ELECTRON MULTIPLICITY IN SLOW COLLISIONS OF AR8-60( IONS WITH C)

Electron capture by Ar8+ in collisions with C-60 fullerene has been in vestigated using coincident measurements of the number n of ejected el ectrons, the mass and charge of multicharged C-60(r+) of recoil ions a nd their fragments C-m(i+) and the final charge state of outgoing proj ectiles Ar(8-s+) (1 less than or equal to s less than or equal to 7). The number of captured electrons r is the sum of the numbers of stabil ized and emitted electrons: r = n+s. The ratio n/s decreases by a fact or three with s increasing from 1 to 7 showing that the multiply excit ed states populated by capture of a large number of electrons are rath er stable against auto-ionisation. Each kinetic energy spectrum of Ar and Ar2+ projectiles is composed of two peaks which we attribute to c ollisions ''inside'' and ''outside'' the C60 cage. The measured energy shift, of the projectile Delta E = 0.3 keV is consistent with the cor responding energy loss Delta E-c = 0.4 keV in a carbon foil with an eq uivalent thickness. Inside collisions are characterized by a strong di ssociation of recoil ions into light monocharged fragments and by a hi gh multiplicity of ejected electrons.