An (e, 2e ion) investigation of dissociative ionization of methane

We present in this paper an (e, 2e + ion) investigation of the dissociative ionization of methane by 54 eV electron impact employing the advanced reaction microscope. By measuring two electrons and the ion in the final state in triple coincidence, the species of the ions are identified and the energies deposited into the target are determined. The species and the kinetic energies of the fragmented ion show strong dependence on the intermediate states of the parent ion. Possible decay pathways for the production of different species of ions are analyzed.