Low-energy electron scattering from hydrocarbons and their perfluorinated derivatives: I. Elastic differential cross section for e- scattering

Abstract

A crossed-beam experiment has been performed to measure differential elastic and vibrationally inelastic cross sections for electron scattering from ethane in the energy range E = 0.3-10 eV. In the present paper, the results for elastic scattering are reported. The energy and angular dependence of the cross sections is determined. Absolute values of the differential cross sections (DCS) are obtained by using -He scattering as a reference system. By use of phase-shift analysis (PSA) and modified effective-range theory (MERT), the measured DCS are extrapolated into the experimentally inaccessible regions. Integral and momentum transfer cross sections are determined which can be compared with the results of electron transmission experiments and swarm experiments. The most important features in the elastic scattering cross section of ethane are a Ramsauer-Townsend minimum below 1 eV and a broad resonance structure at about 7.5 eV.