Three-dimensional fully differential cross sections for heavy-particle-impact ionization of helium are examined. Previously, the three-body distorted-wave (3DW) model has achieved good agreement with experiment in the scattering plane for small momentum transfers, but poor agreement for large momentum transfers. Poor agreement was also observed outside the scattering plane for all momentum transfers. In particular, the 3DW calculations predicted cross sections that were too small both perpendicular to the scattering plane and for large momentum transfers. The important unanswered question concerns the physical effects that cause the significant disagreement between experiment and theory. In previous works, the role of the projectile-ion interaction has been examined. Although the importance of exchange between the ejected electron and the residual bound electrons has been well established, and frequently studied, for electron-impact ionization, the importance of this effect has not been examined for heavy-particle scattering. In this paper we examine the role of this effect for heavy-particle scattering.




National Science Foundation (U.S.)

Keywords and Phrases

Differential cross sections; Electron-ion collisions; Helium

International Standard Serial Number (ISSN)

1050-2947; 2469-9926

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2007 American Physical Society (APS), All rights reserved.

Publication Date

01 Jan 2007

Included in

Physics Commons