Molecular Ion Dissociation Processes in a Partially Cooled Electrostatic Trap

Abstract

An experimental capability being developed at the Oak Ridge National Laboratory Multi-Charged Ion Research Facility (ORNL MIRF) is described that enables stored cooling and state characterization of atomic and molecular ions of essentially any mass. Ions selected from a variety of available (hot and cold) sources are injected into a 1.5 meter long electrostatic mirror trap, in which excited internal states decay by radiative cooling. Ion lifetime studies or direct measurements of ‘in-trap’ interactions of molecular ions with electrons or atomic targets are accomplished with either a crossed electron beam or atomic beam (with recoil ion detection) located in the field-free region of the ion-trap, coupled with product velocity imaging. Similarly, extraction of trap-cooled ions can be used ‘out-of-trap’ for near state-specific electron capture (EC) and dissociative charge exchange (DCE) studies employing higher resolution COLTRIMS techniques coupled with fragment imaging.