Dynamics in the Dissociative Recombination of Small Polyatomic Molecular Ions

Abstract: Dissociative recombination (DR) is a process in which a positive molecular ion recombines with an electron and subsequently dissociates into neutral fragments. Among the different types of molecular ion-electron reactions DR deserves particular attention due to the important role it plays in low-temperature and low-density plasmas. Despite the apparent simplicity of the DR reaction, its investigation has proven to be a difficult task from both experimental and theoretical perspectives. In order to shed more light upon this process the storage ring technique has been introduced and utilised extensively for the last few decades. This thesis is devoted to experimental studies into the DR reaction at the storage ring CRYRING. The DR reaction has been investigated for the following molecular ions; Na+(D2O), PD2+, O3+, N3+, H2+, D2H+, OPCl+, OPCl2+ and H3O+, with the aim to ascertain rotational state effects, to find patterns in the branching products of similar molecular ions, to investigate isotope effects and to study in detail the dynamics involved in the three-body break-up channel.