最新刊期
      卷 0 ， 期 0 ， 2020
      • LIU Linmao JING Shiwei GU Li LI Wensheng ZHANG Chi
        Issue 10, (2001)
        摘要：The experimental system of microwave ion source for intense neutron tube was described. The mode of magnetic field, the relations between microwave absorption efficiency and distribution of magnetic field as well as pressure were presented. Microwave input power was 300-500W, and the microwave absorption efficiency could reach more than 90% when the system was operated in the best mode. The best absorption efficiency was 100%.  
        关键词：Intense neutron tube;Microwave ion source;Absorption efficiency;The mode of magnetic field   
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        发布时间：2021-03-12
      • HE Chengfa BA Weizhen CHEN Zhaoyang
        Issue 10, (2001)
        摘要：The methods for measuring the dose induced by low energy X rays and 60 Co γ rays and the threshold voltage shift the devices are described. The influences of the different biases and irradiation directions on the devices are discussed. The results for the devices packaged by gold plating Kovar aolly under a worst case in which the two kinds of rays are incident from the back side are given. The threshold voltage shift for the low energy X rays is 13.4 times larger than that for the 60 Co gamma rays.  
        关键词：CMOS device;X ray;γ ray;Dose enhancement   
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        发布时间：2021-03-12
      • FAN Hongmei WANG Tongqing GUO Bin ZHANG Li ZHAO Jinghua
        Issue 10, (2001)
        摘要：The modification, new progress and experimental results of the FEBIAD ion source used for isotope separation on-line in Lanzhou were described. After modification, the resolving power of ISOL is increased from 360 to 600 for Xe and efficiency for 199 Hg is higher by an order of magnitude than before. The modified FEBIAD target-ion source has been successfully applied to separate isotopes of Hg, At and Rn. The γ-ray with highest energy of 1.234MeV from the decay of 208 Hg which has a production cross section of 5×10 -34 m 2 can be measured.  
        关键词：Resolving power;Target ion source;On-line isotope separator   
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        发布时间：2021-03-12
      • XIE Heng GAO Zuying
        Issue 10, (2001)
        摘要：Three-dimensional CFD code, Phoenics-3.2, is used to calculate the flow and heat transfer along the gap between the fuel assemblies of 200MW nuclear heating reactor (NHR-200). The actions of important factors which could affect the flow and heat transfer were considered. After these investigations, the optimum scheme of bypass was gotten.  
        关键词：CFD;Phoenics;Nuclear heating reactor   
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        发布时间：2021-03-12
      • ZHNAG Ziping CHEN Hongfang SUN Hao YE Shuwei
        Issue 10, (2001)
        摘要：The application of Iterative Discriminant Analysis (IDA) and Neural Networks (NN) methods for e, μ, π particle identification in BES experiment on BEPC collider was discussed. Under exactly the same condition, satisfactory identification efficiencies and background levels were given by both methods for those particles with momentum in the range from 0.2GeV to 1.6GeV. Although the momentum spectrum of the data samples used for training were non-uniform, it was interesting that the selection efficiencies given by test results from both method were quite uniform in the whole momentum range. It shows that the NN method is slightly better than IDA method. Their characteristics and application condition were also discussed.  
        关键词：Particles indentification;IDA;NN;BES spectrometry   
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        发布时间：2021-03-12
      • DAI Xiongxin WANG Jinchun MAO Xueying CHAI Zhifang OUYANG Hong
        Issue 10, (2001)
        摘要：The adsorption behaviors of iridium on an anion resin were studied through 192 Ir radiotracer technique and near ultra-violet and visible spectrum analysis. An anion exchange preconcentration procedure for iridium in natural seawater sample was established, and the recovery reached 90%. Under ultra-clean condition, the Ir concentration in a coastal seawater sample derived from the China Yellow Sea was determined by neutron activation analysis after this preconcentration procedure to be 2.6×10 -14 g/mL.  
        关键词：Coastal seawater;Iridium;Anion exchange;Neutron activation analysis   
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        发布时间：2021-03-12
      • CHEN Zhiqiang ZHAN Wenlong GUO Zhongyan XIAO Guoqing WANG Meng WANG Jinchuan WANG Jiansong NING Zhenjiang WANG Quanjin LI Jiaxing WANG Jianfeng
        Issue 10, (2001)
        摘要：For particle identification at the Radioactive Ion Beam Line in Lanzhou (RIBLL), a two-fold ionization chamber which consists of two anodes striped in X and Y direction separately was set up. The relative energy resolution for 241 Am α source is about 3.49% by calibrating the energy of IC using 3-component α source. By measuring the secondary products and projectile fragments in the experiment of 80 MeV/u 20 Ne + 58 Ni reaction at RIBLL, the two-dimensional plot of ΔE versus TOF was measured. According to the principle of particle identification, Z distribution of A/Z =2 and Ne,O, N,C isotope distributions could be obtained.  
