最新刊期
      卷 0 ， 期 0 ， 2020
      • ZHANG Haiyan JING Zhengfang SHAO Jie ZHAO Tao CAI Ping
        Vol. 33, Issue 1, (2010)
        摘要：Stability of the corrector power supply is important for beam orbit stability of a synchrotron light source.In this paper,we report a digital control system for corrector power supply of the HLS storage ring,including the hardware,software and the measurement results.The hardware structure and work flow of the digital power supply controller is emphasized.The controller is composed of two cards of ADC and DSP.It adopts advanced DSP and FPGA as core.The controller communicates with IOC via optical fiber,and can easily change parameters of the power supply through the UART port.Operation of the storage ring with the digital control system for correcting the power supply indicates that the upgraded PS system meets the requirement of orbit stability.  
        关键词：Digital controlled power supply;Stability;DSP;ADC   
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        发布时间：2021-03-05
      • LIU Lijuan1 CUI Mingqi1 ZHAO Jia2 MA Yibing3 MA Chenyan1 ZHENG Lei1 ZHAO Yidong1 1
        Vol. 33, Issue 1, (2010)
        摘要：Sulfur is considered to be the forth important nutrient element,and its transformation greatly affects the growth of plants.In this paper,sulfur speciation in different soils is researched.Effects of long-term fertilization in different combinations were studied by sulfur K-edge XANES of the soil samples,and the proportions of S at different oxidation states were determined by fitting the sulfur K-edge XANES spectra.The results indicate that the soil samples contained all kinds of sulfur states,i.e.the most reduced S,intermediate S and highly oxidized S,with the highly oxidized S being the largest proportion.The contents of total sulfur are different in soils in different long-term fertilizer experiment,and both the rates and contents of different oxidation states change.  
        关键词：Soil;Sulfur;XANES   
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        发布时间：2021-03-05
      • WANG Bing WU Jie ZHANG Jie
        Vol. 33, Issue 1, (2010)
        摘要：As the use of private protocols becomes popular in distributed data acquisition system,it is urgent to test interfaces of these systems.The interfaces cannot be tested by general communication protocol testing equipments,so a simple strategy of how to develop an efficient custom interface testing system with a testing module based on PC is proposed.In this paper,we focus on the design and implementation of how to realize an interface testing module based on ARM.Analyses of the interface characteristics,basic structure and software processes of the interface testing module,and application method of interface testing with the PC and the interface testing module,are discussed.Experimental results show that the custom interface testing system well meets the testing requirements.This proposes a way to do a rapid development of custom interface testing systems.  
        关键词：Distribution data acquisition system;Private protocol;High-speed data transfer protocol;Interface testing;ARM   
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        发布时间：2021-03-05
      • ZHANG Limin ZHANG Xiaodong LIU Zhengmin
        Vol. 33, Issue 1, (2010)
        摘要：GaN samples (no yellow luminescence) in their as-grown states were implanted with 1013-1017 C ions/cm2 and studied by photoluminescence spectra and micro-Raman scattering spectra.The photoluminescence study showed that yellow luminescences were produced in the C-implanted GaN after 950°C annealing,and the peaks of the near band edge emissions showed blue-shifts after C implantation.The Raman measurements indicated that the stresses in GaN films did not change after C implantation.The samples implanted with 1015 cm-2 carbon ions had the Raman peak at 300 cm-1,which is associated to the disorder-activated Raman scattering.However,further increasing the implantation dose resulted decreased intensity of the 300 cm-1 peak,due to the ion beam current increase with the implantation dose.  
        关键词：GaN;Ion implantation;Photoluminescence spectra;Micro-Raman scattering spectra   
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        发布时间：2021-03-05
      • HU Jifeng1 DU Hongxin2 YAO Ze’en1,2 JIN Sunjun2 LIANG Yi2 1
        Vol. 33, Issue 1, (2010)
        摘要：To design a recoiled proton telescope for monitoring a D-T neutron generator,the MCNP code was used to simulate the yield,energy spectra and angular distribution of recoiled protons in the polyethylene film bombarded by 14 MeV neutrons.The simulated data were analyzed.The optimum position of detector and thickness of the polyethylene film for the recoiled proton telescope system were presented.A model on the D-T neutron source was developed.The recoiled proton telescope system for monitoring the neutron yield of D-T neutron generator was designed by MCNP simulation.The monitoring efficiencies were presented.  
