Thermionic property of RE2O3 doped molybdenum and pattern recognition application on this kind of material

La₂O₃-Mo as one of the attractive alternatives for ThO₂2-W thermionic cathode has exhibited better performance. However, La₂O₃-Mo cathode can not provide stable emission current . In order to improve its emission stability, a better understanding on its emission mechanism is still required. The key to the emission model is the chemical state of rare earth lanthanum on the surface of carbonized La₂O₃3-Mo surface. The chemical state of lanthanum on the surface of La₂O₃3-Mo cathode and its role in the emission stability improvement was studied in this paper. In addition, in order to get the thermionic cathode possessing high emission property, either single rare earth oxide of La₂O₃3,Y₂O₃, and Sc₂O₃ or a mixture of these rare earth oxides doped molybdenum cathodes have been produced by powder metallurgy method. Furthermore, computer pattern recognition technique has been used to optimize the composition of the material and cathode preparation technique.