Determination of the Charge of Positive Thermions from Measurements of Shot Effect

Several new types of current fluctuations have been studied with special reference to the possible effects of both positive ions and electrons, and the influence of space charge. An emitter of positive potassium ions is described which has proven suitable for shot effect measurements. Results indicate that the discharge may be properly controlled and temperature limited currents obtained, giving a value for the K^+ ion equal in magnitude to the electron charge. Values resulting from an extensive series of electron charge determinations confirm the precision and expediency of several new methods which have been introduced into the experimental procedure. A detailed description is given of a simple and direct method of determining the shot circuit impedance.