The coupled-channel optical method has been applied to study positron scattering by atomic sodium at intermediate energies. The optical potential that accounts only for the continuum has been implemented into the close-coupling framework and includes positron–sodium-atom and the positronium–sodium-ion channels. Elastic, excitation, ionization, positronium formation, and total cross sections are reported and are compared with other theoretical and experimental data, where available.

• Received 2 October 2000

DOI:https://doi.org/10.1103/PhysRevA.63.052707