Angular Distribution of the Outgoing Electrons in Electronic Ionization

The information which can be obtained from measurements on both the outgoing particles in single ionization is discussed for the case of high-energy electrons incident on neutral one- and two-electron atoms. The Born approximation is used to analyze a particular experiment suggested by studies of the nuclear ($p, 2p$) reaction. It is concluded that the momentum distribution for the single-electron orbitals of atomic systems can be determined by experiments of this type. The effects of identity and correlations are investigated, especially for the case of target helium atoms.