Stable operation of the DC-SRF photoinjector

To obtain low-emittance electron beams with high average current, superconducting radio frequency photocathode guns have been developed by several laboratories worldwide. A DC-SRF injector, which combines a DC pierce gun and a superconducting cavity, has been developed at Peking University. Recently, stable operation of the DC-SRF photoinjector has produced encouraging results. The average beam current of 1 mA in macropulses of 7 ms with a repetition rate of 10 Hz has been reached and can be kept at about 0.5 mA for routine operation. In this paper, we describe the DC-SRF photoinjector and will discuss the experiments and the test results.