Observation of simultaneous positronium formation and excitation in positron-CO2scattering

Abstract
Inelastic low-energy positron (e+) scattering has been investigated in some atoms and molecules using a UV-sensitive photomultiplier plus gamma -ray detector coincidence method. In CO2 gas, pronounced effects were found which are due to positronium (Ps) formation with simultaneous excitation of the molecular ion. N2O was found to exhibit similar effects.