Relativistic Study On Isotope Shift Of Li-like Ca¹⁷⁺,Ar¹⁵⁺ Ions And Na-like Xe⁴³⁺ Ions

A difference in energy between spectral lines from different isotopes of the same element is caused by the finite mass of the nucleus and the different distribution of nuclear charge and known as the isotope shift.It comes from the sum of two contributions:the mass shift and the field shift.On the one hand,the study of isotope shift is used to test the accuracy of quantum mechanics theory,explore the influence of electron correlation effect,Breit interaction and QED effect on isotope shift.On the other hand,it is widely used to extract the information of atomic structure such as the difference in the mean-square nuclear charge radius and nuclear deformation,which plays a crucial role in understanding the nuclear structure.Based on the multi-configuration Dirac-Hartree-Fock(MCDHF)method and the active space method,the energies levels,transition probabilities,mass shift parameters,field shift parameters and isotope shifts of Li-like and Na-like ions are calculated in the present work.The effects are systematically studied of electron correlation effect,Breit interaction and QED effect on the parameters.Its main contents include:Firstly,the total energies of 2s 2S1/2,2p 2P1/2 and 2p 2P3/2 states,the transition energies,transition probabilities,mass shift parameters,field shift parameters and isotope shifts of 2s 2S1/2-2p 2P1/2 and 2s 2S1/2-2p 2P3/2 transitions of Li-like Ca17+ ions are calculated in detail.It is found that the mass shift is larger than the field shift for Li-like calcium ions,and the main contribution of mass shift comes from the special mass shift.It is also found that the isotope shift between 48,40Ca is the largest and the value is 1.674 meV.This provides a reference for the related experimental research in the future.Secondly,the total energies of 2s 2S 1/2,2p 2P1/2 and 2p 2P3/2 states,the transition energies,transition probabilities,mass shift parameters,field shift parameters and isotope shifts of 2s 2S1/2-2p 2P1/2 and 2s 2S1/2-2p 2P3/2 transitions of Li-like Ar15+ ions are calculated in detail.It is found that the isotope shift between 32,40Ar is the largest,and the value is 1.953 meV.In addition,the contribution of electron correlation effect,Breit interaction and QED correction to the isotope shift parameters are also studied.It is found that the contribution of Breit interaction is greater than other corrections in the highly ionized light elements.We found the mass shifts of Li-like argon ions are larger than the field shifts.Thirdly,the total energies of 3s 2S1/2,3p 2P1/2 and 3p 2P3/2 states,the transition energies,transition probabilities,mass shift parameters,field shift parameters and isotope shifts of 3s 2S1/2-3p 2P1/2 and 3s 2S1/2-3p 2P3/2 transitions of Na-like Xe43+ions are calculated in detail.Unlike Li-like Ca17+ and Li-like Ar15+ ions,the field shift of Na-like xenon ions is larger than the mass shift.Finally,the root mean square radius of 136,124Xe is calculated by using the mass shift and field shift parameters currently calculated,combined with the isotope shift results of Na-like 136,124Xe observed by Silwal et al..The difference in the mean-square nuclear charge radius is δ<r2>136,124=0.269 fm2,it supports the theoretical prediction of silwal et al..