The semiclassical and quantal inversion problems at fixed energy are solved for a number of nuclear scattering systems at various energies. The scattering function is represented as a particular rational or nonrational function of angular momentum. At low energies the semiclassical inversion generally breaks down; it works, however, surprisingly well in many cases.

• Received 10 April 1984

DOI:https://doi.org/10.1103/PhysRevC.30.434