Angular Momentum Projected Deformed HF Spectra of 46Ti and 48Cr With MSDI

Taking the modified surface delta interaction (MSDI) and using a spherical shell model basis set, we carry out the deformed Hartree-Fock (HF) calculation for the even-even nuclei ⁴⁶Ti and ⁴⁸Cr in the fp shell, and construct the deformed HF intrinsic states which are the Slater determinants from the HF single-particle states.The angular momentum projection program is then carried out and the reasonable results are obtained.     

The Angular Dependence of the Coherence Energy in Dissipative Reaction of 19F+51V

Excitation function fluctuations for projectile-like fragments from ¹⁹F+⁵¹V dissipative reaction within the energy region of 102.25—109.50MeV are reported.The statistical method is applied to the analysis of energy coherence in the cross rection fluctuations and the strong cross correlation between exit channels is obtained.The dependences on charge number and on mass number are presented.The relation between angular velocity damping and the rotational energy dissipation is discussed.     

Further Studies on Halo Nuclei 11Li,14Be and 17B

Based on the three-body model with Yukawa interactions,the halo nuclei ¹¹Li,¹⁴Be and ¹⁷B are further studied by the variation calculation.An analytical expression for the density distribution of the halo neutron is given.The theoretical resultsagree with the recent experimental data.     

The Study of Unbound Nuclei 11N Resonance Energy Level

The excitation functions of elastic scattering proton which were measured with inverse kinematics of elastic resonance scattering reactions in GANIL and MSU have been fitted by the multi-energy level $R$-matrix theory. The final result shows that the new energy levels order for nucleus ¹¹N should be 1/2⁺,1/2^－,5/2⁺,3/2⁺, 3/2^－,5/2⁺,7/2^－,which is consistent with the experimental results of ¹¹Be (the mirror nucleus of ¹¹N) and the theoretical calculation of ¹¹N with GCM theory.     

Excitation Energy and Temperature of Compound Nuclei in the Reaction of 35MeV/u 40Ar+197Au

The fission fragments in the reaction of ⁴⁰Ar+¹⁹⁷Au have been measured coincidently with light charged particles at 35MeV/u by using large area position sensitive detectors and Si-detectors. The velocities of the fissioning compounds are deduced based on the fragments and the excitation energies of the compounds calculated with a hypothesis of massive transfer and taking into account the influence of pre-equilibrium emission of light particles. As the same time,the temperatures of the compounds are extracted by using the energy spectra of the backward light charged particles measured coincidently with fission fragments. The temperature-excitation energy curve does not present the behaviour predicted by the theories.     

The Cross Section Fluctuation of the Isotope Projectile-Like Fragments in the Dissipative Process of Reaction 19F+51V

By using a detection system combining Time-of-Flight(TOF)method with(△E-E)technique,the excitation functions,the dependence of energy coherence widthΓon product mass A and the dependence of Γon the degree of freedom of neutron excess N/Z for some elements and their isotope products in the dissipative process of reaction ¹⁹F+⁵¹V at energies from 102.25MeV to 109.50 MeV(in 250 keV steps)were presented and discussed for the first time.     

Isospin Effect on the Emission Mechanism of Hot Nuclei in 35MeV/u 40Ar +112Sn/124Sn Reactions

As an extension of radioactive ion beam physics, the research on isospin dependent properties of hot nuclei has increasingly attracted considerable interest. The isospin effect on the decay of hot nuclei in reactions 35MeV/u ⁴⁰Ar+¹¹²Sn/¹²⁴Sn has been investigared. It is concluded that due to Coulomb repulsion and instability, proton-rich hot nuclei probably emit prides such as a with high energy to increase their neutron-proton ratio. Moreover, the decay chain for those particles is seemingly long and the emission Probability is high. Thus, the conventional observations, for instance, the ‘slope temperature’ extracted from energy spectrum, may very appreciably with the measured particles.     

Neutrino Energy Loss by Electron Capture on Nucleus ^56Mn, ^56Fe, ^56Co and ^56Ni in Strong Electron Screening

Based on the p-f shell model, the neutrino energy loss rates for nucleus ^56Mn, ^56Fe, ^56Co and ^56Ni in the electron capture process are canvassed in and not in a strong electron screening. The results show that the neutrino energy loss rates for ^56Mn, ^56Fe, ^56Co and ^56Ni decrease about 15%, 10%, 60% and i order of magnitude correspondingly at the temperature T9 = 15 and even debase 2 orders of magnitude at the temperature T9 = 1.     

