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Synthesis of superheavy nuclei with ^(23.)U target

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Science China(Physics,Mechanics & Astronomy) 2009年第10期52卷 1482-1488页

作者： LIU ZuHua1,3.& BAO JingDong2,4 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,beijing Normal University,beijing 100875,China 2 Department of Physics,beijing Normal University,beijing 100875,China 3.China institute of atomic energy,beijing 102413.China 4 Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 73.000,China Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China Department of Physics Beijing Normal University Beijing 100875 China China institute of atomic energy Beijing 102413 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The production of superheavy nuclei with Z=108-116 via hot fusion reactions of the neutron-rich projectiles with 23.U target is systematically *** results show that the production cross sections of superheavy nuclei do not decrease monotonously as the atomic number Z *** cross sections of the superheavy nuclei at Z = 112 and 115 are enhanced as compared with the whole Z-trend in synthesis of the superheavy nuclei,which clearly illustrates that the reactions with large negative Q-value and shell correction are more favorable to synthesize superheavy nuclei.

关键词： superheavy nuclei fusion reaction cross section 23.U target

Influence of some factors on alpha energy spectrum of^(241)Am fire alarm source

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Nuclear Science and Techniques 1999年第1期10卷 11-13页

作者： FENG Gensheng FENG Xinzhan LI Shujuan (China institute of atomic energy, {3. 102413. China institute of atomic energy Beijing 102413 China

Several primary factors influencing the alpha energy spectrum of 241Am fire alarm source have been studied in order to get better alpha energy spectrum. The results show that the homogeneity and the thickness of metal surface coat and the size of active area of the source have considerable influence on the alpha energy spectrum of the source.

关键词：火警 241Am警报源 α-能谱

The dynamical properties of Rydberg hydrogen atom near a metal surface

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Science China(Physics,Mechanics & Astronomy) 2005年第6期48卷 667-675页

作者： GE Meihua1, ZHANG Yanhui1, WANG Dehua2, DU Mengli3.& LIN Shenglu1 1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, China 2. Department of Mathematics and Physics, Shandong institute of Architecture and Engineering, Jinan 250014, China 3. institute of Theoretical Physics, Chinese Academy of Sciences, beijing 100080, China 1. College of Physics and Electronics Shandong Normal University 250014 Jinan China 2. Department of Mathematics and Physics Shandong Institute of Architecture and Engineering 250014 Jinan China 3. institute of Theoretical Physics Chinese Academy of Sciences 100080 Beijing China

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 20. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.

关键词： Rydberg hydrogen atom, van der Waals interaction, Poincaré surface of section, closed orbit theory, chaos.

Measurement of Neutron Capture Cross Section for ^(180)Hf

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Chinese journal of nuclear physics 1997年第2期19卷 110-114页

作者： Chen Jinxiang Shi Zhaomin Tang Guoyou Zhang Guohui institute of Heavy Ion Physics,Peking University,beijing 100871Lu Hanlin Han Xiaogang Huang Xiaolong China institute of {3. energy,P.O.Box 275(3.,beijing 102413 北京大学重离子物理所北京中国原子能科学院北京

The neutron capture cross section for 180Hf relative to the 197Au（n,γ）198Au reaction ismeasured at neutron energies of 0.52,1.10 and 1.60 MeV using the activation *** of the products are measured with a high resolution HPGe detector gamma ray *** errors of the measured results are 5%～6%.Our results have a good agreementwith those of other authors within *** sections for the reaction are calculated withUNF code and recommended data are also given.

关键词： 100Hf 198Au Neutron capture cross section Activition method

Probing Nuclear Symmetry energy with Giant Dipole Resonances in Finite Nuclei

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原子核物理评论 2009年第S1期26卷 181-184页

作者： CAO Li-gang1,3.MA Zhong-yu2,3.(1 institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 73.000,China 2 China institute of atomic {3.,beijing 102413.China 3.Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Research Facility in Lanzhou,Lanzhou 73.000,China) institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China China institute of atomic energy Beijing 102413China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

The relationship between the centroid energies of the isovector giant dipole resonance of finite nuclei and the symmetry energy has been studied. It is found the excitation energies of the dipole resonance in finite nuclei are correlated linearly with the symmetry energy at and below the saturation density. This linear correlation leads to the symmetry energy at the saturation density at the interval 3..0 MeV ≤ S(ρ0) ≤ 3..0 MeV,and the symmetry energy at ρ = 0.1 fm-3.at the interval 21.2-22.5 MeV. It is proposed that a precise measurement of the dipole mode in nuclei could set up an important constraint on the equation of state for nuclear matter.

