Electron impact excitation and dissociation of halogen-containing molecules

• Autorzy: Kitajima M. , Suzuki R. , Tanaka H. , Pichl L. , Cho H.
• Konferencja: Proceedings of the Low Energy Electron-Molecule Interactions - 2nd International Symposium, August 29th - September 2nd, 2002, Chlewiska/Siedlce, Poland
• Języki publikacji: EN

Abstrakty

EN

A systematic analysis of the absolute differential cross sections (DCSs) for electron scattering by halogen-containing molecules CF3X (X = H, F, Cl, Br, I) has been performed with impact energy and scattering angle ranging from 1.5 to 100 eV and 15 to 130°, respectively. Three of the results of these experiments are described in the present report. Firstly, a clear difference is demonstrated in the elastic-scattering cross section angular distributions of polar and nonpolar molecules with the substitution of one of the F atoms in CF4 for a H, Cl, Br or I atom. Secondly, vibrational excitation spectra of the unresolved composite modes (mainly CF3 stretching) for CF3X reveal a common broad structure in the region from 7 to 9 eV due to shape resonance. The third result presented is the observation of a low-lying electronic state of CF3Cl, CF3Br, and CF3I. This feature is enhanced at lower incident energies and larger scattering angles. Also discussed are some preliminary results on the formation of negative and neutral fragments from SiF4 and CH4 by electron impact.

Słowa kluczowe

EN

crossed beam experiment; dissociation; dissociative attachment; differential cross section; electron impact

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2003
• Tom: Vol. 48, nr 2
• Strony: 89--93
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Kitajima M.

• Department of Physics, Sophia University, Tokyo 102-8554, Japan, Tel.: [phone], Fax: [phone]

autor

Suzuki R.

• Department of Physics, Sophia University, Tokyo 102-8554, Japan, Tel.: [phone], Fax: [phone]

autor

Tanaka H.

• Department of Physics, Sophia University, Tokyo 102-8554, Japan, Tel.: [phone], Fax: [phone]

autor

Pichl L.

• Department of Computer Software, The University of Aizu, Aizu-Wakamatsu 965-8580, Japan

autor

Cho H.

• Physics Department, Chungnam National University, Daejeon 305-704, Korea

Bibliografia

• 1. Herzberg G (1966) Molecular spectra and molecular structure III. Electronic spectra and electronic structure of polyatomic molecules. Van Nostrand Reinhold, New York
• 2. Iga I, Rao MVVS, Srivastava SK, Nogueira JC (1992) Formation of negative ions by electron impact on SiF4 and CF4. Z Phys D: At Mol Clusters 24:111−115
• 3. King GC, McConkey JW (1978) Electron energy-loss spectroscopy in the chloro-fluoro-methanes. J Phys B: At Mol Opt Phys 11:1861−1877
• 4. Mason NJ, Limao Vieira P, Eden S et al. (2002) VUV and low energy electron impact study of electronic state spectroscopy of CF3I. Int J Mass Spectrom 12261:1−14
• 5. Tanaka S, Sueoka O (2001) Mechanisms of electron transport in electrical discharges and electron collision cross sections. Adv At Mol Opt Phys 44:1−31
• 6. Toyoda H, Kojima H, Sugai H (1989) Mass spectroscopic investigation of the CH3 radicals in a methane discharge. Appl Phys Lett 54:1507−1509
• 7. Varella MT do N, Winstead C, McKoy V, Kitajima M, Tanaka H (2002) Low-energy electron scattering by CH3F, CH2F2, CHF3 and CF4. Phys Rev A 65:022702−1−17
• 8. Ying JF, Mathers CP, Leung KT, Pritchard HP, Winstead C, McKoy V (1993) Observation of a “new” quadrupole transition at 7.7 eV in CF3Cl by momentum-transfer-resolved electron energy loss spectroscopy. Chem Phys Lett 212:289−297