The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding en...The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding energies. We find that the energy back shift EI shows complicated behavior and depends on the type of the nucleus, even-even, odd mass, and odd-odd. The spin cut-off factor has also been investigated for nuclei mentioned above. The results are compared with the previous results and different experimental data on level densities.展开更多
Nuclear level density(NLD) is a characteristic property of many-body quantum mechanical systems.NLDs are of special importance to make statistical calculations in reactor studies and various theoretical and experiment...Nuclear level density(NLD) is a characteristic property of many-body quantum mechanical systems.NLDs are of special importance to make statistical calculations in reactor studies and various theoretical and experimental nuclear physics and engineering applications.In this study,we have investigated a set of particle states in distinct rotational and vibrational bands to calculate nuclear level density parameters and the NLDs of accessible states of some deformed Dy radionuclides using a collective model approach,which included different excitation bands of the observed nuclear spectra.The method used assumes equidistant spacing of collective coupled state bands of the considered nuclei.The results of the calculated NLD have been compared with the experimental and compiled data obtained by the Oslo group,shell model Monte Carlo,Hartree-Fock-Bogoliubov + combinatorial approach,Bardeen-Cooper-Schrieffer approach and are in a good agreement.展开更多
We report a theoretical study on the rotational spectra of Ar-D232S. The intermolecular po- tential energy surface was transformed from our latest ab initio three-dimensional potential of Ar-H232S. The rotational ener...We report a theoretical study on the rotational spectra of Ar-D232S. The intermolecular po- tential energy surface was transformed from our latest ab initio three-dimensional potential of Ar-H232S. The rotational energy levels and wavefunctions of the complex were calcu- lated by using the radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm. The calculated rotational transition frequencies and structural parameters were found to be in good agreement with the available experimental values.展开更多
We employ the invariant eigen-operator （lEO） method to find the invariant eigen-operators of N-body singular oscillators＇ Hamiltonians and then derive their energy gaps. The Hamiltonians of parametric amplifiers wi...We employ the invariant eigen-operator （lEO） method to find the invariant eigen-operators of N-body singular oscillators＇ Hamiltonians and then derive their energy gaps. The Hamiltonians of parametric amplifiers with singular potential are also discussed in this way.展开更多
We establish the path integral formalism for nondegenerate parametric amplifiers in the entangled state representations. Its advantage in obtaining the energy level gap of this system is analyzed.
If a coherent perturbation field is used to couple the excited level of the coupling transition in the five-level K-type atom with another higher excited level, the two-photon electromagnetically induced transparency ...If a coherent perturbation field is used to couple the excited level of the coupling transition in the five-level K-type atom with another higher excited level, the two-photon electromagnetically induced transparency can be locally modulated by altering the parameters of the additional perturbation field. With different detunings of the coherent perturbation field, the absorption peak or transparency window with sharp and high-contrast speetrM feature can be generated in the two-photon absorption spectrum. The physical interpretation of these phenomena is given in terms of the dressed states.展开更多
文摘The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding energies. We find that the energy back shift EI shows complicated behavior and depends on the type of the nucleus, even-even, odd mass, and odd-odd. The spin cut-off factor has also been investigated for nuclei mentioned above. The results are compared with the previous results and different experimental data on level densities.
文摘Nuclear level density(NLD) is a characteristic property of many-body quantum mechanical systems.NLDs are of special importance to make statistical calculations in reactor studies and various theoretical and experimental nuclear physics and engineering applications.In this study,we have investigated a set of particle states in distinct rotational and vibrational bands to calculate nuclear level density parameters and the NLDs of accessible states of some deformed Dy radionuclides using a collective model approach,which included different excitation bands of the observed nuclear spectra.The method used assumes equidistant spacing of collective coupled state bands of the considered nuclei.The results of the calculated NLD have been compared with the experimental and compiled data obtained by the Oslo group,shell model Monte Carlo,Hartree-Fock-Bogoliubov + combinatorial approach,Bardeen-Cooper-Schrieffer approach and are in a good agreement.
文摘We report a theoretical study on the rotational spectra of Ar-D232S. The intermolecular po- tential energy surface was transformed from our latest ab initio three-dimensional potential of Ar-H232S. The rotational energy levels and wavefunctions of the complex were calcu- lated by using the radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm. The calculated rotational transition frequencies and structural parameters were found to be in good agreement with the available experimental values.
基金The project supported by the Specialized Research Fund for the Doctorial Program of Higher Education of China
文摘We employ the invariant eigen-operator （lEO） method to find the invariant eigen-operators of N-body singular oscillators＇ Hamiltonians and then derive their energy gaps. The Hamiltonians of parametric amplifiers with singular potential are also discussed in this way.
文摘We establish the path integral formalism for nondegenerate parametric amplifiers in the entangled state representations. Its advantage in obtaining the energy level gap of this system is analyzed.
基金Supported by National Natural Science Foundation of China under Grant Nos.10775100 and 10974137
文摘If a coherent perturbation field is used to couple the excited level of the coupling transition in the five-level K-type atom with another higher excited level, the two-photon electromagnetically induced transparency can be locally modulated by altering the parameters of the additional perturbation field. With different detunings of the coherent perturbation field, the absorption peak or transparency window with sharp and high-contrast speetrM feature can be generated in the two-photon absorption spectrum. The physical interpretation of these phenomena is given in terms of the dressed states.
文摘慢速中子俘获过程(s过程)是合成比铁重元素的重要途径之一。^(22)Ne(α, n)^(25)Mg反应是大质量AGB星中s过程主要的中子源,其中的^(22)Ne主要通过14N(α,γ)18F(β+)18O(α,γ)^(22)Ne反应链合成。该反应链中关键反应18O(α,γ)^(22)Ne在天体物理感兴趣能区的截面非常低,其天体反应率主要来自于^(22)Neα分离阈附近低能共振态的贡献,但目前相关能级的共振参数严重缺失。在HI-13串列加速器的Q3D磁谱仪上,通过测量18O(6Li, d)^(22)Ne反应的角分布,利用DWBA分析确定了^(22)Ne分离阈附近共振能级Eα=470 ke V的自旋宇称为0+,为后续计算18O(α,γ)^(22)Ne的天体反应率打下了基础。
