Study Of The Energy Level Structure And Radiative Transition Properties Of He-like And Be-like Inner-shell Double-hole State Atoms

The structure and properties of inner shell double-hole atoms（hollow atoms）are among the most important research subjects in modern atomic physics.The study of inner shell double hole atoms not only helps us to obtain the structure information and decay dynamics properties of electrons in exotic atoms,but also provides some important diagnostic information on the temperature,density and the charge state distribution in the astrophysics and laboratory plasma.Based on the fully relativistic multiconfiguration Dirac-Hartree-Fock（MCDHF）method combined with the active space method（AS）,the energy level structure and radiative transition properties of inner shell double-hole state atoms are analyzed and discussed in detail.In this process,the GRASP2K package is applied and the electron correlation effect,finite volume effects of the nucleus,Breit interaction and Quantum electrodynamic（QED）effects are effectively taken into account.The main contents are given as follows:1.The transition energies and transition rates of one-electron one-photon（OEOP）transition（2s2p→1s2s）and two-electron one-photon（TEOP）transition（2s2p→1s²）for He-like N,Ne,Fe,Cu,Zn,Ga,Ge,As,Se,Br,Kr,Xe,W ions.The current calculations were found to be in good agreement with the other results.The theoretical transition spectra of OEOP and TEOP transitions were predicated at different resolutions and the effect of strong Breit interaction on the OEOP transition energies were analyzed.It is shown that as the atomic number Z increases,the transition energies of ¹P₁→¹S₀ and ³P₂→³S₁ in the one-electron one-photon transition are reversed at mid-Z due to strong Breit interaction.At high Z,Coulomb interactions,Breit interaction and QED effects combine to cause a reversal of the ¹P₁→¹S₀ and³P₂→³S₁ transition energies in the one-electron one-photon transition.In the one-electron one-photon transition,the ³P₁→¹S₀ and ¹P₁→³S₁ are spin-forbidden transitions and their intensities increases gradually with increasing atomic number,with progressively more pronounced peaks in the transition spectrum.In the two-electron one-photon transition,³P₁→¹S₀ is the forbidden transition,while ¹P₁→¹S₀ is the allowed transition.2.The excitation energies of Be-like ion（4≤Z≤74）inner shell double excited configurations 1s²2p² and 2s2p³ and the E2 and M1 transition energies and transition rates for 1s²2p²→1s²2s² are calculated based on the Multi-Configuration Dirac-Hartree-Fock method.The contributions of the relativistic,Breit interaction,and QED effects to the excitation energies are analyzed and discussed in detail.A reasonable electron correlation model was constructed with the aid of the active space method.The calculated results are in good agreement with the available theoretical and experimental data.It is found that the contribution of the relativistic effect,Breit interaction,and QED effect to the energy level becomes more and more significant with the increase of Z.The contribution of the relativistic effects reaches about 8.5%at Z=74.The ³P₀ level of the inner shell excited state 1s²2p² is sensitive to the Breit interaction and the QED effects,but these two contributions canceled out each other.For the double K hole state 2s2p³,the Breit interaction and QED effects are almost equally important,and their maximum contribution is about 0.5%.The present results will provide helpful references for the future theoretical and experimental work.