        关键词：Anode striped twin-fold ionization chamber;Energy calibration of ionization chamber;Particle identification   
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        发布时间：2021-03-12
      • WANG Guangfu 1,2 ZHANG Huixing 1 1
        Issue 10, (2001)
        摘要：It is justified first time by experiments that the magnetic filtering duct influences the cathode vacuum arc discharge by working as second anode of the MEVVA plasma source. An equivalent circuit for the filtered cathode vacuum arc discharge was derived, and used to explain and analyses the arc discharge phenomena with two anodes.  
        关键词：Magnetic macroparticle filter;Vacuum arc deposition;Second anode;Equivalent circuit   
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        发布时间：2021-03-12
      • FU Xiaoguo LIU Kezhao WANG Xiaolin BAI Chaomao ZHAO Zhengping
        Issue 10, (2001)
        摘要：The initial oxidation of uranium-niobium alloy in oxygen atmosphere at 298K was studied by X-ray photoelectron spectroscopy. The changes of U4f,Nb3d and O1s spectrum during in-situ oxidation indicated that the adsorption of oxygen on uranium-niobium alloy surface first led to the formation of UO 2, UO 2- x and NbO, then NbO 2 and Nb 2O 5 were detected with increasing exposure of oxygen. The segregation of uranium and niobium to the surface was observed at different oxidation stages.  
        关键词：X-ray photoelectron spectroscopy;Uranium-niobium alloy;Oxygen   
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        发布时间：2021-03-12
      • FANG Yue’e ZENG Kunwei WANG Hengdong
        Issue 10, (2001)
        摘要：The degradation of solid-state chitosan was studied by γ-ray irradiation. The experimental results demonstrated that if the absorber dose was 184.1 kGy the molecular weight decreased from 1.07×10 6 to 1.16×10 5 (in air) and 1.72×10 5 (in N 2),and the values of G (S) were 0.75 and 0.57 respectively. Another degradation process by the electron beam irradiation was also investigated. If the absorber dose was 200 kGy the molecular weight decreased from 1.14×10 6 to 7.67×10 4,and the value of G (S) was determined to be 1.02 (in air).  
        关键词：Chiosan;Radiation degradation;Molecular weight;G (S) value   
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        发布时间：2021-03-12
      • JIANG Shaoen SUN Kexu HUANG Tianxuan CUI Yanli WANG Hongbin CHEN Jiusen YI Rongqing
        Issue 10, (2001)
        摘要：A filtered differential measurement system for soft X-ray spectrum using Ross filters was established. The principle of the system was introduced. Five matched differential pairs were designed. The system was used to measure soft X-ray spectra emitted from laser plasmas and good experimental results were obtained. The measured results show that this system has properties of good monochromaticity, unfolding simply and high accuracy.  
        关键词：Filtered difference;Soft X-ray spectrum;Matched differential pairs   
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        发布时间：2021-03-12
      • HUANG Runsheng JI Shengmou ZHONG Xiaohua LIU Xiankun XU Jianjian
        Issue 10, (2001)
        摘要：An improved velocity control unit for Mssbauer spectrometer was developed. Its characteristics are (1) velocity range of Mssbauer spectrometer can be easily set (2) velocity control precision of Mssbauer spectrometer can be improved. Detail analyses and experimental results were also presented.  
        关键词：Mssbauer spectrometer;Velocity control unit   
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        发布时间：2021-03-12
      • WU Pin LI Quanfeng ZHANG Yunkai
        Issue 10, (2001)
        摘要：With the development of accelerator technologies, it is important to find a rapid and precise way in which the electron spectrum can be diagnosed on real time. For its advantages of relatively simple setting-up, fast response, little disturbance to a beam and so forth OTR (Optical Transition Radiation) technologies has gradually attracted our attention. In this article real time spectrum analysis on OTR technologies was introduced. The prelimicnary result from parts of the instrument was listed and studied. The width of OTR was 20mm, in accordance with the theoretical result.  
        关键词：OTR;Spectrum analysis;Electron bunches diagnose   
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        发布时间：2021-03-12
      • PENG Shixiang
        Issue 10, (2001)
        摘要：A review of early microbeam apparatuses used to study the biological responses caused by irradiation was given along with a summary of the investigation results on the single cell experiments. The deficiences of the early apparatus were analyzed and used to guide our charged particle microbeam design.  
        关键词：Early;Microbeam facilities;Biological responses;Deficiency   
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        发布时间：2021-03-12
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