Electronic Discharge from Cold Wires in Intense Electric Fields

Abstract

Measurements were obtained for cold electronic currents at a pressure of ${10}^{-8\mathrm{}}$mm, using thoroughly outgassed electrodes made of a minimum amount of metal. A silver plated glass cylinder served as an anode, with a coaxial tungsten filament cathode. Pure tungsten was used to avoid the changing surface conditions incident to outgassing thoriated tungsten. The gradient necessary for a given current was increased more than three fold by heating the filament for three hours at 2700°K, the approximate period necessary for maximum gradient. The type of current-gradient curve at room temperature verifies the observations of Millikan and Eyring.