Characteristic energy losses by slow electron impact on thin-film alkanes at 77 °K

Abstract
Characteristic energy losses by slow electron impact have been measured on thin films of several alkanes at 77 °K. The cross section for the lowest loss at [inverted lazy s] 0.6 eV increases tenfold in the series n ‐pentane to n ‐nonane with increasing carbon number. For a given carbon number it decreases markedly with branching. Losses at [inverted lazy s] 3, [inverted lazy s] 6, [inverted lazy s] 9, and [inverted lazy s] 22 eV are common to all alkanes with no strong dependence on molecular size or configuration. The lowest losses may be due to temporary negative ion states or to pre‐existing trapping potentials. Losses at [inverted lazy s] 3 eV may be due to the highest temporary negative ions or to triplets. If the former is correct, then [inverted lazy s] 6 eV losses can be attributed to triplets. The [inverted lazy s] 9 eV losses are due to upper singlet states, and the [inverted lazy s] 22 eV losses may be due to collective excitations.