Relativistic Distorted Wave Study On The Electronatom (Ion) Impact Excitations

At present,we have developed a new rapid and accurate fully relativistic distorted-wave(RDW)program to calculate EIE cross sections based on the more efficient and well-known MCDF packages Grasp92 and Ratip.The method and program provided a good chance for us to study electron-impact excitations of the complex atoms.The Be-like C²⁺ion multiplet 1s²2p^{2 3}P can be excited by electron impacts out of the metastable 1s²2s2p ³P,the ratios of the intensities of this line to other emission lines are particularly valuable for density diagnostics of solar plasmas,cataclysmic variable binary systems,and cool stars in all stages of evolution.As a first application,the EIE cross sections for C²⁺ion 1s²2s^{2 1}S₀ - 1s²2s2p ¹P₁ and 1s²2s2p ³P - 1s²2p^{2 3}P are calculated systematically,and compared with the other theoretical results and recent measurements [Phys.Rev.A 73,032709(2006)]quit good agreements are obtained.Furthermore,the inner- shell EIE cross sections are also investigated,we noted that for spin-allowed excitation 1s²2s^{2 1}S₀ - 1s2s²2p ¹P₁ the cross sections lager than spin-forbidden excitations1s²2s^{2 1}S₀ - 1s2s²2p ³P_0,1,2and for spin forbidden the ratios of cross sections approach 1:3:5,which corresponds to the ratios of final state statistical weights.For the metastable states of rare gas,in addition to their long lifetime,these states have much larger EIE cross sections than the corresponding cross sections from the ground states.During the past ten years,a number of theoretical and experimental studies have been carried out on the excitations of the metastable states of the neon,argon and krypton,and some of good agreements were obtained.However,the EIE processes of xenon serves as a typical example in the study of electron collision with heavy elements, but there highly challenging,because of stronger correlations and relativistic effects.In the forth chapter,the electron impact excitation cross sections from the metastable levels 5p⁵6s J=2 and J=0 to the ten levels of 5p⁵6p configuration of xenon are calculated systematically.In order to discuss the correlation effects of target states on the electrons impact excitation cross sections,two models are used basis on the Large-scale multiconfiguration Dirac-Fock(MCDF)method to describe the target states,and find that the correlations effects plays a very important role on low energy impact.A good agreement is found when the results are compared with recent measurements[Phys.Rev. A 72,022723(2005)]and calculations[Phys.Rev.A 74,012715(2006)] In the fifth chapter,the energy levels,transition probabilities,transition wavelengths,oscillator strengths and the EIE cross sections of the excitation configurations 2s²2p⁵31 and 2s2p⁶31(l=s,p,d)of Ne-like ions(Z=50～57)related with X-ray laser have been systematically calculated.The effects of correlation and relaxation on the level lifetimes,transition probabilities and oscillator strengths and cross sections of the ions were discussed.It is found that there are strong configuration interactions in this Z region,which can cause a dramatic change of the related transition probabilities and cross sections.