THEORETICAL CROSS-SECTIONS, ANGULAR-CORRELATION PARAMETERS AND POLARIZATION FRACTIONS FOR ELECTRON-HYDROGEN SCATTERING

The recent technological advances in electron-atom scattering experime nts enable scientists to examine experimentally the excitation of not only the lowest, but also higher-lying states. The important question then arises as to whether these higher states contain significant new information. It has been suggested that the scattering amplitudes shou ld scale with principal quantum number and thus contain no new informa tion. The purpose of this work is to examine the N-dependence of the e lectron-hydrogen scattering. Two different approaches, the convergent close-coupling and second-order distorted-wave methods are used to cal culate scattering amplitudes for excitation of the N = 2, 3 and 4 leve ls of the atomic hydrogen. The integrated and differential cross secti ons, polarization fractions and angular-correlation parameters are dis cussed for energies from 20 to 1000 eV.