        关键词：D-T neutron generator;Polyethylene film;Recoiled proton telescope;MCNP code   
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        发布时间：2021-03-05
      • QIAN Nan1 WANG Dezhong1 BAI Yunfei1 LIU Cheng1 ZHANG Yong2 YANG Yongliang2 1
        Vol. 33, Issue 1, (2010)
        摘要：The efficiency matrix calculation of tomographic gamma scanning technique can be affected severely by HPGe crystal model used in the Monte Carlo simulation.With the producer-provided dead layer thickness,the calculated detector efficiency is up to 119% larger than the measured efficiency.By adjusting the dead layer thickness,the relative error could be minimized.A linear correlation between the dead layer thickness and the average relative error was established.With the corrected geometry of HPGe detector,the spatial efficiency of the detector under the radioactive point source is studied and the function,which could be used to calculate the efficiency matrix quickly between the detection efficiency,radiation energy and the position of the point source.  
        关键词：Monte Carlo method;Function of detection efficiency;Thickness of dead layer;Tomographic gamma scanning technique   
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        发布时间：2021-03-05
      • MA Weijiang TANG Qiang ZHANG Chunxiang LIU Xiaowei
        Vol. 33, Issue 1, (2010)
        摘要：MgB4O7 phosphors doped with Mn and Dy were prepared,and thermoluminescence spectra were observed.The results based on the thermoluminescence spectra show that the glow peaks located in 580 nm broad wavelength band were observed at 180°C and 300°C for MgB4O7:Mn,and the ones of 480,580,680 and 750 nm due to the energy transitions of Dy3+ were observed at 200°C and 350°C for MgB4O7:Dy.It was found that for MgB4O7 co-doped with 0.5 mol% Dy and 0.05-1.0 mol% Mn,the peaks of 480,680 and 750 nm became weak,and so did the low temperature peaks,while the peak of 580 nm at 350°C became stronger,and broader.  
        关键词：Dy;Mn;MgB4O7;Thermoluminescent spectra   
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        发布时间：2021-03-05
      • ZHANG Guiying1 CAO Lei2 DENG Jun2 WANG Chengguo3 ZHANG Wenyi4 NI Bangfa1 TIAN Weizhi1 SUN Quanfu2 1
        Vol. 33, Issue 1, (2010)
        摘要：X-rays produced by medical accelerator have been widely used in radiotherapy.During the process of therapy,a certain level of photonuclear neutrons are produced by the (γ,n) and (γ,2n) reactions of the X-rays and surrounding materials.The neutron dose distribution caused by the Prim μs-M linac at 15 MV in the standard exposure field of 10 cm×10 cm was M-C simulated,and measured at the treatment plane by CR-39 solid state nuclear track detector and neutron bubble detector (NBD).The results show that the measured neutron doses are lower than the simulated ones by up to 30%.The main reason for this difference is that the neutrons with energies below 100 keV produced by inelastic scattering of fast neutrons with surrounding materials are below the threshold energies of both detectors,and thus not detected.These results provide some basis for the optimal design of the facility shielding aiming at controllable and minimized contaminating neutron dose.  
        关键词：Medical accelerator;Neutron contamination;Monte-Carlo simulation;Radiation protection design   
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        发布时间：2021-03-05
      • WANG Xinhua AN Li ZHENG Pu GUO Haiping HE Tie
        Vol. 33, Issue 1, (2010)
        摘要：In order to optimize the design of γ-ray detectors and data analysis of the system for inspection of explosive with associated alpha particle technique,Monte Carlo code EGSnrc was used to simulated detection efficiency and response function of inorganic scintillator detector for γ-rays,aimed at choosing the right type detector.Pulse height spectra of γ-rays of Φ5″×8″ NaI(Tl) from graphite,water,ammonium nitrate and simulated explosive induced by 14 MeV neutron were simulated.The calculated results were analyzed and compared with experiments results,demonstrating that simulation method is reliable and it can be used to obtain the database of response function for explosive inspection.  
