Cross sections for the production of cations by electron impact on methanol

Utilizing a crossed electron beam and a molecular beam collision geometry and the single particle counting technique, cross sections for the production of positive ions by electron impact on methanol have been measured for electron impact energies ranging from 0 to 500 eV. Appearance potentials for the various ionic fragments have also been obtained. These potentials are compared with values calculated from the heats of formation for methanol and for neutral and cationic products in order to identify the various channels of dissociation at threshold energies.