Ion trapping in the low mass regime.

摘要

The long term storage of a large numbers of ions has been achieved with the University of Calgary ion trap, with the principal species of interest being atomic Magnesium and molecular Nitrogen. Over long storage times the ion species distribution was found to evolve due to collisional charge transfer of electrons from the light atomic species (Helium ions) to the higher mass species contained within the ion trap system. Lifetimes for the various reagent ions were measured as a function of the partial pressure of reagent gases in order to gain insight into the reaction process.; Further experimental studies of the q-scan mass spectrometry technique used to analyse the ion trap's contents were conducted on mixtures of trapped low mass (mass 30 u) ions. These results confirmed a linear dependence of the mass to charge ratio on its expulsion potential during the mass spectrometric process, contradicting published theoretical models that predict a quadratic dependence. Numerical simulations of the ion trap environment were used to confirm this result and provide insight into the shortcomings of the simple theoretical model. The results of the simulations showed an agreement with experimental data and indicated that the simple model does not perform well under conditions of large applied perturbations to the trap system.