Very High Charge, High Polarization Gradient-Doped Strained GaAs Photocathode

摘要

A high-gradient-doping technique is applied to strained polarized photocathodes. The electron spin-polarization increases significantly as the highly doped layer thickness is reduced. A 5.0 - 7.5 nm p-type surface layer doped to 5 times 10 the the 19th power cm to the minus 3 power is found sufficient to overcome the surface charge limit. It is shown that the charge requirements of the Next Linear Collider can be met with a polarization approaching 80%.