最新刊期
      卷 0 ， 期 0 ， 2020
      • JIANG Jiayou CHEN Zhihao
        Vol. 34, Issue 4, (2011)
        摘要：The three bump magnets in the booster extraction system of SSRF are driven by a signal generator with an external trigger.The signal generator must have three independent and controllable outputs,and both amplitude and make-and-break should be controllable,with current state information being readable.In this paper,we describe a signal generator based on FPGA and DAC boards.It makes use of characteristics of both FPGA flex programmable and rich reconfigurable IO resources.The system has a 16-bit DAC with four outputs,using Matlab to write a GUI based on RS232 protocol for control.It was simulated in Modelsim and tested on board.The results indicate that the system is well designed and all the requirements are met.The arbitrary waveform is writable,and the pulse width and period can be controlled.  
        关键词：FPGA;DAC;Matlab GUI;Signal generator   
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        发布时间：2021-03-05
      • SUN Fuquan1,2 FU Yuan1 ZHU Wanqian1 XUE Song1 1
        Vol. 34, Issue 4, (2011)
        摘要：The sag of mirror due to gravity induces unacceptable slope errors in beamline mirror-bending system of a synchrotron radiation facility,and approaches must be found to eliminate the unwanted gravity effect.According to the beam bending theory,the multi-point gravity compensation method is applicable.Taking an example of the bent collimating mirror for the XAFS beam-line(BL14W) at Shanghai Synchrotron Radiation Facility(SSRF),the best position and value of the equilibrant were calculated through minimizing the gravity effect.With two,three and four points gravity compensation,slope errors were 0.179,0.067 and 0.032 μrad,respectively,i.e.the multi-point gravity compensation is better than the two-point gravity compensation,which is used for the Phase I beamlines of SSRF.The four-point gravity compensation method reduces more slope error and stress due to four support points.  
        关键词：Mirror bending system;Multi-point gravity compensation;Synchrotron radiation   
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        发布时间：2021-03-05
      • XIONG Liang1,2 YIN Chongxian1 LIU Ming1 CHEN Jianfeng1 1
        Vol. 34, Issue 4, (2011)
        摘要：Both DC current transformer(DCCT) and integrating current transformer(ICT) can be used in DC beam current measurement.The ICT has strong capability of resisting electromagnetic interference,but its measurement accuracy cannot satisfy the DC beam current measurement requirement when using traditional high speed A/D.With high resolution A/D and equivalent sampling system,DC beam current measuring system based on ICT can reach high accuracy compared with DCCT system.In this paper,the ICT-based DC beam current measurement,equivalent sampling method and testing results at Shanghai Synchrotron Radiation Facility(SSRF) is described.  
        关键词：Beam current;Equivalent sampling;PLL   
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        发布时间：2021-03-05
      • TANG Xinghua1,2 LI Jiacai2 XU Jinzhang1 KE Zunjian2 AN Guangpeng2 YANG Tao2,3 ZHANG Shaoping2 1
        Vol. 34, Issue 4, (2011)
        摘要：In target chamber Ⅱ of the BEPCII-LINAC Test Beam,radiation field of mixed particles(mainly proton,neutron,gamma,pion,positron and electron) of consecutive energy is generated from the object target bombarded by the 1.89 GeV pulsed electron beams from the linear accelerator.This mixed radiation field is ideal for irradiating materials or biological samples.However,these experiments need to know the dose of various particles delivered to the samples.In light of this,a mixed radiation detector(phoswich detector) was developed.In this paper,the basic process of the detector development and its key properties are reported.The basic structure of detector and principles of detection are given.GEANT4 simulation results of detection efficiency of different particle and performance of n-γ discrimination are given.The results show that the mixed radiation detector,with the design specifications being achieved,satisfies the measurements of mixed field in the Test Beam.  
        关键词：Phoswich detector;GEANT4 simulation;n-γ discrimination   
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        发布时间：2021-03-05
      • YANG Tao1,2 LI Jiacai2 TANG Xinghua2,3 GU Yunting1 KE Zunjian2 AN Guangpeng2 ZHANG Shaoping2 1
        Vol. 34, Issue 4, (2011)
        摘要：Bombarding a beryllium target with 1.89 GeV pulsed electron beams produces a large number of secondary particles(protons,neutrons,gamma phones,pions,positrons and electrons).The energy spectrum and angular distribution of the secondary particles are simulated with the Geant4 code.The results indicate that the protons of over 35 MeV have a yield of 3.97×108 s-1 and flux of 6.32×105 s-1.cm-2.Measurement at fixed-angle of 41° magnetic spectrometer of the BEPCII-LINAC Test-Beam is consistent with the simulation results.Protons of secondary beam at BEPCII-LINAC Test-Beam can be used in Single Event Effects(SEE) research of the semiconductor devices.  
