Title :
An in situ emission microscopy study of barium supply to the surface of scandium-coated porous tungsten
Author :
Vaughn, Joel M. ; Jamison, Keith D. ; Kordesch, Martin E.
Author_Institution :
Dept. of Phys. & Astron., Ohio Univ., Athens, OH, USA
Abstract :
The transport of Ba to the surface of a porous tungsten disk packed with barium oxide powder is observed directly with emission microscopy. The W disk surface is patterned with sputter deposited scandium metal squares. Thermionic electron emission is observed from the Ba/Sc/W areas at temperatures below those required for thermionic electron emission from the non-Sc coated areas. The ldquodispensingrdquo process is observed directly, in situ.
Keywords :
barium; porous materials; thermionic electron emission; tungsten; Ba; W; barium oxide powder; emission microscopy; porous tungsten disk; scandium-coated porous tungsten; sputter deposited scandium metal squares; thermionic electron emission; Barium; Cathodes; Current density; Electron emission; Photoelectron microscopy; Powders; Temperature; Thermionic emission; Transistors; Tungsten; Barium; dispenser cathode; porous tungsten; scandium;
Conference_Titel :
Vacuum Electronics Conference, 2009. IVEC '09. IEEE International
Conference_Location :
Rome
Print_ISBN :
978-1-4244-3500-5
Electronic_ISBN :
978-1-4244-3501-2
DOI :
10.1109/IVELEC.2009.5193467
