Paper | Title | Page |
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THP204 | Corrections to Quantum Efficiency Predictions for Low Work Function Electron Sources | 2504 |
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Funding: Funding by the Joint Technology Office and the Office of Naval Research. The Three-Step Model of Spicer, or the analogous Moments-based models, can be used to predict photoemission from metals and cesiated metals. In either, it is a convenient approximation to neglect electrons that have undergone scattering. Using Monte Carlo to follow scattered electrons, we assess the utility of the approximation particularly for low work function (cesiated) surfaces. |
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THP208 | Development of Alkali-Based High Quantum Efficiency Semiconductors for Dispenser Photocathodes | 2510 |
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Funding: This work is supported by the Office of Naval Research. Photocathodes as electron beam sources can meet the stringent requirements of high performance FELs, but exhibit a lifetime-efficiency tradeoff. High quantum efficiency (QE) cathodes are typically semiconductors, well described by recently enhanced theory*. Cesium dispenser technology, proven to extend lifetime of tungsten cathodes**, can be extended to high QE via the development of semiconductor coatings which are suitable for rejuvenation. Rejuvenation occurs via controlled cesium diffusion through a sintered substrate to resupply the surface (as described by models of pore*** and surface**** diffusion). Compatible coatings must be thermally stable materials with a cesium-based surface layer. Following standard fabrication processes*****, we discuss alkali antimonides and alkali aurides as cesium dispenser photocathode coatings and analyze future prospects. We also describe improvements to experimental techniques. *K.L. Jensen et al., (this conference) **Moody et al., J. Appl. Phys. 102(10), 2010 ***B.C. Riddick et al., (this conference) ****P.Z. Pan et al., (this conference) *****S.A. Khan et al., (this conference) |
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