Design of the Pohang Accelerator Laboratory (PAL) X-ray Free Electron Laser (XFEL) Test Machine

The Pohang Accelerator Laboratory is going to build an X-ray free electron laser (FEL) based on self-amplified spontaneous emission (SASE). This new machine will utilize the existing 2.5-GeV injection linac to the storage ring by upgrading its energy up to 3.7 GeV or more. The target wavelength will be 0.3 - 0.45 nm and its third harmonic 0.1 - 0.15 nm will also be used. The project will proceed in two stages: In the first stage, a visible light SASE machine with an energy of 200 MeV will be constructed and tested for the proof of principle. The full X-ray machine will be constructed in the next stage. This paper describes the updated design status of the first-stage test machine.