Zhao, G. Chen, C.H. Chiu, Y.C. Huang, S. Huang, Y.-C. Liu, K.X. Qin, W. Zeng, L. TUB05 FEL laser electron radiation simulation 2015 2015-12 In the THz spectrum, radiation sources are relatively scarce. Although recent advancement on optical technologies has enabled THz radiation generation covering a broad spectral range, free-electron laser (FEL) continues to be the most importance source for generating high-power THz radiation. Here we present an ongoing collaboration between Peking University (PKU) and National Tsinghua University (NTHU) to demonstrate high peak and average powers from a THz free-electron laser amplifier driven by a superconducting accelerator system at PKU. The superconducting accelerator comprises the DC-SRF photoinjector and a linac utilizing two 1.3 GHz Tesla-type cavities. It is expected to deliver high repetition rate electron beam with the energy of 10-25 MeV and rms bunch length of about 3 ps. The driver laser of the photoinjector is a mode-locked frequency-quadrupled Nd:YVO4 laser at 266 nm. We use the remaining gun driver laser power at 1064 nm to pump a THz parametric amplifier (TPA) which designed at NTHU and generate the THz seed radiation for the FEL amplifier. The signal laser of the TPA is tunable over 2 THz, permitting generation of radiation between 0.5 and 2.5 THz to seed the FEL amplifier. With our design parameters and computer simulation in GENESIS, we expect to generate narrow-band, wavelength-tunable THz radiation with sub-MW peak power and Watt-level average power.