Collision measurements and excited-level lifetime measurements on ions stored in Paul, Penning and Kingdon ion traps

Abstract

Ion-collision and ion-excited level mean lifetime measurements carried out in Paul, Penning and Kingdon ion traps are briefly reviewed. Low energy spin-dependent charged particle collisions which have been studied include electron-atom spin exchange, spin-dependent electron-atom elastic collisions, spin-dependent excitation of atoms by polarized electrons, and spin-dependent electron transfer. Cross sections for electron recombination with molecules have been measured, as were the rate coefficients for ion-molecule reactions at temperatures between 11 K and 60 K. The rate coefficients or cross sections for electron transfer from atoms or molecules to atomic ions with charge states as high as 10 +, and energies in the eV range or below, have been obtained. The mean lifetimes of atomic and molecular ion states, with lifetimes ranging from 10-9s to tens of seconds, decaying by E1, intercombination E1, 2E1, M1 and E2 transitions, have been measured. The experimental data are presented in tabular form to simplify retrieval. The operation of the ion traps, and certain properties of the ion motion in the traps, are discussed, particularly from the point of view of the storage of ion numbers typically used in collisional research. The background and motivation for individual measurements, as well as salient features of the experimental technique, are also presented. © 1993.