QE MEASUREMENTS of a Nb-Pb SRF PHOTOINJECTOR

We report recent progress in the development of a hybrid lead/niobium superconducting RF (SRF) photoinjector. The goal of this effort is to produce an injector with the SRF properties of a niobium cavity along with the superior quantum efficiency (QE) of a lead photocathode. A prototype hybrid injector, consisting of an all-niobium cavity arc-deposited with lead in the cathode region, has been constructed. We present the results of QE measurements on this cavity under RF field, and an arc-deposited cathode under DC bias at cryogenic temperatures.

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