Paper | Title | Page |
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WG1017 |
Photocathode R&D for High Average Current ERL Photoinjectors at Daresbury Laboratory | |
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Significant effort has been expended over several years at Daresbury on R&D in the procedures underlying the preparation of the GaAs photocathode family for use as electron sources in ERL injectors. Having established robust chemical and thermal cleaning processes, and carried out lifetime studies on activated photocathodes by deliberately poisoning them, we will present data showing the different levels of quantum efficiency achievable using a heterostructure photocathode when activating with both oxygen and nitrogen-triflouride. The next goal in our research programme is to investigate the ultimate emittance achievable from the GaAs photocathode family. One option under consideration is the cooling of photocathodes to Liquid Nitrogen (LN) temperature, and two experimental programmes have been instigated on this basis. The first is intended to measure the energy spread of electrons emitted from the photocathode, and observe how the energy spread evolves during photocathode degradation. The second programme aims to characterise photocathode emittance and response time in a relatively low energy 160 kV photocathode gun. | ||
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Slides WG1017 [1.586 MB] | |