最新刊期
      卷 0 ， 期 0 ， 2020
      • ZHAO Guobi,LENG Yongbin,YUAN Renxian,CHEN Zhichu,ZHOU Weimin
        Vol. 37, Issue 5, Article number: 050101(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050101
        摘要：Background: The measurement resolution of the button-type beam position monitor (BPM) pickups could be affected by the heat and deformation due to the beam load and the probes might even malfunction in extreme situations. Purpose: This effect becomes more critical in storage rings under high current conditions, which needs to be studied very carefully. Methods: This article introduces the modeling and analyzing method of the beam load effect of the BPM in Shanghai Synchrotron Radiation Facility (SSRF) and the simulations of the heating problem under various beam currents and filling patterns using ANASYS. Results: The results showed that the deformation due to the beam load operating at any designed modes in SSRF would not outstrip the manufacturing tolerance so that the effect to the position measurement could be neglected. Conclusion: Meanwhile, the temperature of some parts of the probe could be as high as 270?C in some cases, and hence further studies are needed to reduce the risk of instrument damage.Cited  
          
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        发布时间：2021-03-03
      • LIU Zhanjun,XU Huichao,GONG Peirong
        Vol. 37, Issue 5, Article number: 050102(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050102
        摘要：Background: The X-ray Beam Position Monitor (XBPM) is an important device to measure the X-ray position of synchrotron radiation beamline. Previous signal processing unit of XBMP at Shanghai Synchrotron Radiation Facility (SSRF) beamline is based on I/V converter and Analog to digital converter (ADC) module E2240 manufactured by MOXA which results in low spatial resolution and insufficient data acquisition rate. Purpose: In order to improve the performance of XBMP at SSRF, an upgrading of the XBPM is undertaken by using new all-in-one processor. The application of this new processor is briefly described in this paper. Methods: In the hardware side, a new generation digital BPM processor Libera Photon is adopted which can achieve a best position resolution of 0.01 μm and provides two parallel data paths that operate at different frequencies for flexible process. In the software side, relevant EPICS interfaces are modified in both Operator Interface (OPI) level and Input/output Controller (IOC) level to coordinate the new processor according to the control requirements. Results: The upgraded system can capture XBMP signal change within 2 ms by using the Fast Acquisition (FA) dataflow at approximately 10 kHz, which can be used for fast feedback control. Observed Slow Acquisition (SA) dataflow is typically around 10Hz, which can be used to monitor long-time signal changes and predict the varying trend of beam position. Conclusion: Libera Photon processor is successfully applied to the XBMP at SSRF beamline to achieve high position resolution and feasible control requirements.Cited  
          
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        发布时间：2021-03-03
      • GUO Xin,SU Haijun,LI Deming,WANG Shengli,GUO Honglei
        Vol. 37, Issue 5, Article number: 050103(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050103
        摘要：Background: Dynamitron, an electron irradiation accelerator of high-voltage, is used as a radiation source for industrial and agricultural production. The control system is an important component of dynamitron. Purpose: The aim is to improve the control system to meet the performance requirements of dynamitron for the stability. Methods: A distributed control system for the 1.5-MeV dynamitron is proposed to gain better performance. On this basis, an electron beam trajectory automatic correction method based on Cerebellar Model Articulation Controller and Proportional-Integral-Derivative (CMAC-PID) controller is designed to improve the function of electron beam extraction system. Results: The distributed control system can meet the control requirements of the accelerator. The stability of the CMAC-PID controller is better than that of conventional PID controller for the electron beam trajectory automatic correction system, and hence the CMAC-PID controller can provide better protection of dynamitron when electron beam deflection occurs. Conclusion: The distributed control system and the electron beam trajectory automatic correction method system can effectively improve the performance and reduce the failure probability of the accelerator, thereby enhancing the efficiency of the accelerator.Cited  
          
