Positron and electron impact multiple-ionization of rare gases

We present a theoretical treatment of the multiple-ionization by light projectiles, which is valid in an extended energy range (from near threshold to the keV region). It covers the direct ionization and the post- collisional electron emission, and takes into account charge and mass effects: projectile trajectory, finite momentum transferred, energy threshold. Our results for positron and electron-impact on Ne, Ar, Kr and Xe, are compared with a detailed compilation of experimental data of multiple and of total ionization cross sections. These values and previous ones for antiproton and proton-impact let us to present an extended picture of the particle-antiparticle multiple-ionization. (paper)