Suppression of the Surface Charge Limit in Strained GaAs Photocathodes
Abstract
Single strained, medium-doped (5×1018 /cm3) GaAs photocathodes show the surface charge limit (SCL). The SCL poses a serious problem for operation of polarized electron sources at future linear colliders such as the NLC/JLC. A high-gradient-doping technique has been applied to address this problem. A 5 -7.5 nm p-type surface layer doped to 5×1019/cm3 is found sufficient to overcome the SCL, while maintaining high beam polarization. This technique can be employed to meet the charge requirements of the NLC with a polarization approaching 80%.
- Publication:
-
SPIN 2002
- Pub Date:
- July 2003
- DOI:
- 10.1063/1.1607301
- Bibcode:
- 2003AIPC..675.1083M
- Keywords:
-
- 29.25.Bx;
- 29.27.Hj;
- Electron sources;
- Polarized beams