| 摘要 |
A reservoir dispenser cathode includes a cup for receiving a material adapted to decompose when heated which passes to the upper surface of a porous plug at the top of the cup and coats this surface, thus producing a low work function surface. The plug may include a circumferential band while the cup has a radial flange resting on a cylindrical heater body and extending therebeyond. The flange is employed as a welding material for providing a continuous circumferential weld. To produce the weld, a laser is directed to the seam between the flange and the heater body while the assembly of the cup, flange and heater body is rotated around a common axis. The weld provides a hermetic seal between cup and plug and is accomplished without impairment of the emissive material or the plug.
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