Procedure associated with Fourier transform-ion cyclotron resonance-mass spectrometers to facilitate ion/neutral reactions such as low-energy collision-induced dissociation in which a radio-frequency electric field, slightly off-resonance with respect to the cyclotron frequency of the reactant ion, cyclically accelerates and decelerates the reactant ion that is confined in the Penning ion trap. As a consequence, the orbit does not exceed the dimensions of the ion trap but maintains a high average translational energy for an extended time that activates an ion/neutral process.