Long range effects on the longitudinal electron localization over a helium film

The peripheral electron behaviour over a dipole-electrified helium film has been theoretically studied. It is shown that, even without account for the polarization effects, the infinite dipole plane attracts a peripheral electron, if the negative charges are nearer to it than the positive ones. It is concluded that the critical (maximum) surface electron concentration over the helium film covering a metal plate, is attained even in case of the plate zero potential. It is shown as well that under real experimental conditions, because of the long-range nature of the interaction potentials, the image forces of all neighbouring electrons give a very large contribution to the transverse electron localization over the helium film covering the solid substrate. Under these conditions the effective holding field acting on a separate electron is calculated