Calculation of electron scattering on hydrogenic targets

We concentrate in this chapter on one of the latest electron scattering methods, the covergent close-coupling (CCC) method, developed by the authors. It takes the close-coupling (CC) formalism to completeness, and the present indications are that it satisfies the requirements of a general, reliable, and practical scattering theory. The target states are obtained by diagonalizing the target Hamiltonian in a large truncated orthogonal Laguerre basis. This ensures that the obtained target states are all square integrable. The orthogonality of the basis ensures that {open_quotes}completeness{close_quotes} of the expansion is approached as the basis size is increased. We say we have convergence whenever further increase in basis size does not have a significant effect on the results of interest. The CCC method has proved to be one of the most successful in describing electron scattering from light targets. We take this opportunity to combine here the ideas that appear in a number of publications and provide further detail not given elsewhere. This chapter is structured in the following way. First, we will give an outline of the various electron scattering methods currently in use, then discuss their strengths and weaknesses, and contrast these with the CCC method. This will be followed bymore » a section devoted to the detailed description of the CCC method. Subsequently, various comparisons of experimentation, the CCC method, and other available theories will be presented for a number of targets. We will not attempt to give a comprehensive survey, but rather concentrate on issues of greatest interest to us, namely where treatment of the target continuum is of great importance or where there are unresolved discrepancies with experiment.« less

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