In this study,we calculated the photon absorption cross sections of even–even neodymium(Nd)isotopes using the Dirac Quasiparticle Finite Amplitude Method(relativistic QFAM),combined with the Tiny Smearing Approximati...In this study,we calculated the photon absorption cross sections of even–even neodymium(Nd)isotopes using the Dirac Quasiparticle Finite Amplitude Method(relativistic QFAM),combined with the Tiny Smearing Approximation(TSA)method.This approach enables the efficient reproduction of experimental photon absorption data for both spherical and deformed nuclei.We demonstrate that relativistic QFAM calculations with any smearing parameter γ can be scaled using the TSA method,significantly reducing the computational cost.Our method was applied to Nd isotopes,with experimental data reproduced for ^(142,144,146,148,150)Nd and predictions for ^(152)Nd.By optimizing the three key parameters,the total χ^(2) between the calculations and experimental data was reduced by nearly an order of magnitude.Furthermore,the role of nuclear deformation in the Giant Dipole Resonance(GDR)structure was analyzed,highlighting its impact on the emergence of double peaks in the photon absorption cross sections of deformed nuclei.This work provides a robust microscopic approach to improve photonuclear data for applications in nuclear physics and astrophysics.展开更多
An accurate and simultaneous ab initio prediction for both light nuclei and nuclear matter has been a longstanding challenge in nuclear physics, due to the significant uncertainties associated with the three-nucleon f...An accurate and simultaneous ab initio prediction for both light nuclei and nuclear matter has been a longstanding challenge in nuclear physics, due to the significant uncertainties associated with the three-nucleon forces.In this Letter, we develop the relativistic quantum Monte Carlo methods for the nuclear ab initio problem, and calculate the ground-state energies of A ≤ 4 nuclei using the two-nucleon Bonn force with an unprecedented high accuracy. The present relativistic results significantly outperform the nonrelativistic results with only twonucleon forces. We demonstrate that both light nuclei and nuclear matter can be well described simultaneously in the relativistic ab initio calculations, even in the absence of three-nucleon forces, and a correlation between the properties of light A ≤ 4 nuclei and the nuclear saturation is revealed. This provides a quantitative understanding of the connection between the light nuclei and nuclear matter saturation properties.展开更多
The photoionization cross section of the ground state 2s22p 2Po1/2 and the first excited state 2s22p2po1/2 of C II ions are systematically calculated using the fully relativistic R-matrix code DARC. The detailed reson...The photoionization cross section of the ground state 2s22p 2Po1/2 and the first excited state 2s22p2po1/2 of C II ions are systematically calculated using the fully relativistic R-matrix code DARC. The detailed resonances are presented and identified for the photon energy ranging from threshold （24.38 eV） up to 41.5 eV where the L-shell （2p, 2s） photoionization process is dominant. In the calculations, the relativistic effect and electronic correlation effect are well considered. It is found that the relativistic effect is very important for the light atomic system CII, which accounts for experimentally observed fine structure resonance peaks. A careful comparison is made between the present results and the experimental values, and also other theoretical data available in the literature, showing that good agreement is obtained for the resonance peaks.展开更多
Electron-impact single-ionization(EISI)cross sections for W^(q+)(q=9,10)ions have been calculated by using the level-to-level distorted-wave(LLDW)method with emphasis on the contribution of metastable states to the to...Electron-impact single-ionization(EISI)cross sections for W^(q+)(q=9,10)ions have been calculated by using the level-to-level distorted-wave(LLDW)method with emphasis on the contribution of metastable states to the total ionization cross sections.Contributions from direct-ionization(DI)and excitation-autoionization(EA)processes are taken into account.The calculated cross sections include the contributions from both the ground configuration and the long-lived metastable states with lifetimes exceeding 10^(-6)s.Calculated cross sections are in good agreement with experimental measurements when the influence of metastable states on the total ionization cross section are well considered.展开更多
This paper calculates the electron impact excitation rate coefficients from the ground term 2s^22p^2 3p to the excited terms of the 2s^22p^2, 2s^2p^3, 2s^22p3s, 2s^22p3p, and 2s^22p3d configurations of N II. In the ca...This paper calculates the electron impact excitation rate coefficients from the ground term 2s^22p^2 3p to the excited terms of the 2s^22p^2, 2s^2p^3, 2s^22p3s, 2s^22p3p, and 2s^22p3d configurations of N II. In the calculations, multiconfiguration Dirac-Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.展开更多
The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabiliti...The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabilities of the ground state and low-lying excited states are determined.Then,the magic wavelengths of the magnetic sublevel 6s_(1/2,m=1/2)→5d_(3/2,m=±3/2,±1/2)and 6s_(1/2,m=1/2)→5_(d5/2,m=±5/2,±3/2,±1/2)transitions in the linearly,right-handed,and left-handed polarized light are further determined.The dependence of the magic wavelengths upon the angle between the direction of magnetic field and the direction of laser polarization is analyzed.展开更多
基金supported by the National Key Research and Development(R&D)Program(Nos.2022YFA1602403,2021YFA1601500)Key Program of the National Natural Science Foundation of China(No.12435007)+3 种基金the National Natural Science Foundation of China(Nos.12075104,12447106,and 12147101)the Basic Research Project of China National Nuclear Corporation(CNNC)(No.CNDC-JCYJ-202402)CNNC Youth Innovation Team Project Key Laboratory Fund,the Key Laboratory Fund Key Projects(No.JCKY2023201C153-5)Continuous Support Basic Scientific Research Project(BJ010261223282).
