Towards a Robust, Efficient Dispenser Photocathode: the Effect of Recesiation on Quantum Efficiency
- Institute for Research in Electronics and Applied Physics, University of MD, College Park, MD 20742 (United States)
- Code 6843, ESTD, Naval Research Laboratory, Washington D.C. 20375-5347 (United States)
Future electron accelerators and Free Electron Lasers (FELs) require high brightness electron sources; photocathodes for such devices are challenged to maintain long life and high electron emission efficiency (high quantum efficiency, or QE). The UMD dispenser photocathode design addresses this tradeoff of robustness and QE. In such a dispenser, a cesium-based surface layer is deposited on a porous substrate. The surface layer can be replenished from a subsurface cesium reservoir under gentle heating, allowing cesium to diffuse controllably to the surface and providing demonstrably more robust photocathodes. In support of the premise that recesiation is able to restore contaminated photocathodes, we here report controlled contamination of cesium-based surface layers with subsequent recesiation and the resulting effect on QE. Contaminant gases investigated include examples known from the vacuum environment of typical electron guns.
- OSTI ID:
- 21255286
- Journal Information:
- AIP Conference Proceedings, Vol. 1086, Issue 1; Conference: 13. advanced accelerator concepts workshop, Santa Cruz, CA (United States), 27 Jul - 2 Aug 2008; Other Information: DOI: 10.1063/1.3080975; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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