Browsing by Author "Zengin, V."

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    High-voltage optical emission in binary gaseous mixtures of N2
    (Elsevier, 1995) Zengin, V.; Gökmen, A.; Dinçer, S.; Süzer, Ş.
    Optical emission in 1:1 binary gaseous mixtures under high voltage displays a varying character depending on pressure, applied voltage polarity, and chemical nature of the mixture. Under negative polarity, in pure N2 and 50% mixture of Ar, O2 and CO2, emission stemming from N2 + is enhanced relative to emission from neutral N2. In mixtures of N2 with gases containing halogens (CCl4, CHCl3, CH2Cl2, CF3H, CF2Cl2 and SF6) a reversal is observed, i.e. the N2 + emission is suppressed. An enhancement factor is defined as the ratio of the emission under negative polarity to positive polarity to quatify this polarity dependence. This enhancement factor varies between 0.01 and 50 depending on the second component in the mixture © 1995 Elsevier Science B.V.
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    A study of the chemiionization reactions of Ca, Sr and Ba with O2(X 3Σ-g)
    (1994) Shaw, A. M.; Dyke, J. M.; Zengin, V.; Süzer, Şefik
    Chemielectron and chemiion spectra resulting from the reactions of effusive beams of Ca, and Sr and Ba (in their ground 1S states) with ground state molecular oxygen O2(X 3Σ- g) have been recorded using electron spectroscopy and mass spectrometry. The chemielectron spectra are similar for all three reactions exhibiting a strong near-zero energy band and another band at higher electron energies. The chemiion spectra show O+ 2, M+ and M2O+ 2 as the major ions. The total ion current as well as the individual ion intensities, have been recorded as a function of the extraction potential on the reaction cell. The results obtained indicate that the metal oxide dimer ion is the primary chemiion, formed via an associative ionization reaction of a metal atom with a long-lived metal superoxide intermediate MO*2. A two state potential energy curve model is proposed for the M+MO*2 reaction to explain the shape of the experimental electron distribution. © 1994.