Electron-electron interaction in projectile electron loss

H.-P. Hülskötter; B. Feinberg; W. E. Meyerhof; A. Belkacem; J. R. Alonso; L. Blumenfeld; E. A. Dillard; H. Gould; N. Guardala; G. F. Krebs; M. A. McMahan; M. E. Rhoades-Brown; B. S. Rude; J. Schweppe; D. W. Spooner; K. Street; P. Thieberger; H. E. Wegner

doi:10.1103/PhysRevA.44.1712

Electron-electron interaction in projectile electron loss

H.-P. Hülskötter, B. Feinberg, W. E. Meyerhof, A. Belkacem, J. R. Alonso, L. Blumenfeld, E. A. Dillard, H. Gould, N. Guardala, G. F. Krebs, M. A. McMahan, M. E. Rhoades-Brown, B. S. Rude, J. Schweppe, D. W. Spooner, K. Street, P. Thieberger, and H. E. Wegner

Phys. Rev. A 44, 1712 – Published 1 August 1991

Abstract

In ion-atom collisions where the projectile is ionized, target electrons act not only coherently by screening the target nucleus but they may also act incoherently by directly ejecting a projectile electron. This electron-electron interaction should be relatively most important for targets that have a low nuclear charge, since the cross section for a neutral target is roughly proportional to $Z_{t}^{2}$ + $Z_{t}$ , where $Z_{t}^{2}$ is the contribution due to the target nucleus and $Z_{t}$ comes from the target electrons. In order to investigate the electron-electron interaction, we have measured and calculated cross sections for ${Li}^{2 +}$ , $C^{5 +}$ , and $O^{7 +}$ on $H_{2}$ and He, ${Au}^{52 +}$ on $H_{2}$ , He, C, and $N_{2}$ , ${Au}^{75 +}$ on $H_{2}$ and $N_{2}$ , $U^{86 +}$ on $H_{2}$ and He, and $U^{90 +}$ on $H_{2}$ . The collision energies range from 0.75 to 405 MeV/nucleon. The calculations have been performed in the plane-wave Born approximation. We demonstrate that for energies where the target electrons have sufficient kinetic energy in the projectile frame to ionize the projectile, the electron-electron interaction can lead to a significant increase in the total electron-loss cross section.

Received 17 December 1990

DOI:https://doi.org/10.1103/PhysRevA.44.1712

Authors & Affiliations

H.-P. Hülskötter

Department of Physics, Stanford University, Stanford, California 94305

B. Feinberg

Accelerator and Fusion Research Division, Lawrence Berkeley Laboratory, One Cyclotron Road, Berkeley, California 94720

W. E. Meyerhof

Department of Physics, Stanford University, Stanford, California 94305

A. Belkacem

Department of Physics, Stanford University, Stanford, California 94305
Chemical Sciences Division, Building 71-259, Lawrence Berkeley Laboratory, One Cyclotron Road, Berkeley, California 94720

J. R. Alonso