A merged beam analysis of the dissociative recombination of molecular ions of importance to ionospheric and interstellar chemistry.

摘要

Experimental studies of the dissociative recombination of electrons with molecular ions, using merged beam techniques, have been performed for more than two decades now. This technique has proven to be very successful. There have, however, been instances in which the results from different merged beam labs have appeared to be in disagreement. This thesis presents a comprehensive review of the MEIBE merged beam lab at the University of Western Ontario. This review confirms that all components of the apparatus are functioning correctly, and establishes bounds of accuracy. Included is a novel measurement of the efficiency of a silicon surface barrier detector. After the correct functioning and accuracy of the MEIBE apparatus was confirmed, a series of old experiments was repeated. The molecular species selected ( CH+,CH+2,CH +3,CH+4, CH+5,N+2 ,NO+ , and O+2 ) are ones of particular interest to ionospheric and interstellar chemists. The originally published dissociative recombination cross sections for these species, obtained in the MEIBE lab, were confirmed. Where applicable, solutions are suggested for the apparent discrepancies between these results and those obtained elsewhere with storage rings. Finally, the results of original measurements of the dissociative recombination cross sections of several species of ions (HCO+, CN+, HCN+ and HNC+) of importance to interstellar chemists are presented.