A brief account is given of work on the quenching of XeF(B) and other excited rare-gas systems. A more detailed report is given of the studies of the vacuum uv photolysis of XeO/sub 4/ and reactions of Xe(/sup 3/P/sub 2/) and Ar(/sup 3/P/sub 2/) with XeO/sub 4/. (DLC)

Tunable dye laser fluorescence has been combined with the flowing afterglow technique as a method for studying reactive intermediates present in the flowing afterglow. The radiative lifetimes and two-body quenching rate constants (with Ar carrier gas) for the Ar*(3p/sup 5/,4p) and Ar*(3p/sup 5/,5p) excited states were reported in the preceding year. During this year, we have measured the Ar* product states from the two-body quenching. More than 50% of the quenching leads directly to intermultiplet transfer to Ar(4s) states, rather than to intramultiplet cascade down the Ar(4p) manifold. Using this technique we also have studied the Xe(5p/sup 5/,6p') and Xe(5p/sup 5/,7p) excited states and radiative lifetimes, two-body quenching and the product states from quenching have been ascertained. These data should be of value for modeling energy flow pathways of rare gases excited by high energy electrons. A method has been developed for studying the quenching of the XeF(B) and KrF(B) by a variety of reagent molecules. A preliminary account of this work was published (number 5 in the publication list). Much additional experimental work has been done and a definitive study of the electronic quenching of XeF(B) and KrF(B) is in progress. Efforts to interpret (and publish) our comprehensive studies …

The status of photosensitized studies of reactions of Xe(/sup 3/P/sub 2/) and Kr(/sup 3/P/sub 1/) with fluorine, chlorine, bromine, and iodine donors is reported. Results for KrCl and KrF are summarized.

Analysis of XeF(B) and XeF(C) state quenching from photodissociation of XeF/sub 2/ was continued and progress was made on reactive quenching of the resonance states, Xe(/sup 3/P/sub 1/) and Kr(/sup 3/P/sub 1/). The study of the reactions of the resonance states of the rare gases was concentrated on the Kr* + Cl/sub 2/ reaction.

The quenching of XeF(B) was studied using the steady-state photolysis of XeF/sub 2/ as the source of XeF(B). The product states from the sensitized reaction of Xe(/sup 3/P/sub 1/) with Cl/sub 2/ and COCl/sub 2/ also were studied. The new XeF(B) quenching rate constants are described. The pulsed laser induced fluorescence technique was used to measure radiative lifetimes and two-body quenching rate constant (with Ar) for the low energy Xe(6p)* states. Serious signal/noise problems for the lowest two states in the Xe(6p) manifold were encountered. A transient digitizer is on order, which should improve the signal/noise by a factor of 10. The Xe(6p)* work can then be completed. The radiative branching ratios of all the Ar(4p), Kr(5p) and Xe(6p) states were measured. Combining these branching ratios with the measured radiative lifetimes permits the assignment of the oscillator strengths for the Ar(4s-4p), Kr(5s-5p) and Xe(6s-6p) optical transitions. The manuscript describing the Ar(4p) work is complete (except for editing).

Quenching of XeF(B) was studied using the steady-state photolysis of XeF/sub 2/ as the source of XeF(B). The XeF(C) state was observed, as well as the XeF(B) state, by using a very clean CO(A-X) resonance lamp to photolyze the XeF/sub 2/. Some of the preliminary data are discussed in this report. XeF(C) must be included in the kinetic scheme in order to understand the quenching of XeF*. The pulsed laser induced fluorescence technique was used to measure radiative lifetimes and two-body quenching rate constants for the Xe(6p), Kr(5p) and Ne(3p) states. The transient digitizer, has been delivered and is being interfaced to the computer for signal averaging. Some of the work with Ne(3p) is mentioned in this report, as well as attempts to use a resonance lamp to give Kr(/sup 3/P/sub 1/) which would be subsequently pumped with the pulsed laser.

The reactions of Kr(/sup 3/P/sub 1/) and Xe(/sup 3/P/sub 1/) with halogen compounds, producing rare gas halides, was studied. Abstracts of two papers on excited rare gas states are included. (DLC)

Photosensitized studies of Xe(/sup 3/P/sub 1/) and Kr(/sup 3/P/sub 1/) reactions with fluorine, chlorine, bromine, and iodine donors have been very productive. Work on the laser excitation methods for generating selected states of the rare gas atoms lying above the np/sup 5/,n + 1s set of levels continued.