Methods have been developed for depositing electrons on the surface of liquid helium, either from the gas side or from the liquid side. In a suitable applied electric field they escape from the surface into the gas and the rate of escape has been measured. Electrons inside the surface escape by a thermally activated process. Those outside the surface escape much more rapidly by what appears to be a tunneling process. Analysis of the equilibrium between bound and free electrons identifies important features of the binding which have not previously been considered.

• Received 17 September 1971

DOI:https://doi.org/10.1103/PhysRevA.5.2183