Photoionization microscopy of the hydrogen atom in parallel electric and magnetic fields

In photoionization microscopy experiments, an atom in an electric field is ionized by a laser with sharply defined frequency, the electron is drawn toward a position-sensitive detector, and the current is measured as a function of position. Multiple classical paths lead from the atom to any point in the classically allowed region on the detector, and waves traveling along these paths produce an interference pattern. If a magnetic field is added parallel to the electric field, trajectories become chaotic. There is an infinite set of different families of trajectories, leading to an extremely complicated interference patterns on the detector. We present calculations predicting the kind of structure that will be seen in experiments.