Calculations of Ion-Atom Differential Scattering Cross-Sections Using Inverse Power Potential

Differential elastic scattering cross-sections in ion-atom or atom-atom collisions can in general be calculated, using classical mechanics, except at very small scattering angles, provided the form of the interaction potential is known. In case where the interaction potential can be expressed by an inverse power law, calculations of the cross-sections are possible under certain circumstances using the Mott-Smith expansion for the scattering angle in terms of the impact parameter. Usually the first term in the expansion is used for calculating the cross-sections at small scattering angles. In the present work, the method of calculation has been extended, considering upto second order terms in the Mott-Smith expansion. Comparison with experimental data, when the form of the potential is accurately known, shows better agreement than cross sections calculated from first order Mott-Smith formula