The electron-impact single-ionization cross sections on the helium isoelectronic targets He,
Li+, B 3+, C 4+, N 5+, O 5+, Ne 8+, Na 9+, Fe 24+, Ag 45+, and U 90+, are calculated using
the recent simplified version of the binary-encounter dipole (siBED) model as applied by
Huo [Phys. Rev. A 64, 042719 (2001)] to various molecular targets. The simple siBED model
is good for the helium atom, but it is inadequate for ionic targets. Our proposed
modifications:(i) ionic correction of the siBED model (QIBED) and (ii) relativistic corrections …

The cross sections for electron-impact single ionization of helium-like targets,—Li, B3, C4,
N5, O6, Ne8, Na9, Fe24, Ag45, and U90—are calculated using a recently propounded
parameter-free relativistic binary encounter (RBEA) model, which remains valid up to the
relativistic energy domain. Our RBEA results are compared with those of the Coulomb–Born
(CB) approximation, distorted wave Born approximation (DWBA), relativistic two-potential
DWBA (RTPD), the simple empirical model of Brenshtam et al.(BRY), and the model of …