Two- and three-body effects in single ionization of Li by 95-MeV/u Ar18+ projectiles: Analogies with photoionization

N. Stolterfoht (1) , J.-Y. Chesnel (1) , M. Grether (1) , J. A. Tanis (2) , B. Skogvall (3) , F. Frémont (4) , D. Lecler (4) , D. Hennecart (4) , X. Husson (4) , J. P. Grandin (4) , Cs. Koncz (5) , L. Gulyás (5) , B. Sulik (5)

1 Hahn-Meitner-Institut Berlin
2 Western Michigan University [Kalamazoo]
3 TU - Technical University of Berlin / Technische Universität Berlin
4 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
5 ATOMKI - Institute for Nuclear Research [Budapest]

Cross sections for single electron emission have been measured in collisions of 95-MeV/u Ar18+ projectiles with atomic Li for electron energies ranging from 3 to 1000 eV and angles ranging from 25° to 155°. Models based on the Born approximation are introduced to separate two- and three-body effects in the angular distributions of the ejected electrons. Both experiment and theory provide information about the separability of the two- and three-body effects. The high projectile velocity and the use of the Li target are shown to be essential for the present analysis. The emission of the 1s electron is attributed mainly to three-body effects. The cross section for three-body collisions rapidly decreases with the electronic energy transfer involving a power law with an exponent of −3.5. Consequently, two-body effects dominate at high electron emission energies. Remarkably large contributions from two-body collisions were also observed for the low-energy emission of the 2s electrons. Demonstrating the analogy in ionization by photons and ions, the two- and three-body processes are associated with Compton scattering and photoabsorbtion, respectively.

Mots clés: Ionization; Single ionization; Electron emission; Ion-induced ionization; Ion-atom collisions; Fast ion-atom collisions; Electron spectroscopy; Born approximation; Energy distribution; Angular distribution; Cross sections; Differential cross section; Compton scattering; Photoionization; Two-body processes; Three-body processes

Domaines: Physique Atomique [physics.atom-ph]; Physique [physics]

N. Stolterfoht, J.-Y. Chesnel, M. Grether, J. A. Tanis, B. Skogvall, et al.. Two- and three-body effects in single ionization of Li by 95-MeV/u Ar18+ projectiles: Analogies with photoionization. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 1999, 59 (2), pp.1262. ⟨10.1103/PhysRevA.59.1262⟩. ⟨hal-01216837⟩