Preparation of Rhenium Emitters and Measurements of Their Thermionic Properties

A method is described for electroplating stable rhenium on a tungsten wire. The thermionic emission properties of rhenium were investigated and values of the work function, $\phi =4.74\mathrm{}$ ev and of the emissivity $A=720\mathrm{}$ amp./${\mathrm{cm}}^2$/${\mathrm{deg}.\mathrm{}}^2$ were obtained. An increase of temperature produces no change of activation in a rhenium cathode. Emission results were reproducible.