The Theoretical Research On The Excitation States ?1s²nl,l=2,3? For Y³⁶⁺ And Zr³⁷⁺ Ion

Most of the matter in the universe is composed of atoms and molecules,so the composition and structure of atoms determine the properties of macroscopic matters.In the field of atomic and molecular physics,research on highly charged ion is very important.Knowledge of the structure and spectrum of highly charged ions is of great importance to many fields.The sun is an important natural resource for the study of highly charged ions,and solar physics is an important part of the physics of highly ionized ions.For example,the study of rays from the universe can provide information of space and astronomy,the existence of highly charged ions is confirmed with studies of the active regions of the sun?especially solar flares?,and the structure of the chromosphere and corona of the sun can be obtained by studying the spectra.However,most of the highly charged ions does not exist on Earth and the atmosphere absorbs x-rays with high intensity.To a large extent,the study of highly charged ions is limited^[1].Therefore,the theoretical study of the structure and properties of highly charged atomic systems is particularly important.Y³⁶⁺and Zr³⁷⁺ions are lithium-like highly charged ions.At present,there are many methods to study lithium-like systems.For example,the basic Hartree-Fock method,the Configuration-Interaction method^],the Hylleraas method^],and the 1/Z expansion method.In this paper,the three electrons outside the nucleus are divided into two parts by using the multi-configuration interaction method^[5-7]:two 1s electrons are putted together with the nucleus to form 1s²-core wave function,which is treated as a separate part,and a sufficiently good CI wave function is introduced to describe the interactions between valence electron and1s²-core and electron-electron.The convergence rate of wavefunction is improved greatly with this wavefunctuin.Finally,the eigenvalue of the wavefunction is determined.In this paper,the structure and spectra of Y³⁶⁺ion and Zr³⁷⁺ion have been studied theoretically by using the system wavefunction determined.The ionization energy,excitation energy,transition energy and their wavelengths of the excited states?1s²nl,l=2,3?of the two ions have been calculated.The ionization energy of higher excited states is extrapolated by combining the single-channel QDT with the results obtained.After that,The relativistic dipole transition oscillator strength of Y³⁶⁺ion and Zr³⁷⁺ion have been calculated.Combining the single-channel QDT with oscillator strength theory,The oscillator strength is extrapolated,so that we realize the theoretical prediction from discrete state to continuous state,and the study of the dipole transitions of whole energy region is realized.