最新刊期
      卷 0 ， 期 0 ， 2020
      • ZHANG Guohui TANG Guoyou CHEN Jinxiang SHI Zhaomin LIU Guangzhi
        Issue 4, (2001)
        摘要：By using a gridded ionization chamber, the differential cross sections and angle integrated cross sections for the 6Li(n,t) 4He reaction were measured at neutron energies of 3.67 and 4.42MeV. The neutrons were produced through D(d,n) 3He reaction by a deuteron gas target. Absolute neutron flux was determined through 238 U(n,f) and H(n,p) reactions. At 3.67MeV the differential cross section for triton is almost 90° symmetric but it is obviously forward peaked at 4.42MeV in the center-of-mass reference system.  
          
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        发布时间：2021-03-12
      • QIAN Wanyan WANGXiaorong YANG Chunbin ZHOU Daicui CAI Xu
        Issue 4, (2001)
        摘要：The laws of fluctuations in high energy heavy ion collisions were studied with the multiplicitydistribution of EMU01 international collaboration. The dynamical factors d q and their ratios D q≡d q/d 1 were introduced to measure dynamical fluctuations quantitatively, and power scaling law between D q and D 2 was obtained. The exponents in the scaling were shown to be power scaling with q -1, and the scaling exponent γ was about the same for various collisions systems.  
        关键词：High energy heavy ion collision;Multiplicity distribution;Dynamical fluctuation   
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        发布时间：2021-03-12
      • ZHANG Tianhao WENG Huimin FAN Yangmei DU Jiangfeng ZHOU Xianyi HAN Rongdian
        Issue 4, (2001)
        摘要：Si(100) crystal implanted by 5×10 16 cm -2 , 140keV He + was probed by slow positron beam, and defect distribution along depth was obtained from the relation between S parameter and positron incidence energy. The near surface region of implanted sample was only slightly damaged. Small vacancies and vacancy clusters less than 1nm in diameter were the dominant defects, while the deeper region around the He + projected range was heavily damaged and had dense larger helium microbubbles and microvoids. Thermal anneal study at different temperatures showed that low temperature annealing could remove most vacancy-type defects effectively. However, annealing at high temperature enlarged the diameters of microbubbles and microvoids.  
        关键词：He + implanted Si;Defects;Slow positron beam;S parameter   
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        发布时间：2021-03-12
      • WANG Hongwei XIAO Zhigang LIU Yongying WU Heyu WEI Zhiyong DUAN Limin LI Zuyu ZHANG Baoguo JIN Genming LU Zhaohui WANG Sufang
        Issue 4, (2001)
        摘要：A two-dimensional position sensitive detector (PSD) which will be used in the measurement of the radioactive ion beam has been tested. By carefully selecting the pulse shaping time contants in the electronics and improving the method of data analysis; i.e. as the main amplifier’s shaping time was more than 6μs and position signal’s shaping time was 0.5—1μs, and used the energy signal as the denominator in the formula of position, better position resolution, energy resolution and position linearity have been obtained. The result shows that these type detectors can be used in the measurement of low energy radioactive ion beam.  
        关键词：Position sensitive detector;Radioactive ion beam;Position resolution;Energy resolution   
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        发布时间：2021-03-12
      • HOU Xinsheng MA Yingjie FANG Fang QIAO Yuande ZHOU Rongsheng
        Issue 4, (2001)
        摘要：The elemental contents in coal produced from southwest china were determined by NAA. the distribution of the harmful elements in coal was obtained. The results are helpful to control the air pollution caused by coal buning. the transformation behaviours of the major elements from the mine coal to burnt ash were also presented.  
        关键词：NAA;Coal;Trace element;Harmful element   
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        发布时间：2021-03-12
      • WANG Zhaomin HUANG Shengli XU Zizong WU Chong
        Issue 4, (2001)
        摘要：The ratio of signal to noise for single photon resolution time spectrometer and their influence factors were studied. A method to depress the background, to shorten the measurement time and to increase the ratio of signal to noise was discussed. Resuts show that ratio of signal to noise is proportional to solid angle of detector to source and detection efficiency, and inverse proportional to electronics noise. Choose the activity of the source was important for decreasing of random coincidence counting. To use a coincidence gate and a discriminator of single photon were an effective way of increasing measurement accuracy and detection efficiency.  
