Nanocomposite W-4.5%ThO2 thermionic cathode

A novel tungsten cathode activated with 4.5% nano-oxide (in weight), has been prepared by the swaging technique. We have investigated the effect of high content nano-ThO2 addition on the operating characteristics of the cathode. It is found that the arc voltage and minimum open circuit voltage (OCV) can be reduced as varying the content of ThO2 nanoparticles from 2% to 4.5%, implying that the increasing of quantity of the thoria in the electrode takes effect on its characteristics importantly. (C) 2002 Elsevier Science B.V. All rights reserved.