INVERSION OF ELECTRON-WATER ELASTIC-SCATTERING DATA

Fixed-energy inverse scattering theory has been used to analyze the di fferential cross sections for the elastic scattering of electrons from water molecules. Both semiclassical (WKB) and fully quantal inversion methods have been used with data taken in the energy range 100-1000 e V. Constrained to be real, the local inversion potentials are found to be energy dependent, a dependence that can be interpreted as the loca l equivalence of true nonlocality in the actual interaction. Further i mprovement in fits to the data was found by allowing the interactions to be complex, reflecting the role of coupling of the elastic to nonel astic channels.