@phdthesis{Eritt2008,
  author    = {Markus Eritt},
  title     = {Observations on Small Anionic Atomic Clusters in an Electrostatic Ion Beam Trap},
  journal    = {Untersuchungen an kleinen anionischen Atomclustern in einer elektrostatischen Ionenstrahl Falle},
  url       = {https://nbn-resolving.org/urn:nbn:de:gbv:9-000555-9},
  year      = {2008},
  abstract  = {The term atomic cluster relates to compounds of at least two or three atoms. Thereby the physical properties are size dependent and the property transitions between single atoms and bulk material are not always smooth. Ion traps allow it to observe internal cluster properties independent from the influence of external forces. In this work the electron induced decay of singly negatively charged atomic clusters was observed. The dissociation cross section of the clusters is dominated by detachment of the only weakly bound outer electrons. For simple atoms at low electron energies a simple scaling law can be obtained that includes only the binding energies of the valence electrons. Nevertheless for larger sizes theoretical calculations predict so called \"giant resonances\" as dominant decay process in metal clusters. Due to mass limitations in storage rings exist so far only cross section measurements for simple anions and small negative molecules. In this work the electron detachment cross sections of small negatively charged carbon (Cn- n=2-12), aluminium (Aln- n=2-7) and silver clusters (Agn- n=1-11) were measured in an electrostatic ion beam trap. The classical scaling law, including only the binding energies of the valence electrons, turned out to be not sufficient, especially for larger clusters. In order to improve the correlation between measured and predicted values it was proposed to involve the influence of the cluster volume and the specific polarisability induced by long range coulomb interaction. For silver clusters the best agreement was obtained using a combination of the projected area reduced by the polarisability. The existence of \"giant resonances\" could not be confirmed. According to theory for clusters with a broad internal energy distribution, a power-law decay close to 1/time is expected. For some clusters the lifetime behaviour would be strongly quenched by photon emission. The thermionic evaporative decay of anionic aluminium and silver clusters in a size range from one to ten constituents was tested but a correlation could be only found incidentally for a few cluster sizes.},
  language  = {en}
}