最新刊期
      卷 0 ， 期 0 ， 2020
      • ZHANG Zhiyuan CHEN Jianfeng SHEN Liren
        Vol. 33, Issue 9, (2010)
        摘要：SSRF,as a national scientific base in China to provide synchrotron radiations from IR to hard X-rays for hundreds of scientists working simultaneously on the experimental stations,needs an efficient software platform for the facility control and user service.It uses a distributed control system of EPICS,which is commonly used home and abroad in large scientific facilities.Channel Archiver is an archiving toolset for EPICS,which is used to store and retrieve different types of data generated by EPICS.Based on analysis of Archive System,we have found some ways to overcome the defects in existing,and designed a new archiver system using Oracle database.This offers a unified interface for varieties of programs.  
        关键词：SSRF;EPICS;Channel Archiver;Oracle;Web Service   
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        发布时间：2021-03-05
      • SUN Xiaoying CHEN Guanghua LIU Yiyong CHEN Jianfeng JIANG Dikui DAI Zhimin
        Vol. 33, Issue 9, (2010)
        摘要：In this paper,we report the design and implementation of a Web-based database system for the SSRF storage ring vacuum status.A vacuum data acquisition system based on EPICS was developed for implementation of the system.By storing the vacuum gauge readings,the average pressure,beam lifetime and beam current to the historical database using Channel Archiver,the data can be retrieved from any online computers.A proper and effective platform for sharing the SSRF storage ring vacuum data has been built.It offers usable and reliable vacuum data of the storage ring for operators and the users.  
        关键词：Database;Web;EPICS;Vacuum control   
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        发布时间：2021-03-05
      • FU Zechuan1,2 ZHAO Yubin1 ZHAO Zhentang1 1
        Vol. 33, Issue 9, (2010)
        摘要：A new RF front-end was designed and tested for Shanghai Synchrotron Radiation Facility.An L-C filter low-pass circuit was introduced in the design,which remarkably reduced the volume of the front-end,with granteed performance.The use of active mixer,the needed local signal can be as low as-10 dBm,and this significantly reduces the system requirement for local amplifier.Linearity of the system reaches 30 dB.Variable gain amplifier enables a power match in the system.The amplitude inaccuracy is less than ±0.15%,and the phase inaccuracy is less than ±0.2°.Crosstalk between adjacent channels is lower than-60 dB.  
        关键词：Digital LLRF;RF front-end;RF receiver;Linearity;IC   
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        发布时间：2021-03-05
      • LIU Xin JIANG Geyang SHEN Liren CHEN Jianfeng
        Vol. 33, Issue 9, (2010)
        摘要：The interlock system is a control subsystem designed to protect essential equipment of Shanghai Synchrotron Radiation Facility(SSRF).As a part of the interlock system,the fast interlock system based on FPGA and ARM acts within 1 ms after a vacuum leak signal is given.In this paper,we describe the implementation of the fast interlock system.The design makes use of strong software capacity of the ARM,flexible logic process capability of FPGA,and rich IO resources to achieve the response time requirements of the system.The system solutions,hardware architecture and the test result of the controller are given,too.  
        关键词：Fast interlock system;FPGA;ARM   
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        发布时间：2021-03-05
      • ZHANG Xiangzhi XU Zijian ZHEN Xiangjun WANG Yong GUO Zhi YAN Rui TAI Renzhong
        Vol. 33, Issue 9, (2010)
        摘要：The BL08U soft X-ray microspectroscopy station of Shanghai Synchrotron Radiation Facility has been built and open to users successfully.The spatial resolution is about 30 nm.Due to limitation of mechanical precision and errors in repeatability,the drift of scanned images is inevitable at different scan energies.This gives rise to serious errors and data analysis inaccuracy.Therefore,the images scanned by X-rays at different-energies should be registered before data analysis.For solving the problem,efforts have been made in both hardware and software.A laser interferometer is used to precisely detect the sample position and measure its position drift,and the drift rates can be calculated with a standard sample(pattern) using the slope function.The drift rates are used for dynamic calibration of the sample stage position,which is initiated automatically once there is a sample moving.To a large extent,this eliminates the position drifts.On the other hand,a multi-window cross correlation technique to automatically register the scanned images has been developed.The result shows that the technique can reach a precision of 1 pixel.  
        关键词：Image registration;Multi-window;Correlation function;Laser interferometer;STXM   
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        发布时间：2021-03-05
      • LUO Tao DONG Lan LI Bo WANG Xiaolong MEN Linlin
        Vol. 33, Issue 9, (2010)
        摘要：For reconstruction of the Beijing Electron Positron Collider(BEPCⅡ),performance of the industrial total station Leica TDA 5005 was combined with technical requirements of BEPCⅡ.The control points and instruments reference points of the storage ring were measured repeatedly.In this paper,we analyze the accuracy and reliability of automatic target recognition(ATR) measurement with TDA5005,and discuss the feasibility of applying it in the accelerator alignment measurement.The results can be of help in this kind of applications in alignment measurements of similar accelerators.  
