DISSOCIATION OF ETHANE BY ELECTRON-IMPACT

The absolute total dissociation cross section for ethane is reported for electron energies between 10 and 600 eV. A maximum value of 7.6 × 10-16 cm2 occurs at 80 eV while the apparent threshold is ≈ 10 eV. Dissociative ionization is more probable than dissociation into neutral fragments at all energies except in the threshold region. The data indicates that fragmentation involving methane elimination (c- + C2 H6 → e- + CH4 + CH2) occurs in less than 2% of the dissociative events for 50 < E < 600 eV. Arguments are presented which suggest that some of the lower excited states of ethane are stable against dissociation. © 1979.