Electron impact dissociative ionization of methane: Formation of protons

Production of protons from dissociative ionization of methane by electron impact is investigated using the reaction microscope. By the triple coincidence measurement of all the three charged particles in the final state, we found that the (2a1)−1(npt2)1, (2a1)−1, (1t2)−2(3a1)1 and (2a1)−2(3a1)1 states of the intermediate CH4+ give major contributions to the formation of protons, and each state dissociates in a different mechanism