In this paper, we will report on fully differential cross sections (FDCS) for single ionization of helium by 75 keV proton impact for fixed ejected electron energies and different momentum transfers. These measurements show major discrepancies in the absolute magnitude between experiment and the theoretical, 3DW (three-distorted-wave) model. The 3DW model treats the collision as a three-body process (projectile, ion, ejected electron), and for the scattering plane it has accurately predicted the FDCS for higher energy C6+ impact ionization of helium. The lack of agreement between the 3DW model and experiment for low energy collisions suggests that a three-body model may not be appropriate for lower collision energies. We will present a four-body model that includes full initial-state correlation.

Meeting Name

13th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions



Keywords and Phrases

Atom-Ion Collisions; Helium Neutral Atoms; Impact Ionisation; Numerical analysis

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2006 American Institute of Physics (AIP), All rights reserved.

Publication Date

01 Jan 2006

Included in

Physics Commons