Study of New Materials to Replace the Thoriated-tungsten Electrode

Thoriated-tungsten (ThO2-W) is popularly used for the electrodes of a super-high pressure mercury lamp, or for arcwelding, because of its excellent performance as to the electron emission. Because it is radioactive, however, a new material which can replace it would be desirable. To find a material to replace ThO2W as the electrode, we have made many kinds of electrodes by a new process, which is different from the traditional process, and evaluated their performance. We have found that neodymium oxide or samarium oxide made by the new process produces encouraging results.