Study On The Perfect Quantities Of Excited Atom Scattered By Electron And The Correlative Spin Effects

The study of electronic and atomic collision processes continues to be a very active and rapidly developing field of physics. The traditional object of electronic and atomic collision studies is a total or differential cross section. People analyse the structure information of target atom through the spectrum, the energy spectrum or the momentum spectrum. With the rapid developing of the computer power and the technology of scattering experiment, the quantum theory and experiment measurement of perfect observable quantities in electron-atom inelastic scattering are become the very interesting and meaningful subject.The so-called perfect observable quantities in electron-atom inelastic scattering are a set of optimal parameters which are based on the quantum scattering theory and are structured by the scattering amplitudes on the magnetic quantum sublevel, and these observable quantities can be measured by experiments and can describe the information of excited atom state and the dynamics of scattering.In this paper, we choose the alkali atoms as targets. According to the quantum scattering theory and density matrix theory, we use the state multipoles to describe the excited taget atom assemble, and set up the correlations between the scattering amplitudes of magnetics quantum sublevel and observable quantities by state multipoles and the Stokes parameters of radiation re-excited from the excited state. We use two types of distorted wave Born methods to calculate the alkali atom scattering matrix from S state to P state excited by electrons at low and moderate incident energy, i.e, non-relativity distorted wave Born approach (DWBA) and indirect-relarivity distorted wave Born approach (IR-DWBA). Then, we calculate the obervalbe quantities through the angular momentum theory and couple technology. The perfect observable quantities studied in this paper, are the orientation parameter, alignment angle and linear polarization degree which describle the excited atom state and the STU parameters which describe the spin changes before and after scattering.In DWBA, we calculate the scattering angle distribution of observable quantities of excited atom from S state to P state scattered by electron with sodium and potassium at different incident energies. The orientation parameter and aligment angles change regularly to the scattering angles and incident energies.The calculated results are partially agreement with reported experiment measurements, and some calculations need to be tested by experiments. From the calculations of STU parameters, we conclude that spin exchange effect is relative not only to the incident energy but also to the scattering angle. The spin exchange effect of electron is significant in the electron scattering with alkalli atoms at the low incident energy.We have explored to use the multi-configuration Dirac-Fock method (MCDF) to describe the wavefunction of alkali atoms, and use the Schrodinger equation to describe the continued electrons. In such IR-DWBA, we study the relativity effects in the scattering of electron excitedt with alkali-atom, and compare with the results of DWBA and measurements. We find that the results of IR-DWBA is prior to the calculations of DWBA when we treat with the DCS and the observable quantities of electron scattering with rubidium at 20 eV incident energy.