Number of electrons active in slow collisions of O8+ and Ar8+ with C-60

Electron multiplicity has been measured for collisions of O8+ and Ar8+ With C-60 fullerene in coincidence with the number of electrons stabilized on t he projectile. Measurements have been performed at the same velocity nu = 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 coll isions "outside" the C-60 cage which show a narrow peak and collisions "ins ide" the C-60 cage which show a road shifted energy loss peak. The cross-se ctions sigma(r)(s) for stabilization df s electrons have been measured vers us r for each s value corresponding to peripheral collisions, i.e. s = 1-4 for O-8(+) and s = 1-7 for Ar8+. Their sum over s, the total cross-section ar, shows a similar behavior for Ar8+ and O8+ up to r = 10. It gives a clea r indication of identical multicapture processes for these two systems. The very different s number distribution is interpreted by the different relax ation modes of the multiply excited states of O(8-r)+ and Ar(8-r)+.