Fractal Escape Times and the Chaotic Ionization of Hydrogen in Parallel Fields
Abstract
We examine the ionization of photoexcited states of a hydrogen atom in parallel electric and magnetic fields. This process is a useful and experimentally accessible model of chaotic decay in a Hamiltonian system. The electron dynamics reduces to an areapreserving chaotic map of the phase plane; the initial conditions of the electron form an ensemble of states populating a line in the phase plane. Decay is studied by examining segments of this line that escape at various iterates of the discrete map. These segments exhibit what we call "epistrophic selfsimilarity": the segments organize themselves into selfsimilar geometric sequences, which we call "epistrophes", but the beginnings of these sequences are only partially predictable. Initial states that do not ionize form an "epistrophic fractal". We propose new experiments which demonstrate the importance of epistrophic fractals on the ionization rate of hydrogen. Such experiments are now possible due to recent advances in atomic physics.
 Publication:

APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
 Pub Date:
 May 2003
 Bibcode:
 2003APS..DMP.G3004M