| 摘要 |
PURPOSE: A cathode is provided to allow for an effective transfer of heat from the sleeve to the gaseous metal by increasing the contact area between the sleeve and the gaseous metal. CONSTITUTION: A cathode comprises a cylindrical sleeve(22) in which a heater(4) for heating the cathode is accommodated; a gaseous metal(11) welded on the top of the sleeve; a holder(5) welded at the bottom of the sleeve, and which supports the sleeve; and an electron radiation material layer(3) formed on the gaseous metal. The sleeve has an outer surface on which a plurality of grooves are formed, and the gaseous metal has an inner surface corresponding to a convex-concave portion of the sleeve, wherein the inner surface has a plurality of protrusions to be engaged with the grooves formed at the outer surface of the sleeve.
|
