Is the dissociative recombination of H3(+) really slow? A new spectroscopic measurement of the rate constant

Abstract

The decay of an infrared absorption signal of H 3 + was measured as a function of time. The decay curve was analyzed and found to fit very well to the form expected for a recombination decay. The signal decay is attributed to the dissociative recombination with electrons and the rate constant was determined to be (1.8 ±0.2) x 10-7 cm 3 s _1 , which disagrees with the recent value (<2 x 10-8 cm 3 s" 1) obtained with the flowing afterglow/Langmuir probe (FALP) technique.