| 摘要 |
<p>PURPOSE:To avoid influence of welding heat upon a cathode base body and suppress heat dispersion from the cathode by supporting with a W wire welded to a sleeve, and welding it with a cup in a specified position. CONSTITUTION:A cathode base body 1 is retained in a space bounded by a cut 2 and a sleeve 3. At the oversurface this sleeve 3 is provided with cruciform grooves 3, 6 when undergoing press shaping. W wires 5 are set cruciformly in these grooves 3, 6 with the central parts overlapped, and welded with the sleeve fast. The sleeve 3 and cup 2 are laser welded together in the laser welding part 4 not in direct contact with the cathode base body 1. Accordingly the cathode base body 1 is free from risk of damage due to the heat generated from laser welding. The cathode structure is fixed to a support by the W wires 5. Because of this fixing by use of thin wire, there is less dispersion of the heat from the cathode structure.</p> |
