INTERACTION BETWEEN A NEUTRAL ATOMIC OR MOLECULAR BEAM AND A CONDUCTING SURFACE

The deflection of a beam of neutral atoms by an uncharged conducting surface has been observed. This deflection is a result of the attraction between the instantaneous electric dipole moment of an atom in the beam and the image dipole induced in the metal. The measured deflections agree in form and magnitude with those predicted from theoretical interaction potentials. Changes in the geometry of the deflecting surface give results that are in agreement with predictions. The deflection of a beam of polar molecules by metal and dielectric surfaces has also been observed. It can be explained by the interaction between the surface and the total instantaneous electric dipole moment of the molecule, including one characterized by motion at the frequency of molecular rotation, and one by motion at electronic frequencies. © 1969 The American Physical Society.