Prevalence of different double ionization pathways and traces of three-body collisions in strongly driven Helium

Abstract

We present a unified treatment of the prevalence of different double ionization (DI) pathways as a function of the sum of the final electron energies in strongly driven Helium. We do so as a function of laser frequency and intensity. At small total energy a new DI pathway prevails where both electrons are ionized with a delay after re-collision. We find that three-body collisions between the two electrons and the nucleus underly this pathway--we refer to it as triple collision (TC) pathway. At high total energy the pathway that prevails is the one where one electron is ionized with a delay following re-collision---we refer to it as Delayed pathway. Asymptotic observables that trace the prevalence of the latter pathways are identified.