        关键词：Inspection of explosive;Detection efficiency;Response function;Monte Carlo simulation;Neural network   
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        发布时间：2021-03-05
      • YAN Long1 ZHOU Guangying1,2 ISHAQ Ahmad1,2 HE Suixia1 GONG Jinlong1 ZHU Dezhang1 1
        Vol. 33, Issue 1, (2010)
        摘要：Amorphous structure transformation of multiwalled carbon nanotubes (MWCNTs) irradiated by 70 keV protons at room temperature was investigated.It was found that some of the proton-irradiated MWCNTs were covered with homogeneous amorphous structure with the inner tube walls in graphite structure.Moreover,the amorphous structure continuously proceeds and the graphite structure was reduced during the proton irradiation until the irradiated MWCNTs become amorphous nanowires with a hollow structure.The proton-induced structural transformation of MWCNTs was a unique graphite-to-amorphous structural transition from the outer walls to the inner walls of the irradiated MWCNTs.The structural evolutionary mechanism of proton-beam-irradiated MWCNTs has been discussed.  
        关键词：Multiwalled carbon nanotubes;Proton beam irradiation;Structural transformation   
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        发布时间：2021-03-05
      • LI Gui1,2 ZHENG Huaqing1,2 WU Yican1,3 FDS Team 1
        Vol. 33, Issue 1, (2010)
        摘要：The reconstruction to the electron dose map in radiation therapy was investigated by constructing the inversion model of electron dose map with different algorithms.The inversion model of electron dose map based on nonlinear programming was used,and this model was applied the penetration dose map to invert the total space one.The realization of this inversion model was by several inversion algorithms.The test results with seven samples show that except the NMinimize algorithm,which worked for just one sample,with great error,though,all the inversion algorithms could be realized to our inversion model rapidly and accurately.The Levenberg-Marquardt algorithm,having the greatest accuracy and speed,could be considered as the first choice in electron dose map inversion.Further tests show that more error would be created when the data close to the electron range was used (tail error).The tail error might be caused by the approximation of mean energy spectra,and this should be considered to improve the method.The time-saving and accurate algorithms could be used to achieve real-time dose map inversion.By selecting the best inversion algorithm,the clinical need in real-time dose verification can be satisfied.  
        关键词：Electron dose map;Inversion algorithm;Monte Carlo;Accurate radiation therapy   
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        发布时间：2021-03-05
      • DAI Qiusheng ZHAO Cuilan QI Yujin
        Vol. 33, Issue 1, (2010)
        摘要：This work is aimed at developing a compact gamma camera module of high spatial resolution,based on block scintillation crystal coupling with position sensitive photomultiplier (PSPMT).Monte Carlo simulation was used to study the shrinkage effect and intrinsic spatial resolution of miniature gamma camera module with crystal parameters.The readout electronics and the position determination method of the PSPMT were improved by using a novel truncated center-of-gravity method.Imaging experiments were performed to evaluate our design.The results demonstrate that readout circuit with truncated center-of-gravity (TCOG) can restrict the shrinkage effect;the spatial resolution and shrinkage effect of crystal are improved with reduced thickness and increased light output.It can be concluded that a crystal wafer coupled to PSPMT will have 1-2 mm intrinsic resolution,hence a high cost-effective solution compared to crystal array design.  
        关键词：High resolution miniature gamma camera module;Monte Carlo simulation;Truncated center-of-gravity method   
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        发布时间：2021-03-05
      • HE Jiaheng LUO Junyi JIAN Yuan WANG Guanquan LIU Guoping
        Vol. 33, Issue 1, (2010)
        摘要：Stability in vitro,lipophility and acute toxicity of p-Boc-Trp-Trp-NH(CH2)6NH-PO (ONH4)-O-Ph131I are studied in this work.The complex,with labeling yield of around 85%,was obtained using sealed-tube method.Stability of the complex was obtained by measuring labeling yield at different time.Its lipophility was studied through swaging-flask method,and its impacts to liver function and peripheral blood of the experimental animals were also studied.The results indicate the complex is lipophilic and less toxic,and the iodine removal rate was about 13% three days later.The rabbit model with VX2 liver tumor was established successfully.The organ and tissue uptake and retention of p-Boc-Trp-Trp-NH(CH2)6NH-PO(ONH4)-O-Ph131I were studied in a model subject.Blood,liver,lungs,kidneys,spleen and tumour tissue samples were assayed in a well counter for radioactivity and the results were compared with the biodistribution studies in five normal mice.The complex trends to concentrate into adipose tissues in tumour-bearing and normal animals,and the uptake rate in tumor tissue is relatively high,hence its potential possibility as radiopharmaceuticals.But it cleared quickly.Further researches are underway to improve the stability of complexes to prolong concentration time in target tissue.  
