Session GO7: Electron Sources and Terahertz Generation
9:30 AM–11:54 AM, Tuesday, November 9, 2010
Room: Columbus IJ
Chair: Richard Temkin, Massachusetts Institute of Technology
Abstract ID: BAPS.2010.DPP.GO7.1
Abstract: GO7.00001 : Effect of LaB6 films on field emission by knife edge cathodes
9:30 AM–9:42 AM
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Authors:
John Booske
(University of Wisconsin-Madison)
Matt Kirley
(University of Wisconsin-Madison)
Marcus Weber
(University of Wisconsin-Madison)
Nishant Sule
(University of Wisconsin-Madison)
Bozidar Novakovic
(University of Wisconsin-Madison)
John Scharer
(University of Wisconsin-Madison)
Irena Knezevic
(University of Wisconsin-Madison)
We present experimental and modeling results of electron field emission from metallic knife edge cathodes coated with LaB6 films. The cathodes are machined from copper, coated with Ti, and then sputter-coated with LaB6. The LaB6 work function (2.3 eV) is significantly lower than that of copper (4.7 eV) or Ti (4.3 eV). However, thick LaB6 films (100-300 nm) significantly reduce the field emission currents compared with the bare copper or Ti-coated cathodes. In contrast, field emission with thin (5-10 nm) LaB6 films significantly increase the emission currents. Modeling studies are investigating a hypothesis that explains these observations as resulting from a quantum transport barrier at the metal-LaB6 interface. It is hypothesized that penetration of the applied field reduces the interfacial barrier for the thinnest films.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.DPP.GO7.1