Ionization of excited hydrogen atoms interacting with a metal surface under the influence of an external electric field

Ionization probabilities for highly excited hydrogen atoms interacting with a metal surface are calculated within the time-dependent close-coupling approach. In order to simulate current experiments, the effect of a uniform external electric field is taken into account. Adiabatic resonance states determined in the fixed-atom approximation are used as basis states in the time-dependent calculations. The velocity-dependent dynamic couplings acting between the resonance states are found to influence the total ion production for low-velocity Rydberg atoms.