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The α preformation factor and penetration probability have been analyzed for even-even nuclei of Po,Rn,Ra using experimental released energies and α decay half-lives in the frame of the double folding model.It is shown that N = 126 is a neutron magic number from α preformation and shell effects play an important role in α preformation.The closer the nucleon number is to the magic number,the more difficult α formation in the parent nucleus is.The preformation factor can supply information on the nuclear structure and the penetration probability mainly determines α decay half-life. 相似文献
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α decay half-lives of some new synthesized superheavy elements, possibly synthesized superheavy elements and decay products are calculated theoretically within the WKB approximation by using microscopic α-nucleus interaction potentials. These nuclear potentials between the α particle and daughter nuclei are obtained by using the double folding integral of the matter density distribution of the α particle and daughter nuclei with a density-dependent effective nucleon-nucleon interaction, in which the zero-range exchange term is supplemented. The calculated α decay half-lives are compared with those of the different models and experimental data. It is shown that the present calculation successfully provides the half-lives of the observed decays for some new superheavy elements and therefore gives reliable predictions for α decay of possibly synthesized superheavy elements in future experiments. 相似文献
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The Monte Carlo method is used to simulate the 12C+12C reaction process. Taking into account the size of the incident 12C beam spot and the thickness of the 12C target, the distributions of scattered 12C on the MWPC and the CsI detectors at a detective distance have been simulated. In order to separate elastic scattering from the inelastic scattering with 4.4 MeV excited energy, we set several variables: the kinetic energy of incident 12C, the thickness of the 12C target, the ratio of the excited state, the wire spacing of the MWPC, the energy resolution of the CsI detector and the time resolution of the plastic scintillator. From the simulation results, the preliminary establishment of the experiment system can be determined to be that the beam size of the incident 12C is φ 5 mm, the incident kinetic energy is 200-400 A MeV, the target thickness is 2 mm, the ratio of the excited state is 20%, the ight distance of scattered 12C is 3 m, the energy resolution of the CsI detectors is 1%, the time resolution of the plastic scintillator is 0.5%, and the size of the CsI detectors is 7 cm×7 cm, and we need at least 16 CsI detectors to cover a 0° to 5° angular distribution. 相似文献
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在回顾和总结强脉冲电子束表面改性实验的基础上, 利用有限元数值计算方法对强脉冲电子束辐照铝和304不锈钢产生的温度场进行模拟, 给出了靶的近表面区域流体状态存在的特征尺度和特征时间, 并对不同材料特性下熔坑的产生原因进行了讨论. 采用两相流模型, 通过水平集方法和有限元方法结合的计算流体力学模拟了熔坑和表面突起形貌在表面处于熔融状态下的运动特征, 通过和实验数据相对比, 验证了对于高黏度, 高表面张力的高熔点金属, 表面处于流体状态下的张力驱动效应是熔坑等表面形貌演化的重要原因. 相似文献
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The interaction potential between a spherical and a deformed nucleus is calculated within the double-folding model for deformed nuclei. We solve the double folding potential numerically by using the truncated multipole expansion method. The shape, separation and orientation dependence of the interaction potential, fusion cross section and barrier distribution of the system 16O+154Sm are investigated by considering the quadrupole and hexadecapole deformations of 154Sm. It is shown that the height and the position of the barrier depend strongly on the deformation and the orientation angles of the deformed nucleus. These are quite important quantities for heavy-ion fusion reactions, and hence produce great effects on the fusion cross section and barrier distribution. 相似文献
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重核大集团(14C-34Si)发射的半衰期在理论上用Wentzel-Kramers-Brillouin近似进行了计算.利用双折叠模型计算大集团和剩余子核间的核相互作用,在折叠积分中选取了密度依赖的、零力程交换项的核子-核子相互作用.计算得到的半衰期和液滴模型结果、系统公式的结果以及实验数据进行了比较,表明目前的计算能够很好地给出重核大集团(14C-34Si)发射的寿命.这可为重核其他大集团(15N, 46Ar,48Ca等)的发射提供可靠的预测.
关键词:
半衰期
双折叠模型
集团发射 相似文献
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Nucleus-nucleus potentials are determined in the framework of double folding model for M3Y-Reid and M3Y-Paris effective nucleon-nucleon(NN) interactions.Both zero-range and finite-range exchange parts of NN interactions are considered in the folding procedure.In this paper the spherical projectile-spherical target system 16O+208Pb is selected for calculating the barrier energies,fusion cross sections and barrier distributions with the density-independent and density-dependent NN interactions on the basis of M3Y-Reid and M3Y-Paris NN interactions.The barrier energies become lower for Paris NN interactions in comparison with Reid NN interactions,and also for finite-range exchange part in comparison with zero-range exchange part.The density-dependent NN interactions give similar fusion cross sections and barrier distributions,and the density-independent NN interaction causes the barrier distribution moving to a higher position.However,the density-independent Reid NN interaction with zero-range exchange part gives the lowest fusion cross sections.We find that the calculated fusion cross sections and the barrier distributions are in agreement with the experimental data after renormalization of the nuclear potential due to coupled-channel effect. 相似文献
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