s-Wave Elastic Positron-Hydrogen Scattering in the Ionization Region

The method of extrapolating the $t$ matrix from complex energies to real energies is tested on the positron-hydrogen $s$-wave amplitude at 29 energies in the elastic and inelastic regions, including 10 energies in the ionization region. The error in the extrapolated $t$ matrix is not expected to be more than 10% in the ionization region.