The angular distribution and polarization of the x-ray photoemission of highly charged helium-like ions is studied following the K-LL dielectronic recombination of initially hydrogen-like ions.Calculation is carried o...The angular distribution and polarization of the x-ray photoemission of highly charged helium-like ions is studied following the K-LL dielectronic recombination of initially hydrogen-like ions.Calculation is carried out within the framework of the density matrix theory combined with the multiconfiguration Dirac-Fock approach.Attention is paid to magnetic sublevel alignment in the resonant intermediate state and to its nonuniform radiative decay processes.It is shown that the Breit interaction between the incident and target electrons plays a significant role for the alignment of the resonant state and thus causes a substantial change in the x-ray emission characteristic,when compared to the incorporation of only the(non-relativistic)Coulomb interaction.The most prominent difference in alignment parameter is found in the 2s2p_(1/2) J=1 resonant state for a wide range of atomic numbers from 9 to 92.For this resonant state of helium-like ions,the Breit interaction becomes significant for ions with nuclear charge Z~30 already.展开更多
Ve systematically study the decay properties of the K-shell excited F-like ions with 10≤Z≤36 based on the multiconfiguration Dirac-Fock method.The Breit interaction,the QED corrections and the nuclear finite mass ef...Ve systematically study the decay properties of the K-shell excited F-like ions with 10≤Z≤36 based on the multiconfiguration Dirac-Fock method.The Breit interaction,the QED corrections and the nuclear finite mass effects are also considered as perturbation.Auger transition rates,radiative,Auger and natural widths,as well as fluorescence and Auger yields for K-shell excited F-like ions are presented.It is shown by means of concrete figures that the decay properties change significantly with the increase of the atomic number Z;the Auger rate is overtaken at Z =30 by the radiative decay rate.Several fitting formulae for the radiative and Auger widths and the fluorescence yields have been evaluated which is expected to be useful in plasma analysis and plasma modeling.展开更多
Detailed calculations are carried out for the electron-impact excitation cross sections from the ground state to the individual magnetic sublevels of the 1s2s^(2)2p^(3)/2 J=2 excited state of highly-charged beryllium-...Detailed calculations are carried out for the electron-impact excitation cross sections from the ground state to the individual magnetic sublevels of the 1s2s^(2)2p^(3)/2 J=2 excited state of highly-charged beryllium-like ions by using a fully relativistic distorted-wave(RDW)method.The contributions of the Breit interaction to the linear polarization of the 1s2s^(2)2p^(3)/2 J=2→1s22s2 J=0 magnetic quadrupole(M2)line are investigated systematically for the beryllium isoelectronic sequence with 42≤Z≤92.It is found that the Breit interaction depolarizes significantly the linear polarization of the M2 fluorescence radiation and that these depolarization effects increase as the incident electron energy and/or the atomic number is enlarged.展开更多
The multi-configuration Dirac-Fock method is employed to calculate the energy levels and transition probabilities for the electric dipole allowed (El) and forbidden (M1,E2) lines for the 4s^(2) 4p,4s4p^(2) and 4s^(2) ...The multi-configuration Dirac-Fock method is employed to calculate the energy levels and transition probabilities for the electric dipole allowed (El) and forbidden (M1,E2) lines for the 4s^(2) 4p,4s4p^(2) and 4s^(2) 4d configurations of highly charged Ga-like ions from Z =68-95.The lifetimes of the 4s^(2) 4p^(2) P3/2 level of the ground configuration are also derived.Based on our calculations,it is found that the energy level of the 4s2 4p 2P3/2 is higher than that of the 4s4p24P1/2 for the high-Z Ga-like ions with Z ≥ 74,so as to generate an energy crossing at Z =74.The effect of the energy crossing is important to the calculation of the 4s^(2) 4p^(2) P3/2 level lifetime for Ga-like ions with Z≥ 74.展开更多
The shake-up processes accompanied by 3d photoionization and subsequent Auger decay are studied using multiconfiguration Dirac-Fock methods.Generalagreement is obtained with the experimental results for both the photo...The shake-up processes accompanied by 3d photoionization and subsequent Auger decay are studied using multiconfiguration Dirac-Fock methods.Generalagreement is obtained with the experimental results for both the photoelectron and Auger electron spectra.The energy and relative intensity of the 5s → 6s shake-up accompanied by the 3d photoionization process are identified quantitatively.展开更多
