Eur. Phys. J. D 12, 27-32 (2000)
https://doi.org/10.1007/s100530070039

Number of electrons active in slow collisions of O⁸⁺ and Ar⁸⁺ with C₆₀

Laboratoire de Spectrométrie Ionique et Moléculaire, Université Lyon 1, Campus de la Doua, 69622 Villeurbanne Cedex, France

Received: 12 November 1999
Revised: 28 February 2000
Published online: 15 October 2000

Abstract

Electron multiplicity has been measured for collisions of O⁸⁺ and Ar⁸⁺ with C₆₀ fullerene in coincidence with the number of electrons stabilized on the projectile. Measurements have been performed at the same velocity v=0.24 a.u. for both systems. The number of active electrons r is deduced from the number of stabilized electrons s and the number of ejected electrons n. The kinetic energy spectra of outgoing projectiles are different for collisions "outside"the C₆₀ cage which show a narrow peak and collisions "inside"the C₆₀ cage which show a broad shifted energy loss peak. The cross-sections for stabilization of s electrons have been measured versus r for each s value corresponding to peripheral collisions, i.e. for O⁸⁺ and for Ar⁸⁺. Their sum over s, the total cross-section , shows a similar behavior for Ar⁸⁺ and O⁸⁺ up to r=10. It gives a clear indication of identical multicapture processes for these two systems. The very different s number distribution is interpreted by the different relaxation modes of the multiply excited states of O and Ar.