Electron-scattering cross sections of fluoromethanes in the energy range from 0.1 to 10 keV

Abstract

Total electron-scattering cross section for ${\mathrm{CF}}_{4}$ has been measured in the energy range from 300 to 5000 eV. Semiempirical values for the total cross sections of ${\mathrm{CF}}_{4},$ ${\mathrm{CF}}_{3}\mathrm{H},$ ${\mathrm{CF}}_{2}{\mathrm{H}}_{2},$ and ${\mathrm{CFH}}_{3}$ between 0.5 and 10 keV are also given, obtained by means of a formula that depends only on the total number of electrons and the polarizability of the molecule, and which was previously deduced by the authors. Experimental and semiempirical values have been compared with previously published experimental data. Differential and integral elastic cross sections are given at several incident electron energies in the range from 100 to 10 keV, calculated by means of a scattering potential method, assuming that the independent-atom model is valid, and the results compared with other published data. Integral inelastic cross-section values are also given as the difference between the total cross section and the integral elastic cross-section data. Finally, in order to facilitate the use of the present results in computation work, our integral elastic and inelastic cross sections have been fitted to expressions based on Born-Bethe formulas, which allows one to obtain these cross sections at any energy within the energy range considered.