关键词： symmetry energy dipole resonance Pygmy resonance

Approximation analytical solutions for a unified plasma sheath model by double decomposition method

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Nuclear Science and Techniques 1998年第4期9卷 193-197页

作者： Fang Jin-Qing (China institute of atomic energy {3. 102413.

A anified plasma sheath model and its potential equation are proposed. Any higher-ordor-approximation analytical solutions for the unified plasma sheath potential equa tiop are derived by double decomposition method.

关键词：等离子体屏蔽模型双分解方法近似分析

Integrated Numerical Experiment of an Intense RF Linac for CIAE Far-Infrared FEL

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Chinese journal of nuclear physics 1997年第2期19卷 121-127页

作者： Fu Shinian Chen Yinbao Huang Zhibin China institute of atomic energy,P.O.Box 275(17),{3. 102413 中国原子能科学院北京

An L band RF linac is now under installation at CIAE to provide intense electronbeam for a far-infrared free-electron laser *** linac consists of a DC thermionicgun,a subharmonic prebuncher,a buncher,an accelerating section and a beam transport *** the INEX(Integrated Numerical Experiment)conducted for prediction of the perfor-mance of the complex and the comparison of some of the simulation results with available ex-perimental data,it shows that the beam quality can satisfy our FEL requirements.

关键词： RF linac Free electron laser Integrated numerical experiments

Heavy ion reactions around the Coulomb barrier

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中国科学：物理学、力学、天文学英文版 2011年第S1期54卷 6-13页

作者： ZHANG HuanQiao1, LIN ChengJian1, JIA HuiMing1, ZHANG ChunLei1,2, ZHANG GaoLong1,3. YANG Feng1, LIU ZuHua1, AN GuangPeng1, WU ZhenDong1, XU XinXing1 & JIA Fei1 1 China institute of atomic energy, P. O. Box 275(10), {3. 102413. China 2 Particle Astrophysics Center, institute of High energy Physics, Chinese Academy of Sciences, {3. 10003., China 3.School of Physics and Nuclear energy Engineering, Beihang University, {3. 100191, China 1. China institute of atomic energy P. O. Box 275(10) Beijing 102413 China2. Particle Astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039 China3. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China

The angular distributions of fission fragments for the 3.S+184W reaction near Coulomb barrier energies are measured. The ex perimental fission excitation function is obtained. The measured fission cross sections are decomposed into fusion-fission, quasi-fission and fast fission contributions by the dinuclear system (DNS) model. The hindrance to completing fusion both at small and large collision energies is explained. The fusion excitation functions of 3.S+90,96Zr in an energy range from above to below the Coulomb barrier are measured and analyzed within a semi-classical model. The obvious effect of positive Q-value multi-neutron transfers on the sub-barrier fusion enhancement is observed in the 3.S+96Zr system. In addition, the excitation functions of quasi-elastic scattering at a backward angle have been measured with high precision for the systems of 16O+208Pb, 196Pt, 184W, and 154,152Sm at energies well below the Coulomb barrier. Considering the deformed coupling effects, the extracted diffuseness parameters are close to the values extracted from the systematic analysis of elastic and inelastic scattering data. The elastic scattering angular distribution of 17F+12C at 60 MeV is measured and calculated by using the continuum-discretized coupled-channels (CDCC) approach. It is found that the diffuseness parameter of the real part of core-target potential has to be increased by 20% to reproduce the experimental result, which corresponds to an increment of potential depth at the surface re gion. The breakup cross section and the coupling between breakup and elastic scattering are small.

关键词： fusion-fission quasi-fission fusion hindrance fusion enhancement surface diffuseness parameter exotic nuclei

Properties of the 3.2^-[521] band in the odd-N rare-earth nuclei

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Science China(Physics,Mechanics & Astronomy) 2011年第S1期54卷 37-43页

作者： CHEN Liang1,2, ZHOU XiaoHong1,2, ZHANG YuHu1, ZHANG ShuangQuan3.& ZHU LiHua4 1institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73.000, China 2Graduate University of Chinese Academy of Sciences, beijing 100049, China 3.tate Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, beijing 100871, China 4China institute of atomic energy, beijing 102413. China 1. institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing 100871 China4. China Institute of Atomic Energy Beijing 102413 China

High-spin states in 161Er have been studied experimentally via the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. Three rotational bands built on the 5/2+[642], 3.2-[521], and 11/2-[505] configurations have been extended up to high-spin states, and particularly, the α = -1/2 branch of the ground state 3.2-[521] band has been revised significantly. It is found that signature inversion occurs in the 3.2-[521] band after the band crossing in 161Er. The systematics of the signature inversion associated with the 3.2-[521] configuration in the rare-earth region is discussed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and a triaxial deformation is proposed to the 3.2-[521] band.

关键词： high-spin states signature inversion triaxial particle-rotor model