Effect Of Exchange And Absorption Potential In The Distorted Wave Calculation Of Electron Impact Excitation Of Autoionizing State Of Cesium

ABSTRACT

Study of electron impact excitation of autoionizing states of alkali metal atom is very important because it can explain the near threshold features observed in the ionization curves of these atoms. Many theoretical methods, for example, R-matrix, close coupling and distorted wave methods have been used for this study. In the distorted wave method no calculations have been performed for electron impact- excitation of cesium atom using complex distortion potential. That is why in this study, I have used the distorted wave method to calculate differential cross sections and integral cross sections for the electron impact excitation of the lowest autoionizing level of cesium (Cs) atom using the complex distortion potential which comprises of, static, exchange and absorption potentials. I have applied a linear combination of the static potentials of the target atom in its initial and final states plus exchange and absorption potentials as the final channel distortion potential and the static potential of the target atom in its initial state plus exchange and absorption potentials as the initialchannel distortion potential. I have used multi zeta (MZ) wave function by Mclean and Mcleanfor cesium atom. Numerical calculations have been performed using modified computer code DWBA1 developed by Madison and Bartschart. The results of this study have been compared with previous experimental data and theoretical data available in literature. It is seen that the present differential cross section, integral cross section and angular correlation parameters are in reasonable agreement with the available theoretical and experimental results. Inclusion of absorption potential lowers the integral cross sections at intermediate energy region and brings them closer to the experimental results.