Investigation of Electron Capture Cross Section Additivity for CF4 C2F6 and C4F8 at Ep = 0.8 and 1.5 MeV

We have investigated single electron capture cross section additivity for the fluorocarbon molecules, CF4, C2F6 and C4F8 at proton energies of 0.8 and 1.5 MeV. Applying the post-collision-interaction (PCI) model to the case where the electron capture cross sections,σ10, for C and F are quite similar, we are able to provide an internally consistent parameterization of these molecular electron capture cross sections at each proton energy, σ10 (CmFn), in terms of "atomic" σ10 values for C and F, using the relationships σ10 (CmFm) = TmnC mσ10 (C) + TmnF nσ10 (F) or σ10 (CmFn) = σmnCF [mσ1010(C) + nσ10(F)] The Tmn terms are transmission fractions directly calculable from the PCI model; γmnCF is the weighted transmission fraction which characterizes each molecule