• W. Xu, S.W. Quan, K. Zhao, J. Zhuang
  PKU/IHIP, Beijing

High quality electron beam with low transverse emittance in 3.5‐cell DC‐SC photo‐injector is crucial significance for PKU‐ERL‐FEL facility. In this paper, we analyse the emittance evolution in the 3.5‐cell DC‐SC photo‐injector by simply model with consideration of DC acceleration, RF acceleration and space charge effect. The results are compared with Astra simulation. The matching condition of DC‐gun and Superconducting cavity, which is critical for the final emittance at the exit of the injector, is also presented.

• K. Yu, S.W. Quan, W. Xu, K. Zhao, F. Zhu, J. Zhuang
  PKU/IHIP, Beijing

The PKU Terahertz facility (PTF) is planned as a compact, high power Terahertz user facility based on the coherent undulator radiation concept and the superconducting radiofrequency technology for the linear accelerator. By utilizing a 3.5-cell DC-SC (DC-Superconducting) photoinjector, the PTF will provide high average power, coherent terahertz radiation with quasi-monochromaticity and wavelength tunable between 400um ~ 1200um, serving as a powerful tool for frontier researches and practical applications in the THz realm. Key components of the 3.5-cell DC-SC photoinjector have been prepared and the beamline is under construction. In this paper, the technical layout of the injector and the conceptual design of the PTF will be presented.