and F3 scores may also be used as climate proxy indexes for changes in temperature and precipitation, respectively. Varve chronology over past 700 years from this core gives a precise time scale for evaluating this sediment sequence, climatic and environmental changes. Conclusion: Particularly during the Little Ice Age (LIA), the climate was not homogenous but characterized by three cold spells. After AD1890, the region had generally a warm and humid climate and concomitant trends of rising temperature and falling precipitation could be observed as a reflection of global warming in the 20th century.Cited  
        关键词：Synchrotron radiation X-ray fluorescence analysis (SRXRF);Lake sediments;Element geochemistry;Erlongwan;Environmental change records;Varve chronology   
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        发布时间：2021-03-03
      • LEI Jieying,CHEN Zhi,LI Juexin,YU Guobing,GU Xianbao,XU Xie
        Vol. 38, Issue 2, Article number: 020201(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020201
        摘要：Background: With the extensive application of industrial irradiation accelerator, more and more people get involved in this field. It is necessary to know the whole radiation distribution in accelerator room for the consideration of the human radiation safety. Purpose: In order to acquire qualitative knowledge for radiation distribution in machine hall, quantitatively calculation of the dose at points locating in the vertical and horizontal situation around the drift tube was carried out to achieve the distribution of radiation field and the best type of the hole when different types of holes were employed. Methods: The major source roots in the scattering radiation through the pore outside the drift tube, thus the MCNP5 was applied to the multi-step simulation of radiation field distribution on a 3-MeV Dynamitron. Results: The size and shape of hole have tiny effect on the dose rate in vertical direction; while the dose rates at different points from drift tube in the horizontal direction change with the type of holes apparently, and the best type of hole is circular hole with a diameter of 40?60 cm when the diameter of drift tube is about 10cm. Conclusion: Selecting the appropriate type of the hole is essential both for radiation room and machine hall. Adding stair-step platform in accelerating pipe hole not only help to save the axial height of accelerator, but also reduce the radiation level around drift tube effectively. Abstract  
        关键词：Radiation field of machine hall;The hole;Shielding design;MCNP5   
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        发布时间：2021-03-03
      • ZHOU Daming,ZHU Jianhua
        Vol. 38, Issue 2, Article number: 020301(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020301
        摘要：Background: Folate receptor is highly expressed in tumor cells. Labeling folic acid offers a way of tumor targeting. Purpose: This study aims to explore the synthesis and in vivo imaging of 18F labeled folic derivative [18F]FPTZFA. Method: Starting from folic acid, through the amino and carboxyl ester forming reaction, we get FA-N3, and then FA-N3 is labeled with 18F-Pykyne in the presence of CuSO4, VcNa to get the compound of [18F]FPTZFA. [18F]FPTZFA then characterized by Radio-HPLC (High Performance Liquid Chromatography) and separated by Semi-HPLC. In vivo imaging was carried out in KB tumor-bearing nude mice after intravenous injection of [18F]FPTZFA via tail vein and biodistribution of [18F]FPTZFA was performed in these mice. Results: The overall reaction time lasts for 40 min, with radiochemical purity of 51%, and radiochemical yield of 37%. The autoradiography of mice tissues showed [18F]FPTZFA concentrated in liver, kidney and tumor. The %ID/g ratio in tumor tissue and muscle is 3.6, %ID/g ratio in tumor tissue and blood is 3.2. Conclusion: The high efficiency and high yield make the synthesis of [18F]FPTZFA more convenient and the %ID/g ratio indicates [18F]FPTZFA as a promising tumor targeting tracer. Abstract  
        关键词：18F;Folic acid;Click chemistry   
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        发布时间：2021-03-03
      • WANG Guanquan,YANG Yuqing,HU Rui,LIU Yebing,XIONG Xiaoling,LUO Shunzhong
        Vol. 38, Issue 2, Article number: 020401(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020401
        摘要：Background: Betavoltaic battery is a hot spot in micro isotope batteries due to its advantages of small volume, maintenance-free, high energy conversion efficiency, ease of integration and so on. GaN is a promising wide bandgap semiconductor for energy converter of betavoltaic battery. Purpose: This study aims to explore the performance of GaN diode as the energy converter of betavoltaic battery, and to compare it with the performance of Si diode. Methods: Two kinds of GaN and Si PiN diodes were prepared to be the energy converters of betavoltaic batteries, and irradiated by 63Ni and 3H radioactive sources. Their electrical performances, temperature and irradiation tolerance, were compared. Results: The results showed that the Voc of GaN diode was higher than that of Si diode, while Isc was lower; the electrical performance of GaN diode under the conditions of high temperature and high energy irradiation were better than that of Si diode. Conclusion: GaN diode could increase the Voc of betavoltaic battery, and improve electrical performance under high temperature and high energy irradiation conditions. Abstract  
