Electron-Ion Recombination in Atmospheric and Laboratory Plasmas

Sammanfattning: In this thesis, the measurements performed at CRYRING, Stockholm University, on the dissociative recombination of C2H+, C2H4+, C2D5+, C3H7+, C3D7+, C4D9+, Na+(D2O), CF+, CF2+ and CO2+ are presented. The dissociative recombination is the reaction in which a positive molecular ion captures an electron and stabilizes the capture by dissociation into neutral fragments. This reaction is of importance in many plasma environments, both naturally occurring, such as planetary atmospheres and interstellar clouds, and man-made, such as plasma enhanced reactors.The results from this study show that the hydrocarbon ions have a large probability for breaking several hydrogen bonds as well as a carbon-carbon bond. In the DR reaction of Na+(D2O), the fracture of the cluster bond is by far the dominating pathway, and the single F detachment is shown to be the main dissociation channel for the fluorocarbon ions. The carbon dioxide cation, CO2+, dissociates exclusively into CO and O, which makes a difference in atmospheric models. The DR rate coefficient is also presented for the different ions. Besides a discussion of the results, this thesis also includes a presentation of the experimental technique and analyzing procedure.