General Considerations on the Emission of Electrons from Conductors under Intense Fields

Abstract

With the classical picture of the electron, a thermodynamic discussion is given of the current drawn from metals by intense fields, using the Volta difference of potential between two metals to produce the intense field. It is found that the order of the metals arranged according to the magnitude of their field currents is the same as their order arranged according to their Volta potential differences. It is also found that the density of the electron atmosphere in equilibrium with the metal is the same with a given field whether the direction of the field is such as to drive the electrons toward the metal or to pull them away from it. The modifications demanded in these conclusions by the wave-mechanics picture of the electron are briefly discussed; it seems probable that the first result will stand but that the second would have to be much modified, the precise method of modification not being now evident. In connection with the present wave-mechanics picture it is suggested that the potential discontinuity imagined to be encountered by all of the electrons in leaving the metal may be statistical in character. Expressions are given for the change in heat of evaporation of electrons and in the photoelectric threshold efficiency produced by intense fields in terms of a slight change of Volta difference. Attention is called to a temperature correction which should be applied to various experimental determinations which will have the effect of making the field current not absolutely independent of temperature at low temperatures, as has been supposed.