| 摘要 |
PURPOSE:To maintain improved stability of electron emission for a long time and to increase the strength of the cathode body structure, by dispersing in a carrier of Mo an oxide or carbide and a dispersion reinforcing agent so that the same form groups of lines, or trains, along the direction of the length with certain train lengths and by bringing the state of the dispersion within specified ranges. CONSTITUTION:An oxide or carbide of one element selected from the group of Ce, Hf, Tb, and so on and a dispersion reinforcing agent including Al, etc. are added to a carrier of Mo and adapted so that each of the added substances is aligned along the direction of the length and a plurality of lines, or trains, of those substances are formed there. On the outermost surface is formed a carbide layer. The content of the oxide or carbide is 1-5wt%, both the grain size and the intergranular distance are less than 2mum, the train length is more than 2.5mum, the train-to-train distance both lengthwise and sidewise are more than 2mum, while the contents of Al, K, and Si are respectively 10-200, 10-300, and 10-200ppm and the thickness of the carbide layer is 1-10% of the total thickness. |
