FEL simulation of the 0.1-nm Hard X-ray from the PAL-XFEL

The Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) will provide X-ray FEL radiation in the range of 0.1 and 10 nm with five undulator beamlines. An undulator beamline for hard X-ray is designed for 0.1-nm self-amplified spontaneous emission FEL. When a 200-pC electron bunch with a 10-GeV energy and a 0.5-mu m center dot rad normalized emittance passes the undulators, 10(12) photons at 0.1 nm will be generated within 100 fs. The wakefield effect of the vacuum chamber may reduce the radiation power significantly, but a proper tapering in the undulator can recover the power. We present a study in which GENESIS 1.3 was used for the FEL simulation.