Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 12: Posters Thursday (Ion/Atom/Molecule/Surface Scattering)
A 12.19: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT3
Electron transfer and stabilization in slow Arq+-C60 collisions — •Jens Jenses1, Alexander Langereis1, Henning Zettergren2, Stefan Schwartz2, Henning Schmidt2, Afshin Fardi2, and Henrik Cederquist2 — 1Manne Siegbahn Laboratory, Stockholm, Sweden — 2Stockholm University, Frecativägen 24, S-104 05 Stockholm, Sweden
We discuss hollow atom formation and stabilization of electrons on Arq+-ions following Arq+ + C60 → Ar(q−s)+ + ... collisions at 3.3q keV (q=4-18). The experimental information consists of the final projectile charge-state distributions fqs, i.e. the relative distributions of the number of stabilized electrons, s, and the corresponding mean values ⟨s⟩=∑s=1qs·fqs as functions of q. We use the classical over-the-barrier model [1] to deduce sequences of effective principal quantum numbers and find that the hollow atom formation is completed 3-4 a0 above the surface of the C60-cage for all q. For q≤8 (filled L-shells), the last electrons are transferred from delocalized outer C60-orbitals directly to the projectile M-shell (side-feeding), while several intermediate shells are left open for larger q leading to further electron transfer at intermediate distances and simultaneous electron emission (shake-off) from higher projectile shells. At still closer distances localized carbon K-shell electrons are transferred directly to the argon L- (q=10 and 11) and M-shells (q≥12) [2]. The direct transfer to the L-shell of Ar10+ and Ar11+ is manifested as strong enhancements of ⟨s⟩ for q=10 and q=11. 1mm [1] H. Cederquist et al., Phys. Rev. A 61, 022712 (2000). 1mm [2] A. Langereis et al., Phys. Rev. A submitted (2000).