Experimental Investigation of the Energy Broadening of Thermionic Electrons

Abstract

Thermionic emitters play a crucial role in many fields of science and technology given their prevalence in electron beam instruments and devices. It is believed that the energy spread of thermionic electrons is larger than the intrinsic thermal width, due to extrinsic phenomena such as the Boersch effect. Here, we report on measurements of the energy spread of a single-crystalline tungsten thermionic emitter and the extraction of the Boersch contribution.