The SRF photo injector at ELBE, status of development and operation

The production of beams with low emittance as well as high average current is one of the key techniques for future electron accelerators and next generation light sources. The superconducting radio-frequency photo electron source (SRF gun) has the potential to fulfill the requirements for these new accelerators. At the radiation source ELBE an SRF gun has been developed and put into operation. The gun has a 3 ½ cell niobium cavity for 1.3 GHz and uses normal-conducting photo cathodes. Since 2010 the gun has delivered beam into the ELBE linac. Recently a new driver laser with 13 MHz pulse repetition rate allows us to operate the IR free-electron lasers (FEL) with the SRF gun. The successful operation of the SRF gun confirms the general design with an elliptical cavity, superconducting RF choke filter, and normal-conducting photocathodes as well as the proper design of most of the subsystems like couplers and tuners. At present, the main draw-back is the low acceleration gradient of the present cavity, and we expect assembly of the new cavity in an improved cryomodule and its commissioning in 2014