        关键词：BEPCⅡ;Industrial total station;TDA 5005;ATR   
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        发布时间：2021-03-05
      • LI Min WANG Liyan GOU Chengjun WU Zhangwen HOU Qing
        Vol. 33, Issue 9, (2010)
        摘要：Modulated electron radiation therapy(MERT),which delivers conformal dose to shallow tumors and protects distal structures and surrounding tissues,but,the photon multileaf collimator(MLC) is no longer suitable for MERT.In this paper,the PENELOPE code is used to simulate an electron-specific MLC(EMLC) for the optimal choice of the material and geometry of leave.The results demonstrate that tungsten is more suitable for EMLC than lead,iron,copper;and 2 cm thickness is sufficient to resist most of the electrons with relatively less bremsstrahlung;leaf with straight end shape produces less dose penumbra and moreover the width of 1 cm is the most suitable choice for leaf width.  
        关键词：MERT;EMLC;PENELOPE   
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        发布时间：2021-03-05
      • WANG Xinhua AN Li HE Tie ZHENG Pu GUO Haiping YANG Jian MOU Yunfeng YANG Xiaofei ZHU Chuanxin
        Vol. 33, Issue 9, (2010)
        摘要：In developing a neutron generator-based security check system for explosives using associated α particles and neutron flight of time technique,it is important to avoid possible influences by the D-T neutron and secondary γ-rays to the inspection equipment,staffs,passengers and ambient environment.In this paper,the MCNP5 code is used to simulate the coupled transport of neutrons and γ-rays,for calculating the shield effect of inspection equipment and the individual dose equivalent.The results show that after effective shielding,the fast neutron equivalent of inspection equipment can be reduced to 3.44% of the source flux,satisfying the shielding requirement.The individual dose equivalent meets the national regulations in specified access areas.The influences to surrounding environment can be neglected.  
        关键词：Explosive inspection;D-T neutron;Monte-Carlo simulation;Shielding design   
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        发布时间：2021-03-05
      • LIN Fan ZHANG Qingxian GE Liangquan ZENG Guoqiang GU Yi
        Vol. 33, Issue 9, (2010)
        摘要：Monte Carlo method is an important approaches for radiation physics simulation.In this paper,we report a Geant4-based Monte Carlo method to simulate the γ-ray spectrum produced by a multi-crystal airborne spectrometer.Spectral difference among the NaI(Tl) scintillators,the diversification of spectrum in upside scintillator due to terrestrial radiation with different energy,and deviation of the radon correction coefficient caused by the terrestrial radiation,were studied.The results will provide a theoretical basis for analysis of multi-crystal airborne γ-ray spectrum.  
        关键词：Airborne gamma spectrometer;Airborne geophysical prospecting;NaI(Tl) detector;GEANT4;Monte Carlo method   
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        发布时间：2021-03-05
      • PENG Mei SUN Liangwei CHEN Liang LI Xinxi XIE Chaomei ZHU Chengyin
        Vol. 33, Issue 9, (2010)
        摘要：Velocity selector is a key component of small angle neutron scattering instrument,and single wavelength neutron beam of small spectral width can be acquired by a velocity selector.In this work,a rotor-type velocity selector was simulated using the Vitess code to optimize design parameters of the velocity selector for certain experimental requirement.Spectral characteristic of the selected neutrons was analyzed,and it was found that divergence of the incident neutron beam and tilt angle of the rotor affected the spectral characteristic of neutron beam markedly.  
        关键词：Velocity selector;Parameter designing;Optimization calculation;Spectral characteristic of neutron   
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        发布时间：2021-03-05
      • ZHOU Lin JIANG Shilun QI Jianmin
        Vol. 33, Issue 9, (2010)
        摘要：A compact magnetic analyzer for magnetic proton recoil spectrometer has been developed at CAEP.Nd-Fe-B permanent dipole is used as the analyzing magnet,with a focal plane detector of CR39.Performance of the analyzer was studied with the actual magnetic field distribution and charged particle transport code.Experiments were performed with a 239Pu α source.Capability of the spectrometer was studied with Monte Carlo simulations and the transport code.The results show that proton and alpha particles of 3.5-8.5 MeV can be analyzed by the magnetic analyzer with an excellent capability of momentum dispersion and radial focuses,which meet the requirements of compact MPR spectrometer.The MPR spectrometer has an energy resolution of about 4% and detection efficiency of about 10-8 for DT fusion neutrons.  
        关键词：Neutron spectrum;Magnetic proton recoil(MPR);Magnetic analyzer;Monte Carlo   
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        发布时间：2021-03-05
      • LIU Dan1,2 WU Shengwei1 MA Mingwang1,2 ZHANG Zengyan1 ZHU Zhiyong1 1
        Vol. 33, Issue 9, (2010)
        摘要：Terahertz time domain spectra(THz-TDS) of liquid water,dioxane and their mixtures were measured using 0.3-1.8 THz waves.The results show that the dioxane is nearly transparent to THz waves and the absorption of dioxane-water increases with the water content.The mixtures behave as ideal liquid at high water content,but the mixture’s absorption coefficient is remarkably higher than that of ideal liquid when water content is less than 20 vol%.This noticeable deviation of low water content mixtures from ideality is due to the particular properties of nano-water or interface water.  
