Recent studies of differential ionization by positron impact being performed at the University of Missouri-Rolla are described. Recoil ion-scattered positron and recoil ion-scattered positron-ejected electron coincidences are measured to provide doubly and triply differential ionization data (DDCS and TDCS) for e+ - Ar collisions. The DDCS and TDCS studies are for 750 and 200 eV impact respectively. For the TDCS studies the positron scattering angles are between approximately ± 5º and electrons ejected with energies less than 15 eV and angles between 90º ± 50º with respect to the beam direction are detected. Examples of TDCS data for the scattered positron and the ejected electron are presented.
Positrons; Ionizations; Differential
