Thermionic Emission Including Both Space Charge and Image Forces

Abstract

The net emission current for a uniform plane thermionic emitter is determined for a range of voltages, temperatures, and various values of the work function. Poisson’s equation is self‐consistently solved, using numerical techniques, without any additional phenomenological assumptions. This work accurately specifies the net current in the transition region between space‐charge‐limited and temperature‐limited emission, and we present the first determination of the shape of the interelectrode potential there. A comparison with earlier approximate techniques is also included.