We confirm that the candidate under our supervision carried out the work reported in this thesis.

We have calculated the differential and integral cross sections for electron impact excitation of the lowest autoionizing level of caesium atoms in the energy range 13 – 500 eV using the distorted wave method. In this study we have used a complex distortion potential as the distortion potential both at the initial and the final channels. Our results are compared amongst themselves to establish the effect of exchange and imaginary absorption potentials. We also compared with other available theoretical and experimental results to determine the suitability of our present method. From the results it is seen that when an absorption potential is included in the distortion potential, the integral cross section moves closer to the experimental result in the intermediate energy range 19 – 40 eV.