Stability and delayed fragmentation of highly charged C60 trapped in a conic-electrode electrostatic ion resonator (ConeTrap)

We employed a conic-electrode electrostatic ion resonator (ConeTrap) to store the recoil ions (C60r+) resulting from collision between 56 keV Ar8+ ions and C60 in order to study their stability over a long time range (several milliseconds). The originality of our method, based on the trapping of a single ion to preserve the detection in coincidence of all the products of the collision, is presented in detail. Our results show that C60 ions produced in such collisions are stable in the considered observation time. By employing the ConeTrap as a secondary mass spectrometer in order to let the ions oscillate only for a single period, we have been able to observe delayed evaporation of cold C603+ ions 20 μs after the collision. We interpret quantitatively the relative yields of daughter ions with a cascade model in which the transition rates are estimated via the commonly used Arrhenius law, taking into account the contribution of the radiative decay.