        关键词：Betavoltaic;GaN diodes;Si diodes;Electrical performance   
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        发布时间：2021-03-03
      • PU Yanan,ZENG Yun,ZHAO Yubin,LI Huaishen,WU Wenhuan,CHEN Shaojia
        Vol. 38, Issue 2, Article number: 020402(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020402
        摘要：Background: An application specific integrated circuit (ASIC) chip applied to the Multi-anode Photo Multiplier Tubes (MaPMT) readout electronics system for the scintillator neutron detector was developed by the Institute of High Energy Physics (IHEP). It is a key equipment for the General Purpose Powder Diffractometer (GPPD) of China Spallation Neutron Source (CSNS). The chip includes 16 electronic channels, and each channel contains charge pre-amplifier, shaper, discriminator and mono-stable block. Purpose: This study aims to describe the chip design philosophy, verify its functionalities, and obtain its performance parameters. Methods: A circuit board designed for testing the ASIC MaPMT_v10 is implemented as a platform in which the input signals generated in two ways go through the ASIC and are measured at the output nodes of pre-amplifier, shaper and discriminator respectively. We also use one FPGA chip to function as a controller of the circuit and a USB module to communicate with PC for user interface and visualization of measuring results. The shaping waveforms of the simulation signals from the MaPMT are also tested through the test circuit board. Results: The integral nonlinearity (INL) of the MaPMT_v10 is between 0.72%?1.1%. And the value of signal-to-noise ratio (SNR) is 29. The shaped waveforms show that the MaPMT_v10 could distinguish neutron signals from gamma signals easily by setting appropriate threshold. Conclusion: Test results indicate that the chip realizes the function of identifying the particles by the amount of charge. In order to meet the actual needs of the project, the chip will be further optimized and improved on the integration. Abstract  
        关键词：Position-sensitive Scintillation Neutron Detector (SSND);Nuclear electronics;Application-specific integrated circuit;Integral nonlinearity (INL)   
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        发布时间：2021-03-03
      • CHEN Wenjun,Ma Lizhen,CAI Guozhu,WANG Shaoming,YANG Yaqing,YIN Xuejun,YUAN Jiandong
        Vol. 38, Issue 2, Article number: 020403(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020403
        摘要：Background: Separated Sector Cyclotron Linac Radio Frequency Quadrupolec (SSC-Linac RFQ) is the first domestic high charge state accelerator developed together by Institute of Modern Physical, Chinese Academy of Sciences and Peking University. High precision mechanical control is one of the key indicators for RFQ to obtain needful beam. Purpose: The aim is to detect the mechanical tolerances of form and position of large scale workpiece shape. Methods: The new survey method that combining laser tracker and articulated arm are adopted to overcome the shortcomings of measuring the shape and position tolerances of large-scale workpiece. Results: The measuring efficiency was effectively improved, which ensured the high precision RFQ measurement results. Conclusion: SSC-Linac RFQ beam was successfully obtained on April 4, 2014, with the output energy of 141.9 keV?u?1, current 149.5 ?A, and the transmission efficiency higher than 80%. The combined application of measurement using laser tracker and a measuring arm ensures the accuracy of mechanical measurement of SSC-Linac small line in RFQ. Abstract  
        关键词：Laser tracker;Articulated arm;Radio Frequency Quadrupolec (RFQ)   
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        发布时间：2021-03-03
      • YANG Zhenlei,WANG Xiaohui,SU Hong,LIU Jie,YANG Haibo,CHENG Ke,TONG Teng
        Vol. 38, Issue 2, Article number: 020404(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020404
        摘要：Background: With the increased application of Field Programmable Gate Array (FPGA) in the field of spaceflight, Single Event Effect (SEE) of FPGA is attracting more and more attentions recently. Purpose: The aim is to study single event effect in flash-based FPGA manufactured by Microsemi. Methods: VersaTile and RAM Block from the flash-based FPGA are selected as the research object. First of all, the simulation verification of the method was performed by using ModelSim toolkit. Then the experimental tests of FPGA samples were carried out using SEE testbed based on the Heavy Ion Research Facility in Lanzhou (HIRFL). Results and Conclusion: The simulation results verify that the test methods are effective, and the Single Event Upset (SEU) are detected timely and accurately. Experimental results on the SEE test base using 86Kr of HIRFL showed its rationality and validation. Abstract  
