The preparation technology of tungsten cathodes doped with Y, La and Ce

Summary form only given. Tungsten cathodes doped with Y, La and Ce has better thermionic electron emission properties than thoria tungsten. Its fabrication technology has hampered its application. In this paper, its preparation technology was investigated and its role on the preparation process was discussed. Results showed that the doping process was very important for the cathode fabrication as it could determine the RE distribution in the tungsten matrix. Two stage hydrogen reduction processes were adopted as they can control the reduction parameter precisely. By altering the reduction temperature gradients can control the tungsten particles size. In sintering, the tungsten cathode was kept a longer time at low temperature and then sintered at high temperature up to 2600 °C in a short time. The sintered rods can be drew to 0.5mm diameter wires. At last the application fields this type of cathode may be used were discussed.