| 摘要 |
PURPOSE:To eliminate the necessity for a binding agent and solvent and prevent generation of unevenness in a characteristic due to an excessive or short amount of a solder material, by providing annular hollowed grooves in an inner surface of end hats, composing an annular compression sintered body from a mixture of molybdenum powder and ruthenium powder, filling the sintered body under pressure as the solder material into the hollowed groove and thermally melting the solder material after temporary assembly of an electrode. CONSTITUTION:The second lead wire 4 is extended through without being contacted to the first end hat 2 and cathode main unit 3, and the second end hat 5 is secured to the top part of the second lead wire 4. The cathode main unit 3 is constituted by a spirally formed thorium tungsten wire, and the first and second lead wires 1, 4 are made of molybdenum. The first and second end hats 2, 5 are constituted by a compression sintered body of molybdenum powder, and ring-shaped hollowed grooves 7, 8 are provided respectively in faces of the end hats at a face-to-face position to each other, then ring-shaped solder materials 9, 10 are filled under pressure in the hollowed grooves 7, 8. The solder materials 9, 10 are constituted by a compression sintered body of mixture in proportion about 3:2 by weight of the molybdenum powder and ruthenium powder. |