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        发布时间：2021-03-03
      • ZHANG Bin,CHENG Huansheng,ZHENG Jianming
        Vol. 37, Issue 5, Article number: 050201(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050201
        摘要：Background: Zhejiang Province is an important producing area of proto-porcelain. Huoshaoshan kiln site in Deqing County is the only kiln known currently for firing proto-porcelain from the late Western Zhou Dynasty to the late Spring and Autumn Period. Also it is the earliest kiln site unearthed for only firing proto-porcelain so far. It is of great significance for the exploration of Chinese early celadon firing technology. Purpose: The aim is to disclose the elemental characteristics of these proto-porcelains and study the sources of the raw materials and relationship between these proto-porcelains. Methods: We selected 18 samples made at the early period (from the late Western Zhou Dynasty to the early Spring and Autumn Period), 15 samples made at the middle and last period (the last period of the middle Spring and Autumn Period), and 17 samples made at the last period (the last period of the late Spring and Autumn Period). Proton Induced X-ray Emission (PIXE) was used to analyze these samples and measure the chemical compositions of these proto-porcelains. The factor analysis is used to study the sources of the raw materials and relationship between these proto-porcelains made in the different periods. Results: The results show that for the raw materials of body and glaze, the proto-porcelains at the last period are different from those at the early period, while the same as those at the middle and last period. Conclusion: PIXE combining with factor analysis can be used to study effectively the sources of the raw materials and relationship between these proto-porcelains.Cited  
          
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        发布时间：2021-03-03
      • YANG Jingyi,YAN Long,HUAI Ping
        Vol. 37, Issue 5, Article number: 050202(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050202
        摘要：Background: C/C composites are an attractive choice for components in nuclear reactors because of their excellent performance in high temperature resistance, corrosion resistance and radiation resistance. However, to the best of our knowledge, the radiation research on their morphology and microstructure are scant. Purpose: The aim is to investigate the morphology and microstructure of C/C composites induced by irradiation. Methods: The C/C composites were irradiated with 0.5MeV and 1 MeV Ar ions at room temperature. The samples prepared before and after irradiation have been characterized by Raman spectroscopy and scanning electron microscope (SEM). Results: With the increment of irradiation dose, the surface defects in the irradiated samples greatly increase. Moreover, some cracks and holes are found in the matrix surfaces, and the largest ones are even up to the size of one micrometer. Conclusion: The surface defects in the matrix caused by 0.5 MeV Ar ion with dose of 2.4×1016 ions?cm?2 are much more than those by 1 MeV Ar ion with dose of 3×1016 ions?cm?2.Cited  
        关键词：C/C composites;Ion irradiation;Surface structure   
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        发布时间：2021-03-03
      • GUO Jingyuan,TANG Qiang,JIA Yuxin,LIU Xiaowei,LIU Yanbing
        Vol. 37, Issue 5, Article number: 050203(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050203
        摘要：Background: Dosimetry material used for the evaluation of radiation accident dose is an important basis for the reconstruction of accident dose. It is of great significance to select materials for dosimeters suitable for the emergency and accident site to evaluate absorbed dose. Purpose: SMD resistors which are widely used in the circuit components were chosen, and the optimized optically stimulated luminescence (OSL) measurement conditions were studied. Methods: Under different measurement conditions such as preheating temperature and bleach time, the linearity and stability of dose response were studied, and the optimized conditions were determined. Results: It was found that the linearity and stability of OSL dose response performed well in the dose range from 0.1 Gy to 10 Gy under the optimized conditions. Conclusion: It is a good choice to use the SMD resistor as a suitable dosimeter for the accident dose reconstruction.Cited  
          
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        发布时间：2021-03-03
      • JIANG Huaikun,JIANG Yun,ZHANG Chunfa,ZHANG Wenjuan
        Vol. 37, Issue 5, Article number: 050204(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050204
        摘要：Background: Instrument neutron activation analysis is a nondestructive analytic method. Some elements after irradiation produce short half-life radio-nuclides (<60 s), and others produce both long-lived and short-lived nuclides. For these short-lived nuclides, the single measurement has big error. Purpose: In order to reduce the error, cyclic neutron activation analysis can be used to improve the sensitivity. Methods: A device was designed to be connected to the sample transporter, detector and irradiation pipeline in the reactor, which can automatically control the irradiation time and counting time. According to the nuclear parameters of certain elements, irradiation time and counting time and cycle times were determined by experiment. Cyclic activation analysis method was established at the mini-reactor. Results: This paper studied cyclic activation analysis conditions of 17 kinds of element, and applied to the determination of actual samples. Cyclic epithermal neutron activation analysis (CENAA) method was discussed too. By the analysis of national standard reference materials, the reliability of this method was confirmed. Conclusion: Cyclic neutron activation analysis (CNAA) is an effective analytic method for only short life nuclide elements. For both short and long lived nuclides of elements, the cyclic activation analysis method can make the analytical cycle shorten, from a few days or several weeks to within a few minutes. Cyclic activation analysis has the advantages of high sensitivity, and its precision and accuracy are better than single short irradiation activation analysis.Cited  
          
