最新刊期
      卷 39 ， 期 5 ， 2016
      • Junqin LI,Ying ZOU,Zhenhua CHEN,Lian XUE,Yong WANG,Renzhong TAI
        Vol. 39, Issue 5, Article number: 050101(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050101
        摘要：Background:The measurement of energy resolution is an essential task for commissioning a beamline in synchrotron radiation facility. The ionization chamber plays an important role in the evaluation of energy resolution. The conventional type based on electrode probe has the disadvantage of a low detection upper limit for energy resolution due to collision broadening on peak profiles by high working pressure(up to 1.33Pa).Purpose:To improve the upper limit of resolution measurement, we aim to set up and deploy the ionization chamber based on multichannel plate(MCP) in China, including vacuum system, gas inlet system, detection system and data acquisition and processing system.Methods:Taking advantage of high amplification of a MCP detector, gas ionization absorption spectra can be measured under much low working pressure(1.33×10-4Pa). By analyzing the width of absorption peak, the instrument broadening caused by a beam line can be obtained.Results:An ionization chamber based on MCP can achieve higher upper limit than those based on electrode probe in evaluating energy resolution.Conclusion:A MCP ionization chamber provides an important diagnosis for energy resolution in commissioning high performance beamlines.  
        关键词：Synchrotron radiation facility;Ionization chamber;MCP;Ionization absorption spectrum;Energy resolution   
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        发布时间：2021-05-25
      • Changliang LI,Shunqiang TIAN,Wenzhi ZHANG
        Vol. 39, Issue 5, Article number: 050102(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050102
        摘要：Background:The spectral brightness is an important parameter for the synchrotron radiation light source. It is intimately associated with beam current, horizontal emittance and vertical emittance. The beam current is limited by collective effects and the horizontal emittance is decided by the lattice structure, which has almost been fixed in a machine. Reducing the vertical emittance to improve the brightness is a simple and feasible method. Other benefits such as the increase of transverse coherence and the reduction of vertical spot size can be obtained in reducing the vertical emittance.Purpose:The aim is to study the sensitivity of the vertical emittance to magnetic alignment errors and correct the vertical emittance for the Shanghai Synchrotron Radiation Facility(SSRF) Phase Ⅱ project.Methods:Singular values decomposition(SVD) is used to correct the vertical closed orbit distortion(COD). Sixty skew quadrupole magnets are utilized to correct the emittance coupling with gradient descent algorithm.Results:An approximate mean of 0.06-mm vertical COD is obtained after orbit correction. The emittance coupling of each seed can be corrected below 0.5% by using 60 skew quadrupole magnets.Conclusion:If the alignment tolerances of all magnets in the SSRF Phase Ⅱ project are the same as those in the currently operational SSRF storage ring, the vertical emittance is primarily determined by vertical misalignments of the sextupole magnets, and the emittance coupling can be corrected below 0.5% by using 60 skew quadrupole magnets.  
        关键词：SSRF Phase Ⅱ project;Magnetic alignment errors;Vertical emittance;Coupling correction   
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        发布时间：2021-05-25
      • Xiaoxun WANG,Hongfei WANG,Qiaogen ZHOU,Ya ZHU
        Vol. 39, Issue 5, Article number: 050103(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050103
        摘要：Background:A set of high-precision magnetic field measuring system can guarantee the undulator magnetic field optimization and meet the measurement requirements.Purpose:We can operate magnetic field measurement in an enclosed space and construct a set of measuring system to obtain the coordinates of the Hall sensor.Methods:The base is designed using Solid Edge and data acquisition program can be written by LabVIEW. Position sensitive detector(PSD) is used to acquire the exact position coordinates of Hall probe. At last, we create points and plot by MATLAB to analyze the data change.Results:The position measuring system based on PSD accurately reflects the position changes and the fitting curve shows the guide rail variation trend.Conclusion:The measurement accuracy can reach 5 μm. PSD has an advantage over optical system, which can be widely used in measurements of position and small displacement.  