        关键词：Field Programmable Gate Array (FPGA);Single Event Effect (SEE);VeasaTile;RAM Block   
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        发布时间：2021-03-03
      • CHANG Le,LIU Yingdu,DU Long,WANG Yuting,CAO Xiguang,ZHANG Guoqiang,WANG Hongwei,MA Chunwang,ZHANG Song,ZHONG Chen,LI Chen
        Vol. 38, Issue 2, Article number: 020501(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020501
        摘要：Background: EJ301 liquid scintillation detector has good time characteristics, pulse shape discrimination ability and the neutron detection efficiency. Purpose: This study aims to achieve the energy calibration, the pulse shape discrimination (PSD) ability etc. of EJ301 organic liquid scintillation detector. Methods: The waveform digital sampler DT5720 and digital pulse processing-pulse shape discrimination (DPP-PSD) control software were employed to simplify the data acquisition system. The pulse shape discrimination parameters such as the widths of long and short gates could be set up by software. The Compton peaks of 241Am (0.0595MeV), 137Cs-60Co (0.662 MeV, 1.171MeV, 0.662 MeV) and 40K (1.461 MeV) sources were used to obtain experimental data for pulse shape discrimination and the energy calibration of EJ301. Results: Experimental results show EJ301 detector has high efficiency, strong neutron/gamma-PSD ability. Conclusion: DT5720 and DPP-PSD control software have powerful function and are easy to use for both the PSD and energy calibration of EJ301. EJ301 organic liquid scintillation detector can be used for neutron measurement, and is suitable for measuring fast neutron energy spectrum and time of flight. Abstract  
        关键词：Scintillation detector;Compton scattering;Gamma sources;Energy calibration   
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        发布时间：2021-03-03
      • WANG Siguang,WEI Jiangbo,ZHANG Huan
        Vol. 38, Issue 2, Article number: 020502(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020502
        摘要：Background: Although counts under peaks in overlap region of multi-channel spectrum from X- and ?-rays can provide useful information, they are usually discarded because of much difficulty in being unfolded. The line-shape of X-ray peak could be asymmetric in left and right side caused by an energy-dependent detector efficiency. Purpose: To accurately fit out the shapes for the counts under the peaks, X- and ?-ray shapes should be described accurately, and all known information should be used as constraints for reliable results. Methods: With RooFit package, a method to describe the X-ray shape is proposed: take its intrinsic shape of X-ray described by a Lorentz function and multiplied by a detector efficiency function, then convoluted with a resolution function. Results: The results tested with the codes included in this paper show: the events number of input and output agrees within their statistical errors checked even with very heavily overlapped peaks unfolded with branch ratio constraint method. Conclusion: The method and the code introduced in this paper are feasible, and they can be used as an example to unfold overlap regions in X- and ?-ray multi-channel spectrum. Abstract  
        关键词：Spectrum unfolding;Fit;Multi-channel spectrum   
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        发布时间：2021-03-03
      • WANG Quanquan,YIN Congcong,SUN Xuejing,HAN Lifeng,CHEN Yongzhong,LI Yongping,LIU Wei
        Vol. 38, Issue 2, Article number: 020601(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020601
        摘要：Background: Power Control System (PCS) is one of the most significant systems in Reactor Control System (RCS). PCS accomplishes functions such as power lifting, power maintain and power regulation. Purpose: In the solid reactor design scheme in Thorium-based Molten-Salt Reactor (TMSR) nuclear energy system, power controller is designed to generate signals for control rod moving direction and distance according to the deviation and deviation change trend between the measurement power value and preset value with classical Proportional Integral Derivative (PID) control algorithm. Methods: The PID design of PCS has a relationship with the characteristics of closed control loop which is constructed by reactor neutron physics, thermodynamics and transmission performance of control rods. Different design parameters determine various control system steady and dynamic performance. It is important and necessary to give a parameter set that can provide required characteristics for the control models. With the perspective of control engineering, this paper gives simulation and parameter analysis of PID algorithm of PCS on the basis of control rod control system and positioning system that has already been constructed and fundamentals of neutron physics. Apart from this, the controllable and measurable characteristics of two control models (a traditional control model and an improved multiple-loop control model) are investigated. Results: The system controllable and measurable characteristics analysis from transfer function of two control model showed that our control objects were completely controlled and completely measured in any state. The PID design and the simulation results demonstrated that the two control model both achieved satisfactory tracking performance and robustness with appropriate control parameters. Conclusion: In fact, compared with the traditional model, the improved control model which is of practical significance has better dynamic characteristics, especially in working against unmeasurable disturbances. Abstract  
