Detection of sputtered and evaporated carbon aggregates: relative and absolute electron ionization fragmentation yields

The present study is a first attempt to determine electron impact ionization efficiencies for C2 and C3. A novel method has been applied to obtain the partial cross-section values for the reactions C2+e→C+,C2+e→C2+ and C3+e→C+,C3+e→C2+ and C3+e→C3+. The neutral target consisting of C, C2 and C3 is produced by thermal evaporation from a heated graphite sample and the neutral precursors in the subsequent ionization process can be distinguished by their different flight-time distributions acquired in the evaporation process. The partial ionization cross-section ratios obtained in this experiment have been calibrated with calculated absolute total ionization cross section curves of C2 and C3 using the Deutsch-Märk (DM) formalism.