title: Ionization of xenon Rydberg atoms at a metal surface.
abstract: Experiments in which a thermal-energy beam of xenon Rydberg atoms is directed at near grazing incidence onto a flat Au(111) surface are described that provide new insight into charge transfer and electron tunneling during atom/surface interactions. Analysis of the data shows that for the present range of principal quantum number n, 13 < or = n < or = 20, ionization occurs at an atom/surface separation Z(i) = (4.5+/-0.9)n2a0, where n2a0 is the Bohr radius of the atom. This result is in good agreement with the value Z(i) approximately 3.8n2a0 predicted by ab initio hydrogenic theory.
authors.affiliation: Department of Physics and Astronomy and Rice Quantum Institute, Rice University, P.O. Box 1892, Houston, Texas 77251, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Hill
authors.forename: C B
authors.initials: CB
authors.lastname: Haich
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.forename: P
authors.initials: P
authors.lastname: Nordlander
authors.forename: F B
authors.initials: FB
authors.lastname: Dunning