A TIME-OF-FLIGHT STUDY OF WATER MOLECULAR ION AND NEUTRAL SCATTERING FROM COPPER SURFACES

Collision of water molecule ions with solid surfaces can result in neutralization and fragmentation of the molecule. The energy distribution of total scattered yield was measured with a time‐of‐flight mass spectrometer. The major spectral peak energy is close to the value expected for a binary collision of OH with a copper atom, and the energy distribution can be accounted for by the existing dissociation models. Comparisons are made between the scattering of water molecule ions and that of He+ and Ne+ ions in terms of the spectral full width at half‐maximum, shape and the scattered yield. It is found that significant water vapour neutral peaks appear in the spectra of scattered Ne. This implies that strong non‐resonance charge exchange mechanisms occur in the projectile beams. The spectral peak heights of the water ion and neutral scattered at different incident angles are compared to those of Ne. Copyright © 1990 John Wiley & Sons Ltd.