Detailed theoretical calculations are performed for the 4f and 5p inner-shell excitations of W-W^(3+) ions using the multiconfiguration Hartree–Fock method in order to better understand the origin of the XUV photoabs...Detailed theoretical calculations are performed for the 4f and 5p inner-shell excitations of W-W^(3+) ions using the multiconfiguration Hartree–Fock method in order to better understand the origin of the XUV photoabsorption spectra of W atoms from the dual laser-produced plasma experiment(Costello et al.J.Phys.B 24(1991)5063 and the spectra of photon-induced single ionization of W^(q+) ions(q=1,2,3)(Müller et al.Phys.Scr.T1441(2011)014052)from photon-ions merged beam experiments,respectively.Two broad and strong resonances in the experimental spectra have also been theoretically identified mainly from 5p–5d resonance.The 4f–5d,6d and 5p–6d transitions also make a small contribution to each spectrum,which are superimposed on the 5p–5d transition arrays.Based on the assumption of a normalized Boltzmann distribution among the excited states,we succeed in reproducing spectra which are in good agreement with experiments.展开更多
The radiative and Auger decay processes of K-shell ionized Np ions are studied theoretically using the flexible atomic code(FAC).Relativistic effects,Breit interaction,QED corrections and nuclear finite mass and volum...The radiative and Auger decay processes of K-shell ionized Np ions are studied theoretically using the flexible atomic code(FAC).Relativistic effects,Breit interaction,QED corrections and nuclear finite mass and volume effects are considered systematically.The resulting calculated K x-rays and Auger spectra of Np are compared with the measured spectra emitted after the electron-capture(EC)-decay of mass-separated ^(237)Pu.The general consistency between theory and experiment is good;the relative intensities and relative positions of the peaks in the measured spectra are reproduced with good accuracy,in spite of the existence of different ways to produce the primary K-shell vacancy,enabling identification of the observed structure in the experimental spectra.We find that most of the radiative transition rates are greater than the Auger transition rates,and the latter decrease rapidly with the transfer of initial vacancies to the outer shell.展开更多
In the frame of quantum defect theory,the state-testate dielectronic recombination rate coefficients of Fe^(25+) ion are calculated by a simple relativistic configuration interaction method.The calculated results are ...In the frame of quantum defect theory,the state-testate dielectronic recombination rate coefficients of Fe^(25+) ion are calculated by a simple relativistic configuration interaction method.The calculated results are further expressed with a two-parameter fitting formula,and then the dependence of fitting parameters on radiative decay final channel is studied.展开更多
A simplified relativistic configuration interaction method is used to study the dielectronic satellite transition processes,in which the whole high-n dielectronic satellite transition processes can be treated convenie...A simplified relativistic configuration interaction method is used to study the dielectronic satellite transition processes,in which the whole high-n dielectronic satellite transition processes can be treated conveniently in the frame of quantum defect theory.The theoretical results for heliumlike iron are in good agreement with the experimental measurements.展开更多
The mutual neutralization cross sections of Na^(+)/O^(-) ions at low energy have been calculated by using the multichannel LandaZener theory.An asymptotic method is used for estimating tBe coupling matrix elements bet...The mutual neutralization cross sections of Na^(+)/O^(-) ions at low energy have been calculated by using the multichannel LandaZener theory.An asymptotic method is used for estimating tBe coupling matrix elements between tbe ionic and covalent states at the crossing points of diabatic potential curves.The results of calculation are compared with available experimental data.展开更多
In this work, the KLL dielectronic recombination （DR） processes of highly charged He-like to O-like xenon ions are studied systematically by using a DR program, which is based on the multi-configuration Dirac-Fock ...In this work, the KLL dielectronic recombination （DR） processes of highly charged He-like to O-like xenon ions are studied systematically by using a DR program, which is based on the multi-configuration Dirac-Fock （MCDF） method. The KLL DR resonant energies and the corresponding resonant strengths are calculated, emphasizing especially the effect of the Breit interaction on the DR strengths. The theoretical KLL DR spectra are obtained and compared with the latest experimental results obtained in the Shanghai Electron Beam Ion Trap.展开更多
Electron impact excitation cross sections from the ground state and the lowest metastable state 5p56s J=2 to the excited states of the 5p57p configuration of xenon are calculated systematically using the fully relativ...Electron impact excitation cross sections from the ground state and the lowest metastable state 5p56s J=2 to the excited states of the 5p57p configuration of xenon are calculated systematically using the fully relativistic distorted wave method. Special attention is paid to the configuration interaction effects in the wave-function expansion of target states. The results are in good agreement with the recent experimental data by Jung et al. [Phys. Rev. A 80 （2009） 062708] over the measured energy range. These accurate theoretical results can be used in the modeling and diagnosis of plasmas containing xenon.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274254,91126007,10964010,11264033,and 11147018.
