2011 Particle Accelerator Conference - List of Authors (Pan, P.Z.)

Paper	Title	Page
THP208	Development of Alkali-Based High Quantum Efficiency Semiconductors for Dispenser Photocathodes	2510
	E.J. Montgomery, D.W. Feldman, S.A. Khan, P.G. O'Shea, P.Z. Pan, B.C. Riddick UMD, College Park, Maryland, USA K. L. Jensen NRL, Washington, DC, USA
	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)

Paper

Title

Page

Development of Alkali-Based High Quantum Efficiency Semiconductors for Dispenser Photocathodes

2510

E.J. Montgomery, D.W. Feldman, S.A. Khan, P.G. O'Shea, P.Z. Pan, B.C. Riddick
UMD, College Park, Maryland, USA
K. L. Jensen
NRL, Washington, DC, USA

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)