Theoretical Study Of The Photoionization Of Mg-like Ions And Photorecombination Process Of He-like Ions

Photoionization(PI) and photorecombination(PR) process is a fundamental atomic process of photo with atoms and atomic ions interact that plays important roles in many physical systems, including a broad range of astrophysical objects. PI process includes direct PI and resonant PI process, PR process consists of the coherent contribution from resonant dielectronic recombination(DR) and direct radiative recombination(RR). PI and PR cross sections of atoms and atomic ions are crucial in the modeling of astrophysical and laboratory plasmas with an external radiation field. Among the many applications, the most extensive is perhaps the calculation of the overall radiative opacity of the plasma. For example, the calculation of stellar opacities requires the computation of PI cross sections of all astrophysically abundant elements, in all ionization stages and for all bound states. PR process is an important dynamics process in hot, low-density plasmas, such as those found in the sun or in magnetic-fusion devices. It strongly affects both the ionization balance of a plasma and its emitted x-ray spectrum.In this thesis, the PI and PR process of highly charged ions are studied systematically by using the software package Dirac Atomic R-matrix Code(DARC)which is based on the fully relativistic R-matrix method and GRASP2 K based on the multi-configuration Dirac-Fock method. The details are as follows:1. Photoionization(PI) cross sections of the ground state 1s22s22p63s2 1S0 and exited state 1s22s22p63s3 p 3P0,1,2 of Mg-like Fe14+, Ni16+, Xe42+ and W62+ ions are calculated by using the Dirac Atomic R-matrix Code(DARC) based on a fully relativistic R-matrix method.To identify and analyze the locations and strengths for all resonant peaks, detailed calculations are performed for known resonant states by use the Flexible Atomic Code(FAC)basted on the relativity configuration interaction(RCI) method, the resonant energies and strengths together with radiative and auger transition rates are listed. For the Mg-like, good agreement is found between the present results and available theoretical calculations and experimental data.2.The partial and total photorecombination(PR) cross section for the ground state 1s2 1S0 to finial state 1s22 s 2S1/ and 1s22 p 2P(1/2,3/2) of He-like Fe24+, Ni26+, Mo40+ and Ba54+ ions are calculated by using the Dirac Atomic R-matrix Code(DARC) based on a fully relativistic R-matrix method. To identify and analyze the locations and strengths for all resonant peaks,detailed calculations are performed for all known KLL resonant states by use the Flexible Atomic Code(FAC) basted on the relativity configuration interaction(RCI) method,the resonant energies and strengths together with radiative and auger transition rates are listed.For the He-like, good agreement is found between the present results and available theoretical calculations and experimental data.