Orientation Effects in Excitation-Ionization of Helium

We present fully differential cross sections (FDCS) for electron-impact excitation-ionization of helium when the ionized electron is found outside of the scattering plane. When the final state He$+$ ion is left in a non-spherically symmetric state, such as a p-state, an orientation for the ion can be defined. Using our 4-Body Distorted Wave and First Born Approximation models, we examine FDCS in search of effects due to the orientation of the final state He$+$ ion.