High-Polarization Electron Sources
This program is aimed at producing high ( > 90%) polarization, high ( > 1012 e-) charge bunchs/bunch trains for SLAC’s experimental program (E-122 through E-158) and the International Linear Collider.
High polarization development has progressed from bulk GaAs (22% P at RT) photocathodes to high-gradient-doped strained-layer superlattice structures based on GaAs1-xPx compounds. Exciting laser wavelength is 780 nmeters. Both charge and polarization requirements for the ILC have been demonstrated.
The Polarized Photocathode Research Collaboration includes PEL, ILC, ARDA and Univ. of Wisconsin.
Further reading: "A very high charge, high polarization gradient-doped strained GaAs photocathode", PPRC Collaboration, Nucl. Instr. And Meth. In Phys. Res. A492, 199-211 (2002). (SLAC Document Server)
