Structures And Fully Differential Cross Sections For Proton-impact Single Ionization Of Helium

Fully differential cross sections (FDCS) are calculated using the modified Coulomb-Born approximation including the internuclear interaction (MCB-PI) for helium single ionization by 75KeV proton in both the scattering and the perpendicular planes. The present results are compared with experimental data and other theoretical predictions. Furthermore, to study the importance of the postcollision interaction (PCI) and internuclear interaction (PI) in the single ionization process, we have made calculations neglecting the PCI and PI interactions, respectively. It is showed that the PI interaction have a more profound impact than the PCI on the position of the fully differential cross section in the scattering plane. However, in the perpendicular plane, the PI effect in reproducing the shape of cross sections is greatly important at small q,. But at largest q1, the PCI effect should be more important. We also consider the influence of the distorted effect to the FDCS in the scattering and perpendicular planes. It is found that, with the increasing q1,, the role of the distorted effect becomes more and more important. The shape and position of the peak are primarily determined by the amplitude Tiv and then modified by the amplitude Tid. Then it can be better agreement with the data.Finally, we also assess the distorted effect to the FDCS, while the PCI or PI interaction is disappeared. It turns out that in the scattering plane, there is an important relation between the distorted effect and the high-order effects. In the perpendicular plane, at largestql, the PCI and PI interactions have a more profound influence on the perturbation potential. And with the increasing q1, the influence of the PCI and PI interactions becomes more and more obvious on the distorted effect.