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For the research of CCD neutron radiography,a neutron collimator was designed based on the exit of thermal neutron of the Boron Neutron Capture Therapy(BNCT)reactor.Based on the Geant4 simulations,the preliminary choice of the size of the collimator was determined.The materials were selected according to the literature data.Then,a collimator was constructed and tested on site.The results of experiment and simulation show that the thermal neutron flux at the end of the neutron collimator is greater than 1.0×106n/cm2/s,the maximum collimation ratio(L/D)is 58,the Cd-ratio(Mn)is 160 and the diameter of collimator end is 10 cm.This neutron collimator is considered to be applicable for neutron radiography. 相似文献
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Optical Potential Parameters for Halo Nucleus System ^6He+^12C from Transfer Reaction ^11B(^7Li, ^6He)^12C 下载免费PDF全文
The optical potential parameters for the halo nucleus system ^6He+^12C are extracted from fits to the measured angular distributions of ^11B(^7Li, ^6He)12C reaction at energies of 18.3 and 28.3MeV with distorted-wave Born approximation analysis. The characters of the obtained optical potentiM parameters are basically consistent with the results extracted from the fits to the elastic-scattering angular distributions in the literature. 相似文献
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Coulomb potentials for spherical-deformed reaction as well as the conventional formulas. Our results approaches have quite different behaviours in the partners are calculated in terms of the double folding model show that the Coulomb potentials calculated with different internal region of the potential. Because fusion process is sensitive to the barrier height and the internal part of the potential, the fusion excitation function, especially the fusion barrier distribution, should provide a strict test of the interaction potentials. Therefore, we calculate the fusion excitation function and barrier distribution for the ^16O +^154Sm system with different versions of the Coulomb potentials, in comparison with the experimental results. It is found that the fusion excitation function and barrier distribution of ^16O+^154Sm are obviously different for the different versions of the Coulomb potentials. By means of this comparison, we may conclude that the double folding model with the accurate approximate form can provide rather reasonable Coulomb potentials. 相似文献
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In order to further obtain the information of three-body force(TBF) from 200–400 Me V/u12C+12C elastic scattering, we plan to perform this experiment on a SHARAQ spectrometer. Based on the experimental condition of the Radioactive Ion Beam Factory(RIBF)-SHARAQ facility, a simulation is given to find a compromise between the better energy and angular resolutions, and higher yield by optimizing the target thickness, beam transport mode, beam intensity and angular step. From the simulation, we found that the beam quality mainly limits the improvements of energy and angular resolutions. A beam tracking system as well as a lateral and angular dispersionmatching technique are adopted to reduce the influence of beam quality. According to the two angular settings of SHARAQ as well as the expected cross sections on the basis of the theoretical model, the energy and angular resolutions, and statistical accuracy are estimated. 相似文献
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The simulation is performed for the monitors of beam direction and beam position for p-p elastic scattering. We set several variables to simulate the monitors of incident beam condition changes: beam positions at the quadrupole magnet and target in beam line polarimeter (BLP2), distance between quadrupole magnet and target, size of plastic scintillators, distance between the target in BLP2 and the centers of plastic scintillators, and beam polarization. Through the rotation of the coordinate system, the distributions of scattered and recoiled protons in the laboratory system were obtained. By analyzing the count yields in plastic scintillators at different beam positions, we found that the beam incident angular change (0.35°) could be detected when the asymmetry of geometries of left and right scintillators in BLP2 was changed by 6%. Therefore, the scattering angle measured in the experiment can be tracked by these monitors. 相似文献
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吴翠娥 叶沿林 江栋兴 郑涛 华辉 李智焕 李湘庆 陈志强 胡青元 张高龙 庞丹阳 王佳 Yamaguchi Y Ozawa A Tanihata I 《中国物理 C》2005,29(11):1052-1056
利用日本理化学研究所的放射性束流线RIPS, 测量了能量为79A MeV的17C在12C反应靶上的反应截面, 并同时得到了17C的移去1个、2个及3个中子的截面; 分别利用有限力程Glauber模型和少体Glauber模型结合壳模型的谱因子分析了反应截面和移去1个中子截面, 研究了17C的密度分布、结构和价中子布居. 反应截面和中子移去截面是两个相互独立的量, 通过对两者的分析, 都可以得出17C由芯核16C和价中子组成, 并且价中子主要处于d5/2轨道的结论. 总结了现有的碳同位素的反应截面和相互作用截面的工作. 相似文献