| 摘要 |
PURPOSE:To control the depth of penetration of a brazing material into the holes of a porous base accurately by using a ring-like or pellet-like brazing member to fuse the base and a cathode sleeve together and then burying a heater inside the sleeve. CONSTITUTION:A ring-like or a pellet-like brazing member 6 made of a Ru-Mo alloy is used to fuse together a porous cathode base 1 impregnated with an electron-emitting and a sleeve 2 made of Mo or similar material. The weight of the brazing member (Mmg) and the diameter of the brazed area (Dmm) are adjusted according to formula M=[0.3XpiX(DX2)<2>]-[0.7XpiX (D/2)<2>]. After fusion, the thus formed body is packed with filler containing a heater 3, thereby making an impregnated cathode structure. Accordingly, the amount of the brazing member 6 can be easily controlled. Besides, the depth of penetration of the brazing material into the base 1 is accurately controlled, thereby increasing the reliability of the cathode structure. |
