DETERMINATION OF RATE CONSTANTS FOR $^{1}\Delta 0_{2}$ ELECTRONIC QUENCHING IN A FLOW TUBE REACTOR
Loading...
Date
1990
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
A flow tube reactor was built to provide an experimental device to measure electronic quenching rate constants for singlet delta oxygen ($^{1}\Delta 0_{2}$) in the gas phase and at the wall of the tube. Experiments with a cylindrical Pyrex tube have been completed. The source of $^{1}\Delta O_{2}$ was a microwave cavity operated at 2.45 GHz. The detection system for the $^{1}\Delta O_{2}$ consisted of an intrinsic germanium infrared detector, filters, fiber optics, and associated electronics. The emission from the $O_{2}$ (a-X) transition at $1.268\mu$ was transmitted from observation stations at the flow tube reactor by means of a fiber optic cable through a band pass filter to the detector. The chopped signal from the detector was passed into a lock-in amplifier system. The digitized signal was then passed into an IBM PC AT computer for storage and subsequent analysis. A thorough error analysis was performed on the data. The room temperature quenching coefficient for the Pyrex surface was determined to be $7 - 2.5 - 0.5 \times 10^{-5}$ and the gas phase electronic quenching rate constant for quenching with ground state oxygen was determined to be $k = 3.1 -1.8 \times 10^{-18} cc/sec$. The kinetic and mathematical models which were used to determine the values for the rate constants will be discussed.
Description
Author Institution: WL/ARDJ, WEAPONS LABORATORY, KIRTLAND AF BASE