title: Thermal radiation and fragmentation pathways of photo-excited silicon clusters.
abstract: The fragmentation of laser heated silicon clusters was studied by time-of-flight mass spectrometry. For Si(n)(+) (n = 5-19, 21), the lowest energy fragmentation pathways were identified as the metastable decay channel occurring after the primary acceleration of the ions. The radiative cooling of laser excited Si(n)(+) (n = 5-9, 11, and 13) was quantified via its quenching effect on the amount of metastable fragmentation. The quenching varied strongly with cluster size, from no observable amount for Si7(+) to a cooling constant of 3 ⋅ 10(5) s(-1) for Si13(+). In addition, based on the observed fragmentation channels, the ionization energies and the relative binding energies of the clusters were partially ordered, and several ionization energies have been bracketed more precisely.
authors.affiliation: Laboratory of Solid State Physics and Magnetism, KU Leuven, 3001 Leuven, Belgium.
authors.forename: Piero
authors.initials: P
authors.lastname: Ferrari
authors.affiliation: Laboratory of Solid State Physics and Magnetism, KU Leuven, 3001 Leuven, Belgium.
authors.forename: Ewald
authors.initials: E
authors.lastname: Janssens
authors.affiliation: Laboratory of Solid State Physics and Magnetism, KU Leuven, 3001 Leuven, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Lievens
authors.affiliation: Department of Physics, University of Gothenburg, 41296 Gothenburg, Sweden and Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark.
authors.forename: Klavs
authors.initials: K
authors.lastname: Hansen