Structure And Spectral Properties Of Atomic Systems In Plasmas

In recent years, with the development of study on controlled nuclear fusion, plas-ma diagnosis, interaction of laser and matters, soure of universe radial, astronomy andearth problem, the research on the structure and spectrum of atoms, molecules and ionsembeded in plasmas has been a hot topic.The interactions between electrons of multi-electron systems make it difcult to s-tudy the structure and spectrum properties of multi-electron systems in plasmas. Manystudies are performed so far on one-and two-electron systems. With the application ofplasma physics in new energy, laser boost, plasma diagnosis and astronomy, it is insuf-cient to just study one-and two-electron systems. The structure and spectrum propertiesof alkali-metal atoms and hydrogenic ions in plasmas are studied in this thesis. In ourwork, we tansform the multi-electron problem to on-electron problem by using the modelpotential. We apply the model potential to the study of polarizability and dispersion coef-ficient and calculate the polarizabilities and dispersion coefcients of alkali-metal atomsby using symplectic algorithm. In the plasma environments, the resonant Compton scat-tering of hydrogenic ions are also studied by symplectic algorithm, which provides theoryreference for the application of Compton scattering in plasma diagnosis. The main workof this thesis are summarized as follows:In the research of the static polarizabilities of alkali-metal atoms described by modelpotential in plasmas, the ground and first excited eigen energies and corresponding wavefunctions of Li, Na and K atoms are calculated firstly by using symplectic algorithm. Thenthe efect of plasma screening on the probability of the valence electron in ground and firstexcited states are studied. We find that the bound energy of ground state decreases andthe maximum probability place moves far away the core with the increasing screeningstrength. Then the dipole transition energies and dipole oscillator strengths of Li, Naand K atoms in diferent plasmas are calculated. It is found by research that the dipoletransition energies decrease and the dipole oscillator strengths wave with the increasingscreening strength. Finally, the dipole, quadruple and octuple polarizabilities of Li, Naand K atoms in diferent plasma screening parameters are calculated. We find that thescreening efects make the dipole, quadruple and octuple polarizabilities increase. For that the van der Walls interaction between atoms widens the resonant line ofatom, so we calculated the van der Walls dispersion coefcients between Li, Na, K andH atoms in symplectic algorithm. The dispersion coefcients C₆, C₈and C₁₀of Li-Li,Na-Na, K-K, Li-Na, Li-K, Na-K, H-Li, H-Na and H-K systems are calculated. Our re-sults are in good accordance with the reported results. It is found by research that thethe dispersion coefcients C₆, C₈and C₁₀of above mentioned systems all increase withincreasing plasma screening strength.In order to measure the redshift of spectrum line of alkali-metal atoms embeded inplasmas, we propose a new method to find the resonant frequency of alkali-metal atoms byusing the responding relation between external monochrome field frequency and dynamicpolarizability. The dynamic dipole, quadruple, and octuple polarizabilities of Li, Na andK atoms described by model potential in plasmas are calculated. By using the respondingrelation between external monochrome field frequency and dynamic polarizability, we getthe dipole, octuple, and octuple transition resonant frequency. For unscreend case, ourresults are good accordant with the reported result. It means that it is feasible to apply thismethod to the measurement of resonant frequency. For screened case, our results showthat all the resonant frequencies of Li, Na and K atoms have the phenomenon of redshift.The relation of screening efects on dipole, quadruple and octuple resonant transitionenergies of the same atom is dipole <quadruple <octuple. The relation of screeningefects on the same polarizability resonant transition energies of Li, Na and K atoms is Li<Na <K.To go further on the atomic structure diagnosis, on the basis of front chapters, westudy the resonant Compton scattering of hydrogenic ion in Lorentzian plasmas in the lastchapter. The resonant Compton scattering cross section of photon from the ground statehydrogenic ion is calculated by symplectic algorithm. A modefication of the reportedresults is given. The cross section of photon from the excited hydrogenic ion are alsocalculated. It is found by study that the cross section of resonant Compton scattering forthe photon from the hydrogenic ion all increase with increasing plasmas screenig strength.