A theoritical study of excitation cross section for helium atom and calculation of Its ground state energy

Abstract

The present work deals with the theoretical study of excitation cross section for Helium atom & calculation of its ground state energy. The excitation scattering of electrons from helium atom is investigated in order to examine quantitatively errors introduced by the fact that the description of the helium target is only approximately known. The cross section is calculated in Born Approximation using matrix elements which weight wave functions differently. Similar shapes for angular distribution and total cross section versus energy curves are obtained although absolute values differ. The ground state energy of Helium atom is calculated by: (i) Perturbation method (ii) Variational method and (iii) Hartree-Fock method. The ground state energy of helium atom obtained by the Hartree-Fock method is much close to the experimental value than the variational and the perturbation method.