Partial ionization cross-sections of C2F6

The dissociative ionization of perfluoroethane, C2F6, by electron impact has been measured under single-collision conditions using Fourier transform mass spectrometry. The total ionization cross-section rises to a maximum value of 8.9±1.3×10−16 cm2 at 70 eV. CF3+ is the most prominent ion fragment at all energies, followed by C2F5+, CF+, and CF2+. C2F6+ is not observed. The ratio of dissociative ionization to total dissociation increases from 27±5% at 22 eV to 89±11% at 70 eV. The total cross-section and the partitioning among the dissociative channels is examined in the context of the binary encounter Bethe (BEB) molecular orbital model.