        关键词：PSD;Iris;In-vacuum undulator;Magnetic field measurement;Data acquisition   
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        发布时间：2021-05-25
      • Xianfang MENG,Guangshui GUO,Long ZHANG,Peizhong QIN,Chao SUN,Huiling MA,Xinmiao ZENG,Liancai WANG
        Vol. 39, Issue 5, Article number: 050201(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050201
        摘要：Background:With the development of nuclear technique, neutron shielding materials have been used widely in many fields. Up to now, there is still no standard test method for neutron shielding property both at home and abroad.Purpose:This study aims to find an easy and feasible way to test the shielding effectiveness of materials in a wide range of neutron energy.Methods:Models for3H proportional counter cooperating together with polyethylene(PE) moderating spheres of different diameters were calculated using MCNP(Monte Carlo N Particle Transport Code) and the neutron transmittance of some materials was tested.Results:The combination detection method by using moderating sphere detectors has consistent response in a wide range of neutron energy from 1×10-5MeV to 1.25MeV. The article tested the neutron transmittance of 2cm-and 4cm-thick PE plates for252Cf neutrons. The results coincide with multi-sphere spectrometer within ±1.0% and the ordinary shielding rules of different type materials for neutrons.Conclusion:The method is validated to be feasible and simple to neutron shielding.  
        关键词：Moderation sphere detector;Neutron shielding property;Neutron transmittance   
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        发布时间：2021-05-25
      • Yuxuan ZHANG,Yongjun YE,Detao XIAO,Junting JIANG,Dexin DING,Yongming ZHONG,Chao XIE
        Vol. 39, Issue 5, Article number: 050202(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050202
        摘要：Background:The blind roadway is one of the most important places where radon and its progeny’s concentration is high in uranium mine exploitation.Purpose:The aim is to guide the design of exhaustion of radon and its progeny in blind roadway.Methods:The simplified mathematical relationships were primarily improved between radon concentration and radon progeny alpha potential energy concentration in the wind in uranium mine, and the influence of ventilation resistance force on rock wall radon release rate was analyzed; the mathematical calculation models of distribution for the concentration of radon and radon progeny in the blind roadway with driving-force ventilation were obtained, respectively, and through the models the minimum wind volume formulas for exhausting radon and its progeny in blind roadway were obtained. According to some particular roadways, the influence of different ventilation volumes and exhalation rates of radon on rock wall on radon and its progeny concentration, the influence of variable physical parameters on the wind volume for exhausting radon and its progeny in the blind roadway were discussed, respectively.Results &#38; Conclusion:The results show that, the further it is from the roadway inlet, the higher the concentration of the radon and its progeny in the blind roadway is. And the concentration of radon and its progeny decreases with the increment of the wind volume, while increases with the increment of exhalation rate of radon on rock wall; the minimum wind volume needed for exhausting radon and radon progeny in the blind roadway with driving-force ventilation increases with the increment of the rock wall radon release rates and the length of the blind roadway.  
        关键词：Exhaust ventilation;Blind roadway;Radon and its progeny;Concentration distribution   
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        发布时间：2021-05-25
      • Ruiying SONG,Shoubo HE,Peng WANG
        Vol. 39, Issue 5, Article number: 050203(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050203
        摘要：Background:A dual-mode congeneric mid-energy accelerating waveguide for medical electron linac is a crucial device in imaging guided radiation therapy(IGRT) technology.Purpose:To ensure the linac producing stable and high quality beam bunches for both imaging and treatment beams, a 14-MeV side-coupled standing wave waveguide accelerator structure for medical accelerator based on a novel microwave energy switch technology was developed in Shanghai United Imaging Healthcare Co., Ltd(UIH).Methods:First of all, the designs on the transverse focusing and the longitudinal bunching for the linac accelerating structure were generated using the beam dynamics simulation code Parmela to certify the optimization goal of the accelerating cavity structure which can be used in both dual-photon mode and multi-energy electron mode. Then the accelerating structure was designed and the optimized microwave parameters were obtained by using the electromagnetic code Superfish and the commercial software CST(Computer Simulation Technology).Results:A 1.3-m long π/2 mode standing-wave bi-periodic side-coupled accelerating wave-guide resonating at 2.998GHz was obtained. The accelerating structure can be adjusted to output both 3-MV imaging photon beam and dual-mode treatment photon beams, including 6-MV and 10-MV electron beam. In addition, multi-energy electron beams with maximum electron beam energy of 14MeV can be achieved.Conclusion:So far, the accelerating waveguide was machined and brazed completely. It is found that the numerical design shows very good agreement with the microwave cold test result. Recently, the frequency tuning is achieved accurately and the RF conditioning is in progress.  
