Photocathodes for RF Guns
LASA is active since the 90s in the study and growth of photoemissive materials (antimony and tellurium compounds with alkali metals) to be used as high-brilliance electron sources in radiofrequency (RF) guns and in the development and realization of the ultra-high vacuum systems required for their deposition, handling and transport.These materials, when lighted with lasers synchronized to the accelerator RF, emit electrons due to the photoelectric effect. LASA carried an intense research program for the study of the behaviour of these materials and of the properties of the electrons emitted by them. The results of these activities lead to the optimization of the growth processes of the photocathodes, which allowed their use in the modern facilities requiring brilliant electron beams.
Photocathodes grown at LASA are routinely used at:
FLASH and PITZ at DESY, APEX at Berkeley, FAST at Fermilab.
The Cs2Te photocathodes produced at LASA are the state-of-the-art in this technology. A total of 140 photocathodes have been produced at LASA until now. Their current operational lifetime in accelerator facilities driven by electron guns operating 24/7 has increased up to 180 days.
Photocathode
