TUYD1
BNL, Upton, New York, USA
At Brookhaven National Lab, we have constructed a high intensity polarized electron gun with an inverted electrode geometry and large cathode area. The DC gun showed stable operation at 300 KV with bunch charge up to 16 nC. It also incorporates new technologies such as an active cathode cooling system, a biased anode, and a unique high voltage cable with a semiconductor jacket. Lifetime tests with a biased anode has showed exceptional performance. This gun exceeds EIC polarized gun requirements — high voltage, bunch charge, average current and charge lifetime — with ease. In this talk, we report on the design and performance of the gun including high voltage performance and cathode lifetime tests.
TUYD2
Stony Brook University, Stony Brook, USA
BNL, Upton, New York, USA
We describe new activation techniques, developed using Cs-Te and Cs-O-Te as a activation layers, to achieve Negative Electron Affinity (NEA) surfaces of GaAs. X-Ray photoelectron spectroscopic and Low Energy Electron Microscopic studies have been performed on these surfaces. The results indicate that both layers achieve NEA of GaAs and lead to longer charge lifetime compared to traditional Cs-O/GaAs photocathodes.