The Calculation of the Primary Radiolysis Yield of Water Vapor Irradiated by 10-keV Electrons

The yields for the ionization and excitation from each molecular orbital of a water molecule irradiated by 10 keV electrons were calculated using the classical binary-encounter approximation. On further assuming fragmentation processes of the excited or ionized states consistent with the photochemical and mass spectrometrical results in the literature, we obtained, as the radiolysis yields of water vapor: G(electron)=2.96; G(OH−)=0.04; G(H3O+)=3.00; G(H)=4.83–5.21, including G(‘hot’ H-atoms)≤0.87; G(H2)=0.28–1.15; G(O)=0.83–1.21; G(OH)=6.70–7.08, and G(–H2O)=G(ionized water)+G(excited water)=2.91+4.96=7.87.