文摘The angular distribution and polarization of the x-ray photoemission of highly charged helium-like ions is studied following the K-LL dielectronic recombination of initially hydrogen-like ions.Calculation is carried out within the framework of the density matrix theory combined with the multiconfiguration Dirac-Fock approach.Attention is paid to magnetic sublevel alignment in the resonant intermediate state and to its nonuniform radiative decay processes.It is shown that the Breit interaction between the incident and target electrons plays a significant role for the alignment of the resonant state and thus causes a substantial change in the x-ray emission characteristic,when compared to the incorporation of only the(non-relativistic)Coulomb interaction.The most prominent difference in alignment parameter is found in the 2s2p_(1/2) J=1 resonant state for a wide range of atomic numbers from 9 to 92.For this resonant state of helium-like ions,the Breit interaction becomes significant for ions with nuclear charge Z~30 already.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91126007,10964010 and 11064012.
文摘Ve systematically study the decay properties of the K-shell excited F-like ions with 10≤Z≤36 based on the multiconfiguration Dirac-Fock method.The Breit interaction,the QED corrections and the nuclear finite mass effects are also considered as perturbation.Auger transition rates,radiative,Auger and natural widths,as well as fluorescence and Auger yields for K-shell excited F-like ions are presented.It is shown by means of concrete figures that the decay properties change significantly with the increase of the atomic number Z;the Auger rate is overtaken at Z =30 by the radiative decay rate.Several fitting formulae for the radiative and Auger widths and the fluorescence yields have been evaluated which is expected to be useful in plasma analysis and plasma modeling.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274254,91126007 and 11264033.
文摘Detailed calculations are carried out for the electron-impact excitation cross sections from the ground state to the individual magnetic sublevels of the 1s2s^(2)2p^(3)/2 J=2 excited state of highly-charged beryllium-like ions by using a fully relativistic distorted-wave(RDW)method.The contributions of the Breit interaction to the linear polarization of the 1s2s^(2)2p^(3)/2 J=2→1s22s2 J=0 magnetic quadrupole(M2)line are investigated systematically for the beryllium isoelectronic sequence with 42≤Z≤92.It is found that the Breit interaction depolarizes significantly the linear polarization of the M2 fluorescence radiation and that these depolarization effects increase as the incident electron energy and/or the atomic number is enlarged.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10876028,10847007 and 10964010the Scientific Research Foundation of the Higher Education Institutions of Gansu Province.
文摘The multi-configuration Dirac-Fock method is employed to calculate the energy levels and transition probabilities for the electric dipole allowed (El) and forbidden (M1,E2) lines for the 4s^(2) 4p,4s4p^(2) and 4s^(2) 4d configurations of highly charged Ga-like ions from Z =68-95.The lifetimes of the 4s^(2) 4p^(2) P3/2 level of the ground configuration are also derived.Based on our calculations,it is found that the energy level of the 4s2 4p 2P3/2 is higher than that of the 4s4p24P1/2 for the high-Z Ga-like ions with Z ≥ 74,so as to generate an energy crossing at Z =74.The effect of the energy crossing is important to the calculation of the 4s^(2) 4p^(2) P3/2 level lifetime for Ga-like ions with Z≥ 74.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91126007,10964010,11064012 and 11147018the Scientific Research Foundation of the Higher Education Institutions of Gansu Provincethe Foundation of Northwest Normal University(NWNU-KJCXGC-03-71).
文摘The shake-up processes accompanied by 3d photoionization and subsequent Auger decay are studied using multiconfiguration Dirac-Fock methods.Generalagreement is obtained with the experimental results for both the photoelectron and Auger electron spectra.The energy and relative intensity of the 5s → 6s shake-up accompanied by the 3d photoionization process are identified quantitatively.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10875017,10876028,11064012,10964010,91126007.
