Fully Differential Ionization Cross Sections in Fast Ion-Atom Collisions

Fully differential cross sections for helium ionization by fast ion collisions are analyzed. The emitted-electron angular distributions for fixed momentum transfer and electron energies are described theoretically and compared to the experiment. The effect of uncertainties in the determination of the momentum is considered within the theoretical model. The cross sections are found to be extremely sensitive to the inclusion of the uncertainties. Important quantitative and qualitative modifications of the calculated cross sections are obtained by including small uncertainties in the determination of the momentum transferred by the projectile to the target