Ionic fragmentation of a CH4molecule induced by 10-keV electrons: Kinetic-energy-release distributions and dissociation mechanisms

Abstract

The dynamics of ionic fragmentation of CH${}_{4}$ molecules under impact of 10-keV electrons has been studied. The technique of recoil ion momentum spectroscopy is employed to obtain information about the kinetic energy release and the dissociation mechanisms of different pathways arising from the fragmentation of a CH${}_{4}$ dication. The results show that there are altogether eight dissociation pathways that arise from the complete and the incomplete Coulomb explosions of the CH${}_{4}$${}^{2+}$ molecular ions. The kinetic energy release for these pathways is compared with earlier data from the literature for the impact of different charged particles, photons, and their impact energies. The present results indicate that mostly the lower electronic states of CH${}_{4}$${}^{2+}$ are involved for the observed dissociation channels. Also, the dissociation mechanisms associated with these channels are suggested and discussed. Further, we have also estimated the relative ion intensities of different channels of fragmentation of CH${}_{4}$ dication produced under impact of considered energy of electrons.