Electron-impact excitation of H2O and D2O at various scattering angles and impact energies in the energy-loss range 4.2–12 eV

Abstract

The electron-impact excitation of H2O and D2O has been studied at electron energies close to threshold and at large scattering angles in order to enhance spin and/or symmetry forbidden electronic transitions; and at energies far from threshold and at small scattering angles to enhance optically allowed transitions. The energy-loss range covered is 4.2–12 eV. From a comparison of the present measurements and recent, accurate ab initio calculations, several new assignments of electronic transitions in both H2O and D2O have been made or suggested. Also suggested are future works which could be carried out in order to unravel the complex Rydberg spectra above 11 eV.