Positron and electron total cross sections for collisions with C 2F 6 and C 2H 3F 3 molecules

Abstract

The experimental total cross sections (TCSs) data for 0.7–600 eV positrons and 0.8–600 eV electrons colliding with hexafluoroethane (C 2F 6) and 1,1,1-trifluoroethane (C 2H 3F 3) molecules are presented. These data are compared with the data of ethane (C 2H 6) measured previously. On the positron TCS data below 5 eV, the TCS curves are quite different from each other. For energies 7–25 eV, the data for these three kinds of molecules are comparable, though above 60 eV the C 2F 6 TCS data are roughly twice those of C 2H 6. The C 2H 3F 3 TCS data have magnitudes almost midway between those of C 2F 6 and C 2H 6. The TCS curves for electrons show the same variation with energy as the positron data above 60 eV. In the low energy region, a few weak resonant peaks are observed in the C 2F 6 and C 2H 3F 3 electron TCS curves. On the electron TCS data in the range 5.5–14 eV, the C 2F 6 data are lower than the C 2H 6 data.