Date Published:

MAR

Abstract:

An iterated map which mimics the dynamics of a high Rydberg electron revolving around an anisotropic ionic core is described. The map specifies the change in the quantum numbers of the electron due to its passage near to the rotating core. Attention is centered on the limiting case of physical interest where the rotation of the core is faster than the orbital motion of the electron. While the map does provide for a very efficient way to numerically simulate the motion, its main advantage is in that it delineates the various dimensionless coupling parameters that govern the dynamics. To make contact with many experiments, external electrical and magnetic fields are included in the Hamiltonian. The stretch of the kinetic time axis due to the presence of external fields is discussed. The full map can be further approximated by a one-dimensional map which captures the essence of the dynamics. The primary aspects having to do with the three-dimensional character of the actual motion are incorporated in the magnitude of the dimensionless coupling parameters. A simple but realistic limit of the one-dimensional map is discussed which can be considered as the electron undergoing diffusion in its energy. The mean first passage time out of the detection window and the branching fractions for ionization vs. stabilization of the electron are computed in the diffusion approximation. As is experimentally observed, the lifetime of the high Rydberg states exhibits a maximal value when plotted vs. the energy.

Notes:

Meeting of the Deutsche-Bunsen-Gesellschaft-fur-Physikalische-Chemie on Molecular Spectroscopy and Molecular Dynamics - Theory and Experiment, GRAINAU, GERMANY, AUG 28-SEP 01, 1994