文摘In this study,we calculated the photon absorption cross sections of even–even neodymium(Nd)isotopes using the Dirac Quasiparticle Finite Amplitude Method(relativistic QFAM),combined with the Tiny Smearing Approximation(TSA)method.This approach enables the efficient reproduction of experimental photon absorption data for both spherical and deformed nuclei.We demonstrate that relativistic QFAM calculations with any smearing parameter γ can be scaled using the TSA method,significantly reducing the computational cost.Our method was applied to Nd isotopes,with experimental data reproduced for ^(142,144,146,148,150)Nd and predictions for ^(152)Nd.By optimizing the three key parameters,the total χ^(2) between the calculations and experimental data was reduced by nearly an order of magnitude.Furthermore,the role of nuclear deformation in the Giant Dipole Resonance(GDR)structure was analyzed,highlighting its impact on the emergence of double peaks in the photon absorption cross sections of deformed nuclei.This work provides a robust microscopic approach to improve photonuclear data for applications in nuclear physics and astrophysics.
基金supported in part by the National Natural Science Foundation of China (Grant Nos. 12141501, 123B2080, 12435006, 12475117, and 11935003)the National Key Laboratory of Neutron Science and Technology (Grant No. NST202401016)+2 种基金the National Key R&D Program of China (Grant No. 2024YFE0109803)the High-performance Computing Platform of Peking Universitythe funding support from the State Key Laboratory of Nuclear Physics and Technology, Peking University (Grant No. NPT2023ZX03)。
文摘An accurate and simultaneous ab initio prediction for both light nuclei and nuclear matter has been a longstanding challenge in nuclear physics, due to the significant uncertainties associated with the three-nucleon forces.In this Letter, we develop the relativistic quantum Monte Carlo methods for the nuclear ab initio problem, and calculate the ground-state energies of A ≤ 4 nuclei using the two-nucleon Bonn force with an unprecedented high accuracy. The present relativistic results significantly outperform the nonrelativistic results with only twonucleon forces. We demonstrate that both light nuclei and nuclear matter can be well described simultaneously in the relativistic ab initio calculations, even in the absence of three-nucleon forces, and a correlation between the properties of light A ≤ 4 nuclei and the nuclear saturation is revealed. This provides a quantitative understanding of the connection between the light nuclei and nuclear matter saturation properties.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0402300)the National Natural Science Foundation of China(Grant Nos.U1530142,11474032,and 11774344)the Young Teachers Scientific Research Ability Promotion Plan of Northwest Normal University(Grant No.NWNU-LKQN-15-3)
文摘The photoionization cross section of the ground state 2s22p 2Po1/2 and the first excited state 2s22p2po1/2 of C II ions are systematically calculated using the fully relativistic R-matrix code DARC. The detailed resonances are presented and identified for the photon energy ranging from threshold （24.38 eV） up to 41.5 eV where the L-shell （2p, 2s） photoionization process is dominant. In the calculations, the relativistic effect and electronic correlation effect are well considered. It is found that the relativistic effect is very important for the light atomic system CII, which accounts for experimentally observed fine structure resonance peaks. A careful comparison is made between the present results and the experimental values, and also other theoretical data available in the literature, showing that good agreement is obtained for the resonance peaks.
基金Project supported by the National Natural Science Foundation of China(Grant No.11404152)Fundamental Research Funds for the Central Universities(Grant No.lzujbky2017-94)。
文摘Electron-impact single-ionization(EISI)cross sections for W^(q+)(q=9,10)ions have been calculated by using the level-to-level distorted-wave(LLDW)method with emphasis on the contribution of metastable states to the total ionization cross sections.Contributions from direct-ionization(DI)and excitation-autoionization(EA)processes are taken into account.The calculated cross sections include the contributions from both the ground configuration and the long-lived metastable states with lifetimes exceeding 10^(-6)s.Calculated cross sections are in good agreement with experimental measurements when the influence of metastable states on the total ionization cross section are well considered.
基金supported by the National Natural Science Foundation of China (Grant Nos.10774122 and 10876028)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20070736001)the Technology and Innovation Program of Northwest Normal University (Grant No.NWNU-KJCXGC-03-21)
文摘This paper calculates the electron impact excitation rate coefficients from the ground term 2s^22p^2 3p to the excited terms of the 2s^22p^2, 2s^2p^3, 2s^22p3s, 2s^22p3p, and 2s^22p3d configurations of N II. In the calculations, multiconfiguration Dirac-Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.
基金the National Key Research and Development Program of China(Grant No.2022YFA1602500)the National Natural Science Foundation of China(Grant Nos.12174316 and 12174268)+2 种基金the Young Teachers Scientific Research Ability Promotion Plan of Northwest Normal University(Grant No.NWNU-LKQN2020-10)the Innovative Fundamental Research Group Project of Gansu Province,China(Grant No.20JR5RA541)the Project of the Educational Commission of Guangdong Province of China(Grant No.2020KTSCX124)。
文摘The wave functions,energy levels and matrix elements of Yb+ions are calculated using the relativistic configuration interaction plus core polarization(RCICP)method.The static and dynamic electric dipole polarizabilities of the ground state and low-lying excited states are determined.Then,the magic wavelengths of the magnetic sublevel 6s_(1/2,m=1/2)→5d_(3/2,m=±3/2,±1/2)and 6s_(1/2,m=1/2)→5_(d5/2,m=±5/2,±3/2,±1/2)transitions in the linearly,right-handed,and left-handed polarized light are further determined.The dependence of the magic wavelengths upon the angle between the direction of magnetic field and the direction of laser polarization is analyzed.
