Electron multiplicity in slow collisions of Ar8+ ions with C60
Laboratoire de Spectrométrie Ionique et Moléculaire (UMR-CNRS 5579) ,
Université Claude Bernard, Lyon I, Bâtiment 207, Campus de la Doua, 69622 Villeurbanne
Accepted: 9 June 1998
Published online: 15 October 1998
Electron capture by Ar8+ in collisions with C60 fullerene has been investigated using coincident measurements of the number n of ejected electrons, the mass and charge of multicharged C recoil ions and their fragments C and the final charge state of outgoing projectiles Ar (). The number of captured electrons r is the sum of the numbers of stabilized and emitted electrons: r=n+s. The ratio n/s decreases by a factor three with s increasing from 1 to 7 showing that the multiply excited states populated by capture of a large number of electrons are rather stable against auto-ionisation. Each kinetic energy spectrum of Ar+ and Ar2+ projectiles is composed of two peaks which we attribute to collisions "inside" and "outside" the C60 cage. The measured energy shift of the projectile keV is consistent with the corresponding energy loss keV in a carbon foil with an equivalent thickness. Inside collisions are characterized by a strong dissociation of recoil ions into light monocharged fragments and by a high multiplicity of ejected electrons.
PACS: 36.40.Qv – Stability and fragmentation of clusters / 34.70.+e – Charge transfer
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998