Accession Number : ADA189518

Title :   Molecular Collision Processes in Gases and at Surfaces.

Descriptive Note : Final rept. 1 Mar 85-31 Jul 87,

Corporate Author : YALE UNIV NEW HAVEN CONN

Personal Author(s) : Fenn, John B

PDF Url : ADA189518

Report Date : 12 Dec 1987

Pagination or Media Count : 18

Abstract : Results have been obtained by Fourier Transform Infrared Emission Spectrometry (FTIES) to determine the internal energy distribution in molecules whose states are consequent to three kinds of inelastic and/or reactive collision processes. (1) Free Jet Expansion. Gas that is vibrationally excited in the source by heating, corona discharge or chemical reaction is interrogated by FTIES after free jet expansion into vacuum. The observed marked departures from equilibrium give insight on RR, RT, RV and VV exchanges where R, T and V refer to rotational, vibrational and translational energy. (2) Inelastic Scattering from Surfaces. When free jets of CO2, CO2, N2O, and OCS are incident on a hot Pt surface the reflected molecule have enough vibrational excitation to be analyzed by FTIES. Vibrational and Rotational accommodation coefficients have been determined for these species over a range of surface temperatures. (3) Reactive Scattering from Surfaces. FTIES analysis has been carried out on nascent carbon dioxide molecules formed by the catalytic oxidation of carbon monoxide molecules incident on a Pt surface bathed in oxygen. Results indicated vibrational and rotational temperatures much higher than surface temperatures.

Descriptors :   *COLLISIONS, *GASES, *MOLECULAR PROPERTIES, CHEMICAL REACTIONS, ELECTRICAL CORONA, ENERGY, ENERGY TRANSFER, HEATING, INTERNAL, MOLECULES, REACTIVITIES, SOURCES, VACUUM, VIBRATION, SURFACES

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE