Spatial interferences of photodetachment near a repulsive center

We study the detached-electron flux distributions from the photodetachment of a negative ion near a repulsive center. Using a semiclassical approach, we calculate the electron flux on spherical detectors with various radii. The classically allowed angular range of the interference patterns on the spherical screen increases as the detached-electron energy is increased. In the classically allowed range, we find that there are always two trajectories going from the negative ion to the observation point on the screen, inducing quantum interference patterns. We have also extended the formulas into the tunneling region. The interference patterns also reflect the quantum angular distribution of electrons leaving the ion. A scaling property for the detached-electron flux is investigated. The accuracy of our semiclassical formulas is established by comparison with a quantum treatment using the exact Coulomb Green's function.