Electroionization study of ethylene: structures in the ionization and appearance curves

Abstract

Ionization-efficiency curves with very high signal-to-noise ratios for ethylene and all fragments consisting of at least one carbon atom are presented and analyzed. The curves are produced by monoenergetic electron impact and extend up to 10 eV above threshold. Most of the structures observed thus far by this method for these regions are reported here for the first time. Competition between [Formula: see text] production and [Formula: see text] and [Formula: see text] fragment production is clearly seen in the respective curves. Features occurring at the same energy in several of the curves indicate that these are due to a common progenitor, particularly the [Formula: see text] complex. The appearance of different fragmentation processes accounts for the onset-type structure found in some of the fragment-ion curves.