Resonance and interference phenomena in the photoionization of a hydrogen atom in a uniform electric field. IV. Differential cross sections

For pt.III see ibid., vol.23, no.1, p.21-43 (1990). The differential cross section for the photoionization of an atom in a uniform electric field can be observed if the photocurrent is registered on the plane screen perpendicular to the uniform field axis. In the photodetachment case the differential cross section structure is interpreted exclusively in terms of the interference between two photoelectron classical trajectories passing through a given point on the screen. When the photoionization of the neutral atom is considered the resonance effects should be taken into account. If the photon energy is chosen so that the photoionization proceeds into a particular resonance state then the differential cross section represents essentially the squared resonance wavefunction in the parabolic coordinate xi .