Electron-ion recombination rate coefficient measurements in a flowing afterglow plasma

The flowing-afterglow technique in conjunction with computer modelling of the flowing plasma has been used to determine accurate dissociative-recombination rate coefficients α for the ions O2+, HCO+, CH5+, C2H5+, H3O+, CO2+, HCO2+, HN2O+, and N2O+ at 295 K. We find that the simple form of data analysis that was employed in earlier experiments was adequate and we largely confim earlier results. In the case of HCO+ ions, published coefficients range from 1.1 × 10−7 to 2.8 × 10−7 cm3/s, while our measurements give a value of 1.9 × 10−7 cm3/s.