
%0 Journal Article
%A McCarthy, IE 
%A Stelbovics, AT 
%T Study of Approximations for Electron?Atom Direct Reactions
%J Australian Journal of Physics
%D 1983/10/01
%V 36
%N 5
%P 665-674
%K 
%R https://doi.org/10.1071/PH830665
%U https://www.publish.csiro.au/paper/PH830665 
%X The electron-hydrogen system is a true three-body system which provides an excellent test for theories of reactions in many-body systems that approximately involve only three-body degrees of freedom. The coupled-channels optical approximation reproduces experimental data in most cases within experimental error. The approximation may be extended to a larger space of coupled channels by various approximations which are tested with the example of 54·42 e V electron scattering on the Is, 2s and 2p space for hydrogen, extended by the addition of 3s and 3p channels. Channels outside this five-state space are treated by including the corresponding polarization potentials. 