文摘Detailed theoretical calculations are performed for the 4f and 5p inner-shell excitations of W-W^(3+) ions using the multiconfiguration Hartree–Fock method in order to better understand the origin of the XUV photoabsorption spectra of W atoms from the dual laser-produced plasma experiment(Costello et al.J.Phys.B 24(1991)5063 and the spectra of photon-induced single ionization of W^(q+) ions(q=1,2,3)(Müller et al.Phys.Scr.T1441(2011)014052)from photon-ions merged beam experiments,respectively.Two broad and strong resonances in the experimental spectra have also been theoretically identified mainly from 5p–5d resonance.The 4f–5d,6d and 5p–6d transitions also make a small contribution to each spectrum,which are superimposed on the 5p–5d transition arrays.Based on the assumption of a normalized Boltzmann distribution among the excited states,we succeed in reproducing spectra which are in good agreement with experiments.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91126007,10847007,10964010,11064012.
文摘The radiative and Auger decay processes of K-shell ionized Np ions are studied theoretically using the flexible atomic code(FAC).Relativistic effects,Breit interaction,QED corrections and nuclear finite mass and volume effects are considered systematically.The resulting calculated K x-rays and Auger spectra of Np are compared with the measured spectra emitted after the electron-capture(EC)-decay of mass-separated ^(237)Pu.The general consistency between theory and experiment is good;the relative intensities and relative positions of the peaks in the measured spectra are reproduced with good accuracy,in spite of the existence of different ways to produce the primary K-shell vacancy,enabling identification of the observed structure in the experimental spectra.We find that most of the radiative transition rates are greater than the Auger transition rates,and the latter decrease rapidly with the transfer of initial vacancies to the outer shell.
基金Supported by National Natural Science Foundation of China under Grant No.19474039Natural Science Foundation of Gansu Province under Grant No.ZQ-96-02.
文摘In the frame of quantum defect theory,the state-testate dielectronic recombination rate coefficients of Fe^(25+) ion are calculated by a simple relativistic configuration interaction method.The calculated results are further expressed with a two-parameter fitting formula,and then the dependence of fitting parameters on radiative decay final channel is studied.
基金Supported by the National Natural Science Foundation of China under Grant No.19674011Postdoctor Foundation of China,and National Youth Foundation of High Technology.
文摘A simplified relativistic configuration interaction method is used to study the dielectronic satellite transition processes,in which the whole high-n dielectronic satellite transition processes can be treated conveniently in the frame of quantum defect theory.The theoretical results for heliumlike iron are in good agreement with the experimental measurements.
基金Supported by the National Natural Science Foundation of China.
文摘The mutual neutralization cross sections of Na^(+)/O^(-) ions at low energy have been calculated by using the multichannel LandaZener theory.An asymptotic method is used for estimating tBe coupling matrix elements between tbe ionic and covalent states at the crossing points of diabatic potential curves.The results of calculation are compared with available experimental data.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10774122 and 10876028)the Natural ScienceFoundation of Gansu Province,China(Grant No.1010RJZA014)the Foundation of Northwest Normal University,China(Grant No.NWNU-KJCXGC-03-72)
文摘In this work, the KLL dielectronic recombination （DR） processes of highly charged He-like to O-like xenon ions are studied systematically by using a DR program, which is based on the multi-configuration Dirac-Fock （MCDF） method. The KLL DR resonant energies and the corresponding resonant strengths are calculated, emphasizing especially the effect of the Breit interaction on the DR strengths. The theoretical KLL DR spectra are obtained and compared with the latest experimental results obtained in the Shanghai Electron Beam Ion Trap.
基金Supported by the National Natural Science Foundation of China Grant Nos 11274254 and 11147018, and the Scientific Research Foundation of the Higher Education Institutions of Gansu Province.
文摘Electron impact excitation cross sections from the ground state and the lowest metastable state 5p56s J=2 to the excited states of the 5p57p configuration of xenon are calculated systematically using the fully relativistic distorted wave method. Special attention is paid to the configuration interaction effects in the wave-function expansion of target states. The results are in good agreement with the recent experimental data by Jung et al. [Phys. Rev. A 80 （2009） 062708] over the measured energy range. These accurate theoretical results can be used in the modeling and diagnosis of plasmas containing xenon.
