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Experimental chemical kinetics: a study of chemical reactions by means of moleclar beam techniques. Progress report, October 1972--October 1973

Description: The unfolding of molecular beam scattering data to yield cross sections, the interpretation of the amplitudes of the glory oscillations in the velocity dependence of the total cross section and the construction of a simple molecular beam apparatus for student experiments on reactive scattering are described in publications. Inelastic scattering of CsCl and CsI by Ar and Xe are studied over a range of relative kinetic energy of 1 to 2 kcal mole/sup -1/ at several laboratory angles. The inelastic cross sections are a substantial fraction of the elastic cross sections at large angles. Beams of halogen containing molecules produce negative ions when they hit surfaces of Nb and LaB/sub 6/. On the latter the efficiency of formation of negative ions can be as great as 0.1 for iodides and still larger for bromides. Experiments have shown that a beam of CH/sub 2/Cl/sub 2/ molecules can be accelerated without significant attenuation by interaction with a beam of electrons. The increase in velocity was up to 20%. Attempts to study the elastic cross sections for the scattering of halogen atoms by the rare gases and the reactive cross sections for the scattering of molecules with internal excitation are continuing. A list of publications is included. (auth)
Date: January 1, 1973
Creator: Greene, E.F.
Partner: UNT Libraries Government Documents Department

Experimental chemical kinetics: a study of chemical reactions by means of molecular beam techniques. Progress report, October 1974--October 1975

Description: Beams of electrons are shown to be able to control the motions of neutral molecules. A beam of electrons coaxial with a neutral beam of KCl molecules can restrict the divergence of the KCl beam to increase its signal on a detector by up to a factor of 10$sup 4$. Further, an electron beam can pump molecules from the residual gas in a vacuum chamber by forcing them to move preferentially along the electron beam into another chamber where they are detected by a mass spectrometer. Inelastic scattering of CsI by Ar and Xe and of CsCl by Ar with velocity selection and analysis at thermal energies shows large cross sections for the transfer of energy in amounts up to several vibrational quanta for both excitation and deexcitation of the molecules. The reaction LiCl + H $Yields$ Li + HCl is studied as it occurs on a Re surface as are the yields of positive and negative ions formed from cesium halides incident on a Nb surface. (auth)
Date: October 1, 1975
Creator: Greene, E.F.
Partner: UNT Libraries Government Documents Department