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        发布时间：2021-03-03
      • GONG Chunhui,ZENG Guoqiang,GE Liangquan,TANG Xiaobin,TAN Chengjun
        Vol. 37, Issue 5, Article number: 050205(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050205
        摘要：Background: Airborne γ-ray spectrometer has been used extensively over several decades for mineral exploration and geological mapping purposes to look for the peaks of potassium, uranium and thorium. And the low-energy ray is ignored. Purpose: In order to provide a basis for obtaining effective environmental radioactivity measurement results, Minimum detectable activity (MDA) values in monitoring ground radiation of the polycrystalline airborne γ-ray spectrometer need to be calculated. Methods: MDA is related with the detection efficiency. A Monte Carlo simulation was performed using the MCNP5 code for different radionuclides in the ground environment. Equivalent mass thickness was proposed to reduce variance, and the secondary source was used in the MCNP5 input. Results: The pulse height distributions of external detectors and internal detectors for 137Cs and 131I at different heights were obtained, which represent the counting rate decreased as the altitude increases. And the MDA of external detectors is better than that of internal detectors. Conclusion: The external detector is suggested to adopt in flight measurement for enhancing MDA.Cited  
          
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        发布时间：2021-03-03
      • WU Guanghua,YAN Huaihai,CHEN Youxin,HUANG Yuzhen,ZHOU Zhongzhu,GAO Daqing
        Vol. 37, Issue 5, Article number: 050401(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050401
        摘要：Background: This paper introduces the application of embedded MySQL database in the real-time monitoring system of the digital power supply system in Heavy Ion Research Facility in Lanzhou (HIRFL). Purpose: The aim is to optimize the real-time monitoring system of the digital power supply system for better performance. Methods: The MySQL database is designed and implemented under Linux operation system running on ARM processor, together with the related functions for real-time data monitoring, such as collection, storage and query. All status parameters of digital power supply system is collected and communicated with ARM by a FPGA, whilst the user interface is realized by Qt toolkits at ARM end. Results: The actual operation indicates that digital power supply can realize the function of real-time data monitoring, collection, storage and so on. Conclusion: Through practical application, we have found some aspects we can improve and we will try to optimize them in the future.Cited  
        关键词：Embedded;Digital power supply;MySQL   
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        发布时间：2021-03-03
      • LIN Jianbo,LI Aiguo,HE Shangming,YU Xiaohan
        Vol. 37, Issue 5, Article number: 050601(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050601
        摘要：Background: The invalidation problems of irradiated Hastelloy N alloy caused by high temperature, intense irradiation and severe corrosion are the key factors to the service life of structural materials of molten salt reactor (MSR). Purpose: The aim is to investigate the effect of absorbed dose on the corrosion resistance of Hastelloy N alloy. Methods: Hastelloy N alloy was irradiated by 4.5-MeV He+ ions, and the absorbed doses were 0 He+?cm?2, 1×1015 He+?cm?2, 5×1015 He+?cm?2 and 1×1016 He+?cm?2 respectively. The virgin and irradiated specimens were immersed into molten fluoride salts at 700 oC for 300 h. Then the corroded specimens were imaged by scanning electron microscopy and analyzed by synchrotron radiation microbeam X-ray fluorescence (?-XRF). Results: The weight-loss results showed that the corrosion generally correlated with the absorbed dose of the alloy. The ?-XRF results indicated that the corrosion was mainly due to the dealloying of alloying element Cr in the matrix. Conclusion: The density of dislocations of Hastelloy N alloy increased with the absorbed dose, which acted as quick paths for Cr element diffusion, and the diffusion of element Cr out of matrix became easier. Finally became weak of the corrosion resistance of Hatelloy N alloy.Cited  
          