        关键词：Medical mid-energy linac;Energy switch;IGRT;Imaging beam;High dose rate   
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        发布时间：2021-05-25
      • Yichao MA,Na ZHU,Hongshe DANG,Sen QIAN,Jingkai XIA,Zhigang WANG,Chao LIU,Guangpeng AN,Feng GAO,Yinhong ZHANG
        Vol. 39, Issue 5, Article number: 050401(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050401
        摘要：Background:With the increasing demand of light emitting diode(LED), radiation effect of the electron beam on LED is becoming a research hotspot.Purpose:This study aim is to build up a data acquisition system for monitoring the changes of LED parameters during the irradiation process.Methods:First of all, a small current meter, power meter, spectrum analyzer, low-voltagepower supply and other equipments were used to build the hardware platform. Then communication protocols for RS-232, USB and LAN interface were implemented by using LabVIEW software developing platform. Functionalities for data storage and real-time display of LED optoelectronic properties, environmental parameters and track changes of LED photoelectric parameters with radiation time were achieved through this system. Finally, remote monitoring is realized by using the remote desk process technologyviathe local area network(LAN).Results:The above mentioned system was successly applied to a practical irradiation experiment on LED with electron beam energy of 1.5 GeV to real-timely store and display the LED optoelectronic properties and environmental parameters during irradiation process.Conclusion:The system is reliable and suitable for monitoring changes of LED photoelectric parameters with irradiation.  
        关键词：LED;Electron beam irradiation;Online monitor system   
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        发布时间：2021-05-25
      • Wei WANG,Junrun WANG,Zhongping LI,Zheng WEI,Yu ZHANG,Xiaolong LU,Ziming ZHANG,Zeen YAO
        Vol. 39, Issue 5, Article number: 050402(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050402
        摘要：Background:Compact D-D neutron generator provides the stable and reliable 2.5-MeV neutrons with higher neutron yields, which can be applied in neutron activation analysis, fast neutron radiography, and detection of explosives and drugs. In this work, a control system of neutron generator was developed to realize remote adjustment and measurement.Purpose:The control system of neutron generator is used to adjust and monitor field devices remotely to ensure normal work for neutron generator.Methods:According to the characteristics of the devices’ interface, serial port server is used as the hardware for control system. Based on LabVIEW, the control system integrates and monitors all equipments of neutron generator, which duly saves and queries main operating parameters of neutron generator by accessing MySQL database.Results:The control system operates stably for long time, and is applied successfully to debug and test of the neutron generator.Conclusion:The design of control system for compact D-D neutron generator meets the designed goal, and realizes remote control mode for adjustment and measurement.  
        关键词：Neutron generator;LabVIEW;MySQL database;Distributed control system   
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        发布时间：2021-05-25
      • Tingting WANG,Liang WANG,Zhaohong MO,Deshan ZHAO,Zhonghua XIONG
        Vol. 39, Issue 5, Article number: 050403(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050403
        摘要：Background:The light output function is an elementary aspect for neutron spectrometry measured by an organic scintillator to unfold the neutron spectrum from the pulse height distribution.Purpose:This paper aims to investigate the properties of a boron-loaded liquid scintillator EJ339A, using photon sources and neutrons from a252Cf source.Methods:The light output was defined using Compton electron spectra. Pulse shape discrimination(PSD) and time of flight(TOF) were used to distinguish neutron and γ-rays. Combining theoretical modeling and experimental research, four different gamma sources are applied to achieve equivalent calibration of electronic energy, namely22Na,133Ba,137Cs, and60Co, respectively. Accordingly, based on TOF method,252Cf, a spontaneous fission neutron source, is treated as several quasi-monoenergetic neutron sources under different time-windows.Results:The electron light output scale was calibrated by the measured detector response. Neutrons deposit energy in the detector and give a light output function with the neutron energy in the range of 1.9-7.8MeV.Conclusion:It shows that experimental data of light output function are in good agreement with simulation result in the low energy section, while discrepancies arise in the high energy section.  
