[′ī‚än ki¦ned·ik ′en·ər·jē spek′träm·ə·trē] (spectroscopy) A spectrometric technique that uses a beam of ions of high kinetic energy passing through a field-free reaction chamber from which ionic products are collected and energy analyzed; it is a generalization of metastable ion studies in which both unimolecular and bimolecular reactions are considered.