POSITRON-IMPACT IONIZATION OF THE HELIUM ATOM

Triple differential cross sections (TDCS) of the helium atom by positr on impact ionization have been calculated for coplanar geometry in the intermediate and high energy regime. Since the two outgoing particles are treated on unequal footing, the present prescription is particula rly suitable for asymmetric geometry. The final state wave function wh ich involves the electron-positron correlation effect satisfies the th ree-body asymptotic boundary condition for the ionization process in a symmetric geometry. The TDCS have been computed for some sets of dynam ical parameters for which good agreement is noted with experiment in c ase of electron impact ionization.