The fine-structure energy levels of 1 s2s and 1 s2p atomic states for the He-like Ar ion immersed in dense plasmas are calculated. The ion sphere model is used to describe the plasma screening effect on the tested ion...The fine-structure energy levels of 1 s2s and 1 s2p atomic states for the He-like Ar ion immersed in dense plasmas are calculated. The ion sphere model is used to describe the plasma screening effect on the tested ion. The influences of the hard sphere confinement and plasma screening on the fine-structure energy levels are investigated respectively. The calculated results show that the confined effect of the hard sphere on the fine-structure energy levels increases with decreasing hard sphere radius, and the plasma screening effect on the fine-structure energy levels increases with the increase of free electron density. In dense plasmas, the confined effect of the hard generally, compared with the contribution from free electron crossing is found among 1 s2s （1 So） and 1 s2p （3P0,1） atomic plasma diagnostics. sphere on the fine-structure energy levels can be neglected screening. An interesting phenomenon about the energy level states. The results reported at the present work are useful for展开更多
A programme is developed to calculate the polarizations of the radiation emitted after electron impact excitation. The fully relativistic distorted-wave method is used in cross-section calculations. The programme is a...A programme is developed to calculate the polarizations of the radiation emitted after electron impact excitation. The fully relativistic distorted-wave method is used in cross-section calculations. The programme is applied to He- and Li-like ions. The calculated values of line polarization are compared with other theoretical results and experimental values. For He-like U, at lower incident energy, the present polarization agrees with the other theoretical ones within 1%, while at higher energy, the differences increase up to about 10%. For He-like Fe and Ti, the present results of polarization degree for most of the lines agree with the experimental data within the experimental error bars. For the Li-like Ti line q （ls2s2p^2p3/2 to ls^22s）, the present value of the polarization agree excellently with another theoretical one, and both the values are consistent with the measured data within the experimental error bar.展开更多
Debye-screening effects on the electron-impact excitation(EIE)processes for the dipole-allowed transition 1 s_(2)^(1)S→1 s2 p^(1)P in He-like Al^(11+)and Fe^(24+)ions are investigated using the fully relativistic dis...Debye-screening effects on the electron-impact excitation(EIE)processes for the dipole-allowed transition 1 s_(2)^(1)S→1 s2 p^(1)P in He-like Al^(11+)and Fe^(24+)ions are investigated using the fully relativistic distorted-wave methods with the Debye-Huckel(DH)model potential.Debye-screening effects on the continuum-bound(CB)interaction and target ion are discussed,both of which result in reduction of EIE cross sections.This reduction due to screening on the CB interaction is dominant.The non-spherical and spherical DH potentials are adopted for considering the screening effect on the CB interaction.It is found that the spherical DH potential could significantly overestimate the influence of plasma screening on EIE cross sections for multielectron He-like ions.展开更多
We report accurate wavelengths for the three most intense lines (resonance line: 1s2 1S0 - 1s2p 1P1, intercombination line: 1s2 1S0 - 1s2p 3P1 and forbidden line: 1s2 1S0 - 1s2s 3S1) along with wavelengths for the 1s2...We report accurate wavelengths for the three most intense lines (resonance line: 1s2 1S0 - 1s2p 1P1, intercombination line: 1s2 1S0 - 1s2p 3P1 and forbidden line: 1s2 1S0 - 1s2s 3S1) along with wavelengths for the 1s2 1S0 - 1snp1P1 and 1S0 - 1snp3P2 (2 ≤ n ≤ 25) transitions in He-like systems (Z = 2 – 13). The first spectral lines that belong to the above transitions are established in the framework of the Screening Constant per Unit Nuclear Charge method. The results obtained agree excellently with various experimental and theoretical literature data. The uncertainties in wavelengths between the present calculations and the available literature data are less than 0.004Å. A host of new data listed in this paper may be of interest in astrophysical and laboratory plasmas diagnostic.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11474208)the Doctoral Science Foundation of Longdong University,China(Grant No.XYBY1704)
文摘The fine-structure energy levels of 1 s2s and 1 s2p atomic states for the He-like Ar ion immersed in dense plasmas are calculated. The ion sphere model is used to describe the plasma screening effect on the tested ion. The influences of the hard sphere confinement and plasma screening on the fine-structure energy levels are investigated respectively. The calculated results show that the confined effect of the hard sphere on the fine-structure energy levels increases with decreasing hard sphere radius, and the plasma screening effect on the fine-structure energy levels increases with the increase of free electron density. In dense plasmas, the confined effect of the hard generally, compared with the contribution from free electron crossing is found among 1 s2s （1 So） and 1 s2p （3P0,1） atomic plasma diagnostics. sphere on the fine-structure energy levels can be neglected screening. An interesting phenomenon about the energy level states. The results reported at the present work are useful for
基金Supported by the National Natural Science Foundation of China under Grant No 10434050, and the Science and Technology Funds of China Academy of Engineering Physics （20050215）.
文摘A programme is developed to calculate the polarizations of the radiation emitted after electron impact excitation. The fully relativistic distorted-wave method is used in cross-section calculations. The programme is applied to He- and Li-like ions. The calculated values of line polarization are compared with other theoretical results and experimental values. For He-like U, at lower incident energy, the present polarization agrees with the other theoretical ones within 1%, while at higher energy, the differences increase up to about 10%. For He-like Fe and Ti, the present results of polarization degree for most of the lines agree with the experimental data within the experimental error bars. For the Li-like Ti line q （ls2s2p^2p3/2 to ls^22s）, the present value of the polarization agree excellently with another theoretical one, and both the values are consistent with the measured data within the experimental error bar.
基金Project supported by the Science Challenge Project(Grant No.TZ2016001)the National Key Research and Development Program of China(Grants Nos.2017YFA0403200 and 2017YFA0402300)+1 种基金the Funds for Innovative Fundamental Research Group Project of Gansu Province,China(Grant No.20JR5RA541)the National Natural Science Foundation of China(Grants Nos.11774037 and 12064041)。
文摘Debye-screening effects on the electron-impact excitation(EIE)processes for the dipole-allowed transition 1 s_(2)^(1)S→1 s2 p^(1)P in He-like Al^(11+)and Fe^(24+)ions are investigated using the fully relativistic distorted-wave methods with the Debye-Huckel(DH)model potential.Debye-screening effects on the continuum-bound(CB)interaction and target ion are discussed,both of which result in reduction of EIE cross sections.This reduction due to screening on the CB interaction is dominant.The non-spherical and spherical DH potentials are adopted for considering the screening effect on the CB interaction.It is found that the spherical DH potential could significantly overestimate the influence of plasma screening on EIE cross sections for multielectron He-like ions.
文摘We report accurate wavelengths for the three most intense lines (resonance line: 1s2 1S0 - 1s2p 1P1, intercombination line: 1s2 1S0 - 1s2p 3P1 and forbidden line: 1s2 1S0 - 1s2s 3S1) along with wavelengths for the 1s2 1S0 - 1snp1P1 and 1S0 - 1snp3P2 (2 ≤ n ≤ 25) transitions in He-like systems (Z = 2 – 13). The first spectral lines that belong to the above transitions are established in the framework of the Screening Constant per Unit Nuclear Charge method. The results obtained agree excellently with various experimental and theoretical literature data. The uncertainties in wavelengths between the present calculations and the available literature data are less than 0.004Å. A host of new data listed in this paper may be of interest in astrophysical and laboratory plasmas diagnostic.
