Correlation between CH(A) and H+ produced by dissociative ionization of ethylene

Dissociative ionization of ethylene by controlled electron impact has been investigated using a new fragment ion–photon coincidence apparatus. There is a clear correlation between the CH(A–X) emission and H+ production. The H+ band shape in the spectrum is simulated well, based on the CH(A–X) emission lifetime and H+ translational energy. An average translational energy of H+ is estimated to be about 0.1 eV. This small value implies sequential dissociation of the parent ion and/or dissociation from a doubly excited state.