Theoretical Study On Precision Spectroscopy Of Oxygen-Like Highly Charged Ions

Accurate atomic spectral parameters not only can be used to explore the internal structure of the atom,but also model and diagnose astrophysical and laboratory plasmas.While as a result of the limitation of conditions,the experiment methods sometimes cannot provide enough large and accurate atomic spectra,which requires us to use the method of theoretical calculation to obtain these data.In this paper,two-state-of-the-art fully relativistic methods,the the many-body per-turbation theory(MBPT)method and multiconfiguration Dirac-Hartree-Fock(MCDHF)method are used to calculate level structures and transition characteristics of oxygen-like Mo XXXVand oxygen-like Ge XXV.A large number of configuration interactions are considered,including elec-tron correlation effects,relativistic effects,and QED effects.Thus,accurate and consistent data sets are obtained.The specific work is as follows:First,calculate the fine spectra of Mo XXXV using the many-body perturbation theory(MBP-T)method implemented in the FAC package,highly accurate atomic data are obtained for the low-est 318 fine-structure levels arising from the 2s~22p~4,2s2p~5,2p~6,2s~22p~33l(l=s,p,d),2s2p~43l(l=s,p,d),2p~53l(l=s,p,d),2s~22p~34l(l=s,p,d,f),and 2s2p~44s configurations in O-like Mo XXXV,including excitation energies,lifetimes,hyperfine structures constant,and Electric dipole(E1),Magnetic dipole(M1),Electric quadrupole(E2),Magnetic quadrupole(M2)wavelengths,transition rates,line strengths,and oscillator strengths.To verify the accuracy of this set of data,the multiconfiguration Dirac-Hartree-Fock(MCDHF)and subsequent relativistic configuration interaction(RCI)method implemented in the GRASP2K package are used to get another set of parameters.Comparisons are made between the present two data sets,as well as with other avail-able experimental and theoretical values.Our MBPT and MCDHF results show good agreement with each other.The present data are accurate enough for identification and deblending of emission lines and also useful for modeling and diagnosing fusion plasmas.These data can be considered as a benchmark for other calculations.In addition,the atomic data involving n=3,4 in this work also fill in the gaps in the theoretical data of the current oxygen-like Mo XXXV.Second,calculate the fine spectra of Ge XXV using the many-body perturbation theory(MBPT)method implemented in the FAC package,highly accurate atomic data are obtained for the lowest 427 fine-structure levels arising from the 2s~22p~4,2s2p~5,2p~6,2s~22p~33l(l=s,p,d),2s2p~43l(l=s,p,d),2p~53l(l=s,p,d),2s~22p~34l(l=s,p,d,f)and 2s2p~44l(l=s,p,d,f)configurations in oxygen-like Ge XXV,including excitation energies,lifetimes,hyperfine struc-tures constant,and Electric dipole(E1),Magnetic dipole(M1),Electric quadrupole(E2),Magnet-ic quadrupole(M2)wavelengths,transition rates,line strengths,and oscillator strengths.To verify the accuracy of this set of data,the multiconfiguration Dirac-Hartree-Fock(MCDHF)and subse-quent relativistic configuration interaction(RCI)method implemented in the GRASP2K package are used to get another set of parameters.Comparisons are made between the present two data sets,as well as with other available experimental and theoretical values.The results show that most of the data are in good agreement with the experimental values.Some spectral lines with great differences are discussed.Suggestions for modification of possible errors in the experimental values are put forward.The present data are accurate enough for identification and deblending of emission lines and are also useful for modeling and diagnosing fusion plasmas.These data can be considered as a benchmark for other calculations.In addition,the atomic data involving n=3,4 in this work also fill in the gaps in the theoretical data of the current oxygen-like Ge XXV.