The tubular fast-flow reactor, previously used for reaction kinetic measurements at temperatures up to only 1000K, has been adapted to reach temperatures up to 2000K and has been applied to studies of gas phase reactions of metal atoms with O2. The most extensive set of results obtained so far is for the Fe/O2 reaction in an N2 bath at 1600K. Preliminary results for the Al reaction with O2 at 1700K are discussed. The experimental technique described here allows measurements to be made under reaction conditions overlapping those used in flame and shock-tube studies. A design study for a wall-less reactor which would allow extension of metal atom oxidation studies down to about 200 to 300K is also reported. (Author).

This experimental work is providing kinetic data on metal oxidation reactions for Air Force rocket propulsion and ramjet technology programs using the HTFFR (High-Temperature Fast-Flow Reactor) technique over the temperature range 300 to 1900 K. The reaction mechanisms and rate coefficients have been obtained from optical absorption and fluorescence measurements of the consumption of metal atoms or metal monoxide/monohalide radicals, as functions of pressure, oxidizer concentration, reaction time, and temperature; these variables are independently controlled.

The oxidation of Ge and Sn by various gases including N2O, has been studied by flash photolysis at room temperature and the kinetics determined. The rate of Sn + N2O is probably too slow to permit construction of a chemical laser based on this reaction. A new set of techniques involving laser pumping of alkaline earth atoms is also described which will permit the study of the kinetic behavior of their low-lying excited levels in bimolecular collisions. (Author).

The book brings together, for the first time, all aspects of reactions of metallic species in the gas phase and gives an up-to-date overview of the field. Reactions covered include those of atomic, other free radical and transient neutral species, as well as ions. Experimental and theoretical work is reviewed and the efforts to establish a closer link between these approaches are discussed. The field is mainly approached from a fundamental point-of-view, but the applied problems which have helped stimulate the interest are pointed out and form the major subject of the final chapters. These emphasize the competition between purely gas-phase and gas-surface reactions.

Because of the need for quantitative information on gaseous metal atom oxidation kinetics, an experimental research program has been initiated to determine the mechanism and rate coefficients of the homogeneous reactions of free Fe and Al atoms with O2. The apparatus used is a cylindrical fast-flow reactor, adapted for the study of the kinetics of refractory gaseous species at temperatures up to 1900 K. The Fe/O2 reaction at 1600 K was investigated in N2/O2 flows by observing the rate of decay of Fe-atom concentrations, measured in absorption, at pressures from 15 to 60 Torr. The gas phase reaction has been determined to be Fe + O2 yields FeO + O, with a rate coefficient k sub 2=4 x 10 to the minus 13 power ml/molecule/sec. This result is estimated to be accurate to within a factor of about 2. Evidence for heterogeneous oxidation of Fe in the presence of O2 has also been obtained; the lower limit for the probability of Fe oxidation per collision with the reactor wall, is found to be on the order of 1/10. (Author).