Fully differential cross sections for C6+ single ionization of helium

We have examined the fully differential cross section (FDCS) for single ionization of helium by a 2 MeV amu(-1) C6+ ion. The FDCS is presented for a variety of momentum transfers and ejected electron energies. The theoretical model we use, labelled 3DW-EIS (three-body distorted wave-eikonal initial state), treats the collision as a three-body problem (projectile, active electron, residual ion). In the final state, each two-particle pair is treated exactly and the initial state is an eikonal state which contains the proper asymptotic forms of the projectile-target ion and projectile-electron interactions. Most importantly, the final state of the ejected electron is treated as a distorted wave calculated numerically from the static Hartree-Fock potential for the ion. Our theoretical results are compared with both absolute experimental measurements and previous theoretical calculations. It is shown that the 3DW-EIS results are in good agreement with experiment for all cases except large momentum transfer and low ejected-electron energies.