FIRST TEST RESULTS FROM SRF PHOTOINJECTOR FOR THE R&D ERL AT BNL*

An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is presently under commissioning at Brookhaven National Laboratory (BNL) [1]. This facility enables testing of concepts relevant for high-energy coherent electron cooling, electron-ion colliders, and high repetition rate FreeElectron Lasers. The ERL will be capable of providing electron beams with sufficient quality to produce high repetition rate THz and X-ray radiation. When completed the SRF photoinjector will provide 2 MeV energy and 300 mA average beam current. The injector for the RD this includes a 704MHz SRF gun with multi-alkali photocathode, cryo-system upgrade and a novel emittance preservation zigzag-like low energy merger system. We describe the design and major components of the R&D ERL injector then report the first experimental results and experiences learned in the first stage of beam commissioning of the BNL R&D ERL.