| 摘要 |
<p>PATENT APPLICATION of LOUIS R. FALCE for METHOD OF FABRICATING A DISPENSER CATHODE A dispenser cathode is fabricated by covering a reservoir of electron emitting material with a perforated metal foil having an appropriate pattern of pore-sized apertures thereon for providing uniform electron emission from the cathode surface. The electron emitting material is in the form of a pellet of barium oxide impregnated with a wax or resinous material to minimize chemical reduction of the barium oxide in air. The impregnated barium oxide pellet is sandwiched between the apertured foil and a support structure to which the foil is welded. During tube bake-out or subsequently during cathode activation, the wax or resinous material evaporates and barium oxide migrates through the apertures to cover the surface of the foil in a uniform manner. The barium oxide pellet is obtained from the carbonate and is wax impregnated prior to assembly into the cathode. Thus no carbonate is present at the tube bake out or cathode activation stages, thereby avoiding the carburization of electron emitting metal surfaces.</p> |
