Energetics in charge-separation processes of highly charged fullerene ions

We have measured the kinetic energy release for the decay ${\mathrm{C}}_{60}^{q+}\to {\mathrm{C}}_{60-2m}^{\left(q-1\right)+}+{\mathrm{C}}_{2m}^{+}$ for charge states $q=4\mathrm{}–8$ and $m=1\mathrm{}$ and 2. The measured kinetic-energy release increases linearly with the fullerene charge state. The estimates of the barrier heights, deduced from the kinetic-energy releases, agree well with the observations regarding the stability and the competition between charge separation $({\mathrm{C}}_2^{+}$ emission) and neutral ${\mathrm{C}}_2$ emission of highly charged fullerenes.