        关键词：Thorium-based Molten-Salt Reactor (TMSR);Power Control System (PCS);Proportional Integral Derivative (PID);Rod control and rod positioning system   
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        发布时间：2021-03-03
      • LIU Ke,XU Liang,LIU Zhe,LONG Shilei,CAO Lingling,BAO Liangman,LI Xiaolin,ZHANG Guilin,LI Yan
        Vol. 38, Issue 2, Article number: 020602(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020602
        摘要：Background: The demand for energy is growing with the rapid population growth and the expansion of the economy. As one of the six most promising Generation IV reactors, Thorium Molten Salt Reactor (TMSR) has been attracting increasing attention. Unlike the traditional Pressure Water Reactor (PWR), operating temperature of TMSR is varying from 565 oC to 850 oC and the nuclear fuels are dissolved in the molten salt LiF-BeF2-ZrF4-UF4 (65-29.1-5-0.9 mol%). Considering the causticity of the molten salt, there are more stringent demands on the loops materials, including good mechanical properties, low activity, good chemical compatibility with the molten salt, and resistance to corrosion. To ensure the safe operation of the reactor, it is necessary to investigate the behavior of loop material corrosion in high-temperature molten salt. Purpose: This study is to explore the corrosion mechanism based on the change of microstructure and weight of the alloys corroded with same corrosion time and different corrosion temperatures. Methods: Data for the weight loss of the alloys before and after corrosion were obtained by weighing experiment. To identify microstructure changes of the alloys after corrosion, Scanning Electron Microscope/Energy Dispersive Spectrometer (SEM/EDS) were applied to measure the micro-elements changes and obtain corrosive morphology. Results: After molten salt corrosion, corroded areas of all samples exhibited enrichment of Mo and Cr elements loss. Considering the Cr oxides and fluorides generated during etching in the saturation solubility of the molten salt, which will be deposited on the surface of the alloy to form a protective layer for certain inhibition to corrosion, resulting the corrosion weight loss increases but the increasing rate decreases with the temperature of corrosion rises. Be different from the un-corroded alloy, grain boundary structure of the alloy revealed significantly widened after corrosion, and the grain size occurs after the first refinement coarsening phenomenon as the corrosion temperature increases. Conclusion: Corrosive environment has a great impact on alloy corrosion, molten salt corrosion showed significant intergranular corrosion characteristics, and corrosion at different temperatures showed different corrosion characteristics due to the effect of temperature on the rate of diffusion of atoms. Abstract  
        关键词：Molten salt;Ni-based alloy;Corrosion temperature;Scanning Electron Microscope/Energy Dispersive Spectrometer (SEM/EDS)   
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        发布时间：2021-03-03
      • ZENG Youshi,DU Lin,PI Li,WU Shengwei,QIAN Yuan,WANG Guanghua,HUANG Yu,ZHU Haiyun,LIU Wei
        Vol. 38, Issue 2, Article number: 020603(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020603
        摘要：Background: Molten salt FLiNaK(LiF-NaF-KF) has potential to be used as heat-transfer fluid of molten salt nuclear reactor, because of its high chemical stability, moderate specific heat and sufficient thermal conductivity. One adverse characteristic was that tritium was produced at relatively high rates in such reactors, which could diffuse through metals at high temperature and thus required to evaluate the behavior of tritium in FLiNaK. Purpose: This study aims to the permeation behavior of hydrogen in molten salt FLiNaK, providing the basis for tritium permeation behavior in molten salt. Methods: Plentiful experiments were conducted in a testing system for permeation and diffusion characteristics of hydrogen isotope in molten salt. Numerical fitting method of experimental results was performed to obtain the hydrogen permeation characteristics in molten salt FLiNaK. Results: The results showed that hydrogen was diffusing as H+ species in molten salt FLiNaK. The diffusion coefficients and solubility constants of hydrogen in molten salt FLiNaK can be correlated to DFLiNaK-H=1.12×10?4exp(?66.40×103/RgT) (m2?s?1) and KFLiNaK-H=2.1×10?5exp(?0.94×103/RgT) (mol?m?3?Pa?1/2). Conclusion: The diffusion coefficients and solubility constants of hydrogen in molten salt FLiNaK were derived from the experimental results.Cited  
        关键词：Molten salt FLiNaK;Hydrogen;Permeability;Diffusion;Solubility   
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        发布时间：2021-03-03
      • JIAO Xiaowei,WANG Kai,HE Zhaozhong,CHEN Kun