        关键词：Liquid scintillator;Light output function;Energy calibration   
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        发布时间：2021-05-25
      • Jiguo GENG,Kuan WANG
        Vol. 39, Issue 5, Article number: 050501(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050501
        摘要：Background:Chemical sensors that work as electronic noses have attracted extensive attention, yet research about sensor application of C-doped boron nitride nanotubes is still rare.Purpose:In order to realize the gas sensing properties of boron nitride nanotubes(BNNTs) and C-doped BNNTs for some small gas molecules, such as NO2, O2and F2, we calculated the adsorption property of those gas molecules.Methods:The gas sensing properties of C-doped BNNTs for some small gas molecules have been investigated by using the density functional theory.Results:The interaction distance between gas molecule and BNNT and adsorption energy of gas molecule on the BNNTs and the C-doped BNNTs are obtained by density functional theory(DFT) calculation. We also calculated the electron densities of states for an O2molecule or a NO2molecule or a F2molecule to adsorb on the different positions of C-doped BNNTs.Conclusion:The calculated results show that BNNTs present high sensitivity to the gaseous NO2, O2and F2molecules. The chemical reactivity of BNNTs has been changed by carbon molecules, and C-doped BNNTs can improve the interaction between the gas molecules and the BNNTs.  
        关键词：C-doped boron nitride nanotubes;Adsorption;Gas molecules;Density functional theory   
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        发布时间：2021-05-25
      • Zhenhua ZHOU,Deng PAN,Yushuang CHEN,Jianping HUANG,Xiaohan YU,Naxiu WANG
        Vol. 39, Issue 5, Article number: 050601(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050601
        摘要：Background:In the thermal-hydraulic design of molten salt reactor(MSR) with liquid fuel, the structure and the flow field distribution of lower plenum play a decisive role for the core flow distribution.Purpose:The mass flow distribution of core inlet is designed to match with the release heat distribution, so that the core power distribution will be flattened in radical.Methods:To realize the reasonable distribution of core flow, the flow field of lower plenum is optimized through adjusting the geometry of core lower plenum and flow distribution device using FLUENT software to simulate three-dimensional flow field of core.Results:The simulation results showed that the mass flow rate standard deviation of salt channels of trumpet-shape lower plenum is reduced by 4.2% compared with that of the ellipsoid-shape. The mass flow rate standard deviation of salt channel is reduced by 29.2% by setting the flow distribution plate.Conclusion:Changing the structure of lower plenum and setting the flow distribution plate are useful measures to adjust the mass flow distribution and power matching. The results can provide the basis for the optimization design of MSR with liquid fuel.  
        关键词：MSR;Flow distribution;Lower plenum structure;Flow distribution device;Computational fluid dynamics(CFD)   
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        发布时间：2021-05-25
      • Xiaolei PAN,Jiaqun WANG,Liqin HU,Jianye WANG,Jin WANG
        Vol. 39, Issue 5, Article number: 050602(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050602
        摘要：Background:Passive system has been widely applied in the design of the new generation reactor, and the reliability analysis has become a key matter in the Probabilistic Safety Analysis(PSA) frame.Purpose:A response-surface-fitting method for the reliability analysis of passive systems is presented and applied in Reactor Vessel Air Cooling System(RVCAS) of China lead-based research reactor(CLEAR-I).Methods:The inputs and outputs for Fluent model of RVCAS were set as the input samplings, and least square method and bootstrap method were used to solve the performance function of response surface which was used to evaluate the reliability of passive RVCAS, instead of Fluent model.Results:The results showed that two of four sets RVACS pipes can remove residual heat of reactor during loss of power with the probability of 0.9938.Conclusion:The system is highly reliable.  
