Electron impact ionization of a ion from its ground (1S) and excited (2S, 2P) states

Abstract

An approach is proposed to study the ionization cross sections of a hydrogenic ion by electron impact using coplanar geometry, for intermediate and high incident energies. The final-state wavefunction is chosen as the correlated 3-body Coulomb wavefunction satisfying the exact asymptotic boundary condition. The long-range Coulomb interaction in the initial channel between the ionic target and the projectile has also been taken into account properly. Triple differential cross sections (TDCSs) have been calculated for the ionization of a ion in its ground and excited states (2S and 2P). Apart from the usual double-peaked structure of the TDCS, as is found in ground-state ionization, some secondary structures also appear for the excited states, particularly at higher scattering angles. A strong recoil peak is noted in the TDCS structure at lower incident energies for both ground and excited states of the ion.