        关键词：THz-TDS;Water;Dioxane-water mixture;Dielectric properties   
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        发布时间：2021-03-05
      • HU Chunming
        Vol. 33, Issue 9, (2010)
        摘要：A cold neutron source(CNS) is a reactor facility to slow down thermal neutrons into clod neutrons of 0.1-0.5 meV.If the cryogenic hydrogen loop leaks(including the moderator chamber),and the injecting hydrogen contacts the inner surface of the vacuum containment,the thermal stress shall concentrate on the impacted zone by cryogenic hydrogen.A finite element stress analysis was conducted,and it was found that the maximum stresses are 195 and 213 MPa,corresponding to the impacted area of 1.0-2.25 cm2,respectively.The max stresses are less than the stress limit of the material.So it is concluded that the cryo-hydrogen injecting accident does not threat the safety of the vacuum containment.  
        关键词：CNS vacuum containment;Cryogenic hydrogen;Injecting;Stress   
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        发布时间：2021-03-05
      • SONG Hongzhi1 WU Jie2 ZHANG Jie2 KONG Yang2 MA Yichao2 1
        Vol. 33, Issue 9, (2010)
        摘要：Multi-level trigger architecture is commonly used in data acquisition systems for large scale high energy physics experiments.In multi-level architecture,data is sent to higher level systems through network,which is usually based on Ethernet technology.In order to improve system efficiency and find out optimization methods for data transmission,in this paper we describe the network data receiving process of Linux 2.4 kernel in terms of data flow that based on ARM platform,and combined with the data obtained from the kernel.Reasons of changing network performance are analyzed,too,and system optimization recommendations are given.  
        关键词：Embedded system;ARM;Linux;TCP/IP   
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        发布时间：2021-03-05
      • SONG Zifeng YE Shuzhen CHEN Ziyu SHEN Ji
        Vol. 33, Issue 9, (2010)
        摘要：In this paper,was reported preparation of 10B film as neutron convertor used in GEM-based thermal neutron detector.The boron target was prepared using pressurized vacuum sintering of boron powder.It is found that the 10B content in the target was closely related to the vacuum environment.The 10B film was evaporated on an Al-coated polyimide film via pulsed laser deposition(PLD).At 100℃ of the substrate,growth rate of the boron film was about 0.56 nm/min.Composition of the film was analyzed by XPS.The XPS data shows that it consists of boron and borides,both of that can be used as neutron convertor layer.  
        关键词：Thermal neutron;Boron convertor;GEM;PLD;XPS   
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        发布时间：2021-03-05
      • JIAO Xixiang1,2 JING Lan1 QIAO Weimin1 MA Yunhai1 1
        Vol. 33, Issue 9, (2010)
        摘要：The hardware platform of digital adjustor for HIRFL-CSR power system has been developed.It is based on CycloneⅢFPGA,which is of 1 mm BGA package.The platform can run digital adjustor algorithm and satisfy specific technical requirements.ARM(Advanced RISC Machines) EP9315 microprocessor is used as the core of the control system to deal with the task of multi-threaded.And there are 1 G SFP connecting with FPGA to transmit data processed by DSP on other board,hence a great improvement of the system’s real-time performance.The hardware platform can realize a stable,reliable,real-time control for the HIRFL-CSR power supply system.  
        关键词：CycloneⅢ;EP9315;Digital adjustor;Embedded system;Cooling storage ring   
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        发布时间：2021-03-05
      • XIE Quanxin CONG Yikun WU Jianjun
        Vol. 33, Issue 9, (2010)
        摘要：A mathematical model is established for the quasi-ideal cascade with an additional feed flow.A numerical calculation method to solve the cascade equation was presented and analytical solution of the cascade equation was obtained.Analytical expressions are given for calculating the relative product and waste flows,the total substance flow,and the component concentrations in the product and waste flows.Calculations for the enrichment of recycled uranium are carried out by using the model of quasi-ideal cascade,in which the natural uranium is supplied as a base feed flow while the recycled is supplied as an additional one.  
        关键词：Multicomponent isotope;Separation;Quasi-ideal cascade;Additional flow;Recycled uranium   
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        发布时间：2021-03-05
      • WANG Zhentao1 YANG Yifang1 WANG Haijun1 WANG Yuexing1 ZHANG Jianguo1 LIU Daihao2 1
        Vol. 33, Issue 9, (2010)
        摘要：A strippable film of polyvinyl alcohol (PVA) for decontamination of radioactive dusts on stainless steel (SS) device surface was developed by investigating the film-stripping ability from the SS surface and the contamination-removal efficiency of the films of various preparation parameters. They include PVA concentration of the film-making solution, and amounts of EDTA-Na-Ca as complexing agent, CMC-2Na as thickening agent, PEG-200 as plasticizer, nmCaCO3 as surfactant, and 1.85 mol/L HCl. The PVA film, which can be dried in 8 h, is capable of removing over 80% of surface contamination of 90Sr at 0.02-0.20 Bq/cm2.  
        关键词：Strippable film;Surface contamination;Radioactive;Removal   
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        发布时间：2021-03-05
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