        关键词：Beryllium target;Secondary particles;GEANT4;Proton;Energy spectrum;SEE   
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        发布时间：2021-03-05
      • XUE Lingui1 XU Junquan1 ZHANG Hong2,4 WU Zhenhua2,4 ZHAO Xu1 1
        Vol. 34, Issue 4, (2011)
        摘要：Perilla seeds were irradiated by 80 MeV/u 12C6+ ion beams and cultivated in experimental field.The physiological characteristics of the Perilla mutant were analyzed,so as to obtain experimental data for the breeding of Perilla.The results show that the contents of soluble sugar,proline(Pro) and flavonoids compounds from the perilla mutant leaves increased with the dose first,whereas at larger doses they decreased with increasing doses,but this trend was not clearly observed with the chlorophyll content.Also,the results show that with the increasing doses,the contents of catalase(CAT),peroxidase(POD),superoxide dismutase(SOD) activity and malondialdehyde(MDA) increased first and then decreased,but the proteins reduced first and increased afterward.These indicate that the heavy ion treatment can change some physiological and biochemical characteristics,being in favor of improving stress tolerance and accumulating nutrients of Perilla.  
        关键词：Perilla frutescens;Heavy ion irradiation;Mutagenic breeding;Physiological characteristics   
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        发布时间：2021-03-05
      • LIU Yang1 SHEN Fei1 YANG Yao1 YAN Yonghong1 YAN Yan1 LI Bingying1 YAO Zeen1,2 1
        Vol. 34, Issue 4, (2011)
        摘要：A beam-shaping-assembly(BSA) of D-T neutron generator for fast neutron radiography was designed.The D-T neutron transportation in the BSA was simulated using the MCNP code.The neutron energy spectrum,neutron flux,γ-ray energy spectrum and γ-ray flux of the shaped neutron beam were given.The results show that the shaped neutron beam,based on 150 keV/1 mA D-T neutron generator and the designed BSA,can meet the need of the fast neutron radiography.  
        关键词：D-T neutron generator;Fast neutron radiography;Beam-shaping-assembly(BSA);Neutron energy spectrum;Neutron flux   
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        发布时间：2021-03-05
      • ZHOU Cheng ZHAO Fuxiang
        Vol. 34, Issue 4, (2011)
        摘要：In this paper,we report the environmental radioactivity survey in an abandoned uranium mine in China.The air gamma ray absorption dose rate was measured.Radionuclides in uranium mine slag,soil,water,sediment and biological samples,were analyzed.Radon in the air was monitored.The annual radiation dose of the residents in the uranium mine region was assessed.All the work was conducted in line with national standards of China.The survey results show that the radioactive pollution in the region should be disposed immediately.According to the characteristics of the uranium mining pollution sources,we propose some reasonable ways of radiation protection and disposal.  
        关键词：Uranium mine;Radioactive pollution;Radon;γ radiation;Radiation dose   
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        发布时间：2021-03-05
      • ZHAO Liping WU Jing XIE Chunyi LUO Guangnan
        Vol. 34, Issue 4, (2011)
        摘要：In contemporary tokamaks,hydrogen isotope retention is evaluated by in-situ and post-mortem analyses.Mechanisms of the retention are implantation-trapping and co-deposition.Studies on hydrogen isotope retention at JT-60U,DIII-D,JET,ASDEX-U,C-MOD,TEXTOR and TORE SUPRA reveal that the nature of material,divertor geometry,structure and alignment of tiles,and temperature can affect the retention.This paper gives a review in this field of research at these tokamaks.The post-mortem plan at the EAST tokamak is briefed,too.  
        关键词：Retention;Hydrogen isotopes;Tokamak   
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        发布时间：2021-03-05
      • XU Xiaoping1,2 ZHANG Yuanqing1,2 SHEN Yumei1 1
        Vol. 34, Issue 4, (2011)
        摘要：Dendrimers can target tumor taking advantage of enhanced permeation and retention effect(EPR).In this study,partially acetylated generation 5(G5) polyamidoamine(PAMAM) dendrimer was conjugated with the active targeting moiety(avidin).The nanoparticles which have passive and active tumor-targeting were radiolabel with 99mTc.The nano-particle conjugated with avidin(avidin-G5-1B4M-99mTc) exhibited much higher cellular uptake into Hela cells than those without avidin conjugate.Using this conjugate,excellent SPECT imaging results were obtained in tumor-bearing nude.This radiolabelling nano-particle has the potential of early stage cancer diagnosis,and cancer therapy.  
