Positron collisions with C3H6 isomers

Abstract

We report calculated elastic integral (ICS) and differential (DCS) cross sections for positron collisions with C3H6 isomers, propene and cyclopropane. The ICSs computations were performed with the Schwinger multichannel method, at the static plus polarization level of approximation from 0.001 up to 8 eV. These ICSs are compared with the only experimental total cross sections (TCSs) available in literature for low energy positron scattering by these isomers [Makochekanwa C et al 2008 Phys. Rev. A 77 042717]. Even though there are significant differences between the two molecules (for instance propene has a dipole moment while cyclopropane has not), the ICSs for both systems are remarkably similar. This is mainly due to the fact that the dipole moment of propene is very small (0.39 D), and the increase of cyclopropane’s ICS at low impact energy is possibly due to the presence of a virtual state. This same resemblance occurs for the DCSs at lower energies, with the differences between the isomers becoming clearer as the energy increases.