| 摘要 |
PROBLEM TO BE SOLVED: To manufacture an impregnated cathode with high reliability at a good yield.SOLUTION: A porous metallic cathode substrate 11 is brazed to one end of a cylindrical sleeve 12 with a brazing material 13. A heater 14 fixed by an embedding material 15 is arranged in the sleeve 12. One surface of the cathode substrate 11 is covered with a metal mesh 18, and a powdery electron emitting substance 19 containing barium oxide is located on a surface of the metal mesh 18. Under such as condition, the electron emitting substance 19 is heated and molten, made to pass through a net of the metal mesh 18, and impregnated with the cathode substrate 11, so as to remove the metal mesh 18 from the cathode substrate 11. |
