Iv. Microwave Spectroscopy

The side-arm method for observing chemical recombinations described in the Quarterly Progress Report of April 15, 1958, page 24, is being used to study oxygen-atom recombination within the gas volume and on surfaces. Two modes of volume recombination have been considered: (a) O + 0O3 +0 203 0 03 + O 02 + 02 (b) O + O + 0 2 O + O 2 Reaction (a), involving ozone as an intermediate, proceeds at a rate that is proportional to the atomic oxygen concentration; reaction (b), the direct process, proceeds with a rate constant that varies quadratically with the atomic oxygen concentration. For reaction (a) and surface recombination, a steady-state solution of the diffusion equation in a cylindrical geometry was obtained. Green's function for this problem was used to generate a perturbation solution that includes the direct volume recombination reaction (b). Analysis of data taken, thus far, indicates a surface recombination efficiency of -5 14 6 -2 -1 1. 3 X 10 and a rate constant for reaction (a) of 1.7 X 10 cm mole sec . Our data show that only reaction (a) contributes appreciably to volume recombination at room temperature. D. W. Oliver