Department High Brightness Beams
Photoemission Sources for Electron Accelerators - Photocathodes
The beam quality of a SRF photoinjector in terms of brightness and current is ultimately given by the electron source itself. In an SRF photoinjector electrons are generated by illuminating a photocathode with light pulses from a drive laser. This photocathode must be embedded into the SRF cavity, such that the electrons can be quickly accelerated to mitigate space charge effects. The focus of the activities is to understand correlations between cathode material, preparation, treatment and electron beam parameters such as transverse emittance, which is linked to the brightness of the beam generated with the SRF photoinjector. Our goal is to provide high quantum efficiency bialkali antimonide photocathodes for the operation of the SRF-photoinjector and beyond that to understand fatigue effects and fundamental electronic and optical properties in collaboration with Prof. C. Cocchi from U Oldenburg.
The photocathode laboratory
The photocathode laboratory of the Department High Brightness Beams (photo courtesy J. Kühn).
The MTE laboratory
PhoTEx: Photoemission and Transverse Energy Experiment (photo courtesy J. Dube).
Publications
- C. Wang et al., Triple evaporation growth of sodium–potassium–antimonide thin films as photoemission source for electron accelerators. J. Phys. D: Appl. Phys. 59 075102 (2026).
- J. Dube et al., Triple evaporation growth and photoemission characterization of bialkali antimonide photocathodes. J. Appl. Phys. 138, 045704 (2025).