Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 12: Posters Thursday (Ion/Atom/Molecule/Surface Scattering)
A 12.13: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT3
Z/v dependence of the mechanisms for producing double K-shell vancancies in Li by fast Kr34+ an Ar18+ ion impact — •Jimmy RANGAMA1, Jean-Yves CHESNEL1, John A. TANIS2, Bela SULIK3, Bengt SKOGVALL4, Francois FREMONT1, Xavier HUSSON1, Amine CASSIMI1, Dominique HENNECART1, Allen LANDERS2, Volker HOFFMANN4, and Nikolaus STOLTERFOHT4 — 1Centre Interdisciplinaire de Recherches Ions Lasers, Unite Mixte CEA-CNRS-ISMRA-Universite de Caen Basse-Normandie, 6 Bd Marechal Juin, F-14050 Caen Cedex 04, FRANCE — 2Western Michigan University Kalamazoo, Michigan 49008, USA — 3Institute of Nuclear Research (ATOMKI) H-4001 Debrecen, HUNGARY — 4Hahn-Meitner-Institut Berlin GmbH, Bereich Strukturforshung, D-14109 Berlin, GERMANY
Mechanisms for production of single and double K-shell vacancies in atomic Li, produced by 60.5 MeV/u Kr34+ projectiles, have been investigated. Spectra for high-resolution Auger electron emission, occuring in the energy range 50-90 eV and resulting from the deexcitation of singly- or doubly-excited states, were measured for various electron emission angles. Double K-vacancy production by ion impact is generally attributed to two mechanisms, which are governed either by two independent nucleus-electron interactions or by electron correlation. These mechanisms depend differently on the perturbation parameter Z/v (Z and v are the projectile charge and velocity, respectively). Since Z/v for 60.5 MeV/u Kr34+ is larger by about a factor of 2 than that for 95 MeV/u Ar18+ ions which were used previously [1], the relative importance of the uncorrelated mechanism is expected to be enhanced when operating with Kr34+ ions. Compared to the case of 95 MeV/u Ar18+ projectiles, the relative line intensities attributed to the 2ln’l’ P states (n’ >= 2) have been observed to increase significantly when using 60.5 MeV/u Kr34+ projectiles. The comparison between the spectra obtained with Ar18+ and Kr34+ provide substantial information on mechanisms responsible for production of the double K-shell vacancies in lithium.
[1] J. A. Tanis et al., Phys. Rev. A 62, 2715 (2000).