高阶超精细相互作用及其对原子亚稳态性质的影响

原子超精细相互作用是原子核物理和原子物理之间的一座桥梁。通过超精细结构的实验测量与原子结构精密计算结合，人们可以提取原子核，特别是亏中子和丰中子奇异核素的电磁多极矩，这将有助于人们更深入理解原子核内强相互作用的性质，发展核模型理论，改进原子核结构计算方法。本项目中，我们将在多组态Dirac-Hartree-Fock理论框架下发展计算磁八极超精细相互作用的程序；结合微扰理论，细致研究电子关联效应对磁偶极、电四极和磁八极超精细结构的影响，重点分析复杂原子中与内壳层电子相关的关联效应对超精细相互作用的影响规律，发展原子结构高精密计算方法；进一步，我们将推导包括超精细相互作用高阶微扰修正的超精细结构计算公式，与精密测量实验结合，提取磁八极超精细结构。另外，我们还将研究超精细相互作用对原子亚稳态能级寿命、朗德g因子和原子电四极矩的影响规律，探索其在寻找下一代光钟和等离子体诊断中的应用。

Hyperfine interaction is a bridge between nuclear physics and atomic physics. It is allowed to extract nuclear electromagnetic multipole moments from measured hyperfine structures in combination with high-precision atomic structure calculations. Nuclear multipole moments, especially for neutron-deficient or neutron-rich nuclei, are important physical quantities, which can help us to deeply understand specific properties of the strong nucleon-nucleon interaction, test nuclear models and improve nuclear structure theories. In the framework of the multiconfiguration Dirac-Hartree-Fock method, we plan to develop a code for calculating the magnetic octupole hyperfine interaction; with the assistance of perturbation theory, we will investigate the effects of electron correlations on magnetic dipole, electric quadrupole and magnetic octupole hyperfine structures in detail. In particular, we hope to capture the correlations related to inner shell electrons in complex atomic systems in order to evaluate uncertainties in the calculation. Furthermore, including the higher-order hyperfine interaction corrections, we will derive the formulas so that the magnetic octupole hyperfine interaction can be extracted from measurements. In addition, the influence of hyperfine interactions on the level lifetimes, Landé-g factor and atomic electric quadrupole for metastable states will be studied for exploring potential applications in the search of next-generation atomic clocks and the diagnostics of plasma.