| 摘要 |
<p>PURPOSE:To enable the generation of a high output and stable electron beam even via a long cathode by forming an anode to have a rod shape and providing a support means in contact with the bottom of the cathode between both ends thereof. CONSTITUTION:A filament 2a working as a cathode swells when heated and in particular, the axial elongation thereof is remarkable as overall length is large. A leaf spring 20 supporting the filament 2a is so adjusted that the deformation amount of the filament 2a due to a set bolt 23 before the supply of electric current will be more or less larger than an elongation amount after electric supply and heating. The filament 2a, therefore, still has appropriate tension after heated and elongated and the deformation thereof can be minimized. Also, a rod-shaped anode 5b has no corner part arising from downward bend construction and a discharge gas can be easily diffused upward, thereby lowering an opportunity of a discharge occurrence due to gas stagnation between the filament 2a and the anodes 5a to 5b.</p> |
