PRODUCTION AND STABILITY OF MULTIPLY CHARGED C-60 AND C-70 FULLERENE IONS

The stability of multiply charged C60 and C70 fullerene ions has been investigated through studies of charge transfer reactions with Cs at 1-2 keV energies. A simple electron impact ion source is used to produce surprisingly intense beams of C60(2+), C70(2+), C60(3+), C70(3+), and C60(4+). Fragmentation of C60(3+) and C60(4+) following successive charge transfer reactions is observed by (energy/charge analysis of the product ions. The usefulness of producing internally excited C60 ions via electron capture from Cs is demonstrated' The results indicate that the lifetime of C60n+ against metastable decomposition is on the order of 10-100-mu-s for internal energies of 30-35 Ev. The stability of C60(4+) against Coulomb explosion is discussed.