Classical descriptionof threshold effects in ion-atom ionization collisions

Abstract

We employ a three-body classical trajectory Monte Carlo (CTMC) methodto calculate the recoil-ion momentum distribution at its kinematicthreshold in ion-atom ionization collisions. We analyse how thisthreshold is intertwined by dynamical constraints to the electroncapture to the continuum cusp in the electron double differentialcross section. We compare these calculations with those from a fullquantum-mechanical description and explore how these structures dependon the interactions among the three particles in the final state.