Electron Photodetachment fromO−and Elastic Scattering from Atomic Oxygen

Cross sections have been determined for the photodetachment of an electron from the negative atomic-oxygen ion. Calculations are made for the three transitions ${\mathrm{O}}^{-} {}_{}{}^2{}_{}{}^{}P$ to $\mathrm{O} {}_{}{}^3{}_{}{}^{}P$, $\mathrm{O} {}_{}{}^1{}_{}{}^{}D$, and $\mathrm{O} {}_{}{}^1{}_{}{}^{}S$ with photon energies from threshold to 13.6 eV. A method is used wherein wave functions for both bound-state and continuum electrons are obtained through a modified version of Slater's approximation to the Hartree-Fock equations. Correlation effects are included through a polarization potential obtained from an application of first-order perturbation theory to the Hartree-Fock atomic system. Results are compared with the experiments of Smith and of Branscomb, Smith, and Tisone, giving very good low-energy agreement. In addition, the elastic-scattering cross section for neutral oxygen, the dipole polarizability, the attachment cross section, and attachment coefficient for electron capture were also determined. Agreement is quite good between these observables and available experimental data.