原子核的反常宇称能谱研究

将具有负宇称的 fp 空间扩大到包含1g9/2 轨道, 采用修正的表面相互作用(MSDI), 对64Ge, 66Ge, 68Ge, 70Se, 72Se, 74Se, 76Kr 和 78Kr等偶偶核作了形变Hartree Fock计算, 得到了基态和一些激发态的解. 同时, 还用近似角动量投影形变Hartree Fock（PDHF）方法对偶偶核64Ge, 74Se和奇A核79Kr进行了能谱计算, 得到其正、 负宇称带的解, 计算结果与实验谱基本一致.Using modified surface delta interaction, enlarging the fp configuration space to include the 1g9/2 orbit with the abnormal parity, the deformed Hartree Fock calculations for the eight nuclei: 64Ge, 66Ge, 68Ge, 70Se, 72Se , 74Se, 76Kr and 78Kr are performed. The ground state and some particle hole excited configurations are obtained. The approximate angular momentum projected deformed Hartree Fock (PDHF) method is applied to even even nuclei 64Ge and 74Se and odd A nuclus 79Kr. Both of their normal and abnormal parity bands are obtained. The calculated energy spectra are consistent well with experimental spectra.     

A Three-Body Model of 11Li,14Be and 17B

The nuclei ¹¹Li,¹⁴Be and ¹⁷B are considered as three-body systems composed of the N=2Z core and two outside neutrons.The core-neutron and neutronneutron interactions are assumed to be the attractive exponential potentials.It has been shown that the three-body system can have a bound state although any two constituents of the system cannot have a bound state. The experimental data of the binding energy and extraordinarily large matter root-mean-square radius can be explained in the frame of the three-body model.     

Study on Charge Form Factors of the Exotic Nuclei 6,8He

Charge radius and charge form factors of different charge density distributions for ^6,8He are calculated with the relativistic Eikonal approximation. Detailed comparisons and discussions are presented. It is found that the charge form factors curves of ^6,8He are much lower than the experimental ones of ⁴He. This is, in principle, consistent with the experimental fact. Whereas detailed comparison among the charge form factors which correspond to different charge distributions show significant deviations. This indicates that the effects of the correlations between the halo neutrons and the α-core in ^6,8He with different charge density distributions are quite different. This result would provide a useful reference for the possible experiments on the next-generation electron-nucleus collider and for the tests of different theoretical models for the exotic nuclei ^6,8He.     

Angular Distribution of the 12C(6He, 7Li)11B Reaction

Angular distribution of the ¹²C(⁶He,⁷Li)¹¹B transfer reaction is measured with a secondary ⁶He beam of 36.4MeV for the first time. The experimental angular distribution is well reproduced by the distorted-wave Born approximation (DWBA) calculation. The success of the present experiment shows that it is feasible to measure one-nucleon transfer reaction on a light nucleus target with the secondary beam facility of the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), Beijing.     

Charge Symmetry Breaking Effects in Elastic Nucleon Scattering From the 3H and 3He Mirror Nuclei

Using a microscopic momenteum space optical potential and the method for treating the Coulomb force, which is propose by R Crespo and J. A. Tostevin, we calculated the differential cross section of elastic nucleon scattering from the ³H and ³He mirror nuclei at 500MeV and the ratio of cross sections. The charge symmetry breaking effects due to the Coulomb force between the proton and nuclei are shown.     

