Double ionization of helium by relativistic highly charged ion impact

We consider an interesting realization of the fundamental four-body problem: double ionization of helium in superintense electromagnetic fields generated by highly charged ions in relativistic collisions. We show how the simultaneous interaction of such fields with all three target constituents (which is not described by first-order theory) strongly influences the collision dynamics even at very high collision energies and how a “genuine” photoemission-like pattern may emerge in collisions at extreme relativistic energies. A very good agreement with available experimental data is obtained.