Masked Photocathode for Photoinjector

Qiang, Ji

关键词: 43;    BEAM DYNAMICS;    BRIGHTNESS;    ELECTRODES;    ELECTRON BEAMS;    ELECTRON EMISSION;    LASERS;    LIFETIME;    PHOTOCATHODES;    SHIELDS Photocathode;    photoinjector;   

DOI  :  10.2172/981726
RP-ID  :  LBNL-3042E
PID  :  OSTI ID: 981726
Others  :  TRN: US1004101

美国|英语

来源: SciTech Connect

【 摘 要 】

In this research note, we propose a scheme to insert a photocathode inside a photoinjector for generating high brightness electron beam. Instead of mounting the photocathode onto the electrode, a masked electrode with small hole is used to shield the photocathode from the accelerating vacuum chamber. Using such a masked photocathode will make the replacement of photocathode material very simple by rotating the photocathode behind the mask into the hole. This will significantly increase the usage lifetime of a photocathode. Furthermore, this also helps reduce the dark current or secondary electron emission from the photocathode. The hole on the mask also provides a transverse cut-off to the Gaussian laser profile which can be beneficial from the beam dynamics point of view.