Theoretical Study On The Hyperfine Structures And The Isotope Shifts For Mg-like Ions

With rapid improvement of the experimental technique,such as the laser spectroscopy,electronic beams ion traps and accelerator,a large number of finer atomic spectrums have been measured with high precision.On the theoretical side,the improvement of the atomic structure theory and the computer capability allowed people to investigate the atomic properties more accurate and in-depth.Nowadays,high-precision atomic data have been applied in the studied of the astrophysics,plasma diagnosis and nuclear physics,and the demand is increasing.The investigating of the hyperfine structures and the isotope shifts are not only helpful for improving the accuracy of the atomic parameters but also extracting the reliable nuclear parameters,which are difficult to measure directly.The nuclear-model-independent nuclear electric quadrupole moments Q and charge mean square radii <R2> can be extracted by combining the measured hyperfine structures and isotope shifts with the theoretical prediction of the electric field gradient and the isotope shift factors.These parameters are important for understanding the many-body interactions within the nucleus and improving the nuclear structure theory.In this work,we investigated the fine structures,the hyperfine interactions and the isotope shifts in Mg-like ions using the Multi-configuration Dirac-Hartree-Fock method.The main studies include:We discussed the effects of different electron correlations on the hyperfine interaction constants of the 3s³ p ^3,1P₁^o states,and the isotope shift factors for transitions from these states to the ground state 3s² 1S0 in Al⁺ ion.Based on our discussions we shown a reasonable computational model for calculating these physical quantities accurately.Subsequently,we calculated the magnetic dipole and the electric quadrupole hyperfine interaction constants of 3s³ p ^3,1P₁^o states and the isotope shift factors?massand field-shifts?for transitions 3s² 1S0-3s³ p ^3,1P₁^o in Al⁺ ion.The effects of the electron correlations and the Breit interaction on the above physical quantities were investigated in detail.We extended our computational model to the Mg-like isoelectronic sequence.The highly charged ions: Ca⁸⁺,Zn¹⁸⁺,Zr²⁸⁺,Sn³⁸⁺,Nd⁴⁸⁺,Yb⁵⁸⁺,Hg^{68 +},Th⁷⁸⁺ and Fm⁸⁸⁺ were selected for investigating the effects of the electron correlations and Breit interactions on the hyperfine interactions constants and isotope shift factors in Mg-like ions.The effects of the electron correlations decrease with the increase of the number of nuclear charges.On the contrary,the contributions of the relativistic nuclear recoil corrections increase with the increase of the number of nuclear charges.We hope this work could support the relevant experimental and theoretical investigations in the future.