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        发布时间：2021-03-03
      • WANG Zhe,HONG Zhenying
        Vol. 37, Issue 5, Article number: 050602(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050602
        摘要：Background: Probability of neutron-initiating persistent fission chain, which has to be calculated in analysis of critical safety, start-up of reactor, burst waiting time on pulse reactor, bursting time on pulse reactor, etc., is an inherent parameter in a multiplying assembly. Purpose: We aim to derive time-dependent integro-differential equation for such probability in relative velocity space according to the probability conservation, and develop the deterministic code Dynamic Segment Number Probability (DSNP) based on the multi-group SN method. Methods: The reliable convergence of dynamic calculation was analyzed and numerical simulation of the evolvement process of dynamic probability for varying concentration was performed under different initial conditions. Results: On Highly Enriched Uranium (HEU) Bare Spheres, when the time is long enough, the results of dynamic calculation approach to those of static calculation. The most difference of such results between DSNP and Partisn code is less than 2%. On Baker model, over the range of about 1 ?s after the first criticality, the most difference between the dynamic and static calculation is about 300%. As for a super critical system, the finite fission chains decrease and the persistent fission chains increase as the reactivity aggrandizes, the dynamic evolvement curve of initiation probability is close to the static curve within the difference of 5% when the Keff is more than 1.2. The cumulative probability curve also indicates that the difference of integral results between the dynamic calculation and the static calculation decreases from 35% to 5% as the Keff increases. This demonstrated that the ability of initiating a self-sustaining fission chain reaction approaches stabilization, while the former difference (35%) showed the important difference of the dynamic results near the first criticality with the static ones. The DSNP code agrees well with Partisn code. Conclusions: There are large numbers of finite fission chains near the first criticality, which can survive until after the second criticality. So the results of dynamic calculation here will be greater than those of static calculation. The numerical simulation on HEU Bare Spheres and Baker model validated the accuracy of the DSNP code, which can calculate initiation probability of dynamic system. Relative to the static method, the DSNP code can describe perfectly the evolvement process of probability of ignition of fissile system.Cited  
        关键词：Probability of persistent fission chain;Dynamic fissile system;Multi-group SN method   
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        发布时间：2021-03-03
      • DAI Yuelai,DAI Zhimin,WU Yanhua
        Vol. 37, Issue 5, Article number: 050603(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050603
        摘要：Background: As a passive check valve, vortex diode is applied to the design of several fluoride salt-cooled high-temperature reactors. It is installed in the emergency heat removal system that is designed to passively remove reactor decay heat under natural circulation. Purpose: By analyzing FLiBe and FLiNaK’s fluidic performance in vortex diode by numerical simulation and comparing with that of water, we could provide a reference for the design of vortex diode applied for the Pool Reactor Auxiliary Cooling System (PRACS) of Thorium Molten Salt Reactor (TMSR). Methods: According to the conceptual design of PRACS, a model of vortex diode was simulated under different working conditions by using Fluent. Taking measures of the best tangential angle and the converging-diverging axial tube is to get better performance. Results: The forward and reverse pressure drops increase with the flow rate, and the diodicity is related to the Reynolds number of working medium, and increases with Re number until a certain value, where the diodicity basically remains unchanged. After structure optimization, the value of diodicity is enhanced to some extent. Conclusion: Based on the results, there is a critical Re number both for FLiBe and FLiNaK in vortex diode. Optimizing the structure design of the vortex diode can improve FLiBe and FLiNaK’s performances in vortex diode.Cited  
        关键词：Vortex diode;FLiBe;FLiNaK;Performance parameters;Structure optimization   
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        发布时间：2021-03-03
      • ZONG Guoqiang,CHEN Bo,ZHANG Long,SUN Jiahong,DONG Qun’an,CHEN Wei,XIAO Jichang
        Vol. 37, Issue 5, Article number: 050604(2014) DOI: 10.11889/j.0253-3219.2014.hjs.37.050604
        摘要：Background: Possessing a series of advantages, such as low neutron absorption cross section, much lower vapor pressure and good heat transfer performance fluoride molten salts are widely used in the high-temperature hydrogen, solar storage, nuclear fuel and other energy fields. Among them, ternary mixture of LiF-NaF-KF (FLiNaK) is one of the most common candidate molten salt systems. Purpose: We aim to examine the effect of temperature, time, crucible material and fluoride reagents on the quality of the molten salt, and preliminarily master key process parameters for preparation of FLiNaK molten salt. Methods: The formation of FLiNaK molten salt was studied by a vacuum melting platform. The optional preparation conditions were obtained through the screening of melting temperature, timing, crucible material and fluorination reagent. Results: In the presence of NH4HF2, the oxygen content in FLiNaK salt could be controlled below 2×10?4. Metal ion impurities in molten salt, according to the general requirements of the quality standard for molten salt reactor, of which Be, Cu, Fe, Zr and Cd contents are less than 5×10?6. And impurities of sulfate and phosphate anions are less than 1×10?4 and 3×10?5, respectively. Conclusion: Using the present preparation method, the corrosion of furnace was greatly reduced. It was an efficient, low-cost, and safe process for the preparation of FLiNaK molten salt.Cited  
        关键词：FLiNaK molten salt;Preparation;Ammonium hydrogen fluoride;Recrystallization   
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        发布时间：2021-03-03
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