Projectile angular distribution in single ionization of helium by proton impact at high and intermediate energies

The CDW-EIS theoretical method is applied to explain recent measurements of helium single ionization by proton and deuteron impact. This theory can cope with the proton angular distribution data for a wide range of projectile energy from 100 keV amu(-1) to 6 MeV amu(-1). At intermediate energies the CDW-EIS is shown to considerably improve the first Born approximation. The theoretical angular differential cross sections consider the internuclear interaction required for large scattering angles. A seminumerical technique for the introduction of the internuclear interaction is developed.