PPT Slide

Summary and Conclusions

• High average current photinjectors require long-lifetime cathodes

with high QE at visible wavelengths.

• This is necessary to reduce the drive laser cost and complexity.

• Metal cathode QE’s have improved a factor of three or more

(surface processing and polarization effects), but are small fraction

of percent and require UV drive laser.

• Cs2Te has long lifetime and high QE but requires UV drive laser

• Coating K2CsSb with a thin film of CsBr and operating at an

elevated temperature may lead to desired long lifetime cathode with

high QE in the visible.