title: Simultaneous ionization and excitation of molecules by positron impact.
abstract: Cross sections for ionization excitation of molecules by positron impact have been measured for the first time by scattering a positron beam from CO2 and N2. The cross sections have been observed to exceed those for electron impact by up to a factor of approximately 3 for CO2 and approximately 5 for N2. The enhancement arises primarily via positronium formation. The cross sections account for up to approximately 12% and 20% of the total cross sections for positron scattering from N2 and CO2, respectively.
authors.affiliation: UCL Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
authors.forename: D A
authors.initials: DA
authors.lastname: Cooke
authors.forename: D J
authors.initials: DJ
authors.lastname: Murtagh
authors.forename: G
authors.initials: G
authors.lastname: Laricchia