        关键词：Time spectrometer;Ratio of signal to noise;Detection efficiency   
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        发布时间：2021-03-12
      • WANG Rong XU Yongjun HUANG Long ZHU Shengyun
        Issue 4, (2001)
        摘要：The radiation effect of N-type GaP irradiated by 2.4×10 15 /cm 2 and 2.2×10 16 /cm 2 85MeV 19 F ions was investigated by positron annihilation lifetime technique. Monovacancies were created in the irradiated N-type GaP, and the concentration of produced monovacancies increases with the increasing of irradiation fluence.  
        关键词：GaP;19 F ions;Radiation effect;Positron annihilation   
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        发布时间：2021-03-12
      • LI Qiang ZHOU Guangming WANG Jufang LI Wenjian WEN Xiaoqiong DANG Bingrong XIE Hongmei WEI Zengquan
        Issue 4, (2001)
        摘要：Survival fractions of melanoma B16 cells at different penetration depths exposed to 49.30MeV/u 12 C ion beam and modulated 74.55MeV/u 12 C ion beam with a ridge filter to form a spread-out Bragg peak (SOBP) were measured. The results show the survival response of B16 cells as the biological endpoint to heavy ions increases synchronously with the deposited energy along the beam traversal, that is, the survival fraction near or at the Bragg peak or SOBP is far lower than that at the beam’s entrance or exit channel. Comparisons of the experimental data with calculated survival fractions at different depths predicted by the linear-quadratic survival model combined with dose-averaged LET display a good agreement within the experimental errors. It is prompted that the linear-quadratic model combined with dose-averaged LET possibly is a valid way to calculate the survival effect of B16 cells along the beam penetration under the exposure of the intermediate energy heavy-ion beam.  
        关键词：Heavy ion beam;Spread-out Bragg peak beam;Cell survival;Penetration depth   
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        发布时间：2021-03-12
      • WANG Xinfu ZHU Guanghua SHEN Xinyin 1
        Issue 4, (2001)
        摘要：A particulate filter sample from IAEA for interlaboratory comparison and a NIST SRM-1633a sample for quality control were analyzed by INAA technique. The experimental results obtained show that the measured values of the particulate filter sample are in agreement with the reference values from IAEA and the average values reported by all the participants; the measured values of NIST SRM-1633a sample are in good agreement with the certified values. It also shows that NAA is an accurate and reliable method for the super-trace, trace and normal constituent analysis in samples.  
        关键词：INAA;Particulate filter;Standard reference material;Elemental concentration   
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        发布时间：2021-03-12
      • LIU Changlong ZHU Zhiyong JIN Yunfan SUN Youmei HOU Mingdong WANG Yanbin WANG Zhiguang CHEN Xiaoxi LIU Jie ZHANG Chonghong LI Baoquan
        Issue 4, (2001)
        摘要：Semicrystalline polyethylene terephthalate (PET) film stacks were irradiated at room temperature with 35MeV/u Ar ions. Ion beam induced structural and compositional modifications were studied by means of X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. Significant amorphous transformation and chemical chain scissions were observed, which depended strongly on ion fluence and electronic energy loss near the sample surface. The chemical chain scissions were mainly found at carbonyl and methoxyl groups, which led to the relative decrease of amount of carbon and oxygen in these functional groups. The effects of amorphization and bond breaking increased with increase of ion fluence and electronic energy loss. The results were qualitatively discussed.  
        关键词：Polyethylene terephthalate;Ar ion irradiation;Surface structural and compositional modifications;X-ray diffractometer;X-ray photoelectron spectroscopy   
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        发布时间：2021-03-12
      • WANG Chao
        Issue 4, (2001)
        摘要：Changes of surface hardness and wear resistances in M2 type steel implanted by Cu Al ions were reported. The dependence of surface strengthening on ion species and dose was studied by X-ray diffraction (XRD) and Rutherford Backscaterring Spectroscopy (RBS) for microhardness and wear resistances measurement. It is shown that both hardness and wear resistance increases apparently after ion implantation. XRD analysis indicates that different phases formed after Al Cu ions implanted. It is also suggested that Cu, Al ions have different role in surface strengthening.  
        关键词：M2 type steel;Ion implantation;Wear resistance;Microhardness   
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        发布时间：2021-03-12
      • ZHONG Heli WU Hegou LI Longxing LU Peifang
        Issue 4, (2001)
        摘要：A mathematical model of extrapolating percent depth dose (PDD) was presented according to the principle of interaction between X-ray and water. The difference of extrapolated PDD by the model and measured PDD by 3D radiation field analizer is very small. For fields of different sizes within 20cm depth, the maximum absolute difference is 0.006×100% and the maximum relative difference is 1.1%. With the mathematical model, appropriate PDD values for different field sizes can be abtained without 3D radiation field analyses.  
