Berlin 2005 – wissenschaftliches Programm

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A: Atomphysik

A 6: Atomic Clusters and Cold Atoms I

A 6.1: Hauptvortrag

Samstag, 5. März 2005, 10:30–11:00, HU 3075

On the Interatomic Coulombic Decay — •Simona Scheit, R. Santra, J. Zobeley, and L. S. Cederbaum — Universität Heidelberg, Theoretische Chemie, Im Neuenheimer Feld 229, 69120 Heidelberg

The Interatomic Coulombic Decay (ICD) is the mechanism by which a weakly bound atomic or molecular cluster decays via electron emission following inner valence ionization. The ICD is an electronic decay process of interatomic nature, based on electron correlation between neighboring monomers in a weakly bound cluster, and as such has to be distinguished from the well known Auger decay, which interests core ionized states and is of intraatomic character. In the ICD the inner valence hole, which is localized on one of the monomers building up the cluster, is filled by an outer valence electron of the same monomer; the energy gained by the system in this transition is efficiently transferred to a neighboring monomer and used for the emission of an outer valence electron. The resulting system, which eventually undergoes fragmentation, is a doubly ionized cluster with two outer valence holes localized on two different but neighboring monomers. The relatively large distance between the two positive charges reduces the Coulomb repulsion between them and lowers the threshold for double ionization, rendering a decay via electron emission energetically possible. The ICD process with its underlying dynamics has been theoretically predicted a few years ago and very recently experimentally observed in Ne clusters of various sizes. In this contribution the theoretical description of the ICD with its underlying nuclear dynamics will be presented. As example the ICD in Ne clusters will be discussed.