Temperatures and Excitation Energies of Hot Nuclei in Reactions of 40Ar+natAg,209Bi at MeV/u

Coincidence measurements of fission fragment and light charged particle have been perfotrmed for the reactions of ⁴⁰Ar+^natAg,²⁰⁹Bi at E/A=25MeV using 4 PPAC and 11 sets of ΔE-E telescopes.Angular correlations of fission fragment were ploted as a function of the folding angle between the two detected fission fragments.The linear momentum transfer distributions were derived by measuring angular correlations.The backward spectra of light particles detected in coincidence with fission fragments having different average〈LMT〉are analyzed with Maxwell distribution.After some corrections the initial temperatures of the hot nuclei are determined from the energy spectra.The excitation energies corresponding to the different average〈LMT〉are obtained considering the reaction Q values and pre-equilibrum emission.In the central collision of the ⁴⁰Ar+^natAg,²⁰⁹Bi reactions,excitation energies are measured to be about 4.2MeV/u,2.4MeV/u and temperatures about 6.1MeV,5.5MeV,respecdvely.In semi-central collision,excitaionen energies are measured to be about 3.5MeV/u,1.9MeV/u and temperatures about 5.8MeV,4.8MeV respectively.     

Complete and Incomplete Fusion in the Reaction of 65Cu With 16O Ions

The excitation functions,angular distributions and differential range distributions have been measured for target residues from the reaction of ⁶⁵Cu induced by 45—96MeV ¹⁶O ions with radiochemical techniques.A comparison of the experimental data with Monte-Carlo simulations based on the statistcal model of compound nucleus that the heavy residues are produced by the decay of a compound nucleus formed by complete fusion.Incomplete fusion or massive transfer are the main reaction mechnisms leading to production of the residues with mass number close to that of the target.     

46.7MeV/u 12C轰击159Tb、197Au和209Bi的裂变测量及分析

用46.7MeV/u~(12)C轰击~(159)Tb、~(197)Au、~(209)Bi,测量关联裂片的速度和角度,研究了线性动量转移(LMT)、质量和出平面角分布,提取了核温度,应用级联两体统计衰变理论进行了拟合与解释,结果表明:在～50MeV/u入射能的中能重离子碰撞中,以非完全熔合方式形成了核温度高达4～5MeV的类复合核,其后通过裂变、蒸发级联统计两体衰变而退激。 The velocities and angles of fission partners emitted from reactions in ~(12)C+~(159)Tb, ~(197)Au,~(209)Bi systems with bombarding energy of 46.7MeV/u are measured. The linear momentum transferfrom projectile to target、mass and out-of-reaction plane angle distributions of fission fragments arestudied, and the temperatures of the target residues are extracted. These results have been explained by statistical binary decay model. It seems that the compound-likesystem with high temperature...     

A Comparison Between Two Different Optical Potentials for the 3He+ 12C Scattering at the Energy 72MeV

Through the analysis of the ³He elastic scattering on the ¹²C nucleus, two different folded optical potentials, one is constructed based on the α-particle model of the ¹²C nucleus, another is constructed based on the nucleon component model of ¹²C, are compared. The comparison shows that the former optical potential has some advantages.     

几种磺酰脲类除草剂的1H NMR谱的理论研究

在HF/6-31G(d)水平上对8种N-(4′-甲基嘧啶)-N-取代基-2-硝基苯磺酰脲化合物I1-8进行全参数优化和振动分析,并在HF/6-31G(d)水平上所得的优化构型的基础上,用GIAO方法在B3LYP/6-31G(d)水平上计算了它们的核磁共振氢谱,计算结果与实验值较为吻合.     

The Energy Dissipation,Productions of the Subthreshold Pion Mesons and Flowangle in Interdediate-Energy 86Kr+197Au Reaction

The dissipative energy,productions of subthreshold pion mesons and flowangle in intermediate-energy heavy system ⁸⁶Kr+¹⁹⁷Au reaction have been calculated by the extended BUU model,meanwhile,the relation of the energy dissipation to the charge number of PLF and the correlation of the charge number between the PLF and TLF have been reproduced.     

Analysis of the Energy Autocorrelation Functions in Dissipative Heavy Ion Collision of 27Al+27Al

The excitation functions of the dissipative fragments emitted from the reaction of ²⁷Al+²⁷Al have been measured in the energy region from 114MeV to 127MeV in steps of 200keV. The detection system covered continuous angles from 10° to 57° in laboratory system. The energy autocorrelation functions of the dissipative fragments have been analyzed by using different approaches,especially using the statistical nuclear reaction model with memory. The results indicate that the intermediate dinuclear system formed in the dissipative process is set in a damped coherent nuclear rotation which causes the nonself averaging oscillation structure in the excitation functions and originates from a typical quantum chaotic motion.