Effect of heavy particles interaction on the behaviour of ionisation double differential cross sections

The effect of interaction of an incident particle with the nucleus of a target atom on behaviour of double differential ionization cross sections is investigated within the frames of the earlier suggested method based on Faddeev three-particle equations modified for Coulomb potentials. It is revealed on the example of ionization of helium atoms by protons that accountancy of this interaction essentially improves agreement of the theory with the experiment in a wide energy range of colliding particles