        关键词：Percent depth dose;Extrapolation;Accelerator;X-ray radiation field   
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        发布时间：2021-03-12
      • LI Wenjian WEI Zengquan ZHOU Guangming WANG Jufang LI Qiang XIE Hongmei DANG Bingrong CAI Xichen HE Jing
        Issue 4, (2001)
        摘要：The relationship between penetration depth of X-rays and heavy ions in water and corresponding cell survival fraction, with Hela and B 16 cells, were studied, respectively. The results showed there were significantly different variation rules for X-rays and heavy ions in correlation between depth and cell survival. The relationship between depth and survival fraction for X-rays displayed highly positive correlation, i. e. r =0.92. However, heavy ions had less damage effect on cells and existed a plateau region with 80%—92% survival fraction following passing through the cells; while at the end of their range, cells were greatly damaged and their survival fraction decreased dramatically, presenting an inverse Bragg peak. It is suggested that tumor therapy with heavy ions have a better curing efficiency compared to X-rays.  
        关键词：Heavy ion;X-ray;Cancer cell;Penetration depth;Cell inactivation   
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        发布时间：2021-03-12
      • LI Jiaxing ZHAN Wenlong GUO Zhongyan XIAO Guoqing SUN Zhiyu JIANG Shanhong MENG Xiangwei WANG Jinchuan NING Zhenjiang WANG Quanjin WANG Meng WANG Jianfeng
        Issue 4, (2001)
        摘要：The TOF, ΔE and energy detectors in RIBLL were described. The time, ΔE and energy signals of the reaction products were obtained, then the particles were identified. And through the analysis of the experimental results in RIBLL, the detectors were verified to be reliable.  
        关键词：RIBLL;Time of flight(TOF);Particle identification   
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        发布时间：2021-03-12
      • LI Liwu
        Issue 4, (2001)
        摘要：A basalt sample and a plagioclase rock sample were implanted with low energy/high dose argon ions. The energy of argon ions was 120keV, argon ion dose was 5×10 18 ions/cm 2. The surface elemental compositions of implanted and virgin samples were analyzed by an X ray fluorescent spectrometer. The release modes of implanted gases, and the retention of rocks to argon were investigated by stepwise heating. The gas release mode by stepwise heating was preliminarily discussed.  
        关键词：Ion implantation;Simulation;Solar wind;Lunar rocks   
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        发布时间：2021-03-12
      • YANG Benfu CAO Xiaohua LUO Shunzhong
        Issue 4, (2001)
        摘要：Tritium release behavior from the pellets of γ-LiAlO 2 was studied by the thermodesorption method. According to the measured curves of different heating rates, the nominal diffusion activation energies of HT and HTO were calculated. Their values were (127±5)kJ·mol -1 and (253±50)kJ·mol -1 respectively.  
        关键词：Tritium;Lithium ceramics;Diffusion;Thermodesorption;Activation energy   
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        发布时间：2021-03-12
      • YUAN Xiangqun HUO Yukun WANG Pingxiao KONG Qing SHAO Lei FENG Liang
        Issue 4, (2001)
        摘要：The effect of laser polarization direction on electron inelastic scattering and acceleration with extra-intense linear-polarized pulsed lasers was studied by means of 3D simulation of the relativistic Newton-Lorentz equation of motion. It has been found that when Q 0 is less than ten (Q 0=eE/m e ωc measures the laser intensity), there is no noticeable polarization effect, which is consistent with the traditional ponderomotive potential model. While Q 0>30, the electron scattering and acceleration are found to be sensitive to the laser polarization direction. Tthe characteristics of the polarization effect examined were in details. This study is of significance not only in understanding the features of non-linear Compton scattering which underlies the acceleration effect, but also in experimentally testing the laser-driven electron acceleration as well as designing laser accelerator in the future.  
        关键词：Laser acceleration;Incidence azimuth angle;Compton scattering   
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        发布时间：2021-03-12
      • QIN Zhi GUO Junsheng GAN Zaiguo MA Taotao WANG Xiuying
        Issue 4, (2001)
        摘要：The extraction and separation of uranium from lead and bismuth with TBP-benzene was studied by radiotracer technique. The experimental results demonstrated that using TBP-benzene as an extracting solvent in 6mol/L HNO 3 could quantitatively remove the impurities of lead and bismuth from uranium。After purification of uranium, 233 U isotopic target with thickness of 500μg/cm 2 was obtained by means of molecular electrodeposition.  
        关键词：Extraction separation;Uranium;Lead and bismuth;Radiotracer;233 U target   
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        发布时间：2021-03-12
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