Speaker
Description
Properties such as high quantum efficiency (QE), low thermal emittance, and longevity are crucial features for the rapidly developing electron accelorators. Compared to the traditional sequential deposition, the co-evaporation method is reported to yield better surface roughness, film crystallinity, and high quantum efficiency for photocath-ode materials. Here we present the effort in upgrading the coherent electron cooling (CeC) photocathode deposition system to adapt the co-evaporation growth method, the development of the co-evaporation recipe, and the prepa-ration of K-Cs-Sb photocathode using the developed system. QE of about 6.3% at wavelength 532 nm was obtained for co-deposited K2CsSb photocathode, where stoichiometry was determined by the deposition rate of each element. The system upgrade also enables the prepa-ration of GaAs photocathodes activating with Cs-Te. In our study, both CsTe and CsTe/CsO activated GaAs are prepared using the “yo-yo” method. QE of about 3.6% and 5% at wavelength 532 nm are obtained respectively. Lifetime measurements are performed and results are reported.
Funding Agency
Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704, DE-SC0013190 with the U.S. Department of Energy.
Footnotes
*M. Gaowei et al., PHYSICAL REVIEW ACCELERATORS AND BEAMS 22, 073401 (2019)
| Region represented | North America |
|---|---|
| Paper preparation format | Word |