        Vol. 38, Issue 2, Article number: 020604(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020604
        摘要：Background: For solid fuel molten salt reactor, the Station Blackout Anticipated Transient Without Scram (SBO-ATWS) is an accident with very low probability, but the consequences are more serious compared with other design basis accidents. The decay heat may not be removed timely and the core safety will be challenged. Purpose: The aim is to study the core safety features under SBO-ATWS accident. Methods: The transient characteristic of simplified system for solid fuel molten salt reactor under SBO-ATWS accident was calculated by using RELAP5/MOD4.0 code which was modified to suit to solid molten salt reactor. Two scenarios (valid or not) of Passive Residual Heat Removal System (PRHR) were simulated. Results: The calculation results show that the effect of PRHR in early accident is not obvious, but the long-term effect is disctinct. The PRHR will ultimately make the core temperature and coolant temperature to reach a stable state even if it is failure.The fuel element temperature rises very slowly in the circumstance of SBO-ATWS which provides more than 20 day’s grace period for human intervention and taking necessary measures. Conclusion: The results show that the solid fuel molten salt reactor has high safety in response to SBO-ATWS. Abstract  
        关键词：Solid fuel molten salt reactor;Station Blackout Anticipated Transient Without Scram (SBO-ATWS);Passive Residual Heat Removal System (PRHR);RELAP5/MOD4.0   
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        发布时间：2021-03-03
      • XIA Shaoxiong,WANG Jiaqun,PAN Xiaolei,LI Yazhou,HU Liqin
        Vol. 38, Issue 2, Article number: 020605(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020605
        摘要：Background: Because of the safety and the competition in economy, Generation IV reactors represent the development tendency of innovative nuclear systems. Lead cooled fast reactor is a variety of Generation IV reactors and many of them around the world adopt passive systems to remove residual heat. Purpose: The driving force of passive system is approximate at the same level of resistance, so an analysis on the reliability of passive system becomes necessary. Methods: This study made some improvements of the response surface method and applied it to Reactor Vessel Air Cooling System (RVACS) of China lead-based research reactor (CLEAR-I). During the analysis, the process of removing residual heat of RVACS was simulated by Fluent in order to find out how inputs would affect the safety of reactor. On the base of a mass of simulations, this study established relationships between inputs and outputs to find failure probability of RVACS. Results: The advanced response surface method raised the sampling efficiency for small-probability events by as much as four times. Through this method, we got the failure probability of RVACS. Conclusion: The results showed that two of four sets RVACS pipes can safely remove residual heat of reactor during loss of power. Abstract  
        关键词：China lead-based research reactor (CLEAR-I);Reactor Vessel Air Cooling System (RVACS);Reliability analysis;Uncertainty   
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        发布时间：2021-03-03
      • ZHANG Xiaoying,YAO Tingting,LI Zhiwei,HUANG Kai
        Vol. 38, Issue 2, Article number: 020606(2015) DOI: 10.11889/j.0253-3219.2015.hjs.38.020606
        摘要：Background: The study on the transient ablation of the pressure vessel wall, acted by the detained melt core, is very important for damage prediction after occurrence of serious loss of coolant accident (LOCA), and design of accident mitigation scheme. Purpose: This paper attempts to study the ablation process of downward part of pressure vessel of AP600, in condition of losing all coolant. Methods: A two-layer of melt material model was used to simulate the structure of melt core, and the heat flux on the vessel wall was computed. The unsteady 2-D heat conduction model was developed for the downward part of pressure vessel, and water boiling in containment was considered as cooling of outer wall. A moving boundary model was used to simulate the decreasing wall thickness on some point in the ablation process. The variation of wall temperature and thickness with time, from occurrence of the accident, till 3000s after the accident, was computed in detail. Results and Conclusion: Simulation results shows that heat flux from the molten UO2 on the vessel wall grows up with increasing inclination angle, and heat flux from the molten metal is a little small. Temperature on internal wall grows up rapidly with time, which causes the ablation firstly appearing at interface of the two molten layers, and the ablation zone tends to deepen and widen after that. The heat balance between molten material, vessel wall and containment pool will come 9000s after occurrence of accident, and temperature and ablation zone would not change after 9000s. Abstract  
        关键词：Reactor;Coolant loss;Core melt;Pressure vessel;Wall ablation   
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