Electron-electron coincidence measurements of CH₄

Abstract

A measurement of fast electron scattering from CH4 at low momentum transfers in coincidence with the ejected electrons is reported. A complete collection is made of ionization electrons ejected over the entire solid angle with kinetic energies up to 20 eV and a novel method has been developed for testing the transmission of the extraction system as a function of the initial kinetic energy of the electrons. The results are presented as optical data i.e. relative oscillator strengths for absorption (0 to 90 eV) and ionization (IP up to 27.5 eV) and the absolute photoionization efficiency.