        关键词：Dendrimer;Avidin;EPR;Active targeting;Radiolabelled   
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        发布时间：2021-03-05
      • ZHANG Xiaoming1 MENG Cui1 WEI Ming2 LIU Shanghe2 1
        Vol. 34, Issue 4, (2011)
        摘要：In this paper,we report the design and test of a wideband sensor for measuring transient electric field,which is consist of a monopole antenna,high input resistance receiving circuit,electro-optic modulating circuit and fiber links.In the end,a photoelectric conversion is conducted and the E-field signal can be watched on the oscilloscope.Test results show that it can satisfy time-domain and frequency-domain requirements.The sensor may play an important role in the EMP and EMC research.  
        关键词：Nuclear electromagnetic pulse;Electric field sensor;Frequency domain;Time domain;Fiber system   
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        发布时间：2021-03-05
      • SHEN Fengjun GE Liangquan YANG Qiang ZHANG Qingxian GU Yi
        Vol. 34, Issue 4, (2011)
        摘要：In this paper,we report key technologies and challenges in designing an X-ray fluorescence logging device developed especially for field drilling sites.The data obtained with the X-ray fluorescence logging device at a copper mine are compared with the results of chemical analysis,and it is demonstrated that this device can be used for field applications.  
        关键词：Logging device;X-ray fluorescence;Element content   
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        发布时间：2021-03-05
      • XIE Feng JIANG Wengang HE Xiaobing LI Xuesong CHANG Yongfu
        Vol. 34, Issue 4, (2011)
        摘要：In order to satisfy the requirement of mobile measurement,we developed a low background measurement equipment for radioactive gas.It uses an internal gas proportional counter as main detector,which is inserted into a well-type NaI(Tl) detector to form an anticoincidence detector.Test results show that a low background system has good performance in radioactive gas measurement.In a 24-h measurement,the minimum detectable activities for 3H and 85Kr were 4.08 and 3.73 mBq,respectively.  
        关键词：Low background;Internal gas proportional counters;Well-type NaI(Tl);3H;85Kr;Anticoincidence   
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        发布时间：2021-03-05
      • WANG Sanbing HE Chaohui
        Vol. 34, Issue 4, (2011)
        摘要：To meet the requirement of future missions of deep space exploration,a new nuclear battery system,nuclear battery driven by external neutron source,was introduced in this paper.The ratio of power over weight and power output of the nuclear battery calculated with MCNP in a simple model were 4.45 W/g and 9.88 kW,respectively.Compared with radioactive thermal-electric generator(RTG),this nuclear battery could supply 8 times ratio-power and 3.54 times power output than GPHS-RTG,respectively.Also,the ratio-power and power output of the nuclear battery were calculated in the detail model of GPHS-RTG,and each module could generate 4.3293 W/g of ratio-power and 698.253 W of power output,which are 9.55 times and 10.2 times more than GPHS-RTG,respectively.For a multi-module system,this nuclear battery could generate 6.83 W/g of ratio-power and 22.04 kW of power supply.The advantage of the nuclear battery driven by external neutron source is obvious.  
        关键词：Nuclear battery driven by external neutron source;MCNP(X);RTG   
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        发布时间：2021-03-05
      • ZHANG Donghua1,2 HU Jun1 1
        Vol. 34, Issue 4, (2011)
        摘要：In this paper,vibrating scanning polarization force microscopy(VSPFM) technique is used to study the adsorption of ethanol gas molecules on mica surface at room temperature,and the relationship between bias and imaging quality.Experiment results showed that the best images can be acquired when the tip is biased at AC 5 V.VSPFM is a useful technique to investigate air-solid interaction.Using this technique,we found that ethanol gas molecule did not adsorb quickly on mica surface,and the ethanol adsorption behavior could not be illustrated by Langmuir adsorption model,as it took hours for the ethanol vapor molecules to be adsorbed on mica to form a nanoscale film from nucleated dots or islands.  
        关键词：VSPFM;Ethanol gas molecule;Mica;Adsorption   
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        发布时间：2021-03-05
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