Total absorption and the energy dependence of the partial oscillator strengths for “photoionization” of the valence orbitals of H2O using an electron-electron coincidence method

Abstract

Partial oscillator strengths (β dependent), from threshold to 49 eV, for the ionisation of 1b1, 2a1, 1b2, 1a1 electrons from the valence shell of water vapour have been determined using fast (3.5 keV) electron impact with coincidence detection of the scattered and ejected electrons. The total oscillator strength (photoabsorption) was determined from the forward scattered electron intensity and placed on an absolute basis by normalisation to a total f value of 8 for the valence shell.