Abstract
The existence of phase-equivalent ambiguities in the generalized optical model is investigated using a coupled-channel analysis of α+Mg24 at 17 MeV. When compound-nucleus contributions are included in the analysis it is found that the phase-equivalent ambiguities typical of the spherical optical potential still occur when the potential is nonspherical. The values obtained for the deformation parameter which are appropriate for the rotational states of Mg24 are found to be relatively insensitive to the choice of a phase-equivalent potential. A simple explanation of this insensitivity has not yet been found.