        关键词：China lead-based research reactor;Passive decay heat removal system;Response-surface-fitting-method;Least square method;bootstrap   
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        发布时间：2021-05-25
      • Xiaowen LYU,Changqi CHEN,Xiaobin XIA,Jie HE,Zhihong ZHANG,Jun CAI
        Vol. 39, Issue 5, Article number: 050603(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050603
        摘要：Background:Dispersion of radioactive airborne effluents in the near field is an important content of environment impact assessment of nuclear facilities. Due to the effect of complex building, the Gaussian plume model is not suitable for simulation of atmospheric dispersion in near field.Purpose:This paper attempts to analyze the atmospheric dispersion factors in near-field area of 2-MW liquid-fueled molten salt experimental reactor(TMSR-LF1) and provide data for environment impact assessment.Methods:Based on the building layout of proposed site of TMSR-LF1, the distribution of atmospheric dispersion factors were calculated by using method of Computational Fluid Dynamics(CFD) and the influences to the distribution of different factors were analyzed.Results:For elevated emission, because of the plume rise, the greater the wind speed is, the higher the concentration is in nearfield area; the pollutant accumulation areas will be prone to present at upwind side of buildings along the direction of wind.Conclusion:All these provide important data for nuclear emergency, and environmental impact assessment for TMSR-LF1.  
        关键词：TMSR-LF1;Atmospheric dispersion;Near-field simulation;CFD   
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        发布时间：2021-05-25
      • Yuan JIN,Jinhui CHENG,Kun WANG,Xuehui AN,Guohong MA,Peng ZHANG,Zhong LI
        Vol. 39, Issue 5, Article number: 050604(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050604
        摘要：Background:As an ideal coolant, molten salt has been successfully used in molten salt reactor, and its thermo-physical properties have dramatic impact on heat transfer performances. However, the diversity in molten salt pretreatment and preparation induce discrepancies among the existing data which may cause puzzle in its applications.Purpose:The aim is to systematically investigate and evaluate thermo-physical properties of FLiNaK and HTS, especially viscosity in abnormal operation temperature range, and measure thermo-physical properties of CloKmag salt accurately.Methods:Molten salt coolants were prepared normatively, and their thermo-physical properties were systematically measured through testing instruments including the differential scanning calorimetry, self-developed Archimedes density device, improved thermal conductivity meter based on laser flash method, and self-developed rotating viscometer.Results:Through the measurement and analysis above, we have systematically obtained the thermo-physical properties of FLiNaK, CloKmag and HTS accurately, especially viscosity in abnormal operation temperature range.Conclusion:Heat capacity and thermal conductivity of molten salt are almost unaffected by temperature and can be regarded as constants. Viscosity at 80 K above melting point decreases with the increase of temperature and tends to that of room-temperature water in high temperature range. The thermo-physical properties of FLiNaK, CloKmag and HTS can provide accurate and reliable basic data for the application of molten salt.  
        关键词：Thermo-physical properties;FLiNaK;CloKmag;HTS   
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        发布时间：2021-05-25
      • Pan WU,Xiangzhou CAI,Chenggang YU,Jingen CHEN,Gang XU
        Vol. 39, Issue 5, Article number: 050605(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.050605
        摘要：Background:The neutron spectrum plays an important role in thorium-based fuel utilization efficiency and temperature feedback coefficient concerning reactor operation safety, so it is very important to study the new moderator material used in molten salt reactor(MSR).Purpose:This study aims to analyze the thorium-uranium conversion performance of a ZrH-moderated molten salt reactor and analyze the feasibility of ZrH as moderator in molten salt reactor.Methods:SCALE program is used to calculate neutron spectrum, thorium uranium conversion ratio,233U concentration, total temperature feedback coefficient and burnup calculation with different lattice parameters.Results:The thorium uranium conversion ratio and total temperature feedback coefficient can be improved significantly by reducing lattice size or increasing salt volume ratio; the initial233U concentration for start reactor can be easily controlled under 2.5×10-2when the volume share of added ZrH is 0.1.Conclusion:Compared to the graphite-moderated MSR, ZrH-moderated MSR reduces initial233U inventory and transuraniums(TRUs) production, and makes its core more compact.  
        关键词：ZrH moderator;MSR;Thorium uranium conversion performance;233U inventory   
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