Development of a methyl radical source for use in reaction dynamics studies

Abstract

A source for methyl radicals based on the thermal decomposition of azomethane was subjected to an analysis of products by mass spectrometry. This source was used previously by Schwanke et al. to study the reaction with F atoms and to probe the product mixture by IR chemiluminescence. It was found that the CH 3 yield was less than 18%, the exact number depending on the temperature of the tungsten oven. Other products were CH 4, C 2H 6, C 2H 4, C 2H 2 and C 2H 3 radicals. A computer study including 32 elementary reactions suggests that the composition of the source beam can only be explained by heterogeneous processes occurring on the oven walls.