Evolution of Magic Numbers in Mass Spectra of Clusters after Ionization
Clusters of various materials have been generated by adiabatic expansion, ionized by electron impact and analysed by a time-of-flight mass spectrometer. The size distribution of the ions is determined either at the end of the acceleration gap (a few microseconds after ionization) or at the entrance to the detector (a factor of ten later). These experiments demonstrate that the well-known intensity anomalies of water clusters evolve very slowly via evaporation of monomers from the cluster ions. In the cases of CO2 and 2,2-dimethylpropane (C5H12) similar processes are observed. It seems that the corresponding timescale for the evolution of “ magic numbers” in xenon cluster ions is much shorter.
Digital Object Identifier (DOI)
D. Kreisle, O. Echt, M. Knapp and E. Recknagel, Evolution of Magic Numbers in Mass Spectra of Clusters after Ionization, Surf. Sci. 156 (1985) 321