Positron-impact single ionization of helium using the Faddeev–Merkuriev equations

Abstract

We present the study of the positron-impact single ionization process of helium in the case where the residual ion remains in its ground state. We calculated the total cross-section for incident-positron energies ranging from the ionization threshold to 150 eV, and the triple differential cross-sections (TDCSs), using a single continuum wave function built through the Faddeev–Merkuriev differential equations. A comparison of the results of the total cross-section obtained with our approach and other theoretical models as well as with existing experimental data, shows a good agreement. Due to the lack of experimental and theoretical results for comparison, and to be more general and predictable in our investigation, the two- and three-dimensional representation of the TDCSs covering all possible values of the angle of the ejected electron for different values of its energy are presented and discussed.