METASTABLE FRACTIONS IN FULLERENES

Metastable fractions were determined for the series of reaction C(n)--> C(n-2)+ + C2 in fullerene samples. A reverse-geometry double-focus ing instrument was employed with electron impact ionization and high e nergy resolution. Reactions were studied in the second field-free regi on and corrections were made for artifact peaks due to decompositions in the first field-free region. The metastable fractions D were conver ted into apparent decay constants kBAR and the results were compared w ith previous data from sector and time-of-flight instruments, respecti vely. The differences in the behaviour of evaporative ensembles from l aser ablation of graphite and of ionized fullerenes are discussed.