Derivation of surface-atom polarizability from field-ion energy deficits

The field dependence of the difference in standarized energy between helium ions produced from the field-adsorbed position and from the critical surface has recently been interpreted in terms of field penetration into a jellium surface. A model that takes the atomic structure of the real surface into account interprets these results in terms of the proper polarizability of emitter surface atoms. Values obtained for tungsten are 2.01 and 2.07 meV V−2 nm2.