Electron scattering from hexafluoride molecules: WF₆and C₂F₆. Absolute total cross section measurements from 1 to 250 eV

Abstract

Electron-scattering absolute total cross sections for tungsten hexafluoride (WF6) and hexafluorethane (C2F6) molecules have been measured in a linear transmission electron-beam experiment within the impact energy range from about 1 to 250 eV. For electron scattering from WF6 the cross section shows a prominent resonant-like peak centred at 3 eV and a very broad enhancement in the energy range between 20 and 70 eV overlaid with some much less pronounced features. The cross section for C2F6 has two resonant structures at 5 and 9 eV, respectively, and a very broad hump ranging from 20 to 60 eV with a distinct shoulder near 20 eV. Comparison of the e--C2F6 total cross section with available low-energy data from other experiments is made. The effect of fluorination is indicated.

Total and ionization cross sections of electron scattering by fluorocarbons

“…Total cross section values for C 2 F 6 are plotted in figure 5 and compared with the experimental results of Nishimura et al [39], Szmytkowski et al [47], Sueoka et al [48] and Ariyasinghe [49]. Our results are in agreement with all these experiments [39,47,49] at all energies. However, once again the values of Sueoka et al [48] are much lower and the discrepancy increases as the energy decreases.…”

“…-Bart et al [46] (experiment); filled circle-BEB [33] and filled square-DM from [46] (theory). Dash-Jiang et al [32] (AR); dashed-dotted-Jiang et al [32] (EGAR); -Nishimura et al [39] (experiment); filled circles-Szmytkowski et al [47] (experiment); filled inverted triangles-Sueoka et al [48] (experiment) and filled squares-Ariyasinghe [49] (experiment).…”

Electron collision with sulfuryl chloride (SO2Cl2) molecule

“…It was also possible to observe some substitutional effect, e.g. replacing hydrogen atoms in a molecule with fluorine distinctly changes the shape of the TCS low-energy function and strongly increases the cross-section magnitude above the ionization threshold ( perfluorination effect; cf [18][19][20][21][22][23][24][25][26]). Most of the aforementioned experiments concerned, however, perhydroand/or perfluoro-carbons only.…”