An L2approach to the solution of coupled-channel scattering equations

Abstract
It is proposed to solve a coupled-channel scattering equation representing the effect of all but a few channels by an optical potential. This optical potential is expanded on an L2 basis and it is shown how the resulting pseudoresonances can be eliminated using the 'equivalent weight' hypothesis of Heller (1973). These ideas are applied to a model problem posed by Burke, Berrington and Sukumar (1981) and accurate singularity-free solutions are obtained. The extension of the method to electron-atom scattering is discussed.