        关键词：Di-peptide;131I;Biodistribution   
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        发布时间：2021-03-05
      • CHEN Wenjun MAN Kaidi WANG Shaoming CAI Guozhu YANG Shengli GUO Yizhen YUAN Jiandong
        Vol. 33, Issue 1, (2010)
        摘要：This paper mainly described the alignment for the facility of heavy ion therapy at Institute of Modern Physics,Chinese Academy of Sciences.We set up the control network by laser tracker and transform multi-coordinate frame.The accuracy of adjusting magnets has reached ±(0.05-0.1)mm,and accuracy of the horizontal and vertical vacuum pipes has reached ±(0.1-0.2)mm.  
        关键词：The facility of treating tumor with heavy ion beams;3D control survey network;Laser tracker;Collimation   
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        发布时间：2021-03-05
      • LI Jia1,2 LONG Pengcheng1,2 LUO Yuetong1,3 HUANG Shanqing1,2 YAN Feng1,3 LI Gui1,2 SONG Gang1,2 WU Yican1,4 FDS Team 1
        Vol. 33, Issue 1, (2010)
        摘要：In radiotherapy treatment planning,in order to delivery of a high dose to the tumor accurately while maintaining an acceptably low dose to the normal tissues,particularly those adjacent to the target,it is necessary to reconstruct the three dimensional anatomical structure from planar contour information.The existing methods could not satisfy the clinical demand in terms of the speed and accuracy.By improving the isosurface extraction algorithm,we designed a fast 3D-reconstruction algorithm pipeline implemented by Visualization Tool Kit (VTK).A serial of test results from real patient image dataset show that this method could reconstruct the surface smoothly and evade the "ladder effect" effectively.The number of points and triangles had been reduced in great extent.The rendering time had been decreased from 8 seconds to less than 3 seconds by comparing with standard iso-extraction algorithm.On the premise of preserving the original anatomical structure,this method improved the reconstruction effect,accelerated the rendering speed and it would be applied to not only accurate radiotherapy treatment planning system but also other fields that need 3D reconstruction.  
        关键词：3D-reconstruction;Accurate radiotherapy;Isosurface   
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        发布时间：2021-03-05
      • ZHOU Juying WANG Lili CAI Xiaojun GUO Jian QIN Songbing XU Xiaoting LI Li YU Zhiying
        Vol. 33, Issue 1, (2010)
        摘要：In order to observe impact of PET/CT on precise and accurate radiotherapy (PAR) planning of patients with non-small cell lung cancer (NSCLC),21 patients with NSCLC had CT and FDG-hybrid PET examinations prospectively in radiation treatment position.Five radiation oncologists delineated independently the GTV including positive lymph nodes of 21 lung cancer patients on CT.The same observers delineated the GTV of the 21 patients on matched PET/CT scans.The size of GTV and coefficient of variation were used to assess inter-observer variability.The results show that all patients’ GTVCT differed from their GTVPET/CT,and the variability in the contouring of GTVCT among different physicians was statistically significant (F=9.25,P<0.001),but less significant in the contouring of GTVPET/CT.The mean coefficient of variation for GTV based on PET/CT was significantly smaller (t=-7.46,P<0.001) than that for CT data only.It van be concluded that PET/CT may have notable impact on clinical staging of NSCLC and on its PAR planning,and will result in a reduction in this variation of the contouring of GTVs among different radiation oncologists.  
        关键词：Non-small cell lung cancer;PET/CT;Precise and accurate radiotherapy;Gross tumor volume   
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        发布时间：2021-03-05
      • NIE Peng NI Bangfa TIAN Weizhi
        Vol. 33, Issue 1, (2010)
        摘要：In this paper,an empirical formula for the efficiency calibration of bulky source in cylindrical geometry is proposed.The simple but accurate empirical formula is able to effectively predict the efficiencies of summing effect free γ-rays from a cylindrical bulky source (Φ30 mm × 40 mm) at different source-to-detector distance.The relative difference between experimental and calculated data at 0,20,40,and 80 mm source-to-detector distances is smaller than 5%.  
        关键词：HPGe γ detector;Bulky sources;Efficiency calibration;Empirical formula   
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        发布时间：2021-03-05
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