| AVS 60th International Symposium and Exhibition | |
| Vacuum Technology | Wednesday Sessions |
| Session VT+AS+SS+TF-WeA |
| Session: | Surface Science for Accelerator Applications |
| Presenter: | L. Cultrera, Cornell University |
| Authors: | L. Cultrera, Cornell University I. Bazarov, Cornell University B. Dunham, Cornell University Y. Li, Cornell University X. Liu, Cornell University A. Bartnik, Cornell University K. Smolenski, Cornell University S. Karkare, Cornell University W. Schaff, Cornell University T. Moore, Cornell University |
| Correspondent: | Click to Email |
Electrons generated by photoemission process are nowadays recognized as the brighest beams source to drive X-ray Free Electron Lasers or Energy Recovery Linacs. Part of the Cornell University ERL R&D project is aimed at developing photocathodes for electron guns that can support the production of very high brightness beams with high average current for extended periods of time
We focused our studies to III-V semiconductors activated to negative electron affinity and to alkali antimonide semiconductors.
Both classes of materials show high quantum efficiency on the visible part of the spectrum but are extremely sensitive to poor vacuum conditions.Because of this a dedicated apparatus consisting of different interconnected UHV chambers has been realized in the phtocathode lab. This allows transferring samples from preparation to analysis chamber while keeping them under UHV. A movable vacuum suitcase is used the transfer selected samples from the photocathode lab to the photoinjector.
The procedure and challenges for preparing high quantum efficiency photocathodes will be illustrated as well as the characterization performed in photocathode lab and by using them in the photoinjector.
Aiming at a better understanding of the photemission process we recently developed a Montecarlo code to simulate the photoemission from GaAs activated to negative electron affinity. This tool will eventually guide us in engineering new photocathode materials.
Perspectives for further development on the generation of high brightness electron beams will be discussed.